title: Mercury-in-glass thermometer

text: These points are adequate for approximate calibration, but both the freezing and boiling points of water vary with atmospheric pressure. Later thermometers that used a liquid other than mercury also gave slightly different temperature readings. In practice, these variations were very slight and remained close to the thermodynamic temperature, once the latter was discovered. These issues were explored experimentally with the gas thermometer. Until the discovery of true thermodynamic temperature, the mercury thermometer usually "defined" the temperature.


title: Mercury-in-glass thermometer

text: Modern thermometers are often calibrated using the triple point of water instead of the freezing point; the triple point occurs at 273.16 kelvins (K), 0.01 °C.


title: Mercury-in-glass thermometer

text: One special kind of mercury-in-glass thermometer, called a maximum thermometer, works by having a constriction in the neck close to the bulb. As the temperature rises, the mercury is pushed up through the constriction by the force of expansion. When the temperature falls, the column of mercury breaks at the constriction and cannot return to the bulb, thus remaining stationary in the tube. The observer can then read the maximum temperature over the set period of time. To reset the thermometer it must be swung sharply. This design is used in the traditional type of medical thermometer.


title: Mercury-in-glass thermometer

text: A maximum minimum thermometer, also known as Six's thermometer, is a thermometer which registers the maximum and minimum temperatures reached over a period of time, typically 24 hours. The original design contains mercury, but solely as a way to indicate the position of a column of alcohol whose expansion indicates the temperature; it is not a thermometer operated by the expansion of mercury; mercury-free versions are available.


title: Mercury-in-glass thermometer

text: Mercury thermometers cover a wide temperature range from ; the instrument's upper temperature range may be extended through the introduction of an inert gas such as nitrogen. This introduction of an inert gas increases the pressure on the liquid mercury and therefore its boiling point is increased, this in combination with replacing the Pyrex glass with fused quartz allows the upper temperature range to be extended to .


title: Mercury-in-glass thermometer

text: Mercury cannot be used below the temperature at which it becomes solid, . If the thermometer contains nitrogen, the gas may flow down into the column when the mercury solidifies and be trapped there when the temperature rises, making the thermometer unusable until returned to the factory for reconditioning. To avoid this, some weather services require that all mercury-in-glass thermometers be brought indoors when the temperature falls to .


title: Mercury-in-glass thermometer

text: To measure lower meteorological temperatures, a thermometer containing a mercury-thallium alloy which does not solidify until the temperature drops to may be used.


title: Mercury-in-glass thermometer

text: , many mercury-in-glass thermometers are used in meteorology; however, they are becoming increasingly rare for other uses, as many countries banned them for medical use due to the toxicity of mercury. Some manufacturers use galinstan, a liquid alloy of gallium, indium, and tin, as a replacement for mercury.


title: Mercury-in-glass thermometer

text: The typical "fever thermometer" contains between of elemental mercury. Swallowing this amount of mercury would pose little danger but the inhaling of the vapour could lead to health problems.


title: Mercury-in-glass thermometer

text: In February 2009, the Argentine Health Ministry instructed by resolution 139/09 that all health centres and hospitals should buy mercury-free thermometers and blood pressure meters and called on dentists, medical technicians, and environmental health specialists to start eliminating this toxin. , mercury thermometers were still on sale to the public at pharmacies.


title: Mercury-in-glass thermometer

text: There was a voluntary take-back action for thermometers containing mercury based on the Federal Waste Management Plan 2006, and carried out in close cooperation between the Austrian Chamber of Pharmacists (Österreichische Apothekerkammer), the Federal Ministry of Environment, a private waste disposer, a producer of electronic thermometers and a pharmaceutical distributor. The disposal company supplied each pharmacy (approximately 1,200) with a collection bin and covered the cost of disposal. The pharmaceutical distributor covered the logistical costs for the distribution of the thermometers. The pharmacies accepted a refund of only 0.50 Euro per thermometer for handling (which is far below their normal margin). The supplier provided the thermometers at a reduced price. The Federal Ministry supported each sold thermometer (covering about 30% of the direct costs) and advertised the project. During the collection period, consumers could bring in a mercury thermometer and buy an electronic thermometer for a subsidised price of 1 Euro. Between October 2007 and January 2008, about 465,000 electronic thermometers were sold and about one million mercury thermometers (together containing about 1 tonne of mercury) were collected.


title: Mercury-in-glass thermometer

text: By the Philippines Department of Health’s Administrative Order 2008-0221, all mercury equipment from hospitals, including mercury-in-glass thermometers, will be phased out in the Philippines by September 28, 2010. Even before the order was released, 50 hospitals have already banned mercury from their establishments. Among these fifty hospitals, the Philippine Heart Center was the first one to do so. San Juan de Dios Hospital, Philippine Children’s Medical Center, San Lazaro Hospital, Ospital ng Muntinlupa, Lung Center of the Philippines, the National Kidney and Transplant Institute, Manila Adventist Medical Center and Las Piñas Hospital also made steps to ban the toxic chemical. The country was the first one to make a step to ban mercury from its health care system in Southeast Asia.


title: Mercury-in-glass thermometer

text: Since European Union directive 2007/51/EC came into force on 3 April 2009, the UK Health Protection Agency (HPA) reported that mercury thermometers could no longer be sold to the general public. Shops holding stocks of unsold thermometers had to withdraw them from sale; mercury thermometers purchased before this date could be used without legal implications. The purpose of these restrictions is to protect the environment and public health by decreasing the amount of mercury waste released. The HPA had, in 2007, released a guide to dealing with small spills of mercury.


title: Mercury-in-glass thermometer

text: Despite the phasing-out of mercury thermometers in the United Kingdom, British media continues to refer to temperature measurements, especially for weather forecasts, as "the mercury".


title: Mercury-in-glass thermometer

text: In the United States, both the American Academy of Pediatrics and the United States Environmental Protection Agency recommend that alternative thermometers be used in the home.


title: Thierry Baudet

text: Thierry Henri Philippe Baudet (; born 28 January 1983) is a Dutch far-right politician, author and self-declared conspiracy theorist. He is the founder and leader of Forum for Democracy (FvD), and has been a member of the House of Representatives since 2017. He also serves as the party's parliamentary leader. He is a controversial politician due to his political views, his promotion of conspiracy theories and disinformation, and his use of personal attacks against his opponents.


title: Thierry Baudet

text: Baudet was born in Heemstede into a family of partial Walloon ancestry. His forefather, Pierre Joseph Baudet, immigrated to the Batavian Republic in 1795 when his home in Hainaut was annexed by the French Republic, fleeing from conscription into the French Army. Baudet's great-great-grandmother, Ernestine van Heemskerck, was born in the Dutch East Indies and was of partly Indonesian parentage.


title: Thierry Baudet

text: Baudet attended a Haarlem gymnasium, a college preparatory school with compulsory Latin and Ancient Greek. His first degree, from the University of Amsterdam, was in history, and from 2007 to 2012 he was a PhD student at Leiden University (assisting in lecturing, but not constituting a "Lecturer" position as understood in the AngloSaxon academic world, as he misleadingly has been claiming in the past), where in 2012 he graduated as a Doctor of Philosophy with a thesis on national identity, European identity, and multiculturalism. The dissertation was directed by Leiden professor Paul Cliteur and the British philosopher Roger Scruton and was published in Dutch as "The Attack on the Nation-State". An English translation was also published, called "The Significance of Borders".


title: Thierry Baudet

text: Baudet was a post-doctoral fellow at Tilburg University in 2013. He also wrote a newspaper column in "NRC Handelsblad" from 2011 to 2012.


title: Thierry Baudet

text: In 2016, he founded the Forum for Democracy (FvD, ), which became a political party, and he was elected along with Theo Hiddema to the House of Representatives in the 2017 general election.


title: Thierry Baudet

text: Baudet had his personal piano installed in his parliamentary office in the Hague. In 2018, he said that his current girlfriend was an Iranian refugee.


title: Thierry Baudet

text: Baudet is a national conservative and Eurosceptic, advocating for both the Netherlands' exit from the European Union and the eventual dissolution of the EU. He is against unskilled immigration into the Netherlands. In a speech he described immigration as causing a homeopathic dilution of the Dutch culture, and in an interview said he wants to preserve the native cultures and ethnicities of Europe as they are.


title: Thierry Baudet

text: Baudet is opposed to the European Union–Ukraine Association Agreement. Together with GeenStijl and the Burgercomité EU association, Forum for Democracy was one of the behind the campaign to collect the signatures required for the 2016 Dutch Ukraine–European Union Association Agreement referendum. Baudet and Forum for Democracy campaigned for the "No"-vote in this referendum. During the campaign, Baudet at multiple occasions spread fake news, including false reports of purported crimes by the Ukrainian military, and associated himself with pro-Russian activist Vladimir Kornilov.


title: Thierry Baudet

text: In November 2016, Baudet co-signed a letter, initiated by the journalists Billy Six and Joost Niemöller, which questioned the independence of the MH17 investigations and requested Donald Trump to press for a new investigation. This led to criticism from surviving relatives. In May 2018, he supported the Dutch cabinet in holding Russia accountable for the MH17 shootdown incident. Baudet's WhatsApp chats were leaked to the media in 2020; these revealed his close contacts with Vladimir Kornilov, who Baudet described as "a Russian paid by Putin", and demonstrated a significant influence of Kornilov on Baudet's actions on Ukraine, the referendum and future anti-NATO campaigns. In the chats with his FvD colleagues, Baudet also alluded to financial support from Kornilov. Baudet disagreed with the conclusions drawn from these texts, and said that the text messages were quoted out of context. In February 2022, after Russia officially recognized separatist regions in Ukraine as independent nations and deployed military troops to the Donbas, Baudet voiced his approval of Vladimir Putin's actions. On 24 February 2022, during the Russian invasion of Ukraine, Baudet stated that Russia was "unnecessarily being vilified". During a debate in parliament on February 28, he explicitly refused to condemn the invasion. In August 2022, Baudet described Putin as "a huge hero" fighting a "heroic" fight against "globalists".


title: Thierry Baudet

text: Baudet has strong opinions on the arts, the topic of his book "Oikofobie"; he considers non-Western art and Western post-1900 modernism in visual arts inferior to Western Realism, encourages education and programmation of tonal music opposed to atonal music, and dislikes modern post-1950 architecture. In reaction to this, musicologist Yuri Landman warned Baudet for approaching the concept of degenerate art with his conservative criticism.


title: Thierry Baudet

text: Baudet frequently speaks about the perceived existence of a "party cartel", in which the main ruling parties of the Netherlands divide power among themselves and conspire towards the same goals, despite claiming to be competitors.


title: Thierry Baudet

text: He is not religious, but he expressed sympathy for Christianity on several occasions. In an interview in 2017, he called himself an "agnostic cultural Christian". In an interview in 2022, however, he distanced himself from this religion, saying it's a belief "for losers" that "lacks masculinity."


title: Thierry Baudet

text: Baudet is critical of Islam and has expressed concern about both high levels and lack of assimilation of migrants from Islamic societies. He has stated his disagreement with the proposals made by another Dutch politician, Geert Wilders, to ban copies of the Quran. Meanwhile, he also praised Wilders as someone who "has put on the agenda the significant problem that we have with radical Islam in our time and Muslim immigration". Baudet has called for Islamic schools in the Netherlands to sign up with Western values. He has criticised both Dutch and wider European handling of immigration and assimilation. During the 2017 Dutch general election, Baudet was one of the few Dutch politicians who said he would form a coalition with Wilders' Party for Freedom. Baudet has also expressed admiration for murdered Dutch politician Pim Fortuyn, and both ideological and personality comparisons between the two men have been made by both Dutch and overseas media.


title: Thierry Baudet

text: In February 2018, Baudet was confronted with the question of whether there is a relation between IQ and race in a debate with Femke Halsema. Hiddema and the number two on Baudet's party list for the 2018 Dutch municipal elections in Amsterdam, Yernaz Ramautarsing, stated they believed it to be true while Baudet refused to answer the question. Deputy Prime Minister Kajsa Ollongren stated that Forum for Democracy is a bigger threat than the Party for Freedom and that members have an unhealthy fascination for race differences; Baudet made a complaint for defamation at an Amsterdam police station. Hiddema supported him as his advocate. In February 2021, "Elsevier" reported it had uncovered WhatsApp messages sent by Baudet to fellow party members, in which he claims white people have a higher IQ than Hispanics and African-Americans. Baudet and several other members reportedly also sent messages in which they used racial slurs and expressed their opposition to interracial relationships.


title: Thierry Baudet

text: Baudet is an adherent of the Cultural Marxism conspiracy theory that suggests a calculated effort to destroy Western culture by academic and intellectual means. Baudet accuses the European Union of being "a Cultural Marxist project, with the aim of destroying European Civilization".


title: Thierry Baudet

text: Baudet has been alleged to have stated that COVID-19 was introduced by George Soros to "steal freedom", a claim he denies. He has also allegedly made anti-semitic comments. Following these claims in November 2020, published by one of his party's Senators, Baudet temporarily resigned as leader of the party and the party allegedly split. Soon he returned as party leader, but by then many party members had left Forum for Democracy, including the majority of the Senators and all of the party's members of the European Parliament.


title: Thierry Baudet

text: In 2021, Baudet responded to an article about the migrant population of Brussels by tweeting that an "escape-strategy, Madagascar or something" was needed. This was widely perceived as a reference to the Madagascar Plan, the plan by the government of Nazi Germany to forcibly relocate the entire European Jewish population to Madagascar.


title: Thierry Baudet

text: Baudet and Members of Parliament of his party have repeatedly compared measures to combat the spread of COVID-19 to the persecution of Jews by Nazi Germany. In May 2021, this led to another split in the party. In September 2021, Baudet attended a protest against the measures to combat COVID-19, in which several protesters wore Jewish badges, which drew condemnation. This led five Jewish organisations to ask parliament to explicitly distance itself from comparisons of the measures with the persecution of Jews and the Holocaust. In response, Baudet issued a tweet in which he stated that Jewish organisations "do not own the war", and wrote the word "Holocaust" within quotation marks, which was interpreted as an antisemitic dog whistle. Baudet was widely condemned by other politicians and Jewish organisations. He is pro-Russian, and has said that the 2022 war in Ukraine is the fault of the West. He also stated that the September 11 attacks were false flag operations, implemented by the government of the USA.


title: Thierry Baudet

text: In an October 2022 interview, Baudet promoted the conspiracy theory that the world is controlled by "evil reptilians". He also said he was a fan of Vladimir Putin, whom he called "a hero we need". He said the Russian president is the only one who can take on the elite. He believes Putin must win the war against Ukraine and says "we must do everything we can to support him".


title: Sol–gel process

text: In materials science, the sol–gel process is a method for producing solid materials from small molecules. The method is used for the fabrication of metal oxides, especially the oxides of silicon (Si) and titanium (Ti). The process involves conversion of monomers into a colloidal solution ("sol") that acts as the precursor for an integrated network (or "gel") of either discrete particles or network polymers. Typical precursors are metal alkoxides. Sol-gel process is used to produce ceramic nanoparticles.


title: Sol–gel process

text: In this chemical procedure, a "sol" (a colloidal solution) is formed that then gradually evolves towards the formation of a gel-like diphasic system containing both a liquid phase and solid phase whose morphologies range from discrete particles to continuous polymer networks. In the case of the colloid, the volume fraction of particles (or particle density) may be so low that a significant amount of fluid may need to be removed initially for the gel-like properties to be recognized. This can be accomplished in any number of ways. The simplest method is to allow time for sedimentation to occur, and then pour off the remaining liquid. Centrifugation can also be used to accelerate the process of phase separation.


title: Sol–gel process

text: Removal of the remaining liquid (solvent) phase requires a drying process, which is typically accompanied by a significant amount of shrinkage and densification. The rate at which the solvent can be removed is ultimately determined by the distribution of porosity in the gel. The ultimate microstructure of the final component will clearly be strongly influenced by changes imposed upon the structural template during this phase of processing.


title: Sol–gel process

text: Afterwards, a thermal treatment, or firing process, is often necessary in order to favor further polycondensation and enhance mechanical properties and structural stability via final sintering, densification, and grain growth. One of the distinct advantages of using this methodology as opposed to the more traditional processing techniques is that densification is often achieved at a much lower temperature.


title: Sol–gel process

text: The precursor sol can be either deposited on a substrate to form a film (e.g., by dip-coating or spin coating), cast into a suitable container with the desired shape (e.g., to obtain monolithic ceramics, glasses, fibers, membranes, aerogels), or used to synthesize powders (e.g., microspheres, nanospheres). The sol–gel approach is a cheap and low-temperature technique that allows the fine control of the product's chemical composition. Even small quantities of dopants, such as organic dyes and rare-earth elements, can be introduced in the sol and end up uniformly dispersed in the final product. It can be used in ceramics processing and manufacturing as an investment casting material, or as a means of producing very thin films of metal oxides for various purposes. Sol–gel derived materials have diverse applications in optics, electronics, energy, space, (bio)sensors, medicine (e.g., controlled drug release), reactive material, and separation (e.g., chromatography) technology.


title: Sol–gel process

text: The interest in sol–gel processing can be traced back in the mid-1800s with the observation that the hydrolysis of tetraethyl orthosilicate (TEOS) under acidic conditions led to the formation of SiO in the form of fibers and monoliths. Sol–gel research grew to be so important that in the 1990s more than 35,000 papers were published worldwide on the process.


title: Sol–gel process

text: The sol–gel process is a wet-chemical technique used for the fabrication of both glassy and ceramic materials. In this process, the sol (or solution) evolves gradually towards the formation of a gel-like network containing both a liquid phase and a solid phase. Typical precursors are metal alkoxides and metal chlorides, which undergo hydrolysis and polycondensation reactions to form a colloid. The basic structure or morphology of the solid phase can range anywhere from discrete colloidal particles to continuous chain-like polymer networks.


title: Sol–gel process

text: The term "colloid" is used primarily to describe a broad range of solid-liquid (and/or liquid-liquid) mixtures, all of which contain distinct solid (and/or liquid) particles which are dispersed to various degrees in a liquid medium. The term is specific to the size of the individual particles, which are larger than atomic dimensions but small enough to exhibit Brownian motion. If the particles are large enough, then their dynamic behavior in any given period of time in suspension would be governed by forces of gravity and sedimentation. But if they are small enough to be colloids, then their irregular motion in suspension can be attributed to the collective bombardment of a myriad of thermally agitated molecules in the liquid suspending medium, as described originally by Albert Einstein in his dissertation. Einstein concluded that this erratic behavior could adequately be described using the theory of Brownian motion, with sedimentation being a possible long-term result. This critical size range (or particle diameter) typically ranges from tens of angstroms (10 m) to a few micrometres (10 m).


title: Sol–gel process

text: In either case (discrete particles or continuous polymer network) the sol evolves then towards the formation of an inorganic network containing a liquid phase (gel). Formation of a metal oxide involves connecting the metal centers with oxo (M-O-M) or hydroxo (M-OH-M) bridges, therefore generating metal-oxo or metal-hydroxo polymers in solution.


title: Sol–gel process

text: In both cases (discrete particles or continuous polymer network), the drying process serves to remove the liquid phase from the gel, yielding a micro-porous amorphous glass or micro-crystalline ceramic. Subsequent thermal treatment (firing) may be performed in order to favor further polycondensation and enhance mechanical properties.


title: Sol–gel process

text: With the viscosity of a sol adjusted into a proper range, both optical quality glass fiber and refractory ceramic fiber can be drawn which are used for fiber optic sensors and thermal insulation, respectively. In addition, uniform ceramic powders of a wide range of chemical composition can be formed by precipitation.


title: Sol–gel process

text: The Stöber process is a well-studied example of polymerization of an alkoxide, specifically TEOS. The chemical formula for TEOS is given by Si(OCH), or Si(OR), where the alkyl group R = CH. Alkoxides are ideal chemical precursors for sol–gel synthesis because they react readily with water. The reaction is called hydrolysis, because a hydroxyl ion becomes attached to the silicon atom as follows:


title: Sol–gel process

text: Depending on the amount of water and catalyst present, hydrolysis may proceed to completion to silica:


title: Sol–gel process

text: Complete hydrolysis often requires an excess of water and/or the use of a hydrolysis catalyst such as acetic acid or hydrochloric acid. Intermediate species including [(OR)−Si−(OH)] or [(OR)−Si−(OH)] may result as products of partial hydrolysis reactions. Early intermediates result from two partially hydrolyzed monomers linked with a siloxane [Si−O−Si] bond:


title: Sol–gel process

text: Thus, polymerization is associated with the formation of a 1-, 2-, or 3-dimensional network of siloxane [Si−O−Si] bonds accompanied by the production of H−O−H and R−O−H species.


title: Sol–gel process

text: By definition, condensation liberates a small molecule, such as water or alcohol. This type of reaction can continue to build larger and larger silicon-containing molecules by the process of polymerization. Thus, a polymer is a huge molecule (or macromolecule) formed from hundreds or thousands of units called monomers. The number of bonds that a monomer can form is called its functionality. Polymerization of silicon alkoxide, for instance, can lead to complex branching of the polymer, because a fully hydrolyzed monomer Si(OH) is tetrafunctional (can branch or bond in 4 different directions). Alternatively, under certain conditions (e.g., low water concentration) fewer than 4 of the OR or OH groups (ligands) will be capable of condensation, so relatively little branching will occur. The mechanisms of hydrolysis and condensation, and the factors that bias the structure toward linear or branched structures are the most critical issues of sol–gel science and technology. This reaction is favored in both basic and acidic conditions.


title: Sol–gel process

text: Sonication is an efficient tool for the synthesis of polymers. The cavitational shear forces, which stretch out and break the chain in a non-random process, result in a lowering of the molecular weight and poly-dispersity. Furthermore, multi-phase systems are very efficient dispersed and emulsified, so that very fine mixtures are provided. This means that ultrasound increases the rate of polymerisation over conventional stirring and results in higher molecular weights with lower polydispersities. Ormosils (organically modified silicate) are obtained when silane is added to gel-derived silica during sol–gel process. The product is a molecular-scale composite with improved mechanical properties. Sono-Ormosils are characterized by a higher density than classic gels as well as an improved thermal stability. An explanation therefore might be the increased degree of polymerization.


title: Sol–gel process

text: For single cation systems like SiO and TiO, hydrolysis and condensation processes naturally give rise to homogenous compositions. For systems involving multiple cations, such as strontium titanate, SrTiO and other perovskite systems, the concept of steric immobilisation becomes relevant. To avoid the formation of multiple phases of binary oxides as the result of differing hydrolysis and condensation rates, the entrapment of cations in a polymer network is an effective approach, generally termed the Pechini Process. In this process, a chelating agent is used, most often citric acid, to surround aqueous cations and sterically entrap them. Subsequently, a polymer network is formed to immobilize the chelated cations in a gel or resin. This is most often achieved by poly-esterification using ethylene glycol. The resulting polymer is then combusted under oxidising conditions to remove organic content and yield a product oxide with homogeneously dispersed cations.


title: Sol–gel process

text: In the processing of fine ceramics, the irregular particle sizes and shapes in a typical powder often lead to polydisperse (non-uniform) packing morphologies that result in packing density variations in the powder compact. Uncontrolled flocculation of powders due to attractive van der Waals forces can also give rise to microstructural heterogeneities.


title: Sol–gel process

text: Differential stresses that develop as a result of non-uniform drying shrinkage are directly related to the rate at which the solvent can be removed, and thus highly dependent upon the distribution of porosity. Such stresses have been associated with a plastic-to-brittle transition in consolidated bodies, and can yield to crack propagation in the unfired body if not relieved.


title: Sol–gel process

text: In addition, any fluctuations in packing density in the compact as it is prepared for the kiln are often amplified during the sintering process, yielding heterogeneous densification.


title: Sol–gel process

text: Some pores and other structural defects associated with density variations have been shown to play a detrimental role in the sintering process by growing and thus limiting end-point densities. Differential stresses arising from heterogeneous densification have also been shown to result in the propagation of internal cracks, thus becoming the strength-controlling flaws.


title: Sol–gel process

text: It would therefore appear desirable to process a material in such a way that it is physically uniform with regard to the distribution of components and porosity, rather than using particle size distributions which will maximize the green density. The containment of a uniformly dispersed assembly of strongly interacting particles in suspension requires total control over particle-particle interactions. Monodisperse colloids provide this potential.


title: Sol–gel process

text: Monodisperse powders of colloidal silica, for example, may therefore be stabilized sufficiently to ensure a high degree of order in the colloidal crystal or polycrystalline colloidal solid which results from aggregation. The degree of order appears to be limited by the time and space allowed for longer-range correlations to be established. Such defective polycrystalline structures would appear to be the basic elements of nanoscale materials science, and, therefore, provide the first step in developing a more rigorous understanding of the mechanisms involved in microstructural evolution in inorganic systems such as sintered ceramic nanomaterials.


title: Sol–gel process

text: The applications for sol gel-derived products are numerous. For example, scientists have used it to produce the world's lightest materials and also some of its toughest ceramics.


title: Sol–gel process

text: One of the largest application areas is thin films, which can be produced on a piece of substrate by spin coating or dip-coating. Protective and decorative coatings, and electro-optic components can be applied to glass, metal and other types of substrates with these methods. Cast into a mold, and with further drying and heat-treatment, dense ceramic or glass articles with novel properties can be formed that cannot be created by any other method. Other coating methods include spraying, electrophoresis, inkjet printing, or roll coating.


title: Sol–gel process

text: With the viscosity of a sol adjusted into a proper range, both optical and refractory ceramic fibers can be drawn which are used for fiber optic sensors and thermal insulation, respectively. Thus, many ceramic materials, both glassy and crystalline, have found use in various forms from bulk solid-state components to high surface area forms such as thin films, coatings and fibers. Also, thin films have found their application in the electronic field and can be used as sensitive components of a resistive gas sensors.


title: Sol–gel process

text: Ultra-fine and uniform ceramic powders can be formed by precipitation. These powders of single and multiple component compositions can be produced at a nanoscale particle size for dental, biomedical, agrochemical, or catalytic applications. Powder abrasives, used in a variety of finishing operations, are made using a sol–gel type process. One of the more important applications of sol–gel processing is to carry out zeolite synthesis. Other elements (metals, metal oxides) can be easily incorporated into the final product and the silicate sol formed by this method is very stable. Semi-stable metal complexes can be used to produce sub-2nm oxide particles without thermal treatment. During base-catalyzed synthesis, hydroxo (M-OH) bonds may be avoided in favor of oxo (M-O-M) using a ligand which is strong enough to prevent reaction in the hydroxo regime but weak enough to allow reaction in the oxo regime (see Pourbaix diagram).


title: Sol–gel process

text: Another application in research is to entrap biomolecules for sensory (biosensors) or catalytic purposes, by physically or chemically preventing them from leaching out and, in the case of protein or chemically-linked small molecules, by shielding them from the external environment yet allowing small molecules to be monitored. The major disadvantages are that the change in local environment may alter the functionality of the protein or small molecule entrapped and that the synthesis step may damage the protein. To circumvent this, various strategies have been explored, such as monomers with protein friendly leaving groups (e.g. glycerol) and the inclusion of polymers which stabilize protein (e.g. PEG).


title: Sol–gel process

text: Other products fabricated with this process include various ceramic membranes for microfiltration, ultrafiltration, nanofiltration, pervaporation, and reverse osmosis. If the liquid in a wet gel is removed under a supercritical condition, a highly porous and extremely low density material called aerogel is obtained. Drying the gel by means of low temperature treatments (25-100 °C), it is possible to obtain porous solid matrices called xerogels. In addition, a sol–gel process was developed in the 1950s for the production of radioactive powders of UO and ThO for nuclear fuels, without generation of large quantities of dust.


title: Sol–gel process

text: Macroscopic optical elements and active optical components as well as large area hot mirrors, cold mirrors, lenses, and beam splitters all with optimal geometry can be made quickly and at low cost via the sol–gel route. In the processing of high performance ceramic nanomaterials with superior opto-mechanical properties under adverse conditions, the size of the crystalline grains is determined largely by the size of the crystalline particles present in the raw material during the synthesis or formation of the object. Thus a reduction of the original particle size well below the wavelength of visible light (~500 nm) eliminates much of the light scattering, resulting in a translucent or even transparent material.


title: Sol–gel process

text: Furthermore, results indicate that microscopic pores in sintered ceramic nanomaterials, mainly trapped at the junctions of microcrystalline grains, cause light to scatter and prevented true transparency. it has been observed that the total volume fraction of these nanoscale pores (both intergranular and intragranular porosity) must be less than 1% for high-quality optical transmission, i.e. the density has to be 99.99% of the theoretical crystalline density.


title: Sol–gel process

text: Unique properties of the sol–gel provide the possibility of their use for a variety of medical applications. A sol–gel processed alumina can be used as a carrier for the sustained delivery of drugs and as an established wound healer. A marked decrease in scar size was observed because of the wound healing composite including sol–gel processed alumina. A novel approach to thrombolysis treatment is possible by developing a new family of injectable composites: plasminogen activator entrapped within alumina.


title: Gunboat

text: A gunboat is a naval watercraft designed for the express purpose of carrying one or more guns to bombard coastal targets, as opposed to those military craft designed for naval warfare, or for ferrying troops or supplies.


title: Gunboat

text: In the age of sail, a gunboat was usually a small undecked vessel carrying a single smoothbore cannon in the bow, or just two or three such cannons. A gunboat could carry one or two masts or be oar-powered only, but the single-masted version of about length was most typical. Some types of gunboats carried two cannons, or else mounted a number of swivel guns on the railings.


title: Gunboat

text: The small gunboat had advantages: if it only carried a single cannon, the boat could manoeuvre in shallow or restricted areas – such as rivers or lakes – where larger ships could sail only with difficulty. The gun that such boats carried could be quite heavy; a 32-pounder for instance. As such boats were cheap and quick to build, naval forces favoured swarm tactics: while a single hit from a frigate's broadside would destroy a gunboat, a frigate facing a large squadron of gunboats could suffer serious damage before it could manage to sink them all. For example: in the Battle of Alvøen (1808) during the Gunboat War of 1807–1814, five Dano-Norwegian gunboats defeated the lone frigate . Gunboats used in the Battle of Valcour Island (1776) on Lake Champlain during the American Revolutionary War were mostly built on the spot, attesting to the speed of their construction.


title: Gunboat

text: All navies of the sailing era kept a number of gunboats on hand. Gunboats saw extensive use in the Baltic Sea during the late 18th century as they were well-suited for the extensive coastal skerries and archipelagoes of Sweden, Finland and Russia. The rivalry between Sweden and Russia, in particular, led to an intense expansion of gunboat fleets and the development of new gunboat types. The two countries clashed during the Russo-Swedish war of 1788–90, a conflict that culminated in the massive Battle of Svensksund in 1790, in which over 30,000 men and hundreds of gunboats, galleys and other oared craft took part. The majority of these were vessels developed from the 1770s and onwards by the naval architect Fredrik Henrik af Chapman for the Swedish archipelago fleet. The designs, copied and refined by the rival Danish and Russian navies, spread to the Mediterranean and to the Black Sea.


title: Gunboat

text: Many of the Baltic navies kept gunboats in service well into the second half of the 19th century. British ships engaged larger Russian gunboats off Turku in southeast Finland in 1854 during the Crimean War. The Russian vessels had the distinction of being the last oared vessels of war in history to fire their guns in anger.


title: Gunboat

text: Gunboats played a key role in Napoleon Bonaparte's plan for the invasion of England in 1804. Denmark-Norway used them heavily in the Gunboat War. Between 1803 and 1812 the United States Navy had a policy of basing its navy on coastal gunboats, experimenting with a variety of designs. President Thomas Jefferson (in office: 1801–1809) and his Democratic-Republican Party opposed a strong navy, regarding gunboats as adequate to defend the United States' major harbors. They proved useless against the British blockade during the War of 1812.


title: Gunboat

text: With the introduction of steam power in the early 19th century, the Royal Navy and other navies built considerable numbers of small vessels propelled by side paddles and later by screws. Initially, these vessels retained full sailing rigs and used steam engines for auxiliary propulsion.


title: Gunboat

text: The British Royal Navy deployed two wooden paddle-gunboats in the Lower Great Lakes and St. Lawrence River during the Rebellions of 1837 in Upper and Lower Canada. The United States Navy deployed an iron-hulled paddle gunboat, , to the Great Lakes in 1844.


title: Gunboat

text: Britain built a large number of wooden screw-gunboats during the 1850s, some of which participated in the Crimean War (1853–1856), Second Opium War (1856–1860) and Indian Mutiny (1857–1859). The requirement for gunboats in the Crimean War was formulated in 1854 to allow the Royal Navy to bombard shore facilities in the Baltic. The first ships the Royal Navy built that met this requirement were the s. Then in mid-1854 the Royal Navy ordered six s followed later in the year by an order for 20 s. In May 1855 the Royal Navy deployed six "Dapper"-class gunboats in the Sea of Azov, where they repeatedly raided and destroyed stores around its coast. In June 1855 the Royal Navy reentered the Baltic with a total of 18 gunboats as part of a larger fleet. The gunboats attacked various coastal facilities, operating alongside larger British warships from which they drew supplies such as coal.


title: Gunboat

text: Gunboats experienced a revival during the American Civil War (1861–1865). Union and Confederate forces quickly converted existing passenger-carrying boats into armed sidewheel steamers. Later, some purpose-built boats, such as , joined the fray. They frequently mounted 12 or more guns, sometimes of rather large caliber, and usually carried some armor. At the same time, Britain's gunboats from the Crimean War period were starting to wear out, so a new series of classes was ordered. Construction shifted from a purely wooden hull to an iron–teak composite.


title: Gunboat

text: In the later 19th century and early 20th century, "gunboat" was the common name for smaller armed vessels. These could be classified, from the smallest to the largest, into river gunboats, river monitors, coastal-defense gunboats (such as ), and full-fledged monitors for coastal bombardments. In the 1870s and 1880s, Britain took to building so-called "flat-iron" (or Rendel) gunboats for coastal defence. When there would be few opportunities to re-coal, vessels carrying a full sailing rig continued in use as gunboats; , a sloop preserved at Chatham Historic Dockyard in the United Kingdom, exemplifies this type of gunboat.


title: Gunboat

text: In the United States Navy, these boats had the hull classification symbol "PG", which led to their being referred to as "patrol gunboats". They usually displaced under , were about long, draught and sometimes much less, and mounted several guns of calibers up to . An important characteristic of these was the ability to operate in rivers, enabling them to reach inland targets in a way not otherwise possible before the development of aircraft. In this period the naval powers used gunboats for police actions in colonies or in weaker countries, for example in China (see e.g. Yangtze Patrol). This category of gunboat inspired the term "gunboat diplomacy". With the addition of torpedoes, they became "torpedo gunboats", designated by the hull classification symbol "PTG" (Patrol Torpedo Gunboat).


title: Gunboat

text: In Britain, Admiral Fisher's reforms in the 1900s saw the disposal of much of the gunboat fleet. A handful remained in service in various roles at the start of World War I in 1914. The last in active service were two of the second which survived until 1926, carrying out river patrols in west Africa.


title: Gunboat

text: In the circumstances of World War I (1914–1918), however, the Royal Navy re-equipped with small , shallow-draught gunboats (12 ships of the ) with sufficient speed to operate in fast-flowing rivers and with relatively heavy armament. During the war and in the post-war period, these were deployed in Romania on the Danube, in Mesopotamia on the Euphrates and Tigris, in northern Russia on the Northern Dvina and in China on the Yangtze. In China, during anarchic and war conditions, they continued to protect British interests until World War II; other western Powers acted similarly.


title: Gunboat

text: More and larger gunboats were built in the late 1930s for the Far East. Some sailed there; others were transported in sections and reassembled at Shanghai.


title: Gunboat

text: Most British gunboats were based initially in East Asia. When war with Japan broke out, many of these vessels withdrew to the Indian Ocean. Others were given to the Republic of China Navy (such as , which was renamed "Ying Hao") and some were captured by the Japanese.


title: Gunboat

text: Some were later redeployed to the Mediterranean theatre and supported land operations during the North African campaign, as well in parts of Southern Europe.


title: Gunboat

text: In late 1941 the US Navy's Yangtze Patrol boats based in China were withdrawn to the Philippines or scuttled. Following the US defeat in the Philippines most of the remaining craft were scuttled. However, survived until being sunk in action during the Battle of Java in 1942.


title: Gunboat

text: During the 1930s, the Soviet Navy began developing small armoured riverboats or "riverine tanks": vessels displacing 26 to 48 tons, on which the turrets of tanks were mounted.


title: Gunboat

text: With crews of 10 to 20 personnel, riverine tanks displaced 26 to 48 tons, had armour 4–14 mm thick, and were 23 to 25 metres long. They saw significant action in the Baltic and Black Seas between 1941 and 1945.


title: Gunboat

text: US riverine gunboats in the Vietnam War, included Patrol Boats River (PBR), constructed of fiberglass; Patrol Craft Fast (PCF), commonly known as Swift Boats, built of aluminum; and Assault Support Patrol Boats (ASPB) built of steel. U.S. Coast Guard 82-foot s supplemented these US Navy vessels. The ASPBs were commonly referred to as "Alpha" boats and primarily carried out mine-sweeping duties along the waterways, due to their all-steel construction. The ASPBs were the only US Navy riverine craft specifically designed and built for the Vietnam War. All of these boats were assigned to the US Navy's "Brownwater Navy".


title: Corruption in the United States

text: Corruption in the United States is the act of government officials abusing their political powers for private gain, typically through bribery or other methods, in the United States government. Corruption in the United States has been a perennial political issue, peaking in the Jacksonian era and the Gilded Age before declining with the reforms of the Progressive Era.


title: Corruption in the United States

text: As of 2022 the United States is the 27th least corrupt country according to the Corruption Perceptions Index.


title: Corruption in the United States

text: Corruption in the United States dates back to the founding of the country. The American Revolution was, in part, a response to the perceived corruption of the British monarchy. Separation of powers was developed to enable accountability. Freedom of association also served this end, allowing citizens to organize independently of the government. This was in contrast to some European powers at the time where all associations and economic activities were implicitly managed by the government.


title: Corruption in the United States

text: During the 1st United States Congress, Secretary of the Treasury Alexander Hamilton proposed several new economic initiatives that involved taxes, tariffs, debts, and a national bank. Fears that these proposals would lead to corruption grew so great that the Democratic-Republican Party was formed to oppose them.


title: Corruption in the United States

text: Corruption reemerged as a major theme in American politics in the 1824 United States presidential election, where Andrew Jackson ran as an anti-corruption candidate. The issue was only exasperated by the controversial results of the election preventing Jackson's victory, known as the corrupt bargain. Following Jackson's victory in the next election, a dispute over the national bank again became relevant in the issue of corruption.


title: Corruption in the United States

text: In state governments, authorities would authorize corporate charters to authorize the creation of new corporations. These faced some resistance due to their potential for corruption. While they were generally used in ways that promoted the economic development of the states, there were instances of charters being given preferential treatment to political allies. The Albany Regency, for example, authorized charters for banks in exchange for political and financial support. This issue was eventually solved as state governments standardized the process of incorporation throughout the 1840s.


title: Corruption in the United States

text: The Gilded Age was a period of increased prosperity and growth in the United States. This growth resulted in a corresponding increase of corruption and bribery in the government and in business. The main issue of contention was the spoils system, in which government jobs were given in exchange for political support. This issue was addressed by civil service reform.


title: Corruption in the United States

text: The Presidency of Ulysses S. Grant during the Gilded Age was mired with instances of corruption. Grant had been elected without political experience, and he had little ability to control or regulate the members of his government, who proceeded to take advantage of his inexperience. Notable examples include the Whiskey Ring, the Star Route scandal, and the trader post scandal. The Crédit Mobilier scandal also became public information at this time.


title: Corruption in the United States

text: The Progressive Era was a period of anti-corruption fervor in the United States led by the progressive movement. During this time, political machines and monopolies were targeted and disestablished. Theodore Roosevelt was a major figure in the Progressive Era, leading the efforts of trustbusting.


title: Corruption in the United States

text: The Teapot Dome scandal was a major instance of corruption during the Presidency of Warren G. Harding. Secretary of the Interior Albert B. Fall had accepted bribes from oil companies in exchange for access to government petroleum reserves. After the corruption was discovered, Fall was sentenced to prison.


title: Corruption in the United States

text: Richard Nixon was notably the subject of multiple corruption allegations. While running for Vice President in 1952, Nixon famously gave a speech declaring that he accepted one gift, a dog named Checkers, and that he had no intention of returning it. During Nixon's presidency, he was implicated in the Watergate scandal. Shortly before, his Vice President Spiro Agnew had been found guilty of tax fraud.


title: Corruption in the United States

text: In the 1970s, the FBI conducted the sting operation codenamed Abscam to uncover corruption in Congress. Seven members of Congress were convicted of bribery.


title: Corruption in the United States

text: The United States' perceived resistance to corruption has declined in recent years, dropping its rank as 18th in 2016 to 27th out of 180 on the Transparency International Corruption Perceptions Index of 2021. In 2019, Transparency International stated that the United States is "experiencing threats to its system of checks and balances", along with an "erosion of ethical norms at the highest levels of power", citing populism, nativism, and political polarization as factors that may increase corruption. Some state governments are also currently known to have corruption issues compared to other states with Louisiana, Illinois and Tennessee were labeled "The worst of the worst" in 2018.


title: Corruption in the United States

text: The FBI is responsible for investigating corruption in the United States with several initiatives to investigate both domestic and foreign corruption, and it recognizes public corruption as its "top criminal investigative priority".


title: Corruption in the United States

text: In 2019, Stephen Walt argued that the United States was becoming increasingly corrupt, pointing to the Trump administration, the causes of the Great Recession, the failure of the Boeing 737 MAX, and the 2019 college admissions bribery scandal as examples. Walt argues that these examples show that corruption is a growing problem in the United States and in the longer term threaten the country's soft power. The United States has been cited as a tax haven. The Foreign Account Tax Compliance Act make it so that foreign governments had to reveal American accounts abroad, though they made it so the US was also under no compunction, legal or otherwise, to share information on non-Americans opening up accounts in the US. In 2020 U.S. ranked second in the Financial Secrecy Index behind only the Cayman Islands. In 2016 one estimate placed the total offshore wealth in the US at $800 billion.


title: Hostile work environment

text: In United States labor law, a hostile work environment exists when one's behavior within a workplace creates an environment that is difficult or uncomfortable for another person to work in, due to illegal discrimination. Common complaints in sexual harassment lawsuits include fondling, suggestive remarks, sexually-suggestive photos displayed in the workplace, use of sexual language, or off-color jokes. Small matters, annoyances, and isolated incidents are usually not considered to be statutory violations of the discrimination laws. For a violation to impose liability, the conduct must create a work environment that would be intimidating, hostile, or offensive to a reasonable person. An employer can be held liable for failing to prevent these workplace conditions, unless it can prove that it attempted to prevent the harassment and that the employee failed to take advantage of existing harassment counter-measures or tools provided by the employer.


title: Hostile work environment

text: A hostile work environment may also be created when management acts in a manner designed to make an employee quit in retaliation for some action. For example, if an employee reported safety violations at work, was injured, attempted to join a union, or reported regulatory violations by management, and management's response was to harass and pressure the employee to quit. Employers have tried to force employees to quit by imposing unwarranted discipline, reducing hours, cutting wages, or transferring the complaining employee to a distant work location.


title: Hostile work environment

text: The United States Supreme Court stated in "Oncale v. Sundowner Offshore Services, Inc." that Title VII is "not a general civility code". Thus, federal law does not prohibit simple teasing, offhand comments, or isolated incidents that are not extremely serious. Rather, the conduct must be so objectively offensive as to alter the conditions of the individual's employment. The conditions of employment are altered only if the harassment culminates in a tangible employment action or is sufficiently severe or pervasive.


title: Hostile work environment

text: Where a hostile environment is alleged, the legality of behaviors must be determined on a case by case basis. In the workplace, such a claim focuses on the working conditions that must be experienced by the victim as a condition of employment, rather than on tangible job changes. To establish whether the situation is actionable the "totality of circumstances" must be weighed with an eye to determining "that the harassment affected a term, condition, or privilege of employment in that it was sufficiently severe or pervasive to alter the condition of the victim's employment and create an abusive working environment".


title: Hostile work environment

text: In many United States jurisdictions, a hostile work environment is not an independent legal claim. That is, an employee could not file a lawsuit on the basis of a hostile work environment alone. Instead, an employee must prove they have been treated in a hostile manner "because" of their membership in a protected class, such as gender, age, race, national origin, disability status, and similar protected traits. Importantly, the hostile work environment is gender neutral, that is, men can sexually harass men or women and women can sexually harass men or women.


title: Hostile work environment

text: Likewise, a hostile work environment can be considered the "adverse employment action" that is an element of a whistleblower claim or a reprisal (retaliation) claim under a civil rights statute. When an employee claims that a hostile work environment is an adverse employment action, the legal analysis is similar to the burdens of proof described above. However, to recover damages, the employee must also establish all other elements of the claim, such as that the employee engaged in protected conduct such as making a report of discrimination or reporting an employer's violation of law, and also establish that the employer created the hostile work environment, at least in part, because the employee engaged in the protected activity.


title: Lucius Artorius Castus

text: Lucius Artorius Castus (fl. 2nd century AD) was a Roman military commander. A member of the "gens Artoria" (possibly of Messapic or Etruscan origin), he has been suggested as a potential historical basis for King Arthur.


title: Lucius Artorius Castus

text: What little is known of Lucius Artorius Castus comes from inscriptions on fragments of a sarcophagus, and a memorial plaque, found in Podstrana, on the Dalmatian coast in Croatia. Although the inscriptions cannot be precisely dated, Castus probably served in the Roman army some time between the mid-late 2nd century AD or early to mid-3rd century AD.


title: Lucius Artorius Castus

text: The memorial inscription, which was broken into two pieces at some point prior to the 19th century and set into the wall of the Church of St Martin in Podstrana, Croatia, reads (note that ""7"" is a rendering of the symbol used by scribes to represent the word centurio; ligatured letters are indicated with underlines):


title: Lucius Artorius Castus

text: Manfred Clauss of the Epigraphik-Datenbank Clauss-Slaby (EDCS), following the readings and expansions provided in CIL 03, 01919; CIL 03, 08513; CIL 03, 12813; Dessau 2770; IDRE-02, 303; BritRom-07, 00001; JIES-2019-432 expands the text as:


title: Lucius Artorius Castus

text: <nowiki>*</nowiki>Note that the double -ff- in PRAEFF should be indicative of the plural (often dual), though it might be a scribal error here.


title: Lucius Artorius Castus

text: <nowiki>**</nowiki>Birley follows Pflaum's expansion of the text where [duaru]m "of two" is reinstated before Britanicimiarum. Previous editors have preferred to restore the word as "alarum" "to/for the alae", which may make better sense if "duci legg" is to be understood as the title dux legionum.


title: Lucius Artorius Castus

text: <nowiki>***</nowiki>Birley does not translate the final phrase, [...ex te]st(amento), which (if correct) should be rendered "...according to the terms of (his) will"


title: Lucius Artorius Castus

text: As of 2009, the two stone fragments bearing this inscription have been removed from the wall of the Church of St. Martin for scientific analysis and restoration; they have since been replaced by a copy. As of 2012 the large inscription had been cleaned and returned to display in the Chapel of St. Martin in Podstrana, Croatia. The smaller inscription is still in storage in the museum. The piece bearing the name Castus can still be located. The other two pieces sent for cleaning have been lost. The whereabouts of the fourth piece remains unknown.


title: Lucius Artorius Castus

text: The memorial plaque, which was discovered not far away from the first inscription and was also broken at some point prior to the 19th century, reads:


title: Lucius Artorius Castus

text: Which Clauss (following CIL 03, 12791 (p 2258, 2328,120); CIL 03, 14224; IDRE-02, 304), expands: <br>


title: Lucius Artorius Castus

text: L(ucius) Artorius | Castus p(rimus) p(ilus) | leg(ionis) V Ma[c(edonicae)] pr|aefec[t]us leg(ionis) | VI Victric(is)|[...]


title: Lucius Artorius Castus

text: Lucius Artorius Castus, Primus Pilus of the legion V Macedonica, Prefect of the Legion VI Victrix [...]


title: Lucius Artorius Castus

text: An undated, unprovenanced inscription on a stamp, supposedly discovered in Rome but recorded as being in Paris in the 19th century reads:


title: Lucius Artorius Castus

text: As inscription shows the text is in the genitive form. In fact, the rendered expansion will be Lucii Artorii Casti which means: (It belongs to) Lucius Artorius Castus.


title: Lucius Artorius Castus

text: Without further information on the inscription, we cannot say whether or not it refers to our Lucius Artorius Castus, or simply another man of the same name.


title: Lucius Artorius Castus

text: The first unit mentioned on Castus's inscription is the legio III Gallica – for most of the 2nd and 3rd centuries the unit was stationed in Syria. He held the rank of centurion in this legion – most Roman soldiers only achieved the rank of centurion after about 15–20 years of service, but it was not unknown for some politically connected civilians of the equestrian class to be directly commissioned as centurions upon entering the Army, though these equestrian centurions (known as "ex equite Romano") were in the minority. We cannot tell whether or not Castus had a lengthy career as a legionary soldier before attaining the centurionate, or whether he was directly commissioned at this rank, as the vast majority of career centurions' inscriptions do not mention any ranks that they might have held below the centurionate. Successful officers often omitted the record of any ranks lower than primus pilus, as Castus did on his memorial plaque.


title: Lucius Artorius Castus

text: From the middle of the 2nd century until at least the early 3rd century the legio VI Ferrata was stationed in Judea.


title: Lucius Artorius Castus

text: From the early 2nd century onward the legio II Adiutrix were based at Aquincum (modern Budapest) and took part in several notable campaigns against the Parthians, Marcomanni, Quadi and, in the mid-3rd century, the Sassanid empire.


title: Lucius Artorius Castus

text: The legio V Macedonica was based in Roman Dacia throughout the 2nd century and through most of the 3rd – the unit took part in battles against the Marcomanni, Sarmatians and Quadi.


title: Lucius Artorius Castus

text: The legio V Macedonica after 185 CE was called "Pia Fidelis" or "Pia Constans" (shortened as P.F. or P.C.), so Castus served in this unit as centurion and primus pilus before 185 CE (in the inscription these nicknames are missing).


title: Lucius Artorius Castus

text: Castus next acted as Provost (Praepositus) of the Misenum fleet in Italy. This title (generally given to "Equites") indicated a special command over a body of troops, but somewhat limited in action and subject to the Emperor's control.


title: Lucius Artorius Castus

text: The Legio VI Victrix was based in Britain from c. 122 AD onward, though their history during the 3rd century AD is rather hazy. Throughout the 2nd century AD and into the 3rd, the headquarters of the VI Victrix was at "Eboracum" (modern York). The unit was removed briefly to "Lugdunum" (Lyons) in 196 AD by Clodius Albinus, during his doomed revolt against the emperor Severus, but returned to York after the revolt was quelled – and the unit suffered a significant defeat – in 197 AD.


title: Lucius Artorius Castus

text: Castus's position in the Legio VI Victrix, Prefect of the Legion ("Praefectus Legionis"), was equivalent to that of the Praefectus Castrorum. Men who had achieved this title were normally 50–60 years old and had been in the army most of their lives, working their way up through the lower ranks and the centurionate until they reached Primus Pilus (the rank seems to have been held exclusively by primipilares ). They acted as third-in-command to the legionary commander, the legatus legionis, and senior tribune and could assume command in their absence. Their day-to-day duties included maintenance of the fortress and management of the food supplies, sanitation, munitions, equipment, etc. For most who had attained this rank, it would be their last before retirement. During battles, the Praefectus Castrorum normally remained at the unit's home base with the reserve troops, so, given his administrative position and (probably) advanced age, it is unlikely that Castus actually fought in any battles while serving in Britain.


title: Lucius Artorius Castus

text: Castus could have overseen vexillations of troops guarding Hadrian's Wall, but his inscriptions do not provide us with any precise information on where he might have served while in Britain. Given his duties as "Praefectus Legionis", it is reasonable to assume that he spent some – if not all – of his time in Britain at the VI Victrix's headquarters in York.


title: Lucius Artorius Castus

text: It is interesting that the title is spelled (P)RAEFF on Castus's sarcophagus – doubled letters at the end of abbreviated words on Latin inscriptions usually indicated the plural (often dual) and some legions are known to have had multiple praefecti castrorum. The title is given in the singular on the memorial plaque, though, so we might have a scribal error on the sarcophagus. If not, then Castus was probably one of two prefects of this legion.


title: Lucius Artorius Castus

text: Before finishing his military career, Castus led an expedition of some note as a Dux Legionum, a temporary title accorded to officers who were acting in a capacity above their rank, either in command of a collection of troops (generally combined vexillations drawn from legions) in transit from one station to another or in command of a complete unit (the former seems to be the case with Castus, since the units are spoken of in the genitive plural).


title: Lucius Artorius Castus

text: For many years it has been believed that Castus's expedition was against the Armoricans (based on the reading ADVERSUS ARM[...]S, reconstructed as "adversus *Armoricanos" – "against the Armoricans" – by Theodor Mommsen in the CIL and followed by most subsequent editors of the inscription), but the earliest published reading of the inscription, made by the Croatian archaeologist in 1850, was ADVERSUS ARME[...], with a ligatured ME (no longer visible on the stone, possibly due to weathering, since the stone has been exposed to the elements for centuries and was reused as part of a roadside wall next to the church of St. Martin in Podstrana; the mutilated word falls along the broken right-hand edge of the first fragment of the inscription). If Carrara's reading is correct, the phrase is most likely to be reconstructed as "adversus *Armenios", i.e. "against the Armenians", since no other national or tribal name beginning with the letters *Arme- is known from this time period.


title: Lucius Artorius Castus

text: The regional names Armoricani or Armorici are not attested in any other Latin inscriptions, whereas the country Armenia and derivatives such as the ethnic name Armenii and personal name Armeniacus are attested in numerous Latin inscriptions. Furthermore, no classical sources mention any military action taken against the Armorici/Armoricani (which was in origin a regional name that encompassed a number of different tribes) in the 2nd or 3rd centuries. While there are literary references to (and a small amount of archaeological evidence for) minor unrest in northwestern Gaul during this time period – often referred to as, or associated with, the rebellion of the Bagaudae, there is no evidence that the Bagaudae were connected with the Armorici/Armoricani, or any other particular tribe or region for that matter, making the possible reference to the Armorici/Armoricani somewhat strange (especially since Armorica otherwise experienced a period of prosperity in the late 2nd century AD, when some scholars believe that Castus's expedition took place). Armenia, on the other hand, was the location of several conflicts involving the Romans during the 2nd and 3rd centuries.


title: Lucius Artorius Castus

text: The alternate, "Armenian" translation was supported in 1881 by the epigrapher and classical scholar Emil Hübner, and most recently taken up again by the historian and epigrapher Xavier Loriot, who (based on the contextual and epigraphic evidence) suggests a floruit for Castus in the early mid-3rd century AD (Loriot's analysis of the inscription has recently been adopted by the Roman historians Anthony Birley and Marie-Henriette Quet).


title: Lucius Artorius Castus

text: With external wars against a foreign enemy the tribe or people are named. Another example from the Severan period reads: duci exercitus Illyrica expeditione Asiana item Parthica item Gallica, ’Leader of the Illyrican army on the Asian, Parthian and Gallic expeditions.’


title: Lucius Artorius Castus

text: There are also a number of literary and epigraphical pieces of evidence demonstrating Roman military campaigns in Armenia against Armenians.


title: Lucius Artorius Castus

text: In the Parthian War of AD 161-6 under Lucius Verus the general Priscus led the advance through Armenia and captured the Armenian capital at Artaxata. Marcus Aurelius and Lucius Verus subsequently awarded themselves the titles of Armeniacus, Parthicus, Medicus and pater patriae. Around ad 214–216 the Armenia King Khosrov I was imprisoned by the Romans. The Armenians rebelled and Caracalla sent Theocritus who led an army to defeat. However after a subsequent successful campaign Caracalla did eventually grant the Armenian crown to Tiridates II c. AD 217 and Armenia returned under Roman influence.


title: Lucius Artorius Castus

text: In the reign of Macrinus, AD 217-8, the Historia Augusta states there was a ‘dux Armeniae erat et item legatus Asiae atque Arabiae’. In c. AD 233 Severus Alexander launched a three prong attack against the Persians with the northern army invading through Armenia. Alexander drew troops from the Rhine and Danube on his march east, and we have various inscriptions dated to ad 232–5 honouring men who died in ‘expediteone Partica et Armeniaca’.


title: Lucius Artorius Castus

text: The name of the units that Castus led in this expedition, ""Britanicimiarum"", seems to be corrupt – it might be reconstructed as "*Britanniciniarum" or "*Britannicianarum". If so, they were probably units similar in nature to the "ala" and "cohors I Britannica" (also known as the "I Flavia Britannica" or" Britanniciana", among other titles), which were stationed in Britain in the mid-1st century AD, but removed to Vindobona in Pannonia by the late 80s AD (they would later take part in Trajan's Parthian War of 114–117 AD and Trebonianus Gallus' Persian war of 252 AD). Though the name of the unit was derived from its early service in Britain, the unit was not generally composed of ethnic Britons. No units of this name are believed to have been active in Britain during the late 2nd century.


title: Lucius Artorius Castus

text: In an inscription from Sirmium in Pannonia dating to the reign of the emperor Gallienus (CIL 3, 3228), we have mention of vexillations of legions "*Brittan(n)icin(arum)" (""militum vexill(ationum) legg(ionum) ]G]ermaniciana[r(um)] [e]t Brittan(n)icin(arum)"") – another form that is very similar to the "*Britan(n)icimiarum" from Castus's inscription.


title: Lucius Artorius Castus

text: Exceptionally talented, experienced and/or connected Praefects Castrorum/Legionis could sometimes move on to higher civilian positions such as Procurator, which Castus indeed managed to accomplish after retiring from the army. He became "procurator centenarius" (governor) of Liburnia, a part of Roman Dalmatia, today's Croatia. ("centenarius" indicates that he received a salary of 100,000 sesterces per year).


title: Lucius Artorius Castus

text: Castus was appointed procurator centenarius of the province of Liburnia with ius gladii, the power to put anyone, even Senators, to death. Nothing further is known of him. Other Artorii are attested in the area, but it is unknown if Lucius Artorius Castus started this branch of the family in Dalmatia, or whether the family had already been settled there prior to his birth (if the latter, Castus might have received the Liburnian procuratorship because he was a native of the region).


title: Lucius Artorius Castus

text: No dates are given in either inscription, making it difficult to offer a precise date for them, no less Lucius Artorius Castus's "floruit". The late French epigraphy expert Xavier Loriot suggested that Lucius Artorius Castus's expedition against the Armenians (as he reads the main inscription) could have taken place in 215 AD, under the reign of emperor Caracalla, or perhaps later, in 232 AD, under the reign of Severus Alexander (when P. Aelius Hammonius led a Cappadocian force in Severus's Persian war). Three Croatian archaeologists examined the inscriptions in 2012, as part of an international conference on Lucius Artorius Castus organized by authors Linda Malcor and John Matthews: Nenad Cambi, Željko Miletić, and Miroslav Glavičić. Cambi proposes that Lucius Artorius Castus' career can be dated to the late 2nd century AD and his death to the late 2nd, or perhaps early 3rd century AD. Glavičić dates Lucius Artorius Castus's military career to the middle- through late-2nd century AD and proposes that he was the first governor of the province of Liburnia, which Glavičić suggests was only established as a separate province from Dalmatia circa 184–185 AD. Miletić dates Lucius Artorius Castus's military career to circa 121–166 AD and his procuratorship of the province of Liburnia to circa 167–174 AD. Cambi, Miletić, and Glavičić all accept the reading "(adversus) Armenios", "against the Armenians" (with Cambi offering "Armorios" [an abbreviation of "Armoric[an]os"] as an alternate possibility); Miletić places the expedition against the Armenians during emperor Lucius Verus's Parthian war of 161–166 AD.


title: Lucius Artorius Castus

text: In 1924, Kemp Malone was the first to suggest the possibility that Lucius Artorius Castus was the inspiration for the figure of Arthur in medieval European literature. More recent champions have included authors C. Scott Littleton and Linda Malcor. The hypothesis has been heavily criticized by prominent Arthurian scholars due to the historical Artorius Castus having very little in common with the Arthurian legends and the arguments relying excessively on speculation and wishful thinking.


title: Lucius Artorius Castus

text: Due to the significant differences between the persons and careers of the historical Lucius Artorius Castus and the traditional King Arthur, the consensus of mainstream historians is that it is very unlikely the former inspired the latter. For example, Lucius Artorius Castus was not contemporaneous with the Saxon invasions of Britain in the 5th century CE which gave rise to the Arthurian legends, and some of the earliest written references to Arthur are of him fighting against the Saxons. The strongest link between them may be the extended family or clan name "Artorius" which may have developed into the personal name "Arthur", but this does not necessarily mean Lucius Artorius Castus himself inspired the legends. The possibility, however unlikely or remote, is nonetheless real that he was remembered in local tales that grew in the retelling. No definitive proof, however, has yet been established that Lucius Artorius Castus was the "real" King Arthur.


title: Lucius Artorius Castus

text: In the film "King Arthur" (2004), Lucius Artorius Castus is partially identified with King Arthur. The film asserts that Arthur's Roman name was "Artorius Castus", and that Artorius was an ancestral name derived from that of a famous leader. His "floruit" ("prime time") is, however, pushed a few centuries later so that he is made a contemporary of the invading Saxons in the 5th century CE. This would be in agreement with native Welsh tradition regarding Arthur, although his activities are placed many decades or sometimes centuries earlier than the medieval sources assign to him. As a research consultant for the film "King Arthur" (2004), Linda Malcor's hypotheses regarding Lucius Artorius Castus were the primary inspiration for the screenplay.


title: Inertial confinement fusion

text: Inertial confinement fusion (ICF) is a fusion energy process that initiates nuclear fusion reactions by compressing and heating targets filled with thermonuclear fuel. In modern machines, the targets are small spherical pellets about the size of a pinhead typically containing a mixture of about 10 milligrams of deuterium H and tritium H.


title: Inertial confinement fusion

text: To compress and heat the fuel, energy is deposited in the outer layer of the target using high-energy beams of photons, electrons or ions, although almost all ICF devices used lasers. The beams heat the outer layer, which explodes outward. This produces a reaction force against the remainder of the target, which accelerates it inwards and compresses the fuel. This process also creates shock waves that travel inward through the target. Sufficiently powerful shock waves can compress and heat the fuel at the center such that fusion occurs.


title: Inertial confinement fusion

text: ICF is one of two major branches of fusion energy research, the other is magnetic confinement fusion. When it was first publicly proposed in the early 1970s, ICF appeared to be a practical approach to power production and the field flourished. Experiments during the 1970s and '80s demonstrated that the efficiency of these devices was much lower than expected, and reaching ignition would not be easy. Throughout the 1980s and '90s, many experiments were conducted in order to understand the complex interaction of high-intensity laser light and plasma. These led to the design of newer machines, much larger, that would finally reach ignition energies.


title: Inertial confinement fusion

text: The largest operational ICF experiment is the National Ignition Facility (NIF) in the US. In 2021, a test "shot" reached 70% of the energy put into it, slightly besting the best results for the magnetic machines set in the 1990s. On 13 December 2022, the National Ignition Facility announced that they achieved fusion ignition for the first time, by delivering 2.05 megajoules (MJ) of energy to the target, resulting in 3.15 MJ of fusion energy output.


title: Inertial confinement fusion

text: Fusion reactions join together smaller atoms to form larger ones. This occurs when two atoms (or ions, atoms stripped of their electrons) come close enough that the nuclear force pulls them together. Atomic nuclei are positively charged, and thus repel each other due to the electrostatic force. Overcoming this repulsion to bring the nuclei close enough requires an input of kinetic energy, known as the "Coulomb barrier" or "fusion barrier energy".


title: Inertial confinement fusion

text: Less energy is needed to cause lighter nuclei to fuse, as they have less electrical charge and thus a lower barrier energy. This means the barrier is lowest for hydrogen. Conversely, the nuclear force increases with the total number of nuclei, so the isotopes of hydrogen with additional neutrons further reduce the required energy. The easiest fuel to use for fusion production is the combination of deuterium, H, and tritium, H. This combination is known as D-T.


title: Inertial confinement fusion

text: Even under ideal conditions, the chance that a D and T pair of ions will undergo fusion is very small; the chance is much higher that they will scatter instead. For this reason, the fuel must be held together for a period of time to give the ions many chances to approach other ions. Increasing the density of the fuel also helps, as it means the ions will have more encounters in a given time. Finally, the chance that the reaction will take place is not linear, this cross section is heavily dependent on individual ion energies. It is the combination of these three factors, energy (temperature), density and confinement time that is important. This combination is known as the fusion triple product, and the value of the triple product needed to produce net energy is known as the Lawson criterion.


title: Inertial confinement fusion

text: The first ICF devices were the hydrogen bombs invented in the early 1950s. A hydrogen bomb consists of two bombs in a single case. The first, the "primary stage", is a fission-powered device normally using plutonium. When it explodes it gives off a burst of thermal X-rays that fill the interior of the specially designed bomb casing. These X-rays are absorbed by a special material surrounding the "secondary stage", which consists mostly of the fusion fuel. The X-rays heat this material and cause it to explode outward. Due to Newton's Third Law, this causes the fuel inside to be driven inward, compressing and heating it. This causes the fusion fuel to reach the temperature and density where fusion reactions begin.


title: Inertial confinement fusion

text: In the case of D-T fuel, most of the energy is released in the form of alpha particles and neutrons. Under normal conditions, an alpha can travel about 10 mm through the fuel, but in the ultra-dense conditions in the compressed fuel, they can travel about 0.01 mm before their electrical charge interacting with the surrounding plasma causes them to lose velocity. This means the majority of the energy released by the alphas will be deposited back in the fuel. This transfer of kinetic energy heats the surrounding particles to the energies they need to undergo fusion as well. This process causes the fusion fuel to burn outward from the center. The electrically neutral neutrons travel longer distances in the fuel mass and do not contribute to this self-heating process. In a bomb, they are instead used to either breed more tritium through reactions in a lithium-deuteride fuel, or are used to fission additional fissionable fuel surrounding the secondary stage, often part of the bomb casing.


title: Inertial confinement fusion

text: The requirement that the reaction has to be sparked by a fission bomb makes the method impractical for power generation. Not only would the fission triggers be expensive to produce, but the minimum size of such a bomb is large, defined roughly by the critical mass of the plutonium fuel used. Generally, it seems difficult to build efficient nuclear devices much smaller than about 1 kiloton in yield, and the fusion secondary would add to this yield. This makes it a difficult engineering problem to extract power from the resulting explosions. Project PACER studied solutions to the engineering issues, but also demonstrated that it was not economically feasible. The cost of the bombs was far greater than the value of the resulting electricity.


title: Inertial confinement fusion

text: The energy needed to overcome the Coulomb barrier corresponds to the energy of the average particle in a gas heated to 100 million Kelvin. The specific heat of hydrogen is about 14 Joule per gram-Kelvin, so considering a tiny amount of fusion fuel, 1 milligram for instance, the energy needed to raise the mass as a whole to this temperature is 1.4 million Joules, or ~1 megajoule (MJ).


title: Inertial confinement fusion

text: In the more widely developed magnetic fusion energy (MFE) approach, confinement times are on the order of a second. This is not a physical limit, modern machines can maintain a plasma for minutes. In this case the confinement time represents the amount of time it takes for the energy from the reaction to be lost to the environment through a variety of mechanisms. For a one second confinement, the density needed to meet the Lawson criterion is about 10 particles per cubic centimetre. For comparison, air at sea level has about 2.7 x 10 particles per cubic centimetre, so the MFE approach has been described as "a good vacuum".


title: Inertial confinement fusion

text: Considering a 1 milligram drop of D-T fuel in liquid form, the size is about 1 mm and the density is about 4 x 10. There is nothing holding the fuel together in this case, any heat created within it by fusion events will cause it to expand at the speed of sound, which leads to a confinement time around 2 x 10. At liquid density the required confinement time to reach the Lawson criterion is about 2 x 10. In this case only about 0.1 percent of the fuel will have fused before the drop is blown apart.


title: Inertial confinement fusion

text: The trick to ICF is that the rate of the fusion reactions is a function of density, and density can be improved through compression. If the drop is compressed from 1 mm to 0.1 mm in diameter, the confinement time drops by the same factor of 10 because the particles have less distance to go before they escape. At the same time the density, which is the cube of the dimensions, increases by 1,000 times. This means the overall rate of fusion increases 1,000 times while the confinement drops by 10 times, a 100-fold improvement. In this case 10% of the fuel undergoes fusion; 10% of 1 mg of fuel will produce about 30 MJ of energy, 30 times that of the energy needed to compress it to that density.


title: Inertial confinement fusion

text: The other key concept in ICF is that the entire fuel mass does not have to be raised to 100 million K. Recall that in a fusion bomb the reaction continues because the alpha particles released in the interior heat the fuel around it. At liquid density the alphas will travel about 10 mm and thus their energy will escape the 1 mm fuel. In the 0.1 mm compressed fuel, the alphas will have a range of about 0.016 mm, meaning that they will stop within the fuel and heat it. In this case a "propagating burn" can be caused by heating only the center of the fuel to the needed temperature. This requires far less energy; calculations suggested 1 kJ would be enough to reach the compression goal alone.


title: Inertial confinement fusion

text: Some method would be needed to heat the interior to fusion temperatures, and do so at the right time when the fuel was compressed and the density was high enough. In modern ICF devices, the density of the resulting fuel mixture is as much as one-thousand times the density of water, or one-hundred times that of lead, around 1000 g/cm. Much of the work since the 1970s has been on ways to create the central hot-spot that starts off the burning, and dealing with the many practical problems that cropped up while trying to reach the desired densities.


title: Inertial confinement fusion

text: Early calculations suggested that the amount of energy needed to start the propagating burn would be very small; only a tiny amount of fuel had to be raised to the required temperature. This has proven difficult and new methods have emerged in an effort to make this process more efficient.


title: Inertial confinement fusion

text: The initial solution to the heating problem involved the careful "shaping" of the energy delivery. The idea was to use an initial lower-energy pulse to vaporize the capsule and cause compression, and then a very short, very powerful pulse near the end of the compression cycle. The goal is to launch a shock wave into the compressed fuel that travels inward to the center. When it reaches the center it meets the same wave travelling in from the other sides. This causes a brief period where the density in the center reaches much higher values, over 800 g/cm.


title: Inertial confinement fusion

text: Known as "central hot spot ignition", the concept was the first to suggest ICF was not only a practical route to fusion, but relatively simple. This led to numerous efforts to build working systems in the early 1970s. These experiments revealed a number of unexpected loss mechanisms. Early calculations suggested about 4.5x10 J/g would be needed, but modern calculations place it closer to 10 J/g. Further control of the process on modern machines has led to complex shaping of the pulse into multiple sections in time.


title: Inertial confinement fusion

text: In the "fast ignition" approach, a separate laser is used to provide the additional energy directly to the center of the fuel. This can be arranged through mechanical means, often using a small metal cone that punctures the outer fuel pellet wall to allow the laser light access to the center. In tests, this approach has failed as the pulse of light has to reach the center at a precise time, when it is obscured by the debris and especially free electrons from the compression pulse. It also has the disadvantage of requiring a second laser pulse, which generally demands a completely separate laser.


title: Inertial confinement fusion

text: "Shock ignition" is similar in concept to the hot-spot technique, but instead of ignition being achieved via compression heating of the hotspot, a final powerful, shock is sent into the fuel at a late time to trigger ignition through a combination of compression and shock heating. This increases the efficiency of the process with an eye to lowering the overall amount of power required.


title: Inertial confinement fusion

text: In the simplest method of inertial confinement, the fuel is arranged as a sphere. This allows it to be pushed inward uniformly from all sides. To produce the inward force, the fuel is placed within a thin capsule that absorbs energy from the driver beams, causing the capsule shell to explode outwards. The capsule shell is usually made of a lightweight plastic, and the fuel is deposited as a layer on the inside by injecting a gaseous fuel into the shell and then freezing it.


title: Inertial confinement fusion

text: Shining the driver beams directly onto the fuel capsule is known as "direct drive". In order for the fusion fuel to reach the required conditions, the implosion process must be extremely uniform in order to avoid significant asymmetry due to Rayleigh–Taylor instability and similar effects. For a beam energy of 1 MJ, the fuel capsule cannot be larger than about 2 mm before these effects disrupt the implosion symmetry. This limits the size of the beams to a narrow diameter that is difficult to achieve in practice.


title: Inertial confinement fusion

text: This difficulty has led to a method called "indirect drive", in which the beam does not shine on the fuel capsule directly. Instead, it shines into a small cylinder of heavy metal, often gold or lead, known as a "hohlraum". The beams are arranged so they do not hit the fuel capsule suspended in the center. The beam energy heats the hohlraum until it emits X-rays. These X-rays fill the interior of the hohlraum and heat the capsule. The advantage of indirect drive is that the beams can be larger and less accurate, which greatly eases driver design. The disadvantage is that much of the delivered driver energy is used to heat the hohlraum until it is "X-ray hot", so the end-to-end energy efficiency is much lower than the direct drive method.


title: Inertial confinement fusion

text: In order to focus the shock wave on the center of the target, the target must be made with great precision and sphericity with aberrations of no more than a few micrometres over its (inner and outer) surface. Likewise, the aiming of the laser beams must be precise in space and time. Beam timing is relatively simple and is solved by using delay lines in the beams' optical path to achieve picosecond timing accuracy. The other major problem plaguing the achievement of high symmetry and high temperatures/densities of the imploding target are so called "beam-beam" imbalance and beam anisotropy. These problems are, respectively, where the energy delivered by one beam may be higher or lower than other beams impinging on the target and of "hot spots" within a beam diameter hitting a target which induces uneven compression on the target surface, thereby forming Rayleigh-Taylor instabilities in the fuel, prematurely mixing it and reducing heating efficacy at the time of maximum compression. The Richtmyer-Meshkov instability is also formed during the process due to shock waves.


title: Inertial confinement fusion

text: All of these problems have been significantly mitigated by beam smoothing techniques and beam energy diagnostics to balance beam to beam energy; however, RT instability remains a major issue. Target design has improved tremendously. Modern cryogenic hydrogen ice targets tend to freeze a thin layer of deuterium on the inside of the shell while irradiating it with a low power IR laser to smooth its inner surface and monitoring it with a microscope equipped camera, thereby allowing the layer to be closely monitored ensuring its "smoothness". Cryogenic targets filled with D-T are "self-smoothing" due to the small amount of heat created by tritium decay. This is often referred to as "beta-layering".


title: Inertial confinement fusion

text: In the indirect drive approach, the absorption of thermal x-rays by the target is more efficient than the direct absorption of laser light. However, the hohlraums take up considerable energy to heat, significantly reducing the energy transfer efficiency. Most often, indirect drive hohlraum targets are used to simulate thermonuclear weapons tests due to the fact that the fusion fuel in them is also imploded mainly by X-ray radiation.


title: Inertial confinement fusion

text: A variety of ICF drivers are evolving. Lasers have improved dramatically, scaling up from a few joules and kilowatts to megajoules and hundreds of terawatts, using mostly frequency doubled or tripled light from neodymium glass amplifiers.


title: Inertial confinement fusion

text: Heavy ion beams are particularly interesting for commercial generation, as they are easy to create, control, and focus. However, it is difficult to achieve the energy densities required to implode a target efficiently, and most ion-beam systems require the use of a hohlraum surrounding the target to smooth out the irradiation.


title: Inertial confinement fusion

text: ICF history began as part of the "Atoms For Peace" conference in 1957. This was a large, international UN sponsored conference between the superpowers of the US and the Soviet Union. Some thought was given to using a hydrogen bomb to heat a water-filled cavern. The resulting steam would then be used to power conventional generators, and thereby provide electrical power.


title: Inertial confinement fusion

text: This meeting led to the Operation Plowshare efforts, formed in June 1957 and formally named in 1961. Three primary concepts were part of Plowshare; energy generation under Project PACER, the use of nuclear explosions for excavation, and for fracking in the natural gas industry. PACER was directly tested in December 1961 when the 3 kt Project Gnome device was detonated in bedded salt in New Mexico. While the press looked on, radioactive steam was released from the drill shaft, at some distance from the test site. Further studies led to engineered cavities replacing natural ones, but the Plowshare efforts turned from bad to worse, especially after the failure of 1962's Sedan which produced significant fallout. PACER continued to receive funding until 1975, when a 3rd party study demonstrated that the cost of electricity from PACER would be ten times the cost of conventional nuclear plants.


title: Inertial confinement fusion

text: Another outcome of the "Atoms For Peace" conference was to prompt Nuckolls to consider what happens on the fusion side of the bomb as the fuel mass is reduced. This work suggested that at very small sizes, on the order of milligrams, very little energy would be needed to ignite it, much less than a fission primary. He proposed building, in effect, tiny all-fusion explosives using a tiny drop of D-T fuel suspended in the center of a hohlraum. The shell provided the same effect as the bomb casing in an H-bomb, trapping x-rays inside to irradiate the fuel. The main difference is that the X-rays would not be supplied by a fission bomb, but by some sort of external device that heated the shell from the outside until it was glowing in the x-ray region. The power would be delivered by a then-unidentified pulsed power source he referred to, using bomb terminology, the "primary".


title: Inertial confinement fusion

text: The main advantage to this scheme is the efficiency of the fusion process at high densities. According to the Lawson criterion, the amount of energy needed to heat the D-T fuel to break-even conditions at ambient pressure is perhaps 100 times greater than the energy needed to compress it to a pressure that would deliver the same rate of fusion. So, in theory, the ICF approach could offer dramatically more gain. This can be understood by considering the energy losses in a conventional scenario where the fuel is slowly heated, as in the case of magnetic fusion energy; the rate of energy loss to the environment is based on the temperature difference between the fuel and its surroundings, which continues to increase as the fuel temperature increases. In the ICF case, the entire hohlraum is filled with high-temperature radiation, limiting losses.


title: Inertial confinement fusion

text: In 1956 a meeting was organized at the Max Planck Institute in Germany by fusion pioneer Carl Friedrich von Weizsäcker. At this meeting Friedwardt Winterberg proposed the non-fission ignition of a thermonuclear micro-explosion by a convergent shock wave driven with high explosives. Further reference to Winterberg's work in Germany on nuclear micro explosions (mininukes) is contained in a declassified report of the former East German Stasi (Staatsicherheitsdienst).


title: Inertial confinement fusion

text: In 1964 Winterberg proposed that ignition could be achieved by an intense beam of microparticles accelerated to a velocity of 1000 km/s. And in 1968, he proposed to use intense electron and ion beams, generated by Marx generators, for the same purpose. The advantage of this proposal is that the generation of charged particle beams is not only less expensive than the generation of laser beams but can entrap the charged fusion reaction products due to the strong self-magnetic beam field, drastically reducing the compression requirements for beam ignited cylindrical targets.


title: Inertial confinement fusion

text: In 1967, research fellow Gurgen Askaryan published an article proposing the use of focused laser beams in the fusion of lithium deuteride or deuterium.