Ausbildung und wissenschaftsstandort deutschland

In the ongoing discussions about the qualities of Germany regarding economic activities and especially industrial production in a unifying Europe and with respect to worldwide economic competition, it is important to carefully consider the conditions for innovative and competitive scientific research. Germany as a site for science is dependent not only on the resources of public research institutes, on available research funds and on industrial R&D investment, but just as decisively on the existing framework of conditions for scientific-technological progress. Thus, the whole educational system is of utmost importance since it must form and develop the coming generations of researchers. Their knowledge and their attitudes, as acquired in this educational process, determine not only their future scientific productivity, but also the public acceptance of high-tech production in Germany.     

Elimination of endocrine disrupting chemicals nonylphenol and bisphenol A and personal care product ingredient triclosan using enzyme preparation from the white rot fungus Coriolopsis polyzona

The biocatalytic elimination of the endocrine disrupting chemicals (EDC) nonylphenol (NP) and bisphenol A (BPA) and the personal care product ingredient triclosan (TCS) by the enzyme preparation from the white rot fungus Coriolopsis polyzona was investigated. Analysis of variance methodology showed that the pH and the temperature are statistically significant factors in the removal of NP, BPA and TCS. The elimination of NP and TCS was best at a temperature of 50 degrees C and the disappearance of BPA at 40 degrees C, whereas the most suitable pH for all three micropollutants was 5. After a 4-h treatment of the three target compounds at concentrations of 5 mg l(-1) all of the NP and BPA were eliminated. In the case of TCS, 65% was removed after either a 4 or an 8-h treatment. The utilisation of 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) in the laccase/mediator system significantly increased the efficiency of the enzymatic treatment. The elimination of NP and BPA was directly associated with the disappearance of the estrogenic activity. Mass spectrometry analysis showed that the enzymatic treatment produced high molecular weight metabolites through a radical polymerization mechanism of NP, BPA and TCS. These oligomers were produced through the formation of C-C or C-O bonds. The polymerization of NP produced dimers, trimers, tetramers and pentamers which had molecular weights of 438, 656, 874 and 1092 amu respectively. The polymerization of BPA produced dimers, trimers and tetramers which had molecular weights of 454, 680 and 906 amu. Finally, the polymerization of TCS produced dimers, trimers and tetramers which had molecular weights of 574, 859 and 1146 amu.     

On the Environmental Efficiency of Water Storage: the Case of a Conjunctive use of Ground and Rainwater

Rainwater harvesting, consisting in collecting runoff from precipitation, has been widely developed to stop groundwater declines and even raise water tables. However, this expected environmental effect is not self-evident. We show in a simple setting that the success of this conjunctive use depends on whether the runoff rate is above a threshold value. Moreover, the bigger the storage capacity, the higher the runoff rate must be to obtain an environmentally efficient system. We also extend the model to include other hydrological parameters and ecological damages, which respectively increase and decrease the environmental efficiency of rainwater harvesting.     

Singular air entrapment at vertical and horizontal supported jets: plunging jets versus hydraulic jumps

Environmental Fluid Mechanics - In plunging jets and at hydraulic jumps, large amounts of air bubbles are entrained at the impingement of the liquid jet into the receiving body. Air is entrapped...     

Modeling of Cs migration in soils using an 80-year soil archive: role of fertilizers and agricultural amendments

An 80-year soil archive, the 42-plot experimental design at the INRA in Versailles (France), is used here to study long-term contamination by ¹³⁷Cs atmospheric deposition and the fate of this radioisotope when associated with various agricultural practices: fallow land, KCl, NH₄(NO₃), superphosphate fertilizers, horse manure and lime amendments. The pertinence of a simple box model, where radiocaesium is supposed to move downward by convectional mechanisms, is checked using samples from control plots which had been neither amended, nor cultivated since 1928. This simple model presents the advantage of depending on only two parameters: α, a proportional factor allowing the historical atmospheric ¹³⁷Cs fluxes to be reconstructed locally, and k, an annual loss coefficient from the plow horizon. Another pseudo-unknown is however necessary to run the model: the shape of historical ¹³⁷Cs deposition, but this function can be easily computed by merging several curves previously established by other surveys. A loss of ∼1.5% per year from the plow horizon, combined with appropriate fluxes, provides good concordance between simulated and measured values. In the 0–25 cm horizon, the residence half time is found to be ∼18 yr (including both migration and radioactive decay). Migration rate constants are also calculated for some plots receiving continuous long-term agricultural treatments. Comparison with the control plots reveals significant influence of amendments on ¹³⁷Cs mobility in these soils developed from a unique genoform.     

Fluoride Emissions and Forest Growth

Abstract

The October 1995 court decision allowing Ethyl Corporation to offer methylcyclopentadienyl manganese tricarbonyl (MMT) for sale to refiners for introduction into unleaded gasoline as an octane enhancer is likely to result in increased fine (PM_2.5) manganese (Mn) concentrations in ambient air. Concern exists regarding possible health effects. In this paper, recent fine Mn concentrations in three monitoring networks and one U.S. Environmental Protection Agency (EPA) study of personal exposure are analyzed. One network consists mainly of rural sites in national parks in the United States, a second consists mainly of urban sites in California, and the third consists mainly of urban sites in Canada where MMT has been used for a number of years. During the late 1980s and early 1990s, mean ambient concentrations ranged from 1 ng/m³ in the mostly rural network to 3 ng/m³ in the mostly urban California network to 12 ng/m³ in the MMT-impacted Canadian network. Several lines of evidence suggested that some of the fine Mn observed in the United States during the 1986-1992 period was contributed by automobiles using leaded gasoline, for which MMT was a registered fuel additive. However, the near-disappearance of leaded gasoline has resulted in a very small portion of fine Mn being attributed to automobiles in the years since 1992.A source apportionment analysis suggested that crustal contributions to ambient fine Mn are on the order of 1-2 ng/m³ in both the United States and Canada.