bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dental Materials
Authors: Tesk John A. , Antonucci Joseph M. , Carey Clifton M. , Eichmiller Fred C. , Kelly J. Robert , Rupp Nelson W. , Waterstrat Richard W. , Fraker Anna C. , Chow Lawrence C. , George Laurie A. , Schumacher Gary E. , Stansbury Jeffrey W. , Parry Edward E. 
Published: July 2004

AbstractDentistry is a healing science that involves a huge number and variety of different materials. Restoring diseased teeth and supporting tissues can require the use of ceramics, metals, polymers, inorganic cements, and waxes. These materials are often ties used in various combinations. The one key factor that sets dental materials apart from most other uses of materials is that the clinician is often responsible for the formulation or manufacture of the final material. Most dental materials used to directly restore teeth are delivered in a state were the operating dentist controls the final setting reaction. When fillings are prefabricated in a laboratory, the cements or adhesives used for placing these restorations are still under the control of the operating dentist. For this reason, the physical properties of these materials can only be determined by laboratory simulations and may not completely reflect the properties achieved in actual use. This article describes these materials and their most common uses in clinical dentistry and in dental laboratories.
Design of Experiments
Authors: Hahn Gerald J. , Patterson Angela N. 
Published: July 2004

AbstractThe statistical design of experiments is an essential ingredient of successful product development and improvement, and provides an efficient and scientific approach to obtaining meaningful information. In contrast to traditional “vary one‐factor‐at‐a‐time experimentation, variables are changed together, permitting evaluation of interactions. Standard texts give details about the construction of specific test plans, such as incomplete block, full and fractional factorial, and response surface designs, and the analysis of the resulting data. This article gives a brief overview. We focus on the fundamental elements of experimental design: defining the purpose and scope of the experiment, differentiating between alternative types of experimental variables, understanding the underlying environment and constraints, and conducting stage‐wise experimentation. Brief discussions dealing with the emerging topic of combinatorial chemistry, statistical analysis tools, multiple response variables, and some historical background are also provided. Two key features of the article are the description of commercial software for the design and analysis of experiments, and a detailed discussion, including recommendations, of texts on experimental design; both of these include comparative tabulations of technical features.
Dewatering
Authors: Morey Booker 
Published: July 2004

AbstractThe basic process of dewatering is the removal of residual liquid left in a filter, centrifuge, or other cake from a soid‐iquid separation step. Forces used for dewatering are compression, expression, and displacement. The mechanical and electrical methods of dewatering as well as the chemical and mechanical pretreatments of slurries to improve the final dewatering step are discussed. Many of the methods are useful for deliquoring in general and are not limited to water removal. Pretreatments enhance the separation of liquid from solid by lowering the viscosity of the liquid (raising temperature, adding another liquid), lowering surface tension (adding surfactants), increasing porosity or changing compressibility (coagulation, flocculation, pelletizing flocculation, oil agglomeration, pH change, hot or cold thermal treatment, biological conditioning, adding filter aids, magnetic agglomeration), or displacement of the residual moisture (with a gas or a different liquid or by extraction of the solid into a different liquid). Electrical processes can be used to increase the migration of water through a filter cake, to retard the movement of particles into a filter cake, or to be combined with an acoustical field to improve the removal of water from a filter cake.
Dialysis
Authors: Lysaght Michael J. , Baurmeister Ulrich 
Published: July 2004

Abstract

Dialysis is a membrane separation process in which permeating species diffuse across a selective barrier in response to a difference in concentration. Less efficient than other industrial membrane unit operations, dialysis finds appeal chiefly in those biotechnology and food processing applications requiring gentle, isothermal, nondenaturing operating conditions. The popularity of dialysis as general laboratory technique for the separation, concentration, and purification of macromolecules has waned. In contrast, microdialysis, a continuous technique for estimating solute concentration
in vivo
without blood sampling, is increasing in importance, especially in neuropharmacological protocols. By far the largest and most formidable application of dialysis is for the chronic intermittent extracorporeal therapy of end stage kidney disease. In 1992, over 60 million highly optimized disposable hemodializers were produced to support a population of over 400,000 patients with renal failure.
Diamines and Higher Amines, Aliphatic
Authors: Sridhar Srivasan , Carter Richard G. 
Published: July 2004

AbstractThe aliphatic diamine and higher amine family encompasses a wide range of multifunctional and multireactive compounds. The so‐called ethyleneamines family, which includes ethylenediamine and its homologues, the polyethylene polyamines, have found the broadest commercial application. Representative physical and chemical properties are given. Three main processes are used currently to produce the ethyleneamines: the reaction of ethylene dichloride with ammonia to produce the whole spectrum of ethyleneamine products; the reductive amination of monoethanolamine to produce the lighter ethyleneamines, mainly ethylenediamine; and the catalytic reaction of monoethanolamine with ethylenediamine to produce higher ethyleneamines. Worldwide capacity for ethyleneamines is about 295 t/yr. Typical specifications and test methods, storage and handling guidelines, and health and safety factors are discussed. This family of compounds finds use in a wide variety of applications by virtue of their unique combination of reactivity, basicity, and surface activity. With a few significant exceptions, they are used predominantly as intermediates in the production of functional products. Significant applications include fungicides, lubricant and fuel additives, epoxy curing agents, polyamide resins, paper resins, and chelates.
Amines, Aromatic, Diaminotoluenes
Authors: Toseland Bernard A. , Simpson Mark S. 
Published: July 2004

AbstractToluenediamine (diaminotoluene,m‐TDA) is an important industrial chemical intermediate; it is produced in the largest volume of any arylamine and is the lowest priced diamine. The principal use for TDA is in the manufacture of toluenediisocyanate (TDI), the predominant diisocyanate in the flexible foams and elastomers industries. Although all six possible toluenediamine isomers are made in the commercial synthesis, only two products are available commercially. The aromatic toluenediamines undergo typical amine reactions. The general chemistry is similar to that of the phenylenediamines or the cyclohexanediamines. Reactions of industrial importance involving commercial toluenediamines include phosgenation, ring alkylation, alkoxylation, and diazotization. Dinitrotoluenes can be catalytically hydrogenated to toluenediamines under a wide variety of temperatures, pressures, and solvents. Toluenediamine is classed as toxic. TDA is readily absorbed through the skin and this is the major route of human exposure.
Amines, Aromatic, Diarylamines
Authors: Layer Robert W. 
Published: July 2004

AbstractDiarylamines are compounds that have two aromatic groups and one hydrogen atom attached to nitrogen. Diphenylamine (DPA) orN‐phenylbenzenamine, is the most commercially significant diarylamine. It is manufactured by heating aniline by itself, or with phenol, and with an acid catalyst at high temperatures. It is used as a stabilizer for nitrocellulose propellants. When alkylated, diphenylamine finds its largest application as an antioxidant and stabilizer for oils, greases, polymers, and elastomers. Diarylamines that contain other functional groups, such as hydroxyl or amino, are useful dye intermediates, antiozonants, hair dyes, and color photography intermediates. Important reactions of diarylamines include C‐alkylation and oxidation. Diarylamines are manufactured by the self‐condensation of a primary aromatic amine in the presence of an acid, or the reaction of an arylamine with a phenol at high temperatures. Industrial poisoning by diphenylamine has been encountered and appears clinically as bladder symptoms, tachycardia, hypertension, and skin problems. There is no federal standard for permissible exposure limits in air, but the American Conference of Government Industrial Hygienists (1983/1984) has adopted a time‐weighted average value of 10 mg/m3and set a short‐term exposure limit of 20 mg/m3.N‐Nitrosodiphenylamine can act as a nitrosating agent for other amines. Diarylamines based on polycyclic aromatic amines also tend to be more harmful.
Diatomite
Authors: Engh Kenneth R. 
Published: July 2004

Abstract
Diatomite, also known as kieselguhr, or diatomaceous earth, is a naturally occurring, highly structured, fine hydrous silica powder made up of the remains of planktonic algae. Diatomite is used in many applications as the uniquely porous nature of each particle gives diatomite high surface area, low bulk density, high permeability, high water absorption, and low abrasion. Diatomite filter aids are used to prevent blinding of filter elements and are used to clarify liquids in brewing, water treatment, wine making, sugar refining, fruit juice production, and in industrial chemicals. Diatomite functional fillers are used in paints, rubber, plastics, pharmaceuticals, toothpastes, polishes, and chemicals where performance is improved by the unique properties of diatomite.
Dichlorine Monoxide, Hypochlorous Acid, and Hypochlorites
Authors: Wojtowicz John A. 
Published: July 2004

AbstractThe hydrolysis of chlorine gives rise to a pH‐dependent complex system involving no less than six equilibria in which the oxidizing power of the parent element is preserved in hypochlorous acid, chlorine monoxide, and hypochlorite ion. The physical and chemical aspects of this unique family of compounds, including organic and other nonmetal hypochlorites, are outlined, their preparation and manufacturing processes are surveyed, and important uses are cited. Corrosion problems and potential hazards in handling and use of these compounds are also discussed. Hypochlorous acid is the active biocidal agent when hypochlorites are employed in disinfection and sanitation. It is an intermediate in the manufacture of hypochlorites, chloramines, and chlorohydrins. A process for production of HOCl in concentrations as high as 60% has been developed. The commercially important hypochlorites are Ca(OCl)2, NaOCl solution, LiOCl, chlorinated trisodium phosphate, and to a lesser extent hemibasic Ca(OCl)2and bleaching powder. They are used primarily in sanitation and bleaching applications. The most important solid hypochlorite is Ca(OCl)2, which along with lithium hypochlorite is used mainly for swimming pool and spa sanitation. Several new processes for manufacture of Ca(OCl)2are described. Continued research interest involves use of hypochlorites for selective epoxidation, oxidation, and chlorination, and use of chlorine monoxide as a highly selective agent for aromatic ring and side‐chain chlorination.
Dietary Fiber
Authors: Lewis B. A. 
Published: July 2004

AbstractDietary fiber is a complex mixture of nondigestible polysaccharides and lignin, the exact composition depends on the plant or other food source, maturity, growing conditions, and processing. Plant cell wall polysaccharides are extensively fermented by the microbial enzymes in the lower digestive tract. The particle size and shape, density, crystallinity, water‐holding capacity, and the level and type of dietary fiber affect the rate of passage of the digests through the digestive tract. Dietary fiber itself and the microbial fermentation in the colon give rise to various beneficial physiological effects. Dietary sources of soluble and insoluble fiber and their properties and methods for analysis are summarized.
Dimer Acids
Authors: Breuer Thomas E. 
Published: July 2004

Abstract
Dimerization of unsaturated fatty acids occurs by self‐condensation, reaction with acrylic acid, or reaction with carbon monoxide. The physical properties of the resultant di‐(or poly‐) carboxylic acid species are listed for a few common cases. The reactions, catalysts, conditions, and equipment used for synthesis and manufacture are discussed. Analytical methods that may be used in characterization of these materials are covered with some evaluation of alternative methods. Since some use of these materials is made in food contact applications, a review of toxicity and safety and handling aspects is included. The uses of these materials are quite varied, although the majority of them involve reactive or nonreactive polyamides being made from them. Bibliographical references are included for those seeking more detail on the history, production, or use of these products.
Dimethylacetamide
Authors: Watts J. C. , Larson P. A. 
Published: July 2004

Abstract

Dimethylacetamide, DMAC, mol wt 87.12, CH
3
CON (CH
3
)
2
, is a colorless, high boiling polar solvent. DMAC is a good solvent for a wide range of organic and inorganic compounds. The polar nature of DMAC enables it to act as a combined solvent and reaction catalyst, often producing high yields in short time periods. The chemical reactions of DMAC are typical of those of disubstituted amides. Dimethylacetamide can be produced by the reaction of acetic acid and dimethylamine, or by the reaction of acetic anhydride and dimethylamine. DMAC is capable of producing systemic injury, principally cumulative damage to the liver and kidney, when repeatedly inhaled or absorbed through the skin. The uses of dimethylacetamide are very similar to those for dimethylformamide.

DMAC is used where higher temperatures are needed for solution of resins as deactivation of chemical reaction.
Fluorine Compounds, Organic, Direct Fluorination
Authors: Lagow Richard J. 
Published: July 2004

AbstractThe development, methodology, and applications of direct fluorination technology to produce organofluorine compounds and fluorocarbon polymers is discussed in detail, including historic difficulties with direct fluorination. Techniques such as use of metal fluorides as an alternative to direct fluorination and the use of hydrogen fluoride electrochemical cell methods to affect direct fluorination are covered. The thermochemistry and kinetic control of direct fluorination are discussed. Fluorocarbon materials such as polytetrafluoroethylene and polycarbon monofluoride and their excellent high temperature properties are described. The experimental techniques that have led to the successful control of direct fluorination are described as are modern direct fluorination methods now practiced on a commercial scale by 3M Co. and Exfluor Research Corp. Examples of important direct fluorination processes such as synthesis of simple and complex organic molecules, new fluorocarbon polymers from hydrocarbon polymers, new polymeric materials with inert surfaces produced by surface fluorination, and technology for blow‐molding polymeric objects during fluorination are discussed.
Dispersants
Authors: van den Haak Henk J. W. 
Published: July 2004

AbstractDispersants are compounds that are used to maintain particles suspended in a liquid medium, either water or an organic solvent. They can prevent or delay flocculation of the particles by providing repulsive forces, counteracting the van der Waals attraction. This attraction occurs through electrostatic or steric stabilization or through a combination of these mechanisms, electrosteric stabilization.Unlike classical dispersants, which are usually random polymers, modern dispersants consist of an anchoring section, which adheres to the particle surface, and a soluble section, which builds a protective shell around the particle. They can have different architectures: AB dispersants, AB‐diblock polymers, ABA‐ or ABC‐triblock polymers, and comb polymers. Syntheses of such architectures are discussed.Dispersants have some similarity, but also some clear differences, with other materials, like surfactants, chelants, precipitation inhibitors, and flocculants.Dispersants have numerous applications. They are used, among others, in cooling and heating water applications, in geothermal fluids, seawater distillation and reverse osmosis, in oilfield and mineral processing, in cements, asphalt, caulks, sealants and roof coatings, in detergents and cleaners, and in paints and printing inks.
Powders, Handling, Dispersion of Powders In Liquids
Authors: Nelson Ralph D. 
Published: July 2004

Abstract
This article explains the fundamental principles and practical aspects of the three steps in making a good dispersion: wetting the dry powder into the liquid, breaking up the wetted clumps, and preventing reagglomeration of the dispersed particles. It describes a variety of techniques for wetting powders into liquids of low, medium, and high viscosity, noting the design elements that provide effective operation. Simple equations illustrate how particle attractions and repulsions are related to basic physical forces and how the forces may be modified by changes in the chemical environment or by adsorption of dispersants. Several unusual methods of stabilizing dispersions are noted. Finally there is a brief section on evaluating the degree of dispersion, with reference to numerous standard methods, guidance for selecting a method appropriate to the need, and warnings of difficulties that limit the application of the methods.
Distillation, Azeotropic, and Extractive
Authors: Doherty Michael F. , Knapp Jeffrey P. 
Published: July 2004

AbstractMany industrial processes depend on efficient methods for separating azeotropic, close‐boiling, or other low relative volatility mixtures. Ordinary distillation is typically either uneconomical or impossible in these cases. However, by adding specially chosen separating agents, the separation can generally be accomplished. The principal distillation‐based techniques employed for separating such mixtures are discussed: extractive or homogeneous azeotropic distillation, where a completely miscible liquid separating agent is added to alter the relative volatilities; heterogeneous azeotropic distillation, where the agent, known as the entrainer, forms one or more azeotropes and causes immiscibility; distillation in the presence of ionic salts that alter the relative volatilities of the components; and pressure‐swing distillation, wherein some azeotropes can be circumvented using a series of columns operating at different pressures. Residue curve maps, material balance lines, and column sequences are given for several example systems. Methods for identifying feasible separating agents are also discussed.
Distillation
Authors: Fair James R. 
Published: July 2004

Abstract
Distillation is the most widely used industrial method for separating liquid mixtures into their constituents. In chemical plants and petroleum refineries, distillations are normally carried out in vertical columns containing devices for bringing the flowing liquid mixture into intimate contact with a flowing vapor mixture that is generated by partial vaporization of the liquid. This article covers the fundamental physical and mathematical relationships that are needed for the design of new distillation columns as well as the analysis of existing columns.
The article is divided into four main topics: vapor‐liquid equilibria; distillation processes; distillation columns, both plate and packed; and distillation as a separation method. Minor divisions include such special topics as steam distillation, molecular distillation, distillation literature sources, and economics. Sufficient information is given to enable the user to carry out preliminary designs of a variety of systems, and guidance is provided for cases where additional resources might be needed.
Diuretic Agents
Authors: Cervoni Peter , Chan Peter S. 
Published: July 2004

AbstractDiuretics are agents that increase urine output or flow. The effects of diuretic agents on electrolyte and water excretion in the kidney for the treatment of edema, congestive heart failure, ascites, and hypertension are reviewed. The structure and function of the kidney in the formation of urine are presented using the functional unit of the kidney, the nephron. The various sites where absorption, secretion, and the passive and active transport of water and electrolytes alter the composition of the glomerular filtrate from Bowman's capsule as it passes through the lumen of the nephron to the collecting ducts on its way to becoming urine are described. Diuretics are classified as low ceiling, high ceiling (loop), and potassium‐sparing diuretics, natriuretic peptides, atrial natriuretic peptides, atrial natriuretic peptide potentiators, osmotic diuretics, carbonic anhydrase inhibitors, methylxanthines, organomercurials, and aquaretics. The pharmacology, mechanisms or site of action in the nephron, and clinical effectiveness are discussed. Included is a discussion of the risk factors and side effects of diuretic agents.
Driers and Metallic Soaps
Authors: Landau Marvin 
Published: July 2004

Abstract
This article briefly outlines the evolution of metal soaps over the years from an art form to a reliable quality raw material. Methods of manufacture and the analytical tests utilized to ensure specificity of properties are described. Also included are tables indicating the volume of the various carboxylates manufactured and figures on the individual metals produced. A general description of the health and safety factors associated with these products is provided.
In application the specific metals and the attributes they provide are stated. Emphasis is placed on their use as driers for paint and printing inks as well as heat stabilizers and lubricants in plastics. Governmental legislation responding to environmental pressures has promoted the development of new technologies, yet metal soaps still remain an integral ingredient in coatings.
Drying
Authors: McCormick Paul Y. , Mujumdar Arun S. 
Published: July 2004

AbstractDrying is an operation in which volatile liquids are separated from solids, slurries, and solutions to yield solid products. Drying mechanisms and processes, including psychometry, heat‐ and mass‐transfer principles, and a description of liquid and vapor flow encountered during drying are discussed. In freeze drying (lyophilization), wet material is cooled to freeze the liquid and vaporization occurs by sublimation.Industrial dryers may be broadly classified according to the method of heat transfer as being either direct‐heat or indirect‐heat dryers. The types of dryers employed in the chemical industry, which may also be classified as batch or continuous, are described. Conventional, radiant, dielectric, and microwave heat sources are discussed as are emission control and energy usage of the various dryer types.