Cracking of Charged Polytropes with Generalized Polytropic Equation of State

We discuss the occurrence of cracking in charged anisotropic polytropes with generalized polytropic equation of state through two different assumptions; (i) by carrying out local density perturbations under conformally flat condition (ii) by perturbing anisotropy, polytropic index and charge parameters. For this purpose, we consider two different definitions of polytropes exist in literature. We conclude that under local density perturbations scheme cracking does not appears in both types of polytropes and stable configuration are observed, while with second kind of perturbation cracking appears in both types of polytropes under certain conditions.Comment: 24 pages, 11 figure

Investigation of the utilisation of social networks in e-learning at universities

Over the years universities have considered to use social networks for learning purposes as most of their students now engage on them. However, questions on the impact social networks would have on learning and how they can be utilised further for more effective teaching and learning are still unclear. To solve these questions, an in-depth investigation has been conducted to understand the benefits and drawback of social network features available for students. The investigation results show that students strongly believe that social network features will help enhance learning and the key ways of utilising such features have been suggested

Fate of Electromagnetic Field on the Cracking of PSR J1614-2230 in Quadratic Regime

In this paper, we study the cracking of compact object PSR J1614-2230 in quadratic regime with electromagnetic field. For this purpose, we develop a general formalism to determine the cracking of charged compact objects. We apply the local density perturbations to the hydrostatic equilibrium equation as well as all the physical variables involve in the model. We plot the force distribution function against radius of the star with different values of model parameters both with and without charge. It is found that PSR J1614-2230 remains stable (no cracking) corresponding to different values of parameters when charge is zero, while it exhibit cracking (unstable) when charge is introduced. We conclude that stability region increases as amount of charge increases.Comment: 21 pages, 8 figures, version to appear in advances in high energy physic

Study of polytropes with Generalized polytropic Equation of State

The aim of this paper is to discuss the theory of Newtonian and relativistic polytropes with generalized polytropic equation of state. For this purpose, we formulated the general framework to discuss the physical properties of polytrops with anisotropic inner fluid distribution under conformally flat condition in the presence of charge. We investigate the stability of these polytrops in the vicinity of generalized polytropic equation through Tolman-mass. It is concluded that one of the derived models is physically acceptable.Comment: 21 pages, 3 figure

Upaya Penguatan “Motivasi Berakhlakul Karimah” terhadap Peserta Didik Beribu Nenek dengan Pembelajaran Kitab Ta'lim Muta'alim (Studi di Mts Plus Nururrohmah Tambaksari Kuwarasan Kebumen, Jawa Tengah)

The students who has grand mother as mother were in danger on moral. The students were only controlled by the grand mothers, and it made less education. The grand mothers were too over on giving love, it made the students were spoiled and they did deviant behavior. The Islamic Secondary School Nururohmah has many students who have grand mother as mother did a special way on educating students by understanding Kitab Ta'lim Muta'alim. The results showed that the students more open minded and aware to do the right thing

Resonate and Fire Neuron with Fixed Magnetic Skyrmions

In the brain, the membrane potential of many neurons oscillates in a subthreshold damped fashion and fire when excited by an input frequency that nearly equals their eigen frequency. In this work, we investigate theoretically the artificial implementation of such "resonate-and-fire" neurons by utilizing the magnetization dynamics of a fixed magnetic skyrmion in the free layer of a magnetic tunnel junction (MTJ). To realize firing of this nanomagnetic implementation of an artificial neuron, we propose to employ voltage control of magnetic anisotropy or voltage generated strain as an input (spike or sinusoidal) signal, which modulates the perpendicular magnetic anisotropy (PMA). This results in continual expansion and shrinking (i.e. breathing) of a skyrmion core that mimics the subthreshold oscillation. Any subsequent input pulse having an interval close to the breathing period or a sinusoidal input close to the eigen frequency drives the magnetization dynamics of the fixed skyrmion in a resonant manner. The time varying electrical resistance of the MTJ layer due to this resonant oscillation of the skyrmion core is used to drive a Complementary Metal Oxide Semiconductor (CMOS) buffer circuit, which produces spike outputs. By rigorous micromagnetic simulation, we investigate the interspike timing dependence and response to different excitatory and inhibitory incoming input pulses. Finally, we show that such resonate and fire neurons have potential application in coupled nanomagnetic oscillator based associative memory arrays