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61.
Hoda Farahani Jafar Sadeghi Hassan Saadat 《International Journal of Theoretical Physics》2012,51(12):3721-3726
In this paper, corrected entropy of a class of BTZ black holes, include charge and rotation, studied. We obtain corrected Bekenstein-Hawking entropy and find that effect of charge viewed at order A ?2, and effect of rotation viewed at order A ?6, therefore Q and J don’t have contribution in corrected entropy lower than the second order. We also write the first law of black hole thermodynamics for the case of charged rotating BTZ black hole. 相似文献
62.
63.
Davood Nori‐Shargh Bita Soltani Nasrin Saroogh‐Farahani Farzad Deyhimi 《国际化学动力学杂志》2006,38(2):144-151
The kinetics of the addition reaction of aniline to ethyl propiolate in dimethylsulfoxide (DMSO) as solvent was studied. Initial rate method was used to determine the order of the reaction with respect to the reactants, and pseudo‐first‐order method was used to calculate the rate constant. This reaction was monitored by UV–Vis spectrophotometer at 399 nm by the variable time method. On the basis of the experimental results, the Arrhenius equation for this reaction was obtained as log k = 6.07 ‐ (12.96/2.303 RT). The activation parameters, Ea, ΔH#, ΔG#, and ΔS# at 300 K were 12.96, 13.55, 23.31 kcal mol?1 and ?32.76 cal mol?1 K?1, respectively. The results revealed a first‐order reaction with respect to both aniline and ethyl propiolate. In addition, based on the experimental results and using also density functional theory (DFT) at B3LYP/6‐31G* level, a mechanism for this reaction was proposed. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 38: 144–151, 2006 相似文献
64.
Amir Ahmadi-Javid Amir Ardestani-Jaafari Leslie R Foulds Hossein Hojabri Reza Zanjirani Farahani 《The Journal of the Operational Research Society》2015,66(8):1399-1412
In this paper, we investigate the weighted maximal planar graph (WMPG) problem. Given a complete, edge-weighted, simple graph, the WMPG problem involves finding a subgraph with the highest sum of edge weights that is maximal planar, namely, it can be embedded in the plane without any of its edges intersecting, and no additional edge can be added to the subgraph without violating its planarity. We present a new integer linear programming (ILP) model for this problem. We then develop a cutting-plane algorithm to solve the WMPG problem based on the proposed ILP model. This algorithm enables the problem to be solved more efficiently than previously reported algorithms. New upper bounds are also provided, which are useful in evaluating the quality of heuristic solutions or in generating initial solutions for meta-heuristics. Computational results are reported for a set of 417 test instances of size varying from 6 to 100 nodes including 105 instances from the literature and 312 randomly generated instances. The computational results indicate that instances with up to 24 nodes can be solved optimally in reasonable computational time and the new upper bounds for larger instances significantly improve existing upper bounds. 相似文献
65.
Negin Fasih Ramandi Farzaneh Shemirani Malihe Davudabadi Farahani 《Mikrochimica acta》2014,181(15-16):1833-1841
We demonstrate the application of an ionic liquid-based ferrofluid to the dispersive solid phase extraction of lead(II) using PAN as the chelator. The ionic liquid contains silica nanoparticles with a magnetic core as the dispersion medium, and its use results in improved stability of the colloidal dispersion and a complete extraction of lead(II) within a few seconds. In addition, there is no need for centrifugation. Specifically, the effect of different variables on the extraction of lead(II) was studied using an experimental design. Lead(II) was quantified by AAS. Under optimized conditions, the calibration graph for lead(II) is linear in the range from 5 to 372 μg L?1, the relative standard deviation is 1.34 % (for n?=?7), the limit of detection is 1.66 μg L?1, and the enrichment factor is 200. The maximum adsorption capacity of sorbent was calculated to be 10.7 mg g?1, and adsorption follows a Langmuir isotherm. Figure
A schematic view of D-SPE experimental set up. We demonstrate the application of an ionic liquid-based ferrofluid to the dispersive solid phase extraction of lead(II) using PAN as the chelator. The ionic liquid contains silica nanoparticles with a magnetic core as the dispersion medium 相似文献
66.
S Rezapour R Zanjirani Farahani T Drezner 《The Journal of the Operational Research Society》2011,62(10):1784-1795
A model for designing the network of a new entrant supply chain under inelastic demand and in the presence of pre-existing competing chains is proposed. These supply chains provide an identical product for a market area. The model considers the location of distribution centres and retail outlets on a discrete set of potential locations. The assumptions of the model are: (1) static competition between the new and pre-existing chains and (2) a probabilistic customer behaviour based on an attraction function depending on both the location and the quality of the retailers. This model also incorporates the impact of the facilities’ location decisions on the operational inventory and shipment decisions. The resulting model is formulated as a mixed integer non-linear programme (MINLP). To solve the MINLP it is transformed to a linear one. We illustrate the model, discuss the results of a real-world case, and investigate the effectiveness of the proposed algorithm using randomly generated examples. 相似文献
67.
In this work we study viscous Chaplygin gas and obtain modified Friedmann equations due to viscosity. We calculate time-dependent energy density for the case of non-flat universe. By using stability condition and speed of sound we find critical value of viscosity coefficient where speed of sound is finite. 相似文献
68.
J. Sadeghi M. Khurshudyan M. Hakobyan H. Farahani 《International Journal of Theoretical Physics》2014,53(7):2246-2260
In this paper we are interested to consider mathematical ways to obtain different phenomenological fluids from two-component Tachyonic scalar fields. We consider interaction between components and investigate problem numerically. Statefinder diagnostics and validity of the generalized second law of thermodynamics performed and checked. We suppose that our Universe bounded by Hubble horizon. 相似文献
69.
A. Pourdarvish J. Sadeghi H. Farahani B. Pourhassan 《International Journal of Theoretical Physics》2013,52(10):3560-3563
In this paper we consider Gödel black hole and study thermodynamics and statistics with logarithmic correction. We calculate some important quantities such as free energy, specific heat and partition function. 相似文献
70.
Flow pattern analysis of linear gradient flow distribution 总被引:1,自引:0,他引:1
This paper uses the Oseen transformation to solve the differential equations governing motion of the vertical linear gradient flow distribution close to a wall surface. The Navier-Stokes equations are used to consider the inertia term along the flow direction. A novel contour integral method is used to solve the complex Airy function. The boundary conditions of linear gradient flow distribution for finite problems are determined. The vorticity function, the pressure function, and the turbulent velocity profiles are provided, and the stability of particle trajectories is studied. An Lx-function form of the third derivative circulation is used to to simplify the solution. Theoretical results are compared with the experimental measurements with satisfactory agreement. 相似文献