bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aluminum Compounds, Introduction
Authors: Sleppy William C. 
Published: July 2004

AbstractThe CAS registry lists 5037 aluminum‐containing compounds exclusive of alloys and intermetallics. The aluminum containing compound having the largest worldwide market is metal‐grade alumina. Second is aluminum hydroxide. Bauxite is the principal ore used for alumina production. Additive applications include those as flame retardants in products such as carpets, and to enhance the properties of paper, plastic, polymer, and rubber products. Significant quantities are also used in pharmaceuticals, cosmetics, adhesives, polishes, dentifrices, and glass. Aluminum sulfate,, also known as alum cake, is industrially produced for major applications as a sizing agent in the paper industry and as a coagulant to clarify municipal and industrial water supplies. In terms of worldwide production, it ranks third behind alumina and aluminum hydroxide. All the halogens form covalent aluminum compounds having the formula AlX3. The most important commercially are the anhydrous chloride and fluoride, and aluminum chloride hexahydrate. The latter is used in pharmaceuticals and cosmetics as a flocculant and for impregnating textiles. The alkyls and aryls, R3Al (in monomer form), are colorless liquids or low melting solids easily oxidized and hydrolyzed when exposed to the atmosphere. Triethylaluminum (TEA), one of the most commercially important members of this family of chemicals, is so reactive it bursts into flame on contact with air, ie, it is pyrophoric, and it reacts violently with water. Special techniques are necessary for the safe handling and use of organoaluminum compounds, which are used commercially in multimillion kg/yr quantities as catalysts or starting materials for the manufacture of organic compounds such as plastics, elastomers biodegradable detergents, and organometallics containing zinc, phosphorus, or tin. Sodium aluminate is used in water purification, in the paper industry, for the after‐treatment of TiO2pigment, and in the manufacture of aluminum‐containing catalysts and zeolite. A large and growing industrial use of aluminum hydroxide and sodium aluminate is the manufacture of synthetic zeolite. Zeolites are aluminosilicates with Si/Al ratios between 1 and infinity. There are 40 natural, and over 100 synthetic, zeolites. Zeolite‐based materials are extremely versatile: uses include detergent manufacture, ion‐exchange resins (ie, water softeners), catalytic applications in the petroleum industry, separation processes, and as an adsorbent for water, carbon dioxide, mercaptans, and hydrogen sulfide.
Iodine and Iodine Compounds
Authors: Lauterbach Armin , Ober Gustavo 
Published: July 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.
Ionomers
Authors: Rees Richard W. 
Published: July 2004

AbstractRees, Richard W. (E. I. du Pont de Nemours & Co., Inc.). Commercial ionomers are copolymers of ethylene with 5–10 wt % methacrylic or acrylic acid, which have been partly neutralized with mono‐ or divalent metal ions, the most important being sodium and zinc. The presence of the ion results in strong ionic forces between the polymer chains. These forces have profound effects on both solid‐state and melt properties, resulting in a spectrum of end uses; this is quite distinct from that of other ethylene‐based resins. The relationships between ionic forces and properties are covered in this article. Information is also presented on manufacture and applications of the products sold as Surlyn, Hi‐Milan, or Iolon resins. Other types of ionomers, such as styrenics, which have been extensively studied but have not become commercial, are also reviewed briefly. Vol. 14, pp. 815–829, 76 refs. to June 1992.
Iron and Steel, Economic Aspects
Authors: Geiger Gordon H. 
Published: July 2004

AbstractThe economics of iron and all of its derivative materials is dominated by the fact that iron is the most widespread and ubiquitous metallic element found in the earth's crust. Iron ore deposits are present and mined on all the inhabited continents. From these ores, iron has been extracted for centuries, through the Iron Age and eventually the Industrial Revolution. The economics of iron production from ore is therefore the starting point, but then the preparation of steel from the base iron incurs further costs. And after centuries of iron products entering the world economies, iron in the metallic form, as iron and steel scrap, is now recycled in significant quantities, having a significant effect on the overall economics of steel. Therefore, in this article, the economics of iron and steel scrap will also be considered.
Iron
Authors: Lepinski J. A. , Myers Jeffrey C. 
Published: July 2004

Abstract
Iron, the fourth most abundant element in the earth's crust, is the world's least expensive, most useful metal. Iron is alloyed with other elements for commercial applications. Iron‐bearing minerals of economic importance are hematite, magnetite, goethite, siderite, ilmenite, and pyrite. These ores can be beneficiated through crushing, grinding, magnetic separation, flotation, electrostatic separation, roasting, sintering, or pelletizing. Iron oxides in the form of pellet, lump, and/or sinter are fed along with coke and limestone into the blast furnace wherein the iron oxide is reduced and melted into hot metal (pig iron); the pig iron is further refined in an oxygen converter to make steel. New technologies are being developed as alternatives to the blast furnace for reducing iron oxide. These include direct reduction and direct smelting processes. In the foundry, ferrous scrap can be melted along with coke in a cupola or induction furnace to make cast iron. Cast iron can be classified into gray, white, malleable, or ductile iron.
Iron by Direct Reduction
Authors: Lepinski J. A. 
Published: July 2004

Abstract
Lepinski, J.A. (Midrex Direct Reduction Corp.). Direct reduction is the process of converting iron ore into metallic iron without melting. Direct reduced iron (DRI) is used as a high quality feed material in electric arc furnace steelmaking, oxygen steelmaking, ladle metallurgy, blast furnace ironmaking, and foundries. Normally 90 to 95% of the iron in DRI is in the metallic form. Carbon is normally present in the DRI to balance any remaining iron oxide, and the level of residual elements is very low. The reduction of iron oxide proceeds from hematite to magnetite to wustite to iron. Some of the iron may combine with carbon to form cementite; DRI having high percentages of cementite is sometimes called iron carbide. The most common reductants are reformed natural gas and coal. The main commercially proven direct reduction processes are discussed. Hot briquetted iron (HBI), a densified form of DRI, is more resistant to reoxidation and corrosion. Vol. 14, pp. 855–872, 7 refs. to April 1994.
Isocyanates, Organic
Authors: Richter Reinhard H. , Priester Ralph D. 
Published: July 2004

AbstractIsocyanates are highly reactive compounds which have found wide utilities in synthetic transformations and industrial applications. These materials are synthesized by reaction of primary aliphatic or aromatic amines and phosgene (carbonyl dichloride) to form carbamoyl chlorides which are subsequently pyrolyzed to the desired isocyanates. A characteristic reaction of isocyanates and alcohols to form carbamates (urethanes) has been used for the qualitative identification of the latter. Extension of this reaction to difunctional isocyanates and difunctional or polyfunctional alcohols is the basis of the polyurethane industry, with products ranging from flexible and rigid insulating foams to thermoplastic elastomers, coatings, and adhesives, as well as a variety of automotive and recreational products.p‐Toluenesulfonyl isocyanate is used in the synthesis of drugs for diabetics. A unique feature of isocyanates is their tendency to oligomerize or polymerize in presence of catalysts. In addition, isocyanates easily form adducts with carbodiimides, isothiocyanates, ketenes, or with substrates containing activatedorbonds. Low boiling isocyanates are strong lachrymators and irritants. Several isocyanates and their precursors have been identified as mutagens. Guidelines for safe handling of isocyanates are discussed. Vol. 14, pp. 902–934, 100 refs. to January 15, 1993.
Isopropyl Alcohol
Authors: Logsdon John E. , Loke Richard A. 
Published: July 2004

AbstractIsopropyl alcohol is a colorless, volatile, flammable liquid having a low order of toxicity and a mild odor. Its main uses are as a chemical intermediate and in solvent applications in medicine and industry. The majority of the isopropyl alcohol in the United States is produced by indirect hydration of propylene in the weak sulfuric acid process. Outside the United States, several acid‐catalyzed direct hydration of propylene processes are also used. The indirect process can use refinery‐grade propylene streams and lower operating pressures than the direct process, but suffers from higher corrosion and maintenance costs. These processes and the various catalysts employed are described. Isopropyl alcohol demand in the United States has been declining slowly since 1983. Demand is expected to grow slightly owing to increasing use as a chemical intermediate. In addition to its use in the production of acetone, isoproyl alcohol is consumed in the production of higher ketones, amines, esters, and other chemicals. The use of diisopropyl ether as a fuel oxygenate may become a significant outlet for isopropyl alcohol.
Isoprene
Authors: Lybarger Hugh M. 
Published: July 2004

AbstractIsoprene is a colorless, volatile liquid that is soluble in most hydrocarbons but is practically insoluble in water. Isoprene forms binary azeotropes with water, methanol, methylamine, acetonitrile, methyl formate, bromoethane, ethyl alcohol, methyl sulfide, acetone, propylene oxide, ethyl formate, isopropyl nitrate, methylal, ethyl ether, andn‐pentane. The exact conformation of the isoprene molecule is still in doubt. It generally is accepted that there is no free rotation around the central C–C single bond. Isoprene may be considered as an equilibrium of two conformations, namely a cisoid conformation in which both vinyl groups are located on the same side of the C–C bond, and the transoid one with the vinyl groups located on the opposite sides of the bond. Physical properties, polymerization, production, economic aspects, and health and safety factors are described.
Ketenes, Ketene Dimers, and Related Substances
Authors: Abaecherli Claudio , Miller Raimund J. 
Published: July 2004

AbstractThis article describes monomeric ketenes, ketene dimers, and acetoacetic acid derivatives. The parent substance, ketene itself, is the only ketene to be manufactured in large industrial quantities. The manufacturing process, chemical and physical properties, and industrial uses of ketene are described in detail. A table is included that lists examples of higher ketenes, thioketenes. The manufacture of acetic anhydride is described.The article gives a thorough review of all aspects of diketene which is an important product derived from ketene on an industrial scale. Diketene gives access to open‐chain acetoacetic acid derivatives as well as heterocyclic systems. An overview is provided on dimeric aldoketenes and ketoketenes.Acetoacetic acid derivatives are of significant economic importance. The manufacturing processes of diketene esters and of acetoacetarylides are outlined. This includes methyl acetoacetate and acetoacetanilide. Industrial uses of the various ketene and diketene derivatives are discussed with emphasis on the most important life science applications. Vol. 14, pp. 953–978, 157 refs. to December 1993.
Kinetic Measurements
Authors: Magde Doug 
Published: July 2004

Abstract
Kinetic measurements measure the rates of reactions. The information obtained is useful for fundamental understanding of chemical mechanism and for a variety of applications. The overall rate law for a reaction and the definition of associated rate constants must be consistent with the stoichiometric chemical equation for the reaction, but cannot be predicted from the stoichiometric equation alone. A detailed reaction scheme (or an even more descriptive reaction mechanism), which specifies any intermediates that occur in the reaction and describes exactly which atoms or molecules react in each elementary step, is needed to predict a rate law. The goal of kinetic measurements is to verify the functional form of the rate law and determine any constants in the rate law. The constants are quantities that do not vary when concentrations of reactants change; but they do vary with temperature, solvent, and other reaction conditions. Kinetic measurements involve preparing reactants at concentrations different from equilibrium values and then monitoring concentrations as they approach equilibrium. Simple manual mixing may suffice. More rapid reactions may be studied by flow‐mixing reactants in a moving stream or by injecting and mixing rapidly in a stopped‐flow device. Even faster reactions require perturbation techniques that start with a homogeneous mixture and perturb conditions away from equilibrium. This can be accomplished by changing external thermodynamic conditions such as temperature or pressure. Altematively, a reagent precursor may be switched suddenly to an active form by a flash of light (flash photolysis) or a pulse of electrons (pulse radiolysis). A host of reaction schemes are possible, but the Michaelis‐Menten scheme applicable to much enzyme catalysis receives special attention. The temperature dependence of rate constants is discussed in terms of an activation energy, and the dependence on pressure is characterized by an activation volume. Brief mention is made of recent progress in reaction dynamic studies, which provide in a few cases both experimental and theoretical treatments at the full quantum mechanical level.
Lanthanides
Authors: Leveque A. , Sabot J. L. , Maestro P. 
Published: July 2004

AbstractLanthanides is the name given collectively to the 15 elements from lanthanum to lutetium sharing the same space in Mendeleev's original Periodic Table. Lanthanides have a unique electronic structure because of partially filled 4forbitals. Occurrence and preparation of the rare earths is described. Mining of lanthanide ores and the various separation methods are discussed. Except for cerium and europium, the lanthanides are separated industrially of solvent extraction. The production of lanthanide metals is also presented.Industrial applications of lanthanides encompass a number of different fields, including the high technology field of electronics. Uses in metallurgy, catalysis, and the glass and ceramics industry are based on unique chemical and structure properties. Uses as luminescent materials for phosphor applications or in medical imaging technology are limited to specific optical properties. Uses of lanthanides and their alloys as high energy magnets result from the special magnetic properties. Information storage is but one of many industries in which lanthanide usage is expected to grow. Vol. 14, pp. 1091–1116, 51 refs. to January 1993.
Lead Compounds
Authors: Carr Dodd S. , Spangenberg William C. , Chronley Kevin , Meshri Dayal T. 
Published: July 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.About 80% 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.
Lead
Authors: King Michael , Ramachandran Venkoba 
Published: July 2004

AbstractOn a weight basis lead is the fifth most used metal in the world. As a metal, lead is prized for properties such as high density, ease of fabrication, chemical stability in air and water, ability to absorb high energy radiation, and for its electrochemistry, especially the reaction with sulfuric acid. The lead–acid storage battery is used worldwide. Lead also forms alloys and compounds.Lead is generally recovered from ores containing 2–6% lead sulfide. After concentration, the sulfide is smelted to metal, refined to remove impurities, and the valuable by‐products such as silver and gold recovered. Several newer technologies for smelting have come into commercial operation outside of the United States to replace the traditional sinter/blast furnace process. Refining and by‐product recovery are achieved by traditional pyrometallurgical and electrolytic methods. These primary production methods are described.Recycling of the lead in scrap lead–acid batteries is steadily increasing and, in the United States, accounts for two‐thirds of the lead consumed annually. Secondary production methods are described, including technologies under development to improve recycling capabilities.World consumption of lead has increased despite environmental concerns of health and safety factors. Future growth in the lead industry, however, depends on the market for lead–acid batteries.
Lecithin
Authors: Wendel Armin 
Published: July 2004

AbstractLecithins and phospholipids occur in all living organisms. They are components of biological membranes. Commercial lecithins are by‐products of the industrial production of vegetable oils. They are referred to as soya, sunflower, rape lecithin, etc, depending on their origins. The most important of these preparations is soya lecithin, so the term lecithin almost always refers to this.Commercial lecithins are mixtures. They are made up of ca 50% phospholipids, ca 10% carbohydrates and glycolipids, and of ca 40% triglycerides, free fatty acids, sterols, and other minor components of vegetable oils. The significant components are the phospholipids, whose surface‐active properties endow the lecithins with their unique position as emulsifier and dispersants. Because they are permitted in foodstuffs throughout the world without limitations, they find their broadest application in food. Native, ie, unprocessed, lecithins have also been found useful as additives to animal feed and in technical products.Fractionation or chemical modification of lecithins yields preparations with improved activity or with a wider range of application. The surfactant and wetting properties of vegetable lecithins are improved by acetylation, hydroxylation, and partial hydrolysis. Hydrogenation improves the resistance to oxidation and aging and increases the water‐binding capacity of the preparation. In spite of the multiplicity of possible applications only about 10% of the available lecithin is produced (ca 130,000 t).
Licensing
Authors: Ku Katharine 
Published: July 2004

Abstract
A license is an agreement which conveys specified patent, copyright, trademark, or know‐how rights from one party to another. The main terms and conditions of a license generally include diligence provisions, financial obligations, and a conveyance of the rights exclusively or nonexclusively. The considerations in valuing a technology are discussed. Licensing is usually a business arrangement for the mutual benefit of the parties and should be part of an overall commercialization and business strategy.
Light‐Emitting Diodes
Authors: Kish Fred 
Published: July 2004

Abstract

Light Generation (Light‐emitting diodes). The light‐emitting diode (LED) is one of the most technologically fundamental and commercially important of compound semiconductor devices. Such emitters consist of a
p
–
n
junction diode formed in compound semiconductor material that emits radiation in the ultraviolet, visible, or infrared in response to an electrical current passing through a forward‐biased device. Radiative recombination in these devices is strongly influenced by a variety of material and structural properties, including the nature of the energy gap of the semiconductor and the presence of impurities or defects in the device. An important challenge in these devices is the ability to extract light from the high index semiconductor material into the outside world. Generally, LEDs may be grouped into two categories depending on performance and application. Visible or display emitters are utilized in lighting applications, and communications LEDs (mostly infrared) are utilized to optically transmit data. The various optoelectronic components, materials systems, and types of layered structures and dopants are discussed. Device design, fabrication techniques, and performance and presented.
Lignin
Authors: Lebo Stuart E. , Gargulak Jerry D. , McNally Timothy J. 
Published: July 2004

AbstractThe word lignin is derived from the latin wordlignummeaning wood. It is one of the main components of all vascular plants and the second most abundant polymer in nature. This article describes the current understanding of the structure of this complex natural polymer. The number and types of different chemical bonds present in lignin are discussed as are the ways in which different lignins are identified and their distributions determined in plant tissues. Means for isolating lignin from wood are described, and the chemical and physical properties of the resulting lignins are reviewed. The various chemical and instrumental methods for characterizing isolated lignins are also discussed. This article concludes with a review of commercial lignin products including a discussion of producers, production methods, modification reactions, and the many industries in which lignins are used.
Lignite and Brown Coal
Authors: Vorres Karl S. 
Published: July 2004

AbstractLignite and brown coal are intermediate between peat and bituminous coal. These coals are high in moisture content, low in density, and frequently low in sulfur, and tend toward spontaneous ignition in air. The brown coals are geologically younger than the firmer, fibrous lignite. Deposits, from 2–60 million years old, are found mainly in Russia, central Europe, Australia, and the United States. Proved reserves, about 300 billion metric tons, represent close to a 290 year supply at 1990 production rates.Most lignite and brown coal is burned for electric power generation and mines are usually close to utilization sites for both economic and safety reasons. Lignite briquettes are also used for domestic heating in various parts of the world. Processes for lignite and brown coal conversion to synthesis gas for feedstock utilization, to both gaseous and liquid fuels, and to materials for use as soil conditioners, wax, and so on, are described.