In this work, we present a new theory to treat multicomponent liquids based on quantum-chemically calculated clusters. The starting point is the binary quantum cluster equilibrium theory, which is able to treat binary systems. The theory provides one equation with two unknowns.
View Article and Find Full Text PDFWhile so far it has been possible to calculate vibrational spectra of mixtures at a particular composition, we present here a novel cluster approach for a fast and robust calculation of mole fraction dependent infrared and vibrational circular dichroism spectra at the example of acetonitrile/()-butan-2-ol mixtures. By assigning weights to a limited number of quantum chemically calculated clusters, vibrational spectra can be obtained at any desired composition by a weighted average of the single cluster spectra. In this way, peak positions carrying information about intermolecular interactions can be predicted.
View Article and Find Full Text PDFThe exposure of employees to airborne dust and microorganisms was assessed in a waste processing plant established to recover reusable materials from unsorted domestic and industrial waste. Exposure criteria considered relevant were the quantity of the individual size-selected particle fractions, the morphological properties of the particles, their heavy metal content, and the degree of their contamination with various microorganisms and mold. In addition, separate microbiological analyses to determine potential pathogen concentrations in the air were made.
View Article and Find Full Text PDFChiral styrene metabolites obtained during initial styrene exposure of test persons were determined in urine samples using capillary gas chromatography. A typical time-dependent urinary concentration profile of one person over a 49-h period is presented and compared with the results of a previous study of occupationally exposed workers and an unexposed control group. Maximum levels of excretion of all styrene metabolites were observed at about the end of a 9-h workshift.
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