42,701 research outputs found
Holographic entanglement thermodynamics for higher dimensional charged black hole
In this paper, we have investigated the entanglement thermodynamics for
-dimensional charged black hole by studying the holographic
entanglement entropy in different cases. We have first computed the holographic
entanglement entropy in extremal and non-extremal cases in two different
regimes, namely, the low temperature and high temperature limits. We then
obtain the first law of entanglement thermodynamics for boundary field theory
in the low temperature regime in -dimensions.Comment: 28 pages Late
Reliability based robust design optimization based on sensitivity and elasticity factors analysis
In this paper, a Reliability Based Robust Design Optimization (RBRDO) based on sensitivity and elasticity factors analysis is presented. In the first step, a reliability assessment is performed using the First-and Second Order Reliability Method (FORM)/ (SORM), and Monte Carlo Simulation. Furthermore, FORM method is used for reliability elasticity factors assessment, which can be carried out to determine the most influential parameters, these factors can be help to reduce the size of design variables vector in RBRDO process. The main objective of the RBRDO is to improve both reliability and design of a cylindrical gear pair under uncertainties. This approach is achieved by integration of two objectives which minimize the variance and mean values of performance function. To solve this problem a decoupled approach of Sequential Optimization and Reliability Assessment (SORA) method is implemented. The results obtained shown that a desired reliability with a robust design is progressively achieved
A class of interior solutions corresponding to a dimensional asymptotically anti-de Sitter spacetime
Lower dimensional gravity has the potential of providing non-trivial and
valuable insight into some of the conceptual issues arising in four dimensional
relativistic gravitational analysis. The asymptotically anti-de Sitter (2+1)
dimensional spacetime described by Baados, Teitelboim and Zanelli
(BTZ) which admits a black hole solution, has become a source of fascination
for theoretical physicists in recent years. By suitably choosing the form of
the mass function , we derive a new class of solutions for the interior
of an isotropic star corresponding to the exterior (2+1) asymptotically anti-de
Sitter BTZ spacetime. The solution obtained satisfies all the regularity
conditions and its simple analytical form helps us to study the physical
parameters of the configuration in a simple manner.Comment: 5 pages, 5 figures. Accepted for publication in Phys. Lett. B, some
typos are correcte
Wormhole inspired by non-commutative geometry
In the present work we search for a new wormhole solution inspired by
noncommutative geometry with the additional condition of allowing conformal
Killing vectors (CKV). A special aspect of noncommutative geometry is that it
replaces point-like structures of gravitational sources with smeared objects
under Gaussian distribution. However, the purpose of this paper is to obtain
wormhole solutions with noncommutative geometry as a background where we
consider a point-like structure of gravitational object without smearing
effect. It is found through this investigation that wormhole solutions exist in
this Lorentzian distribution with viable physical properties.Comment: 15 pages, 6 figures, 1 table, Substantial modifications in the whole
manuscript, Accepted in Phys. Lett.
African Water: Supporting African involvement in the EU Framework Programme.
Water researchers in developing countries have yet to take full advantage of the funding and collaborative research opportunities presented by the EU Framework Programme. There are a variety of reasons for this, such as insufficient information and a lack of previous experience. The African Water initiative aims to increase the involvement of African water researchers through a range of activities including communication and dissemination, capacity building and development, and complementary initiatives. The project has demonstrated that there is a demand for such sector-specific support activities. However, African Water is a small component of a much larger process of partnership between the developed and the less-developed countries of the world, involving many different European and African organisations working across political, institutional and technical domains, and complementing the wide range of actions already being undertaken
Detection of Noble Gas Scintillation Light with Large Area Avalanche Photodiodes (LAAPDs)
Large Area Avalanche Photodiodes (LAAPDs) were used for a series of
systematic measurements of the scintillation light in Ar, Kr, and Xe gas.
Absolute quantum efficiencies are derived. Values for Xe and Kr are consistent
with those given by the manufacturer. For the first time we show that argon
scintillation (128 nm) can be detected at a quantum efficiency above 40%.
Low-pressure argon gas is shown to emit significant amounts of non-UV
radiation. The average energy expenditure for the creation of non-UV photons in
argon gas at this pressure is measured to be below 378 eV.Comment: 16 pages, 7 figure
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