28,567 research outputs found
The Crystallography of Strange Quark Matter
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
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
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
and whose position-space dependence is that of two
plane waves with wave vectors and 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 limit as expected, find that it correctly predicts
that decreases with increasing angle between and meaning that the phase with has the lowest
free energy, and find that the Ginzburg-Landau approximation is conservative in
the sense that it underestimates at all values of the angle between
and .Comment: 16 pages, 6 figures. Small changes only. Version to appear in Phys.
Rev.
The general dielectric tensor for bi-kappa magnetized plasmas
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
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
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
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
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
- …