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Separator (electricity) Nonwovens consist of a manufactured sheet, web or mat of directionally or randomly oriented fibers. Supported liquid membranes consist of a solid and liquid phase contained within a microporous separator. Some polymer electrolytes form complexes with alkali metal salts, which produce ionic conductors that serve as solid electrolytes. Solid ion conductors, can serve as both separator and the electrolyte. Separators can use a single or multiple layers/sheets of material. Polymer separators generally are made from microporous polymer membranes. Such membranes are typically fabricated from a variety of inorganic, organic and naturally occurring materials. Pore sizes are typically larger than 50-100 Å. Membranes synthesized by dry processes are more suitable for higher power density, given their open and uniform pore structure, while those made by wet processes are offer more charge/discharge cycles because of their tortuous and interconnected pore structure. This helps to suppress the conversion of charge carriers into crystals on anodes during fast or low temperature charging. The dry process involves extruding, annealing and stretching steps. The final porosity depends on the morphology of the precursor film and the specifics of each step. The extruding step is generally carried out at a temperature higher than the melting point of the polymer resin. This is because the resins are melted to shape them into a uniaxially-oriented tubular film, called a precursor film | https://en.wikipedia.org/wiki?curid=30038658 |
Separator (electricity) The structure and orientation of the precursor film depends on the processing conditions and the resin's characteristics. In the annealing process, the precursor is annealed at a temperature slightly lower than the polymer's melting point. The purpose of this step is to improve the crystalline structure. During stretching, the annealed film is deformed along the machine direction by a cold stretch followed by a hot stretch followed by relaxation. The cold stretch creates the pore structure by stretching the film at a lower temperature with a faster strain rate. The hot stretch increases pore sizes using a higher temperature and a slower strain rate. The relaxation step reduces internal stress within the film. The dry process is only suitable for polymers with high crystallinity. These include but are not limited to: semi-crystalline polyolefins, polyoxymethylene, and isotactic poly (4-methyl-1-pentene). One can also use blends of immiscible polymers, in which at least one polymer has a crystalline structure, such as polyethylene-polypropylene, polystyrene-polypropylene, and poly (ethylene terephthalate) - polypropylene blends. The wet process consists of mixing, heating, extruding and additive removal steps. The polymer resins are first mixed with, paraffin oil, antioxidant and other additives. The mixture is heated to produce a homogenous solution. The heated solution is pushed through a sheet die to make a gel-like film. The additives are then removed with a volatile solvent to form the microporous result | https://en.wikipedia.org/wiki?curid=30038658 |
Separator (electricity) The wet process is suitable for both crystalline and amorphous polymers. Wet process separators often use ultrahigh-molecular-weight polyethylene. The use of these polymers enables the batteries with favorable mechanical properties, while shutting it down when it becomes too hot. Specific types of polymers are ideal for the different types of synthesis. Most polymers currently used in battery separators are polyolefin based materials with semi-crystalline structure. Among them, polyethylene, polypropylene, and their blends such as polyethylene-polypropylene are widely used. Recently, graft polymers have been studied in an attempt to improve battery performance, including micro-porous poly(methyl methacrylate)-grafted and siloxane grafted polyethylene separators, which show favorable surface morphology and electrochemical properties compared to conventional polyethylene separators. In addition, polyvinylidene fluoride (PVDF) nanofiber webs can be synthesized as a separator to improve both ion conductivity and dimensional stability. Another type of polymer separator, polytriphenylamine (PTPAn)-modified separator, is an electroactive separator with reversible overcharge protection. Always the separator is placed between the anode and the cathode. The pores of the separator are filled with the electrolyte and packaged for use. Many structural defects can form in polymer separators due to temperature changes. These structural defects can result in a thicker separators | https://en.wikipedia.org/wiki?curid=30038658 |
Separator (electricity) Furthermore, there can be intrinsic defects in the polymers themselves, such as polyethylene often begins to deteriorate during the stages of polymerization, transportation, and storage. Additionally, defects such as tears or holes can form during the synthesis of polymer separators. There are also other sources of defects can come from doping the polymer separator. Polymer separators, similar to battery separators in general, act as a separator of the anode and cathode in the Li-ion battery while also enabling the movement of ions through the cell. Additionally, many of the polymer separators, typically multilayer polymer separators, can act as “shutdown separators”, which are able to shut down the battery if it becomes too hot during the cycling process. These multilayered polymer separators are generally composed of one or more polyethylene layers which serve to shut down the battery and at least one polypropylene layer which acts as a form of mechanical support for the separator. In addition to polymer separators, there are several other types of separators. There are nonwovens, which consist of a manufactured sheet, web, or mat of directionally or randomly oriented fibers. Supported liquid membranes, which consist of a solid and liquid phase contained within a microporous separator. Additionally there are also polymer electrolytes which can form complexes with different types of alkali metal salts, which results in the production of ionic conductors which serve as solid electrolytes | https://en.wikipedia.org/wiki?curid=30038658 |
Separator (electricity) Another type of separator, a solid ion conductor, can serve as both a separator and the electrolyte in a battery. Plasma technology was used to modify a polyethylene membrane for enhanced adhesion, wettability and printability. These are usually performed by modifying the membrane on only its outermost several molecular levels. This allows the surface to behave differently without modifying the properties of the remainder. The surface was modified with acrylonitrile via a plasma coating technique. The resulting acrylonitrile-coated membrane was named PiAn-PE. The surface characterization demonstrated that PiAN-PE's enhanced adhesion resulted from the increased polar component of surface energy. The sealed rechargeable nickel-metal hydride battery offers significant performance and environmental friendliness above alkaline rechargeable batteries. Ni/MH, like the lithium-ion battery, provides high energy and power density with long cycle lives. This technology's greatest problem is its inherent high corrosion rate in aqueous solutions. The most commonly used separators are porous insulator films of polyolefin, nylon or cellophane. Acrylic compounds can be radiation-grafted onto these separators to make their properties more wettable and permeable. Zhijiang Cai and co-workers developed a solid polymer membrane gel separator. This was a polymerization product of one or more monomers selected from the group of water-soluble ethylenically unsaturated amides and acid | https://en.wikipedia.org/wiki?curid=30038658 |
Separator (electricity) The polymer-based gel also includes a water swellable polymer, which acts as a reinforcing element. Ionic species are added to the solution and remain embedded in the gel after polymerization. Ni/MH batteries of bipolar design (bipolar batteries) are being developed because they offer some advantages for applications as storage systems for electric vehicles. This solid polymer membrane gel separator could be useful for such applications in bipolar design. In other words, this design can help to avoid short-circuits occurring in liquid-electrolyte systems. Inorganic polymer separators have also been of interest as use in lithium-ion batteries. Inorganic particulate film/poly(methyl methacrylate) (PMMA)/inorganic particulate film trilayer separators are prepared by dip-coating inorganic particle layers on both sides of PMMA thin films. This inorganic trilayer membrane is believed to be an inexpensive, novel separator for application in lithium-ion batteries from increased dimensional and thermal stability. | https://en.wikipedia.org/wiki?curid=30038658 |
Hagemann's ester Hagemann's ester, or ethyl-2-methyl-4-oxo-2-cyclohexenecarboxylate, is an organic compound that was first prepared and described in 1893 by German chemist Carl Hagemann. The compound is used in organic chemistry as a reagent in the synthesis of many important natural products including sterols, trisporic acids, and terpenoids. Methylene iodide and two equivalents of acetoacetic ester react in the presence of sodium methoxide to form the diethyl ester of 2,4-diacetyl pentane. This precursor is treated with base to induce cyclization. Finally, heat is applied to generate Hagemann's ester. Soon after Hagemann, Emil Knoevenagel presented the following modified procedure. Formaldehyde and two equivalents of acetoacetic ester undergo condensation in the presence of catalytic piperidine to produce the diethyl ester of 2,4-diacetyl pentane. This precursor is treated with base to induce cyclization. Finally, heat is applied to generate Hagemann's ester. 2-Methoxy-1,3-butadiene and ethyl-2-butynoate undergo a Diels Alder reaction to generate a precursor. The precursor is hydrolyzed to obtain Hagemann's ester. By varying the substituents on the butynoate starting material, this approach allows for different C2 alkylated derivatives to be synthesized. Methyl vinyl ketone, acetoacetic ester, and diethyl-methyl-(3-oxo-butyl)-ammonium iodide react to form a cyclic aldol product. Sodium methoxide is added to generate Hagemann's ester | https://en.wikipedia.org/wiki?curid=30040436 |
Hagemann's ester Methyl vinyl ketone and acetoacetic ester undergo aldol cyclization in the presence of catalytic pyrrolidinum acetate or Triton B or sodium ethoxide to produce Hagemann's ester. | https://en.wikipedia.org/wiki?curid=30040436 |
MetPetDB is a relational database and repository for global geochemical data on and images collected from metamorphic rocks from the earth's crust. is designed and built by a global community of metamorphic petrologists in collaboration with computer scientists at Rensselaer Polytechnic Institute as part of the National Cyberinfrastructure Initiative and supported by the National Science Foundation. is unique in that it incorporates image data collected by a variety of techniques, e.g. photomicrographs, backscattered electron images (SEM), and X-ray maps collected by wavelength dispersive spectroscopy or energy dispersive spectroscopy. was built for the purpose of archiving published data and for storing new data for ready access to researchers and students in the petrologic community. This database facilitates the gathering of information for researchers beginning new projects and permits browsing and searching for data relating to anywhere on the globe. provides a platform for collaborative studies among researchers anywhere on the planet, serves as a portal for students beginning their studies of metamorphic geology, and acts as a repository of vast quantities of data being collected by researchers globally. The basic structure of is based on a geologic sample and derivative subsamples. Geochemical data are linked to subsamples and the minerals within them, while image data can relate to samples or subsamples | https://en.wikipedia.org/wiki?curid=30055561 |
MetPetDB is designed to store the distinct spatial/textural context of mineral analysis that is a crucial to petrologic interpretation. A web-based user interface allows a user to become members and download their search results. Approved members may become contributors and upload data to catalogue and share with the public. More information about the data model and the design of the database is available on the Support Wiki. The database houses a wide range of information available for samples from all over the globe to be grouped into two categories: (a) observations and measurements (e.g. mineral data, images, chemical analyses), for which robust data models already exist, and (b) interpretative results (e.g. P-T conditions, crystallization ages, cooling rates, etc.), which are conclusions based on the observational data. Development of a robust data model for interpretative data is currently underway as of December 2010. The database system is beginning to incorporate a number of tools for data analysis and calculation that adds considerable power to the researcher. differs from other Geochemistry relational databases (e.g. GEOROC, NAVDAT, PetDB) in that it incorporates unpublished data in addition to data published in peer-reviewed journals. The vast majority of data collected by metamorphic geologists is not presented in publication, and therefore a forum for sharing this data with the public is an objective of MetPetDB | https://en.wikipedia.org/wiki?curid=30055561 |
MetPetDB Contributors to also have the ability to store private data and create projects, or collections of private, public, and published data for sharing and organization. A comprehensive list of the publications and their published samples are located at Published Samples | https://en.wikipedia.org/wiki?curid=30055561 |
Nanogenerator A is a type of technology that converts mechanical/thermal energy as produced by small-scale physical change into electricity. A has three typical approaches: piezoelectric, triboelectric, and pyroelectric nanogenerators. Both the piezoelectric and triboelectric nanogenerators can convert mechanical energy into electricity. However, pyroelectric nanogenerators can be used to harvest thermal energy from a time-dependent temperature fluctuation. "Nanogenerators are referred as a field that uses displacement current as the driving force for effectively converting mechanical energy into electric power/signal, disregarding if nanomaterials are used or not." The nanogenerators represent the energy technology for the new era - the era of internet of things and sensor networks. Maxwell's equations, which are among the top 10 most important equations for physics, have the following basic forms: formula_1 (1.1) formula_2 (1.2) formula_3 (1.3) formula_4 (1.4) where the displacement current, formula_5, was first introduced by Maxwell in 1861 to satisfy the continuity equation for electric charges. The electric displacement vector D is given by formula_6, and for an isotropic dielectric medium, formula_7, thus formula_8 . The displacement current density is presented as formula_9 (2.1) Recently, the Maxwell's equations have been expanded to calculate the power output of nanogenerators | https://en.wikipedia.org/wiki?curid=30057479 |
Nanogenerator An additional term P was first added into D by Wang in 2017, where P is "the polarization created by the electrostatic surface charges owing to mechanical triggering, different from the electric field induced medium polarization P. The D" can be rewritten as formula_10, so the displacement current density is obtained by formula_11 (2.2) Then the Maxwell's equations can be expanded as formula_12 (3.1) formula_2 (3.2) formula_3 (3.3) formula_15 (3.4) These equations are the cornerstones for deriving the output characteristics of nanogenerators, from which the output current and voltage, and the related electromagnetic radiation of a nanogenerator have all been derived. The polarization P created by the electrostatic surface charges can be expressed by the following equation, when defining the charge density function "σ"(r,"t") on the media surface by a shape function of "f"(r,"t")=0. formula_16 (4) where the delta function "δ"("f"(r,"t")) is introduced to confine the media shape. Through solving the scalar electric potential formula_17 from the surface charges formula_18 (5) the P can be obtained by formula_19 This indicates that the output energy per cycle E can be calculated as the encircled area of the closed loop in the V–Q curve, and all V-Q cycles are named as ‘cycles for energy output’ (CEO). By periodic transformation between in load and short circuit conditions, cycles for maximum energy output can be obtained | https://en.wikipedia.org/wiki?curid=30057479 |
Nanogenerator When the load equals infinite, the V-Q becomes a trapezoid shape, the vertices of which are determined by the maximum short-circuit transferred charge Q, and the maximum output energy can be calculated as: formula_20 formula_21 For the TENG operating in CMEO with infinite load resistance, the period T includes two parts of time. One part is from the relative motion in TENG, and the other part is from the discharging process in short-circuit condition. The breakdown effect is widely existing in triboelectric nanogenerators, which will seriously affects the effective maximized energy output, E. Therefore, the average output power P at CMEO considering the breakdown effect should satisfy: formula_22 Where v is the average velocity value of the relative motion in TENG, which depends on the input mechanical motions. In this equation, formula_23 is the only term that depends on the characteristics of the TENG itself. The energy-conversion efficiency of the TENG can be expressed as (at CMEO with R=∞ considering breakdown effects): formula_24 Here F stands for the average dissipative force during the operation of the TENG. This force can be frictional force, air resistance force or others. stands for the average dissipative force during the operation of the TENG. This force can be frictional force, air resistance force or others. Therefore, it can be concluded that the term formula_23 determines both the average power and the energy-conversion efficiency from the characteristics of TENG itself | https://en.wikipedia.org/wiki?curid=30057479 |
Nanogenerator E contains Q that is proportional to the triboelectrification area A. Therefore, to exclude the effect of the TENG size on the output energy, the area A should be placed in denominator of this term and then the term formula_26 determines the merits of TENG. Q, V and V’ are all proportional to the surface charge density σ. Therefore, E is proportional to the square of the surface charge density σ. Then, a dimensionless structural FOM (FOM) of TENG can be defined, as the factor only depends on the structural parameters and x: formula_27 Here ε is the permittivity of the vacuum. This structural FOM represents the merit of the TENG from the structural design. And then the performance FOM (FOM) of TENG can be defined as: formula_28 Here, formula_29 which is the only component related to the material properties. The FOM can be considered as the universal standard to evaluate varieties of TENGs, since it is directly proportional to the greatest possible average output power and related to the highest achievable energy-conversion efficiency, regardless of the mode and the size of the TENG. With the breakdown effect considered, a standardized method is proposed for output capability assessment of nanogenerators, which can experimental measure the breakdown limit and E of nanogenerators. Former studies on the theoretical model implies that TENG can be considered as a voltage source combining with a capacitor in series, of which the capacitance varies during operation | https://en.wikipedia.org/wiki?curid=30057479 |
Nanogenerator Based on the capacitive property, the assessment method is developed by charging the target TENG (TENG1) at different displacement x to measure the breakdown condition. Another TENG (TENG2) is added as the high-voltage source to trigger the target TENG to approach the breakdown condition. Switch 1 (S1) and switch 2 (S2) are used to enable different measurement steps. Detailed process flow of this method, including an experiment part and a data analysis part. First of all, it is critical to keep the surface charge density identical as reflected by Q, to ensure the consistency of measurement at different x. Thus in Step 1, S1 was turned on and S2 was turn off to measure Q; if Q is lower than the expected value, additional triboelectrification process is conducted to approach that. And then in Step 2, x was set into a certain value, and the short-circuit charge transfer Q(x) at a certain x was measured by coulometer Q1. In step 3, S1 was turned off, S2 was turn on, and then the TENG2 was triggered to supply high-voltage output for TENG1. The charge flowing into TENG1 and the voltage across TENG1 was measured at the same time, in which the charge was measured by coulometer Q2, and the voltage was obtained by multiplying the resistance R with the current flowing through it as measured by current meter I, as detailed in Methods. The turning points obtained in this (Q, V) were considered as the breakdown points | https://en.wikipedia.org/wiki?curid=30057479 |
Nanogenerator And then, if x<xmax, the process was repeated starting from step 1 with an increased x, until x was achieved to finish the experimental measurement part. For the data analysis part, first, C(x) was calculated from the slope of the linear part in the measured (Q, V), by considering it as the non-breakdown part. And then, the first turning point (Q(x), V (x)) was determined at the variant R2 value by linearly fitting C(x), which was considered as the threshold breakdown point. Finally, for any x∈[0, x], all the (Q(x), V (x)) can be transferred into (Q(x)- Q(x), V (x)) as the breakdown points plotted in the V-Q cycle to calculate E of TENG. A pyroelectric nanogenerator is an energy harvesting device converting the external thermal energy into an electrical energy by using nano-structured pyroelectric materials. Usually, harvesting thermoelectric energy mainly relies on the Seebeck effect that utilizes a temperature difference between two ends of the device for driving the diffusion of charge carriers. However, in an environment that the temperature is spatially uniform without a gradient, such as in outdoor in our daily life, the Seebeck effect can not be used to harvest thermal energy from a time-dependent temperature fluctuation. In this case, the pyroelectric effect has to be the choice, which is about the spontaneous polarization in certain anisotropic solids as a result of temperature fluctuation. The first pyroelectric nanogenerator was introduced by Prof | https://en.wikipedia.org/wiki?curid=30057479 |
Nanogenerator Zhong Lin Wang at Georgia Institute of Technology in 2012. By harvesting the waste heat energy, this new type of nanogenerator has the potential applications such as wireless sensors, temperature imaging, medical diagnostics, and personal electronics. The working principle of pyroelectric nanogenerator will be explained for 2 different cases: the primary pyroelectric effect and the secondary pyroelectric effect. The working principle for the first case is explained by the primary pyroelectric effect, which describes the charge produced in a strain-free case. The primary pyroelectric effect dominates the pyroelectric response in PZT, BTO, and some other ferroelectric materials. The mechanism is based on the thermally induced random wobbling of the electric dipole around its equilibrium axis, the magnitude of which increases with increasing temperature. Due to thermal fluctuations under room temperature, the electric dipoles will randomly oscillate within a degree from their respective aligning axes. Under a fixed temperature, the total average strength of the spontaneous polarization form the electric dipoles is constant, resulting in no output of the pyroelectric nanogenerator. If we apply a change in temperature in the nanogenerator from room temperature to a higher temperature, the increase in temperature will result in that the electric dipoles oscillate within a larger degree of spread around their respective aligning axes | https://en.wikipedia.org/wiki?curid=30057479 |
Nanogenerator The total average spontaneous polarization is decreased due to the spread of the oscillation angles. The quantity of induced charges in the electrodes are thus reduced, resulting in a flow of electrons. If the nanogenerator is cooled instead of heated, the spontaneous polarization will be enhanced since the electric dipoles oscillate within a smaller degree of spread angles due to the lower thermal activity. The total magnitude of the polarization is increased and the amount of induced charges in the electrodes are increased. The electrons will then flow in an opposite direction. For the second case, the obtained pyroelectric response is explained by the secondary pyroelectric effect, which describes the charge produced by the strain induced by thermal expansion. The secondary pyroelectric effect dominates the pyroelectric response in ZnO, CdS, and some other wurzite-type materials. The thermal deformation can induce a piezoelectric potential difference across the material, which can drive the electrons to flow in the external circuit. The output of the nanogenerator is associated with the piezoelectric coefficient and the thermal deformation of the materials. The output current I of the pyroelectric nanogenerators can be determined by the equation of I=pA(dT/dt), where p is the pyroelectric coefficient, A is the effective area of the NG, dT/dt is the rate of change in temperature | https://en.wikipedia.org/wiki?curid=30057479 |
Nanogenerator Pyroelectric nanogenerator is expected to be applied for various applications where the time-dependent temperature fluctuation exists. One of the feasible applications of the pyroelectric nanogenerator is used as an active sensor, which can work without a battery. One example has been introduced by Professor Zhong Lin Wang's group in 2012 by using a pyroelectric nanogenerator as the self-powered temperature sensor for detecting a change in temperature, where the response time and reset time of the sensor are about 0.9 and 3 s, respectively. In general, the pyroelectric nanogenerator gives a high output voltage, but the output current is small. It not only can be used as a potential power source, but also as an active sensor for measuring temperature variation. | https://en.wikipedia.org/wiki?curid=30057479 |
C22H26O11 The molecular formula CHO (molar mass: 466.43 g/mol, exact mass: 466.147512 u) may refer to: | https://en.wikipedia.org/wiki?curid=30073529 |
C10H14N2O The molecular formula CHNO may refer to: | https://en.wikipedia.org/wiki?curid=30075787 |
Edwin Haslam (1932 – 3 October 2013) was an organic chemist and an author of books on polyphenols. He was an alumnus of Sir John Deane's College in Northwich, Cheshire, United Kingdom and was for many years Professor of Organic Chemistry at the University of Sheffield. Haslam proposed a first comprehensive definition of plant polyphenols based on the earlier proposals of Bate-Smith, Swain and White, which includes specific structural characteristics common to all phenolics having a tanning property. It is referred to as the White–Bate-Smith–Swain–Haslam (WBSSH) definition. | https://en.wikipedia.org/wiki?curid=30087572 |
Dipolar compound In organic chemistry, a dipolar compound or simply dipole is an electrically neutral molecule carrying a positive and a negative charge in at least one canonical description. In most dipolar compounds the charges are delocalized. Unlike salts, dipolar compounds have charges on separate atoms, not on positive and negative ions that make up the compound. Dipolar compounds exhibit a dipole moment. Dipolar compounds can be represented by a resonance structure. Contributing structures containing charged atoms are denoted as zwitterions. Some dipolar compounds can have an uncharged canonical form. | https://en.wikipedia.org/wiki?curid=30102322 |
R. Norris Shreve Randolph Norris Shreve (March 9, 1885 – February 17, 1975) was a chemical engineer, inventor, entrepreneur, educator and collector. After joining the Purdue University faculty in 1930, he helped to build the University's School of Chemical Engineering, the Purdue-Taiwan Engineering Project, and National Cheng Kung University in Taiwan. He and his wife Eleanor are the namesakes of the Shreve Professorship of Organic Technology and Shreve Residence Hall at Purdue, and Shreve Hall on the Cheng Kung University campus. He is the namesake of the Norris Shreve Award for Outstanding Teaching in Chemical Engineering. Shreve was born in St. Louis, Missouri on March 9, 1885. After graduating from Ferguson High School in Ferguson, Missouri, he was unable to afford college, and instead began work as a laboratory boy at the Mallinckrodt Chemical Works in St. Louis, where he learned chemistry from Charles Luedeking and William Lamar. Mallinckrodt loaned him enough money to allow him to attend Harvard University, where he graduated "summa cum laude" in 1907 after only three years of attendance (a record at Harvard that would remain for more than 40 years). After graduating, he returned to Mallinckrodt, where he became a chemist in the alkaloidal department. Lamar and Shreve left Mallinckrodt and St. Louis in 1911 for northern New Jersey, where Lamar founded Lamar Chemical Works, which Shreve soon took over. At age 29, he founded Shreve Chemical Company, before becoming a chemical engineering consultant in 1919 | https://en.wikipedia.org/wiki?curid=30105262 |
R. Norris Shreve In 1923 Shreve became the chief stockholder and president of Ammonite Company, which was then based at the Nixon Nitration Works in what is now Edison, New Jersey. On March 1, 1924, Ammonite, which was involved in extracting ammonium nitrate from shells from the Raritan Arsenal, triggered a massive explosion and resulting fire (known as the 1924 Nixon Nitration Works disaster) that destroyed the Nitration Works. This led to the dissolution of Ammonite in 1926. Shreve joined the Purdue University College of Engineering faculty in 1930, becoming a full professor the next year. He defined his main research field as “organic chemical technology.” Rising through the ranks, he chaired the School of Chemical Engineering from 1947 to 1951. He has been recognized as “the main proponent of teaching industrial chemistry in U.S. chemical engineering departments in the second quarter of the 20th century.” In 1951 he became director of the Purdue-Taiwan Engineering Project, which was intended to improve engineering education in Taiwan, modernize its industries, and improve connections between its colleges of engineering and industries. This also played an important role in the modernization of Taiwan Provincial College of Engineering into Taiwan Provincial Cheng Kung University. From 1952 until 1961, he and his wife spent several months each year in Taiwan assisting the University's development. In 1961, he became a professor emeritus, and was awarded the honorary degree of Doctor of Engineering from Purdue | https://en.wikipedia.org/wiki?curid=30105262 |
R. Norris Shreve Shreve is holder or co-holder of five patents. He wrote several books, most notably "Chemical Process Industries", a major text now in its fifth edition. In 2008 it was recognized by the American Institute of Chemical Engineers and its Centennial Celebration Committee, which included Shreve and "Chemical Process Industries" on its list of "30 Authors and their Groundbreaking Chemical Engineering Books." Mr. and Mrs. Shreve also collected of Asian jade and gems. He eventually donated their jade collection to the Indianapolis Museum of Art, where it is one of the Museum's best-known collections. Their gem collection was donated to Purdue. Shreve died on February 17, 1975, and was interred in Bellafontaine Cemetery, in St. Louis. | https://en.wikipedia.org/wiki?curid=30105262 |
Barium azide is an inorganic azide with the formula Ba(N). Like most azides, it is explosive. It is less sensitive to mechanical shock than lead azide. can be used to make azides of magnesium, sodium, potassium, lithium, rubidium and zinc with their respective sulfates. It can also be used as a source for high pure nitrogen by heating: This reaction liberates metallic barium, which is used as a getter in vacuum applications. | https://en.wikipedia.org/wiki?curid=30107409 |
Diacetyl peroxide is the organic peroxide with the formula (CHCO). It is a white solid or oily liquid with a sharp odor. Since the pure material poses an explosion hazard, it is often used as a solution, e.g., in dimethyl phthalate as a solvent. forms upon combining hydrogen peroxide and excess acetic anhydride. Peracetic acid is an intermediate. Organic peroxides are typically explosive since they contain both the oxidizer, the O-O bond, and reducing agents, the C-C and C-H bonds. It is shock sensitive and explosive. The threshold quantity for Process Safety Management per Occupational Safety and Health Administration 1910.119 is if the concentration of the diacetyl peroxide solution is greater than 70%. There have been reports of detonation of the pure material. The 25% solution also has explosive potential. The crystalline peroxide is especially shock sensitive and a high explosion risk. Contact with liquid causes irritation of eyes and skin. If ingested, irritates mouth and stomach. | https://en.wikipedia.org/wiki?curid=30122659 |
Protein serine/threonine phosphatase (PSP) is a form of phosphoprotein phosphatase that acts upon phosphorylated serine/threonine residues. Serine and threonine phosphates are stable under physiological conditions, so a phosphatase enzyme has to remove the phosphate to reverse the regulation signal. Ser/Thr-specific protein phosphatases are regulated partly by their location within the cell and by specific inhibitor proteins. Serine and threonine are amino acids which have similar side-chain compositions that contain a hydroxyl group and thus can be phosphorylated by enzymes called serine/threonine protein kinases. The addition of the phosphate group can be reversed by enzymes called serine/threonine phosphatases. The addition and removal of phosphate groups regulates many cellular pathways involved in cell proliferation, programmed cell death (apoptosis), embryonic development, and cell differentiation. There are several known groups with numerous members in each: (links are to the catalytic subunit) All but PPP2C have sequence homology in the catalytic domain, but differ in substrate specificity. | https://en.wikipedia.org/wiki?curid=30128701 |
Thallium(III) nitrate Thallium(III) nitrate, also known as thallic nitrate, is a thallium compound with chemical formula Tl(NO). It is normally found as the trihydrate. It is a colorless and highly toxic solid. It is a strong oxidizing agent useful in organic synthesis. Among its many transformations, it oxidizes methoxyl phenols to quinone acetals, alkenes to acetals, and cyclic alkenes to ring-contracted aldehydes. | https://en.wikipedia.org/wiki?curid=30129341 |
Electrochemical engineering is the branch of chemical engineering dealing with the technological applications of electrochemical phenomena, such as electrosynthesis of chemicals, electrowinning and refining of metals, flow batteries and fuel cells, surface modification by electrodeposition, electrochemical separations and corrosion. This discipline is an overlap between electrochemistry and chemical engineering. According with the IUPAC, the term "electrochemical engineering" is reserved for electricity intensive processes for industrial or energy storage applications, and should not be confused with "applied electrochemistry", which comprises small batteries, amperometric sensors, microfluidic devices, microelectrodes, solid-state devices, voltammetry at disc electrodes, etc. More than 6% of the electricity is consumed by large-scale electrochemical operations in the US. combines the study of heterogeneous charge transfer at electrode/electrolyte interphases with the development of practical materials and processes. Fundamental considerations include electrode materials and the kinetics of redox species. The development of the technology involves the study of the electrochemical reactors, their potential and current distribution, mass transport conditions, hydrodynamics, geometry and components as well as the quantification of its overall performance in terms of reaction yield, conversion efficiency, and energy efficiency | https://en.wikipedia.org/wiki?curid=30129507 |
Electrochemical engineering Industrial developments require further reactor and process design, fabrication methods, testing and product development. considers current distribution, fluid flow, mass transfer, and the kinetics of the electro reactions in order to design efficient electrochemical reactors. Most electrochemical operations are performed in filter-press reactors with parallel plate electrodes or, less often, in stirred tanks with rotating cylinder electrodes. Fuel cell and flow battery stacks are types of filter-press reactors. Most of them are continuous operations. This branch of engineering emerged gradually from chemical engineering as electrical power sources became available in the mid 19th century. Michael Faraday described his laws of electrolysis in 1833, relating for the first time the amount of electrical charge and converted mass. In 1886 Charles Martin Hall developed a cheap electrochemical process for the extraction of aluminium from its ore in molten salts, constituting the first true large-scale electrochemical industry. Later, Hamilton Castner improved the process aluminium manufacturing and devised the electrolysis of brine in large mercury cells for the production of chlorine and caustic soda, effectively founding the chlor-alkali industry with Karl Kellner in 1892. The next year, Paul L. Hulin patented filter-press type electrochemical cells in France. Charles Frederick Burgess developed the electrolytic refining of iron ca. 1904 and later ran a successful battery company | https://en.wikipedia.org/wiki?curid=30129507 |
Electrochemical engineering Burgess published one of the first texts on the field in 1920. During the first three decades of the 20th century, industrial electrochemistry followed an empirical approach. After the Second World War, interest focused towards the fundaments of electrochemical reactions. Among other developments, the potentiostat (1937) enabled such studies. A critical advance was provided by the work of Carl Wagner and Veniamin Levich in 1962 who linked the hydrodynamics of a flowing electrolyte towards a rotating disc electrode with the mass transport control of the electrochemical reaction through a rigorous mathematical treatment. The same year, Wagner described for the first time "The Scope of Electrochemical Engineering" as a separated discipline from a physicochemical perspective. During 60s and 70s Charles W. Tobias, who is regarded as the "father of electrochemical engineering" by the Electrochemical Society, was concerned with ionic transport by diffusion, migration, and convection, exact solutions of potential and current distribution problems, conductance in heterogeneous media, quantitative description of processes in porous electrodes. Also in the 60s, John Newman pioneered the study of many of the physicochemical laws that govern electrochemical systems, demonstrating how complex electrochemical processes could be analysed mathematically to correctly formulate and solve problems associated with batteries, fuel cells, electrolyzers and related technologies | https://en.wikipedia.org/wiki?curid=30129507 |
Electrochemical engineering In Switzerland, Norbert Ibl contributed with experimental and theoretical studies of mass transfer and potential distribution in electrolyses, especially at porous electrodes. Fumio Hine carried out equivalent developments in Japan. Several individuals, including Kuhn, Kreysa, Rousar, Fleischmann, Alkire, Coeuret, Pletcher and Walsh established many other training centers and, with their colleagues, developed important experimental and theoretical methods of study. Currently, the main tasks of electrochemical engineering consist in the development of efficient, safe and sustainable technologies for the production of chemicals, metal recovery, remediation and decontamination technologies as well as the design of fuel cells, flow batteries and industrial electrochemical reactors. The history of electrochemical engineering has been summarised by Wendt, Lapicque, and Stankovic. is applied in industrial water electrolysis, electrolysis, electrosynthesis, electroplating, fuel cells, flow batteries, decontamination of industrial effluents, electrorefining, electrowinning, etc. The main example of an electrolysis based process is the Chloralkali process for production of caustic soda and chlorine. Other inorganic chemicals produced by electrolysis include: The established performance criteria, definitions and nomenclature for electrochemical engineering can be found in Kreysa et al. and an IUPAC report. | https://en.wikipedia.org/wiki?curid=30129507 |
Maltese cross (optics) In polymer physics, Maltese Cross is a set of four symmetrically disposed sectors of high extinction that is displayed when a polymer is observed under polarized lights. This is usually observed when trying to observe spheruliltes in polymers. | https://en.wikipedia.org/wiki?curid=30130669 |
IL 17 family The IL17 family is a family of cytokines. Its members are.: T cells expressing these are called "Th17". | https://en.wikipedia.org/wiki?curid=30131172 |
Momordicin is one of several compounds found in the bitter melon vine, including: | https://en.wikipedia.org/wiki?curid=30133192 |
Momordicilin or 24-[1′-hydroxy,1′-methyl-2′-pentenyloxyl]-ursan-3-one is a chemical compound, a triterpenoid with formula , found in the fresh fruit of the bitter melon ("Momordica charantia"). The compound is soluble in ethyl acetate and chloroform but not in petrol. It crystallizes as needles that melt at 170−171 °C. It was isolated in 1997 by S. Begum and others. | https://en.wikipedia.org/wiki?curid=30134314 |
FANC proteins are a group of proteins associated with Fanconi anemia. They are involved in DNA replication and damage response. Components include: | https://en.wikipedia.org/wiki?curid=30136372 |
Mode coupling In the term mode coupling, as used in physics and electrical engineering, the word "mode" refers to eigenmodes of an idealized, "unperturbed", linear system. The superposition principle says that eigenmodes of linear systems are independent of each other: it is possible to excite or to annihilate a specific mode without influencing any other mode; there is no dissipation. In most real systems, however, there is at least "some" perturbation that causes energy transfer between different modes. This perturbation, interpreted as an interaction between the modes, is what is called "mode coupling". Important applications are: | https://en.wikipedia.org/wiki?curid=30139196 |
C9H8N2 The molecular formula CHN may refer to: | https://en.wikipedia.org/wiki?curid=30141033 |
Insertion reaction An insertion reaction is a chemical reaction where one chemical entity (a molecule or molecular fragment) interposes itself into an existing bond of typically a second chemical entity "e.g.": The term only refers to the result of the reaction and does not suggest a mechanism. Insertion reactions are observed in organic, inorganic, and organometallic chemistry. In cases where a metal-ligand bond in a coordination complex is involved, these reactions are typically organometallic in nature and involve a bond between a transition metal and a carbon or hydrogen. It is usually reserved for the case where the coordination number and oxidation state of the metal remain unchanged. When these reactions are reversible, the removal of the small molecule from the metal-ligand bond is called extrusion or elimination. There are two common insertion geometries— 1,1 and 1,2 (pictured above). Additionally, the inserting molecule can act either as a nucleophile or as an electrophile to the metal complex. These behaviors will be discussed in more detail for CO, nucleophilic behavior, and SO, electrophilic behavior. Homologation reactions like the Kowalski ester homologation provide simple examples of insertion process in organic synthesis. In the Arndt-Eistert reaction, a methylene unit is inserted into the carboxyl-carbon bond of carboxylic acid to form the next acid in the homologous series | https://en.wikipedia.org/wiki?curid=30149053 |
Insertion reaction "Organic Syntheses" provides the example of "t"-BOC protected ("S")-phenylalanine (2-amino-3-phenylpropanoic acid) being reacted sequentially with triethylamine, ethyl chloroformate, and diazomethane to produce the α-diazoketone, which is then reacted with silver trifluoroacetate / triethylamine in aqueous solution to generate the "t"-BOC protected form of ("S")-3-amino-4-phenylbutanoic acid. Mechanistically, the α-diazoketone undergoes a Wolff rearrangement to form a ketene in a 1,2-rearrangement. Consequently, the methylene group α- to the carboxyl group in the product is the methylene group from the diazomethane reagent. The 1,2-rearrangement has been shown to conserve the stereochemistry of the chiral centre as the product formed from "t"-BOC protected ("S")-phenylalanine retains the ("S") stereochemistry with a reported enantiomeric excess of at least 99%. A related transformation is the Nierenstein reaction in which a diazomethane methylene group is inserted into the carbon-chlorine bond of an acid chloride to generate an α-chloromethyl ketone. An example, published in 1924, illustrates the reaction in a substituted benzoyl chloride system: Perhaps surprisingly, α-bromoacetophenone is the minor product when this reaction is carried out with benzoyl bromide, a dimeric dioxane being the major product. Organic azides also provide an example of an insertion reaction in organic synthesis and, like the above examples, the transformations proceed with loss of nitrogen gas | https://en.wikipedia.org/wiki?curid=30149053 |
Insertion reaction When tosyl azide reacts with norbornadiene, a ring expansion reaction takes place in which a nitrogen atom is inserted into a carbon-carbon bond α- to the bridge head: The Beckmann rearrangement is another example of a ring expanding reaction in which a heteroatom is inserted into a carbon-carbon bond. The most important application of this reaction is the conversion of cyclohexanone to its oxime, which is then rearranged under acidic conditions to provide ε-caprolactam, the feedstock for the manufacture of Nylon 6. Annual production of caprolactam exceeds 2 billion kilograms. Carbenes undergo both intermolecular and intramolecular insertion reactions. Cyclopentene moieties can be generated from sufficiently long-chain ketones by reaction with trimethylsilyldiazomethane, (CH)Si–CHN: Here, the carbene intermediate inserts into a carbon-hydrogen bond to form the carbon-carbon bond needed to close the cyclopentene ring. Carbene insertions into carbon-hydrogen bonds can also occur intermolecularly: Carbenoids are reactive intermediates that behave similarly to carbenes. One example is the chloroalkyllithium carbenoid reagent prepared "in situ" from a sulfoxide and "t"-BuLi which inserts into the carbon-boron bond of a pinacol boronic ester: Many reactions in organometallic chemistry involve insertion of one ligand (L) into a metal-hydride or metal-alkyl/aryl bond. Generally it is the hydride, alkyl, or aryl group that migrates onto L, which is often CO, an alkene, or alkyne | https://en.wikipedia.org/wiki?curid=30149053 |
Insertion reaction The insertion of carbon monoxide and alkenes into metal-carbon bonds is a widely exploited reaction with major industrial applications. Such reactions are subject to the usual parameters that affect other reactions in coordination chemistry, but steric effects are especially important in determining the stereochemistry and regiochemistry of the reactions. The reverse reaction, the de-insertion of CO and alkenes, are of fundamental significance in many catalytic cycles as well. Widely employed applications of migratory insertion of carbonyl groups are hydroformylation and the carbonylative production of acetic acid. The former converts alkenes, hydrogen, and carbon monoxide into aldehydes. The production of acetic acid by carbonylation proceeds via two similar industrial processes. More traditional is the rhodium-based Monsanto acetic acid process, but this process has been superseded by the iridium-based Cativa process. By 2002, worldwide annual production of acetic acid stood at 6 million tons, of which approximately 60% is produced by the Cativa process. The Cativa process catalytic cycle, shown above, includes both insertion and de-insertion steps. The oxidative addition reaction of methyl iodide with (1) involves the formal insertion of the iridium(I) centre into the carbon-iodine bond, whereas step (3) to (4) is an example of migratory insertion of carbon monoxide into the iridium-carbon bond | https://en.wikipedia.org/wiki?curid=30149053 |
Insertion reaction The active catalyst species is regenerated by the reductive elimination of acetyl iodide from (4), a de-insertion reaction. The insertion of ethylene and propylene into titanium alkyls is the cornerstone of Ziegler-Natta catalysis, the commercial route of polyethylene and polypropylene. This technology mainly involves heterogeneous catalysts, but it is widely assumed that the principles and observations on homogeneous systems are applicable to the solid-state versions. Related technologies include the Shell Higher Olefin Process which produces detergent precursors. the olefin can be coordinated to the metal before insertion. Depending on the ligand density of the metal, ligand dissociation may be necessary to provide a coordination site for the olefin. Many electrophilic oxides insert into metal carbon bonds; these include sulfur dioxide, carbon dioxide, and nitric oxide. These reactions have limited practical significance, but are of historic interest. With transition metal alkyls, these oxides behave as electrophiles and insert into the bond between metals and their relatively nucleophilic alkyl ligands. As discussed in the article on Metal sulfur dioxide complexes, the insertion of SO has been examined in particular detail. Electropositive metals such as sodium, potassium, magnesium, zinc, etc. can insert into alkyl halides, breaking the carbon-halide bond ( halide could be chlorine, bromine, iodine ) and forming a carbon-metal bond | https://en.wikipedia.org/wiki?curid=30149053 |
Insertion reaction This reaction happens via a SET mechanism ( single-electron-transfer mechanism ). If magnesium reacts with an alkyl halide, it forms a Grignard reagent, or if lithium reacts, an organolithium reagent is formed. Thus, this type of insertion reactions has important applications in chemical synthesis. | https://en.wikipedia.org/wiki?curid=30149053 |
Pyrosulphite may refer to: | https://en.wikipedia.org/wiki?curid=30154930 |
Trinitramide is a compound of nitrogen and oxygen with the molecular formula N(NO). The compound was detected and described in 2010 by researchers at the Royal Institute of Technology (KTH) in Sweden. It is made of a nitrogen atom bonded to three nitro groups(-NO). Earlier, there had been speculation whether trinitramide could exist. Theoretical calculations by Montgomery and Michels in 1993 showed that the compound was likely to be stable. has a potential use as one of the most efficient and least polluting of rocket propellant oxidizers, as it is chlorine-free. This is potentially an important development, because the Tsiolkovsky rocket equation implies that even small improvements in rocket delta-v can make large improvements in the size of practical rocket launch payloads. The density impulse (impulse per volume) of a trinitramide based propellant could be 20 to 30 per cent better than most existing formulations, however the specific impulse (impulse per mass) of formulations with liquid oxygen is higher. | https://en.wikipedia.org/wiki?curid=30157198 |
Flory–Fox equation Flory function<br>"Synonym": viscosity function, formula_1, SI unit: mol Coefficient connecting the intrinsic viscosity, the mean-square radius of gyration, and the molar mass of a chain macromolecule, according to the equation Kirkwood–Riseman theory Theory, based on the "pearl-necklace model", that describes the translational diffusive and viscous flows of an isolated linear macromolecule in solution in the "theta state" and accounts for the gradual change from "freedraining" behaviour at lower molecular weights to "impermeable" behaviour at higher molecular weights. The Kirkwood–Riseman theory is usually applied in the "impermeable" limit when it essentially relates the "equivalent hydrodynamic radius" to the "root-mean-square unperturbed radius of gyration", <formula_5>, with where formula_6 and formula_7 are the "equivalent hydrodynamic radii" in translational diffusive flow and viscous flow. Flory–Fox assumption Asumption that the "Kirkwood–Riseman theory" can be applied to linear isolated macromolecules in solution, independent of whether they are in the "theta state". The Kirkwood–Riseman relationships between formula_6 and formula_7 and the "root-mean-square radius of gyration", <formula_3>, are then where formula_6 and formula_7 are the "equivalent hydrodynamic radii" in translational diffusive flow and viscous flow, and formula_13 and formula_14 are the corresponding "expansion factors" | https://en.wikipedia.org/wiki?curid=30160065 |
Flory–Fox equation In polymer chemistry, the is a simple empirical formula that relates molecular weight to the glass transition temperature of a polymer system. The equation was first proposed in 1950 by Paul J. Flory and Thomas G. Fox while at Cornell University. Their work on the subject overturned the previously held theory that the glass transition temperature was the temperature at which viscosity reached a maximum. Instead, they demonstrated that the glass transition temperature is the temperature at which the free space available for molecular motions achieved a minimum value. While its accuracy is usually limited to samples of narrow range molecular weight distributions, it serves as a good starting point for more complex structure-property relationships. The relates the number-average molecular weight, "M", to the glass transition temperature, "T", as shown below: where "T" is the maximum glass transition temperature that can be achieved at a theoretical infinite molecular weight and "K" is an empirical parameter that is related to the free volume present in the polymer sample. It is this concept of “free volume” that is observed by the Flory–Fox equation. Free volume can be most easily understood as a polymer chain's “elbow room” in relation to the other polymer chains surrounding it. The more elbow room a chain has, the easier it is for the chain to move and achieve different physical conformations | https://en.wikipedia.org/wiki?curid=30160065 |
Flory–Fox equation Free volume decreases upon cooling from the rubbery state until the glass transition temperature at which point it reaches some critical minimum value and molecular rearrangement is effectively “frozen” out, so the polymer chains lack sufficient free volume to achieve different physical conformations. This ability to achieve different physical conformations is called segmental mobility. Free volume not only depends on temperature, but also on the number of polymer chain ends present in the system. End chain units exhibit greater free volume than units within the chain because the covalent bonds that make up the polymer are shorter than the intermolecular nearest neighbor distances found at the end of the chain. In other words, chain end units are less dense than the covalently bonded interchain units. This means that a polymer sample with long chain lengths (high molecular weights) will have fewer chain ends per total units and less free volume than a polymer sample consisting of short chains. In short, chain ends can be viewed as an “impurity” when considering the packing of chains, and more impurity results in a lower "T". Thus, glass transition temperature is dependent on free volume, which in turn is dependent on the average molecular weight of the polymer sample. This relationship is described by the Flory–Fox equation | https://en.wikipedia.org/wiki?curid=30160065 |
Flory–Fox equation Low molecular weight values result in lower glass transition temperatures whereas increasing values of molecular weight result in an asymptotic approach of the glass transition temperature to "T" . The figure to the left clearly displays this relationship – as molecular weight increases, the glass transition temperature increases asymptotically to "T" (in this arbitrary case shown in the image, "T" = 365 K). While the describes many polymers very well, it is more reliable for large values of "M" and samples of narrow weight distribution. As a result, other equations have been proposed to provide better accuracy for certain polymers. For example: This minor modification of the Flory–Fox equation, proposed by Ogawa, replaces the inverse dependence on "M" with the square of the product of the number-average molecular weight, "M" , and weight-average molecular weight, "M" . Additionally, the equation: was proposed by Fox and Loshaek, and has been applied to polystyrene, polymethylmethacrylate, and polyisobutylene, among others. However, it is important to note that despite the dependence of "T" on molecular weight that the Flory-Fox and related equations describe, molecular weight is not necessarily a practical design parameter for controlling "T" because the range over which it can be changed without altering the physical properties of the polymer due to molecular weight change is small | https://en.wikipedia.org/wiki?curid=30160065 |
Flory–Fox equation The serves the purpose of providing a model for how glass transition temperature changes over a given molecular weight range. Another method to modify the glass transition temperature is to add a small amount of low molecular weight diluent, commonly known as a plasticizer, to the polymer. The presence of a low molecular weight additive increases the free volume of the system and subsequently lowers "T" , thus allowing for rubbery properties at lower temperatures. This effect is described by the Fox equation: Where "w" and "w" are weight fractions of components 1 and 2, respectively. In general, the accuracy of the Fox equation is very good and it is commonly also applied to predict the glass transition temperature in (miscible) polymer blends and statistical copolymers. | https://en.wikipedia.org/wiki?curid=30160065 |
Microalgal bacterial flocs Microalgae do not settle by gravity, therefore expensive harvesting techniques must be applied. This is a major bottleneck of microalgal technology. Bioflocculation of microalgae and bacteria addresses this. MaB-flocs or Microalgal Bacterial flocs settle by gravity, up to density of 20 g per liter. This is a major improvement for microalgal technology for wastewater treatment. Currently, MaB-flocs are being applied for sewage treatment on lab and pilot scale in Germany, New Zealand and Belgium. The idea is to scavenge nutrients such as nitrogen and phosphorus from the wastewater, sometimes combined with flue gas treatment. | https://en.wikipedia.org/wiki?curid=30167273 |
Paleostress Palaeo means past, thus paleostress (or palaeostress) means stresses that acted in the geological past (i.e. thousands to millions of years ago). In Geology paleostress analysis is concerned with deriving the directions along which the stress acted and gave rise to present structural feature in the rocks on earth. is a subset of mechanical stress within geology. Variations in stress fields within the Earth's crust can result in a variety of mechanical responses: Traditionally, deformation—either folding or fracturing—without dissolution are collectively termed mechanical strain. Both macroscopic and microscopic strain may be elastic, and only exist as long as differential stress exists, or it may be inelastic -- that is the deformation due to a particular stress event remains even after the stress is removed. In the latter case, inelastic deformation, the stress field responsible for the deformation if it can be inferred, is, then, the "paleostress". Anderson's classic analysis of faulting serves as a simple application of paleostress analysis in terms of principal components of stress. Zoback and Zoback's (1986) synthesis of contemporary stress measurements in North America was subsequently expanded to a global study (Zoback et al., 1989) which continues as the World Stress Project. Only a small subset of measurements in the WSP database qualify as paleostresses | https://en.wikipedia.org/wiki?curid=30188279 |
Paleostress A number of regional studies of paleostresses has been undertaken, including Europe (Bergerat, 1987); North America (synthesized by Bird, 2002; Pilger, 2003), Australia (Pilger, 1982). | https://en.wikipedia.org/wiki?curid=30188279 |
Fluorescent chloride sensors are used for chemical analysis. The discoveries of chloride (Cl) participations in physiological processes stimulates the measurements of intracellular Cl in live cells and the development of fluorescent tools referred below. quinolinium - based Cl indicators are based on the capability of halides to quench the fluorescence of heterocyclic organic compounds with quaternary nitrogen. Fluorescence is quenched by a collision mechanism with a linear Stern–Volmer relationship: formula_1 where:<br> formula_2 is the fluorescence in the absence of halide<br> formula_3 is the fluorescence in the presence of halide<br> formula_4 is the Stern–Volmer quenching constant, which depends on the chloride concentration, formula_5. in a linear manner. Thus, quinoline-based indicators are one-wavelength dyes - the signal results from monitoring the fluorescence at a single wavelength. Ratiometric measurement of halide concentration is not possible with quinolinium dyes. The kinetics of collision quenching are diffusion-limited only, and these indicators provide submillisecond time resolution. Quinolinium-based dyes are insensitive to physiological changes in pH, but they are prone to strong bleaching and demand ultraviolet excitation, which is harmful for living organisms. Because quinolinium is not occurring in the cells naturally, cell loading is necessary. However, quinolinium-based dyes aren't retained perfectly in the cell and can't be targeted easily to subcellular organelles | https://en.wikipedia.org/wiki?curid=30189546 |
Fluorescent chloride sensors Also, they cannot be designed specific to a certain type of cell. The most used quinolinium-based Cl indicators are 6-methoxy-1-(3-sulfonatopropyl) quinolinium (SPQ), 6-methoxy-N-ethylquinolium Cl (MEQ), and N-(6-methoxyquinolyl)-acetoethyl ester (MQAE). Clindicators can be designed on the basis of endogenously expressed fluorescent proteins such as Yellow fluorescent protein (YFP). An advantage of endogenously expressed probes over dye-based probes is their ability to achieve cell-type-specificity by the choice of Promoter_(genetics) promotor. YFP based indicators are mutated forms of Green fluorescent protein (GFP). YFP contains four point mutations and has a red-shifted excitation and emission spectrum compared with GFP. YFP fluorescence is sensitive to various small anions with relative potencies iodine > nitrate > chloride > bromide > formate > acetate. YFP sensitivity to these small anions results from ground-state binding near the chromophore, which apparently alters the chromophore ionization constant and hence the fluorescence emission. The fluorescence of YFP is sensitive to [Cl ] and pH. The effect is fully reversible. YFP is excited at visible range and is a genetically encoded probe. YFP based Cl sensors have rather low kinetics of Cl association / dissociation. The half time association/dissociation constants for YFP mutant range from 50 ms (YFP-H148Q I152L) to 2 sec (YFP-H148Q V163S) | https://en.wikipedia.org/wiki?curid=30189546 |
Fluorescent chloride sensors If a fluorescent indicators is based on one fluorescent protein only, it doesn't allow for ratiometric measurements. Hence, a rationale for ratiometric fluorescent indicators results. Förster resonance energy transfer (FRET)-based Cl indicators consist of two fluorescent proteins, Cyan fluorescent protein (CFP) and YFP connected via a polypeptide linker. This allows ratiometric Cl measurements based on the Cl sensitivity of YFP and Cl insensivity of CFP. Clomeleon and Cl Sensor are FRET-based Cl indicators that allow ratiometric non-invasive monitoring of chloride activity in living cells. | https://en.wikipedia.org/wiki?curid=30189546 |
Metamaterials Handbook is a two-volume handbook on metamaterials edited by Filippo Capolino (University of California). The series is designed to cover all theory and application topics related to electromagnetic metamaterials. Disciplines have combined to study, and develop electromagnetic metamaterials. Some of these disciplines are optics, physics, electromagnetic theory (including computational methods) microfabrication, microwaves, nanofabrication, nanotechnology, and nanochemistry. "Theory and Phenomena of Metamaterials" is the first volume of the "Metamaterials Handbook". It contains contributions from researchers (scientists) who have produced accepted results in the field of metamaterials. Most of the contributors are associated with Metamorphose VI AISBL, a non-profit, European organization that focuses on artificial electromagnetic materials and metamaterials. Metamorphose provided access to the network of contributors (researchers) who work in a variety of scientific disciplines, involved with metamaterials This book is in an article review format, covering prior work in metamaterials. It focuses on theories underpinning metamaterial research along with the properties of metamaterials. The text covers all areas of metamaterial research. "Applications of Metamaterials" is the second volume of the "Metamaterials Handbook". This book derives its organization for discussion of its topics from the previous volume | https://en.wikipedia.org/wiki?curid=30193699 |
Metamaterials Handbook Theory, modeling, and basic properties of metamaterials that were explored in the first volume, are now shown how they work when applied. Devices based on electromagnetic metamaterials continue to expand understanding of principles and modeling begun in the first volume. The applications for metamaterials are shown to be wide-ranging, encompassing electronics, telecommunications, sensing, medical instrumentation, and data storage. This book also discusses the key domains of where metamaterials have already been developed. The material in this book is obtained from highly regarded sources, such as many scientific, peer reviewed, journal articles. | https://en.wikipedia.org/wiki?curid=30193699 |
Liquid junction interface In mass spectrometry, liquid junction interface is an ion source or set-up that couples peripheric devices, such as capillary electrophoresis, to mass spectrometry. See the IUPAC recommendation definition as a means of coupling capillary electrophoresis to mass spectrometry in which a liquid reservoir surrounds the separation capillary and transfer capillary to the mass spectrometer. The reservoir provides electrical contact for the capillary electrophoresis. The term liquid junction interface has also been used by Henry M. Fales and coworkers for ion sources where the analyte is in direct contact with the high voltage supply. This includes in particular nanospray ion sources where a wire made of stainless steel, gold or other conducting material makes contact with the sample solution inside uncoated spray capillaries. The principle is also applied when a stainless steel union connects a chromatography outlet to a spray capillary. Its use has a number of advantages with respect to simplification of interface or source design, easy handling and cost. Electrolysis effects have to be controlled. Liquid junction interfaces have been used for on-line desalting in conjunction with mass spectrometry. Thereby, chromatographic material such as C18 phase was directly placed in the flow path coming from a pump or an HPLC device. In a variation of the method, fine capillaries were densely packed with chromatographic phase to form separation columns and act as electrospray capillaries at the same time | https://en.wikipedia.org/wiki?curid=30197642 |
Liquid junction interface This method is commonly employed in many proteomics laboratories. It is of note that experimental designs where the direct application of high voltages to liquids to form aerosols and sprays has been described as early as 1917 in the context of not ionization, but atomization of liquids. Liquid junction potential - the process which occurs when two solutions of different concentrations are in contact with each other | https://en.wikipedia.org/wiki?curid=30197642 |
Momordicoside is any of several related cucurbitane triterpenoid glycosides that can be extracted from the bitter melon vine ("Momordica charantia"). They include: Momordicosides A, B, F, F K–N, and S can be extracted from the fruit with methanol. | https://en.wikipedia.org/wiki?curid=30209803 |
Goyaglycoside is any of several related triterpenoid glycosides found in the fruits bitter melon vine ("Momordica charantia"), called "goya" in Okinawan language. They include: Goyaglycosides c and d can be extracted from the fresh fruit with methanol and ethyl acetate. | https://en.wikipedia.org/wiki?curid=30209858 |
Karaviloside is any of several related cucurbitane triterpenoid glycosides found in bitter melon vine ("Momordica charantia"). They include: Karavilosides I, II, and III can be extracted from the "M. charantia" fruit with methanol. Karavilosides III, V, and XI can be extracted from the "M. charantia" roots by methanol. | https://en.wikipedia.org/wiki?curid=30209874 |
Beta-Eleostearic acid β-Eleostearic acid, or (9"E",11"E",13"E")-octadeca-9,11,13-trienoic acid, is an organic compound with formula or HC(CH)(CH=CH)(CH)COOH. It is the all-"trans" conformational isomer of octadecatrienoic acid. | https://en.wikipedia.org/wiki?curid=30210534 |
Seymour Shapiro Seymour Lester Shapiro (1916 - 1961) was an organic chemist best known for his pioneering work on a class of drugs used to treat symptoms of adult-onset diabetes. Phenformin was marketed under the name "DBI" until it was taken off the market after being linked to increased incidence of lactic acidosis, a potentially fatal condition. Shapiro was born in New York City, New York, on October 1, 1916. After graduation at age 14 from the storied Abraham Lincoln High School (Brooklyn, New York) in 1931, he entered Brooklyn College where he majored in Chemistry and received the degree of Bachelor of Science in June 1935 at the age of 19. In 1934 while a junior in Brooklyn College, he tied for first place in a citywide contest in handling difficult problems of calculus. He completed the degree of Master of Science in June 1937 at Brooklyn Polytechnic Institute (now part of New York University), New York. His thesis, "Equimolecular Condensation of Aldehydes with Phenols" was published in the Journal of the American Chemical Society (JACS) in 1937. During the period 1936 - 41, Shapiro was employed in the Railway Mail Service and as a quantitative organic microanalyst at Van Ameringen-Haebler in Elizabeth, NJ (later part of International Flavors & Fragrances). In July, 1941 he entered the United States Army. His initial tour within the United States included an assignment covered by "Time" magazine | https://en.wikipedia.org/wiki?curid=30211428 |
Seymour Shapiro During this period he was assigned the task of making injectable poison ivy extract for use in treatment of poison ivy infections. While it proved quite successful on the troops, Shapiro himself developed an extreme sensitivity to the extract and the ivy plant itself. He was then assigned as Toxicologist in the 15th Medical General Laboratory and then as Chemist of the Board for the Study of the Severely Wounded, Mediterranean Theater of Operations. The findings of this group were published in the book entitled, "The Physiologic Effects of Wounds." As an additional outgrowth of this work, Shapiro published "A Suggested Simplification of Blood Volume Analysis Using the Dye T 1824," For his work on this Board, Shapiro was awarded the Bronze Star Medal. He was discharged from the army in 1946 with the rank of Major. Following his military service, Shapiro became Director of the Biological Laboratory, Arlington Chemical Co., Yonkers, New York, and, in January 1952, was assigned as Assistant Director, Organic Research, US Vitamin Corp., Yonkers, New York. His work there drew attention from "The Talk of the Town" section of "The New Yorker". The work for Shapiro's doctoral thesis, "Reaction of Phenyl Biguanide with Esters and Related Compounds", published in JACS in 1954, was performed at the Polytechnic Institute of Brooklyn and in the laboratories of the Arlington Chemical Co. and US Vitamin Corp. under the direction of Prof. Charles G. Overberger. His work there led to the development of DBI | https://en.wikipedia.org/wiki?curid=30211428 |
Seymour Shapiro Shapiro was the author or co-author of 70 articles in scientific journals specializing in organic and pharmaceutical chemistry. The subject range included blood chemistry, anesthetics, androgens, biguanides, diuretics, indanols, indandiones, triazines and others. A total of 76 patents bear his name as inventor or co-inventor, all on subjects related to organic and pharmaceutical chemistry. In an ironic turn, after a successful career in the field of hypoglycemic and blood chemistry, he fell victim to diabetes (Type 1, against which DBI was not effective) and leukemia. After a protracted illness he died on December 9, 1961, at 45 years of age. In 1962, the Seymour L. Shapiro Award in Organic Chemistry was established at the Polytechnic Institute of Brooklyn. The award is given as merited to an outstanding graduate in Organic Chemistry. Shapiro was posthumously awarded the Freedman Patent Award from the American Institute of Chemists in 1968. Shapiro married Florence Susan Mintz in 1951, and had two sons, Mitchell and Saul Shapiro. | https://en.wikipedia.org/wiki?curid=30211428 |
Octadecatrienoic acid An octadecatrienoic acid is a chemical compounds with formula , a fatty acid with whose molecule has an 18-carbon unbranched backbone with three double bonds. The name refers to many different structural and conformational isomers, that differ in the position of the double bonds along the backbone and on whether they are in "cis" ('Z') or "trans" ('E') conformation. Some isomers have considerable biological, pharmaceutical, or industrial importance, such as: | https://en.wikipedia.org/wiki?curid=30212398 |
Edward M. Burgess Professor Burgess served as Secretary-Treasurer of the Organic Division of the American Chemical Society from 1974 to 1977. Edward Meredith Burgess was born in Birmingham, Alabama in 1934. He attended Shades Valley High School in that city and was awarded the school's science award upon graduation in 1951. During the summers of his junior and senior high school years he obtained a job performing routine chores at the University of Alabama at Birmingham (UAB) Department of Biochemistry. It was during this period at UAB that Burgess began his career in chemical research. Under the guidance of the noted carbohydrate chemist, William Ward Pigman, he was given his own research project, the “"Anhydrous Reaction of Nitrogen Dioxide with some Selected Sugars."” In 1952 Burgess was awarded an NROTC scholarship and entered Auburn University with a dual major in chemistry and physics. During his undergraduate years at Auburn he undertook research in the laboratories of Frank Stevens (Chemistry) on the Synthesis of Indole Derivatives useful as Plant Growth Regulators and Howard Carr (Physics) on the construction of a mass spectrometer. He obtained his B.Sc. Degree ("cum laude") in 1956. From 1956-1959 Burgess served as an officer aboard the US Navy destroyer, USS Stormes (DD-780), a ship assigned to both the U.S. Atlantic and Mediterranean fleets. As a graduate student in the Büchi group at the Massachusetts Institute of Technology, Burgess's research focused largely on synthetic organic chemistry and photochemistry | https://en.wikipedia.org/wiki?curid=30222453 |
Edward M. Burgess His doctoral dissertation was titled “Photochemical isomerization of eucarvone and cyclooctatrienone; Studies toward the synthesis of samandarin.” An interest in photochemistry and synthetic methodology would mark many of Burgess's contributions to chemistry. In addition to his publications with Professor Büchi connected with his dissertation, Burgess also published independently on the epoxidation of chloestadienone.<br> | https://en.wikipedia.org/wiki?curid=30222453 |
Wilhelm Steinkopf Georg (28 June 1879 – 12 March 1949) was a German chemist. Today he is mostly remembered for his work on the production of mustard gas during World War I. Georg was born on 28 June 1879 in Staßfurt, in the Prussian Province of Saxony in the German Empire, the son of Gustav Friedrich Steinkopf, a merchant, and his wife Elise Steinkopf (née Heine). In 1898 he began studying chemistry and physics at the University of Heidelberg. In 1899 he moved to the "Technische Hochschule Karlsruhe" (today the Karlsruhe Institute of Technology), where he finished his studies with a degree as "Diplomingenieur" in 1905. In Karlsruhe, he also met his future colleagues Fritz Haber and Roland Scholl. After receiving his Doctor of Science and eventually his Habilitation in 1909, he worked as an associate professor at the "TU Karlsruhe" until 1914, when he volunteered for service in World War I. In 1916 Fritz Haber, who was now the director of the Kaiser Wilhelm Institute for Physical Chemistry and Electrochemistry ("KWIPC", today the Fritz Haber Institute of the Max Planck Society) in Berlin, invited Steinkopf to join his institute as the head of a team devoted to research on chemical weapons. Together with chemical engineer Wilhelm Lommel, Steinkopf developed a method for the large-scale production of bis(2-chloroethyl) sulfide, commonly known as mustard gas. Mustard gas was subsequently assigned the acronym LOST (LOmmel/STeinkopf) by the German military | https://en.wikipedia.org/wiki?curid=30230629 |
Wilhelm Steinkopf Steinkopf's work on mustard gas and related substances had a negative impact on his health, which caused him to switch to another department of the KWIPC in 1917, supervising the production of gas ammunition. Although Fritz Haber wanted him to stay in Berlin, Steinkopf moved to Dresden after the end of World War I. Succeeding as the associate professor in organic chemistry at the Technische Universität Dresden, he worked there from 1919 until his retirement. His research focussed on organic arsenic compounds, thiophene compounds, and the formation of petroleum. In 1924, Steinkopf became a member of the "Beirat des Heereswaffenamts" ("Heereswaffenamt" advisory council), an agency of the German military responsible for weapons research and development. He worked under strict secrecy and most of his friends and colleagues in Dresden did not know about this activity. After the "Machtergreifung" of the National Socialists in 1933, "Reichswehrminister" Werner von Blomberg demanded the Saxonian "Volksbildungsministerium" (Ministry of the People's Education) to show more recognition for Steinkopf's work during World War I. In 1935, Steinkopf was promoted to full professor, and continued to work at the TU Dresden until his retirement in 1940. His health being fragile due to his work with mustard gas and related substances, Steinkopf died on 12 March 1949 in Stuttgart. Aside from his scientific research, Steinkopf wrote several poems, novellas, and novels. | https://en.wikipedia.org/wiki?curid=30230629 |
Infiltration/Inflow (I/I) causes dilution in sanitary sewers. Dilution of sewage decreases the efficiency of treatment, and may cause sewage volumes to exceed design capacity. Although inflow is technically different from infiltration, it may be difficult to determine which is causing dilution problems in inaccessible sewers. The United States Environmental Protection Agency defines the term infiltration/inflow as combined contributions from both. Early combined sewers used surface runoff to dilute waste from toilets and carry it away from urban areas into natural waterways. Sewage treatment can remove some pollutants from toilet waste, but treatment of diluted flow from combined sewers produces larger volumes of treated sewage with similar pollutant concentrations. Modern sanitary sewers are designed to transport domestic and industrial wastewater directly to treatment facilities without dilution. Groundwater entering sanitary sewers through defective pipe joints and broken pipes is called "infiltration". Pipes may leak because of careless installation; they may also be damaged after installation by differential ground movement, heavy vehicle traffic on roadways above the sewer, careless construction practices in nearby trenches, or degradation of the sewer pipe materials. In general, volume of leakage will increase over time. Damaged and broken sewer cleanouts are a major cause of infiltration into municipal sewer systems. Infiltration will occur where local groundwater elevation is higher than the sewer pipe | https://en.wikipedia.org/wiki?curid=30233522 |
Infiltration/Inflow Gravel bedding materials in sewer pipe trenches act as a French drain. Groundwater flows parallel to the sewer until it reaches the area of damaged pipe. In areas of low groundwater, sewage may exfiltrate into groundwater from a leaking sewer. Water entering sanitary sewers from inappropriate connections is called "inflow". Typical sources include sump pumps, roof drains, cellar drains, and yard drains where urban features prevent surface runoff, and storm drains are not conveniently accessible or identifiable. Inflow tends to peak during precipitation events, and causes greater flow variation than infiltration. Peak flows caused by inflow may generate a foul flush of accumulated biofilm and sanitary solids scoured from the dry weather wetted perimeter of oversized sewers during peak flow turbulence. Sources of inflow can sometimes be identified by smoke testing. Smoke is blown into the sewer during dry weather while observers watch for smoke emerging from yards, cellars, or roof gutters. Dilution of sewage directly increases costs of pumping and chlorination, ozonation, or ultraviolet disinfection. Physical treatment structures including screens and pumps must be enlarged to handle the peak flow. Primary clarifiers must also be enlarged to treat average flows, although primary treatment of peak flows may be accomplished in detention basins | https://en.wikipedia.org/wiki?curid=30233522 |
Infiltration/Inflow Biological secondary treatment is effective only while the concentration of soluble and colloidal pollutants (typically measured as biochemical oxygen demand or BOD) remains high enough to sustain a population of microorganisms digesting those pollutants. Secondary treatment is expected to remove 85 percent of soluble and colloidal organic pollutants from sewage containing 200 mg/L BOD; but BOD removal by conventional biological secondary treatment becomes less effective with dilution and practically ceases as BOD concentrations entering the treatment facility are diluted below about 20 mg/L. Unremoved organics are potentially converted to disinfection by-products by chemical disinfection prior to discharge. High rates of infiltration/inflow may make the sanitary sewer incapable of carrying sewage from the design service area. Sewage may back up into the lowest homes during wet weather, or street manholes may overflow. Smoke test results may not correlate well with flow volumes; although they can identify potential problem locations. Where sewage flow is expected to be relatively uniform, significance of infiltration and inflow may be estimated by comparison of sewage flow at the same point during wet and dry weather or at two sequential points within the sewer system. Small areas with large flow differences can be identified if the sewer system provides adequate measuring locations | https://en.wikipedia.org/wiki?curid=30233522 |
Infiltration/Inflow It may be necessary to replace a section of sewer line if flow differences cannot be corrected by removing identified connections. | https://en.wikipedia.org/wiki?curid=30233522 |
Float (liquid level) Liquid level floats, also known as float balls, are spherical, cylindrical, oblong or similarly shaped objects, made from either rigid or flexible material, that are buoyant in water and other liquids. They are non-electrical hardware frequently used as visual sight-indicators for surface demarcation and level measurement. They may also be incorporated into switch mechanisms or translucent fluid-tubes as a component in monitoring or controlling liquid level. Liquid level floats, or float switches, use the principle of material buoyancy (differential densities) to follow fluid levels. Solid floats are often made of plastics with a density less than water or other application liquid, and so they float. Hollow floats filled with air are much less dense than water or other liquids, and are appropriate for some applications. Stainless Steel Magnetic floats are tubed magnetic floats, used for reed switch activation; they have a hollow tubed connection running through them. These magnetic floats have become standard equipment where strength, corrosion resistance and buoyancy are necessary. They are manufactured by welding two drawn half shells together. The welding process is critical for the strength and durability of the float. The weld is a full penetration weld providing a smoothly finished seam, hardly distinguishable from the rest of the float surface. | https://en.wikipedia.org/wiki?curid=30250063 |
International trade and water is the relationship between international trade and the water being used by humans. The substantial increase in human population during the 20th century combined with rapid increases in overall global economic development has resulted in rising challenges for the future of public water management. The developing world has been particularly impacted by the lack of access to clean water. Each year, millions of people die due to illnesses, diseases, and lack the capital to create the infrastructure necessary to combat the problem. These conditions have increased the global demand for clean water and in turn, have pressured free market economists to suggest that wealthy market players are the most efficient solution to addressing water issues. Several nations can benefit from international trade in water. Particularly nations with excess fresh water and abundant capital are looking forward to making healthy profits from either the export of water to other nations, or are interested in the investment returns they will earn from participation in foreign markets. However, not everyone agrees that market forces are best capable of solving water issues. NGO’s, human rights organizations, and various stakeholders oppose viewing water in economic terms. These individuals accuse international trade agreements and international economic institutions including the World Bank and the International Monetary Fund (IMF) of attempting to privatize a resource that they consider a basic human right | https://en.wikipedia.org/wiki?curid=30256789 |
International trade and water The lack of a common understanding of whether or not water should be viewed as a commodity or a basic human right has resulted in heated debates among legal professionals and leading members of the academia. Prior to the industrial period, water had been extracted by whichever local community lived around it. As the industrial period progressed however, this view began to be replaced by a more economic oriented approach. Today, most water goes through a complicated industrial process that begins with its extraction and ends in a complicated process involving pipes, dams, and other sorts of unnatural facilities. Even fresh water that is located in rivers and lakes must somehow be extracted. In general these considerations involve the use of land, labor and capital thereby replacing the notion of a common resource into a value based product. Desalinization and desalinization plants play a major role also. In 2000, out of the 40 IMF loans distributed 12 had requirements of partial or full privatization of water supplies.iv Likewise 50 percent of World Bank loans issued in 2002 to developing countries contained a clause that requested privatization of water services. In addition to international institutions pushing for privatization, trade agreements in the 20th century have also created the legal framework for allowing the sale of water | https://en.wikipedia.org/wiki?curid=30256789 |
International trade and water The GATS, known as the General Agreement on Trade in Services, operates on a list in approach, meaning it allows privatization in areas that the nation has agreed to open to other members. The Doha Development Round of negotiations aims at changing this stature. During these negotiations it was declared that no sector is to be excluded from the negotiations to the new agreement. If water services negotiations succeed then once a member chooses to open their markets to their own private sector, then will have to afford other members the same rights to invest in that sector. Many regional trade agreements do not have a list in approach and are therefore subject to the same conditions mentioned above. For example, in the US-CAFTA agreement only Costa Rica directly specified that water services were to be excluded from foreign investment the other nations made no similar request. Due to the mixed results obtained from privatization of water services and the difficulty of reversing that decision, several actors have strongly opposed the export of bulk fresh water. These actors claim that once such an action is allowed to occur then it will establish a precedent of treating water just like any other export. This in turn will become legally binding and irreversible. Canada is one of the largest owners of fresh water and has for years been engaged in a legal dispute over its possession of the resource | https://en.wikipedia.org/wiki?curid=30256789 |
International trade and water In 1990 an American company named Sunbelt was invited by the government of British Columbia to invest in a water exporting operation. Due to setbacks, the contract never matured and Sunbelt sued the government of British Columbia for failing to meet its obligations. After years of battle the Canadian government declared in 1999 that water in its fresh state as those found in rivers and lakes contains no economic value, and is therefore outside the obligations of its trade agreement. In addition, the government cited article XI of GATT (G). This article allows for the conservation of a natural resource as long as the action taken by the government is done in a non-discriminatory manner. Sunbelt however, disagreed with the applicability of this clause and claimed that Canada’s actions are in direct violation of several international trade agreements. Particularly, Sunbelt addressed Article XI of GATT which forbids a member nation from imposing measures other than taxes, levies and other charges on the export of its good. Likewise, Sunbelt argued that the water located in British Columbia belonged to US companies just as much as it belongs to Canadian companies. This argument is based on Article 11 of NAFTA known as the investment chapter. Once water is extracted from its natural state for whatever reason that same right must be given to foreign investors. Sunbelt argues that Canadian companies had such extractions in the past and therefore opened the door for foreign investors to come in and do likewise | https://en.wikipedia.org/wiki?curid=30256789 |
International trade and water In 2002, Israel agreed to buy 1.75 billion cubic feet of water from Turkey every year for a period of 20 years. The method of transport involved the use of large plastic bubbles that would bring the water to the storage facility. In regards to the talks, the foreign minister of Turkey declared that this agreement will increase the cooperation between the two countries and also lead to peace and stability in the Middle East. Economically Israel concluded that the cost of importing water would be higher than choosing the desalinization option but chose to import anyway. In addition to hoping to achieve peace the foreign minister also mentioned that the landmark agreement turns water into an internationally accepted "commodity," and that Turkey hopes to sell water to other countries. Turkey canceled the deal after the Gaza Flotilla Raid by IDF commandos Gaza Flotilla Raid on May 31 2010. During this incident several Turkish nationals were killed by Israeli armed forces. In July 2010, the UN General Assembly declared that access to clean water and sanitation is a human right. The assembly did not specify whether a public authority or the private sector would be best capable of providing this right. i (Segerfeldt 2005) ii (Saefong 2006) iii (Overbeke 2004) iv (Shiva 2002) v (Public Citizen.org 2002) vi (Mann 2006) vii (Mann 2006) viii (Dr. Isabel Al-Assar 2008) ix (US Water News Online 2004) x (US Water News Online 2004) | https://en.wikipedia.org/wiki?curid=30256789 |
Magnetoelectrochemistry is a branch of electrochemistry dealing with magnetic effects in electrochemistry. These effects have been supposed to exist since the time of Michael Faraday. There have also been observations on the existence of Hall effect in electrolytes. Until these observations, magnetoelectrochemistry was an esoteric curiosity, though this field has had a rapid development in the past years and is now an active area of research. Other scientific fields which contributed to the development of magnetoelectrochemistry are magnetohydrodynamics and convective diffusion theory. There are three types of magnetic effects in electrochemistry: | https://en.wikipedia.org/wiki?curid=30258345 |
Mercury(I) oxide Mercury(I) oxide, also known as mercurous oxide, is an inorganic metal oxide with the chemical formula HgO. It is a brown/black powder, insoluble in water, toxic but without taste or smell. It is chemically unstable and converts to mercury(II) oxide and mercury metal. | https://en.wikipedia.org/wiki?curid=30265855 |
Society of Biological Inorganic Chemistry The is a learned society established to advance research and education in the field of biological inorganic chemistry. It holds training courses, workshops and conferences to facilitate exchange of information between scientists involved in the research and teaching of biological inorganic chemistry. It has an official journal, the "Journal of Biological Inorganic Chemistry". The society was founded in 1995, following discussions within the Steering Committee of the European Science Foundation program "The Chemistry of Metals in Biological Systems". The first president was C. David Garner (1995–1998). Later presidents were Elizabeth C. Theil (1998–2000), Alfred X. Trautwein (2000–2002), Harry B. Gray(2002–2004), Fraser Armstrong (2004–2006), and Jose J. G. Moura (2010–2012). | https://en.wikipedia.org/wiki?curid=30268552 |
An Album of Fluid Motion The book is a collection of black-and-white photographs of flow visualizations for different types of fluid flows. These flows include: The book was self-published by its editor, Milton Van Dyke, fluid mechanics professor at Stanford University. | https://en.wikipedia.org/wiki?curid=30270501 |
Topology (chemistry) In chemistry, topology provides a convenient way of describing and predicting the molecular structure within the constraints of three-dimensional (3-D) space. Given the determinants of chemical bonding and the chemical properties of the atoms, topology provides a model for explaining how the atoms ethereal wave functions must fit together. Molecular topology is a part of mathematical chemistry dealing with the algebraic description of chemical compounds so allowing a unique and easy characterization of them. Topology is insensitive to the details of a scalar field, and can often be determined using simplified calculations. Scalar fields such as electron density, Madelung field, covalent field and the electrostatic potential can be used to model topology. Each scalar field has its own distinctive topology and each provides different information about the nature of chemical bonding and structure. The analysis of these topologies, when combined with simple electrostatic theory and a few empirical observations, leads to a quantitative model of localized chemical bonding. In the process, the analysis provides insights into the nature of chemical bonding. Applied topology explains how large molecules reach their final shapes and how biological molecules achieve their activity. Circuit topology is a topological property of folded linear polymers. This notion has been applied to structural analysis of biomolecules such as proteins and RNAs | https://en.wikipedia.org/wiki?curid=30275938 |
Topology (chemistry) It is possible to set up equations correlating direct quantitative structure activity relationships with experimental properties, usually referred to as topological indices (TIs). Topological indices are used in the development of quantitative structure-activity relationships (QSARs) in which the biological activity or other properties of molecules are correlated with their chemical structure. | https://en.wikipedia.org/wiki?curid=30275938 |
Vitexin (data page) This page provides supplementary chemical data on vitexin. The handling of this chemical may incur notable safety precautions. It is highly recommend that you seek the Material Safety Datasheet (MSDS) for this chemical from a reliable source such as MSDS Search Engine, and follow its directions. Reference: | https://en.wikipedia.org/wiki?curid=30278857 |
Pheromone biosynthesis activating neuropeptide The pheromone biosynthesis activation neuropeptide (PBAN) is a neurohormone (member of the PBAN/pyrokinin neuropeptide family) that activates the biosynthesis of pheromones in moths. Female moths release PBAN into their hemolymph during the scotophase to stimulate the biosynthesis of the unique pheromone that will attract the conspecific males. PBAN release is drastically reduced after mating, contributing to the loss in female receptivity. In "Agrotis ipsilon" (black cutworm), it has been shown that the Juvenile Hormone helps induce release of PBAN which goes on to influence pheromone production and responsiveness in females and males, respectively. In the Helicoverpa assulta, the circadian rhythm of pheromone production is closely associated with PBAN release. The precise regulatory mechanisms exerted by PBAN on the different steps of pheromone biosynthesis remain to be determined. However, the receptor of this neuropeptide has been already cloned. The receptor belongs to the G-protein coupled receptors, and its activation leads to an increase of intracellular Calcium levels. According to the effects of gene disruption in the pheromone synthesis of Bombykol (the main pheromone component of the silk moth "Bombyx mori" and the corn earworm moth), the increase in intracellular calcium levels turns to activate different key enzymes of the last steps of pheromone biosynthesis. | https://en.wikipedia.org/wiki?curid=30280355 |
Structure of liquids and glasses The structure of liquids, glasses and other non-crystalline solids is characterized by the absence of long-range order which defines crystalline materials. Liquids and amorphous solids do, however, possess a rich and varied array of short to medium range order, which originates from chemical bonding and related interactions. Metallic glasses, for example, are typically well described by the dense random packing of hard spheres, whereas covalent systems, such as silicate glasses, have sparsely packed, strongly bound, tetrahedral network structures. These very different structures result in materials with very different physical properties and applications. The study of liquid and glass structure aims to gain insight into their behavior and physical properties, so that they can be understood, predicted and tailored for specific applications. Since the structure and resulting behavior of liquids and glasses is a complex many body problem, historically it has been too computationally intensive to solve using quantum mechanics directly. Instead, a variety of diffraction, NMR, Molecular dynamics, and Monte Carlo simulation techniques are most commonly used. The pair distribution function (or pair correlation function) of a material describes the probability of finding an atom at a separation "r" from another atom | https://en.wikipedia.org/wiki?curid=30283480 |
Structure of liquids and glasses A typical plot of "g" versus "r" of a liquid or glass shows a number of key features: The static structure factor, "S(q)", which can be measured with diffraction techniques, is related to its corresponding "g(r)" by Fourier transformation where "q" is the magnitude of the momentum transfer vector, and ρ is the number density of the material. Like "g(r)", the "S(q)" patterns of liquids and glasses have a number of key features: The absence of long-range order in liquids and glasses is evidenced by the absence of Bragg peaks in X-ray and neutron diffraction. For these isotropic materials, the diffraction pattern has circular symmetry, and in the radial direction, the diffraction intensity has a smooth oscillatory shape. This diffracted intensity is usually analyzed to give the static structure factor, "S(q)", where "q" is given by "q"=4πsin(θ)/λ, where 2θ is the scattering angle (the angle between the incident and scattered quanta), and λ is the incident wavelength of the probe (photon or neutron). Typically diffraction measurements are performed at a single (monochromatic) λ, and diffracted intensity is measured over a range of 2θ angles, to give a wide range of "q". Alternatively a range of λ, may be used, allowing the intensity measurements to be taken at a fixed or narrow range of 2θ. In x-ray diffraction, such measurements are typically called “energy dispersive”, whereas in neutron diffraction this is normally called “time-of-flight” reflecting the different detection methods used | https://en.wikipedia.org/wiki?curid=30283480 |
Structure of liquids and glasses Once obtained, an "S(q)" pattern can be Fourier transformed to provide a corresponding radial distribution function (or pair correlation function), denoted in this article as "g(r)". For an isotropic material, the relation between "S(q)" and its corresponding "g(r)" is The "g(r)", which describes the probability of finding an atom at a separation "r" from another atom, provides a more intuitive description of the atomic structure. The "g(r)" pattern obtained from a diffraction measurement represents a spatial, and thermal average of all the pair correlations in the material, weighted by their coherent cross-sections with the incident beam. By definition, "g(r)" is related to the average number of particles found within a given volume of shell located at a distance "r" from the center. The average density of atoms at a given radial distance from another atom is given by the formula: where "n"("r") is the mean number of atoms in a shell of width Δ"r" at distance "r". The "g(r)" of a simulation box can be calculated easily by histograming the particle separations using the following equation where "N" is the number of "a" particles, |r| is the magnitude of the separation of the pair of particles "i,j". Atomistic simulations can also be used in conjunction with interatomic pair potential functions in order to calculate macroscopic thermodynamic parameters such as the internal energy, Gibbs free energy, entropy and enthalpy of the system | https://en.wikipedia.org/wiki?curid=30283480 |
Structure of liquids and glasses Other experimental techniques often employed to study the structure of glasses include Nuclear Magnetic Resonance (NMR), X-ray absorption fine structure (XAFS) and other spectroscopy methods including Raman spectroscopy. Experimental measurements can be combined with computer simulation methods, such as Reverse Monte Carlo (RMC) or molecular dynamics (MD) simulations, to obtain more complete and detailed description of the atomic structure. Early theories relating to the structure of glass included the crystallite theory whereby glass is an aggregate of crystallites (extremely small crystals). However, structural determinations of vitreous SiO and GeO made by Warren and co-workers in the 1930s using x-ray diffraction showed the structure of glass to be typical of an amorphous solid In 1932 Zachariasen introduced the random network theory of glass in which the nature of bonding in the glass is the same as in the crystal but where the basic structural units in a glass are connected in a random manner in contrast to the periodic arrangement in a crystalline material. Despite the lack of long range order, the structure of glass does exhibit a high degree of ordering on short length scales due to the chemical bonding constraints in local atomic polyhedra. For example, the SiO tetrahedra that form the fundamental structural units in silica glass represent a high degree of order, i.e | https://en.wikipedia.org/wiki?curid=30283480 |
Structure of liquids and glasses every silicon atom is coordinated by 4 oxygen atoms and the nearest neighbour Si-O bond length exhibits only a narrow distribution throughout the structure. The tetrahedra in silica also form a network of ring structures which leads to ordering on more intermediate length scales of up to approximately 10 Angstroms. Alternative views of the structure of liquids and glasses include the interstitialcy model and the model of "string-like" correlated motion. Molecular dynamics computer simulations indicate these two models are closely connected Oxide glass components can be classified as network formers, intermediates, or network modifiers. Traditional network formers (e.g. silicon, boron, germanium) form a highly cross-linked network of chemical bonds. Intermediates (e.g. titanium, aluminium, zirconium, beryllium, magnesium, zinc) can behave both as a network former or a network modifier, depending on the glass composition. The modifiers (calcium, lead, lithium, sodium, potassium) alter the network structure; they are usually present as ions, compensated by nearby non-bridging oxygen atoms, bound by one covalent bond to the glass network and holding one negative charge to compensate for the positive ion nearby. Some elements can play multiple roles; e.g. lead can act both as a network former (Pb replacing Si), or as a modifier | https://en.wikipedia.org/wiki?curid=30283480 |
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