bluuebunny/crossref_metadata_2025_split huggingface dataset:
Graphite, Processing Artificial
Authors: Turk D. L. 
Published: July 2004

AbstractCalcined petroleum coke arrives at the graphite manufacturer's plant in particle sizes ranging typically from dust to 50–80 mm diameter. In the first step of artificial graphite production, the run‐of‐kiln coke is crushed, sized, and milled to prepare it for the subsequent processing steps. The size of the largest particle is generally set by application requirements. The manufacturing process begins with the mixing operation. The purpose of mixing is to blend the coke filler materials and distribute the pitch binder over the surfaces. The intergranular bond ultimately determines the properties and structural integrity of the graphite. Thus the more uniform the binder distribution throughout the filler components, the greater the likelihood for a structurally sound product. After the forming operation, the purpose of which is to compress the mix so that pitch‐coated filler particles and flour are in intimate contact, in the next stage, the baking operation, the product is fired to 800–1000°C. One function of this step is to convert the thermoplastic pitch binder to solid coke. Another is to remove most of the shrinkage in the product associated with pyrolysis of the pitch binder at a slow heating rate. This procedure avoids cracking during subsequent graphitization. A variety of baking furnaces are in use. One common baking facility is the pit furnace, so named because it is positioned totally or partially below ground level to facilitate improved insulation. Another common baking facility is the so‐called ring furnace. Two equal rows of pit furnaces are arranged in a rectangular ring. A more recent development is the carbottom furnace, which is mounted on wheels and movable. The method used to improve those properties necessary for many high performance applications of graphite is impregnation with coal‐tar or petroleum pitches. Graphitization is an electrical heat treatment of the product to ca 3000°C. The purpose of this step is to cause the carbon atoms in the petroleum coke filler and pitch coke binder to orient into the graphite lattice configuration, producing graphite with intermetallic properties useful in many applications. In the temperature range of 1500–2000°C, most petroleum cokes and coal‐tar pitch cokes undergo an irreversible volume increase known as puffing, associated with thermal removal of sulfur. Depending on particle size and on the product size, heating rates must be adjusted in the puffing range to avoid splitting the product. Fortunately, the use of puffing inhibitors has eased the problem.
Fine Chemicals, Production
Authors: Pollak Peter 
Published: July 2004

AbstractFine chemicals are low volume, high priced chemical intermediates and bulk active ingredients primarily used in the preparation of pharmaceuticals and agrochemicals, but also in other specialties, such as dyestuffs and pigments, flavors and fragrances, and food and feed additives. In contrast to specialty chemicals, these are mostly sold within the chemical industry and according to specifications rather than performance criteria. Fine chemicals typically are manufactured in multipurpose plants starting from commodity chemicals and involving several distinct synthetic steps. The core production unit is a train of one or more modules where several fine chemicals can be produced in compaign fashion in the same production train. A complete plant also contains other facilities. Research and development play an important role, as does plant design.
Product Liability
Authors: Twerski Aaron 
Published: July 2004

Abstract
This article charts the changes of American products liability laws. It examines such topics as implied warranty of merchantability, prima facie case and affirmative defense, as well as the Second and Third Restatements, defining in the process such terms as defect, proximate cause, foreseeability, and the role of plaintiff conduct. Actual liability cases are used to illustrate the discussion.
Propylene
Authors: Calamur Narasimhan , Carrera Martin 
Published: July 2004

AbstractPropylene is an important industrial chemical used as a feedstock in the production of polypropylene, acrylonitrile, propylene oxide, 2‐propanol, alkylated fuels, and other chemicals. It is obtained from steam cracking in pyrolysis furnaces in olefins plants and in refinery catalytic‐cracking reactors. Propane dehydrogenation is a new production technology not yet exploited on a large scale. Distillation in multitray columns yields purities in excess of 99.5 wt %. The physical and chemical properties of propylene are well characterized. Under ambient conditions, it is a colorless gas and has anesthetic properties at high concentrations. Propylene is usually transported in the liquid state at high pressures. Proper precautions must be taken when handling propylene.
Sugar, Properties of Sucrose
Authors: Colonna William J. , Samaraweera Upasiri 
Published: July 2004

AbstractSucrose is a nonreducing disaccharide produced by crystallization from syrups derived from processing sugarcane and sugarbeets. World production averaged\documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}${{\rm{\sim }}113}$\end{document}million t/yr between 1990 and 1995, with\documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}${{\rm{\sim }}65{\%}}$\end{document}derived from cane. Sucrose's most important properties are its water solubility and its sweetness. The latter is influenced by temperature, pH, etc, and is synergistic with other sweeteners. Sucrose is destroyed by strong oxidizing agents, and extremes of pH. Optical rotation, enzymatic analysis, and instrumental methods are used for sucrose quantitation. Sucrose is the leading food additive and contributes sweetness, mouthfeel, texture, body, humectancy, and appearance to foods. Sugar also enhances the taste of foods and minimizes undesirable flavors.Esters, ethers, acids, polyurethanes, and other polymers are synthesized from sucrose. Sucrose esters are used as food emulsifiers, fat mimetics, detergents, bleach boosters, and antibacterials. Selective chlorination converts sucrose into sucralose, a noncaloric, high intensity sweetener. Alcohols, organic acids, antibiotics, dextrans, levans, and noncariogenic sweeteners are derived from sucrose by fermentation. Sucrose is used in medicines to mask unpleasant tastes, in tablet formulations, and to promote wound healing. Sucrose derivatives are used in treating ulcers and as antitumor agents. At current consumption rates, dietary sucrose promotes dental caries, but does not cause diabetes, hyperactivity, obesity, or heart disease.
Glycols, Propylene Glycols
Authors: Martin Alton E. , Murphy Frank H. 
Published: July 2004

Abstract
The propylene glycol family of chemical compounds consists of monopropylene glycol (PG), dipropylene glycol (DPG), and tripropylene glycol (TPG). These chemicals are manufactured as copoducts and are used commercially in a large variety of applications. They are available as highly purified products which meet well‐defined manufacturing and sales specifications. All commercial production is via the hydrolysis of propylene oxide.
The propylene glycols are clear, viscous, colorless liquids that have very little odor, a slightly bittersweet taste, and low vapor pressures. The most important member of the family is monopropylene glycol, also known as 1,2‐propylene glycol, 1,2‐dihydroxypropane, 1,2‐propanediol, methylene glycol, and methyl glycol. All of the glycols are totally miscible with water.

Propylene glycol, when produced according to the U.S. Food and Drug Administration good manufacturing practice guidelines at a registered facility, meets the requirements of the U.S. Food, Drug, and Cosmetic Act. It is listed in the regulation as a direct additive for specified foods and is classified as generally recognized as safe (GRAS). In addition, it meets the requirements of the
Food Chemicals Codex
and the specifications of the
U.S. Pharmacopeia XXIII.
Because of its low human toxicity and desirable formulation properties it has been an important ingredient for years in food, cosmetic, and pharmaceutical products.
Propylene Oxide
Authors: Trent David L. 
Published: July 2004

AbstractPropylene oxide, a commercially important chemical worldwide, is very reactive, finding application in many derivative businesses. Use is primarily as an intermediate for a wide array of products, such as polyether polyols for the polyurethane industry; propylene glycol for food, cosmetics, and heat‐transfer fluids; polyglycols as lubricants, antifoam agents, and metalworking fluids; glycol ethers for protective coatings, inks, and cleaners; and isopropanolamines for adhesives, corrosion inhibitors, and agricultural products.Propylene oxide is produced by two process chemistries. The first, and oldest, is the chlorohydrin process. Epoxidation by caustic or milk of lime produces the epoxide. The second process involves the oxidation of an organic such as isobutane or ethylbenzene to the corresponding hydroperoxide, then epoxidation of propylene using the hydroperoxide to the epoxide and an alcohol. The alcohol,tert‐butanol or 1‐phenylethanol, is further processed to provide the commercially viable coproducts, such as methyl‐tert‐butyl ether and styrene. The global capacity for propylene oxide is about half from the chlorohydrin process and a quarter each from the hydroperoxide processes producingtert‐butanol and styrene as coproducts. These and several other potentially commercial processes are discussed.
n
‐Propyl Alcohol
Authors: Unruh J. D. , Pearson D. 
Published: July 2004

Abstract

n
‐Propyl alcohol (1‐propanol) is used primarily as a specialty solvent for printing inks or as a chemical intermediate. The predominant derivatives of
n
‐propyl alcohol are the acetate ester and
n
‐propylamines. The latter are used in herbicide production. Smaller‐volume uses of
n
‐propyl alcohol are as a flavor or fragrance in foods and as feed additive. 1‐Propanol is manufactured in most of the Western world by hydroformylation of ethylene followed by hydrogenation of propanal. The hydroformylation or oxo process is catalyst‐driven. This process is described. In South Africa, 1‐propanol is also produced from coal through Fischer‐Tropsch processes.
Prostaglandins
Authors: Collins Paul W. 
Published: July 2004

AbstractProstaglandins are a family of naturally occurring substances found in animals and humans. They are produced from 20 carbon fatty acidsin vivoand play important and diverse roles in both health and disease. Unlike circulating hormones, prostaglandins are synthesized and released by most tissues, act near their site of synthesis, and then are rapidly inactivated by metabolic enzymes. They are among the most potent substances known and exert regulatory influences on virtually all tissues and organs.Because of their diverse biological effects and their potential as therapeutic agents, prostaglandins underwent intense scrutiny following their structural elucidation and availability in the early 1960s. Both academic and industrial laboratories studied their biosynthesis, metabolism, physiological and pharmacological effects, and their chemical and physical properties. The total synthesis of prostaglandins presented formidable challenges. Because of their structural and stereochemical complexity and chemical instability, they provided a strong impetus to the development of new synthetic methodologies. The prostaglandins and many analogues are available by total synthesis and some have reached the marketplace as therapeutic agents. Examples are prostaglandin E1(PGE1), used in cardiovascular and reproductive indications; analogues of prostaglandin F2 α, used in estrus synchronization in farm animals; misoprostol, an analogue of PGE1, used in the treatment of ulcers; prostacyclin and some of its analogues, used for cardiovascular diseases; and latanoprost, used in the treatment of glaucoma.
Protein Engineering
Authors: Davis June P. , Copeland Robert A. 
Published: July 2004

AbstractProtein engineering aims to provide insights into the interplay of forces that relate protein structure to stability and function. Genetic engineering techniques allow the identity of an amino acid residue within a protein to be altered, typically replacing one residue systematically with others that differ in only one functional aspect, such as size, charge, hydrogen‐bonding capacity, etc. De novo design of proteins is being used to help understand the forces that stabilize specific protein structural motifs. Applications of de novo protein design to the construction of α‐helical bundles and all β‐sheet proteins are discussed. The power of mutagenic analysis for the identification of the structural determinants of biological function are illustrated through protein engineering studies of the proteolytic enzyme subtilisin, and of the G‐protein‐coupled β‐adrenergic receptor. Methods that allow for the replacement of an amino acid residue within a protein by unnatural amino acids are described.
Psychopharmacological Agents
Authors: Martin J. R. , Godel T. , Hunkeler W. , Jenck F. , Moreau J.‐L. , Sleight A. J. , Widmer U. 
Published: July 2004

AbstractMartin, James R.; Godel, T.; Hunkeler, W.; Jenck, F.; Moreau, J‐L.; Sleight, A. J.; and Widmer, U. (F. Hoffmann‐La Roche Ltd.). A number of important advances have occurred in the understanding and the treatment of disorders of the central nervous system including mood disorders, schizophrenia, anxiety disorders, insomnia, substance use disorders, and dementias. The plethora of novel drugs act by means of diverse neurobiological mechanisms and represent a great diversity of chemical structures. Along with improvements in the therapeutic index of anxiolytics, sedative–hypnotics, antidepressants, and antipsychotics, some progress has also been made in the search for drugs effective in the treatment of substance use disorders, as well as Alzheimer's disease and other dementias. Nonetheless, such improvements in symptomatic therapy have not been accompanied by the discovery of effective etiological and pathophysiological interventions. It is from here that the successful psychopharmacological agents of the future must come.
Pulp
Authors: Genco Joseph M. 
Published: July 2004

AbstractPulp, the raw material used in the production of paper, paperboard, fiberboard, and other similar manufactured products, is produced from wood and nonwood plant matter by separating cellular components using mechanical and/or chemical methods. Wood is the dominant source of fiber used in the manufacture of pulp in the western hemisphere. Nonwood fiber sources are used in those locations where wood is in short supply or for pulps requiring special characteristics. In addition to wood, recovered (recycled) fiber represents a growing segment of the overall fiber supply worldwide.Commercial pulp is classified according to the method of manufacture as mechanical, chemical, chemimechanical, and semichemical. Economic factors, product requirements, and desired fiber properties determine the method of pulping. Mechanical pulps, produced through the application of mechanical energy, give rise to materials having high yield, small average particle size, high opacity, and excellent printing characteristics. Mechanical pulps have some undesirable properties such as low tensile strength and lack of permanence. Chemical pulps are produced by digesting wood using chemicals to remove lignin, extractives, and low molecular weight polysaccharides, frequently resulting in the loss of wood solids which are dissolved during the pulping and bleaching processes. Chemical pulps are used in the bleached or the unbleached state and are composed of longer, stronger fibers that are more stable than mechanical pulps, but have lower yields and less desirable print qualities. Chemimechanical and semichemical pulps are produced in hybrid processes based on the application of both chemicals and mechanical energy.Wood solids originating in the pulping process are recovered in the form of steam and electrical energy. Pulping chemicals are also recovered for reuse in the manufacturing process. Environmental management includes improvements in chemical recovery, process modification to minimize the use of elemental chlorine, and the treatment of process waste streams.
Pumps
Authors: Nelik Lev 
Published: July 2004

AbstractPumps are used in a wide range of industrial applications in the chemical processing industries. Pumping equipment varies widely in terms of pump type, size, and materials of construction. The two principal pump types, kinetic, which is mainly centrifugal, and positive displacement, are presented and basic operating parameters such as capacity, head, power, efficiency, and specific speed are defined. Fundamentals of operation are discussed, selection guidelines given, and examples of pump applications and reliability concerns provided. Pump auxiliaries such as couplings and seals, as well as effects of cavitation, recirculation, internal hydraulic forces, wear, and corrosion, are described. Cost approximation methodology is presented along with a list of manufacturers.
Silicon, Pure
Authors: Runyan W. R. 
Published: July 2004

AbstractElemental silicon, a metal, does not occur in nature, but as the oxide is a constituent of various rocks comprising about 28% of the earth's crust. There are three naturally occurring stable isotopes and several radioactive ones. Except at very high pressures, silicon has a diamond cubic structure and is a semiconductor.High purity silicon is used primarily for its semiconducting properties and is the primary constituent of silicon diodes, transistors, and integrated circuits. Ordinary metallurgical‐grade silicon is made by reducing quartz sand with coke in an electric furnace. That silicon may then be used to produce a silicon compound such as a chlorosilane that is relatively easy to purify. After purification, the compound is reduced to give high purity, semiconductor‐grade silicon, where most of the impurities are in the parts per billion range. Purification methods are discussed and properties of the electronics‐grade silicon given.
Pyrotechnics
Authors: Conkling John A. 
Published: July 2004

Abstract
Pyrotechnics involves the combination of science and art to chemically generate heat, and from that heat create light, color, audible effects, and gas pressure for entertainment, emergency signaling, and military applications. The civilian side of pyrotechnics includes fireworks, highway flares (fusees), air bag inflators, and special effects devices for the entertainment industry. Military and aerospace pyrotechnics include a wide range of devices for illumination, signaling, obscuration, and gas generation. A pyrotechnic mixture typically contains one or more oxygen‐rich oxidizers and one or more fuels, which undergo an exothermic reaction when heated to the ignition temperature of the mixture. The heat that is produced then creates the desired pyrotechnic effect. The selection of the chemicals used in a pyrotechnic composition, as well as the particle sizes of the chemicals and the degree of intimacy to which the composition is blended, determine in large part the speed of the pyrotechnic reaction. Safety in all aspects of manufacturing and using pyrotechnic mixtures and devices is important.
Quinolines and Isoquinolines
Authors: Finley K. Thomas 
Published: July 2004

AbstractThe fusion of a pyridine and a benzene ring produces two heterocyclic aromatic systems, usually referred to by their common names, quinoline and isoquinoline. Besides the chemistry to be expected, this combination opens a wide range of additional possibilities. It is therefore not surprising that both quinoline and isoquinoline have been the subject of extensive studies ranging from the theoretical to the most actively applied. The dye and photographic industries, the metallurgical, analytical, and polymer sciences all provide extensive examples. However, it continues to be the medical field and the pharmaceutical industry which provide the principal driving force for an impressive array of studies of the synthesis and properties of molecules containing these structures. The toxicity of these compounds is sufficient to warrant care in their handling.
Quinones
Authors: Finley K. Thomas 
Published: July 2004

AbstractQuinones, possessing two α,β‐unsaturated carbonyl groups usually in a six‐carbon atom ring, represent a unique structural unit. Their centrality in the synthesis of such important commercial substances as dyes and pharmaceuticals has resulted in extensive study of a variety of synthons. In living matter they are ubiquitous and vital to human metabolism. Quinones are of special interest to biochemists and to both synthetic and theoretical organic chemists. The types of reactions most often reported are nucleophilic addition, photochemistry, cycloaddition, electrophilic addition, radical alkylation, electrochemistry, oxidation, and nucleophilic substitution. The synthesis of quinones is usually accomplished through oxidation of phenols or anilines. A wide variety of oxidants have been used, but quinones of higher oxidation potential are often the reagent of choice. Quinones of low molecular weight should be treated with care in their storage and handling.
Antibacterial Agents, Quinolones
Authors: Kadow John. F. , Barrett J.F. , Beaulieu D. , Dougherty T.J. , Meanwell N.A. , Ohemeng‐Paratek K.A. , Ryan B. 
Published: July 2004

AbstractQuinolone carboxylic acids are totally synthetic antibacterial agents. Initial compounds possessed relatively limited clinical utility. Since the 1980s, the discovery of fluoroquinolones with better safety profiles and broader spectrums of activity have made this class of antibacterial agents one of the most important in clinical usage. New des‐F(6)‐quinolone analogues are expected to provide improved activity against gram‐positive organisms and as a result, members of this class should become true broad spectrum antibiotics of major clinical importance.
Radioactive Elements
Authors: Beres Laszlo 
Published: July 2004

AbstractThis article is an overview of radioactive tracers technology focusing on compounds labeled with hydrogen‐3 (tritium), carbon‐14, sulfur‐35, phosphorus‐32, phosphorus‐33, and iodine‐125. The general approaches for the synthesis of labeled compounds, such as organic chemical methods and biochemical techniques, are described. The factors affecting the stability of labeled compounds are discussed, along with methods of detection and quantitation of the commonly used radioactive isotopes. Considerations in the safe handling of radioactive tracers and regulatory issues related to working with radioactive materials are summarized. The uses and applications of labeled compounds in biomedical research, pharmaceutical development, gene analysis, and agricultural experiments are discussed.
Radioisotopes
Authors: Helmer Richard G. 
Published: July 2004

Abstract
Radioisotopes, also called nuclides or radionuclides, are not stable, but rather decay to more stable elements or other atoms by emission of high energy radiation. Study of radioisotopes has led to increased understanding of the forces of nature, especially those forces such as those prevalent in nuclei binding exhibited solely in the microscopic world. Naturally occurring radioisotopes are used to determine the ages of materials, as radiopharmaceuticals or radiation sources or tracers in medicine, for nondestructive evaluation, for the tracking of groundwater or air flow, and for scientific analysis.
The nuclear physic properties of radioisotopes and the various radiation particles are summarized, including half‐lives, decay constants, angular momentum, and parities. The modes of nuclear decay and the accompanying radiation are described, as are combined nuclear and atomic processes, and atomic decays and corresponding radiations. Decay data for useful radioisotopes are given.