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Bismuth pentafluoride is an inorganic compound with the formula BiF. It is a white solid that is highly reactive. The compound is of interest to researchers but not of particular value. BiF is polymeric and consists of linear chains of "trans"-bridged corner sharing BiF octahedra. This is the same structure as "α"-UF. BiF can be prepared by treating BiF with F at 500 °C. In an alternative synthesis, ClF is the fluorinating agent at 350 °C. is the most reactive of the pnictogen pentafluorides and is an extremely strong fluorinating agent. It reacts vigorously with water to form ozone and oxygen difluoride, and with iodine or sulfur at room temperature. BiF fluorinates paraffin oil (hydrocarbons) to fluorocarbons above 50 °C and oxidises UF to UF at 150 °C. At 180 °C, bismuth pentafluoride fluorinates Br to BrF and Cl to ClF. BiF also reacts with alkali metal fluorides, MF, to form hexafluorobismuthates, M[BiF], containing the hexafluorobismuthate anion, [BiF]. | https://en.wikipedia.org/wiki?curid=23089402 |
Europium(III) oxide (EuO), is a chemical compound of europium and oxygen. It is widely used as a red or blue phosphor in television sets and fluorescent lamps, and as an activator for yttrium-based phosphors. It is also an agent for the manufacture of fluorescent glass. Europium fluorescence is used in the anti-counterfeiting phosphors in Euro banknotes. Europium oxide has two common structures: Monoclinic (mS30, SpaceGroup = C2/m, No. 12) and cubic (cI80, SpaceGroup = Ia-3, No. 206). The cubic structure is similar to that of manganese(III) oxide. It may be formed by ignition of europium metal. It can react with acids to form the corresponding europium(III) salts. | https://en.wikipedia.org/wiki?curid=23090487 |
Fractional anisotropy (FA) is a scalar value between zero and one that describes the degree of anisotropy of a diffusion process. A value of zero means that diffusion is isotropic, i.e. it is unrestricted (or equally restricted) in all directions. A value of one means that diffusion occurs only along one axis and is fully restricted along all other directions. FA is a measure often used in diffusion imaging where it is thought to reflect fiber density, axonal diameter, and myelination in white matter. The FA is an extension of the concept of eccentricity of conic sections in 3 dimensions, normalized to the unit range. A Diffusion Ellipsoid is completely represented by the Diffusion Tensor, D. FA is calculated from the eigenvalues (formula_1) of the diffusion tensor. The eigenvectors formula_2 give the directions in which the ellipsoid has major axes, and the corresponding eigenvalues formula_3 give the magnitude of the peak in that direction. with formula_5 being the mean value of the eigenvalues. An equivalent formula for FA is which is further equivalent to: where R is the "normalized" diffusion tensor: Note that if all the eigenvalues are equal, which happens for isotropic (spherical) diffusion, as in free water, the FA is . The FA can reach a maximum value of (this rarely happens in real data), in which case D has only one nonzero eigenvalue and the ellipsoid reduces to a line in the direction of that eigenvector. This means that the diffusion is confined to that direction alone | https://en.wikipedia.org/wiki?curid=23092863 |
Fractional anisotropy This can be visualized with an ellipsoid, which is defined by the eigenvectors and eigenvalues of D. The FA of a sphere is "0" since the diffusion is isotropic, and there is equal probability of diffusion in all directions. The eigenvectors and eigenvalues of the Diffusion Tensor give a complete representation of the diffusion process. FA quantifies the pointedness of the ellipsoid, but does not give information about which direction it is pointing to. Note that the FA of most liquids, including water, is unless the diffusion process is being constrained by structures such as network of fibers. The measured FA may depend on the effective length scale of the diffusion measurement. If the diffusion process is not constrained on the scale being measured (the constraints are too far apart) or the constraints switch direction on a smaller scale than the measured one, then the measured FA will be attenuated. For example, the brain can be thought of as a fluid permeated by many fibers (nerve axons). However, in most parts the fibers go in all directions, and thus although they constrain the diffusion the FA is . In some regions, such as the corpus callosum the fibers are aligned over a large enough scale (on the order of a mm) for their directions to mostly agree within the resolution element of a magnetic resonance image, and it is these regions that stand out in an FA image | https://en.wikipedia.org/wiki?curid=23092863 |
Fractional anisotropy Liquid crystals can also exhibit anisotropic diffusion because the needle or plate-like shapes of their molecules affect how they slide over one another. When the FA is 0 the tensor nature of D is often ignored, and it is called the diffusion constant. A drawback of the Diffusion Tensor model is that it can account only for Gaussian diffusion processes, which has been found to be inadequate in accurately representing the true diffusion process in the human brain. Due to this, higher order models using spherical harmonics and Orientation Distribution Functions (ODF) have been used to define newer and richer estimates of the anisotropy, called Generalized Fractional Anisotropy. GFA computations use samples of the ODF to evaluate the anisotropy in diffusion. They can also be easily calculated by using the Spherical Harmonic coefficients of the ODF model. | https://en.wikipedia.org/wiki?curid=23092863 |
Air separation An air separation plant separates atmospheric air into its primary components, typically nitrogen and oxygen, and sometimes also argon and other rare inert gases. The most common method for air separation is fractional distillation. Cryogenic air separation units (ASUs) are built to provide nitrogen or oxygen and often co-produce argon. Other methods such as membrane, pressure swing adsorption (PSA) and vacuum pressure swing adsorption (VPSA) are commercially used to separate a single component from ordinary air. High purity oxygen, nitrogen, and argon, used for semiconductor device fabrication, require cryogenic distillation. Similarly, the only viable source of the rare gases neon, krypton, and xenon is the distillation of air using at least two distillation columns. Pure gases can be separated from air by first cooling it until it liquefies, then selectively distilling the components at their various boiling temperatures. The process can produce high purity gases but is energy-intensive. This process was pioneered by Carl von Linde in the early 20th century and is still used today to produce high purity gases. He developed it in the year 1895; the process remained purely academic for seven years before it was used in industrial applications for the first time (1902). The cryogenic separation process requires a very tight integration of heat exchangers and separation columns to obtain a good efficiency and all the energy for refrigeration is provided by the compression of the air at the inlet of the unit | https://en.wikipedia.org/wiki?curid=23096495 |
Air separation To achieve the low distillation temperatures an air separation unit requires a refrigeration cycle that operates by means of the Joule–Thomson effect, and the cold equipment has to be kept within an insulated enclosure (commonly called a "cold box"). The cooling of the gases requires a large amount of energy to make this refrigeration cycle work and is delivered by an air compressor. Modern ASUs use expansion turbines for cooling; the output of the expander helps drive the air compressor, for improved efficiency. The process consists of the following main steps: The separated products are sometimes supplied by pipeline to large industrial users near the production plant. Long distance transportation of products is by shipping liquid product for large quantities or as dewar flasks or gas cylinders for small quantities. Pressure swing adsorption provides separation of oxygen or nitrogen from air without liquefaction. The process operates around ambient temperature; a zeolite (molecular sponge) is exposed to high pressure air, then the air is released and an adsorbed film of the desired gas is released. The size of compressor is much reduced over a liquefaction plant, and portable oxygen concentrators are made in this manner to provide oxygen-enriched air for medical purposes. Vacuum swing adsorption is a similar process; the product gas is evolved from the zeolite at sub-atmospheric pressure. Membrane technologies can provide alternate, lower-energy approaches to air separation | https://en.wikipedia.org/wiki?curid=23096495 |
Air separation For example, a number of approaches are being explored for oxygen generation. Polymeric membranes operating at ambient or warm temperatures, for example, may be able to produce oxygen-enriched air (25-50% oxygen). Ceramic membranes can provide high-purity oxygen (90% or more) but require higher temperatures (800-900 deg C) to operate. These ceramic membranes include Ion Transport Membranes (ITM) and Oxygen Transport Membranes (OTM). Air Products and Chemicals Inc and Praxair are developing flat ITM and tubular OTM systems, . Membrane gas separation is used to provide oxygen-poor and nitrogen-rich gases instead of air to fill the fuel tanks of jet liners, thus greatly reducing the chances of accidental fires and explosions. Conversely, membrane gas separation is currently used to provide oxygen-enriched air to pilots flying at great altitudes in aircraft without pressurized cabins. Oxygen-enriched air can be obtained exploiting the different solubility of oxygen and nitrogen. Oxygen is more soluble than nitrogen in water, so if air is degassed from water, a stream of 35% oxygen can be obtained. In steelmaking oxygen is required for the basic oxygen steelmaking. Today, modern basic oxygen steelmaking uses almost two tons of oxygen per ton of steel. Nitrogen used in the Haber process to make ammonia. Large amounts of oxygen are required for coal gasification projects; cryogenic plants producing 3000 tons/day are found in some projects | https://en.wikipedia.org/wiki?curid=23096495 |
Air separation Inerting with nitrogen storage tanks of ships and tanks for petroleum products, or for protecting edible oil products from oxidation. | https://en.wikipedia.org/wiki?curid=23096495 |
Enhancement or quenching of QD, Q-wire and QW radiations In the field of solid-state physics, enhancement or quenching of the radiation of QDs, Q-wires, and QW are methods used to reduce the radiative emission of quantum dots, wires and wells. Many methods have been developed to enhance or quench the radiation by adjusting the size, changing the structure, and adding other materials to the quantum structures. By doing these, the radiation patterns are regulated, which are expected to have the potential to lead to a new class of light sources. In this page, recent research on zinc oxide (ZnO) nanostructures is introduced and the principles of the enhancement and quenching in the structures are discussed. The optical properties of ZnO quantum dots can be controlled by changing of the size. As the size of the ZnO nanocolloids increases, the absorbance increases, but optical band gap of the nanocolloids decreases. The third-order optical susceptibility increases with increasing particle size. Radiation fields are changed by the methods to fabricate the quantum wires. Micro photoluminescence spectra of an individual suspended as-grown ZnO nanowire and an individual ZnO nanowire processed by sonication/dispersion procedure. The thickness of the nanowire tends to change the radiation fields. The thickness of the nanowire is also related to the peak wavelength. For the nanowire with regular shape shown, only slight difference in UV to visible emission ratios was observed for the two parts with different diameters | https://en.wikipedia.org/wiki?curid=23097121 |
Enhancement or quenching of QD, Q-wire and QW radiations Correspondingly, UV emission peaks have almost the same position at 375.2 nm. On the other hands, for the nanowire with irregular shape and rougher surface, with the decrease of the diameter, dramatically increased green emission and decreased UV emission can be observed, which was accompanied by the red shift of the UV emission peak energy. Radiation fields of ZnO quantum wells can be adjusted by coupling through localized surface plasmons. By sputtering Ag islands onto ZnO films, their band gap emission coming through the Ag island films was enhanced by threefolds, while the defect emission was quenched. The enhancement is mainly dependent on the Ag island size. photoluminescence spectra of seven samples which have different Ag island sizes are represented; #4 sample has the largest size of island, but # 1 sample has the smallest size of the island. It is revealed that sputtering time related to the island size have an effect on the enhancement of 380 nm band and 530 nm band. The PL enhancement or quenching may be due to the coupling of the light emission with the localized surface plasmon resonance of the Ag islands. When localized surface Plasmon resonance scattering dominates over the absorption process, the localized surface Plasmon energy can be recovered to free space emission, leading to the enhancement of light emission. Otherwise, light emission will be attenuated due to non-radiative dissipation of localized surface plasmon absorption. | https://en.wikipedia.org/wiki?curid=23097121 |
Jacobi coordinates In the theory of many-particle systems, often are used to simplify the mathematical formulation. These coordinates are particularly common in treating polyatomic molecules and chemical reactions, and in celestial mechanics. An algorithm for generating the for "N" bodies may be based upon binary trees. In words, the algorithm is described as follows: Let "m" and "m" be the masses of two bodies that are replaced by a new body of virtual mass "M" = "m" + "m". The position coordinates x and x are replaced by their relative position r = x − x and by the vector to their center of mass R = ("m" "q" + "m""q")/("m" + "m"). The node in the binary tree corresponding to the virtual body has "m" as its right child and "m" as its left child. The order of children indicates the relative coordinate points from x to x. Repeat the above step for "N" − 1 bodies, that is, the "N" − 2 original bodies plus the new virtual body. For the "N"-body problem the result is: with The vector formula_4 is the center of mass of all the bodies: The result one is left with is thus a system of "N"-1 translationally invariant coordinates formula_5 and a center of mass coordinate formula_6, from iteratively reducing two-body systems within the many-body system. | https://en.wikipedia.org/wiki?curid=23098762 |
Resazurin (7-Hydroxy-3"H"-phenoxazin-3-one 10-oxide) is a phenoxazine dye that is weakly fluorescent, nontoxic, cell-permeable, and redox‐sensitive. has a blue to purple color (at pH > 6.5) and is used in microbiological, cellular, and enzymatic assays because it can be irreversibly reduced to the pink-colored and highly fluorescent resorufin (7-Hydroxy-3"H"-phenoxazin-3-one). At circum-neutral pH, resorufin can be detected by visual observation of its pink color or by fluorimetry, with an excitation maximum at 530-570 nm and an emission maximum at 580-590 nm. When a solution containing resorufin is submitted to reducing conditions (E < -110 mV), almost all resorufin is reversibly reduced to the translucid non-fluorescent dihydroresorufin (sin. hydroresorufin) and the solution becomes translucid (the redox potential of the resorufin/dihydroresorufin pair is -51 mV vs. standard hydrogen electrode at pH 7.0). When the E of this same solution is increased, dihydroresorufin is oxidized back to resorufin, and this reversible reaction can be used to monitor if the redox potential of a culture medium remains at a sufficiently low level for anaerobic organisms. solution has one of the highest values known of Kreft's dichromaticity index. This means that it has a large change in perceived color hue when the thickness or concentration of observed sample increases or decreases. Usually, resazurin is available commercially as the sodium salt | https://en.wikipedia.org/wiki?curid=23103610 |
Resazurin is reduced to resorufin by aerobic respiration of metabolically active cells, and it can be used as an indicator of cell viability. It was first used to quantify bacterial content in milk by Pesch and Simmert in 1929. It can be used to detect the presence of viable cells in mammalian cell cultures. It was introduced commercially initially under Alamar Blue trademark (Trek Diagnostic Systems, Inc), and now also available under other names such as AB assay, Vybrant (Molecular Probes) and UptiBlue (Interchim). based assays show excellent correlation to reference viability assays such as formazan-based assays (MTT/XTT) and tritiated thymidine based techniques. The low toxicity makes it suitable for longer studies, and it has been applied for animal cells, bacteria, and fungi for cell culture assays such as cell counting, cell survival, and cell proliferation.. To take the place of a standard live/dead assay, resazurin also be multiplexed with chemiluminescent assays, such as cytokine assays, caspase assays to measure apoptosis, or reporter assays to measure a gene or a protein expression. The irreversible reaction of resazurin to resorufin is proportional to aerobic respiration. is effectively reduced in mitochondria, making it useful also to assess mitochondrial metabolic activity. Usually, in the presence of NADPH dehydrogenase or NADH dehydrogenase as the enzyme, NADPH or NADH is the reductant that converts resazurin to resorufin | https://en.wikipedia.org/wiki?curid=23103610 |
Resazurin Hence the resazurin/diaphorase/NADPH system can be used to detect NADH, NADPH, or diaphorase level, and any biochemical or enzyme activity that is involved in a biochemical reaction generating NADH or NADPH. can be used to assay L-Glutamate, achieving a sensitivity of 2.0 pmol per well in a 96 well plate. can also be used to measure the aerobic biodegradation of organic matter found in effluents. is used to measure the amount of aerobic respiration in streams Since most aerobic respiration occurs in the stream bed, the conversion of resazurin to resorufin is also a measure of the amount of exchange between the water column and the stream bed. is prepared by acid-catalyzed condensation between resorcinol and 4-nitrosoresorcinol followed by oxidation of the intermediate with manganese(IV) oxide: Treatment of the crude reaction product with excess sodium carbonate yields the sodium salt of resazurin, which is typically the commercial form of the dye. Running the condensation step in alcohols is possible but results in lower yields of the product; in pure water or acetic acid, the reaction does not proceed satisfactorily. 10-acetyl-3,7-dihydroxyphenoxazine (also known as Amplex Red), structurally related to resazurin, reacts with HO in a 1:1 stoichiometry to produce the same by-product resorufin (used in many assays combining for example horseradish peroxidase (HRP), or NADH, NADPH using enzymes) | https://en.wikipedia.org/wiki?curid=23103610 |
Resazurin 7-ethoxyresorufin, is a compound used as the substrate in the measurement of cytochrome P450 (CYP1A1) induction using the ethoxyresorufin-O-deethylase (EROD) assay system in cell culture and environmental samples, produced in response to exposure to aryl hydrocarbons. The compound is catalysed by the enzyme to produce the same fluorescent product, resorufin. 1,3-dichloro-7-hydroxy-9,9-dimethylacridin-2(9"H")-one (DDAO dye), fluorescent dye used for oligonucleotide labeling. | https://en.wikipedia.org/wiki?curid=23103610 |
Primordial nuclide In geochemistry, geophysics and geonuclear physics, primordial nuclides, also known as primordial isotopes, are nuclides found on Earth that have existed in their current form since before Earth was formed. Primordial nuclides were present in the interstellar medium from which the solar system was formed, and were formed in, or after, the Big Bang, by nucleosynthesis in stars and supernovae followed by mass ejection, by cosmic ray spallation, and potentially from other processes. They are the stable nuclides plus the long-lived fraction of radionuclides surviving in the primordial solar nebula through planet accretion until the present. Only 286 such nuclides are known. All of the known 252 stable nuclides, plus another 34 nuclides that have half-lives long enough to have survived from the formation of the Earth, occur as primordial nuclides. These 34 primordial radionuclides represent isotopes of 28 separate elements. Cadmium, tellurium, xenon, neodymium, samarium and uranium each have two primordial radioisotopes (, ; , ; , ; , ; , ; and , ). Because the age of the Earth is (4.6 billion years), the half-life of the given nuclides must be greater than about (100 million years) for practical considerations. For example, for a nuclide with half-life (60 million years), this means 77 half-lives have elapsed, meaning that for each mole () of that nuclide being present at the formation of Earth, only 4 atoms remain today. The four shortest-lived primordial nuclides (i.e | https://en.wikipedia.org/wiki?curid=23105042 |
Primordial nuclide nuclides with shortest half-lives) are , , , and . These are the 4 nuclides with half-lives comparable to, or less than, the estimated age of the universe. (In the case of Th, it has a half life of more than 14 billion years, slightly longer than the age of the universe.) For a complete list of the 34 known primordial radionuclides, including the next 30 with half-lives much "longer" than the age of the universe, see the complete list below. For practical purposes, nuclides with half-lives much longer than the age of the universe may be treated as if they were stable. Th and U have half-lives long enough that their decay is limited over geological time scales; K and U have shorter half-lives and are hence severely depleted, but are still long-lived enough to persist significantly in nature. The next longest-living nuclide after the end of the list given in the table is , with a half-life of . It has been reported to exist in nature as a primordial nuclide, although later studies could not detect it. Likewise, the second-longest-lived non-primordial has a half-life of , about double that of the third-longest-lived non-primordial (). Taking into account that all these nuclides must exist for at least , Pu must survive 57 half-lives (and hence be reduced by a factor of 2 ≈ ), Sm must survive 67 (and be reduced by 2 ≈ ), and Nb must survive 130 (and be reduced by 2 ≈ ) | https://en.wikipedia.org/wiki?curid=23105042 |
Primordial nuclide Considering the likely initial abundances of these nuclides, possibly measurable quantities of Pu and Sm should persist today, while they should not for Nb and all shorter-lived nuclides. Nuclides such as Nb that were present in the primordial solar nebula but have long since decayed away completely are termed extinct radionuclides if they have no other means of being regenerated. Because primordial chemical elements often consist of more than one primordial isotope, there are only 83 distinct primordial chemical elements. Of these, 80 have at least one observationally stable isotope and three additional primordial elements have only radioactive isotopes (bismuth, thorium, and uranium). Some unstable isotopes which occur naturally (such as , , and ) are not primordial, as they must be constantly regenerated. This occurs by cosmic radiation (in the case of cosmogenic nuclides such as and ), or (rarely) by such processes as geonuclear transmutation (neutron capture of uranium in the case of and ). Other examples of common naturally occurring but non-primordial nuclides are isotopes of radon, polonium, and radium, which are all radiogenic nuclide daughters of uranium decay and are found in uranium ores. A similar radiogenic series is derived from the long-lived radioactive primordial nuclide Th. All of such nuclides have shorter half-lives than their parent radioactive primordial nuclides | https://en.wikipedia.org/wiki?curid=23105042 |
Primordial nuclide Some other geogenic nuclides do not occur in the decay chains of Th, U, or U but can still fleetingly occur naturally as products of the spontaneous fission of one of these three long-lived nuclides, such as Sn, which makes up about 10 of all natural tin. There are 252 stable primordial nuclides and 34 radioactive primordial nuclides, but only 80 primordial stable "elements" (1 through 82, i.e. hydrogen through lead, exclusive of 43 and 61, technetium and promethium respectively) and three radioactive primordial "elements" (bismuth, thorium, and uranium). Bismuth's half-life is so long that it is often classed with the 80 primordial stable elements instead, since its radioactivity is not a cause for serious concern. The number of elements is fewer than the number of nuclides, because many of the primordial elements are represented by multiple isotopes. See chemical element for more information. As noted, these number about 252. For a list, see the article list of elements by stability of isotopes. For a complete list noting which of the "stable" 252 nuclides may be in some respect unstable, see list of nuclides and stable nuclide. These questions do not impact the question of whether a nuclide is primordial, since all "nearly stable" nuclides, with half-lives longer than the age of the universe, are also primordial | https://en.wikipedia.org/wiki?curid=23105042 |
Primordial nuclide Although it is estimated that about 34 primordial nuclides are radioactive (list below), it becomes very difficult to determine the exact total number of radioactive primordials, because the total number of stable nuclides is uncertain. There exist many extremely long-lived nuclides whose half-lives are still unknown. For example, it is predicted theoretically that all isotopes of tungsten, including those indicated by even the most modern empirical methods to be stable, must be radioactive and can decay by alpha emission, but this could only be measured experimentally for . Similarly, all four primordial isotopes of lead are expected to decay to mercury, but the predicted half-lives are so long (some exceeding 10 years) that this can hardly be observed in the near future. Nevertheless, the number of nuclides with half-lives so long that they cannot be measured with present instruments—and are considered from this viewpoint to be stable nuclides—is limited. Even when a "stable" nuclide is found to be radioactive, it merely moves from the "stable" to the "unstable" list of primordial nuclides, and the total number of primordial nuclides remains unchanged. These 34 primordial nuclides represent radioisotopes of 28 distinct chemical elements (cadmium, neodymium, samarium, tellurium, uranium, and xenon each have two primordial radioisotopes). The radionuclides are listed in order of stability, with the longest half-life beginning the list | https://en.wikipedia.org/wiki?curid=23105042 |
Primordial nuclide These radionuclides in many cases are so nearly stable that they compete for abundance with stable isotopes of their respective elements. For three chemical elements, indium, tellurium, and rhenium, a very long-lived radioactive primordial nuclide is found in greater abundance than a stable nuclide. The longest-lived radionuclide has a half-life of , which is 160 trillion times the age of the Universe. Only four of these 34 nuclides have half-lives shorter than, or equal to, the age of the universe. Most of the remaining 30 have half-lives much longer. The shortest-lived primordial isotope, U, has a half-life of 704 million years, about one sixth of the age of the Earth and the Solar System. | https://en.wikipedia.org/wiki?curid=23105042 |
Alexander Selligue Alexander François Selligue (1784-1845) was a French engineer. In 1832, he together with David Blum patented an application of shale oil for direct illumination. In 1838, he patented "the employment of mineral oils for lighting". His process of distilling bituminous shales (oil shale) was first described in the "Journal des Connaissances Usuelles" in 1834. This process for the oil shale retorting was first used in Autun, France, in 1838. This is considered the start of the modern oil shale industry. | https://en.wikipedia.org/wiki?curid=23106631 |
Ductile iron pipe is pipe made of ductile cast iron commonly used for potable water transmission and distribution. This type of pipe is a direct development of earlier cast iron pipe, which it has superseded. The ductile iron used to manufacture the pipe is characterized by the spheroidal or nodular nature of the graphite within the iron. Typically, the pipe is manufactured using centrifugal casting in metal or resin lined moulds. Protective internal linings and external coatings are often applied to ductile iron pipes to inhibit corrosion: the standard internal lining is cement mortar and standard external coatings include bonded zinc, asphalt or water-based paint. In highly corrosive environments loose polyethylene sleeving (LPS) to encase the pipe may also be used. Life expectancy of unprotected ductile iron pipes depends on the corrosiveness of soil present and tends to be shorter where soil is highly corrosive. However, a lifespan in excess of 100 years has been estimated for ductile iron pipelines installed using "evolved laying practices", including use of properly installed LPS (polyethylene encasement). Studies of ductile iron pipe's environmental impact have differing findings regarding emissions and energy consumed. manufactured in the United States has been certified as a sustainable product by the Institute for Market Transformation to Sustainability. is sized according to a dimensionless term known as the Pipe Size or Nominal Diameter (known by its French abbreviation, DN) | https://en.wikipedia.org/wiki?curid=23107410 |
Ductile iron pipe This is roughly equivalent to the pipe's internal diameter in inches or millimeters. However, it is the external diameter of the pipe that is kept constant between changes in wall thickness, in order to maintain compatibility in joints and fittings. Consequently, the internal diameter varies, sometimes significantly, from its nominal size. Nominal pipe sizes vary from 3 inches up to 64 inches, in increments of at least 1 inch, in the United States. Pipe dimensions are standardised to the mutually incompatible AWWA C151 (U.S. Customary Units) in the United States, ISO 2531 / EN 545/598 (metric) in Europe, and AS/NZS 2280 (metric) in Australia and New Zealand. Although both metric, European and Australian are not compatible and pipes of identical nominal diameters have quite different dimensions. Pipe dimensions according to the American AWWA C-151 European pipe is standardized to ISO 2531 and its descendent specifications EN 545 (potable water) and EN 598 (sewage). European pipes are sized to approximately match the internal diameter of the pipe, following internal lining, to the nominal diameter. ISO 2531 maintains dimensional compatibility with older German cast iron pipes. Older British pipes, however, which used the incompatible imperial standard, BS 78, require adapter pieces when connecting to newly installed pipe | https://en.wikipedia.org/wiki?curid=23107410 |
Ductile iron pipe Coincidentally, the British harmonization with European pipe standards occurred at approximately the same time as its transition to ductile iron, so almost all cast iron pipe is imperial and all ductile pipe is metric | https://en.wikipedia.org/wiki?curid=23107410 |
Ductile iron pipe Other European Standards give specifications on more dedicated products: EN 15655:2009 - Ductile iron pipes, fittings and accessories - Internal polyurethane lining for pipes and fittings - Requirements and test methods EN 877:1999/A1:2006 - Cast iron pipes and fittings, their joints and accessories for the evacuation of water from buildings - Requirements, test methods and quality assurance CEN/TR 15545:2006 - Guide to the use of EN 545 CEN/TR 16017:2010 - Guide to the use of EN 598 EN 877:1999 - Cast iron pipes and fittings, their joints and accessories for the evacuation of water from buildings - Requirements, test methods and quality assurance EN 877:1999/A1:2006/AC:2008 - Cast iron pipes and fittings, their joints and accessories for the evacuation of water from buildings - Requirements, test methods and quality assurance EN 598:2007+A1:2009 - Ductile iron pipes, fittings, accessories and their joints for sewerage applications - Requirements and test methods EN 12842:2012 - Ductile iron fittings for PVC-U or PE piping systems - Requirements and test methods CEN/TR 16470:2013 - Environmental aspects of ductile iron pipe systems for water and sewerage applications EN 14628:2005 - Ductile iron pipes, fittings and accessories - External polyethylene coating for pipes - Requirements and test methods EN 15189:2006 - Ductile iron pipes, fittings and accessories - External polyurethane coating for pipes - Requirements and test methods EN 14901:2014 - Ductile iron pipes, fittings and accessories - Epoxy coating (he | https://en.wikipedia.org/wiki?curid=23107410 |
Ductile iron pipe vy duty) of ductile iron fittings and accessories - Requirements and test methods EN 969:2009 - Ductile iron pipes, fittings, accessories and their joints for gas pipelines - Requirements and test methods EN 15542:2008 - Ductile iron pipes, fittings and accessories - External cement mortar coating for pipes - Requirements and test methods EN 545:2010 - Ductile iron pipes, fittings, accessories and their joints for water pipelines - Requirements and test methods EN 14525:2004 - Ductile iron wide tolerance couplings and flange adaptors for use with pipes of different materials: ductile iron, Grey iron, Steel, PVC-U PE, Fibre-cement Australian and New Zealand pipes are sized to an independent specification, AS/NZS 2280, that is not compatible with European pipes even though the same nomenclature is used. Australia adopted at an early point the imperial British cast iron pipe standard BS 78, and when this was retired on British adoption of ISO 2531, rather than similarly harmonizing with Europe, Australia opted for a 'soft' conversion from imperial units to metric, published as AS/NSZ 2280, with the physical outer diameters remaining unchanged, allowing continuity of manufacture and backwards compatibility. Therefore, the inner diameters of lined pipe differ widely from the nominal diameter, and hydraulic calculations require some knowledge of the pipe standard. Individual lengths of ductile iron pipe are joined either by flanges, couplings, or some form of spigot and socket arrangement | https://en.wikipedia.org/wiki?curid=23107410 |
Ductile iron pipe Flanges are flat rings around the end of pipes which mate with an equivalent flange from another pipe, the two being held together by bolts usually passed through holes drilled through the flanges. A deformable gasket, usually elastomeric, placed between raised faces on the mating flanges provides the seal. Flanges are designed to a large number of specifications that differ because of dimensional variations in pipes sizes and pressure requirements, and because of independent standards development. In the U.S. flanges are either threaded or welded onto the pipe. In the European market flanges are usually welded onto the pipe. In the US flanges are available in a standard 125 lb. bolt pattern as well as a 250 lb (and heavier) bolt pattern (steel bolt pattern). Both are usually rated at . A flanged joint is rigid and can bear both tension and compression as well as a limited degree of shear and bending. It also can be dismantled after assembly. Due to the rigid nature of the joint and the risk of excessive bending moment being imposed, it is advised that flanged pipework is not buried. Current flange standards used in the water industry are ANSI B16.1 in the USA, EN 1092 in Europe, and AS/NZS 4087 in Australia and New Zealand. Spigot and sockets involve a normal pipe end, the spigot, being inserted into the socket or bell of another pipe or fitting with a seal being made between the two within the socket | https://en.wikipedia.org/wiki?curid=23107410 |
Ductile iron pipe Normal spigot and socket joints do not allow direct metal to metal contact with all forces being transmitted through the elastomeric seal. They can consequently flex and allow some degree of rotation, allowing pipes to shift and relieve stresses imposed by soil movement. The corollary is that unrestrained spigot and socket joints transmit essentially no compression or tension along the axis of the pipe and little shear. Any bends, tees or valves therefore require either a restrained joint or, more commonly, thrust blocks, which transmit the forces as compression into the surrounding soil. A large number of different socket and seals exist. The most modern is the 'push-joint' or 'slip-joint', whereby the socket and rubber seal is designed to allow the pipe spigot to be, after lubrication, simply pushed into the socket. Push joints remain proprietary designs. Also available are locking gasket systems. These locking gasket systems allow the pipe to be pushed together but do not allow the joint to come apart without using a special tool or torch on the gasket. The earliest spigot and socket cast iron pipes were jointed by filling the socket with a mixture of water, sand, iron filings and sal-ammoniac (ammonium chloride.) A gasket ring was pushed into the socket round the spigot to contain the mixture which was pounded into the socket with a caulking tool and then pointed off. This took several weeks to set and produced a completely rigid joint | https://en.wikipedia.org/wiki?curid=23107410 |
Ductile iron pipe Such pipe systems are often to be seen in nineteenth century churches in the heating system. In the late 1950s, ductile iron pipe was introduced to the marketplace, featuring higher strength and similar corrosion resistance compared to cast iron. According to a 2004 study, an expected lifespan of 100 years is likely for ductile iron pipe, based on test results, field inspections and in-service operations over 50 years. In 2012, the American Water Works Association reported that ductile iron pipes in benign soil or installed in more aggressive soils using "evolved laying practices" had an estimated life up to 110 years, based on a nationwide analysis of water pipes in the U.S. Like most ferrous materials, ductile iron is susceptible to corrosion, therefore its useful life depends on the impact of corrosion. Corrosion can occur in two ways in ductile iron pipes: graphitization, the leaching away of iron content through corrosion leading to a generally weakened pipe structure, and corrosion pitting, which is a more localized effect also causing weakening of the pipe structure. Over the last 100 years, the average thickness of iron pipes has decreased due to increased metal strength, through metallurgical advancements as well as improved casting technique. The potential for corrosion, leading to pipe failure, is significantly impacted by the corrosivity of soil. Unprotected pipes in highly corrosive soil tend to have shorter lifespans | https://en.wikipedia.org/wiki?curid=23107410 |
Ductile iron pipe The lifespan of ductile iron pipe installed in an aggressive environment without appropriate protection may be between 21 and 40 years. The introduction of corrosion mitigation methods for ductile pipe, including the use of polyethylene sleeving, can reduce corrosion by controlling the effect of corrosive soil on piping. In the United States, the American National Standards Institute and American Water Works Association have standardized the use of polyethylene sleeving to protect ductile iron pipe from the effects of corrosion.<ref name="ANSI/AWWA 105"></ref> A 2003 report by researchers from the National Research Council of Canada noted that "both good and poor performances" of polyethylene sleeving had been reported. However, a study in the Ductile Iron Pipe Research Association's Florida test site found that, compared with uncoated pipes exposed to a corrosive environment, pipes encased in loose polyethylene sleeving were "in excellent condition". Based on a 2005 meta analysis of 1,379 pipe specimens, loose polyethylene sleeving was found to be highly effective at mitigating corrosion. The only environment for which the analysis found the polyethylene sleeving did not provide effective corrosion control was for "uniquely severe" environments, a classification of a rare but extremely corrosive environment. The analysis found that a lifespan of 37 years could be expected in these "uniquely severe" environments | https://en.wikipedia.org/wiki?curid=23107410 |
Ductile iron pipe Pipes manufactured under International Organization for Standardization (ISO) standards are typically coated with zinc, to provide protection against corrosion. In instances of more aggressive soils, polyethylene sleeving is installed over the zinc coated pipe to provide added protection.<ref name="ISO/FDIS 2531"></ref> Cathodic protection may also be used to prevent corrosion and tends to be advocated by corrosion engineers for pipes in corrosive soils as an addition to external dielectric coatings. Engineers and water authorities in the United States are divided on the use of different coatings or cathodic protection. Mixed results have been found for all methods of protection. However, this may be due to the impact of variations in local soil corrosiveness and temperature or by damage occurring during installation, which can impact effectiveness of protective coatings. is somewhat resistant to internal corrosion in potable water and less aggressive forms of sewage. However, even where pipe material loss and consequently pipe wall reduction is slow, the deposition of corrosion products on the internal pipe wall can reduce the effective internal diameter. A variety of linings are available to reduce or eliminate corrosion, including cement mortar, polyurethane and polyethylene. Of these, cement mortar lining is by far the most common. Polyurethane is an option offered as an internal lining for ductile iron pipes in lieu of cement mortar | https://en.wikipedia.org/wiki?curid=23107410 |
Ductile iron pipe However, as PUR provides only passive protection it becomes vitally important that the coating is not damaged during handling and installation. Manufacturers will specify strict handling, transport and installation procedures to ensure PUR coatings are protected. If pipes are deformed Polyurethane's elasticity, does in some situations allow the coating to remain intact. Corrosion Experts Polyurethane coatings were first used in 1972. In comparison with other coatings, the internal polyurethane lining exhibits a high resistance to various different media such as drinking water, wastewater, de-mineralised water, industrial water and gas, as well as to aggressive solutions such as sulphuric acid. Polyurethane is a thermosetting plastic with no solvents, with a three-dimensionally linked molecular structure giving it mechanical stability. The polyurethane lining used for internal coating has the following standard properties is standardised by EN 15655:2009 (Ductile iron pipes, fittings and accessories - Internal polyurethane lining for pipes and fittings - Requirements and test methods). The predominant form of lining for water applications is cement mortar centrifugally applied during manufacturing. The cement mortar comprises a mixture of cement and sand to a ratio of between 1:2 and 1:3.5. For potable water, portland cement is used; for sewage it is common to use sulfate resisting or high alumina cement. Cement mortar linings have been found to dramatically reduce internal corrosion | https://en.wikipedia.org/wiki?curid=23107410 |
Ductile iron pipe A DIPRA survey has demonstrated that the Hazen-Williams factor of cement lining remains between 130 and 151 with only slight reduction with age. Unprotected ductile iron, similarly to cast iron, is intrinsically resistant to corrosion in most, although not all, soils. Nonetheless, because of frequent lack of information on soil aggressiveness and to extend the installed life of buried pipe, ductile iron pipe is commonly protected by one or more external coatings. In the U.S. and Australia, loose polyethylene sleeving is preferred. In Europe, standards recommend a more sophisticated system of directly bonded zinc coatings overlaid by a finishing layer be used in conjunction with polyethylene sleeving. Loose Polyethylene sleeving was first developed by CIPRA (since 1979, DIPRA) in the U.S. in 1951 for use in highly corrosive soil. It was employed more widely in the U.S. in the late 1950s and first employed in the UK in 1965 and Australia in the mid-1960s. Loose Polyethylene Sleeving (LPS) remains as one of the most cost effective corrosion protection methods available today with a proven track record for reliability and effectiveness. LPS comprises a loose sleeve of polyethylene that completely wraps the pipe, including the bells of any joints. The sleeving inhibits corrosion by a number of mechanisms. It physically separates the pipe from soil particles, preventing direct galvanic corrosion | https://en.wikipedia.org/wiki?curid=23107410 |
Ductile iron pipe By providing an impermeable barrier to ground water, the sleeve also inhibits the diffusion of oxygen to the ductile iron surface and limits the availability of electrolytes that would accelerate corrosion. It provides a homogeneous environment along the pipe surface so that corrosion occurs evenly over the pipe. The sleeve also restricts the availability of nutrients which could support sulfate-reducing bacteria, inhibiting microbially induced corrosion. LPS is not designed to be completely water-tight but rather to greatly restrict the movement of water to and from the pipe surface. Water present beneath the sleeve and in contact with the pipe surface is rapidly deoxygenated and depleted of nutrients and forms a stable environment in which limited further corrosion occurs. An improperly installed sleeve that continues to allow the free flow of ground water is not effective in inhibiting corrosion. Polyethylene sleeves are available in a number of materials. The most common contemporary compositions are linear low-density polyethylene film which requires an 8 mil or 200 μm thickness and high-density cross-laminated polyethylene film which requires only a 4 mil or 100 μm thickness. The latter may or may not be reinforced with a scrim layer. Polyethylene sleeving does have limitations. In European practice, its use in the absence of additional zinc and epoxy protective coatings is discouraged where natural soil resistivity is below 750 ohm/cm | https://en.wikipedia.org/wiki?curid=23107410 |
Ductile iron pipe Where resistivity is below 1500 ohm/cm and where the pipe is installed at or below the water table, where there are additional artificial soil contaminants and particularly stray currents again it is recommended for use in addition to zinc and epoxy coating. Because of the vulnerability of polyethylene to UV degradation, sleeving, or sleeved pipe should not be stored in sunlight, although carbon pigments included in the sleeving can provide some limited protection. Polyethylene sleeving is standardised according to ISO 8180 internationally, AWWA C105 in the U.S., BS 6076 in the UK and AS 3680 and AS 3681 in Australia. In Europe and Australia, ductile iron pipe is typically manufactured with a zinc coating overlaid by either a bituminous, polymeric, or epoxy finishing layer. EN 545/598 mandates a minimum zinc content of 200 g/m (at 99.99% purity) and a minimum average finishing layer thickness of 70 μm (with local minimum of 50 μm). AS/NZS 2280 mandates a minimum zinc content of 200 g/m (with a local minimum of 180 g/m at 99.99% purity) and a minimum average finishing layer thickness of 80 μm. No current AWWA standards are available for bonded coatings (zinc, coal tar epoxy, tape-wrap systems as seen on steel pipe) for ductile iron pipe, DIPRA does not endorse bonded coatings, and AWWA M41 generally views them unfavourably, recommending they be used only in conjunction with cathodic protection. Zinc coatings are generally not employed in the U.S | https://en.wikipedia.org/wiki?curid=23107410 |
Ductile iron pipe In order to protect ductile iron pipe prior to installation, pipe is instead supplied with a temporary 1 mil or 25 μm thick bituminous coating. This coating is not intended to provide protection once the pipe is installed. Water based pipe coatings, are an environmentally friendly coating that is applied to the inner & outer diameter of ductile iron pipe. They protect against corrosion from the outside and inside, and also protect the product from contamination. The coating is an emulsion manufactured using asphaltene and water primarily, with other raw materials according to the manufacturer's specifications. They came in use in the early 1990s, replacing coatings based on dangerous and environmental harmful solvents, such as benzenes, toluenes, hexanes and other volatile organic compounds. In the United States, the Ductile Iron Pipe Research Association represents manufacturers of ductile iron pipe. The association provides research on and promotes the use of ductile iron piping in utility projects (water and sewer), focusing on its strength, recyclability and life cycle cost compared with alternative products such as PVC. The U.S. industry is also represented by the National Association of Pipe Fabricators. Outside of the U.S., the ductile iron pipe industry is supported by associations including the European Association for Ductile Iron Pipe Systems. Following the financial crisis of 2008, the pipe industry as a whole, experienced a decrease in sales in the U.S | https://en.wikipedia.org/wiki?curid=23107410 |
Ductile iron pipe due to municipalities deferring replacement of water mains and reduction in new home construction. According to a report published by The Freedonia Group in 2011, economic recovery from the 2008 crisis is likely to expand ductile iron's market share in the large diameter pipe market. in the developed world is normally manufactured exclusively from recycled material including scrap steel and recycled iron. The pipe can be recycled after use. In terms of environmental impact, several studies have compared ductile iron pipe's impact on the environment with that of other pipe materials. A study by Jeschar et al. in 1995 compared the energy use and carbon dioxide (CO2) emissions produced in manufacturing pipes of various materials including concrete, ductile iron, cast iron and PVC, based on pipes with nominal diameter of 100 mm to 500 mm. The energy consumed in manufacturing ductile iron pipe was 19.55 MJ per kg and volume of emissions released during manufacture was 1.430 kg CO2 per kg, compared to 68.30 MJ per kg of energy and 4.860 kg CO2 per kg emissions for PVC pipes, and 1.24 MJ per kg and 0.148 kg CO2 per kg for concrete pipes of the same diameter. Another study the following year, by the Forschungsinstitut für Chemie und Umwelt, had similar findings. However, it also took the lifetime of pipes into account. This study found improved environmental performance for ductile iron pipe in terms of energy consumed and emissions produced during manufacture due to its longer life span | https://en.wikipedia.org/wiki?curid=23107410 |
Ductile iron pipe A more recent study, published August 2012, by Du et al., carried out a life cycle analysis on six types materials used for water and waste water pipes, including ductile iron, PVC, high-density polyethylene (HDPE) and concrete. They found that at diameters of ≤ 24 in, ductile iron pipe had the highest "global warming potential" based on emissions from manufacturing, transportation and installation. At larger diameters, ≥ 30 in, ductile iron pipe had a lower "global warming potential", while PVC had the highest. According to a 2008 study by Koo et al., ductile iron pipe had the lowest impact on natural resource depletion, compared to HDPE pipe and PVC pipe. In November 2012, ductile iron pipe manufactured in the United States received certification as a sustainable product from the Institute for Market Transformation to Sustainability. | https://en.wikipedia.org/wiki?curid=23107410 |
Bifunctional In organic chemistry, when a single organic molecule has two different functional groups, it is called a bifunctional molecule . A bifunctional molecule has the properties of two different types of functional groups, such as an alcohol (-OH), amide (CONH), aldehyde (-CHO), nitrile (-CN) or carboxylic acid (-COOH). Many bifunctional molecules are used to produce medicines and catalysts, while others are used in condensation polymerization like polyester and polyamide. In organic molecules, functional groups are atoms or molecules that are responsible for the characteristic properties of that molecule, with the exceptions of double and triple bonds, which are also functional groups. | https://en.wikipedia.org/wiki?curid=23118227 |
Physic garden A physic garden is a type of herb garden with medicinal plants. Botanical gardens developed from them. Modern botanical gardens were preceded by medieval physic gardens that originated at the time of Emperor Charlemagne. Gardens of this time included various sections including one for medicinal plants called the or . Pope Nicholas V set aside part of the Vatican grounds in 1447 for a garden of medicinal plants that were used to promote the teaching of botany, and this was a forerunner to the academic botanical gardens at Padua and Pisa established in the 1540s. Certainly the founding of many early botanic gardens was instigated by members of the medical profession. The naturalist William Turner established physic gardens at Cologne, Wells, and Kew; he also wrote to Lord Burleigh recommending that a physic garden be established at Cambridge University with himself at its head. The 1597 "Herball, or Generall Historie of Plantes" by herbalist John Gerard was said to be the "catalogue raisonné" of physic gardens, both public and private, which were instituted throughout Europe. It listed 1,030 plants found in his physic garden at Holborn, and was the first such catalogue printed. The garden in Oxford, founded by Henry Danvers, 1st Earl of Danby, with Jacob Bobart the Elder as Superintendent, dates to 1632. Begun in Westminster and later moved to Chelsea, the Apothecaries founded the Chelsea Physic Garden in 1673, of which Philip Miller, author of "The Gardeners Dictionary", was the most notable Director | https://en.wikipedia.org/wiki?curid=23122539 |
Physic garden By 1676, the position of "Keeper of the Physic Garden" was held by the Professor of Botany at the University of Edinburgh. Some of the earliest physic gardens included: | https://en.wikipedia.org/wiki?curid=23122539 |
Professor Pyg is a supervillain who appears in comic books published by DC Comics. Pyg was created by Grant Morrison and Andy Kubert, and debuted as a corpse in the alternate reality story "Batman" #666 (July 2007) before being introduced as a recurring character in the mainstream DC Universe two years later in "Batman and Robin" #1 (June 2009). was re-introduced following DC's The New 52 comics relaunch in 2011, appearing throughout the continuity and the subsequent DC Rebirth relaunch that began in 2016. The character's in-world real name is Lazlo Valentin, a scientist who suffered a schizophrenic breakdown that led him to become a supervillain who wears a pig mask. Morrison intended Pyg to seem disconnected from reality, believing him to be one of the "weirdest, most insane" characters in Batman comic books. Pyg is an obsessive perfectionist who sees human beings as broken individuals; he commonly kidnaps people and uses surgery and chemicals to permanently change them into mind-controlled automatons known as Dollotrons, and sometimes into human–animal hybrids instead. Morrison took the name "Professor Pig" from the song "Pygmalism" by Momus and Kahimi Karie; the name "Pyg" is also being shorthand for "Pygmalion", referring both to the mythical sculptor who fell in love with his own creation and the 1913 stage play, both of which serving as parallels for Lazlo Valentin and his love for his Dollotron creations. The character's origin story alludes to real-life animal testing carried out in the mid-twentieth century | https://en.wikipedia.org/wiki?curid=23122647 |
Professor Pyg He has a makeshift mother made of nails and boards, from which he associates auditory hallucinations commanding him to constantly improve his surgical work. Pyg began making substantial appearances in other media in 2013 with the animated series "Beware the Batman" and has since appeared in video games, television, and film. The character has been received by entertainment journalists as a strange and disturbing addition to Batman's list of enemies. Writer Grant Morrison stated a new Batman villain must have "a gimmick. Creepiness. A distinctive look ... You kind of evolve those themes into new forms". and his mind-controlled Dollotrons first appeared as crucified corpses in the 2007 story "Batman in Bethlehem" by Morrison and artist Andy Kubert, published in "Batman" #666 by DC Comics. The story is set in a future in which Bruce Wayne's son Damian helms the Batman vigilante persona. Although Morrison had developed a detailed backstory for Pyg, he was unsure the character would be used again. The name "Professor Pyg" originates from the song "Pygmalism" written by Momus for Kahimi Karie, "Pyg" being shorthand for "Pygmalion". The first storyline of the "Batman and Robin" series that ran from June to August 2009 saw the character's debut in the main DC Universe. The storyline, titled "Batman Reborn", focuses on Dick Grayson, who takes over the Batman mantle after Bruce Wayne is pronounced dead and partners with a younger Damian Wayne, who is now Robin | https://en.wikipedia.org/wiki?curid=23122647 |
Professor Pyg In the story, Lazlo Valentin was an "extreme" circus mob boss until something turned him into Professor Pyg, leading him to begin funding his scientific experiments by selling narcotics to the criminal underworld. Batman and Robin learn from interrogating his underlings, members of a gang called the Circus of Strange, that Pyg is planning to spread a mind-control virus across Gotham City to hold the population for ransom. Pyg is stopped and placed in Blackgate Penitentiary but medics cannot save his infected minions known as Dollotrons. "Batman and Robin" #13, published in July 2010, marked Professor Pyg's return as part of the "Batman and Robin Must Die" storyline. Pyg had been working for the supervillain Doctor Simon Hurt during the events of "Batman Reborn" and a virus has contaminated the population without Batman (Dick Grayson) or the public realizing it. Grayson discovers this as the virus becomes active. He is swarmed by a mob of infected people in the city streets. Pyg uses the virus as a diversion to escape Blackgate Penitentiary. The following issue focuses on Professor Pyg's business relationship with Doctor Hurt, who says he has "challenged [Pyg] to outline his personal vision for Gotham". As the virus spreads across the city, riots occur under Hurt's command. The story concludes with Bruce Wayne returning to stop Doctor Hurt after being trapped in the timestream. The infected civilians are quarantined and is captured and transferred to Arkham Asylum | https://en.wikipedia.org/wiki?curid=23122647 |
Professor Pyg The character's backstory, including his origin, is significantly expanded upon in "Batman Incorporated: Leviathan Strikes!" (December 2011). Lazlo Valentin was a scientist working for a corrupt United Nations agency known as Spyral and was driven insane by a product that he was developing, which mimics some effects of Alzheimer's disease. Lazlo develops paranoid schizophrenia, leading to drug abuse and self-inflicted surgeries that turn him into Professor Pyg. Lazlo fathered a son named Janosz Valentin, who serves the criminal organization Leviathan and claimed his father taught him to be immune to pain. In September 2011, DC Comics rebooted their line of comic books under the New 52 banner, establishing a new continuity while keeping landmark stories intact. This timeline's iteration of Professor Pyg, still Lazlo Valentin, was introduced in "Batman" #1 (September 2011) among other established Batman villains during an escape riot at Arkham Asylum, which was thwarted by Batman (Wayne) and Nightwing (Grayson). He continued to make cameo appearances as an Arkham Asylum inmate in later comics. In the storyline "Forever Evil", the inmates of Arkham Asylum and Blackgate Penitentiary battle for control of Gotham. Pyg and his Dollotrons briefly gain control over a district of the city but are usurped by Bane. He is later forced by Scarecrow to ingest the steroid Venom to combat the usurper | https://en.wikipedia.org/wiki?curid=23122647 |
Professor Pyg In October 2013, a prequel to "Batman in Bethlehem" titled "Damian: Son of Batman", in which an older Damian Wayne succeeds his father as Batman, was written by Andy Kubert under the New 52 imprint. Having plotted the mini-series in 2008, Kubert wanted to return to that timeline, saying, "I had always wanted to write. In talking with editor Mike Marts, he suggested I come up with a mini-series I would like to write and draw. I really loved that Batman and the whole world that Grant [Morrison] dreamed up. So I thought it would be fun to do a story of how Damian actually becomes that #666 Batman." An aging Pyg appears in the second issue and his henchmen in the third. Batman (Damian) attempts to stop him from experimenting on kidnapped children but Pyg's Dollotrons expel Batman from the area. Pyg is never caught. The character plays a larger role in the first volume of the weekly series "Batman Eternal", which ran from April to August 2014, beginning with a brief confrontation with Batman in the first issue. Carmine Falcone attempts to take over Gotham City's criminal underworld, initiating a gang war with Penguin. To provide a distraction, Falcone frames Batman for the destruction of Professor Pyg's laboratory. Angry his work has been destroyed, Pyg sends his remaining Dollotrons to assault Batman, who persuades Pyg that Falcone was responsible. Pyg retaliates by destroying the laboratory of one of Falcone's paid scientists | https://en.wikipedia.org/wiki?curid=23122647 |
Professor Pyg He later turns several people into human–animal hybrids, whom he labels his "farm hands", and finds Falcone. After the farm hands kill Falcone's guards, Pyg straps Falcone to a table with the intention of operating on him but Batman intervenes. He is arrested and sent to Arkham Asylum under the supervision of Dr. Achilles Milo. In "Convergence", the New 52 crosses over with the previous iteration of the DC Universe, during which Pyg's pre-New 52 counterpart is killed. Pyg is also featured in a chapter of the anthology digital comic series "Sensation Comics, featuring Wonder Woman". During "Robin War", a crossover between several Robin-related publications published from December 2015 to January 2016, Pyg uses an abandoned theatre for his criminal activities while working for the supervillain Brother Blood. Pyg escaped a confrontation with the Teen Titans. Professor Pyg, voiced by Brian George, became a recurring villain in the 2013 animated series "Beware the Batman", which was intended to focus on lesser-known members of Batman's rogues' gallery to set it apart from previous "Batman" television shows. He appears alongside Mister Toad (Udo Kier), a humanoid toad, as eco-terrorists who hunt people for what they deem to be crimes against the animal kingdom. Pyg is still portrayed as a surgeon, transforming his victims into human–animal hybrids. The character later appeared in a side quest of the 2015 video game "", in which he is voiced by Dwight Schultz | https://en.wikipedia.org/wiki?curid=23122647 |
Professor Pyg Pyg is described as "a gifted scientist who suffered a schizophrenic break" that caused him to develop his persona. In the game, Pyg uses his Circus of Strange business as a front for abducting people to turn into Dollotrons. After leaving behind a trail of corpses of failed experiments, Pyg is investigated and apprehended in a confrontation with Batman, the player character. Pyg also made minor appearances in "" and "Injustice 2". Lazlo Valentin played by Michael Cerveris makes his live-action debut in the fourth season of the television series "Gotham". The character is introduced under his alias as a vigilante who slaughters corrupt policemen and dresses their corpses with pigs' heads. Executive producer Bryan Wynbrandt described him as the "big villain" of the first half of the season. The character's "modus operandi" later expands; he targets the wealthy, who he claims "fed on the poor of Gotham". Police captain James Gordon learns "Professor Pyg" is a persona used by Valentin, a contract murderer who impersonates serial killers. He is hired by crime figure Sofia Falcone in a conspiracy to turn the corrupt police against kingpin Oswald Cobblepot and usurp his criminal empire. Falcone kills Valentin to keep the conspiracy quiet. In May 2016, DC Comics again relaunched their entire line of comic books under the DC Rebirth brand, restoring elements of the DC Universe that were erased under the New 52 while maintaining the continuity | https://en.wikipedia.org/wiki?curid=23122647 |
Professor Pyg Pyg re-appears in 2017's "Nightwing" #18, operating in Paris and creating Dollotron versions of Grayson and Damian Wayne, known as Deathwing and Robintron. Grayson and Wayne overcome Pyg, who tells them he created Deathwing and Robintron for Simon Hurt. He later appears in "Harley Quinn" #43–44 and "Batgirl and the Birds of Prey". He appears again in "Batwoman" #11, in which Batwoman saves her ally Julia Pennyworth from Pyg after Alice leaks her secret identity to him. is among the villains who feature in the intercompany crossover "The Shadow/Batman", in which Batman and The Shadow team up to combat a conspiracy. Pyg makes his film debut voiced by James Urbaniak in the 2018 animated movie "", in which he is depicted as an underground surgeon-for-hire for supervillains. In the limited series "Doomsday Clock", a sequel to the seminal 1986 "Watchmen", Pyg is among the supervillains who attend an underground meeting held by Riddler. In a story in DC's 2018 Halloween anthology "Cursed Comics Cavalcade", Damian Wayne teams up with the zombie Solomon Grundy against Professor Pyg, after he kidnaps a group of children. In January 2019, the "Mister Miracle" creative team Tom King and Mitch Geralds reunited for "Batman" #62, which was promoted as a "special issue". Pyg holds Batman captive, as he recalls the mythical Pygmalion and considers how he psychologically mirrors Pyg. is usually characterized in comic books as someone who is suffering from severe mental illness | https://en.wikipedia.org/wiki?curid=23122647 |
Professor Pyg Co-creator Grant Morrison envisioned him as "one of the weirdest, most insane characters that's ever been in Batman [comics]" and said, "we hear a lot about Batman facing crazy villains but we tried to make this guy seem genuinely disturbed and disconnected ... isn't from another world; he's from here, but he's very, very sick". Taking inspiration from the works of David Lynch, Morrison wanted the visuals in "Batman Reborn", illustrated by Frank Quitely, to feel like a real world crossing over with a world of schizophrenia, paranoia, and the use of narcotics. He stated when Batman and Robin are facing Pyg and his Dollotrons, they are dealing with "the eerie, creepy, mentally-ill dark corners of life". The character uses drugs, lobotomy, and doll masks permanently molded onto people's faces to turn them into genderless Dollotrons, which he believes are perfected human beings. The name Pyg is a shortening of "Pygmalion", George Bernard Shaw's play that was adapted into the musical "My Fair Lady" starring Rex Harrison, which tells the story of a professor's attempt to convert a street urchin into an educated, high-society woman. According to Morrison, "Movie enthusiasts will know that Rex Harrison also played Doctor Doolittle, who by strange coincidence was famed for teaching barnyard animals to speak proper, so our mixes all these characteristics and influences together to create a monster who wants to make everything and everyone 'perfect,' as he sees it" | https://en.wikipedia.org/wiki?curid=23122647 |
Professor Pyg On the DC Comics website, journalist Meg Downey notes parallels between Professor Pyg's view of his Dollotrons and the Greek mythological figure Pygmalion, who carved a statue of a woman out of ivory that was so realistic and beautiful he fell in love with his creation. Morrison referred to the character's experiments to force biology to conform to his will as an "attempt to dominate and redefine the feminine principle", comparing it to the wire mother experiments performed by psychologist Harry Harlow on infant monkeys and to the proto-mother mythologies of Mesopotamia and ancient Babylon: "The shattered mind of Lazlo Valentin has mashed all of these connections into a frightening personal 'mythos', constructed to justify his deranged activities as Professor Pyg". Morrison also said Pyg's deranged rants in "Batman and Robin Must Die" allude to animal experimentation carried out in the US in the mid-twentieth century, including Harlow and John B. Calhoun's Rockville barn rat population research, which collectively influenced the character's origin story. In the comics, Pyg has a makeshift mother constructed from boards and nails from which auditory hallucinations continuously compel him to improve his work. In "Batman" #62, Bruce Wayne compares Pyg's love for his work to his own fixation with vigilantism, having built up his ideals and philosophies since he witnessed his parents being murdered as a boy | https://en.wikipedia.org/wiki?curid=23122647 |
Professor Pyg Pyg was adapted differently from the comics in the television series "Beware the Batman"; developer Glen Murakami said, "it's not like we're trying to change it, but we only have 22 minutes to tell that story. The theme that we went in with Pyg and Toad was kind of "Wind in the Willows", but they also became like a twisted [Sherlock] Holmes and Watson. It felt like it flowed, it felt like it had a theme. That seemed more important for that to track rather than all the backstory." Chris Sims of the journalism website "ComicsAlliance" said the changes are "about as far from melting people's faces, stripping in front of a wire mother and dosing Gotham City with a psychotropic drug as you're likely to get". According to "Comic Book Resources" writer Kieran Shiach, the "Arkham Knight" iteration is a very accurate facsimile of the original comic book portrayal, the major difference being the character's new enthusiasm for opera music. Pyg's in-game attributes label him a perfectionist and an amateur opera vocalist. Before his confrontation with Batman, during which Pyg describes his surgical operations as "fixing" his victims who are unique and broken, Batman is warned by Alfred Pennyworth that Pyg is "unhinged, even by Gotham's standards". After Pyg's capture, he claims his mutilated victims are works of art, and while in a police lockup, he expresses concern for how they are being treated. In the television series "Gotham", Lazlo Valentin is portrayed as a contract killer who impersonates other serial killers | https://en.wikipedia.org/wiki?curid=23122647 |
Professor Pyg He creates an elaborate persona of a murderer under the alias to aid Sofia Falcone's rise to power in Gotham City's criminal underworld. Actor Michael Cerveris said of the faux persona, "is a brilliant and chameleon-like person who has a highly developed sense of what's right and wrong—it just might not be a sense of right and wrong that corresponds with everybody else's". Executive producer John Stephens said the character was chosen for the show because "He hits that sweet spot of being grotesque and terrifying, but also a little bit in that fairy-tale-esque world". Cerveris said Pyg takes delight in his actions and sees himself as a mirror image to James Gordon, who also wants to end corruption in the Gotham City Police Department. Pyg spells his name with a "y" as an homage to Pygmalion and because he wants to remake Gotham City in his own image. He also wants to make Gordon into a better version of himself; according to Cerveris, "He is almost looking at Gordon as an ally, like 'I'm on your side, Jim'. And Jim is saying, 'No, you're actually a sociopath'. So it works in many ways as a seduction on Pyg's part as he tries to pull (Jim) in." In early episodes of "Gotham", Pyg claims to have suffered at the hands of Gotham City's elite, implying a troubled past for the Pyg persona and a vengeful motive. Cerveris stated Pyg is aware of his actions but may not be comfortable with himself, which may be partly because he is covering his true identity | https://en.wikipedia.org/wiki?curid=23122647 |
Professor Pyg Layers of his disguise are continuously stripped down and reapplied. Hailing from the southern United States, Valentin uses implanted, shifting metal plates and facial reconstruction to help him hide his true identity. Before the Pyg persona is revealed to be fake, Cerveris said he lacks his alter ego's trademark surgical prowess because it was intended to focus more on his relationship with the city and James Gordon, and that the Dollotrons are not the sole purpose of his existence. Cerveris also said the Dollotrons might be a later part of Valentin's life because the show is about the origins of the Batman mythos. most commonly wears a pig mask, a makeshift surgical outfit, and a butcher's apron. Much of his original wardrobe in the comic books was designed by Frank Quitely and is a homage to the Edwardian suits worn by Rex Harrison in "My Fair Lady". The television series "Gotham" was planned feature a pig mask that more closely resembled the comic book version but it was deemed "a little too cheery and pink". Executive producer Danny Cannon decided the mask should look like decapitated pig flesh. Cerveris found the change to be simultaneously comical and disturbing; he had some difficulty acting in the mask due to its weight and the heat underneath, and because it blocked his peripheral vision. According to Cerveris, "the mask is a really freeing aspect, and I felt naked when I didn't have the mask on, and couldn't really be Professor Pyg". Pyg retains his apron from the source material | https://en.wikipedia.org/wiki?curid=23122647 |
Professor Pyg Professor Pyg's opera suite titled "Ode to Perfection" was composed by David Buckley for the "Batman: Arkham Knight" soundtrack. An action figure of the character was released as part of the third series of "Arkham Knight" figures from DC Collectibles in February 2016. Meg Downey said is one of Batman's most disturbing villains. In 2015, IGN writers Jesse Schedeen and Joshua Yehl ranked as the twenty-third-greatest Batman villain of all time and in a separate editorial, Schedeen called Pyg "one of the crazier and more unusual" Batman villains created by Grant Morrison. Beth Elderkin of "io9" called the character "one of the weirdest villains to come out of the "Batman" canon" while "Bustle" referred to him as "one of the comics' modern masterpieces, and one of its most horrifying creations". David Pepose of "Newsarama" praised the inclusion of and Jason Bard in "Batman Eternal" for emphasizing elements of the DC Universe that were underused following the New 52. "Comic Book Resources"'s Mike Fugere said the character is a "bigger monster" than Solomon Grundy, an undead creature within the DC Universe who Fugere calls "terrifying". He cited the comic book "Cursed Comics Cavalcade" #1 as his reason, a story in which Grundy tries to stop Pyg from mutilating a group of children. According to Fugere, Pyg is "basically Hannibal Lecter on steroids and is a reminder that not all superhero comics are for kids" | https://en.wikipedia.org/wiki?curid=23122647 |
Professor Pyg He also said Grant Morrison accomplished his goal of making Pyg one of the weirdest and most insane characters in Batman comic books. In 2017, John Stephens said is one of his favorite recently-created Batman villains for being demented, grotesque, and funny. Because the character was created recently, he also said Pyg is more contemporary than the classic rogues and did not have to be revitalized as much. When it was announced would appear on "Gotham", "Digital Spy" commented, ""Gotham" season 4 is going to introduce its most disturbing villain ever, so forget about sleeping ever again". Charlie Ridgely of "Comicbook.com" stated Pyg's appearance on "Gotham" proved he is "one of the most disturbed" villains who has served as an antagonist to Batman. | https://en.wikipedia.org/wiki?curid=23122647 |
Ammonium azide is the chemical compound with the formula NHN, being the salt of ammonia and hydrazoic acid. Like other inorganic azides, this colourless crystalline salt is a powerful explosive, although it has a remarkably low sensitivity. NHN is physiologically active and inhalation of small amounts causes headaches and palpitations. It was first obtained by Theodor Curtius in 1890, along with other azides. is ionic. contains about 93% nitrogen by weight as ammonium cation and azide anion. It is a structural isomer of tetrazene. | https://en.wikipedia.org/wiki?curid=23125145 |
Acylhydrazine Acylhydrazines are a class of organic compounds and can be regarded as nitrogen derivatives of carboxylic acids having the general structure R-CO-NR-NRR, where R, R and R can be organic radicals or hydrogen. They are analogous to an amide, but the -OH portion of a carboxylic acid is replaced by hydrazine rather than ammonia (one less hydrogen at the point of attachment). Acylhydrazines are a type of hydrazides. Carboxylic hydrazides can be prepared by reacting acyl halides with hydrazine (or correspondingly substituted hydrazines) or by reduction of "N"-nitroso carboxamides. Carboxylic hydrazides are stable, polar solids and partially pharmacologically active. Acylhydrazines are intermediates in chemical syntheses, for example in the synthesis of nitrogen heterocycles and acyl azides. An applied example is a synthesis of sunitinib begins by mixing 5-fluoroisatin slowly into hydrazine hydrate. After 4 hours at 110 °C, the indole ring structure has been broken into (2-amino-5-fluoro-phenyl)-acetic acid hydrazide with reduction of the ketone at the 3-position. Subsequent annelation in strong acid creates the 1,3-dihydro-2-oxo indole structure required for the drug. | https://en.wikipedia.org/wiki?curid=23127480 |
Anti-graffiti coating An anti-graffiti coating is a coating that prevents graffiti paint from bonding to surfaces. Cleaning graffiti off buildings costs billions of dollars annually. Many cities have started anti-graffiti programs but vandalism is still a problem. Companies across the globe are attempting to develop coatings to prevent vandals from defacing public and private property. The coatings being developed can be the paint itself, or a clear coat added on top of existing paint or building facades. Depending on the substrate and the severity of graffiti, different coatings give different benefits and disadvantages. There are two common types of paint used today. The first are water-based paints such as latex and acrylic paint, and the second are oil-based paints. The paint of choice will depend on the substrate to be painted upon and the desired end result. All paints have the same basic structure: There actually is no chemical bond between paint and an underlying surface. Paint adheres simply through physical forces like Van der Waals. When paint is first applied to a surface it goes on as a thick wet coating. As the solvent is allowed to evaporate out, the pigment plates which are attracted to one another stack up to form layers. The binder polymerizes essentially locking the pigment plates together. What remains is a uniform coating of binder and pigment. Anti-graffiti coatings make paints unable to adhere to the surface. Anti-graffiti coatings can be invisible to the naked eye | https://en.wikipedia.org/wiki?curid=23134898 |
Anti-graffiti coating There are two different categories of anti-graffiti coatings. The first, sacrificial coatings, are applied to a surface and then removed when graffiti is applied. The surface underneath will be left clean and a new sacrificial coating can be applied. The other type of coating are permanent coatings that prevent graffiti from adhering to a surface in the first place. Newer coatings are made of charged polymeric materials that form a gel on the surface of the building or substrate. Some of the most important characteristics of anti-graffiti coatings are: A sacrificial coating forms a clear coat barrier over the wall or surface being protected. If the surface is vandalized the coating can be removed (sacrificed) using a high-pressure washer taking the graffiti with it. The coating then must be reapplied. The materials used to make a sacrificial coating are usually inexpensive optically clear polymers such as acrylates, biopolymers, and waxes. These polymers form weak bonds with the substrate to allow for easy removal. A semi sacrificial coating known as a safety shield acts as a penetrating sealer on the wall or surface protecting the surface pores. If the surface is vandalized the coating can be particularly removed using a combination of graffiti removal solvent and high-pressure washer. The anti graffiti safety shield is generally reapplied every second attack. While it is possible to use only pressure to remove coating, this will cause additional surface erosion | https://en.wikipedia.org/wiki?curid=23134898 |
Anti-graffiti coating Permanent coatings are often more expensive than sacrificial coatings, but if used appropriately only have to be applied once. These work by creating a protective surface that spray paint cannot bond to. After the surface has been vandalized, often all that is needed to remove the paint is a simple solvent (toluene) and some manual labor. The underlying surface and the protective coating will remain undamaged. Some of the types of permanent coatings include those based on polyurethanes, nano-particles, fluorinated hydrocarbons, or siloxanes. Polyurethane coatings are useful because of their barrier properties. High chain stiffness and high crosslinking density reduces the ability of the polymer to swell and absorb graffiti paint. Fluorinated coatings are some of the most effective in the field of graffiti prevention. Fluorine is the most electronegative element, meaning that it shows very little affinity for the electrons of other elements. When fluorine is attached to a surface it will decrease surface energy at the interface, minimizing the contact with the graffiti paint. For the same reason that a Teflon-coated pan repels both water and oil, a fluorinated coating will repel water and oil-based paints. These coatings also have the added benefit of being chemically inert as well as very durable. They are also expensive and can be difficult to apply. Silicon based coatings are hydrophobic, which means the surface repels water. This reduces the effects of photo-oxidation of surfaces | https://en.wikipedia.org/wiki?curid=23134898 |
Anti-graffiti coating One of the newer additions to this ever growing market are nanoparticle based coatings. Silica particles are formed using the sol-gel method. The resulting silica particles have both reactive (Si-OH) and nonreactive (Si=O) groups on the surface. The reactive groups provide locations for further chemical processing, which allow you to change the surface properties of the nanoparticles. For anti-graffiti coatings, hydrophobic and oleophobic (oil-fearing) ligands are grafted onto the silica nanoparticles. Hydrophobic ligands are non-polar molecules such as hydrocarbon chains. Oleophobic ligands consist of polar molecules. Normally these two different types of molecules would phase separate in solution, for the same reason that water and oil do not mix. By chemically grafting the ligands onto the silica particles, this effect is counteracted. The effect is a coating that shows an equal dislike for both water-based and oil-based paints. The use of anti-graffiti barrier coatings to protect graffiti-prone historic buildings, monuments, and other culturally-sensitive surfaces may seem to be an easy solution to a persistent problem. Research suggests that the application of such coatings can cause physical or aesthetic changes or otherwise damage historic substrates. Both the National Park Service and English Heritage advise against the use of anti-graffiti coatings and promote the exercise of caution when they are applied to historic buildings and monuments | https://en.wikipedia.org/wiki?curid=23134898 |
Anti-graffiti coating In the United States, many state and local historic district commissions and review boards have regulations that require approval for both graffiti removal work and the application of coatings applied to the facades on designated landmarks or properties located in local historic districts. Alternatives to anti-graffiti barrier coatings include security measures such as night lighting and surveillance cameras, design strategies such as barrier plantings and fences, improved maintenance of the general area and rapid graffiti removal, as well as community awareness raising programs like a neighborhood watch. Anti-graffiti coatings are frequently used by a number of charities that use public installations to raise money for their respective causes. In cases where pieces of art and sculptures may be put out into the public, these coatings have been used to protect the pieces against graffiti attacks. These sculptures are protected by anti-graffiti coatings, often polysiloxane clear coatings so as to protect them from graffiti and weather damage. | https://en.wikipedia.org/wiki?curid=23134898 |
Calcium titanate is an inorganic compound with the chemical formula CaTiO. As a mineral, it is called perovskite, named after Russian mineralogist, L. A. Perovski (1792-1856). It is a colourless, diamagnetic solid, although the mineral is often coloured owing to impurities. CaTiO can be prepared by the combination of CaO and TiO at temperatures >1300 °C. Sol-gel processes has been used to make a more pure substance, as well as lowering the synthesis temperature. These compounds synthesized are more compressible due to the powders from the sol-gel process as well and bring it closer to its calculated density (~4.04 g/ml). is obtained as orthorhombic crystals, more specifically perovskite structure. In this motif, the Ti(IV) centers are octahedral and the Ca centers occupy a cage of 12 oxygen centres. Many useful materials adopt related structures, e.g. barium titanate or variations of the structure, e.g. yttrium barium copper oxide. has relatively little value except as one of the ores of titanium, together with several others. It is reduced to give titanium metal or ferrotitanium alloys. | https://en.wikipedia.org/wiki?curid=23136733 |
Compound 48/80 is a polymer produced by the condensation of "N"-methyl-"p"-methoxyphenethylamine with formaldehyde. It promotes histamine release, and in biochemical research, compound 48/80 is used to promote mast cell degranulation. | https://en.wikipedia.org/wiki?curid=23142393 |
Walter Thiel (chemist) Walter Thiel (7 March 1949 in Treysa, Hesse – 23 August 2019) was a German theoretical chemist. He was the president of the World Association of Theoretical and Computational Chemists (WATOC) from 2011. Walter Thiel studied chemistry at the University of Marburg (West Germany) from 1966 to 1971, where he subsequently obtained his doctorate with A. Schweig in 1973. After a post-doctoral stint at the University of Texas at Austin with M. J. S. Dewar (1973–1975), he obtained his habilitation from the University of Marburg in 1981. He was appointed Professor of Theoretical Chemistry at the University of Wuppertal (West Germany) in 1983 and Professor of Chemistry at the University of Zurich (Switzerland) in 1992. In 1987 he was a visiting professor at the University of California at Berkeley. Since 1999, he was a director at the Max Planck Institute for Coal Research in Mülheim an der Ruhr (Germany) and an honorary professor at the neighboring University of Düsseldorf (Germany) since 2001. Walter Thiel's research interests included the broad areas of theoretical chemistry, in particular quantum chemistry, and computational chemistry, with a focus on large molecules, spectroscopy, and catalysis. His group was involved in the development of new theoretical methods, in particular for the treatment of large molecules, and applied theoretical calculations to concrete chemical problems, usually in close collaboration with experimentalists. Selected methodological contributions Selected application areas | https://en.wikipedia.org/wiki?curid=23146182 |
Kendomycin is an anticancer macrolide first isolated from "Streptomyces violaceoruber". It has potent activity as an endothelin receptor antagonist and anti-osteoporosis agent. It also has strong cytotoxicity against various tumor cell lines. Because of its potent biological activities, kendomcyin has attracted interest as a target of total synthesis. The first total synthesis of kendomycin was accomplished by Lee and Yuan in 2004. The total number of syntheses stands at 6 | https://en.wikipedia.org/wiki?curid=23147198 |
Indian Institute of Science Education and Research, Kolkata Indian Institute of Science Education and Research Kolkata (IISER-K or IISER Kolkata) is an autonomous public research university in science and education field located in Nadia district, West Bengal, India. It was established by the Ministry of Human Resource Development in 2006 and promoted to the status of an Institute of National Importance in 2012 vide the NIT Amendment Act. It is one of seven Indian Institutes of Science Education and Research, and was the first of the IISERs to be established along with IISER Pune. Admission is done through the three channels open for all IISERs: A maximum of 50% of the seats are assigned to KVPY and JEE-Advanced students. Students applying through SCBs also need to take Common IISER Aptitude Test, and are assigned by merit on this test. The institute has five major departments: biological sciences; chemical sciences; earth sciences; mathematics and statistics; and physical sciences. The institute hosts the Centre of Excellence for Space Sciences (CESSI) and a Max Planck-DST Partner Group of Chemical Ecology funded by the Max Planck Society. It also has a field station for ecological, environmental and field studies, and a broadband seismological observatory. The institute jointly runs the Göttingen-Kolkata: Open shell systems (G-KOSS) in fundamentals of molecular spintronics with Georg-August-Universität Göttingen. The institute also hosts the Dirac Supercomputer, which was inaugurated on April 2019.The Dirac cluster has both GNU and Intel compilers | https://en.wikipedia.org/wiki?curid=23151073 |
Indian Institute of Science Education and Research, Kolkata The performance of the Dirac Supercomputing facility is 78.8 Teraflops which includes 60 Teraflops of CPU) and 4×4.7 Teraflops of GPU. The college organizes a major annual festival, Inquivesta, which is promoted as one of the first and the biggest science fest of the country. Inquivesta sees a footfall of 1000+, and has been visited by artists such as Zakir Khan, Sapan Verma, Nalayak(band) and Anubhav Singh Bassi. It has also received brands such as Baskin-Robbins and Domino's Pizza as its previous partners IISER Kolkata has also been hosting VIJYOSHI (the national science camp), along with IISc Bangalore and the Department of Science and Technology, Govt. of India, since 2014. Internationally, the institute was ranked 301–350 among institutes in emerging economics, by the "Times Higher Education" "Emerging Economies University Rankings 2020". In India, the National Institutional Ranking Framework (NIRF) ranked the institute 40 overall in 2019, and 25 among universities. It was also ranked 8th in India by the Nature Index(compiled by Nature Research) with respect to it's research outputs | https://en.wikipedia.org/wiki?curid=23151073 |
Lindgren oxidation is a selective method for oxidizing aldehydes to carboxylic acids. The reaction is named after Bengt O. Lindgren. The oxidation takes place in water containing solvent mixtures under slightly acidic conditions (pH 3–5) with sodium chlorite as oxidizer. To avoid complicated oxidation reactions the hypochlorite, which is formed in the reaction, has to be removed from the reaction mixture by scavengers. In the original publication, sulfamic acid and resorcinol were used. George A. Kraus and co-workers were the first to use 2-methyl-2-butene as scavenger under buffered conditions for the oxidation of an aliphatic and an α,β-unsaturated aldehyde. Later hydrogen peroxide also proved to work to remove the hypochlorite. | https://en.wikipedia.org/wiki?curid=23153191 |
Hash oil Hash oil, also known as honey oil or cannabis oil, is an oleoresin obtained by the extraction of cannabis or hashish. It is a cannabis concentrate containing many of its resins and terpenes – in particular, tetrahydrocannabinol (THC), cannabidiol (CBD), and other cannabinoids. There are various extraction methods, most involving a solvent, such as butane or ethanol. is usually consumed by smoking, vaporizing or eating. may be sold in cartridges used with pen vaporizers. Preparations of hash oil may be solid or colloidal depending on both production method and temperature and are usually identified by their appearance or characteristics. Color most commonly ranges from transparent golden or light brown, to tan or black. Cannabis retailers in California have reported about 40% of their sales are from cannabis oils. is an extracted cannabis product that may use any part of the plant, with minimal or no residual solvent. It is generally thought to be indistinct from traditional hashish, according to the 1961 UN Single Convention on Narcotic Drugs (Schedule I and IV), as it is "the separated resin, whether crude or purified, obtained from the cannabis plant". The tetrahydrocannabinol (THC) content of hash oil varies tremendously, since the manufacturers use a varying assortment of marijuana plants and preparation techniques. Dealers sometimes cut hash oils with other oils | https://en.wikipedia.org/wiki?curid=23154203 |
Hash oil Following an outbreak of vaping related pulmonary illnesses and deaths in 2019 NBCNews conducted tests on different THC vape cartridges and found cartridges containing up to 30% Vitamin E acetate and trace amounts of fungicides and pesticides that may be harmful. seized in the 1970s had a THC content ranging from 10% to 30%. The oil available on the U.S. West Coast in 1974 averaged about 15% THC. Samples seized across the United States by the Drug Enforcement Administration over an 18-year period (1980–1997) showed that THC content in hashish and hashish oil averaging 12.9% and 17.4%, respectively, did not show an increase over time. The highest THC concentrations measured were 52.9% in hashish and 47.0% in hash oil. Hash oils in use in the 2010s had THC concentrations as high as 90% and other products achieving higher concentrations The following compounds were found in naphtha extracts of Bedrocan Dutch medical cannabis: The form of the extract varies depending on the extraction process used; it may be liquid, a clear amber solid (called “shatter"), a sticky semisolid substance (called "wax"), or a brittle honeycombed solid (called "honeycomb wax"). The hash oils made in the nineteenth century were made from hand collected hashish called charas and kief. The term hash oil was hashish that had been dissolved or infused into a vegetable oil for use in preparing foods for oral administration | https://en.wikipedia.org/wiki?curid=23154203 |
Hash oil Efforts to isolate the active ingredient in cannabis were well documented in the nineteenth century and Cannabis extracts and tinctures of cannabis were included in the British Pharmacopoeia and the Pharmacopoeia of the United States. These solvent extracts were termed cannabin (1845), cannabindon, cannabinine, crude cannabinol and cannabinol. So called "butane honey oil" was available briefly in the 1970s. This product was made in Kabul, Afghanistan and smuggled into the United States by The Brotherhood of Eternal Love. Production is thought to have ceased when the facility was destroyed in an explosion. Traditional ice-water separated hashish production utilizes water and filter bags to separate plant material from resin, though this method still leaves much residual plant matter and is therefore poorly suited for full vaporization. Gold described the use of alcohol and activated charcoal in honey oil production by 1989, and Michael Starks further detailed procedures and various solvents by 1990. Large cannabis vaporizers gained popularity in the twentieth century for their ability to vaporize the Cannabinoids in cannabis and extracts without burning plant material using temperature controlled vaporization. Colorado and Washington began licensing hash oil extraction operations in 2014. Small portable vape pens saw a dramatic increase in popularity in 2017. is consumed usually by ingestion, smoking or vaporization | https://en.wikipedia.org/wiki?curid=23154203 |
Hash oil Smoking or vaporizing hash oil is known colloquially as "dabbing", from the English verb to daub (Dutch dabben, French dauber), "to smear with something adhesive". Dabbing devices include special kinds of water pipes ("oil rigs"), vaporizers and vape pens similar in design to electronic cigarettes. Oil rigs include a glass water pipe and a quartz bucket which is often covered with a bubble or directional cap to direct the airflow and disperse the oil amongst the hot areas of the quartz "nail". The pipe is often heated with a butane blowtorch rather than a cigarette lighter. The oil can also be sold in pre-filled atomizer cartridges. The cartridge is used by connecting it to a battery and inhaling the vaporized oil from the cartridge's mouthpiece. is produced by solvent extraction (maceration, infusion or percolation) of marijuana or hashish. After filtering and evaporating the solvent, a sticky resinous liquid with a strong herbal odor (remarkably different from the peculiar odor of hemp) remains. Fresh, undried plant material is less suited for hash oil production, because much THC and CBD will be present in their carboxylic acid forms (THCA and CBDA), which may not be highly soluble in some solvents. The acids are decarboxylated during drying and heating (smoking). A wide variety of solvents can be used for extraction, such as chloroform, dichloromethane, petroleum ether, naphtha, benzene, butane, methanol, ethanol, isopropanol, and olive oil | https://en.wikipedia.org/wiki?curid=23154203 |
Hash oil Currently, resinoids are often obtained by extraction with supercritical carbon dioxide. The alcohols extract undesirable water-soluble substances such as chlorophyll and sugars (which can be removed later by washing with water). Non-polar solvents such as benzene, chloroform and petroleum ether will not extract the water-soluble constituents of marijuana or hashish while still producing hash oil. In general, non-polar cannabis extracts taste much better than polar extracts. Alkali washing further improves the odor and taste. The oil may be further refined by 1) alkali washing, or removing the heavy aromatic carboxylic acids with antibiotic properties, which may cause heartburn, gallbladder and pancreas irritation, and resistance to hemp antibiotics; 2) conversion of CBD to THC. Process 1) consists of dissolving the oil in a non-polar solvent such as petroleum ether, repeatedly washing (saponifying) with a base such as sodium carbonate solution until the yellow residue disappears from the watery phase, decanting, and washing with water to remove the base and the saponified components (and evaporating the solvents). This process reduces the oil yield, but the resulting oil is less acidic, more easily digestible and much more potent (almost pure THC). Process 2) consists of dissolving the oil in a suitable solvent such as absolute ethanol containing 0.05% hydrochloric acid, and boiling the mixture for 2 hours. One pound of marijuana yields from 1/5 to 1/10 of a pound of hash oil | https://en.wikipedia.org/wiki?curid=23154203 |
Hash oil The oil may retain considerable residual solvent: oil extracted with longer-chain volatile hydrocarbons (such as naphtha) is less viscous (thinner) than oil extracted with short-chain hydrocarbons (such as butane). Colored impurities from the oil can be removed by adding activated charcoal to about one third to one half the weight or volume of the solvent containing the dissolved oil, mixing well, filtering, and evaporating the solvent. When decolorizing fatty oils, oil retention can be up to 50 wt % on bleaching earths and nearly 100 wt % on activated charcoal. The many different textures/types of hydrocarbon extracts include : Hash rosin has recently become a top quality, highly prized product in the cannabis market. For dabbing, it is considered to be the cleanest form of concentrating cannabis, as it requires only ice, water (instead of chemical solvents like butane), heat, pressure, and collection tools. Cannabis flower material is washed with ice water, and strained using filters in sequential micron size to isolate intact trichomes and their heads into ice water hash. The microns that are held in highest regards are the 73u and 90u, as this is where the resin heads reside. These are sometimes isolated and sold as one of the highest quality, most expensive cannabis products in the market today, known as "full melt" because it will dab fine without having to be pressed | https://en.wikipedia.org/wiki?curid=23154203 |
Hash oil "Full spectrum" hash rosin will normally come from 45u-159u, as smaller and larger particles are likely to be too unrefined or broken stalks of the trichomes. This hash is then pressed at the appropriate temperature and pressure to squeeze the oils out of the hash, and is collected with metal tools and parchment paper. Just like hydrocarbon extraction, the quality of the final product depends greatly on the quality of the starting material. This is emphasized even more so with hash rosin due to its lower yield percentages compared to solvent-derived concentrates (.3-8% rosin vs 10-20% hydrocarbon). Hash rosin produces often touch on how growing cannabis for hash production is different than growing for flower production, as some strains will be deceptive with their looks regarding yields. In Canada, hash oil – defined as a chemically concentrated extract having up to 90% THC potency – was approved for commerce in October 2018. In the United States, regulations specifically for hash oil have not been issued as of 2019, but hemp seed oil – along with hulled hemp seeds and hemp seed protein – were approved as generally recognized as safe (GRAS) in December 2018, indicating that "these products can be legally marketed in human foods for these uses without food additive approval, provided they comply with all other requirements and do not make disease treatment claims" | https://en.wikipedia.org/wiki?curid=23154203 |
Hash oil On September 5, 2019, the United States Food and Drug Administration (US FDA) announced that 10 out of 18, or 56% of the samples of vape liquids sent in by states, linked to recent vaping related lung disease outbreak in the United States, tested positive for vitamin E acetate which had been used as a thickening agent by illicit THC vape cartridge manufacturers. On November 8, 2019, the Centers for Disease Control and Prevention (CDC) identified vitamin E acetate as a very strong culprit of concern in the vaping-related illnesses, but has not ruled out other chemicals or toxicants as possible causes. The CDC's findings were based on fluid samples from the lungs of 29 patients with vaping-associated pulmonary injury, which provided direct evidence of vitamin E acetate at the primary site of injury in all the 29 lung fluid samples tested. Research suggests when vitamin E acetate is inhaled, it may interfere with normal lung functioning. "Vitamin E oil might be in 60-70% of street carts, insiders say.". Counterfeit THC oil has been detected to contain synthetic cannabinoids. Several school kids in Greater Manchester collapsed after vaping Spice mis-sold as 'natural cannabis'. the health effects of using hash oil were poorly documented. Cannabis extracts have less plant matter and create less harmful smoke. However, trace amounts of impurities are not generally regarded as safe (GRAS) | https://en.wikipedia.org/wiki?curid=23154203 |
Hash oil In 2019 following an outbreak of illnesses additives added to vape pen mixtures were found to be causing breathing problems, lung damage, and deaths. Most of the solvents employed vaporize quickly and are flammable, making the extraction process dangerous. Several explosion and fire incidents related to hash oil manufacturing attempts in homes have been reported. Solvents used to extract THC are flammable or combustible and have resulted in explosions, fires, severe injuries, and deaths. The LD50 for THC (Delta 9 Tetrahydrocannabinol) is not precisely known, as there have been no recorded fatalities. can contain up to 80% THC, though up to 99% is possible with other methods of extraction. While health issues of the lungs may be exacerbated by use of hash oil, it is not known to cause side effects not already found in other preparations of cannabis. When exposed to air, warmth and light (especially without antioxidants), the oil loses its taste and psychoactivity due to aging. Cannabinoid carboxylic acids (THCA, CBDA, and maybe others) have an antibiotic effect on gram-positive bacteria such as (penicillin-resistant) Staphylococcus aureus, but gram-negative bacteria such as Escherichia coli are unaffected. | https://en.wikipedia.org/wiki?curid=23154203 |
Methylamide In chemistry, an "N"-methylamide (NME) is a blocking group for the C-terminus end of peptides. When the carboxyl group of the C-terminus is replaced with a methylamide, further elongation of the peptide chain is prevented. C-Terminal modified peptides are also useful for the modulation of structure-activity relationships and for modifying conformational properties of peptides. "N"-Methylamides can be prepared directly from solid phase resin-bound peptides. | https://en.wikipedia.org/wiki?curid=23154241 |
Philippe de Clermont (1831–1921) was a French organic chemist. He was known for the synthesis of the first organophosphate cholinesterase inhibitor (tetraethyl pyrophosphate, TEPP). He worked in Adolphe Wurtz's laboratory in Paris. | https://en.wikipedia.org/wiki?curid=23157510 |
Franz Anton Voegeli (1825–1874) was a Swiss chemist who was the first to synthesize triethyl phosphate (TEP) while he was working in Gustav Magnus's laboratory in Berlin. | https://en.wikipedia.org/wiki?curid=23157584 |
Thermal dissolution is a method of liquefaction of solid fossil fuels. It is a hydrogen-donor solvent refining process. It may be used for the shale oil extraction and coal liquefaction. Other liquids extraction processes from solid fuels are pyrolysis and hydrogenation. Compared to hydrogenation, the process of thermal dissolution has milder conditions, simpler process, and no consumption of catalyst. | https://en.wikipedia.org/wiki?curid=23157899 |
Laminar–turbulent transition In fluid dynamics, the process of a laminar flow becoming turbulent is known as laminar–turbulent transition. The main parameter characterizing transition is the Reynolds number. Transition is often described as a process proceeding through a series of stages. "Transitional flow" can refer to transition in either direction, that is laminar–turbulent transitional or turbulent–laminar transitional flow. The process applies to any fluid flow, and is most often used in the context of boundary layers. In 1883 Osborne Reynolds demonstrated the transition to turbulent flow in a classic experiment in which he examined the behaviour of water flow under different flow rates using a small jet of dyed water introduced into the centre of flow in a larger pipe. The larger pipe was glass, so the behaviour of the layer of dyed flow could be observed, and at the end of this pipe was a flow-control valve used to vary the water velocity inside the tube. When the velocity was low, the dyed layer remained distinct through the entire length of the large tube. When the velocity was increased, the layer broke up at a given point and diffused throughout the fluid's cross-section. The point at which this happened was the transition point from laminar to turbulent flow. Reynolds identified the governing parameter for the onset of this effect, which was a dimensionless constant later called the Reynolds number. Reynolds found that the transition occurred between Re = 2000 and 13000, depending on the smoothness of the entry conditions | https://en.wikipedia.org/wiki?curid=23163934 |
Laminar–turbulent transition When extreme care is taken, the transition can even happen with Re as high as 40000. On the other hand, Re = 2000 appears to be about the lowest value obtained at a rough entrance. Reynolds' publications in fluid dynamics began in the early 1870s. His final theoretical model published in the mid-1890s is still the standard mathematical framework used today. Examples of titles from his more groundbreaking reports are: A boundary layer can transition to turbulence through a number of paths. Which path is realized physically depends on the initial conditions such as initial disturbance amplitude and surface roughness. The level of understanding of each phase varies greatly, from near complete understanding of primary mode growth to a near-complete lack of understanding of bypass mechanisms. The initial stage of the natural transition process is known as the Receptivity phase and consists of the transformation of environmental disturbances – both acoustic (sound) and vortical (turbulence) – into small perturbations within the boundary layer. The mechanisms by which these disturbances arise are varied and include freestream sound and/or turbulence interacting with surface curvature, shape discontinuities and surface roughness. These initial conditions are small, often unmeasurable perturbations to the basic state flow. From here, the growth (or decay) of these disturbances depends on the nature of the disturbance and the nature of the basic state | https://en.wikipedia.org/wiki?curid=23163934 |
Laminar–turbulent transition Acoustic disturbances tend to excite two-dimensional instabilities such as Tollmien–Schlichting waves (T-S waves), while vortical disturbances tend to lead to the growth of three-dimensional phenomena such as the crossflow instability. Numerous experiments in recent decades have revealed that the extent of the amplification region, and hence the location of the transition point on the body surface, is strongly dependent not only upon the amplitude and/or the spectrum of external disturbances but also on their physical nature. Some of the disturbances easily penetrate into the boundary layer whilst others do not. Consequently, the concept of boundary layer transition is a complex one and still lacks a complete theoretical exposition. If the initial, environmentally-generated disturbance is small enough, the next stage of the transition process is that of primary mode growth. In this stage, the initial disturbances grow (or decay) in a manner described by linear stability theory. The specific instabilities that are exhibited in reality depend on the geometry of the problem and the nature and amplitude of initial disturbances. Across a range of Reynolds numbers in a given flow configuration, the most amplified modes can and often do vary. There are several major types of instability which commonly occur in boundary layers. In subsonic and early supersonic flows, the dominant two-dimensional instabilities are T-S waves | https://en.wikipedia.org/wiki?curid=23163934 |
Laminar–turbulent transition For flows in which a three-dimensional boundary layer develops such as a swept wing, the crossflow instability becomes important. For flows navigating concave surface curvature, Görtler vortices may become the dominant instability. Each instability has its own physical origins and its own set of control strategies - some of which are contraindicated by other instabilities – adding to the difficulty in controlling laminar-turbulent transition. Simple harmonic sound as a precipitating factor in the sudden transition from laminar to turbulent flow might be attributed to Elizabeth Barrett Browning. Her poem, Aurora Leigh (1856), revealed how musical notes (the pealing of a particular church bell), triggered wavering turbulence in the previously steady laminar-flow flames of street gaslights (“...gaslights tremble in the streets and squares”: Hair 2016). Her instantly acclaimed poem might have alerted scientists (e.g., Leconte 1859) to the influence of simple harmonic (SH) sound as a cause of turbulence. A contemporary flurry of scientific interest in this effect culminated in Sir John Tyndall (1867) deducing that specific SH sounds, directed perpendicular to the flow had waves that blended with similar SH waves created by friction along the boundaries of tubes, amplifying them and triggering the phenomenon of high-resistance turbulent flow. His interpretation re-surfaced over 100 years later (Hamilton 2015) | https://en.wikipedia.org/wiki?curid=23163934 |
Laminar–turbulent transition Tollmien (1931) and Schlichting (1929) proposed that friction (viscosity) along a smooth flat boundary, created SH boundary layer (BL) oscillations that gradually increased in amplitude until turbulence erupted. Although contemporary wind tunnels failed to confirm the theory, Schubauer and Skramstad (1943) created a refined wind tunnel that deadened the vibrations and sounds that might impinge on the wind tunnel flat plate flow studies. They confirmed the development of SH long-crested BL oscillations, the dynamic shear waves of transition to turbulence. They showed that specific SH fluttering vibrations induced electromagnetically into a BL ferromagnetic ribbon could amplify similar flow-induced SH BL flutter (BLF) waves, precipitating turbulence at much lower flow rates. Furthermore, certain other specific frequencies interfered with the development of the SH BLF waves, preserving laminar flow to higher flow rates. An oscillation of a mass in a fluid is a vibration that creates a sound wave. SH BLF oscillations in boundary layer fluid along a flat plate must produce SH sound that reflects off the boundary perpendicular to the fluid laminae. In late transition, Schubauer and Skramstad found foci of amplification of BL oscillations, associated with bursts of noise (“turbulent spots”). Focal amplification of the transverse sound in late transition was associated with BL vortex formation | https://en.wikipedia.org/wiki?curid=23163934 |
Laminar–turbulent transition The focal amplified sound of turbulent spots along a flat plate with high energy oscillation of molecules perpendicularly through the laminae, might suddenly cause localized freezing of laminar slip. The sudden braking of “frozen” spots of fluid would transfer resistance to the high resistance at the boundary, and might explain the head-over-heels BL vortices of late transition. Osborne Reynolds described similar turbulent spots during transition in water flow in cylinders (“flashes of turbulence,” 1883). When many random vortices erupt as turbulence onsets, the generalized freezing of laminar slip (laminar interlocking) is associated with noise and a dramatic increase in resistance to flow. This might also explain the parabolic isovelocity profile of laminar flow abruptly changing to the flattened profile of turbulent flow – as laminar slip is replaced by laminar interlocking as turbulence erupts (Hamilton 2015). The primary modes themselves don't actually lead directly to breakdown, but instead lead to the formation of secondary instability mechanisms. As the primary modes grow and distort the mean flow, they begin to exhibit nonlinearities and linear theory no longer applies. Complicating the matter is the growing distortion of the mean flow, which can lead to inflection points in the velocity profile a situation shown by Lord Rayleigh to indicate absolute instability in a boundary layer. These secondary instabilities lead rapidly to breakdown | https://en.wikipedia.org/wiki?curid=23163934 |
Laminar–turbulent transition These secondary instabilities are often much higher in frequency than their linear precursors. | https://en.wikipedia.org/wiki?curid=23163934 |
Shading coefficient (SC) is a measure of thermal performance of a glass unit (panel or window) in a building. It is the ratio of solar gain (due to direct sunlight) passing through a glass unit to the solar energy which passes through 3mm Clear Float Glass. It is an indicator of how well the glass is thermally insulating (shading) the interior when there is direct sunlight on the panel or window. The shading coefficient depends on the color of glass and degree of reflectivity. It also depends on the type of reflective metal oxides for the case of reflective glass. Sputter-coated reflective and/or sputter-coated low-emissivity glasses tend to have lower SC compared to the same pyrolitically-coated reflective and/or low-emissivity glass. The value ranges between 1.00 to 0.00, but experiments show that the value of the SC is typically between 0.98~0.10. The lower the rating, the less solar heat is transmitted through the glass, and the greater its shading ability. Solar properties play a significant role in the selection of glass, especially in regions or cardinal directions with high solar exposure. It becomes less significant in situations where direct sunlight is not a major factor (e.g., windows completely shaded by overhangs). Window design methods have moved away from Shading Coefficient to Solar Heat Gain Coefficient (SHGC), which is defined as the fraction of incident solar radiation that actually enters a building through the entire window assembly as heat gain (not just the glass portion) | https://en.wikipedia.org/wiki?curid=23164211 |
Shading coefficient Though shading coefficient is still mentioned in manufacturer product literature and some industry computer software, it is no longer mentioned as an option in the handbook widely used by building energy engineers or model building codes. Industry technical experts recognized the limitations of SC and pushed towards SHGC before the early 1990s. A conversion from SC to SHGC is not necessarily straightforward, as they each take into account different heat transfer mechanisms and paths (window assembly vs. glass-only). To perform an approximate conversion from SC to SHGC, multiply the SC value by 0.87. | https://en.wikipedia.org/wiki?curid=23164211 |
Kreft's dichromaticity index (DI) is a measure for quantification of dichromatism. It is defined as the difference in hue angle (Δh) between the color of the sample at the dilution, where the chroma (color saturation) is maximal, and the color of four times more diluted (or thinner) and four times more concentrated (or thicker) sample. The two hue angle differences are called the dichromaticity index towards lighter (Kreft's DI) and dichromaticity index towards darker (Kreft's DI) respectively. Kreft's dichromaticity indexes DI and DI for pumpkin seed oil, which is one of the most dichromatic substances, are −9 and −44, respectively. This means, that pumpkin seed oil changes its color from green-yellow to orange-red (for 44 degrees in Lab color space) when the thickness of the observed layer is increased from cca 0.5 mm to 2 mm; and it changes slightly towards green (for 9 degrees) if its thickness is reduced for four-fold. The color of pumpkin oil at increasing thickness or concentration presented in CIELAB colorspace diagram. Straight lines are vectors showing hue (angle) and chroma (length) of the color at maximal chroma (toward the square mark), and the colors of four-fold less or more diluted or thick pumpkin oil (DI and DI). Note that DI is −44.1 degrees and DI corresponds to −8.97 degrees | https://en.wikipedia.org/wiki?curid=23167524 |
Kreft's dichromaticity index Dichromaticity (DI and DI) of selected substances, calculated from their VIS absorption spectra by the computer algorithm “Dichromaticity index calculator”: Maximal chroma: chroma at concentration (thickness) where the color of the substance has maximal chroma (saturation). Angle at maximal chroma: the hue, which is represented by the angle of the vector to the color with maximal chroma in the CIELAB colorspace diagram. | https://en.wikipedia.org/wiki?curid=23167524 |
Ernesto Estrada (born 2 May 1966) is a Cuban-Spanish scientist. He is the Chair in Complexity Science, Full Professor at the Department of Mathematics and Statistics, and a member of the Institute of Complex Systems of the University of Strathclyde, Glasgow, United Kingdom. He is known by his contributions in different disciplines including chemistry, and the mathematics and physics of Complex Systems. Estrada was born in the city of Sancti Spiritus, in the central region of Cuba. Since the age of 11 he studied in a school which specialized in exact sciences. He later studied for a technical degree as an analytical chemist in a technological institute in Havana. At the age of 28 he presented his first scientific paper in an international congress together with his mentor, Dr. Jose F. Fernandez-Bertran. The paper was about the detection of polyatomic anions in matrices of NaCl using infrared spectroscopy. Between 1985 and 1990, he studied chemical sciences at the Central University of Las Villas in Santa Clara, Cuba, where he obtained his degree in only 4 of the 5 years established for the program. In the first years after graduation, Estrada investigated the synthesis and spectroscopic characterization of new organic molecules with biological activity. This research introduced him to the world of computational chemistry due to the requirement of using efficient methods to design biologically active molecules. In 1997, he obtained his Ph.D in Chemistry under the direction of Prof. Luis A | https://en.wikipedia.org/wiki?curid=23169584 |
Ernesto Estrada Montero Cabrera on the topic of "Graph Theory Applied to Molecular Design". By this time, Estrada had published 8 scientific papers in major chemistry journals. After completing his Ph.D., Estrada spent some time as post-doctoral research at the University of Valencia, Spain working with Prof. Jorge Galvez and at the Lisa-Meitner Institute for Computational Quantum Chemistry, Hebrew University of Jerusalem with Prof. David Avnir. In 2000, he officially emigrated to Spain where he obtained a fellowship at the University of Santiago de Compostela. Between 2002 and 2003, Estrada worked as a scientist at the Safety and Environmental Assurance Centre, Unilever in Colworth, U.K. He then obtained a position as "Ramon y Cajal" researcher at the University of Santiago de Compostela, Spain. Since 2008, Estrada occupies the newly created Chair in Complexity Science at the University of Strathclyde and has published more than 160 papers, 10 book Chapters and 2 books. He is a Cuban and Spanish citizen, resident in Scotland, U.K. Estrada has been a major contributor in the area of study of complex network, where he has developed several approaches to investigate the structure and dynamics of such systems. An index introduced by him in 1999 to characterise the degree of folding of proteins, and then generalised to the study of complex networks in 2005, has eventually became the Estrada index of a graph or network, and it is the subject of intensive research in mathematics and other fields | https://en.wikipedia.org/wiki?curid=23169584 |
Ernesto Estrada Estrada is also known in the field of spectral graph theory where he has introduced several approaches to characterise the organizational architecture of complex networks, such as the "subgraph centrality", "communicability", "spectral scaling", "golden spectral graphs", etc. Estrada is also known in the area of Mathematical Chemistry, in particular to the development and use of molecular descriptors based on the use of Graph Theory. He is known for the introduction of several approaches in this field, such as the Topological Sub-Structural Molecular Design (TOPS-MODE) approach, and the generalization of topological indices. In 2007, Estrada received the prize as Outstanding Scientist from the International Academy of Mathematical Chemistry. The prize recognizes his valuable contributions in developing and applying graph theory to solve problems in many interdisciplinary areas, such as chemistry, physics, biology, ecology and technology. In 2014 Estrada received the prestigious Royal Society Wolfson Research Merit Award of the Royal Society of London, which recognises "scientists of outstanding achievement and potential". Estrada has been visiting Professor at the Statistical and Applied Mathematical Sciences Institute in North Carolina, USA, the Centre of Mathematical Research in Guanajuato, Mexico, the Quantititative Methods and Theory Institute and the Department of Mathematics and Computer Science at Emory University in Atlanta, USA | https://en.wikipedia.org/wiki?curid=23169584 |
Ernesto Estrada Since 2013 Estrada is the Editor-in-Chief of the Journal of Complex Networks published by Oxford University Press. In 2019 he was named a SIAM Fellow "for outstanding contributions to mathematical chemistry and network science". | https://en.wikipedia.org/wiki?curid=23169584 |
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