Showing papers by "National University of Cuyo published in 1972"
TL;DR: In this article, the formation of junctions between a moving dislocation and the trees of a dislocation forest has been calculated for f.c.z. crystals, and the concept of the orientation-dependent line energy and a more realistic averaging procedure was used.
Abstract: The formation of junctions between a moving dislocation and the trees of a dislocation forest has been calculated for f.c.c. crystals. In contrast to previous estimates the concept of the orientation-dependent line energy and a more realistic averaging procedure was used. In a random forest in which the tree length is equal to the tree separation only about 20% of the trees form junctions. The stress to overcome the junctions is higher for screw dislocations than for edges but the exact values depend on the nature of the forest.
Die Bildung von Versetzungsreaktionen zwischen einer bewegten Versetzung und den Baumen eines Versetzungswaldes wurde fur k.f.z. Kristalle berechnet. Im Gegensatz zu fruheren Abschatzungen wurde die Orientierungsabhangigkeit der Linienenergie berucksichtigt und eine realistischere Mittelung vorgenommen. In einem regellosen Wald, dessen Baumlange gleich dem Baumabstand ist, reagieren nur etwa 20% der Baume. Die Spannung, um die Rekombinationen aufzulosen, ist hoher fur Schraubenversetzungen als fur Stufenversetzungen. Die genauen Werte hangen jedoch von der Natur des Waldes ab.
146 citations
TL;DR: The low temperature specific heat of the weakly magnetic system Th U has been measured in both the normal and superconducting states as mentioned in this paper, and impurities are found to enhanve the normal state electronic specific heat coefficient γ at an unusually large rate of 4.85 ± 0.50 mJ/mole °K2 at.
34 citations
21 citations
TL;DR: In all the species studied, their plasma shows strong bradykininolytic activity, which disappears on boiling, and no kininogen was detected in toad, chicken, poultry, and turkey.
19 citations
TL;DR: In this paper, the second and fourth-order spin-lattice coefficients have been measured as a function of temperature between 4 and 360 \ifmmode^\circ\else\textdegree\fi{}K by electron-paramagnetic resonance experiments in uniaxially stressed crystals.
Abstract: The second- and fourth-order spin-lattice coefficients of ${\mathrm{Gd}}^{3+}$ in cubic positions of Th${\mathrm{O}}_{2}$ and Ce${\mathrm{O}}_{2}$ crystals have been measured as a function of temperature between 4 and 360 \ifmmode^\circ\else\textdegree\fi{}K by electron-paramagnetic-resonance experiments in uniaxially stressed crystals. The second-order coefficients are considerably different for the two crystals, and these coefficients show a large variation with temperature. A detailed theoretical calculation of these coefficients has not been carried out; however, it is possible to qualitatively interpret the observed temperature variation in terms of effects due to the modulation of the orbit-lattice interaction by the lattice vibrations. The temperature-variation curves are explained using an Einstein model for the vibrations of the oxygen ligands of the paramagnetic ions. The fourth-order coefficients are similar for the two crystals and are temperature independent in the range studied. The effect of a hydrostatic strain on the energy levels of the ion is used to explain the observed temperature variation of the cubic field parameter in terms of the thermal expansion of the crystal.
15 citations
TL;DR: In this article, large and transparent platelets of red HgI 2 have been obtained by sublimation in vacuum and these platelets grow directly in the tetragonal phase.
14 citations
TL;DR: Renin content is lowest in fish, amphibians and reptiles, higher in aves (about 5–9 ng/mg), reaching its highest level in most mammals (hare and rabbit have more than ten times the content of the lowest group), but in the mammal there are some exceptions.
14 citations
TL;DR: In this article, the temperature dependence of the second order spin-lattice coefficients of Gd 3+ in CaF 2 was measured and compared with those obtained for Gd3+ in ThO 2 and CeO 2.
8 citations
TL;DR: Strain 89 of Clostridium botulinum type G produces a protein which behaves as a cryoprotein, and it is shown that this protein can be converted to a non-volatile substance which can be injected into the body and excites the immune system.
Abstract: Strain 89 of Clostridium botulinum type G produces a protein which behaves as a cryoprotein.
6 citations
TL;DR: The fact that divalent rare earth impurities have a strong effect in lowering the α-γ transition temperature in Ce, allows the γ phase to become stable at low temperature without much change in its physical properties as discussed by the authors.
5 citations
TL;DR: In this paper, the contributions of three mechanisms to second-order spin-lattice coefficients of Gd3+ in CaO, CaF2, Tho2, and CeO2, are calculated with a point-charge approach for the orbit-Lattice parameters.
Abstract: The contributions of three mechanisms to second-order spin-lattice coefficients of Gd3+ in CaO, CaF2, Tho2, and CeO2, are calculated with a point-charge approach for the orbit-lattice parameters. It is seen that for Gd3+ the Blume and Orbach mechanism has not the importance as for the 3d5 ions, Mn2+ and Fe3+. With the Blume and Orbach mechanism, a relativistic second-order and a mechanism of fourth order a sign agreement for both coefficients of Gd3+ in CaO and for the tetragonal coefficient in the other lattices is obtained, but not for the trigonal distortions.
Die Beitrage von drei Mechanismen zu den Spin-Gitter-Koeffizienten zweiter Ordnung von Gd3+ in CaO, CaF2, Tho2, und CeO2, sind mit einem punktformigen Ladungsmodell fur die Bahn-Gitter-Parameter berechnet worden. Es ergibt sich, das der Blume- und Orbach-Mechanismus fur Gd3+ nicht dieselbe Bedeutung wie fur die 3d5-Ionen, Mn2+ und Fe3+, hat. Mit dem Blume- und Orbach-Mechanismus, einem relativistischen Mechanismus zweiter Ordnung und einem Mechanismus vierter Ordnung, stimmen die Vorzeichen der gemessenen und berechneten Spin-Gitter-Koeffizienten fur CaO uberein. Fur die anderen Gitter werden die richtigen Vorzeichen der tetragonalen Koeffizienten erhalten, doch nicht die der trigonalen.
TL;DR: L'activité de la rénine de coupes de reins de rats et celle de the rénine libérée par elles pendant une incubation de 2 heures ont été mesurées.
Abstract: L'activite de la renine de coupes de reins de rats et celle de la renine liberee par elles pendant une incubation de 2 heures ont ete mesurees. Les coupes temoins ont libere 22% de leur contenu original. Apres adjonction d'albumine serique, la quantite de renine liberee etait de 49%.
TL;DR: Las isoenzimas de la LDH se separan por electroforesis en gel de agar, y luego de colorear con una sal de tetrazolio, se cuantifican empleando una técnica rápida de elución; los resultados no difieren significativamente de los obtenidos por cuantIFICación densitométrica.
Abstract: Las isoenzimas de la LDH se separan por electroforesis en gel de agar, y luego de colorear con una sal de tetrazolio, se cuantifican empleando una tecnica rapida de elucion; los resultados no difieren significativamente de los obtenidos por cuantificacion densitometrica.