Showing papers by "Helmholtz Centre for Environmental Research - UFZ published in 1995"
TL;DR: Changing hydrocarbon content in soils resulted in characteristic shifts of the substrate utilization patterns as tested with the Biolog system, suitable for rapidly assessing dynamics of autochthonous soil communities and evaluating their biodegradative potential.
154 citations
TL;DR: In this paper, the analytical advantages of these techniques are applied to the analysis of technical products containing high amounts of LAS as well as river water samples with very low LAS concentrations using preconcentration steps.
Abstract: High-performance liquid chromatography and capillary zone electrophoresis have been used for the separation of homologues and structural isomers of linear alkylbenzenesulfonates with subsequent UV detection. The analytical advantages of these techniques are applied to the analysis of technical products containing high amounts of LAS as well as river water samples with very low LAS concentrations using preconcentration steps.
30 citations
TL;DR: The results indicate that the transient-state method is useful in deriving kinetic parameters with appropriate accuracy in a rather short time as compared to steady-state treatment.
14 citations
25 Jun 1995
TL;DR: In this paper, a comprehensive 1D-model for the whole 6-region (D/L, D film thickness, L, Debye length) sensor model is developed for ZnO and SrTiO3-thin films.
Abstract: Chemisorption of gas species (e.g. oxygen) and bulk diffusion of oxygen through stochiometric defects (vacancies) are the two gadsolidinteractions, which mainly affect the electronic behaviour of typical metal oxides (MO). Restricting to the thermodynamic equilibrium a comprehensive 1D-model is developed for the whole 6-region ({= D/L,, D film thickness, L, Debye length). The 1D-thin-film sensor model, which was developed in [5], is extended by the Schottky-defect-model. As examples ZnOand SrTiO3-thin films are considered.
2 citations
25 Jun 1995
TL;DR: In this article, the Volkenstein model was applied to Ga,O, thin films (e l, 10, 100, 1000 nm) in a temperature region between 80°C and 180OC.
Abstract: In the present paper we discuss earlier work function measurements at SnO2-thin-films [ 11 in terms of the Volkenstein model, which takes into account both dipol contribution of weak and strong chemisorbed species and charge transfer contributions. New work function measurements are presented for Ga,O,-thin films ( e l , 10, 100, 1000 nm) in a temperature region between 80°C and 180OC. Testing gases are NO, and NH,. It is well-known that GqO,-thin film-conductivity sensors exhibit in the medium temperature region (-600°C) an excellent long-term stability [2].
1 citations