NASTRAN cyclic symmetry capability

A development for NASTRAN which facilitates the analysis of structures made up of identical segments symmetrically arranged with respect to an axis is described. The key operation in the method is the transformation of the degrees of freedom for the structure into uncoupled symmetrical components, thereby greatly reducing the number of equations which are solved simultaneously. A further reduction occurs if each segment has a plane of reflective symmetry. The only required assumption is that the problem be linear. The capability, as developed, will be available in level 16 of NASTRAN for static stress analysis, steady state heat transfer analysis, and vibration analysis. The paper includes a discussion of the theory, a brief description of the data supplied by the user, and the results obtained for two example problems. The first problem concerns the acoustic modes of a long prismatic cavity imbedded in the propellant grain of a solid rocket motor. The second problem involves the deformations of a large space antenna. The latter example is the first application of the NASTRAN Cyclic Symmetry capability to a really large problem

X-ray ptychography on low-dimensional hard-condensed matter materials

Tailoring structural, chemical, and electronic (dis-)order in heterogeneous media is one of the transformative opportunities to enable new functionalities and sciences in energy and quantum materials. This endeavor requires elemental, chemical, and magnetic sensitivities at the nano/atomic scale in two- and three-dimensional space. Soft X-ray radiation and hard X-ray radiation provided by synchrotron facilities have emerged as standard characterization probes owing to their inherent element-specificity and high intensity. One of the most promising methods in view of sensitivity and spatial resolution is coherent diffraction imaging, namely, X-ray ptychography, which is envisioned to take on the dominance of electron imaging techniques offering with atomic resolution in the age of diffraction limited light sources. In this review, we discuss the current research examples of far-field diffraction-based X-ray ptychography on two-dimensional and three-dimensional semiconductors, ferroelectrics, and ferromagnets and their blooming future as a mainstream tool for materials sciences

Ökologische Tierzucht: Status Quo, Möglichkeiten und Erfordernisse in der Rinder- und Schweinezucht

Die im Rahmen der Status-quo-Analyse durchgeführte Befragung der ökologischen Verbände, der Zuchtverbände und -unternehmen sowie der Verarbeitungs- und Vermarktungsbetriebe ergab, dass die ökologisch wirtschaftenden Betriebe auf vorhandene Rassen zurückgreifen. Die alten und gefährdeten Haustierrassen spielen im ökologischen Landbau eine untergeordnete Rolle, da sie in den Leistungsmerkmalen den übrigen Rassen unterlegen sind. Als Zuchtziele für die Schweinezucht werden neben den ökonomisch wichtigen Merkmalen MFA, TZ und FUA auf der Vaterseite die Merkmale Stressresistenz und Fleischbeschaffenheit und auf der Mutterseite die Merkmale Vitalität und Muttereigenschaften als Zuchtzielmerkmale vorgeschlagen. Darüber hinaus sollte die Grundfutterverwertung aufgrund des geforderten Raufutteranteils beachtet werden. Für das Zuchtziel in einem Zuchtprogramm für ökologisch erzeugte Rinder wird eine stärkere Gewichtung der funktionalen Merkmale und insbesondere der funktionalen Nutzungsdauer gefordert. Von den Zuchtverbänden und -unternehmen wurde betont, dass ein eigenes Zuchtprogramm sowohl in der ökologischen Rinder- als auch in der ökologischen Schweinezucht zu hohe Kosten verursachen würde, da der Absatzmarkt zu klein ist. Die anschließende Evaluierung verschiedener Zuchtplanungsalternativen für die ökologische Rinderzucht ergab, dass der Anteil künstlicher Besamung nicht unter 50 % fallen sollte, da es sonst zu einem starken Abfall des Zuchtfortschrittes und des Züchtungsgewinnes kommt. Die Erhöhung der wirtschaftlichen Gewichte der funktionalen Merkmale um 50 und um 100 % führte zu einer Verbesserung der naturalen Zuchtfortschritte der funktionalen Merkmale allerdings auf Kosten der Produktionsmerkmale. Ebenfalls eine Verbesserung der funktionalen Merkmale kann durch eine Erhöhung der Anzahl Töchter/Testbulle auf 100 und mehr erzielt werden

The oxygen-independent metabolism of cyclic monoterpenes in Castellaniella defragrans 65Phen

BACKGROUND: The facultatively anaerobic betaproteobacterium Castellaniella defragrans 65Phen utilizes acyclic, monocyclic and bicyclic monoterpenes as sole carbon source under oxic as well as anoxic conditions. A biotransformation pathway of the acyclic β-myrcene required linalool dehydratase-isomerase as initial enzyme acting on the hydrocarbon. An in-frame deletion mutant did not use myrcene, but was able to grow on monocyclic monoterpenes. The genome sequence and a comparative proteome analysis together with a random transposon mutagenesis were conducted to identify genes involved in the monocyclic monoterpene metabolism. Metabolites accumulating in cultures of transposon and in-frame deletion mutants disclosed the degradation pathway. RESULTS: Castellaniella defragrans 65Phen oxidizes the monocyclic monoterpene limonene at the primary methyl group forming perillyl alcohol. The genome of 3.95 Mb contained a 70 kb genome island coding for over 50 proteins involved in the monoterpene metabolism. This island showed higher homology to genes of another monoterpene-mineralizing betaproteobacterium, Thauera terpenica 58Eu(T), than to genomes of the family Alcaligenaceae, which harbors the genus Castellaniella. A collection of 72 transposon mutants unable to grow on limonene contained 17 inactivated genes, with 46 mutants located in the two genes ctmAB (cyclic terpene metabolism). CtmA and ctmB were annotated as FAD-dependent oxidoreductases and clustered together with ctmE, a 2Fe-2S ferredoxin gene, and ctmF, coding for a NADH:ferredoxin oxidoreductase. Transposon mutants of ctmA, B or E did not grow aerobically or anaerobically on limonene, but on perillyl alcohol. The next steps in the pathway are catalyzed by the geraniol dehydrogenase GeoA and the geranial dehydrogenase GeoB, yielding perillic acid. Two transposon mutants had inactivated genes of the monoterpene ring cleavage (mrc) pathway. 2-Methylcitrate synthase and 2-methylcitrate dehydratase were also essential for the monoterpene metabolism but not for growth on acetate. CONCLUSIONS: The genome of Castellaniella defragrans 65Phen is related to other genomes of Alcaligenaceae, but contains a genomic island with genes of the monoterpene metabolism. Castellaniella defragrans 65Phen degrades limonene via a limonene dehydrogenase and the oxidation of perillyl alcohol. The initial oxidation at the primary methyl group is independent of molecular oxygen