Development and use

The investigation of molecular structures and of their properties is one of the most fascinating topics in chemistry. Chemistry has a language of its own for molecular structures which has been developed from the first alchemy experiments to modem times. With the improvement of computational methods for chemical information processing, several descriptors for the handling of molecular information have been developed and used in a wide range of applications. 

Guner O F (Editor) 2000. Pharmacophore Perception, Development, and Use in Drug Design. International University Line Biotechnology Series, 2. 

The three major commercial Hcensors of xylenes isomerization processes are Engelhard, UOP, and Mobil. Several other companies have developed and used their own catalysts. These companies include Mitsubishi Gas—Chemical, Toray, ICI, Amoco, and Shell. AH of these processes are discussed herein. 

G. M. Reistad, paper presented at the Proceedings of the 2nd UN Symposium on the Development and Use of Geothermal Resources, Vol. 1, Lawrence Berkeley Laboratory, San Erancisco, 1975, pp. 2155—2164 "Analysis of the Economic Potential of Solar Thermal Energy to Provide Industrial Process Heat," U.S. ERDN Contract, EY-No-C-02-2829, Intertechnology Corp., 1977. 

Most Type A processes might be classified as chemical processes, whereas most Type B processes are classified as mechanical processes. Representative examples of both types of processes foUow. Type B processes tend to be promoted by organizations that seU and service equipment for producing microcapsules. Most Type A processes are not promoted by equipment manufacturers, but are developed and used by organizations that produce microcapsules. 

The Foundation fora Fantastic Tomorrow, Farm Chemicals Anniversary, 1894—1994, Meister Publishing Co., Willoughby, Ohio, Sept. 1994. Over 60 general articles on topics related to development and use of agrochemicals. 

A number of cationic muds have been developed and used. These ate formulated around quaternary amines or positively charged polymers (108,109). The polymer in some iastances may be a cationic polyacrylamide. Poly(dimethylarnine-fi9-epichloiohydrin) is another material that has been used successfiiUy for drilling shale formations (110,111). Some of these additives may requite a salt such as sodium or potassium chloride for best results. 

The Platinum Group Metal Reviews is a specialized review series focusiag on the new developments and uses of PGMs. Each issue also provides a brief description of recent patents issued ia the field. 

This shift in emphasis by the mining iadustry has led to the development and use of a variety of improved techniques, in particular the commercial avadabihty of several metal specific extractants. These techniques are particularly useful in the separations and recycling of metals from metal sludges and metal salt solutions. 

Soiling of Antistatic Finishes. Soiling of fabrics having a tendency for accumulation of charges has been assumed to be an electrostatic phenomenon, and therefore it follows that if static is eliininated, soiling will be reduced. However, most antistatic agents have been developed and used for reasons other than the reduction of soiling. 

L. H. Bailey, development and Use of Baking Powder and Baking Chemicals, Circular No. 138, United States Department of Agriculture, May 1940. 

J. W. Hassler, Jictivated Carbon Chemical Publishing Co., Inc., New York, 1963, pp. 1—14. A comprehensive account of the development and use of activated carbon products to about 1960. 

E. Sagarki, ed.. Cosmetics—Science and Technolog Interscience Pubhshers, New York, 1957. A good history of the development and use of cosmetics. Includes some treatment of the colorants used. 

Theoretically based correlations (or semitheoretical extensions of them), rooted in thermodynamics or other fundamentals are ordinarily preferred. However, rigorous theoretical understanding of real systems is far from complete, and purely empirical correlations typically have strict limits on apphcabihty. Many correlations result from curve-fitting the desired parameter to an appropriate independent variable. Some fitting exercises are rooted in theory, eg, Antoine s equation for vapor pressure others can be described as being semitheoretical. These distinctions usually do not refer to adherence to the observations of natural systems, but rather to the agreement in form to mathematical models of idealized systems. The advent of readily available computers has revolutionized the development and use of correlation techniques (see Chemometrics Computer technology Dimensional analysis). 

Use of the peUetted converter, developed and used by General Motors starting in 1975, has declined since 1980. The advantage of the peUetted converter, which consists of a packed bed of small spherical beads about 3 mm in diameter, is that the pellets were less cosdy to manufacture than the monolithic honeycomb. Disadvantages were the peUetted converter had 2 to 3 times more weight and volume, took longer to heat up, and was more susceptible to attrition and loss of catalyst in use. The monolithic honeycomb can be mounted in any orientation, whereas the peUetted converter had to be downflow. AdditionaUy, the pressure drop of the monolithic honeycomb is one-half to one-quarter that of a similar function peUetted converter. 

The detection and analysis, including quantification, of cyanobacterial toxins are essential for monitoring their occurrence in natural and controlled waters used for agricultural purposes, potable supplies, recreation and aquaculture. Risk assessment of the cyanobacterial toxins for the protection of human and animal health, and fundamental research, are also dependent on efficient methods of detection and analysis. In this article we discuss the methods developed and used to detect and analyse cyanobacterial toxins in bloom and scum material, water and animal/clinical specimens, and the progress being made in the risk assessment of the toxins. 

For VOCs, control options are multiple. Source reduction or removal includes product substitution or reformulation. Particleboard or pressed w ood has been developed and used extensively in building materials for cabinet bases and subflooring and in furniture manufacturing for frames. If the product is not properly manufactured and cured prior to use as a building material, VOCs can outgas into the interior of the residence or building. Other sources of VOCs may be paints, cleaning solutions, fabrics, binders, and adhesives. Proper use of household products will lower volatile emissions. 

For the control of SOj, several systems are currently in development and use. Table 29-6 briefly explains these systems, which are presented in greater detail in Chapter 30. 

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