Photoelectret state in poly(vinylcarbazole)

The photoelectret charge in the aluminum–poly(vinylcarbazole) (PVK) conducting-glass (NESA), sandwich cell configuration has been observed to decrease with voltage above some critical voltage, depending on the intensity of illumination. This critical voltage corresponds to the value at which a time-independent photocurrent is observed and also to the “knee-point” voltage in the current voltage plot. The results are explained on the basis of field-assisted detrapping setting in at high field.     

A numerical study of magnetohydrodynamic flow between a rotating and a stationary porous coaxial discs

The magnetohydrodynamic flow of an electrically conducting viscous fluid between a rotating and a stationary disc has been studied numerically by the Newton-Raphson method and the method of continuation. The results have been calculated for a wide range of parameters involved, thus indicating the efficiency of the methods. The induced electric field has also been calculated for various values of suction Reynolds number.     

Fixed point theory for admissible multimaps defined on closed subsets of Fréchet spaces

This paper presents new fixed point results for a general class of maps defined on Fréchet spaces. Our results in particular apply to Kakutani, acyclic, O'Neill, approximable, admissible with respect to Gorniewicz and maps.     

Asymptotic behavior of nonlinear difference systems

In this paper, we consider two-dimensional nonlinear difference systems of the form

We classify their solutions according to asymptotic behavior and give some necessary and sufficient conditions for the existence of solutions of such classes.     

Periodicity and Stability in Periodic <Emphasis Type="Italic">n</Emphasis>-Species Lotka-Volterra Competition System with Feedback Controls and Deviating Arguments

By using the method of coincidence degree and Lyapunov functional, a set of easily applicable criteria are established for the global existence and global asymptotic stability of strictly positive(componentwise)periodic solution of a periodic n-species Lotka-Volterra competition system with feedback controls and several deviating arguments.The problem considered in this paper is in many aspects more general and incorporate as special cases various problems which have been studied extensively in the literature.Moreover,our new criteria,which improve and generalize some well known results, can be easily checked.     

Strong-driving-assisted multipartite entanglement in cavity QED

We propose a method of generating multipartite entanglement by considering the interaction of a system of N two-level atoms in a cavity of high quality factor with a strong classical driving field. It is shown that, with a judicious choice of the cavity detuning and the applied coherent field detuning, vacuum Rabi coupling produces a large number of important multipartite entangled states. It is even possible to produce entangled states involving different cavity modes. Tuning of parameters also permits us to switch from Jaynes-Cummings to anti-Jaynes-Cummings-like interaction.     

Generalized Schrödinger cat states in cavity QED

A method of generating generalized Schrödinger cat states by considering the resonant interaction of a high-quality cavity with N two-level atoms driven by a strong classical field is proposed.     

Mössbauer and X-ray investigations of YBa2−x Sn x Cu3O7−δ superconductors

Mössbauer spectra of YBa_2?x Sn _x Cu₃O_7?δ compounds withx=0.2 and 0.3 have revealed two components, both with isomer shifts corresponding to 4⁺ valency for Sn. The temperature dependence of the area of only one component shows an anomaly near the superconducting temperature for both samples, thus suggesting anisotropic behaviour for the lattice rigidity. In the case ofx=0.2 sample X-ray diffraction studies further indicate similar anomaly in the orthorhombic strain. It is concluded that such anomalies are precursors for the superconductivity to occur in these compounds.