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Algorithms for Chemical Computations ACS Symposium Series No. 4 6 Ralph E. Christoffersen, Editor The University of Kansas A symposium sponsored by the Division of Computers in Chemistry of the American Chemical Society. This multidisciplinary collection of state-of-the-art papers assesses significant developments in algorithms for several important areas of chemistry and pinpoints places where currently available algorithms are inadequate. Leading experts not only evaluate the |tremendous opportunities for progress in chemical research that algorithms provide but also analyze the substantial difficulties that algorithms may present. Topics covered include those of particular interest to scientists doing 'significant amounts of computing in Ithe fields of quantum chemistry. Iscattering, computer handling of " :hemical information, and solid state heory. CONTENTS Graph Algorithms in Chemical Computation · Algorithm Design in Computational Quantum Chemistry · Rational Selection of Algorithms for| Molecular Scattering Calculations · Molecular Dynamics and Transition State Theory · Newer1 Computing Techniques for Molecular Structure Studies by X-ray Crystallography · Algorithms in the Computer Handling of Chemical Information
Model SF-330 spectrofluorometer, designed for operational simplicity and user convenience, is intended for food processing, drug manufacturing, biological, and chemical laboratory applications that require a moderately priced sensitive instrument for analysis of trace concentrations of organic and inorganic chemicals. Features include two photomultiplier detectors, a 150-W xenon lamp source, two concave grating monochromators, selectable spectral bandwidth combinations, scan speeds of 25 or 50 nm/min, and digital readout. $5795. Varian Instrument Div. 406
Dual-Wavelength Detector System D-137 is designed to be added to the Durrum-Gibson stopped-flow mixing chamber. It employs split-beam dual-detection optics to measure fast reactions at t w o wavelengths simultaneously. The t w o signals are then processed by solid state electronics to provide the ratio and difference of the t w o signals. By selecting appropriate wavelengths, small absorbance changes of fast reactions can be measured in turbid solutions where single-wavelength measurements are hampered by effects of scattered light. Durrum Instrument Corp. 418
151 p a g e s ( 1 9 7 7 ) C l o t h b o u n d $ 1 2 . 7 5 L C 7 7 - 5 0 3 0 ISBN 0 - 8 4 1 2 - 0 3 7 1 - 7 SIS/American· Chemical Society 1155 16th St., N.W./Wash., DC. 20036 Please send copies of SS 46 Algorithms for Chemical Computations at $12.75 per copy D Check enclosed for $ . • Bill me. Postpaid in U.S. and Canada, plus 40 cents elsewhere. Name Address City
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Carbon Analyzers These carbon analyzers use a new c o u lometric carbon dioxide titrator t o provide high accuracy in a wide variety of carbon analyses including mineral carbon, total carbon, and organic carbon in water, oils, and solids. Carbon levels from sub ppm t o 1 0 0 % can be determined. The coulometer can also be used for other high-accuracy CO2 measuring applications. Coulometrics Inc. 419
914 A · ANALYTICAL CHEMISTRY, VOL. 49, NO. 11, SEPTEMBER 1977
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An interface to combine liquid chromatograph and mass spectrometer systems permits mass spectral analysis of those chemicals difficult to identify with a GC/MS. Among its features, the interface allows free choice of electron impact or chemical ionization and does not interfere with GC/MS or solid probe operation. It provides high sensitivity LC detection, high sample yield, and high chromatographic integrity. It is particularly useful in mass spectral analysis of mycotoxins, polycylic aromatic compounds, pesticides, steroids, triglycerides, coumarins, and many drug metabolites, and will have wide applications in pharmaceutical and biomedical research, and in petroleum, energy, pollution, and pesticide studies. The interface can be added to any Finnigan mass spectrometer with a differential pumping system. It can be installed on a new mass spectrometer or retrofitted to an existing system. Finnigan Corp. 403
