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There is tentative evidence that saline nasal irrigation may help with long term cases of rhinosinusitis. Evidence for use in cases of rhinosinusitis of short duration is unclear. | 0 | Salts |
Pure bismuth is a semimetal, containing a small band gap, which leads to it having a relatively high conductivity ( at 20 °C). When the bismuth is doped with antimony, the conduction band decreases in energy and the valence band increases in energy. At an antimony concentration of 4%, the two bands intersect, forming a Dirac point (which is defined as a point where the conduction and valence bands intersect). Further increases in the concentration of antimony result in a band inversion, in which the energy of the valence band becomes greater than that of the conduction band at specific momenta. Between Sb concentrations of 7 and 22%, the bands no longer intersect, and the BiSb becomes an inverted-band insulator. It is at these higher concentrations of Sb that the band gap in the surface states vanishes, and the material thus conducts at its surface. | 1 | Semiconductor Materials |
Selenosulfide groups can be found in almost all living organisms as part of various peroxidase enzymes, such as glutathione peroxidase and thioredoxin reductase. They are formed by the oxidative coupling of selenocysteine and cysteine residues. This reaction is powered by the decomposition of cellular peroxides, which can be highly damaging and a source of oxidative stress. Selenocysteine has a lower reduction potential than cysteine, making it very suitable for proteins that are involved in antioxidant activity.
Selenosulfides have been identified in some species of Allium and in roasted coffee. The mammalian version of the protein thioredoxin reductase contains a selenocysteine residue which forms a thioselenide (analogous to a disulfide) upon oxidation. | 1 | Semiconductor Materials |
Currently, in many countries, such as Spain, Israel, Chile and Australia, the development of a rigorous environmental impact assessment process is required, both for the construction and operational phases. During its developent, the most important legal management tools are established within the local environmental regulation, to prevent and adopt mitigation measures that guarantee the sustainable development of desalination projects. This includes a series of administrative tools and periodic environmental monitoring, to adopt preventive, corrective and further monitoring measures of the state of the surrounding marine environment.
Under the context of this environmental assessment process, numerous countries require compliance with an Environmental Monitoring Program (PVA), in order to evaluate the effectiveness of the preventive and corrective measures established during the environmental assessment process, and thus guarantee the operation of desalination plants without producing significant environmental impacts. The PVAs establishes a series of mandatory requirements that are mainly related to the monitoring of discharge, using a series of measurements and characterizations based on physical-chemical and biological information. In addition, the PVAs could also include different requirements related to monitoring the effects of seawater intake and those that may potentially be related to effects on the terrestrial environment. | 0 | Salts |
Tin(IV) oxide can be used as a polishing powder, sometimes in mixtures also with lead oxide, for polishing glass, jewelry, marble and silver. Tin(IV) oxide for this use is sometimes called as "putty powder" or "jeweler's putty". | 1 | Semiconductor Materials |
Europium hydride is the most common hydride of europium with a chemical formula EuH. In this compound, europium atom is in the +2 oxidation state and the hydrogen atoms are -1. It is a ferromagnetic semiconductor. | 1 | Semiconductor Materials |
Lead tetroxide ("red lead"), a valence-mixed oxide with formula (red), may be thought of as lead(II) orthoplumbate(IV), . Lead sesquioxide, , is also known (reddish yellow), and has the structure of lead(II) metaplumbate(IV), . | 0 | Salts |
At the beginning of 2008, potash prices started a meteoric climb from less than US$200 a tonne to a high of US$875 in February 2009. These subsequently dropped dramatically to an April 2010 low of US$310 level, before recovering in 2011–12, and relapsing again in 2013. For reference, prices in November 2011 were about US$470 per tonne, but as of May 2013 were stable at US$393. After the surprise breakup of the world's largest potash cartel at the end of July 2013, potash prices were poised to drop some 20 percent. At the end of Dec 2015, potash traded for US$295 a tonne. In April 2016 its price was US$269. In May 2017, prices had stabilised at around US$216 a tonne down 18% from the previous year. By January 2018, prices have been recovering to around US$225 a tonne. World potash demand tends to be price inelastic in the short-run and even in the long run. | 0 | Salts |
Abraum salts is the name given to a mixed deposit of salts, including halite (sodium chloride), carnallite, and kieserite (magnesium sulfate), found in association with rock salt at Aschersleben-Staßfurt in Germany. The term comes from the German Abraum-salze, "salts to be removed."
Abraum, which is red, is used to darken mahogany. | 0 | Salts |
Iron phosphide is a hazardous substance.
Proper eye protection such as goggles should always be used when handling iron phosphide. It can be very harmful to the eyes, especially for individuals wearing contact lenses. Contact lenses have been known to react poorly with iron phosphide due to its corrosive properties, but the scientific world does not all agree on the use of contact lenses in association with iron phosphide.
In case of inhalation, the person should be moved to fresh air or given artificial respiration if not breathing. In case of ingestion, the person's mouth should be rinsed with water unless unconscious. In case of eye contact, immediate eye flushing is necessary. | 1 | Semiconductor Materials |
Bismuth selenide is a semiconductor and a thermoelectric material. While stoichiometric bismuth selenide should be a semiconductor with a gap of 0.3 eV, naturally occurring selenium vacancies act as electron donors, so BiSe is intrinsically n-type.
Bismuth selenide has a topologically insulating ground-state. Topologically protected Dirac cone surface states have been observed in Bismuth selenide and its insulating derivatives leading to intrinsic topological insulators, which later became the subject of world-wide scientific research.
Bismuth selenide is a van der Waals material consisting of covalently bound five-atom layers (quintuple layers) which are held together by van der Waals interactions and spin-orbit coupling effects. Although the (0001) surface is chemically inert (mostly due to the inert-pair effect of Bi), there are metallic surface states, protected by the non-trivial topology of the bulk. For this reason, the BiSe surface is an interesting candidate for van der Waals epitaxy and subject of scientific research. For instance, different phases of antimony layers can be grown on BiSe, by means of which topological pn-junctions can be realised. More intriguingly, Sb layers undergo topological phase transitions when attached to the BiSe surface and thus inherit the non-trivial topological properties of the BiSe substrate. | 1 | Semiconductor Materials |
Copper indium gallium (di)selenide (CIGS) is a I-III-VI semiconductor material composed of copper, indium, gallium, and selenium. The material is a solid solution of copper indium selenide (often abbreviated "CIS") and copper gallium selenide. It has a chemical formula of CuInGaSe, where the value of x can vary from 0 (pure copper indium selenide) to 1 (pure copper gallium selenide). CIGS is a tetrahedrally bonded semiconductor, with the chalcopyrite crystal structure, and a bandgap varying continuously with x from about 1.0 eV (for copper indium selenide) to about 1.7 eV (for copper gallium selenide). | 1 | Semiconductor Materials |
Most ionic compounds are very brittle. Once they reach the limit of their strength, they cannot deform malleably, because the strict alignment of positive and negative ions must be maintained. Instead the material undergoes fracture via cleavage. As the temperature is elevated (usually close to the melting point) a ductile–brittle transition occurs, and plastic flow becomes possible by the motion of dislocations. | 0 | Salts |
In the Atacama Desert in northern Chile, vast deposits of a mixture, also referred to as caliche, are composed of gypsum, sodium chloride and other salts, and sand, associated to salitre ("Chile saltpeter"). Salitre, in turn, is a composite of sodium nitrate (NaNO) and potassium nitrate (KNO). Salitre was an important source of export revenue for Chile until World War I, when Europe began to produce both nitrates industrially in large quantities.
The deposits contain an average of 7.5% sodium nitrate, as well as sodium sulfate (18.87%), sodium chloride (4.8%), and smaller amounts of potassium, calcium, magnesium, borate, iodine, and perchlorate. About two-thirds of the deposits are insoluble gangue minerals. The caliche beds are from 2 cm to several meters thick in alluvial deposits, where the soluble minerals form a cement in unconsolidated regolith. Nitrate-bearing caliche is also found impregnating bedrock to form bedrock deposits. | 0 | Salts |
Since the end of the repository for radioactive waste Morsleben in 1998, the salt dome stability deteriorated to a state where it could collapse. Since 2003, a volume of m of salt-concrete has been pumped into the pit to temporarily stabilize the upper levels. In addition another m of salt-concrete will be used to temporarily stabilize the lower levels. | 0 | Salts |
When the Na (sodium) predominates, soils can become sodic. The pH of sodic soils may be acidic, neutral or alkaline.
Sodic soils present particular challenges because they tend to have very poor structure which limits or prevents water infiltration and drainage. They tend to accumulate certain elements like boron and molybdenum in the root zone at levels that may be toxic for plants. The most common compound used for reclamation of sodic soil is gypsum, and some plants that are tolerant to salt and ion toxicity may present strategies for improvement.
The term "sodic soil" is sometimes used imprecisely in scholarship. It's been used interchangeably with the term alkali soil, which is used in two meanings: 1) a soil with a pH greater than 8.2, 2) soil with an exchangeable sodium content above 15% of exchange capacity. The term "alkali soil" is often, but not always, used for soils that meet both of these characteristics. | 0 | Salts |
Converting amines into their hydrochlorides is a common way to improve their water solubility, which can be desirable for substances used in medications. The European Pharmacopoeia lists more than 200 hydrochlorides as active ingredients in medications. These hydrochlorides, compared to free bases, may more readily dissolve in the gastrointestinal tract and be absorbed into the bloodstream more quickly. Additionally, many hydrochlorides of amines have a longer shelf-life than their respective free bases.
Amine hydrochlorides represent latent forms of a more reactive free base. In this regard, formation of an amine hydrochloride confers protection. This effect is illustrated by the hydrochlorides of the amino acids. Glycine methyl ester hydrochloride is a shelf-stable salt that can be readily converted to a reactive glycine methyl ester, a compound that is not shelf-stable. | 0 | Salts |
Surlyn is the brand name of an ionomer resin created by DuPont, a copolymer of ethylene and methacrylic acid used as a coating and packaging material.
DuPont neutralizes the acid with NaOH, yielding the sodium salt.
Crystals of ethylene-methacrylic acid ionomers exhibit dual melting behavior. | 0 | Salts |
Estropipate has been discontinued in the United States. In the past, estropipate has also been marketed in Canada, the United Kingdom, Ireland, Switzerland, Australia, South Africa, Mexico, and Indonesia. | 0 | Salts |
In France, by the second half of the 15th century, the semi-industrialized professional manufacture of soap was concentrated in a few centers of Provence—Toulon, Hyères, and Marseille—which supplied the rest of France. In Marseilles, by 1525, production was concentrated in at least two factories, and soap production at Marseille tended to eclipse the other Provençal centers. English manufacture tended to concentrate in London.
Finer soaps were later produced in Europe from the 16th century, using vegetable oils (such as olive oil) as opposed to animal fats. Many of these soaps are still produced, both industrially and by small-scale artisans. Castile soap is a popular example of the vegetable-only soaps derived from the oldest "white soap" of Italy. In 1634 Charles I granted the newly formed Society of Soapmakers a monopoly in soap production who produced certificates from foure Countesses, and five Viscountesses, and divers other Ladies and Gentlewomen of great credite and quality, besides common Laundresses and others, testifying that the New White Soap washeth whiter and sweeter than the Old Soap.
During the Restoration era (February 1665 – August 1714) a soap tax was introduced in England, which meant that until the mid-1800s, soap was a luxury, used regularly only by the well-to-do. The soap manufacturing process was closely supervised by revenue officials who made sure that soapmakers' equipment was kept under lock and key when not being supervised. Moreover, soap could not be produced by small makers because of a law that stipulated that soap boilers must manufacture a minimum quantity of one imperial ton at each boiling, which placed the process beyond the reach of the average person. The soap trade was boosted and deregulated when the tax was repealed in 1853.
Industrially manufactured bar soaps became available in the late 18th century, as advertising campaigns in Europe and America promoted popular awareness of the relationship between cleanliness and health. In modern times, the use of soap has become commonplace in industrialized nations due to a better understanding of the role of hygiene in reducing the population size of pathogenic microorganisms. | 0 | Salts |
Pure single crystals of β-LiGaO with a length of several inches can be grown by the Czochralski method. Their cleaved surfaces have lattice constants that match those of ZnO and GaN and are therefore suitable for epitaxial growth of thin films of those materials. β-LiGaO is a potential nonlinear optics material, but its direct bandgap of 5.6 eV is too wide for visible light applications. It can be reduced down to 3.2 eV by alloying β-LiGaO with ZnO. The bandgap tuning is discontinuous because ZnO and β-LiGaO do not mix but form a ZnLiGaO phase when their ratio is between ca. 0.2 and 1.
LiGaTe crystals with a size up to 5 mm can be grown in three steps. First, Li, Ga, and Te elements are fused in an evacuated quartz ampoule at 1250 K for 24 hours. At this stage Li reacts with the ampoule walls, releasing heat, and is partly consumed. In the second stage, the melt is homogenized in a sealed quartz ampoule, which is coated inside with pyrolytic carbon to reduce Li reactivity. The homogenization temperature is selected ca. 50 K above the melting point of LiGaTe. The crystals are then grown from the homogenized melt by the Bridgman–Stockbarger technique in a two-zone furnace. The temperature at the start of crystallization is a few degrees below the LiGaTe melting point. The ampoule is moved the cold zone at a rate of 2.5 mm/day for 20 days.
*m stands for metastable, d for direct and i for indirect bandgap | 1 | Semiconductor Materials |
Lead iodide prepared from cold solutions usually consists of many small hexagonal platelets, giving the yellow precipitate a silky appearance. Larger crystals can be obtained by exploiting the fact that solubility of lead iodide in water (like those of lead chloride and lead bromide) increases dramatically with temperature. The compound is colorless when dissolved in hot water, but crystallizes on cooling as thin but visibly larger bright yellow flakes, that settle slowly through the liquid — a visual effect often described as "golden rain". Larger crystals can be obtained by autoclaving the with water under pressure at 200 °C.
Even larger crystals can be obtained by slowing down the common reaction. A simple setup is to submerge two beakers containing the concentrated reactants in a larger container of water, taking care to avoid currents. As the two substances diffuse through the water and meet, they slowly react and deposit the iodide in the space between the beakers.
Another similar method is to react the two substances in a gel medium, that slows down the diffusion and supports the growing crystal away from the container's walls. Patel and Rao have used this method to grow crystals up to 30 mm in diameter and 2 mm thick.
The reaction can be slowed also by separating the two reagents with a permeable membrane. This approach, with a cellulose membrane, was used in September 1988 to study the growth of crystals in zero gravity, in an experiment flown on the Space Shuttle Discovery.
can also be crystallized from powder by sublimation at 390 °C, in near vacuum or in a current of argon with some hydrogen.
Large high-purity crystals can be obtained by zone melting or by the Bridgman–Stockbarger technique. These processes can remove various impurities from commercial . | 1 | Semiconductor Materials |
GraphExeter is a material consisting of a few graphene sheets with a layer of ferric chloride molecules in between each graphene sheet. It was created by The Centre for Graphene Science at the University of Exeter in collaboration with the University of Bath. | 1 | Semiconductor Materials |
Copper(I) thiocyanate forms from the spontaneous decomposition of black copper(II) thiocyanate, releasing thiocyanogen, especially when heated. It is also formed from copper(II) thiocyanate under water, releasing (among others) thiocyanic acid and the highly poisonous hydrogen cyanide. It is conveniently prepared from relatively dilute solutions of copper(II) in water, such as copper(II) sulphate. To a copper(II) solution sulphurous acid is added and then a soluble thiocyanate is added (preferably slowly, while stirring). Copper(I) thiocyanate is precipitated as a white powder. Alternatively, a thiosulfate solution may be used as a reducing agent. | 1 | Semiconductor Materials |
The method of production influences the polymorph generated. For example, thin films of pure γ-InSe have been produced from trimethylindium (InMe) and hydrogen selenide via MOCVD techniques.
A conventional route entails heating the elements in a seal-tube: | 1 | Semiconductor Materials |
Bismuth telluride () is a gray powder that is a compound of bismuth and tellurium also known as bismuth(III) telluride. It is a semiconductor, which, when alloyed with antimony or selenium, is an efficient thermoelectric material for refrigeration or portable power generation. is a topological insulator, and thus exhibits thickness-dependent physical properties. | 1 | Semiconductor Materials |
Originally, an alcoholate was the crystalline form of a salt in which alcohol took the place of water of crystallization, such as [SnCl(OCH)·CHOH] and CHNO·CHOH. However this denomination should not be used anymore for the ending -ate often occurs in names for anions.
The second meaning of the word is that of a tincture, or alcoholic extract of plant material.
The third, and more usual meaning of the word is as a synonym for alkoxide— is the conjugate base of an alcohol. | 0 | Salts |
Excessive respiratory disease due to environmental hazards, such as radon and asbestos, has been a concern for potash miners throughout history. Potash miners are liable to develop silicosis. Based on a study conducted between 1977 and 1987 of cardiovascular disease among potash workers, the overall mortality rates were low, but a noticeable difference in above-ground workers was documented. | 0 | Salts |
Indian Salt Service is a Central Engineering Service of the Government of India. Under the administrative control of the Ministry of Commerce and Industry, it is one of the smallest Central services under the Government of India. | 0 | Salts |
Copper(I) iodide reacts with mercury vapors to form copper tetraiodomercurate:
:4CuI + Hg → CuHgI + 2Cu
This reaction can be used for the detection of mercury since the white (CuI) to brown (CuHgI) color change is dramatic.
Copper(I) iodide is used in the synthesis of Cu(I) clusters such as .
Copper(I) iodide dissolves in acetonitrile, yielding diverse complexes. Upon crystallization, molecular or polymeric compounds can be isolated. Dissolution is also observed when a solution of the appropriate complexing agent in acetone or chloroform is used. For example, thiourea and its derivatives can be used. Solids that crystallize out of those solutions are composed of hybrid inorganic chains. | 1 | Semiconductor Materials |
Salt lakes form when the water flowing into the lake, containing salt or minerals, cannot leave because the lake is endorheic (terminal). The water then evaporates, leaving behind any dissolved salts and thus increasing its salinity, making a salt lake an excellent place for salt production. High salinity can also lead to halophilic flora and fauna in and around the lake; sometimes, in fact, the result may be an absence or near absence of multicellular life in the salt lake.
If the amount of water flowing into a lake is less than the amount evaporated, the lake will eventually disappear and leave a dry lake (also called playa or salt flat).
Brine lakes consist of water that has reached salt saturation or near saturation (brine), and may also be heavily saturated with other materials.
Most brine lakes develop as a result of high evaporation rates in an arid climate with a lack of an outlet to the ocean. The high salt content in these bodies of water may come from minerals deposited from the surrounding land. Another source for the salt may be that the body of water was formerly connected to the ocean. While the water evaporates from the lake, the salt remains. Eventually, the body of water will become brine.
Because of the density of brine, swimmers are more buoyant in brine than in fresh or ordinary salt water. Examples of such brine lakes are the Dead Sea and the Great Salt Lake.
Bodies of brine may also form on the ocean floor at cold seeps. These are sometimes called brine lakes, but are more frequently referred to as brine pools. It is possible to observe waves on the surface of these bodies.
Man-made bodies of brine are created for edible salt production. These can be referred to as brine ponds. | 0 | Salts |
In a domestic setting, "soap" usually refers to what is technically called a toilet soap, used for household and personal cleaning. When used for cleaning, soap solubilizes particles and fats/oils, which can then be separated from the article being cleaned.
The insoluble oil/fat molecules become associated inside micelles, tiny spheres formed from soap molecules with polar hydrophilic (water-attracting) groups on the outside and encasing a lipophilic (fat-attracting) pocket, which shields the oil/fat molecules from the water making them soluble. Anything that is soluble will be washed away with the water. | 0 | Salts |
The polyatomic ion , sometimes called allylide, is found in and . The ion is linear and is isoelectronic with . The C–C distance in MgC is 133.2 pm. yields methylacetylene, CHCCH, and propadiene, CHCCH, on hydrolysis, which was the first indication that it contains . | 0 | Salts |
The high concentration of bromide and magnesium in the Dead Sea salt may help relieve allergic reactions of the skin by reducing inflammation. | 0 | Salts |
Samarium arsenide forms crystals of a cubic system, space group Fm3m, cell parameters a = 0.5921 nm, Z = 4, of NaCl-structure.
The compound melts congruently at 2257 °C. | 1 | Semiconductor Materials |
An electride is an ionic compound in which an electron serves the role of the anion. Solutions of alkali metals in ammonia are electride salts. In the case of sodium, these blue solutions consist of [Na(NH)] and solvated electrons:
:Na + 6 NH → [Na(NH)] + e
The cation [Na(NH)] is an octahedral coordination complex. | 0 | Salts |
also possesses mechanical strength, electrical conductivity, and can emit light, opening possible applications such as photodetectors. has been investigated as a component of photoelectrochemical (e.g. for photocatalytic hydrogen production) applications and for microelectronics applications. | 1 | Semiconductor Materials |
Molybdenite is an important ore of molybdenum, and is the most common source of the metal. While molybdenum is rare in the Earths crust, molybdenite is relatively common and easy to process, and accounts for much of the metals economic viability. Molybdenite is purified by froth flotation, and then oxidized to form soluble molybdate. Reduction of ammonium molybdate yields pure molybdenum metal, which is used for fertilizer, as a catalyst, and in battery electrodes. By far the most common use of molybdenum is as an alloy with iron. Ferromolybdenum is an important component of high strength and corrosion-resistant steel. | 1 | Semiconductor Materials |
Brine is a byproduct of many industrial processes, such as desalination, power plant cooling towers, produced water from oil and natural gas extraction, acid mine or acid rock drainage, reverse osmosis reject, chlor-alkali wastewater treatment, pulp and paper mill effluent, and waste streams from food and beverage processing. Along with diluted salts, it can contain residues of pretreatment and cleaning chemicals, their reaction byproducts and heavy metals due to corrosion.
Wastewater brine can pose a significant environmental hazard, both due to corrosive and sediment-forming effects of salts and toxicity of other chemicals diluted in it.
Unpolluted brine from desalination plants and cooling towers can be returned to the ocean. From the desalination process, reject brine is produced, which proposes potential damages to the marine life and habitats. To limit the environmental impact, it can be diluted with another stream of water, such as the outfall of a wastewater treatment or power plant. Since brine is heavier than seawater and would accumulate on the ocean bottom, it requires methods to ensure proper diffusion, such as installing underwater diffusers in the sewerage. Other methods include drying in evaporation ponds, injecting to deep wells, and storing and reusing the brine for irrigation, de-icing or dust control purposes.
Technologies for treatment of polluted brine include: membrane filtration processes, such as reverse osmosis and forward osmosis; ion exchange processes such as electrodialysis or weak acid cation exchange; or evaporation processes, such as thermal brine concentrators and crystallizers employing mechanical vapour recompression and steam. New methods for membrane brine concentration, employing osmotically assisted reverse osmosis and related processes, are beginning to gain ground as part of zero liquid discharge systems (ZLD). | 0 | Salts |
In those cases where salt layers do not have the conditions necessary to develop passive salt structures, the salt may still move into relatively low pressure areas around developing folds and faults. Such structures are described as reactive. | 0 | Salts |
Limnologists and chemists often define salinity in terms of mass of salt per unit volume, expressed in units of mg/L or g/L. It is implied, although often not stated, that this value applies accurately only at some reference temperature because solution volume varies with temperature. Values presented in this way are typically accurate to the order of 1%. Limnologists also use electrical conductivity, or "reference conductivity", as a proxy for salinity. This measurement may be corrected for temperature effects, and is usually expressed in units of μS/cm.
A river or lake water with a salinity of around 70 mg/L will typically have a specific conductivity at 25 °C of between 80 and 130 μS/cm. The actual ratio depends on the ions present. The actual conductivity usually changes by about 2% per degree Celsius, so the measured conductivity at 5 °C might only be in the range of 50–80 μS/cm.
Direct density measurements are also used to estimate salinities, particularly in highly saline lakes. Sometimes density at a specific temperature is used as a proxy for salinity. At other times an empirical salinity/density relationship developed for a particular body of water is used to estimate the salinity of samples from a measured density. | 0 | Salts |
Phosphorene 2D materials are composed of individual layers held together by van der Waals forces in lieu of covalent or ionic bonds that are found in most materials. There are five electrons on 3p orbitals of phosphorus atom, thus, giving rise to sp hybridization of phosphorus atom within phosphorene structure. Monolayered phosphorene exhibits the structure of a quadrangular pyramid because three electrons of P atom bond with three other P atoms covalently at 2.18 Å leaving one lone pair. Two of the phosphorus atoms are in the plane of the layer at 99° from one another, and the third phosphorus is between the layers at 103°, yielding an average angle of 102°.
According to density functional theory (DFT) calculations, phosphorene forms in a honeycomb lattice structure with notable nonplanarity in the shape of structural ridges. It is predicted that crystal structure of black phosphorus can be discriminated under high pressure. This is mostly due to the anisotropic compressibility of black phosphorus because of the asymmetrical crystal structures. Subsequently, the van der Waals bond can be greatly compressed in the z-direction. However, there is a great variation in compressibility across the orthogonal x-y plane.
It is reported that controlling the centrifugal speed of production may aid in regulating the thickness of a material. For example, centrifuging at 18000 rpm during synthesis produced phosphorene with an average diameter of 210 nm and a thickness of 2.8 ± 1.5 nm (2–7 layers). | 1 | Semiconductor Materials |
Bismuth telluride is a well-studied topological insulator. Its physical properties have been shown to change at highly reduced thicknesses, when its conducting surface states are exposed and isolated. These thin samples are obtained through either epitaxy or mechanical exfoliation.
Epitaxial growth methods such as molecular beam epitaxy and metal organic chemical vapor deposition are common methods of obtaining thin samples. The stoichiometry of samples obtained through such techniques can vary greatly between experiments, so Raman spectroscopy is often used to determine relative purity. However, thin samples are resistant to Raman spectroscopy due to their low melting point and poor heat dispersion.
The crystalline structure of allows for mechanical exfoliation of thin samples by cleaving along the trigonal axis. This process is significantly lower in yield than epitaxial growth, but produces samples without defects or impurities. Similar to extracting graphene from bulk graphite samples, this is done by applying and removing adhesive tape from successively thinner samples. This procedure has been used to obtain flakes with a thickness of 1 nm. However, this process can leave significant amounts of adhesive residue on a standard Si/SiO substrate, which in turn obscure atomic force microscopy measurements and inhibit the placement of contacts on the substrate for purposes of testing. Common cleaning techniques such as oxygen plasma, boiling acetone and isopropyl alcohol are ineffective in removing residue. | 1 | Semiconductor Materials |
Lead iodide is very toxic to human health. Ingestion will cause many acute and chronic consequences characteristic of lead poisoning. Lead iodide has been found to be a carcinogen in animals suggesting the same may hold true in humans. Lead iodide is an inhalation hazard, and appropriate respirators should be used when handling powders of lead iodide. | 1 | Semiconductor Materials |
The mitigation measures that are typically employed to prevent negatively impact sensitive marine enviorment are listed below:
* A well-designed discharge mechanisms, employing the use of efficient diffusers or pre-dilution of discharges with seawater
* An environmental evaluation study, which assesses the correct location of the discharge point, considering geomorphological and oceanographic variables, such as currents, bathymetry, and type of bottom, which favor a rapid mixing process of the discharges;
* The implementation of an adequate environmental surveillance program, which guarantees the correct operation of the desalination plants during their operational phase, allowing an accurate and early diagnostics of potential environmental threats | 0 | Salts |
Tungsten disilicide can react violently with substances such as strong acids, fluorine, oxidizers, and interhalogens. | 1 | Semiconductor Materials |
Because of the properties of europium(II) oxide, thin layers of the oxide deposited on silicon are being studied for use as spin filters. Spin filter materials only allow electrons of a certain spin to pass, blocking electrons of the opposite spin. | 1 | Semiconductor Materials |
Quantum beats are observable in systems in which the total optical polarization is due to a finite number of discrete transition frequencies which are quantum mechanically coupled, e.g., by common ground or excited states.
Assuming for simplicity that all these transitions have the same dipole matrix element, after excitation with a short laser pulse at the optical polarization of the system evolves as
where the index labels the participating transitions.
A finite number of frequencies results in temporal modulations of the squared modulus of the polarization and thus of the intensity of the emitted electromagnetic field with time periods
For the case of just two frequencies the squared modulus of the polarization is proportional to
i.e., due to the interference of two contributions with the same amplitude but different frequencies, the polarization varies between a maximum and zero.
In semiconductors and semiconductor heterostructures, such as quantum wells, nonlinear optical quantum-beat spectroscopy has been widely used to investigate the temporal dynamics of excitonic resonances.
In particular, the consequences of many-body effects which depending on the excitation conditions may lead to, e.g., a coupling among different excitonic resonances via biexcitons and other Coulomb correlation contributions and to a decay of the coherent dynamics by scattering and dephasing processes, has been explored in many pump-probe and four-wave-mixing measurements.
The theoretical analysis of such experiments in semiconductors requires a treatment on the basis of quantum mechanical many-body theory as is provided by the SBEs with many-body correlations incorporated on an adequate level. | 1 | Semiconductor Materials |
Cobalt oxide/graphene composite are synthesized by first forming cobalt(II) hydroxide on the graphene sheet from a cobalt(II) salt and ammonium hydroxide , which is then heated to 450 °C for two hours to yield the oxide. | 1 | Semiconductor Materials |
Brine consists of concentrated solution of Na and Cl ions. Sodium chloride per se does not exist in water: it is fully ionized. Other cations found in various brines include K, Mg, Ca, and Sr. The latter three are problematic because they form scale and they react with soaps. Aside from chloride, brines sometimes contain Br and I and, most problematically, . Purification steps often include the addition of calcium oxide to precipitate solid magnesium hydroxide together with gypsum (CaSO), which can be removed by filtration. Further purification is achieved by fractional crystallization. The resulting purified salt is called evaporated salt or vacuum salt. | 0 | Salts |
Pyrite oxidation is sufficiently exothermic that underground coal mines in high-sulfur coal seams have occasionally had serious problems with spontaneous combustion. The solution is the use of buffer blasting and the use of various sealing or cladding agents to hermetically seal the mined-out areas to exclude oxygen.
In modern coal mines, limestone dust is sprayed onto the exposed coal surfaces to reduce the hazard of dust explosions. This has the secondary benefit of neutralizing the acid released by pyrite oxidation and therefore slowing the oxidation cycle described above, thus reducing the likelihood of spontaneous combustion. In the long term, however, oxidation continues, and the hydrated sulfates formed may exert crystallization pressure that can expand cracks in the rock and lead eventually to roof fall. | 1 | Semiconductor Materials |
To be of use for connecting molecules, MWs need to self-assemble following well-defined routes and form reliable electrical contacts between them. To reproducibly self-assemble a complex circuit based on single molecules. Ideally, they would connect to diverse materials, such as gold metal surfaces (for connections to outside world), biomolecules (for nanosensors, nanoelectrodes, molecular switches) and most importantly, they must allow branching. The connectors should also be available of pre-determined diameter and length. They should also have covalent bonding to ensure reproducible transport and contact properties.
DNA-like molecules have specific molecular-scale recognition and can be used in molecular scaffold fabrication. Complex shapes have been demonstrated, but unfortunately metal coated DNA which is electrically conducting is too thick to connect to individual molecules. Thinner coated DNA lacks electronic connectivity and is unsuited for connecting molecular electronics components.
Some varieties of carbon nanotubes (CNTs) are conducting, and connectivity at their ends can be achieved by attachment of connecting groups. Unfortunately manufacturing CNTs with pre-determined properties is impossible at present, and the functionalized ends are typically not conducting, limiting their usefulness as molecular connectors. Individual CNTs can be soldered in an electron microscope, but the contact is not covalent and cannot be self-assembled.
Possible routes for the construction of larger functional circuits using MoSI MWs have been demonstrated, either via gold nanoparticles as linkers, or by direct connection to thiolated molecules. The two approaches may lead to different possible applications. The use of GNPs offers the possibility of branching and construction of larger circuits. | 1 | Semiconductor Materials |
Uranium dioxide or uranium(IV) oxide (), also known as urania or uranous oxide, is an oxide of uranium, and is a black, radioactive, crystalline powder that naturally occurs in the mineral uraninite. It is used in nuclear fuel rods in nuclear reactors. A mixture of uranium and plutonium dioxides is used as MOX fuel. Prior to 1960, it was used as yellow and black color in ceramic glazes and glass. | 1 | Semiconductor Materials |
A significant proportion of the world's hydrocarbon reserves are found in structures related to salt tectonics, including many in the Middle East, the South Atlantic passive margins (Brazil, Gabon and Angola), the Gulf of Mexico, and the Pricaspian Basin. | 0 | Salts |
Due to weak van der Waals interactions between the sheets of sulfide atoms, has a low coefficient of friction. in particle sizes in the range of 1–100 µm is a common dry lubricant. Few alternatives exist that confer high lubricity and stability at up to 350 °C in oxidizing environments. Sliding friction tests of using a pin on disc tester at low loads (0.1–2 N) give friction coefficient values of <0.1.
is often a component of blends and composites that require low friction. For example, it is added to graphite to improve sticking. A variety of oils and greases are used, because they retain their lubricity even in cases of almost complete oil loss, thus finding a use in critical applications such as aircraft engines. When added to plastics, forms a composite with improved strength as well as reduced friction. Polymers that may be filled with include nylon (trade name Nylatron), Teflon and Vespel. Self-lubricating composite coatings for high-temperature applications consist of molybdenum disulfide and titanium nitride, using chemical vapor deposition.
Examples of applications of -based lubricants include two-stroke engines (such as motorcycle engines), bicycle coaster brakes, automotive CV and universal joints, ski waxes and bullets.
Other layered inorganic materials that exhibit lubricating properties (collectively known as solid lubricants (or dry lubricants)) includes graphite, which requires volatile additives and hexagonal boron nitride. | 1 | Semiconductor Materials |
A detergent similar to soap was manufactured in ancient China from the seeds of Gleditsia sinensis. Another traditional detergent is a mixture of pig pancreas and plant ash called zhuyizi (). Soap made of animal fat did not appear in China until the modern era. Soap-like detergents were not as popular as ointments and creams. | 0 | Salts |
Pyrite is distinguishable from native gold by its hardness, brittleness and crystal form. Pyrite fractures are very uneven, sometimes conchoidal because it does not cleave along a preferential plane. Native gold nuggets, or glitters, do not break but deform in a ductile way. Pyrite is brittle, gold is malleable.
Natural gold tends to be anhedral (irregularly shaped without well defined faces), whereas pyrite comes as either cubes or multifaceted crystals with well developed and sharp faces easy to recognise. Well crystallised pyrite crystals are euhedral (i.e., with nice faces). Pyrite can often be distinguished by the striations which, in many cases, can be seen on its surface. Chalcopyrite () is brighter yellow with a greenish hue when wet and is softer (3.5–4 on Mohs' scale). Arsenopyrite (FeAsS) is silver white and does not become more yellow when wet. | 1 | Semiconductor Materials |
Terbium(III) oxide, also known as terbium sesquioxide, is a sesquioxide of the rare earth metal terbium, having chemical formula . It is a p-type semiconductor, which conducts protons, which is enhanced when doped with calcium. It may be prepared by the reduction of Terbium(III,IV) oxide| in hydrogen at 1300 °C for 24 hours.
It is a basic oxide and easily dissolved to dilute acids, and then almost colourless terbium salt is formed.
: TbO + 6 H → 2 Tb + 3 HO
The crystal structure is cubic and the lattice constant is a = 1057 pm. | 1 | Semiconductor Materials |
For many applications, the counterion simply provides charge and lipophilicity that allows manipulation of its partner ion. The counterion is expected to be chemically inert. For counteranions, inertness is expressed in terms of low Lewis basicity. The counterions are ideally rugged and unreactive. For quaternary ammonium and phosphonium countercations, inertness is related to their resistance of degradation by strong bases and strong nucleophiles. | 0 | Salts |
*Priority existing chemical Report No. 5 [https://web.archive.org/web/20110223034648/http://nicnas.gov.au/Publications/CAR/PEC/PEC5/PEC_5_Full_Report_PDF.pdf Sodium Ethyl Xanthate], [http://www.nicnas.gov.au/ National Industrial Chemicals Notification and Assessment Scheme], Dep. of Health and Ageing, Australian Government (1995)
*Priority Existing Chemical. Secondary Notification Assessment Report No. 5S [https://web.archive.org/web/20110223034732/http://nicnas.gov.au/Publications/CAR/PEC/PEC5s/PEC_5s_Full_Report_PDF.pdf Sodium Ethyl Xanthate], National Industrial Chemicals Notification and Assessment Scheme, Dep. of Health and Ageing, Australian Government, (February 2000) | 0 | Salts |
Europium(II) oxide is a violet compound as a bulk crystal and transparent blue in thin film form. It is unstable in humid atmosphere, slowly turning into the yellow europium(II) hydroxide hydrrate and then to white europium(III) hydroxide. EuO crystallizes in a cubic sodium chloride structure with a lattice parameter a = 0.5144nm. The compound is often non-stoichiometric, containing up to 4% Eu and small amounts of elemental europium. However, since 2008 high purity crystalline EuO films can be created in ultra high vacuum conditions. These films have a crystallite size of about 4 nm.
Europium(II) oxide is ferromagnetic with a Curie Temperature of 69.3 K. With the addition of about 5-7% elemental europium, this increases to 79 K. It also displays colossal magnetoresistance, with a dramatic increase in conductivity below the Curie temperature. One more way to increase the Curie temperature is doping with gadolinium, holmium, or lanthanum.
Europium(II) oxide is a semiconductor with a band gap of 1.12 eV. | 1 | Semiconductor Materials |
NaH is a base of wide scope and utility in organic chemistry. As a superbase, it is capable of deprotonating a range of even weak Brønsted acids to give the corresponding sodium derivatives. Typical "easy" substrates contain O-H, N-H, S-H bonds, including alcohols, phenols, pyrazoles, and thiols.
NaH notably deprotonates carbon acids (i.e., C-H bonds) such as 1,3-dicarbonyls such as malonic esters. The resulting sodium derivatives can be alkylated. NaH is widely used to promote condensation reactions of carbonyl compounds via the Dieckmann condensation, Stobbe condensation, Darzens condensation, and Claisen condensation. Other carbon acids susceptible to deprotonation by NaH include sulfonium salts and DMSO. NaH is used to make sulfur ylides, which in turn are used to convert ketones into epoxides, as in the Johnson–Corey–Chaykovsky reaction. | 1 | Semiconductor Materials |
While the formation of other caliches is relatively well understood, the origin of Chilean caliche is not clearly known. One possibility is that the deposits were formed when a prehistoric inland sea evaporated. Another theory is that it was deposited due to weathering of the Andes.
One of the world's largest deposits of calcrete is in the Makgadikgadi Pans in Botswana, where surface calcretes occur at the location of a now-desiccated prehistoric lake.
Highly indurated (hardened) caliche is known as calcrete, and it gives rise to characteristic landforms in arid environments. Calcrete is found throughout the geologic record, forming a record of past climate. Examples include Mississippian calcretes in South Wales and Pliocene to Pleistocene caprock of the Llano Estacado of Texas, US, and Mormon Mesa, Nevada, US.
Caliches can store significant amounts of carbon, making them of significance to the overall global carbon cycle.
In Jurassic geological settings, the caliche is often indicator of warm climate with well marked wet-dry seasonality that could indicate seasonal monsoons. | 0 | Salts |
InS nanoparticles luminesce in the visible spectrum. Preparing InS nanoparticles in the presence of other heavy metal ions creates highly efficient blue, green, and red phosphors, which can be used in projectors and instrument displays. | 1 | Semiconductor Materials |
Copper(I) thiocyanate forms one double salt with the group 1 elements, CsCu(SCN). The double salt only forms from concentrated solutions of CsSCN, into which CuSCN dissolves. From less concentrated solutions, solid CuSCN separates reflecting its low solubility. When brought together with potassium, sodium or barium thiocyanate, and brought to crystallisation by concentrating the solution, mixed salts will crystallise out. These are not considered true double salts. As with CsCu (SNC), copper(I) thiocyanate separates out when these mixed salts are redissolved or their solutions diluted. | 1 | Semiconductor Materials |
Pyrite oxidation by atmospheric in the presence of moisture () initially produces ferrous ions () and sulfuric acid which dissociates into sulfate ions and protons, leading to acid mine drainage (AMD). An example of acid rock drainage caused by pyrite is the 2015 Gold King Mine waste water spill. | 1 | Semiconductor Materials |
The alkali metal thioxanthates are produced by treating a thiol with a base in the presence of carbon disulfide, as illustrated by the preparation of sodium ethyl thioxanthate:.
:EtSH + NaOH + CS → EtSCSNa + HO
Sodium ethyl thioxanthate is similar structurally to sodium ethyl xanthate.
Alkylation of such thioxanthate anions gives thioxanthate esters, as illustrated by the preparation of ethyl methyl thioxanthate:
:EtSCSNa + MeI → EtSCSMe + NaI
Thioxanthate esters are also called esters of trithiocarbonate. | 0 | Salts |
Salt-like carbides are composed of highly electropositive elements such as the alkali metals, alkaline earth metals, lanthanides, actinides, and group 3 metals (scandium, yttrium, and lutetium). Aluminium from group 13 forms carbides, but gallium, indium, and thallium do not. These materials feature isolated carbon centers, often described as "C", in the methanides or methides; two-atom units, "", in the acetylides; and three-atom units, "", in the allylides. The graphite intercalation compound KC, prepared from vapour of potassium and graphite, and the alkali metal derivatives of C are not usually classified as carbides. | 0 | Salts |
FeO has a cubic inverse spinel group structure which consists of a cubic close packed array of oxide ions where all of the Fe ions occupy half of the octahedral sites and the Fe are split evenly across the remaining octahedral sites and the tetrahedral sites.
Both FeO and γ-FeO have a similar cubic close packed array of oxide ions and this accounts for the ready interchangeability between the three compounds on oxidation and reduction as these reactions entail a relatively small change to the overall structure. FeO samples can be non-stoichiometric.
The ferrimagnetism of FeO arises because the electron spins of the Fe and Fe ions in the octahedral sites are coupled and the spins of the Fe ions in the tetrahedral sites are coupled but anti-parallel to the former. The net effect is that the magnetic contributions of both sets are not balanced and there is a permanent magnetism.
In the molten state, experimentally constrained models show that the iron ions are coordinated to 5 oxygen ions on average. There is a distribution of coordination sites in the liquid state, with the majority of both Fe and Fe being 5-coordinated to oxygen and minority populations of both 4- and 6-fold coordinated iron. | 1 | Semiconductor Materials |
When simple salts dissolve, they dissociate into individual ions, which are solvated and dispersed throughout the resulting solution. Salts do not exist in solution. In contrast, molecular compounds, which includes most organic compounds, remain intact in solution.
The solubility of salts is highest in polar solvents (such as water) or ionic liquids, but tends to be low in nonpolar solvents (such as petrol/gasoline). This contrast is principally because the resulting ion–dipole interactions are significantly stronger than ion-induced dipole interactions, so the heat of solution is higher. When the oppositely charged ions in the solid ionic lattice are surrounded by the opposite pole of a polar molecule, the solid ions are pulled out of the lattice and into the liquid. If the solvation energy exceeds the lattice energy, the negative net enthalpy change of solution provides a thermodynamic drive to remove ions from their positions in the crystal and dissolve in the liquid. In addition, the entropy change of solution is usually positive for most solid solutes like ionic compounds, which means that their solubility increases when the temperature increases. There are some unusual ionic compounds such as cerium(III) sulfate, where this entropy change is negative, due to extra order induced in the water upon solution, and the solubility decreases with temperature.
The lattice energy, the cohesive forces between these ions within a solid, determines the solubility. The solubility is dependent on how well each ion interacts with the solvent, so certain patterns become apparent. For example, salts of sodium, potassium and ammonium are usually soluble in water. Notable exceptions include ammonium hexachloroplatinate and potassium cobaltinitrite. Most nitrates and many sulfates are water-soluble. Exceptions include barium sulfate, calcium sulfate (sparingly soluble), and lead(II) sulfate, where the 2+/2− pairing leads to high lattice energies. For similar reasons, most metal carbonates are not soluble in water. Some soluble carbonate salts are: sodium carbonate, potassium carbonate and ammonium carbonate. | 0 | Salts |
Strong salts or strong electrolyte salts are chemical salts composed of strong electrolytes. These salts dissociate completely or almost completely in water. They are generally odorless and nonvolatile.
Strong salts start with Na__, K__, NH__, or they end with __NO, __ClO, or __CHCOO. Most group 1 and 2 metals form strong salts. Strong salts are especially useful when creating conductive compounds as their constituent ions allow for greater conductivity.
Weak salts or weak electrolyte salts are composed of weak electrolytes. These salts do not dissociate well in water. They are generally more volatile than strong salts. They may be similar in odor to the acid or base they are derived from. For example, sodium acetate, CHCOONa, smells similar to acetic acid CHCOOH. | 0 | Salts |
Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal to ‰).
Salinity is an important factor in determining many aspects of the chemistry of natural waters and of biological processes within it, and is a thermodynamic state variable that, along with temperature and pressure, governs physical characteristics like the density and heat capacity of the water.
A contour line of constant salinity is called an isohaline, or sometimes isohale. | 0 | Salts |
Iron pyrite is unstable when exposed to the oxidizing conditions prevailing at the Earths surface: iron pyrite in contact with atmospheric oxygen and water, or damp, ultimately decomposes into iron oxyhydroxides (ferrihydrite, FeO(OH)) and sulfuric acid (). This process is accelerated by the action of Acidithiobacillus' bacteria which oxidize pyrite to first produce ferrous ions (), sulfate ions (), and release protons (, or ). In a second step, the ferrous ions () are oxidized by into ferric ions () which hydrolyze also releasing ions and producing FeO(OH). These oxidation reactions occur more rapidly when pyrite is finely dispersed (framboidal crystals initially formed by sulfate reducing bacteria (SRB) in argillaceous sediments or dust from mining operations). | 1 | Semiconductor Materials |
Saline (also known as saline solution) is a mixture of sodium chloride (salt) and water. It has a number of uses in medicine including cleaning wounds, removal and storage of contact lenses, and help with dry eyes. By injection into a vein, it is used to treat dehydration such as that from gastroenteritis and diabetic ketoacidosis. Large amounts may result in fluid overload, swelling, acidosis, and high blood sodium. In those with long-standing low blood sodium, excessive use may result in osmotic demyelination syndrome.
Saline is in the crystalloid family of medications. It is most commonly used as a sterile 9 g of salt per litre (0.9%) solution, known as normal saline. Higher and lower concentrations may also occasionally be used. Saline is acidic, with a pH of 5.5 (due mainly to dissolved carbon dioxide).
The medical use of saline began around 1831. It is on the World Health Organization's List of Essential Medicines. In 2020, sodium was the 274th most commonly prescribed medication in the United States, with more than 1million prescriptions. | 0 | Salts |
Ions in ionic compounds are primarily held together by the electrostatic forces between the charge distribution of these bodies, and in particular, the ionic bond resulting from the long-ranged Coulomb attraction between the net negative charge of the anions and net positive charge of the cations. There is also a small additional attractive force from van der Waals interactions which contributes only around 1–2% of the cohesive energy for small ions. When a pair of ions comes close enough for their outer electron shells (most simple ions have closed shells) to overlap, a short-ranged repulsive force occurs, due to the Pauli exclusion principle. The balance between these forces leads to a potential energy well with minimum energy when the nuclei are separated by a specific equilibrium distance.
If the electronic structure of the two interacting bodies is affected by the presence of one another, covalent interactions (non-ionic) also contribute to the overall energy of the compound formed. Ionic compounds are rarely purely ionic, i.e. held together only by electrostatic forces. The bonds between even the most electronegative/electropositive pairs such as those in caesium fluoride exhibit a small degree of covalency. Conversely, covalent bonds between unlike atoms often exhibit some charge separation and can be considered to have a partial ionic character. The circumstances under which a compound will have ionic or covalent character can typically be understood using Fajans' rules, which use only charges and the sizes of each ion. According to these rules, compounds with the most ionic character will have large positive ions with a low charge, bonded to a small negative ion with a high charge. More generally HSAB theory can be applied, whereby the compounds with the most ionic character are those consisting of hard acids and hard bases: small, highly charged ions with a high difference in electronegativities between the anion and cation. This difference in electronegativities means that the charge separation, and resulting dipole moment, is maintained even when the ions are in contact (the excess electrons on the anions are not transferred or polarized to neutralize the cations).
Although chemists classify idealized bond types as being ionic or covalent, the existence of additional types such as hydrogen bonds and metallic bonds, for example, has led some philosophers of science to suggest that alternative approaches to understanding bonding are required. This could be by applying quantum mechanics to calculate binding energies. | 0 | Salts |
The alkali metal halides exist as colourless crystalline solids, although as finely ground powders appear white. They melt at high temperature, usually several hundred degrees to colorless liquids. Their high melting point reflects their high lattice energies. At still higher temperatures, these liquids evaporate to give gases composed of diatomic molecules.
These compounds dissolve in polar solvents to give ionic solutions that contain highly solvated anions and cations. Alkali halides dissolve large amounts of the corresponding alkali metal: caesium is completely miscible at all temperatures above the melting point.
The table below provides links to each of the individual articles for these compounds. The numbers beside the compounds show the electronegativity difference between the elements based on the Pauling scale. The higher the number is, the more ionic the solid is. | 0 | Salts |
Cellulose reacts with carbon disulfide (CS) in presence of sodium hydroxide (NaOH) to produces sodium cellulose xanthate, which upon neutralization with sulfuric acid (HSO) gives viscose rayon or cellophane paper (Sellotape or Scotch Tape).
Xanthate salts (e.g. sodium alkyl xanthates, dixanthogen) are widely used as flotation agents in mineral processing. | 0 | Salts |
Acid salts are a class of salts that produce an acidic solution after being dissolved in a solvent. Its formation as a substance has a greater electrical conductivity than that of the pure solvent. An acidic solution formed by acid salt is made during partial neutralization of diprotic or polyprotic acids. A half-neutralization occurs due to the remaining of replaceable hydrogen atoms from the partial dissociation of weak acids that have not been reacted with hydroxide ions () to create water molecules. | 0 | Salts |
Copper(II) chloride is a mild oxidant. It starts to decompose to copper(I) chloride and chlorine gas around and is completely decomposed near :
The reported melting point of copper(II) chloride of is a melt of a mixture of copper(I) chloride and copper(II) chloride. The true melting point of can be extrapolated by using the melting points of the mixtures of CuCl and . Copper(II) chloride reacts with several metals to produce copper metal or copper(I) chloride (CuCl) with oxidation of the other metal. To convert copper(II) chloride to copper(I) chloride, it can be convenient to reduce an aqueous solution with sulfur dioxide as the reductant: | 1 | Semiconductor Materials |
High levels of soil salinity can be tolerated if salt-tolerant plants are grown. Sensitive crops lose their vigor already in slightly saline soils, most crops are negatively affected by (moderately) saline soils, and only salinity-resistant crops thrive in severely saline soils. The University of Wyoming and the Government of Alberta report data on the salt tolerance of plants.
Field data in irrigated lands, under farmers' conditions, are scarce, especially in developing countries. However, some on-farm surveys have been made in Egypt, India, and Pakistan. Some examples are shown in the following gallery, with crops arranged from sensitive to very tolerant.
Calcium has been found to have a positive effect in combating salinity in soils. It has been shown to ameliorate the negative effects that salinity has such as reduced water usage of plants. | 0 | Salts |
Molybdenum disilicide (MoSi, or molybdenum silicide), an intermetallic compound, a silicide of molybdenum, is a refractory ceramic with primary use in heating elements. It has moderate density, melting point 2030 °C, and is electrically conductive. At high temperatures it forms a passivation layer of silicon dioxide, protecting it from further oxidation. The thermal stability of MoSi alongside its high emissivity make this material, alongside WSi attractive for applications as a high emissivity coatings in heat shields for atmospheric entry.
MoSi is a gray metallic-looking material with tetragonal crystal structure (alpha-modification); its beta-modification is hexagonal and unstable. It is insoluble in most acids but soluble in nitric acid and hydrofluoric acid.
While MoSi has excellent resistance to oxidation and high Young's modulus at temperatures above 1000 °C, it is brittle in lower temperatures. Also, at above 1200 °C it loses creep resistance. These properties limits its use as a structural material, but may be offset by using it together with another material as a composite material.
Molybdenum disilicide and MoSi-based materials are usually made by sintering. Plasma spraying can be used for producing its dense monolithic and composite forms; material produced this way may contain a proportion of β-MoSi due to its rapid cooling.
Molybdenum disilicide heating elements can be used for temperatures up to 1800 °C, in electric furnaces used in laboratory and production environment in production of glass, steel, electronics, ceramics, and in heat treatment of materials. While the elements are brittle, they can operate at high power without aging, and their electrical resistivity does not increase with operation time. Their maximum operating temperature has to be lowered in atmospheres with low oxygen content due to breakdown of the passivation layer.
Other ceramic materials used for heating elements include silicon carbide, barium titanate, and lead titanate composite materials.
Molybdenum disilicide is used in microelectronics as a contact material. It is often used as a shunt over polysilicon lines to increase their conductivity and increase signal speed. | 1 | Semiconductor Materials |
Nano particles of FeO are used as contrast agents in MRI scanning.
Ferumoxytol, sold under the brand names Feraheme and Rienso, is an intravenous FeO preparation for treatment of anemia resulting from chronic kidney disease. Ferumoxytol is manufactured and globally distributed by AMAG Pharmaceuticals. | 1 | Semiconductor Materials |
reacts with HCl or other chloride sources to form complex ions: the red (found in potassium trichloridocuprate(II) ) (it is a dimer in reality, , a couple of tetrahedrons that share an edge), and the green or yellow (found in potassium tetrachloridocuprate(II) ).
Some of these complexes can be crystallized from aqueous solution, and they adopt a wide variety of structures.
Copper(II) chloride also forms a variety of coordination complexes with ligands such as ammonia, pyridine and triphenylphosphine oxide:
: (tetragonal)
: (tetrahedral)
However "soft" ligands such as phosphines (e.g., triphenylphosphine), iodide, and cyanide as well as some tertiary amines induce reduction to give copper(I) complexes. | 1 | Semiconductor Materials |
Characterization of crystalline g-CN can be carried out by identifying the triazine ring existing in the products by X-ray photoelectron spectroscopy (XPS) measurements, photoluminescence spectra and Fourier transform infrared spectroscopy (FTIR) spectrum (peaks at 800 cm, 1310 cm and 1610 cm). | 1 | Semiconductor Materials |
Salts of , , , etc. are labeled as iodoplumbates. Lead perovskite semiconductors are often described as plumbates. | 0 | Salts |
When heated to 700 °C, indium(III) oxide forms InO, (called indium(I) oxide or indium suboxide), at 2000 °C it decomposes.
It is soluble in acids but not in alkali.
With ammonia at high temperature indium nitride is formed:
: InO + 2 NH → 2 InN + 3 HO
With KO and indium metal the compound KInO containing tetrahedral InO ions was prepared.
Reacting with a range of metal trioxides produces perovskites for example:
:InO + CrO → 2InCrO | 1 | Semiconductor Materials |
Mercury(II) iodide is a chemical compound with the molecular formula HgI. It is typically produced synthetically but can also be found in nature as the extremely rare mineral coccinite. Unlike the related mercury(II) chloride it is hardly soluble in water (<100 ppm). | 1 | Semiconductor Materials |
It is uncertain as to who was the first to invent soap. The earliest recorded evidence of the production of soap-like materials dates back to around 2800 BC in ancient Babylon. A formula for making soap was written on a Sumerian clay tablet around 2500 BC; the soap was produced by heating a mixture of oil and wood ash, the earliest recorded chemical reaction, and used for washing woolen clothing.
The Ebers papyrus (Egypt, 1550 BC) indicates the ancient Egyptians used soap as a medicine and combined animal fats or vegetable oils with a soda ash substance called trona to create their soaps. Egyptian documents mention a similar substance was used in the preparation of wool for weaving.
In the reign of Nabonidus (556–539 BC), a recipe for soap consisted of uhulu [ashes], cypress [oil] and sesame [seed oil] "for washing the stones for the servant girls".
In the Southern Levant, the ashes from barilla plants, such as species of Salsola, saltwort (Seidlitzia rosmarinus) and Anabasis, were used in soap production, known as potash. Traditionally, olive oil was used instead of animal lard throughout the Levant, which was boiled in a copper cauldron for several days. As the boiling progresses, alkali ashes and smaller quantities of quicklime are added and constantly stirred. In the case of lard, it required constant stirring while kept lukewarm until it began to trace. Once it began to thicken, the brew was poured into a mold and left to cool and harden for two weeks. After hardening, it was cut into smaller cakes. Aromatic herbs were often added to the rendered soap to impart their fragrance, such as yarrow leaves, lavender, germander, etc. | 0 | Salts |
Pliny the Elder, whose writings chronicle life in the first century AD, describes soap as "an invention of the Gauls".
The word , Latin for soap, likely was borrowed from an early Germanic language and is cognate with Latin , "tallow". It first appears in Pliny the Elders account, Historia Naturalis, which discusses the manufacture of soap from tallow and ashes. There he mentions its use in the treatment of scrofulous sores, as well as among the Gauls as a dye to redden hair which the men in Germania were more likely to use than women. The Romans avoided washing with harsh soaps before encountering the milder soaps used by the Gauls around 58 BC. Aretaeus of Cappadocia, writing in the 2nd century AD, observes among "Celts, which are men called Gauls, those alkaline substances that are made into balls [...] called soap". The Romans preferred method of cleaning the body was to massage oil into the skin and then scrape away both the oil and any dirt with a strigil. The standard design is a curved blade with a handle, all of which is made of metal.
The 2nd-century AD physician Galen describes soap-making using lye and prescribes washing to carry away impurities from the body and clothes. The use of soap for personal cleanliness became increasingly common in this period. According to Galen, the best soaps were Germanic, and soaps from Gaul were second best. Zosimos of Panopolis, circa 300 AD, describes soap and soapmaking. | 0 | Salts |
Bamboo salt (, ) is a Korean condiment and traditional remedy. It is prepared by packing sea salt in a thick bamboo stem, and baking it nine times at high temperature using pine firewood. During the baking processes, the impurities in the salt are claimed to be removed or neutralized while its inorganic contents, such as calcium, potassium, iron, copper, and zinc are increased. | 0 | Salts |
Several carbides are assumed to be salts of the acetylide anion (also called percarbide, by analogy with peroxide), which has a triple bond between the two carbon atoms. Alkali metals, alkaline earth metals, and lanthanoid metals form acetylides, for example, sodium carbide NaC, calcium carbide CaC, and LaC. Lanthanides also form carbides (sesquicarbides, see below) with formula MC. Metals from group 11 also tend to form acetylides, such as copper(I) acetylide and silver acetylide. Carbides of the actinide elements, which have stoichiometry MC and MC, are also described as salt-like derivatives of .
The C–C triple bond length ranges from 119.2 pm in CaC (similar to ethyne), to 130.3 pm in LaC and 134 pm in UC. The bonding in LaC has been described in terms of La with the extra electron delocalised into the antibonding orbital on , explaining the metallic conduction. | 0 | Salts |
Sodium ethyl xanthate (SEX) is an organosulfur compound with the chemical formula . It is a pale yellow powder, which is usually obtained as the dihydrate. Sodium ethyl xanthate is used in the mining industry as a flotation agent. A closely related potassium ethyl xanthate (KEX) is obtained as the anhydrous salt. | 0 | Salts |
Macroscopically, Maxwell's equations show that in the absence of free charges and currents an electromagnetic field interacts with matter via the optical polarization . The wave equation for the electric field reads and shows that the second derivative with respect to time of , i.e., , appears as a source term in the wave equation for the electric field . Thus, for optically thin samples and measurements performed in the far-field, i.e., at distances significantly exceeding the optical wavelength , the emitted electric field resulting from the polarization is proportional to its second time derivative, i.e., . Therefore, measuring the dynamics of the emitted field provides direct information on the temporal evolution of the optical material polarization .
Microscopically, the optical polarization arises from quantum mechanical transitions between different states of the material system. For the case of semiconductors, electromagnetic radiation with optical frequencies is able to move electrons from the valence () to the conduction () band. The macroscopic polarization is computed by summing over all microscopic transition dipoles via , where is the dipole matrix element which determines the strength of individual transitions between the states and , denotes the complex conjugate, and is the appropriately chosen system's volume.
If and are the energies of the conduction and valence band states, their dynamic quantum mechanical evolution is according to the Schrödinger equation given by phase factors and , respectively.
The superposition state described by is evolving in time according to .
Assuming that we start at with , we have for the optical polarization
Thus, is given by a summation over the microscopic transition dipoles which all oscillate with frequencies corresponding to the energy differences between the involved quantum states.
Clearly, the optical polarization is a coherent quantity which is characterized by an amplitude and a phase.
Depending on the phase relationships of the microscopic transition dipoles, one may obtain constructive or destructive interference, in which the microscopic dipoles are in or out of phase, respectively, and temporal interference phenomena like quantum beats, in which the modulus of varies as function of time.
Ignoring many-body effects and the coupling to other quasi particles and to reservoirs, the dynamics of photoexcited two-level systems can be described by a set of two equations, the so-called optical Bloch equations.
These equations are named after Felix Bloch who formulated them in order to analyze the dynamics of spin systems in nuclear magnetic resonance.
The two-level Bloch equations read
and
Here, denotes the energy difference between the two states and is the inversion, i.e., the difference in the occupations of the upper and the lower states.
The electric field couples the microscopic polarization to the product of the Rabi energy and the inversion .
In the absence of the driving electric field, i.e., for , the Bloch equation for describes an oscillation, i.e., .
The optical Bloch equations enable a transparent analysis of several nonlinear optical experiments.
They are, however, only well suited for systems with optical transitions between isolated levels in which many-body interactions are of minor importance as is sometimes the case in atoms or small molecules.
In solid state systems, such as semiconductors and semiconductor nanostructures, an adequate description of the many-body Coulomb interaction and the coupling to additional degrees of freedom is essential and thus the optical Bloch equations are not applicable. | 1 | Semiconductor Materials |
Most types of molecular wires are derived from organic molecules. One naturally occurring molecular wire is DNA. Prominent inorganic examples include polymeric materials such as LiMoSe and MoSI, [Pd(CO)(OAc)Pd(acac)], and single-molecule extended metal atom chains (EMACs) which comprise strings of transition metal atoms directly bonded to each other. Molecular wires containing paramagnetic inorganic moieties can exhibit Kondo peaks. | 1 | Semiconductor Materials |
Due to the lack of spatial inversion symmetry, odd-layer MoS2 is a promising material for valleytronics because both the CBM and VBM have two energy-degenerate valleys at the corners of the first Brillouin zone, providing an exciting opportunity to store the information of 0s and 1s at different discrete values of the crystal momentum. The Berry curvature is even under spatial inversion (P) and odd under time reversal (T), the valley Hall effect cannot survive when both P and T symmetries are present. To excite valley Hall effect in specific valleys, circularly polarized lights were used for breaking the T symmetry in atomically thin transition-metal dichalcogenides. In monolayer MoS2, the T and mirror symmetries lock the spin and valley indices of the sub-bands split by the spin-orbit couplings, both of which are flipped under T; the spin conservation suppresses the inter-valley scattering. Therefore, monolayer MoS2 have been deemed an ideal platform for realizing intrinsic valley Hall effect without extrinsic symmetry breaking. | 1 | Semiconductor Materials |
Since they are salts of fatty acids, soaps have the general formula (RCO)M, where R is an alkyl, M is a metal and n is the charge of the cation. The major classification of soaps is determined by the identity of M. When M is Na (sodium) or K (potassium), the soaps are called toilet soaps, used for handwashing. Many metal dications (Mg, Ca, and others) give metallic soap. When M is Li, the result is lithium soap (e.g., lithium stearate), which is used in high-performance greases. A cation from an organic base such as ammonium can be used instead of a metal; ammonium nonanoate is an ammonium-based soap that is used as an herbicide.
When used in hard water, soap does not lather well and a scum of stearate, a common ingredient in soap, forms as an insoluble precipitate. | 0 | Salts |
In conjunction with vanadium oxide, it is used as a catalyst for the oxidation of aromatic compounds in the synthesis of carboxylic acids and acid anhydrides. | 1 | Semiconductor Materials |
The Indian Salt Service is part of India's Salt Organization which is headquartered in Jaipur. The service is headed by the Salt Commissioner below whom are five Deputy Salt Commissioners and nine Assistant Salt Commissioners who man the agency with the help of other supporting staff. The Deputy Salt Commissioners head regional offices and the Assistant Salt Commissioners are in charge of divisional offices of the organisation. The Service has four regional offices at Chennai, Mumbai, Ahmedabad and Kolkata and field offices in the salt producing states. | 0 | Salts |
Uranium dioxide is produced by reducing uranium trioxide with hydrogen.
:UO + H → UO + HO at 700 °C (973 K)
This reaction plays an important part in the creation of nuclear fuel through nuclear reprocessing and uranium enrichment. | 1 | Semiconductor Materials |
Sodium hydride is the chemical compound with the empirical formula NaH. This alkali metal hydride is primarily used as a strong yet combustible base in organic synthesis. NaH is a saline (salt-like) hydride, composed of Na and H ions, in contrast to molecular hydrides such as borane, silane, germane, ammonia, and methane. It is an ionic material that is insoluble in all solvents (other than molten sodium metal), consistent with the fact that H ions do not exist in solution. | 1 | Semiconductor Materials |