Quasi-Local Energy Distribution and Thermodynamics of Reissner-Nordstrom Black Hole Surrounded by Quintessence

We investigate quasi-local energy distribution and thermodynamics of the Reissner-Nordstr6m black hole space-time surrounded by quintessence. We use the quasi-local energy distribution from Einstein energy-momentum complex. We plot the variation of the energies, temperature and heat capacity with the state parameter related to the quintessence ωq. We show that due to the presence of quintessence, the total energy of the outer region as well as the temperature and heat capacity decreases with the increase of the density of quintessence, while the total energy of the black hole region increases.

Travelling Wave Solutions to Stretched Beam's Equation: Phase Portraits Survey

In this paper, following the phase portraits analysis, we investigate the integrability of a system which physically describes the transverse oscillation of an elastic beam under end-thrust. As a result, we find that this system actually comprises two families of travelling waves： the sub- and super-sonic periodic waves of positive- and negative- definite velocities, respectively, and the localized sub-sonic loop-shaped waves of positive-definite velocity. Expressing the energy-like of this system while depicting its phase portrait dynamics, we show that these multivaiued localized travelling waves appear as the boundary solutions to which the periodic travelling waves tend asymptotically

On the Conversion of High-Frequency Soliton Solutions to a （1＋1）-Dimensional Nonlinear Partial Differential Evolution Equation

From the dynamical equation of barotropic relaxing media beneath pressure perturbations, and using the reductive perturbative analysis, we investigate the soliton structure of a （1＋1）-dimensional nonlinear partial differential evolution （NLPDE） equation δy（δη ＋ uδy ＋ （u^2/2）δy）u ＋ auy ＋ u = 0, describing high-frequency regime of perturbations. Thus, by means of Hirota＇s bilinearization method, three typical solutions depending strongly upon a characteristic dissipation parameter are unearthed.

On High-Frequency Soliton Solutions to a （2＋1）-Dimensional Nonlinear Partial Differential Evolution Equation

A （2＋1）-dimensional nonlinear partial differential evolution （NLPDE） equation is presented as a model equation for relaxing high-rate processes in active barothropic media. With the aid of symbolic computation and Hirota＇s method, some typical solitary wave solutions to this （2＋1）-dimensional NLPDE equation are unearthed. As a result, depending on the dissipative parameter, single and multivalued solutions are depicted.

Prolongation Structure Analysis of a Coupled Dispersionless System

We address the problem of integrability of a coupled dispersionless system recently introduced by Zhaqilao,Zhao and Li[Chin.Phys.B 18(2009)1780]which physically describes the propagation of electromagnetic fields within an optical nonlinear medium,but also arrives in the physical description of a charged object dynamics in an external magnetic field.Following the prolongation structure analysis developed by Wahlquist and Estabrook,we derive a more general form of Lax pairs of the previous coupled dispersionless system and its concrete nonAbelian Lie algebra resorting to a hidden symmetry.Also,we construct the Bäcklund transformation of the system using the Riccati form of the linear eigenvalue problem.

Determination of a Suitable Solar Radiation Model for the Sites of Chad

The aim of this study is the determination of a suitable solar radiation model for the twelve cities of Chad based on meteorological data. Three appropriate models are used to estimate the solar radiation of each site. The choice of these models is based on statistical tests such as the Root Mean Square Error (RMSE), the Mean Bias Error (MBE), the Mean Percentage Error (MPE), and the Nash-Sutcliffe Equation (NSE). The obtained results show that the Angstrom-Prescott model is the most suitable for the calculation of global solar radiation in the sites of Bongor, Pala, Am-timan and Mongo. For the sites of Moundou, Sarh and Bokoro the Allen model is the most adapted for the calculation of global solar radiation. On the other hand the Sabbagh model is the most appropriate for the sites of Faya-Largeau, Abeche, N’Djamena, Ati and Moussoro. It has been revealed that Abeche is the site with the highest solar radiation value equal to 6.354 kWh/m2 and Ati is the site where the solar radiation has the lowest value around 5.523 kWh/m2. Based on the obtained results, it is demonstrated that the three climatic zones of Chad have a good solar potential and consequently suitable for the exploitation of the solar energy systems.

Assessment of Wind Energy Potential in the Sudanese Zone in Chad

In this study, wind characteristics and wind power potential are analyzed for three meteorological stations in the Sudanese zone of Chad for the period of 35 years (from 1975 to 2010). Assessment of the wind power potential was carried out using the two parameters of Weibull distribution. Results of the study shows that the average annual wind speeds at 10 m above ground for Moundou, Pala and Sarh are 2.69, 2.33 and 1.91 m/s, respectively. The mean annual value of the Weibull shape parameter k and scale parameter c range from 2.376 to 3.255 and 2.099 to 3.007, respectively. The maximum annual power density of 204.85 W/m2 was obtained at Moundou. Results of this study further shows that the selected locations are not suitable for large-scale wind energy production at 10 m altitude. However, by extrapolation, assessment of wind speed at 67 m altitude combines with wind turbine Vestas 2 MW/80 that adapts to the Sudanese local conditions, and the wind power potential can be exploited for water pumping, heating and production of electricity.

Signature of chaos in the semi quantum behavior of a classically regular triple well heterostructure

We analyze the phenomenon of semiquantum chaos in the classically regular triple well model from classical to quantum. His dynamics is very rich because it provides areas of regular be-havior, chaotic ones and multiple quantum tun-neling depending on the energy of the system as the Planck’s constant varies from 0 to 1. The Time Dependent Variational Principle TDVP using generalized Gaussian trial wave function, which, in many-body theory leads to the Hartree Fock Approximation TDHF, is added to the tech-niques of Gaussian effective potentials and both are used to study the system. The extended classical system with fluctuation variables non- linearly coupled to the average variables exhibit energy dependent transitions between regular behavior and semi quantum chaos monitored by bifurcation diagram together with some numerical indicators.

Energy and Thermodynamics of the Quantum-Corrected Schwarzschild Black Hole

Energy and thermodynamics are investigated in the Schwarzschild black hole spacetime when considering corrections due to quantum vacuum fluctuations. The Einstein and M？ller prescriptions are used to derive the expressions of the energy in the background. The temperature and heat capacity are also derived. The results show that due to the quantum fluctuations in the background of the Schwarzschild black hole, all the energies increase and the Einstein energy differs from M？ller＇s one. Moreover, when increasing the quantum correction factor aa, the difference between Einstein and M？ller energies, the Unruh–Verlinde temperature as well as the heat capacity of the black hole increases while the Hawking temperature remains unchanged.

Quasi-Normal Modes of Gravitational Perturbation around a Reissner-Nordstroem Black Hole Surrounded by Quintessence

We investigate quasi-normal （QN） modes of gravitational perturbation around a Reissner-Nordstroem black hole surrounded by quintessence. The third-order Wentzel-Kramers-Brillouin approximation is used to evaluate QN frequencies. The behavior of the gravitational perturbation is plotted for some frequencies. Due to the presence of quintessence, QN modes of the Reissner-Nordstroem black hole damp at a slower rate.

Hawking radiation from a five-dimensional Lovelock black hole

We investigate Hawking radiation from a five-dimensional Lovelock black hole using the Hamilton- Jacobi method. The behavior of the rate of radiation is plotted for various values of tile ultraviolet correction parameter and the cosmological constant. The results show that, owing to the ultraviolet correction and the presence of dark energy represented by the cosmological constant, the black hole radiates at a slower rate in comparison to the case without ultraviolet correction or cosmological constant. Moreover, the presence of the cosmological constant makes the effect of the ultraviolet correction on the black hole radiation negligible.