1,254 research outputs found
Dynamics of Axial Symmetric System in Self-Interacting Brans-Dicke Gravity
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 , collapses for and becomes unstable
for .Comment: 24 pages, no figure, accepted for publication in publication in Eur.
Phys. J.
Stellar Filaments in Self-Interacting Brans-Dicke Gravity
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
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
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
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
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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