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Dross is a mass of solid impurities floating on a molten metal or dispersed in the metal, such as in wrought iron. It forms on the surface of low-melting-point metals such as tin, lead, zinc or aluminium or alloys by oxidation of the metal. For higher melting point metals and alloys such as steel and silver, oxidized i... | 8 | Metallurgy |
Pyroglutamyl-histidyl-glycine (pEHG) is an endogenous tripeptide that acts as a tissue-specific antimitotic and selectively inhibits the proliferation of colon epithelial cells. Early research indicated that pEHG had anorectic effects in mice and was possibly involved in the pathophysiology of anorexia nervosa. However... | 1 | Biochemistry |
Total organic carbon (TOC) is an analytical parameter representing the concentration of organic carbon in a sample. TOC determinations are made in a variety of application areas. For example, TOC may be used as a non-specific indicator of water quality, or TOC of source rock may be used as one factor in evaluating a ... | 3 | Analytical Chemistry |
Examples are numerous: combustion, the thermite reaction, combining strong acids and bases, polymerizations. As an example in everyday life, hand warmers make use of the oxidation of iron to achieve an exothermic reaction:
:4Fe  + 3O  → 2FeO  ΔH⚬ = - 1648 kJ/mol
A particular... | 7 | Physical Chemistry |
Development of theoretical models describing grain growth is an active field of research. Many models have been proposed for grain growth, but no theory has yet been put forth that has been independently validated to apply across the full range of conditions and many questions remain open. By no means is the following ... | 8 | Metallurgy |
Another purpose of this titration is determination of the optimum dose of surfactant for achieving stabilization or flocculation of a heterogeneous system. | 7 | Physical Chemistry |
In neuroscience and anatomy, nodes of Ranvier ( ), also known as myelin-sheath gaps, occur along a myelinated axon where the axolemma is exposed to the extracellular space. Nodes of Ranvier are uninsulated and highly enriched in ion channels, allowing them to participate in the exchange of ions required to regenerate t... | 1 | Biochemistry |
Human polypeptide C5a contains 74 amino acids and has 11kDa. NMR spectroscopy proved that the molecule is composed of four helices and connected by peptide loops with three disulphide bonds between helix IV and II, III. There is a short 1.5 turn helix on N-terminus but all agonist activity take place in the C-terminus... | 1 | Biochemistry |
According to popular legend, Galvani discovered the effects of electricity on muscle tissue when investigating an unrelated phenomenon which required skinned frogs in the 1780s and 1790s. His assistant is claimed to have accidentally touched a scalpel to the sciatic nerve of the frog and this resulted in a spark and an... | 7 | Physical Chemistry |
Complex metallic alloys (CMAs) or complex intermetallics (CIMs) are intermetallic compounds characterized by the following structural features:
#large unit cells, comprising some tens up to thousands of atoms,
#the presence of well-defined atom clusters, frequently of icosahedral point group symmetry,
#the occurrence ... | 8 | Metallurgy |
Single nucleotide polymorphisms (SNPs) in TCF7L2 gene have shown an increase in susceptibility to schizophrenia in Arab, European and Chinese Han populations. In the Chinese Han population, SNP rs12573128 in TCF7L2 is the variant that was associated with an increase in schizophrenia risk. This marker is used as a pre-d... | 1 | Biochemistry |
The refrigeration industry has been seeking replacements for R-410A because of its high global warming potential. R-454B, formerly known as DL-5A, has been selected by several manufacturers, including Mitsubishi Electric, Carrier, Johnson Controls, and others.
R-454B was developed at and is manufactured by Chemours. Ca... | 2 | Environmental Chemistry |
Water may be tested by a bioassay comparing survival of an aquatic test species in the wastewater in comparison to water from some other source. Water may also be evaluated to determine the approximate biological population of the wastewater. Pathogenic micro-organisms using water as a means of moving from one host to ... | 3 | Analytical Chemistry |
The intrinsic hydrophobicity of a surface can be enhanced by being textured with different length scales of roughness. The red rose takes advantage of this by using a hierarchy of micro- and nanostructures on each petal to provide sufficient roughness for superhydrophobicity. More specifically, each rose petal has a co... | 7 | Physical Chemistry |
The Harbor Branch Oceanographic Institution licensed (+)-discodermolide to Novartis, which began a phase 1 clinical trial in 2004. The trial concluded that the drug resulted in minimal toxicities and represents a novel mechanism of action. Amos B. Smith's research group, in collaboration with Kosan Biosciences, has a p... | 0 | Organic Chemistry |
The Rabi frequency is the frequency at which the probability amplitudes of two atomic energy levels fluctuate in an oscillating electromagnetic field. It is proportional to the transition dipole moment of the two levels and to the amplitude (not intensity) of the electromagnetic field. Population transfer between the l... | 7 | Physical Chemistry |
The standards are listed in . Primary standards are designed to protect human health, with an adequate margin of safety, including sensitive populations such as children, the elderly, and individuals suffering from respiratory diseases. Secondary standards are designed to protect public welfare, damage to property, t... | 2 | Environmental Chemistry |
A coccolithophore is a unicellular, eukaryotic phytoplankton (alga). Understanding calcification changes in coccolithophores may be particularly important because a decline in the coccolithophores may have secondary effects on climate: it could contribute to global warming by decreasing the Earth's albedo via their eff... | 9 | Geochemistry |
*J. D. Bjorken, S. D. Drell, Relativistic Quantum Mechanics, 1964
*P. Roman, Introduction to Quantum Theory, 1969
*W. Greiner, J. Reinhardt, Quantum Electrodynamics, 1994
*R. G. Newton. Scattering Theory of Waves and Particles. McGraw Hill, 1966. | 7 | Physical Chemistry |
Wootz is characterized by a pattern caused by bands of clustered particles made by melting of low levels of carbide-forming elements. Wootz contains greater carbonaceous matter than common qualities of cast steel.
The distinct patterns of Wootz steel that can be made through forging are wave, ladder, and rose patterns... | 8 | Metallurgy |
The outer portion of a SLMD consists of a section of sealed, flat, semi-permeable polyethylene tubing. Sealed inside this tubing is a 1:1 mixture of a hydrophobic metal complexing agent and a long chain organic acid. The organic acid diffuses through the tubing to the outer surface, where the carboxylic acid portion ca... | 3 | Analytical Chemistry |
-homoserine product bound at the dizinc metal center. The zinc ions are shown as cyan spheres. All ligand molecules are shown in ball-and-stick form. Carbon, oxygen, and nitrogen atoms are colored white, red, and blue, respectively. -->
A dinuclear zinc binding site is conserved in all known lactonases and essential fo... | 1 | Biochemistry |
Although E varies greatly across the periodic table, some patterns emerge. Generally, nonmetals have more positive E than metals. Atoms whose anions are more stable than neutral atoms have a greater E. Chlorine most strongly attracts extra electrons; neon most weakly attracts an extra electron. The electron affinities ... | 7 | Physical Chemistry |
β-Hydroxybutyric acid is the precursor to polyesters, which are biodegradable plastics. This polymer, poly(3-hydroxybutyrate), is also naturally produced by the bacteria Alcaligenes eutrophus.
β-Hydroxybutyrate can be extracted from poly(3-hydroxybutyrate) by acid hydrolysis.
The concentration of in blood plasma is me... | 1 | Biochemistry |
Ultrasensitivity can be achieved through several mechanisms:
#Multistep mechanisms (examples: cooperativity) and multisite phosphorylation
#Buffering mechanisms (examples: decoy phosphorylation sites) or stoichiometric inhibitors
#Changes in localisation (such as translocation across the nuclear envelope)
#Saturation ... | 1 | Biochemistry |
In a laminar flow reactor, the fluid flows through a long tube or parallel plate reactor and the flow is in layers parallel to the walls of the tube. The velocity of the flow is a parabolic function of radius. In the absence of molecular diffusion, the RTD is
The variance is infinite. In a real reactor, diffusion will... | 9 | Geochemistry |
* Fructone (fruity, apple-like)
* Ethyl methylphenylglycidate (Strawberry)
* alpha-Methylbenzyl acetate (Gardenia) | 0 | Organic Chemistry |
Colloid vibration potential measures the AC potential difference generated between two identical relaxed electrodes, placed in the dispersion, if the latter is subjected to an ultrasonic field. When a sound wave travels through a colloidal suspension of particles whose density differs from that of the surrounding mediu... | 7 | Physical Chemistry |
Used as drugs, compounds with different configuration normally have different physiological activity, including the desired pharmacological effect, the toxicology and the metabolism. Enantiomeric ratios and purity is an important factor in clinical assessments. Racemic mixtures are those that contain equimolar amounts ... | 4 | Stereochemistry |
A systematic review of clinical studies found an association between low vitamin D levels with cognitive impairment and a higher risk of developing Alzheimer's disease. However, lower vitamin D concentrations are also associated with poor nutrition and spending less time outdoors. Therefore, alternative explanations fo... | 1 | Biochemistry |
Murexide is prepared by treating alloxantin with ammonia to 100 °C, or by treating uramil (5-aminobarbituric acid) with mercury oxide. It may also be prepared by digesting alloxan with alcoholic ammonia. | 3 | Analytical Chemistry |
An important occurrence of phosphates in biological systems is as the structural material of bone and teeth. These structures are made of crystalline calcium phosphate in the form of hydroxyapatite. The hard dense enamel of mammalian teeth may contain fluoroapatite, a hydroxy calcium phosphate where some of the hydroxy... | 0 | Organic Chemistry |
Modafinil was developed in France by neurophysiology professor Michel Jouvet and Lafon Laboratories. It is part of a series of benzhydryl sulfinyl compounds, including adrafinil, initially used as a treatment for narcolepsy in France in 1986. Modafinil, the primary metabolite of adrafinil, has been prescribed in France... | 4 | Stereochemistry |
Chemical-based transfection can be divided into several kinds: cyclodextrin, polymers, liposomes, or nanoparticles (with or without chemical or viral functionalization. See below).
*One of the cheapest methods uses calcium phosphate, originally discovered by F. L. Graham and A. J. van der Eb in 1973 (see also). HEPES-... | 1 | Biochemistry |
Spermine synthase (, spermidine aminopropyltransferase, spermine synthetase) is an enzyme that converts spermidine into spermine. This enzyme catalyses the following chemical reaction
: S-adenosylmethioninamine + spermidine S-methyl-5'-thioadenosine + spermine
Spermine synthase is an enzyme involved in polyamine biosy... | 1 | Biochemistry |
Electrochlorination is the process of producing hypochlorite by passing electric current through salt water. This disinfects the water and makes it safe for human use, such as for drinking water or swimming pools. | 7 | Physical Chemistry |
BEI is very hazardous since it attacks nucleic acids and proteins as described above. It can be neutralised by sodium thiosulfate; the thiosulfate is a nucleophile which opens the three-membered ring.
The presence of BEI can be tested for using silver nitrate solution. | 0 | Organic Chemistry |
Lipid bilayers are structures of lipid molecules consisting of a hydrophobic tail and a hydrophilic head group. Therefore, these structures experience all the characteristic Interbilayer forces involved in that regime. | 6 | Supramolecular Chemistry |
Aliphatic nitro compounds can be synthesized by various methods; notable examples include:
*Free radical nitration of alkanes. The reaction produces fragments from the parent alkane, creating a diverse mixture of products; for instance, nitromethane, nitroethane, 1-nitropropane, and 2-nitropropane are produced by treat... | 0 | Organic Chemistry |
The complete quantum mechanical description was first performed by Bethe and Heitler. They assumed plane waves for electrons which scatter at the nucleus of an atom, and derived a cross section which relates the complete geometry of that process to the frequency of the emitted photon. The quadruply differential cross s... | 7 | Physical Chemistry |
Thiamine triphosphate (ThTP) is a biomolecule found in most organisms including bacteria, fungi, plants and animals. Chemically, it is the triphosphate derivative of the vitamin thiamine. | 1 | Biochemistry |
Hydroxylamine-O-sulfonic acid (HOSA) or aminosulfuric acid is the inorganic compound with molecular formula HNOS that is formed by the sulfonation of hydroxylamine with oleum. It is a white, water-soluble and hygroscopic, solid, commonly represented by the condensed structural formula HNOSOH, though it actually exists... | 0 | Organic Chemistry |
Ocean salinity has been constant at about 3.5% for a very long time. Salinity stability in oceanic environments is important as most cells require a rather constant salinity and do not generally tolerate values above 5%. The constant ocean salinity was a long-standing mystery, because no process counterbalancing the sa... | 9 | Geochemistry |
Ouabain is a highly toxic compound, however, it has a low bioavailability and is absorbed poorly from the alimentary tract as so much of the oral dose is destroyed. Intravenous administration results in greater available concentrations. After intravenous administration, the onset of action occurs within 2–10 minutes in... | 0 | Organic Chemistry |
S. Finch and R. H. Collier, in a paper entitled "Insects can see clearly now the weeds have gone", showed experimentally that flying pests are far less successful if their host-plants are surrounded by other plants or even "decoy-plants" coloured green. Pests find hosts in stages, first detecting plant odours which ind... | 1 | Biochemistry |
Second sound has been observed in solid He and He,
and in some dielectric solids such as Bi in the temperature
range of 1.2 to 4.0 K with a velocity of 780 ± 50 m/s,
or solid sodium fluoride (NaF) around 10 to 20 K. In 2021 this effect was observed in a BKT superfluid as well as in a germanium semiconductor | 7 | Physical Chemistry |
In (forward) osmosis, the solvent moves from an area of low solute concentration (high water potential), through a membrane, to an area of high solute concentration (low water potential). The driving force for the movement of the solvent is the reduction in the Gibbs free energy of the system in which the difference in... | 3 | Analytical Chemistry |
Prior to, and during the 1920s, refrigerators used toxic gases as refrigerants, including ammonia, sulphur dioxide, and chloromethane. Later in the 1920s after a series of fatal accidents involving the leaking of chloromethane from refrigerators, a major collaborative effort began between American corporations Frigidai... | 2 | Environmental Chemistry |
In the region close to the minimum of the objective function, , the system approximates to a linear least-squares system, for which
Therefore, the parameter values are (approximately) linear combinations of the observed data values and the errors on the parameters, , can be obtained by error propagation from the observ... | 7 | Physical Chemistry |
Tre recombinase is an experimental enzyme that in lab tests has removed DNA inserted by HIV from infected cells. Through selective mutation, Cre recombinase which recognizes loxP sites are modified to identify HIV long terminal repeats (loxLTR) instead. As a result, instead of performing Cre-Lox recombination, the new ... | 1 | Biochemistry |
When first invented, the Haber process competed against another industrial process, the cyanamide process. However, the cyanamide process consumed large amounts of electrical power and was more labor-intensive than the Haber process.
As of 2018, the Haber process produces 230 million tonnes of anhydrous ammonia per yea... | 7 | Physical Chemistry |
The word polyurea is derived from the Greek words πολυ- - poly- meaning "many"; and ουρίας - oûron meaning "to urinate" (referring to the substance urea, found in urine). Urea or carbamide is an organic compound with the chemical formula (NH)CO. The molecule has two amine groups (–NH) joined by a carbonyl functional gr... | 7 | Physical Chemistry |
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 (abo... | 8 | Metallurgy |
Certain materials, such as glass and glycerol, may harden without crystallizing; these are called amorphous solids. Amorphous materials, as well as some polymers, do not have a freezing point, as there is no abrupt phase change at any specific temperature. Instead, there is a gradual change in their viscoelastic proper... | 1 | Biochemistry |
The Edinburgh Handedness Inventory is a measurement scale used to assess the dominance of a person's right or left hand in everyday activities, sometimes referred to as laterality. The inventory can be used by an observer assessing the person, or by a person self-reporting hand use. The latter method tends to be less r... | 4 | Stereochemistry |
RNA Pol II-mediated gene transcription induces a local opening of chromatin state through the recruitment of histone acetyltransferases and other histone modifiers that promote euchromatin formation. It was proposed that the presence of these enzymes could also induce an opening of chromatin at enhancer regions, which ... | 1 | Biochemistry |
In quantum physics, the scattering amplitude is the probability amplitude of the outgoing spherical wave relative to the incoming plane wave in a stationary-state scattering process.
At large distances from the centrally symmetric scattering center, the plane wave is described by the wavefunction
where is the positio... | 7 | Physical Chemistry |
Ali Akbar Moosavi-Movahedi (born in Shiraz, Iran, February 1953) is an Iranian Biophysicist, and Biophysical Chemist at the Institute of Biochemistry and Biophysics, University of Tehran. He is the founder of the [http://isobc.com/ Iran Society of Biophysical Chemistry] . He is the fellow of The World Academy of Scien... | 7 | Physical Chemistry |
Homolytic bond cleavage is a process where the electron pair comprising a bond is split, causing the bond to break. This is denoted by two single barbed curved arrows pointing away from the bond. The consequence of this process is the retention of a single unpaired electron denoted by a dot on each of the atoms that we... | 0 | Organic Chemistry |
The substituents on the diazirine affect which carbene species is generated upon irradiation and subsequent photolytic cleavage. Diazirine substituents that are electron donating in nature can donate electron density to the empty p-orbital of the carbene that will be formed, and hence can stabilize the singlet state. F... | 5 | Photochemistry |
The ground state is believed to be a bent triplet, with two orthogonal sp hybrid orbitals singly occupied by unpaired spins. One electron occupies an orbital of sigma symmetry in the plane of the rings, while the other occupies an orbital of pi symmetry, which interacts with the pi systems of the adjacent aromatic ring... | 0 | Organic Chemistry |
Xing enjoyed collecting crafts relevant the tortoise.
Xings father Duan () was a member of Hanlin Academy in the Late Qing dynasty, he once studied in Japan and used to be an officer at the Beiyang government. Xings mother, Zhang Xian (), was a housewife. Xing and his wife Qian Cunrou (), a microbiologist, had two sons... | 0 | Organic Chemistry |
The cell cycle is a four-stage process that a cell goes through as it develops and divides. It includes Gap 1 (G1), synthesis (S), Gap 2 (G2), and mitosis (M).The cell either restarts the cycle from G1 or leaves the cycle through G0 after completing the cycle. The cell can progress from G0 through terminal differentiat... | 1 | Biochemistry |
The disaster prompted many countries to introduce tougher rules for the testing and licensing of drugs, such as the 1962 Kefauver Harris Amendment (US), 1965 Directive 65/65/EEC1 (EU), and the Medicines Act 1968 (UK). In the United States, the new regulations strengthened the FDA, among other ways, by requiring applic... | 4 | Stereochemistry |
The heteronuclear single quantum coherence or heteronuclear single quantum correlation experiment, normally abbreviated as HSQC, is used frequently in NMR spectroscopy of organic molecules and is of particular significance in the field of protein NMR. The experiment was first described by Geoffrey Bodenhausen and D. J.... | 7 | Physical Chemistry |
3-Carboxy-cis,cis-muconic acid is a metabolite of the catechin degradation by Bradyrhizobium japonicum.
The enzyme 3-carboxy-cis,cis-muconate cycloisomerase uses 2-carboxy-2,5-dihydro-5-oxofuran-2-acetate to produce 3-carboxy-cis,cis-muconate.
The enzyme carboxy-cis,cis-muconate cyclase uses 3-carboxy-2,5-dihydro-5-oxo... | 1 | Biochemistry |
A variety of complexes - a subset of metallaborane - are known with one or two dicarbollide ligands. An example of a 1:1 complex is [Mn(CO)(η-7,8-CBH)].
Most heavily studied are complexes with two dicarbollide ligands, especially sandwich complexes. Thus, these are prepared by salt metathesis reactions, as illustrated... | 7 | Physical Chemistry |
Polyunsaturated aldehydes are oxylipins that are formed from lipids (specifically the fatty acid portion of lipids) when diatoms are exposed to environmental stresses. Stresses can include nutrient limitations, grazing by predators, and wounding.
In particular, damage to diatom cells as a result of grazing by zooplankt... | 1 | Biochemistry |
In elementary applications, Raoults law is generally valid when the liquid phase is either nearly pure or a mixture of similar substances. Raoults law may be adapted to non-ideal solutions by incorporating two factors that account for the interactions between molecules of different substances. The first factor is a co... | 7 | Physical Chemistry |
The process is commonly used in control of the morphology of polymer blends, for applications in thermoelectrics, solid-state lighting, polymer electrolytes, composites, membrane formation, and surface pattern formations. | 7 | Physical Chemistry |
To be effective on a given ore slurry, the collectors are chosen based upon their selective wetting of the types of particles to be separated. A good collector will adsorb, physically or chemically, with one of the types of particles. The wetting activity of a surfactant on a particle can in principle be quantified by ... | 8 | Metallurgy |
Palliser and Parry have examined about 100 scales and found that they can use them for locating B-strands on the surface of proteins. Hydrophobicity scales were also used to predict the preservation of the genetic code. Trinquier observed a new order of the bases that better reflect the conserved character of the gene... | 6 | Supramolecular Chemistry |
The electrolyte for this process is a mixture of lead fluorosilicate ("PbSiF") and hexafluorosilicic acid (HSiF) operating at 45 °C (113 °F). Cathodes are thin sheets of pure lead and anodes are cast from the impure lead to be purified. A potential of 0.5 volts is applied. At the anode, lead dissolves, as do metal impu... | 8 | Metallurgy |
The purpose of using RNA FISH is to detect target mRNA transcripts in cells, tissue sections, or even whole-mounts. The process is done in 3 main procedures: tissue preparation (pre-hybridization), hybridization, and washing (post-hybridization).
The tissue preparation starts by collecting the appropriate tissue sectio... | 1 | Biochemistry |
Under lab conditions, xDNA orients itself in the syn conformation. This unfortunately does not expose the binding face of the xDNA nucleotides to face the neighbouring strand for binding, meaning that extra measures must be applied to alter the conformation of xDNA before attempting to form helices. However, the anti a... | 1 | Biochemistry |
Kathlyn Ann Parker is a chemist known for her work on synthesis of compounds, especially organic compounds with biological roles. She is an elected fellow of the American Chemical Society and a recipient of the Garvan–Olin Medal in chemistry. | 0 | Organic Chemistry |
Therapy is supportive and includes removal from further beryllium exposure. For very severe cases mechanical ventilation may be required. | 1 | Biochemistry |
In food chemistry and medicinal chemistry, the term "contamination" is used to describe harmful intrusions, such as the presence of toxins or pathogens in food or pharmaceutical drugs. | 9 | Geochemistry |
Hypothermia is defined as a body core temperature below in humans. Symptoms depend on the temperature. In mild hypothermia, there is shivering and mental confusion. In moderate hypothermia, shivering stops and confusion increases. In severe hypothermia, there may be hallucinations and paradoxical undressing, in which ... | 1 | Biochemistry |
Hierlemann's research initially was mostly in the area of chemical sensors and microsensors. In particular, he worked on the detection of organic volatiles and the discrimination of enantiomers in the gas phase. He then adopted microtechnology and, specifically, CMOS-based microelectronics to devise complex microsensor... | 7 | Physical Chemistry |
Ballentine earned his Ph.D. at the University of Cambridge in 1992. He went on to hold research positions at the Paul Scherrer Institut, Switzerland, the University of Michigan, and ETH Zurich, Switzerland. From 2001 to 2013, he held positions at the University of Manchester before joining the faculty at the University... | 9 | Geochemistry |
A separation process is a method that converts a mixture or a solution of chemical substances into two or more distinct product mixtures, a scientific process of separating two or more substances in order to obtain purity. At least one product mixture from the separation is enriched in one or more of the source mixture... | 3 | Analytical Chemistry |
Classical variables that time reversal negates include:
:, the time when an event occurs
:, velocity of a particle
:, linear momentum of a particle
:, angular momentum of a particle (both orbital and spin)
:, electromagnetic vector potential
:, magnetic field
:, magnetic auxiliary field
:, density of electric current
:... | 7 | Physical Chemistry |
Traces are better known in their fossilized form than in modern sediments. This makes it difficult to interpret some fossils by comparing them with modern traces, even though they may be extant or even common. The main difficulties in accessing extant burrows stem from finding them in consolidated sediment, and being a... | 2 | Environmental Chemistry |
Regular achiral organocatalysts are based on nitrogen such as piperidine used in the Knoevenagel condensation. DMAP used in esterifications and DABCO used in the Baylis-Hillman reaction. Thiazolium salts are employed in the Stetter reaction. These catalysts and reactions have a long history but current interest in org... | 0 | Organic Chemistry |
It takes a noble gas atom in an excited electronic state to form an excimer molecule such as a noble gas dimer or noble gas halide. Sufficiently high energy (approximately 10 eV) is required to obtain a noble gas atom in the lowest excited electronic state, which provides the formation of an excimer molecule. The most ... | 5 | Photochemistry |
Geometrical constraints in a molecule can cause a severe distortion of idealized tetrahedral geometry. In compounds featuring "inverted" tetrahedral geometry at a carbon atom, all four groups attached to this carbon are on one side of a plane. The carbon atom lies at or near the apex of a square pyramid with the other... | 4 | Stereochemistry |
These forces arise due to dipole–dipole interactions (induced/permanent) between molecules of bilayers. As molecules come closer, this attractive force arises due to the ordering of these dipoles; like in the case of magnets that align and attract each other as they approach. This also implies that any surface would ex... | 6 | Supramolecular Chemistry |
The temperature of a muscle has a significant effect on the velocity and power of the muscle contraction, with performance generally declining with decreasing temperatures and increasing with rising temperatures. The Q coefficient represents the degree of temperature dependence a muscle exhibits as measured by contract... | 7 | Physical Chemistry |
The fugacity capacity constant (Z) is used to help describe the concentration of a chemical in a system (usually in mol/mPa). Hemond and Hechner-Levy (2000) describe how to utilize the fugacity capacity to calculate the concentration of a chemical in a system. Depending on the chemical, fugacity capacity varies. The co... | 7 | Physical Chemistry |
As of 2006, the most precise measurement of R had been obtained by measuring the speed of sound c(P, T) in argon at the temperature T of the triple point of water at different pressures P, and extrapolating to the zero-pressure limit c(0, T). The value of R is then obtained from the relation:
where:
*γ is the heat cap... | 7 | Physical Chemistry |
1954 marks the birth of Markovitsi, daughter of Tryfon and Eleftheria, in Athens. From 1958 to 1969, she resided at Krya Vrysi, Pella. Then she returned to Athens, where she finished with a degree in chemical engineering from the National Technical University (1978). Thanks to a scholarship from the French government, ... | 5 | Photochemistry |
To minimize degradation by solvents, reactions involving tert-butyllithium are often conducted at very low temperatures in special solvents, such as the Trapp solvent mixture.
More so than other alkyllithium compounds, tert-butyllithium reacts with ethers. In diethyl ether, the half-life of tert-butyllithium is about 6... | 0 | Organic Chemistry |
Most of the characterized thiopeptides have been isolated from Actinobacteria. General structural features of thiopeptide macrocycles, are dehydrated amino acids and thiazole rings formed from dehydrated serine/threonine and cyclized cysteine residues, respectively
The thiopeptide macrocycle is closed with a six-member... | 1 | Biochemistry |
An example of the operations of the nucleic acid extraction apparatus which incorporates
Tajima pipette are typically as shown in Fig. 1. | 1 | Biochemistry |
The European Food Safety Authority (EFSA) in 2016 reviewed the current evidence, finding the relationship between serum 25(OH)D concentration and musculoskeletal health outcomes is widely variable. They considered that average requirements and population reference intakes values for vitamin D cannot be derived, and tha... | 1 | Biochemistry |
As a hybrid technique, GISAS combines concepts from transmission small-angle scattering (SAS), from grazing-incidence diffraction (GID), and from diffuse reflectometry. From SAS it uses the form factors and structure factors. From GID it uses the scattering geometry close to the critical angles of substrate and film, a... | 7 | Physical Chemistry |
The previously described work of Martin and Synge impacted the development of the previously known column chromatography and inspired new forms of chromatography such as countercurrent distribution, paper chromatography, and gas-liquid chromatography which is more commonly known as gas chromatography. The modification ... | 3 | Analytical Chemistry |
When any group is present at ortho position to an amide group (NH) in aniline then the basic character of that compound becomes weaker. For example, see the order of basicity of following substituted aniline:-
* p-Toluidine > m-Toluidine > Aniline > o-Toluidine
* Aniline > m-Nitroaniline > p-Nitroaniline > o-Nitroanil... | 4 | Stereochemistry |
Recent excavations in Middle Ganga Valley done by archaeologist Rakesh Tewari show iron working in India may have begun as early as 1800 BCE. Archaeological sites in India, such as Malhar, Dadupur, Raja Nala Ka Tila and Lahuradewa in the state of Uttar Pradesh show iron implements in the period between 1800 BCE – 1200 ... | 8 | Metallurgy |
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