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Phantom Accretion onto the Schwarzschild de-Sitter Black Hole

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Chinese Physics Letters 2011年第9期28卷 34-37页

作者： M Sharif G abbas Department of Mathematics University of the PunjabQuaid-e-Azam CampusLahore-54590Pakistan

We deal with phantom energy accretion onto the Schwarzschild de-Sitter black *** energy flux conservation,relativistic Bernoulli equation and mass flux conservation equation are formulated to discuss the phantom *** discuss the conditions for critical *** is found that the mass of the black hole decreases due to phantom *** exist two critical points which lie in the exterior of horizons(black hole and cosmological horizons).The results for the phantom energy accretion onto the Schwarzschild black hole can be recovered by takingΛ→0.

关键词： accretion horizon black

An Efficient Numerical Solution Method for Elliptic Problems in Divergence Form

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Advances in Applied Mathematics and Mechanics 2014年第3期6卷 327-344页

作者： Ali abbas Department of Mathematics Lebanese International UniversityBekaa-RayakLebanon

In this paper the problem−div(a(x,y)∇u)=f with Dirichlet boundary conditions on a square is solved iteratively with high accuracy for u and∇u using a new scheme called“hermitian box-scheme”.The design of the scheme is based on a“hermitian box”,combining the approximation of the gradient by the fourth order hermitian derivative,with a conservative discrete formulation on boxes of length *** iterative technique is based on the repeated solution by a fast direct method of a discrete Poisson equation on a uniform rectangular *** problem is suitably scaled before *** numerical results obtained show the efficiency of the numerical *** work is the extension to strongly elliptic problems of the hermitian box-scheme presented by abbas and Croisille(***.,49(2011),pp.239–267).

关键词： Hermitian scheme box-scheme Kronecker product fast solver iterative method Poisson problem

Fabrication and Growth Mechanism of Single-crystalline Rutile TiO_2 Nanowires by Liquid-phase Deposition Process in a Porous Alumina Template

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Journal of Materials Science & Technology 2015年第8期31卷 828-833页

作者： abbas Sadeghzadeh Attar Zahra Hassani Department of Metallurgy and Materials Engineering University of Kashan Department of Materials Institute of Science and High Technology and Environmental SciencesGraduate University of Advanced Technology

TiO2 nanowire arrays were successfully fabricated by liquid-phase deposition method using porous alumina templates. The obtained TiO2 nanowires were characterized using Raman spectroscopy, X-ray diffraction （XRD）, scanning electron microscopy （SEM）, field emission scanning electron microscopy （FE- SEM）, transmission electron microscopy （TEM）, and selected area electron diffraction （SAED） analysis. Results of electron microscopic observations indicated that the nanowires were smooth and uniform with a diameter of about 50-80 nm and several micrometers in length. SAED, Raman, and XRD mea- surements showed that TiO2 nanowires were single-crystalline with a pure rutile structure after heating at 800 ~C for 10 h. In this situation, the nanowire constituents grew preferentially along the 〈001〉 direction. Furthermore, the formation process and mechanistic study of the Ti02 nanowire arrays were proposed and discussed in detail. The nanowires are clearly produced by the deposition of TiO2 particles on the inner wall of the template nanochannels.

关键词： TiO2 nanowire arrays Single crystal Rutile phase Liquid-phase deposition process

Determination of Trace Amounts of Nickel (Ⅱ) by Graphite Furnace Atomic Absorption Spectrometry Coupled with Cloud Point Extraction

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Chemical Research in Chinese Universities 2011年第3期27卷 366-370页

作者： SHAH Syed mazhar WANG Hao-nan SU Xing-guang College of Chemistry Jilin University Changchun 130012 P. R. China College of Environment and Resources Jilin University Changchun 130012 P. R. Chin~

A new method based on the cloud point extraction（CPE） for separation and preconcentration of nickel（Ⅱ） and its subsequent determination by graphite furnace atomic absorption spectrometry（GFAAS） was proposed, 8-hydroxyquinoline and Triton X-100 were used as the ligand and surfactant respectively. Nickel（Ⅱ） can form a hy-drophobic complex with 8-hydroxyquinoline, the complex can be extracted into the small volume surfactant rich phase at the cloud point temperature（CPT） for GFAAS determination. The factors affecting the cloud point extraction, such as pH, ligand concentration, surfactant concentration, and the incubation time were optimized. Under the optimal conditions, a detection limit of 12 ng/L and a relative standard deviation（RSD） of 2.9% were obtained for Ni（Ⅱ） determination. The enrichment factor was found to be 25. The proposed method was successfully applied to the determination of nickel（Ⅱ） in certified reference material and different types of water samples and the recovery was in a range of 95%―103%.

关键词： Cloud point extraction Phase separation Graphite furnace atomic absorption spectrometry Nickel(Ⅱ)

Interaction due to various sources in saturated porous media with incompressible fluid

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Journal of Central South University 2016年第5期23卷 1232-1242页

作者： Rajneesh Kumar Ibrahim A.abbas Department of Mathematics Kurukshetra University Department of Mathematics Faculty of Science and Arts-KhulaisUniversity of Jeddah Nonlinear Analysis and Applied Mathematics Research Group (NAAM) Department of MathematicsKing Abdulaziz University Department of Mathematics Faculty of ScienceSohag University

The disturbance due to mechanical and thermal sources in saturated porous media with incompressible fluid for two-dimensional axi-symmetric problem is *** Laplace and Hankel transforms techniques are used to investigate the *** concentrated source and source over circular region have been taken to show the utility of the *** transformed components of displacement,stress and pore pressure are *** inversion techniques are used to obtain the resulting quantities in the physical domain and the effect of porosity is shown on the resulting *** the field quantities are found to be sensitive towards the porosity *** is observed that porosity parameters have both increasing and decreasing effect on the numerical values of the physical *** the values of the physical quantities are affected by the different boundaries.A special case of interest is also deduced.

关键词： axi-symmetry incompressible porous medium pore pressure Laplace transform Hankel transform concentrated source and source over circular region

Neuro-optimized numerical treatment of HIV infection model

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International Journal of Biomathematics 2021年第5期14卷 199-220页

作者： Anas Bilal Guangmin Sun Sarah mazhar Zhang Junjie Faculty of Information Technology Beijing University of TechnologyChaoyang District Beijing 100124P.R.China

In this paper,a neuro-optimized numerical method is presented for approximation of HIV virus progression model in the human *** model is composed of coupled nonlinear system of differential equations(DEs)containing healthy and infected T-Cells and HIV free virus *** coupled system is transformed into feedforward artificial neural network(ANN)with Mexican hat wavelet function in the hidden *** meta-heuristic algorithms based on chaotic particle swarm optimization(CPSO)and its hybrid version with local search technique are exploited to tune the parameters of ANN in an unsupervised manner of error function.A comprehensive testbed is established to observe the virus growth per day with performance metric containing fitness value,computational time complexity and *** proposed solutions are compared with state of art Runge-Kutta method and Legendre Wavelet Collocation Method(LWCM).The core advantages of the proposed scheme are getting the solution on continuous grid,consistent convergence,simplicity in implementation and handling strong nonlinearity effectively.

关键词： HIV infection Mexican hat wavelet artificial neural network chaotic particle swarm optimization hybrid computational method Monte Carlo simulations

Evaluation of plasma sprayed YSZ thermal barrier coatings with the CMAS deposits infiltration using impedance spectroscopy

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Progress in Natural Science:Materials International 2012年第1期22卷 40-47页

作者： Musharaf abbas Key Laboratory of Aerospace Materials & Performance(Ministry of Education) School of Materials Science and EngineeringBeihang Univerisity

The yttria-stabilized zirconia(YSZ) thermal barrier coatings(TBCs) prepared by atmospheric plasma spraying with different heat treatment period at the temperature of 1250 1C were studied in the present *** impedance spectroscopy(EIS) was employed to nondestructively examine the impedance and capacitance behavior of free standing YSZ coatings deposited by plasma spray with CMAS(calcium-magnesium-alumino-silicate) *** circuit was established on the basis of the biomodal structure in *** sintering behavior of the coatings can be reflected by the changes of resistance and capacitance of the *** EIS,the microstructure evolution of the coating with CMAS deposits was discussed in detail.

关键词： Calcium-magnesium-alumino-silicate Thermal barrier coatings Plasma spray Impedance spectroscopy

On systematic development of FSI solvers in the context of particle methods

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Journal of Hydrodynamics 2022年第3期34卷 395-407页

作者： abbas Khayyer Hitoshi Gotoh Yuma Shimizu Department of Civil and Earth Resources Engineering Kyoto UniversityKyotoJapan

This paper presents a review on state-of-the-art of developments corresponding to fluid-structure interaction(FSI)solvers developed within the context of particle *** paper reviews and highlights the potential robustness of entirely Lagrangian meshfree FSI solvers in reproducing FSI corresponding to extreme events and portrays the future perspectives for systematic developments towards reliable engineering applications with respect to rapid advances in technology and emergence of so-called advanced materials that can result in complex and highly non-linear structural ***,the paper highlights the necessity for reproduction of comprehensive structural responses,including viscoelastic,elastoplastic and progressive damages/failures,by the advanced FSI solvers developed within the context of particle *** this regard,extensions of the structure model are suggested to be conducted in a variationally consistent framework to ensure stability,accuracy and physical reliability including thermodynamic *** paper reviews basics of mathematical and numerical modelling for entirely Lagrangian meshfree hydroelastic FSI solvers and presents a brief background on extensions of such solvers towards reproducing viscoelastic structural *** preliminary numerical results on structural viscoelasticity achieved by an extended Hamiltonian SPH(HSPH)model are *** vision paper also concisely portrays the future perspectives for systematic development of particle-based FSI solvers.

关键词： Fluid-structure interaction(FSI) entirely Lagrangian meshfree smoothed particle hydrodynamics(SPH) Hamiltonian SPH(HSPH) viscoelasticity

Numerical simulation of underground seasonal cold energy storage for a 10 MW solar thermal power plant in north-western China using TRNSYS

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Frontiers in Energy 2021年第2期15卷 328-344页

作者： Zulkarnain abbas Yong LI Ruzhu WANG Institute of Refrigeration and Cryogenics Shanghai Jiao Tong UniversityShanghai 200240China College of Environmental Science and Engineering Donghua UniversityShanghai 201620China

This paper aims to explore an efficient, cost-effective, and water-saving seasonal cold energy storage technique based on borehole heat exchangers to cool the condenser water in a 10 MW solar thermal power plant. The proposed seasonal cooling mechanism is designed for the areas under typical weather conditions to utilize the low ambient temperature during the winter season and to store cold energy. The main objective of this paper is to utilize the storage unit in the peak summer months to cool the condenser water and to replace the dry cooling system. Using the simulation platform transient system simulation program (TRNSYS), the borehole thermal energy storage (BTES) system model has been developed and the dynamic capacity of the system in the charging and discharging mode of cold energy for one-year operation is studied. The typical meteorological year (TMY) data of Dunhuang, Gansu province, in north-western China, is utilized to determine the lowest ambient temperature and operation time of the system to store cold energy. The proposed seasonal cooling system is capable of enhancing the efficiency of a solar thermal power plant up to 1.54% and 2.74% in comparison with the water-cooled condenser system and air-cooled condenser system respectively. The techno-economic assessment of the proposed technique also supports its integration with the condenser unit in the solar thermal power plant. This technique has also a great potential to save the water in desert areas.

关键词： seasonal cold energy storage borehole heat exchangers typical meteorological data TRNSYS condenser cooling techno-economic assessment