28,567 research outputs found

    The Crystallography of Strange Quark Matter

    Get PDF
    Cold three-flavor quark matter at large (but not asymptotically large) densities may exist as a crystalline color superconductor. We explore this possibility by calculating the gap parameter Delta and free energy Omega(Delta) for possible crystal structures within a Ginzburg-Landau approximation, evaluating Omega(Delta) to order Delta^6. We develop a qualitative understanding of what makes a crystal structure stable, and find two structures with particularly large values of Delta and the condensation energy, within a factor of two of those for the CFL phase known to characterize QCD at asymptotically large densities. The robustness of these phases results in their being favored over wide ranges of density and though it also implies that the Ginzburg-Landau approximation is not quantitatively reliable, previous work suggests that it can be trusted for qualitative comparisons between crystal structures. We close with a look ahead at the calculations that remain to be done in order to make contact with observed pulsar glitches and neutron star cooling.Comment: 6 pages, 3 figures. Contribution to the proceedings of Strangeness in Quark Matter 2006, UCLA. Talk given by Rishi Sharm

    Rare Coinfection of Scrub Typhus and Malaria in Immunocompetent Person

    Get PDF
    Scrub Typhus, or tsutsugamushi disease is a febrile illness caused by bacteria of the family Rickettsiaceae and named Orientia tsutsugamushi. Recently it has been found to endemic in Subhimalayan region of India.Malaria is highly endemic in rest of India but its prevalence is low in Subhimalayan region because of the altitude. We report a rare case of a patient having coinfection with scrub typhus and malaria

    Testing the Ginzburg-Landau approximation for three-flavor crystalline color superconductivity

    Full text link
    It is an open challenge to analyze the crystalline color superconducting phases that may arise in cold dense, but not asymptotically dense, three-flavor quark matter. At present the only approximation within which it seems possible to compare the free energies of the myriad possible crystal structures is the Ginzburg-Landau approximation. Here, we test this approximation on a particularly simple "crystal" structure in which there are only two condensates Δexp(iq2r) \sim \Delta \exp(i {\bf q_2}\cdot {\bf r}) and Δexp(iq3r) \sim \Delta \exp(i {\bf q_3}\cdot {\bf r}) whose position-space dependence is that of two plane waves with wave vectors q2{\bf q_2} and q3{\bf q_3} at arbitrary angles. For this case, we are able to solve the mean-field gap equation without making a Ginzburg-Landau approximation. We find that the Ginzburg-Landau approximation works in the Δ0\Delta\to 0 limit as expected, find that it correctly predicts that Δ\Delta decreases with increasing angle between q2{\bf q_2} and q3{\bf q_3} meaning that the phase with q2q3{\bf q_2}\parallel {\bf q_3} has the lowest free energy, and find that the Ginzburg-Landau approximation is conservative in the sense that it underestimates Δ\Delta at all values of the angle between q2{\bf q_2} and q3{\bf q_3}.Comment: 16 pages, 6 figures. Small changes only. Version to appear in Phys. Rev.

    The general dielectric tensor for bi-kappa magnetized plasmas

    Get PDF
    In this paper we derive the dielectric tensor for a plasma containing particles described by an anisotropic superthermal (bi-kappa) velocity distribution function. The tensor components are written in terms of the two-variables kappa plasma special functions, recently defined by Gaelzer and Ziebell [Phys. Plasmas 23, 022110 (2016)]. We also obtain various new mathematical properties for these functions, which are useful for the analytical treatment, numerical implementation and evaluation of the functions and, consequently, of the dielectric tensor. The formalism developed here and in the previous paper provides a mathematical framework for the study of electromagnetic waves propagating at arbitrary angles and polarizations in a superthermal plasma.Comment: Accepted for publication in Physics of Plasma

    Proposed Model for Degradation of Gunn Diodes as Observed from Study of the I-V Characteristics

    Get PDF
    The effect of heat treatment on the functional Gunn diodes has been investigated in the temperature range of 200-300°C. The influence of electricfield during heat treatment has also been studied. The simple variations in I-V characteristics with annealing time have been utilized to interpret the contact behaviour

    Confinement and Viscoelastic effects on Chain Closure Dynamics

    Full text link
    Chemical reactions inside cells are typically subject to the effects both of the cell's confining surfaces and of the viscoelastic behavior of its contents. In this paper, we show how the outcome of one particular reaction of relevance to cellular biochemistry - the diffusion-limited cyclization of long chain polymers - is influenced by such confinement and crowding effects. More specifically, starting from the Rouse model of polymer dynamics, and invoking the Wilemski-Fixman approximation, we determine the scaling relationship between the mean closure time t_{c} of a flexible chain (no excluded volume or hydrodynamic interactions) and the length N of its contour under the following separate conditions: (a) confinement of the chain to a sphere of radius D, and (b) modulation of its dynamics by colored Gaussian noise. Among other results, we find that in case (a) when D is much smaller than the size of the chain, t_{c}\simND^{2}, and that in case (b), t_{c}\simN^{2/(2-2H)}, H being a number between 1/2 and 1 that characterizes the decay of the noise correlations. H is not known \`a priori, but values of about 0.7 have been used in the successful characterization of protein conformational dynamics. At this value of H (selected for purposes of illustration), t_{c}\simN^3.4, the high scaling exponent reflecting the slow relaxation of the chain in a viscoelastic medium

    Genetic Evaluation and AMMI Analysis for Salinity Tolerance in Diverse Wheat Germplasm

    Get PDF
    Soil salinity is one of the major environmental constraints in increasing agricultural crop production, especially wheat production in India. Screening of diverse germplasm in representative growing conditions is prerequisite for exploring traits with stable expression imparting salinity tolerance. A study was undertaken during 2011–2012 for characterizing wheat germplasm in three environments representing growing conditions of crop in Northern parts of India, estimating inter-relationship among traits and evaluating stability of trait conferring salinity tolerance. Significant value of mean square for observed trait across the environments signified presence of large variability in genotypes. Significant yield reduction was recorded in almost all genotypes in saline environment compared to non-saline condition. Ratio of potassium and sodium ion in leaf tissue (KNA); a key salt tolerance traits was found to be significantly correlated with biomass, SPAD value and plant height. Due to the presence of significant genotype × environment interaction (G × E) for KNA, additive main effect and multiplicative interaction (AMMI) model was utilized to study stability of KNA among genotypes and environments. IPCA1 and IPCA2 were found to be significant and explained more than 99 per cent of variation due to G × E. KRICHAUFF was having maximum trait value with specific adaptation while DUCULA 4 and KRL 19 were having general adaptability. AMMI2 biplot revealed high stability of Kharchia 65 and KRL 99 across environments. E1 (timely sown, non-saline soil) recorded maximum site mean while E2 (timely sown, sodic soil) was having minimum interaction with genotypes (AMMI1 = 1.383). Thus, our studies suggest that AMMI model is also useful for estimating adaptability of traits other than yield utilized for breeding salt tolerant wheat varieties

    A low energy theory for superfluid and solid matter and its application to the neutron star crust

    Full text link
    We formulate a low energy effective theory describing phases of matter that are both solid and superfluid. These systems simultaneously break translational symmetry and the phase symmetry associated with particle number. The symmetries restrict the combinations of terms that can appear in the effective action and the lowest order terms featuring equal number of derivatives and Goldstone fields are completely specified by the thermodynamic free energy, or equivalently by the long-wavelength limit of static correlation functions in the ground state. We show that the underlying interaction between particles that constitute the lattice and the superfluid gives rise to entrainment, and mixing between the Goldstone modes. As a concrete example we discuss the low energy theory for the inner crust of a neutron star, where a lattice of ionized nuclei coexists with a neutron superfluid.Comment: 21 pages, 1 figur
    corecore