bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chromatography, Affinity
Authors: Hage David S. 
Published: July 2004

AbstractAffinity chromatography is a liquid chromatographic technique that uses a biologically related ligand for the specific retention or analysis of a given target. The general theory of affinity chromatography is considered and several examples are given of its typical applications. A number of items to consider in the use of this method are discussed, including the choice of ligand, support material, immobilization method, and solvent conditions. Several types of affinity chromatography are then examined in more detail. Particular attention is given to the techniques of bioaffinity chromatography, immunoaffinity chromatography, boronate affinity chromatography, immobilized metal‐ion affinity chromatography, dye‐ligand affinity chromatography, and biomimetic affinity chromatography. The use of affinity chromatography in the measurement of thermodynamic and kinetic constants is also considered, as well as the use of this method in sample pretreatment, purification, and analysis. Other items that are discussed include recent developments in the use of molecular imprints as affinity ligands and the use of biosensors for the study of biological interactions.
Controlled Release Technology, Agricultural
Authors: Wilkins Richard M. 
Published: July 2004

Abstract
Controlled release formulations (CRFs) are intended to improve the delivery of pesticides and related biologically active substances. The consequent improvement in efficiency reduces losses in use and has many benefits, such as reduction in exposure to both workers and the environment, particularly in minimizing leaching and evaporation. This article introduces the advantages of CRFs and provides a theoretical rationale for their use based on pseudo‐first‐order loss kinetics, which are typical for pesticide dissipation in the environment. Thus, the greater the loss rate, especially for pesticides of short duration, the greater the potential for improvement in delivery to the target pest. As a consequence of this principle, reduced levels of pesticide delivered efficiently can be as efficacious as higher amounts of conventional formulations.
The types of CRFs are introduced and are classified as physical, chemical, or biological. The kinetics of release from CRFs is central to their successful use, and the mathematical basics of this are described. The mechanisms of release vary according to the type of formulation, and these are covered for physical and chemical types. Common release characteristics include first order, diffusion (square root of time) based, and zero order (constant). Release kinetics are usually measured under controlled laboratory conditions, but field determination are preferable.
Design of properties of CRFs then follow. The main groups of the physical‐type formulations, such as reservoirs with release‐rate controlling membranes and without membrane and the monolith or matrix structures, are those based on microencapsulated liquid cores in sprayable concentrate formulations, and polymeric matrix methods that are often fabricated as granules. The polymers used and the approaches employed for designing these types of CRFs are introduced with emphasis on encapsulation methods, such as phase separation and interfacial polymerization. In addition, other formulation types are included, such as laminates, coated granules, microparticles, matrix granules (swellable and nonswellable), matrix devices for animal and public health protection, plastic films, and mulches. The article closes with the recent biological approach to formulation based on living or dead genetically modified microorganisms containing proteinaceous toxins.
Air Pollution
Authors: Allen David T. 
Published: July 2004

Abstract

Air pollution is the presence of any substance in the atmosphere at a concentration high enough to produce an undesirable effect on humans, animals, vegetation, or materials, or to significantly alter the natural balance of any ecosystem. Air pollutants can be solids, liquids, or gases, and can be produced by anhropogenic activities or natural sources. Current concerns regarding air pollutants are on the effects of long term, chronic exposures to nonlethal concentrations of air pollutants, especially the pollutants defined in the Clean Air Act. These pollutants include: sulfur dioxide (SO
2
); carbon monoxide (CO); nitrogen dioxide, (NO
2
); ozone (O
3
); suspended particluates; volatile organic compounds (VOCs); and lead, (Pb). The impacts of indoor air quality on health, the effects of air pollution on global and regional climate, and the effects of air pollutants on global and regional atmospheric cycles (eg, stratospheric ozone depletion and acid deposition) have also emerged as concerns.
Alkanolamines from Olefin Oxides and Ammonia
Authors: Edens Martha R. , Lochary J. Fred 
Published: July 2004

AbstractEthylene oxide, propylene oxide, or butylene oxide react with ammonia to produce alkanolamines. Ethanolamines, NH3‐n(C2H4OH)n(C2HOH)n(\documentclass{article}\pagestyle{empty}\begin{document}${n=1,2,3}$\end{document}, mono‐, di‐, and tri‐), are derived from the reaction of ammonia with ethylene oxide. Isopropanolamines, NH3‐n(CH2CHOHCH3)n(mono‐, di‐, and tri‐), result from the reaction of ammonia with propylene oxide. Secondary butanolamines, NH3‐n(CH2CHOHCH2CH3)n(mono‐, di‐, and tri‐), are the result of the reaction of ammonia with butylene oxide. Mixed alkanolamines can be produced from a mixture of oxides reacting with ammonia. Ethanolamines have been commercially available for over 50 years and isopropanolamines, for over 40 years.sec‐Butanolamines have been prepared in research quantities, but are not available commercially. A variety of substituted alkanolamines are also available commercially, but have not reached the volume popularity of the ethanolamines and isopropanolamines. The freezing points of alkanolamines are moderately high. The ethanolamines are colorless liquids at or near room temperature. Alkanolamines are bifunctional molecules because of the alcohol and the amine functional groups in the same compound. This allows them to react in a wide variety of ways. Consumption of ethanolamines in the United States in chemical processing intermediates (captive use for ethyleneamine and surfactant applications) has increased significantly since the 1960s. Alkanolamines generally have low acute oral toxicity, but swallowing substantial quantities could have serious toxic effects. Exposure of the eye to undiluted alkanolamines can cause serious injury. Monoethanolamine and monoisopropanolamine are skin irritants, capable of producing serious injury in concentrations of 10% or higher. Alkanolamines and their derivatives are used in a wide variety of household and industrial applications. The amides are useful as foam stabilizers and aid cleaning in laundry detergents, dishwashing liquids, etc. Reaction of alkanolamines with a fatty acid at room temperature produces neutral alkanolamine soaps, found in cosmetics, polishes, household cleaners, and pharmaceuticals. Alkanolamine salts add to the surfactants line used in detergents, cosmetics, textiles, polishes, agricultural sprays, household cleaners, and metalworking compounds. Salts of alkanolamines and inorganic acids are useful chemical intermediates, and are used in corrosion inhibitors and antistatic agents, among other products.
Alkoxides, Metal
Authors: Horn M. , Horns U. 
Published: July 2004

AbstractMetal alkoxides are compounds in which a metal is attached to one or more alkyl groups by an oxygen atom. Alkoxides are derived from alcohols by the replacement of the hydroxyl hydrogen by metal. The metal alkoxides exhibit great differences in physical properties. Many metal alkoxides are soluble in the corresponding alcohols, but magnesium alkoxides are practically insoluble. The most outstanding property of the metal alkoxides is the ease of hydrolysis, used for sol–gel applications. Metal alkoxides catalyze the Tishchenko condensation of aldehydes, the transesterification of carboxylic esters, and other enolization and condensation reactions. Commercial alkoxides include alkali metal alkoxides (sodium methylate, sodium ethylate, sodiumtert‐butylate, sodiumtert‐amylate, potassium methylate, potassium ethylate, and potassiumtert‐butylate), alkaline‐earth metal alkoxides (magnesium methylate, magnesium ethylate, and calcium methylate and ethylate), aluminum alkoxides (aluminum isopropylate and aluminumsec‐butylate), transition‐metal alkoxides (titanium alkoxides, zirconium alkoxides, and vanadium alkoxides), and antimony trialkoxides. Metal alkoxides are strongly caustic requiring the use of protective glasses and gloves. Metal alkoxides are mainly used as catalysts (in Ziegler‐Natta polymerization, transesterifications, and condensations); in coatings for plastics, textiles, glass, and metals; in additives for adhesives and paints; for sol–gel applications; for synthesis of minerals capable of safely enclosing radioactive nuclear waste; and for the cross‐linking or hardening of natural and synthetic materials. Alkali metal alkoxides find their principal use in organic synthesis where they act as strong bases.
Allyl Chloride
Authors: Kneupper Chris , Saathoff Lester 
Published: July 2004

AbstractA history of allyl chloride production and alternative technologies is presented. The properties needed for use of this material are given and common reactions and reaction products are discussed. Manufacture and processing of allyl chloride is covered including discussion of the high temperature propylene chlorination reaction mechanism, significant reaction by‐products, reaction conditions, industrial reactor design, product recovery through fractional distillation, and materials of construction. Techniques for maintenance of product integrity during storage and shipment are discussed, and transport equipment to maximize safety and minimize potential environmental impact is mentioned. Current production facilities for allyl chloride are listed. Most production is used for captive use as raw material for epichlorohydrin production. Sales specifications, statistical quality control parameters and analytical methods are briefly covered. Health hazards, exposure limits, personal protective equipment, and emergency response information are given. Current commercial products manufactured from allyl chloride are discussed.
Allyl Alcohol and Monoallyl Derivatives
Authors: Nagato Nobuyuki 
Published: July 2004

AbstractThe technology of introducing a new functional group to the double bond of allyl alcohol was developed in the mid‐1980s. Allyl alcohol is accordingly used as an intermediate compound for synthesizing raw materials such as epichlorohydrin and 1,4‐butanediol, and this development is bringing about expansion of the range of uses of allyl alcohol. Allyl alcohol is a colorless liquid having a pungent odor; its vapor may cause severe irritation and injury to eyes, nose, throat, and lungs. It is also corrosive. Allyl alcohol is freely miscible with water and miscible with many polar organic solvents and aromatic hydrocarbons. It forms an azeotropic mixture with water and a ternary azeotropic mixture with water and organic solvents. Hydroformylation of allyl alcohol is a synthetic route for producing 1,4‐butanediol, a raw material for poly(butylene terephthalate), an engineering plastic. The CC double bond of allyl alcohol undergoes epoxidation by peroxide, yielding glycidol, applied in manufacturing glycidol as an intermediate for industrial production of glycerol. There are two processes for industrial production of allyl alcohol being used industrially at present: isomerization of propylene oxide, and a new process developed by Showa Denko K. K. The monoallyl derivative allyl chloride (AC) is a transparent, mobile, and irritative liquid produced by chlorination of propylene at high temperature. It is used mostly as an intermediate compound for producing epichlorohydrin. Allyl acetate is produced mostly for manufacturing allyl alcohol. Allyl methacrylate (AMA) is used mostly as a raw material for silane coupling agents. Allyl glycidyl ether is used mainly as a raw material for silane coupling agents and epichlorohydrin rubber. Dimethylallylamine is used in the production of insecticides and pesticides. Most allyl compounds are toxic and many are irritants. Precautions should be taken at all times to ensure safe handling.
Aluminum Sulfate and Alums
Authors: Darragh K. V. , Ertell C. A. 
Published: July 2004

AbstractAluminum sulfate octadecahydrate,\documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document} $ {{\rm{Al}}{_{2}}{(}{\rm{SO}}{_{4}}{)}_{3}{\rm{{\cdot{}}}}18{\rm{H}}{_{2}}{\rm{O}}} $ \end{document}, and its aqueous solutions are used primarily in the paper industry for sizing and as a flocculating agent in water and wastewater treatment. This material is often called papermakers' alum or alum and is sometimes referred to as cake alum or patent alum. The solid commercial hydrate also called dry alum, ground or lump. Anhydrous aluminum sulfate, Al2(SO4)3, is a specialty item used in food applications. Over 50 acidic, basic, and neutral aluminum sulfate hydrates have been reported. Commercial dry alum is likely not a single crystalline hydrate, but rather it contains significant amounts of amorphous material. In the United States, aluminum sulfate is usually produced by the reaction of bauxite or clay with sulfuric acid. Unfortunately, the term alum is now used for several different materials. Papermakers' alum or simply alum refers to commercial aluminum sulfate. Common alum or ordinary alum usually refers to potash alum which can be written in the form\documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document} $ {{\rm{K}}{_{2}}{\rm{SO}}_{4}{\rm{{\cdot{}}}}{\rm{Al}}_{2}{(}{\rm{SO}}_{4}{)}_{3}{\rm{{\cdot{}}}}24{\rm{H}}{_{2}}{\rm{O}}} $ \end{document}, or it can refer to ammonium alum, ammonium aluminum sulfate. The term is also applied to a whole series of crystallized double sulfates having the same crystal structure as the common alums. Some examples of alums are cesium alum,\documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document} $ {{\rm{CsAl}}{(}{\rm{SO}}{_{4}}{)}_{2}{\rm{{\cdot{}}}}12{\rm{H}}{_{2}}{\rm{O}}} $ \end{document}; iron alum,\documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document} $ {{\rm{KFe}}{(}{\rm{SO}}{_{4}}{)}_{2}{\rm{{\cdot{}}}}12{\rm{H}}{_{2}}{\rm{O}}} $ \end{document}; chrome alum,\documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document} $ {{\rm{KCr}}{(}{\rm{SO}}{_{4}}{)}_{2}{\rm{{\cdot{}}}}12{\rm{H}}{_{2}}{\rm{O}}>} $ \end{document}; and chromoselenic alum\documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document} $ {{\rm{KCr}}{(}{\rm{SeO}}{_{4}}{)}_{2}{\rm{{\cdot{}}}}12{\rm{H}}{_{2}}{\rm{O}}} $ \end{document}. In industrial practice it is generally the aluminum content of alums that is important. Because aluminum sulfate is widely available, other alums are more in the nature of specialty items.
Aluminates
Authors: Keller Robert J. , Len Joseph J. 
Published: July 2004

AbstractAmong industrial users of sodium aluminate are producers of paper, paint pigments, silica, alumina or alumina‐based catalysts, dishwasher detergents, molecular sieves, concrete, antacids, and others. Sodium aluminate is used in removal of phosphates from municipal and industrial waste waters and for clarification of industrial process and potable water. Commercial sodium aluminate products are available as liquids, and to a lesser degree, in solid form. The formula of anhydrous sodium aluminate is variously given as NaAlO2(aluminum sodium oxide),\documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}${{\rm{Na}}{_{2}}{\rm{O}}{\rm{{\cdot{}}}}{\rm{Al}}{_{2}}{\rm{O}}{_{3}}}$\end{document}, or Na2Al2O4. Commercial sodium aluminates are not accurately represented by these formulas because the products contain more than the stoichiometric amount of sodium oxide, Na2O. The amount of excess caustic in commercial products is indicated by ratios of Na2O/Al2O3. Commercial quantities of sodium aluminate are made from hydrated alumina, in the form of aluminum hydroxy oxide, AlO(OH), or aluminum hydroxide, Al(OH)3, a product of the Bayer process which is used to refine bauxite, the principal aluminum ore. In addition to treatment of industrial and municipal water supplies, sodium aluminate is used in large quantities in papermaking where it improves sizing, filler retention, and pitch deposition. Sodium aluminate is also widely used in the preparation of alumina‐based catalysts.
Aluminum Carboxylates
Authors: McKenna Arthur L. 
Published: July 2004

AbstractAluminum salts of carboxylic acids, aluminum carboxylates, may occur as aluminum tricarboxylates (normal aluminum carboxylates), Al(OOCR)3; monohydroxy (monobasic) aluminum dicarboxylates, (RCOO)2Al(OH); and dihydroxy (dibasic) aluminum monocarboxylates, RCOOAl(OH)2. Aluminum carboxylates are used in three general areas: textiles, gelling, and pharmaceuticals. Derivatives of low molecular weight carboxylic acids have been mainly associated with textile applications; those of fatty carboxylic acids are associated with gelling salts; and more complex carboxylates find applications in pharmaceuticals. Commercial products can be combinations of mono‐, di‐, and tricarboxylates and not just the individual species. Some aluminum carboxylates of commercial interest are monobasic aluminum acetate, C4H7AlO5; dihydroxyaluminum aminoacetate, C2H6AlNO4; aluminum monostearate, C18H37AlO4; aluminum distearate, C36H71AlO5; and aluminum tristearate, C54H108AlO6.
Amides, Fatty Acid
Authors: Johansson Ingegärd 
Published: July 2004

AbstractFatty acid amides, which contain a saturated or unsaturated alkyl chain derived from a fatty acid, can be divided into three categories. The first is primary monoamides in which R is a fatty alkyl or alkenyl chain of C5C23and R′ = R″ = H. The second is substituted monoamides, including secondary, tertiary, and alkanolamides in which R is a fatty alkyl or alkenyl chain of C5C23; R′ and R″ may be a hydrogen, fatty alkyl, aryl, or alkylene oxide condensation groups with at least one alkyl, aryl, or alkylene oxide group. The third category is bisamides where R groups are fatty alkyl or alkenyl chains. R′ and R″ may be hydrogen, fatty alkyl, aryl, or alkylene oxide condensation groups. Primary and secondary amides show strong hydrogen bonding that account for their high melting points and low solubilities in most solvents. With tertiary amides (disubstituted amides), hydrogen bonding is not possible, as exhibited by their increased solubility and lower melting points. Many fatty acid amides are essentially insoluble in water. Amides have a strong tendency to reduce friction on various surfaces by forming a layer on surfaces. This coating action may be attributed to their hydrophobic character and strong hydrogen bonding. Primary, secondary, and bisamides are widely used as lubricating or slip agents and alkanolamides. Their ethoxylated counterparts are commonly used as surfactants in personal care and detergent applications. Amides in general are stable to elevated processing temperatures, air oxidation, and dilute acids and bases. The dehydration of amides that produces nitriles is of great commercial value. The most widely used synthetic route for primary amides is the reaction of a fatty acid with anhydrous ammonia. Alkanol amides are made from triglycerides or fatty acid methyl esters reacted with monoethanolamine or diethanolamine that then can be ethoxylated with ethylene oxide under basic catalyses. Common products are stearamide, cocamide, ethylene bis(stearamide), cocamide, DEA or MEA, cocamidopropyl dimethyl amine, and cocamide monoethanolamine ethoxylate.
Amine Oxides
Authors: Maisonneuve B. 
Published: July 2004

AbstractAmine oxides, known asN‐oxides of tertiary amines, are classified as aromatic or aliphatic, depending on whether the nitrogen is part of an aromatic ring system or not. This structural difference accounts for the difference in chemical and physical properties between the two types. The higher aliphatic amine oxides are commercially important because of their surfactant properties and are used extensively in detergents. Amine oxides that have surface‐acting properties can be further categorized as nonionic surfactants; however, because under acidic conditions they show cationic properties, they have also been called cationic surfactants. Most amine oxides undergo thermal decomposition between 90 and 200°C. Aromatic amine oxides, have some pharmaceutical importance, do not demonstrate surface‐acting properties and are more resistant than aliphatic amine oxides to reduction. Linear alpha‐olefins are the source of the largest volume of aliphatic amine oxides. Fatty alcohols and fatty acids are also used to produce amine oxides. Amine oxides used in industry are prepared by oxidation of tertiary amines with hydrogen peroxide solution. Amine oxides are used in the detergent, organic synthesis, textile, and pharmaceutical industries. Aliphatic amine oxides range from practically nontoxic to slightly toxic. Among the aromatics, 4‐nitroquinolineN‐oxide is a powerful carcinogen, producing malignant tumors on the skin of mice. 2‐Methyl, 2‐ethyl, and 6‐chloro derivatives of 4‐nitroquinoline oxide are also carcinogens.
Silica, Amorphous Silica
Authors: Waddell Walter H. , Evans Larry R. 
Published: July 2004

AbstractAmorphous silica, a three‐dimensional, inorganic polymeric silicon dioxide, SiO2, does not have a crystalline structure as defined by the absence of definitive lines in x‐ray diffraction measurements. Amorphous silica can be naturally occurring or synthetic, and either anhydrous or surface‐hydrated with silanol groups. Synthetic amorphous silica can be divided into microamorphous silica and vitreous silica (glass) made by fusing quartz at temperatures greater than approximately 1700°C. A discussion of microamorphous silica is presented, including colloidal silica, ie, sol or stable dispersion of discrete particles; silicas gelled or precipitated from solution; and pyrogenic and fused silica. Amorphous silica is characterized by chemical composition, physical properties, and characteristics of its particles, with exact analytical procedures depending on the type and application. Various methods to prepare and characterize each type of amorphous silica, commercial applications including principal global manufacturers, and health and safety issues are discussed.