Dynamics of Charged Bulk Viscous Collapsing Cylindrical Source With Heat Flux

In this paper, we have explored the effects of dissipation on the dynamics of charged bulk viscous collapsing cylindrical source which allows the out follow of heat flux in the form of radiations. Misner-Sharp formulism has been implemented to drive the dynamical equation in term of proper time and radial derivatives. We have investigated the effects of charge and bulk viscosity on the dynamics of collapsing cylinder. To determine the effects of radial heat flux, we have formulated the heat transport equations in the context of M$\ddot{u}$ller-Israel-Stewart theory by assuming that thermodynamics viscous/heat coupling coefficients can be neglected within some approximations. In our discussion, we have introduced the viscosity by the standard (non-casual) thermodynamics approach. The dynamical equations have been coupled with the heat transport equation equation, the consequences of resulting coupled heat equation have been analyzed in detail.Comment: 17 Pages, no figur

Higher Dimensional Inhomogeneous Perfect Fluid Collapse in \emph{f(R)} Gravity

This paper is about the $n+2$-dimensional gravitational contraction of inhomogeneous fluid without heat flux in the framework of $f(R)$ metric theory of gravity. Matching conditions for two regions of a star has been derived by using the Darmois junction conditions. For the analytic solution of equations of motion in modified $f(R)$ theory of gravity, we have taken scalar curvature as constant. Hence final result of gravitational collapse in this frame work is the existence of black hole and cosmological horizons, both of these form earlier than singularity. It has been shown that constant curvature term $f(R_{0})$ ($R_0$ is constant scalar curvature) slows down the collapsing process.Comment: 17 Pages, to appear in European Physical Journal

Evaluating the Success of Malaysia’s Exchange Controls (1998-99)

The paper evaluates in depth, the exchange control measures imposed by Malaysia in September-1998. Controls are evaluated using three alternative benchmarks—Malaysia vs. itself (pre-controls), vs. ex-ante forecasts of Malaysia for the year-1999, and Malaysia vs. the other affected East Asian economies. The comparisons suggest that controls were effective in turning some key variables around, especially the stock market index, and also enabled Malaysia to incur fewer social costs vis-à-vis the other crisis-economies. Finally, a GARCH measure of Malaysia’s interest-rate and stock-market volatility is obtained and the impact of controls on volatility studied. Evidence was found of volatility responding differentially to the Russian crisis (before controls) and the Brazilian crisis (after controls), indicating that controls helped insulate Malaysia from developments in global financial markets. Overall the paper confirms the necessity of LDCs retaining the capital controls option in the absence of material efforts to reform the international financial architecture and the inadequacy of conventional policy tools to effectively deal with present-day capital flows.

Effects of Electromagnetic Field on Gravitational Collapse

In this paper, the effect of electromagnetic field has been investigated on the spherically symmetric collapse with the perfect fluid in the presence of positive cosmological constant. Junction conditions between the static exterior and non-static interior spherically symmetric spacetimes are discussed. We study the apparent horizons and their physical significance. It is found that electromagnetic field reduces the bound of cosmological constant by reducing the pressure and hence collapsing process is faster as compared to the perfect fluid case. This work gives the generalization of the perfect fluid case to the charged perfect fluid. Results for the perfect fluid case are recovered.Comment: 17 pages, accepted for publication in Mod. Phys. Lett

M-ATTEMPT: A New Energy-Efficient Routing Protocol for Wireless Body Area Sensor Networks

In this paper, we propose a new routing protocol for heterogeneous Wireless Body Area Sensor Networks (WBASNs); Mobility-supporting Adaptive Threshold-based Thermal-aware Energy-efficientMulti-hop ProTocol (M-ATTEMPT). A prototype is defined for employing heterogeneous sensors on human body. Direct communication is used for real-time traffic (critical data) or on-demand data while Multi-hop communication is used for normal data delivery. One of the prime challenges in WBASNs is sensing of the heat generated by the implanted sensor nodes. The proposed routing algorithm is thermal-aware which senses the link Hot-spot and routes the data away from these links. Continuous mobility of human body causes disconnection between previous established links. So, mobility support and energy-management is introduced to overcome the problem. Linear Programming (LP) model for maximum information extraction and minimum energy consumption is presented in this study. MATLAB simulations of proposed routing algorithm are performed for lifetime and successful packet delivery in comparison with Multi-hop communication. The results show that the proposed routing algorithm has less energy consumption and more reliable as compared to Multi-hop communication.Comment: arXiv admin note: substantial text overlap with arXiv:1208.609