Entwurf und Ausführung der Seidewitztalbrücke im Zuge der BAB A 17

Design and construction of the new roadwaybridge across the Seidewitztal on the highway Dresden– Prague. The following article deals with the investigations made for the construction of the 568 m long bridge across the Seidewitztal near Dresden during preliminary design and tender design. The new bridge will be part of the new highway from Dresden to the border of the Czech Republic. Main part of the new bridge will be an arch with a span length of 154 m.     

Interaction of thermally induced and mechanical fatigue

The influence of superimposed total strain controlled HCF loadings on TMF life is presented and discussed for several cast Al-Si alloys, the Ni-base superalloy Inconel 617 and the cast iron GJS-700. Except for GJS-700, a threshold of the superimposed HCF loading is observed, below of which TMF life is not significantly affected. The strong decrease of TMF life as soon as the HCF amplitude exceeds this threshold is due to fundamental changes in the crack propagation mechanisms. The paper closes with a brief overview on lifetime prediction methods for TMF and their application in the case of TMF/HCF loadings.     

Characterization of Palladium Nanoparticles Adsorpt on Polyacrylic Acid Particles as Hydrogenation Catalyst

Palladium particles can be prepared in sizes of a few nanometers from Pd(OAc)₂in the presence of a block copolymer in aromatic unpolar solvents with suitable reducing agents like NaBH₄ or LiAlH₄. After mixing the organic metal solution with a polyacrylic acid (PAA) dispersion of defined concentration and following a crosslinking process with an epoxide, reactive membranes with a well-defined pore diameter were obtained. The catalytic activity of the prepared palladium particles incorporated in the crosslinked PAA network has been proven by the gas phase hydrogenation of propyne in a special membrane reactor.     

Effect of roasting on the radical scavenging activity of cocoa beans

The free-radical scavenging activity of cocoa samples subjected to different roasting treatments has been determined. The samples (raw, pre-roasted and roasted) were separated into four molecular weight fractions per sample (>30, 30–10, 10–5, and <5 kDa). The free-radical scavenging activity was determined with the DPPH^• (1,1-dipheny-2-picrylhydrazyl), and ABTS^•+ [2,2’-azinobis (3-ethylbenzothiazoline-6-sulfonic acid)] free-radical scavenging assays for all samples. Both tests were compared in terms of sensitivity and measurement precision, at different reaction times. Comparing the results from each test, the free-radical scavenging activity trends were similar for each fraction but with notable differences in the sensitivity of the assays. Analysis of the concentration of reducing substances, such as water soluble phenolics, melanoidins, carbohydrates, etc, in these fractions by the photometric Folin–Ciocalteu assay, showed a similar pattern to the free-radical scavenging activity trend. Moreover, this comparison showed that there were significantly (P < 0.05) more reducing substances and free-radical scavenging activity in the 10–5 kDa roasted cocoa bean fraction.     

The role of the concept of "history of safe use" in the safety assessment of novel foods and novel food ingredients. Opinion of the Senate Commission on Food Safety (SKLM) of the German Research Foundation (DFG)

The Council of the European Union has proposed a revision on the EU regulation on novel foods and novel food ingredients concerning safety assessment of traditional foods from non-EU countries and their introduction onto the EU market. The proposal stipulates that such foods may be placed on the EU market if their history of safe use in the country of origin is appropriately documented. The present statement of the SKLM gives an overview on current discussions on practical implementation of the "history of safe use" concept as well as examples of its application. The SKLM, in principle, agrees with these concepts, underscores, however, in connection with convincing evidence for a "history of safe use" the need for a range of additional information to achieve a comprehensive risk assessment. In the opinion of the SKLM such information must comprise compositional data as well as experience on adverse effects. A list of questions considered essential is presented. The following opinion was adopted on December 23rd 2010.     

Digitale Bildverarbeitung spannungsoptischer Isochromatenbilder

Digitale Bildanalysesysteme bieten die Möglichkeit, Verfahren der Bildverarbeitung wirkungsvoll auch in der Spannungsoptik einzusetzen. Es wird über die Bearbeitung, insbesondere über die Filterung von spannungsoptischen Isochromatenbildern berichtet, und zwar über die Hochpaßfilterung mit anschließender Konturverstärkung, über die Gradientenfilterung mit einem Sobel-Operator und über die Skelettierung. Als Beispiel dient ein I-Träger mit nebeneinanderliegenden, ovalen Löchern unter Querkraftbelastung. Es werden Schubspannungsverteilungen für die verschiedenen Bearbeitungsmethoden dargestellt.     

Linear mappings ofn-dimensional uniform recurrences ontok-dimensional systolic arrays

We propose two methods for the synthesis of systolic arrays from uniform recurrence equations. First, we discuss a synthesis method for mappingn-dimensional uniform recurrence equations ontok-dimensional systolic arrays with a two-dimensional system clock. In this method we are led by the idea that all space-time conflicts caused by a scalar valued causal timing function and an allocation function can be rule out by a second scalar valued timing function. Stacking both timing functions yields a two-dimensional clock. Second, we develop a method to synthesizek-dimensional arrays with a scalar valued clock from a large subclass ofn-dimensional uniform recurrence equations containing important algorithms from signal and image processing. This method is based on a decomposition of the domain of the uniform recurrence equations into subdomains according to a given procesor allocation which allows the construction of a timing function for the whole domain from timing functions for the subdomains. In this way, the problem of finding optimal timing functions is reduced to finding optimal functions for the subdomains which are usually easier to establish. This synthesis method exhibits simplicity but its drawback lies in its limited applicability.