bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ethylene
Authors: Sundaram K. M. , Shreehan M. M. , Olszewski E. F. 
Published: August 2004

AbstractIn this comprehensive discussion of the production of and uses for ethylene, the topics covered include the properties of ethylene; industrial production; storage, shipping, handling; and economics. Extensive coverage of the commercial production of ethylene via thermal cracking is provided. The reaction is discussed as well as the methods employed to predict the feedstock conversion. Product distributions are given for a variety of feedstocks. A description of the industrial furnaces available is given, as well as a typical process description and process flow diagram. Information is provided on coke deposition during the cracking process, giving the methods used to inhibit coke production and methods used to remove coke deposited. Recent improvements in the design of ethylene plants plus possible other routes to produce ethylene are presented.
Ferrites
Authors: Kools F. X. N. M. , Stoppels D. 
Published: August 2004

AbstractTwo main groups of commercial ferrites are emphasized; the soft magnetic spinel ferrites having as the most important representatives MnZn‐, NiZn, and MgZn‐ferrites; and the hard magnetic hexagonalM‐type ferrites having as the main representatives BaM‐ and SrM‐ferrites. These materials are primarily ceramics. The cubic spinel and the hexagonalM‐type crystal structures produce differing magnetic and electrical properties, which result from electron configurations and mutual interactions of the constituent ions. Properties can be optimized for specific applications in the areas of consumer electronics, telecommunication, power conversion, and the automotive industry. Optimum ceramic processing, often including microstructural engineering, is required to obtain fine‐tunings of the various parameters for ferrite applications.
Fiber Optics
Authors: Kosinski Sandra , MacChesney John B. 
Published: August 2004

AbstractFiber‐optic based communication depends on the availability of high quality low loss optical fibers. Light guidance within a fiber is discussed.Operating wavelengths have been extended by controlling fiber attenuation and dispersion. Fiber fabrication methods are presented. The use of high purity starting materials and vapor deposition techniques allows the production of glass fibers having optical losses that approach the intrinsic loss of silica. Fiber drawing processes determine strength. Active optical fibers have been exploited to amplify light, extending the range of transmission systems and allowing increased capacity. Erbium‐doped fibers are being used for signal amplification in fiber‐optic cable. Devices taking advantage of gratings written in optical fibers include filters and lasers. The market for fiber‐optics materials is expected to continue to grow.
Filtration
Authors: Svarovsky Ladislav 
Published: August 2004

AbstractThis article defines and reviews the field of filtration, with a particular emphasis on cake filtration of liquids as the most dominant unit operation in the field. The necessary definitions are given and are followed by a discussion of operations closely related to or used in conjunction with filtration. A brief account of cake filtration theory is followed by descriptions of available individual groups of filtration technology.A section on vacuum filters discusses the nutsche filter, enclosed agitated vacuum filters, vacuum leaf filters, tipping pan filters, horizontal rotating pan filters, horizontal belt vacuum filters, rotary vacuum drum filters, and rotary vacuum disk filters. The very large field of pressure filtration is subdivided into batch and continuous filters. Batch pressure filters include filter presses, pressure vessel filters, cartridge filters, and batch compression filters; continuous pressure filters include disk filters, drum filters, horizontal belt pressure filters, continuous compression filters (belt presses and screw presses), and thickening pressure filters (including cross‐flow filtration and dynamic filters). A separate section on centrifugal filters deals with fixed‐bed centrifuges and moving bed centrifuges.
Fuel Cells
Authors: Kinoshita Kimio , Cairns Elton J. 
Published: August 2004

Abstract

Fuel Cells.
Fuel cells are electrochemical devices that convert the chemical energy of a fuel directly into electrical and thermal energy. In a typical fuel cell, gaseous fuels are fed continuously to the anode (negative electrode) compartment, and an oxidant, eg, oxygen or air, is fed continuously to the cathode (positive electrode) compartment. The electrochemical reactions take place at the electrodes to produce an electric (direct) current. The fuel cell theoretically has the capability of producing electrical energy for as long as the fuel and oxidant are fed to the electrodes. In reality, degradation or malfunction of components limits the practical operating life of fuel cells.

Besides the direct production of electricity, heat is also produced in fuel cells. This heat can be effectively utilized for the generation of additional electricity or for other purposes, depending on the temperature. A practical consideration for fuel cells is compatibility with the available fuels and oxidants. One of the main attractive features of fuel cell systems is the expected high fuel‐to‐electricity efficiency. This efficiency, which runs from 40–60% based on the lower heating value (LHV) of the fuel, is higher than that of almost all other energy conversion systems. The two primary impediments to the widespread use of fuel cells are high initial cost and short operational lifetime. A variety of fuel cells has been developed for terrestrial and space applications. Fuel cells are usually classified according to the type of electrolyte used in the cells as polymer electrolyte fuel cell (PEFC), alkaline fuel cell (AFC), phosphoric acid fuel cell (PAFC), molten carbonate fuel cell (MCFC), and solid oxide fuel cell (SOFC).

Fuel cells operating on pure H
2
and O
2
provide a useful power source in remote areas such as in space or under the sea where system weight and volume are important parameters. On the other hand, fuel cell power plants operating on fossil fuels and air offer the potential for environmentally acceptable, highly efficient, and low cost power generation. The minimum technical requirements for fuel cells for four different types of applications, ie, for buildings, industry, transportation, and utilities are given. From the standpoint of commercialization of fuel cell technologies, there are two challenges: initial cost and reliable life.

Several activities, would strongly boost the prospects for fuel cell technology and include the development of
(1)
an active electrocatalyst for the direct electrochemical oxidation of methanol;
(2)
improved electrocatalysts for oxygen reduction; and
(3)
a more CO‐tolerant electrocatalyst for hydrogen.
Gas, Natural
Authors: Woodcock Kermit E. , Gottlieb Myron 
Published: August 2004

Abstract
Natural gas is a mixture of naturally occurring hydrocarbon and non‐hydrocarbon gases found in porous geologic formations beneath the earth's surface. Methane is a principal constituent and the mixture may contain higher hydrocarbons such as ethane, propane, butane, and pentane. Gases such as carbon dioxide, nitrogen, hydrogen sulfide, various mercaptans, and water vapor along with trace amounts of other inorganic and organic compounds can also be present. Natural gas is found in a variety of geological formations including sandstones, shales, and coals. Worldwide natural gas reserves have continued to increase as the demand for gas has increased and exploration efforts have expanded. Natural gas production on a worldwide basis has also continued to increase. The composition of natural gas at the wellhead depends on the characteristics of the reservoir and is highly variable with respect to both the constituents present and the concentrations of these constituents. Natural gas obtained at the wellhead usually undergoes some type of treatment or processing prior to its use for safety, economic, or system and material compatibility reasons. Gases are odorless, but for safety reasons, natural gas is odorized before distribution to provide a distinct odor to warn users of possible gas leaks in equipment.
Natural gas is used as a fuel and source of heat throughout the industrialized countries for a broad range of residential, commercial. Both natural gas and natural gas liquids are used as feedstocks in the chemical industry. Production takes place both at onshore installations and on offshore platforms which service wells drilled to provide access to reservoirs located below the floor of the ocean.
Glass‐Ceramics
Authors: Pinckney Linda R. 
Published: August 2004

AbstractGlass‐ceramics are polycrystalline materials formed by the controlled crystallization of glass. Most commercial glass‐ceramic products are formed by highly automated glass‐forming processes and converted to a crystalline product by the proper heat treatment. Glass‐ceramics can also be prepared via powder processing methods in which glass frits are sintered and crystallized. The range of potential glass‐ceramic compositions is therefore extremely broad, requiring only the ability to form a glass and control its crystallization.Glass‐ceramics can provide significant advantages over conventional glass or ceramic materials, by combining the ease and flexibility of forming and inspection of glass with improved and often unique physical properties in the glass‐ceramic. Their physical properties are highly reproducible.Unlike conventional ceramic materials, glass‐ceramics are fully densified with zero porosity. They generally are at least 50% crystalline by volume and often are greater than 90% crystalline.More than $500 million in glass‐ceramic products are sold yearly worldwide. These range from transparent, zero‐expansion materials with excellent optical properties and thermal shock resistance to jade‐like highly crystalline materials with excellent strength and toughness. The highest volume is in cookware and tableware, architectural cladding, and stovetops and stove windows. Glass‐ceramics are also referred to as Pyrocerams, vitrocerams, devitrocerams, sitalls, slagceramics, melt‐formed ceramics, and devitrifying frits.
Gold and Gold Compounds
Authors: Cohn J. G. , Stern Eric W. 
Published: August 2004

AbstractGold is characterized by high density, high electrical and thermal conductivities, and high ductility. At least 26 unstable gold isotopes have been made.Gold is the most noble of the noble metals. Other than in the atomic state, the metal does not react with oxygen, sulfur, or selenium at any temperature. It does, however, react with tellurium at elevated temperatures to produce gold ditelluride which is also found in the naturally occurring mineral, calaverite. Gold reacts with the halogens, particularly in the presence of moisture.Gold reacts with various oxidizing agents at ambient temperatures provided a good ligand is present to lower the redox potential below that of water. Thus, gold is not attacked by most acids under ordinary conditions and is stable in basic media. Gold does, however, dissolve readily aqua regia and in alkaline cyanide solutions in the presence of air or hydrogen peroxide to form (Au(CN)2)−. These reactions are important to the extraction and refining of the metal. Gold is very corrosion and tarnish resistant and imparts corrosion resistance to most of the commonly used gold alloys.Placer mining is the oldest form of gold mining. The technique is still in use in places where appropriate alluvial or marine deposits exist, such as Alaska, but requires large quantities of water. At present, most gold is obtained either by deep mining, most notably in South Africa, or by open pit mining such as in the United States. In refining precious metal scrap and some concentrates, the gold is converted to HAuCl4by treatment with aqua regia. After heating to remove nitrogen oxides, gold is precipitated from solution by reduction with sulfur dioxide or ferrous sulfate. Gold is widely distributed and the average content in the earth's crust is estimated to be 3.5 ppb. The gold content of ocean water varies considerably with location. The average value is of the order of 10 ppt, which is well below the concentration (3 ppm) required for economic recovery.Chrysotherapy, therapy with gold compounds, remains as one of the few treatments capable of slowing or halting the damage caused by rheumatoid arthritis. Besides its use for monetary reserves, gold is used in the private sector principally for investment and fabrication. By far, the largest commercial use is jewelry. In the electronics industry, gold is used as fine wires or thin film coatings and frequently in the form of alloys to economize on gold consumption and to impart properties such as hardness.In dentistry, gold is used for a variety of restorations.The chemistry of nonmetallic gold is predominantly that of Au(I) and Au(III) compounds and complexes.Common gold compounds include halides, cyanides, oxides and hydroxides hydroxide, Au(OH)3), and sulfides. Both alkyl and aryl complexes of Au(I) and Au(III) as well as olefin and acetylene complexes have been prepared and studied. An increasing amount of interest has developed in gold‐containing bimetallic cluster compounds.
Hydrides
Authors: Sullivan Edward A. 
Published: August 2004

AbstractSullivan, Edward A. (Morton International). Hydrides may be divided into two groups: simple and complex. The simple or binary hydrides may be ionic, covalent, or interstitial as are most of the transition metal hydrides. The important properties, methods of manufacture, safe handling, and important uses of the commercial binary hydrides and certain hydrogen storage alloys are reviewed. Alkali metal, alkaline‐earth, and Group 4, 5, 13, and 14 hydrides find use in a variety of industries among which are the electronics, pulp and paper, dyeing, and clay industries.The most important complex hydrides are the borohydrides and alumino‐hydrides. The important alkali metal salts of these hydrides are described. Complex hydrides are used principally in the synthesis of organic compounds effecting specific and nonspecific reductions. Alkoxyborohydrides, cyanoborohydride, acyloxyborohydrides, and alkoxy‐aluminohydrides, are also discussed.
Carbides, Industrial Hard
Authors: Stoll W. M. , Santhanam A. T. 
Published: August 2004

AbstractThe four most important carbides for the production of hard metals are tungsten carbide, WC, titanium carbide, TiC, tantalum carbide, TiC, and niobium carbide, NbC. The binary and ternary solid solutions of these carbides such as WC–TiC and WC–TiC–TaC (NbC) are also of great importance. Carbides and their solid solutions are generally combined with cobalt and used in the form of cemented carbides. The carbides of the actinides, Th, U, Pu, and Np, have gained importance in reactor technology as nuclear fuels. In general, the carbides of metals of Groups 4–6 (IVB–VIB) are prepared by reaction of elementary carbon or hydrocarbons and metals and metal compounds at high temperatures. Methods include carburization by fusion, carburization by thermal diffusion, carburization by menstruum process, carburization by thermochemical reaction, and reduction. Two categories of refining support manufacturers of cemented carbides. The first involves extraction of tungsten in the form of tungstic oxide, WO3, or ammonium paratungstate APT, from mineral concentrates. The second converts the APT and other starting materials to primary carbides of tungsten and other metals. Some refining is carried out by the cemented carbide manufacturers themselves. Cemented carbide manufacturers also utilize independent refiners. A number of cemented carbide producers market some or all primary materials, ranging from monocarbides to binary or ternary solid solutions involving TiC, TaC, NbC, or WC.
Peroxides and Peroxide Compounds, Inorganic Peroxides
Authors: Comyns Alan E. 
Published: August 2004

AbstractInorganic peroxides and peroxo compounds, with the exception of hydrogen peroxide, are described. Ozonides and superoxides are also included. Emphasis is placed on the commercially important main group species such as the sodium peroxoborates, sodium carbonate peroxohydrate, peroxodisulfate salts, calcium peroxide, sodium peroxide, and potassium superoxide. Most of these compounds are made from hydrogen peroxide; some, such as the peroxodisulfates, are made electrochemically. Applications of inorganic peroxides and peroxo compounds include bleaching, polymerization catalysts, dough‐conditioning, effluent treatment, pyrotechnics, as well as uses in medicines, household detergents, hydrometallurgy, and organic synthesis.
Titanium Compounds, Inorganic
Authors: Egerton Terry A. 
Published: August 2004

AbstractProperties and applications of technologically important inorganic compounds of titanium are surveyed. The most important compound is titanium dioxide which, because of its high refractive index, is manufactured as a white pigment at a scale of ca\documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}${4\times 10^{6}{\hskip0.167em}{\hskip0.167em}{\rm{t}}/{\rm{yr}}}$\end{document}. Raw materials and pigment production processes are reviewed. Mixed oxides, eg, barium titanate, are important raw materials for electroceramics.Titanium hydrides provide a convenient method of hydrogen storage. Titanium boride, titanium carbide, and titanium nitride are used as components of hard materials, eg, for cutting tools. They are electrically conducting.The chlorides are the most important halides. Titanium trichloride is the basis of widely used polymerization catalysts. Titanium tetrachloride is an intermediate in the production of both titanium metal and (via the chloride process) titanium dioxide pigment. Titanium dioxide pigment is also made (in the sulfate process) by precipitation from solutions of titanium in sulfuric acid. Titanium sulfides may be used as cathodes in high efficiency batteries. The properties of some titanium compounds with silicon and phosphorus are reviewed. Analytical methods and health & safety aspects are summarized.
Cellulose Esters, Inorganic Esters
Authors: Fengl Richard 
Published: August 2004

AbstractCellulose esters are cellulose derivatives which result from the esterification of the free hydroxyl groups of cellulose with one or more acids. Cellulose nitrate is the oldest cellulose derivative and the only inorganic ester of commercial importance. Manufacturing and uses of sulfur‐ and phosphorus containing cellulose esters are discussed. An analysis of the oldest and most important inorganic ester of cellulose, cellulose nitrate, is presented.
Fluorine compounds, Organic, Introduction
Authors: Bajzer William X. , Kim Yung K. 
Published: August 2004

AbstractOrganic compounds bearing fluorine substituents are commercially important in many applications. The refrigerant application is over six decades old and continues to receive wide global attention due to the environmental impact of the chlorofluorocarbon (CFC) materials. Alternative hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) materials are under development to replace the CFCs. The properties of many fluorinated organic compounds are contrasted with their hydrocarbon analogues. Various methods are described for introduction of fluorine singly or multiply into organic compounds. Attention is focused on the recommended commercial method to manufacture many fluorinated organic compounds. Fluorinated compounds are discussed by class, with examples given for each. Global production patterns and capacity by company are reviewed along with significant commercial trends. Toxicology of this class of materials is addressed from a brief overview perspective. Bibliographic references and suggestions for general reading are listed.
Iodine and Iodine Compounds
Authors: Lauterbach Armin , Ober Gustavo 
Published: August 2004

AbstractIodine is used in a wide variety of fields, among which are included industrial, pharmaceutical, nutritional, agricultural, electrical, and metallurgical. Iodine is produced as a nitrate ore by‐product or from brines or seaweed. As found in nature it has only one stable isotope. Several radioactive isotopes have been prepared and have found use as radiopharmaceuticals or radioactive tracers for medical imaging. Iodine is the only halogen that is solid at ambient temperatures and pressures. Having the highest atomic weight of the common halogens, iodine begins to exhibit metallic properties. Besides exhibiting properties of luster and opacity, it is classed as a semiconductor of electricity. It is an essential human nutrient. Commercially available inorganic and organic compounds are described.
Kinetic Measurements
Authors: Magde Douglas 
Published: August 2004

Abstract

Magde, Douglas (University of California at San Diego). The goal of kinetic measurements, which determine the rate of chemical changes, is to determine the form of a rate law. This law relates rates to reactant concentrations and one or more rate constants which remain unchanged as long as thermodynamic conditions are fixed. Measurements may be made by mixing components and measuring concentration changes over time. Methods, including stopped‐flow and continuous flow mixing for millisecond times, have been introduced to study reactions too fast for manual approaches. Faster reactions require perturbation methods employing temperature, pressure (including sound), and electrical field strength. Flash photolysis, also a perturbation, uses lasers to measure chemical or physical changes taking place in less than

\documentclass{article}\pagestyle{empty}\begin{document}${10^{-13}}$\end{document}

s. Other perturbation methods can approach

\documentclass{article}\pagestyle{empty}\begin{document}${10^{-9}}$\end{document}

s. Besides direct measurements of changing concentrations, kinetic studies can exploit linewidth measurements in optical spectroscopy and magnetic resonance. All these measurements of macroscopic behavior are then interpreted at the microscopic, atomic level in terms of mechanisms. The combination of increasingly detailed, fast measurements of primary processes and sophisticated computer modeling is starting to generate rigorous atomic level descriptions of kinetic change. Vol. 14, pp. 1021–1044, 16 refs. to December 1993.
Lead Salts
Authors: Carr Dodd S. , Spangenberg William C. , Chronley Kevin 
Published: August 2004

AbstractAll lead‐containing compounds are produced from pig lead through a series of steps, except for the small amount of lead in leaded zinc oxide for which high grade lead ore is used. Most lead compounds are prepared directly or indirectly from lead monoxide, commonly known as litharge.As of the 1990s over half of the lead in the United States is allocated to use in batteries supplied as either a mixed oxide or as metal. Lead is also consumed in the production of plastics, gasoline additives, rubber, ceramics, glass, and electronics. Physical properties and health and safety factors, as well as OSHA and EPA regulations, are given.
Methylene Chloride
Authors: Holbrook Michael T. 
Published: August 2004

Abstract

Methylene chloride is a colorless, heavy liquid with a pleasant ethereal odor. Its outstanding solvent properties are the basis of its principal industrial interest. It is produced almost exclusively by the chlorination of lesser chlorinated methanes along with coproducts chloroform and carbon tetrachloride. U.S. capacity has been estimated at 265,000 t/yr although there is considerable flexibility to change the mix of the coproducts made. Methylene chloride production has declined significantly since 1985 because of an unfavorable carcinogenicity test. Projected growth rates of

to

per year are typical for the early 1990s. Its primary uses are for paint stripping and metal cleaning. It is regulated by many federal and state laws.