1,253 research outputs found

    Dynamics of Axial Symmetric System in Self-Interacting Brans-Dicke Gravity

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    This paper investigates dynamics of axial reflection symmetric model in self-interacting Brans-Dicke gravity for anisotropic fluid. We formulate hydrodynamical equations and discuss oscillations using time-dependent perturbation for both spin as well as spin-independent cases. The expressions of frequency, total energy density and equation of motion of oscillating model are obtained. We study instability of oscillating models in weak approximations. It is found that the oscillations and stability of the model depend upon the dark energy source along with anisotropy and reflection effects. We conclude that the axial reflection system remains stable for stiffness parameter Γ=1\Gamma=1, collapses for Γ>1\Gamma>1 and becomes unstable for 0<Γ<10<\Gamma<1.Comment: 24 pages, no figure, accepted for publication in publication in Eur. Phys. J.

    Stellar Filaments in Self-Interacting Brans-Dicke Gravity

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    This paper is devoted to study cylindrically symmetric stellar filaments in self-interacting Brans-Dicke gravity. For this purpose, we construct polytropic filamentary models through generalized Lane-Emden equation in Newtonian regime. The resulting models depend upon the values of cosmological constant (due to scalar field) along with polytropic index and represent a generalization of the corresponding models in general relativity. We also investigate fragmentation of filaments by exploring the radial oscillations through stability analysis. This stability criteria depends only upon the adiabatic index.Comment: 21 pages, 4 figures, accepted for publication in EPJ

    Energy Consumption Rate based Stable Election Protocol (ECRSEP) for WSNs

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    In recent few yearsWireless Sensor Networks (WSNs) have seen an increased interest in various applications like border field security, disaster management and medical applications. So large number of sensor nodes are deployed for such applications, which can work autonomously. Due to small power batteries in WSNs, efficient utilization of battery power is an important factor. Clustering is an efficient technique to extend life time of sensor networks by reducing the energy consumption. In this paper, we propose a new protocol; Energy Consumption Rate based Stable Election Protocol (ECRSEP). Our CH selection scheme is based on the weighted election probabilities of each node according to the Energy Consumption Rate (ECR) of each node. We compare results of our proposed protocol with Low Energy Adaptive Clustering Hierarchy (LEACH), Distributed Energy Efficient Clustering (DEEC), Stable Election Protocol (SEP), and Enhanced SEP(ESEP). Our simulation results show that our proposed protocol, ECRSEP outperforms all these protocols in terms of network stability and network lifetime

    Economic Evaluation of Pesticide Use Externalities in the Cotton Zones of Punjab, Pakistan

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    The crop protection strategy in Pakistan is almost entirely based on pesticide use whereas development of integrated pest management (IPM) based technologies is in its initial phases of scrutiny as well as implementation. The inefficient use of chemicals has resulted in environmental pollution and sub-optimal returns to the society on the costly investments. This study estimates the social cost of pesticide use and suggests appropriate guidelines for regulating the safe use of pesticides. An overall economic evaluation of the externalities for the current pesticide use levels shows that external costs are quite higher than the currently paid price at the farm gate level. The environmental degradation and public health costs inflicted on the society due to the inefficient chemical use on cotton crop amounts to twelve thousand million rupees. The reduced reliance on crop protection through chemical methods seems inevitable for a sustainable and healthy crop production.economic evaluation; externalities; pesticide use; social cost; crop protection; Punjab; Pakistan

    Q-LEACH: A New Routing Protocol for WSNs

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    Wireless Sensor Networks (WSNs) with their dynamic applications gained a tremendous attention of researchers. Constant monitoring of critical situations attracted researchers to utilize WSNs at vast platforms. The main focus in WSNs is to enhance network life-time as much as one could, for efficient and optimal utilization of resources. Different approaches based upon clustering are proposed for optimum functionality. Network life-time is always related with energy of sensor nodes deployed at remote areas for constant and fault tolerant monitoring. In this work, we propose Quadrature-LEACH (Q-LEACH) for homogenous networks which enhances stability period, network life-time and throughput quiet significantly

    Entanglement of Gaussian states using beam splitter

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    We study an experimental scheme to generate Gaussian two-mode entangled states via beam splitter. Specifically, we consider a nonclassical Gaussian state (squeezed state) and a thermal state as two input modes, and evaluate the degree of entanglement at the output. Experimental conditions to generate entangled outputs are completely identified and the critical thermal noise to destroy entanglement is analytically obtained. By doing so, we discuss the possibility to link the resistance to noise in entanglement generation with the degree of single-mode nonclassicality.Comment: 6 pages, 3 figures, references added (particularly [19]), more detailed discussion
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