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

Generalized second law of thermodynamic in modified teleparallel theory

This study is conducted to examine the validity of the generalized second law of thermodynamics (GSLT) in flat FRW for modified teleparallel gravity involving coupling between a scalar field with the torsion scalar T and the boundary term B=2∇μTμB=2∇μTμ . This theory is very useful, since it can reproduce other important well-known scalar field theories in suitable limits. The validity of the first and second law of thermodynamics at the apparent horizon is discussed for any coupling. As examples, we have also explored the validity of those thermodynamics laws in some new cosmological solutions under the theory. Additionally, we have also considered the logarithmic entropy corrected relation and discuss the GSLT at the apparent horizon

Situating Islamic feminism(s): Lived religion, negotiation of identity and assertion of third space by Muslim women in Pakistan

© 2017 This paper reports the findings of an exploratory, qualitative study with Pakistani women to explore how Muslim women studying English in higher education contexts in Pakistan engage with feminist thought. The broader aim of the study was to capture the relationship between these women's ‘secular’ education and their religious (and secular) social identities as young, urban, middle class working women in a Pakistani higher education context. In particular, the study sets out to explore how Pakistani women at higher education institutions interact with and use ‘new’ forms of knowledges, particularly those dominated by western frameworks of intellectual thought and reasoning, in the context of their own potentially different social lives and self-identities as Muslim women. The findings show that the young women academics in addition to negotiating with the Western notions of Feminism also simultaneously challenge the indigenous patriarchal hegemonies and conservative religious discourses in their social context by attempting to rework notions of Muslim women's identity in Pakistan, envisaging what Bhabha has termed a third space

Thermodynamics in f(R,RαβRαβ,ϕ) theory of gravity

First and second laws of black hole thermodynamics are examined at the apparent horizon of FRW spacetime in f(R,RαβRαβ,ϕ) gravity, where R, RαβRαβ and ϕ are the Ricci invariant, Ricci tensor and the scalar field respectively. In this modified theory, Friedmann equations are formulated for any spatial curvature. These equations can be presented into the form of first law of thermodynamics for ThdSˆh+ThdiSˆh+WdV=dE, where diSˆh is an extra entropy term because of the non-equilibrium presentation of the equations and ThdSˆh+WdV=dE for the equilibrium presentation. The generalized second law of thermodynamics (GSLT) is expressed in an inclusive form where these results can be represented in GR, f(R) and f(R,ϕ) gravities. Finally to check the validity of GSLT, we take some particular models and produce constraints of the parameters

Static spherically symmetric wormholes in generalized f(R, ϕ) gravity

In this paper, we examine static spherically symmetric wormhole solutions in generalized f(R,ϕ) gravity. To do this, we consider three different kinds of fluids: anisotropic, barotropic and isotropic. We explore different f(R,ϕ) models and inspect the energy conditions for all of those three fluids. It is found that under some models in this theory, it is possible to obtain wormhole solutions without requiring exotic matter. The discussion about the conditions where the standard energy conditions (WEC and NEC) are valid for the fluids is discussed in details. From our results and for our cases, we conclude that for anisotropic and isotropic fluids, realistic wormhole geometries satisfying the energy conditions can be constructed

Scalable parallel communications

Coarse-grain parallelism in networking (that is, the use of multiple protocol processors running replicated software sending over several physical channels) can be used to provide gigabit communications for a single application. Since parallel network performance is highly dependent on real issues such as hardware properties (e.g., memory speeds and cache hit rates), operating system overhead (e.g., interrupt handling), and protocol performance (e.g., effect of timeouts), we have performed detailed simulations studies of both a bus-based multiprocessor workstation node (based on the Sun Galaxy MP multiprocessor) and a distributed-memory parallel computer node (based on the Touchstone DELTA) to evaluate the behavior of coarse-grain parallelism. Our results indicate: (1) coarse-grain parallelism can deliver multiple 100 Mbps with currently available hardware platforms and existing networking protocols (such as Transmission Control Protocol/Internet Protocol (TCP/IP) and parallel Fiber Distributed Data Interface (FDDI) rings); (2) scale-up is near linear in n, the number of protocol processors, and channels (for small n and up to a few hundred Mbps); and (3) since these results are based on existing hardware without specialized devices (except perhaps for some simple modifications of the FDDI boards), this is a low cost solution to providing multiple 100 Mbps on current machines. In addition, from both the performance analysis and the properties of these architectures, we conclude: (1) multiple processors providing identical services and the use of space division multiplexing for the physical channels can provide better reliability than monolithic approaches (it also provides graceful degradation and low-cost load balancing); (2) coarse-grain parallelism supports running several transport protocols in parallel to provide different types of service (for example, one TCP handles small messages for many users, other TCP's running in parallel provide high bandwidth service to a single application); and (3) coarse grain parallelism will be able to incorporate many future improvements from related work (e.g., reduced data movement, fast TCP, fine-grain parallelism) also with near linear speed-ups

Mikroenkapsulasi Antosianin Kulit Buah Kakao (Theobroma Cacao L.) Dengan Metode Koaservasi Kompleks: Microencapsulation of Anthocyanine of Kakao (Theobroma Cacao L.) Bark with Complex Coaservation

Anthocyanin is a class of antioxidants that are widely found in the skin of cocoa fruit (Theobroma cacao L.). Anthocyanin degradation occurs not only during the extraction process from plant tissues but also during the storage process. The microencapsulation process can protect the active substance from environmental influences or improve the stability of the preparation. This study aims to characterize anthocyanin microcapsules from cocoa (Theobroma cacao L.) fruit peel using a complex coacervation method, therefore, it can provide economic value added from this plant. Anthocyanin microencapsulation was formulated using a coating of  gelatin: arabic gom with different concentrations of 1:1, 3:2, and 2:1. Microcapsule characterization was organoleptic and morphological test, particle size distribution, moisture content test, absorption efficiency, recovery test, antioxidant activity of the preparation, and FTIR analysis. The results showed that extract yield was 39.82%, optimum microcapsule characterization was obtained from 1: 1 concentration with 36.65% recovery test, 80.40% absorption efficiency, and antioxidant activity with IC50 of 20.52 ppm

Ewald methods for inverse power-law interactions in tridimensional and quasi-two dimensional systems

In this paper, we derive the Ewald method for inverse power-law interactions in quasi-two dimensional systems. The derivation is done by using two different analytical methods. The first uses the Parry's limit, that considers the Ewald methods for quasi-two dimensional systems as a limit of the Ewald methods for tridimensional systems, the second uses Poisson-Jacobi identities for lattice sums. Taking into account the equivalence of both derivations, we obtain a new analytical Fourier transform intregral involving incomplete gamma function. Energies of the generalized restrictive primitive model of electrolytes ($\eta$-RPM) and of the generalized one component plasma model ($\eta$-OCP) are given for the tridimensional, quasi-two dimensional and monolayers systems. Few numerical results, using Monte-Carlo simulations, for $\eta$-RPM and $\eta$-OCP monolayers systems are reported.Comment: to be published in Journal of Physics A: Mathematical and Theoretical (19 pages, 2 figures and 3 tables