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Vacuum plasma spraying (VPS) is a technology for etching and surface modification to create porous layers with high reproducibility and for cleaning and surface engineering of plastics, rubbers and natural fibers as well as for replacing CFCs for cleaning metal components. This surface engineering can improve properties such as frictional behavior, heat resistance, surface electrical conductivity, lubricity, cohesive strength of films, or dielectric constant, or it can make materials hydrophilic or hydrophobic.
The process typically operates at 39–120 °C to avoid thermal damage. It can induce non-thermally activated surface reactions, causing surface changes which cannot occur with molecular chemistries at atmospheric pressure. Plasma processing is done in a controlled environment inside a sealed chamber at a medium vacuum, around 13–65 Pa.
The gas or mixture of gases is energized by an electrical field from DC to microwave frequencies, typically 1–500 W at 50 V. The treated components are usually electrically isolated. The volatile plasma by-products are evacuated from the chamber by the vacuum pump, and if necessary can be neutralized in an exhaust scrubber.
In contrast to molecular chemistry, plasmas employ:
* Molecular, atomic, metastable and free radical species for chemical effects.
* Positive ions and electrons for kinetic effects.
Plasma also generates electromagnetic radiation in the form of vacuum UV photons to penetrate bulk polymers to a depth of about 10 μm. This can cause chain scissions and cross-linking.
Plasmas affect materials at an atomic level. Techniques like X-ray photoelectron spectroscopy and scanning electron microscopy are used for surface analysis to identify the processes required and to judge their effects.
As a simple indication of surface energy, and hence adhesion or wettability, often a water droplet contact angle test is used.
The lower the contact angle, the higher the surface energy and more hydrophilic the material is. | 0 | Metallurgy |
The protein encoded by this gene is a transcriptional coactivator that can interact with nuclear hormone receptors to enhance their transcriptional activator functions. The encoded protein has been shown to be involved in the hormone-dependent coactivation of several receptors, including prostanoid, retinoid, vitamin D, thyroid hormone, and steroid receptors. The encoded protein may also act as a general coactivator since it has been shown to interact with some basal transcription factors, histone acetyltransferases, and methyltransferases. | 1 | Gene expression + Signal Transduction |
*DAD1 Defender against cell death
*DAP3 Involved in mediating interferon-gamma-induced cell death.
*DAXX Death Associated Protein 6 | 1 | Gene expression + Signal Transduction |
Artifact replication plays an important role in comparing artifact use. Often objects are made not just to prove a manufacturing process or to sit in a display case, but to show that a given object will show signs of wear that are similar to those present in the archaeological record. Roberts and Ottaway conducted such experimental reconstructions by casting bronze axes using them in a preconceived manner and then comparing the results against known archaeological remains. Results gathered from such experimentation have found that objects have comparable wear patterns and there are European socketed axes that were deposited used as well as unused. Tool mark identification can also go the opposite ways using experimental reconstruction to show the difference between various material media and the wear patterns they leave. Greenfield gives one such experiment where steel, bronze, and stone tool marks on bone are all researched and examples are given for how they might be seen in the archaeological record.
Energy consumption and efficiency is another topic of interest in archaeometallurgy. Tree felling and land clearing experiments involving comparison of stone, bronze, and steel axes are popular with a number of archaeologists In these types of experiments, factors such as time spent and oxygen intake of the researchers are taken into account to try to find similarities in past life ways use of energy. | 0 | Metallurgy |
The following advantages have been reported for the BBOC:
* very high oxygen efficiency – the injection of oxygen directly into the reaction zone within the furnace results in much greater oxygen efficiency (close to 100%) than with reverberatory furnaces (8% for the Niihama furnace) or top-blown rotary converters (about 30%)
* reduced off-gas volume – the use of industrial oxygen and the high oxygen efficiency of the process means that excess air is not required to achieve the results. This reduces the off-gas volume and thus the cost of the off-gas train and handling equipment. Rand Refinery reported that the off-gas volume of the BBOC was about 75% of that of a TBRC with a special lance conversion and only 19% of that of top-submerged lance smelting. Niihama refinery reported that its BBOC had 15% of the off-gas volume of its reverberatory furnace while producing 1.8 times the product
* higher reaction rates – by injecting the oxygen directly into the reaction zone, the reaction rates are much higher than in reverberatory furnaces where the oxygen has first to penetrate the slag layer. BRM reported a reaction rate per unit of furnace volume of 10–20 times that of the reverberatory furnace
* lower refractory wear – Rand Refinery reported that the refractory linings of its TBRC furnaces needed replacing after approximately two weeks, while the linings of its BBOC furnace lasted about 14 weeks
* lower precious metal inventories – a consequence of the higher reaction rates is that smaller furnace volumes are required and there are smaller cycle times. This results in lower precious metal inventories. In lead slimes bullion processing, the silver inventory was reduced from 4.5 t to 1.25 t after replacing a reverberatory furnace with a BBOC and at BRM the silver inventory fell from 11.5 t to 3.1 t with the introduction of the BBOC furnace
* better energy efficiency – a supplementary burner is needed only during heating the charge and doré casting operations. During cupellation, the oxidation reactions provide sufficient heat to maintain temperature. There was a 92% reduction in fuel consumption per tonne of doré treated reported for the BBOC at the Niihama refinery
* better product quality – BHAS reported that lead and copper levels in silver produced from the BBOC of 0.01% and 0.1% respectively were possible when the furnace was operating under design conditions, compared to 0.04% and 0.2% for the old reverberatory furnace, and 0.8% and 0.4% for the Sirosmelt furnace. Rand Refinery reported that a doré bullion of 99.2% was achievable. BRM reported that its doré is 99.7% silver
* higher recoveries of precious metals – due to changes in the way the BBOC is operated compare to reverberatory furnaces, notably in being able to use deeper layers of slag, there is an increase in the recovery of precious metals compared to the reverberatory furnaces. Replacement of reverberatory furnaces with BBOC furnaces saw the direct silver recovery increase from 92.5% to 97.5% at BRM and from 70% to over 95% at Niihama
* simple vessel design – the BBOC has a relatively simple vessel design, without the complex moving parts of TBRCs
* good process control – the high oxygen utilization allows good process control, particularly when combined with an oxygen sensor in the off-gas system
* lower labor requirements – the BBOC has a lower labor requirement than reverberatory furnaces, top-submerged lance furnaces and TBRCs
* lower operating costs – lower labor requirements, lower fuel requirements and longer refractory life contributed to a 28.3% reduction in overall operating costs when the BBOC was installed at the Rand Refinery
* lower capital cost – the BBOC is a simpler furnace than TBRC or top-submerged lance furnaces. Rand Refinery reported a capital cost comparison indicating that its BBOC option was 67% of the cost of a top-submerged lance option. | 0 | Metallurgy |
Coupon holders are used to fix corrosion coupons inside a pipe or tank and attaches itself to a solid plug or hollow plug. They are usually made from stainless steel 316/316L or Monel and inconel or other corrosion resistant materials. | 0 | Metallurgy |
At the turn of the 17th-18th centuries, the country's need for metal was exacerbated by the outbreak of wars for access to the Black and Baltic Seas. Olonets and Kashiro-Tula plants in the central and northwestern parts of Russia had already depleted forest and ore bases and did not meet the growing demand for weapons-grade metal, and could not produce high-quality metal due to the presence of harmful impurities in the ores, primarily sulfur and phosphorus. These same prerequisites contributed to the shift of priority from the smelting of non-ferrous and noble metals towards iron. After the defeat of the Russian troops at Narva on November 19, 1700, the Swedes were left with all the Russian artillery, which exacerbated the need for accelerated production of guns. To make up for these losses, Peter I gave the order to melt the church bells into cannons and mortars. As a result, 300 cannons were cast in one year.
In 1696, at the initiative of the head of the Siberian order, the Duma clerk A.A. Vinius, the ore found in the Verkhotursky district was sent for examination to the Moscow gunsmiths and the Tula blacksmith N. D. Antufiev (Demidov). The samples were highly appraised, which played a decisive role in government decision-making. On May 10 and June 15, 1697, decrees of Peter I were issued on the construction of the first Ural blast furnace plants. The construction was supervised by the Siberian Order headed by A. A. Vinius. The first craftsmen arrived in the Urals to build the Nevyansk and Kamensk factories in the spring of 1700. By 1717, out of 516 workers at the Nevyansk plant, 118 people came from central Russia, including 52 from Tula, and 66 people from Moscow and the Moscow region. The launch of the first two plants in 1701 showed good prospects for Ural metallurgy. In 1702, the Uktussky, Verkhne- and Nizhne-Alapaevsky plants were launched, supplying metal, including for the construction of buildings in St. Petersburg.
On March 4, 1702, by the decree of Peter I, the unfinished Nevyansk plant was transferred to the private property of N. D. Demidov. He proved to be a talented organizer and was able to significantly increase production volumes, with the support of the authorities. Demidov easily achieved the registration of additional peasants to factories, as well as relaxation in taxes and supervision by local administrations. Since 1716, the Demidovs became the first Russian exporters of iron to Western Europe. In total, the Demidovs built 55 metallurgical plants, including 40 in the Urals. By 1740, the Demidov factories produced about 64% of all Ural and 46% of Russian iron. At the same time, the productivity of the Demidovs' factories was on average 70% higher than that of state-owned.
In April 1703, the first convoy with guns and iron made in the Urals (323 cannons, 12 mortars, 14 howitzers) was sent from the Utkinskaya pier on the Chusovaya River. From the factories, the guns were transported by horse-drawn transport 176 versts to Chusovaya, then they were delivered by water to Moscow or St. Petersburg, wintering in Tver. The first convoy arrived in Moscow in 11 weeks and 6 days, on July 18, 1703. Tests of the first guns, which had been cast in a hurry, were unsuccessful: of the first two guns, one was torn into 20 parts due to the poor quality of the cast iron. Later, in the course of mass testing of the guns, 102 guns out of 323 were torn apart. After that, A. A. Vinius ordered the guns to be tested at the factories before shipment. Later, due to the unsatisfactory quality of the metal and high transportation costs, the manufacture of cannons was moved to the factories of the Central part of Russia. By a decree on 19 January 1705, the smelting of cannons at the Ural factories was terminated.
In the first years of the 18th century, with the launch of the first state-owned and private factories, the production base of mining districts and the management system of the enterprises included in them began to be built. Almost all of the first Ural factories were built by local peasants, who were then assigned to factories. In 1700, the first registration of more than 1.6 thousand peasants to the Nevyansk plant was carried out. In 1703, an additional postscript was made to the same plant, which was already owned by N. D. Demidov. By 1762, about 70% of state peasants were assigned to factories in the Middle Urals and Kamsky Urals. The registered peasants at the factories performed mainly auxiliary work: they prepared firewood for the production of coal and heating houses, mined and fired ore and limestone, transported goods, and erected dams. On December 10, 1719, the privileges of miners were enshrined in law with the Berg Privilege, which allowed representatives of all classes to search for ores and build metallurgical plants. At the same time, manufacturers and artisans were exempted from state taxes and recruiting, and their houses were exempt from the post of troops. The law also guaranteed the inheritance of the ownership of factories, proclaimed industrial activity a matter of state importance and protected manufacturers from interference in their affairs by local authorities. The same law established the Berg Board, and managed the entire mining and metallurgical industry, and local administrations. The provisions of the Berg Privilege were extended to foreign nationals in 1720, and remained in force until the early 19th century.
In the 1720s, V.N. Tatishchev and, later, V. de Gennin, who founded the Yekaterinburg state-owned plant in 1723, were sent to the Urals as leaders of the local mining administration. Tatishchev came into conflict with Demidov, trying to weaken his power at the beginning of his work in the Urals. Demidov complained of infringement in Petersburg, and Tatishchev was recalled. Later, de Gennin, who came to replace Tatishchev, and completed the construction of the plant in 1722-1723, confirmed the abuse of the Demidovs in organizing the work of private plants. In 1720, Tatishchev established the Office of Mining Affairs in Kungur, and in 1722 transferred it to the Uktussky plant and renamed it the Siberian Mining Authority, and then the Siberian Higher Mining Authority. De Gennin transferred the Office to Yekaterinburg in 1723 and renamed the institution the Siberian Ober-Bergamt. The achievements of Tatishchev include creating competition for the Demidovs by inviting other mining companies to the Urals, developing rules for managing mining plants and staffing standards.
In the 1720s and 1740s, the Yekaterinburg plant, which gave rise to Yekaterinburg, was the largest metallurgical plant in Europe. The blast furnaces of the plant were more economical and more productive than the English and Swedish ones, which were considered the best in the industry at that time. If the specific consumption of charcoal per 100 kg of iron in Swedish furnaces ranged from 300 to 350 kg, then in Yekaterinburg the consumption of coal was 150–170 kg.
On January 18, 1721, a decree was issued that allowed factory owners, regardless of whether they had a noble rank, to buy serfs. At the same time, the villages purchased by the tycoon with their population could only be sold together with the factory. Later, these peasants and the factories that used their labor became known as possessory factories. Later, in 1744, the norms for the purchase of peasants with factories were established: in the factories of ferrous metallurgy with one blast furnace — 100 peasants, and in the copper smelters - 200 men for every thousand pounds of copper. The addition of peasants to factories led to unrest and riots, which were suppressed during the 2nd half of the 18th century. Later, until the middle of the 19th century, free labor contributed to the intensive development of the metallurgical industry.
In the first quarter of the 18th century, 20 blast furnaces were built in the Urals, and in 1725 they smelted about 0.6 million poods of cast iron. During the same period, small businesses built several small metallurgical plants: Mazuevsky, Shuvakishsky, and Davydovsky. All of them existed for no more than 40 years. After the end of the Northern War, due to a decrease in demand for ferrous metals, the construction of iron smelters was suspended, mainly copper smelters were built. From 1721 to 1725, 11 plants were built in the Urals, of which only Nizhny Tagil was blast-furnace and iron-making, the rest were either copper-smelting (Polevskoy and Pyskorsky), or copper-smelting and iron-making (Verkhne-Uktussky and Yekaterinburg). In total, from 1701 to 1740, 24 state and 31 private metallurgical plants were built in the Urals, which determined the specialization of the region as a quality industrial metallurgical center. Private factories were characterized by higher profitability compared to state-owned. The growth of iron smelting in the Urals over 25 years (from 1725 to 1750) amounted to 250%: from 0.6 million poods to 1.5 million poods.
In the 1730s, the construction of fortresses and factories began in the Southern Urals, on the lands of the Bashkirs. In 1734, Anna Ioannovna approved the project of colonization of the Southern Urals submitted by the Chief Secretary of the Senate, I. K. Kirilov, and appointed him the Chief Commander of the Orenburg expedition. The tasks of the expedition included the construction of the fortress city of Orenburg, a line of defensive fortresses in order to exclude the raids of the Bashkirs, development of the natural resources of the region, and the opening of trade routes to Asia. In autumn of 1736, 100 versts to the south-east of Ufa and 10 versts from the Tabynsky fortress, the construction of the Resurrection (Tabynsky) copper smelter, the first in the Southern Urals, was started. On May 22, 1744, a decree of the Berg Collegium was issued, which allowed for the purchase from the Bashkirs and other owners of the deposit, forests and land for the construction of mining plants. In the period from 1745 to 1755, 20 factories were built on the territory of Bashkiria. By 1781, there were 38 factories in total. During the years of the Peasant War, 89 mining plants were damaged to varying degrees. With the beginning of the uprising, in the first half of October 1773, the closest private copper plants to Orenburg were seized: Verkhotorsky, Voskresensky, Preobrazhensky and Kano-Nikolsky plants. From November to December, all plants in the Southern Urals (24 plants) were seized. By the beginning of 1774, the uprising covered the Middle Urals, the number of captured factories in January reached 39, in February - 92. Individual factories resumed work for short periods of time in 1774, despite the occupation. With the suppression of the uprising, the work of the factories began to recover. By the beginning of 1775, about two thirds of all the Ural factories were working. By the end of 1775, the least destroyed factories of the Southern Urals began to resume their work.
Since the middle of the 18th century, state-owned Ural factories began to produce gold, and since 1819, platinum. Later, mining was permitted for all Russian subjects, which led to the rapid propagation of gold mines in the Urals. In the 1750s and 1760s, the construction of factories in the Urals continued intensively, thanks to the high profitability of production and the support of the authorities. In addition to the Demidovs and Stroganovs, entrepreneurs Osokins, Tverdyshevs, I. S. Myasnikov, and M. M. Pokhodyashin, as well as officials and nobles: P. I. Shuvalov, M. M. Golitsyn, and A. I. Glebov began to build factories. Only the Yekaterinburg and Kamensky plants remained in the state administration, the rest were transferred to private management. Later, many private factories were returned to the treasury for debts (in 1764 — the factories of Count Shuvalov, in 1770 — Count Chernyshevs, in 1781 — Count Vorontsovs). By the end of the 17th century, the largest companies in Russia were the Demidovs, Yakovlevs, Batashovs and Mosolovs, which produced about half of all iron in the country.
In 1767, about 140 metallurgical plants operating in the Urals made the region a leader in world iron production and secured a monopoly position in Russia in copper smelting. By the end of the 18th century, the number of serf workers in the Ural factories reached 74.1 thousand people, and the number of registered peasants reached 212.7 thousand people. In 1800, the Ural factories produced 80.1% of cast iron, 88.3% of iron, and 100% of copper of the all-Russian production volume. Thanks to this, Russia came out on top in the world for iron production and smelted from 20 to 27% of the world's copper.
From the end of the 18th century to the beginning of the 19th century, problems with the supply of wood worsened at most of the Ural mining plants. The forests of the factory dachas were cut down at a distance of 5 to 25 versts. The old factories had even greater distances: the Kamensk plant had 50-55 versts, and the Nevyansk plant had 40-70 versts. Decrees were issued prohibiting unauthorized logging. | 0 | Metallurgy |
Phosphorylation involves the transfer of phosphate groups from ATP to the enzyme, the energy for which comes from hydrolysing ATP into ADP or AMP. However, dephosphorylation releases phosphates into solution as free ions, because attaching them back to ATP would require energy input.
Cysteine-dependent phosphatases (CDPs) catalyse the hydrolysis of a phosphoester bond via a phospho-cysteine intermediate.
The free cysteine nucleophile forms a bond with the phosphorus atom of the phosphate moiety, and the P-O bond linking the phosphate group to the tyrosine is protonated, either by a suitably positioned acidic amino acid residue (Asp in the diagram below) or a water molecule. The phospho-cysteine intermediate is then hydrolysed by another water molecule, thus regenerating the active site for another dephosphorylation reaction.
Metallo-phosphatases (e.g. PP2C) co-ordinate 2 catalytically essential metal ions within their active site. There is currently some confusion of the identity of these metal ions, as successive attempts to identify them yield different answers. There is currently evidence that these metals could be Magnesium, Manganese, Iron, Zinc, or any combination thereof. It is thought that a hydroxyl ion bridging the two metal ions takes part in nucleophilic attack on the phosphorus ion. | 1 | Gene expression + Signal Transduction |
* 2002 and 2005 Grossman Award, ASM International
* 2005 Grunfeld Medal, Institute of Materials, Minerals and Mining (IOM3)
* 2010 Harvey Flower Titanium prize, Institute of Materials, Minerals and Mining
* 2014 Defence Aerospace award, Rolls-Royce
* 2017 Cook/Ablett Medal, Institute of Materials, Minerals and Mining
* 2018 EPD Division Science awards, The Minerals, Metals & Materials Society (TMS)
* 2022 Silver Medal, Acta Materialia | 0 | Metallurgy |
Lipid signaling, broadly defined, refers to any biological cell signaling event involving a lipid messenger that binds a protein target, such as a receptor, kinase or phosphatase, which in turn mediate the effects of these lipids on specific cellular responses. Lipid signaling is thought to be qualitatively different from other classical signaling paradigms (such as monoamine neurotransmission) because lipids can freely diffuse through membranes (see osmosis). One consequence of this is that lipid messengers cannot be stored in vesicles prior to release and so are often biosynthesized "on demand" at their intended site of action. As such, many lipid signaling molecules cannot circulate freely in solution but, rather, exist bound to special carrier proteins in serum. | 1 | Gene expression + Signal Transduction |
Some of the oldest known examples of the lost-wax technique are the objects discovered in the Nahal Mishmar hoard in southern Land of Israel, and which belong to the Chalcolithic period (4500–3500 BC). Conservative Carbon-14 estimates date the items to around 3700 BC, making them more than 5700 years old. | 0 | Metallurgy |
Cast iron farm tools and weapons were widespread in China by the 5th century BC, employing workforces of over 200 men in iron smelters from the 3rd century onward. The earliest known blast furnaces are attributed to the Han dynasty in the 1st century AD. These early furnaces had clay walls and used phosphorus-containing minerals as a flux. Chinese blast furnaces ranged from around two to ten meters in height, depending on the region. The largest ones were found in modern Sichuan and Guangdong, while the 'dwarf" blast furnaces were found in Dabieshan. In construction, they are both around the same level of technological sophistication
There is no evidence of the bloomery in China after the appearance of the blast furnace and cast iron. In China, blast furnaces produced cast iron, which was then either converted into finished implements in a cupola furnace, or turned into wrought iron in a fining hearth. If iron ores are heated with carbon to 1420–1470 K, a molten liquid is formed, an alloy of about 96.5% iron and 3.5% carbon. This product is strong, can be cast into intricate shapes, but is too brittle to be worked, unless the product is decarburized to remove most of the carbon. The vast majority of Chinese iron manufacture, from the late Zhou dynasty onward, was of cast iron. However forged swords began to be made in the Warring-States-period: "Earliest iron and steel Jian also appear, made by the earliest and most basic forging and folding techniques." Iron would become, by around 300 BCE, the preferred metal for tools and weapons in China.
The primary advantage of the early blast furnace was in large scale production and making iron implements more readily available to peasants. Cast iron is more brittle than wrought iron or steel, which required additional fining and then cementation or co-fusion to produce, but for menial activities such as farming it sufficed. By using the blast furnace, it was possible to produce larger quantities of tools such as ploughshares more efficiently than the bloomery. In areas where quality was important, such as warfare, wrought iron and steel were preferred. Nearly all Han period weapons are made of wrought iron or steel, with the exception of axe-heads, of which many are made of cast iron.
The effectiveness of the Chinese human and horse powered blast furnaces was enhanced during this period by the engineer Du Shi (c. AD 31), who applied the power of waterwheels to piston-bellows in forging cast iron. Early water-driven reciprocators for operating blast furnaces were built according to the structure of horse powered reciprocators that already existed. That is, the circular motion of the wheel, be it horse driven or water driven, was transferred by the combination of a belt drive, a crank-and-connecting-rod, other connecting rods, and various shafts, into the reciprocal motion necessary to operate a push bellow.
Donald Wagner suggests that early blast furnace and cast iron production evolved from furnaces used to melt bronze. Certainly, though, iron was essential to military success by the time the State of Qin had unified China (221 BC). Usage of the blast and cupola furnace remained widespread during the Song and Tang dynasties. By the 11th century, the Song dynasty Chinese iron industry made a switch of resources from charcoal to coke in casting iron and steel, sparing thousands of acres of woodland from felling. This may have happened as early as the 4th century AD.
Blast furnaces were also later used to produce gunpowder weapons such as cast iron bomb shells and cast iron cannons during the Song dynasty. | 0 | Metallurgy |
The boundary between one grain and its neighbour (grain boundary) is a defect in the crystal structure and so it is associated with a certain amount of energy. As a result, there is a thermodynamic driving force for the total area of boundary to be reduced. If the grain size increases, accompanied by a reduction in the actual number of grains per volume, then the total area of grain boundary will be reduced.
In the classic theory, the local velocity of a grain boundary at any point is proportional to the local curvature of the grain boundary, i.e.:
where is the velocity of grain boundary, is grain boundary mobility (generally depends on orientation of two grains), is the grain boundary energy and is the sum of the two principal surface curvatures. For example, shrinkage velocity of a spherical grain embedded inside another grain is
where is radius of the sphere. This driving pressure is very similar in nature to the Laplace pressure that occurs in foams.
In comparison to phase transformations the energy available to drive grain growth is very low and so it tends to occur at much slower rates and is easily slowed by the presence of second phase particles or solute atoms in the structure.
Recently, in contrast to the classic linear relation between grain boundary velocity and curvature, grain boundary velocity and curvature are observed to be not correlated in Ni polycrystals, which conflicting results has been revealed and be theoretically interpreted by a general model of grain boundary (GB) migration in the previous literature. According to the general GB migration model, the classical linear relation can only be used in a specical case. | 0 | Metallurgy |
DSIF (DRB Sensitivity Inducing Factor) is a protein complex that can either negatively or positively affect transcription by RNA polymerase II (Pol II). It can interact with the negative elongation factor (NELF) to promote the stalling of Pol II at some genes, which is called promoter proximal pausing. The pause occurs soon after initiation, once 20-60 nucleotides have been transcribed. This stalling is relieved by positive transcription elongation factor b (P-TEFb) and Pol II enters productive elongation to resume synthesis till finish. In humans, DSIF is composed of hSPT4 and hSPT5. hSPT5 has a direct role in mRNA capping which occurs while the elongation is paused.
SPT5 is preserved in humans to bacteria. SPT4 and SPT5 in yeast are the homologs of hSPT4 and hSPT5. In bacteria, the homologous complex only contains NusG, a Spt5 homolog. Archaea have both proteins.
The complex locks the RNA polymerase (RNAP) clamp into a closed state to prevent the elongation complex (EC) from dissociating. The Spt5 NGN domain helps anneal the two strands of DNA upstream. The single KOW domain in bacteria and archaea anchors a ribosome to the RNAP. | 1 | Gene expression + Signal Transduction |
Streptococcus pyogenes has evolved an interwoven complex of gene regulatory mechanisms in the SIP signaling pathway by implanting a pH sensitive histidine switch onto the quorum-sensing ropB protein. During the neutral to basic pH conditions whether synthetically induced or naturally caused by low population density of S. pyogenes, the interaction between the unprotonated functionally involved histidine (H144) with relevant sidechains (Y176, Y182, E185) in the SIP binding pocket domain is impaired and speB protease expression is inhibited. On the other hand, as extracellular pH decreases to be more acidic in cases of high population density, S. pyogenes has no elaborate pH homeostatic capabilities relative to non-lactic bacteria, therefore intracellular cytosolic pH levels will more easily resemble extracellular levels. Cytosolic acidification mobilizes the SIP pathway to allow for the SIP-ropB protein complex to form and increasing SIP production. Furthermore, increased cytosolic acidity enhances the maturation of speB zymogen (speBz) into mature speB protease (speBm) to dramatically increase its proteolytic activity and virulence. | 1 | Gene expression + Signal Transduction |
The Ribose repressor (RbsR) is a bacterial DNA-binding transcription repressor protein and a member of the LacI/GalR protein family. In Escherichia coli, RbsR is responsible for regulation of genes involved in D-ribose metabolism. In Bacillus subtilis, RbsR was shown to interact with Histidine-containing protein (HPr), an allosteric effector of the related LacI/GalR protein Catabolite Control Protein A (CcpA). | 1 | Gene expression + Signal Transduction |
After the successful operation of the BBOC at BRM, MIM Holdings Limited (“MIM”) decided to license the technology to other smelter and refinery operators. Early adopters included Hindustan Zinc Limited, which by 1995 had two 1 t BBOC plants operating in India, and ASARCO Inc., which was operating a 3 t BBOC furnace at its Omaha, Nebraska, refinery. | 0 | Metallurgy |
As shown in the table below, the three chief national producers of copper, respectively, in 2002, were Chile, Indonesia, and the United States. In 2013, they were Chile, China, and Peru. Twenty-one of the 28 largest copper mines in the world (as of 2006) are not amenable to expansion. | 0 | Metallurgy |
RNA polymerase binding in bacteria involves the sigma factor recognizing the core promoter region containing the −35 and −10 elements (located before the beginning of sequence to be transcribed) and also, at some promoters, the α subunit C-terminal domain recognizing promoter upstream elements. There are multiple interchangeable sigma factors, each of which recognizes a distinct set of promoters. For example, in E. coli, σ is expressed under normal conditions and recognizes promoters for genes required under normal conditions ("housekeeping genes"), while σ recognizes promoters for genes required at high temperatures ("heat-shock genes"). In archaea and eukaryotes, the functions of the bacterial general transcription factor sigma are performed by multiple general transcription factors that work together. The RNA polymerase-promoter closed complex is usually referred to as the "transcription preinitiation complex."
After binding to the DNA, the RNA polymerase switches from a closed complex to an open complex. This change involves the separation of the DNA strands to form an unwound section of DNA of approximately 13 bp, referred to as the "transcription bubble". Supercoiling plays an important part in polymerase activity because of the unwinding and rewinding of DNA. Because regions of DNA in front of RNAP are unwound, there are compensatory positive supercoils. Regions behind RNAP are rewound and negative supercoils are present. | 1 | Gene expression + Signal Transduction |
Prp24 has a molecular weight of 50 kDa and has been shown to contain four RNA recognition motifs (RRMs) and a conserved 12-amino acid sequence at the C-terminus. RRMs 1 and 2 have been shown to be important for high-affinity binding of U6, while RRMs 3 and 4 bind at lower affinity sites on U6. The first three RRMs interact extensively with each other and contain canonical folds that contain a four-stranded beta-sheet and two alpha-helices. The electropositive surface of RRMs 1 and 2 is a RNA annealing domain while the cleft between RRMs 1 and 2 including the beta-sheet face of RRM2 is a sequence-specific RNA binding site. The C-terminal motif is required for association with LSm proteins and contributes to substrate (U6) binding and not the catalytic rate of splicing. | 1 | Gene expression + Signal Transduction |
Early iron smelting used charcoal as both the heat source and the reducing agent. By the 18th century, the availability of wood for making charcoal was limiting the expansion of iron production, so that England became increasingly dependent for a considerable part of the iron required by its industry, on Sweden (from the mid-17th century) and then from about 1725 also on Russia.
Smelting with coal (or its derivative coke) was a long sought objective. The production of pig iron with coke was probably achieved by Dud Dudley around 1619, and with a mixed fuel made from coal and wood again in the 1670s. However this was probably only a technological rather than a commercial success. Shadrach Fox may have smelted iron with coke at Coalbrookdale in Shropshire in the 1690s, but only to make cannonballs and other cast iron products such as shells. However, in the peace after the Nine Years War, there was no demand for these. | 0 | Metallurgy |
The inscription covers an area of 2′9.5″× 10.5″(65.09 cm x 26.67 cm). The ancient writing is preserved well because of the corrosion-resistant iron on which it is engraved. However, during the engraving process, iron appears to have closed up over some of the strokes, making some of the letters imperfect.
It contains verses composed in Sanskrit language, in shardulvikridita metre. It is written in the eastern variety of the Gupta script. The letters vary from 0.3125″ to 0.5″ in size, and resemble closely to the letters on the Allahabad Pillar inscription of Samudragupta. However, it had distinctive s (diacritics), similar to the ones in the Bilsad inscription of Kumaragupta I. While the edges of the characters on the Allahabad inscription are more curved, the ones on the Delhi inscription have more straight edges. This can be attributed to the fact that the Allahabad inscription was inscribed on softer sandstone, while the Delhi inscription is engraved on the harder material (iron).
The text has some unusual deviations from the standard Sanskrit spelling, such as:
* instead of : the use of dental nasal instead of anusvāra
* instead of : omission of the second t
* instead of : omission of the second t
* instead of śatru (enemy): an extra t | 0 | Metallurgy |
During elongation, RNA polymerase slides down the double stranded DNA, unwinding it and transcribing (copying) its nucleotide sequence into newly synthesized RNA. The movement of the RNA-DNA complex is essential for the catalytic mechanism of RNA polymerase. Additionally, RNA polymerase increases the overall stability of this process by acting as a link between the RNA and DNA strands. New nucleotides that are complementary to the DNA template strand are added to the 3 end of the RNA strand. The newly formed RNA strand is practically identical to the DNA coding strand (sense strand or non-template strand), except it has uracil substituting thymine, and a ribose sugar backbone instead of a deoxyribose sugar backbone. Because nucleoside triphosphates (NTPs) need to attach to the OH- molecule on the 3 end of the RNA, transcription always occurs in the 5 to 3 direction. The four NTPs are adenosine-5-triphosphate (ATP), guanoside-5-triphosphate (GTP), uridine-5-triphosphate (UTP), and cytidine-5-triphosphate (CTP). The attachment of NTPs onto the 3' end of the RNA transcript provides the energy required for this synthesis. NTPs are also energy producing molecules that provide the fuel that drives chemical reactions in the cell.
Multiple RNA polymerases can be active at once, meaning many strands of mRNA can be produced very quickly. RNA polymerase moves down the DNA rapidly at approximately 40 bases per second. Due to the quick nature of this process, DNA is continually unwound ahead of RNA polymerase and then rewound once RNA polymerase moves along further. The polymerase has a proofreading mechanism that limits mistakes to about 1 in 10,000 nucleotides transcribed. RNA polymerase has lower fidelity (accuracy) and speed than DNA polymerase. DNA polymerase has a very different proofreading mechanism that includes exonuclease activity, which contributes to the higher fidelity. The consequence of an error during RNA synthesis is usually harmless, where as an error in DNA synthesis could be detrimental.
The promoter sequence determines the frequency of transcription of its corresponding gene. | 1 | Gene expression + Signal Transduction |
It was founded in 1945. The inaugural meeting was held on 28 November 1945; the organization was formed by the Iron and Steel Institute and the Institute of Metals.
The International Iron and Steel Institute was formed in 1967, which is now the World Steel Association. by the late 1960s the Institution had around 10,000 metallurgists.
It was involved in the formation of the Association of Professional Scientists and Technologists (APST) in 1971, which was formed as a result of the Industrial Relations Act 1971. | 0 | Metallurgy |
A superalloy, or high-performance alloy, is an alloy with the ability to operate at a high fraction of its melting point. Key characteristics of a superalloy include mechanical strength, thermal creep deformation resistance, surface stability, and corrosion and oxidation resistance.
The crystal structure is typically face-centered cubic (FCC) austenitic. Examples of such alloys are Hastelloy, Inconel, Waspaloy, Rene alloys, Incoloy, MP98T, TMS alloys, and CMSX single crystal alloys.
Superalloy development relies on chemical and process innovations. Superalloys develop high temperature strength through solid solution strengthening and precipitation strengthening from secondary phase precipitates such as gamma prime and carbides. Oxidation or corrosion resistance is provided by elements such as aluminium and chromium. Superalloys are often cast as a single crystal in order to eliminate grain boundaries, which decrease creep resistance (even though they may provide strength at low temperatures).
The primary application for such alloys is in aerospace and marine turbine engines. Creep is typically the lifetime-limiting factor in gas turbine blades.
Superalloys have made much of very-high-temperature engineering technology possible. | 0 | Metallurgy |
Gene expression in mammals is regulated by many cis-regulatory elements, including core promoters and promoter-proximal elements that are located near the transcription start sites of genes. Core promoters are sufficient to direct transcription
initiation, but generally have low basal activity. Other important cis-regulatory modules are localized in DNA regions that are distant from the transcription start sites. These include enhancers, silencers, insulators and tethering elements. Among this constellation of elements, enhancers and their associated transcription factors have a leading role in the regulation of gene expression. An enhancer localized in a DNA region distant from the promoter of a gene can have a very large effect on gene expression, with some genes undergoing up to 100-fold increased expression due to an activated enhancer.
Enhancers are regions of the genome that are major gene-regulatory elements. Enhancers control cell-type-specific gene expression programs, most often by looping through long distances to come in physical proximity with the promoters of their target genes. While there are hundreds of thousands of enhancer DNA regions, for a particular type of tissue only specific enhancers are brought into proximity with the promoters that they regulate. In a study of brain cortical neurons, 24,937 loops were found, bringing enhancers to their target promoters. Multiple enhancers, each often at tens or hundreds of thousands of nucleotides distant from their target genes, loop to their target gene promoters and can coordinate with each other to control the expression of their common target gene.
The schematic illustration in this section shows an enhancer looping around to come into close physical proximity with the promoter of a target gene. The loop is stabilized by a dimer of a connector protein (e.g. dimer of CTCF or YY1), with one member of the dimer anchored to its binding motif on the enhancer and the other member anchored to its binding motif on the promoter (represented by the red zigzags in the illustration). Several cell function specific transcription factors (there are about 1,600 transcription factors in a human cell) generally bind to specific motifs on an enhancer and a small combination of these enhancer-bound transcription factors, when brought close to a promoter by a DNA loop, govern level of transcription of the target gene. Mediator (a complex usually consisting of about 26 proteins in an interacting structure) communicates regulatory signals from enhancer DNA-bound transcription factors directly to the RNA polymerase II (pol II) enzyme bound to the promoter.
Enhancers, when active, are generally transcribed from both strands of DNA with RNA polymerases acting in two different directions, producing two Enhancer RNAs (eRNAs) as illustrated in the Figure. Like mRNAs, these eRNAs are usually protected by their 5′ cap. An inactive enhancer may be bound by an inactive transcription factor. Phosphorylation of the transcription factor may activate it and that activated transcription factor may then activate the enhancer to which it is bound (see small red star representing phosphorylation of transcription factor bound to enhancer in the illustration). An activated enhancer begins transcription of its RNA before activating transcription of messenger RNA from its target gene. | 1 | Gene expression + Signal Transduction |
A variety of compounds are added to stabilize the foams. These additives include pine oil, various alcohols (methyl isobutyl carbinol (MIBC)), polyglycols, xylenol (cresylic acid). | 0 | Metallurgy |
CKIδ activity is implicated in mitosis and in response to DNA damage. During interphase, CKIδ associates with the Golgi Apparatus and appears to regulate the budding of clathrin coated vesicles from the TGN; it also appears to associate with tubulin. While undamaged mitotic cells shows no CKIδ association with tubulin, the kinase was recruited during mitosis in cells with DNA damage, indicative of a role for CKIδ in arranging the microtubule network during mitosis. The mechanisms for these biochemical interactions remain unknown. | 1 | Gene expression + Signal Transduction |
The multiple hearth furnaces consist of several circular hearths or kilns superimposed on each other. Material is fed from the top and is moved by the action of rotating "rabble arms", and the revolving mechanical rabbles attached to the arms move over the surface of each hearth to continuously shift the ore. The arms are attached to a rotating central shaft that passes through the center of the roaster. As the material is moved, the ore that is charged at the top hearth gradually moves downward as it passes through windows in the floor of each hearth or through alternate passages around the shaft and the periphery until it finally emerges at the bottom. | 0 | Metallurgy |
The integrated stress response can be triggered within a cell due to either extrinsic or intrinsic conditions. Extrinsic factors include hypoxia, amino acid deprivation, glucose deprivation, viral infection and presence of oxidants. The main intrinsic factor is endoplasmic reticulum stress due to the accumulation of unfolded proteins. It has also been observed that the integrated stress response may trigger due to oncogene activation. The integrated stress response will either cause the expression of genes that fix the damage in the cell due to the stressful conditions, or it will cause a cascade of events leading to apoptosis, which occurs when the cell cannot be brought back into homeostasis. | 1 | Gene expression + Signal Transduction |
* Chemical Vapour Deposition (CVD). This was a major development area at Fulmer. A wide range of metals and inorganic compounds were deposited. Examples are: tungsten coating of graphite rocket nozzles for ablation resistance, boron nitride crucibles for melting gallium arsenide, alumina coatings on carbon fibres for reinforcement of aluminium, zinc sulphide infrared radomes for heat-seeking missiles. Fulmers profound understanding of subhalide disproportionation led its chemists to devise a process in which halide vapour, pulsed at low partial pressure could be used to put uniform oxidation resistant coatings of aluminium or chromium on gas turbine blades. This was especially difficult because the coated surface had to include the insides of the blades long narrow cooling passages – 2mm diameter and 180 mm long for example. In 1975 Fulmer hosted the fifth International Conference on Chemical Vapor Deposition.
* The Fulmer tension meter is a device for measuring the tension in ropes and cables. A fixed length of cable is displaced at right angles using a lever and cam. The tension in the cable is arrived at by measuring the consequent displacement in the frame of the meter. In 1971 Fulmer set up a joint company with the sponsor of this development and subsequently acquired all the shares. The meter continues to be produced and marketed by a successor company.
* Fulmer devised the RPD system for project planning under uncertainty and gave about a hundred training seminars to R&D investigators in the UK and abroad.
* The Fulmer Materials Optimizer (FMO). This was an information system designed to enable a rapid comparison of materials competing for any given application. Many of Fulmer's technical staff contributed information to the FMO and many clients subscribed to support its preparation. It was published in 1974 as four loose-leaf large format files. The FMO included many data sheets, nomograms and other charts. It illustrates the approach needed in 1974, before the days of hypertext and the World Wide Web.
* Ion Engine. In the early 1970s Fulmer participated in a collaborative programme on the development of ion thrusters for space propulsion. They constructed a Type T4A mercury ion thruster and a high-vacuum test facility. Grid life testing totalling over 2000 hours was successfully completed.
* In 1975 Fulmer obtained a two-year contract from UNIDO to set up a Metals Advisory Service (MAS) in Lahore Pakistan. The laboratories established then are now the Technical Service Centre of the Pakistan Standards and Quality Control Authority (PSQCA).
* Solar water-heating trials. In 1976 Fulmer built a solar laboratory on the Stoke Poges site. This was the approximate size and shape of a two-storey domestic dwelling and was mounted on a circular track so that it could be rotated to any orientation. Solar hot-water panels were mounted on the roof. Investigations determined the economical viability of various systems for space and water heating and which materials and processes should be used.
* The development of frame-to-hull bonding methods in GRP ships. The project enabled the construction of for the Royal Navy, (Wilton was a prototype coastal minesweeper/minehunter and the first warship in the world to be constructed from glass-reinforced plastic) and supported the development of the Royal Navy's Hunt class Mine countermeasures vessels.
* Shape Memory alloys. When an object made of a shape-memory alloy is deformed under suitable conditions it can be made to return to its original shape by heating. Researchers at Fulmer discovered that this phenomenon is not confined to intermetallic compounds such as NiTi, but is exhibited in many metal solid solutions also. They did extensive work on many alloy systems. Two example applications developed at Fulmer are: heat-shrinkabe sleeves for use as pipe couplings and an actuator for the deployment of solar panels on spacecraft.
* Starting in 1977 YRL undertook small scale synthesis of specified organic chemicals many of them the organo-fluorine compounds widely used in pharmaceutical research and as precursors in drug manufacture. This was successful and in 1988 a joint venture with Shell Chemicals UK was launched as Yarsley Fluorochemicals Ltd. This was later purchased by Shell. After a management buy-out, it now continues as JRD Fluorochemicals Ltd.
* Superdart. A marksman training system in which the point of impact of a rifle round on a target is computed by triangulation from the signals received from a number of acoustic sensors and is then displayed on a screen next to the firing point. This gives the marksman instant feedback on his accuracy. This is an example of a multi-disciplinary project. It involved ballistics, sensor technology and mathematical modelling as well as the development of new materials.
* Acoustic emission monitoring.
* Hydrophilic polymers for soft contact lenses. YTEC devised novel homopolymer and copolymer systems for soft contact lens preparations. A polymer system was formulated to exhibit a high degree of water containment in the swollen state and yet be sufficiently stable to form a precision lens to an individual prescription. YTEC developed a process to full production scale and commissioned the production facility on the client's premises.
* Body Armour.
* Fabrication of targets for the ISIS neutron source at the Rutherford-Appleton Laboratory. These consisted of an assembly of depleted uranium discs clad in zircalloy. The production process involved machining the uranium discs, sealing their zircalloy containers by electron-beam welding, hot isostatic pressing to develop a diffusion bond between the zircalloy and the uranium and then ultrasonic testing to verify the integrity of the bond before final assembly.
* Fulmer devised techniques for probabilistic mathematical modelling and in 1986 hosted the first international conference on Modelling under Uncertainty. | 0 | Metallurgy |
A new ironmaking process was devised in the Namur region of what is now Belgium in the 15th century. This spread to the pays de Bray on the eastern boundary of Normandy and then to the Weald. The new smelting process involved a blast furnace and finery forge. It was introduced in about 1490 at Queenstock in Buxted parish. The number of ironworks increased greatly from about 1540. | 0 | Metallurgy |
Copper was probably the first metal mined and crafted by humans. It was originally obtained as a native metal and later from the smelting of ores. Earliest estimates of the discovery of copper suggest around 9000 BC in the Middle East. It was one of the most important materials to humans throughout the Chalcolithic and Bronze Ages. Copper beads dating from 6000 BC have been found in Çatalhöyük, Anatolia and the archaeological site of Belovode on the Rudnik mountain in Serbia contains the world's oldest securely dated evidence of copper smelting from 5000 BC. It was recognised as an element by Louis Guyton de Morveau, Antoine Lavoisier, Claude Berthollet, and Antoine-François de Fourcroy in 1787.
It is believed that lead smelting began at least 9,000 years ago, and the oldest known artifact of lead is a statuette found at the temple of Osiris on the site of Abydos dated around 3800 BC. It was recognised as an element by Guyton de Morveau, Lavoisier, Berthollet, and Fourcroy in 1787.
The earliest gold artifacts were discovered at the site of Wadi Qana in the Levant. Silver is estimated to have been discovered in Asia Minor shortly after copper and gold.
There is evidence that iron was known from before 5000 BC. The oldest known iron objects used by humans are some beads of meteoric iron, made in Egypt in about 4000 BC. The discovery of smelting around 3000 BC led to the start of the Iron Age around 1200 BC and the prominent use of iron for tools and weapons. It was recognised as an element by Guyton de Morveau, Lavoisier, Berthollet, and Fourcroy in 1787.
Tin was first smelted in combination with copper around 3500 BC to produce bronze (and thus giving place to the Bronze Age (except in some places which did not experience a significant Bronze Age, passing directly from the Neolithic Stone Age to the Iron Age)). Kestel, in southern Turkey, is the site of an ancient Cassiterite mine that was used from 3250 to 1800 BC. The oldest artifacts date from around 2000 BC. It was recognised as an element by Guyton de Morveau, Lavoisier, Berthollet, and Fourcroy in 1787. | 0 | Metallurgy |
The internodes are the myelin segments and the gaps between are referred to as nodes. The size and the spacing of the internodes vary with the fiber diameter in a curvilinear relationship that is optimized for maximal conduction velocity. The size of the nodes span from 1–2 μm whereas the internodes can be up to (and occasionally even greater than)1.5 millimetres long, depending on the axon diameter and fiber type.
The structure of the node and the flanking paranodal regions are distinct from the internodes under the compact myelin sheath, but are very similar in CNS and PNS. The axon is exposed to the extra-cellular environment at the node and is constricted in its diameter. The decreased axon size reflects a higher packing density of neurofilaments in this region, which are less heavily phosphorylated and are transported more slowly. Vesicles and other organelles are also increased at the nodes, which suggest that there is a bottleneck of axonal transport in both directions as well as local axonal-glial signaling.
When a longitudinal section is made through a myelinating Schwann cell at the node, three distinctive segments are represented: the stereotypic internode, the paranodal region, and the node itself. In the internodal region, the Schwann cell has an outer collar of cytoplasm, a compact myelin sheath, and inner collar of cytoplasm, and the axolemma. At the paranodal regions, the paranodal cytoplasm loops contact thickenings of the axolemma to form septate –like junctions. In the node alone, the axolemma is contacted by several Schwann microvilli and contains a dense cytoskeletal undercoating. | 1 | Gene expression + Signal Transduction |
Plants express the mechanistic target of rapamycin (mTOR) and have a TOR kinase complex. In plants, only the TORC1 complex is present unlike that of mammalian target of rapamycin which also contains the TORC2 complex. Plant species have TOR proteins in the protein kinase and FKBP-rapamycin binding (FRB) domains that share a similar amino acid sequence to mTOR in mammals.
Role of mTOR in plants
The TOR kinase complex has been known for having a role in the metabolism of plants. The TORC1 complex turns on when plants are living the proper environmental conditions to survive. Once activated, plant cells undergo particular anabolic reactions. These include plant development, translation of mRNA and the growth of cells within the plant. However, the TORC1 complex activation stops catabolic processes such as autophagy from occurring. TOR kinase signaling in plants has been found to aid in senescence, flowering, root and leaf growth, embryogenesis, and the meristem activation above the root cap of a plant. mTOR is also found to be highly involved in developing embryo tissue in plants. | 1 | Gene expression + Signal Transduction |
Studies have shown that the binding of TFIIB to TBP is affected by the length of the polyglutamine tract in TBP. Extended polyglutamine tracts such as those found in neurodegenerative diseases cause increased interaction with TFIIB. This is thought to affect transcription in these diseases as it reduces the availability of TFIIB to other promoters in the brain as the TFIIB is instead interacting with the expanded polyglutamine tracts. | 1 | Gene expression + Signal Transduction |
Calthemite is a secondary deposit, derived from concrete, lime, mortar or other calcareous material outside the cave environment. Calthemites grow on or under, man-made structures and mimic the shapes and forms of cave speleothems, such as stalactites, stalagmites, flowstone etc. Calthemite is derived from the Latin calx (genitive calcis) "lime" + Latin < Greek théma, "deposit" meaning ‘something laid down’, (also Mediaeval Latin thema, "deposit") and the Latin –ita < Greek -itēs – used as a suffix indicating a mineral or rock. The term "speleothem", due to its definition (spēlaion "cave" + théma "deposit" in ancient Greek) can only be used to describe secondary deposits in caves and does not include secondary deposits outside the cave environment. | 0 | Metallurgy |
Stone wool or rock wool is a spun mineral fibre used as an insulation product and in hydroponics. It is manufactured in a blast furnace fed with diabase rock which contains very low levels of metal oxides. The resultant slag is drawn off and spun to form the rock wool product. Very small amounts of metals are also produced which are an unwanted by-product. | 0 | Metallurgy |
A continuous cooling transformation (CCT) phase diagram is often used when heat treating steel. These diagrams are used to represent which types of phase changes will occur in a material as it is cooled at different rates. These diagrams are often more useful than time-temperature-transformation diagrams because it is more convenient to cool materials at a certain rate (temperature-variable cooling), than to cool quickly and hold at a certain temperature (isothermal cooling). | 0 | Metallurgy |
The near-instantaneous quenching of the metal causes the metal to have a near-amorphous crystalline structure, which is very uncharacteristic of a typical crystal. This structure is very similar to liquids, and the only difference between liquids and amorphous solids is the high viscosity of the solid. Solids in general have a crystalline structure instead of an amorphous structure because the crystalline structure has a stronger binding energy. The way a solid can have the irregular spacing between its atoms is when a liquid is cooled below its melting temperature. The reason for this is the molecules do not have enough time to rearrange themselves in a crystalline structure, and therefore stay in the liquid-like structure. | 0 | Metallurgy |
*EIF1 aka SUI1
*EIF1AD
*EIF1B
*EIF2A
*EIF2AK1
*EIF2AK3
*EIF2AK4
*EIF2AK1
*EIF2B2
*EIF2B3
*EIF2B4
*EIF2S2
*EIF3A
*EIF3B
*EIF3D formerly EIF3S4
*EIF3G
*EIF3I
*EIF3H
*EIF3J
*EIF3K
*EIF3L
*EIF3M
*EIF3S5
*EIF3S8
*EIF4A1
*EIF4A2
*EIF4A3
*EIF4E2
*EIF4G1
*EIF4G2
*EIF4G3
*EIF4H
*EIF5
*EIF5
*EIF5A
*EIF5AL1
*EIF5B
*EIF6
*TUFM Tu translational elongation factor mitochondrial | 1 | Gene expression + Signal Transduction |
During the Eastern Front (World War II) or the Great Patriotic War, the plant was almost completely destroyed (immediately before the start of the battles for the liberation of the city, on September 6–7, 1943. The underground workers operating at the plant, led by I.I. Kholoshin, including prisoners of war and assistants from the factory guards, disarmed the factory guards, occupied and saved warehouses, a garage, a telephone exchange and a special factory workshop from destruction).. Already in the fall of 1943, the restoration of the plant began. After the end of the war the plant was reconstructed and expanded. | 0 | Metallurgy |
Before 1800 A.D., the iron and steel industry was located where raw material, power supply and running water were easily available. After 1950, the iron and steel industry began to be located on large areas of flat land near sea ports. The history of the modern steel industry began in the late 1850s. Since then, steel has become a staple of the worlds industrial economy. This article is intended only to address the business, economic and social dimensions of the industry, since the bulk production of steel began as a result of Henry Bessemers development of the Bessemer converter, in 1857. Previously, steel was very expensive to produce, and was only used in small, expensive items, such as knives, swords and armor. | 0 | Metallurgy |
Prepainted metal is used in a variety of products. It can be formed for many different applications, including those with T bends, without loss of coating quality. Major industries use prepainted metal in products such as building panels, metal roofs wall panels, garage doors, office furniture (desks, cubicle divider panels, file cabinets, and modular cabinets), home appliances (refrigerators, dishwashers, freezers, range hoods, microwave ovens, and washers and dryers), heating and air-conditioning outer panels and ductwork, commercial appliances, vending machines, foodservice equipment and cooking tins, beverage cans, and automotive panels and parts (fuel tanks, body panels, bumpers), The list continues to grow, with new industries making the switch from post-painted to prepainted processes each year.
Some high-tech, complex coatings are applied with the coil coating process. Coatings for cool metal roofing materials, smog-eating building panels, antimicrobial products, anti-corrosive metal parts, and solar panels use this process. Pretreatments and coatings can be applied with the coil coating process in very precise, thin, uniform layers, and makes some complex coatings feasible and more cost-effective.
The largest market for prepainted metal is in both commercial and residential construction. It is chosen for the quality, low cost, design flexibility, and environmentally beneficial properties. Using prepainted metal can contribute to credit toward LEED certification for sustainable design. A wide arrange of color options are available with prepainted metal, including vibrant colors for modern designs, and natural weathered finishes in rustic expressions. Prepainted metal also can be formed, almost like plastic, in fluid shapes. This flexibility allows architects to achieve unique, expressive designs using metal.
The output of the coil coating industry is a prepainted metal strip. This has numerous applications in various industries, including in:
* The construction industry for both indoor and outdoor applications;
* The automotive and transport industries;
* The production of white goods including washing machines;
* Cabinets for electronic goods;
* Office furniture;
* Lighting envelopes;
* Bakeware. | 0 | Metallurgy |
The earliest metal manipulation was probably hammering (Craddock 1995, 1999), where copper ore was pounded into thin sheets. The ore (if there were large enough pieces of metal separate from mineral) could be beneficiated (made better) before or after melting, where the prills of metal could be hand-picked from the cooled slag. Melting beneficiated metal also allowed early metallurgists to use moulds and casts to form shapes of molten metal (Craddock 1995). Many of the metallurgical skills developed in the Bronze Age were still in use during Roman times. Melting—the process of using heat to separate slag and metal, smelting—using a reduced oxygen heated environment to separate metal oxides into metal and carbon dioxide, roasting—process of using an oxygen rich environment to isolate sulphur oxide from metal oxide which can then be smelted, casting—pouring liquid metal into a mould to make an object, hammering—using blunt force to make a thin sheet which can be annealed or shaped, and cupellation—separating metal alloys to isolate a specific metal—were all techniques which were well understood (Zwicker 1985, Tylecote 1962, Craddock 1995). However, the Romans provided few new technological advances other than the use of iron and the cupellation and granulation in the separation of gold alloys (Tylecote 1962).
While native gold is common, the ore will sometimes contain small amounts of silver and copper. The Romans utilised a sophisticated system to separate these precious metals. The use of cupellation, a process developed before the rise of Rome, would extract copper from gold and silver, or an alloy called electrum. In order to separate the gold and silver, however, the Romans would granulate the alloy by pouring the liquid, molten metal into cold water, and then smelt the granules with salt, separating the gold from the chemically altered silver chloride (Tylecote 1962). They used a similar method to extract silver from lead.
While Roman production became standardised in many ways, the evidence for distinct unity of furnace types is not strong, alluding to a tendency of the peripheries continuing with their own past furnace technologies. In order to complete some of the more complex metallurgical techniques, there is a bare minimum of necessary components for Roman metallurgy: metallic ore, furnace of unspecified type with a form of oxygen source (assumed by Tylecote to be bellows) and a method of restricting said oxygen (a lid or cover), a source of fuel (charcoal from wood or occasionally peat), moulds and/or hammers and anvils for shaping, the use of crucibles for isolating metals (Zwicker 1985), and likewise cupellation hearths (Tylecote 1962). | 0 | Metallurgy |
Common high-activity activators are mineral acids, often together with halides, amines, water or alcohols:
* hydrochloric acid, most common
* phosphoric acid, less common, use limited by its polymerization at higher temperatures
Inorganic acids are highly corrosive to metals even at room temperature, which causes issues during storage, handling and applications. As soldering involves high temperatures, compounds that decompose or react, with acids as products, are frequently used:
* zinc chloride, which at high temperatures reacts with moisture, forming oxychloride and hydrochloric acid
* ammonium chloride, thermally decomposing to ammonia and hydrochloric acid
* amine hydrochlorides, decomposing to the amine and hydrochloric acid | 0 | Metallurgy |
The practice of tinning ironware to protect it against rust is an ancient one. According to Pliny the Elder tinning was invented by the Gallic Bituriges tribe (based near modern Bourges), who boiled copper objects in a tin solution in order to make them look as if they were made from silver. The first detailed account of the process appears in Zosimus of Panopolis, Book 6.62, part of a work on alchemy written in Roman Egypt around 300 AD. Aside from an attestation in 14th century England, the process is not attested again in Europe until the description in Lazarus Erckers Das Kleine Probierbuch' (1556)
The manufacture of tinplate was long a monopoly of Bohemia, but in about the year 1620 the industry spread to Saxony. Tinplate was apparently produced in the 1620s at a mill of (or under the patronage of) the Earl of Southampton, but it is not clear how long this continued.
Andrew Yarranton, an English engineer and agriculturist, and Ambrose Crowley (a Stourbridge blacksmith and father of the more famous Sir Ambrose Crowley III) were commissioned to go to Saxony and if possible discover the methods employed. They visited Dresden in 1667 and found out how it was made. In doing so, they were sponsored by various local ironmasters and people connected with the project to make the River Stour navigable. In Saxony, the plates were forged, but when they conducted experiments on their return to England, they tried rolling the iron. This led to two of the sponsors, the ironmasters Philip Foley and Joshua Newborough, erecting a new mill, Wolverley Lower Mill (or forge), in 1670. This contained three shops: one being a slitting mill, which would serve as a rolling mill, the others being forges. In 1678 one of these was making frying pans and the other drawing out blooms made in finery forges elsewhere. It is likely that the intention was to roll the plates and then finish them under a hammer, but the plan was frustrated by one William Chamberlaine renewing a patent granted to him and Dud Dudley in 1662. Yarranton described the patent as "trumped up".
The slitter at Wolverley was Thomas Cooke. Another Thomas Cooke, perhaps his son, moved to Pontypool and worked there for John Hanbury (1664–1734). According to Edward Lhuyd, by 1697, John Hanbury had a rolling mill at Pontypool for making "Pontypoole Plates" machine. This has been claimed as a tinplate works, but it was almost certainly only producing (untinned) blackplate. However, this method of rolling iron plates by means of cylinders, enabled more uniform black plates to be produced than was possible with the old plan of hammering, and in consequence the English tinplate became recognised as superior to the German.
Tinplate first begins to appear in the Gloucester Port Books (which record trade passing through Gloucester, mostly from ports in the Bristol Channel) in 1725. The tinplate was shipped from Newport, Monmouthshire. This immediately follows the first appearance (in French) of Réaumurs Principes de lart de fer-blanc, and prior to a report of it being published in England.
Further mills followed a few years later, initially in many ironmaking regions in England and Wales, but later mainly in south Wales. In 1805, 80,000 boxes were made and 50,000 exported. The industry continued to spread steadily in England and especially Wales, and after 1834 its expansion was rapid, Great Britain becoming the chief source of the world's supply. In that year her total production was 180,000 boxes of 108 lb each (around 50 kg, in America a box is 100 lb), in 1848 it was 420,000 boxes, in 1860 it reached 1,700,000 boxes. But subsequently the advance was rapid, and the production reached about 2,236,000 lb in 1891. One of the greatest markets was the United States of America, but that market was cut off in 1891, when the McKinley tariff was enacted there. This caused a great retrenchment in the British industry and the emigration to America of many of those who could no longer be employed in the surviving tinplate works.
In 1891, the United States made 11,000 tons of tinplate and imported 325,100 tons, but in 1899, it made 360,900 tons, importing only 63,500 tons (mostly for re-export). British exports were further hindered by the Dingley tariff, which removed the advantage of Welsh plate on America's Pacific coast, had by 1900 increased to more than 849,000,000 lb, of which over 141,000,000 lb were terne-plates. The total imports in that year were only 135,264,881 lb. In later years, again, there was a decline in the American production, and in 1907 only 20% of the American tinplate mills were at work, while the British production reached 14 million boxes.
Despite this blow, the industry continued, but on a smaller scale. Nevertheless, there were still 518 mills in operation in 1937, including 224 belonging to Richard Thomas & Co. However the traditional pack mill had been overtaken by the improved strip mill, of which the first in Great Britain was built by Richard Thomas & Co. in the late 1930s. Strip mills rendered the old pack mills obsolete and the last of them closed in about the 1960s. | 0 | Metallurgy |
In metallurgy, gas flushing removes dissolved gases from the molten metal prior to the material being processed. For example, before casting aluminium alloys, argon bubbles are injected into liquid aluminium using a rotary degasser. The argon bubbles rise to the surface, bringing with them some of the dissolved hydrogen. The degassing step reduces the occurrence of hydrogen gas porosity. In the steel making process, this method is used very commonly for duplex steel and some high reactivity metals. | 0 | Metallurgy |
Fast hole drilling EDM was designed for producing fast, accurate, small, deep holes. It is conceptually akin to sinker EDM but the electrode is a rotating tube conveying a pressurized jet of dielectric fluid. It can make a hole an inch deep in about a minute and is a good way to machine holes in materials too hard for twist-drill machining. This EDM drilling type is used largely in the aerospace industry, producing cooling holes into aero blades and other components. It is also used to drill holes in industrial gas turbine blades, in molds and dies, and in bearings. | 0 | Metallurgy |
The iron pillar of Delhi is a structure high with a diameter that was constructed by Chandragupta II (reigned c. 375–415 CE), and now stands in the Qutub complex at Mehrauli in Delhi, India. The metals used in its construction have a rust-resistant composition. The pillar weighs more than six tonnes and is thought to have been erected elsewhere, perhaps outside the Udayagiri Caves, and moved to its present location by Anangpal Tomar in the 11th century. | 0 | Metallurgy |
The rapamycin analog temsirolimus (CCI-779) is also a noncytotoxic agent which delays tumor proliferation.
Temsirolimus is a prodrug of rapamycin. It is approved by the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA), for the treatment of renal cell carcinoma (RCC). Temsirolimus has higher water solubility than rapamycin and is therefore administered by intravenous injection. It was approved on May 30, 2007, by FDA for the treatment of advanced RCC.
Temsirolimus has also been used in a Phase I clinical trial in conjunction with neratinib, a small-molecule irreversible pan-HER tyrosine kinase inhibitor. This study enrolled patients being treated for HER2-amplified breast cancer, HER2-mutant non-small-cell lung cancer, and other advanced solid tumors. While common toxicities included nausea, stomatitis, and anemia; responses were noted. | 1 | Gene expression + Signal Transduction |
* J. Day and R. F. Tylecote, The Industrial Revolution in Metals (The Institute of Metals, London 1991).
* Söderberg, A. 2011. [http://web.comhem.se/vikingbronze/soderberg_situne_dei_2011.pdf Eyvind Skáldaspillir's silver - refining and standards in pre-monetary economies in the light of finds from Sigtuna and Gotland]. Situne Dei 2011. Edberg, R. Wikström, A. (eds). Sigtuna.
* R. F. Tylecote, A history of metallurgy (Institute of materials, London 1992).
* [http://www.ncl.ac.uk/library/specialcollections/collections/daguerreotypes/pattinson.php Newcastle University: Hugh Lee Pattinson] | 0 | Metallurgy |
Aluminium granules have been found safer and economical compared to atomized aluminium powder. Aluminium granules have lower explosion risk in production and in use of the product itself. | 0 | Metallurgy |
Archaeometallurgical slag is slag discovered and studied in the context of archaeology. Slag, the byproduct of iron-working processes such as smelting or smithing, is left at the iron-working site rather than being moved away with the product. As it weathers well, it is readily available for study. The size, shape, chemical composition and microstructure of slag are determined by features of the iron-working processes used at the time of its formation. | 0 | Metallurgy |
When using different types of microspheres, SAT is capable of simultaneously testing multiple variables, such as DNA and proteins, in a given sample. This allows SAT to analyze variety of molecular targets during a single reaction. The common nucleic acid detection method includes direct DNA hybridization. The direct DNA hybridization approach is the simplest suspension array assay whereby 15 to 20 bp DNA oligonucleotides attached to microspheres are amplified using PCR. This is the optimized probe length as it minimizes the melting temperature variation among different probes during probe-target hybridization. After amplifying one DNA oligoprobe of interest, it can be used to create 100 different probes on 100 different sets of microspheres, each with the capability of capturing 100 potential targets (if using a 100-plex array). Similarly, target DNA samples are usually PCR amplified and labeled. Hybridization between the capture probe and the target DNA is achieved by melting and annealing complementary target DNA sequences to their capture probes located on the microspheres. After washing to remove non-specific binding between sequences, only strongly paired probe-targets will remain hybridized. | 1 | Gene expression + Signal Transduction |
The Ames process was used on August 3, 1942, by a group of chemists led by Frank Spedding and Harley Wilhelm at the Ames Laboratory as part of the Manhattan Project. It is a type of thermite-based purification, which was patented in 1895 by German chemist Hans Goldschmidt. Development of the Ames process came at a time of increased research into mass uranium-metal production. The desire for increased production was motivated by a fear of Nazi Germany's developing nuclear weapons before the Allies. The process originally involved mixing powdered uranium tetrafluoride and powdered magnesium together. This mixture was placed inside an iron pipe that was welded shut on one side and capped shut on another side. This container, called a "bomb" by Spedding, was placed into a furnace. When heated to a temperature of , the contents of the container reacted violently, leaving a 35-gram ingot of pure uranium metal. The process was quickly scaled up; by October 1942 the "Ames Project" was producing metal at a rate of per week. The uranium tetrafluoride and magnesium were sealed in a refractory-lined reactor vessel, still referred to as a "bomb". The thermite reaction was initiated by furnace heating the assembly to ; the large difference in density between slag and metal allowed complete separation in the liquid state, yielding slag-free metal. By July 1943, the production rate exceeded of uranium metal per month. Approximately 1000 tons of uranium ingots were produced at Ames before the process was transferred to industry.
The Ames project received the Army-Navy "E" Award for Excellence in Production on October 12, 1945, signifying 2.5 years of excellence in industrial production of metallic uranium as a vital war material. Iowa State University is unique among educational institutions to have received this award for outstanding service, an honor normally given to industry. | 0 | Metallurgy |
Fas receptor has been shown to interact with:
* Caspase 8,
* Caspase 10,
* CFLAR,
* FADD,
* Fas ligand,
* PDCD6, and
* Small ubiquitin-related modifier 1. | 1 | Gene expression + Signal Transduction |
Heusler compounds are magnetic intermetallics with face-centered cubic crystal structure and a composition of XYZ (half-Heuslers) or XYZ (full-Heuslers), where X and Y are transition metals and Z is in the p-block. The term derives from the name of German mining engineer and chemist Friedrich Heusler, who studied such a compound (CuMnAl) in 1903. Many of these compounds exhibit properties relevant to spintronics, such as magnetoresistance, variations of the Hall effect, ferro-, antiferro-, and ferrimagnetism, half- and semimetallicity, semiconductivity with spin filter ability, superconductivity, topological band structure and are actively studied as thermoelectric materials. Their magnetism results from a double-exchange mechanism between neighboring magnetic ions. Manganese, which sits at the body centers of the cubic structure, was the magnetic ion in the first Heusler compound discovered. (See the Bethe–Slater curve for details of why this happens.) | 0 | Metallurgy |
The term pewter covers a variety of alloys consisting primarily of tin. As a pure metal, tin is much too soft to use for most practical purposes. However, during the Bronze Age, tin was a rare metal in many parts of Europe and the Mediterranean, so it was often valued higher than gold. To make jewellery, cutlery, or other objects from tin, workers usually alloyed it with other metals to increase strength and hardness. These metals were typically lead, antimony, bismuth or copper. These solutes were sometimes added individually in varying amounts, or added together, making a wide variety of objects, ranging from practical items such as dishes, surgical tools, candlesticks or funnels, to decorative items like ear rings and hair clips.
The earliest examples of pewter come from ancient Egypt, around 1450 BC. The use of pewter was widespread across Europe, from France to Norway and Britain (where most of the ancient tin was mined) to the Near East. The alloy was also used in China and the Far East, arriving in Japan around 800 AD, where it was used for making objects like ceremonial vessels, tea canisters, or chalices used in shinto shrines. | 0 | Metallurgy |
Viral genes and host genes that are required for viruses to replicate or enter the cell, or that play an important role in the life cycle of the virus are often targeted by antiviral therapies. RNAi has been used to target genes in several viral diseases, such as the human immunodeficiency virus (HIV) and hepatitis. In particular, siRNA was used to silence the primary HIV receptor chemokine receptor 5 (CCR5). This prevented the virus from entering the human peripheral blood lymphocytes and the primary hematopoietic stem cells. A similar technique was used to decrease the amount of the detectable virus in hepatitis B and C infected cells. In hepatitis B, siRNA silencing was used to target the surface antigen on the hepatitis B virus and led to a decrease in the number of viral components. In addition, siRNA techniques used in hepatitis C were able to lower the amount of the virus in the cell by 98%.
RNA interference has been in commercial use to control virus diseases of plants for over 20 years (see Plant disease resistance). In 1986–1990, multiple examples of "coat protein-mediated resistance" against plant viruses were published, before RNAi had been discovered. In 1993, work with tobacco etch virus first demonstrated that host organisms can target specific virus or mRNA sequences for degradation, and that this activity is the mechanism behind some examples of virus resistance in transgenic plants. The discovery of small interfering RNAs (the specificity determinant in RNA-mediated gene silencing) also utilized virus-induced post-transcriptional gene silencing in plants. By 1994, transgenic squash varieties had been generated expressing coat protein genes from three different viruses, providing squash hybrids with field-validated multiviral resistance that remain in commercial use at present. Potato lines expressing viral replicase sequences that confer resistance to potato leafroll virus were sold under the trade names NewLeaf Y and NewLeaf Plus, and were widely accepted in commercial production in 1999–2001, until McDonald's Corp. decided not to purchase GM potatoes and Monsanto decided to close their NatureMark potato business. Another frequently cited example of virus resistance mediated by gene silencing involves papaya, where the Hawaiian papaya industry was rescued by virus-resistant GM papayas produced and licensed by university researchers rather than a large corporation. These papayas also remain in use at present, although not without significant public protest, which is notably less evident in medical uses of gene silencing.
Gene silencing techniques have also been used to target other viruses, such as the human papilloma virus, the West Nile virus, and the Tulane virus. The E6 gene in tumor samples retrieved from patients with the human papilloma virus was targeted and found to cause apoptosis in the infected cells. Plasmid siRNA expression vectors used to target the West Nile virus were also able to prevent the replication of viruses in cell lines. In addition, siRNA has been found to be successful in preventing the replication of the Tulane virus, part of the virus family Caliciviridae, by targeting both its structural and non-structural genes. By targeting the NTPase gene, one dose of siRNA 4 hours pre-infection was shown to control Tulane virus replication for 48 hours post-infection, reducing the viral titer by up to 2.6 logarithms. Although the Tulane virus is species-specific and does not affect humans, it has been shown to be closely related to the human norovirus, which is the most common cause of acute gastroenteritis and food-borne disease outbreaks in the United States. Human noroviruses are notorious for being difficult to study in the laboratory, but the Tulane virus offers a model through which to study this family of viruses for the clinical goal of developing therapies that can be used to treat illnesses caused by human norovirus. | 1 | Gene expression + Signal Transduction |
Salmonella encodes a LuxR homolog, SdiA, but does not encode an AHL synthase. SdiA detects AHLs produced by other species of bacteria including Aeromonas hydrophila, Hafnia alvei, and Yersinia enterocolitica. When AHL is detected, SdiA regulates the rck operon on the Salmonella virulence plasmid (pefI-srgD-srgA-srgB-rck-srgC) and a single gene horizontal acquisition in the chromosome srgE. Salmonella does not detect AHL when passing through the gastrointestinal tracts of several animal species, suggesting that the normal microbiota does not produce AHLs. However, SdiA does become activated when Salmonella transits through turtles colonized with Aeromonas hydrophila or mice infected with Yersinia enterocolitica. Therefore, Salmonella appears to use SdiA to detect the AHL production of other pathogens rather than the normal gut flora. | 1 | Gene expression + Signal Transduction |
Hexagonal crystals of green rust (carbonate and/or sulfate) have also been obtained as a byproducts of bioreduction of ferric oxyhydroxides by dissimilatory iron-reducing bacteria, such as Shewanella putrefaciens, that couple the reduction of with the oxidation of organic matter. This process has been conjectured to occur in soil solutions and aquifers.
In one experiment, a 160 mM suspension of orange lepidocrocite γ- in a solution containing formate (), incubated for 3 days with a culture of S. putrefaciens, turned dark green due to the conversion of the hydroxide to GR(), in the form of hexagonal platelets with diameter ~7 µm. In this process, the formate was oxidized to bicarbonate which provided the carbonate anions for the formation of the green rust. The live bacteria were shown to be necessary for the formation of the green rust. | 0 | Metallurgy |
A fusible alloy is a metal alloy capable of being easily fused, i.e. easily meltable, at relatively low temperatures. Fusible alloys are commonly, but not necessarily, eutectic alloys.
Sometimes the term "fusible alloy" is used to describe alloys with a melting point below . Fusible alloys in this sense are used for solder. | 0 | Metallurgy |
Circular RNA (CircRNA) are a novel class of endogenous noncoding RNAs and are characterized by their covalently closed loop structures. This class of ncRNA does not have a 5’ cap or 3’ Poly A tail. It has been hypothesized that cirRNAs may function as potential molecular markers for disease diagnosis and treatment and play an important role in the initiation and progression of human diseases. | 1 | Gene expression + Signal Transduction |
*[http://www.prepaintedmetal.eu prepaintedmetal.eu]
*[http://www.prepaintedmetalacademy.eu prepaintedmetalacademy.eu]
*[http://www.creativebuilding.eu creativebuilding.eu]
*[http://www.creativeroofing.eu creativeroofing.eu] | 0 | Metallurgy |
Gold mining began in Gedebey in 2009. In 2016, Azer Gold CJSC began gold mining in the Chovdar deposit. In 2017, 6,390.8 kg of gold was mined (which exceeded the 2016 production by 3.4 times. Gold production in January–May 2018 amounted to 2,081.7 kg, which exceeds last years data by 19.5%. In the first quarter of 2018, the companys exports amounted to $30 million. In 2017, 59,617 ounces of gold produces by Anglo Asian Mining PLC (the main gold producer in Azerbaijan) from Gadir Ugur and Gosha deposits. | 0 | Metallurgy |
In contrast to receptor uncoupling, endocytosis can occur through multiple pathways. GPCR endocytosis has been shown to be either dependent or independent of arrestin activity, depending on the cell type used in the experiment; however, the former is more common. Furthermore, the same receptor expressed in two distinct cell types can be endocytosed through different mechanisms due to differences in GRK and arrestin expression: either through clathrin-coated vesicles or caveolae. In general, receptor sequestration preferentially affects receptors that are both activated and phosphorylated, but the phosphorylation is not always a necessary component of endocytosis. After being sequestered, the affected receptors can either be degraded by lysosomes or reinserted into the plasma membrane, which is called receptor recycling.
Post-translational modification also affects receptor endocytosis. For example, different glycosylations on the exterior N-terminus of dopamine receptors D and D were associated with specific endocytotic pathways. Additionally, palmitoylation, which primarily mediates receptor localization within the membrane, can also affect endocytosis. It is required for the endocytosis of thyrotropin-releasing hormone and D receptors, and it is inhibitory for leutinizing hormone and vasopressin receptor 1A receptors. It has been shown to have no effect on adrenergic receptors (specifically ß and α). | 1 | Gene expression + Signal Transduction |
Corrosion engineering involves good design. Using a rounded edge rather than an acute edge reduces corrosion. Also not coupling by welding or other joining method, two dissimilar metals to avoid galvanic corrosion is best practice. Avoiding having a small anode (or anodic material) next to a large cathode (or cathodic material) is good practice. As an example, weld material should always be more noble than the surrounding material. Corrosion in ballast tanks on marine vessels can be an issue if good design is not undertaken. Other examples include simple design such as material thickness. In a known corrosion situation the material can just be made thicker so it will take much longer to corrode. | 0 | Metallurgy |
Froth flotation efficiency is determined by a series of probabilities: those of particle–bubble contact, particle–bubble attachment, transport between the pulp and the froth, and froth collection into the product launder. In a conventional mechanically-agitated cell, the void fraction (i.e. volume occupied by air bubbles) is low (5 to 10 percent) and the bubble size is usually greater than 1 mm. This results in a relatively low interfacial area and a low probability of particle–bubble contact. Consequently, several cells in series are required to increase the particle residence time, thus increasing the probability of particle–bubble contact. | 0 | Metallurgy |
Mutations in super-enhancers have been noted in various diseases, including cancers, type 1 diabetes, Alzheimer’s disease, lupus, rheumatoid arthritis, multiple sclerosis, systemic scleroderma, primary biliary cirrhosis, Crohn’s disease, Graves disease, vitiligo, and atrial fibrillation. A similar enrichment in disease-associated sequence variation has also been observed for stretch enhancers.
Super-enhancers may play important roles in the misregulation of gene expression in cancer. During tumor development, tumor cells acquire super-enhancers at key oncogenes, which drive higher levels of transcription of these genes than in healthy cells. Altered super-enhancer function is also induced by mutations of chromatin regulators. Acquired super-enhancers may thus be biomarkers that could be useful for diagnosis and therapeutic intervention.
Proteins enriched at super-enhancers include the targets of small molecules that target transcription-regulating proteins and have been deployed against cancers. For instance, super-enhancers rely on exceptional amounts of CDK7, and, in cancer, multiple papers report the loss of expression of their target genes when cells are treated with the CDK7 inhibitor THZ1. Similarly, super-enhancers are enriched in the target of the JQ1 small molecule, BRD4, so treatment with JQ1 causes exceptional losses in expression for super-enhancer—associated genes. | 1 | Gene expression + Signal Transduction |
Unlike traditional steel or titanium, this material dissolves in organisms at a rate of roughly 1 millimeter per month and is replaced with bone tissue. This speed can be adjusted by varying the content of zinc.
Amorphous CaZnMg alloy exhibits extremely poor corrosion resistance. Wang et al. reported that the said amorphous alloy completely disintegrated after no more than 3 hours exposure in biocorrosion environment. In static distilled water at room temperature, Dahlman et al. also reported destructive corrosion reactions of the same material, decomposing into a multiphase powder.
Ca-BMGs with higher Zn contents as reported by Cao et al. showed an elastic modulus in the range of 35–46 GPa, and a hardness of 0.7–1.4 GPa. | 0 | Metallurgy |
As well as circulating coins, where they are generally restricted to high-denomination coins, bi-metallic coins are often used in commemorative issues, often made of precious metals. For example, the only bi-metallic coin issued by the United States is the $10 Library of Congress commemorative, made of a gold ring around a platinum center. They are used primarily as a way of securing against coin counterfeiting. | 0 | Metallurgy |
* Баньковский Л. [https://viewer.rusneb.ru/ru/rsl01004581977?page=1&rotate=0&theme=white История и экология: очерки об истоках исторической гидрогеографии] — Соликамск: 2008. — 356 с. — ISBN 978-5-89469-055-1 — OTRS — Книга доступна по лицензии CC BY-SA 4.0, 3.0
* Барбот де Марни Е. Н. [http://book.uraic.ru/elib/book-ural/161564/oglav.htm Урал и его богатства]. — Yekaterinburg, типография газеты «Уральская жизнь»: Издание П. И. Певина, 1910. — 413 с.
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* Белов В. Д. [http://elib.uraic.ru/handle/123456789/40158 Исторический очерк уральских горных заводов] / Выс. утв. Постоян. совещат. контора железозаводчиков. — СПб.: Типография Исидора Гольдберга, 1896. — 177 с.
* Валериус Б. Металлургия чугуна. Переведено и дополнено В. Ковригиным / Учёный комитет Корпуса горных инженеров. — СПб.: Типография Иосафата Огризко, 1862. — 687 с.
* Васильев Г. А., Никитин Д. И., Новиков И. А. [http://elib.cspu.ru/xmlui/bitstream/handle/123456789/4881/%D0%9D%D0%BE%D0%B2%D0%B8%D0%BA%D0%BE%D0%B2%20%D0%98.%D0%90.%20%D0%9C%D0%B5%D1%82%D0%B0%D0%BB%D0%BB%D1%83%D1%80%D0%B3%D0%B8%D1%8F%20%D0%AE%D0%B6%D0%BD%D0%BE%D0%B3%D0%BE%20%D0%A3%D1%80%D0%B0%D0%BB%D0%B0.pdf Металлургия Южного Урала: история и современность]. — Челябинск: ГБУ ДПО «Челябинский институт ГБУ ДПО «Челябинский институт переподготовки и повышения квалификации работников образования», 2018. — 112 с. — 100 экз. — ISBN 978-5-503-00345-1.
* Гаврилов Д. В. [https://www.wikidata.org/wiki/Q106199506 Горнозаводский Урал XVII—XX вв.]: Избранные труды — Екатеринбург: УрО РАН, 2005. — 616 с. — ISBN 5-89516-172-3
* Georg Wilhelm de Gennin, [https://history-kamensk.ru/books/gennin1.pdf Описание Уральских и Сибирских заводов]. 1735 — М.: Государственное издательство «История заводов», 1937. — 691 с.
* Гудков Г. Ф., Гудкова З. И. Из истории южноуральских горных заводов XVIII—XIX веков : Историко-краеведческие очерки. — Уфа : Башкирское книжное издательство, 1985. — Т. Часть 1. — 424 с. — 5000 экз.
* Alexei Ivanov (writer), [https://books.google.com/books?id=SEeNAgAAQBAJ Горнозаводская цивилизация] — М.: АСТ, 2014. — 283 с. — 4000 экз. — ISBN 978-5-17-079642-7
* Карабасов Ю. С., Черноусов П. И., Коротченко Н. А., Голубев О. В. Металлургия и время : Энциклопедия : в 6 т. — М. : Издательский Дом МИСиС, 2011. — [https://omk.ru/press/miv/Time_metal_part2.pdf Т. 2 : Фундамент индустриальной цивилизации. Возрождение и Новое время] . — 216 с. — 1000 экз. — ISBN 978-5-87623-537-4 (т. 2).
* Карабасов Ю. С., Черноусов П. И., Коротченко Н. А., Голубев О. В. Металлургия и время : Энциклопедия : в 6 т. — М. : Издательский Дом МИСиС, 2012. — Т. 4 : Русский вклад. — 232 с. — 1000 экз. — ISBN 978-5-87623-539-8 (т. 4).
* Карабасов Ю. С., Черноусов П. И., Коротченко Н. А., Голубев О. В. Металлургия и время : Энциклопедия : в 6 т. — М. : Издательский Дом МИСиС, 2014. — Т. 6 : Металлургия и социум. Взаимное влияние и развитие. — 224 с. — 1000 экз. — ISBN 978-5-87623-760-6 (т. 6).
* Кашинцев Д. А. История металлургии Урала / под ред. академика М. А. Павлова. — М., Л.: Государственное объединенное научно-техническое издательство, Редакция литературы по чёрной и цветной металлургии, 1939. — Т. 1 (и единственный): Первобытная эпоха XVII и XVIII веков. — 293 с. — 2000 экз.
* [https://www.wikidata.org/wiki/Q101518601 Кириллов В. М.], Корепанов Н. С., Микитюк В. П., Дашкевич Л. А. [https://gedenkbuch.rusdeutsch.ru/upload/files/El-knigi/Nemty-na-Urale.pdf Немцы на Урале XVII—XXI вв.]: Коллективная монография — Nizhny Tagil: [https://www.wikidata.org/wiki/Q4318940 НТГСПА], 2009. — 288 с. — 200 экз. — ISBN 978-5-8299-0122-6
* Лоранский А. М. [https://viewer.rusneb.ru/ru/rsl01003556534?page=1&rotate=0&theme=white Краткий исторический очерк административных учреждений горного ведомства в России 1700—1900 гг.]. — СПб.: Типография инж. Г. А. Бернштейна, 1900. — 207 с.
* Лотарёва Р. М. Города-заводы России : XVIII — первая половина XIX века. — Екатеринбург : Издательство «Сократ», 2011. — 288 с., 16 с. ил. — 1000 экз. — ISBN 978-5-88664-372-5.
* Неклюдов Е. Г. [https://www.wikidata.org/wiki/Q101218350 Горная реформа в России второй половины XIX — начала XX века]: От замысла к реализации / под ред. Г. Е. Корнилов — СПб.: [https://www.wikidata.org/wiki/Q101219930 Нестор-История], 2018. — 576 с. — 300 экз. — ISBN 978-5-4469-1344-2
* Павленко Н. И. История металлургии в России XVIII века : Заводы и заводовладельцы / отв. ред. А. А. Новосельский. — М. : Nauka (publisher), 1962. — 566 с. — 2000 экз.
* Stanislav Strumilin, [https://archive.org/details/istoriya_chernoy_metallurgii_v_SSSR_vol_1/mode/2up История чёрной металлургии в СССР] / под ред. Ivan Bardin — М.: Nauka (publisher), 1954. — Т. 1-й (и единственный). Феодальный период (1500—1860 гг.). — 533 с. — 5000 экз.
* Струмилин С. Г. Очерки экономической истории России и СССР. — М.: Наука, 1966. — 512 с. — 2500 экз.
* Хью Хадсон-мл. [https://www.academia.edu/35380624 Первые Демидовы и развитие чёрной металлургии России в XVIII веке] = The rise of the Demidov Family and the Russian iron industry in the eighteenth century / пер. с англ. И. В. Кучумова, отв. ред. И. Н. Юркин. — 2-е, исправленное и дополненное. — СПб.: ООО «Своё издательство», 2014. — 116 с. — (Башкортостан в зарубежных исследованиях). — 150 экз. — ISBN 978-5-4386-0282-8.
* [http://ihist.uran.ru/files/2002_Yekaterinburg.pdf Екатеринбург] : Энциклопедия / глав. ред. В. В. Маслаков. — Екатеринбург : Издательство «Академкнига», 2002. — 728 с. — 3900 экз. — ISBN 5-93472-068-6.
* [http://i.uran.ru/nasledie/content/istoriya-urala-s-drevneyshih-vremen-do-1861-g История Урала с древнейших времён до 1861 года] / под ред. [https://www.wikidata.org/wiki/Q104532574 А. А. Преображенский] — М.: Nauka (publisher), 1989. — 608 с. — 4100 экз. — ISBN 5-02-009432-3
* История Урала / Под общ. ред. И. С. Капцуговича. — 2-е изд. — Пермь : Пермское книжное издательство, 1976. — Т. 1. Первобытнообщинный строй. Период феодализма. Период капитализма. / ред. тома В. В. Мухин. — 396 с. — 5000 экз.
* История Урала с древнейших времён до конца XIX века / под ред. акад. Б. В. Личмана. — Екатеринбург: СВ-96, 1997. — 448 с. — 5000 экз. — ISBN 5-89516-035-2.
* История Урала: XX век / под. ред. Б. В. Личмана, В. Д. Камынина. — Екатеринбург: СВ-96, 1998. — 432 с. — 5000 экз. — ISBN 5-89516-036-0.
* [http://www.ihist.uran.ru/files/2001_MetallPlants.pdf Металлургические заводы Урала XVII—XX вв.]: Энциклопедия / глав. ред. В. В. Алексеев. — Екатеринбург : Издательство «Академкнига», 2001. — 536 с. — 1000 экз. — ISBN 5-93472-057-0.
* [https://library.gorobr.ru/p?view=content&id=30199 Очерки истории техники в России с древнейших времён до 60-х годов XIX века] / Председатель редколлегии И. И. Артоболевский. — М.: Наука, 1978. — 374 с. — 7550 экз. | 0 | Metallurgy |
A plasma arc furnace (PAF) uses plasma torches instead of graphite electrodes. Each of these torches has a casing with a nozzle and axial tubing for feeding a plasma-forming gas (either nitrogen or argon) and a burnable cylindrical graphite electrode within the tubing. Such furnaces can be called plasma arc melt (PAM) furnaces; they are used extensively in the titanium-melting industry and similar specialty metal industries. | 0 | Metallurgy |
In materials science, the yield strength anomaly refers to materials wherein the yield strength (i.e., the stress necessary to initiate plastic yielding) increases with temperature.
For the majority of materials, the yield strength decreases with increasing temperature. In metals, this decrease in yield strength is due to the thermal activation of dislocation motion, resulting in easier plastic deformation at higher temperatures.
In some cases, a yield strength anomaly refers to a decrease in the ductility of a material with increasing temperature, which is also opposite the trend in the majority of materials. Anomalies in ductility can be more clear, as an anomalous effect on yield strength can be obscured by its typical decrease with temperature. In concert with yield strength or ductility anomalies, some materials demonstrate extrema in other temperature dependent properties, such as a minimum in ultrasonic damping, or a maximum in electrical conductivity.
The yield strength anomaly in β-brass was one of the earliest discoveries such a phenomenon, and several other ordered intermetallic alloys demonstrate this effect. Precipitation-hardened superalloys exhibit a yield strength anomaly over a considerable temperature range. For these materials, the yield strength shows little variation between room temperature and several hundred degrees Celsius. Eventually, a maximum yield strength is reached. For even higher temperatures, the yield strength decreases and, eventually, drops to zero when reaching the melting temperature, where the solid material transforms into a liquid. For ordered intermetallics, the temperature of the yield strength peak is roughly 50% of the absolute melting temperature. | 0 | Metallurgy |
The FSHR consists of 695 amino acids and has a molecular mass of about 76 kDa. Like other GPCRs, the FSH-receptor possesses seven membrane-spanning domains or transmembrane helices.
* The extracellular domain of the receptor contains 11 leucine-rich repeats and is glycosylated. It has two subdomains, a hormone-binding subdomain followed by a signal-specificity subdomain. The hormone-binding subdomain is responsible for the high-affinity hormone binding, and the signal-specificity subdomain, containing a sulfated tyrosine at position 335 (sTyr) in a hinge loop, is required for the hormone activity.
* The transmembrane domain contains two highly conserved cysteine residues that build disulfide bonds to stabilize the receptor structure. A highly conserved Asp-Arg-Tyr triplet motif is present in GPCR family members in general and may be of importance to transmit the signal. In FSHR and its closely related other glycoprotein hormone receptor members (LHR and TSHR), this conserved triplet motif is a variation Glu-Arg-Trp sequence.
* The C-terminal domain is intracellular and brief, rich in serine and threonine residues for possible phosphorylation. | 1 | Gene expression + Signal Transduction |
The plasticity region is at the top of deformation map (at the highest normalized stresses), and is below the boundary set by the ideal strength. In this region the strain rate involves an exponential term. This equation is shown below, where is the applied shear stress, is the shear modulus, is the energy barrier to dislocation glide, k is the Boltzmann constant, and is the "athermal flow strength" which is a function of the obstacles to dislocation glide. | 0 | Metallurgy |
The lac repressor is a four-part protein, a tetramer, with identical subunits. Each subunit contains a helix-turn-helix (HTH) motif capable of binding to DNA. The operator site where repressor binds is a DNA sequence with inverted repeat symmetry. The two DNA half-sites of the operator together bind to two of the subunits of the repressor. Although the other two subunits of repressor are not doing anything in this model, this property was not understood for many years.
Eventually it was discovered that two additional operators are involved in lac regulation. One (O) lies about −90 bp upstream of O in the end of the lacI gene, and the other (O) is about +410 bp downstream of O in the early part of lacZ. These two sites were not found in the early work because they have redundant functions and individual mutations do not affect repression very much. Single mutations to either O or O have only 2 to 3-fold effects. However, their importance is demonstrated by the fact that a double mutant defective in both O and O is dramatically de-repressed (by about 70-fold).
In the current model, lac repressor is bound simultaneously to both the main operator O and to either O or O. The intervening DNA loops out from the complex. The redundant nature of the two minor operators suggests that it is not a specific looped complex that is important. One idea is that the system works through tethering; if bound repressor releases from O momentarily, binding to a minor operator keeps it in the vicinity, so that it may rebind quickly. This would increase the affinity of repressor for O. | 1 | Gene expression + Signal Transduction |
The G subunit will eventually hydrolyze the attached GTP to GDP by its inherent enzymatic activity, allowing it to re-associate with G and starting a new cycle. A group of proteins called Regulator of G protein signalling (RGSs), act as GTPase-activating proteins (GAPs), are specific for G subunits. These proteins accelerate the hydrolysis of GTP to GDP, thus terminating the transduced signal. In some cases, the effector itself may possess intrinsic GAP activity, which then can help deactivate the pathway. This is true in the case of phospholipase C-beta, which possesses GAP activity within its C-terminal region. This is an alternate form of regulation for the G subunit. Such G GAPs do not have catalytic residues (specific amino acid sequences) to activate the G protein. They work instead by lowering the required activation energy for the reaction to take place. | 1 | Gene expression + Signal Transduction |
British physician George Oliver and physiologist Edward Albert Schäfer, professor at University College London, collaborated on the physiological effects of adrenal extracts. They first published their findings in two reports in 1894, a full publication followed in 1895. Though frequently falsely attributed to secretin, found in 1902 by Bayliss and Starling, Oliver and Schäfer's adrenal extract containing adrenaline, the substance causing the physiological changes, was the first hormone to be discovered. The term hormone would later be coined by Starling. | 1 | Gene expression + Signal Transduction |
The N- terminal domain consists of amino acids 1-56 and is an amino terminal responsible DNA-binding and is a key mediator in the linkage between the C-terminal domain of the opposite dimer. The dimer interface II has its I255 side chain located in the N-terminal. | 1 | Gene expression + Signal Transduction |
SMIE is less common that LMIE and much less common that other failure mechanisms such as hydrogen embrittlement, fatigue, and stress-corrosion cracking. Still, embrittlement mechanisms can be introduced during fabrication, coatings, testing or during service of the material components. Susceptibility for SMIE increases with the following material characteristics:
* Increase in strength of high-strength material
* Increasing grain size
* Materials with more planar-slip than wavy-slip | 0 | Metallurgy |
Class I PTPs constitute the largest family. They contain the well-known classical receptor (a) and non-receptor PTPs (b), which are strictly tyrosine-specific, and the DSPs (c) which target Ser/Thr as well as Tyr and are the most diverse in terms of substrate specificity. | 1 | Gene expression + Signal Transduction |
Noric steel was a steel from Noricum, a kingdom located in modern Austria and Slovenia.
The proverbial hardness of Noric steel is expressed by Ovid: "...durior [...] ferro quod noricus excoquit ignis..." which roughly translates to "...harder than iron which Noric fire tempers [was Anaxarete towards the advances of Iphis]..." and it was widely used for the weapons of the Roman military after Noricum joined the Empire in 16 BC.
The iron ore was quarried at two mountains in modern Austria still called Erzberg "ore mountain" today, one at Hüttenberg, Carinthia and the other at Eisenerz, Styria, separated by . The latter is the site of the modern Erzberg mine.
Buchwald identifies a sword of found in Krenovica, Moravia as an early example of Noric steel due to a chemical composition consistent with Erzberg ore. A more recent sword, dating to and found in Zemplin, eastern Slovakia, is of extraordinary length for the period (95 cm, 37 in) and carries a stamped Latin inscription (?V?TILICI?O), identified as a "fine sword of Noric steel" by Buchwald. A center of manufacture was at Magdalensberg. | 0 | Metallurgy |
Primarily produced by Gram-negative bacteria, acylated homoserine lactones (AHLs) are a class of small neutral lipid molecules composed of a homoserine lactone ring with an acyl chain. AHLs produced by different species of Gram-negative bacteria vary in the length and composition of the acyl side chain, which often contains 4 to 18 carbon atoms. AHLs are synthesized by AHL synthases. They diffuse in and out of cells by both passive transport and active transport mechanisms. Receptors for AHLs include a number of transcriptional regulators called “R proteins,” which function as DNA binding transcription factors or sensor kinases. | 1 | Gene expression + Signal Transduction |
Continuous network models of GRNs are an extension of the Boolean networks described above. Nodes still represent genes and connections between them regulatory influences on gene expression. Genes in biological systems display a continuous range of activity levels and it has been argued that using a continuous representation captures several properties of gene regulatory networks not present in the Boolean model. Formally most of these approaches are similar to an artificial neural network, as inputs to a node are summed up and the result serves as input to a sigmoid function, e.g., but proteins do often control gene expression in a synergistic, i.e. non-linear, way. However, there is now a continuous network model that allows grouping of inputs to a node thus realizing another level of regulation. This model is formally closer to a higher order recurrent neural network. The same model has also been used to mimic the evolution of cellular differentiation and even multicellular morphogenesis. | 1 | Gene expression + Signal Transduction |
Micro pitting is a fatigue failure of the surface of a material commonly seen in rolling bearings and gears.
It is also known as grey staining, micro spalling or frosting. | 0 | Metallurgy |
In 2007 it was reported that a preliminary dating of a Pločnik copper workshop with a furnace and copper tools to 5,500 BCE, if correct, indicated the Copper Age could have started in Europe 500 years or more earlier than previously thought. The sophisticated furnace and smelter featured earthen pipe-like air vents with hundreds of tiny holes in them. Also there was a chimney to ensure that air goes into the furnace to feed the fire, and smoke comes out away from the workers. Copper workshops from later periods thought to indicate the beginning of the Copper Age were less advanced, lacked chimneys and workers blew air on the fire with bellows.
In 2008, a copper axe was found at Pločnik that was dated to 5,500 BC. This pushed back the start of the Copper Age by 500 years.
A study published in December 2013 reported an in situ discovery of a tin bronze foil from Plocnik dated to . This is the oldest tin bronze so far found in the world - a significant technological advance.
This discovery was further supported by a reanalysis of 14 other tin bronze artefacts from neighbouring sites in Bulgaria and Serbia dated to before 4000 BC. This showed that early tin bronze was more common than previously thought, and developed independently in Europe 1,500 years before the first tin bronze alloys in the Near East.
Another artifact similar to the Plocnik foil is a bronze ring from :fr:Gomolava in Serbia. When analyzed, the ring showed that it has above 8% tin content. The Plocnik foil has 11.7% tin. Tin bronzes above 8% tin require the high annealing temperatures in the range of 500–800C, so this was the temperatures already achieved at that time. These are considerably higher that the temperatures needed for the production of copper artifacts.
According to the authors, the next horizon of bronzes in Serbia is dated to the third millennium BC, so this means there was a significant interruption, when this technology appears to have been lost. In Bulgaria, on the other hand, the production of bronze continued in the fourth millennium BC, but only arsenic bronzes were produced; so this was a different technology. In Serbia, likewise, mostly arsenical bronzes were produced in later times. | 0 | Metallurgy |
The process requirements for (Pb-free) SAC solders and Sn-Pb solders are different both materially and logistically for electronic assembly. In addition, the reliability of Sn-Pb solders is well established, while SAC solders are still undergoing study, (though much work has been done to justify the use of SAC solders, such as the iNEMI Lead Free Solder Project).
One important difference is that Pb-free soldering requires higher temperatures and increased process control to achieve the same results as that of the tin-lead method. The melting point of SAC alloys is 217–220°C, or about 34°C higher than the melting point of the eutectic tin-lead (63/37) alloy. This requires peak temperatures in the range of 235–245°C to achieve wetting and wicking.
Some of the components susceptible to SAC assembly temperatures are electrolytic capacitors, connectors, opto-electronics, and older style plastic components. However, a number of companies have started offering 260 °C compatible components to meet the requirements of Pb-free solders. iNEMI has proposed that a good target for development purposes would be around 260°C.
Also, SAC solders are alloyed with a larger number of metals so there is the potential for a far wider variety of intermetallics to be present in a solder joint. These more complex compositions can result in solder joint microstructures that are not as thoroughly studied as current tin-lead solder microstructures. These concerns are magnified by the unintentional use of lead-free solders in either processes designed solely for tin-lead solders or environments where material interactions are poorly understood. For example, the reworking of a tin-lead solder joint with Pb-free solder. These mixed-finish possibilities could negatively impact the solder's reliability. | 0 | Metallurgy |
The endogenous cannabinoids, or endocannabinoids, are endogenous lipids that activate cannabinoid receptors. The first such lipid to be isolated was anandamide which is the arachidonoyl amide of ethanolamine. Anandamide is formed via enzymatic release from N-arachidonoyl phosphatidylethanolamine by the N-acyl phosphatidylethanolamine phospholipase D (NAPE-PLD). Anandamide activates both the CB1 receptor, found primarily in the central nervous system, and the CB2 receptor which is found primarily in lymphocytes and the periphery. It is found at very low levels (nM) in most tissues and is inactivated by the fatty acid amide hydrolase. Subsequently, another endocannabinoid was isolated, 2-arachidonoylglycerol, which is produced when phospholipase C releases diacylglycerol which is then converted to 2-AG by diacylglycerol lipase. 2-AG can also activate both cannabinoid receptors and is inactivated by monoacylglycerol lipase. It is present at approximately 100-times the concentration of anandamide in most tissues. Elevations in either of these lipids causes analgesia and anti-inflammation and tissue protection during states of ischemia, but the precise roles played by these various endocannabinoids are still not totally known and intensive research into their function, metabolism, and regulation is ongoing. One saturated lipid from this class, often called an endocannabinoid, but with no relevant affinity for the CB1 and CB 2 receptor is palmitoylethanolamide. This signaling lipid has great affinity for the GRP55 receptor and the PPAR alpha receptor. It has been identified as an anti-inflammatory compound already in 1957, and as an analgesic compound in 1975. Rita Levi-Montalcini first identified one of its biological mechanisms of action, the inhibition of activated mast cells. Palmitoylethanolamide is the only endocannabinoid available on the market for treatment, as a food supplement. | 1 | Gene expression + Signal Transduction |
Stress corrosion cracking is a phenomenon where a synergistic action of corrosion and tensile stress leads to brittle fracture of normally ductile materials at generally lower stress levels. During stress corrosion cracking, the material is relatively unattacked by the corrosive agent (no general corrosion, only localized corrosion), but fine cracks form within it. This process has serious implications on the utilisation of the material because the applicable safe stress levels are drastically reduced in the corrosive medium. Season cracking and caustic embrittlement are two stress corrosion cracking processes which affected the serviceability of brass cartridge cases and riveted steel boilers respectively. | 0 | Metallurgy |
Riboswitch sequences (in the mRNA leader transcript) bind molecules such as amino acids, nucleotides, sugars, vitamins, metal ions and other small ligands which cause a conformational change in the mRNA. Most of these attenuators are inhibitory and are employed by genes for biosynthetic enzymes or transporters whose expression is inversely related to the concentration of their corresponding metabolites.
Example- Cobalamine biosynthesis, Cyclic AMP-GMP switch, lysin biosynthesis, glycine biosynthesis, fluroide switch etc. | 1 | Gene expression + Signal Transduction |
Following is the Roman script transliteration of the text:
J. F. Fleet's 1888 translation is as follows:
Due to the tablets installed on the building in 1903 by Pandit Banke Rai, the reading provided by him enjoys wide currency. However, Bankelals reading and interpretation have been challenged by more recent scholarship. The inscription has been revisited by Michael Willis in his book Archaeology of Hindu Ritual, his special concern being the nature of the kings spiritual identity after death. His reading and translation of verse 2 is as follows:
The Sanskrit portion given above can be translated as follows:
Willis concludes: | 0 | Metallurgy |
This describes the preparation of what Agricola calls "juices": salt, soda, nitre, alum, vitriol, saltpetre, sulphur and bitumen. Finally glass making is covered. Agricola seems less secure about this process. He is not clear about making glass from the raw ingredients but clearer about remelting glass to make objects.
Prof. Philippus Bechius (1521–1560), a friend of Agricola, translated De re metallica libri XII into German. It was published with the German title Vom Bergkwerck XII Bücher in 1557. The Hoovers describe the translation as "a wretched work, by one who knew nothing of the science," but it, like the Latin original, saw further editions. In 1563 Agricola's publisher, Froben and Bischoff ("Hieronimo Frobenio et Nicolao Episcopio") in Basel, published an Italian translation by Michelangelo Florio as well. | 0 | Metallurgy |
Type R (87%Pt/13%Rh–Pt, by weight) thermocouples are used 0 to 1600 °C. Type R Thermocouples are quite stable and capable of long operating life when used in clean, favorable conditions. When used above 1100 °C ( 2000 °F), these thermocouples must be protected from exposure to metallic and non-metallic vapors. Type R is not suitable for direct insertion into metallic protecting tubes. Long term high temperature exposure causes grain growth which can lead to mechanical failure and a negative calibration drift caused by Rhodium diffusion to pure platinum leg as well as from Rhodium volatilization. This type has the same uses as type S, but is not interchangeable with it. | 0 | Metallurgy |
Each cell typically contains several hundred of a special class of enhancers that stretch over many kilobases long DNA sequences, called "super-enhancers". These enhancers contain a large number of binding sites for sequence-specific, inducible transcription factors, and regulate expression of genes involved in cell differentiation. During inflammation, the transcription factor NF-κB facilitates remodeling of chromatin in a manner that selectively redistributes cofactors from high-occupancy enhancers, thereby repressing genes involved in maintaining cellular identify whose expression they enhance; at the same time, this F-κB-driven remodeling and redistribution activates other enhancers that guide changes in cellular function through inflammation. As a result, inflammation reprograms cells, altering their interactions with the rest of tissue and with the immune system. In cancer, proteins that control NF-κB activity are dysregulated, permitting malignant cells to decrease their dependence on interactions with local tissue, and hindering their surveillance by the immune system. | 1 | Gene expression + Signal Transduction |
Although this page is devoted to genes that should be ubiquitously expressed, this section is for genes whose current name reflects their relative upregulation in testes
*SPAG7
*SRM Spermidine synthase
*TEGT Bax-1 inhibitor
*DAZAP2 Deleted in azoospermia
*MEA1 Male enhanced antigen | 1 | Gene expression + Signal Transduction |
Microbial corrosion, also called microbiologically influenced corrosion (MIC), microbially induced corrosion (MIC), or biocorrosion, is when microbes affect the electrochemical environment of the surface they are on. This usually involves building a biofilm, which can lead to either an increase in corrosion of the surface or, in a process called microbial corrosion inhibition, protect the surface from corrosion.
With every surface that is in some way exposed to the environment also exposed to microbes, microbial corrosion causes trillions of dollars in damage around the globe annually.
Microbes act by either producing byproducts from their cellular processes that corrode metals, or preventing normal corrosion inhibitors from functioning and leaving surfaces open to attack from other environmental factors. | 0 | Metallurgy |
The site was occupied by the pre-Roman Britons, likely as part of an iron working industry. It was continually occupied throughout the Roman era, and the scale of industrial activity increased over the period. It is clear that there was a focus of settlement activity near Bromsash, but the area appears to some archaeologists to have contained dispersed centres of activity and settlement rather than a Roman town. Ariconiums only documented significance is as a station on Iter XIII of the Iter Britanniarum', with the single mention there being its only mention in classical history.
It seems to have been abandoned shortly after 360. Its sudden abandonment is consistent with a violent end, and may be related to the collapse of authority and widespread marauding at that time, as reported by Ammianus, a situation that lasted for almost a decade, and from which parts of Roman Britain never recovered. Evidence of later occupation of the site has not been found. | 0 | Metallurgy |
Bases: adenine (A), cytosine (C), guanine (G) and thymine (T) or uracil (U).
Amino acids: Alanine (Ala, A), Arginine (Arg, R), Asparagine (Asn, N), Aspartic acid (Asp, D), Cysteine (Cys, C), Glutamic acid (Glu, E), Glutamine (Gln, Q), Glycine (Gly, G), Histidine (His, H), Isoleucine (Ile, I), Leucine (Leu, L), Lysine (Lys, K), Methionine (Met, M), Phenylalanine (Phe, F), Proline (Pro, P), Serine (Ser, S), Threonine (Thr, T), Tryptophan (Trp, W), Tyrosine (Tyr, Y), Valine (Val, V). | 1 | Gene expression + Signal Transduction |