Index Maine, University

The Society of the Plastics Industry main page information about plastics, environmental issues http //www.plasticsindustry. org/outreach/environment/index.htm University of Southern Mississippi, Dept, of Polymer Science, The Macrogalleria ... 

Isis Current Bibliography of the History of Science and its Cultural Influences. 1975-. Chicago University of Chicago Press. It is published as a supplement of the History of Science Society journal Isis. It indexes mainly books, articles in journals and symposia, dissertations, book chapters, and book reviews from all areas of the history of science. These data are being incorporated into the History of Science, Technology and Medicine database. It has a journal list and is divided into 24 subject sections. 

Typical methods are those of F. C. Zevnik and R. L. Buchanan [Chem. Eng. Progi , 59, 70-77 (Feb. 1963)] and J. H. Taylor Eng. 6-Proc. Econ., 2, 259-267, 1977). The former is mainly a graphical method of estimating the cost per functional unit (Cp) based on the capacity, the maximum pressure, the maximum temperature, and the materials of construction. The Taylor method requires the determination of the costliness index, which is dependent on the complexity of the process. A simpler method was suggested by S. R. Timms (M.Phil. thesis, Aston University, England, 1980) to give the battery hmits cost for gas phase processes only in U.S. dollars with a Marshall and Swift index of 1000. The simple equation is... 

The appearance of n as the index of jc in Eq. (3.28) needs to be Justified. Combustion in gas turbines usually involves substantial excess air and the molecular weight of the mixed products is little changed from that of the air supplied, since nitrogen is the main component gas for both air and products. Thus the mean gas constant (universal gas constant divided by mean molecular weight) is virtually unchanged by the combustion. It then follows that... 

Since the development of HPLC as a separation technique, considerable effort has been spent on the design and improvement of suitable detectors. The detector is perhaps the second-most important component of an HPLC system, after the column that performs the actual separation it would be pointless to perform any separation without some means of identifying the separated components. To this end, a number of analytical techniques have been employed to examine either samples taken from a fraction collector or the column effluent itself. Although many different physical principles have been examined for their potential as chromatography detectors, only four main types of detectors have obtained almost universal application, namely, ultraviolet (UV) absorbance, refractive index (RI), fluorescence, and conductivity detectors. Today, these detectors are used in about 80% of all separations. Newer varieties of detector such as the laser-induced fluorescence (LIE), electrochemical (EC), evaporative light scattering (ELS), and mass spectrometer (MS) detectors have been developed to meet the demands set by either specialized analyses or by miniaturization. 

Liquid chromatographs are equipped with a means to continuously monitor the column effluent and recognize the presence of solute. Only small sample sizes are used with most HPLC columns, so a detector must have high sensitivity. The type of detector that has the most universal application is the differential refiractometer. This device continuously monitors the refractive index difference between the mobile phase (pure solvent) and the mobile phase containing sample (column effluent). The sensitivity of this detector is on the order of 0.1 ju,g, which, compared to other detectors, is only moderately sensitive. The major advantage of the refractometer detector is its versatility its main limitation is that there must be at least 10 7 refractive index units between the mobile phase and sample. 

There are excellent HPLC systems available on the market today, yet there is one area of concern with this instrumentation, and this rests with the detection units. Certainly the most widely used detector system employs a low dead-volume micro-ultraviolet detector. This latter unit operates near 200 nm and detects mainly unsaturated linkages in phospholipids (or lipid) samples. Some contribution by carbonyl functions can be expected. This approach is an advantage when the sample under study contains olefinic groups, but will not detect those with saturated side (hydrocarbon) chains. An alternative detector is the refractive index monitor which is often called a universal detector, since it is based on the concept that the refractive index of the solvent changes when a solute is present. The drawback of the latter unit lies in its sensitivity, which is approximately 15- to 20-fold less than that of the ultraviolet monitor. 

Georgia (Mercer and University of Georgia) Restricted 5 http //www.rx.uga.edu/ main/home/ntpharmd/index.htm ... 

The Chemical Information Sources Wiki (http //cheminfo. informatics.indiana.edu/cicc/cis/index.php/Main Page) is a guide to the many sources of reference materials available for those with questions related to chemistry. The site includes information on primary, secondary, and tertiary pubheation sources, chemical information databases, physical property information, chemical patent searching, and molecular visualization tools and sites. The material is based on an undergraduate course offered for many years in the Indiana University Department of Chemistry by Gary Wiggins. 

Economics. No consideration of the literature would be complete without the economic study made by the Food Research Institute of Stanford University (66). The studies are mainly concerned with crops, markets, and economics, and comprise a monumental contribution to the literature of wheat. Some technical papers on wheat in the diet, wheat protein, starch and flour quality, bread staling, utilization of wheat germ, and physical tests of flour quality are included. An index to this series (62) consists of abstracts of the annual reviews and special studies, and a chronological list of the individual issues, and lists, by author and subject, of the special studies. 

The evaporative light-scattering detector (ELSD) is a near universal detector suitable for the determination of (mainly) neutral compounds that are less volatile than the mobile phase used for the separation [151,152]. Primary uses include the detection of compounds with a weak response to the UV detector, especially carbohydrates, lipids, surfactants, polymers and petroleum products. Its greater sensitivity and ease of use in gradient elution separations makes it preferable to the refractive index detector for these applications. The ELSD is compatible with most volatile solvents used for normal and... 

Refractive index detectors also have several applications in lipid analysis. They are "universal" detectors, but lack sensitivity, require isocratic elution conditions and are sensitive to minor fluctuations in temperature. Their main value is probably in small-scale preparative applications, say with 1-2 mg of a lipid extract. For example, a refractive index detector was utilized with a column (4.6 x 250 mm) of Ultrasil Si (5 micron silica gel) and isocratic elution with isooctane-tetrahydrofuran-formic acid (90 10 0.5 by volume) to separate most of the common simple lipid classes encountered in animal tissue extracts, such as those of liver [304]. Cholesterol esters, triacylglycerols and cholesterol were each resolved and gave symmetrical peaks. 

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