Assessment of noise attenuating powertrain components

Forschung im Ingenieurwesen - Wind turbine noise used to be dominated by aerodynamic blade noise, effectively masking mechanical noise, originating from the drivetrain. Successful blade noise...     

Bericht über neue ferromagnetische Werkstoffe

Ohne ZusammenfassungMit 5 Textabbildungen.     

Spectral reflectance response of Fraxinus mandshurica leaves to above- and belowground competition

The responses of leaf spectral reflectance of Fraxinus mandshurica saplings to above- and belowground competition were studied under field conditions in a temperate forest near the Changbai Mountain Nature Reserve in northeast China. Two sets of four treatments, each inducing different levels of competition, were applied under the shade of the forest canopy and in a clear felling area under full light exposure. The heights of the saplings were measured once a month and leaf reflectance was measured at the same time. At the end of the experiment, all target saplings were excavated, and their biomass and root morphological traits were analysed. All these traits were then compared with the leaf spectral reflectance values and different spectral indices. We found that changes in height and biomass were significantly affected by the treatment and site, and that the differences between the four treatments coincided well with the differences in the spectral indices. The final biomass and all root morphological attributes were significantly affected by the treatment and site. Again, these differences corresponded well with the differences in the spectral indices and the spectral reflectance curves. In conclusion, we found that leaf spectral reflectance was sensitive to competition and showed a close relation with other responses, which makes it a reliable indicator of the response of F. mandshurica to varying competition intensities, especially when competition is very severe.     

Endocrine disrupting nonylphenols are ubiquitous in food

4-Nonylphenols (NPs) are common products of biodegradation of a widely used group of nonionic surfactants, the nonylphenol ethoxylates (NPEs). These compounds are known to be persistent, toxic, and estrogen active. There is a worldwide scientific and public discussion on the potential consequences of human long term dietary exposure to such endocrine disrupters. Despite numerous determinations of NPs in environmental samples no systematical reports exist relating to concentrations of NPs in food. We analyzed NPs in 60 different foodstuff commercially available in Germany. The results indicate that NPs are ubiquitous in food. The concentrations of NPs on a fresh weight basis varied between 0.1 and 19.4 microg/kg regardless of the fat content of the foodstuff. Based on data on German food consumption rates and these first analyses of NPs in food, the daily intake for an adult was calculated to be 7.5 microg/day NPs. For infants exclusively fed with breast milk or infant formulas daily intakes of 0.2 microg/day and 1.4 microg/day NPs, respectively, can be estimated.     

Purification and characterisation of relevant natural and recombinant apple allergens

Apple (Malus domestica) is the most widely cultivated fruit crop in Europe and frequently causes allergic reactions with a variable degree of severity. So far, four apple allergens Mal d 1, Mal d 2, Mal d 3 and Mal d 4 have been identified. Mal d 1, a Bet v 1 related allergen, and Mal d 4, apple profilin, are sensitive to proteolytic degradation, whereas Mal d 2, a thaumatin-like protein and Mal d 3, a nonspecific lipid transfer protein, are rather stable to proteolytic processes. Mal d 1 and Mal d 4 were purified after expression in Escherichia coli expression system, while Mal d 2 and Mal d 3 were purified from apple fruit tissue. All purified proteins were subjected to detailed physicochemical characterisation to confirm their structural integrity and maintained IgE binding capacity. Detailed investigations of carbohydrate moieties of Mal d 2 demonstrated their involvement in the overall IgE binding capacity of this allergen. It was concluded that the folded structure and IgE binding capacity of all four allergens were preserved during purification.     

Some Relations between Approximation Problems and PCPs over the Real Numbers

In [10] it was recently shown that that is the existence of transparent long proofs for was established. The latter denotes the class of real number decision problems verifiable in polynomial time as introduced by Blum et al. [6]. The present paper is devoted to the question what impact a potential full real number theorem would have on approximation issues in the BSS model of computation. We study two natural optimization problems in the BSS model. The first, denoted by MAX-QPS, is related to polynomial systems; the other, MAX-q-CAP, deals with algebraic circuits. Our main results combine the PCP framework over with approximation issues for these two problems. We also give a negative approximation result for a variant of the MAX-QPS problem.     

Compliance by design – Bridging the chasm between auditors and IT architects

System and process auditors assure – from an information processing perspective – the correctness and integrity of the data that is aggregated in a company’s financial statements. To do so, they assess whether a company’s business processes and information systems process financial data correctly. The audit process is a complex endeavor that in practice has to rely on simplifying assumptions. These simplifying assumptions mainly result from the need to restrict the audit scope and to focus it on the major risks. This article describes a generalized audit process. According to our experience with this process, there is a risk that material deficiencies remain undiscovered when said simplifying assumptions are not satisfied. To address this risk of deficiencies, the article compiles thirteen control patterns, which – according to our experience – are particularly suited to help information systems satisfy the simplifying assumptions. As such, use of these proven control patterns makes information systems easier to audit and IT architects can use them to build systems that meet audit requirements by design. Additionally, the practices and advice offered in this interdisciplinary article help bridge the gap between the architects and auditors of information systems and show either role how to benefit from an understanding of the other role’s terminology, techniques, and general work approach.