The microstructure and electrical conductivity of mixed-valence TlIn(4)S(5)Cl quaternary compound micro- and nanowires

Quaternary mixed-valence compound TlIn(4)S(5)Cl micro-?and nanowires are prepared by partial substitution of chalcogen with halogen starting from a stoichiometric mixture of TlCl, In?and S. Their electrical conductivity and gas sensitivity properties are investigated by using standard four-terminal systems. The specific nanowire resistivity is about 10(7)?Ω?cm and corresponds to the value of a typical undoped semiconductor in air. This resistivity is, however, extremely sensitive to NO(2) (sensitivity about 150) or NH(3), with a rapid response of about 2?s and recovery times. This phenomenon is supposed to be particularly important for future nanodevice applications.     

Temperature dependence of anaerobic TCE-dechlorination in a highly enriched Dehalococcoides-containing culture

Temperature dependence of reductive trichloroethene (TCE) dechlorination was investigated in an enrichment culture (KB-1), using lactate or propionate as electron donors at a temperature interval from 4 to 60 degrees C. Dechlorination was complete to ethene at temperatures between 10 and 30 degrees C (lactate-amended) and between 15 and 30 degrees C (propionate-amended). Dechlorination stalled at cis-1,2-dichloroethene (cDCE) at 4 degrees C (lactate-amended), at and below 10 degrees C (propionate-amended), and at 40 degrees C with both electron donors. No dechlorination of TCE was observed at 50 and 60 degrees C. Concentrations of Dehalococcoides had increased or remained constant after 15 days of incubation at temperatures involving complete dechlorination to ethene. Temperature dependence of dechlorination rates was compared using zero order degradation kinetics and a Monod growth-rate model for multiple electron acceptor usage with competition. Maximum growth rates (mu) and zero order degradation rates were highest for TCE dechlorination at 30 degrees C with lactate as substrate (mu(TCE) of 7.00+/-0.14 days(-1)). In general, maximum growth rates and dechlorination rates of TCE were up to an order of magnitude higher than rates for utilization of cis-dichloroethene (cDCE, mu(c)(DCE) up to 0.17+/-0.02 days(-1)) and vinyl chloride (VC, mu(VC) up to 0.52+/-0.09 days(-1)). Temperature dependence of maximum growth rates and degradation rates of cDCE and VC were similar and highest at 15-30 degrees C, with growth rates on cDCE being lower than on VC. This study demonstrates that bioaugmentation of chlorinated ethene sites may be more efficient at elevated temperatures.     

Die Entwicklung der Verfahrenstechnik an der TU Kaiserslautern

In 1970 the twin university of Kaiserslautern-Trier was founded, from which the two independent universities of Trier and Kaiserslautern emerged in 1975. In 2003, in order to emphasize the focus of the University of Kaiserslautern in engineering, it was renamed to äTechnical University of Kaiserslauternä. In the 50 years of its existence, the development and further development of process engineering was one of the focal points of the mechanical and process engineering department. The article illuminates this path of development and presents the then and current research areas of the four process engineering chairs of the TU Kaiserslautern.