Solutions in water containing ascorbic acid and copper ions and/or peroxide, resulting in rapid oxidation of ascorbic acid to dehydroascorbic acid, have been shown to possess powerful but short- lived antimicrobial, antifungal, and antiviral properties, and have been used to treat gingivitis, periodontal disease, and dental plaque.Ericsson, Sten et al. "Anti Infectant Topical Preparations." U.S. Patent 3,065,139, filed Nov.
|
|
Copiapite is a hydrated iron sulfate mineral with formula: Fe2+Fe3+4(SO4)6(OH)2·20(H2O). Copiapite can also refer to a mineral group, the copiapite group. Copiapite is strictly a secondary mineral forming from the weathering or oxidation of iron sulfide minerals or sulfide-rich coal. Its most common occurrence is as the end member mineral from the rapid oxidation of pyrite.
|
|
However, NAPL contaminant concentrations can still result in rapid oxidation reactions with an associated temperature increase and more potential for surfacing even with reagent stabilization. The hydroxyl radicals can be scavenged by carbonate, bicarbonate, and naturally occurring organic matter in addition to the targeted contaminant, so it important to evaluate a site's soil matrix and apply additional reagent when these soil components are present in significant abundance.
|
|
These were not part of the inhabited cabin, though the radiator tubing, whose silicone coolant flowed through the cabin, was also made of the same material. All examples burned up in the atmosphere upon reentry. Another concern for the thoriated magnesium alloys is the low melting point and rapid oxidation of the metal. This can result in dangerous flash fires during the production of the alloys.
|
|
It occurs in manganese-iron nodules on the Atlantic and Pacific Ocean floors. It is also found in the Baltic, White, and Kara Seas.Handbook of Mineralogy Forms under high pressure conditions and reverts to goethite on exposure to surface conditions. It also occurs as cement and coatings on clasts in poorly drained soils and sediments, formed by the rapid oxidation of iron(II) oxide compounds.
|
|
Electrical-breakdown technique provides a means for separating and selecting desired type of nanotubes. Carbon nanotubes are known to withstand very large current densities up to 109 A/cm2 partly due to the strong sigma bonds between carbon atoms. However, at sufficiently high currents the nanotubes fail primarily due to rapid oxidation of the outermost shell. This results in a partial conductance drop that becomes apparent within a few seconds.
|
|
In the 1980s the discovery of zinc peroxide’s ability to complement pyrotechnical mixtures was discovered. It was noted that ZnO2 was preferable to the usage of barium compounds, as it was deemed to be less toxic. The zinc compound proves an effective component in explosives because of its oxidizing properties. Many chemical explosives rely on rapid oxidation reactions, for this reason ZnO2 is an ideal candidate for use in pyrotechnics.
|
|
Many review articles exist documenting the development of these materials. Rubrene-based OFETs show the highest carrier mobility 20–40 cm2/(V·s). Another popular OFET material is pentacene, which has been used since the 1980s, but with mobilities 10 to 100 times lower (depending on the substrate) than rubrene. The major problem with pentacene, as well as many other organic conductors, is its rapid oxidation in air to form pentacene-quinone.
|
|
Nitrates are mainly produced for use as fertilizers in agriculture because of their high solubility and biodegradability. The main nitrate fertilizers are ammonium, sodium, potassium, calcium, and magnesium salts. Several million kilograms are produced annually for this purpose. The second major application of nitrates is as oxidizing agents, most notably in explosives where the rapid oxidation of carbon compounds liberates large volumes of gases (see gunpowder for an example).
|
|
479–480 (1993). An explosive is classified as a low or high explosive according to its rate of combustion: low explosives burn rapidly (or deflagrate), while high explosives detonate. While these definitions are distinct, the problem of precisely measuring rapid decomposition makes practical classification of explosives difficult. Traditional explosives mechanics is based on the shock-sensitive rapid oxidation of carbon and hydrogen to carbon dioxide, carbon monoxide and water in the form of steam.
|
|
D. Clayton, New Astronomy Reviews 55, 155–65 (2011), section 5.5, p. 163] According to that principle rapid oxidation actually intensifies growth of large grains of carbon by keeping the population of carbon solids small so that those few can grow large by accreting the continuously replenished free carbon. This topic establishes another new aspect of carbon's uniquely versatile chemistry. Their 2017 paper also computes the abundances of molecules and of Buckminsterfullerene grains ejected along with the graphite grains.
|
|
These bacteria are commonly found in iron and manganese deposits on surfaces exposed intermittently to plumes of hydrothermal and bottom seawater. However, due to the rapid oxidation of Fe2+ in neutral and alkaline waters (i.e. freshwater and seawater), bacteria responsible for the oxidative deposition of iron would be more commonly found in acidic waters. Manganese- oxidizing bacteria would be more abundant in freshwater and seawater compared to iron-oxidizing bacteria due to the higher concentration of available metal.
|
|
A modern blacksmith in Finland practicing ironworking in a manner similar to more archaic methods that resulted in the production of hammerscale Flake Hammerscale forms due to the rapid oxidation of hot iron in air. A heated piece of iron will develop an external layer of iron oxide which then may separate from the original piece due to a hammer strike or differential thermal contraction .Dorling, P. “New Weir Forg, Witchurch, Herefordshire: A Report on Excavations in 2009 and 2010.” Herefordshire Archeology.
|
|
Brazing (sometimes known as silver soldering or hard soldering) requires a much higher temperature than soft soldering, sometimes over 850 °C. As well as removing existing oxides, rapid oxidation of the metal at the elevated temperatures has to be avoided. This means that fluxes need to be more aggressive and to provide a physical barrier. Traditionally borax was used as a flux for brazing, but there are now many different fluxes available, often using active chemicals such as fluorides as well as wetting agents.
|
|
Fire is the rapid oxidation of a material in the exothermic chemical process of combustion, releasing heat, light, and various reaction products. Fire is hot because the conversion of the weak double bond in molecular oxygen, O2, to the stronger bonds in the combustion products carbon dioxide and water releases energy (418 kJ per 32 g of O2); the bond energies of the fuel play only a minor role here. At a certain point in the combustion reaction, called the ignition point, flames are produced. The flame is the visible portion of the fire.
|
|
Chemical King is a mutant with the power to act as a human catalyst. He can speed up or slow down any chemical reaction; for example, he can cause iron to rapidly rust, or even burst into flames from rapid oxidation. His powers can affect the chemical reactions in the human body, rendering an opponent unconscious from shock, but take several seconds and can only focus on a single opponent at a time. Late in his career, Chemical King displayed the ability to change energy reaction rates as well, causing batteries to drain of power and force fields to decay.
|
|
The activity of succinate dehydrogenase (SDH), which interconverts succinate into fumarate participates in mitochondrial reactive oxygen species (ROS) production by directing electron flow in the electron transport chain. Under conditions of succinate accumulation, rapid oxidation of succinate by SDH can drive reverse electron transport (RET). If mitochondrial respiratory complex III is unable to accommodate excess electrons supplied by succinate oxidation, it forces electrons to flow backwards along the electron transport chain. RET at mitochondrial respiratory complex 1, the complex normally preceding SDH in the electron transport chain, leads to ROS production and creates a pro-oxidant microenvironment.
|
|
Pentacene is a popular choice for research on organic thin-film transistors and OFETs, being one of the most thoroughly investigated conjugated organic molecules with a high application potential due to a hole mobility in OFETs of up to 5.5 cm2/(V·s), which exceeds that of amorphous silicon. Pentacene, as well as other organic conductors, is subject to rapid oxidation in air, which precludes commercialization. If the pentacene is preoxidized, the pentacene-quinone is a potential gate insulator, then the mobility can approach that of rubrene – the highest-mobility organic semiconductor – namely, 40 cm2/(V·s). This pentacene oxidation technique is akin to the silicon oxidation used in the silicon electronics.
|
|
In order to produce the energy needed for everyday activities, our body needs to go through the process of glycolysis, which breaks down glucose into pyruvate. In this pathway, one very important part is the reduction of NAD+ to NADH and then the rapid oxidation of NADH back into NAD+. The oxidation phase mainly occurs in the mitochondria as part of the electron transport chain, but the transfer of NADH into the mitochondria from the cytosol is impossible, due to the impermeability of the inner mitochondrial membrane to NADH. Therefore, the malate-aspartate shuttle is needed to transfer reducing equivalents across the mitochondrial membrane for energy production.
|
|
Since the 1850s, a large proportion of the world's grasslands have been tilled and converted to croplands, allowing the rapid oxidation of large quantities of soil organic carbon. However, in the United States in 2004 (the most recent year for which EPA statistics are available), agricultural soils including pasture land sequestered 0.8% (46 megatonne) as much carbon as was released in the United States by the combustion of fossil fuels (5,988 megatonne). The annual amount of this sequestration has been gradually increasing since 1998. Methods that significantly enhance carbon sequestration in soil include no-till farming, residue mulching, cover cropping, and crop rotation, all of which are more widely used in organic farming than in conventional farming.
|
|
Acidification may also have played a role in the extinction of the calcifying foraminifera, and the higher temperatures would have increased metabolic rates, thus demanding a higher food supply. Such a higher food supply might not have materialized because warming and increased ocean stratification might have led to declining productivity and/or increased remineralization of organic matter in the water column, before it reached the benthic foraminifera on the sea floor (). The only factor global in extent was an increase in temperature. Regional extinctions in the North Atlantic can be attributed to increased deep-sea anoxia, which could be due to the slowdown of overturning ocean currents, or the release and rapid oxidation of large amounts of methane.
|
|
Propane Octane In daily life, the vast majority of flames one encounters are those caused by rapid oxidation of hydrocarbons in materials such as wood, wax, fat, plastics, propane, and gasoline. The constant-pressure adiabatic flame temperature of such substances in air is in a relatively narrow range around 1950 °C. This is because, in terms of stoichiometry, the combustion of an organic compound with ncarbons involves breaking roughly 2nC–H bonds, nC–C bonds, and 1.5nO2 bonds to form roughly nCO2 molecules and nH2O molecules. Because most combustion processes that happen naturally occur in the open air, there is nothing that confines the gas to a particular volume like the cylinder in an engine.
|
|