Psychometrische Analyse, Dimensionalität und Leistungskorrelate von Mental Toughness im Springreiten

Mental Toughness gilt mittlerweile als wichtiger Faktor für Erfolg. In der vorliegenden Studie sollen Österreichische Springreiter hinsichtlich dieser Aussage und weiterer Leistungskorrelate untersucht werden. Abschließend wurde eine Dominanzanalyse vorgenommen, die die Erfolgsfaktoren gewichten sollte. Als wichtigster Faktor stellte sich Erfahrung, Training und die Anzahl der Turnierpferde mit 70.9914% heraus. Während die Hand-grip strength und die Persönlichkeit noch 16.9483% und 8.2787% der erklärten Varianz betragen, erzielt die Mental Toughness ein geringeres Ergebnis von 2.9885%. Für das 2D:4D Fingerlängenverhältnis konnte der erwartete Geschlechtsunterschied nicht gefunden werden. Auch hinsichtlich der Mental Rotation von Springreitern bedarf es noch weiterer Forschung. Ebenso stand eine Analyse der drei Verfahren zur Untersuchung des Konstrukts Mental Toughness mittels explorativer und konfirmatorischer Faktorenanalyse im Vordergrund, wodurch die Schwächen und Stärken der verschiedenen Verfahren gezeigt werden konnten

Phase-field modelling of ternary eutetic solidification in hot dip galvanization

Continuous hot dip galvanizing is one of the commercially most important process techniques used for protecting steel sheets against corrosion. Preheated steel sheets are con-tinuously drawn through a pot with a molten zinc alloy. After passing a gas jet that controls the layer thickness multiple cooling units act to cool down the sheet. During passing these aggregates nucleation, dendritic primary solidification and the formation of a binary and ter-nary eutectic occurs. In the present paper, the coupled modelling of macroscopic heat flow, multiphase thermodynamics and crystal growth during solidification of a Zn-2.5 wt.% Al-1.5 wt.% Mg alloy is presented. The heat flow problem requires a numerical domain in the order of meters, growth of primary Zn-dendrites in the order of several hundred micrometers, and the interdendritic eutectic in the order of several nanometers. For technical alloys like the ternary system considered here, a thermodynamic database has been online linked to a phase-field model to describe phase transformations including all occurring solid/liquid or sol-id/solid interfaces. Process simulations have been used for getting appropriate thermal bound-ary conditions for 3D phase field simulations which were performed at three different length-scales. For modelling primary dendritic Zn-a seed density model was used for predicting the grain structure within the Zn layer. At a smaller length-scale, a small part of a Zn-dendrite surface was taken as starting point for simulating the transition between primary binary eutec-tic and ternary eutectic coupled growth of Zn-rich, Al-rich, and MgZn2-phases. Finally, the morphology of the ternary eutectic has been evaluated at the smallest length scale. The com-parison with real solidification microstructure reveals encouraging agreements

Investigation of Peritectic Solidification Morphologies by Using the Binary Organic Model System TRIS-NPG

Under pure diffusive growth conditions, layered peritectic solidification is possible. In reality, the competitive growth of the primary α-phase and the peritectic β-phase revealed some complex peritectic solidification morphologies due to thermo-solutal convection. The binary organic components Tris-(hydroxylmenthyl) aminomethane-(Neopentylglycol) were used as a model system for metal-like solidification. The transparency of the high-temperature non-faceted phases allows for the studying of the dynamic of the solid/liquid interface that lead to peritectic solidification morphologies. Investigations were carried out by using the Bridgman technic for process conditions where one or both phases solidify in a non-planar manner. Different growth conditions were observed, leeding to competitive peritectic growth morphologies. Additionally, the competitive growth was solved numerically to interpret the observed transparent solidification patterns

Phase-field modelling of ternary eutetic solidification in hot dip galvanization

Continuous hot dip galvanizing is one of the commercially most important process techniques used for protecting steel sheets against corrosion. Preheated steel sheets are con-tinuously drawn through a pot with a molten zinc alloy. After passing a gas jet that controls the layer thickness multiple cooling units act to cool down the sheet. During passing these aggregates nucleation, dendritic primary solidification and the formation of a binary and ter-nary eutectic occurs. In the present paper, the coupled modelling of macroscopic heat flow, multiphase thermodynamics and crystal growth during solidification of a Zn-2.5 wt.% Al-1.5 wt.% Mg alloy is presented. The heat flow problem requires a numerical domain in the order of meters, growth of primary Zn-dendrites in the order of several hundred micrometers, and the interdendritic eutectic in the order of several nanometers. For technical alloys like the ternary system considered here, a thermodynamic database has been online linked to a phase-field model to describe phase transformations including all occurring solid/liquid or sol-id/solid interfaces. Process simulations have been used for getting appropriate thermal bound-ary conditions for 3D phase field simulations which were performed at three different length-scales. For modelling primary dendritic Zn-a seed density model was used for predicting the grain structure within the Zn layer. At a smaller length-scale, a small part of a Zn-dendrite surface was taken as starting point for simulating the transition between primary binary eutec-tic and ternary eutectic coupled growth of Zn-rich, Al-rich, and MgZn2-phases. Finally, the morphology of the ternary eutectic has been evaluated at the smallest length scale. The com-parison with real solidification microstructure reveals encouraging agreements

Determination of Cooling Rate and Temperature Gradient during Formation of Cathode Spot Craters in a Vacuum Arc

Due to the extreme thermal conditions and short lifetimes, experimental exploration of cathode spots in vacuum arcs is very difficult. The intensive heat in the cathode spot is believed to be generated by ion bombardment and by Joule heating. However, thermal conditions occurring inside the re-melted material in craters created by cathode spots are not accurately known. During the exposure to cathodic arc plasmas, an Al-Cr cathode’s surface was locally melted by successive ignition and extinction of cathode spots. The melted layer, that quickly solidified, was characterized by the formation of several thin layers with a thickness of a few micrometers that were stacked on top of each other. The corresponding solidification patterns displayed cellular and dendritic microstructures. A phase field-based model was used to simulate and determine the thermal process conditions that led to the dendritic structures observed within the re-melted layer. Different combinations of cooling rates and temperature gradients were numerical explored to determine the most probable thermal conditions under which the cathode material re-solidifies. The results showed that the material in the vicinity of the cathode spot crater re-solidified under the condition of a cooling rate of about 3 × 105 K/s and a temperature gradient of about 6 × 107 K/m. These results constitute valuable data for the validation of numerical models dedicated to cathode spot formation

Advanced solidification studies on transparent alloy systems: A new european solidification insert for Material Science Glovebox on board the International Space Station

International audienceInvestigations on solidifying transparent model alloys have served frequently to gain knowledge on physical phenomena occurring during solidification of metallic alloys. However, quantitative results were only possible to obtain in thin samples where convection can successfully be suppressed. Quantitative studies on three dimensional phenomena not being affected by natural convection are thus only possible under microgravity conditions. Therefore, the European Space Agency (ESA) is planning to launch a new insert for the Material Science Glovebox (MSG) on board of the International Space Station (ISS) for studies on solidification phenomena in thick samples. Four different classes of transparent model alloys will be used to address the following scientific topics: (i) Columnar to Equiaxed Transition in Solidification Processing, (ii)Novel Peritectic Structures and In-Situ Composites; (iii) Solidification alongan Eutectic Path in Binary Alloys; and (iv) Solidification along an Eutectic Path in Ternary Alloys. Here, we give details on the scientific objectives and the operational features ESA's new solidification device will offer

Advanced solidification studies on transparent alloy systems: A new european solidification insert for Material Science Glovebox on board the International Space Station

International audienceInvestigations on solidifying transparent model alloys have served frequently to gain knowledge on physical phenomena occurring during solidification of metallic alloys. However, quantitative results were obtainable in thin samples where convection can successfully be suppressed. Quantitative studies on three-dimensional phenomena not being affected by natural convection are thus only possible under microgravity conditions. Therefore, the European Space Agency (ESA) is planning to launch a new insert for the material science glovebox on board of the International Space Station for studies on solidification phenomena in thick samples. Four different classes of transparent model alloys will be used to address the following scientific topics: (I) columnar to equiaxed transition in solidification processing, (II) novel peritectic structures and in situ composites; (III) solidification along an eutectic path in binary alloys; and (IV) solidification along an eutectic path in ternary alloys. In this article, we give details on the scientific objectives and the operational features ESA's new solidification device will offer