Über die Stickstoffbestimmung nach Kjeldahl im Kreatin.

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Environmental occurrence, analysis, and toxicology of toxaphene compounds.

Toxaphene production, in quantities similar to those of polychlorinated biphenyls, has resulted in high toxaphene levels in fish from the Great Lakes and in Arctic marine mammals (up to 10 and 16 microg g-1 lipid). Because of the large variabiliity in total toxaphene data, few reliable conclusions can be drawn about trends or geographic differences in toxaphene concentrations. New developments in mass spectrometric detection using either negative chemical ionization or electron impact modes as well as in multidimensional gas chromatography recently have led researchers to suggest congener-specific approaches. Recently, several nomenclature systems have been developed for toxaphene compounds. Although all systems have specific advantages and limitations, it is suggested that an international body such as the International Union of Pure and Applied Chemistry make an attempt to obtain uniformity in the literature. Toxicologic information on individual chlorobornanes is scarce, but some reports have recently appeared. Neurotoxic effects of toxaphene exposure such as those on behavior and learning have been reported. Technical toxaphene and some individual congeners were found to be weakly estrogenic in in vitro test systems; no evidence for endocrine effects in vivo has been reported. In vitro studies show technical toxaphene and toxaphene congeners to be mutagenic. However, in vivo studies have not shown genotoxicity; therefore, a nongenotoxic mechanism is proposed. Nevertheless, toxaphene is believed to present a potential carcinogenic risk to humans. Until now, only Germany has established a legal tolerance level for toxaphene--0.1 mg kg-1 wet weight for fish

Wissenschaftliche Grundlagen fuer das ISOFACH Waerme-Plus-Fenster T. 2 des Abschlussberichts

The past 15 years have seen a revolution in window glazing, with heat losses reduced by a factor of 10. Window frames have not been able to keep up, but efficient window frames are indispensable if the potential savings are to be used fully. In passive buildings and very good low-energy buildings, prevention of heat gaps is the main concern. The project aimed at the development of window frame profiles with optimum thermal insulation.In den letzten fuenfzehn Jahren hat sich eine revolutionaere Entwicklung der Verglasungsqualitaet vollzogen, wodurch sich die Waermeverluste von Fensterverglasungen um den Faktor 10 reduzieren liessen. Die thermischen Eigenschaften der Fensterrahmen haben bei dieser Entwicklung nicht mitgehalten. Das Einsparpotential der Verglasung laesst sich jedoch nur mit einem sehr guten Rahmen voll ausschoepfen. Bei Passivhaeusern und sehr guten Niedrigenergiehaeusern ist die Vermeidung bzw. Verringerung von Waermebruecken eine unbedingte Notwendigkeit. Zielsetzung des Vorhabens ist es, Rahmenprofile zu entwickeln mit einem angepassten Waermedaemmwert. (orig.)SIGLEAvailable from TIB Hannover: F01B773 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDeutsche Bundesstiftung Umwelt, Osnabrueck (Germany)DEGerman