bluuebunny/crossref_metadata_2025_split huggingface dataset:
Herbicides
Authors: Bradow Judith M. , Dionigi Christopher P. , Johnson Richard M. , Wojkowski Suhad 
Published: July 2004

AbstractWeeds, ie, unwanted plants, reduce crop yields and quality. Of the many approaches used to control weeds, the use of chemical herbicides is considered the most effective and efficient. Herbicides are a critical factor in agricultural productivity and represent a significant economic input in crop production. In the United States, over 280 million kilograms of herbicide are applied annually. This review discusses herbicide mode of action, environmental fate, and chemistry, as well as the historical perspectives and future trends in herbicide development. Topics addressed include analytical methods, allelopathy and natural products, biological control, carcinogenicity, herbicide degradation, leaching, sorption, volatilization, movement in soil, enzyme and biosynthesis inhibition, free radical induction, photosynthesis and pigment bleaching, plant growth regulators, seed safeners, water quality, and weed seeds. Primary herbicide groups include acid amides, amino acid analogues, aliphatic carboxylic acids, benzonitriles, bipyridiniums, carbamates, dinitroanilines, diphenyl ethers, imidazoles, inorganic and metallorganic compounds, mycoherbicides, phenoxy acids, phenoxyalkanoic acids, pyridines, pyridazones, phthalics, sulfonylureas, thiocarbamates, triazines, and ureas. Miscellaneous herbicides include acrolein, cinmethylin, clethodim, clomazone, ethofumesate, sethoxydim, and tridiphane. A list of herbicide, agrichemical, and toxicology databases is provided.
Polyethylene, High Density
Authors: Kissin Yury V. 
Published: July 2004

AbstractHigh density polyethylene (HDPE) is a product of ethylene polymerization with a density of 0.940 g/cm3or higher. HDPE resins include both homopolymers of ethylene and its copolymers with α‐olefins. HDPE resins include a large variety of products that differ in molecular weight, molecular weight distribution, and density; they are produced with several classes of catalysts: Phillips catalysts based on chromium oxides, catalysts containing chromium complexes, Ziegler catalysts based on titanium or vanadium compounds, and, in some special cases, metallocene catalysts. Two of the most important industrial processes for manufacturing HDPE are polymerization in a slurry and gas‐phase polymerization.HDPE is one of the largest volume commodity plastics produced in the world, with a worldwide capacity in 1994 of over\documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}${14\times 10^{6}{\hskip0.167em}{\hskip0.167em}{\rm{t}}/{\rm{yr}}}$\end{document}. Blow‐molded products represent the biggest use for HDPE resins. They also used for bottles, housewares, toys, pails, drums, tanks, and other similar products. Injection‐molding products are the second largest application; they include housewares, toys, food containers, pails, crates, and cases. HDPE is also used for film manufacture, pipes of various diameters, wire and cable coatings, and foam. Low molecular weight HDPE waxes are used for paper coatings, spray coatings, emulsions, and in printing inks. High molecular weight HDPE is a specialty plastic with a high impact strength and abrasion resistance; it is used in such industrial applications as chemical and mineral processing, electrical equipment, municipal plants, and medical implants. High strength fibers produced with this polymer are used in bullet‐proof jackets and armor.
Hormones, Human Growth Hormone
Authors: Becker Gerald W. , MacKellar Warren C. , Riggin Ralph M. , Wroblewski Victor J. 
Published: July 2004

AbstractHuman growth hormone (hGH), a protein hormone produced and secreted by the somatotropic cells of the anterior pituitary, plays a key role in somatic growth through its effects on the metabolism of proteins, carbohydrates, and lipids. The biological properties of hGH are diverse and complex, with the molecule exhibiting anabolic activity, insulin‐like and diabetogenic activities, and lactogenic activity, as well as producing effects on water and salt retention. First isolated from the pituitary gland, hGH is produced using recombinant DNA technology and has been approved for use as a human pharmaceutical in the treatment of growth failure owing to hGH deficiency and in the treatment of Turner's syndrome in Europe and Japan. In addition, hGH is being investigated for use in treating burns, various wounds, osteoporosis, cachexia, and other conditions. Human growth hormone is one of the largest selling therapeutic proteins produced by recombinant DNA technology.
Hydantoin and Its Derivatives
Authors: Avendaño Carmen , Menendez J. Carlos 
Published: July 2004

AbstractHydantoins are a group of closely related substances for which several general patterns regarding their physical properties, chemical reactivity, synthesis, and analysis can be found. Physical properties of hydantoin derivatives, including melting point and ionization properties, are discussed in terms of their relationship with molecular association through hydrogen bonds. A survey of their spectral properties (uv, ir, nmr, luminescence, and mass spectra) is also given. Treatment of chemical reactivity is descriptive, with little or no emphasis on mechanistic aspects. The most common synthetic and analytical methods are also briefly discussed. Medicinal applications are commented on and various other industrial applications of hydantoins are also covered.
Hydrogen
Authors: Baade William F. , Parekh Uday N. , Raman Venkat S. 
Published: July 2004

AbstractHydrogen is one of the most important industrial commodities. Physical thermodynamic, and chemical properties are described. The chemistry of hydrogen from a commercial perspective is followed by a description of manufacturing methods. Steam reforming of hydrocarbons and partial oxidiation of hydrocarbons account for almost all hydrogen production. Other, less conventional manufacturing methods are also presented, such as produced as a by‐product of chemical processes. Hydrogen purification is reviewed. The storage of hydrogen is discussed, including conventional methods for gas and liquid storage, and possible future methods, such as in metal hydride systems and microcapsules. Analysis of hydrogen, specifications health and safety issues, recycling, and environmental considerations are discussed. Hydrogen consumption figures are presented, and the possible future usage of hydrogen is discussed.
Hydroxycarboxylic Acids
Authors: Datta Rathin 
Published: July 2004

AbstractHydroxycarboxylic acids are an important group of chemicals, with several members that are commercially manufactured in large volumes and have a wide range of applications. Two α‐hydroxycarboxylic acids, lactic and glycolic, and a derivative of γ‐hydroxycarboxylic acid γ‐butyrolactone are discussed in detail because of their relative commercial importance, both current and future. General classes of reactions that these acids undergo are also discussed, with specific examples of those reactions that are or could become commercially important.Current manufacturing processes for lactic and glycolic acids and γ‐butyrolactone are briefly outlined, with estimates of the production volume and market size for various applications. For lactic acid production and manufacture of its derivatives for biodegradable polymers, new processes are emerging, and some of the recent patents and emerging technologies are highlighted. Some of the important uses of hydroxycarboxylic acids are related to environmentally friendly products and processes such as biodegradable plastics for consumer products and nontoxic and easily degradable solvents, cleaning agents, plasticizers, etc. The emergence of new technologies for efficient and economical manufacture of these chemicals, combined with these product opportunities, could make these hydroxycarboxylic acids very large‐volume chemicals of global commercial importance.
Hydrothermal Processing
Authors: Dawson William J. , Krijgsman Pieter 
Published: July 2004

AbstractHydrothermal processing encompasses a broad set of technologies that share a range of operating temperatures and pressures and require the use of engineered pressure systems. Technologies include pressure leaching and precipitation reactions used in mineral recovery, hydrothermal synthesis for manufacture of fine oxide powders, hydrothermal crystallization of α‐quartz and other large crystals, wet oxidation for treatment of organic sludges, and supercritical water oxidation for destruction of hazardous organic wastes. Development and utilization of hydrothermal processes are described including the use of hydrothermal synthesis for zeolites, electronic ceramics, magnetics, inorganic pigments, and silicates. A description of process systems and equipment is given.
Hydraulic Fluids
Authors: Denniston Alan D. 
Published: July 2004

Abstract
Hydraulic power utilizes hydraulic fluids which may be based on mineral oils, fire‐resistant fluids, high water‐base fluids, water‐in‐oil emulsions, oil‐in‐water emulsions, synthetic fluids, synthetic lubricants, olefin oligimers, alkylated aromatics, polybutenes, cycloaliphatics, diesters, polyol esters, polyglycols, phosphate esters, silicones, silicate esters, or halogenated fluids. These fluids are discussed.
Most fluids require additives which act as pour‐point depressants, viscosity index improvers, defoamers, antioxidants, corrosion and rust inhibitors, and/or anti‐wear compounds. Hydraulic fluids basically serve as lubricants to the hydraulic system utilized. Industries employing hydraulic systems include transportation, manufacturing, mining, metal foundries, agriculture, and timber.
Hydrogen‐Ion Activity
Authors: Durst Richard A. , Bates Roger G. 
Published: July 2004

Abstract
Hydrogen ions are involved in a wide variety of chemical and biochemical reactions, the equilibria and kinetics of which are directly affected by the activity of these ions. This activity, expressed in terms of pH, is therefore of fundamental importance in many areas of science and technology; the determination of pH is one of the most widely performed analytical measurements, ranging in application from research and clinical laboratories to monitoring industrial processes.
Of the two methods for measuring pH, electrometric and chemical indicator (optical), the most common is based on the pH glass electrode used in combination with a reference electrode and pH meter. The indicator method, using pH‐sensitive dyes, can be combined with optical readout devices, such as fiber optics and photometers, or simply by visual color comparison. The pH scale is defined by a series of reference buffer solutions which are used to calibrate the pH measurement system. Although pH measurements are among the most specific with respect to possible interferences, there are a number of potential sources of error that can affect the accuracy of the measurements. These errors, which include fouling of the electrodes, flow variations, suspended matter, temperature variation, and dehydration of the glass membrane in nonaqueous media, are discussed.
Hydroquinone, Resorcinol, and Catechol
Authors: KRUMENACKER Léon , Costantini Michel , Pontal P. , Sentenac J. 
Published: July 2004

AbstractWorldwide manufacturing capacities of hydroquinone, resorcinol, and catechol are 50,000, 30,000, and 25,000 t/y, respectively. Selective processes leading to hydroquinone are achieved by the oxidation of aniline using manganese dioxide or the hydroperoxidation ofpara‐diisopropylbenzene. Selective resorcinol synthesis use alkali fusion of them‐benzenedisulfonic acid and the hydroperoxidation ofm‐diisopropylbenzene. Coproduction of hydroquinone and catechol is based on phenol hydroxylation by hydrogen peroxide. Much research has been devoted to the hydroxylation of phenol by hydrogen peroxide, in order to try to better master the ratio hydroquinone–catechol. In homogeneous catalysis, it has been found that it is possible to favor the formation of hydroquinone using benzaldehydes or benzophenones in conjunction with a strong acid. In the field of heterogeneous catalysis, the discovery of titanium silicalite (a synthetic molecular sieve) allowed phenol conversion up to 20%. In this case, solvent effects can favor the formation of hydroquinone. Numerous syntheses of hydroquinone, resorcinol, and catechol derivatives have been described.
Hydrocarbon Resins
Authors: Lowery R. Derric 
Published: July 2004

AbstractHydrocarbon resins are low molecular weight thermoplastic polymers synthesized via the polymerization of coal‐tar fractions, cracked petroleum distillates, terpenes, or pure olefinic monomers. In general, these polymers may be categorized as coumarone–indene, petroleum, or polyterpene resins. Coumarone–indene resins are synthesized from aromatic monomers obtained from the coking of coal. Petroleum distillates, such as piperylenes and styrene, are obtained from the vapor‐phase cracking of light to heavy petroleum naphthas and are used for the production of petroleum resins. Petroleum resins may be grouped into C‐5 aliphatic, C‐5–C‐9 aromatic modified aliphatic, cycloaliphatic diene (dicyclopentadiene), and C‐9 aromatic resins. Polyterpenes are produced from monoterpenic monomers such as limonene and β‐pinene, which are obtained from the citrus and wood industries, respectively. Most coumarone–indene, petroleum, and polyterpene resins are produced by carbocationic polymerization using Lewis acid catalysis. Cycloaliphatic diene‐based resins are typically produced via thermal polymerization techniques. The hydrogenation of hydrocarbon resins is typically accomplished using supported monometallic and bimetallic catalyst systems based on the Group VI and VIII transition elements. Uses and applications for hydrocarbon resins include adhesives, sealants, inks, paints, varnishes, plastics, and oil field applications. They are rarely used alone.
Hydroxybenzaldehydes
Authors: Maliverney Christian , Mulhauser Michel 
Published: July 2004

AbstractAmong the hydroxybenzaldehydes, only mono‐, di‐ and trihydroxybenzaldehydes are known. Salicylaldehyde (2‐hydroxybenzaldehyde) and 4‐hydroxybenzaldehyde represent more than 99% of the hydroxybenzaldehydes' market. The physical and chemical properties of hydroxybenzaldehydes are described. 2‐Hydroxy and 4‐hydroxybenzaldehydes react in a similar manner as phenol toward electrophiles. The aldehyde function can be reduced or oxidized to form a variety of compounds depending on the reagents and conditions used. Hydroxybenzaldehydes undergo the normal reactions of aromatic aldehydes.Most industrial methods for the manufacture of hydroxybenzaldehydes are based on phenol, but other routes exist, starting from hydroxybenzoic acids, by reduction, or from cresols, by oxidation. Bothp‐hydroxybenzaldehyde and salicylaldehyde have a low to moderate acute oral toxicity, but salicylaldehyde is, in addition, corrosive toward skin and appreciably irritating to the eyes.The hydroxybenzaldehydes are used primarily as chemical intermediates to a variety of products. The largest single use of salicylaldehyde is in the manufacture of coumarin. Both are used as intermediates in the synthesis of agrochemicals, pharmaceuticals, fragrances, and in electroplating. Condensation products of salicylaldehyde and diamines have important chelation properties, and have wide use in the stabilization of petroleum products, and in chemical processing, especially as oxidation catalysts. These and other applications to polymer chemistry are described.
Hydrazine and Its Derivatives
Authors: Schiessl Henry W. 
Published: July 2004

AbstractHydrazine (diamide), N2H4, a colorless liquid having an ammoniacal odor, is the simplest diamine and unique in its class because of the N—N bond.Hydrazine and its simple methyl and dimethyl derivatives have endothermic heats of formation and high heats of combustion. Hence these compounds are used as rocket fuels. Other derivatives are used as gas generators and explosives. Hydrazine, a base slightly weaker than ammonia, forms a series of useful salts. As a strong reducing agent, hydrazine is used for corrosion control in boilers and hot‐water heating systems; also for metal plating, reduction of noble‐metal catalysts, and hydrogenation of unsaturated bonds in organic compounds. Hydrazine is also an oxidizing agent under suitable conditions. Having two active nucleophilic nitrogens and four replaceable hydrogens, hydrazine is the starting material for many derivatives, among them foaming agents for plastics, antioxidants, polymers, polymer cross‐linkers and chain‐extenders, as well as fungicides, herbicides, plant‐growth regulators, and pharmaceuticals. Hydrazine is also a good ligand; numerous complexes have been studied. Many heterocyclics are based on hydrazine, where the rings contain from one to four nitrogen atoms as well as other heteroatoms.The many advantageous properties of hydrazine assure continued‐commercial utility. Hydrazine is available in anhydrous form as well as aqueous solutions, typically 35, 51.2, 54.4, and 64 wt % N2H4(54.7, 80, 85, and 100% hydrazine hydrate).The commercially feasible processes involve partial oxidation of ammonia (or urea) using hypochlorite or hydrogen peroxide. Most hydrazine is produced by some variation of the Raschig process, which is based on the oxidation of ammonia using alkaline hypochlorite.Hydrazine is toxic and readily absorbed by oral, dermal, or inhalation routes of exposure.
Hydroboration
Authors: Zaidlewicz Marek 
Published: July 2004

AbstractThe hydroboration reaction and transformations of its organoborane products are described. The mechanism and the chemo‐, regio‐, and stereoselectivity of the hydroboration reaction are presented, as well as the synthesis and characteristics of the most common hydroborating agents. Transformations of organoboranes may involve carbon‐hetero atom bond formation and lead to stereoselective synthesis of organic halides, amines, aziridines, sulfur, selenium, and mercury compounds. Hydroboration‐protonolysis is a nonocatalytic method of cis‐hydrogenation of multiple bonds. Hydroboration‐oxidation is a standard method for cis‐anti‐Markovnikov hydroxylation of multiple bonds.Carbon‐carbon bond formation can be accomplished by transformation of organoboranes through coupling of groups attached to boron, cross‐coupling of organoboranes with organic halides, organoborate rearrangements providing access to alkynes, (E)‐ and (Z)‐alkenes, (E,E)‐, (E,Z)‐, (Z,Z)‐dienes, and enynes. Single‐carbon insertion reactions include carbonylation, cyanidation, and the DCME and related reactions. Other reactions include α‐ and β‐alkylation of carbonyl compounds, the addition of alkynyl, alkenyl, and allylic boranes to aldehydes, leading to proparylic alcohols and stereodefined allylic and homoallylic alcohols, boron‐stabilized carbanions, the boron Wittig reaction, and concerted reactions of allylic and vinylic boranes. Contrathermodynamic isomerization of olefins is discussed. The synthesis of boron‐containing polymers and of isotopically labeled compounds is covered. Asymmetric synthesis via chiral organoboranes is covered in detail.
Hypnotics, Sedatives, Anticonvulsants, and Anxiolytics
Authors: Williams Michael , Holladay Mark W. 
Published: July 2004

AbstractCompounds that are clinically used as hypnotics, sedatives, anxiolytics, and anticonvulsants share a spectrum of related activities that may reflect a common molecular substrate within the brain. The alcohols, benzodiazepines, and barbiturates represent the principal classes of compounds reviewed. Whereas the mode of action of a number of hypnotics, sedatives, and anxiolytics is known, many agents used as anticonvulsant agents act by unknown mechanisms and as a result have considerable side effect liabilities. Newer agents including γ‐aminobutyric acid (GABA) modulators, glutamate andN‐methyl‐D‐aspartate acid (NMDA)‐receptor antagonists, nonbenzodiazepine ligands for the central benzodiazepine (BZ)receptor, and a variety of miscellaneous agents including CCK‐A receptor antagonists (CI‐988) and 5HT receptor modulators are also discussed.
Immunotherapeutic Agents
Authors: Wong Stewart 
Published: July 2004

AbstractImmunotherapeutic agents are used in treatment of primary immunodeficiencies as well as those immune system aberrations resulting from other diseases. A number of natural and synthetic agents have been discovered that can modulate components of the immune system. Furthermore, cytokines, such as interleukins, and immune cells having specific markers, such as antibodies, continue to be defined, leading to a complex although incomplete picture of immune responses. The immune system and its responses are discussed.Immunomodulators that play a role in the treatment of acquired immune deficiency syndrome as well as those used in therapy for rheumatoid arthritis, an autoimmune dysfunction, are described. Immunosuppressants used in anticancer therapy and organ transplants are presented.
Lead Compounds, Industrial Toxicology
Authors: DeVito Stephen C. , Breen Joseph 
Published: July 2004

AbstractLead is toxic to the kidney, cardiovascular system, developing red blood cells, peripheral and central nervous systems, testes, and fetus. Exposure to lead may occur from a variety of occupational and nonoccupational sources. Although in the United States regulatory and voluntary efforts have been quite successful in reducing worker and population exposure to lead, over two million workers remain at risk of workplace lead exposure. The concern for lead as a significant public health problem has increased as evidence has mounted regarding adverse health effects at successively lower levels of lead exposure, leading to downward revision of criteria for acceptable blood lead concentrations. Exposure, toxicity, and detection of lead in humans is discussed as is the treatment of lead poisoning.
Water, Industrial Water Treatment
Authors: Robinson James 
Published: July 2004

AbstractAbundant supplies of fresh water are essential to the development of industry. Enormous quantities are required for the cooling of products and equipment, for process needs, for boiler feed, and for sanitary and potable water supply. This article gives details on the various impurities found in water and how the water is treated to make it acceptable for industrial use. Clarification, precipitation, settling, filtration, ion exchange, and membrane processes are all detailed. Particular attention is given to corrosion control in boilers. Condensate systems can be chemically treated to reduce metal corrosion, especially important in cooling systems. Types of corrosion, eg, pitting, galvanic corrosion, are discussed. Deposit accumulations in cooling systems, biofouling and microfouling organisms are also summarized.