Relativistic mean field theory for deformed nuclei with pairing correlations

We develop a relativistic mean field (RMF) description of deformed nuclei with the pairing correlations in the BCS approximation. The treatment of the pairing correlations for nuclei with the Fermi surface being close to the threshold of unbound states needs a special attention. To this end, we take the delta function interaction for the pairing interaction with the hope to pick up those states with the wave function being concentrated in the nuclear region and perform the standard BCS approximation for the single particle states generated by the RMF theory with deformation. We apply the RMF + BCS method to the Zr isotopes and obtain a good description of the binding energies and the nuclear radii of nuclei from the proton drip line to the neutron drip line.Comment: the version to be published in Progress of Theoretical Physic

Determining All Universal Tilers

A universal tiler is a convex polyhedron whose every cross-section tiles the plane. In this paper, we introduce a certain slight-rotating operation for cross-sections of pentahedra. Based on a selected initial cross-section and by applying the slight-rotating operation suitably, we prove that a convex polyhedron is a universal tiler if and only if it is a tetrahedron or a triangular prism.Comment: 18 pages, 12 figure

An analysis of the United States renal transplant patient population and organ survival characteristics: 1977 to 1980

An analysis of the United States renal transplant patient population and organ survival characteristics: 1977 to 1980. This study examines the relationship between renal transplant organ survival and the extent of HLA (human leukocyte antigen) A and B loci antigen matching. Combined dialysis and transplant records for patients in the End Stage Renal Disease Medical Information System (ESRD MIS), 1977 to 1980, were analyzed to examine transplant organ survival characteristics and changes in demographic pattern and donor types compared to previously reported studies of the United States transplant patients. Actuarial survival curves for high match (3 or 4 HLA A and B loci antigen matches) versus low match (0, 1, or 2 HLA A and B loci antigen matches) groups were analyzed for their relative difference and its statistical significance. In addition, this relationship was analyzed with controls for age, sex, race, mixed lymphocyte culture (MLC), crossmatch, and prior time on dialysis. For both cadaver and living related donor transplants, statistically significant differences were found between the survival curves of high and low match groups. Comparing low match and high match groups, there were differences in 1-year organ survival of 4.8 and 11.3%, respectively, for cadaver and living related donor transplants. MLC negative and crossmatch positive status appear to improve transplant organ survival beyond the effects of HLA matching. The study also designates several methodological problems inherent in transplant organ survival studies including: whether or not to include patient deaths as therapeutic failures, and whether or not to analyze transplant organ survival at one point in time or to compare overall survival curves for the entire study period.Analyse des caracteristiques de la population de malades transplantes renaux et de la survie d'organes aux etats-unis: 1977 à 1980. Cette étude examine la relation entre la survie de reins de transplantés et l'importance de la compatibilité HLA (antigène leucocytaire humain), pour les locus A et B. Les dossiers combinés de dialyse et de transplantation des malades du End Stage Renal Disease Medical Information System (ESRD MIS), de 1977 à 1980, ont été analysés pour examiner les caractéristiques de la survie des organes transplantés, et les modifications de l'aspect démographique et des types de donneurs par rapport aux études préalablement rapportées de malades transplantés aux Etats-Unis. Les courbes de survie actuarielles pour une forte compatibilité (compatibilité pour 3 ou 4 HLA A et B) par rapport à une faible compatibilité (0, 1 ou 2 HLA A et B) ont été analysées pour leur différence relative et leur signification statistique. En plus, cette relation a été analysée en contrôlant l'âge, le sexe, la race, les cultures mixtes de lymphocytes (MLC), les crossmatch, et la période de dialyse. Pour les transplants à partir de cadavres ou de donneurs vivants apparentés, des différences statistiquement significatives ont été trouvées entre les courbes de survie pour les groupes à forte ou à faible compatibilité HLA. Ce travail met en évidence certains problèmes méthodologiques inhérents aux études de survie des organes transplantés: faut-il ou non considérer les décès comme des échecs thérapeutiques et faut-il ou non analyser la survie de l'organe transplanté à un moment dans le temps ou comparer les courbes globales de survie pour la totalité de la période considérée

Spin Hall effect of conserved current: Conditions for a nonzero spin Hall current

We study the spin Hall effect taking into account the impurity scattering effect as general as possible with the focus on the definition of the spin current. The conserved bulk spin current (Shi et al. [Phys. Rev. Lett. 96, 076604 (2006)]) satisfying the continuity equation of spin is considered in addition to the conventional one defined by the symmetric product of the spin and velocity operators. Conditions for non-zero spin Hall current are clarified. In particular, it is found that (i) the spin Hall current is non-zero in the Rashba model with a finite-range impurity potential, and (ii) the spin Hall current vanishes in the cubic Rashba model with a $\delta$-function impurity potential.Comment: 5 pages, minor change from the previous versio

Hydrogen-Accreting Carbon-Oxygen White Dwarfs of Low Mass: Thermal and Chemical Behavior of Burning Shells

Numerical experiments have been performed to investigate the thermal behavior of a cooled down white dwarf of initial mass M_{\rm WD} = 0.516 M_{\sun} which accretes hydrogen-rich matter with Z = 0.02 at the rate $\dot{M}=10^{-8}$ \msun \yrm1, typical for a recurrent hydrogen shell flash regime. The evolution of the main physical quantities of a model during a pulse cycle is examined in detail. From selected models in the mass range $M_{\rm WD} = 0.52\div 0.68$ \msunend, we derive the borders in the $M_{\rm WD}$ - $\dot{M}$ plane of the steady state accretion regime when hydrogen is burned at a constant rate as rapidly as it is accreted. The physical properties during a hydrogen shell flash in white dwarfs accreting hydrogen-rich matter with metallicities Z = 0.001 and Z = 0.0001 are also studied. For a fixed accretion rate, a decrease in the metallicity of the accreted matter leads to an increase in the thickness of the hydrogen-rich layer at outburst and a decrease in the hydrogen-burning shell efficiency. In the $M_{\rm WD}$-$\dot{M}$ plane, the borders of the steady state accretion band are critically dependent on the metallicity of the accreted matter: on decreasing the metallicity, the band is shifted to lower accretion rates and its width in $\dot{M}$ is reduced.Comment: 31 pages and 10 Postscript figures; Accepted for publication on Ap

Thermo-elasticity for anisotropic media in higher dimensions

In this note we develop tools to study the Cauchy problem for the system of thermo-elasticity in higher dimensions. The theory is developed for general homogeneous anisotropic media under non-degeneracy conditions. For degenerate cases a method of treatment is sketched and for the cases of cubic media and hexagonal media detailed studies are provided.Comment: 33 pages, 5 figure

A G1-like globular cluster in NGC 1023

The structure of a very bright (MV = -10.9) globular cluster in NGC 1023 is analyzed on two sets of images taken with the Hubble Space Telescope. From careful modeling of King profile fits to the cluster image, a core radius of 0.55+/-0.1 pc, effective radius 3.7+/-0.3 pc and a central V-band surface brightness of 12.9+/-0.5 mag / square arcsec are derived. This makes the cluster much more compact than Omega Cen, but very similar to the brightest globular cluster in M31, G1 = Mayall II. The cluster in NGC 1023 appears to be very highly flattened with an ellipticity of about 0.37, even higher than for Omega Cen and G1, and similar to the most flattened clusters in the Large Magellanic Cloud.Comment: 14 pages, 3 figures, 1 table. Accepted for AJ, Oct 200