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gravitational radiation fields in teleparallel equivalent of general relativity and their energies

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Chinese Physics B 2010年第11期19卷 132-139页

作者： gamal g.l.Nashed Mathematics Department Faculty of ScienceAin Shams UniversityCairoEgypt Centre for Theoretical Physics The British University in EgyptEl-Sherouk CityMisr-Ismalia Desert RoadPostal No.11837Egypt

We derive two new retarded solutions in the teleparallel theory equivalent to general relativity （TEgR）. One of these solutions gives a divergent energy. Therefore, we use the regularized expression of the gravitational energymomentum tensor, which is a coordinate dependent. A detailed analysis of the loss of the mass of Bondi space-time is carried out using the flux of the gravitational energy-momentum.

关键词： teleparallel equivalent of general relativity energy-momentum tensor Bondi mass gravitational radiation

Nonlinear electrodynamics coupled to teleparallel theory of gravity

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Chinese Physics B 2011年第2期20卷 73-82页

作者： gamal g.l.Nashed Mathematics Department Faculty of ScienceAin Shams UniversityCairoEgypt

Using nonlinear electrodynamics coupled to teleparallel theory of gravity, regular charged spherically symmetric solutions are obtained. The nonlinear theory is reduced to the Maxwell one in the weak limit and the solutions correspond to charged spacetimes. One of the obtained solutions contains an arbitrary function which we call general solution since we can generate from it the other solutions. The metric associated with these spacetimes is the same, i.e., regular charged static spherically symmetric black hole. In calculating the energy content of the general solution using the gravitational energy momentum within the framework of the teleparallel geometry, we find that the resulting form depends on the arbitrary function. Using the regularized expression of the gravitational energy-momentum we obtain the value of energy.

关键词： tetrad theory of gravitation nonlinear electrodynamics spherically symmetric black holes gravitational energy-momentum

Thermal properties of lense-Thirring spacetime in tetrad theory of gravity

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Chinese Physics B 2012年第8期21卷 51-58页

作者： gamal g.l.Nashed Mathematics Department Faculty of ScienceKing Faisal UniversityP.O.Box 380Al-Ahsaa 31982the Kingdom of Saudi Arabia Mathematics Department Faculty of ScienceAin Shams UniversityCairo 11566Egypt Center for Theoretical Physics British University of EgyptSherouk City 11837P.O.Box 43Egypt

Using the divergence term appearing in the lagrangian of the teleparallel equivalent of general relativity （TEgR）, we calculate the thermodynamic quantities of four tetrads＇ spacetime reproducing lense-Thirring （l... 详细信息

关键词： Euclidean continuation method thermodynamic quantities first law of thermodynamic,quantum statistical relation

Cosmological application on five-dimensional teleparallel theory equivalent to general relativity

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Chinese Physics B 2012年第10期21卷 122-129页

作者： gamal g.l.Nashed Mathematics Department Faculty of ScienceKing Faisal UniversityP.O.Box 380 Al-Ahsaa 31982the Kingdom of Saudi Arabia Mathematics Department Faculty of ScienceAin Shams UniversityCairo 11566Egypt Center for Theoretical Physics British University of EgyptSherouk City 11837P.O.Box 43Egypt

A theory of（4＋1）-dimensional gravity has been developed on the basis of which equivalent to the theory of general relativity by *** fundamental gravitational field variables are the 5-dimensional（5D） vector fields（pentad）,defined globally on a manifold M,and gravity is attributed to the *** lagrangian density is quadratic in the torsion *** then apply the field equations to two different homogenous and isotropic geometric structures which give the same line element,i.e.,FRW in five *** cosmological parameters are calculated and some cosmological problems are discussed.

关键词： 5D teleparallel equivalent of general relativity 5D solutions cosmological parameters cosmological problems

Energy and spatial momentum of charged rotating frames in tetrad gravity

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Chinese Physics B 2011年第11期20卷 90-101页

作者： gamal g.l.Nashed Mathematics Department Faculty of ScienceAin Shams University

We compute the total energy and the spatial momentum of four charged rotating （Kerr-Newman） frames by using the gravitational energy-momentum 3-form within the framework of the tetrad formulation of the general relativity theory. We show how the effect of the inertial always makes the total energy divergent. We use a natural regularization method, which yields the physical value for the total energy of the system. We show how the regularization method works on a number of different rotating frames that are related to each other by the local lorentz transformation. We also show that the inertial has no effect on the spatial momentum components.

关键词： teleparallel gravity energy-momentum Weitzenbock connection regularization teleparallelism

Energy and momentum of general spherically symmetric frames on the regularizing teleparallelism

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Chinese Physics B 2012年第1期21卷 101-109页

作者： gamal g.l.Nashed Centre for Theoretical Physics The British University in EgyptEl-Sherouk City 11837Egypt Mathematics Department Faculty of ScienceAin Shams University

In the context of the covariant teleparallel framework, we use the 2-form translational momentum to compute the total energy of two general spherically symmetric frames. The first one is characterized by an arbitrary function H（r）, which preserves the spherical symmetry and reproduces all the previous solutions, while the other one is characterized by a parameter ξ which ensures the vanishing of the axial of trace of the torsion. We calculate the total energy by using two procedures, i.e., when the WeitzenbSck connection Гα^β is trivial, and show how H（r） and ξ play the role of an inertia that leads the total energy to be unphysical. Therefore, we take into account Гα^β and show that although the spacetimes we use contain an arbitrary function and one parameter, they have no effect on the form of the total energy and momentum as it should be.

关键词： gravitation teleparallel gravity energy-momentum conserved currents

SYNTHESIS, CHARACTERIZATION AND SOME PROPERTIES OF EPOXY RESINS CONTAININg AZOMETHINE BONDINg

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Chinese Journal of Polymer Science 2013年第8期31卷 1087-1095页

作者： smet Kaya Murat gül anakkale Onsekiz Mart University Faculty of Sciences and Arts Department of Chemistry Polymer Research Laboratory

New epoxy resins were prepared from hydroxyl substituted Schiff base monomers in two steps. The first step is based on the synthesis of hydroxyl substituted Schiffbase monomers via condensation reaction. The second step includes the reaction between Schiff base monomers with cpichlorohydrine （EPC） to obtain epoxy resins. The structures of resulting compounds were confirmed by FTIR and H-NMR. Tg-DTA and DSC measurements were made for thermal characterizations of the compounds. Chemical resistances of the cured epoxy-amine systems in acidic, alkaline and organic solvents were determined for coating applications. HC1 （aqueous solution, 10%）, NaOH （aqueous solution, 10%）, DMSO, DMF, N-methylpyrrolidone, ethanol, THF and acetone were used for corrosion tests. Chemical resistance data show that the synthesized resins have good chemical resistance against various acid, alkaline and common organic solvents.

关键词： Epoxy resin Thermal analysis Poly(imine)s.

Brane world black holes in teleparallel theory equivalent to general relativity and their Killing vectors,energy,momentum and angular momentum

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Chinese Physics B 2010年第2期19卷 77-91页

作者： gamal g.l.Nashed Centre for Theoretical Physics The British University in EgyptEl-Sherouk CityMisr-Ismalia Desert Road Postal No.11837P.O.Box 43Egypt Mathematics Department Faculty of ScienceAin Shams UniversityCairoEgypt

The energy--momentum tensor, which is coordinate-independent, is used to calculate energy, momentum and angular momentum of two different tetrad fields. Although, the two tetrad fields reproduce the same space--time their energies are different. Therefore, a regularized expression of the gravitational energy--momentum tensor of the teleparallel equivalent of general relativity （TEgR）, is used to make the energies of the two tetrad fields equal. The definition of the gravitational energy--momentum is used to investigate the energy within the external event horizon. The components of angular momentum associated with these space--times are calculated. In spite of using a static space--time, we get a non-zero component of angular momentum! Therefore, we derive the Killing vectors associated with these space--times using the definition of the lie derivative of a second rank tensor in the framework of the TEgR to make the picture more clear.

关键词： teleparallel equivalent of general relativity brane world black holes gravitational energy--momentum tensor regularized expression of the gravitational energy--momentum

Teleparallel equivalent theory of (1+1)-dimensional gravity

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Chinese Physics B 2010年第11期19卷 124-131页

作者： gamal g.l.Nashed Mathematics Department Faculty of ScienceAin Shams UniversityCairoEgypt Centre for Theoretical Physics The Bvitish University in EgyptEl-Sherouk CityMisr-Ismalia Desert RoadPostal No.11837P.O.Box 43Egypt

A theory of （1＋1）-dimensional gravity is constructed on the basis of the teleparallel equivalent of general relativity. The fundamental field variables are the tetrad fields ei^μ and the gravity is attributed to the torsion. A dilatonic spherically symmetric exact solution of the gravitational field equations characterized by two parameters M and Q is derived. The energy associated with this solution is calculated using the two-dimensional gravitational energy- momentum formula.

关键词： teleparallel equivalent theory of (1+1)-dimensional gravity two-dimensional spherically symmetric dilatonic black hole energy