Effect of horizontal magnetic field on K\"{u}ppers-Lortz instability

We investigate the effect of an external horizontal magnetic field on the K\"{u}ppers-Lortz instability (KLI) in rotating Rayleigh-B\'{e}nard convection of Boussinesq fluids using weakly nonlinear theory along with linear theory. By KLI, we mean the instability where the two-dimensional roll solutions of the system occurring at the onset of convection becomes unstable against the perturbations by rolls oriented at different angle with the previous one as the rotation rate exceeds a critical value. The governing parameters, namely, the Prandtl number ($\mathrm{Pr}$), Taylor number ($\mathrm{Ta}$) and Chandrasekhar number ($\mathrm{Q}$) are varied in the ranges $0.8 \leq \mathrm{Pr} < \infty$, $0 < \mathrm{Ta} \leq 10^4$ and $0 \leq \mathrm{Q} \leq 10^4$ respectively by considering the vanishingly small magnetic Prandtl number limit. In the $\mathrm{Pr}\rightarrow \infty$ limit, magnetic field is found to inhibit the KLI by enhancing the critical Taylor number ($\mathrm{Ta}_c$) for its onset. On the other hand, for finite Prandtl number fluids, KLI is favored for lower $\mathrm{Q}$, and it is inhibited for higher $\mathrm{Q}$. Interestingly, in the finite Prandtl number range both KLI and small angle instability are manifested depending on the Prandtl number. No small angle instability is observed for $\mathrm{Pr} \geq 50$ and the rotation induced KLI is inhibited predominantly by the magnetic field. While, for $\mathrm{Pr} < 50$, along with the K\"{u}ppers-Lortz instability, small angle instability is also observed. However, in this case, KLI is favored for lower $\mathrm{Q}$, while it is inhibited for higher $\mathrm{Q}$.Comment: 13 pages, 13 figure

Chiral Properties of QCD Vacuum in Magnetars- A Nambu-Jona-Lasinio Model with Semi-Classical Approximation

The breaking of chiral symmetry of light quarks at zero temperature in presence of strong quantizing magnetic fiels is studied using Nambu-Jona-Lasinio (NJL) model with Thomas-Fermi type semi-classical formalism. It is found that the dynamically generated light quark mass can never become zero if the Landau levels are populated and the mass increases with the increase of magnetic field strength.Comment: REVTEX 11 Pages, One .eps figure (included

Exploitation of IAA Producing PGPR on mustard (Brassica nigra L.) seedling growth under cadmium stress condition in comparison with exogenous IAA application

Soil pollution by cadmium (Cd) is a global threat for plants and animals. Exogenous auxin application reduces the Cd stress on plants. Moreover, IAA production by rhizospheric bacteria can play a key role in plant growth and development by promoting cell division, cell elongation, cell differentiation, flowering and lateral root formation. The present study was to evaluate the efficiency of IAA producing, Cd tolerant plant growth promoting rhizobacteria for plant (Brassica nigra L.) growth under Cd stressed condition comparing with the external synthetic auxin application. Lysinibacillus varians and Pseudomonas putida were isolated previously as IAA producing PGPR and selected in this study for their exploitation in plant growth development under Cd stressed condition. The impact of external synthetic IAA application significantly increased the plant growth under Cd amended soil. Whereas, PGPR inoculation also showed significant (p&lt;0.05) elevation in germination percentage, root and shoot length, chlorophyll content and other growth parameters of Cd stressed Brassica plants which were comparative to synthetic IAA application. So, these selected PGPRs (L. varians and P. putida) can be used as biofertilizer which ameliorate the adverse effect of cadmium

Relativistic Version of Landau Theory of Fermi Liquid in Presence of Strong Quantizing Magnetic Field- An Exact Formalism

An exact formalism for the relativistic version of Landau theory of Fermi liquid in presence of strong quantizing magnetic field is developed. Both direct and exchange type interactions with scalar and vector coupling cases are considered.Comment: REVTEX File, eight pages, no figure, accepted for Annals of Physic

On the Crustal Matter of Magnetars

We have investigated some of the properties of dense sub-nuclear matter at the crustal region (both the outer crust and the inner crust region) of a magnetar. The relativistic version of Thomas-Fermi (TF) model is used in presence of strong quantizing magnetic field for the outer crust matter. The compressed matter in the outer crust, which is a crystal of metallic iron, is replaced by a regular array of spherically symmetric Wigner-Seitz (WS) cells. In the inner crust region, a mixture of iron and heavier neutron rich nuclei along with electrons and free neutrons has been considered. Conventional Harrison-Wheeler (HW) and Bethe-Baym-Pethick (BBP) equation of states are used for the nuclear mass formula. A lot of significant changes in the characteristic properties of dense crustal matter, both at the outer crust and the inner crust, have been observed.Comment: 29 pages REVTEX manuscript, 15 .eps figures (included