Molten-salt fueled reactors

The classic MSFR has been very exciting to many nuclear engineers. Its most prominent champion was Alvin Weinberg, who patented the light-water reactor and was a director of the U.S.’s Oak Ridge National Laboratory, a prominent nuclear research center.

Two concepts were investigated. The “two fluid” reactor had a high-neutron-density core that burned uranium-233 from the thorium fuel cycle. A blanket of thorium salt absorbed the neutrons and was eventually transmuted to 233U fuel. The weakness of the two-fluid design at the time of development was that its known designs included complex plumbing, and no suitable material was known to make the pipes. Ordinary steels and nickel alloys either absorbed too many neutrons or corroded too easily. Graphite was thought to be too brittle, and swells slightly under intense neutron exposure. Zirconium is sufficiently transparent to neutrons, but corrodes too easily when exposed to hot fluoride salts.

Two problems were subsequently solved by researchers at the Oak Ridge National Laboratory. The corrosion of the pipes was stopped by the addition of a trace amount of titanium to Hastelloy-N alloy.

The engineers discovered that by carefully sculpting the moderator rods (to get neutron densities similar to a core and blanket), and modifying the fuel reprocessing chemistry, both thorium and uranium salts could coexist in a simpler, less expensive yet efficient “one fluid” reactor.

The power reactor design produced by Weinberg’s research group was similar to the

Technological advantages

The advantages cited by Weinberg and his associates at Oak Ridge National Laboratory include:

*It is safe to operate and maintain: Molten fluoride salts are mechanically and chemically stable at sea-level pressures at intense heats and radioactivity. Fluoride combines ionically with almost any transmutation product, keeping it out of circulation. Even radioactive noble gases& — notably xenon-135, an important neutron absorber& — come out in a predictable, containable place, where the fuel is coolest and most dispersed, namely the pump bowl. Even given an accident, dispersion into a biome is unlikely. The salts do not burn in air or water, and the fluoride salts of the actinides and radioactive fission products are generally not soluble in water.

*There’s no high pressure steam in the core, just low-pressure molten salt. This means that the MSR’s core cannot have a steam explosion, and does not need the most expensive item in a light water reactor, a high-pressure steam vessel for the core. Instead, there is a vat and low-pressure pipes (for molten salt) constructed of thick sheet metal. The metal is an exotic nickel alloy that resists heat and corrosion, Hastelloy-N, but there is much less of it, and the thin metal is less expensive to form and weld.

*The thorium breeder reactor uses low-energy thermal neutrons, similarly to light water reactors. It is therefore much safer than fast-neutron breeder reactors that the uranium-to-plutonium fuel cycle requires. The thorium fuel cycle therefore combines safe reactors, a long-term source of abundant fuel, and no need for expensive fuel-enrichment facilities.

*The molten-salt-fueled reactor operates much hotter than LWR reactors, from 650& °C in the tested MSRE (see above) and related designs, to as hot as 950& °C in untested designs. So, very efficient Brayton cycle (gas turbine) generators are possible. The MSRE already demonstrated operation at 650°C, making the MSR the most advanced of the “generation IV reactors.” The efficiency from high temperatures reduces fuel use, waste emission and the cost of auxiliary equipment (major capital expenses) by 50% or more.

*MSRs work in small sizes, as well as large, so a utility could easily build several small reactors (say 100& MWe) from income, reducing interest expense and business risks.

*Molten salt fuel reactors are not experimental. Several have been constructed and operated at 650& °C temperatures for extended times, with simple, practical validated designs. There’s no need for new science at all, and very little risk in engineering new, larger or modular designs.

*In most new reactor designs, the longest-lead item is the safety testing of solid fuel elements. Fuel tests for a new reactor design usually must cover several three-year refueling cycles, and therefore take more than ten years. Since the MSR uses molten salts, the fuel has already been validated, and development can proceed more quickly.

*The reactor, like all nuclear plants, has little effect on biomes. In particular, it uses only small amounts of land, relatively small amounts of construction, and the waste is separated from the biome, unlike both fossil and renewable energy projects.

Technological disadvantages

*When optimized for breeding, thorium breeder reactors may require on-site reprocessing to remove protactinium-233 from the breeding blanket so it can beta decay to uranium-233 instead of neutron capture to uranium-234. This might allow diversion of fuels to weaponry, so a decision can be made to simply allow Pa isotopes to remain in the salts, especially since there are far more effective neutron absorbers in the fission products, such as Argon, which will be removed continuously as gas at the reactor’s plenum. Chemical extraction of protactinium will extract any isotopes of protactinium including 231Pa which has a half-life of 31,000 years. Thus, there’s good reason to simply allow Pa to remain within the salt, and so decay, or be converted by neutron capture.

*The uranium-233 contains trace amounts of uranium-232, which produces a hard gamma emitter thallium-208 in its decay chain. This gamma radiation would increase the difficulty of making nuclear weapons. Removal of U-232 by isotopic separation would be even more difficult than enrichment of U-235 in natural uranium. These features may offer some non-proliferation advantage, over conventional, enriched-uranium reactors. If the uranium is purified of thorium and other elements, its radioactivity is initially low and increases with accumulation of thorium-228 (halflife 2 years) and further short-lived thorium series decay products. An easier route to produce nuclear weapons already exists by enrichment of natural uranium.

*Fluoride salts naturally produce HF when in contact with moisture, which may lead to release of hydrofluoric acid fumes during reactor shutdowns, decommissioning, or flooding. However, competent reactor designs would never allow the salt plumbing to ingest or become exposed to moisture or other contaminants, whether in operation or shutdown. Similarly, de-commissioning procedures for all reactors are always fastidious, and the nature of the MSR’s continuous operation makes de-commissioning infrequent.

On-line reprocessing advantages

A molten salt reactor’s fuel can be continuously reprocessed with a small adjacent chemical plant. Weinberg’s groups at Oak Ridge National Laboratory found that a very small reprocessing facility can service a large 1& GW power plant: All the salt has to be reprocessed, but only every ten days. The reactor’s total inventory of expensive, poisonous radioactive materials is therefore much smaller than in a conventional light-water-reactor’s fuel cycle, which have to store spent fuel rod assemblies. Also, everything except fuel and waste stays inside the plant. The reprocessing cycle is:

*A sparge of fluorine to remove uranium-233 fuel from the salt as uranium hexafluoride, which will be accompanied by similarly volatile high-valence fluorides of some other elements such as technetium hexafluoride and selenium hexafluoride of the long-lived fission products technetium-99 and selenium-79, as well as fluorides of various strongly radioactive short-lived fission products such as iodine-131, molybdenum-99, and tellurium-132. See fluoride volatility for boiling points.

*A 4-meter-tall molten bismuth column separates protactinium from the fuel salt.

*A small storage facility to let the protactinium from the bismuth column decay to uranium-233. With a half-life of 27& days, ten months of storage assures that 99.9% of 233Pa decays to 233U fuel, with any 231Pa remaining.

*A vapor-phase fluoride-salt distillation system distills the salts. Each salt has a distinct temperature of vaporization. The light carrier salts beryllium fluoride and lithium fluoride form the bulk of the salt and evaporate at 1169 °C and 1676 °C, or less under vacuum. Thorium(IV) fluoride evaporates at temperatures about 1680 °C or less under vacuum. Only the lanthanide and alkaline earth fluorides such as strontium fluoride have higher boiling points and remain; these include the worst long-term neutron poisons. The amount of waste involved is about 800& kg per gigawatt-year generated, so the equipment is very small. Salts of long-lived transuranic metals go back into the reactor as fuel. With salt distillation, an MSFR can burn plutonium, or even fluorinated nuclear waste from light water reactors.

*Theoretically, a “two-fluid” reactor design could separate the fertile thorium from the fissile fuel salts. This would eliminate the technologically challenging separation of thorium fluoride (boiling point 1680 °C) and lanthanide fission product fluorides via high-temperature distillation, at the cost of a more complex reactor. Oak Ridge researchers abandoned two-fluid designs because no good pipe materials were known to operate in the high-temperature, high-neutron, corrosive environment of a MSR core.

Thorium cycle advantages

The thorium fuel cycle, like other breeder reactor fuel cycles with reprocessing, can potentially burn all the actinides that produce most of the radioactivity of spent nuclear fuel in the time range from several hundred years after fuel use, after the decay of the 30-year fission products cesium-137 and strontium-90, up to several hundred thousand years, when long-lived fission products like technetium-99 become significant. The open fuel cycle of the light-water reactors of the current nuclear power industry leaves substantial quantities of isotopes of plutonium and minor actinides in its spent fuel.

Reduction of radiation in this time range is dependent on nearly complete actinide removal and recycling during reprocessing. If even small amounts are not removed and instead are disposed as part of reprocessing wastes, much of the advantage is lost.

The thorium cycle produces lower levels of heavy actinides than the uranium-238 and plutonium cycle, because the mass of the starting point is lower, giving more opportunities for destruction by fission before reaching higher masses. However, the thorium cycle produces protactinium-231 (half-life 31,000 years) via (n,2n) reactions with fast neutrons. Both 231Pa and the heavy actinides can be eventually destroyed in a closed fuel cycle via neutron capture and fission. However if a MSR chemically isolates protactinium-233 outside the reactor core to avoid neutron capture, any 231Pa will come with it, and continue to accumulate while the 233Pa decays to 233U and returns to the reactor.

Technological advantages

*Control of the salt’s corrosivity is easy. The uranium buffers the salt, forming more from as more fluorine is present. can be regenerated by adding small amounts of metallic beryllium to absorb F. In the MSRE, a beryllium rod was inserted into the salt until the was the correct concentration.

*Extensive validation (fuel rod design validation normally takes years and prevents effective deployment of new nuclear technologies) is not needed. The fuel is molten, chemical reprocessing eliminates reaction products, and there are tested fuel mixtures, notably FLi7BeU.

*Molten-fuel reactors can be made to have passive nuclear safety: Tested fuel-salt mixtures have negative reactivity coefficients, so that they decrease power generation as they get too hot. Most fuel-salt reactor vessels also have a freeze plug at the bottom that has to be actively cooled. If the cooling fails, the fuel drains to a subcritical storage facility.

*Continuous reprocessing simplifies numerous reactor design and operating issues. For example, the neutron absorbing effects of xenon-135 are not present. Neutron absorption from fission products is continuously mitigated. Transuranic elements, the long-lived “wastes” of light water reactors, are burned as fuel.

*A fuel-salt reactor is mechanically and neutronically simpler than light-water reactors. There are only two items in the core: fuel salts and moderators. This reduces concerns with moderating interactions with positive void coefficients as water boils, chemical interactions, etc. (In fact since water is a moderator, boiling produces a stabilizing negative void coefficient in a thermal reactor)

*Coolant and piping need never enter the high-neutron-flux zone, because the fuel is used to cool the core. The fuel is cooled in low-neutron-flux heat-exchangers outside the core. This reduces worries about neutron effects on pipes, testing, development issues, etc.

*The salt distillation process means that chemical separation and recycling of fission products, say for nuclear batteries, are quite cheap. Xenon and other valuable transmuted noble gases separate out of the molten fuel in the pump-bowl. Any transuranic elements go right back into the fuel for burn-up.

*Graphite moderated, water-cooled, solid-fueled reactor designs can be susceptible to increases in reactivity with voids in their coolant (positive coolant void coefficient – if the reactor loses coolant, the reaction speeds up), making such designs unsafe. Unlike other reactors, however, in the single-fluid MSR, the fuel and the coolant are intimately mixed molten salts. So, if the MSR has an incident that causes voids in the coolant, this incident will also cause voids in the fuel, leading to cessation of the nuclear reaction. In addition, the coolant/fuel can be easily removed from the reactor within seconds by opening a valve below the reactor, and allowing gravity to push the molten salt into holding tanks set aside for this purpose, designed to store the salts in a non-critical configuration.

Design challenges

Molten salt reactors, nevertheless, present a number of design challenges. Known issues include:

*High neutron fluxes and temperatures in a compact MSR core can change the shape of a graphite moderator element, causing it to require refurbishing in as little as four years of operation. Eliminating graphite from sealed piping was a major incentive to switch to a single-fluid design. Most MSR designs do not use graphite as a structural material, and arrange for it to be easy to replace. At least one design used graphite balls floating in salt, which could be removed and inspected continuously without shutting down the reactor.

*The high neutron density in the core rapidly transmutes lithium-6 to tritium, a radioactive isotope of hydrogen. In an MSR, the tritium forms hydrogen fluoride (HF). Tritium fluoride is a corrosive, chemically reactive, radioactive gas. Because of this, all MSR designs use lithium-7 isotope for their carrier salts in order to prevent tritium formation. The MSRE proved that lithium-6 removal from the fuel salt worked to prevent tritium formation. Since lithium-7 is at least 14% heavier than lithium-6, and represents the most common isotope of lithium, the lithium-6 is comparatively easy and inexpensive to extract from naturally occurring lithium in isotopic separation, as gaseous lithium diffuses at dramatically different speeds due to the difference in atomic weights. Vacuum distillation of lithium achieves efficiencies of up to 8% per stage and only requires heating of raw lithium in a vacuum chamber.

*Some slow corrosion occurs even in the special nickel alloy, Hastelloy-N used for the reactor. The corrosion is faster if the reactor is exposed to hydrogen which forms corrosive HF gas. Exposure to water-vapor within the piping causes uptake of corrosive amounts of hydrogen, so practical MSRs operate the salt under a blanket of dry inert gas, usually helium.

*When cold, the fuel salts radiogenically produce corrosive, chemically reactive fluorine gas. Although a very slow process, the salts should be defueled and wastes removed before extended shutdowns to avoid (non-radioactive) fluorine gas production. Unfortunately, this was discovered the unpleasant way, while the MSRE was shut-down over a 20-year period.

An MSR based on chloride salts (e.g. sodium chloride as the carrier salt) has many of the same advantages. However, the heavier nuclei of chlorine are less moderating, which causes the reactor to be a fast reactor. Theoretically, it wastes even fewer neutrons and breeds more efficiently, though it may be less safe. It would require isotopically-pure chlorine-37, to avoid neutron activation of chlorine-35 into the long-lived radioactive activation product chlorine-36.

Fuel cycle concerns

*There is no need for fuel fabrication. This greatly reduces the MSR’s fuel expenses. It poses a business challenge, because reactor manufacturers customarily get their long-term profits from fuel fabrication. A government agency could, however, type-license a design, which utilities could replicate. Since it uses raw fuel, basically just a mixture of chemicals, current reactor vendors don’t want to develop it. They derive their long-term profits from sales of fabricated fuel assemblies.

*A safe thorium breeder reactor using slow thermal-energy neutrons also has a low breeding rate. Each year it can only breed thorium into about 109% of the uranium-233 fuel it consumes. This means that obtaining enough uranium-233 for a new reactor can take eight years or more, which would slow deployment of this type of reactor. Most practical, fast deployment plans would start the new thorium reactors with plutonium from existing light-water reactor wastes or decommissioned nuclear weapons. The U.S. Department of Energy has a stockpile of enough U233 to start a few reactors at once. This scheme also decreases society’s stock of high-level wastes. An alternate starting procedure is use of a simple, medical proton-beam source, as used for cancer treatments—the Japanese have researched this for their FUJI project.

Economical and social advantages

Combining the above, some form of molten-salt thorium breeder could be the most efficient well-developed energy source known, whether measured by cost per kW, capital cost or social costs.

*Thorium’s fuel cycle resists proliferation in two ways:

**It is verifiable because the epithermal thorium breeder produces only at most 9% more fuel than it burns in each year. Building bombs quickly will take power plants out of operation.

**Also, an easy variation of the thorium fuel cycle would contaminate the thorium-232 breeding material with chemically inseparable thorium-230. The thorium-230 breeds into uranium-232, which has a powerful gamma-ray emitter in its decay chain (thallium-208) that makes the reactor fuel 233U/232U impractical in a bomb, because it harms electronics.

*The Earth’s crust contains about three times as much thorium as 238U, or 400 times as much as 235U, which makes it about as abundant as lead.

*Thorium is cheap. Currently, it costs US$& 30/kg. In the 2000s, the price of uranium has risen above $100/kg, not including the cost of enrichment, and fuel element fabrication.

Molten-salt cooled reactors

Molten-salt-fueled reactors are quite different from molten-salt-cooled solid-fuel reactors, called simply “Molten Salt Reactor System” in the Generation IV proposal, also called MSCR, which is also the acronym for the Molten Salt Converter Reactor design. It cannot reprocess fuel easily and has fuel rods that need

to be fabricated and validated, delaying deployment by up to twenty years from project inception. However, since it uses fabricated fuel, reactor manufacturers can still profit by selling fuel assemblies.

The MSCR retains the safety and cost advantages of a low-pressure, high-temperature coolant, also shared by liquid metal cooled reactors. Notably, there’s no steam in the core to cause an explosion, and no large, expensive steel pressure vessel. Since it can operate at high temperatures, the conversion of the heat to electricity can also use an efficient, lightweight Brayton cycle gas turbine.

Much of the current research on MSCRs is focused on small compact heat exchangers. By using smaller heat exchangers, less molten salt needs to be used and therefore significant cost savings could be achieved.

Molten salts can be highly corrosive, more so as temperatures rise. For the primary cooling loop of the MSR, a material is needed that can withstand corrosion at high temperatures and intense radiation. Experiments show that Hastelloy-N and similar alloys are quite suited to the tasks at operating temperatures up to about 700 °C. However, long-term experience with a production scale reactor has yet to be gained. Higher operating temperatures would be desirable, but at 850 °C thermo chemical production of hydrogen becomes possible, which creates serious engineering difficulties. Materials for this temperature range have not yet been found, though carbon composites, carbides, and refractory metal based or ODS alloys might be feasible.

Fused salt selection

The salt mixtures are chosen to make the reactor safer and more practical. Fluorides are favored because fluorine doesn’t need expensive isotope separation (as chlorine does). It does not easily become radioactive under neutron bombardment. It also absorbs fewer neutrons and slows (“moderates”) neutrons better. Low-valence fluorides boil at high temperatures, though many pentafluorides and hexafluorides boil at low temperatures. They also must be very hot before they break down into their simpler components, such molten salts are “chemically stable” when maintained well below their boiling points.

Reactor salts are also eutectic mixtures to reduce their melting point. This makes a heat engine more efficient, because more heat can be removed from the salt before reheating it in the reactor.

Some salts are so useful that isotope separation is worthwhile. Chlorides permit fast breeder reactors to be constructed using molten salts. Not nearly as much work has been done on reactor designs using them. Chlorine must be purified to Cl37 to reduce production of radioactive elements. Also, any lithium in a salt mixture must be purified lithium-7 to reduce tritium production.

Due to the high “redox window” of fused fluoride salts, the chemical potential of the fused salt system can be changed. Fluorine-Lithium-Beryllium (“FLiBe”) can be used with beryllium additions to lower the electrochemical potential and almost eliminate corrosion. However, since beryllium is extremely toxic, special precautions must be engineered into the design to prevent its release into the environment. See Asimov’s 1954 novella Sucker Bait for a scenario based on the real toxicity of beryllium. Many other salts can cause plumbing corrosion, especially if the reactor is hot enough to make highly reactive hydrogen.

To date, most research has focused on FLiBe, because Lithium and Beryllium are reasonably effective moderators, and form a eutectic salt mixture with a lower melting point than each of the constituent salts. Beryllium also performs neutron doubling, improving the neutron economy. This process occurs when the Beryllium nucleus re-emit two neutrons after absorbing a single neutron. For the fuel carrying salts, generally 1% or 2% (by mole) of UF4 is added. thorium and plutonium fluorides have also been used. The MSFR is the only system that has run a single reactor, the MSRE, from all three known nuclear fuels.

Fused salt purification and reprocessing

Salts must be extremely pure initially, and would most likely be continuously cleaned in a large-scale molten salt reactor. Any water vapor in the salt will form hydrofluoric acid (HF) which is extremely corrosive. Other impurities can cause non-beneficial chemical reactions and would most likely have to be cleansed from the system. Most power plants have to ensure that the primary coolant they are using is extremely pure; otherwise, they would encounter corrosion issues as well.

The possibility of online reprocessing can be an advantage of the MSR design. Continuous reprocessing ensures a low inventory of fission products at all times, which improves neutron economy. This makes the MSR particularly suited to the neutron-poor thorium fuel cycle. To allow breeding from thorium, the intermediate product protactinium-233 has to be removed from the reactor and stored for some months while it decays into uranium-233. Left in the fuel it would absorb too many neutrons to make breeding with a graphite moderator and thermal spectrum possible (though with alternate designs in which the thorium is kept in a separate fluid from the fuel, the protactinium can simply be diluted with a larger volume of thorium fluid which proportionately reduces the neutron absorption; also some heavy water moderated reactor designs could overcome this, albeit at a lower thermal efficiency). The necessary reprocessing technology, which has to process the complete fuel every 10 days, has only been demonstrated at laboratory scale. For a power reactor such a large reprocessing facility is currently deemed uneconomic.

Adapted from the Wikipedia article Molten salt reactor, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

No related posts.

On the abolition of the Holy Roman Empire in 1806, Holstein was practically, though not formally, incorporated in Denmark. Under the administration of the Danish prime minister Count Bernstorff, himself from Schleswig, many reforms were carried out in the duchies, for example, abolition of torture and of serfdom; at the same time Danish laws and coinage were introduced, and Danish was made the official language for communication with Copenhagen. Since, however, the Danish court itself at the time was largely German in language and feeling, this produced no serious expressions of resentment.

The settlement of 1806 was reversed, and while Schleswig remained as before, Holstein and Lauenburg were included in the new German Confederation. The opening up of the Schleswig-Holstein question thus became sooner or later inevitable. The Germans of Holstein, influenced by the new national enthusiasm evoked by the War of Liberation, resented more than ever the attempts of the government of Copenhagen to treat them as part of the Danish monarchy and, encouraged by the sympathy of the Germans in Schleswig, early tried to reassert in the interests of Germanism the old principle of the unity of the duchies. The political atmosphere, however, had changed at Copenhagen also; and their demands were met by the Danes with a nationalist temper as intractable as their own. Affairs were ripe for a crisis, which the threatened failure of the common male heirs to the kingdom and the duchies precipitated.

The Duchy of Schleswig was originally an integrated part of Denmark, but was in medieval times establis

The duchy of Schleswig was legally a Danish fief and not part of the Holy Roman Empire or, after 1815, of the German Confederation (German: ”Deutscher Bund”, Danish: ”Tysk Forbund”), but the duchy of Holstein was a German fief and part of both the Empire and later the German Confederation of 1815–1866. It was one of the oddities of both the Holy Roman Empire and of the German Confederation that foreign heads of state could be and often were also members of the constitutional organs of the Empire and the Confederation if they held a territory that was part of the Empire or the Confederation. The King of Denmark had a seat in the organs of the German Confederation because he was also Duke of Holstein.

Schleswig-Holstein Question

The Schleswig-Holstein Question was the name given to the whole complex of diplomatic and other issues arising in the 19th century out of the relations of the two duchies, Schleswig and Holstein, to the Danish crown and the German Confederation on the other.

In 1806–1815 the government of Denmark had claimed Schleswig and Holstein to be parts of the monarchy of Denmark, which was not popular among the German population in Schleswig-Holstein, who had traditionally the large majority. However, this development sparked a German national awakening after the Napoleonic wars and led to a strong popular movement in Holstein and Southern Schleswig for re-unification of Holstein and also Schleswig with a new Prussian-dominated Germany.

The childlessness of King Frederick VII of Denmark worked in favor of the Germans, as did the ancient Treaty of Ribe, which stipulated that the two duchies must never be separated. A counter-movement developed among the Danish population in northern Schleswig and (from 1838) in Denmark, where the Liberals insisted that Schleswig as a fief had belonged to Denmark for centuries and that the Eider River, the historic border between Schleswig and Holstein, should mark the frontier between Germany and Denmark. The Danish nationalists thus aspired to incorporate Schleswig into Denmark, in the process separating it from Holstein. The Germans conversely sought to confirm Schleswig’s association with Holstein, in the process detaching Schleswig from Denmark and bringing it into the German Confederation.

The Danish succession

When Christian VIII succeeded his first cousin Frederick VI in 1839 the elder male line of the house of Oldenburg was obviously on the point of extinction, the king’s only son and heir having no children. Ever since 1834, when joint succession, consultative estates had been re-established for the duchies, the question of the succession had been debated in this assembly. To German opinion the solution seemed clear enough. The crown of Denmark could be inherited by female heirs (see Louise of Hesse); in the duchy of Holstein the Salic law had never been repealed and, in the event of a failure of male heirs to Christian VIII, the succession would pass to the Dukes of Augustenburg — although this was debatable as the dynasty itself had received Holstein by Christian I of Denmark being the son of the ”sister” of the last Schauenburg, Adolf VIII.

Danish opinion, on the other hand, clamoured for a royal pronouncement proclaiming the principle of the indivisibility of the monarchy and its transmission intact to a single heir, in accordance with the royal law. To this Christian VIII yielded so far as to issue in 1846 letters patent declaring that the royal law in the matter of the succession was in full force so far as Schleswig was concerned, in accordance with the letters patent of August 22, 1721, the oath of fidelity of September 3, 1721, the guarantees given by France and Great Britain in the same year and the treaties of 1767 and 1773 with Russia. As to Holstein, he stated that certain circumstances prevented him from giving, in regard to some parts of the duchy, so clear a decision as in the case of Schleswig. The principle of the independence of Schleswig and of its union with Holstein were expressly reaffirmed. An appeal against this by the estates of Holstein to the German diet received no attention.

On January 28, Christian VIII issued a rescript proclaiming a new constitution which, while preserving the autonomy of the different parts of the country, incorporated them for common purposes in a single organization. The estates of the duchies replied by demanding the incorporation of Schleswig-Holstein, as a single constitutional state, in the German Confederation.

First War of Schleswig

In March 1848 these differences led to an open uprising by the German-minded Estate assemblies in the duchies in support of independence from Denmark and of close association with the German Confederation. The military intervention of Prussia helped the rising: the Prussian army drove Denmark’s troops from Schleswig and Holstein.

Frederick VII, who had succeeded his father at the end of January, declared (March 4) that he had no right to deal in this way with Schleswig, and, yielding to the importunity of the Eider-Danish party, withdrew the rescript of January (April 4) and announced to the people of Schleswig (March 27) the promulgation of a liberal constitution under which the duchy, while preserving its local autonomy, would become an integral part of Denmark.

A Liberal constitution for Holstein was not seriously considered in Copenhagen since it was a well-known fact that the German political elite of Holstein was far more conservative than the one in Copenhagen. This proved to be true, as the politicians of Holstein demanded that the Constitution of Denmark be scrapped, not only in Schleswig but also in Denmark, as well as demanding that Schleswig immediately follow Holstein and become a member of the German Confederation and eventually a part of the new united Germany.

The rebels established a provisional government at Kiel; and the duke of Augustenburg had hurried to Berlin to secure the assistance of Prussia in asserting around 1848 his rights. This was at the very crisis of the revolution in Berlin, and the Prussian government saw in the proposed intervention in Denmark in a popular cause an excellent opportunity for restoring its damaged prestige. Prussian troops were accordingly marched into Holstein.

This war between Denmark one the one hand and the two duchies and Prussia on the other lasted three years (1848–1850) and only ended when the Great Powers pressured Prussia into accepting the London Convention of 1852. Under the terms of this peace agreement, the German Confederation returned the duchies of Schleswig and Holstein to Denmark. In an agreement with Prussia under the London Protocol of 1852, the Danish government in return undertook not to tie Schleswig more closely to Denmark than to the duchy of Holstein.

In 1848 King Frederick VII of Denmark declared that he would grant Denmark a Liberal Constitution and the immediate goal for the Danish national movement was to secure that this Constitution would not only give rights to all Danes, that is, not only to the Kingdom of Denmark, but also to Danes (and Germans) living in Schleswig. Furthermore, they demanded the protection of the Danish language in Schleswig since the dominating language in almost a quarter of Schleswig had changed from Danish to German since the beginning of the nineteenth century.

Nationalist circles in Denmark advocated danification of Schleswig (but not of Holstein) as Danish national culture had risen much in past decades.

On April 12, 1848 the diet recognized the provisional government of Schleswig and commissioned Prussia to enforce its decrees, General Wrangel was ordered to occupy Schleswig also.

But the Germans had reckoned without the European powers, which were united in opposing any dismemberment of Denmark, even Austria refusing to assist in enforcing the German view. Swedish troops landed to assist the Danes; Nicholas I of Russia, speaking with authority as Head of the elder Gottorp line, pointed out to King Frederick William IV the risks of a collision; Great Britain, though the Danes rejected her mediation, threatened to send her fleet to assist in preserving the status quo. Frederick William new ordered Wrangel to withdraw his troops from the duchies; but the general refused to obey, on the plea that he was under the command not of the king of Prussia but of the regent of Germany, and proposed that, at least, any treaty concluded should be presented for ratification to the Frankfort government. This the Danes refused; and negotiations were broken off. Prussia was now confronted on the one side by the German nation urging her clamorously to action, on the other side by the European powers with one voice threatening the worst consequences should she persist.

On August 26, 1848, after painful hesitation, Frederick William chose what seemed the lesser of two evils, and Prussia signed at Malmö a convention which yielded practically all the Danish demands. The Holstein estates appealed to the German parliament, which hotly took up their cause; but it was soon clear that the central government had no means of enforcing its views, and in the end the convention was ratified at Frankfurt.

The convention was only in the nature of a truce establishing a temporary ”modus vivendi”, and the main issues, left unsettled, continued to be hotly debated. At a conference held in London in October, Denmark suggested an arrangement on the basis of a separation of Schleswig from Holstein, which was about to become a member of the new German empire, Schleswig to have a separate constitution under the Danish crown. This was supported by Great Britain and Russia.

On January 27, 1849 it was accepted by Prussia and the German government. The negotiations broke down, however, on the refusal of Denmark to yield the principle of the indissoluble union with the Danish crown.

On February 23 the truce was at an end, and on April 3, the war was renewed.

The principles which Prussia was commissioned to enforce as the mandatory of Germany were:

#that they were independent states

#that their union was indissoluble

#that they were hereditary only in the male line

At this point the tsar intervened in favour of peace; and Prussia, conscious of her restored strength and weary of the intractable temper of the Frankfort government, determined to take matters into her own hands.

On July 10, 1849 another truce was signed; Schleswig, until the peace, was to be administered separately, under a mixed commission, Holstein was to be governed by a vicegerent of the German empire – an arrangement equally offensive to German and Danish sentiment. A settlement seemed as far off as ever; the Danes still clamoured for the principle of succession in the female line and union with Denmark, the Germans for that of succession in the male line and union with Holstein.

In 1849 the Constitution of Denmark was adopted. This complicated matters further, as many Danes wished for the new democratic constitution to apply for all Danes, including in the Danes in Schleswig. The constitutions of Holstein and Schleswig were dominated by the Estates system, giving more power to the most affluent members of society, with the result that both Schleswig and Holstein were politically dominated by a predominantly German class of landowners. Thus two systems of government co-existed within the same state: democracy in Denmark, and absolutism in Schleswig and Holstein. The three units were governed by one cabinet, consisting of liberal ministers of Denmark who urged for economical and social reforms, and conservative ministers of the Holstein nobility who opposed political reform. This caused a deadlock for practical lawmaking. Moreover, Danish opponents of this so-called Unitary State (”Helstaten”) feared that Holstein’s presence in the government and, at the same time, membership of the German Confederation would lead to increased German interference with Schleswig, or even into purely Danish affairs.

In Copenhagen, the Palace and most of the administration supported a strict adherence to the status quo. Same applied to foreign powers such as Great Britain, France and Russia, who would not accept a weakened Denmark in favour of Germany, nor that Prussia acquired Holstein with the important naval harbour of Kiel or controlled the entrance to the Baltic.

In April 1850, in utter weariness Prussia proposed a definitive peace on the basis of the ”status quo ante bellum” and the postponement of all questions as to mutual rights. To Palmerston the basis seemed meaningless, the proposed settlement to settle nothing. The emperor Nicholas, openly disgusted with Frederick William’s weak-kneed truckling to the Revolution, again intervened. To him the duke of Augustenburg was a rebel; Russia had guaranteed Schleswig to the Danish crown by the treaties of 1767 and 1773; as for Holstein, if the king of Denmark was unable to deal with the rebels there, he himself would intervene as he had done in Hungary. The threat was reinforced by the menace of the European situation. Austria and Prussia were on the verge of war, and the sole hope of preventing Russia from throwing her sword into the scale of Austria lay in settling the Schleswig-Holstein question in the sense desired by her. The only alternative, an alliance with the devil’s nephew, Louis Napoleon, who already dreamed of acquiring the Rhine frontier for France at the price of his aid in establishing German sea-power by the cession of the duchies, was abhorrent to Frederick William.

After the First War of Schleswig

On July 2, 1850 was signed at Berlin a treaty of peace between Prussia and Denmark. Both parties 1850. reserved all their antecedent rights; but for Denmark it was enough, since it empowered the king-duke to restore his authority in Holstein with or without the consent of the German Confederation.

Danish troops now marched in to coerce the refractory duchies; but while the fighting went on negotiations among the powers continued, and on August 2, 1850 Great Britain, France, Russia and Norway-Sweden signed a protocol, to which Austria subsequently adhered, approving the principle of restoring the integrity of the Danish monarchy. The Copenhagen government. which in May 1851 made an abortive attempt to come to an understanding with the inhabitants of the duchies by convening an assembly of notables at Flensburg, issued on December 6, 1851 a project for the future organization of the monarchy on the basis of the equality of its constituent states, with a common ministry; and on January 28, 1852 a royal letter announced the institution of a unitary state which, while maintaining the fundamental constitution of Denmark, would increase the parliamentary powers of the estates of the two duchies. This proclamation was approved by Prussia and Austria, and by the German federal diet insofar as it affected Holstein and Lauenburg. The question of the succession was the next approached. Only the question of the Augustenburg succession made an agreement between the powers impossible, and on March 31, 1852 the duke of Augustenburg resigned his claim in return for a money payment. Further adjustments followed.

Another factor which doomed Danish interests, was that not only was the power of German culture rising, but conflicts with German States in the south, namely Prussia and Austria. Schleswig and Holstein would, of course and inevitable, become the subject of a territorial dispute involving military encounters among the three states, Denmark, Prussia and Austria.

Danish government found itself nervous as it became expected that Frederik VII would leave no son, and that upon his death, under Salic law, the possible Crown Princess would have no actual legal right to Schleswig and Holstein (of course that was debatable, as the dynasty itself had received Holstein by Christian I being son of the sister of last Schauenburg count of Holstein, but Salic Law was convenient to German nationalists in this case, furthermore was Schleswig a fief to the kings of Denmark with the Danish Kings Law, Kongeloven). Ethnic-Danish citizens of Schleswig (South Jutland) panicked over the possibility of being separated from their mother country, agitated against the German element, and demanded that Denmark declare Schleswig, as an integral part of Denmark, which outraged German nationalists.

Holstein was part of the territory of the German Confederation, with which an annexation of whole Schleswig and Holstein to Denmark would have been incompatible. This gave a good pretext to Prussia to engage in war with Denmark in order to seize Schleswig and Holstein for itself, both by pleasing nationalists by ‘liberating’ Germans from Danish rule, and by implementing the law of the German Confederation.

After the renunciation by the emperor of Russia and others of their eventual rights, Charlotte, landgravine of Hesse, sister of Christian VIII, and her son Prince Frederick transferred their rights to the latter’s sister Louise, who in her turn transferred them to her husband Prince Christian of Glucksburg.

On May 8, 1852, this arrangement received international sanction by the protocol signed in London by the five great powers and Norway and Sweden.

On July 31, 1853, Frederick VII of Denmark gave his assent to a law settling the crown on Prince Christian, prince of Denmark, and his heirs male. The protocol of London, while consecrating the principle of the integrity of Denmark, stipulated that the rights of the German Confederation in Holstein and Lauenburg should remain unaffected. It was, in fact, a compromise, and left the fundamental issues unsettled. The German federal diet had not been represented in London, and the terms of the protocol were regarded in Germany as a humiliation. As for the Danes, they were far from being satisfied with the settlement, which they approved only insofar as it gave them a basis for a more vigorous prosecution of their unionist schemes.

On February 15 and June 11, 1854 Frederick VII, after consulting the estates, promulgated special constitutions for Schleswig and Holstein respectively, under which the provincial assemblies received certain very limited powers.

On July 26, 1854 he published a common Danish constitution for the whole monarchy; it was little more unitary than a veiled absolutism.

On October 2, 1855 it was superseded by a parliamentary constitution of a modified type. The legality of this constitution was disputed by the two German great powers, on the ground that the estates of the duchies had not been consulted as promised in the royal letter of December 6, 1851.

On February 11, 1858 the diet of the German Confederation refused to admit its validity so far as Holstein and Lauenburg were concerned.

In the early 1860s the “Schleswig-Holstein Question” once more became the subject of lively international debate, but with the difference that support for the Danish position was in decline. The Crimean War had crippled the power of Russia, and France was prepared to renounce support for Danish interests in the duchies in exchange for compensations to herself elsewhere.

Queen Victoria and the Prince Consort Albert had sympathy for the German position, but it was tempered by British ministers who saw the growth of German sea-power in the Baltic Sea as a danger to British naval supremacy, and consequently Great Britain sided with the Danes.

To that was added a grievance about tolls charged on shipping passing through the Danish Straits to pass between the Baltic Sea and the North Sea. To avoid that expense, Prussia planned the Kiel Canal, which could not be built as long as Denmark ruled Holstein.

The secessionist movement continued throughout the 1850s and 1860s, as proponents of German unification increasingly expressed the wish to include two Danish-ruled provinces Holstein and Schleswig in a ‘Greater Germany’. Holstein was completely German, while the situation in Schleswig was complex. It was linguistically mixed between German, Danish and North Frisian. The population was predominantly of Danish ethnicity, but many of them had switched to the German language since the 17th century. German culture dominated in clergy and nobility, whereas Danish had a lower social status. For centuries, when the rule of the King was absolute, these conditions had created few tensions. When ideas of democracy spread and national currents emerged from ca. 1820, some professed sympathy with German, others with Danish nationality.

The medieval Treaty of Ribe had proclaimed that Schleswig and Holstein were indivisible, however in another context. As the events of 1863 threatened to politically divide the two duchies, Prussia was handed a good pretext to engage in war with Denmark to seize Schleswig-Holstein for itself, both by pleasing nationalists in “liberating” Germans from Danish rule, and by implementing the law of the German Confederation.

On July 29, 1853, In response to the renewed Danish claim to Schleswig as integral Danish territory, the German Diet (instructed by Bismarck) threatened German federal intervention.

On November 6, 1853, Frederick VII issued a proclamation abolishing the Danish constitution so far as it affected Holstein and Lauenburg, while keeping it for Denmark and Schleswig.

Even this concession violated the principle of the indissoluble union of the duchies, but the German diet, fully occupied at home, determined to refrain from further action till the Danish parliament should make another effort to pass a law or budget affecting the whole kingdom without consulting the estates of the duchies.

In July 1860 this happened, and in the spring of 1861 the estates were once more at open odds with the Danish government. The German diet now prepared for armed intervention; but it was in no condition to carry out its threats, and Denmark decided, on the advice of Great Britain, to ignore it and open negotiations directly with Prussia and Austria as independent powers. These demanded the restoration of the union between the duchies, a question beyond the competence of the Confederation. Denmark replied with a refusal to recognize the right of any foreign power to interfere in her relations with Schleswig; to which Austria, anxious to conciliate the smaller German princes, responded with a vigorous protest against Danish infringements of the compact of 1852.

Lord John Russell now intervened, on behalf of Great Britain, with a proposal for a settlement of the whole question on the basis of the independence of the duchies under the Danish crown, with a decennial budget for common expenses to be agreed on by the four assemblies, and a supreme council of state consisting in relative proportion of Danes and Germans. This was accepted by Russia and by the German great powers, and Denmark found herself isolated in Europe. The international situation, however, favoured a bold attitude, and she met the representations of the powers with a flat defiance. The retention of Schleswig as an integral part of the monarchy was to Denmark a matter of life and death; the German Confederation had made the terms of the protocol of 1852, defining the intimate relations between the duchies, the excuse for unwarrantable interference in the internal affairs of the Denmark.

On March 30, 1863, as a result of this, a royal compact’s proclamation was published at Copenhagen repudiating the compacts of 1852, and, by defining the separate position of Holstein in the Danish monarchy, negativing once for all the claims of Germany upon Schleswig.

Three main movements had evolved, each with its goal:

*A German movement in the two duchies dreamt of an independent Schleswig-Holstein under a liberal constitution. First a personal union with Denmark was outlined, as proposed by Uwe Jens Lornsen in 1830. Later, as it the succession problem appeared and the national sympathies of Danish royalty became evident, the Schleswig-Holstein movement called for an independent state ruled by the house of Augustenburg, a cadet branch of the Danish royal family. The movement largely ignored the fact that the northern half of Schleswig was predominantly Danish-minded.

*In Denmark, nationalists wished a ””Denmark to the Eider River””, implying a reincorporation of Schleswig into Denmark and an end to the century-long German dominance in this region’s politics. This scenario would mean a total exclusion of Holstein from the Danish monarchy, barring the conservative aristocracy of Holstein from Danish politics, thus easing liberal reforms. The Eider movement underestimated the German element of Southern Schleswig or thought they could be re-convinced of their Danish heritage.

*A less vociferous, but more influential stance was the keeping of the Danish unitary state as it was, one kingdom and two duchies. This would avoid any partition, but it would also not solve the ethnical controversy and the constitutional issues. Most Danish civil servants and the major powers of Russia, England and France supported this ”status quo”.

*A fourth scenario, that Schleswig and Holstein should both be incorporated into Prussia as a mere province, was hardly considered before or during the war of 1864. However, it was to be the outcome after the Austro-Prussian War two years later.

As the heir-less king Frederick VII grew older, Denmark’s successive National-Liberal cabinets became increasingly focused on maintaining control of Schleswig following the king’s future death.

Both duchies were ruled by the kings of Denmark and shared a long mutual history, but their association with Denmark was extremely complex. Holstein was a German fief and a member of the German Confederation. Denmark, and Schleswig (as it was a Danish fief), were outside the German Confederation. German nationalists claimed that the succession laws of the two duchies were different from the similar law in Denmark. Danes, however, claimed that this only applied to Holstein, but that Schleswig was subject to the Danish law of succession. A further complication was a much-cited reference in the 1460 Treaty of Ribe stipulating that Schleswig and Holstein should “be together and forever unseparated”. As counter-evidence, and in favour of the Danish view, rulings of a Danish clerical court and a German Emperor, of 1424 and 1421 respectively, were produced.

In 1863 King Frederick VII of Denmark died leaving no heir. According to the line of succession of Denmark and Schleswig, the crowns of both Denmark and Schleswig would now pass to Duke Christian of Glücksburg (the future King Christian IX), the crown of Holstein was considered to be more problematic. This decision was challenged by a rival pro-German branch of the Danish royal family, the House of Augustenburg (Danish: Augustenborg) who demanded, like in 1848, the crowns of both Schleswig and Holstein. This happened at a particularly critical time as work on a new constitution for the joint affairs of Denmark and Schleswig had just been completed with the draft awaiting his signature.

The November Constitution

The new so-called November Constitution would not annex Schleswig to Denmark directly, but instead create a joint parliament (with the medieval title ”Rigsraadet”) to govern the joint affairs of both Denmark and Schleswig. Both entities would maintain their individual parliaments as well. A similar initiative, but also including Holstein, had been attempted in 1855, but proved a failure because of the opposition of the people in Schleswig and their support in Germany. Most importantly, Article I clarified the question of succession: ”The form of government shall be that of a constitutional monarchy. Royal authority shall be inherited. The law of succession is specified in the law of succession of July 31, 1853 applying for the entire Danish monarchy.” [http://www.roennebech.dk/www_fredericiashistorie/html/fredericia/artikler/novemberforfatningen.html]

Denmark’s new king, Christian IX, was in a position of extraordinary difficulty. The first sovereign act he was called upon to perform was to sign the new constitution. To sign was to violate the terms of the London Protocol which would probably lead to war. To refuse to sign was to place himself in antagonism to the united sentiment of his Danish subjects, which was the basis of his reign. He chose what seemed the lesser of two evils, and on November 18 signed the constitution.

The news was seen as a violation of the London Protocol, which prohibited such a change in the status quo. It was received in Germany with manifestations of excitement and anger. Frederick, duke of Augustenburg, son of the prince who in 1852 had renounced the succession to the duchies, now claimed his rights on the ground that he had had no share in the renunciation. In Holstein an agitation in his favor had begun from the first, and this was extended to Schleswig when the terms of the new Danish constitution became known. His claim was enthusiastically supported by the German princes and people, and in spite of the negative attitude of Austria and Prussia the federal diet at the initiative of Otto von Bismarck decided to occupy Holstein pending the settlement of the decree of succession.

Second War of Schleswig

On December 24, 1863, Saxon and Hanoverian troops marched into the German duchy of Holstein in the name of the German Confederation, and supported by their presence and by the loyalty of the Holsteiners the duke of Augustenburg assumed the government under the style of Duke Frederick VIII.

It was clear to Bismarck that Austria and Prussia, as parties to the London-protocol of 1852, must and uphold the succession as fixed by it, and that any action they might take in consequence of the violation of that compact by Denmark must be so correct as to deprive Europe of all excuse for interference. The publication of the new constitution by Christian IX was in itself sufficient to justify them. As to the ultimate outcome of their effective intervention, that could be left to the future to decide. Austria had no clear views. King William wavered between his Prussian feeling and a sentimental sympathy with the duke of Augustenburg. Bismarck alone knew exactly what he wanted, and how to attain it. “From the beginning”, he said later (”Reflections”, ii. 10), “I kept annexation steadily before my eyes.”

After Christian IX of Denmark merged Schleswig (not Holstein) into Denmark in 1863 after his ascension to the Danish throne that year, Bismarck’s diplomatic abilities finally convinced Austria to participate in the war, with the assent of the other European large powers and under the auspices of the German Confederation.

The protests of Great Britain and Russia against the action of the German diet, together with the proposal of Count Beust, on behalf of Saxony, that Bavaria should bring forward in that assembly a formal motion for the recognition of Duke Frederick’s claims, helped Bismarck to persuade Austria that immediate action must be taken.

On December 28 a motion was introduced in the diet by Austria and Prussia, calling on the Confederation to occupy Schleswig as a pledge for the observance by Denmark of the compacts of 1852. This implied the recognition of the rights of Christian IX, and was indignantly rejected; whereupon the diet was informed that the Austrian and Prussian governments would act in the matter as independent European powers.

On January 16, 1864 the agreement between them was signed. An article drafted by Austria, intended to safeguard the settlement of 1852, was replaced at Bismarck’s instance by another which stated that the two powers would decide only in concert on the relations of the duchies, and that they would in no case determine the question of the succession save by mutual consent; and Bismarck issued an ultimatum to Denmark demanding that the November Constitution should be abolished within 48 hours. This was rejected by the Danish government.

The Austrian and Prussian forces crossed the Eider into Schleswig on February 1, 1864, and war was inevitable.

An invasion of Denmark itself had not been part of the original programme of the allies; but on February 18 some Prussian hussars, in the excitement of a cavalry skirmish, crossed the frontier and occupied the village of Kolding. Bismarck determined to use this circumstance to revise the whole situation. He urged upon the Austrians the necessity for a strong policy, so as to settle once for all not only the question of the duchies but the wider question of the German Confederation; and Austria reluctantly consented to press the war.

On March 11 a fresh agreement was signed between the powers, under which the compacts of 1852 were declared to be no longer valid, and the position of the duchies within the Danish monarchy as a whole was to be made the subject of a friendly understanding.

Meanwhile, however, Lord John Russell on behalf of Great Britain, supported by Russia, France and Sweden, had intervened with a proposal that the whole question should once more be submitted to a European conference. The German powers agreed on condition that the compacts of 1852 (London-protocoll) should not be taken as a basis, and that the duchies should be bound to Denmark by a personal tie only. But the proceedings of the conference, which opened at London on April 25, only revealed the inextricable tangle of the issues involved.

Beust, on behalf of the Confederation, demanded the recognition of the Augustenburg claimant; Austria leaned to a settlement on. the lines of that of 1852; Prussia, it was increasingly clear, aimed at the acquisition of the duchies. The first step towards the realization of this latter ambition was to secure the recognition of the absolute independence of the duchies, and this Austria could only oppose at the risk of forfeiting her whole influence in Germany. The two powers, then, agreed to demand the complete political independence of the duchies bound together by common institutions. The next move was uncertain. As to the question of annexation Prussia would leave that open, but made it clear that any settlement must involve the complete military subordination of Schleswig-Holstein to herself. This alarmed Austria, which had no wish to see a further extension of Prussia’s already overgrown power, and she began to champion the claims of the duke of Augustenburg. This contingency, however, Bismarck had foreseen and himself offered to support the claims of the duke at the conference if he would undertake to subordinate himself in all naval and military matters to Prussia, surrender Kiel for the purposes of a Prussian war-harbour, give Prussia the control of the projected North Sea Canal, and enter the Prussian Customs Union. On this basis, with Austria’s support, the whole matter might have been arranged without—as Beust pointed out (”Mem.” 1. 272)

Austria, the other leading state of the German Confederation was reluctant to engage in a “war of liberation” because of its own problems with various nationalities. After Christian IX of Denmark merged Schleswig and Holstein into Denmark in 1863 after his ascension to the Danish throne that year, Bismarck’s diplomatic abilities finally convinced Austria to participate in the war, with the assent of the other European large powers and under the auspices of the German Confederation.

On June 25 the London conference broke up without having arrived at any conclusion. On the 24th, in view of the end of the truce, Austria and Prussia had arrived at a new agreement, the object of the war being now declared to be the complete separation of the duchies from Denmark. As the result of the short campaign that followed, the preliminaries of a treaty of peace were signed on August 1, the king of Denmark renouncing all his rights in the duchies in favour of the emperor of Austria and the king of Prussia.

The definitive treaty was signed at Vienna on October 30, 1864. By Article XIX, a period of six years was allowed during which the inhabitants of the duchies might opt for Danish nationality and transfer themselves and their goods to Denmark; and the right of indigenacy was guaranteed to all, whether in the kingdom or the duchies, who enjoyed it at the time of the exchange of ratifications of the treaty.

This Second War of Schleswig of 1864 was presented by invaders to be an implementation of the law of the Confederation (”Bundesexekution”) in Germany. After the defeat in the Battle of Dybbøl, the Danes were unable to defend the borders of Schleswig, then had to retreat to Denmark proper, and finally were pushed out of the entire Jutland peninsula. Denmark capitulated and Prussia and Austria took over the administration of Schleswig and Holstein respectively under the Gastein Convention of August 14, 1865.

The north border of Schleswig-Holstein as from 1864 to 1920 differs a little from the north border of the modern Danish county of Sønderjylland: in the east Hejls and the Skamlingsbanke hill were not in Schleswig-Holstein but are now in Sønderjylland county; in the west Hviding and Rejsby were in Schleswig-Holstein but are now in Ribe County.

After the Second War of Schleswig

It did not take long for disagreements between Prussia and Austria over both the administration and the future of the duchies to surface. Bismarck used these as a pretext to engineer what became the Austro-Prussian War of 1866. Austria’s defeat at the Battle of Königgrätz was followed by the dissolution of the German Confederation and Austria’s withdrawal from Holstein, which, along with Schleswig, in turn was annexed by Prussia.

Following the Austro-Prussian War of 1866, section five of the Peace of Prague stated that the people on Northern Schleswig should be granted the right to a referendum on whether they would remain under Prussian rule or return to Danish rule. This promise was never fulfilled by Germany.

In any case, because of the mix of Danes and Germans who lived there and the various feudal obligations of the players, the Schleswig-Holstein Question problem was considered intractable by many. Lord Palmerston said of the issue that only three people understood the Schleswig-Holstein question: one was dead, the other had gone insane, and the third was himself, but he had forgotten it.

This was convenient for Palmerston, as the government knew that Britain was almost powerless on the continent and had no chance of countering Prussia’s military or manufacturing might. Meanwhile, in 1864, the Danish royal family, impressed by Victoria’s trappings of Empire, arranged the marriage of the Princess to the future Edward VII, so helping to reverse the Anglo-German alliance, which led to the 1914 war. Niall Ferguson in Empire quotes Kitchener in 1914: “We haven’t an army, and we have taken on the foremost military power in Europe”.

The Schleswig-Holstein Question from this time onward became merged in the larger question of the general relations of Austria and Prussia, and its later developments are a result of the war of 1866. It survived, however, as between Danes and Germans, though narrowed down to the question of the fate of the Danish population of the northern duchy. This question is of great interest to students of international law and as illustrating the practical problems involved in the assertion of the modern principle of nationality.

In the Austro-Prussian War of 1866 Prussia took Holstein from Austria.

Danes under German rule

The position of the Danes in Schleswig after the cession was determined, so far as treaty rights are concerned, by two instruments: the Treaty of Vienna (October 30, 1864) and the Peace of Prague (August 23, 1866). Under Article XIX of the former treaty the Danish subjects domiciled in the ceded territories had the right, within six years of the exchange of ratifications, of opting for the Danish nationality and transferring themselves, their families and their personal property to Denmark, while keeping their landed property in the duchies. The last paragraph of the Article ran:

:”Le droit d’indigénat, tant dans le royaume de Danemark que dans les Duchés, est conservé à tous les individus qui le possèdent a l’époque de l’échange des ratifications du présent Traité”.

“The right of an indigenous person, as well in the kingdom of Denmark as in the Duchies, is preserved for all individuals who have it at the time of the exchange of the ratifications of this Treaty.”)

By Article V of the Peace of Prague, Schleswig was ceded by Austria to Prussia with the reservation that the populations of the North of Schleswig shall be again united with Denmark in the event of their expressing a desire so to be by a vote freely exercised. Taking advantage of the terms of these treaties, about 50,000 Danes from North Schleswig (out of a total population of some 150,000) opted for Denmark and were expelled across the frontier, pending the plebiscite which was to restore their country to them. But the plebiscite never came. Its inclusion in the treaty had been no more than a diplomatic device to save the face of the emperor Napoleon III; Prussia had from the first no intention of surrendering an inch of the territory that had been had conquered; the outcome of the Franco-German War made it unnecessary to even pretend that that the plebiscite might occur; and by the Treaty of Vienna of October 11, 1878, the clause relating to the plebiscite was formally abrogated with the assent of Austria.

Meanwhile the Danish optants, disappointed of their hopes, had begun to stream back over the frontier into Schleswig. By doing so they lost, under the Danish law, their rights as Danish citizens, without acquiring those of Prussian subjects; and this disability was transmitted to their children. By Article XIX. of the Treaty of 1864, indeed, they should have been secured the rights of indigenacy, which, while falling short of complete citizenship, implied, according to Danish law, all the essential guarantees for civil liberty. But in German law the right of Indigenat is not clearly differentiated from the status of a subject; and the supreme court at Kiel decided in several cases that those who had opted for Danish nationality had forfeited their rights under the Indigenat paragraph of the Treaty of Vienna. There was thus created in the frontier districts a large and increasing class of people who dwelt in a sort of political limbo, having lost their Danish citizenship through ceasing to be domiciled in Denmark, and unable to acquire Prussian citizenship because they had failed to apply for it within the six years stipulated in the Treaty of 1864. Their exclusion from the rights of Prussian subjects was due, however, to causes other than the letter of the treaty.

The Danes, in spite of every discouragement, never ceased to strive for the preservation and extension of their national traditions and language; the Germans were equally bent on effectually absorbing these recalcitrant Teutons into the general life of the German empire; and to this end the uncertain status of the Danish optants was a useful means. Danish agitators of German nationality could not be touched so long as they were careful to keep within the limits of the law; pro-Danish newspapers owned and staffed by German subjects enjoyed immunity in accordance with the constitution, which guarantees the liberty of the press. The case of the optants was far other. These unfortunates, who numbered a large proportion of the population, were subject to domiciliary visits, and to arbitrary perquisitions, arrest and expulsion. When the pro-Danish newspapers, after the expulsion of several optant editors, were careful to appoint none but German subjects, the vengeance of the authorities fell upon optant type-setters, printers and printers devils. The Prussian police, indeed, developed an almost superhuman- capacity for detecting optants: and since these pariahs were mingled indistinguishably with the mass of the people, no household and no business was safe from official inquisition. One instance out of many may serve to illustrate the type of offence that served as excuse for this systematic official persecution. On April 27, 1896 the second volume for 1895 of the ”Sønderjyske Aarboger” was confiscated for having used the historic term Sonderjylland (South Jutland) for Schleswig. To add to the misery, the Danish government refused to allow the Danish optants expelled by Prussia to settle in Denmark, though this rule was modified by the Danish Nationality Law of 1898 in favour of the children of optants born after the passing of the law. It was not till the signature of the treaty between Prussia and Denmark on January 11, 1907 that these intolerable Treaty of conditions were ended. By this treaty the German January government undertook to allow all children born of Danish optants before the passing of the new Danish Nationality Law of 1898 to acquire Prussian nationality on the usual conditions and on their own application. This provision was not to affect the ordinary legal rights of expulsion as exercised by either power, but the Danish government undertook not to refuse to the children of Schleswig optants who should not seek to acquire or who could not legally acquire Prussian nationality permission to reside in Denmark. The provisions of the treaty apply not only to the children of Schleswig optants, but to their direct descendants in all decrees.

This adjustment, brought about by the friendly intercourse between the courts of Berlin and Copenhagen, seemed to close the last phase of the Schleswig question. Yet, so far from allaying, it apparently only served to embitter the inter-racial feud. The autochthonous Germans of the Northern Marches regarded the new treaty as a betrayal, and refused to give the kiss of peace to their hereditary enemies. For forty years Germanism, backed by all the weight of the empire and imposed with all the weapons of official persecution, had barely held its own in North Schleswig; despite an enormous emigration, in 1905 139,000 of the 148,000 inhabitants of North Schleswig spoke Danish, while of the German-speaking immigrants it was found that more than a third spoke Danish in the first generation, although from 1864 onward, German had gradually been substituted for Danish in the churches, the schools, and even in the playground. After 1888 German was the only language of instruction in schools in Schleswig. But the scattered outposts of Germanism could hardly be expected to acquiesce without a struggle in a situation that threatened them with social and economic extinction. Forty years of dominance, secured by official favour, had filled them with a double measure of aggressive pride of race, and the question of the rival nationalities in Schleswig, like that in Poland, remained a source of trouble and weakness within the frontiers of the German empire.

After World War I

After Germany had lost World War I, in which Denmark had been neutral, the victors offered Denmark to redraw the border between Denmark and Germany. The sitting government of Carl Theodor Zahle chose to hold the Schleswig Plebiscite to let the inhabitants of Schleswig decide which nation they, and the land they lived on, should belong to. King Christian X of Denmark, supported by various groups, was opposed to the division. Using a clause in the Danish constitution that the king appointed and dismissed the Danish cabinet, and using the justification that the he felt the Danish population was at odds with Zahle’s politics, the king dismissed Zahle and asked Otto Liebe to form the Cabinet of Liebe to manage the country until a parliamentary election could be held and a new cabinet formed. Since Zahle’s had support from a small majority in the Folketing his Social Liberal Party and the allied Social Democrats felt that the king had effectively staged a state coup against the Danish democracy. A general strike was organized by Fagbevægelsen to put pressure on the king and his allies. As Otto Liebe was unable to organize an election, M. P. Friis replaced him after a week, and succeeded in holding the election, and as a result the Social Liberal Party lost half their electoral support and their rivals the Liberal Party were able to form the minority cabinet led by Niels Neergaard: the Cabinet of Neergaard II. The whole affair was called the Easter Crisis of 1920.

The Allied powers arranged a referendum in Northern and Central Schleswig. In Northern Schleswig on February 10, 1920 75% voted for re-unification with Denmark and 25% voted for Germany. In Central Schleswig on March 14, 1920 the results were reversed; 80% voted for Germany and just 20% for Denmark, primarily in Flensburg. While in Northern Schleswig some smaller regions (for example Tønder) had a clear majority of voters for Germany in Central Schleswig all regions voted for Germany (see Schleswig Plebiscites). No vote ever took place in the southern third of Schleswig, because the result for Germany was predictable. On June 15, 1920, Northern Schleswig officially returned to Danish rule. Germany continued to hold the whole of Holstein and southern and central Schleswig, later becoming the Prussian province of Schleswig-Holstein. The Danish-German border was the only one of the borders imposed on Germany following World War I which was never challenged by Hitler.

World War II

In the Second World War, after Nazi Germany occupied the whole of Denmark, there was agitation by local Nazi leaders in Schleswig-Holstein to restore the pre-World War I border and re-annex to Germany the areas granted to Denmark after the plebiscite — as the Nazis did in Alsace-Lorraine at the same period. However, Hitler vetoed any such step, out of a general Nazi policy at the time to base the occupation of Denmark on a kind of accommodation with the Danish Government, and avoid outright confrontations with the Danes.

After World War II

After Germany had lost World War II there again was a possibility that Denmark could reacquire some of its lost territory in Schleswig. Though no territorial changes came of it, it had the effect that Prime Minister Knud Kristensen was forced to resign after a vote of no confidence because the Folketing did not support his enthusiasm for incorporating Southern Schleswig into Denmark.

Although there was, as a result, a Danish minority in Southern Schleswig and a German minority in Northern Schleswig, the minorities were granted rights to practice their language and culture, to such a degree that the division and minorities are not a political issue between Denmark and Germany.

Adapted from the Wikipedia article History of Schleswig-Holstein, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

No related posts.

The basic design of gaslight apparatus was established by Boulton & Watt and Samuel Clegg in the period 1805–1812. Further improvements were made at the Gas Light and Coke Company, as well as by the growing number of gas engineers such as John Malam and Thomas Peckston after 1812. Boulton & Watt contributed the basic design of the retort, condenser, and gasometer, while Clegg improved the gasometer and introduced lime purification and the hydraulic main, another purifier.

Retort bench

The retort bench was the construction in which the retorts were located for the carbonization (synonymous with pyrolysis) of the coal feedstock and the evolution of coal gas. Over the many years of manufactured gas production, advances were made that turned the retort-bench from little more than coal-containing iron vessels over an open fire to a massive, highly-efficient, partially-automated, industrial-scale, capital-intensive plant for the carbonization of large amounts of coal. Several retort benches were usually located in a single “retort house”, which there was at least one of in every gas-works.

Initially, retort benches were of many different configurations due to the lack of long use and scientific and practical understanding of the carbonization of coal. Some early retorts were little more than iron vessels filled with coal and thrust upon a coal fire with pipes attached to their top ends. Though practical for the earliest of gas-workings, this quickly changed once the very early gas-works served more than a relatively few customers. As the size of such v

Retorts were usually made of cast iron during the early days of manufactured gas. Early gas engineers experimented extensively with the best shape, size, and setting to adopt. No one form of retort initially came to dominate, and many different cross-sections remained in use; however, after the 1850s, retorts generally became made of fire-clay due to greater heat retention, greater durability under heat, longer life with proper care, and other positive qualities. Cast-iron retorts were still used in the small gas-works, due to their compatibility with the demands of such, with the cast-iron retort’s lower cost, ability to heat up quickly to meet transient demand, and “plug and play” replacement capabilities outweighing the disadvantages of shorter life-time, lower temperature margins, and lack of ability to be manufactured in non-cylindrical shapes. Also, general gas-works practice following the switch to fire-clay retorts favored retorts that were shaped like a “D” turned 90 degrees to the left, sometimes with a slightly pitched bottom section.

With the introduction of the fire-clay retort, higher heats could be held in the retort benches, leading to faster and more complete carbonization of the coal within. As higher heats became possible, advanced methods of retort bench firing were introduced, catalyzed by the development of the open hearth furnace by Siemens, during a period from around 1855 – 1870, leading to a revolution in gas-works efficiency.

Specifically, the two major advances were:

*The introduction of the “indirectly-fired” retort bench. The early “directly-fired” retort bench consisted of retorts suspended over a coke fire, which heated the retorts and drove the carbonization of coal within to coke, and the evolution of gas. The introduction of indirect firing changed this – instead of the retorts being heated directly by the fire – the fire was placed a ways below and to one side of the retorts, brought to a very high heat, while the air supply was reduced and a small amount of steam introduced. Instead of evolving large quantities of heat to directly heat the retorts, the fire now evolved heated gasses – specifically carbon monoxide and – due to the steam – a small amount of hydrogen gas as well, which are both highly combustible. These gasses rise from the fire into a channel which soon brings them to the “tuyeres” – small holes similar to “nostrils”, located adjacent to the retorts, which shoot the “furnace-gasses” out of them. Adjacent “tuyeres” emit a large amount of “secondary air”, which is preheated air, that, upon mixing with the furnace gasses, causes them to ignite and burst into flame and bathe the exterior of the retorts in heat.

*The introduction of heat recuperation for the preheating of the air of primary and secondary combustion. By causing the exhaust of the retort-bench to pass through a labyrinthine maze of refractory brickwork, substantial quantities of heat can be extracted from it. On the other side of the exhaust channels are channels for the passage of the air of combustion. The bricks thus transfer the heat of the exhaust to the air of combustion, preheating it. This provides for a much greater degree of thermal efficiency in the retort-bench, causing it to be able to use far less coke – as air that is preheated by waste heat is already hot when it enters the fire to be burnt, or the “tuyere” to fuel secondary combustion.

These two advances turned the old, “directly-fired” retort bench into the advanced, “indirectly-fired”, “regenerative” or “generative” retort bench, and lead coke usage within the retort benches – at least in the larger works – to drop from upwards of 40% of the coke made by the retorts to factors as low as 15% of the coke made by the retorts, leading to an improvement in efficiency of an order of magnitude. However, these improvements imparted an additional capital cost to the retort bench to incorporate them, which caused them to be only slowly incorporated in the smaller gas-works, if they were incorporated at all.

Further increases in efficiency and safety were seen with the introduction of the “through” retort, which had a door at both its front and its rear. This provided for greater efficiency and safety in loading and unloading the retorts, which was a labor-intensive and often dangerous process. Coal could now be pushed out of the retort – rather than pulled out of the retort. One interesting modification of the “through” retort was the “inclined” retort – coming into its heyday in the 1880s – a retort set on a moderate incline, where coal was poured in at one end, and the retort sealed; following pyrolysis, the bottom was opened and the coke poured out through means of gravity. This was adopted in some gas-works, but the savings in labor were often offset by the uneven distribution and pyrolysis of the coal as well as clumping problems leading to failure of the coal to pour out of the bottom following pyrolysis that were exacerbated in certain coal types. As such, inclined retorts were rendered obsolescent by later advances, including the retort-handling machine and the vertical retort system.

Several advanced retort-house appliances were introduced for improved efficiency and convenience. The compressed-air or steam-driven clinkering pick was found to be especially useful in removing clinker from the primary combustion area of the indirectly-fired benches – previously clinkering was an arduous and time-consuming process that used large amounts of retort house labor. Another class of appliances introduced were apparatuses – and ultimately, machines – for retort loading and unloading. Retorts were generally loaded by using an elongated scoop, into which the coal was loaded – a gang of men would then lift the scoop and ram it into the retort. The coal would then be raked by the men into a layer of even thickness and the retort sealed. Gas production would then ensue – and from 8 – 12 hours later, the retort would be opened, and the coal would be either pulled (in the case of “stop-ended” retorts) or pushed (in the case of “through” retorts) out of the retort. Thus, the retort house had heavy manpower requirements – as many men were often required to bear the coal-containing scoop and load the retort.

”(TBD: Brief description of advanced retort loading apparatus; more detailed description of retort-handling machine.)”

”Coming soon: The introduction of the coke-oven system, and, finally, the vertical retort system.”

Other Gas-Works facilities

From the retort, the gas would first pass through a tar/water “trap” (similar to a trap in plumbing) called a hydraulic main, where a considerable fraction of coal tar was given up and the gas was significantly cooled. Then, it would pass through the main out of the retort house into an atmospheric or water cooled condenser, where it would be cooled to the temperature of the atmosphere or the water used. At this point, it enters the exhauster house and passes through an “exhauster”, an air pump which maintains the hydraulic mains and, consequently, the retorts at a negative pressure (with a zero pressure being atmospheric). It would then be washed in a “washer” by bubbling it through water, to extract any remaining tars. After this, it would enter a purifier. The gas would then be ready for distribution, and pass into a gasholder for storage.

Hydraulic main

Within each retort-house, the retort benches would be lined up next to one another in a long row; each retort had a loading and unloading door; affixed to each door was an ascension pipe, to carry off the gas as it was evolved from the coal within. These pipes would rise to the top of the bench where they would terminate in an inverted “U” with the leg of the “U” disappearing into a long, trough-shaped structure (with a covered top) made of cast iron called a hydraulic main that was placed atop the row of benches near their front edge. It ran continuously along the row of benches within the retort house, and each ascension pipe from each retort descended into it.

The hydraulic main had a level of a liquid mixture of (initially) water, but, following use, also coal tar, and ammoniacal liqueur. Each retort ascension pipe dropped under the water level by at least a small amount, perhaps by an inch, but often considerably more in the earlier days of gas manufacture. The gas evolved from each retort would thus bubble through the liquid and emerge from it into the void above the liquid, where it would mix with the gas evolved from the other retorts and be drawn off through the foul main to the condenser.

There were two purposes to the liquid seal: first, to draw off some of the tar and liquor, as the gas from the retort was laden with tar, and the hydraulic main could rid the gas of it, to a certain degree; further tar removal would take place in the condenser, washer/scrubber, and the tar extractor. Still, there would be less tar to deal with later. Second, the liquid seal also provided defense against air being drawn into the hydraulic main: if the main had no liquid within, and a retort was left open with the pipe not shut off, and air were to combine with the gas, the main could explode, along with nearby benches.

However, after the early years of gas, research proved that a very deep, excessive seal on the hydraulic main threw a backpressure upon all the retorts as the coal within was gasifying, and this had deleterious consequences; carbon would likely deposit onto the insides of retorts and ascension pipes; and the bottom layer of tar with which the gas would have to travel through in a deeply sealed main robbed the gas of some of its illuminating value. As such, after the 1860s, hydraulic mains were run at around 1& inch of seal, and no more.

Later retort systems (many types of vertical retorts, especially ones in continuous operation) which had other anti-oxygen safeguards, such as check valves, etc, as well as larger retorts, often omitted the hydraulic main entirely and went straight to the condensers – as other apparatus and buildings could be used for tar extraction, the main was unnecessary for these systems.

Condenser

Cooled evolved gas to temperature of atmosphere (or water), so that gas would give up a good portion of its remaining volatiles at this point. Most tar (except for very light tar) would be given up.

Exhauster

Maintained hydraulic main and condenser at negative pressure.

There were several types of exhausters.

*The steam ”ejector”/aspirator type exhauster used a substantial steam jet/venturi to maintain the negative pressure in the hydraulic main and condenser. This type of exhauster was mechanically simple, had no moving parts, and thus, had virtually no potential to fail. However, it consumed a comparatively large amount of steam. Often used as a backup exhauster; in this role it continued as a reliable backup until the end of the age of manufactured gas.

*Reciprocating exhausters of various types. Steam engine-driven exhauster used cylinder pump to pump gas. Relatively reliable, but inefficient, using large quantities of steam, but less than the ejector type exhauster. Used in the early days of exhausters, but quickly obsoleted.

*Blower-type exhauster.

*Turboexhauster.

The Washer–scrubber

Final extractions of minor deleterious fractions.

Purifier

Coal gas coming directly from the bench was a noxious soup of chemicals, and removal of the most deleterious fractions was important, for improving the quality of the gas, for preventing damage to equipment or premises, and for recovering revenues from the sale of the extracted chemicals. Several offensive fractions being present in a distributed gas might lead to problems – Tar in the distributed gas might gum up the pipes (and could be sold for a good price), ammoniacal vapours in the gas might lead to corrosion problems (and the extracted ammonium sulfate was a decent fertilizer), naphthalene vapours in the gas might stop up the gas-mains, and even carbon dioxide in the gas was known to decrease illumination; thus various facilities within the gas-works were tasked with the removal of these deleterious effluents. But these do not compare to the most hazardous contaminant in the raw coal gas: the sulfuret of hydrogen (hydrogen sulfide, H2S). This was regarded as utterly unacceptable for several reasons:

# The gas would smell rankly of rotten eggs when burnt;

# The gas-works and adjacent district would smell of rotten eggs when the gas-works was producing gas;

# The gas, upon burning, would form sulfur dioxide, which would be quickly oxidized to sulfur trioxide, and subsequently would react with the water vapor produced by combustion to form sulfuric acid vapour. In a dwelling-house, this could lead to the formation of irritating, poisonous and corrosive atmospheres where and when burnt.

# Manufactured gas was originally distributed in the well-to-do districts, as such were low-hanging fruit for the gas utility. Such persons were of a class known to possess silver goods of varying sorts. If exposed to a sulfurous atmosphere, silver tarnishes – and a sulfurous atmosphere would undoubtedly be present in any house lit with sulfuretted gas.

As such, the removal of the sulfuret of hydrogen was given the highest level of priority in the gas-works. A special facility existed to extract the sulfuret of hydrogen – known as the purifier. The purifier was arguably the most important facility in the gas-works, if the retort-bench itself is not included.

Originally, purifiers were simple tanks of lime-water where the raw gas from the retort bench was bubbled through to remove the sulfuret of hydrogen. This original process of purification was known as the “wet lime” process. But this process created noxious waste, as the combination of the sulfuret and calcium was also accompanied by the combination of the nitrogen of ammonia and the carbon of carbonate (lime being calcium carbonate), mediated by the aqueous environment, forming poisonous cyanide ions. Originally, the waste of the purifier house was flushed into a nearby body of water, such as a river or a canal. However, after fish kills, the nauseating way it made the rivers stink, and the truly horrendous stench caused by exposure of residuals if the river was running low, the public clamoured for better means of disposal. Thus it was piled into heaps for disposal. The lime residue left over from the “wet lime” process was one of the first true “toxic wastes”, a material called “blue billy”. Some enterprising gas entrepreneurs tried to sell it as a weed-killer, but most people wanted nothing to do with it, and generally, it was regarded as waste which was both smelly and poisonous, and gas-works could do little with, except bury. But this was not the end of the “blue billy”, for after burying it, rain would often fall upon its burial site, and leach the poison and stench from the buried waste, which could drain into fields or streams. Following countless fiascoes with “blue billy” contaminating the environment, a furious public, aided by courts, juries, judges, and masters in chancery, were often very willing to demand that the gas-works seek other methods of purification – and even pay for the damages caused by their old methods of purification.

This led to the development of the “dry lime” purification process, which was less effective than the “wet lime” process, but had less toxic consequences. Still, it was quite noxious. Slaked lime (calcium hydroxide) was placed in thick layers on trays which were then inserted into a square or cylinder-shaped purifier tower which gas was then passed through, from the bottom to the top. After the charge of slaked lime had lost most of its absorption effectiveness, the purifier was then shut off from the flow of gas, and either was opened, or air was piped in. Immediately, the sulfur-impregnated slaked lime would react with the air to liberate large concentrations of sulfuretted hydrogen, which would then billow out of the purifier house, and make the gas-works, and the district, stink of sulfuretted hydrogen. Though toxic in sufficient concentrations or long exposures, the sulfuret was generally just nauseating for short exposures at moderate concentrations, and was merely a health hazard (as compared to the outright danger of “blue billy”) for the gas-works employees and the neighbors of the gas-works. The sulfuretted lime was not toxic, but not greatly wanted, slightly stinking of the odor of the sulfuret, and was spread as a low grade fertilizer, being impregnated with ammonia to some degree. The outrageous stinks from many gas-works led many citizens to regard them as public nuisances, and attracted the eye of regulators, neighbors, and courts.

The “gas nuisance” was finally solved by the “iron ore” process. Enterprising gas-works engineers discovered that bog iron ore could be used to remove the sulfuretted hydrogen from the gas, and not only could it be used for such, but it could be used in the purifier, exposed to the air, whence it would be rejuvenated, without emitting noxious sulfuretted hydrogen gas, the sulfur being retained in the iron ore. Then it could be reinserted into the purifier, and reused and rejuvenated multiple times, until it was thoroughly embedded with sulfur. It could then be sold to the sulfuric acid works for a small profit. Lime was sometimes still used after the iron ore had thoroughly removed the sulfuret of hydrogen, to remove carbonic acid (carbon dioxide, CO2), the bisulfuret of carbon (carbon disulfide, CS2), and any ammonia still aeroform after its travels through the works. But it was not made noxious as before, and usually could fetch a decent rate as fertilizer when impregnated with ammonia. This finally solved the greatest pollution nuisances of the gas-works, but still lesser problems remained – not any that the purifier house could solve, though.

Purifier designs also went through different stages throughout the years.

The Gasholder

Held gas.

Minor and incidental coal gas-works facilities

The gasworks had numerous small appertunances and facilities to aid with divers gas management tasks or auxiliary services.

Boilers

As the years went by, boilers (for the raising of steam) became extremely common in most gas-works above those small in size; the smaller works often used gas-powered internal combustion engines to do some of the tasks that steam performed in larger workings.

Steam was in use in many areas of the gasworks, including:

For the operation of the exhauster;

For scurfing of pyrolysis char and slag from the retorts and for clinkering the producer of the bench;

For the operation of engines used for conveying, compressing air, charging hydraulics, or the driving of dynamos or generators producing electric current;

To be injected under the grate of the producer in the indirectly-fired bench, so as to prevent the formation of clinker, and to aid in the water-gas shift reaction, ensuring high-quality secondary combustion;

As a reactant in the (carburetted) water gas plant, as well as driving the equipment thereof, such as the numerous blowers used in that process, as well as the oil spray for the carburettor;

For the operation of fire, water, liquid, liquor, and tar pumps;

For the operation of engines driving coal and coke conveyor-belts;

For clearing of chemical obstructions in pipes, including naphthalene & tar as well as general cleaning of equipment;

For heating cold buildings in the works, for maintaining the temperature of process piping, and preventing freezing of the water of the gasholder, or congealment of various chemical tanks and wells.

Heat recovery appliances could also be classed with boilers. As the gas industry applied scientific and rational design principles to its equipment, the importance of thermal management and capture from processes became common. Even the small gasworks began to use heat-recovery generators, as a fair amount of steam could be generated for “free” simply by capturing process thermal waste using water-filled metal tubing inserted into a strategic flue.

Dynamos/generators

As the electric age came into being, the gas-works began to use electricity – generated on site – for many of the smaller plant functions previously performed by steam or gas-powered engines, which were impractical and inefficient for small, sub-horsepower uses without complex and failure-prone mechanical linkages. As the benefits of electric illumination became known, sometimes the progressive gasworks diversified into electric generation as well, as coke for steam-raising could be had on-site at low prices, and boilers were already in the works.

Coal storage

According to Meade, the gasworks of the early 20th century generally kept on hand several weeks of coal. This amount of coal could cause major problems, due to the fact that coal was liable to spontaneous combustion when in large piles, especially if they were rained upon, due to the protective dust coating of the coal being washed off, exposing the full porous surface area of the coal of slightly to highly activated carbon below; in a heavy pile with poor heat transfer characteristics, the heat generated could lead to ignition. But storage in air-entrained confined spaces was not highly looked upon either, as residual heat removal would be difficult, and fighting a fire if it was started could result in the formation of highly toxic carbon monoxide through the water-gas reaction, caused by allowing water to pass over extremely hot carbon (H2O + C = H2 + CO), which would be dangerous outside, but deadly in a confined space.

Coal storage was designed to alleviate this problem. Two methods of storage were generally used; underwater, or outdoor covered facilities. To the outdoor covered pile, sometimes cooling appurtenances were applied as well; for example, means to allow the circulation of air through the depths of the pile and the carrying off of heat. Amounts of storage varied, often due to local conditions. Works in areas with industrial strife often stored more coal, while nations whose proletariat was under “control” stored less. Other variables included national security; for instance, the gasworks of Tegel in Berlin had some 1 million tons of coal (6 months of supply) in gigantic underwater bunker facilities half a mile long (Meade 2e, p.& 379); as Berlin is on the North German Plain, perhaps this was due to what happened to Paris in the Franco-Prussian War of 1870-1871.

Tar/liquor storage

The chemical industries demanded coal tar, and the gas-works could provide it for them; as such, the coal tar was stored on site in large underground tanks. As a rule, these were single wall metal tanks – that is, if they were not porous masonry. In those days, underground tar leaks were seen as merely a waste of tar; out of sight was truly out of mind; and such leaks were generally addressed only when the loss of revenue from leaking tar “wells”, as these were sometimes called, exceeded the cost of repairing the leak. This practice of bygone days has caused representatives of present-day gas utilities to dive under tables and utter minced oaths when terms like “purportedly responsible party”, “BTEX”, “aquifer plume”, or “Superfund” are mentioned.

Ammoniacal liqueur was stored on site as well, in similar tanks. Sometimes the more progressive gasworks would have an ammonium sulfate plant, to convert the liqueur into fertilizer, which was sold to farmers.

Station meter

This large-scale gas meter precisely measured gas as it issued from the works into the mains. It was of the utmost importance, as the gasworks balanced the account of issued gas versus the amount of paid for gas, and strived to detect why and how they varied from one another. Often it was coupled with a dynamic regulator to keep pressure constant, or even to modulate the pressure at specified times (a series of rapid pressure spikes was sometimes used with appropriately equipped street-lamps to automatically ignite or extinguish such remotely).

Anti-naphthalene minor carburettor

This device injected a fine mist of naphtha into the outgoing gas so as to avoid the crystallization of naphthalene in the mains, and their consequent blockage. Naphtha was found to be a rather effective solvent for these purposes, even in small concentrations. Where troubles with naphthalene developed, as it occasionally did even after the introduction of this minor carburettor, a team of workers was sent out to blow steam into the main and dissolve the blockage; still, prior to its introduction, naphthalene was a very major annoyance for the gasworks.

High pressure distribution booster pump

This steam or gas engine powered device compressed the gas for injection into the high-pressure mains, which in the early 1900s began to be used to convey gas over greater distances to the individual low pressure mains, which served the end-users. This allowed the works to serve a larger area and achieve economies of scale.

Adapted from the Wikipedia article History of manufactured gas, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

No related posts.

At the level of large-scale anatomy, the cerebellum consists of a tightly folded and crumpled layer of cortex, with white matter underneath, several deep nuclei embedded in the white matter, and a fluid-filled ventricle at the base. At the microscopic level, each part of the cerebellar cortex consists of the same small set of neuronal elements, laid out with a highly stereotyped geometry. At an intermediate level, the cerebellum and its auxiliary structures can be decomposed into several hundred or thousand independently functioning modules called “microzones” or “microcompartments”.

Anatomy

The cerebellum is located at the bottom of the brain, with the large mass of the cerebral cortex above it and the portion of the brainstem called the pons in front of it. It is separated from the overlying cerebrum by a layer of leathery dura mater; all of its connections with other parts of the brain travel through the pons. Anatomists classify the cerebellum as part of the metencephalon, which also includes the pons; the metencephalon is the upper part of the rhombencephalon or “hindbrain”. Like the cerebral cortex, the cerebellum is divided into two hemispheres; it also contains a narrow midline zone called the ”vermis”. A set of large folds is, by convention, used to divide the overall structure into 10 smaller “lobules”. Because of its large number of tiny granule cells, the cerebellum contains more neurons than the rest of the brain put together, but it takes up only 10% of total brain volume.

The unusual surface app

Subdivisions

Based on surface appearance, three lobes can be distinguished in the cerebellum, called the flocculonodular lobe, anterior lobe (above the primary fissure), and posterior lobe (below the primary fissure). These lobes divide the cerebellum from rostral to caudal (in humans, top to bottom). In terms of function, however, there is a more important distinction along the medial-to-lateral dimension. Leaving out the flocculonodular part, which has distinct connections and functions, the cerebellum can be parsed functionally into a medial sector called the spinocerebellum and a larger lateral sector called the cerebrocerebellum. A narrow strip of protruding tissue along the midline is called the vermis (Latin for “worm”).

The smallest region, the flocculonodular lobe, is often called the vestibulocerebellum. It is the oldest part in evolutionary terms (archicerebellum) and participates mainly in balance and spatial orientation; its primary connections are with the vestibular nuclei, although it also receives visual and other sensory input. Damage to it causes disturbances of balance and gait.

The medial zone of the anterior and posterior lobes constitutes the spinocerebellum, also known as paleocerebellum. This sector of the cerebellum functions mainly to fine-tune body and limb movements. It receives proprioception input from the dorsal columns of the spinal cord (including the spinocerebellar tract) and from the trigeminal nerve, as well as from visual and auditory systems. It sends fibres to deep cerebellar nuclei that, in turn, project to both the cerebral cortex and the brain stem, thus providing modulation of descending motor systems.

The lateral zone, which in humans is by far the largest part, constitutes the cerebrocerebellum, also known as neocerebellum. It receives input exclusively from the cerebral cortex (especially the parietal lobe) via the pontine nuclei (forming cortico-ponto-cerebellar pathways), and sends output mainly to the ventrolateral thalamus (in turn connected to motor areas of the premotor cortex and primary motor area of the cerebral cortex) and to the red nucleus. There is disagreement about the best way to describe the functions of the lateral cerebellum: It is thought to be involved in planning movement that is about to occur, in evaluating sensory information for action, and in a number of purely cognitive functions as well.

Cellular components

Two types of neuron play dominant roles in the cerebellar circuit: Purkinje cells and granule cells. Three types of axons also play dominant roles: mossy fibers and climbing fibers (which enter the cerebellum from outside), and parallel fibers (which are the axons of granule cells). There are two main pathways through the cerebellar circuit, originating from mossy fibers and climbing fibers, both terminating in the deep cerebellar nuclei.

Mossy fibers project directly to the deep nuclei, but also give rise to the pathway: mossy fiber → granule cells → parallel fibers → Purkinje cells → deep nuclei. Climbing fibers project to Purkinje cells and also send collaterals directly to the deep nuclei. The mossy fiber and climbing fiber inputs each carry fiber-specific information; the cerebellum also receives dopaminergic, serotonergic, noradrenergic, and cholinergic inputs that presumably perform global modulation.

The cerebellar cortex is divided into three layers. At the bottom lies the thick granular layer, densely packed with granule cells, along with much smaller numbers of interneurons, mainly Golgi cells. In the middle lies the Purkinje layer, a narrow zone that contains only the cell bodies of Purkinje cells. At the top lies the molecular layer, which contains the flattened dendritic trees of Purkinje cells, along with the huge array of parallel fibers penetrating the Purkinje cell dendritic trees at right angles. This outermost layer of the cerebellar cortex also contains two types of inhibitory interneurons, stellate cells, and basket cells. Both stellate and basket cells form GABAergic synapses onto Purkinje cell dendrites.

Purkinje cells

Purkinje cells are among the most distinctive neurons in the brain, and also among the earliest types to be recognized — they were first described by the Czech anatomist Jan Evangelista Purkyně in 1837. They are distinguished by the shape of the dendritic tree: The dendrites branch very profusely, but are severely flattened in a plane perpendicular to the cerebellar folds. Thus, the dendrites of a Purkinje cell form a dense planar net, through which parallel fibers pass at right angles. The dendrites are covered with dendritic spines, each of which receives synaptic input from a parallel fiber. Purkinje cells receive more synaptic inputs than any other type of cell in the brain — estimates of the number of spines on a single human Purkinje cell run as high as 200,000. The large, spherical cell bodies of Purkinje cells are packed into a narrow layer (one cell thick) of the cerebellar cortex, called the ”Purkinje layer”. After emitting collaterals that innervate nearby parts of the cortex, their axons travel into the deep cerebellar nuclei, where they make on the order of 1,000 contacts each with several types of nuclear cells, all within a small domain. Purkinje cells use GABA as their neurotransmitter, and therefore exert inhibitory effects on their targets.

Purkinje cells form the heart of the cerebellar circuit, and their large size and distinctive activity patterns have made it relatively easy to study their response patterns in behaving animals using extracellular recording techniques. Purkinje cells normally emit action potentials at a high rate even in the absence of synaptic input. In awake, behaving animals, mean rates averaging around 40& Hz are typical. The spike trains show a mixture of what are called simple and complex spikes. A simple spike is a single action potential followed by a refractory period of about 10& msec; a complex spike is a stereotyped sequence of action potentials with very short inter-spike intervals and declining amplitudes. Physiological studies have shown that complex spikes (which occur at baseline rates around 1& Hz and never at rates much higher than 10& Hz) are reliably associated with climbing fiber activation, while simple spikes are produced by a combination of baseline activity and parallel fiber input. Complex spikes are often followed by a pause of several hundred msec during which simple spike activity is suppressed.

Granule cells

Cerebellar granule cells, in contrast to Purkinje cells, are among the smallest neurons in the brain. They are also easily the most numerous neurons in the brain: In humans, estimates of their total number average around 50 billion, which means that about 3/4 of the brain’s neurons are cerebellar granule cells. Their cell bodies are packed into a thick layer at the bottom of the cerebellar cortex. A granule cell emits only four to five dendrites, each of which ends in an enlargement called a ”dendritic claw”. These enlargements are sites of excitatory input from mossy fibers and inhibitory input from Golgi cells.

The thin, unmyelinated axons of granule cells rise vertically to the upper (molecular) layer of the cortex, where they split in two, with each branch traveling horizontally to form a parallel fiber; the splitting of the vertical branch into two horizontal branches gives rise to a distinctive “T” shape. A parallel fiber runs for an average of 3& mm in each direction from the split, for a total length of about 6& mm (about 1/10 of the total width of the cortical layer). As they run along, the parallel fibers pass through the dendritic trees of Purkinje cells, contacting one of every 3–5 that they pass, making a total of 80–100 synaptic connections with Purkinje cell dendritic spines. Granule cells use glutamate as their neurotransmitter, and therefore exert excitatory effects on their targets.

Granule cells receive all of their input from mossy fibers, but outnumber them 200 to 1 (in humans). Thus, the information in the granule cell population activity state is the same as the information in the mossy fibers, but recoded in a much more expansive way. Because granule cells are so small and so densely packed, it has been very difficult to record their spike activity in behaving animals, so there is little data to use as a basis of theorizing. The most popular concept of their function was proposed by David Marr, who suggested that they could encode combinations of mossy fiber inputs. The idea is that with each granule cell receiving input from only 4–5 mossy fibers, a granule cell would not respond if only a single one of its inputs were active, but would respond if more than one were active. This combinatorial coding scheme would potentially allow the cerebellum to make much finer distinctions between input patterns than the mossy fibers alone would permit.

Mossy fibers

Mossy fibers enter the granular layer from their points of origin, many arising from the pontine nuclei, others from the spinal cord, vestibular nuclei, etc. In the human cerebellum, the total number of mossy fibers has been estimated at about 200 million. These fibers form excitatory synapses with the granule cells and the cells of the deep cerebellar nuclei. Within the granular layer, a mossy fiber generates a series of enlargements called ”rosettes”. The contacts between mossy fibers and granule cell dendrites take place within structures called glomeruli. Each glomerulus has a mossy fiber rosette at its center, and up to 20 granule cell dendritic claws contacting it. Terminals from Golgi cells infiltrate the structure and make inhibitory synapses onto the granule cell dendrites. The entire assemblage is surrounded by a sheath of glial cells. Each mossy fiber sends collateral branches to several cerebellar folia, generating a total of 20–30 rosettes; thus a single mossy fiber makes contact with an estimated 400–600 granule cells.

Climbing fibers

Purkinje cells also receive input from the inferior olivary nucleus (IO) on the contralateral side of the brainstem, via climbing fibers. Although the IO lies in the medulla oblongata, and receives input from the spinal cord, brainstem, and cerebral cortex, its output goes entirely to the cerebellum. A climbing fiber gives off collaterals to the deep cerebellar nuclei before entering the cerebellar cortex, where it splits into about 10 terminal branches, each of which innervates a single Purkinje cell. In striking contrast to the 100,000-plus inputs from parallel fibers, each Purkinje cell receives input from exactly one climbing fiber; but this single fiber “climbs” the dendrites of the Purkinje cell, winding around them and making a total of up to 300 synapses as it goes. The net input is so strong that a single action potential from a climbing fiber is capable of producing an extended complex spike in the Purkinje cell: a burst of several spikes in a row, with diminishing amplitude, followed by a pause during which activity is suppressed. The climbing fiber synapses cover the cell body and proximal dendrites; this zone is devoid of parallel fiber inputs.

Climbing fibers fire at low rates, but a single climbing fiber action potential induces a burst of several action potentials in a target Purkinje cell (a complex spike). The contrast between parallel fiber and climbing fiber inputs to Purkinje cells (over 100,000 of one type versus exactly one of the other type) is perhaps the most provocative feature of cerebellar anatomy, and has motivated much of the theorizing. In fact, the function of climbing fibers is the most controversial topic concerning the cerebellum. There are two schools of thought, one following Marr and Albus in holding that climbing fiber input serves primarily as a teaching signal, the other holding that its function is to shape cerebellar output directly. Both views have been defended in great length in numerous publications. In the words of one review, “In trying to synthesize the various hypotheses on the function of the climbing fibers, one has the sense of looking at a drawing by Escher. Each point of view seems to account for a certain collection of findings, but when one attempts to put the different views together, a coherent picture of what the climbing fibers are doing does not appear. For the majority of researchers, the climbing fibers signal errors in motor performance, either in the usual manner of discharge frequency modulation or as a single announcement of an ‘unexpected event’. For other investigators, the message lies in the degree of ensemble synchrony and rhythmicity among a population of climbing fibers.”

Deep nuclei

The deep nuclei of the cerebellum are clusters of gray matter lying within the white matter at the core of the cerebellum. They are, with the minor exception of the nearby vestibular nuclei, the sole sources of output from the cerebellum. These nuclei receive collateral projections from mossy fibers and climbing fibers, as well as inhibitory input from the Purkinje cells of the cerebellar cortex. The three nuclei (dentate, interpositus, and fastigial) each communicate with different parts of the brain and cerebellar cortex. The fastigial and interpositus nuclei belong to the spinocerebellum. The dentate nucleus, which in mammals is much larger than the others, is formed as a thin, convoluted layer of gray matter, and communicates exclusively with the lateral parts of the cerebellar cortex. The flocculonodular lobe is the only part of the cerebellar cortex that does not project to the deep nuclei — its output goes to the vestibular nuclei instead.

The majority of neurons in the deep nuclei have large cell bodies and spherical dendritic trees with a radius of about 400& μm, and use glutamate as their neurotransmitter. These cells project to a variety of targets outside the cerebellum. Intermixed with them is a lesser number of small cells, which use GABA as neurotransmitter and project exclusively to the inferior olivary nucleus, the source of climbing fibers. Thus, the nucleo-olivary projection provides an inhibitory feedback to match the excitatory projection of climbing fibers to the nuclei. There is evidence that each small cluster of nuclear cells projects to the same cluster of olivary cells that send climbing fibers to it; there is strong and matching topography in both directions.

When a Purkinje cell axon enters one of the deep nuclei, it branches to make contact with both large and small nuclear cells, but the total number of cells contacted is only about 35 (in cats). On the converse, a single deep nuclear cell receives input from approximately 860 Purkinje cells (again in cats).

Compartmentalization

From the viewpoint of gross anatomy, the cerebellar cortex appears to be a homogeneous sheet of tissue, and, from the viewpoint of microanatomy, all parts of this sheet appear to have the same internal structure. There are, however, a number of respects in which the structure of the cerebellum is compartmentalized. There are large compartments that are generally known as ”zones”; these can be decomposed into smaller compartments known as ”microzones”.

The first indications of compartmental structure came from studies of the receptive fields of cells in various parts of the cerebellum cortex. Each body part maps to specific points in the cerebellum, but there are numerous repetitions of the basic map, forming an arrangement that has been called “fractured somatotopy”. A clearer indication of compartmentalization is obtained by immunostaining the cerebellum for certain types of protein. The best-known of these markers are called “zebrins”, because staining for them gives rise to a complex pattern reminiscent of the stripes on a zebra. The stripes generated by zebrins and other compartmentalization markers are oriented perpendicular to the cerebellar folds — that is, they are narrow in the mediolateral direction, but much more extended in the longitudinal direction. Different markers generate different sets of stripes, and the widths and lengths vary as a function of location, but they all have the same general shape.

Oscarsson in the late 1970s proposed that these cortical zones can be partitioned into smaller units called microzones. A microzone is defined as a group of Purkinje cells all having the same somatotopic receptive field. Microzones were found to contain on the order of 1000 Purkinje cells each, arranged in a long, narrow strip, oriented perpendicular to the cortical folds. Thus, as the adjoining diagram illustrates, Purkinje cell dendrites are flattened in the same direction as the microzones extend, while parallel fibers cross them at right angles.

It is not only receptive fields that define the microzone structure: The climbing fiber input from the inferior olivary nucleus is equally important. The branches of a climbing fiber (usually numbering about 10) usually innervate Purkinje cells belonging to the same microzone. Moreover, olivary neurons that send climbing fibers to the same microzone tend to be coupled by gap junctions, which synchronize their activity, causing Purkinje cells within a microzone to show correlated complex spike activity on a millisecond time scale. Also, the Purkinje cells belonging to a microzone all send their axons to the same small cluster of output cells within the deep cerebellar nuclei. Finally, the axons of basket cells are much longer in the longitudinal direction than in the mediolateral direction, causing them to be confined largely to a single microzone. The consequence of all this structure is that cellular interactions within a microzone are much stronger than interactions between different microzones.

In 2005, Richard Apps and Martin Garwicz summarized evidence that microzones themselves form part of a larger entity they call a multizonal microcomplex. Such a microcomplex includes several spatially separated cortical microzones, all of which project to the same group of deep cerebellar neurons, plus a group of coupled olivary neurons that project to all of the included microzones as well as to the deep nuclear area.

Adapted from the Wikipedia article Cerebellum, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

No related posts.

The transmission of electrical energy

In 1891 and 1892, Tesla had used an oscillatory transformer that bears his name in demonstration lectures delivered before meetings of the American Institute of Electrical Engineers (AIEE) in New York City” and the Institute of Electrical Engineers (IEE) in London. Of two striking results that Tesla demonstrated, one was that the wireless transmission of electrical energy was possible. A later presentation, titled “On Light and Other High Frequency Phenomena” (Philadelphia/St. Louis; Franklin Institute in 1893), was a key event in the invention of radio and could also be said to have begun the development of Wardenclyffe.

One-wire transmission

In the early presentations, the first experiment to be demonstrated was the operation of light and motive devices connected by a single wire to only one terminal of a high frequency induction coil, presented during the 1891 New York City lecture at Columbia University. While a single terminal incandescent lamp connected to one of an induction coil’s secondary terminals does not form a closed circuit “in the ordinary acceptance of the term”, the circuit is closed in the sense that a return path is established back to the secondary by what Tesla called “electrostatic induction” (or ‘displacement currents’). This is due to the lamp’s filament or refractory button capacitance relative to the coil’s free terminal and environment and the secondary’s free terminal also has capacitance relative to the lamp and environment.

Wireless transmission

The second result demonstrated how energy could be made to go through space without any connecting wires. This was the first step towards a practical wireless system. The wireless energy transmission effect involved the creation of an electric field between two metal plates, each being connected to one terminal of an induction coil’s secondary winding. Once again, a light-producing device (in this case a gas discharge tube) was used as a means of detecting the presence of the transmitted energy. “The most striking result obtained” involved the lighting of two partially evacuated tubes in an alternating electrostatic field while held in the hand of the experimenter. In Tesla’s words,

Here Tesla describes two different types of wireless transmitters, both employing a high-tension induction coil. One had a sheet of metal suspended from the ceiling and connected to one of the induction coil’s terminals. The other terminal was connected to ground. The other type of transmitter had two sheets of metal suspended from the ceiling, each being connected with one of the coil’s high-voltage terminals.

Theory of wireless transmission

While working to develop an explanation for the two observed effects mentioned above, Tesla recognized that electrical energy can be projected outward into space and detected by a receiving instrument in the general vicinity of the source without the need for any interconnecting wires. He went on to develop two theories related to these observations, which are:

#By using two Tesla coil transmitter-receivers positioned at distant points on the Earth’s surface, it is possible to induce a flow of electrical current between them.

#By incorporating a portion of the Earth as part of a powerful dual-elevated-terminal Tesla coil transmitter the disturbance can be impressed upon the Earth and detected “”at great distance, or even all over the surface of the globe”.”

Tesla also made the assumption that the Earth is a charged body floating in space.

A point of great importance would be first to know what is the capacity of the Earth? and what charge does it contain if electrified? Though we have no positive evidence of a charged body existing in space without other oppositely electrified bodies being near, there is a fair probability that the Earth is such a body, for by whatever process it was separated from other bodies—and this is the accepted view of its origin—it must have retained a charge, as occurs in all processes of mechanical separation.

Tesla was familiar with demonstrations that involved the charging of Leyden jar capacitors and isolated metal spheres with electrostatic influence machines (in modern terms, high-voltage (kV), low-current(μA) electrostatic generators). By bringing these elements into close proximity with each other, and also by making direct contact followed by their separation the charge can be manipulated. He surely had this in mind in the creation of his mental image, not being able to know that the model of Earth’s origin was inaccurate. The presently accepted model of planetary origin is one of accretion and collision.

If it be a charged body insulated in space its capacity should be extremely small, less than one-thousandth of a farad.

We now know that the Earth is a charged body, made so by processes—at least in part—related to the interaction between the continuous stream of charged particles called the solar wind that flows outward from the center of our solar system and Earth’s magnetosphere. And we also know that Tesla’s capacitance estimate was correct: Earth’s self-capacitance is about 710 microfarads.

But the upper strata of the air are conducting, and so, perhaps, is the medium in free space beyond the atmosphere, and these may contain an opposite charge. Then the capacity might be incomparably greater.

We now also know that Earth’s upper atmospheric strata are conducting, or can be made so.

In any case it is of the greatest importance to get an idea of what quantity of electricity the Earth contains.

An additional condition of which we are now aware is that the Earth possesses a naturally existing negative charge with respect to the conducting region of the atmosphere beginning at an elevation of about 50& km. The potential difference between the Earth and this region is on the order of 400,000 volts. Near the Earth’s surface there is a ubiquitous downward directed E-field of about 100 V/m. Tesla referred to this charge as the “electric niveau” or electric level.

It is difficult to say whether we shall ever acquire this necessary knowledge, but there is hope that we may, and that is, by means of electrical resonance. If ever we can ascertain at what period the Earth’s charge, when disturbed, oscillates with respect to an oppositely electrified system or known circuit, we shall know a fact possibly of the greatest importance to the welfare of the human race. I propose to seek for the period by means of an electrical oscillator, or a source of alternating electric currents…

Some maintain the 200& kW wireless facility would have functioned by the production and propagation of electromagnetic radiation also known as the transverse electromagnetic (TEM) radio wave, but this is not the case.

I am not producing radiation in my system; I am suppressing electromagnetic waves. But, on the other hand, my apparatus can be used effectively with electromagnetic waves. The apparatus has nothing to do with this new method except that it is the only means to practice it. So that in my system, you should free yourself of the idea that there is radiation, that energy is radiated. It is not radiated; it is conserved.

By Tesla’s own account, his earth resonance system works by the creation of powerful disturbances in Earth’s natural electric charge. The Wardenclyffe facility had a dual purpose. In addition to point-to-point telecommunications and broadcasting it was also intended to demonstrate the transmission of electrical power on a reduced scale. He stated,

It is intended to give practical demonstrations of these principles with the plant illustrated. As soon as completed, it will be possible for a business man in New York to dictate instructions, and have them instantly appear in type at his office in London or elsewhere. He will be able to call up, from his desk, and talk to any telephone subscriber on the globe, without any change whatever in the existing equipment. An inexpensive instrument, not bigger than a watch, will enable its bearer to hear anywhere, on sea or land, music or song, the speech of a political leader, the address of an eminent man of science, or the sermon of an eloquent clergyman, delivered in some other place, however distant. In the same manner any picture, character, drawing, or print can be transferred from one to another place. Millions of such instruments can be operated from but one plant of this kind. More important than all of this, however, will be the transmission of power, without wires, which will be shown on a scale large enough to carry conviction.

Wardenclyffe was the first of many installations to be constructed near major population centers around the world. If Tesla’s plans had moved forward without interruption the Long Island prototype would have been followed by a second plant built somewhere along the southwest coast of England, perhaps in Cornwall, or on the west coast of Scotland near Glasgow. Each of these facilities would have included a large magnifying transmitter of a design loosely based upon the apparatus which Tesla assembled at the Colorado Springs Experimental Station in 1899.

: “… The plant in Colorado was merely designed in the same sense as a naval constructor designs first a small model to ascertain all the quantities before he embarks on the construction of a big vessel. I had already planned most of the details of the commercial plant, subsequently put up at Long Island, except that at that time the location was not settled upon. The Colorado plant I have used in determining the construction of the various parts, and the experiments which were carried on there were for the practical purpose of enabling me to design the transmitters and receivers which I was to employ in the large commercial plant subsequently erected…”

Using a global array of these magnifying transmitters, it was Tesla’s plan to establish what he called the “World Wireless System,” providing multi-channel global broadcasting, an array of secure wireless telecommunications services, and a long range aid to navigation, including means for the precise synchronization of clocks. In a more highly developed state he envisioned the ‘World System’ would expand to include the wireless industrial transmission of electric power.

At the time the power grid was quite limited in terms of who it reached and the Wardenclyffe prototype represented a way in which to significantly reduce the cost of “electrifying” the countryside. Tesla called his wireless technique the “”disturbed charge of ground and air method””.

There is evidence that Wardenclyffe would have used extremely low frequency signals combined with higher frequency signals. In practice, the transmitter electrically influences both the Earth and the space above it. He made a point of describing the process as being essentially the same as transmitting electricity by conduction through a wire.

Tesla clearly specified the Earth as being one of the conducting media involved in ground and air system technology. The other specified medium is the atmosphere above elevation. While not an ohmic conductor, in this region of the troposphere and upwards, the density or pressure is sufficiently reduced to so that, according to Tesla’s theory, the atmosphere’s insulating properties can be easily impaired, allowing an electric current to flow. His theory further states that the conducting region is developed through the process of atmospheric ionization, in which the effected portions thereof are changed to plasma. The presence of the magnetic fields developed by each plant’s helical resonator suggests that an embedded magnetic field and flux linkage is also involved. Flux linkage with Earth’s natural magnetic field is also a possibility, especially in the case of an earth resonance transmission system.

The atmosphere below is also viewed as a propagating medium for a portion of the above-ground circuit, and, being an insulating medium, electrostatic induction would be involved rather than true electrical conduction. Tesla felt that with a sufficiently high electrical potential on the elevated terminal the practical limitation imposed upon its height could be overcome. He anticipated that a highly energetic transmitter, as was intended at Wardenclyffe, would charge the elevated terminal to the point where the atmosphere around and above the facility would break down and become ionized, leading to a flow of true conduction currents between the two terminals by a path up to and through the troposphere, and back down to the other facility. The ionization of the atmosphere directly above the elevated terminals would be facilitated by the use of an ionizing beam of ultraviolet radiation to form what might be called a high-voltage plasma transmission line. [''ed''. see longitudinal waves and waves in plasmas].

Powered by an industrial alternator, a generator facility’s tower was intended to inject large amounts of energy into a natural Earth circuit, using the Earth-Ionosphere network as the transmission circuit.

In various writings, Tesla explained that the Earth itself behaves as a resonant LC circuit when it is electrically excited at certain frequencies. At Wardenclyffe he operated at frequencies ranging from 1,000 Hz to 100& kHz. Tesla found the frequency range up to 30 – 35& kHz “to be most economical.” Excitation of earth resonance at or near a fundamental frequency of about 11.7 Hz suggests energy transmission by means of a TM00 spherical conductor “single-wire” surface wave transmission line mode. A Schumann resonance mode (the fundamental frequency being about 7.5 to 7.9 Hz) is probably not involved. The entire Earth can be electrically resonated with a single earth-resonance transmitter, so an earth-resonance based system would require, at a minimum, that only one World Wireless System transmitter be constructed. Alternatively, two distantly spaced transmiter-receiver facilities could be constructed. Such a system would not be so dependent upon the excitation of an earth-resonance mode. In either case a surface or ground wave, similar to the Zenneck wave would be utilized. Artificially induced earth currents would be utilized. According to Tesla, the planet’s large cross-sectional area provides a low resistance path for the flow of earth currents. The greatest losses are apt to occur at the points where the transmitting / receiving plants and dedicated receiving stations are connected with the ground. This is why Tesla stated,

You see the underground work is one of the most expensive parts of the tower. In this system that I have invented it is necessary for the machine to get a grip of the Earth, otherwise it cannot shake the Earth. It has to have a grip on the Earth so that the whole of this globe can quiver, and to do that it is necessary to carry out a very expensive construction.

To close the circuit a second path is established between the two transmitter-receiver plants’ elevated high-voltage terminals through the rarefied atmospheric strata above five miles (8& km). The connection is made by some combination of electrostatic induction and electrical conduction through plasma. While a number of his wireless patents, including “Apparatus for transmitting electrical energy,” U.S. Patent No. 1,119,732, December 1, 1914, describe a system which uses the plasma-conduction scheme, his “Art of transmitting electrical energy through the natural mediums,” U.S. Patent No. 787,412, April 18, 1905 and some of his Wardenclyffe design notes from 1901 show that he also had a plan to electrostatically induce oscillations in the potential associated with Earth’s self-capacitance. The two tower earth-resonance transmitter is especially designed for this purpose. Tesla wrote,

The specific plan of producing the stationary waves, here-in described, might be departed from. For example, the circuit which impresses the powerful oscillations upon the earth might be connected to the latter at two points.

Tesla believed that a fully developed system with large high-power stations based upon the smaller Wardenclyffe prototype would permit wireless transmission and reception across large distances with negligible losses.

In the course of this work, I mastered the technique of high potentials sufficiently for enabling me to construct and operate, in 1899, a wireless transmitter developing up to twenty million volts. Some time before I contemplated the possibility of transmitting such high tension currents over a narrow beam of radiant energy ionizing the air and rendering it, in measure, conductive. After preliminary laboratory experiments, I made tests on a large scale with the transmitter referred to and a beam of ultra-violet rays of great energy in an attempt to conduct the current to the high rarefied strata of the air and thus create an auroral such as might be utilized for illumination, especially of oceans at night. I found that there was some virtue in the principal but the results did not justify the hope of important practical applications. . . .

In spite of ridicule, many of Tesla’s ideas have been demonstrated to be essentially correct. For example he correctly predicted the existence of the ionosphere and electrical resonance of the Earth-atmosphere system. Resonance of the earth-ionosphere cavity with a fundamental frequency in the vicinity of 7.3 Hz was demonstrated in the 1950s as the Schumann resonance. The latter phenomenon was named after Schumann, for although Tesla had detected a resonance of the Earth-atmosphere system, he was not taken seriously in his time. Furthermore, Tesla appears to have excited a different terrestrial resonance mode with a fundamental frequency of 11.78 Hz.

Electrical transmission and reception

Tesla’s early experiments involved the propagation of ordinary radio waves, that is to say Hertzian waves, electromagnetic waves propagated through space without artificial guide.

In 1919 Nikola Tesla wrote,

The popular impression is that my wireless work was begun in 1893, but as a matter of fact I spent the two preceding years in investigations, employing forms of apparatus, some of which were almost like those of today. It was clear to me from the very start that the successful consummation could only be brought about by a number of radical improvements. Suitable high frequency generators and electrical oscillators had first to be produced. The energy of these had to be transformed in effective transmitters and collected at a distance in proper receivers. Such a system would be manifestly circumscribed in its usefulness if all extraneous interference were not prevented and exclusiveness secured. In time, however, I recognized that devices of this kind, to be most effective and efficient, should be designed with due regard to the physical properties of this planet and the electrical conditions obtaining on the same.

One of the requirements of the world wireless system is the construction of resonant receivers. The grounded helical resonator of a Tesla Coil and an elevated terminal can be used in receive mode. Tesla himself repeatedly demonstrated the wireless transmission of electrical energy from a Tesla coil transmitter to a Tesla coil receiver. These concepts and methods are part of his wireless transmission system (US1119732 — Apparatus for Transmitting Electrical Energy — 1902 January 18). Tesla made a proposal that there needed to be many more than thirty transmission-reception stations worldwide.

In the principle form of Tesla system receiver, a Tesla coil receiving transformer acts as a step-down transformer with high current output. The parameters of a Tesla Coil transmitter are identically applicable to it being a receiver (”e.g.”., an antenna circuit), due to reciprocity. Impedance, generally though, is not applied in an obvious way; for electrical impedance, the impedance at the load (”e.g.”., where the power is consumed) is most critical and, for a Tesla Coil receiver, this is at the point of utilization (such as at an induction motor) rather than at the receiving node. Complex impedance of an antenna is related to the electrical length of the antenna at the wavelength in use. Commonly, impedance is adjusted at the load with a tuner or a matching networks composed of inductors and capacitors.

In another form of receiving circuit the two input terminals are connected to a device designed to reverse polarity at predetermined intervals of time and charge a capacitor. This form of Tesla system receiver has means for commutating the current impulses in the charging circuit so as to render them suitable for charging an energy storage device, a device for closing the receiving-circuit, and means for causing the receiver to be operated by the accumulated energy.

A variant was suggested by Tesla for exploiting the vertical voltage gradient in the Earth’s atmosphere. A Tesla Coil can receive electromagnetic impulses from atmospheric electricity and radiant energy, besides normal wireless transmissions. Radiant energy throws off with great velocity minute particles which are strongly electrified and other rays falling on the insulated-conductor connected to a condenser (i.e., a capacitor) can cause the condenser to indefinitely charge electrically. The helical resonator can be “shock excited” due to radiant energy disturbances not only at the fundamental wave at one-quarter wave-length but also is excited at its harmonics. Hertzian methods can be used to excite the Tesla Antenna with limitations that result in great disadvantages for utilization, though. The methods of ground conduction and the various induction methods can also be used to excite the Tesla Antenna, but are again at a disadvantages for utilization. The charging-circuit can be adapted to be energized by the action of various other disturbances and effects at a distance. Arbitrary and intermittent oscillations that are propagated via conduction to the receiving resonator will charge the receiver’s capacitor and utilize the potential energy to greater effect. Various radiations can be used to charge and discharge conductors, with the radiations considered electromagnetic vibrations of various wavelengths and ionizing potential. The Tesla Antenna utilizes the effects or disturbances to charge a storage device with energy from an external source (natural or man-made) and controls the charging of said device by the actions of the effects or disturbances (during succeeding intervals of time determined by means of such effects and disturbances corresponding in succession and duration of the effects and disturbances). The stored energy can also be used to operate the receiving device. The accumulated energy can, for example, operate a transformer by discharging through a primary circuit at predetermined times which, from the secondary currents, operate the receiving device.

While Tesla Coils can be used for wireless energy transmission and reception, much of the public and media attention is directed away from such applications since big electrical discharges are fascinating to most people. Tesla did suggest that this variation of the Tesla coil could utilize the phantom loop effect to form a circuit to induct energy from the Earth’s magnetic field and other radiant energy sources (including, but not limited to, electrostatics). With regard to Tesla’s statements on the harnessing of natural phenomena to obtain electric power, he stated:

Ere many generations pass, our machinery will be driven by a power obtainable at any point of the universe.

— “Experiments with Alternate Currents of High Potential and High Frequency” (February 1892)

Tesla stated that the output power from these devices, attained from Hertzian methods of charging, was low, but alternative charging means are available. Tesla receivers operated correctly act as a step-down transformer with high current output. There are, to date, no commercial power generation entities or businesses that have utilized this technology to full effect. The power levels achieved by Tesla Coil receivers have, thus far, been a fraction of the output power of the transmitters.

Adapted from the Wikipedia article Wardenclyffe Tower, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

No related posts.

An incinerator is a furnace for burning waste. Modern incinerators include pollution mitigation equipment such as flue gas cleaning. There are various types of incinerator plant design: moving grate, fixed grate, rotary-kiln, and fluidised bed.

Burn pile

The burn pile, or burn pit is one of the simplest and earliest forms of waste disposal, essentially consisting of a mound of combustible materials piled on bare ground and set on fire. Indiscriminate piles of household waste are strongly discouraged and may be illegal in urban areas, but are permitted in certain rural situations such as clearing forested land for farming, where the stumps are uprooted and burned. Exemptions. The following woodburning facilities are exempt from licensing and all requirements of this section, although a burning permit from the department may still be required during certain times of the year in counties within a forest fire control area. These exempt facilities may not burn wet combustible rubbish, garbage, oily substances, asphalt, plastic or rubber products, unless these substances are exempt under s. NR 429.04.

(a) Burning of trees, limbs, stumps, brush or weeds, except for yard waste, as a result of agricultural or silvicultural activities, if the burning is conducted on the property where the waste is generated.

(d) Burning of yard waste and small quantities of dry combustible household rubbish, including paper, cardboard and clean untreated wood from a single family or household, on property where it is generated, unless prohibited by local ordinance. Rural burn piles of organic yard waste are also sometimes permitted, though not asphalt shingles, plastics, or other petroleum products.

Burn piles can and have spread uncontrolled fires, for example if wind blows burning material off the pile into surrounding combustible grasses or onto buildings. As interior structures of the pile are consumed, the pile can shift and collapse, spreading the burn area. Even in a situation of no wind, small lightweight ignited embers can lift off the pile via convection, and waft through the air into grasses or onto buildings, igniting them.

Burn pits were used extensively by the U.S. military in Iraq and Afghanistan. Initial use was on an emergency basis but use continued for extended periods of time, sometimes years. There have be complaints by military personnel and veterans that toxic chemicals from the burn pits resulted in respiratory problems.

Burn barrel

The burn barrel is a somewhat more controlled form of private waste incineration, containing the burning material inside a metal barrel, with a metal grating over the exhaust. The barrel prevents the spread of burning material in windy conditions, and as the combustibles are reduced they can only settle down into the barrel. The exhaust grating helps to prevent the spread of burning embers. Typically steel 55-gallon drums are used as burn barrels, with air vent holes cut or drilled around the base for air intake. Over time the very high heat of incineration causes the metal to oxidize and rust, and eventually the barrel itself is consumed by the heat and must be replaced.

Private burning of dry cellulosic/paper products is generally clean-burning, producing no visible smoke, but the large amount of plastics in household waste can cause private burning to create a public nuisance and health hazard, generating acrid odors and fumes that make eyes burn and water. The temperatures in a burn barrel are not regulated, and usually do not reach high enough or for enough time to completely break down chemicals such as dioxin in plastics and other waste chemicals. Therefore plastics and other petroleum products must be separated and sent to commercial waste disposal facilities.

Private rural incineration is typically only permitted so long as it is not a nuisance to others, does not pose a risk of fire such as in dry conditions, and the fire is clean-burning, producing no visible smoke. People intending to burn waste may be required to contact a state agency in advance to check current fire risk and conditions, and to alert officials of the controlled fire that will occur.

Moving grate

The typical incineration plant for municipal solid waste is a moving grate incinerator. The moving grate enables the movement of waste through the combustion chamber to be optimised to allow a more efficient and complete combustion. A single moving grate boiler can handle up to of waste per hour, and can operate 8,000& hours per year with only one scheduled stop for inspection and maintenance of about one month’s duration. Moving grate incinerators are sometimes referred to as Municipal Solid Waste Incinerators (MSWIs).

The waste is introduced by a waste crane through the “throat” at one end of the grate, from where it moves down over the descending grate to the ash pit in the other end. Here the ash is removed through a water lock.

Part of the combustion air (primary combustion air) is supplied through the grate from below. This air flow also has the purpose of cooling the grate itself. Cooling is important for the mechanical strength of the grate, and many moving grates are also water cooled internally.

Secondary combustion air is supplied into the boiler at high speed through nozzles over the grate. It facilitates complete combustion of the flue gases by introducing turbulence for better mixing and by ensuring a surplus of oxygen. In multiple/stepped hearth incinerators, the secondary combustion air is introduced in a separate chamber downstream the primary combustion chamber.

According to the European Waste Incineration Directive, incineration plants must be designed to ensure that the flue gases reach a temperature of at least for 2& seconds in order to ensure proper breakdown of toxic organic substances. In order to comply with this at all times, it is required to install backup auxiliary burners (often fueled by oil), which are fired into the boiler in case the heating value of the waste becomes too low to reach this temperature alone.

The flue gases are then cooled in the superheaters, where the heat is transferred to steam, heating the steam to typically at a pressure of for the electricity generation in the turbine. At this point, the flue gas has a temperature of around , and is passed to the flue gas cleaning system.

In Scandinavia scheduled maintenance is always performed during summer, where the demand for district heating is low. Often incineration plants consist of several separate ‘boiler lines’ (boilers and flue gas treatment plants), so that waste can continue to be received at one boiler line while the others are subject to revision.

Fixed grate

The older and simpler kind of incinerator was a brick-lined cell with a fixed metal grate over a lower ash pit, with one opening in the top or side for loading and another opening in the side for removing incombustible solids called clinkers. Many small incinerators formerly found in apartment houses have now been replaced by waste compactors.

Rotary-kiln

The rotary-kiln incinerator is used by municipalities and by large industrial plants.

This design of incinerator has 2 chambers: a primary chamber and secondary chamber. The primary chamber in a rotary kiln incinerator consist of an inclined refractory lined cylindrical tube. Movement of the cylinder on its axis facilitates movement of waste. In the primary chamber, there is conversion of solid fraction to gases, through volatilization, destructive distillation and partial combustion reactions. The secondary chamber is necessary to complete gas phase combustion reactions.

The clinkers spill out at the end of the cylinder. A tall flue gas stack, fan, or steam jet supplies the needed draft. Ash drops through the grate, but many particles are carried along with the hot gases. The particles and any combustible gases may be combusted in an “afterburner”.

Fluidized bed

A strong airflow is forced through a sandbed. The air seeps through the sand until a point is reached where the sand particles separate to let the air through and mixing and churning occurs, thus a fluidised bed is created and fuel and waste can now be introduced.

The sand with the pre-treated waste and/or fuel is kept suspended on pumped air currents and takes on a fluid-like character. The bed is thereby violently mixed and agitated keeping small inert particles and air in a fluid-like state. This allows all of the mass of waste, fuel and sand to be fully circulated through the furnace.

Specialized incineration

Furniture factory sawdust incinerators need much attention as these have to handle resin powder and many flammable substances. Controlled combustion, burn back prevention systems are essential as dust when suspended resembles the fire catch phenomenon of any liquid petroleum gas.

Use of heat

The heat produced by an incinerator can be used to generate steam which may then be used to drive a turbine in order to produce electricity. The typical amount of net energy that can be produced per tonne municipal waste is about 2/3& MWh of electricity and 2& MWh of district heating. Thus, incinerating about per day of waste will produce about 400 MWh of electrical energy per day (17& MW of electrical power continuously for 24 hours) and 1200& MWh of district heating energy each day.

Pollution

Incineration has a number of outputs such as the ash and the emission to the atmosphere of flue gas. Before the flue gas cleaning system, the flue gases may contain significant amounts of particulate matter, heavy metals, dioxins, furans, sulfur dioxide, and hydrochloric acid.

In a study from 1994, Delaware Solid Waste Authority found that, for same amount of produced energy, incineration plants emitted fewer particles, hydrocarbons and less SO2, HCl, CO and NOx than coal-fired power plants, but more than natural gas fired power plants. According to Germany’s Ministry of the Environment, waste incinerators reduce the amount of some atmospheric pollutants by substituting power produced by coal-fired plants with power from waste-fired plants.

Gaseous emissions=

Dioxin and furans

The most publicized concerns from environmentalists about the incineration of municipal solid wastes (MSW) involve the fear that it produces significant amounts of dioxin and furan emissions. Dioxins and furans are considered by many to be serious health hazards.

In 2005, The Ministry of the Environment of Germany, where there were 66 incinerators at that time, estimated that “…whereas in 1990 one third of all dioxin emissions in Germany came from incineration plants, for the year 2000 the figure was less than 1& %. Chimneys and tiled stoves in private households alone discharge approximately 20 times more dioxin into the environment than incineration plants.”

According to the United States Environmental Protection Agency, incineration plants are no longer significant sources of dioxins and furans. In 1987, before the governmental regulations required the use of emission controls, there was a total of of dioxin emissions from US incinerators. Today, the total emissions from the 87& plants are only yearly, a reduction of 99.9& %.

Backyard barrel burning of household and garden wastes, still allowed in some rural areas, generates of dioxins yearly.

Studies conducted by the US-EPA demonstrate that the emissions from just one family using a burn barrel produces more emissions than an incineration plant disposing of of waste per day.

Dioxin cracking methods and limitations

Generally, the breakdown of dioxin requires exposure of the molecular ring to a sufficiently high temperature so as to trigger thermal breakdown of the strong molecular bonds holding it together. Small pieces of fly ash may be somewhat thick, and too brief an exposure to high temperature may only degrade dioxin on the surface of the ash. For a large volume air chamber, too brief an exposure may also result in only some of the exhaust gases reaching the full breakdown temperature. For this reason there is also a time element to the temperature exposure to ensure heating completely through the thickness of the fly ash and the volume of waste gases.

There are trade-offs between increasing either the temperature or exposure time. Generally where the molecular breakdown temperature is higher, the exposure time for heating can be shorter, but excessively high temperatures can also cause wear and damage to other parts of the incineration equipment. Likewise the breakdown temperature can be lowered to some degree but then the exhaust gases would require a greater lingering period of perhaps several minutes, which would require large/long treatment chambers that take up a great deal of treatment plant space.

A side effect of breaking the strong molecular bonds of dioxin is the potential for breaking the bonds of nitrogen gas (N2) and oxygen gas (O2) in the supply air. As the exhaust flow cools, these highly reactive detached atoms spontaneously reform bonds into reactive oxides such as NOx in the flue gas, which can result in smog formation and acid rain if they were released directly into the local environment. These reactive oxides must be further neutralized with selective catalytic reduction (SCR) or selective non-catalytic reduction (see below).

Dioxin cracking in practice

The temperatures needed to break down dioxin are typically not reached when burning of plastics outdoors in a burn barrel or garbage pit, causing high dioxin emissions as mentioned above. While plastic does usually burn in an open-air fire, the dioxins remain after combustion and either float off into the atmosphere, or may remain in the ash where it can be leached down into groundwater when rain falls on the ash pile.

Modern municipal incinerator designs include a high temperature zone, where the flue gas is ensured to sustain a temperature above for at least 2& seconds before it is cooled down. They are equipped with auxiliary heaters to ensure this at all times. These are often fueled by oil, and normally only active for a very small fraction of the time.

For very small municipal incinerators, the required temperature for thermal breakdown of dioxin may be reached using a high-temperature electrical heating element, plus a selective catalytic reduction stage.

CO2

As for other complete combustion processes, nearly all of the carbon content in the waste is emitted as CO2 to the atmosphere. MSW contains approximately the same mass fraction of carbon as CO2 itself (27%), so incineration of 1 ton of MSW produces approximately 1 ton of CO2.

If the waste was landfilled, 1 ton of MSW would produce approximately methane via the anaerobic decomposition of the biodegradable part of the waste. This much methane has more than twice the global warming potential than the 1 ton of CO2, which would have been produced by incineration. In some countries, large amounts of landfill gas are collected, but still the global warming potential of the landfill gas emitted to atmosphere in the US in 1999 was approximately 32& % higher than the amount of CO2 that would have been emitted by incineration.

In addition, nearly all biodegradable waste has biological origin. This material has been formed by plants using atmospheric CO2 typically within the last growing season. If these plants are regrown the CO2 emitted from their combustion will be taken out from the atmosphere once more.

Such considerations are the main reason why several countries administrate incineration of the biodegradable part of waste as renewable energy. The rest – mainly plastics and other oil and gas derived products – is generally treated as non-renewables.

Different results for the CO2 footprint of incineration can be reached with different assumptions. Local conditions (such as limited local district heating demand, no fossil fuel generated electricity to replace or high levels of aluminum in the waste stream) can decrease the CO2 benefits of incineration.

The methodology and other assumptions may also influence the results significantly. For example the methane emissions from landfills occurring at a later date may be neglected or given less weight, or biodegradable waste may not be considered CO2 neutral. A recent study by Eunomia Research and Consulting on potential waste treatment technologies in London demonstrated that by applying several of these (according to the authors) unusual assumptions the average existing incineration plants performed poorly for CO2 balance compared to the theoretical potential of other emerging waste treatment technologies.

Other emissions

Other gaseous emissions in the flue gas from incinerator furnaces include sulfur dioxide, hydrochloric acid, heavy metals and fine particles.

The steam content in the flue may produce visible fume from the stack, which can be perceived as a visual pollution. It may be avoided by decreasing the steam content by flue gas condensation and reheating, or by increasing the flue gas exit temperature well above its dew point. Flue gas condensation allows the latent heat of vaporization of the water to be recovered, subsequently increasing the thermal efficiency of the plant.

Flue gas cleaning

The quantity of pollutants in the flue gas from incineration plants is reduced by several processes.

Particulate is collected by particle filtration, most often electrostatic precipitators (ESP) and/or baghouse filters. The latter are generally very efficient for collecting fine particles. In an investigation by the Ministry of the Environment of Denmark in 2006, the average particulate emissions per energy content of incinerated waste from 16 Danish incinerators were below 2.02& g/GJ (grams per energy content of the incinerated waste). Detailed measurements of fine particles with sizes below 2.5& micrometres (PM2.5) were performed on three of the incinerators: One incinerator equipped with an ESP for particle filtration emitted 5.3& g/GJ fine particles, while two incinerators equipped with baghouse filters emitted 0.002 and 0.013& g/GJ PM2.5. For ultra fine particles (PM1.0), the numbers were 4.889& g/GJ PM1.0 from the ESP plant, while emissions of 0.000 and 0.008& g/GJ PM1.0 were measured from the plants equipped with baghouse filters.

Acid gas scrubbers are used to remove hydrochloric acid, nitric acid, hydrofluoric acid, mercury, lead and other heavy metals. Basic scrubbers remove sulfur dioxide, forming gypsum by reaction with lime.

Waste water from scrubbers must subsequently pass through a waste water treatment plant.

Sulfur dioxide may also be removed by dry desulfurisation by injection limestone slurry into the flue gas before the particle filtration.

NOx is either reduced by catalytic reduction with ammonia in a catalytic converter (selective catalytic reduction, SCR) or by a high temperature reaction with ammonia in the furnace (selective non-catalytic reduction, SNCR). Urea may be substituted for ammonia as the reducing reagent but must be supplied earlier in the process so that it can hydrolyze into ammonia. Substitution of urea can reduce costs and potential hazards associated with storage of anhydrous ammonia.

Heavy metals are often adsorbed on injected active carbon powder, which is collected by the particle filtration.

Solid outputs

Incineration produces fly ash and bottom ash just as is the case when coal is combusted. The total amount of ash produced by municipal solid waste incineration ranges from 4 to 10& % by volume and 15-20& % by weight of the original quantity of waste, and the fly ash amounts to about 10-20& % of the total ash. The fly ash, by far, constitutes more of a potential health hazard than does the bottom ash because the fly ash often contain high concentrations of heavy metals such as lead, cadmium, copper and zinc as well as small amounts of dioxins and furans. The bottom ash seldom contain significant levels of heavy metals. In testing over the past decade, no ash from an incineration plant in the USA has ever been determined to be a hazardous waste. At present although some historic samples tested by the incinerator operators’ group would meet the being ecotoxic criteria at present the EA say “we have agreed” to regard incinerator bottom ash as “non-hazardous” until the testing programme is complete.

Other pollution issues

Odor pollution can be a problem with old-style incinerators, but odors and dust are extremely well controlled in newer incineration plants. They receive and store the waste in an enclosed area with a negative pressure with the airflow being routed through the boiler which prevents unpleasant odors from escaping into the atmosphere. However, not all plants are implemented this way, resulting in inconveniences in the locality.

An issue that affects community relationships is the increased road traffic of waste collection vehicles to transport municipal waste to the incinerator. Due to this reason, most incinerators are located in industrial areas. This problem can be can avoided to an extent through the transport of waste by rail from transfer stations.

Adapted from the Wikipedia article Incineration, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

No related posts.

Bavaria (1898–1924)

Brecht was born in Augsburg, Bavaria (about 50 miles (80& km) north-west of Munich) to a conventionally-devout Protestant mother and a Catholic father (who had been persuaded to have a Protestant wedding). His father worked for a paper mill, becoming its managing director in 1914. Thanks to his mother’s influence, Brecht knew his Bible, a familiarity that would impact on his writing throughout his life. From her, too, came the “dangerous image of the self-denying woman” that recurs in his drama. Brecht’s home life was comfortably middle class, despite what his occasional attempt to claim peasant origins implied. At school in Augsburg he met Caspar Neher, with whom he formed a life-long creative partnership, Neher designing many of the sets for Brecht’s dramas and helping to forge the distinctive visual iconography of their epic theatre.

When he was sixteen, the first World War broke out; initially enthusiastic, Brecht soon changed his mind on seeing his classmates “swallowed by the army”. On his father’s recommendation, Brecht sought a loophole by registering for an additional medical course at Munich University, where he enrolled in 1917. There he studied drama with Arthur Kutscher, who inspired in the young Brecht an admiration for the iconoclastic dramatist and cabaret-star Wedekind.

From July 1916, Brecht’s newspaper articles began appearing under the new name “Bert Brecht” (his first theatre criticism for the ”Augsburger Volkswille” appeared in October 1919).

In July 1919, Brecht and Paula Banholzer (who had begun a relationship in 1917) had a son, Frank. In 1920 Brecht’s mother died.

Some time in either 1920 or 1921, Brecht took a small part in the political cabaret of the Munich comedian Karl Valentin.. Brecht’s diaries for the next few years record numerous visits to see Valentin perform.. Brecht compared Valentin to Chaplin, for his “virtually complete rejection of mimicry and cheap psychology” Writing in his ”Messingkauf Dialogues” years later, Brecht identified Valentin, along with Wedekind and Büchner, as his “chief influences” at that time:

:But the man he [Brecht writes of himself in the third person] learnt most from was the clown ”Valentin”, who performed in a beer-hall. He did short sketches in which he played refractory employees, orchestral musicians or photographers, who hated their employer and made him look ridiculous. The employer was played by his partner, a popular woman comedian who used to pad herself out and speak in a deep bass voice.

Brecht’s first full-length play, ”Baal” (written 1918), arose in response to an argument in one of Kutscher’s drama seminars, initiating a trend that persisted throughout his career of creative activity that was generated by a desire to counter another work (both others’ and his own, as his many adaptations and re-writes attest). “Anyone can be creative,” he quipped, “it’s rewriting other people that’s a challenge.” Brecht completed his second major play, ”Drums in the Night”, in February 1919.

In 1922 while still living in Munich, Brecht came to the attention of an influential Berlin critic, Herbert Ihering: “At 24 the writer Bert Brecht has changed Germany’s literary complexion overnight”—he enthused in his review of Brecht’s first play to be produced, ”Drums in the Night”—”[he] has given our time a new tone, a new melody, a new vision. [...] It is a language you can feel on your tongue, in your gums, your ear, your spinal column.” In November it was announced that Brecht had been awarded the prestigious Kleist Prize (intended for unestablished writers and probably Germany’s most significant literary award, until it was abolished in 1932) for his first three plays (”Baal”, ”Drums in the Night”, and ”In the Jungle”, although at that point only ”Drums” had been produced). The citation for the award insisted that:

:”[Brecht's] language is vivid without being deliberately poetic, symbolical without being over literary. Brecht is a dramatist because his language is felt physically and in the round.”

That year he married the Viennese opera-singer Marianne Zoff. Their daughter—Hanne Hiob (1923–2009)—was a successful German actress.

In 1923, Brecht wrote a scenario for what was to become a short slapstick film, ”Mysteries of a Barbershop”, directed by Erich Engel and starring Karl Valentin. Despite a lack of success at the time, its experimental inventiveness and the subsequent success of many of its contributors have meant that it is now considered one of the most important films in German film history. In May of that year, Brecht’s ”In the Jungle” premiered in Munich, also directed by Engel. Opening night proved to be a “scandal”—a phenomenon that would characterize many of his later productions during the Weimar Republic—in which Nazis blew whistles and threw stink bombs at the actors on the stage.

In 1924 Brecht worked with the novelist and playwright Lion Feuchtwanger (whom he had met in 1919) on an adaptation of Christopher Marlowe’s ”Edward II” that proved to be a milestone in Brecht’s early theatrical and dramaturgical development. Brecht’s ”Edward II” constituted his first attempt at collaborative writing and was the first of many classic texts he was to adapt. As his first solo directorial début, he later credited it as the germ of his conception of ‘epic theatre’. That September, a job as assistant dramaturg at Max Reinhardt’s Deutsches Theater—at the time one of the leading three or four theatres in the world—brought him to Berlin.

Weimar Republic Berlin (1925–33)

In 1923 Brecht’s marriage to Zoff began to break down (though they did not divorce until 1927). Brecht had become involved with both Elisabeth Hauptmann and Helene Weigel. Brecht and Weigel’s son, Stefan, was born in October 1924.

In his role as dramaturg, Brecht had much to stimulate him but little work of his own. Reinhardt staged Shaw’s ”Saint Joan”, Goldoni’s ”Servant of Two Masters” (with the improvisational approach of the ”commedia dell’arte” in which the actors chatted with the prompter about their roles), and Pirandello’s ”Six Characters in Search of an Author” in his group of Berlin theatres. A new version of Brecht’s third play, now entitled ”Jungle: Decline of a Family”, opened at the Deutsches Theater in October 1924, but was not a success.

At this time Brecht revised his important ‘transitional poem’ “Of Poor BB”. In 1925, his publishers provided him with Elisabeth Hauptmann as an assistant for the completion of his collection of poems, ”Devotions for the Home” (”Hauspostille”, eventually published in January 1927). She continued to work with him after the publisher’s commission ran out.

In 1925 in Mannheim the artistic exhibition ”Neue Sachlichkeit” (‘new objectivity’) had given its name to the new post-Expressionist movement in the German arts. With little to do at the Deutsches Theater, Brecht began to develop his ”Man Equals Man” project, which was to become the first product of “the ‘Brecht collective’—that shifting group of friends and collaborators on whom he henceforward depended.” This collaborative approach to artistic production, together with aspects of Brecht’s writing and style of theatrical production, mark Brecht’s work from this period as part of the ”Neue Sachlichkeit” movement. The collective’s work “mirrored the artistic climate of the middle 1920s,” Willett and Manheim argue:

with their attitude of ‘Neue Sachlichkeit’ (or New Matter-of-Factness), their stressing of the collectivity and downplaying of the individual, and their new cult of Anglo-Saxon imagery and sport. Together the ‘collective’ would go to fights, not only absorbing their terminology and ethos (which permeates ”Man Equals Man”) but also drawing those conclusions for the theatre as a whole which Brecht set down in his theoretical essay ‘Emphasis on Sport’ and tried to realise by means of the harsh lighting, the boxing-ring stage and other anti-illusionistic devices that henceforward appeared in his own productions.

Adapted from the Wikipedia article Bertolt Brecht, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

No related posts.

Parts

* Root of the penis (radix): It is the attached part, consisting of the bulb of penis in the middle and the crus of penis, one on either side of the bulb. It lies within the superficial perineal pouch.

* Body of the penis (corpus): It has two surfaces: dorsal (posterosuperior in the erect penis), and ventral or urethral (facing downwards and backwards in the flaccid penis). The ventral surface is marked by a median raphe.

Structure

The human penis is made up of three columns of tissue: two corpora cavernosa lie next to each other on the dorsal side and one corpus spongiosum lies between them on the ventral side.

The enlarged and bulbous-shaped end of the corpus spongiosum forms the glans penis, which supports the foreskin or prepuce, a loose fold of skin that in adults can retract to expose the glans. The area on the underside of the penis, where the foreskin is attached, is called the frenum (or frenulum).

The urethra, which is the last part of the urinary tract, traverses the corpus spongiosum, and its opening, known as the meatus , lies on the tip of the glans penis. It is a passage both for urine and for the ejaculation of semen. Sperm are produced in the testes and stored in the attached epididymis. During ejaculation, sperm are propelled up the vas deferens, two ducts that pass over and behind the bladder. Fluids are added by the seminal vesicles and the vas deferens turns into the ejaculatory ducts, which join the urethra inside the prostate gland. The prostate as well as the bulbourethral glands add further secretions, and the seme

The raphe is the visible ridge between the lateral halves of the penis, found on the ventral or underside of the penis, running from the meatus (opening of the urethra) across the scrotum to the perineum (area between scrotum and anus).

The human penis differs from those of most other mammals, as it has no baculum, or erectile bone, and instead relies entirely on engorgement with blood to reach its erect state. It cannot be withdrawn into the groin, and it is larger than average in the animal kingdom in proportion to body mass.

Penile growth and puberty

On entering puberty, the penis, scrotum and testicles will begin to develop. During the process, pubic hair grows above and around the penis. A large-scale study assessing penis size in thousands of 17–19 year old males found no difference in average penis size between 17 year olds and 19 year olds. From this, it can be concluded that penile growth is typically complete not later than age 17, and possibly earlier.

Sexual homology

In short, this is a known list of sex organs that evolve from the same tissue in females and males.

The glans of the penis is homologous to the clitoral glans; the corpora cavernosa are homologous to the body of the clitoris; the corpus spongiosum is homologous to the vestibular bulbs beneath the labia minora; the scrotum, homologous to the labia minora and labia majora; and the foreskin, homologous to the clitoral hood. The raphe does not exist in females, because there, the two halves are not connected.

Erection

An erection is the stiffening and rising (see Erection Angle) of the penis, which occurs during sexual arousal, though it can also happen in non-sexual situations. The primary physiological mechanism that brings about erection is the autonomic dilation of arteries supplying blood to the penis, which allows more blood to fill the three spongy erectile tissue chambers in the penis, causing it to lengthen and stiffen. The now-engorged erectile tissue presses against and constricts the veins that carry blood away from the penis. More blood enters than leaves the penis until an equilibrium is reached where an equal volume of blood flows into the dilated arteries and out of the constricted veins; a constant erectile size is achieved at this equilibrium.

Erection facilitates sexual intercourse though it is not essential for various other sexual activities.

Erection angle

Although many erect penises point upwards (see illustration), it is common and normal for the erect penis to point nearly vertically upwards or nearly vertically downwards or even horizontally straight forward, all depending on the tension of the suspensory ligament that holds it in position. The following table shows how common various erection angles are for a standing male. In the table, zero degrees is pointing straight up against the abdomen, 90 degrees is horizontal and pointing straight forward, while 180 degrees would be pointing straight down to the feet. An upward pointing angle is most common.

Ejaculation

Ejaculation is the ejecting of semen from the penis, and is usually accompanied by orgasm. A series of muscular contractions delivers semen, containing male gametes known as sperm cells or spermatozoa, from the penis (and into the vagina, if for reproductive intention via sexual intercourse). It is usually the result of sexual stimulation, which may include prostate stimulation. Rarely, it is due to prostatic disease. Ejaculation may occur spontaneously during sleep (known as a nocturnal emission or wet dream). Anejaculation is the condition of being unable to ejaculate.

Ejaculation has two phases: ”emission” and ”ejaculation proper”. The emission phase of the ejaculatory reflex is under control of the sympathetic nervous system, while the ejaculatory phase is under control of a spinal reflex at the level of the spinal nerves S2–4 via the pudendal nerve. A refractory period succeeds the ejaculation, and sexual stimulation precedes it.

Normal variations

*Pearly penile papules are raised bumps of somewhat paler color around the base of the glans and are normal.

*Fordyce’s spots are small, raised, yellowish-white spots 1–2& mm in diameter that may appear on the penis.

*”Sebaceous prominences” are raised bumps similar to Fordyce’s spots on the shaft of the penis, located at the sebaceous glands and are normal.

*Phimosis is an inability to retract the foreskin fully, is harmless in infancy and pre-pubescence, occurring in about 8% of boys at age 10. According to the British Medical Association, treatment (steroid cream, manual stretching) does not need to be considered until age 19.

*Curvature: few penises are completely straight, with curves commonly seen in all directions (up, down, left, right). Sometimes the curve is very prominent but it rarely inhibits sexual intercourse. Curvature as great as 30° is considered normal and medical treatment is rarely considered unless the angle exceeds 45°. Changes to the curvature of a penis may be caused by Peyronie’s disease.

Disorders

Paraphimosis is an inability to move the foreskin forward, over the glans. It can result from fluid trapped in a foreskin left retracted, perhaps following a medical procedure, or accumulation of fluid in the foreskin because of friction during vigorous sexual activity.

In Peyronie’s disease, anomalous scar tissue grows in the soft tissue of the penis, causing curvature. Severe cases can benefit from surgical correction.

A thrombosis can occur during periods of frequent and prolonged sexual activity, especially fellatio. It is usually harmless and self-corrects within a few weeks.

Infection with the herpes virus can occur after sexual contact with an infected carrier; this may lead to the development of herpes sores.

Pudendal nerve entrapment is a condition characterized by pain on sitting and loss of penile (or clitoral) sensation and orgasm. Occasionally there is a total loss of sensation and orgasm. The pudendal nerve can be damaged by narrow, hard bicycle seats and accidents.

Penile fracture can occur if the erect penis is bent excessively. A popping or cracking sound and pain is normally associated with this event. Emergency medical assistance should be obtained. Prompt medical attention lowers likelihood of permanent penile curvature.

In diabetes, peripheral neuropathy can cause tingling in the penile skin and possibly reduced or completely absent sensation. The reduced sensations can lead to injuries for either partner and their absence can make it impossible to have sexual pleasure through stimulation of the penis. Since the problems are caused by permanent nerve damage, preventive treatment through good control of the diabetes is the primary treatment. Some limited recovery may be possible through improved diabetes control.

Erectile dysfunction is the inability to develop and maintain an erection sufficiently firm for satisfactory sexual performance. Diabetes is a leading cause, as is natural aging. A variety of treatments exist, including drugs, such as ”sildenafil citrate” (marketed as Viagra), which works by vasodilation.

Priapism is a painful and potentially harmful medical condition in which the erect penis does not return to its flaccid state. The causative mechanisms are poorly understood but involve complex neurological and vascular factors. Potential complications include ischaemia, thrombosis, and impotence. In serious cases the condition may result in gangrene, which may necessitate amputation. The condition has been associated with a variety of drugs including prostaglandin but not sildenafil (Viagra).

Lymphangiosclerosis is a hardened lymph vessel, although it can feel like a hardened, almost calcified or fibrous, vein. It tends not to share the common blue tint with a vein however. It can be felt as a hardened lump or “vein” even when the penis is flaccid, and is even more prominent during an erection. It is considered a benign physical condition. It is fairly common and can follow a particularly vigorous sexual activity for men, and tends to go away if given rest and more gentle care, for example by use of lubricants.

Carcinoma of the penis is rare with a reported rate of 1 person in 100,000 in developed countries. Circumcision is said to protect against this disease but this notion remains controversial.

Developmental disorders

Hypospadias is a developmental disorder where the meatus is positioned wrongly at birth. Hypospadias can also occur iatrogenically by the downward pressure of an indwelling urethral catheter. It is usually corrected by surgery. The Intersex Society of North America classifies hypospadias as an intersex condition. They believe in halting all medically unnecessary surgeries, including many of those done on people with hypospadias.

A micropenis is a very small penis caused by developmental or congenital problems. Diphallia, or penile duplication (PD), is the condition of having two penises. However, this disorder is exceedingly rare.

Alleged and observed psychological disorders

*Penis panic (”koro” in Malaysian/Indonesian)—delusion of shrinkage of the penis and retraction into the body. This appears to be culturally conditioned and largely limited to Ghana, Sudan, China, Japan, Southeast Asia, and West Africa

* In April, 2008, Kinshasa, Democratic Republic of Congo, West Africa’s ‘Police arrested 14 suspected victims (of penis snatching) and sorcerers accused of using black magic or witchcraft to steal (make disappear) or shrink men’s penises to extort cash for cure, amid a wave of panic. Arrests were made in an effort to avoid bloodshed seen in Ghana a decade before, when 12 penis snatchers were beaten to death by mobs.

*Penis envy the contested Freudian belief of a woman envying men for having a penis.

Altering the genitalia

The penis is sometimes pierced or decorated by other body art. Other than circumcision, genital alterations are almost universally elective and usually for the purpose of aesthetics or increased sensitivity. Piercings of the penis include the Prince Albert, the apadravya, the ampallang, the dydoe, and the frenum piercing. Foreskin restoration or stretching is a further form of body modification, as well as implants under the shaft of the penis.

Male to female transsexuals who undergo sex reassignment surgery, have their penis surgically modified into a neovagina. Female to male transsexuals may have a phalloplasty.

Other practices that alter the penis are also performed, although they are rare in Western societies without a diagnosed medical condition. Apart from a penectomy, perhaps the most radical of these is subincision, in which the urethra is split along the underside of the penis. Subincision originated among Australian Aborigines, although it is now done by some in the U.S. and Europe.

Circumcision

The most common form of genital alteration is circumcision: removal of part or all of the foreskin for various cultural, religious, and more rarely medical reasons. For infant circumcision, modern devices such as the Gomco clamp, Plastibell, and Mogen clamp are available.

With all modern devices the same basic procedure is followed. First, the amount of foreskin to be removed is estimated. The foreskin is then opened via the preputial orifice to reveal the glans underneath and ensured that it is normal. The inner lining of the foreskin (preputial epithelium) is then separated from its attachment to the glans. The device is then placed (this sometimes requires a dorsal slit) and remains there until blood flow has stopped. Finally, part, or all, of the foreskin is then removed.

Adult circumcisions are often performed without clamps and require 4 to 6 weeks of abstinence from masturbation or intercourse after the operation to allow the wound to heal. In some African countries, male circumcision is often performed by non-medical personnel under unsterile conditions. After hospital circumcision, the foreskin may be used in biomedical research, consumer skin-care products, skin grafts, or β-interferon-based drugs. In parts of Africa, the foreskin may be dipped in brandy and eaten by the patient, eaten by the circumciser, or fed to animals. According to Jewish law, after a ”Brit milah”, the foreskin should be buried.

There is controversy surrounding circumcision. Advocates of circumcision argue, for example, that it provides important health advantages that outweigh the risks, has no substantial effects on sexual function, has a low complication rate when carried out by an experienced physician, and is best performed during the neonatal period. Opponents of circumcision argue, for example, that it is a practice that has historically been, and continues to be, defended through the use of various myths; that it interferes with normal sexual function; is extremely painful; and, when performed on infants and children, violates the individual’s human rights.

The American Medical Association stated in 1999: “Virtually all current policy statements from specialty societies and medical organizations do not recommend routine neonatal circumcision, and support the provision of accurate and unbiased information to parents to inform their choice.”

The World Health Organization (WHO; 2007), the Joint United Nations Programme on HIV/AIDS (UNAIDS; 2007), and the Centers for Disease Control and Prevention (CDC; 2008) state that evidence indicates male circumcision significantly reduces the risk of HIV acquisition by men during penile-vaginal sex, but also state that circumcision only provides partial protection and should not replace other interventions to prevent transmission of HIV.

Surgical replacement

The first successful penis allotransplant surgery was done in September 2005 in a military hospital in Guangzhou, China. A man at 44 sustained an injury after an accident and his penis was severed; urination became difficult as his urethra was partly blocked. A newly brain dead man, age 23, was selected for the transplant. Despite atrophy of blood vessels and nerves, the arteries, veins, nerves and the corpora spongiosa were successfully matched. But, on 19 September, the surgery was reversed because of a severe psychological problem (rejection) by the recipient and his wife.

In 2009 researchers Chen, Eberli, Yoo and Atala have produced bioengineered penises and implanted them on rabbits. The animals were able to obtain erection and copulate, with 10 of 12 rabbits achieving ejaculation. This study shows that in the future it could be possible to produce artificial penises for replacement surgeries.

Size

Adapted from the Wikipedia article Penis, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

No related posts.

Conventional treatment focuses on three areas: trigger avoidance, symptomatic control, and prophylactic pharmacological drugs. Patients who experience migraines often find that the recommended migraine treatments are not 100% effective at preventing migraines, and sometimes may not be effective at all. Pharmacological treatments are considered ”effective” if they reduce the frequency or severity of migraine attacks by 50%.

Children and adolescents are often first given drug treatment, but the value of diet modification should not be overlooked. The simple task of starting a diet journal to help modify the intake of trigger foods like hot dogs, chocolate, cheese and ice cream could help alleviate symptoms.

For patients who have been diagnosed with recurring migraines, migraine abortive medications can be used to treat the attack, and may be more effective if taken early, losing effectiveness once the attack has begun. Treating the attack at the onset can often abort it before it becomes serious, and can reduce the near-term frequency of subsequent attacks.

Although there is a large number of medications to treat migraine, their effectiveness varies from person to person. What works from one person may not be effective at all for another one, therefore, early intervention becomes very important. Dr. Joel Saper, director of the Michigan Headache and Neurological Institute explains that according to early data untreated headaches can make the person more vulnerable to pain.

Analgesics

The first line of treatment is over-the-counter abortive medicati

*Some non-steroidal anti-inflammatory drugs (NSAIDs) can effectively alleviate migraines. In particular:

**A randomized controlled trial found that naproxen can abort about one third of migraine attacks, which was 5% less than the benefit of sumatriptan.

**Trials have consistently found that a 1000 mg dose of Aspirin could relieve moderate to severe migraine pain, with similar effectiveness to sumatriptan.

* Paracetamol/acetaminophen benefited over half of patients with mild or moderate migraines in a randomized controlled trial.

* Simple analgesics combined with caffeine may help. During a migraine attack, emptying of the stomach is slowed, resulting in nausea and a delay in absorbing medication. Caffeine has been shown to partially reverse this effect. Excedrin is an example of an aspirin with caffeine product. Caffeine is recognized by the U.S. Food and Drug Administration as an Over The Counter Drug (OTC) treatment for migraine when compounded with aspirin and paracetamol. Even by itself, caffeine can be helpful during an attack, despite the fact that in general migraine-sufferers are advised to limit their caffeine intake.

Patients themselves often start off with paracetamol, aspirin, ibuprofen, or other simple analgesics that are useful for tension headaches. OTC drugs may provide some relief, although they are typically not effective for most sufferers.

In all, the U.S. Food and Drug Administration has approved three OTC products specifically for migraine: Excedrin Migraine, Advil Migraine, and Motrin Migraine Pain. Excedrin Migraine, as mentioned above, is a combination of aspirin, acetaminophen, and caffeine. Both Advil Migraine and Motrin Migraine Pain are straight NSAIDs, with ibuprofen as the only active ingredient.

Analgesics combined with antiemetics

Antiemetics by mouth may help relieve symptoms of nausea and help prevent vomiting, which can diminish the effectiveness of orally taken analgesia. In addition some antiemetics such as metoclopramide are prokinetics and help gastric emptying which is often impaired during episodes of migraine. In the UK, there are three combination antiemetic and analgesic preparations available: MigraMax (aspirin with metoclopramide), Migraleve (paracetamol/codeine for analgesia, with buclizine as the antiemetic) and paracetamol/metoclopramide (Paramax in UK). The earlier these drugs are taken in the attack, the better their effect.

Some patients find relief from taking other sedative antihistamines which have anti-nausea properties, such as Benadryl which in the US contains diphenhydramine (but a different non-sedative product in the UK).

Serotonin agonists

Sumatriptan and related selective serotonin receptor agonists are excellent for severe migraines or those that do not respond to NSAIDs or other over-the-counter drugs. Triptans are a mid-line treatment suitable for many sufferers of typical migraines. They may not work for atypical or unusually severe migraines, transformed migraines, or status (continuous) migraines.

Selective serotonin reuptake inhibitors (SSRIs) are not approved by the U.S. Food and Drug Administration (FDA) for treatment of migraines, but have been found to be effective by clinical consensus.

Antidepressants

Tricyclic antidepressants have been long established as highly efficacious prophylactic treatments. These drugs, however, may give rise to undesirable side effects, such as insomnia, sedation or sexual dysfunction. SSRIs antidepressants are less established than tricyclics for migraines prophylaxis. Despite the absence of FDA approval for migraine treatment, antidepressants are widely prescribed. In addition to tricyclics and SSRIs, the anti-depressant nefazodone may also be beneficial in the prophylaxis of migraines due to its antagonistic effects on the 5-HT2A and 5-HT2C receptors It has a more favorable side effect profile than amitriptyline, a tricyclic antidepressant commonly used for migraine prophylaxis. Anti-depressants offer advantages for treating migraine patients with comorbid depression.

Ergot alkaloids

Until the introduction of sumatriptan in 1991, ergot derivatives (see ergoline) were the primary oral drugs available to abort a migraine once it is established.

Ergot drugs can be used either as a preventive or abortive therapy, though their relative expense and cumulative side effects suggest reserving them as an abortive rescue medicine. However, ergotamine tartrate tablets (usually with caffeine), though highly effective, and long lasting (unlike triptans), have fallen out of favour due to the problem of ergotism. Oral ergotamine tablet absorption is reliable unless the patient is nauseated. Anti-nausea administration is available by ergotamine suppository (or Ergostat sublingual tablets made until circa 1992). Ergot drugs themselves can be so nauseating it is advisable for the sufferer to have something at hand to counteract this effect when first using this drug. Ergotamine-caffeine 1/100& mg fixed ratio tablets (like Cafergot, Ercaf, etc.) are much less expensive per headache than triptans, and are commonly available in Asia and Romania (Cofedol). They are difficult to obtain in the USA. Ergotamine-caffeine can’t be regularly used to abort evening or night onset migraines due to debilitating caffeine interference with sleep. Pure ergotamine tartrate is highly effective for evening-night migraines, but is rarely or never available in the USA. Dihydroergotamine (DHE), which must be injected or inhaled, can be as effective as ergotamine tartrate, but is much more expensive than $2 USD Cafergot tablets.

Steroids

Based on a recent meta analysis a single dose of IV dexamethasone, when added to standard treatment, is associated with a 26% decrease in headache recurrence.

Other agents

If over-the-counter medications do not work, or if triptans are unaffordable, the next step for many doctors is to prescribe Fioricet or Fiorinal, which is a combination of butalbital (a barbiturate), paracetamol (in Fioricet) or acetylsalicylic acid (more commonly known as aspirin and present in Fiorinal), and caffeine. While the risk of addiction is low, butalbital can be habit-forming if used daily, and it can also lead to rebound headaches. Barbiturate-containing medications are not available in many European countries.

Amidrine, Duradrin, and Midrin is a combination of acetaminophen, dichloralphenazone, and isometheptene often prescribed for migraine headaches. Some studies have recently shown that these drugs may work better than sumatriptan for treating migraines.

Antiemetics may need to be given by suppository or injection where vomiting dominates the symptoms.

Recently it has been found that calcitonin gene related peptides (CGRPs) play a role in the pathogenesis of the pain associated with migraine as triptans also decrease its release and action. CGRP receptor antagonists such as olcegepant and telcagepant are being investigated both in vitro and in clinical studies for the treatment of migraine.

Merck Corp is developing a new drug called Telcagepant which is intended to relieve pain without causing vasoconstriction (narrowing of blood vessels) as current medications such as triptans do. Telcagepant would be a safe therapy for migraine suffers with risk factors for cardiovascular disease.

Status migrainosus

Status migrainosus is characterized by migraine lasting more than 72 hours, with not more than four hours of relief during that period. It is generally understood that status migrainosus has been refractory to usual outpatient management upon presentation.

Treatment of status migrainosus consists of managing comorbidities (i.e., correcting fluid and electrolyte abnormalities resulting from anorexia and nausea/vomiting often accompanying status migr.), and usually administering parenteral medication to “break” (abort) the headache.

Although the literature is full of many case reports concerning treatment of status migrainosus, first line therapy consists of intravenous fluids, metoclopramide, and triptans or DHE.

Herbal treatment

The herbal supplement feverfew (more commonly used for migraine prevention, see below) is marketed by the [http://www.gelstat.com/ GelStat Corporation] as an OTC migraine abortive, administered sublingually (under the tongue) in a mixture with ginger. An open-label study (funded by GelStat) found some tentative evidence of the treatment’s effectiveness, but no scientifically sound study has been done. Cannabis, in addition to prevention, is also known to relieve pain during the onset of a migraine.

Cryotherapy and Thermotherapy

During a migraine the blood vessels in the head tend to dilate as a result of many chemical changes in the body. Some believe that these vessels become swollen with blood and thus put pressure on the nerves surrounding the vessels. This pressure causes the nerve to send pain signals to the brain, resulting in the debilitating pain most often associated with migraines. Both heat and cooling therapies uses temperature manipulation to reduce migraine pain. The use of cooling therapy (cyrotherapy) is believed to cause the swollen blood vessels to constrict, thus reducing pulsating migraine pain. The use of thermotherapy, on the other hand, causes blood flow to increase which, in turn, increases the amount of oxygen and nutrients that are sent to the pain site in the brain. Using a product such as [http://www.sootheaway.com/ SootheAway] will allow a migraine sufferer to apply constant temperature therapy to help relieve pain. A recent study published in the Archives of Family Medicine revealed that pressure, heat and cold can help to relieve headache pain.

Exercise

Being a neurological syndrome, tense nerves are normally one of the causes that exacerbate migraine symptoms. Regular exercise is one way to calm nerves. However, this option may be effective for some people but not for others as in some cases it may actually be the cause of migraine. According to Lawrence Newman, MD, director of the Headache Institute at St. Luke’s-Roosevelt Hospital Center in New York migraine sufferers have a heightened neurological system which implies that they have a tendency to develop migraine when anything is out of the ordinary. Therefore, such people establish a regular exercise routine. Exercise can benefit them as it releases endorphins, which are the body’s natural painkillers, therefore, they can lessen the frequency or severity of migraines.

Comparative studies

Regarding comparative effectiveness of these drugs used to abort migraine attacks, a 2004 placebo-controlled trial reveals that high dose acetylsalicylic acid (1000& mg), sumatriptan 50& mg and ibuprofen 400& mg are equally effective at providing relief from pain, although sumatriptan was superior in terms of the more demanding outcome of rendering patients entirely free of pain and all other migraine-related symptoms. [Note that 50& mg of sumatriptan is not a commonly prescribed full dose (100& mg), so would be expected to not be fully comparable.]

Another randomized controlled trial, funded by the manufacturer of the study drug, found that a combination of sumatriptan 85& mg and naproxen sodium 200& mg was better than either drug alone.

Recently the combination of sumatriptan 85& mg and naproxen sodium 500& mg was demonstrated to be effective and well tolerated in an early intervention paradigm for the acute treatment of migraine. Significant pain-free responses in favor of sumatriptan/naproxen were demonstrated as early as 30 minutes, maintained at 1 hour, and sustained from 2 to 24 hours. At 2 and 4 hours, sumatriptan/naproxen provided significantly lower rates of traditional migraine-associated symptoms (nausea, photophobia, and phonophobia) and nontraditional migraine-associated symptoms (neck pain/discomfort and sinus pain/pressure). An initial study by Griffith University on Vitamin B supplements for both prevention and management has yielded promising results.

Medication overuse headaches

Researchers have learned that the brain’s biology can change due to the pain and the medications used to treat it. Furthermore, the constant use of over-the-counter or prescription painkillers -two to three days a week after a long period of time- may cause medication-overuse headaches, also known as rebound headaches. Such headache may be recognized by its shifting pattern where the patient experiences migraine-like characteristics and then the symptoms of a tension-type headache. Such shift can occur during the same day.

Substantial evidence has shown that triptans, ergotamines, simple analgesics, opiods, butalbital compounds, vicodin as well as other compounds may cause Medication Overuse Headaches, MOH. To stop MOH, it is necessary to discontinue the medication causing the MOH. However, withdrawal symptoms will be experienced from two to ten days including withdrawal headache, tachycardia, vomiting, anxiety, arterial hypotension, sleep disorders, nervousness, restlessness.

Adapted from the Wikipedia article Migraine, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

No related posts.

For a fuller discussion of standard, rarely used, and more experimental treatments, see Treatment for depression.

The three most common treatments for depression are psychotherapy, medication, and electroconvulsive therapy.

Psychotherapy is the treatment of choice for people under 18, while electroconvulsive therapy is only used as a last resort. Care is usually given on an outpatient basis, while treatment in an inpatient unit is considered if there is a significant risk to self or others. A significant number of recent studies have indicated that physical exercise has beneficial effects.

Treatment options are much more limited in developing countries, where access to mental health staff, medication, and psychotherapy is often difficult. Development of mental health services is minimal in many countries; depression is viewed as a phenomenon of the developed world despite evidence to the contrary, and not as an inherently life-threatening condition.

Psychotherapy

Psychotherapy can be delivered, to individuals or groups, by mental health professionals, including psychotherapists, psychiatrists, psychologists, clinical social workers, counselors, and suitably trained psychiatric nurses. With more complex and chronic forms of depression, a combination of medication and psychotherapy may be used. In people under 18, according to the National Institute for Health and Clinical Excellence, medication should only be offered in conjunction with a psychological therapy, such as CBT, interpersonal therapy, or family therapy. Psychotherapy has been shown to be effectiv

The most-studied form of psychotherapy for depression is CBT, that teaches clients to challenge self-defeating, but enduring ways of thinking (cognitions) and change counter-productive behaviours. Research beginning in the mid-1990s suggested that CBT could perform as well or better than antidepressants in patients with moderate to severe depression. CBT may be effective in depressed adolescents, although its effects on severe episodes are not definitively known. Combining fluoxetine with CBT appeared to bring no additional benefit, or, at the most, only marginal benefit. Several variables predict success for cognitive behavioral therapy in adolescents: higher levels of rational thoughts, less hopelessness, fewer negative thoughts, and fewer cognitive distortions. CBT is particularly beneficial in preventing relapse.

Several variants of cognitive behavior therapy have been used in depressed patients, most notably rational emotive behavior therapy, and more recently mindfulness-based cognitive therapy.

Psychoanalysis is a school of thought, founded by Sigmund Freud, which emphasizes the resolution of unconscious mental conflicts. Psychoanalytic techniques are used by some practitioners to treat clients presenting with major depression. A more widely practiced, eclectic technique, called psychodynamic psychotherapy, is loosely based on psychoanalysis and has an additional social and interpersonal focus. In a meta-analysis of three controlled trials of Short Psychodynamic Supportive Psychotherapy, this modification was found to be as effective as medication for mild to moderate depression.

Logotherapy, a form of existential psychotherapy developed by Austrian psychiatrist Viktor Frankl, addresses the filling of an “existential vacuum” associated with feelings of futility and meaninglessness. It is posited that this type of psychotherapy may be useful for depression in older adolescents.

Antidepressants

The effects of prescription antidepressants are somewhat superior to those of psychotherapy, especially in cases of chronic major depression, although in short-term trials more patients—especially those with less serious forms of depression—cease medication than cease psychotherapy, most likely due to adverse effects from the medication and to patients’ preferences for psychological therapies over pharmacological treatments.

To find the most effective antidepressant medication with minimal side effects, the dosages can be adjusted, and if necessary, combinations of different classes of antidepressants can be tried. Response rates to the first antidepressant administered range from 50–75%, and it can take at least six to eight weeks from the start of medication to remission, when the patient is back to their normal self. Antidepressant medication treatment is usually continued for 16 to 20 weeks after remission, to minimize the chance of recurrence, and even up to one year of continuation is recommended. People with chronic depression may need to take medication indefinitely to avoid relapse.

Selective serotonin reuptake inhibitors (SSRIs), such as sertraline, escitalopram, fluoxetine, paroxetine, and citalopram are the primary medications prescribed owing to their effectiveness, relatively mild side effects, and because they are less toxic in overdose than other antidepressants. Patients who do not respond to one SSRI can be switched to another, and this results in improvement in almost 50% of cases. Another option is to switch to the atypical antidepressant bupropion. Venlafaxine, an antidepressant with a different mechanism of action, may be modestly more effective than SSRIs. However, venlafaxine is not recommended in the UK as a first-line treatment because of evidence suggesting its risks may outweigh benefits, and it is specifically discouraged in children and adolescents.

For adolescent depression, fluoxetine and escitalopram are the two recommended choices. Antidepressants have not been found to be beneficial in children. Any antidepressant can cause low serum sodium levels (also called hyponatremia); nevertheless, it has been reported more often with SSRIs. It is not uncommon for SSRIs to cause or worsen insomnia; the sedating antidepressant mirtazapine can be used in such cases.

Monoamine oxidase inhibitors, an older class of antidepressants, have been plagued by potentially life-threatening dietary and drug interactions. They are still used only rarely, although newer and better tolerated agents of this class have been developed.

The terms “refractory depression” and “treatment-resistant depression” are used to describe cases that do not respond to adequate courses of at least two antidepressants. In many major studies, only about 35% of patients respond well to medical treatment. It may be difficult for a doctor to decide when someone has treatment-resistant depression or whether the problem is due to coexisting disorders, which are common among patients with major depression.

A study by psychologists at the University of Pennsylvania, Vanderbilt University, the University of Colorado, and the University of New Mexico found that antidepressant drugs hardly have better effects than a placebo in those cases of mild or moderate depression. This study was published in the Journal of the American Medical Association. The study focused on Paxil from GlaxoSmithKline and imipramine.

Pharmacological augmentation

A medication with a different mode of action may be added to bolster the effect of an antidepressant in cases of treatment resistance. Medication with lithium salts has been used to augment antidepressant therapy in those who have failed to respond to antidepressants alone. Furthermore, lithium dramatically decreases the suicide risk in recurrent depression. Addition of a thyroid hormone, triiodothyronine may work as well as lithium, even in patients with normal thyroid function. Addition of atypical antipsychotics when the patient has not responded to an antidepressant is also known to increase the effectiveness of antidepressant drugs, albeit offset by increased side effects.

Comparative efficacy of medication and psychotherapy

Two recent meta-analyses of clinical trial results submitted to the FDA concluded that antidepressants are statistically superior to placebo but their overall effect is low-to-moderate. In that respect they often did not exceed the National Institute for Health and Clinical Excellence criteria for a “clinically significant” effect. In particular, the effect size was very small for moderate depression but increased with severity, reaching “clinical significance” for very severe depression. These results were consistent with the earlier clinical studies in which only patients with severe depression benefited from either psychotherapy or treatment with an antidepressant, imipramine, more than from the placebo treatment. Despite obtaining similar results, the authors argued about their interpretation. One author concluded that there “seems little evidence to support the prescription of antidepressant medication to any but the most severely

depressed patients, unless alternative treatments have failed to provide benefit.” The other author agreed that “antidepressant ‘glass’ is far from full” but disagreed “that it is completely empty”. He pointed out that the first-line alternative to medication is psychotherapy, which does not have superior efficacy.

One interpretation of the research is that antidepressants in general are as effective as psychotherapy for major depression, and that this conclusion holds true for both severe and mild forms of MDD. In contrast, medication gives better results for dysthymia. The subgroup of SSRIs may be slightly more efficacious than psychotherapy. On the other hand, significantly more patients drop off from the antidepressant treatment than from psychotherapy, likely because of the side effects of antidepressants. Successful psychotherapy appears to prevent the recurrence of depression even after it has been terminated or replaced by occasional “booster” sessions. The same degree of prevention can be achieved by continuing antidepressant treatment. However, another argument is that medication and psychotherapy are two very different things and comparisons are not scientifically valid. Psychotherapy involves addressing and understanding the meaning behind emotions, whilst medication involves regulating those emotions through biochemical means. In many cases, both approaches may be necessary either in combination or in sequence.

Antidepressants and suicidality

For children, adolescents, and in some studies also for young adults between 18–24 years old, there is a higher risk of both suicidal ideations and suicidal behavior in those treated with SSRIs. For adults, it is unclear whether or not SSRIs affect the risk of suicidality. One review found no connection between SSRIs and the risk of suicide however states that they were unable to rule it out based on the data; other studies found an increase of suicide attempts in those who use SSRIs as compared to placebo; and yet other studies found that the widespread use of antidepressants in the new “SSRI-era” appeared to have led to highly significant decline in suicide rates in most countries with traditionally high baseline suicide rates.

A black box warning was introduced in the United States in 2007 on SSRI and other antidepressant medications due to increased risk of suicide in patients younger than 24 years old. Similar precautionary notice revisions were implemented by the Japanese Ministry of Health.

Electroconvulsive therapy

Electroconvulsive therapy (ECT) is a procedure whereby pulses of electricity are sent through the brain via two electrodes, usually one on each temple, to induce a seizure while the patient is under a brief period of general anaesthesia. Hospital psychiatrists may recommend ECT for cases of severe major depression which have not responded to antidepressant medication or, less often, psychotherapy or supportive interventions. ECT can have a quicker effect than antidepressant therapy and thus may be the treatment of choice in emergencies such as catatonic depression where the patient has stopped eating and drinking, or where a patient is severely suicidal. ECT is probably more effective than pharmacotherapy for depression in the immediate short-term, although a landmark community-based study found much lower remission rates in routine practice. Used on its own the relapse rate within the first six months is very high; early studies put the rate at around 50%, while a more recent controlled trial found rates of 84% even with placebos. The early relapse rate may be reduced by the use of psychiatric medications or further ECT (although the latter is not recommended by some authorities) but remains high. Common initial adverse effects from ECT include short and long-term memory loss, disorientation and headache. Although objective psychological testing shows memory disturbance after ECT has mostly resolved by one month post treatment, ECT remains a controversial treatment, and debate on the extent of cognitive effects and safety continues.

Deep brain stimulation

Deep brain stimulation (DBS) is a neurosurgical treatment that has been used especially to treat movement disorders such as Parkinson’s disease. It requires a neurosurgeon to drill a hole in the skull and insert an electrode into the patient’s tissue. Then, a device located in the chest transmits a signal to the implanted electrode through wires located underneath the scalp.

Clinical trials are focused on the use of DBS for epilepsy and depression but the FDA has not approved this use. It requires brain surgery and it is therefore the most invasive form of brain stimulation in the treatment of depression.

Physical exercise

Physical exercise is recommended by U.K. health authorities, and a systematic review of 23 studies indicated a “large clinical effect”. Among these, three studies employing intention to treat analysis and other bias-reducing measures were inconclusive. Its benefits are most statistically significant in mild to moderate forms of depression and anxiety.

Some of the effects of exercise include the release of neurotransmitters and endorphins, reduction of immune system chemicals, increase of body temperature, improvement of confidence, distraction, socialization. There is a wide variety of physical activities that can serve as exercise such as gardening, washing a car or taking the stairs instead of the elevator.

Over-the-counter compounds

St John’s wort is available over-the-counter as a herbal remedy in some parts of the world; however, the evidence of its effectiveness for the treatment of major depression is varying and confusing. Its safety can be compromised by inconsistency in pharmaceutical quality and in the amounts of active ingredient in different preparations. Further, it interacts with numerous prescribed medicines including antidepressants, and it can reduce the effectiveness of hormonal contraception.

The efficacy of omega-3 fatty acids for major depression is unclear, with controlled studies and meta-analyses supporting both positive and negative conclusions.

Reviews of short-term clinical trials of S-adenosylmethionine (SAMe) indicate that it may be effective in treating major depression in adults. A 2002 review reported that tryptophan and 5-hydroxytryptophan appear to be better than placebo, but found most of the evidence in their favor to be of poor quality and inconclusive.

Other somatic treatments

Repetitive transcranial magnetic stimulation (rTMS) applies powerful magnetic fields to the brain from outside the head. Multiple controlled studies support the use of this method in treatment-resistant depression; it has been approved for this indication in Europe, Canada, Australia, and the US. rTMS appeared similarly effective for both uncomplicated depression and depression resistant to medication; however, it was inferior to ECT in a side-by-side randomized trial.

Vagus nerve stimulation was approved by the FDA in the United States in 2005 for use in treatment-resistant depression, although it failed to show short-term benefit in the only large double-blind trial when used as an adjunct on treatment-resistant patients; a 2008 systematic review concluded that despite the promising results reported mainly in open studies, further clinical trials are needed to confirm its efficacy in major depression.

Adapted from the Wikipedia article Major depressive disorder, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

No related posts.