Application of enzyme-field effect transistor sensor arrays as detectors in a flow-injection analysis system for simultaneous monitoring of medium components. Part II. Monitoring of cultivation processes

Glucose, maltose, sucrose, lactose, ethanol and urea concentrations were monitored simultaneously during the cultivation of Escherichia coli and Saccharomyces cerevisiae by means of enzyme field effect transistors (EnFETs) applying glucose dehydrogenase (GDH), maltase (MAL)/GDH, invertase (INV)/GDH, β-galactosidase (β-GAL)/galactosedehydrogenase (GALDH), alcoholdehydrogenase (ADH)/aldehydedehydrogenase (ALDH), and urease. These enzymes were (co)immobilized on the pH sensitive gates of an eight-FET array. The FET array was integrated in a commercial FIA system.     

Rotational Motion of a Solute Molecule in a Highly Viscous Liquid Studied byC NMR: 1,3-Dibromoadamantane in Polymeric Chlorotrifluoroethene

The viscosity-dependent retarding effect of a polymeric solvent on the rotation of small solute molecules is investigated by¹³C NMR relaxation measurements. It is found that the relaxation data of 1,3-dibromoadamantane in highly viscous polymeric chlorotrifluoroethene can be explained neither by isotropic nor by realistic anisotropic tumbling in a single environment. The experimental data are rationalized in terms of fast exchange between at least two environments with correlation times differing by up to two orders of magnitude. The study shows that a uniform retardation of molecular tumbling by a polymeric solvent, desirable for shifting the NMR observation window in studies of intramolecular mobility, is not always feasible.     

Monitoring of ionic concentrations in airborne particles and rain water in an urban area of central Germany

The primary objective of this investigation was to document fluctuations of levels of ions in airborne particles and in rain water with the help of ion chromatography. The environmental emission situation in the investigated geographic area is characterized by a widespread use of domestic coal-burning furnaces. The use of a parallel impactor for particulate sampling permits the results to be interpreted additionally in terms of particle size. The anions and cations were extracted from the filters in the sampling devices into ethanol-water mixtures by sonication. Rain water samples were analysed after a simple dilution step. The data obtained on ionic fluctuations are compared with similar data sets published by other laboratories.     

Proof of the Mixing Theorem for Statistical Systems in Classical Physics

In a general measure-theoretic context, it is proved that the action of a stochastic map on a pair of probability distributions can be characterized by the criterion of decreasing mixing distance.     

Reihenentwicklungen im Weylschen Grenzkreisfall über einem halbunendlichen Intervall

Zusammenfassung Im Anschlu an eine frühere Arbeit beweisen wir im Grenzkreisfall für das Intervall s< einen Entwicklungssatz für reelle Funktionen bei vorgeschriebenen reellen Randbedingungen in s=0 und s=. Die Hilfsmittel sind: 1) der reelle Ansatz; 2) der explizite Ausdruck für die Greensche Funktion von Weyl und 3) die allgemeine Parsevalsche Gleichung.     

Accurate determination of wavenumbers for iodine molecular lines in the red spectral region

The hyperfine structure of various absorption lines of molecular iodine with wavenumbers between 12980 and 13890 cm^–1 has been resolved using Doppler-free polarization spectroscopy. The wavenumbers of theo-component of 17 rovibrational lines of I₂ due to the transitionB ³ _ou ⁺ –X¹ _g ⁺ with even rotational quantum numbers have been determined with an accuracy of 0.001 cm^–1. A comparison of the centers of gravity of these 17 lines with the values of the iodine atlas of Gerstenkorn et al. yields a difference of thus corroborating the data of the iodine atlas in the red region within limits of error.