Katalytische Dechlorierung von Chlorkohlenwasserstoffen aus kontaminierten Grundw?ssern

Im Rahmen des Forschungsverbundes SAFIRA wurden zwei neue Katalysatorsysteme zur reduktiven Dehalogenierung von CKW mit H2 entwickelt und am Standort Bitterfeld in Grundwasser-Durchflussreaktoren untersucht. Die katalytisch aktive Komponente Pd wurde zum Schutz vor Vergiftung durch ionische Verbindungen zum einen in hydrophobe Polymermembranen eingebettet, zum anderen wurden Pd-Cluster in den Poren hydrophober Zeolithe erzeugt. Die erreichten Standzeiten beider Katalysatoren waren trotzdem bedingt durch die Bildung von H ₂ S und organischen Schwefelverbindungen durch mikrobiologische Sulfatreduktion gering. Die Katalysatoren waren zwar durch eine Spülung mit Hypochlorit regenerierbar, unterlagen aber nach wenigen Tagen erneuter Vergiftung. Der Einsatz von Pd-Katalysatoren unter Bitterfelder Grundwasserbedingungen wird deshalb als problematisch eingesch?tzt.     

'Landscape' in the Japanese language: Conceptual differences and implications for landscape research

Increasing emphasis on discussing environmental issues at a global level and a rising number of international research projects make it necessary to locate key concepts of international discourses in their cultural context and to pay attention to possible cultural differences. The aim of this paper is to analyse the concepts behind different terms used in Japanese to describe 'landscape' in order to provide an example of the equivalence problem, which is a crucial issue in inter-cultural discourses. The results of ten interviews with theoretically sampled participants suggest that the two terms Fukei and Keikan coexisting in Japanese usage, represent two distinguishable landscape concepts with different meanings and images of landscape as well as different discursive contexts. This indicates a lack of equivalence in two ways. First, the two landscape concepts in contemporary Japanese differ and are not interchangeable. Second, this situation raises the question, whether it is possible to identify terms in other languages that are comparable to the differentiations found in the Japanese language. The implications for landscape research resulting from the different concepts of landscape in Japanese found in this study are discussed.     

Enzymatic (2R,4R)-Pentanediol Synthesis – “Putting a Bottle on the Table”

(2R,4R)-Pentanediol is an interesting precursor for the synthesis of chiral ligands. A ketoreductase (KRED) was employed for the asymmetric reduction of acetylacetone to this diol. Biocatalysis often suffers from low concentrations of hydrophobic substrates and low stability of the enzyme in unconventional media. Here, we present an engineered KRED variant applicable in a neat substrate system, including upscaling to the multi-liter scale and downstream processing (DSP). Our engineered KRED applied in a neat substrate system is a powerful technique for the synthesis of chiral diols yielding product concentrations of 208 g L⁻¹.     

Processes at the sediment water interface after addition of organic matter and lime to an Acid Mine Pit Lake mesocosm

A strategy to neutralize acidic pit lakes was tested in a field mesocosm of 4500 m(3) volume in the Acidic Pit Mine Lake 111 in Germany. Carbokalk, a byproduct from sugar production, and wheat straw was applied near to the sediment surface to stimulate in lake microbial alkalinity generation by sulfate and iron reduction. The biogeochemical processes at the sediment-water interface were studied over 3 years by geochemical monitoring and an in situ microprofiler. Substrate addition generated a reactive zone at the sediment surface where sulfate and iron reduction proceeded. Gross sulfate reduction reached values up to 10 mmol m(-2) d(-1). The neutralization rates between 27 and 0 meq m(-2) d(-1) were considerably lower than in previous laboratory experiments. The precipitation of ferric iron minerals resulted in a growing acidic sediment layer on top of the neutral sediment. In this layer sulfate reduction was observed but iron sulfides could not precipitate. In the anoxic sediment H2S was oxidized by ferric iron minerals. H2S partly diffused to the water column where it was oxidized. As a result the net formation of iron sulfides decreased after 1 year although gross sulfate reduction rates continued to be high. The rate of iron reduction exceeded the sulfate reduction rate, which resulted in high fluxes of ferrous iron out of the sediment.     

Reshaping markets for the benefit of energy saving

Energy saving is an important option for preventing emission of greenhouse gases. Furthermore, when energy saving is reducing the spatial and temporal density of energy consumption, it supports a rising market share of renewable energy sources. Last but not the least, energy saving plays a role in reducing the vulnerability for import dependency and supply disruptions. Despite these virtues energy saving and energy efficiency, being typically demand side options, appear to be harder to ‘sell’ than the other options which focus on the supply side. The currently prevailing market-based approach in energy policy initially brought setbacks for energy saving. The introductory article and the selected contributions to this special issue intend to show that markets can and should be shaped to the benefit of the uptake and of the potential of energy saving. To this end, all elements of the energy efficiency delivery context should be addressed in energy-saving policies. Learning, measurement and observation are important tools in this reshaping process. All contributions are based on papers of the European Council for an Energy Efficient Economy 2003 Summer Study.     

Technical note: Rapid field test for the quantification of vitamin E, β-carotene,and vitamin A in whole blood and plasma of dairy cattle

Fast and easy tests for quantifying fat-soluble vitamins such as vitamin E and vitamin A, as well as β-carotene, in whole blood without a need to preprocess blood samples could facilitate assessment of the vitamin status of dairy cattle. The objective of this study was to validate a field-portable fluorometer/spectrophotometer assay for the rapid quantification of these vitamins in whole blood and plasma of dairy cows and calves. We measured the concentrations of vitamin E and β-carotene in whole blood and plasma from 28 dairy cows and 11 calves using the iCheck test (BioAnalyt GmbH, Teltow, Germany) and compared the results with the current analytical standard (HPLC) in 2 independent laboratories, one at the University of Potsdam (Germany) and at one at DSM Nutritional Products Ltd. (Kaiseraugst, Switzerland). For vitamin A, the HPLC measurements were done only in the laboratory in Germany. The whole-blood concentrations of vitamin E as determined by iCheck (blood-hematocrit-corrected) ranged from 1.82 to 4.99 mg/L in dairy cows and 0.34 to 3.40 mg/L in calves. These findings were moderately correlated (R² = 0.66) with the values assessed by HPLC in dairy cattle (cows + calves). When calves were excluded, the correlation was higher (R² = 0.961). The β-carotene and vitamin A values obtained by the reference method HPLC were highly correlated with the iCheck methods in whole blood (R² = 0.99 and 0.88, respectively). In plasma, we observed strong correlations between the concentrations assessed by iCheck and those of HPLC for vitamin E (R² = 0.97), β-carotene (R² = 0.98), and vitamin A (R² = 0.92) in dairy cattle (cows + calves). For vitamin E, β-carotene, and vitamin A, we compared the relationship between the differences obtained by the iCheck assay and the HPLC measurements, as well as the magnitude of measurements, using Bland–Altman plots to test for systematic bias. For all 3 vitamins, the differences values were not outside the 95% acceptability limits; we found no systematic error between the 2 methods for all 3 analytes.     

Abductive Grounded Theory: a worked example of a study in construction management

Grounded Theory, now more than 50 years old, is a qualitative research approach widely employed in the social and human science studies to develop theories with a high degree of conceptuality. For construction management research, given the nature of this applied sub-discipline of management, a paradigmatic shift in Grounded Theory is needed, from classical positivism to pragmatism. Abductive Grounded Theory is posited as the way to achieve this shift in research methodology. The proposition is explored through a worked example, using Early Contractor Involvement research as a case study to demonstrate the research process. The data analysis process of open coding, axial coding and selective coding is described, together with the process of matching complementary prospect theory to explain the interdependencies between theoretical categories. The issues of validity and reliability are addressed. Of particular importance is the faithfulness to the original analytical coding process and then abduction of existing theories from salient literature to explain the relationships amongst emergent concepts. The findings show that, while the development of the research question is initially influenced by the review of literature, there is no deliberate effort to direct or force the collected information towards any set of pre-defined concepts. The study shows promising potential for using Abductive Grounded Theory to develop conceptual and instrumental theories in construction management research.