bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitrogen
Authors: Hardenburger Thomas L. , Ennis Matthew 
Published: July 2004

Abstract

Nitrogen is an important industrial gas and an element that is essential to all life. Most naturally occurring, noncombined nitrogen exists as a diatomic gas sometimes referred to as dinitrogen. Dinitrogen is an extremely stable, relatively inert molecule. High temperatures are generally required to coax its reactivity. Due to its inert nature, gaseous nitrogen finds wide application in many industrial processes as a blanketing and purging agent. Dinitrogen liquifies at

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to a colorless liquid. Liquid nitrogen is used in many applications as an inert, expendable refrigerant. All commercial nitrogen uses atmospheric air as the feedstock. The principal manufacturing processes include cryogenic distillation, pressure swing adsorption, membrane permeation, and combustion‐based processes. At the present time, cryogenic distillation is the most significant. Commercial nitrogen is distributed in very large volumes by pipeline or in smaller volumes in liquified form for use or vaporization at the use point or in compressed gaseous form in steel cylinders. Nitrogen is nontoxic but does not support life, therefore care is required before entering areas suspected of being nitrogen‐enriched.
Fluorine Compounds, Inorganic, Nitrogen
Authors: Henderson Philip B. , Woytek Andrew J. 
Published: July 2004

Abstract

Nitrogen has four binary fluorides: nitrogen trifluoride, tetrafluorohydrazine, difluorodiazine, and fluorine azide. There are numerous other nitrogen fluorine compounds, the most significant of which are the perfluoroammonium salts based on the NF
+
4
cation. Of all the nitrogen fluorine compounds, only NF
3
has been of commercial importance. Nitrogen trifluoride is used as an etchant gas in the electronic industry and as a fluorine source in high power chemical lasers.
Nitriles
Authors: Mckinney Ronald J. , DeVito Stephen C. 
Published: July 2004

AbstractNitriles are cyano‐substituted organic compounds, ie, organic derivatives of hydrogen cyanide. The combination of unique physical properties imparted by the nitrile group and the ease with which nitrile groups can be converted to other functional groups has made organonitrile compounds commercially important substances. Organonitriles may be prepared by a variety of methods including metathesis of organohalides, ammoxidation of hydrocarbons, dehydration of amides, and addition of hydrogen cyanide to unsaturated organic compounds such as aldehydes, ketones, and olefins. Some of the more common transformations include hydrolysis or alcoholysis to produce amides, acids and esters, and hydrogenation to produce amines, which are intermediates for the production of polyurethanes and polyamides. Nitriles are generally toxic to the extent that they may be metabolized in the body to liberate cyanide, and care in the body to liberate cyanide and care should be taken to prevent skin contact or inhalation of vapors. This article addresses the following organonitrile compounds in some detail: acetonitrile, adiponitrile, a‐aminonitriles, azobisnitriles, benzonitrile, cyanoacetic acid (and esters), isophthalonitrile, methylglutaronitrile, pentenenitriles, and fatty acid nitriles.
Nitrogen Fixation
Authors: Newton William E. 
Published: July 2004

AbstractNitrogen fixation converts inert atmospheric molecular nitrogen gas into reduced forms whereby the nitrogen may be used by all life forms for protein and nucleic acid production. The biological process occurs only in microorganisms and is the principal contributor of fixed nitrogen to the biosphere. Fixed nitrogen is also derived from nonbiological processes, such as fires, volcanoes, and lightning, and from industrial fixation. The Haber‐Bosch ammonia process is highly energy‐intensive but is the most economical industrial process available. Agriculturally, the most important source of biologically fixed nitrogen is the symbiotic system involving leguminous plants which harbor rhizobia bacteria in nodules on their roots. Smaller contributions are made by other, less formal systems and by free‐living microbes. All of the biological systems use a similar metalloenzyme complex, called nitrogenase. Nitrogen fixation research is discussed from a genetic standpoint, as well as in terms of model chemistry and economic advantages of the biological system. The chemical approaches aimed at duplicating the biological process are presented.
Catalyst Deactivation and Regeneration
Authors: Bartholomew Calvin 
Published: July 2004

AbstractThis article focuses on the causes, mechanisms, prevention, modeling, and treatment (experimental and theoretical) of deactivation. The causes of deactivation are basically of three kinds: chemical, mechanical, and thermal. The five intrinsic mechanisms of catalyst decay, (1) poisoning, (2) fouling, (3) thermal degradation, (4) chemical degradation, and (5) mechanical failure, vary in their reversibility and rates of occurrence. Poisoning and thermal degradation are generally slow, irreversible processes while fouling with coke and carbon is generally rapid and reversible by regeneration with O2or H2. Catalyst deactivation is more easily prevented than cured. Poisoning by impurities can be prevented through careful purification of reactants. Carbon deposition and coking can be prevented by minimizing the formation of carbon or coke precursors through gasification, by careful design of catalysts and process conditions and by controlling reaction conditions to minimize effects of carbon and coke formation on activity. Sintering is best avoided by minimizing and controlling the temperature of reaction. Regeneration of deactivated catalysts is possible for many catalytic processes and is widely practiced.The purpose of this article is to provide the reader with a comprehensive overview of the scientific and practical aspects of catalyst deactivation, including mechanisms of catalyst decay, prevention of deactivation, regeneration of catalysts, methods for study and treatment of catalyst decay, and deactivation kinetics. The greatest emphasis is on deactivation and regeneration of heterogeneous catalysts, although decay mechanisms of homogeneous catalysts and enzymes as well as methods of stabilizing these catalyst types are briefly addressed.
Nomenclature
Authors: Smith Peter A. S. 
Published: July 2004

AbstractNames for chemical substances have developed from primitive terms based on their source, properties, or effects into an elaborate system in which names encode precise information about chemical structures. Inorganic chemistry was elaborated first, and is strongly concerned with elemental composition and ionic and oxidation states. Organic nomenclature at first followed the inorganic pattern, but diverged from it because of the importance of connectivity and isomerism in organic compounds. The present system of organic nomenclature is based on the principles of the Geneva Conference of 1892, developed and expanded by international conferences and commissions into the nomenclature recommended by the International Union of Pure and Applied Chemistry (IUPAC). The nomenclatures of inorganic, organic, and macromolecular chemistry and of biochemistry are in a continuing state of development, and new recommendations from the international bodies are published in the appropriate journals, such asPure and Applied ChemistryandBiochemistry.The rules are collected in book form at intervals.
Recycling, Nonferrous Metals
Authors: Richardson H. Wayne 
Published: July 2004

Abstract
Richardson, H. Wayne (Phibro‐Tech, Inc.). The methods of recycle for various nonferrous metals of economic importance are detailed. Principal metals are aluminum, copper, lead, and zinc, although cobalt, nickel, tin, and precious metals such as gold, silver, and palladium are also recycled. Types and sources of scrap and waste metal are given. Much recyclable material arises from discarded automobile parts, beverage cans, and industrial metal industry wastes. Factors that influence the decision to recycle by pyrometallurgical or hydrometallurgical means are discussed. These processes are described, including the types of furnaces employed for smelting operations and the extractants used for solvent extraction systems. Recycling of nonferrous metals is heavily dependent on the economics of using secondary metal feed rather than ore. The role of waste management is also considered. Vol. 20, pp. 1106–1126, 31 refs. to August 1995.
Feeds and Feed Additives, Nonruminant Feeds
Authors: Waldroup Park W. 
Published: July 2004

Abstract
Meat and eggs produced by swine and poultry in the United States contributes significantly toward meeting the nutritional requirements of the human population. The feed required to produce such a quantity of meat and eggs is considerable. Most poultry operations and some swine operations take place in intensive confinement operations. Most of the poultry production take place in vertically integrated operations. This system is not as common in the swine industry. Both swine and poultry are fed diets composed of grains such as corn or grain sorghum with soybean meal the primary protein source. Many human and industrial byproducts that would otherwise go unused are also incorporated into feed for nonruminants. Vitamins and trace minerals are added to ensure an adequate supply. Amino acids produced by fermentation or chemical synthesis are used to fortify diets, resulting in feeds with lower crude protein contnt. Nutrient requirements of swine and poultry are well reserched and nutrient composition of common ingredients has been determined. As ingredient prices change in relation to supply and demand, diet composition can be changed rapidly. There is no “best” feed composition. Animals thrive on diets composed of many different types of diets so long as the diets provide adequate levels of essential nutrients.
Nuclear Fuel Reserves
Authors: Bullen Daniel B. 
Published: July 2004

Abstract
The primary fuel for light‐water nuclear reactors is natural or slightly enriched (3–5%) uranium dioxide. Estimates of the world reserves of uranium resources are based on the cost of recovery for various ore types and classified as reasonably assured, estimated, or additional, speculative resources. World reactor‐related requirements are expected to increase from usage in the early 1990s through the year 2010. Additional sources of uranium are expected to come from the de‐enrichment of weapon‐grade, high enriched uranium mixed with natural uranium in an approximate 1:30 ratio.
Nucleic Acids
Authors: Rehmann Jill 
Published: July 2004

AbstractNucleic acids are essential components of all organisms. Deoxyribonucleic acids (DNA), most commonly double helical, encode the genetic information contained in living cells. Ribonucleic acids (RNA), a more diverse class of biopolymers able to adopt helical and other more complex tertiary structures, carry out a variety of intracellular functions, including transmitting the genetic message to the site of protein synthesis. Both DNA and RNA interact with a host of other molecules, eg, proteins, drugs, as well as other nucleic acids and nucleic acid constituents. The specificity of these interactions may be related to local sequence‐dependent structural variation. The structural characteristics of nucleic acids and their constituents are discussed.Development of techniques to synthesize oligonucleotides, which are short, well‐defined sequences of DNA or RNA, provides an opportunity to study nucleic acid structure in detail. In addition, oligonucleotides have proved invaluable in analytical procedures. The unique ability of nucleic acids to bind to self‐complementary sequences has been exploited in the design of oligonucleotide probes and in antisense drug strategies. Methods for synthesizing nucleic acids and their constituents, including both unmodified and modified analogous, are discussed.
Nucleosides and Nucleotides
Authors: Suhadolnik Robert J. , Reichenbach Nancy L. 
Published: July 2004

AbstractThe naturally occurring nucleoside and nucleotide antibiotics exist as either theC‐ orN‐glycosides. They include ezomycin A1(C26H38N8O15S), ezomycin B1(C26H39N7O17S), ezomycin C1(C26H37N7O16S), ezomycin A2(C19H26N6O12), ezomycin B2(C19H25N5O13), ezomycin C2(C19H25N5O13), showdomycin (C9H11NO6), isoshowdomycin (C9H11NO6), maleimycin (C7H7NO3), oxazinomycin (C9H11NO7), pyrazomycin (pyrazofurin) (C9H13N3O6), formycin (C10H13N5O4), formycin B (C10H12N4O5), oxoformycin B (C10H12N4O6). These antibiotics contain a variety of purine and pyrimidine rings. The naturally occurring nucleoside/nucleotide antibiotics, which have been isolated from bacteria, fungi, blue‐green algae, and marine sponges, have proven to be useful biochemical probes in eucaryotic, procaryotic, viral, fungal, and plant systems. The purine nucleosides inhibit protein synthesis, RNA and DNA synthesis, and methyltransferases; they have antimycoplasmal, antiviral, hypotensive, antifungal, antimycobacterial, and antitumor activities and induce sporulation. The pyrimidine nucleosides inhibit protein synthesis, virus replication, RNA and DNA synthesis, and cAMP phosphodiesterase. The imidazole nucleosides inhibit nucleic acid synthesis. The diazepin nucleosides inhibit adenosine deaminase (ADA). The indole nucleosides inhibit bacteria, yeast, fungi, and viruses. TheN‐nucleotide antibiotics include agrocin 84 (C21H34N6O16P2), thuringiensin (C22H30N5O19P), phosmidosine (C16H24N7O8P), fosfadecin (C13H19N5O10P2), and fosfocytocin (C12H20N4O13P2). Thuringiensin, produced byB. thuringiensis, is a β‐exotoxin that exerts its toxic action on insects and mammals through the inhibition of RNA polymerases. Phosmidosine inhibits pore formation ofBotrytis cinereaandAspergillus niger. Fosfadecin and fosfocytocin inhibit gram‐positive and gram‐negative bacteria.
Nuts
Authors: Young Clyde T. 
Published: July 2004

AbstractNuts, hard‐shelled seeds enclosing a single edible oily kernel, are generally used for human consumption. Nuts may be consumed as shelled whole nuts or, after blanching, roasted. Roasted nuts may be either eaten or ground into nut butters. Peanuts which contain excessive levels of aflatoxin are generally extracted for peanut oil. Production processes are outlined for nut salting, defatting, and the making of peanut butter. With the exception of peanuts, most commercially important nuts are borne on trees. As a whole, nuts have high oil and protein contents and a low percentage of carbohydrate. Approximate composition in terms of amino acid, fatty acid, vitamin and carbohydrate levels are tabulated for selected nuts and nut products. Because of the high oil content of nuts, rancidity is one of the first signs of deterioration in nuts. Optimal storage conditions are discussed as are coatings and antioxidants to delay the onset of rancidity. Non‐edible uses of nuts are as a source of quick drying oils, activated charcoal, dyes, and tannins. Production data are given for the principal edible nuts: almonds, cashews, Brazil nuts, coconuts, English walnuts, filberts or hazelnuts, macadamia nuts, pecans, and pistachios.
Ocean Raw Materials
Authors: Cruickshank Michael J. 
Published: July 2004

AbstractInorganic raw materials are defined as any mineral deposit found in the marine environment. The ocean is host to a variety and quantity of inorganic raw materials equaling or surpassing the resources of these materials available on land. The mineral resources include industrial minerals, mineral sands, phosphorites, metalliferous oxides, hydrothermal metalliferous sulfides, and dissolved minerals, as well as geothermal resources, precious corals, and some algae. The resources are classified as unconsolidated, consolidated, or fluid materials which are chemically enriched in certain elements and are found in or on the seabeds of the continental shelves and ocean basins. With few exceptions these materials are similar to traditional mineral deposits on land. A significant source of minerals for sustainable recovery in the future may be ocean waters, which include nearly all the known elements in some degree of solution. Commercialization of production of dissolved minerals from seawater is limited to fresh water, magnesium, magnesium compounds, salt, bromine, and heavy water, ie, deuterium oxide. There are four basic methods of mining solid minerals: scraping the surface, excavating a pit or trench, removal through a borehole in the form of a slurry or fluid, and tunneling into the deposit. An apparently significant advantage to recovery of mineral raw materials from the marine environment is the benign effects of these activities when compared to the recovery of the same materials from land.
Recycling, Oil
Authors: Becker Donald A. , Brinkman Dennis W. 
Published: July 2004

AbstractThis article discusses the recycling of used petroleum oils. The term oil includes a variety of liquid or easily liquefiable, unctuous, combustible substances that are soluble in ether but not in water and that leave a greasy stain on paper or cloth. These substances can include animal, vegetable, and synthetic oils, but usually the word oil refers to a mineral oil produced from petroleum. An oil that has been used or contaminated, or both, but not consumed, can often be recycled to regain a useful material regardless of its origin. In the past, used or contaminated oil was usually considered a waste and was disposed of in a variety of ways, including incineration, road oiling, landspreading, municipal landfills, and dumping on the ground or into storm sewers. However, on account of the increased concern about pollution, the advent of periodic petroleum shortages, and increased prices for most kinds of oils and oil products, there is a strong interest in developing ways to conserve the valuable energy and resource content of these products.
Fibers, Olefin
Authors: Wust C. J. , Landoll L. M. 
Published: July 2004

Abstract
Olefin fibers, also known as polyolefin fibers, are synthetic fibers of growing commercial importance. Several olefin polymers are capable of forming fibers, but only polypropylene and polyethylene are of practical importance. From the first commercial application of polyethylene in automobile seat covers to multicomponent extrusion for specialty applications, olefin fibers have made a significant impact in the fiber industry. This article reviews the fiber properties, including physical, tensile, chemical, and thermal and ultraviolet stability, which make them ideally suited for these varied applications. Commercial fiber manufacturing and processing is discussed for staple fiber, continuous filament, and directly formed nonwovens. The extrusion, quench, and draw play integral roles in the development of the fiber properties. Bicomponent, high strength, and hard‐elastic fiber technology is examined. Olefin fiber consumption statistics are broken down by use.
Opioids, Endogenous
Authors: Selley Dana E. , Sim Laura J. , Childers Steven R. 
Published: July 2004

AbstractEndogenous opioid peptides represent a significant class of peptide neurotransmitters in brain and peripheral tissues. They share the common property of high affinity binding to one or more of three principal types of opioid receptor, µ, δ, and κ. The endogenous opioid peptides include three classes: the enkephalins, β‐endorphin, and dynorphin. These peptides share the pentapeptide sequence of either Met‐ or Leu‐enkephalin. The peptides in each class are synthesized from high molecular weight precursors; trypsin‐like cleavage between pairs of basic amino acid residues yields intermediate and final peptide products. Each class of peptides possesses a unique regional distribution in the brain, and mediates a variety of functions, including analgesia, respiration, thermoregulation, neuroendocrine regulation, and modulation of immune cell function. Although synthesis of numerous synthetic analogues of opioid peptides have not produced analgesic drugs of practical importance, they have produced analogues with extraordinary specificity and stability which provide valuable information about the structure of opioid binding sites.
Cellulose Esters, Organic Esters
Authors: Gedon Steven , Fengi Richard 
Published: July 2004

AbstractCellulose is one of nature's most abundant structural materials, providing the primary framework of most plants. For industrial purposes cellulose is derived from two primary sources, cotton linters and wood pulp. Cellulose esters are commonly derived from natural cellulose by reaction with organic acids, anhydrides, or acid chlorides. Cellulose esters of almost any organic acid can be prepared, but because of practical limitations esters of acids containing more than four carbon atoms have not achieved commercial significance. Cellulose acetate is the most important organic ester because of its broad application in fibers and plastics; it is prepared in multi‐ton quantities with degrees of substitution (DS) ranging from that of hydrolyzed, water‐soluble monoacetates to those of fully substituted triacetate. Although cellulose acetate remains the most widely used organic ester of cellulose, its usefulness is restricted by its moisture sensitivity, limited compatibility with other synthetic resins, and relatively higher processing temperature. Cellulose esters of higher aliphatic acids, C3and C4, circumvent these shortcomings with varying degrees of success. Mixed cellulose esters containing acetate and either the propionate or butyrate moieties are produced commercially in large quantities by Eastman Chemical Co. in the United States. The properties, manufacturing methods, uses, economics, and safety of organic esters of cellulose are discussed.
Pigments, Organic
Authors: Jaffe Edward E. 
Published: July 2004

Abstract
The article is intended for anyone interested in organic pigments in general or specific pigment classes in particular, with references provided for greater in‐depth review of scientific and theoretical considerations. This article begins with definition, identification, and categorization of organic pigments, followed by a list of 54 commercial pigments, including methods of their preparation. Also described is the origin of color in organic compounds and the relationship between absorbed light and observed color. Technical and durability properties are described in some detail, followed by a description of pigment types, including structural formulas of representative pigments, generalized wherever appropriate. For some pigment classes tables are included to identify additional important pigments of a group. In each case, a short description of pigment attributes and shortcomings as well as applications are included. The pigment types range from the least expensive, simple pigments, to the most sophisticated, complex structures, ranging in properties from poor to excellent. The description of production and economic aspects are based on governmental statistical data and other information available in the literature, private sources and the Internet, and includes worldwide data with particular emphasis on U.S. consumption, exports, and imports. Finally, methods of pigment testing, standardization, and color measurement are briefly described. The article concludes with a brief discussion of health effects, toxicity of pigments, their effect on the ecology, and uses.
Electrochemical Processing, Organic
Authors: King Chris J. H. 
Published: July 2004

AbstractThe technology for electroorganic synthesis is surveyed starting with an overview of the electrochemical cells for this purpose. Cell design, electrode materials, and diapraghms are discussed as are cell current distribution and mass‐transport phenomena. Features influencing good product selectivity for specific cell designs are presented together with the various commercially available cells. Cost analysis for electroorganic synthesis is reviewed. The electroorganic processes that have been commercialized or have been pilot planted are presented.