Einfluß der Gefügeausbildung auf das Korrosionsverhalten von hochmolybdänhaltigen austenitischen Chrom-Nickel-Stählen

Untersuchung der Gefügeausbildung sowie der mechanischen und Korrosionseigenschaften an vier austenitischen CrNi-Stählen mit 4,6, 7,4, 8,5 und 8,8% Mo nach dem Lösungsglühen. Ausscheidungsverhalten nach isothermen Anlaßglühungen und Einfluß der Gefügeausbildung auf das Korrosionsverhalten.     

Intensity and pattern discrimination in turtles after lesions of nucleus rotundus.

In turtles, the nucleus rotundus, a dorsal thalamic cell group, is known to receive a massive input from the optic tectum. Electrophysiological and anatomical data indicate that nucleus rotundus has a role in visual functions. To study role, 21 eastern painted turtles (Chrysemys picta picta) were trained in an appetitive situation on a simultaneous intensity discrimination or a simultaneous pattern discrimination. After reaching criterion, most Ss received lesions aimed at nucleus rotundus. Two Ss in the intensity-discrimination group received sham lesions. Following surgery, Ss were retrained and then sacrificed, and the lesion damage in each S was reconstructed. Ss with severe damage to nucleus rotundus were unable to relearn the discriminative task, and those with moderate amounts of damage required more sessions to relearn than they had required preoperatively. Ss with slight damage to nucleus rotundus were unimpaired. For both the intensity- and the pattern-discrimination groups, there was a significant correlation between postoperative performance and amount of damage to nucleus rotundus. Results suggest that nucleus rotundus plays a critical role in visual discriminative functions in the turtle. (57 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Die Verdampfung von Kupfer,Mangan und Chrom aus Schmelzen des Stahles X 5 CrNi 18 9 unter vermindertem Druck

Untersuchung der Verdampfung von Kupfer, Mangan und Chrom sowie weiterer Begleitelemente aus Schmelzen des Stahles X 5 CrNi 18 9 im Vakuuminduktionsofen bei Drücken zwischen 100 und 10^?4 Torr und Temperaturen zwischen 1550 und 1650 °C. Erörterung der Ergebnisse an Reineisen- und Roheisenvergleichsschmelzen. Beschreibung der Verdampfungsvorgänge durch eine Reaktionsgleichung erster Ordnung.     

Synthesis and characterization of resorcinol-cinnamaldehyde resins

The mechanisms and kinetics of the reaction between resorcinol and cinnamaldehyde were studied by means of ¹³C-NMR spectroscopy, HPLC, and GPC. In the first step the addition of resorcinol to the double bond and to the carbonyl group of cinnamaldehyde takes place. In the second step of reaction the lower molecular weight oligomers form compounds with groups with molecular weights between 1500 and 2500. The red coloured resin reacts at temperatures above 150°C with crosslinking agents to form an insoluble and highly crosslinked product.     

Die Aktivität des Sauerstoffs in molybdän-, wolfram-, niob-oder tantalhaltigen Eisenschmelzen

Anwendung der Festelektrolytzellen PtRh-Luft || stabilisiertes ZrO₂ || Eisenschmelze-festes Eisen und Ir–H₂O, H₂ || stabilisiertes ZrO₂ || Eisenschmelze–festes Eisen zur Bestimmung der Sauerstoffaktivität in molybdän-, wolfram-, niob- oder tantalhaltigen Eisenschmelzen bei 1600 °C. Ermittlung der Wirkungskoeffizienten der Elemente Molybdän, Wolfram, Niob und Tantal für die Beeinflussung der Sauerstoffaktivität aus dem Vergleich der elektrochemisch gemessenen Sauerstoffaktivitäten und der durch die Analyse bestimmten Sauerstoffgehalte der Schmelzen. Zusammenstellung aller von den Verfassern bisher durch EMK-Messungen ermittelten Wirkungsparameter e^X_O in Eisenschmelzen.     

Lack of regression of preestablished gallstones in mice

Feeding a high cholesterol, high cholic acid diet to mice for 28 days caused increased concentrations of plasma and liver cholesterol and formation of gallstones. Removal of cholesterol and cholic acid from the diet led to normalization of plasma and liver cholesterol within 28 days. Regression of the preestablished gallstones did not occur within 107 days.     

Effect of grain size,cold work,loading frequency and temperature on fatigue limit of mild steel

Fatigue tests are performed on mild steel (0.07 pct ?C) having different grain sizes or 5 and 10 pct cold work at frequencies of 83.3 Hz (LF) and 23 kHz (HF) at room and elevated temperatures. The fatigue limit was found to be a function ofd ^?1/2, whered is grain size, for HF loading at different temperature conditions. The ratio between fatigue limits determined at various frequencies and different temperatures during testing was found not to be strongly dependent on grain size. Prior cold work increased the HF fatigue limit atRT. HF tests at room temperature displayed higher fatigue limits than for LF loading. Increases in temperature during HF tests significantly decreased the fatigue limit for different grain sizes and various amounts of cold work. These results are explained by physical-metallurgical models.     

Dependence of the wave-front aberration on the radius of the reference sphere

Wave-front aberration is a basic characteristic of the imaging properties of optical systems. The value of the wave-front aberration is obtained by calculating the difference between the optical path lengths of the real wave front and the reference sphere. The general relations for calculated dependence of the wave-front aberration on the radius of the reference sphere are given.