Über die Kinetik der Reaktion von Eisen(II)-, Nickel(II)-und Kobalt(II)-oxyd mit Graphit

An plattenförmigen Proben aus Eisen(II)-, Nickel(II)- und Kobalt(II)-oxyd sowie an feinkörnigen Eisen(II)-oxydproben Untersuchung der Kinetik der Reaktion mit Graphit bei Temperaturen zwischen 920 und 1200 °C durch Messung der Gewichtsabnahme der Probe und des durch die Reaktion gebildeten Kohlendioxyds. Erörterung der Reaktionsmechanismen.     

Kerbzugversuch und Streckbiegeversuch – Prüfverfahren zur Kennzeichnung der Kaltumformbarkeit warm- und kaltgewalzter Flachprodukte

Beschreibung von zwei besonderen Prüfverfahren zur Kennzeichnung der Kaltumformbarkeit, inbesondere der Kantenrißempfindlichkeit von warm- und kaltgewalzten Blechen. Anwendung auf weiche und höherfeste Stähle im Dickenbereich von 1 mm bis 13 mm. Zusammenhang zwischen Kerbzugdehnung oder Ziehtiefe im Streckbiegeversuch einerseits und Blechdicke, Festigkeit, Gefüge und Einschlußausbildung sowie Textur andererseits. Beurteilung der Aussagefähigkeit beider Verfahren im Vergleich zu herkömmlichen Prüfverfahren.     

Quantitative assessment of thermal–hydraulic codes used for heavy water reactor calculations

The RD-14M large LOCA test, characterized by a reliable set of experimental data, was selected for an international standard problem exercise (SPE) entitled “Intercomparison and validation of computer codes for thermal–hydraulics safety analyses”. The activity was performed within the frame of International Atomic Energy Agency's (IAEAs) Technical Working Group on Advanced Technologies for Heavy Water Reactors (TWG-HWR). In this study, the recently improved fast Fourier transform based method (FFTBM) was used for accuracy quantification of RD-14M large LOCA test B9401 calculations of six participants using four different thermal–hydraulic codes. In addition, developing the capability to calculate the accuracy as a function of time-continues-valued accuracy, did further improvement of FFTBM. Namely, in the past only single valued accuracy parameters for selected time windows and time intervals were calculated. The objective of the study was to demonstrate that the new FFTBM is a powerful tool for quantitative assessment of thermal–hydraulic codes. For demonstration, the test from the facility simulating heavy water reactor was used. The blind accuracy analysis was completed based on solely experimental and calculated data. However, short discussions were held with the representative from Italy (co-author, here) regarding phenomenological windows, variables and void fraction weights selection. In general, the open accuracy analysis confirmed the results obtained in blind accuracy analysis. The main conclusions from accuracy analysis agree with the conclusions from the SPE intercomparison report, which was written independently. Finally, the results suggest that the accuracy of the best calculations of the RD-14M test is comparable with the best calculations of light water reactor experiments.     

A comparison of two practical approaches to preventing inter-span phase contacts during snow shedding on the same 110-kV overhead line

Field experiences in a few particular areas of Slovenia have shown that during periods of snowfall some overhead lines are randomly exposed to short-circuit events between conductors that lie in a vertical disposition. This paper presents two practical approaches to reducing the probability of these inter-span contacts that result from the snow shedding. Both approaches refer to the same overhead line, so that a direct comparison can be made. The first overhead-line circuit is equipped with phase spacers; the second one is equipped with V strings. Up to now, both approaches have served well in practice. In this paper a transmission line is presented, and the differences between the two approaches with regard to the design parameters are given. The advantages and disadvantages of both approaches are summarized.     

Internal oxidation of Ag–VC composites

The internal oxidation (IO) of Ag–VC composites containing 5 vol.% of carbide was examined at three oxidation temperatures (350, 400, 600 °C). Two mechanisms were observed due to the formation of double oxides with relatively low-melting points. At temperatures below the lowest eutectic point in situ, or diffusion less IO, was observed with the formation and growth of oxide layers surrounding the initial carbide. At temperatures above the eutectic point IO resulted in the formation of liquid oxide pools, which grew in size and developed into a network of oxides within the metal matrix. The kinetics confirmed the presence of two distinct mechanisms.     

Adaptive Response, Evidence of Cross-Resistance and Its Potential Clinical Use

Organisms and their cells are constantly exposed to environmental fluctuations. Among them are stressors, which can induce macromolecular damage that exceeds a set threshold, independent of the underlying cause. Stress responses are mechanisms used by organisms to adapt to and overcome stress stimuli. Different stressors or different intensities of stress trigger different cellular responses, namely induce cell repair mechanisms, induce cell responses that result in temporary adaptation to some stressors, induce autophagy or trigger cell death. Studies have reported life-prolonging effects of a wide variety of so-called stressors, such as oxidants, heat shock, some phytochemicals, ischemia, exercise and dietary energy restriction, hypergravity, etc. These stress responses, which result in enhanced defense and repair and even cross-resistance against multiple stressors, may have clinical use and will be discussed, while the emphasis will be on the effects/cross-effects of oxidants.     

An efficient lossy cartoon image compression method

Multimedia Tools and Applications - This paper introduces a new lossy approach for compression of cartoon images. The image is firstly partitioned into regions of roughly the same colour. The chain...     

Computational complexity and parallelization of the meshless local Petrov–Galerkin method

The computational complexity of the meshless local Petrov–Galerkin method (MLPG) has been analyzed and compared with the finite difference (FDM) and finite element methods (FEM) from the user point of view. Theoretically, MLPG is the most complex of the three methods. Experimental results show that MLPG, with appropriately selected integration order and dimensions of support and quadrature domains, achieves similar accuracy to that of FEM. The measurements of parallel complexity and speed-up indicate that parallel MLPG scales well on larger systems. The normalized computational complexity makes FEM the best choice. MLPG remains competitive if human assistance is needed for meshing.     

Zur schnellen Probenahme und Analyse des Wasserstoffs in technischen Stahlschmelzen

Messungen des bei der Probenahme aus technischen Stahlschmelzen in zwei verschieden schnell abkühlenden Typen der ?Absolut-Vakuumsaugkokille? von der erstarrenden und abkühlenden Probe abgegebenen Wasserstoffanteils. Einfluß der Legierungszusammensetzung und des Gefüges auf die Wasserstoffabgabe.