bluuebunny/crossref_metadata_2025 huggingface dataset:
Detergency
Authors: Lynn Jesse L.
Published: July 2004

Many factors determine the ultimate effectiveness of a cleaning system. Knowledge of the substrate to be cleaned, the soil to be removed, the nature of the bath, and the detergent formulation is required to adequately describe the cleaning process. Home laundering, for example, involves removal of particulate or oily soils from textiles of varying compositions in an aqueous bath. Formulated detergents, added to the bath or fabric, significantly affect this process. Hard surface cleaning involves the removal of soil from a nonporous substrate, normally assisted by a detergent formulation.

Detergent formulations differ in complexity, depending on the particular application for which they are designed and the variability in conditions under which they are expected to perform. Laundry detergents can require high water softening capability and therefore significant levels of water softeners. The replacement of phosphate has led to much research and development activity and increased numbers of choices in determining the most suitable formulations for a given purpose. The type and concentration of surfactant is another primary factor in determining the formulation.

Measurement of cleaning efficacy can be done by several methods, ranging from the subjective (panelists rating) to more objective ones, such as reflectometry. Performance profiles are then used to determine more efficient formulations. Once the formulation is identified and deemed ready for commercialization, it must be manufactured. Liquids can be mixed simply by addition of the ingredients to water. The historic method of mixing ingredients for powders is to blend in a crutcher and spray dry in a hot tower. The resulting particle typically dissolves easily because of its porous structure. The formulations also must meet or surpass existing/potential health, safety, and environmental issues. With an understanding of all the appropriate factors involved in detergency, the formulator can more quickly and efficiently determine the optimum formulations to meet the specified objectives.
Deuterium and Tritium
Authors: Katz Joseph J.
Published: July 2004

Deuterium (2H or D) the heavier, stable isotope of hydrogen (1H) occurs in nature, and is always present in all hydrogen‐containing compounds. Deuterium oxide, known as heavy water, is the most important deuterium compound. Heavy water differs from ordinary water in structure of the liquid phase, in nuclear spin, ionic equilibria, and in various spectroscopic properties. Kinetic isotope effects occur in chemical reactions involving bond rupture of H and D. This effect in hydrogen exchange between water and hydrogen sulfide is the basis for the most important separation process for large‐scale deuterium production. Infrared absorption is the method of choice for the analysis of heavy water. Deuterium has far‐reaching biological effects, and it is possible to grow living organisms in which all of the hydrogen normally present is replaced by deuterium. The nuclear properties of deuterium are such that heavy water is the most efficient neutron moderator known for nuclear fission reactors. Deuterium is also important in nuclear fusion technology.

Tritium (3H or T) is the heaviest isotope of hydrogen. Unlike hydrogen or deuterium, T undergoes radioactive decay (B−, ∼ 12 yr half‐life). Thus T compounds experience radiation damage at elevated tritium levels. Tritium is produced by cosmic rays in the higher atmosphere, and by neutron capture in lithium–aluminum alloy in nuclear fission reactors. Tritium can be purified by distillation, by thermal diffusion, by diffusion through palladium‐silver‐nickel membranes, or by chromatography on coated molecular sieves. Tritium is widely used as a tracer in molecular biology experiments. Tritium is a key element in nuclear fusion, in which energy is produced by the controlled fusion of tritium with deuterium.
Diamond, Natural
Authors: Shigley James
Published: July 2004

Naturally occurring diamond is a relatively rare polymorphic form of carbon characterized by a three‐dimensional arrangement of tetrahedrally coordinated carbon atoms. Both natural and synthesized diamond have the highest hardness of all known materials, the highest thermal conductivity at room temperature, a high refractive index and optical dispersion, a low thermal expansion, and a relatively high inertness to chemical attack. This unique combination of properties permits diamond to be foremost in certain applications: as a highly prized gemstone; industrially as an important abrasive material unsurpassed in certain cutting, drilling, sawing, machining, grinding, and polishing operations for many materials; and in electronic and optical applications as a heat sink and window material, respectively. Upstream exploration has sometimes led to the discovery of kimberlite or lamproite pipes. These structures are the principal source of natural diamonds, and there are > 6000 occurrences of them in the world. Only a small number contain a high enough concentration of diamonds to warrant mining. Alluvial diamonds are recovered from streambeds by panning or washing techniques or, more productively, by removal from pockets in the streambed where the water has concentrated them. High quality gemstones are recovered from ocean deposits off the western coast of southern Africa. A modern method for the separation of diamond crystals from rock uses the emission of light by luminescence of diamond when exposed to X‐rays. The diamonds are then separated mostly by hand into two main categories, gem and industrial. Besides the single crystals usually implied in a discussion of diamond, the latter also occurs in nature in the form of polycrystalline aggregates. These can be classified into two types based on origin: carbonado and ballas. Diamond is nominally pure carbon with a
12
C/
13
C ratio of ∼99:1. Although other elements are often reported in analyses, only boron and nitrogen are considered to be truly substitutional in the lattice. The classification of diamonds into four types (Ia, Ib, IIa, IIb) is based primarily on the presence or absence of nitrogen and boron and their location in the lattice. Diamond is the hardest material known because of its combination of a three‐dimensional arrangement of tetrahedrally coordinated CC bonds with a bond distance of 0.154 nm. The Knoop hardness (
K
) is in the range of 68.7–98.1 kN/m
2
(7000–10,000 kgf/mm
2
). Although hard, diamond is also very brittle. The high refractive index (2.42 at 589.3 nm) and dispersion (0.044) are the basis for the “brilliance” and “fire” of a properly cut gemstone. The optical transmission out to 10.6 µm for type IIa diamonds makes possible windows for CO
2
lasers and for devices such as were used in the Venus probe.
Dicarboxylic Acids
Authors: Johnson Robert W. , Pollock Charles M. , Cantrell Robert R.
Published: July 2004

Aliphatic, linear dicarboxylic acids of the general formula HOOC(CH2);ynCOOH, and branched dicarboxylic acids are the subject of this article. These dibasic acids are referred to by their trivial names, IUPAC system, or by adding the suffix “dicarboxylic acid” to the name of the hydrocarbon skeleton. For example, a 10‐carbon atom dibasic acid is designated sebacic acid, decanedioic, or 1,8‐octane‐dicarboxylic acid. Physical and chemical properties of most of the common dibasic acids are given and discussed.

Manufacture, preparation, and processes for glutaric acid, pimelic acid, suberic acid, zelic acid, sebacic acid, dodecanedioic acid, brassylic acid, C‐19, C‐20, C‐21, and C‐22 dicarboxylic acids are given. Also discussed is the preparation of dicarboxylic acids using microorganisms.

The diacids are important industrial intermediates for the manufacture of diesters, polyesters, and polyamides. These derivatives find application as plasticizing agents, lubricants, heat‐transfer fluids, dielectric fluids, fibers, copolymers, inks and coatings resins, surfactants, fungicides, insecticides, hot melt coatings, and adhesives. The prices and mode of shipment for the various commercial grades of the diacids are given. The toxicities and environmental effects of the diacids are also discussed.
Dichloroethylene
Authors: Mertens James A.
Published: July 2004

1,2‐Dichloroethylene, also known as acetylene dichloride, dio‐form,
α
,
β
‐dichloroethylene, and
sym
‐dichloroethylene, exists in two isomers cis[156‐59‐2] and trans[156‐59‐2]. This solvent is used as an extraction solvent and as a chemical intermediate for other chlorinated solvents and compounds. The article describes the manufacturing, chemical and physical properties, storage and handling, toxicity, and its common uses.
Diffusion Separation Methods
Authors: Halle E. Von , Shacter J.
Published: July 2004

Diffusion separation methods refer collectively to processes such as gaseous diffusion and gas centrifugation, developed specifically for difficult separations such as those involving the isotopes of uranium. These processes, used worldwide primarily for uranium enrichment, are based on the differences that exist in the rates of gaseous diffusion of the particular isotopes. These difficult separations almost always involve an aggregation of separation units known as a casade.

Casade design, unit separative capacity, ideal and real casades, and various separation factors are presented. Equipment and plant design for the enrichment of uranium‐235 by gaseous diffusion, by various pressure diffusion processes, and by jet diffusion, also known as the separation nozzle process, is discussed.
Dimethylformamide
Authors: Marsella John A.
Published: July 2004

Dimethylformamide (DMF) is a widely used solvent and reagent, both in the laboratory and in industry. Its industrial applications range from the synthesis and purification of pharmaceutical products to its use as a cleaning solvent for printed circuit boards. This article reviews the properties, uses, manufacture, handling, and safety of DMF. DMF is currently manufactured by one of two carbonylation processes. In a two‐step process, methanol is carbonylated to methyl formate, which then reacts with dimethylamine to give DMF. The other method of commercial significance is the direct carbonylation of dimethylamine to DMF. Uses include pharmaceutical applications, polymer processing and production, extraction and absorption processes, and laboratory synthesis. Although it is generally a safe solvent, it must be handled properly. Its use must take into account its toxicity, reactivity, and tendency to be absorbed through the skin.
Drilling Fluids
Authors: Clark R. K.
Published: July 2004

Drilling fluids (muds) play a vital role in the drilling of oil and gas wells. These muds are typically complex chemical mixtures formulated to perform a variety of functions under a wide range of down hole temperatures and pressures but yet are nondamaging to the environment and safe for personnel to handle. These fluids are circulated down the hollow drill string and up the annulus, formed by the drill string and the hole to remove formation material dislodged by the bit. The fluids must have sufficient density to offset formation pressures to prevent a blowout and to maintain a stable well bore but be formulated to prevent excessive loss of fluid to permeable formations. Other important functions include lubrication of the drill bit and drill string, collection of information about subsurface formations, and noncorrosivity to surface and down hole equipment. Drilling fluids are composed of liquids (water, petroleum oils, and other organic liquids), dissolved inorganic and organic additives, and suspended, finely divided solids of various types. The article describes drilling fluid classification, properties, materials, testing, economics, and environmental considerations.
Drug Delivery Systems
Authors: Kost Joseph , Lapidot Smadar A. , Kumar Neeraj , Chaubal Mahesh , Domb A. J. , Kumar Ravi , Majeti N. V.
Published: July 2004

The rapid advancement of biomedical research has led to many creative applications for biocompatible polymers. As modern medicine discerns more mechanisms of both physiology and pathophysiology, the approach to healing is to mimic, or if possible, to recreate the physiology of healthy functioning. Thus, the area of responsive drug delivery has evolved. Also called “smart” polymers, for drug delivery, the developments fall in two categories: externally regulated or pulsatile systems (also known as “open‐loop” systems) and self‐regulated systems (also called “closed‐loop”). The fundamentals of this research area a detailed account of the most recent advances in both pusatile and self‐regulated drug delivery systems are detailed.

Controlled release technologies present an invaluable scientific and practical tool for improving performance and safety of drugs. These technologies involve designing the system of materials/drugs/site of action in such a way that barriers surrounding the drug to deliver the latter act with efficacy and safety of the drug at the optimum time and the rate needed. Advances in polymer science have led to the development of several novel drug delivery systems. A proper consideration of surface and bulk properties can aid in designing of polymeric systems for various drug delivery applications. This article is an overview of polymeric controlled release technology starting from fundamentals to applications.
Drying Oils
Authors: Wicks Zeno W.
Published: July 2004

The composition of drying oils and mechanisms of film formation are discussed. Various proposals for the mechanism of autoxidation reactions for both nonconjugated and conjugated drying oils are covered. The use, selection, and mechanism of action of driers to catalyze film formation are covered. Modification of drying oils to bodied oils, boiled oils, conjugated oils, higher functionality oils, maleated oils, and vinylated oils are discussed.
Dye Carriers
Authors: de Guzman Ernesto , Sutton Boyce
Published: July 2004

Dye carriers are used most commonly in the dyeing of polyester. Carriers are used to lower the glass‐transition temperature so the dye solution can penetrate the fiber. Carriers, under controlled conditions and selectivity, can give good color yield and fastness properties. Dye carriers are especially needed for atmospheric dyeing and occasionally for high temperature dyeing. However, most high temperature dyeings are run with high temperature levelers. Some carriers have found more acceptance than others due to availability, cost, environmental concerns, odors, etc. All carriers must be homogeneously dispersed in the dyebath to get full color yield. Carriers should be selected according to the equipment and conditions under which they are to be used. The fabric blend, color yield, and migration are also some factors to be considered when selecting carriers. Dye carriers are supplied by many chemical manufacturing companies. A list of these companies is provided.
Dyes, Reactive
Authors: Lewis D. M.
Published: July 2004

Reactive dyes have proven to be one of the most successful classes of modern synthetic dyes. The reasons for this success lie in their shade versatility, their flexibility in application, and the all‐round good fastness properties obtained from dyeings produced with reactive dyes on wool, silk, cotton, and regenerated cellulosic fibers. The chemistry of the different reactive groups used, the chemistry of reactive dye manufacture, and the chemical principles behind their application to cellulosic fibers and polyamide fibers is reviewed.
Economic Evaluation, Synthetic Organic Chemicals
Authors: Moskowitz Sanford L.
Published: July 2004

The synthetic organic chemicals industry supplies materials to a wide range of industrial operations. These include plastics, fibers, solvents, biochemical agents, food chemicals, and materials of construction. The sectors increasingly affected by organic chemicals include electronics and telecommunications, automotive and transportation industry, biotechnology, agriculture, environmental remediation, and the food sciences.

This article gives economic data and patterns for important organic compounds, e.g., methanol, ethylene, benzene, propylene, etc. Economic data include U.S. and International general trends, regional patterns, consumption, supply and demand. History and process technologies are discussed. Environmental data include information on organic chemicals that have come under regulatory control, e.g., methyl‐t‐butylether and the chlorofluorocarbons.
Carboxylic Acids, Economic Aspects
Authors: Sauer E. T.
Published: July 2004

Aliphatic carboxylic acids produced on a reasonably significant commercial scale range from acetic acid (two carbons or C2) through stearic acid (C18). Lesser amounts of commercially available shorter chain‐length acids such as formic (C1), and longer chain‐length acids, such as erucic (unsaturated C22) and behenic (saturated C22), are also produced. As a general rule, all of the even chain‐length, nonisomeric acids from C6 to C22 are produced from naturally occurring fats and oils. A significant proportion of the lower chain‐length (C1‐C6) and longer isomeric chain‐length (C7‐C10) acids are made synthetically. For both oleo‐based and nonoleo‐based acids production and consumption figures, prices, producers, and applications are given.
Economic Evaluation
Authors: Ward Thomas J.
Published: July 2004

Economic evaluation is the quantitative estimate of expected venture profitability, often in comparison with other choices, including the competition. It is part of the analysis that supports the decision‐making task in engineering and management. For essential parts of such an evaluation are problem definition, cost estimatiomn, revenue estimation, and profitability analysis, as well as a characterisation of the uncertainity and risk. The methodology associated with each part is summarised. A highlight is the development of the net rectum rate (NRR) as the logical profitability—a profit rate in which the cost of capital has been separarted out. This profit rate is illustrated for a typical production venture and advantages over historical profitability criteria are discussed.
Eggs
Authors: Bergquist Dwight H.
Published: July 2004

Eggs are used in homes, restaurants, and institutions as shell eggs; they are used in the food industry primarily as egg products. Eggs, which have various functional properties including coagulation by heat, whipping ability, and emulsifying power, are also highly nutritious. Egg products are produced under USDA inspection, which requires that all egg products be pasteurized so they are
Salmonella
‐negative.

There are liquid, frozen, and dried egg products. Automation has come into play for the production of shell eggs and egg products including handling, breaking and separating, processing, and drying of eggs. Eggs are separated into three components in an egg products plant, ie, whites, yolk, and whole egg, at a rate of 32,000 eggs per h per single row, single‐tier egg breaking machine. Eggs are spray‐dried under very mild conditions to preserve quality.
Fibers, Elastomeric
Authors: Boliek John E. , Jensen Arnold W.
Published: July 2004

Most elastomeric fibers are currently produced from either natural rubber or segmented polyurethane polymers. The elastic properties or rubber fibers derive from chemical cross‐links formed by vulcanization of either sheets or extruded threads. The segmented polyurethanes, called spandex fibers, are linear block copolymers with relatively long weakly interacting segments that are interconnected by shorter blocks in which intermolecular interactions are strong. Rubber fibers are formed either by slitting vulcanized sheets or by extruding latex into a coagulation bath followed by heating to vulcanize. Spandex fibers are most commonly formed by passing polymer solution through a spinneret followed by removal of solvent; certain spandex compositions can be formed into fibers by melt extrusion. These fibers are normally blended with hard fibers such as nylon, polyester, or cotton to form fabrics with desirable stretch and recovery characteristics. Stabilizers must be included with elastomeric fibers to provide adequate protection from exposure to heat, sunlight, atmospheric pollutants, and active chlorine materials. The unique properties and availability in fine sizes compared to rubber has recently allowed extensive penetration of spandex fibers into hosiery and sportswear markets.
Electrical Connectors
Authors: Antler Morton
Published: July 2004

Electrical connectors are mechanical devices that connect wires, cables, printed circuit boards, and electronic components to each other and to related equipment. Electronic connectors are designed primarily for low power signal applications as in telecommunications and computers. Another category is the utility and industrial connectors used in power distribution systems. Almost all connectors that join two or more conductors have an insulating body or dielectric, most usually made of a plastic, which separates the contact elements. Connectors are used to make permanent joints or to allow separation and remating of the conductors. Connectors are composed of contact substrates which are generally metallic, contact finishes, lubricants, and an insultating shell. Insulators are also employed for multicontact connectors. The reliability and testing procedures for electrical connectors, together with the thermal, chemical, and mechanical mechanisms of connector failure, are discussed.
Electronics, Coatings
Authors: Cohen Edward , Simmons Howard E.
Published: July 2004

Electronic coatings consist of a wide variety of materials that are used in the manufacture of electronic devices for military, industrial, and consumer usage. Coatings may be organic and inorganic compounds and polymers or metals. These coatings may be functional, providing electrical, magnetic, optic, mechanical, and/or thermal functions; they may be manufacturing aid coatings such as those used in the manufacture of circuit boards, or they may be protective or decorative coatings.

Polymeric materials are used to protect components from the environment and polymers having conductive metallic fillers are used to alleviate electromagnetic interference. Photoresists, inks or screenable resists, and solders all serve as coatings to produce microelectronic components such as printed circuit boards and integrated circuits.

Electronic coatings are applied in a wider range of coating widths and densities, under more stringent conditions, than conventional coatings. Both continuous and discrete coating methods employing a variety of solvents are used in designated clean rooms.
Chromogenic Materials, Electrochromic
Authors: Samat A. , Guglielmetti R.
Published: July 2004

Electrochromism is a reversible color change in a material, often a thin film, that accompanies an oxidation–reduction reaction driven by a small current at low voltage. It occurs at or near room temperature in both cathodically colored and anodically colored inorganic and organic compounds. It is accompanied by ion insertion/extraction (doping/undoping) for charge balance in thin solid films.

Electrochromic chromogenic materials are divided into two groups based on whether or not insertion/extraction occurs or does. For the smaller,noninsertion group, reversible coloration occurs in solution or is associated with reversible electrodeposition from solution. The best known members are viologens, polymers systems such as polyheterocycles, metallopolymers, metal phthalocyanines, and inorganic electrodeposition of silver halides.

In the insertion/extraction group, three main categories of systems have been investigated:

Cathodically colored inorganic materials usually color with either H+or alkali ion insertion. The best known film is amorphous tungsten oxide, in part, because of its relatively high coloration efficiency in the visible region.

Anodically colored inorganic materials, including Prussian blue, also having a high coloration efficiency, and hydrated oxides of iridium and nickel. Often, K+is inserted for Prussian blue. There is a lively debate about whether H+or OH−is active for the hydrated oxides.

Doped/undoped organic films color both anodically and cathodically in general. There is much less known about this type of electrochromism in literature which, as a whole, has been reviewed through 1990. Polyaniline, polypyrrole, polythiophene or tetrathiafulvalene systems with dopants as proton, alkaline metal or ClO4−, BF4−anions have been studied.

A recent system concerns the preparation of electrochromic layers by using sol–gels formation controlling the variation of the viscosity of the electrolyte and polymer.

Many potential applications are possible but some technical aspects have yet to be improved for a commercial availability.
Electroplating
Authors: Schlesinger Mordechay
Published: July 2004

Electroplating has, over recent decades, evolved from an art to an exact science. This development is seen as responsible for the ever‐increasing number and widening types of applications of this branch of practical science and engineering. Some of the technological areas in which means and methods of electroplating constitute an essential component are all aspects of electronics: macro and micro, optics, opto‐electronics, and sensors of most types, to name only a few. In addition a number of key industries such as the automobile industry (that uses, for example, chrome plating to enhance the corrosion resistance of metal parts) adopt the methods even where other methods, such as evaporation, sputtering, chemical vapor deposition (cvd) and the like are an option. That is so for reasons of economy and convenience. By way of illustration it should be noted that modern electroplating equips the practitioner with the ability to predesign the properties of surfaces and in the case of electroforming those of the whole part. Furthermore, the ability to deposit very thin multilayers (less than a millionth of a cm) via electroplating represents yet a new avenue of producing new materials.

A brief historical discussion, the process of electroplating, preparatory (cleaning) steps required, bath formulations, operation conditions as well as the properties of deposits are presented. Recent key changes in the electroplating industry receive special emphasis.
Electroless Deposition
Authors: Durkin Brad , Steinecker Carl
Published: July 2004

Electroless plating is the formation of a metallic coating on a metallic or nonmetallic surface by means of a chemical reaction between metal ions and a reducing agent in an aqueous solution. Also called autocatatalytic plating, the process is useful for improving the properties of metallic substrates and providing conductivity to nonmetalic ones. Although it is more costly than more commonly used electrolytic plating, electroless deposits are able to provide functional properties not obtained in any other manner, such as wear and corrosion resistance as well as uniformity of deposition. A broad range of industry utilizes electroless technology including automotive parts, computer hard drives and electronic circuit boards and components.
Advanced Ceramics, Electronic Ceramics
Authors: Newnham Robert E. , Shrout Thomas R.
Published: July 2004

Electronic ceramics is a generic term describing a class of inorganic, nonmetallic materials utilized in the electronics industry. The term electronic ceramics generally pertains to polycrystalline inorganic solids comprised of randomly oriented crystallites (grains) intimately bonded together. This random orientation of small, micrometer‐size crystals results in an isotropic ceramic possessing equivalent properties in all directions. Electronic ceramics are often combined with metals and polymers to meet the requirements of a broad spectrum of high technology applications, computers, telecommunications, sensors, and actuators. Electronic ceramics encompass a wide range of materials and crystal structure families used as insulators, capacitors, piezoelectrics, magnetics, semiconductor sensors, conductors, and the recently discovered high temperature superconductors. The development of multifunctional three‐dimensional ceramic arrays called monolithic ceramics (MMC), continues the miniaturization process to provide a new generation of robust, inexpensive products. Rapid advances in integrated circuit technology have led to improved processing and manufacturing of multilayer ceramics (MLC), which consist of alternating layers of dielectric and metal electrodes, especially for capacitors and microelectronic packages. Presently, multilayer capacitors and packaging make up more than half the electronic ceramics market. Advances in the field of electronic ceramics are being made in new materials, novel powder synthesis methods, and in ceramic integration. The continuing miniaturization of electronic packaging should see the replacement of components and processes using such thin‐film technologies developed for semiconductors as sputtering, chemical vapor deposition, and sol–gel.
Electroanalytical Techniques
Authors: Sandifer James R.
Published: July 2004

Electroanalytical techniques may be classified as involving active or passive measurements. Active measurements, such as those obtained in coulometry and voltammetry, result from the application of a voltage or current. Passive measurements, such as those from an ion‐selective electrode, are made independently of external waveforms. The various electroanalytical techniques are described, as is the assembly of electrochemical cells for electroanalysis. Electroanalytical cells employ at least two electrodes placed in either aqueous or organic media. Analyte concentrations may be in the picomolar to millimolar range. Electroanalytical systems may be employed independently or in conjunction with a separation technique such as chromatography.
Ceramics, Electronic Properties and Material Structure
Authors: Schwartz Robert
Published: July 2004

The properties of a ceramic material that make it suitable for a given electronic application are intimately related to such physical properties as crystal structure, crystallographic defects, grain boundaries, domain structure, microstructure, and macrostructure. The development of ceramics that possess desirable electronic properties requires an understanding of the relationship between material structural characteristics and electronic properties and how processing conditions may be manipulated to control structural features.

Ceramic insulators are materials used to support electrical conductors and to prevent the flow of electrical charge between them. Ceramic materials suitable for capacitor (charge storage) use are also dependent on the dielectric properties of the material. Materials that show an induced polarization (electric charge) resulting from an applied stress, are referred to as piezoelectric materials, and the effect is referred to as the direct piezoelectric effect. Pyroelectrics are a subset of piezoelectric materials. The most commercially important application that takes advantage of the pyroelectric effect in polycrystalline ceramics is infrared detection. Ferroelectrics, materials that display a spontaneous polarization in the absence of an applied electric field, also display pyroelectric and piezoelectric behavior. Magnetic ceramics or ferrites may be classified according to crystal structure and the type of magnetic properties. The most commonly used ferrites, the so‐called soft ferrites, are used in soft magnet and low field telecommunication applications, low power transformers, television tube scanning yokes, recording heads, magnetic recording media

Varistors are devices that exhibit nonlinear current–voltage behavior. The majority of the electronic ceramics that are used for electronic applications crystallize in the perovskite structure.
Electrophotography
Authors: Stolka Milan , Mort Joseph
Published: July 2004

Electrophotography is a copying and printing technique employing electrostatic forces and photoconductivity. Photoreceptor materials include amorphous silicon, organic polymers, and main group alloys. Organic photoconductors have almost entirely displaced traditional photoconductive materials such as selenium alloys. The light sensitivity of modern photoconductors in the near infrared region of radiation is so high that low power inexpensive solid‐state lasers are used as light sources for digital imaging. Developer materials and the development process are discussed. Toner triboelectrification and the ability to control the uniformity of toner charge have progressed to the point that stable, reliable operation is achieved over a broad range of environmental conditions. Electrophotographic image quality, even in color, is approaching that of lithographic images. The roles of carrier materials, imaging media, and fusing are defined.
Embedding
Authors: Wong C. P. , D'Ambra Paul
Published: July 2004

Advances in electronic technology have had great technological and economic impact on the electronic industry throughout the world. The rapid growth of the number of components per chip, the rapid decrease of device dimension, and the steady increase in IC chip size have imposed stringent requirements not only on IC physical design and fabrication, but also in electronic packaging and embedding. Electronic embedding is one of the most common processes used to encapsulate and protect electronic components. With advances in VLSI technology and multichip modules packaging, embedding of high density packages in electronics has become a challenge. Various polymeric encapsulants are used for embedding these types of electronic components. These materials, such as silicones, silicon‐carbon thermosets, epoxies, polyurethanes, polyesters, polysulfides, and advanced thermoplastics, and their electrical, mechanical, and rheological properties as well as material processes related to molding, potting, casting, and saturaton coating processes, are discussed in detail. Furthermore the studies of material curing by differential calorimetry, ftir, and microdielectrometry are described.
Emulsions
Authors: Kostansek Edward
Published: July 2004

An emulsion is a dispersion of one liquid in another, immiscible liquid usually in the presence of stabilizer molecules called emulsifiers. Emulsions may be either oil droplets dispersed in water or water droplets dispersed in oil, wherein the droplet diameters are in the 0.05–100‐µm range. The droplets are usually formed by high shear mechanical processes and stabilized against coalescence by electrostatic and/or steric barriers around the droplets provided by the emulsifiers. Emulsifiers may be anionic, cationic, nonionic, or combinations of ionic and nonionic. Emulsions often require complex mixtures of emulsifiers and are not thermodynamically stable, therefore preparing them is still somewhat of an art. When an emulsion is destabilized, it is said to “break” into its separate liquid layers. A less severe form of instability called “creaming” involves the droplets rising to the top of the sample where they can be redispersed with proper mixing. The formation and stability of emulsions can be described and explained using the theories of colloid science, the science of small particle dispersions. Emulsions are encountered in a very wide range of applications including food (milk and mayonnaise), personal care and household products (cold cream and furniture polish), coatings (latex paint), pharmaceuticals (lipid emulsions), agricultural chemicals (emulsifiable concentrates), and road surfacing (asphalt).
Enamels, Porcelain Or Vitreous
Authors: Faust William D.
Published: July 2004

Porcelain enamel is a glassy coating applied to various metal substrates through a high temperature fusion process, usually greater than 425C. Enamel glass formulations are primarily alkali borosilicates. The firing, metal selection and preparation, application processes including electrostatic powder and electrophoretic deposition, and various mechanical, physical, and chemical properties are discussed. Standardized test procedures are listed. Porcelain enamels are used as protective, decorative, and functional coatings on steel, cast iron, aluminum, and other alloys. Products produced using porcelain enamel coatings include domestic appliances such as ranges and dishwasters, hot water tank interiors; industrial devices such as heat exhangers, chemical vessels, cast‐iron pipe, and electronic substrates; architectural applications such as interior and exterior panels; and institutional applications such as chalk boards, marker boards, and toilet partitions.
Engineering, Chemical Data Correlation
Authors: Mullins Michael E. , Rogers Tony N. , Radecki Peter P.
Published: July 2004

Methods for correlating experimentally observed data to the known physical, chemical, or molecular properties of a substance or a mixture of substances are discussed. These correlations, once drawn, can be used to estimate values not experimentally obtainable. The correlation methods may be theoretically, semitheoretically, or empirically based. The theoretically based correlations, most often rooted in thermodynamics, are usually preferred.

Data correlation may result from the empirical use of basic mathematical and numerical techniques, nomographs, or reference substances. Alternatively, the methodology may incorporate group contributions, structure‐activity relationships, molecular connectivity indexes, and graph theory. A significant amount of investigation is devoted to the assessment of the degree to which mathematical constructs faithfully mimic real systems.
Enhanced Oil Recovery
Authors: Borchardt John K.
Published: July 2004

The petroleum industry is becoming more dependent on increasing oil production from existing oil fields beyond the recovery in primary production and water flooding. Enhanced oil recovery employs various chemicals to increase the reservoir volume contracted by oil well injected fluids, ie, to increase the volumetric sweep efficiency, and thus increase production. Increases in the oil displacement efficiency can be brought about by a variety of mechanisms. The primary processes used to increase oil displacement efficiency are miscible gas flooding and steam flooding. Micellar polymer flooding and alkaline flooding may also be used. Miscible gas flooding most often employs carbon dioxide and/or hydrocarbon gases. Polymer flooding increases the volumetric sweep efficiency of waterflooding. The two most commonly used polymers used are partially hydrolyzed polyacrylamides and xanthan gum. Polymer injection followed byin situcross‐linking reduces the permeability of fractures and rock thief zones increasing volumetric sweep efficiency. Injection of surfactants and noncondensible gases to generate foamin situalso increases volumetric sweep efficiency.
Enzymes In Organic Synthesis
Authors: Zaks Aleksey
Published: July 2004

This article describes applications of enzymes as catalysts in organic synthesis. It outlines the general mechanistic principles that govern enzyme‐catalyzed asymmetric synthesis and enantioselective resolutions and offers a special emphasis to the widely practiced hydrolytic reaction for the synthesis of monoesters of dicarboxylic acids and monoacylated diols. The use of hydrolytic enzymes for acylations in nonaqueous media is illustrated by the synthesis of chiral lactones and polyesters and regioselective acylations of polyhydroxy compounds. Utilization of hydrolases is also extended to resolution of racemic amines and amino acids, and enzymatic hydrolysis of nitriles. Thermodynamic and kinetic aspects of enzymatic peptide synthesis are analyzed and the most recent trends in enzyme‐catalyzed peptide condensations are illustrated by a number of examples. The synthetic utility of lyases is demonstrated by a number of aldolase‐ and ketolase‐catalyzed condensations of carbon‐carbon bonds and by the synthesis of cyanohydrins by oxynitrilases. Oxidoreductases are represented by dehydrogenases commonly used for the synthesis of chiral alcohols, lactones, hydroxy, and amino acids; by cyclohexanone monooxygenase, the enzyme that catalyzes Baeyer‐Villiger oxidation of ketones; and by lipoxygenase, which incorporates dioxygen into polyunsaturated fatty acids.
Epoxy Resins
Authors: Gannon John
Published: July 2004

Epoxy resins are characterized by the presence of a three‐membered cyclic ether group commonly referred to as an epoxy group, 1,2‐epoxide, or oxirane. The most widely used epoxy resins are diglycidyl ethers of bisphenol A derived from bisphenol A and epichlorohydrin. The outstanding performance characteristics of the resins are conveyed by the bisphenol A moiety (toughness, rigidity, and elevated temperature performance), the ether linkages (chemical resistance), and the hydroxyl and epoxy groups (adhesive agents). In addition to bisphenol A, other starting materials such as aliphatic glycols and both phenol ando‐cresol novolaks are used to produce specialty resins. Epoxy resins may also include compounds based on aromatic amine, triazine, and cycloaliphatic backbones.

A variety of reagents have been described for converting the liquid and solid epoxy resins to the cured state, which is necessary for the development of the inherent properties of the resins. The curing agents or hardeners are categorized as either catalytic or coreactive. Catalytic curing agents initiate resin homopolymerization, either cationic or anionic, as a consequence of using a Lewis acid or base in the curing process. Coreactive curing agents are polyfunctional reagents that are employed in stoichiometric quantities with epoxy resins and possess active hydrogen atoms. The important classes include polyamines, polyamides (formed from polyamines and dimerized fatty acid), polyphenols, polymeric thiols, polycarboxylic acids, and anhydrides.

The largest single use of epoxy resins is in the protective coatings market where high chemical resistance and adhesion is important. Epoxies have gained wide acceptance in protective coatings and electrical and structural applications because of their exceptional combination of properties such as toughness, adhesion, chemical resistance, and superior electrical properties.
Ethanol
Authors: Logsdon John E.
Published: July 2004

Ethanol's unique combination of physical and chemical properties has led to its use as a solvent, a germicide, a beverage, an antifreeze, a fuel, a depressant, and a chemical intermediate for other organic chemicals. Ethanol from fermentation processes is the most important source. Most industrial ethanol is produced from ethylene by the direct hydration process. The subsidized (federal and state) use of fermentation ethanol in gasoline has fueled a rapid growth in U.S. production, which has provided some ethanol for crossover to the industrial market. The 1990 Clean Air Act requiring the use of oxygenates in gasoline has further fueled this growth. Corn is the principal feedstock for fermentation in the United States, and sugar cane is the most important raw material outside the United States. This rapid growth has also caused a renewed interest in research into this ancient process. The main uses for industrial ethanol are as an intermediate for the production of other chemicals and as a solvent. The United States Treasury, Bureau of Alcohol, Tobacco, and Firearms oversees the production, procurement, and use of ethanol in the United States.
Ethers
Authors: Karas Lawrence , Piel W. J.
Published: July 2004

An overview of ethers is provided that covers the general types of ethers, their synthesis reactions, properties, and some general uses in industry. More detail is provided on ethyl ether, tetrahydrofuran (THF), and methyltertiarybutyl ether (MTBE), which represent three of the ethers with the highest commercial volumes. One of the fastest growing and largest uses of ethers is for gasoline blending. Though initially developed to provide octane in gasoline, fuel‐grade ethers are now used to add oxygen to the gasoline mixture, which helps improve combustion and reduce tailpipe emissions from automobiles. Besides MTBE, other possible fuel ethers such as ethyltertiarybutyl ether (ETBE) andtertiaryamyl ether (TAME) are also noted.
Polyethers, Ethylene Oxide Polymers
Authors: Back Darlene M. , Clark Elke M. , Ramachandran Ramesh
Published: July 2004

Ethylene oxide polymers are high molecular weight (\documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}${{\rm{>}}100,000}$\end{document}) water‐soluble thermoplastic polymers. This article reviews the effect of shear, pH, salt, and temperature on the physical and chemical properties of poly(ethylene oxide) solutions and melts. Industrial uses of the unique properties of poly(ethylene oxide) in fields such as flocculation, pharmaceutical excipients, adhesives, coatings, and personal care are summarized.
Ethylene Oxide
Authors: Dever J. P. , George K. F. , Hoffman W. C. , Soo H.
Published: July 2004

Ethylene oxide is a colorless gas that condenses at low temperatures into a liquid and is miscible with water and most organic solvents. Its vapors are flammable and explosive. Ethylene oxide can be relatively toxic as both a liquid or gas, and is considered as a potential human carcinogen and reproductive hazard.

Ethylene oxide was first prepared from ethylene chlorohydrin and aqueous potassium hydroxide in 1859. It was first produced commercially during World War I in Germany by the chlorohydrin process. In 1931, direct oxidation of ethylene to ethylene oxide was achieved by using a silver catalyst. The chlorohydrin process was quickly replaced by the direct oxidation process, and is still the dominate technology.

Ethylene oxide is a highly reactive compound; it is used industrially as an intermediate for many chemical products. The total world consumption in 2002 was 14.7 × 106metric tons, about 73% was used in the production of ethylene glycol. Other derivatives of ethylene oxide include glycol ethers, ethanolamines, and surfactants. Ethylene glycol for polyester production is still a firm market.
Ethyl Chloride
Authors: Miller Matt C.
Published: July 2004

Ethyl chloride (chloroethane), C2H5Cl, is a colorless, mobile liquid with a nonirritating ethereal odor and a pleasant taste. It is flammable, is normally stored as liquefied gas, and burns with a green‐edged flame, producing hydrogen chloride fumes. This article discusses its properties, manufacture, toxicology, and economic aspects. Ethyl chloride has primarily been used in the manufacture of the fuel additive tetraethyllead (TEL). Environmental legislation mandating the use of lead‐free fuels caused a steep decline in production of ethyl chloride. A recent study has shown evidence of carcinogenic activity in female mice exposed to 15,000 ppm. The only other important demand for ethyl chloride is in the production of ethylcellulose.
Ethylene–Propylene Polymers
Authors: Noordermeer Jacobus W. M.
Published: July 2004

Ethylene–propylene polymers (also called EPDM or EPM) continue to be one of the most widely used and fastest growing synthetic rubbers. They are particularly known for their excellent resistance to ozone and aging in comparison with natural rubber and common polydiene synthetic rubbers. The technology of producing EP(D)M‐rubber is still very much in development. Latter years have seen major breakthroughs in production‐technologies relative to the more traditional solution‐ and slurry‐processes, based on Ziegler‐Natta catalysis: ie, Gas‐phase technology and technology based on metallocene catalysis. EPDM‐rubber can be extended with fillers and plasticizers to a very high level, leading to an attractive price/performance ratio in comparison with other rubbers. EPM can be vulcanized radically by means of peroxides; a small amount of built‐in nonconjugated diene monomer in EPDM permits conventional vulcanization with rubber. Typical applications of EP(D)M are in automotive weatherstrip profiles and radiator hoses, in building and construction as sealing profiles and roofing foils; in cable and wire as insulating and jacketing material; in blends with general purpose rubbers to improve ozone resistance; as impact modifier for thermoplastics, and as additive to lubricating oils.