APPARATUS AND PROCEDURE FOR REPRODUCIBLE,HIGH-RESOLUTION GAS CHROMATOGRAPHIC ANALYSIS OF ALCOHOLIC BEVERAGE HEADSPACE VOLATILES

A readily established method is reported for concentrating headspace volatiles on a bed of the porous polymer, Chromosorb 105. The trapped components are transferred by a desorption technique onto a small plug of SF96 coated support material. The volatiles can then be injected onto a high-resolution gas chromatographic column by a simple process. The apparatus required and the steps involved in the procedure are discussed in detail. The precision of the method for the quantitative determination of alcoholic beverage headspace volatiles is assessed for a range of typical compounds. Examples are given of applications of the technique to the analysis of alcoholic spirits and beverages.     

The use of occupancy as a surrogate for particle concentrations in recirculating, zoned cleanrooms

The substantial energy demands of today's cleanroom environmental-maintenance systems provide large opportunities for energy conservation. However, cleanroom environments are subject to much more stringent standards and operate with much smaller tolerances, and therefore simple application of industrial/commercial controls is not sufficient. We conducted a set of measurements in a Class 1000 cleanroom to confirm that humans are the predominant source of particles in a cleanroom, supporting that occupancy can be used as an effective surrogate for particle concentrations. Our data suggest that people release approximately 1.7 × 10⁴ particles per minute into the cleanroom and raise the local concentration of particles by 1742 ± 481 particles m⁻³ person⁻¹. Furthermore, our timescale analysis on control system and ventilation unit responses indicates that a predictive-occupancy system is required for implementing demand-controlled ventilation.     

Reaktionen von Aroyl(Hetaroyl)iminodithiokohlesäureestern mit Carbanionen CH-acider Verbindungen

Reactions of Dimethyl N-Aroyl(Hetaroyl)carbimidodithioates with Carbanions CH-acidic Compounds Reactions of dimethyl N-aroyl(hetaroyl)carbimidodithioates 1 with carbanions 2 present new possibilities to synthesize 3-acyl-amino-3-methylthio-2-subst.-acrylnitriles 3 by monosubstitution of methylthiogroup. The reaction of 1 with 2-alkyl-benzothiazolium salts 4 yield deeply coloured N-acyl-(2,3-dihydrobenzothiazole-2-yliden) thioacetimido acid-methylates 5 of the 2-subst.-benzothiazoliumperchlorates 6 . The structures of the final products are determined by i.r.-, ¹H.-n.m.r.- and u.v.-spectra.     

Numerisch unterstützte Optimierung von Monitoringsystemen an Gewölbesperren

Numeric Based Optimization of Monitoringsystems Applied on Arch Barriers Monitoring of critical structural and process key parameters of concrete barrier structures and associated processes, during construction and operation, provides a quantitative basis for reliability and condition assessment, analytical modelling and decision making. This includes evaluating the conditions and induced effects during construction and operation in terms of maintenance decision making and reliability assessment. Recorded Data can provide direct or derivable information of indigent or existing failure or failure zones. An optimized monitoring system with respect to the interaction and the location of sensors combined with probabilistic nonlinear numerical and analytical methods is a proper instrument essential supporting by such challenges. The objective of this paper is the discussion of a probabilistic based assessment method for barrier structures combining monitoring information, optimized by the presented strategy, and advanced nonlinear Finite Element Methods.