bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nondestructive Evaluation
Authors: Bray Donald E. 
Published: July 2004

Abstract
The technology of nondestructive evaluation (NDE) includes all nondamaging or nonintrusive methods for determining material identity; for evaluating material properties, composition, structure, or serviceability; and for detecting discontinuities and defects in materials. Nondestructive tests commonly are used for quality control, process control, and for reliability assurance of materials, protective coatings, components, welds, assemblies, structures, and operating systems. The use of these tests helps prevent premature failure of materials during processing, manufacturing, or assembly, and during service under anticipated operating stresses and environments. Nondestructive evaluation provides an essential service toward achieving the goal of optimum plant and system operation.
An overview of NDE methods and applications that apply to most inspection demands that can arise in the chemical industry is presented. Candidates for inspection with NDE range from massive aircraft and pressure vessels to minute fibers used in the construction of high strength composites and fine arts objects. Techniques applicable to such a wide range of items may be classified as external energy tests, where the signal or probing medium is generated externally to the system being evaluated, or passive energy tests, where the signal comes from the system itself. Probe sources range from the ultrasonic and microwave through γ‐ and x‐rays. Surface investigation, leak detection, flaw sizing, imaging of material systems, and routine inspections are all carried out using NDE.
Nonlinear Optical Materials
Authors: Dalton Larry R. , Bale Denise H. 
Published: July 2004

AbstractNonlinear optical materials are the building blocks of the emerging technologies of optoelectronics and photonics (photonics uses light to acquire, process, transmit, and store information). These materials perform functions such as modulation, switching, rectification, frequency generation, limiting, and amplification, all of which are typically performed by semiconductors in electronic technology. Nonlinear optical materials and phenomena can be classified as second or third‐order, reflecting the order of electric field interactions involved. Second‐order phenomena are typically observed only for noncentrosymmetric materials. Such phenomena include electrooptic modulation, spatial light modulation, and second harmonic generation. Electrooptic modulation may play a critical role in electric‐to‐optical signal transduction and in switching in local area networks and can be used for specialized applications as diverse as phased array radar and optical gyroscopes. Third‐order phenomena include the dynamic Kerr effect, degenerate four‐wave mixing, third harmonic generation, saturable absorption, reverse saturable absorption, etc. The dynamic Kerr effect can be exploited for all‐optical switching and also for beam focusing, such as in mode‐locking of the Ti:sapphire laser. Reverse saturable absorption can be exploited for sensor protection. Both organic and inorganic materials have been observed to exhibit relatively large optical nonlinearities. Material morphologies ranging from crystalline to polymeric to photonic bandgap have been considered for nonlinear optical applications; examples of materials are given.
Ceramics, Nonlinear Optical and Electrooptic Ceramics
Authors: Phillips Mark L. F. 
Published: July 2004

Abstract
Nonlinear optical (NLO) and electrooptic (EO) processes are events that take place in transparent materials where refractive indexes can vary with electric field intensity. The field elicits a polarization response in which terms dependent on second and higher orders of the field intensity become significant contributions to the overall polarization response. As light propagates through a transparent solid, liquid, or gas, it encounters the electric fields associated with the valence electrons, polarizing them and creating oscillating electric dipoles. These oscillators in turn act as antennas to broadcast or propagate the electric field through the medium.
NLO materials possess a high degree of optical nonlinearity, physical durability and chemical inertness, and high threshold to optical damage. In addition, it must be possible to process the materials into the form required by the intended application.

Optically nonlinear ceramics all contain highly polarizable bonds. In the case of oxide ceramics, such polarizable bonds are often found between oxygen and early transition metals, eg, BaTiO
3
, SrNb
2
O
6
. Nonoxide NLO ceramics include Si and compound semiconductors having the silicon structure, eg, GaAs, InP, and InSb, as well as ferrelectrics such as SbSI. All‐optical wavemixing applications generally require single crystals.

Electrooptic (EO) materials are optical media in which birefringence can be readily induced or altered by an externally applied electric field. As with NLO ceramics, good EO materials tend to be ferroelectrics. EO materials are generally used as either bulk optical elements or guided wave devices.
Odor Modification
Authors: Berry Yvette 
Published: July 2004

AbstractOdor modification is defined by the impact of one odorous substance upon another, thereby altering the perception of the primary odor in some manner. This phenomenon can occur in different ways. The masking of an odor results when the original odor is compounded with an additional odor, and an overall increased perception in intensity is realized. Counteraction occurs when the perception of the combination of the two odorants results in an overall decreased perception in intensity. Both of these relationships are reviewed in detail. Initially, this article examines the basic mechanism of olfaction, classification of odors, and how odor counteraction is evaluated. Finally, it touches upon the use of odors to modify not only the perception of other odors but human behavior as well.
Oil Shale
Authors: Piper Edwin M. , Heistand Robert N. 
Published: July 2004

Abstract
Oil shale, found in numerous geologic deposits throughout the world, has been used commercially on a very limited scale. The organic matter in oil shale exists as a complex, high molecular weight solid polymer in an inorganic rock matrix. Production costs for crude shale oil are generally much higher than those for conventional crude oil, in part because of the high concentrations of heteroatoms in the crude shale oil. Refining costs are also higher. Retorting processes for oil shale, as well as the upgrading processes needed to refine the crude shale oil into fuels and other products, are described. Shale oil asphalt is the most promising of these products. Several commercial oil shale operations exist, but these are all outside of the United States.
Oils, Essential
Authors: Mookherjee Braja D. , Wilson Richard A. 
Published: July 2004

AbstractAn essential oil is defined as the volatile ethereal fraction obtained from a plant or plant part by a physical separation process. The chemistry of essential oils, with particular reference to their use by the flavor and fragrance industry, is described for 63 different oils. Particular attention is paid to the chemical composition of typical commercially available samples of the oils (down to the 1% level) and, where available, comparison with the headspace constituents of the unprocessed or living botanicals. Reference is frequently made to the importance of trace constituents of the aroma and flavor of the oils. Current analytical methodology, economic aspects, as well as health, safety, and regulatory considerations, are discussed.
Olefins, Higher
Authors: Lappin G. R. , Nemec L. H. , Sauer J. D. , Wagner J. D. 
Published: July 2004

Abstract
This article discusses physical and chemical properties, production methods, uses, and safe handling of the even‐carbon‐number linear α‐olefins. Other higher olefins (branched and/or internal) are discussed briefly. The principal classes of chemical reactions for olefins are addition reactions (electrophilic and free‐radical) and substitution reactions. Common classes of transformations in industrial processes include oxo reaction (hydroformylation), oligomerization and polymerization, alkylation reaction, hydrobromination, sulfation and sulfonation, and oxidation. A low flash point is the main hazard associated with olefins. Flammability limits, autoignition temperatures, and flash points are listed. Olefins should be stored and shipped under an inert atmosphere as many applications are adversely impacted by low levels of moisture, peroxides, and oxygenates.

Most linear α‐olefins were produced from ethylene in 1993 with a total annual capacity of 2,136,000 metric tons. Ethylene oligomerization is discussed for the following commercial processes: (
1
) stoichiometric chain growth on aluminum alkyls followed by displacement (Albemarle); (
2
) catalytic chain growth on aluminum alkyls (Chevron‐Gulf); (
3
) catalytic chain growth using a nickel‐ligand catalyst (Shell); and (
4
) catalytic chain growth using a modified zirconium catalyst (Idemitsu).

Significant outlets for higher olefins are in the polymer, surfactant, and detergent industries. The C
4
, C
6
, and C
8
linear α‐olefins impart tear resistance and other desirable properties to linear low and high density polyethylene. The C
6
, C
8
, and C
10
linear α‐olefins give special properties to plasticizers used in flexible poly(vinyl chloride). The C
10
(and other carbon‐number) linear α‐olefins provide premium value synthetic lubricants.
Oligosaccharides
Authors: Girijavallabhan V. M. , Ganguly Ashit K. 
Published: July 2004

AbstractOligosaccharide antibiotics represented by the everninomicins, eg, everninomicin B (C66H99Cl2NO36) and everninomicin C (C63H93Cl2NO34); flambamycins, eg, flambamycin (), avilamycins, eg, avilamycin A (C61H88Cl2O32) and avilamycin B (C59H84Cl2O32); and curamycins, eg, curamycin A (C59H84Cl2O32), have complex and unique structural features. They are sometimes referred to as orthosomycins because characteristically these oligosaccharides possess two acid‐sensitive ortho ester linkages, cleavage of which results in the complete loss of antibiotic activity. Another structural feature common to all the oligosaccharide antibiotics is the presence of a substituted phenol ester derived from dichloroisoeverninic acid attached to the sugar ring B at C‐13, essential for the antibiotic activity. Oligosaccharide antibiotics are colorless solids, are often crystalline, and have defined melting points and optical rotations. They are sensitive to acid pH because of the ortho ester linkages. Yet all of them have an acidic phenolic group which makes the molecule relatively unstable to handling conditions. Everninomicin D is the principal component from cultures ofMicromonospora carbonacae.Chemical modification of the nitro group in everninomicin D has resulted in the formation of amino, mono‐ and dialkylamino,N‐acylamino, andN‐hydroxylamino (and its nitrone derivatives) everninomicin D, all of which possess great antibiotic activity against gram‐positive bacteria. Everninomicin B, a secondary component, has been extensively investigated because of its improved pharmacokinetic properties. Flambamycin, produced byStreptomyces hygroscopicusDS 23230, also has undergone substantial chemical degradative experiments during structure elucidation. The structure, chemical reactions, and biological properties have been thoroughly reviewed. Curamycin A is the primary component of the cultureStreptomyces curacoi.At least 16 avilamycins have been reported. Sporacuracin A, C63H94Cl2O35, mp 145–148°C, [α]D, and sporacuracin B, C63H94Cl2O35, mp 162–165°C, [α]D, are other probable members of the oligosaccharide antibiotic family. Oligosaccharides in general are highly potent, but are narrow‐spectrum antibiotics. Everninomicins are active against a wide variety of gram‐positive aerobes and anaerobes;Neisseria, Mycoplasma, and someMycobacteria.Potential for oligosaccharide antibiotics in both human and animal health care has been claimed.
Information Storage Materials, Optical
Authors: Kämpf Günther , Mergel Dieter 
Published: July 2004

AbstractIn addition to the established magnetic mass storage media (floppy disk, hard disk, tape) optical mass storage media (CD‐ROM (compact disk‐read only memory), WORM (write once, read many times), EOD (erasable optical disk)) are increasingly used. Generally, magnetic and optical media do not compete, but complement each other due to their specific advantages. Progress in optical data storage technology is closely connected with the development of suitable materials. This article illustrates in detail the current state of the art and the ongoing development of materials for optical data storage. For the information layer of WORM disks, dyes with high ir absorption, low heat conductivity, and good solubility are required. Besides polymethine dyes, biaxially substituted silicon–naphthalocyanines are used; also combinations of metal complexes are employed. The magneto‐optical materials for EOD‐disks in MOR (magneto‐optical recording) technique are primarily ferrimagnetic ternary amorphous alloys of rare‐earth (RE) and transition‐metals (TM) (GdTbFe, TbFeCo, DyFeCo). Ferrites with spinel‐ or garnet‐structure, eg, rare‐earth iron‐garnets (RIG), are commercially unimportant mainly due to their high deposition temperature. Co/Pt‐multilayers (MLs) exhibit interesting properties, but are still waiting for commercial introduction. Research concentrates on exchange‐coupled RE‐TM layers, which permit a direct overwrite procedure. Phase‐change materials for EOD‐disks in PCR (phase‐change recording) technique are primarily ternary alloys (eg, GeSbTe, InSbTe). Research focuses on materials with fast crystallization in parallel with high stability even at numerous write/read/erase cycles. As substrate materials for CD‐ROM disks, end group‐modified bisphenol A–polycarbonate (BPA‐PC) is employed exclusively. For WORM and EOD disks mainly BPA‐PC and sometimes glass is applied.
Titanium Compounds, Organic
Authors: Putzig Donald E. , Del Pesco Thomas W. 
Published: July 2004

AbstractOrganic titanium compounds are materials having a covalent bond between titanium and another atom that is also bonded to a carbon‐based group. Titanium tetrachloride, the basic raw material from which organic titanate compounds are made, is readily converted to tetraisopropyl titanate, TYZOR TPT, by the Nelles process. This ester can be converted by alkoxy exchange (transesterification) to a wide variety of tetraalkyl titanates, which in turn react with other ligands and chelating agents to give complexes having properties significantly different from the starting materials. This article covers all aspects of the organic titanium compound, from properties, reactions, and synthesis, to uses and health and safety factors.
Peroxides and Peroxide Compounds, Organic Peroxides
Authors: Sanchez Jose , Myers Terry N. 
Published: July 2004

AbstractOrganic peroxides are compounds possessing one or more oxygen–oxygen bonds that are thermally and photolytically sensitive to facile homolytic cleavage. Thermal decomposition rates are affected by the structure of the organic peroxide and the decomposition conditions. The initially formed free radicals from the oxygen–oxygen bond homolysis are reactive intermediates which quickly undergo a variety of subsequent reactions to form stable products. Thermolysis of organic peroxides is used commercially to initiate free‐radical reactions, eg, halogenation, vinyl monomer polymerization, unsaturated resin cure, polyolefin cross‐linking and rheology modification. Many organic peroxides also undergo reactions in which free radicals are not involved, eg, heterolyses, hydrolyses, reductions, and rearrangements.This article reviews the physical and chemical properties, synthetic methods, and the principal commercial uses of organic peroxides of the following classes: hydroperoxides, dialkyl peroxides, α‐oxygen‐substituted hydroperoxides and dialkyl peroxides, ozonides, peroxyacids, diacyl peroxides, and alkyl peroxyesters. Class discussions cover the broad structural variation that is possible, including organomineral and polymeric derivatives when appropriate. Emphasis is placed on the relationship between peroxide structure and reactivity (thermal stability). Physical hazards associated with organic peroxide manufacture, handling, storage, transportation, and use are discussed. An overview of health hazards associated with handling of organic peroxides is presented.
Petroleum, Origin of
Authors: Barker Colin 
Published: July 2004

AbstractAccumulation of oil and gas in natural reservoirs begins with sediments incorporating organic matter as these are deposited. Upon increasing depth of burial, rising temperature converts the complex insoluble organic material called kerogen into a lower molecular weight, solvent‐extractable material called bitumen. This reaction is essentially first‐order. Generation of bitumen occurs at lower temperatures in older rocks. Part of the bitumen may migrate and accumulate in reservoirs as a commercial accumulation of petroleum. This migration process is not fully understood. Bitumen is probably expelled from the source rock as a separate petroleum phase. The type of organic matter in the source rock exercises initial control on whether oil or gas is generated, but considerable modification of petroleum composition can occur after it accumulates in the reservoir. Rising temperature owing to increasing burial depth, water flowing past an oil reservoir, and bacteria can all play a role. Thus the origin of petroleum involves generation in source rocks, migration to a reservoir, and the possibility of further modification of composition after accumulation.
Glycols, Other Glycols
Authors: PARSONS T. E. 
Published: July 2004

AbstractGlycols such as neopentyl glycol, 2,2,4‐trimethyl‐1,3‐pentanediol, 1,4‐cyclohexanedimethanol, and hydroxypivalyl hydroxypivalate are used in the synthesis of polyesters and urethane foams. Commercial preparation of neopentyl glycol can be via an alkali‐catalyzed condensation of isobutyraldehyde with 2 moles of formaldehyde (crossed Cannizzaro reaction). A number of derivatives of neopentyl glycol have been prepared; some show promise for commercial applications. 2,2,4‐Trimethyl‐1,3‐pentanediol can be produced by hydrogenation of the aldehyde trimer resulting from the aldol condensation of isobutyraldehyde.The manufacture of 1,4‐cyclohexanedimethanol can be accomplished by the catalytic reduction under pressure of dimethyl terephthalate in a methanol solution. Hydroxypivalyl hydroxypivalate may be produced by the esterification of hydoxypivalic acid with neopentyl glycol or by the intermolecular oxidation–reduction (Tishchenko reaction) of hydroxypivaldehyde using an aluminum alkoxide catalyst.Polyester resins are useful for preparation of coatings exhibiting a combination of hydrolytic stability, excellent weather resistance, and good flexibility.
Chloroethylenes
Authors: Snedecor Gayle , Hickman J. C. , Mertens James A. 
Published: July 2004

AbstractThe physical and chemical properties, manufacturing methods, uses, environmental concerns, and toxicity of 1,2‐dichloroethane are discussed.1,2‐Dichloroethylene, also known as acetylene dichloride, dio‐form,α,β‐dichloroethylene, andsym‐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.Trichloroethylene, commonly referred to as “tri”, is a widely used vapor‐degreasing solvent. In recent years its popularity has fallen mostly because of environmental restrictions on its use. Trichloroethylene has excellent solvency properties for a large number of natural and synthetic substances. This article includes physical and chemical properties, production, and use information. In addition, safety, toxicological, and environmental regulations pertinent to trichloroethylene are reviewed.Tetrachloroethylene [127‐18‐4], perchloroethylene, tetrachloroethene, commonly referred to as “perc,” is widely used in the dry‐cleaning industry as well as metal cleaning and vapor degreasing because of its excellent solvent properties. It has no flash point or flammable limits in air or oxygen. This article includes the physical and chemical properties of tetrachloroethylene, historical production within the United States, manufacturing locations and processes, as well as typical quality specifications. In addition, safety and toxicological considerations and environmental regulations pertinent to tetrachloroethylene are reviewed.The Montreal Protocol has had an impact on all of the compounds discussed in this article.
Flame Retardants: An Overview
Authors: Gann Richard G. , Gilman Jeffrey W. 
Published: July 2004

Abstract
Flame retardant additives are ubiquitous in commercial products. They reduce fire losses by decreasing the likelihood of ignition and the rate of heat release of the products in which they are compounded. This article outlines the definition, applications, and functions of fire retardant additives. It also presents the classes of these chemicals and their market presence and risks.
Ceramics, Overview
Authors: Loehman Ronald 
Published: July 2004

Abstract
Ceramics are a class of inorganic, nonmetallic solids that are subjected to high temperature in manufacture or in use. The classification of ceramic, typically a polycrystalline material, extends to glasses, which are noncrystalline, and to such single‐crystal materials as a ruby laser. There are the low value‐added bulk or commodity materials such as pottery and abrasive grain, and the engineering or fine ceramics which are low volume, high value‐added, highly processed materials having carefully controlled properties. The most common ceramics are oxides, carbides, and nitrides, but silicides, borides, phosphides, sulfides, tellurides, and selenides are also ceramics, as well as elemental materials such as carbon and silicon.
Processing techniques play an important role in determining the properties of a ceramic. These techniques, the resultant structures, and the relationship to mechanical and electrical properties of engineered ceramics are discussed as are fracture and wear‐resistant materials, inorganic glasses, and optoelectronic and electronic ceramics.
Oxalic Acid
Authors: Sawada Hiroyuki , Murakami Toru 
Published: July 2004

AbstractThe properties of anhydrous oxalic acid and oxalic acid dihydrate are discussed, tabulating their physical and thermochemical constants. The reactions of oxalic acid are also included.Five manufacturing processes which are employed for commercial production are illustrated: oxidation of carbohydrates, ethylene glycol process, propylene process, dialkyl oxalate process, and sodium formate process. The newest of the five, the dialkyl oxalate process (from UBE) is discussed in depth. Advances are covered, including a new synthetic route from CO2.Economic aspects of oxalic acid are described, outlining the regional features in the world market. Shipment, storage, and handling are included, covering disposal methods. Health and safety factors and toxicology are also presented.Uses of oxalic acid are described, including separation/recovery of rare‐earth elements, metal treatment, bleaching agents, textile treatment, leather tanning, marble polishing, millet jelly production, etc. Derivatives, such as salts/complexes and organic derivatives, are also presented. Vol. 17, pp. 882–902, 91 refs to December 1993.