1,614 research outputs found

    Diffusion constant of slowly rotating black three-brane

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    In this paper, we take the slowly rotating black three-brane background and perturb it by introducing a vector gauge field. We find the components of the gauge field through Maxwell equations and Bianchi identities. Using currents and some ansatz we find Fick's first law at long wavelength regime. An interesting result for this non-trivial supergravity background is that the diffusion constant on the stretched horizon which emerges from Fick's first law is a complex constant. The pure imaginary part of the diffusion constant appears because the black three-brane has angular momentum. By taking the static limit of the corresponding black brane the well known diffusion constant will be recovered. On the other hand, from the point of view of the Fick's second law, we have the dispersion relation ω=iDq2\omega=-iDq^{2} and we found a damping of hydrodynamical flow in the holographically dual theory. Existence of imaginary term in the diffusion constant introduces an oscillating propagation of the gauge field in the dual field theory

    The relation between non-commutative and Finsler geometry in Horava-Lifshitz black holes

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    In this paper we employ the Horava-Lifshitz black holes solutions and obtain the corresponding Hamiltonian. It helps us to take new variables and it will be written by harmonic oscillator form. This leads us to apply non-commutative geometry to the new Hamiltonian and obtain the corresponding Lagrangian. And then, we take some information from Finsler geometry and write the Lagrangian of the different kinds of Horava-Lifshitz black holes. We show that the corresponding Lagrangian in non-commutative and Finsler geometry for above mentioned black holes completely coincidence together with some specification of parameters. But in case of rotation, the place of center of mass energy completely different, so the particle goes to inside of black hole rapidly without falling into singularity. So in that case, two Lagrangians cover each other at 0<r<rh.0<r<r_h.Comment: 15 page

    The Lagrangian of charged test particle in Horava-Lifshitz black hole and deformed phase space

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    In this paper, we use deformation approach and obtain the corresponding Lagrangian of charged test particle. Also, we show the effect of NC parameters on the Lagrangian of test particle in HL background with charge and without charge. Also, we see in case of β=θ\beta=\theta and without charge, the deformed and non-deformed Lagrangian will be same. Also in case of β=θ\beta=\theta and with charge will be the same but the charge or field need some scaling. Finally, We show that two theories in case of βθ\beta\neq\theta with charge is completely different. It means that in case of NC geometry in addition to have time components of field we have rr and xix_{i} components.Comment: 9 page

    Deformation of the quintom cosmological model and its consequences

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    In this paper, we investigate the effects of non-commutative phase-space on the quintom cosmological model. In that case, we discuss Λ1\Lambda_{1}, Λ2\Lambda_{2} and other cosmological parameters and show that they are associated to deformation parameters θ\theta and β\beta. Generally one can say that, the non-commutative parameter plays important role in physics and here also help us to arrange the divergency of cosmological constant. We draw time-dependent scale factor and investigate the effect of non-commutative parameters. Finally, we take advantage from non-commutative phase-space and obtain the deformed Lagrangian for the quintom model. In order to discuss some cosmological phenomena as dark energy and inflation, we employ Neother symmetry.Comment: 17 pages, 1 figure. References added in the revised versio

    Decolorization of Reactive Black-5 High Concentration by Vermicompost Microflora and Detoxification of By-Products by UV-C/H2O2 Post-Treatment

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    The presence of synthetic dyes in textile wastewater is a problematic issue for environmentalist. Nowadays, dye removal is practiced via different methods. Among all these methods, biodecolorization is an ideal technique. The present research apples vermicompost microflora to remove reactive black-C, pH = 7, and under anaerobic condition. At 36h, removal efficiencies of 94.79%, 94.06%, and 93.6% are obtained for concentrations of 800, 850, and 950 mg/L, respectively. It has also been observed that when the initial concentration rises to 1400 mg/L, the efficiency drops to 51.57% at 36h. Also, methyl red, methyl orange, eriochrome black-t, and acid blue-113 could be decolorized by the isolated bacterial strain with an efficiency of 94.29%, 92.10%, 90.83%, and 88.95%, respectively. Phytotoxicity Test shows that the parent form of reactive black-5 has not been toxic for the seeds (100% germination for Triticum aestivum and 90% for Maize). When reactive black-5 is treated with isolated bacterial strain under anaerobic condition, none of the seeds remain germinated which might be due to the possible formation of toxic aromatic amines intermediates. Therefore, ultraviolet C + 100 mM H2O2 has been used as the post-treatment process for detoxifying of by-products. After the integrated treatment of synthetic wastewater, containing RB-5, complete germination (100%) of Triticum aestivum and Maize is observed. In the post-treatment process, due to the generation and activation of hydroxyl radicals, the toxic aromatic amines compounds convert to the less toxic compounds. Keywords:azo dyes; anaerobic removal; integrated treatment; phytotoxicity; hydroxyl radical
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