bluuebunny/crossref_metadata_2025 huggingface dataset:
Insecticides
Authors: Plimmer Jack R. , Gammon Derek W.
Published: July 2004

Insects constitute an immense drain on food resources worldwide, as well as being serious disease vectors. Insecticide applications are made directly to raw agricultural commodities to protect plants and animals from insect attacks. Official national and international bodies regulate pesticide use and set permitted maximum residue levels or MRLs/tolerances for residues of insecticides and degradation products. Insect vectors spread many human and animal diseases. It was estimated in 2000 by the World Health Organization (WHO) that malaria caused close to 3 milllion deaths annually. Major health and economic benefits are associated with the continued use of insecticides, and the combination of newly introduced chemical classes with improved understanding of pest management has done much to reduce both the amounts used and the risks to nontarget species and the environment. Historically, many insecticidal preparations were derived from plant species. Synthetic organic chemicals were introduced in the 1930s, but the scale of their use increased during the immediate postwar years, with the introduction of the chlorinated insecticides, the carbamates and the organophosphates. Chlorinated organic insecticides were used in quantity, particularly for control of disease vectors, but they became recognized as ubiquitous environmental pollutants. Their effectiveness fell as insect resistance became widespread. Newer insecticides based on substantially different modes of action and of greater environmental acceptability are replacing older compounds. Newer types include growth regulators, juvenile hormone analogs, compounds affecting other metabolic pathways, such as chitin synthesis, and compounds affecting insect behavior. Investigations of insect physiology revealed more details of the insect nervous system and identified new targets. Newer screening and synthesis techniques aided developmental work and resulted in newer insecticides effective at extremely low application rates. These include the synthetic pyrethroids, fermentation products such as the spinosads, that act at the nicotinic acetycholine receptor, as do the nitromethylenes compounds acting on the GABA receptor/chloride ionophore complex, voltage‐gated sodium channel effectors, and compounds acting on mitochondrial respiration, among others. Regulatory policy favors the development of new compounds that are compatible with integrated pest management (IPM) systems. Major considerations in selection of the proper insecticide for the IPM program include mode of action, timing, dosage of application, and problems of resistance and resurgence, possible effects of insecticide residues on food crops, and in the environment, and the impact of these on humans, domestic animals, and wildlife.
Insulation, Acoustic
Authors: Hirtle Parker W. , Parssinen Carol E.
Published: July 2004

Acoustic insulation refers to materials and constructions that reduce the passage of sound into or out of a medium such as air, water, or a solid structure. This article is concerned with airborne and structureborne sound and provides an overview of a wide variety of materials and constructions used for acoustic insulation purposes. Included are discussions of sound‐absorbing treatments for reducing the reflection of impinging sounds; sound‐blocking materials and constructions for reducing the transmission of sound from one location to another; vibration isolation devices for reducing the transmission of vibration from vibrating sources into supporting structures (potential sound‐radiators); and vibration damping treatments used to reduce vibrations within and sound radiation from materials and structures. Test methods, measurement units, rating procedures, and specific uses of materials, devices, and constructions for acoustic insulation purposes also are discussed.
Insulation, Thermal
Authors: Tye Ronald P.
Published: July 2004

The applications of both open‐ and closed‐cell cellular plastics for use as thermal insulations to improve energy efficiency in buildings and industrial processes are discussed. Brief details of the types and forms of cellular plastics available for such uses are included as well as typical data on thermal and other relevant performance properties and characteristics. Materials include extruded and expanded polystyrene, block, laminated and sprayed polyisocyanurate (including polyurethane), and phenolic resin based together with a variety of lesser used special application materials such as polyethylene, polyimide, and melamine. The temperature‐dependent properties discussed are thermal performance including aging phenomena and its required accelerated aging testing procedures, mechanical, and structural performance. Flame resistance and other fire‐related parameters are also included as are health and safety issues including environmental effects of CFC and HCFC‐type blowing agents. Finally a brief discussion is included on economic aspects and growth potential of cellular plastics for applications that require thermal insulation for energy efficient operation.
Fluorine Compounds, Organic
Authors: Bajzer William X.
Published: July 2004

The introduction briefly covers the history of organic fluorine compounds along with an overview of their commercial impact founded in special chemical properties imparted by the CF bond. Various important synthetic fluorination methods are discussed with an emphasis on global commercial processes, the corresponding plant sites and their production capacities. The changing global marketplace is discussed as CFC (chlorofluorocarbon) use is banned and their replacements are being commercialized. Specific chemicals are shown as examples of the dependence and the diversity of organic fluorine compounds within our environment. A summary of safe handling aspects is characterized by a wide range of biological activity and inactivity offered by the examples of this interesting group of chemicals. A bibliography and general reading suggestions complete the subject with the literature search covering information through March, 2004.
Recycling, Introduction
Authors: Boerner Christopher , Chilton Kenneth
Published: July 2004

Recycling is the process by which materials that are either not directly usable in their present form (eg, secondary materials or by‐products) or have been separated from waste destined for disposal are remanufactured into usable or marketable materials. The amount of public attention given to recycling has increased noticeably during the last few years; however, the recycling of many industrial and household materials has been a profitable endeavor for decades. More recently, government programs designed to increase recycling rates have distorted recycling markets worldwide. This article provides a broad overview of this politically popular issue. Specifically, the article discusses the amount of material collected and processed for recycling, the composition of this material, how collected material is handled, and the economic aspects of recycling. Although the article is written from an American perspective, most of the concepts examined in the paper are international in nature.
Batteries, Introduction
Authors: Brodd Ralph
Published: July 2004

Batteries are precision miniature chemical reactors that convert chemical reaction energy into electrical energy, on demand. Batteries range in size from large house‐sized batteries for utility storage down to tablet‐sized batteries for hearing aids and paper‐thin batteries for memory protection in electronic devices. The electrons involved in the chemical reactions are transferred from the active materials undergoing oxidation to the oxidizing agent by means of an external circuit. The passage of electrons through this external circuit provides the means for control of for the direct energy conversion without going through heat as an intermediate step. The three main types of batteries are primary, secondary, and reserve. The battery voltage is unique for each group of reactants comprising the battery system and is determined by the thermodynamics of the reaction. The criteria for commercial batteries is described. Only a few reactions have the characteristics requisite for use in commercial batteries. The performance of typical commercial and developing battery systems is summarized.
Electrochemical Processing, Introduction
Authors: Fuller Thomas F. , Newman John
Published: July 2004

Electrochemical systems convert chemical and electrical energy through charge‐transfer reactions. These processes, which may be electrolytic or galvanic, are introduced. Basic definitions and terminology are given. The fundamental principles of thermodynamics, kinetics, and transport as applied to electrochemical systems, the relevance of these principles to the design of electrochemical systems are discussed.
Nuclear Reactors, Waste Management, Introduction
Authors: Murray Raymond L.
Published: July 2004

The nuclear reactor involves a controlled chain reaction wherein fission of uranium by neutrons occurs. By‐products are energy and wastes. A brief history of reactor development is given. Worldwide usage of nuclear reactors for power generation is summarized, including the numbers and types of reactors. Characteristics of the most common reactor types are given.

Environmental aspects of nuclear power plants are presented. Discussion of safety issues includes lessons learned from such previous accidents as those at Three Mile Island and Chernobyl. The high cost of nuclear electricity is discussed and compared to use of coal.
Silica, Introduction
Authors: Patterson Robert E.
Published: July 2004

Silica exists in a variety of stable, unstable, and metastable forms, and commercial usage extends to all types. Some, such as quartz, are crystalline; others are microcrystalline; still others are amorphous. The amorphous silicas vary over a wide range of hydration or hydroxylation to produce sols, gels, fumes, and precipitates, according to the manufacturing process employed. The structures and bonding within the various silicas is presented, as are the transformations between forms. Uses of silica, which are dependent on form, range from quartz crystals for precision instruments to precipitated silicas as a reinforcing filler in rubber, from food additive to principal raw material for glass. Uses of silica are expected to continue to grow throughout the 1990s.
Ion Exchange
Authors: Dickert Charles
Published: July 2004

Ion exchange is a process in which cations (anions) in a liquid are exchanged for cations (anions) on a solid sorbent, maintaining electroneutrality in both phases. Ion‐exchange resins consist of synthetic organic polymeric materials generally categorized according to functionality as either strong or weak acids or bases. Some specialty resins contain other appending groups such as thiols or chelates. The composition and the porosity of the polymer matrix are also important to function. Manufacture, stabilities, and regeneration of resins are described. Particular resins effect chromatographic separation in addition to ion exchange. Many resins may be regenerated after use.

The primary application of ion exchange is in softening and deionization of water. Other uses include waste treatment, food processing, catalysis, and purification procedures in the chemical, pharmaceutical, and plating industries. Ion‐exchange columns are often used in conjunction with such other purification materials as activated charcoal. Cation exchangers generally outsell anion exchangers.
Ion Implantation
Authors: Walter Kevin C. , Nastasi Michael
Published: July 2004

Ion implantation has been used as a research tool since about 1960, as an indispensable part of integrated circuit production since the mid‐1960s, and as a method for beneficially modifying surface sensitive properties since the early 1970s. Ion implantation processes are known to be low temperature (if desired), highly controllable, and reproducible processes capable of exceeding thermodynamic constraints on the types of materials created at, or on, a material's surface. Outside the traditional semiconductor applications for the introduction of dopants into silicon, ion implantation technology has found other applications as a method for modifying the mechanical or chemical properties of material surfaces. In this article the fundamental underlying physical concepts of ion implantation are reviewed, namely, ion stopping, ion range, implanted concentration, channeling, radiation damage, radiation enhanced diffusion, and sputtering. A brief overview of the application of ion implantation to problems in tribology, fatigue, catalysis, and corrosion is provided. As further advances in both the application and the technology of ion implantation are made, and the economic values become realized, interest in ion implantation processes is expected to expand rapidly. In response to anticipated future interest, the state of ion implantation technology and the economic issues associated with the application of ion implantation technology at the industrial level are discussed. Vol. 14, pp. 783–814, 203 refs. to April 1994.
Fluorine Compounds, Inorganic, Iron
Authors: Meshri Dayal T.
Published: July 2004

Iron(II) fluoride and iron(III) fluoride are both known and commercially available. Only the trifluoride has been employed in a variety of industrial applications, the principal ones being manufacture of magnets, as a catalyst in petroleum and organic industry, and in some fire‐retardant formulations. Preparation and properties of the iron fluorides, their hydrates, and complexes are described.
Iron Compounds
Authors: Stolzenberg Alan M.
Published: July 2004

This article provides a brief overview of the preparation, composition, properties, and uses of the principal compounds of iron. The compounds are divided into salts and simple coordination compounds, chelate compounds, organometallic compounds, and compounds of biological relevance. Whereas compounds of iron in the

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oxidation state are the most common, eg, salts of iron(II) are known for almost all the common anions, higher oxidation states are known to exist, even in biological compounds. Moreover, organometallic iron is formally lower in the oxidation state. Iron compounds find commercial applications throughout the chemical industry as catalysts, pharmaceuticals, dyes, pigments, and indicators. Many iron compounds are magnetic and may be found in magnets and in recording media as well as in microwave technology. Sections on economic aspects, analytical methods, and health and safety considerations are included.
Isotope Separation
Authors: Von Halle Edward
Published: July 2004

The high cost of isotope separation has limited the use of separated isotopes in nuclear reactors to those situations where no substitutes are available. Whereas isotopic separation processes vary according to the properties of the specific element, these methods are all energy‐intensive. Isotopes utilized range from the heavy uranium‐235 to the lighter deuterium, tritium, boron‐10, and lithium‐7. Separation procedures for each of these isotopes are described.
Ketones
Authors: Hwang Yng‐Long , Bedard Thomas C.
Published: July 2004

Ketones are a class of organic compounds that contain one or more carbonyl groups bound to two aliphatic, aromatic, or alicyclic substituents. Ketones are an important class of industrial chemicals that have found widespread use as solvents and chemical intermediates. Acetone is the simplest and most important ketone and finds ubiquitous use as a solvent. Higher members of the aliphatic methyl ketone series (eg, methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone) are also industrially significant solvents. Cyclohexanone is the most important cyclic ketone and is primarily used in the manufacture of a precursor for nylon‐6. Other ketones find application in fields as diverse as fragrance formulation and metals extraction. Physical and chemical properties as well as uses, manufacture, and health and safety data are given.
Laboratory Information Management Systems
Authors: Barrett Michael G. , MacFadden Kenneth O. , Taylor Jean A.
Published: July 2004

Laboratory information management systems (LIMS) are used to acquire, store, and manage data generated in the laboratory. A modern laboratory might implement a LIMS to automate data collection and dissemination, ensure product quality, or comply with U.S. federal government regulations. In the past, most LIMS were highly customized packages residing in mainframe computers or minicomputers. More recently, the proliferation of personal computers and local area networks has resulted in LIMS products which provide more flexible user interfaces on a familiar computer platform. However, the number of possible choices has reinforced the need to assemble a complete functional specification for the LIMS before vendors are contacted.
Laminated Materials, Plastic
Authors: Keeling Ronald J.
Published: July 2004

Laminates are composites made from stacked plies of resin‐treated materials that are most often consolidated under heat and pressure to from a unitary structure. Thermally fused layers of various types of thermoplastic film are also considered to be laminates, but the principal topic of this article is reinforced laminates used for decorative and industrial purposes as defined by the National Electrical Manufacturers Association (NEMA) classifications. The reinforcement material is often paper, and the usual resins are thermosets such as melamines, phenolics, polyesters, and epoxies. Solutions of the resins are used to treat the paper, the solvents are evaporated off, and then the dried plies are collated like a deck of cards to make a structure having useful final properties. The stacked plies are inserted together with caul plates into a flat bed press where heat and pressure are applied to cause the resins to flow to form interlaminar bonds between the plies and eventually to cure into a final thermoset state.

After pressing, the laminate edges are trimmed and their backs may be sanded to improve bonding to substrates in later fabrication operations. Laminates may be used for decorative purposes such as countertops or furniture or in industrial applications such as insulator boards or printed circuitry. Laminates may have special fire‐retardant properties or be antistatic for use in computer desks. Being thermoset plastics, laminates are quite inert materials and are safe in many instances for food preparation usage. Direct recycle of scrap is difficult, but regrind is used for fuel, and its use as a filler for molded articles has been suggested. Vol. 14, pp. 1074–1091. 18 refs. to July 1993.
Laminated Materials, Glass
Authors: Nichols R. Terrell , Sowers Robert M.
Published: July 2004

Laminated glass has been in use since the early twentieth century, beginning with automotive applications and expanding to applications in locations where strong, durable, transparent panels were required and hazards to life and injury were critical. Poly(vinyl butyral) (PVB), with suitable additives and plasticizers, has enjoyed the bulk of the market for interlayer material for use with glass. Relatively recently, other materials such as polyurethanes, acrylics, and polycarbonates have found applications as interlayer materials because of their respective properties. Types of applications, properties, and construction details of various laminates are presented, as well as fabrication techniques. Specifications are referenced that govern the use of laminated glass products in motor vehicles and in building construction. In addition to providing shatter resistance and improved security to conventional windows and viewing panels, laminated glass may also be used to provide unique colors, patterns, electromagnetic filtering/shielding, and electrical/electronic capabilities. Many of these applications are discussed in detail.
Lasers
Authors: Ready John F.
Published: July 2004

This article reviews the fundamentals and applications of laser technology. It includes a description of the basic principles of laser operation and a discussion of the unusual properties of laser light, which distinguish it from light emitted by conventional light sources, including collimation, narrow spectral linewidth, coherence, and focusability to small focal areas. It describes the most important types of available lasers and their properties, including gas lasers, solid‐state lasers, organic‐dye lasers, and semiconductor lasers. In addition, it describes newly emerging types of laser devices. It includes discussions of laser safety and of nonlinear optics. A significant portion of the article deals with uses of lasers, including material processing, measurement technology, holography, medical applications, communications, consumer products, spectroscopy, photochemistry, isotope separation, and laser‐assisted thermonuclear fusion.
Latex Technology
Authors: Gelbert Chester H. , Grady Michael C.
Published: July 2004

Latices are colloidal dispersions of discrete polymer particles, usually in an aqueous medium. Technology used to make and use latex involves many aspects of colloidal and polymer chemistry. This article reviews the fundamentals of emulsion polymerization, the techniques used to make most synthetic latices, general properties of latices, as well as colloidal and polymer compounding ingredients to convert latices into useful products, and discusses the wide variety of applications in which latices are used.
Fluorine Compounds, Inorganic, Lead
Authors: Meshri Dayal T.
Published: July 2004

Both lead difluoride and lead tetrafluoride have industrial significance. The main interest in these compounds stems from their use as a component in fluoride glass and as fluorinating agents. Properties and preparation are described.
Lead Alloys
Authors: Prengaman R. David
Published: July 2004

Lead, a soft, low melting point metal that has excellent corrosion resistance and ductility, is normally alloyed with other metals to improve its mechanical properties. The principal metals alloyed with lead are antimony, arsenic, calcium, copper, tin, tellurium, and silver. Minor alloying elements are cadmium, bismuth, selenium, indium, aluminum, and strontium.

Lead alloys are generally melted and cast into molds to produce useful shapes. The alloys are also rolled, extruded, and forged. The primary use for lead alloys is in the production of battery parts for lead–acid batteries. Smaller but significant uses are ammunition, cable sheathing, sheet for roofing and construction, insoluble anodes, solders, and special low melting point materials.

Lead and lead alloys, worldwide commodities, are toxic metals and must be handled with special care to prevent exposure. Lead is the most recycled metal. Over 50% of worldwide consumption is produced from recycled products. In the United States, virtually all lead alloy consumption is supplied from recycled lead, primarily used lead–acid batteries.
Leather‐Like Materials
Authors: Hioki Katsumi
Published: July 2004

Many substitutes for leather have been proposed and have come into general use. Some leather products have been replaced by vinyl‐coated fabrics, and by urethane‐coated fabrics. Man‐made leathers have finally succeeded in simulating leather to such an extent that they are nearly identical in appearance and properties, thanks to their unique structure. Annual production reached more than 30 million m
2
in 1992 and is still growing due to high performance.
Leather
Authors: Thorstensen Thomas C.
Published: July 2004

Tanning and manufacture of leather utilize both natural and synthetic specialty chemicals. Chrome tanning of cattle hides is the most predominant method employed in modern tanning facilities, although vegetable tannins are often introduced once the preliminary tanning is accomplished. Tanning not only preserves a skin or hide, it also makes the resulting leather resistant to rewetting and to cracking from flexing. The structure and composition of the hide, together with the intended usage, dictate the appropriate treatment. The stepwise process of leather manufacture, including the processing of raw hides and the chemistry of both chrome tanning and leather dyeing, is discussed. The importance of treatment of tanning wastes is also emphasized.
Lime and Limestone
Authors: Oates Tony
Published: July 2004

Limestone is a naturally occurring mineral that consists principally of calcium carbonate. It generally contains magnesium carbonate as a secondary component. Limestone is found in many forms and is classified in terms of its origin, chemical composition, structure, and geological formation. Deposits are distributed widely throughout the world.

The lime and limestone industries have generated many traditional expressions. Definitions covering the most common terms are given. Physical and chemical properties of limestone vary so many of the properties discussed here are to be considered typical. Over 95% of limestone is produced by open‐cast quarrying. Limestone is a major mineral product. In most countries, the primary use of limestone is as crushed rock for construction and building mainly as an aggregate and filler. The manufacture of cement is the second largest use.

Only a small proportion of limestone deposits has the necessary properties for the production of quicklime. The factors required for quicklime production are given. Production and processing of quicklime, ground quicklime, slaked lime, milk of lime, and lime putty are detailed. Lime products have many uses in, steel manufacture, chemical and food industries, industrial processes, building materials, environmental protection, and agriculture. Lime producers typically market a relatively large number of grades of lime.

Most countries have their own standards for sampling, sample preparation, and testing. European, American, and British standards are given as examples.

Calcium carbonate and calcium magnesium carbonate are nonhazardous substances. The main environmental issues associated with lime and limestone products are the noise and vibration from quarrying and energy use. Recycling and disposal issues are discussed.
Polyethylene, Linear Low Density
Authors: Kissin Yury V.
Published: July 2004

Linear low density polyethylene (LLDPE) resins are polyethylene (PE) plastic materials with densities in the 0.915–0.925 g/cm3range. They are a family of semicrystalline ethylene copolymers with α‐olefins produced in catalytic polymerization reactions. A variety of resins described by the general term LLDPE differ one from another in several respects: the type of α‐olefin used for copolymerization with ethylene (mostly 1‐butene, 1‐hexene, 4‐methyl‐1‐pentene, and 1‐octene), the content of the α‐olefin in the copolymer (it varies from 1 to\documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}${{\rm{\sim }}10{\hskip0.167em}{\hskip0.167em}{\rm{mol}}{\%}}$\end{document}for different resins), resin density and crystallinity, and compositional uniformity of the copolymers.

LLDPE resins are produced in industry with several classes of catalysts: Ziegler catalysts based on titanium or vanadium compounds, Kaminsky and Dow catalysts utilizing metallocene complexes, and Phillips catalysts based on chromium oxides. These resins are manufactured either in gas‐phase, solution, or slurry polymerization processes.

LLDPE is a significant commodity product with a worldwide manufacture volume in 1994 of around\documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}${13\times 10^{6}{\hskip0.167em}{\hskip0.167em}{\rm{tons}}}$\end{document}. Film is the largest application market for LLDPE resins; it is used to manufacture grocery sacks, trash bags, bags for merchandise packaging, garment, laundry, dry‐cleaning, and ice. LLDPE film is also used for nonpackaging applications such as industrial sheeting and agricultural mulch film. High clarity film produced with LLDPE resins manufactured with metallocene catalysts is used for food packaging and medical applications. Injection molding products, mostly for housewares, represent the second largest market for LLDPE. LLDPE resins are also used for blow molding (bottles, drums), for rotational molding (toys, large containers, tanks), for pipe and tubing, and for wire coating in electrical and telephone industry.
Extraction, Liquid–Liquid
Authors: Lo Teh C. , Baird Malcolm H. I.
Published: July 2004

Liquid‐liquid extraction, also known as solvent extracting, is a well‐established separation technique that depend on the unequal distribution of a solute between two immiscible liquids. The initial feed liquid containing the solute is brought into contact with a solvent which is selected to have a greater affinity for the solute. The partition of the solute can be enhanced by adding a chemical extractant to the solvent; this practice is widespread in the hydrometallurgical and nuclear industries. Most industrial extractors operate continuously with countercurrent flow of the two phases. In mixer‐settlers, the phases are contacted as a well‐agitated dispersion of drops, which are then sent to settling tanks for phase disengagement. In extraction columns, the dispersed drops move countercurrently against the flow of the second (continuous) phase. The physics, chemistry, and practice of extraction, with brief descriptions of important industrial extraction processes and equipment, are presented. Research on hydrodynamic aspects of process design such as axial mixing, drop dispersion, and coalescence is reviewed. New extraction techniques such as membrane extraction, supercritical exctraction, and two‐phase aqueous extraction are discussed.
Lithium and Lithium Compounds
Authors: Kamienski Conrad W. , McDonald Daniel P. , Stark Marshall W. , Papcun John R.
Published: July 2004

Lithium, an element of unique physical and chemical properties, is useful in a wide range of applications as the metal, as the lithium ion in inorganic salts, and as the more covalent species in inorganic compounds. The largest uses of lithium compounds are in traditional areas such as the preparation of glass, glass‐ceramics, and enamels; in aluminum cell broth; in the preparation of lithium greases; and as polymerization initiators. Lithium compounds are also employed as psychopharmacological agents and in organic synthesis, catalysis, absorption, air conditioning, photographic processing, and in batteries. The use of organic lithium compounds as industrial catalysts and the consumption of various lithium compounds in batteries are the most rapidly expanding markets.

The various lithium mineral and brine resources are reviewed along with the processes for lithium extraction and recovery. Manufacturing processes, properties, health and safety factors, and applications for lithium metal and lithium compounds are discussed.
Amines, Lower Aliphatic Amines
Authors: Turcotte Michael G. , Hayes Kathryn S.
Published: July 2004

Lower aliphatic amines are derivatives of ammonia with one, two, or all three of the hydrogen atoms replaced by alkyl groups of five carbons or less. Amines with higher alkyl groups are known as fatty amines. Amines are toxic, colorless gases or liquids, highly flammable, and have strong odors. Lower mol wt amines are water soluble and are sold as aqueous solutions and in pure form. Amines react with water and acids to form alkylammonium compounds analogous to ammonia. The base strengths in water of the primary, secondary, and tertiary amines and ammonia are essentially the same. The lower aliphatic amines are widely used as intermediates in the manufacture of medicinal, agricultural, textile, rubber, and plastic chemicals. Some commercially important alkylamines are methylamine, dimethylamine, ethylamine,
n
‐propylamine, isopropylamine, allylamine,
n
‐butylamine, isobutylamine,
sec
‐butylamine, ethyl‐
n
‐butylamine,
n
‐amylamine. The formation of salts with acids is the most characteristic reaction of amines. Alkylamine are corrosive to copper, copper‐containing alloys (brass), aluminum, zinc, zinc alloy, and galvanized surfaces. Lower aliphatic amines can be prepared by a variety of methods, using many different types of raw materials. By far the largest commercial applications involve the reaction of alcohol with ammonia to form the corresponding amines. Other methods are employed depending on the particular amine desired, raw material availability, and plant economics. The U. S. Department of Transportation requires labeling of all shipments of amines commensurate with the associated hazards. Alkylamines are toxic. Both the liquids and vapors can cause severe irritation to mucous membranes, eyes, and skin. Protective butyl rubber gloves, aprons, chemical face shields, and self‐contained breathing apparatus should be used by all personnel handling alkylamines.
Dendrimers, Luminescent
Authors: Balzani Vincenzo , Ceroni Paola , Maestri Mauro
Published: July 2004

Dendrimers are complex, yet well‐defined, macromolecular compounds exhibiting a high degree of constitutional order, with the possibility of containing selected chemical units in predetermined sites of their structure (core, branches, surface). Functional units can also be noncovalently hosted in the dynamic cavities of a dendrimer or associated at a dendrimer surface.

Luminescent dendrimers are currently attracting much attention since coupling luminescence and dendrimer research can lead to new valuable functions such as light harvesting, sensing with signal amplification, energy and electron‐transfer processes, and shielding effects. In this article, we review recent advances in this field focusing our attention toward a few examples, namely: (a) dendrimers with a luminescent core; (b) dendrimers with luminescent units in the periphery; (c) dendrimers whose luminescence is governed by energy‐transfer processes; and (d) luminescent dendrimers hosting luminescent guests. We illustrate their luminescent properties in fluid solution, elucidating their structures and superstructures.
Machining Methods, Electrochemical
Authors: McGeough J. A. , Chen X. K.
Published: July 2004

Machining Methods, Electrochemical. Electrochemical machining (ECM), a metal removal process based on the laws of electrolysis, was developed for shaping high strength heat‐resistant alloys which are difficult to machine by conventional techniques. Using ECM techniques, hard metals can be shaped as reliably as soft ones and the rate of machining does not depend on hardness. Because the tool electrode used in the process does not wear, soft metals can be used as tools to form shapes on harder workpieces. Other applications include deburring, hole drilling, electrochemical grinding, and removal of fatigue cracks in steel structures. The working principles of ECM are described along with the types of electrolytes used. Parameters for various metals are discussed.
Magnesium Compounds
Authors: Kramer Deborah A.
Published: July 2004

A variety of magnesium compounds and minerals are found both in seawater and in the earth's crust. Commercial magnesium compounds are widely used in chemical processing, whether in the production of paper or rayon fiber, or as a catalyst, filler, flame retardant, alkaline material, stable coating for magnetic recording media, or wastewater or flue gas scrubber. Magnesium hydroxide is a common over‐the‐counter antacid and laxative. Additionally, the branch of synthetic organic chemistry known as Grignard reactions is based on magnesium compounds. Magnesium forms stable salts with most common anions, such as acetate, carbonate, the halides, hydroxide, oxide, and sulfide, as well as with some less common ones such as vanadates. Many magnesium alkyls are also known. The production, properties, economics, uses, safe handling, and analysis of the commercial magnesium compounds are described.
Magnetohydrodynamics
Authors: Kessler Robert
Published: July 2004

Magnetohydrodynamic (MHD) power generation is possible when an electrically conducting fluid such as a hot ionized gas passes through a magnetic field under the appropriate conditions. In electric utility power generation, a magnetohydrodynamic generator is combined with a conventional steam turbine. The system is a combined cycle; the fuel of interest is typically pulverized coal. Environmental intrusion from MHD plants is projected to be minimal.

The fundamentals and system components of MHD power generation are discussed, including the geometries of various MHD generators, types of electrodes and magnets used, materials of component construction, interfaces between the MHD generator and the steam turbine, effect of type of fuel utilized, and the efficiency and economic factors of proposed plants. Projects under development in the United States and around the world are presented.
Information Storage Materials, Magnetic
Authors: Lodder J. C.
Published: July 2004

Magnetic recording is the storage of information achieved through changing the magnetization of a recording medium using a magnetic field generated by the recording head. At the end of the nineteenth century a start was made to use magnetism and magnetic media to store information. The first demonstration of magnetic recording was at the World's Fair in Paris in 1900. From this time on, the magnetic recording medium has gone through dramatic improvements. The steel wire was replaced in the early 1930s by small spherical Fe particles and later by cubic Fe3O4. Since then great improvements have been made by changing the material and the shape and size of the particle.

In 1949, γ‐Fe2O3acicular particles with a length of 0.5 µm and an aspect ratio of 10 were used. Compact cassette tape made from CrO2particles was introduced in 1966. From the early 1950s thin magnetic films have been proposed as a magnetic recording medium. Since then extensive research has been carried out and many thin‐film media have been proposed made by electroless and electrodeposition, vacuum evaporation, and sputtering. At present many recording media are prepared by vacuum deposition technologies; mostly hard disk applications for magnetic recording as well as magnetooptic recording. Sony presented the first evaporated tape for video application in 1989. The so‐called ME tapes have also been made for audio applications. An enormous amount of research is being carried out on the new hard disk media, mostly produced by sputtering, in order to obtain high densities. Since 1977 much research has been carried out on media proposed for the application of perpendicular magnetic recording.
Fluorine Compounds, Inorganic, Magnesium
Authors: Papcun John R.
Published: July 2004

Magnesium fluoride is a by‐product of the manufacture of metallic beryllium and uranium and is used as a flux in magnesium metallurgy and in the ceramics industry; it may also be used in the extraction of aluminum from arc‐furnace alloys with iron, silicon, titanium, and carbon. It finds application as a welding flux for aluminum, as well as for steel. Properties are described.
Maleic Anhydride, Maleic Acid, and Fumaric Acid
Authors: Felthouse Timothy R. , Burnett Joseph C. , Horrell Ben , Mummey Michael J. , Kuo Yeong‐Jen
Published: July 2004

Scientific and technological developments in the manufacture and use of maleic anhydride, maleic acid, and fumaric acid are reviewed over the past 20 years. Physical and chemical properties for these three chemicals are updated with literature citations when available. Key derivatives are summarized, including acid chlorides and reaction products of these chemicals formed from acylation, alkylation, amidation, concerted nonpolar reactions of various kinds, decomposition and decarboxylation, electrophilic addition, esterification, free‐radical reactions, Grignard‐type reactions, halogenation, hydration and dehydration, hydroformylation, isomerization, ligation‐to‐metal atoms, nucleophilic addition, oxidation, polymerization, reduction, and sulfonation. Manufacturing processes for maleic anhydride are described, including those using fixed‐ fluidized‐ and transport‐bed technologies for selective oxidation of butane. A survey is given of catalyst developments through the end of 2000. Regardless of the reactor type used, all catalysts producing maleic anhydride from butane consist of a vanadyl pyrophosphate phase, (VO)2P2O7. Details are presented on maleic anhydride and its two diacid isomers with respect to shipment, economic aspects, specifications, analytical and test methods, toxicology, and principal uses.
Malonic Acid and Derivatives
Authors: Pollak Peter , Romeder Gérard
Published: July 2004

The focus of this article is the class of C3compounds with a central methylene group and terminal carboxylic acid, carboxylate, and nitrile functions. The high reactivity of the central methylene group, the reactivity of the acid, ester, and cyano functions, and the opportunity to build heterocycles make this class of compounds unique in the chemical synthesis. In particular the malonates, cyanoacetates, malonic acid and cyanoacetic acid, and malononitrile have all gained in importance in the life science, dyestuff, and polymer industry. This article provides general and useful technical and commercial information which can be used as a starting point for more in‐depth studies. Some other derivatives of less industrial importance are also covered.
Malts and Malting
Authors: Doncheck James A.
Published: July 2004

The malting process consists of three key steps: steeping, whereby barley is moistened to about 45% moisture; germination, wherein rootlets (sprouts) and a stem (acrospire) emerge while enzymes are formed which alter the cellular structure and composition; and kilning, where barley is dried to preserve enzyme activity and to impart flavor. Nearly all of the malt produced is used to make beer.

Barley is grown in Minnesota, North and South Dakota, Montana, and other western States. Barley varieties are developed specifically for good malting and brewing traits. Less than 50% of the U.S. barley crop is converted into malt.

World malt production in 1992 was approximately 13 million metric tons and was growing at 3% per year; 1992 U.S. production was 2.2 million tons, with stagnant growth during the last few years. Large U.S. and Canadian producers are Ladish (Cargill), Anheuser Busch, Canada and Great Western Malting Companies, Rahr, Froedert (Grand Malteries Modern‐France), and Fleischmann‐Kurth (ADM). There is excess malting capacity, resulting in low margin commodity pricing. Production costs are approximately $225/t.
Manganese and Manganese Alloys
Authors: Matricardi Louis R. , Downing James
Published: July 2004

Manganese minerals, pretreatment of manganese ores, and smelting processes are reviewed. The reduction of manganese ores and the production of high carbon ferromanganese and of silicomanganese are discussed as is the electrolytic production of manganese metal. The safety of ferromanganese production in electric furnaces is presented.

Manganese and manganese alloy production is closely tied to the steel industry. Many specialty steels contain significant quantities of manganese. Other important uses of manganese occur in the cast iron and aluminum industries where manganese metal is used as an alloy addition to aluminum that is used for beverage containers.
Manganese Compounds
Authors: Pisarczyk Kenneth
Published: July 2004

Manganese compounds are used commercially in the iron and steel industries, as a principal component of primary battery systems, and as oxidation reagents and catalysts. These compounds also find application in glassmaking and as fungicides, soft ferrite components, fertilizer, and pigments. Manganese exhibits oxidation states ranging from\documentclass{article}\pagestyle{empty}\begin{document}${{\rm{-}}{\rm{III}}}$\end{document}to VII in its compounds, and many of the known phases of manganese dioxide correspond to variations in degree of stoichiometry. Compounds for each manganese valency are discussed. Emphasis is placed on the manufacture, properties, and uses of a variety of natural and synthetic manganese dioxides and of potassium permanganate.
Carboxylic Acids, Manufacture
Authors: Johnson R. W. , Daniels R. W.
Published: July 2004

Fatty acids are produced primarily from natural fats and oils such as tallow, coconut oil, and palm oil. Tall oil fatty acids are produced by the distillation of crude tall oil. Synthetic routes to fatty acids from petroleum are an important source and include catalytic oxidation of straight‐chain hydrocarbons as carried out in Eastern Europe, Russia, and China; carboxylation and oxidation of straight‐chain 1‐olefins; and oxidation of alcohols. Branched‐chain acids are produced from branched‐chain olefins via the oxo reaction.

Fatty acids are produced from natural fats and oils in essentially four steps or unit operations. Hydrolysis, the first step, is generally carried out by high temperature/pressure splitting. Glycerol is obtained as a by‐product. Second, solid or saturated fatty acids are separated from liquid or unsaturated fatty acids by solvent crystallization or by the hydrophilization process. Several newer methods of separation include adsorption and supercritical fluid extraction. The third step is hydrogenation, which converts unsaturated fatty acids into saturated fatty acids generally with the aid of a nickel catalyst. Finally, distillation is used to remove color and odor bodies and, when desired, to separate fatty acids into relatively pure materials such as lauric, myristic, palmitic, and stearic acids.
Mass Transfer
Authors: Chisti Yusuf
Published: July 2004

Mass transport phenomena influence all kinds of processes, often controlling the rate, the yield, the product spectrum, and product recovery. This article details the mass transfer considerations in production and processing of chemicals. Fundamentals of mass transfer are discussed for gas–liquid, liquid–liquid, and solid–liquid systems. Methods for measurement of the overall gas–liquid volumetric mass transfer coefficient (

k
L
a
L

) are noted. Mass transport behavior is discussed for various kinds of reactors: laboratory shake flasks, vortex aerated devices, stirred tanks, bubble columns, airlift reactors, fluidized beds, packed beds, and other systems. Prediction and estimation of the various mass transfer coefficients are emphasized. Mass transfer within particles is treated as being relevant to adsorption, ion exchange, chromatographic separations, and heterogeneous catalysis. Mass transport in membrane processing is outlined.
Materials Reliability
Authors: Lamberson Leonard
Published: July 2004

Reliability is a parameter of design, such as a system's performance or load ratings, and is concerned with the length of failure‐free operation. It is difficult to conceptualize reliability as part of the usual design calculations. Further complications are the complexity of organizations needed to produce the large systems of today and the usual time and financial constraints on research and development. Reliability, as it relates to products or equipment, can be measured in various ways. Because it is a design parameter, it has to be addressed early in the design cycle. This article discusses terminology, models, and measurement of materials reliability.
Ceramics, Mechanical Properties, and Behavior
Authors: Glass S. Jill , Tandon Rajan
Published: July 2004

Ceramic materials present many advantages for structural applications, especially in extreme environments. Their high melting temperatures, high hardness, inertness, and relatively low densities make them attractive for many applications as replacements for metals and also as enablers for new technologies. For structural applications at low and modest temperatures, the design engineer is concerned about the load‐bearing capacity (stiffness, strength, and fracture toughness), the reliability (strength variability), and the time‐dependent strength (subcritical crack behavior). At elevated temperatures, time‐dependent deformation due to mechanisms such as creep is most important. In wear applications the hardness, toughness, and frictional properties are of interest. This chapter serves as an introduction to these topics. The mechanical properties of ceramics are important not only for the structural applications discussed, but also when these materials are used for electrical, optoelectronic, or biomedical applications.