Einfluß mechanischer Belastungen auf das Kavitationsverhalten metallischer Werkstoffe

Kritische Literaturauswertung. Kavitationsanlage für überlagerte mechanische Spannungen. Ergebnisse für die Werkstoffe technisch reines Eisen, St42-2 und G-X6 CrNiMo 1810 (1.4408). Einführung einer neuen Meßgröße zur Beschreibung des Kavitationsverhaltens sowie des additiven Spannungseinflusses. Beschreibung der ?Kavitations“-Fließgrenze. Diskussion und mathematische Formulierung der Ergebnisse.     

No evidence for enhanced parvalbumin concentration in light muscle of transgenic coho salmon (<Emphasis Type="Italic">Oncorhynchus kisutch</Emphasis>)

The expression of parvalbumin, a major allergenic protein of fish muscle, was determined in rapidly growing transgenic coho salmon (Oncorhynchus mykiss) containing the growth hormone (GH) gene construct OnMTGH1. Three different methods for parvalbumin analysis were used: (1) measurement of the mRNA concentration by real-time RT-PCR; (2) isoelectric focusing of sarcoplasmic proteins; (3) assessment of amount of heat-stable, Ca²⁺-binding sarcoplasmic proteins by measuring absorbance spectra of “stains-all”–protein complexes. Compared to non-transgenic coho salmon, no indication for enhanced expression of parvalbumin in transgenic fish was found either at the mRNA or at the protein level.     

Identification of the fish species of raw or cold-smoked salmon and salmon caviar by single-strand conformation polymorphism (SSCP) analysis

Differentiation between ten salmonid fish species belonging to the genera Salmo, Oncorhynchus and Salvelinus was achieved by single strand conformation polymorphism analysis (SSCP) of PCR products of mitochondrial and nuclear genes. Amplicons (300–460 bp in size) of the genes for cytochrome b, parvalbumin and growth hormone gave species-specific patterns of single-stranded DNA in native polyacrylamide gel electrophoresis (PAGE). The method was successfully used to identify products from raw or cold-smoked salmon, as well as from salmon roe.     

Quality control of beer using high-resolution nuclear magnetic resonance spectroscopy and multivariate analysis

High-resolution nuclear magnetic resonance (NMR) spectroscopy is introduced for the quality control and authenticity assessment of beer in official food control. Measurements were performed using a 400-MHz NMR spectrometer using flow injection technology for automatic sample changing. Only degassing and addition of buffer (pH 5.6 in D₂O for locking and 0.1% TSP for referencing) is required to prepare the beer samples. Differences in the spectral profiles of beers varying in type and origin were studied by principal component analysis (PCA), considering the spectrum to be a characteristic fingerprint. For the first time, the high throughput of a Flow-Injection NMR system allowed a comprehensive database of beer spectra for PCA classification to be established efficiently. Beers made with barley malt could be distinguished from those made with wheat malt. Clustering of beers from the same brewing sites was observed, as well as significant discrimination of beers with deteriorated quality. Using the partial least squares (PLS) method to correlate NMR spectra with results from reference methods, models for calculating the original gravity, ethanol and lactic acid were established. The results obtained suggest that NMR is a useful tool in the quality control of beer samples, since quantitative determination of essential compounds as well as chemometric classification are simultaneously possible. Compared to conventional methods, ¹H NMR spectroscopy is faster and requires simpler sample preparation.     

Simulation of a reversible SOFC with Aspen Plus

A thermodynamic Aspen Plus simulation model for a reversible solid oxide fuel cell (RSOFC) is presented and evaluated. It is composed of an electrolysis and a fuel cell module. The latter is based on an existing non reversible SOFC model. The electrolysis model simulates water electrolysis as well as catalytic reactions of inlet gases. The model has been validated using data from literature. It has been found that the support layer on fuel electrode supported cells has to be treated differently in terms of diffusion than the active layer. Simulation results show that for the investigated cell parameters, the positive effect of adding CO₂ to the steam feed on the electrolysis process is due to water–gas-shift reactions and not CO₂ electrolysis. An analysis of outlet gas compositions in electrolysis mode showed that the assumption of the cell as an equilibrium reactor was justified. A parameter study has been conducted, showing that increasing the operation temperature and pressure can improve the overall performance, while changing the inlet gas compositions in general improves either fuel cell or electrolysis mode and deteriorates performance for the other mode.     

Alaskan flatfishes on the German market: part 1: identification by DNA and protein analytical methods

North Pacific flatfishes are gaining increased popularity on the German market. Isoelectric focusing of sarcoplasmic proteins and PCR-based DNA analysis were applied to identify fillets of nine Alaskan Flatfish species: Artheresthes stomias (Arrow-tooth flounder), Limanda aspera (Yellowfin sole), Isopsetta isolepis (Butter sole), Lepidopsetta bilineata (Southern rock sole), Lepidopsetta polyxystra (Northern rock sole), Hippoglossus stenolepis (Pacific halibut), Hippoglossoides elassodon (Flathead sole), Platichthys stellatus (Starry flounder), and Glyptocephalus zachirus (Rex sole). Characteristic protein patterns were obtained for raw fillets of several species. Reactivity of flatfish DNA against five pairs of primers was tested, amplifying segments of the mitochondrial cytochrome b, cytochrome oxidase subunit I, 16S rRNA gene, as well as the nuclear parvalbumin gene. Amplicons of the cytochrome b gene were sequenced and used for single-strand conformation polymorphism analysis. The survey of deep-frozen commercial yellowfin sole fillets resulted in the detection of 17% of the fillets being mislabelled; Northern rock sole, butter sole and flathead sole had been used as substitutes.     

Lysozyme in wine: A risk evaluation for consumers allergic to hen's egg

Lysozyme used in wine production could present a risk for consumers allergic to hen's egg. Thus, precautionary labeling of lysozyme on wines has been adopted within the European Community by updating Annex IIIa by Directive 2007/68/EC on November 27, 2007. Since no scientific data is known about the actual amounts and risks of lysozyme in wines, various in vitro efforts and skin prick tests were applied in this study to evaluate the presence of lysozyme in wines and the reactivity of those residues in allergic individuals and to fulfill the claim of updating Annex IIIa announced in Directive 2003/89/EC. Depending on the wine's color (red or white wine) and fining with bentonite, which is known as an important step to remove unstable proteins mainly from white wines, diverse results were obtained concerning the amounts of lysozyme in finished wines and their in vitro and in vivo reactivity in humans allergic to hen's egg.     

Optimal divide-and-conquer to compute measure and contour for a set of iso-rectangles

Summary We reconsider two geometrical problems that have been solved previously by line-sweep algorithms: the measure problem and the contour problem. Both problems involve determining some property of the union of a set of rectangles, namely the size and the contour (boundary) of the union. We devise essentially a single time-optimal divide-and-conquer algorithm to solve both problems. This can be seen as a step towards comparing the power of the line-sweep and the divide-and-conquer paradigms. The surprisingly efficient divide-and-conquer algorithm is obtained by using a new technique called separational representation, which extends the applicability of divide-and-conquer to orthogonal planar objects.This work was partially supported by the DAAD (Deutscher Akademischer Austauschdienst) and by the DFG (Deutsche Forschungsgemeinschaft)     

Degree elevation of B-spline curves

An algorithm is presented which expresses any given linear combination of B-splines of order k as a linear combination of B-splines of order k + 1. This algorithm consists of two parts: (1) A simple representation of the curve by a sum of B-splines of order k + 1, and (2) a representation of these splines on a common knot vector by inserting new knots.