1,864 research outputs found
Homological invariants associated to semi-dualizing bimodules
Cohen-Macaulay dimension for modules over a commutative noetherian local ring
has been defined by A. A. Gerko. That is a homological invariant sharing many
properties with projective dimension and Gorenstein dimension. The main purpose
of this paper is to extend the notion of Cohen-Macaulay dimension for modules
over commutative noetherian local rings to that for bounded complexes over
non-commutative noetherian rings.Comment: 19 pages, to appear in J. Math. Kyoto Uni
Upper Cohen-Macaulay Dimension
In this paper, we define a homological invariant for finitely generated modules over a commutative noetherian local ring, which we call upper Cohen-Macaulay dimension. This invariant is quite similar to Cohen-Macaulay dimension that has been introduced by Gerko. Also we
define a homological invariant with respect to a local homomorphism of local rings. This invariant links upper Cohen-Macaulay dimension with Gorenstein dimension.</p
Local cohomology based on a nonclosed support defined by a pair of ideals
We introduce an idea for generalization of a local cohomology module, which
we call a local cohomology module with respect to a pair of ideals (I,J), and
study their various properties. Some vanishing and nonvanishing theorems are
given for this generalized version of local cohomology. We also discuss its
connection with the ordinary local cohomology.Comment: 28 pages, minor corrections, to appear in J. Pure Appl. Algebr
Specific-heat study on successive magnetic transitions in α-Dy2S3 single crystals under magnetic fields
Specific heat measurements in magnetic fields have been performed on !-Dy2S3 single crystal that shows successive magnetic transitions at TN1 = 11.4 K and TN2 = 6.4 K. The specific heat in no magnetic field exhibits sharp peaks at both temperatures of TN1 and TN2.The change of magnetic entropy across each transition is estimated as Rln2/2 per mol-Dy,which suggests magnetic moments on only one Dy site between two crystallographically inequivalent Dy sites order at each transition temperature. When the magnetic field is applied along the b-axis of the orthorhombic system, two peaks of the specific heat shift toward lower temperatures. On the other hand, the magnetic field perpendicular to the b-axis shifts the peaks toward higher temperatures. The TN1 shifts to 9.6 K (H// b) and 12.5 K (H⊥b) under the magnetic field of 2 T. The peak of TN2 broadens gradually with increasing magnetic field for each direction, and the peak is consequently obscure under the field of 2 T
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Hypoxic training increases maximal oxygen consumption in Thoroughbred horses well-trained in normoxia.
Hypoxic training is effective for improving athletic performance in humans. It increases maximal oxygen consumption (V̇O2max) more than normoxic training in untrained horses. However, the effects of hypoxic training on well-trained horses are unclear. We measured the effects of hypoxic training on V̇O2max of 5 well-trained horses in which V̇O2max had not increased over 3 consecutive weeks of supramaximal treadmill training in normoxia which was performed twice a week. The horses trained with hypoxia (15% inspired O2) twice a week. Cardiorespiratory valuables were analyzed with analysis of variance between before and after 3 weeks of hypoxic training. Mass-specific V̇O2max increased after 3 weeks of hypoxic training (178 ± 10 vs. 194 ± 12.3 ml O2 (STPD)/(kg × min), P<0.05) even though all-out training in normoxia had not increased V̇O2max. Absolute V̇O2max also increased after hypoxic training (86.6 ± 6.2 vs. 93.6 ± 6.6 l O2 (STPD)/min, P<0.05). Total running distance after hypoxic training increased 12% compared to that before hypoxic training; however, the difference was not significant. There were no significant differences between pre- and post-hypoxic training for end-run plasma lactate concentrations or packed cell volumes. Hypoxic training may increase V̇O2max even though it is not increased by normoxic training in well-trained horses, at least for the durations of time evaluated in this study. Training while breathing hypoxic gas may have the potential to enhance normoxic performance of Thoroughbred horses
Study on problems in detecting plural cracks by alternating flux leakage testing using 3D nonlinear eddy current analysis
The alternating magnetic flux leakage testing is used for the detection of cracks in a steel plate. A new technique of how to detect plural cracks, which are located at a very short distance from each other, using the parallel (x-) component of the leakage flux density is proposed. The behavior of leakage flux is examined using a three-dimensional edge-based hexahedral finite-element method. The effects of dimensions of search coils and cracks on the detection accuracy are illustrated. </p
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