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The main precursors of glyceroneogenesis are pyruvate, lactate, glutamine, and alanine. Glyceroneogenesis is also known as the branched pathway of gluconeogenesis because its first few steps are the same.
When pyruvate or lactate is used as the precursor for glycerol 3-phosphate, glyceroneogenesis follows the same pathway as gluconeogenesis until it generates dihydroxyacetone phosphate. Lactate catalyzed by lactate dehydrogenase will form pyruvate at the expense of NAD+. By using one ATP and bicarbonate, pyruvate will be converted to oxaloacetate, catalysed by pyruvate carboxylase. The PEPC-K enzyme will catalyze oxaloacetate to generate phosphoenolpyruvate. This phosphorylation and decarboxylation of oxaloacetate is a significant step in glyceroneogenesis, since it regulates the entire pathway. After the production of phosphoenolpyruvate, gluconeogenesis will continue until dihydroxyacetone phosphate is generated, which produces 2-phosphoglycerate, 3-phosphoglycerate, 1,3-bisphosphoglycerate and glyceraldehyde 3-phosphate as intermediates. When dihydroxyacetone phosphate is produced, glyceroneogenesis will branch off from gluconeogenesis. With the expense of NADH, dihydroxyacetone phosphate will convert to glycerol 3-phosphate, which is the final product of glyceroneogenesis. In addition, triglyceride can be generated by re-esterifying 3 fatty acid chains on glycerol 3-phosphate. Instead of producing fructose 1,6- bisphosphate as gluconeogenesis does, glyceroneogenesis converts dihydroxyacetone phosphate to glycerol 3-phosphate.
Alanine can also be used as a precursor of glyceroneogenesis because alanine can be degraded to pyruvate. Alanine will degrade to pyruvate by transferring its amino group to 2-oxoglutarate with an enzyme called alanine aminotransferase. Alanine aminotransferase cleaves off the amino group from alanine and binds it to 2-oxoglutarate, generating pyruvate from alanine, and glutamate from 2-oxoglutarate. Pyruvate generated from alanine will enter glyceroneogenesis and generate glycerol 3-phosphate.
Glutamate can also enter glyceroneogenesis. Since the key reaction of glyceroneogenesis is the decarboxylation and phosphorylation of oxaloacetate to phosphoenolpyruvate, in theory any biochemical pathway which generates oxaloacetate is related to glyceroneogenesis. For example, glutamate can generate oxaloacetate in 2 steps. Firstly, glutamate can be converted to 2-oxoglutarate with the expense of NAD+ and HO with the help of glutamate dehydrogenase. Secondly, 2-oxoglutarate can enter the tricarboxylic acid cycle to generate oxaloacetate. Therefore, theoretically any metabolites in the TCA cycle or any metabolites generating the metabolites of the TCA cycle can be used as a precursor of glyceroneogenesis, but glutamate is the only precursor confirmed. | 1 | Applied and Interdisciplinary Chemistry |
Tertiary alcohols react with hydrochloric acid to produce tertiary alkyl chloride. Primary and secondary alcohols are converted to the corresponding chlorides using thionyl chloride and various phosphorus chloride reagents.
Primary and secondary alcohols, likewise, convert to alkyl bromides phosphorus tribromide, for example:
In the Barton-McCombie deoxygenation an alcohol is deoxygenated to an alkane with tributyltin hydride or a trimethylborane-water complex in a radical substitution reaction. | 0 | Theoretical and Fundamental Chemistry |
By far the most common US civil defense meter on the market today. This is a simple ion chamber radiological survey meter, specifically designed for high-radiation fields for which Geiger counters will give incorrect readings (see above). Survey meters do not read alpha or beta radiation. They work by radiation penetrating the case of the unit and the enclosed ionization chamber to produce a visible reading between 0.1 R/h and 500 R/h (× 0.1, × 1, × 10, and × 100 scales). The CDV-715 ion chamber controls a subminiature type 5886 tube, but no 22.5 volt batteries are necessary for the B circuit of this tube. A transistor oscillator coupled to a step-up transformer furnishes the necessary B current for the tube, with necessary rectifier diodes and filter capacitors. The entire unit is thus powered by a single 1.5 volt D cell. | 0 | Theoretical and Fundamental Chemistry |
Martin Schoell is a German geochemist. His research focuses on using stable isotopes to characterize the geochemistry of petroleum. Schoell is known for his work regarding CO, sedimentary rocks, methane, natural gas, carbon isotopes, and acetate fermentation and how these factors enable identification of the origins of greenhouse gasses. Schoell was the founder, CEO and president of Gas Consult International, Inc., a private natural gas consulting firm, from 2001 to 2015. Schoell was awarded the Alfred Treibs Award by the Geochemical Society in 2008. | 0 | Theoretical and Fundamental Chemistry |
An early publication in this field of study was the article Baubotanik: Mit lebenden Pflanzen konstruieren (translating to “Baubotanik: Designing with Living Plants) by Ferdinand Ludwig in 2005 in the magazine Baumeister. The term “Baubotanik” was defined in 2007 at the Institute of Theory of Architecture and Design (Institut für Grundlagen moderner Architektur und Entwerfen) at the University of Stuttgart, where its concept was scientifically further developed. Within the scope of the research, simple experimental buildings were constructed, such as a footbridge and a Baubotanik tower that illustrated the possibilities of creating larger Baubotanik structures by adding individual plants. Moreover, a two-story bird-watching station was planted in the town of Waldkirchen as part of the Bavarian State Horticultural Show 2007. Subsequently, a three-story plane tree cube was created for the Baden-Württemberg State Horticultural Show 2012 in Nagold.
Since 2017, the Baubotanik field of research has been based at the Professorship for Green Technologies in Landscape Architecture at the Technical University of Munich. | 1 | Applied and Interdisciplinary Chemistry |
For time-dependent vector fields ( unsteady flow) a variant (UFLIC = Unsteady Flow LIC), has been designed that maintains the coherence of the flow animation. | 1 | Applied and Interdisciplinary Chemistry |
Thermal plasmas. can be technically generated, for example, by inductive coupling of high-frequency fields in the MHz range (ICP: Inductively coupled plasma) or by direct current coupling (arc discharges). A thermal plasma is characterized by the fact that electrons, ions and neutral particles are in thermodynamic equilibrium. For atmospheric-pressure plasmas, the temperatures in thermal plasmas are usually above 6000 K. This corresponds to average kinetic energies of less than 1 eV.
Nonthermal plasmas are found in low-pressure arc discharges, such as fluorescent lamps, in dielectrically barrier discharges (DBD), such as ozone tubes, in microwave plasmas (plasma torches, i.e. PLexc oder MagJet) or in GHz-plasmajets. A non-thermal plasma shows a significant difference between the electron and gas temperature. For example, the electron temperature can be several 10,000 K, which corresponds to average kinetic energies of more than 1 eV while a gas temperature close to room temperature is measured. Despite their low temperature, such plasmas can trigger chemical reactions and excitation states via electron collisions. Pulsed coronal and dielectrically impeded discharges belong to the family of nonthermal plasmas. Here the electrons are much hotter (several eV) than the ions/neutral gas particles (room temperature). | 0 | Theoretical and Fundamental Chemistry |
The compressor has operating boundaries at the flow extremes for a particular speed which are caused by different phenomena. The steepness of the high flow part of a constant speed line is due to the effects of compressibility. The position of the other end of the line is located by blade or passage flow separation. There is a well-defined, low-flow boundary marked on the map as a stall or surge line, at which blade stall occurs due to positive incidence separation. Not marked as such on maps for turbochargers and gas turbine engines is a more gradually approached, high-flow boundary at which passages choke when the gas velocity reaches the speed of sound. This boundary is identified for industrial compressors as overload, choke, sonic or stonewall. The approach to this flow limit is indicated by the speed lines becoming more vertical.
Other areas of the map are regions where fluctuating vane stalling may interact with blade structural modes leading to failure, ie rotating stall causing metal fatigue. | 0 | Theoretical and Fundamental Chemistry |
In applications, typically represents the "true" distribution of data, observations, or a precisely calculated theoretical distribution, while typically represents a theory, model, description, or approximation of . In order to find a distribution that is closest to , we can minimize the KL divergence and compute an information projection.
While it is a statistical distance, it is not a metric, the most familiar type of distance, but instead it is a divergence. While metrics are symmetric and generalize linear distance, satisfying the triangle inequality, divergences are asymmetric and generalize squared distance, in some cases satisfying a generalized Pythagorean theorem. In general does not equal , and the asymmetry is an important part of the geometry. The infinitesimal form of relative entropy, specifically its Hessian, gives a metric tensor that equals the Fisher information metric; see . Relative entropy satisfies a generalized Pythagorean theorem for exponential families (geometrically interpreted as dually flat manifolds), and this allows one to minimize relative entropy by geometric means, for example by information projection and in maximum likelihood estimation.
The relative entropy is the Bregman divergence generated by the negative entropy, but it is also of the form of an -divergence. For probabilities over a finite alphabet, it is unique in being a member of both of these classes of statistical divergences. | 0 | Theoretical and Fundamental Chemistry |
The 2014 AP Chemistry exam was the first administration of a redesigned test as a result of a redesigning of the AP Chemistry course. The exam format is now different from the previous years, with 60 multiple choice questions (now with only four answer choices per question), 3 long free response questions, and 4 short free response questions. The new exam has a focus on longer, more in depth, lab-based questions. The penalty for incorrect answers on the multiple choice section was also removed. More detailed information can be found at the related link. | 1 | Applied and Interdisciplinary Chemistry |
Type I interferons (IFNs) are used to treat a wide variety of medical conditions including hepatitis C, cancers, viral and inflammatory diseases. IFNs can either be extracted from a natural source, such as cultured human cells or blood leukocytes, or they can be manufactured with recombinant DNA technologies. Most of these IFN treatments have a low response rate.
The use of viral transformation of the Epstein-Barr virus (EBV) has been recommended to create personalized IFNs. In this process, primary B lymphocytes are transformed with EBV. These cells can then be used to produce IFNs specific for the patient from which the B lymphocytes were extracted. This personalization decreases the likelihood of an antibody response and therefore increases the effectiveness of the treatment. | 1 | Applied and Interdisciplinary Chemistry |
Metallic bonding refers to the specific bonding between positive metal ions and surrounding valence electron clouds. This intermolecular force is relatively strong, and gives rise to the repeated crystalline orientation of atoms, also referred to as its lattice system. There are several types of common lattice formations, and each has its own unique packing density and atomic closeness. The negatively charged electron clouds of the metal ions will sterically hinder the adhesion of negatively charged protein regions due to charge repulsion, thus limiting the available binding sites of a protein to a metal surface.
The lattice formation can lead to connection with exposed potential metal-ion-dependent adhesion sites (MIDAS) which are binding sites for collagen and other proteins. The surface of the metal has different properties than the bulk since the normal crystalline repeating subunits is terminated at the surface. This leaves the surface atoms without a neighboring atom on one side, which inherently alters the electron distribution. This phenomenon also explains why the surface atoms have a higher energy than the bulk, often simply referred to as surface energy. This state of higher energy is unfavorable, and the surface atoms will try to reduce it by binding to available reactive molecules. This is often accomplished by protein adsorption, where the surface atoms are reduced to a more advantageous energy state.
The internal environment of the body is often modeled to be an aqueous environment at 37 °C at pH 7.3 with plenty of dissolved oxygen, electrolytes, proteins, and cells. When exposed to oxygen for an extended period of time, many metals may become oxidized and increase their surface oxidation state by losing electrons. This new cationic state leaves the surface with a net positive charge, and a higher affinity for negatively charged protein side groups. Within the vast diversity of metals and metal alloys, many are susceptible to corrosion when implanted in the body. Elements that are more electronegative are corroded faster when exposed to an electrolyte-rich aqueous environment such as the human body. Both oxidation and corrosion will lower the free energy, thus affecting protein adsorption as seen in Eq. 1. | 1 | Applied and Interdisciplinary Chemistry |
A magnetorheological fluid (MR fluid, or MRF) is a type of smart fluid in a carrier fluid, usually a type of oil. When subjected to a magnetic field, the fluid greatly increases its apparent viscosity, to the point of becoming a viscoelastic solid. Importantly, the yield stress of the fluid when in its active ("on") state can be controlled very accurately by varying the magnetic field intensity. The upshot is that the fluid's ability to transmit force can be controlled with an electromagnet, which gives rise to its many possible control-based applications.
MR fluid is different from a ferrofluid which has smaller particles. MR fluid particles are primarily on the micrometre-scale and are too dense for Brownian motion to keep them suspended (in the lower density carrier fluid). Ferrofluid particles are primarily nanoparticles that are suspended by Brownian motion and generally will not settle under normal conditions. As a result, these two fluids have very different applications. | 1 | Applied and Interdisciplinary Chemistry |
Although the standard model of physics is widely believed to completely describe the composition and behavior of the nucleus, generating predictions from theory is much more difficult than for most other areas of particle physics. This is due to two reasons:
* In principle, the physics within a nucleus can be derived entirely from quantum chromodynamics (QCD). In practice however, current computational and mathematical approaches for solving QCD in low-energy systems such as the nuclei are extremely limited. This is due to the phase transition that occurs between high-energy quark matter and low-energy hadronic matter, which renders perturbative techniques unusable, making it difficult to construct an accurate QCD-derived model of the forces between nucleons. Current approaches are limited to either phenomenological models such as the Argonne v18 potential or chiral effective field theory.
* Even if the nuclear force is well constrained, a significant amount of computational power is required to accurately compute the properties of nuclei ab initio. Developments in many-body theory have made this possible for many low mass and relatively stable nuclei, but further improvements in both computational power and mathematical approaches are required before heavy nuclei or highly unstable nuclei can be tackled.
Historically, experiments have been compared to relatively crude models that are necessarily imperfect. None of these models can completely explain experimental data on nuclear structure.
The nuclear radius (R) is considered to be one of the basic quantities that any model must predict. For stable nuclei (not halo nuclei or other unstable distorted nuclei) the nuclear radius is roughly proportional to the cube root of the mass number (A) of the nucleus, and particularly in nuclei containing many nucleons, as they arrange in more spherical configurations:
The stable nucleus has approximately a constant density and therefore the nuclear radius R can be approximated by the following formula,
where A = Atomic mass number (the number of protons Z, plus the number of neutrons N) and r = 1.25 fm = 1.25 × 10 m. In this equation, the "constant" r varies by 0.2 fm, depending on the nucleus in question, but this is less than 20% change from a constant.
In other words, packing protons and neutrons in the nucleus gives approximately the same total size result as packing hard spheres of a constant size (like marbles) into a tight spherical or almost spherical bag (some stable nuclei are not quite spherical, but are known to be prolate).
Models of nuclear structure include: | 0 | Theoretical and Fundamental Chemistry |
Due to bonds breaking and forming during various processes (changes in state, chemical reactions), there is usually a change in energy. If the energy of the forming bonds is greater than the energy of the breaking bonds, then energy is released. This is known as an exothermic reaction. However, if more energy is needed to break the bonds than the energy being released, energy is taken up. Therefore, it is an endothermic reaction. | 0 | Theoretical and Fundamental Chemistry |
Jiří Linhart (13 April 1924 – 6 January 2011) Nuclear fusion physicist and Czech Olympic swimmer. He competed in the men's 200 metre breaststroke at the 1948 Summer Olympics in London. He stayed on in London after which he took his PhD under the supervision of Denis Gabor. He was a pioneer of Nuclear Fusion, author of [https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/abs/plasma-physics-by-j-g-linhart-amsterdam-north-holland-publishing-co-1960-278-pp-50s/B5B22BC6E784AF39819CB8F40B17D112# "Plasma Physics" (1960) - the first textbook on Plasma science], and many [https://iopscience.iop.org/article/10.1088/0029-5515/10/3/001 academic papers] and early [https://www.freepatentsonline.com/3113917.html patents on nuclear reactors].
In 1956 he became group Head of Acceleration at CERN, and in 1960 he became the head of the EURATOM group in Frascati.
He was also a very keen chess player, playing in the [https://www.chessgames.com/perl/chessplayer?pid=161073 Haifa Olympiad in 1976.] | 0 | Theoretical and Fundamental Chemistry |
Water-gas-tar creosote is also derived from petroleum oil or shale oil, but by a different process; it is distilled during the production of water gas. The tar is a by-product resulting from enrichment of water gas with gases produced by thermal decomposition of petroleum. Of the creosotes derived from oil, it is practically the only one used for wood preservation. It has the same degree of solubility as coal-tar creosote and is easy to infuse into wood. Like standard oil-tar creosote, it has a low amount of tar acids and tar bases, and has less antiseptic qualities. Petri dish tests have shown that water-gas-tar creosote is one-sixth as anti-septically effective as that of coal-tar. | 0 | Theoretical and Fundamental Chemistry |
Progesterone has a number of physiological effects that are amplified in the presence of estrogens. Estrogens through estrogen receptors (ERs) induce or upregulate the expression of the PR. One example of this is in breast tissue, where estrogens allow progesterone to mediate lobuloalveolar development.
Elevated levels of progesterone potently reduce the sodium-retaining activity of aldosterone, resulting in natriuresis and a reduction in extracellular fluid volume. Progesterone withdrawal, on the other hand, is associated with a temporary increase in sodium retention (reduced natriuresis, with an increase in extracellular fluid volume) due to the compensatory increase in aldosterone production, which combats the blockade of the mineralocorticoid receptor by the previously elevated level of progesterone. | 0 | Theoretical and Fundamental Chemistry |
Common side effects associated with the administration of piperacillin-tazobactam include:
* Gastrointestinal: constipation, diarrhea, nausea, vomiting
* Dermatologic: erythema, pain, phlebitis, rash
* Neurologic: headaches, insomnia
Prolonged periods of piperacillin-tazobactam therapy have been associated with the potential development of hematologic adversities such as leukopenia (16.3%), neutropenia (10%), and eosinophilia (10%) in adult patients. The combination of piperacillin-tazobactam with other antibiotics was found to be a major risk factor for leukopenia as well. Additionally, the chances of developing these illnesses increases in younger patients with fewer conditions, prolonging their time to recover.
Other cases of adverse effects include instances of renal dysfunction, hepatitis, hyperactivity, anemia, abnormalities in coagulation, and hypokalemia. Allergic reactions can be induced from the side chains of β-lactam antibiotics such as amoxicillin, or antibodies surrounding the nucleus of penicillin. | 0 | Theoretical and Fundamental Chemistry |
Binding of a number of hormones and steroids, including testosterone, progesterone, and cholesterol, has been found to occur with sigma-2 receptors, though in some cases with lower affinity than to the sigma-1 receptor. Signaling caused by this binding is thought to occur via a calcium secondary messenger and calcium-dependent phosphorylation, and in association with sphingolipids following endoplasmic reticulum release of calcium. Known effects include decrease of expression of effectors in the mTOR pathway, and suppression of cyclin D1 and PARP-1. | 1 | Applied and Interdisciplinary Chemistry |
ASPicDB is a database of human protein variants generated by alternative splicing, a process by which the exons of the RNA produced by transcription of a gene are reconnected in multiple ways during RNA splicing. | 1 | Applied and Interdisciplinary Chemistry |
Objectionable odors are likely when the rate of oxygen transfer from the lagoon surface is less than the rate of oxygen consumption in the lower levels of the lagoon. A facultative lagoon might provide 50 pounds of oxygen per day (5 grams of oxygen per square meter per day) for biochemical catabolism. Biological activity within a facultative lagoon varies directly with temperature. Warm weather will require large oxygen transfer rates, and waste accumulation during cold weather can cause short-term warm weather oxygen requirements to exceed long-term waste loading rates. Algae can provide surface oxygen during daylight hours, but algal respiration can require additional oxygen during darkness. Ice or scum mats can reduce the oxygen transfer surface. Some facultative lagoons use mechanical surface aerators to increase atmospheric oxygen transfer, but aerator mixing depth should not re-suspend anaerobic sludge from the bottom of the lagoon. Aerator operation may be limited to periods of heavy waste loads, high temperatures, darkness, low wind velocity, or other conditions threatening to cause anaerobic conditions on the lagoon surface.
Facultative stabilization ponds stratify with an aerobic surface layer and an anaerobic layer below the surface. The aerobic surface layer limits release of malodorous gas from the anaerobic benthic zone. Algae and cyanobacteria typically grow in the aerobic zone and provide bacteria in the pond with plenty of oxygen during the daytime. However, algal photorespiration may consume oxygen during night time when it is dark. Waste stabilization ponds with large algal populations may show significant diurnal fluctuation in oxygen concentrations with a peak in the late afternoon, and a minimum at dawn.
Kinds of algae growing in treatment ponds include green, red and brown algae. | 1 | Applied and Interdisciplinary Chemistry |
The passive hyperspectral imaging spectroscopy remote sensor observes a target in multi-spectral bands. The HSI camera separates the image spectra into 52 "bins" from 500 nanometers (nm) wavelength at the blue end of the visible spectrum to 1100 nm in the infrared, giving the camera a spectral resolution of 11.5 nm. Although ARCHER records data in all 52 bands, the computational algorithms only use the first 40 bands, from 500 nm to 960 nm because the bands above 960 nm are too noisy to be useful. For comparison, the normal human eye will respond to wavelengths from approximately 400 to 700 nm, and is trichromatic, meaning the eye's cone cells only sense light in three spectral bands.
As the ARCHER aircraft flies over a search area, reflected sunlight is collected by the HSI camera lens. The collected light passes through a set of lenses that focus the light to form an image of the ground. The imaging system uses a pushbroom approach to image acquisition. With the pushbroom approach, the focusing slit reduces the image height to the equivalent of one vertical pixel, creating a horizontal line image.
The horizontal line image is then projected onto a diffraction grating, which is a very finely etched reflecting surface that disperses light into its spectra. The diffraction grating is specially constructed and positioned to create a two-dimensional (2D) spectrum image from the horizontal line image. The spectra are projected vertically, i.e., perpendicular to the line image, by the design and arrangement of the diffraction grating.
The 2D spectrum image projects onto a charge-coupled device (CCD) two-dimensional image sensor, which is aligned so that the horizontal pixels are parallel to the image's horizontal. As a result, the vertical pixels are coincident to the spectra produced from the diffraction grating. Each column of pixels receives the spectrum of one horizontal pixel from the original image. The arrangement of vertical pixel sensors in the CCD divides the spectrum into distinct and non-overlapping intervals. The CCD output consists of electrical signals for 52 spectral bands for each of 504 horizontal image pixels.
The on-board computer records the CCD output signal at a frame rate of sixty times each second. At an aircraft altitude of 2,500 ft AGL and a speed of 100 knots, a 60 Hz frame rate equates to a ground image resolution of approximately one square meter per pixel. Thus, every frame captured from the CCD contains the spectral data for a ground swath that is approximately one meter long and 500 meters wide. | 0 | Theoretical and Fundamental Chemistry |
Cellular respiration is the process of which biological fuels are oxidised in the presence of an inorganic electron acceptor such as oxygen to produce large amounts of energy, to drive the bulk production of ATP.
Anaerobic respiration is used by microorganisms either bacteria or archaea in which neither oxygen (aerobic respiration) nor pyruvate derivatives (fermentation) is the final electron acceptor. Rather, an inorganic acceptor such as sulfate (SO), nitrate (NO), or sulfur (S) is used. Such organisms could be found in unusual places such as underwater caves or near hydrothermal vents at the bottom of the ocean., as well as in anoxic soils or sediment in wetland ecosystems.
In July 2019, a scientific study of Kidd Mine in Canada discovered sulfur-breathing organisms which live below the surface, and which breathe sulfur in order to survive. These organisms are also remarkable due to consuming minerals such as pyrite as their food source. | 1 | Applied and Interdisciplinary Chemistry |
Pitting resistance equivalent number (PREN) is a predictive measurement of a stainless steel's resistance to localized pitting corrosion based on its chemical composition. In general: the higher PREN-value, the more resistant is the stainless steel to localized pitting corrosion by chloride.
PREN is frequently specified when stainless steels will be exposed to seawater or other high chloride solutions. In some instances stainless steels with PREN-values > 32 may provide useful resistance to pitting corrosion in seawater, but is dependent on optimal conditions. However, crevice corrosion is also a significant possibility and a PREN > 40 is typically specified for seawater service.
These alloys need to be manufactured and heat treated correctly to be seawater corrosion resistant to the expected level. PREN alone is not an indicator of corrosion resistance. The value should be calculated for each heat to ensure compliance with minimum requirements, this is due to chemistry variation within the specified composition limits. | 1 | Applied and Interdisciplinary Chemistry |
In organic chemistry, a Bechgaard salt is any one of a number of organic charge-transfer complexes that exhibit superconductivity at low temperatures. They are named for chemist Klaus Bechgaard, who was one of the first scientists to synthesize them and demonstrate their superconductivity with the help of physicist Denis Jérome. Most Bechgaard salt superconductors are extremely low temperature, and lose superconductivity above the 1–2 K range, although the most successful compound in this class superconducts up to almost 12 K.
All Bechgaard salts are formed using a small, planar organic molecule as an electron donor, with any of a number of electron acceptors (such as perchlorate, , or tetracyanoethylene, TCNE). All the organic electron donors contain multiply conjugated heterocycles with a number of properties, including planarity, low ionization potential and good orbital overlap between heteroatoms in neighboring donor molecules. These properties help the final salt conduct electrons by shuttling them through the orbital vacancies left in the donor molecules.
All Bechgaard salts have a variation on a single tetrathiafulvalene motif—different superconductors have been made with appendages to the motif, or using a tetraselenafulvalene center instead (which is a related compound), but all bear this general structural similarity.
There are a wide range of other organic superconductors including many other charge-transfer complexes. | 0 | Theoretical and Fundamental Chemistry |
The pack mill process begins with a tin bar, which is a drawn flat bar that was usually purchased from an ironworks or steel works. The tin bar could be wrought iron or mild steel. The cross-section of the bar needed to be accurate in size as this dictates the length and thickness of the final plates. The bar was cut to the correct length to make the desired size plate. For instance, if a plate is desired the tin bar is cut to a length and width that is divisible by 14 and 20. The bar is then rolled and doubled over, with the number of times being doubled over dependent on how large the tin bar is and what the final thickness is. If the starting tin bar is then it must be at least finished on the fours, or doubled over twice, and if a thin gauge is required then it may be finished on the eights, or doubled over three times. The tin bar is then heated to a dull red heat and passed five or six times through the roughing rolls. Between each pass the plate is passed over (or round) the rolls, and the gap between the rolls is narrowed by means of a screw. The plate is then reheated and run through the finishing rolls.
If the plate is not finished on singles, or without doubling the plate over, it is doubled over in a squeezer. The squeezer was like a table where one half of the surface folds over on top of the other and a press flattens the doubled over plate so the rolled end will fit in the rollers. It is then reheated for another set of rolling. This is repeated until the desired geometry is reached. Note that if the plate needs to be doubled over more than once the rolled end is sheared off. The pack is then allowed to cool. When cool, the pack is sheared slightly undersized from the final dimensions and the plates separated by openers.
At this point, the plates are covered in scale and must be pickled. This involves dipping the plates in sulfuric acid for five minutes. The pickling turns the scales into a greenish-black slime which is removed via annealing. The plates are annealed for approximately 10 hours and then allowed to slowly cool. At this point the plates are known as pickled and annealed black plates. These plates were commonly sold for stamping and enameling purposes.
After this, the plates are rough and not straight, so they are cold rolled several times. The rolling lengthens the plates to their final dimension. They are then annealed again to remove any strain hardening. These plates are called black plate pickled, cold rolled, and close annealed (black plate p. cr. and ca.). To attain perfect cleanliness the plates are pickled again in a weak sulfuric acid. Finally they are rinsed and stored in water until ready to be tinned.
The tinning set consists of at least one pot of molten tin, with a zinc chloride flux on top, and a grease pot. The flux dries the plate and prepares it for the tin to adhere. If a second tin pot is used, called the wash pot, it contains tin at a lower temperature. This is followed by the grease pot, which contains oil and a tinning machine. The tinning machine has two small rollers that are spring-loaded together so that when the tinned plate is inserted the rolls squeeze off any excess tin. The springs on the tinning machine can be set to different forces to give different thicknesses of tin. Finally, the oil is cleaned off with fine bran and dusted clean.
What is described here is the process as employed during the 20th century. The process grew somewhat in complexity over time, as it was found that the inclusion of additional procedures improved quality. The practice of hot rolling and then cold rolling evidently goes back to the early days, as the Knight family's tinplate works had (from its foundation in about 1740) two rolling mills, one at Bringewood (west of Ludlow) which made blackplate, and the other the tin mill at Mitton (now part of Stourport, evidently for the later stages. | 1 | Applied and Interdisciplinary Chemistry |
*Lecturer, 1952–53; assistant professor, 195658, Department of Chemistry, Dhaka University
*Professor, Department of Chemistry and Applied Chemistry, Rajshahi University, 195890
*Nuffield Fellow, Cambridge University, U.K. 196062
*Dean, Faculty of Science, Rajshahi University, 1972
*Commonwealth Senior Fellow, Cambridge University, U.K. 197374
*Member, University Grants Commission (UGC), 197476
*Vice Chancellor, University of Dhaka, 197683
*Fellow of Bangladesh Academy of Sciences, 1979
*Asia Foundation Fellowship, 1984
*President, Bangladesh Chemical Society, 198486
*Senior Advisor in Basic Sciences, UNESCO, New Delhi, 198590
*University of Asia Pacific, Dhaka, 199596
*President, The Rajshahi University Teachers Association
*Provost, Abdul Latif Hall, Rajshahi University
*Senior Researcher, American Association for the Advancement of Science Washington D.C. | 0 | Theoretical and Fundamental Chemistry |
On the evening of March 12, 2018, both Negishi and his wife were reported missing by family members. Police determined that, based on a purchase made earlier in the day, the couple had left their home in West Lafayette, Indiana, and headed north. At about 5 a.m. the next day, officers in Ogle County, Illinois, received a call to check on the welfare of an elderly man who was walking on a rural road south of Rockford. When he was taken to hospital, officers identified him as Negishi and found that police in Indiana were looking for him and his wife. A short time later, Suzukis body was found at the Orchard Hills Landfill in Davis Junction, along with the couples car.
According to a statement from the family, the couple was driving to Rockford International Airport for a trip when their car became stuck in a ditch on a road near the landfill. Negishi went looking for help and was said to be suffering from an "acute state of confusion and shock". The Ogle County Sheriff Department said there was no suspicion of foul play in Suzukis death, although the cause of her death was not immediately released. The family said Suzuki was near the end of her battle with Parkinsons disease.
In May 2018, an autopsy concluded that Suzuki died from hypothermia, but Parkinson's disease and hypertension were contributing factors. | 0 | Theoretical and Fundamental Chemistry |
In instances in which the environment is suboxic or anoxic, organisms will prefer to utilize denitrification to remineralise organic matter as it provides the second largest amount of energy. In depths below where denitrification is favored, reactions such as Manganese Reduction, Iron Reduction, Sulfate Reduction, Methane Reduction (also known as Methanogenesis), become favored respectively. This favorability is governed by Gibbs Free Energy (ΔG). In a water body, sediment seabed, or soil, the sorting of these chemical reactions with depth in order of energy provided is called a redox gradient. | 0 | Theoretical and Fundamental Chemistry |
Surroundings, or environs is an area around a given physical or geographical point or place. The exact definition depends on the field. Surroundings can also be used in geography (when it is more precisely known as vicinity, or vicinage) and mathematics, as well as philosophy, with the literal or metaphorically extended definition.
In thermodynamics, the term (and its synonym, environment) is used in a more restricted sense, meaning everything outside the thermodynamic system. Often, the simplifying assumptions are that energy and matter may move freely within the surroundings, and that the surroundings have a uniform composition. | 0 | Theoretical and Fundamental Chemistry |
The positive feedback of the rising phase slows and comes to a halt as the sodium ion channels become maximally open. At the peak of the action potential, the sodium permeability is maximized and the membrane voltage V is nearly equal to the sodium equilibrium voltage E. However, the same raised voltage that opened the sodium channels initially also slowly shuts them off, by closing their pores; the sodium channels become inactivated. This lowers the membranes permeability to sodium relative to potassium, driving the membrane voltage back towards the resting value. At the same time, the raised voltage opens voltage-sensitive potassium channels; the increase in the membranes potassium permeability drives V towards E. Combined, these changes in sodium and potassium permeability cause V to drop quickly, repolarizing the membrane and producing the "falling phase" of the action potential. | 0 | Theoretical and Fundamental Chemistry |
When drugs are covered under patent protection, only the pharmaceutical company that holds the patent is allowed to manufacture, market, and eventually profit from them. The lifetime of the patent varies between countries and also between drugs; in the United States, most drug patents last about twenty years. Once the patent has expired, the drug can be manufactured and sold by other companies - at which point, it is referred to as a generic drug. Its availability on the market as a generic drug removes the monopoly of the patent holder, thereby encouraging competition and causing a significant drop in drug prices, which ensures that life-saving and important drugs reach the general population at fair prices. However, the company holding the initial patent may get a new patent by forming a new version of the drug that is significantly changed compared to the original compound. Patentability of different isomers has been controversial over the past ten years and there have been a number of related legal issues. In making their determinations, courts have looked at factors including: (i) Whether the racemate was known in the prior art. (ii) The difficulty in resolving the enantiomers. (iii) The stereoselectivity of the relevant receptor. (iv) Other secondary considerations of non-obviousness such as commercial success, unexpected results, and satisfaction of long-felt needs in the art. The decisions made regarding these issues have varied and there is no clear answer to the legality of patenting stereoisomers. These issues have been resolved on a case-by-case basis. With the number of current pharmaceuticals currently being marketed as racemic mixtures, it is likely that patentability will continue to be debated in the near future.
There are examples of common drugs, like ibuprofen, where the use of chiral switching has caused controversy. Ibuprofen is a racemic mixture where the S-enantiomer is known to play a major role in reducing inflammation as it inhibits COX-2 (cooxygenase 2) compared to the R-enantiomer; the fact that the S-enantiomer is stronger is what led to the chiral switching. But, when the racemic ibuprofen enters the body, a little over half of the R-enantiomers experience chiral inversion and transform into the favored S-enantiomer. This observation has led to a conclusion that the racemic and the S-enantiomer are potentially biologically equivalent. Because of this and the more recent evidence suggesting that the R-enantiomer may actually contribute to COX-2 inhibition, as well, but at a slower rate, there is still debate on whether or not the chiral switching seen in ibuprofen is really advantageous or if it is just to give patent protections to the manufacturers. | 0 | Theoretical and Fundamental Chemistry |
Chromatography separates the analyte from the rest of the sample so that it may be measured without interference from other compounds. There are different types of chromatography that differ from the media they use to separate the analyte and the sample. In Thin-layer chromatography, the analyte mixture moves up and separates along the coated sheet under the volatile mobile phase. In Gas chromatography, gas separates the volatile analytes. A common method for chromatography using liquid as a mobile phase is High-performance liquid chromatography. | 0 | Theoretical and Fundamental Chemistry |
Most nonparasitic copepods are holoplanktonic, meaning they stay planktonic for all of their lifecycles, although harpacticoids, although free-living, tend to be benthic rather than planktonic.
During mating, the male copepod grips the female with his first pair of antennae, which is sometimes modified for this purpose. The male then produces an adhesive package of sperm and transfers it to the females genital opening with his thoracic limbs. Eggs are sometimes laid directly into the water, but many species enclose them within a sac attached to the females body until they hatch. In some pond-dwelling species, the eggs have a tough shell and can lie dormant for extended periods if the pond dries up.
Eggs hatch into nauplius larvae, which consist of a head with a small tail, but no thorax or true abdomen. The nauplius moults five or six times, before emerging as a "copepodid larva". This stage resembles the adult, but has a simple, unsegmented abdomen and only three pairs of thoracic limbs. After a further five moults, the copepod takes on the adult form. The entire process from hatching to adulthood can take a week to a year, depending on the species and environmental conditions such as temperature and nutrition (e.g., egg-to-adult time in the calanoid Parvocalanus crassirostris is ~7 days at but 19 days at . | 1 | Applied and Interdisciplinary Chemistry |
Metal whiskering is a phenomenon that occurs in electrical devices when metals form long whisker-like projections over time. Tin whiskers were noticed and documented in the vacuum tube era of electronics early in the 20th century in equipment that used pure, or almost pure, tin solder in their production. It was noticed that small metal hairs or tendrils grew between metal solder pads, causing short circuits. Metal whiskers form in the presence of compressive stress. Germanium, zinc, cadmium, and even lead whiskers have been documented. Many techniques are used to mitigate the problem, including changes to the annealing process (heating and cooling), the addition of elements like copper and nickel, and the inclusion of conformal coatings. Traditionally, lead has been added to slow down whisker growth in tin-based solders.
Following the Restriction of Hazardous Substances Directive (RoHS), the European Union banned the use of lead in most consumer electronic products from 2006 due to health problems associated with lead and the "high-tech trash" problem, leading to a re-focusing on the issue of whisker formation in lead-free solders. | 1 | Applied and Interdisciplinary Chemistry |
There are several magazines and publications that cover topics directly related to the Chesapeake Bay and life and tourism within the Bay region:
*The Bay Journal provides environmental news for the Chesapeake Bay watershed region.
*Bay Weekly is the Chesapeake Bay region's independent newspaper.
*The Capital, a newspaper based in Annapolis, reports about news pertaining to the Western Shore of Maryland and the Annapolis area.
*Chesapeake Bay Magazine and PropTalk focus on powerboating in the Bay, and SpinSheet focuses on sailing.
*Whats Up' Magazine is a free monthly publication with special issues focused on Annapolis and the Eastern Shore. | 1 | Applied and Interdisciplinary Chemistry |
Whole genome sequencing (WGS), also known as full genome sequencing, complete genome sequencing, or entire genome sequencing, is the process of determining the entirety, or nearly the entirety, of the DNA sequence of an organisms genome at a single time. This entails sequencing all of an organisms chromosomal DNA as well as DNA contained in the mitochondria and, for plants, in the chloroplast.
Whole genome sequencing has largely been used as a research tool, but was being introduced to clinics in 2014. In the future of personalized medicine, whole genome sequence data may be an important tool to guide therapeutic intervention. The tool of gene sequencing at SNP level is also used to pinpoint functional variants from association studies and improve the knowledge available to researchers interested in evolutionary biology, and hence may lay the foundation for predicting disease susceptibility and drug response.
Whole genome sequencing should not be confused with DNA profiling, which only determines the likelihood that genetic material came from a particular individual or group, and does not contain additional information on genetic relationships, origin or susceptibility to specific diseases. In addition, whole genome sequencing should not be confused with methods that sequence specific subsets of the genome – such methods include whole exome sequencing (1–2% of the genome) or SNP genotyping (< 0.1% of the genome). | 1 | Applied and Interdisciplinary Chemistry |
A basic NMR line broadening experiment is to determine the rotational energy barrier of a certain chemical bond. If the bond rotates slowly enough compared to the NMR time scale (e.g., amide bond), two different species can be detected by the NMR spectrometer. Considering that the time scale of NMR spectroscopy is about a few seconds, this technique can be used to examine the kinetics and/or thermodynamics of chemical exchange reactions on the order of seconds.
In general, the energy barrier to rotate a bond is low enough at room temperature, which means that the rotation is fast, making the two different species indistinguishable. At low temperatures, however, it is harder for a bond to overcome the energy barrier to rotate, resulting in two separate peaks in the spectrum. With these principles, NMR spectra of a molecule with a high rotational barrier should be obtained at several different temperatures (i.e., variable temperature NMR) to distinguish two different peaks at low temperature in slow exchange and to find the temperature at which the two peaks merge.
Especially at the coalescence temperature (), where the two peaks coalesce, the rate constant of rotation at and the energy barrier of the rotation can be easily calculated. As increasing the temperature, the exchange reaction get faster, and at a certain temperature, which is , the appearance of the peaks changes from two separate peaks in slow exchange to a single peak in fast exchange. The rate constant at can be calculated with the following equation: , and are the chemical shift of each species at lower temperatures where they are in slow exchange.
By using the Eyring equation, the Gibbs free energy of rotation, , can be determined: (Eyring equation) is gas constant, is the Boltzmann constant, and is the Planck constant. | 0 | Theoretical and Fundamental Chemistry |
Columnar structures were first studied in botany due to their diverse appearances in plants. D'Arcy Thompson analysed such arrangement of plant parts around the stem in his book "On Growth and Form" (1917). But they are also of interest in other biological areas, including bacteria, viruses, microtubules, and the notochord of the zebra fish.
One of the largest flowers where the berries arrange in a regular cylindrical form is the titan arum. This flower can be up to 3m in height and is natively solely found in western Sumatra and western Java.
On smaller length scales, the berries of the Arum maculatum form a columnar structure in autumn. Its berries are similar to that of the corpse flower, since the titan arum is its larger relative. However, the cuckoo-pint is much smaller in height (height ≈ 20 cm). The berry arrangement varies with the stem to berry size.
Another plant that can be found in many gardens of residential areas is the Australian bottlebrush. It assembles its seed capsules around a branch of the plant. The structure depends on the seed capsule size to branch size. | 0 | Theoretical and Fundamental Chemistry |
A mass balance must be performed, and used along with Darcys law, to arrive at the transient groundwater flow equation. This balance is analogous to the energy balance used in heat transfer to arrive at the heat equation. It is simply a statement of accounting, that for a given control volume, aside from sources or sinks, mass cannot be created or destroyed. The conservation of mass states that, for a given increment of time (Δt'), the difference between the mass flowing in across the boundaries, the mass flowing out across the boundaries, and the sources within the volume, is the change in storage. | 1 | Applied and Interdisciplinary Chemistry |
The FAST-fluorogen reporting system is used in fluorescence microscopy, flow cytometry and any other fluorometric methods to explore the living world, including biosensors and protein trafficking. FAST has been reported for dynamic imaging of biofilms because of its unique capacity of fluorescence in low-oxygen conditions. For the same reason it allows for imaging and FACSing anaerobes, such as Clostridium, used for biomass fermentation like the ABE fermentation. FAST has also been reported for super-resolution microscopy of living cells.
A number of fluorogens were developed for FAST and its derivates by The Twinkle Factory, varying by their emission wavelength, their brightness and their tag affinity. Some are non permeant, i.e., they cant go through cell membranes, hence specifically labeling membrane proteins or extracellular proteins, allowing for, e.g.', monitoring trafficking from synthesis until excretion. | 1 | Applied and Interdisciplinary Chemistry |
Many gas-fed heating appliances such as ovens and water heaters make use of a pilot flame to ignite the main gas burner when required. If the pilot flame goes out, unburned gas may be released, which is an explosion risk and a health hazard. To prevent this, some appliances use a thermocouple in a fail-safe circuit to sense when the pilot light is burning. The tip of the thermocouple is placed in the pilot flame, generating a voltage which operates the supply valve which feeds gas to the pilot. So long as the pilot flame remains lit, the thermocouple remains hot, and the pilot gas valve is held open. If the pilot light goes out, the thermocouple temperature falls, causing the voltage across the thermocouple to drop and the valve to close.
Where the probe may be easily placed above the flame, a rectifying sensor may often be used instead. With part ceramic construction, they may also be known as flame rods, flame sensors or flame detection electrodes.
Some combined main burner and pilot gas valves (mainly by Honeywell) reduce the power demand to within the range of a single universal thermocouple heated by a pilot (25 mV open circuit falling by half with the coil connected to a 10–12 mV, 0.2–0.25 A source, typically) by sizing the coil to be able to hold the valve open against a light spring, but only after the initial turning-on force is provided by the user pressing and holding a knob to compress the spring during lighting of the pilot. These systems are identifiable by the "press and hold for x minutes" in the pilot lighting instructions. (The holding current requirement of such a valve is much less than a bigger solenoid designed for pulling the valve in from a closed position would require.) Special test sets are made to confirm the valve let-go and holding currents, because an ordinary milliammeter cannot be used as it introduces more resistance than the gas valve coil. Apart from testing the open circuit voltage of the thermocouple, and the near short-circuit DC continuity through the thermocouple gas valve coil, the easiest non-specialist test is substitution of a known good gas valve.
Some systems, known as millivolt control systems, extend the thermocouple concept to both open and close the main gas valve as well. Not only does the voltage created by the pilot thermocouple activate the pilot gas valve, it is also routed through a thermostat to power the main gas valve as well. Here, a larger voltage is needed than in a pilot flame safety system described above, and a thermopile is used rather than a single thermocouple. Such a system requires no external source of electricity for its operation and thus can operate during a power failure, provided that all the other related system components allow for this. This excludes common forced air furnaces because external electrical power is required to operate the blower motor, but this feature is especially useful for un-powered convection heaters. A similar gas shut-off safety mechanism using a thermocouple is sometimes employed to ensure that the main burner ignites within a certain time period, shutting off the main burner gas supply valve should that not happen.
Out of concern about energy wasted by the standing pilot flame, designers of many newer appliances have switched to an electronically controlled pilot-less ignition, also called intermittent ignition. With no standing pilot flame, there is no risk of gas buildup should the flame go out, so these appliances do not need thermocouple-based pilot safety switches. As these designs lose the benefit of operation without a continuous source of electricity, standing pilots are still used in some appliances. The exception is later model instantaneous (aka "tankless") water heaters that use the flow of water to generate the current required to ignite the gas burner; these designs also use a thermocouple as a safety cut-off device in the event the gas fails to ignite, or if the flame is extinguished. | 1 | Applied and Interdisciplinary Chemistry |
An O-acylpseudotropine is any derivative of pseudotropine in which the alcohol group is substituted with an acyl group.
Acylpseudotropines are formed by the action of the enzyme pseudotropine acyltransferase on pseudotropine. | 1 | Applied and Interdisciplinary Chemistry |
Diffuse correlation spectrometry is an extension of single-scattering dynamic light scattering (DLS). Single-scattering theory becomes inadequate as multiple scattering effects take place in biological thick tissues. Therefore, each scattering event contributes to the decay of the correlation function. The fields from individual photon paths are assumed to be uncorrelated; therefore, the total field autocorrelation function can be expressed as the weighted sum of the field autocorrelation function from each photon path.
The physical effect that makes the blood flow measurement possible is the temporal electric field autocorrelation function, shown in equation 1, diffuses through tissue in a manner that is similar to the light fluence rate.
In a highly scattering media, the photon fluence rate obeys the time-dependent diffusion equation, shown in equation 2. Optical imaging variables used in these equation are [https://imgur.com/a/5TDR72u here].
The blood flow measurement can be governed by the diffusion equation. Many tissue optical properties that affect diffusion such as tissue absorption and tissue reduced scattering coefficient are the same for temporal autocorrelation.
Using the same set of approximations, the temporal field autocorrelation function obeys a formally similar diffusion equation, shown in equation 3.
The mean-square particle displacement has been found to be reasonably well approximated as an “effective” Brownian motion, i.e., D represents the effective diffusion coefficient of the moving scatterers. In order to estimate relative blood flow from DCS data, we fit the measured intensity autocorrelation functions to solutions of the equation in equation 3. Currently, there is no evidence explaining why Brownian-motion correlation curves work effectively. This is the current empirical approach. The unit of αD (cm/s) has been found to correlate well with other blood flow measurement modalities and is used to measure blood flow. Therefore, is the blood flow index (BFI). To calculate the relative blood flow (rBF), the equation is shown in equation 4 where BFI is the DCS blood flow measurement at a baseline. | 0 | Theoretical and Fundamental Chemistry |
Comments in the New York Times about the healthfulness of coconut oil in late 2015 were covered in 200+ newspapers globally. Brenna opined that 21th century virgin coconut oil does not cause heart disease but that earlier coconut oils may cause heart disease due to process contaminants. | 0 | Theoretical and Fundamental Chemistry |
Given that polycatenanes are a relatively recent field of study, the properties of these materials are not yet fully explored and understood. The type of bonds that characterize the whole structure (covalent, non covalent or mechanical bonds), the degree of mobility of the chain, the interactions between different chains and the fraction of voids of the catenanes are all factors that contribute to the final properties. As they can be strictly related to the family of Metal Organic Frameworks, the catenanes share all the potential applications of this class of compunds. Among these, there are applications in biomedicine, catalysis, as conducting bridges or in electronic devices, sensing or in very recent and rising fields like molecular machines. | 0 | Theoretical and Fundamental Chemistry |
For the present purposes, the light from a star, and for some particular purposes, the light of the sun, can be treated as a practically collimated beam, but apart from this, a collimated beam is rarely if ever found in nature, though artificially produced beams can be very nearly collimated. The spectral radiance (or specific intensity) is suitable for the description of an uncollimated radiative field. The integrals of spectral radiance (or specific intensity) with respect to solid angle, used above, are singular for exactly collimated beams, or may be viewed as Dirac delta functions. Therefore, the specific radiative intensity is unsuitable for the description of a collimated beam, while spectral flux density is suitable for that purpose. At a point within a collimated beam, the spectral flux density vector has a value equal to the Poynting vector, a quantity defined in the classical Maxwell theory of electromagnetic radiation. | 0 | Theoretical and Fundamental Chemistry |
Feng Yunhe (1898/ April 1900 - 14 December 1988) was a Chinese scientist who worked in the Chinese government from 1949–1954 as the Minister of Textile Industry. Alongside Shi Liang and Li Dequan, who were appointed the same year, she was the first female cabinet minister in China (not counting He Xiangning, who served prior to unification). Feng Yunhe was an expert in ramie fibre. She was one of the founders of the China National Democratic Construction Association, one of the eight legally recognised minor political parties in the People's Republic of China. She was the first woman on record to earn a PhD in chemical engineering in the United States. | 1 | Applied and Interdisciplinary Chemistry |
Levorphanol (brand name Levo-Dromoran) is an opioid medication used to treat moderate to severe pain. It is the levorotatory enantiomer of the compound racemorphan. Its dextrorotatory counterpart is dextrorphan.
It was first described in Germany in 1946. The drug has been in medical use in the United States since 1953. | 0 | Theoretical and Fundamental Chemistry |
Health problems associated with high levels of airborne mold spores include allergic reactions, asthma episodes, irritations of the eye, nose and throat, sinus congestion, and other respiratory problems. Several studies and reviews have suggested that childhood exposure to dampness and mold might contribute to the development of asthma. For example, residents of homes with mold are at an elevated risk for both respiratory infections and bronchitis. When mold spores are inhaled by an immunocompromised individual, some mold spores may begin to grow on living tissue, attaching to cells along the respiratory tract and causing further problems. Generally, when this occurs, the illness is an epiphenomenon and not the primary pathology. Also, mold may produce mycotoxins, either before or after exposure to humans, potentially causing toxicity. | 1 | Applied and Interdisciplinary Chemistry |
Since the U.S. Food and Drug Administration issued a rule in 2001 requiring that virtually all fruit and vegetable juice producers follow HACCP controls, and mandating a 5-log reduction in pathogens, UVGI has seen some use in sterilization of juices such as fresh-pressed. | 0 | Theoretical and Fundamental Chemistry |
* Paul R. Holland and Anthony Kay, “A review of the physics and ecological implications of the thermal bar circulation,” Limnologica - Ecology and Management of Inland Waters 33, no. 3 (September 2003): 153–162.
* C. H. Mortimer, “Lake hydrodynamics." Mitt. Int, Ver. Limnol 20 (1974): 124–197.
* F. Peeters and R. Kipfer, “Currents in Stratified Water Bodies 1: Density-Driven Flows,” in Encyclopedia of Inland Waters (Oxford: Academic Press, 2009), 530–538. | 1 | Applied and Interdisciplinary Chemistry |
Dexmethylphenidate is used as a treatment for ADHD, usually along with psychological, educational, behavioral or other forms of treatment. It is proposed that stimulants help ameliorate the symptoms of ADHD by making it easier for the user to concentrate, avoid distraction, and control behavior. Placebo-controlled trials have shown that once-daily dexmethylphenidate XR was effective and generally well tolerated.
Improvements in ADHD symptoms in children were significantly greater for dexmethylphenidate XR versus placebo. It also showed greater efficacy than osmotic controlled-release oral delivery system (OROS) methylphenidate over the first half of the laboratory classroom day but assessments late in the day favoured OROS methylphenidate. | 0 | Theoretical and Fundamental Chemistry |
This family includes TGF-β1, TGF-β2, TGF-β3, and TGF-β5. They are involved in positively and negatively regulation of cell division, the formation of the extracellular matrix between cells, apoptosis, and embryogenesis. They bind to TGF-β type II receptor (TGFBRII).
TGF-β1 stimulates the synthesis of collagen and fibronectin and inhibits the degradation of the extracellular matrix. Ultimately, it increases the production of extracellular matrix by epithelial cells.
TGF-β proteins regulate epithelia by controlling where and when they branch to form kidney, lung, and salivary gland ducts. | 1 | Applied and Interdisciplinary Chemistry |
Ferroxyl indicator is a solution containing potassium hexacyanoferrate(III) and phenolphthalein. It turns blue in the presence of Fe ions, and pink in the presence of hydroxide ions. It can be used to detect metal oxidation, and is often used to detect rusting in various situations.
It can be prepared by dissolving 10g sodium chloride and 1g potassium hexacyanoferrate(III) in distilled water, adding 10 cm phenolphthalein indicator, then making up to 500 cm with distilled water. | 1 | Applied and Interdisciplinary Chemistry |
Methylnaltrexone bromide is the bromide salt form of methylnaltrexone, a quaternary methyl derivative of noroxymorphone. The methyl group and the quaternary salt formation increase the polarity and reduce the lipid solubility thereby restricts the blood–brain-barrier penetration. Methylnaltrexone has eight times higher affinity for MOR than for κ-opioid receptor (KOR) and δ-opioid receptor (DOR). Naltrexone forms interaction with Asp147 and Tyr148 along with a hydrogen bond with Lys233. | 1 | Applied and Interdisciplinary Chemistry |
In molecular biology, a library is a collection of genetic material fragments that are stored and propagated in a population of microbes through the process of molecular cloning. There are different types of DNA libraries, including cDNA libraries (formed from reverse-transcribed RNA), genomic libraries (formed from genomic DNA) and randomized mutant libraries (formed by de novo gene synthesis where alternative nucleotides or codons are incorporated). DNA library technology is a mainstay of current molecular biology, genetic engineering, and protein engineering, and the applications of these libraries depend on the source of the original DNA fragments. There are differences in the cloning vectors and techniques used in library preparation, but in general each DNA fragment is uniquely inserted into a cloning vector and the pool of recombinant DNA molecules is then transferred into a population of bacteria (a Bacterial Artificial Chromosome or BAC library) or yeast such that each organism contains on average one construct (vector + insert). As the population of organisms is grown in culture, the DNA molecules contained within them are copied and propagated (thus, "cloned"). | 1 | Applied and Interdisciplinary Chemistry |
Global radiative equilibrium can be defined for an entire passive celestial system that does not supply its own energy, such as a planet.
Liou (2002, page 459) and other authors use the term global radiative equilibrium to refer to radiative exchange equilibrium globally between Earth and extraterrestrial space; such authors intend to mean that, in the theoretical, incoming solar radiation absorbed by Earths surface and its atmosphere would be equal to outgoing longwave radiation from Earths surface and its atmosphere. Prevost would say then that the Earth's surface and its atmosphere regarded as a whole were in absolute radiative equilibrium. Some texts, for example Satoh (2004), simply refer to "radiative equilibrium" in referring to global exchange radiative equilibrium. | 0 | Theoretical and Fundamental Chemistry |
The difference in mass density between the colloidal particles of mass density and the medium of suspension of mass density , and the diameter of the particles, have an influence on the value of . As an example, consider a colloidal suspension of polyethylene particles in water, and three different values for the diameter of the particles: 0.1 μm, 1 μm and 10 μm. The volume of a colloidal particles can be calculated using the volume of a sphere .
is the mass density of polyethylene, which is approximately on average 920 kg/m and is the mass density of water, which is approximately 1000 kg/m at room temperature (293K). Therefore is -80 kg/m.
Generally, decreases with . For the 0.1 μm diameter particle, is larger than the diameter, and the particles will be able to diffuse. For the 10 μm diameter particle, is much smaller than the diameter. As is negative the particles will cream, and the substance will no longer be a colloidal suspension.
In this example, the difference is mass density is relatively small. Consider a colloid with particles much denser than polyethylene, for example silicon with a mass density of approximately 2330 kg/m. If these particles are suspended in water, will be 1330 kg/m. will decrease as increases. For example, if the particles had a diameter of 10 μm the sedimentation length would be 5.92×10 μm, one order of magnitude smaller than for polyethylene particles. Also, because the particles are more dense than water, is positive and the particles will sediment. | 1 | Applied and Interdisciplinary Chemistry |
SHIFTCOR generates and reports chemical shift offsets or differences for each nucleus. The results contain the chemical shift analyses (including lists of potential mis-assignments, the estimated referencing errors, the estimated error in the calculated reference offset (95% confidence interval), the applied or suggested reference offset, correlation coefficients, RMSD values) and the corrected BMRB formatted chemical shift file (see Figure 1 for details).
SHIFTCOR uses the chemical shift calculation program SHIFTX to predict 1Hα, 13Cα,15N shifts based on the 3D structure coordinates of the protein being analyzed. By comparing the predicted shifts to the observed shifts, SHIFTCOR is able to accurately identify chemical shift reference offsets as well as potential mis-assignments. A key limitation to the SHIFTCOR approach is that requires that the 3D structure for the target protein be available to assess the chemical shift reference offsets. Given that chemical shift assignments are typically made before the structure is determined, it was soon realized that structure-independent approaches were required to develop. | 0 | Theoretical and Fundamental Chemistry |
Nitrates and nitrites are wastes produced by nitrifying bacteria, just as sulfur and sulfates are produced by the sulfur-reducing bacteria and sulfate-reducing bacteria. Insoluble iron waste can be made by iron bacteria by using soluble forms. In plants, resins, fats, waxes, and complex organic chemicals are exuded from plants, e.g., the latex from rubber trees and milkweeds. Solid waste products may be manufactured as organic pigments derived from breakdown of pigments like hemoglobin, and inorganic salts like carbonates, bicarbonates, and phosphate, whether in ionic or in molecular form, are excreted as solids.
Animals dispose of solid waste as feces. | 1 | Applied and Interdisciplinary Chemistry |
A study published in September 2009 discussed a proof of concept experiment to determine if it was possible to identify causal genetic variants using exome sequencing. They sequenced four individuals with Freeman–Sheldon syndrome (FSS) (OMIM 193700), a rare autosomal dominant disorder known to be caused by a mutation in the gene MYH3. Eight HapMap individuals were also sequenced to remove common variants in order to identify the causal gene for FSS. After exclusion of common variants, the authors were able to identify MYH3, which confirms that exome sequencing can be used to identify causal variants of rare disorders. This was the first reported study that used exome sequencing as an approach to identify an unknown causal gene for a rare mendelian disorder.
Subsequently, another group reported successful clinical diagnosis of a suspected Bartter syndrome patient of Turkish origin. Bartter syndrome is a renal salt-wasting disease. Exome sequencing revealed an unexpected well-conserved recessive mutation in a gene called SLC26A3 which is associated with congenital chloride diarrhea (CLD). This molecular diagnosis of CLD was confirmed by the referring clinician. This example provided proof of concept of the use of whole-exome sequencing as a clinical tool in evaluation of patients with undiagnosed genetic illnesses. This report is regarded as the first application of next generation sequencing technology for molecular diagnosis of a patient.
A second report was conducted on exome sequencing of individuals with a mendelian disorder known as Miller syndrome (MIM#263750), a rare disorder of autosomal recessive inheritance. Two siblings and two unrelated individuals with Miller syndrome were studied. They looked at variants that have the potential to be pathogenic such as non-synonymous mutations, splice acceptor and donor sites and short coding insertions or deletions. Since Miller syndrome is a rare disorder, it is expected that the causal variant has not been previously identified. Previous exome sequencing studies of common single nucleotide polymorphisms (SNPs) in public SNP databases were used to further exclude candidate genes. After exclusion of these genes, the authors found mutations in DHODH that were shared among individuals with Miller syndrome. Each individual with Miller syndrome was a compound heterozygote for the DHODH mutations which were inherited as each parent of an affected individual was found to be a carrier.
This was the first time exome sequencing was shown to identify a novel gene responsible for a rare mendelian disease. This exciting finding demonstrates that exome sequencing has the potential to locate causative genes in complex diseases, which previously has not been possible due to limitations in traditional methods. Targeted capture and massively parallel sequencing represents a cost-effective, reproducible and robust strategy with high sensitivity and specificity to detect variants causing protein-coding changes in individual human genomes. | 1 | Applied and Interdisciplinary Chemistry |
Small molecular direct thrombin inhibitors (smDTIs) are non-peptide small molecules that specifically and reversibly inhibit both free and clot-bound thrombin by binding to the active site of the thrombin molecule. They prevent VTE in patients undergoing hip- and knee replacement surgery. The advantages of this type of DTIs are that they do not need monitoring, have a wide therapeutic index and the possibility of oral administration route. They are theoretically more convenient than both vitamin K antagonist and LMWH. Researches will, however, have to show the indication of the use and their safety.
The smDTIs where derived using a peptidomimetic design with either P1 residue from arginine itself (e.g. argatroban) or arginine-like substrates such as benzamidine (e.g. NAPAP). | 1 | Applied and Interdisciplinary Chemistry |
Biofumigation is a method of pest control in agriculture, a variant of fumigation where the gaseous active substance—fumigant—is produced by decomposition of plant material freshly chopped and buried in the soil for this purpose.
Plants from the Brassicaceae family (e.g., mustards, cauliflower, and broccoli) are primarily used due to their high glucosinolate content; in the process of decomposition, glucosinolates are broken down to volatile isothiocyanates which are toxic to soil organisms such as bacteria, fungi and nematodes, but less toxic and persistent in the environment than synthetic fumigants. Alternatively, grasses such as sorghum can be used, in which case hydrogen cyanide is produced to similar effect.
The method consists of mowing and chopping the plants during flowering to ensure maximum glucosinolate content and speed up decomposition. The ground needs to be irrigated to field capacity, after which the chopped material is incorporated into the top layer and covered with impermeable film to prevent the gas from escaping. After three or four weeks, the film is removed and the ground is ready for planting 24 hours later. Burying biofumigant crops after the growing season to plant cash crops normally next year may in theory lead to buildup of active substance in the soil after a few cycles of crop rotation, but direct short-term suppression of pests is not notable in this case.
The method can be used as a more sustainable and environment-friendly alternative to classic fumigation and other chemical pest control methods. Additionally, it can serve to replenish the nutrient content of the soil and promote growth of beneficial organisms. On the other hand, it requires changes in cultivation practice due to the time needed for the method to take effect, can be costly if biofumigant-producing plants need to be brought from elsewhere (i. e. if they are not used in crop rotation to be chopped and buried on site), and is difficult to standardize due to varying active substance content in different cultivars. | 1 | Applied and Interdisciplinary Chemistry |
Although the modern electric arc furnace is a highly efficient recycler of steel scrap, operation of an arc furnace shop can have adverse environmental effects. Much of the capital cost of a new installation will be devoted to systems intended to reduce these effects, which include:
* Enclosures to reduce high sound levels
* Dust collector for furnace off-gas
* Slag production
* Cooling water demand
* Heavy truck traffic for scrap, materials handling, and product
* Environmental effects of electricity generation
Since EAF steelmaking mainly use recycled materials like scrap iron and scrap steel, as their composition varies the resulting EAF slag and EAF dust can be toxic. EAF dust is collected by air pollution control equipment. It is called collected dust and usually contains heavy metals, such as zinc, lead and dioxins, etc. It is categorized as hazardous industrial waste and disposal is regulated.
Because of the very dynamic quality of the arc furnace load, power systems may require technical measures to maintain the quality of power for other customers; flicker and harmonic distortion are common power system side-effects of arc furnace operation. | 1 | Applied and Interdisciplinary Chemistry |
Design based on supramolecular chemistry has led to numerous applications in the creation of functional biomaterials and therapeutics. Supramolecular biomaterials afford a number of modular and generalizable platforms with tunable mechanical, chemical and biological properties. These include systems based on supramolecular assembly of peptides, host–guest macrocycles, high-affinity hydrogen bonding, and metal–ligand interactions.
A supramolecular approach has been used extensively to create artificial ion channels for the transport of sodium and potassium ions into and out of cells.
Supramolecular chemistry is also important to the development of new pharmaceutical therapies by understanding the interactions at a drug binding site. The area of drug delivery has also made critical advances as a result of supramolecular chemistry providing encapsulation and targeted release mechanisms. In addition, supramolecular systems have been designed to disrupt protein–protein interactions that are important to cellular function. | 0 | Theoretical and Fundamental Chemistry |
The Procellarum KREEP Terrane, or PKT, is a large province on the near side of the Moon that has high abundances of KREEP. KREEP is an acronym built from the letters K (the atomic symbol for potassium), REE (rare-earth elements) and P (for phosphorus), and is a geochemical component of some lunar impact breccia and basaltic rocks. Notably, it is high in the KREEP element thorium, at a level of 4.8 ppm. This is a major factor distinguishing it from the other terranes. The PKT is on the near side of the moon, and covers 10% of the lunar surface, or 16% if one includes the maria lying within the FHT. Despite this, it contains 60% of all basaltic flows. KREEP has been shown to lower the melting point of rocks similar to those found on the Moon, and is expected to have contributed to volcanism in the region.
The Oceanus Procellarum and Mare Imbrium regions lie within the PKT. In general, many maria, such as (but not limited to) Mare Frigoris and Mare Cognitum are members of the PKT. Not all maria are in the PKT, however - Mare Crisium and Mare Orientale are located within the outer Feldspathic Highlands.
The PKT is the only terrane to lie exclusively in the near side of the Moon. Human and robotic missions have been done to this terrane, and samples have been returned to Earth for further study. | 0 | Theoretical and Fundamental Chemistry |
In three-dimensional space there are 14 Bravais lattices. These are obtained by combining one of the seven lattice systems with one of the centering types. The centering types identify the locations of the lattice points in the unit cell as follows:
*Primitive (P): lattice points on the cell corners only (sometimes called simple)
*Base-centered (S: A, B, or C): lattice points on the cell corners with one additional point at the center of each face of one pair of parallel faces of the cell (sometimes called end-centered)
*Body-centered (I): lattice points on the cell corners, with one additional point at the center of the cell
*Face-centered (F): lattice points on the cell corners, with one additional point at the center of each of the faces of the cell
Not all combinations of lattice systems and centering types are needed to describe all of the possible lattices, as it can be shown that several of these are in fact equivalent to each other. For example, the monoclinic I lattice can be described by a monoclinic C lattice by different choice of crystal axes. Similarly, all A- or B-centred lattices can be described either by a C- or P-centering. This reduces the number of combinations to 14 conventional Bravais lattices, shown in the table below. Below each diagram is the Pearson symbol for that Bravais lattice.
Note: In the unit cell diagrams in the following table all the lattice points on the cell boundary (corners and faces) are shown; however, not all of these lattice points technically belong to the given unit cell. This can be seen by imagining moving the unit cell slightly in the negative direction of each axis while keeping the lattice points fixed. Roughly speaking, this can be thought of as moving the unit cell slightly left, slightly down, and slightly out of the screen. This shows that only one of the eight corner lattice points (specifically the front, left, bottom one) belongs to the given unit cell (the other seven lattice points belong to adjacent unit cells). In addition, only one of the two lattice points shown on the top and bottom face in the Base-centered column belongs to the given unit cell. Finally, only three of the six lattice points on the faces in the Face-centered column belongs to the given unit cell.
The unit cells are specified according to six lattice parameters which are the relative lengths of the cell edges (a, b, c) and the angles between them (α, β, γ), where α is the angle between b and c, β is the angle between a and c, and γ is the angle between a and b. The volume of the unit cell can be calculated by evaluating the triple product , where a, b, and c are the lattice vectors. The properties of the lattice systems are given below:
Some basic information for the lattice systems and Bravais lattices in three dimensions is summarized in the diagram at the beginning of this page. The seven sided polygon (heptagon) and the number 7 at the centre indicate the seven lattice systems. The inner heptagons indicate the lattice angles, lattice parameters, Bravais lattices and Schöenflies notations for the respective lattice systems. | 0 | Theoretical and Fundamental Chemistry |
Dialysis has a wide range of applications. These can be divided into two categories depending on the type of dialysis used. | 1 | Applied and Interdisciplinary Chemistry |
EPA's analysis indicated the amount of existing inventory was between 22,700t and 45,400t.
In 2012 the EPA reduced the amount of R-22 by 45%, causing the price to rise by more than 300%. For 2013, the EPA has reduced the amount of R-22 by 29%. | 1 | Applied and Interdisciplinary Chemistry |
*The Alchemical Tarot of Marseille,
*The Tarot of the Sevenfold Mystery 2nd Edition,
*The Alchemical Tarot: Renewed 5th Edition,
*The Tarot of the Alchemical Magnum Opus,
*An Ukiyo-e Lenormand,
*The Raziel Tarot: the Secret Teachings of Adam and Eve,
* The Marziano Tarot,
* The Hermes Playing Card Oracle,
* The New York Lenormand
* The Burning Serpent Oracle,
* Facsimile Italian Renaissance Woodcut Tarocchi
* The Tarot of the Sevenfold Mystery,
* The Annotated Tarot of the Sevenfold Mystery,
* The Vampire Tarot,
* The Buddha Tarot,
* The Tarot of the Saints,
* The Angels Tarot
* The Alchemical Tarot: Renewed, Editions 2, 3, and 4,
* The Alchemical Tarot: Art Edition
* The Alchemical Tarot, | 1 | Applied and Interdisciplinary Chemistry |
A majority of silver nanoparticles in consumer products go down the drain and are eventually released into sewer systems and reach wastewater treatment plants. Primary screening and grit removal in wastewater treatment does not completely filter out silver nanoparticles, and coagulation treatment may lead to further condensation into wastewater sludge. The secondary wastewater treatment process involves suspended growth systems which allow bacteria to decompose organic matter within the water. Any silver nanoparticles still suspended in the water may collect on these microbes, potentially killing them due to their antimicrobial effects. After passing through both treatment processes, the silver nanoparticles are eventually deposited into the environment.
A majority of the submerged portions of wastewater treatment plants are anoxic and rich in sulfur. During the wastewater treatment process, silver nanoparticles either remain the same, are converted into free silver ions, complex with ligands, or agglomerate. Silver nanoparticles can also attach to wastewater biosolids found in both the sludge and the effluent. Silver ions in wastewater are removed efficiently because of their strong complexation with chloride or sulfide.
A majority of the silver found in wastewater treatment plant effluent is associated with reduced sulfur as organic thiol groups and inorganic sulfides. Silver nanoparticles also tend to accumulate in activated sludge, and the dominant form of the silver found in sewage sludge is AgS. Therefore, most of the silver found in wastewater treatment plants is in the form of silver nanoparticles or silver precipitates such as AgS and AgCl.
The amount of silver precipitate formed depends on silver ion release, which increases with increasing dissolved oxygen concentration and decreasing pH. Silver ions account for approximately 1% of total silver after silver nanoparticles are suspended in aerated water. In anoxic wastewater treatment environments, silver ion release is therefore often negligible, and most of the silver nanoparticles in wastewater remain in the original silver nanoparticle form. The presence of natural organic matter can also decrease oxidative dissolution rates and therefore the release rate of free silver ions. The slow oxidation of silver nanoparticles may enable new pathways for its transfer into the environment. | 1 | Applied and Interdisciplinary Chemistry |
Like some fatty acids, carotenoids are lipophilic due to the presence of long unsaturated aliphatic chains. As a consequence, carotenoids are typically present in plasma lipoproteins and cellular lipid structures. | 0 | Theoretical and Fundamental Chemistry |
Dexbrompheniramine is an antihistamine with anticholinergic properties used to treat allergic conditions such as hay fever or urticaria. It is the pharmacologically active dextrorotatory isomer of brompheniramine. It was formerly marketed in combination with pseudoephedrine under the name Drixoral in the US and Canada. It is an alkylamine antihistamine.
Dexbrompheniramine is a first generation antihistamine that reduces the effects of the neurotransmitter histamine in the body; sneezing, itching, watery eyes, and runny nose. | 0 | Theoretical and Fundamental Chemistry |
pH indicators are frequently employed in titrations in analytical chemistry and biology to determine the extent of a chemical reaction. Because of the subjective choice (determination) of color, pH indicators are susceptible to imprecise readings. For applications requiring precise measurement of pH, a pH meter is frequently used. Sometimes, a blend of different indicators is used to achieve several smooth color changes over a wide range of pH values. These commercial indicators (e.g., universal indicator and Hydrion papers) are used when only rough knowledge of pH is necessary. For a titration, the difference between the true endpoint and the indicated endpoint is called the indicator error.
Tabulated below are several common laboratory pH indicators. Indicators usually exhibit intermediate colors at pH values inside the listed transition range. For example, phenol red exhibits an orange color between pH 6.8 and pH 8.4. The transition range may shift slightly depending on the concentration of the indicator in the solution and on the temperature at which it is used. The figure on the right shows indicators with their operation range and color changes. | 0 | Theoretical and Fundamental Chemistry |
In 1991 JETs Preliminary Tritium Experiment achieved the worlds first controlled release of fusion power.
In 1992, Physics Today published Robert McCory's outline of the current state of ICF, advocating for a national ignition facility. This was followed by a review article from John Lindl in 1995, making the same point. During this time various ICF subsystems were developed, including target manufacturing, cryogenic handling systems, new laser designs (notably the NIKE laser at NRL) and improved diagnostics including time of flight analyzers and Thomson scattering. This work was done at the NOVA laser system, General Atomics, Laser Mégajoule and the GEKKO XII system in Japan. Through this work and lobbying by groups like the fusion power associates and John Sethian at NRL, Congress authorized funding for the NIF project in the late nineties.
In 1992 the United States and the former republics of the Soviet Union stopped testing nuclear weapons.
In 1993 TFTR at PPPL experimented with 50% deuterium, 50% tritium, eventually reaching 10 megawatts.
In the early nineties, theory and experimental work regarding fusors and polywells was published. In response, Todd Rider at MIT developed general models of these devices, arguing that all plasma systems at thermodynamic equilibrium were fundamentally limited. In 1995, William Nevins published a criticism arguing that the particles inside fusors and polywells would acquire angular momentum, causing the dense core to degrade.
In 1995, the University of Wisconsin–Madison built a large fusor, known as HOMER. Dr George H. Miley at Illinois built a small fusor that produced neutrons using deuterium and discovered the "star mode" of fusor operation. At this time in Europe, an IEC device was developed as a commercial neutron source by Daimler-Chrysler and NSD Fusion.
The next year, Tore Supra reached a record plasma duration of two minutes with a current of almost 1 M amperes driven non-inductively by 2.3 MW of lower hybrid frequency waves (i.e. 280 MJ of injected and extracted energy), enabled by actively cooled plasma-facing components.
The upgraded Z-machine opened to the public in August 1998. The key attributes were its 18 million ampere current and a discharge time of less than 100 nanoseconds. This generated a magnetic pulse inside a large oil tank, which struck a liner (an array of tungsten wires). Firing the Z-machine became a way to test high energy, high temperature (2 billion degrees) conditions. In 1996.
In 1997, JET reached 16.1 MW (65% of heat to plasma), sustaining over 10 MW for over 0.5 sec. As of 2020 this remained the record output level. Four megawatts of alpha particle self-heating was achieved.
ITER was officially announced as part of a seven-party consortium (six countries and the EU). ITER was designed to produce ten times more fusion power than the input power. ITER was sited in Cadarache. The US withdrew from the project in 1999.
JT-60 produced a reversed shear plasma with the equivalent fusion amplification factor of 1.25 - as of 2021 this remained the world record.
In the late nineties, a team at Columbia University and MIT developed the levitated dipole, a fusion device that consisted of a superconducting electromagnet, floating in a saucer shaped vacuum chamber. Plasma swirled around this donut and fused along the center axis.
In 1999 MAST replaced START. | 0 | Theoretical and Fundamental Chemistry |
Hypolimnetic oxygen depletion can lead to both summer and winter "kills". During summer stratification, inputs or organic matter and sedimentation of primary producers can increase rates of respiration in the hypolimnion. If oxygen depletion becomes extreme, aerobic organisms, like fish, may die, resulting in what is known as a "summer kill". The same phenomena can occur in the winter, but for different reasons. During winter, ice and snow cover can attenuate light, and therefore reduce rates of photosynthesis. The freezing over of a lake also prevents air-water interactions that allow the exchange of oxygen. This creates a lack of oxygen while respiration continues. When the oxygen becomes badly depleted, anaerobic organisms can die, resulting in a "winter kill". | 0 | Theoretical and Fundamental Chemistry |
Microfluidic diffusional sizing (MDS) is a method to measure the size of particles based on the degree to which they diffuse within a microfluidic laminar flow. It allows size measurements to be taken from extremely small quantities of material (nano-grams) and is particularly useful when sizing molecules which may vary in size depending on their environment - e.g. protein molecules which may unfold or become denatured in unfavourable conditions. | 1 | Applied and Interdisciplinary Chemistry |
Storm drains are separate and distinct from sanitary sewer systems. The separation of storm sewers from sanitary sewers helps prevent sewage treatment plants becoming overwhelmed by infiltration/inflow during a rainstorm, which could discharge untreated sewage into the environment.
Many storm drainage systems drain untreated storm water into rivers or streams. In the US, many local governments conduct public awareness campaigns about this, lest people dump waste into the storm drain system. In Cleveland, Ohio, for example, all new catch basins installed have inscriptions on them not to dump any waste, and usually include a fish imprint as well. Trout Unlimited Canada recommends that a yellow fish symbol be painted next to existing storm drains. | 1 | Applied and Interdisciplinary Chemistry |
in which is the number of core samples, is the effective porosity, is the bulk volume of sample, and is the primary drainage capillary pressure data vs. normalized water saturation. | 1 | Applied and Interdisciplinary Chemistry |
* J.G. Nicholls, A.R. Martin, B.G. Wallace and P.A. Fuchs. "From Neuron to Brain". 4th ed. Sinauer Associates, Sunderland, MA. | 1 | Applied and Interdisciplinary Chemistry |
Large steep internal waves containing trapped, reverse-oscillating cores can also transport parcels of water shoreward. These non-linear waves with trapped cores had previously been observed in the laboratory and predicted theoretically. These waves propagate in environments characterized by high shear and turbulence and likely derive their energy from waves of depression interacting with a shoaling bottom further upstream. The conditions favorable to the generation of these waves are also likely to suspend sediment along the bottom as well as plankton and nutrients found along the benthos in deeper water. | 1 | Applied and Interdisciplinary Chemistry |
The Eschenmoser sulfide contraction method has been employed in a number of total synthesis efforts, like that of fuligocandin A and B, cocaine, diplodialide A and isoretronecanol
An example of general synthetic utility is the synthesis of novel carbapenems | 0 | Theoretical and Fundamental Chemistry |
Plastocyanin (CuPc) is reduced (an electron is added) by cytochrome f according to the following reaction:
:CuPc + e → CuPc
After dissociation, CuPc diffuses through the lumen space until recognition/binding occurs with P700, at which point P700 oxidizes CuPc according to the following reaction:
:CuPc → CuPc + e
The redox potential is about 370 mV and the isoelectric pH is about 4. | 0 | Theoretical and Fundamental Chemistry |
Values for log K typically range between -3 (very hydrophilic) and +10 (extremely lipophilic/hydrophobic).
The values listed here are sorted by the partition coefficient. Acetamide is hydrophilic, and 2,2′,4,4′,5-Pentachlorobiphenyl is lipophilic. | 0 | Theoretical and Fundamental Chemistry |
Carbon tetrachloride () can turn into phosgene when exposed to heat in air. This was a problem as carbon tetrachloride is an effective fire suppressant and was formerly in widespread use in fire extinguishers. There are reports of fatalities caused by its use to fight fires in confined spaces. Carbon tetrachloride's generation of phosgene and its own toxicity mean it is no longer used for this purpose. | 0 | Theoretical and Fundamental Chemistry |
* Romanian Academy of Scientists
* Romanian Academy of Scientists (American Branch)
* New York Academy of Sciences
* American Chemical Society
* Royal Australian Chemical Institute
* Australasian Society for Biomaterials and Tissue Engineering
* KPro Study Group | 0 | Theoretical and Fundamental Chemistry |
Since the emitted light can be easily detected with a luminometer, aequorin has become a useful tool in molecular biology for the measurement of intracellular Ca levels. The early successful purification of aequorin led to the first experiments involving the injection of the protein into the tissues of living animals to visualize the physiological release of calcium in the muscle fibers of a barnacle. Since then, the protein has been widely used in many model biological systems, including zebrafish, rats, mice, and cultured cells.
Cultured cells expressing the aequorin gene can effectively synthesize apoaequorin; however, recombinant expression yields only the apoprotein. Therefore it is necessary to add coelenterazine into the culture medium of the cells to obtain a functional protein and thus use its blue light emission to measure Ca concentration. Coelenterazine is a hydrophobic molecule, and therefore is easily taken up across plant and fungal cell walls, as well as the plasma membrane of higher eukaryotes, making aequorin suitable as a Ca reporter in plants, fungi, and mammalian cells.
Aequorin has a number of advantages over other Ca indicators. Because the protein is large, it has a low leakage rate from cells compared to lipophilic dyes such as DiI. It lacks phenomena of intracellular compartmentalization or sequestration as is often seen for Voltage-sensitive dyes, and does not disrupt cell functions or embryo development. Moreover, the light emitted by the oxidation of coelenterazine does not depend on any optical excitation, so problems with auto-fluorescence are eliminated. The primary limitation of aequorin is that the prosthetic group coelenterazine is irreversibly consumed to produce light, and requires continuous addition of coelenterazine into the media. Such issues led to developments of other genetically encoded calcium sensors including the calmodulin-based sensor cameleon, developed by Roger Tsien and the troponin-based sensor, TN-XXL, developed by Oliver Griesbeck. | 1 | Applied and Interdisciplinary Chemistry |
Isothermal flow is a model of compressible fluid flow whereby the flow remains at the same temperature while flowing in a conduit. In the model, heat transferred through the walls of the conduit is offset by frictional heating back into the flow. Although the flow temperature remains constant, a change in stagnation temperature occurs because of a change in velocity. The interesting part of this flow is that the flow is choked at and not at Mach number equal to one as in the case of many other model such as Fanno flow. This fact applies to real gases as well as ideal gases.
For the important practical case of a gas flow through a long tube, the model has applicability in situations where distance is relatively long and heat transfer is relatively rapid so temperature can be treated, for engineering purposes, as a constant. This model also has applicability as upper boundary to Fanno flow. | 1 | Applied and Interdisciplinary Chemistry |
Through this process of time-domain thermoreflectance, the thermal properties of many materials can be obtained. Common test setups include having multiple metal blocks connected together in a diffusion multiple, where once subjected to high temperatures various compounds can be created as a result of the diffusion of two adjacent metal blocks. An example would be a Ni-Cr-Pd-Pt-Rh-Ru diffusion multiple which would have diffusion zones of Ni-Cr, Ni-Pd, Ni-Pt and so on. In this way, many different materials can be tested at the same time. Lowest thermal conductivity for a thin film of solid, fully dense material (i.e. not porous) was also recently reported with measurements using this method.
Once this test sample is obtained, time-domain thermoreflectance measurements can take place, with laser pulses of very short duration for both the pump and the probe lasers (<1 ps). The thermoreflected signal is then measured by a photodiode which is connected to a RF lock-in amplifier. The signals that come out of the amplifier consist of an in phase and out of phase component, and the ratio of these allow thermal conductivity data to be measured for a specific delay time.
The data received from this process can then be compared to a thermal model, and the thermal conductivity and thermal conductance can then be derived. It is found that these two parameters can be derived independently based on the delay times, with short delay times (0.1 - .5 ns) resulting in the thermal conductivity and longer delay times (> 2ns) resulting in the thermal conductance.
There is much room for error involved due to phase errors in the RF amplifier in addition to noise from the lasers. Typically, however, accuracy can be found to be within 8%. | 0 | Theoretical and Fundamental Chemistry |
Sonic black holes are possible because phonons in perfect fluids exhibit the same properties of motion as fields, such as gravity, in space and time. For this reason, a system in which a sonic black hole can be created is called a gravity analogue. Nearly any fluid can be used to create an acoustic event horizon, but the viscosity of most fluids creates random motion that makes features like Hawking radiation nearly impossible to detect. The complexity of such a system would make it very difficult to gain any knowledge about such features even if they could be detected. Many nearly perfect fluids have been suggested for use in creating sonic black holes, such as superfluid helium, one–dimensional degenerate Fermi gases, and Bose–Einstein condensate. Gravity analogues other than phonons in a fluid, such as slow light and a system of ions, have also been proposed for studying black hole analogues. The fact that so many systems mimic gravity is sometimes used as evidence for the theory of emergent gravity, which could help reconcile relativity, and quantum mechanics. | 1 | Applied and Interdisciplinary Chemistry |
In this mechanism, proposed in 1938 by D. D. Eley and E. K. Rideal, only one of the molecules adsorbs and the other one reacts with it directly from the gas phase, without adsorbing ("nonthermal surface reaction"):
: A(g) + S(s) ⇌ AS(s)
: AS(s) + B(g) → Products
Constants are and and rate equation is . Applying steady state approximation to AS and proceeding as before (considering the reaction the limiting step once more) we get . The order is one with respect to B. There are two possibilities, depending on the concentration of reactant A:
:* At low concentrations of A, , and the order is one with respect to A.
:* At high concentrations of A, , and the order is zero with respect to A.
The following reactions follow an Eley–Rideal mechanism:
* CH + ½ O (adsorbed) → (CHCH)O The dissociative adsorption of oxygen is also possible, which leads to secondary products carbon dioxide and water.
* CO + H (ads.) → HO + CO
* 2 NH + 1½ O (ads.) → N + 3HO on a platinum catalyst
* CH + H (ads.) → CH on nickel or iron catalysts | 0 | Theoretical and Fundamental Chemistry |
Perhaps the movement which most influenced Isaac Newton was Rosicrucianism. Although the Rosicrucian movement had caused a great deal of excitement within Europe's scholarly community during the early seventeenth century, by the time Newton had reached maturity the movement had become less sensationalized. However, the Rosicrucian movement still would have a profound influence upon Newton, particularly in regard to his alchemical work and philosophical thought.
The Rosicrucian belief in being specially chosen for the ability to communicate with angels or spirits is echoed in Newtons prophetic beliefs. Additionally, the Rosicrucians proclaimed to have the ability to live forever through the use of the elixir vitae and the ability to produce limitless amounts of time and gold from the use of the philosophers stone, which they claimed to have in their possession. Like Newton, the Rosicrucians were deeply religious, avowedly Christian, anti-Catholic, and highly politicised. Isaac Newton would have a deep interest in not just their alchemical pursuits, but also their belief in esoteric truths of the ancient past and the belief in enlightened individuals with the ability to gain insight into nature, the physical universe, and the spiritual realm.
At the time of his death, Isaac Newton had 169 books on the topic of alchemy in his personal library, and was believed to have considerably more books on this topic during his Cambridge years, though he may have sold them before moving to London in 1696. For its time, his was considered one of the finest alchemical libraries in the world. In his library, Newton left behind a heavily annotated personal copy of The Fame and Confession of the Fraternity R.C., by Thomas Vaughan which represents an English translation of The Rosicrucian Manifestos. Newton also possessed copies of Themis Aurea and Symbola Aurea Mensae Duodecium by the learned alchemist Michael Maier, both of which are significant early books about the Rosicrucian movement. These books were also extensively annotated by Newton.
Newtons ownership of these materials by no means denotes membership within any early Rosicrucian order. Furthermore, considering that his personal alchemical investigations were focused upon discovering materials which the Rosicrucians professed to already be in possession of long before he was born, would seem to some to exclude Newton from their membership. However, in religious terms, the fact that a saint might have found God' would not preclude others from the search – quite the opposite. During his own life, Newton was openly accused of being a Rosicrucian, as were many members of The Royal Society. | 1 | Applied and Interdisciplinary Chemistry |
Pipeline video inspection is a form of telepresence used to visually inspect the interiors of pipelines, plumbing systems, and storm drains. A common application is for a plumber to determine the condition of small diameter sewer lines and household connection drain pipes.
Older sewer lines of small diameter, typically , are made by the union of a number of short sections. The pipe segments may be made of cast iron, with to sections, but are more often made of vitrified clay pipe (VCP), a ceramic material, in , & sections. Each iron or clay segment will have an enlargement (a "bell") on one end to receive the end of the adjacent segment. Roots from trees and vegetation may work into the joins between segments and can be forceful enough to break open a larger opening in terra cotta or corroded cast iron. Eventually a root ball will form that will impede the flow and this may cleaned out by a cutter mechanism or plumbers snake and subsequently inhibited by use of a chemical foam - a rooticide'.
With modern video equipment, the interior of the pipe may be inspected - this is a form of non-destructive testing. A small diameter collector pipe will typically have a cleanout access at the far end and will be several hundred feet long, terminating at a manhole. Additional collector pipes may discharge at this manhole and a pipe (perhaps of larger diameter) will carry the effluent to the next manhole, and so forth to a pump station or treatment plant.
Without regular inspection of public sewers, a significant amount of waste may accumulate unnoticed until the system fails. In order to prevent resulting catastrophic events such as pipe bursts and raw sewage flooding onto city streets, municipalities usually conduct pipeline video inspections as a precautionary measure. | 1 | Applied and Interdisciplinary Chemistry |
Because of the sensitivity of the electrodes to contaminants, cleanliness of the probes is essential for accuracy and precision. Probes are generally kept moist when not in use with a medium appropriate for the particular probe, which is typically an aqueous solution available from probe manufacturers. Probe manufacturers provide instructions for cleaning and maintaining their probe designs. For illustration, one maker of laboratory-grade pH gives cleaning instructions for specific contaminants: general cleaning (15-minute soak in a solution of bleach and detergent), salt (hydrochloric acid solution followed by sodium hydroxide and water), grease (detergent or methanol), clogged reference junction (KCl solution), protein deposits (pepsin and HCl, 1% solution), and air bubbles. | 0 | Theoretical and Fundamental Chemistry |
Scholarly and academic awards of Vasdev's career include:
* Fellow of Society of Nuclear Medicine and Molecular Imaging in 2021, for his distinguished service to the Society, and exceptional achievement in the field of nuclear medicine and molecular imaging.
* Fellow of American Chemical Society in 2020, for his outstanding achievements and contributions to science, the profession and the Society.
* Fellow of Royal Society of Chemistry in 2020, for his impact to the field of chemical sciences
* Research award of John R. Evans Leaders Fund 2019–2024 (specialty: Radiochemistry) from Canada Foundation for Innovation. This funding supports his proposal: "Automated apparatus for PET radiopharmaceuticals to image the living human brain"
* Research award of Endowed Azrieli Chair in Brain and Behaviour 2018–2023 (Specialty: Neuroimaging) from University of Toronto.
* Research Award of Tier 1 Canada Research Chair in Radiochemistry and Nuclear Medicine 2017–2024 (specialty: Radiochemistry and Nuclear Medicine) from Canadian Institutes for Health Research (CIHR).
* Leaders Opportunity Fund (Research Infrastructure) 2009–2014 (specialty: Radiochemistry) from Canadian Foundation for Innovation. | 0 | Theoretical and Fundamental Chemistry |
The European FOCE ([http://efoce.eu eFOCE]) comprises two open-top chambers (control and experimental) as well as a surface buoy housing the electronics and pumps to produce CO-enriched water. The system is powered by solar and wind energy. Data packets are wirelessly sent to the nearby laboratory and can be monitored on the internet. The eFOCE system is currently deployed in the bay of Villefranche-sur-mer (France) at about 12 m depth and 300 m offshore. The eFOCE project has been developed to investigate the long-term effects of acidification on benthic marine communities of the North West Mediterranean Sea, especially Posidonia seagrass beds. Over a 3-year period, the aim of the project is to develop relatively long (> 6 month) experiments. | 0 | Theoretical and Fundamental Chemistry |
Although enzymes are generally specific towards their substrate, enzymatic side activities (enzyme promiscuity) can lead to toxic or useless products. These side reactions proceed at much lower rates than their normal physiological reactions, but build-up of damaged metabolites can still be significant over time. For example, the mitochondrial malate dehydrogenase reduces alpha-ketoglutarate to L-2-hydroxyglutarate 10 times less efficiently than its regular substrate oxaloacetate, but L-2-hydroxyglutarate can still accumulate to several grams per day in a human adult. | 1 | Applied and Interdisciplinary Chemistry |
The Bennett acceptance ratio method (BAR) is an algorithm for estimating the difference in free energy between two systems (usually the systems will be simulated on the computer).
It was suggested by Charles H. Bennett in 1976. | 0 | Theoretical and Fundamental Chemistry |
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