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41.
R. Trendelenburg Botteri Schulz Zimmermann Schulz Gustav G. Klem Frey-Wyssling O. Kratky A. v. Wacek O. Kratky G. Becker Egner Graf B. Thunell M. Lüdtke S. Nickel A. Kraus Klar Finkbeiner Müller E. Becker Zimmermann v. Pohl Lechner Richard Huber L. Metz Thiele Schlüter Egner W. Wenhart Graf Kinberg Kraemer 《Holz als Roh- und Werkstoff》1940,3(5):165-174
Ohne Zusammenfassung 相似文献
42.
Jeremy Rott Eva Teresa Toepfer Maria Bartosova Ana Kolevica Alexander Heuser Michael Rabe Geert Behets Patrick C. DHaese Viktoria Eichwald Manfred Jugold Ivan Damgov Sotirios G. Zarogiannis Rukshana Shroff Anton Eisenhauer Claus Peter Schmitt 《International journal of molecular sciences》2022,23(14)
Serum calcium isotopes (δ44/42Ca) have been suggested as a non-invasive and sensitive Ca balance marker. Quantitative δ44/42Ca changes associated with Ca flux across body compartment barriers relative to the dietary Ca and the correlation of δ44/42CaSerum with bone histology are unknown. We analyzed Ca and δ44/42Ca by mass-spectrometry in rats after two weeks of standard-Ca-diet (0.5%) and after four subsequent weeks of standard- and of low-Ca-diet (0.25%). In animals on a low-Ca-diet net Ca gain was 61 ± 3% and femur Ca content 68 ± 41% of standard-Ca-diet, bone mineralized area per section area was 68 ± 15% compared to standard-Ca-diet. δ44/42Ca was similar in the diets, and decreased in feces and urine and increased in serum in animals on low-Ca-diet. δ44/42CaBone was higher in animals on low-Ca-diet, lower in the diaphysis than the metaphysis and epiphysis, and unaffected by gender. Independent of diet, δ44/42CaBone was similar in the femora and ribs. At the time of sacrifice, δ44/42CaSerum inversely correlated with intestinal Ca uptake and histological bone mineralization markers, but not with Ca content and bone mineral density by µCT. In conclusion, δ44/42CaBone was bone site specific, but mechanical stress and gender independent. Low-Ca-diet induced marked changes in feces, serum and urine δ44/42Ca in growing rats. δ44/42CaSerum inversely correlated with markers of bone mineralization. 相似文献
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44.
Christian F. Janßen Stephan T. Grilli Manfred Krafczyk 《Computers & Mathematics with Applications》2013,65(2):211-229
In this paper, we present extensions, extensive validations and applications of our previously published hybrid volume-of-fluid-based (VOF) model for the simulation of free-surface flow problems. For the solution of the flow field, the lattice Boltzmann method is used, where the free surface is represented by a VOF approach. The advection equation for the VOF fill level is discretized with a finite volume method, on the basis of a 3D Piecewise Linear Interface Reconstruction (PLIC) algorithm. The model is validated for several standard free surface benchmarks, such as breaking dam scenarios and a free falling jet. Finally, the hybrid algorithm is applied to the simulation of a wave breaking by overturning during shoaling, which is considered to be a demanding test case, especially for VOF solvers. In this case, the flow field is initialized early in the shoaling process with a solitary wave solution from inviscid, irrotational potential flow. The wave breaking process is then simulated with the 3D transient and turbulent LBM–VOF solver. All validation and benchmark tests confirm the accuracy of the proposed hybrid model. 相似文献
45.
Manfred Jeitler 《控制论与系统》2013,44(3-4):315-333
This article gives an introduction into the current understanding of time invariance and evidence of its violation in experimental particle physics. The connection between time invariance and other discrete symmetries, particularly, CP-invariance, is explained. The first experimental determination of CP-violation is explained, and recent experiments on CP-violation and on T-violation are discussed. 相似文献
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In case of a reinforced concrete structure being exposed to bond stresses that transfer great forces, a relative displacement between reinforcing bar and concrete occurs. The slip is an important parameter in order to evaluate the quality of the bond concerning repeated pullout loads. A rapid slip increase is caused by bond weakening due to longitudinal cracks resulting from transverse tension. Within the bond area the slip is not uniformly distributed along the reinforcing bar. It is still unexplained how far fatigue and transverse tension affect the distribution. This paper focuses on the development of the slip curve under repeated loading and transverse tension. Results from cyclic pullout tests were applied and particularly the slip difference between the loaded and unloaded end of the pullout bar was investigated. It could be observed that both an increase in load cycles and transverse tension did not cause an appreciable change in slip difference. 相似文献
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49.
Fabian Heinemann Meike Gummich Manfred Radmacher Monika Fritz 《Materials science & engineering. C, Materials for biological applications》2011,31(2):99-105
Mineral growth in nacre and other CaCO3-containing biominerals is controlled by biopolymers. Water-soluble proteins were extracted from nacre of the sea snail Haliotis laevigata by dissolving the mineral phase with 6% acetic acid. The influence of this protein mixture on CaCO3 precipitation rates was investigated at different concentrations. A well-established assay for measuring the pH-value during CaCO3 precipitation with and without protein additives was extended by calculating maximum precipitation rates from the pH-values. It could be shown that precipitation rates are greatly influenced by the mixtures of water-soluble nacre proteins. At very low protein concentrations (0.02 μg/ml) a rate enhancement in comparison to the pure supersaturated calcium carbonate solution by a factor of 1.4 was observed. At higher protein concentrations, a strong inhibitory effect occurred, with total inhibition at concentrations of 1.0 μg/ml and higher. Two unspecific proteins (bovine serum albumin and lysozyme) showed little or no modification of precipitation rates. In vivo, the function of the strong inhibition of CaCO3 precipitation by nacre proteins at higher concentrations is presumably to prevent uncontrolled crystallization in the extrapallial fluid. The rate-enhancing capability of proteins at low concentrations may be explained by the presence of acidic and/or hydrophilic moieties. 相似文献
50.