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Atomically thin crystals have recently been the focus of attention in particular after the synthesis of graphene, a monolayer hexagonal crystal structure of carbon. In this novel material class the chemically derived graphenes have attracted tremendo us interest. It was shown that although bulk graphite is a chemically inert material, the surface of single layer graphene is rather reactive against individual atoms. So far, synthesis of several graphene derivatives have been reported such as hydrogenated graphene graphane (CH), fluorographene (CF) and chlorographene (CCl). Moreover, the stability of bromine and iodine covered graphene were predicted using computational tools. Among these derivatives, easy synthesis, insulating electronic behavior and reversibly tunable crystal structure of graphane make this material special for future ultra-thin device applications. This overview, surveys structural, electronic, magnetic, vibrational and mechanical properties of graphane. We also present a detailed overview of research efforts devoted to the computational modeling of graphane and its derivatives. Furthermore recent progress in synthesis techniques and possible applications of graphane are reviewed as well.
We have studied quasielastic charged current hyperon production induced by $bar u_mu$ on free nucleon and the nucleons bound inside the nucleus and the results are presented for several nuclear targets like $^{40}Ar$, $^{56}Fe$ and $^{208}Pb$. The hy peron-nucleon transition form factors are determined from neutrino-nucleon scattering and semileptonic decays of neutron and hyperons using SU(3) symmetry. The nuclear medium effects(NME) due to Fermi motion and final state interaction(FSI) effect due to hyperon-nucleon scattering have been taken into account. Also we have studied two pion production at threshold induced by neutrinos off nucleon targets. The contribution of nucleon, pion, and contact terms are calculated using Lagrangian given by nonlinear $sigma$ model. The contribution of the Roper resonance has also been taken into account. The numerical results for the cross sections are presented and compared with the experimental results from ANL and BNL.
Working on the framework of Relativistic Mean Field theory, we exposed the effect of nonlinear isoscalar-isovector coupling on G2 parameter set on the density dependence of nuclear symmetry energy in infinite nuclear matter. The observables like symm etric energy and few related coefficients are studied systematically. We presented the results of stiff symmetry energy at sub-saturation densities and a soft variation at normal densities. Correlation between the symmetric energy and the isoscalar-isovector coupling parameter fully demonstrated for wide range of density. The work further extended to the octet system and showed the effect of coupling over the equation of state.
We present the results of our calculation which has been performed to study the nuclear effects in the quasielastic, inelastic and deep inelastic scattering of neutrinos(antineutrinos) from nuclear targets. These calculations are done in the local de nsity approximation. We take into account the effect of Pauli blocking, Fermi motion, Coulomb effect, renormalization of weak transition strengths in the nuclear medium in the case of the quasielastic reaction. The inelastic reaction leading to production of pions is calculated in a $Delta $- dominance model taking into account the renormalization of $Delta$ properties in the nuclear medium and the final state interaction effects of the outgoing pions with the residual nucleus. We discuss the nuclear effects in the $F_{3}^{A}(x)$ structure function in the deep inelastic neutrino(antineutrino) reaction using a relativistic framework to describe the nucleon spectral function in the nucleus.
Cylindrically symmetric inhomogeneous string cosmological model of the universe in presence of electromagnetic field is investigated. We have assumed that F_{12} is the only non-vanishing component of electromagnetic field tensor F_{ij}. The Maxwells equations show that F_{12} is the function of $x$ alone whereas the magnetic permeability is the function of x and t both. To get the deterministic solution, it has been assumed that the expansion ($theta$) in the model is proportional to the eigen value $sigma^{1}_{1}$ of the shear tensor $sigma^{i}_{j}$. Some physical and geometric prperties of the model are also discussed.
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