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Acta Geologica Sinica(English Edition) 2011年第4期85卷 784-791页

作者： Ahmad Afroz SHAH asghar ALI School of Earth and Environmental Sciences James Cook UniversityTownsvilleQld 4811Australia

Successions of FIAs（foliation inflection/intersection axes preserved within porphyroblasts） provide a relative time scale for deformation and ***-situ dating of monazite grains preserved as inclusions within garnet and staurolite porphyroblasts within the foliations defining each FIA from such successions provides a rigorous approach to grouping ages that formed over extended periods of deformation and *** age and FIA progressions confirms the suitability of this approach plus provides access to lengthy histories that cannot otherwise be *** in the Big Thompson region of the Colorado Rocky Mountains,USA began about a SW-NE trending axis defined by FIA set 1 at around 1761±13 *** periods of tectonism occurred around 1712±25 and 1672±21 Ma about W-E and NW-SE trending FIAs 2 and 3, *** in the Balcooma Metamorphic Group NW of Greenvale in NE Queensland, Australia began around 470 Ma with the growth of garnet porphyroblasts about a W-E trending axis defined by FIA set *** monazite grains were preserved as inclusions in this mineral phase but they were in subsequently grown *** then occurred around 443.2±3.8,424±4 and 408.9±8.9 Ma about NNW-SSE,SSW-NNE and W-E trending FIAs 2,3 and 4,*** test of a FIA based approach to monazite dating in tectonic regimes in different parts of the world and with dramatically different ages suggests it can be used in all orogens containing porphyroblasts preserving inclusion trails.

关键词： FIAs porphyroblast monazite Colorado Balcooma Metamorphic Group

Rare Earth Elements Geochemistry of Sheikh-Marut Laterite Deposit,NW Mahabad,West-Azarbaidjan Province,Iran

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Acta Geologica Sinica(English Edition) 2013年第1期87卷 176-185页

作者： Ali ABEDINI Ali asghar CALAGARI Geology Department Faculty of SciencesUrmia University Geology Department Faculty of Natural SciencesUniversity of Tabriz

Laterite deposit at Sheikh-Marut （NW occurred within middle-upper Permian carbonate Mahabad, West-Azarbaidjan province, Iran） rocks. It consists of seven stratiform and/or discontinuous lenticular layers extending over 4.2 km in length and having thicknesses ranging from 3 to 14 m. Mineralogical data show that the ores contain kaolinite and hematite as major and boehmite, diaspore, halloysite, amesite, anatase, and muscovite-illite as minor mineral phases. The computed Ce anomaly values in the ores range from 0.05 to 20.84. Conservative index （e.g., Eu/Eu＊） suggests that this deposit is a product of alteration and weathering of basaltic rocks. Rhythmic increment of EREE values of the ores with approaching to the carbonate bedrocks shows an in-situ occurrence of lateritization processes. Mass change calculations of elements indicate that two competing processes namely leaching and fixation were the major regulating factors in concentration variation of REEs （La-Lu） in this deposit. The obtained results show that pH increase of weathering solutions by carbonate bedrocks, existence of organic matters, and the degree of comlexation with organic ligands played remarkable role in distribution of REEs during lateritization. Further geochemical considerations revealed that secondary phosphates, Mn-oxides and -hydroxides, diaspore, and anatase were the potential hosts for REEs in this deposit.

关键词： laterite geochemistry REEs Sheikh-Marut deposit Mahabad Iran

Existence of a Hartmann layer in the peristalsis of Sisko fluid

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Chinese Physics B 2014年第5期23卷 368-372页

作者： Saleem asghar Tayyaba Minhas Aamir Ali Department of Mathematics COMSATS Institute of Information Technology Department of Mathematics King Abdul Aziz University CNRS UMR 7351 Laboratoire Jean Alexandre DieudonneUniversite de Nice Sophia Antipolis

Analytical solutions for the peristaltic flow of a magneto hydrodynamic （MHD） Sisko fluid in a channel, under the effects of strong and weak magnetic fields, are presented. The governing nonlinear problem, for the strong magnetic field, is solved using the matched asymptotic expansion. The solution for the weak magnetic field is obtained using a regular perturbation method. The main observation is the existence of a Hartman boundary layer for the strong magnetic field at the location of the two plates of the channel. The thickness of the Hartmann boundary layer is determined analytically. The effects of a strong magnetic field and the shear thinning parameter of the Sisko fluid on the velocity profile are presented graphically.

关键词： magneto hydrodynamic Sisko fluid asymmetric channel Peristaltic flow non-Newtonian fluid

Synthesis and Characterization of Nano-hydroxyapatite Powder Using Wet Chemical Precipitation Reaction

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Journal of Materials Science & Technology 2014年第4期30卷 307-310页

作者： Syed Sibte asghar Abidi Qasim Murtaza Centre of Excellence in Materials Science(Nanomaterials) Aligarh Muslim University Mechanical and Production Engineering Department Delhi Technology University(Formerly Delhi College of Engineering)

Hydroxyapatite （HA） nano-powder was synthesized via wet chemical technique in a used precipitation reaction, in which Ca（OH）2 and H3PO4 were used as precursors. Deionised water was used as a diluting media for the reaction and ammonia was used to adjust the pH. The synthetic HA nano-powder has some medical applications such as a coating material in orthopaedic implants and in dental. HA powder has been studied at different temperatures from 100 to 800 ℃ to achieve the stoichiometric Ca/P ratio 1.667. The optimum temperature was found to be 600 ℃. Above this temperature, the HA powder decomposed to CaO. The crystallite size of HA powder was found to be in the range of 8.47-24.47 nm. The crystallographic properties were evaluated by X-ray diffraction, Fourier transform infrared spectroscopy, energy dispersive X- ray spectroscopy and scanning electron microscopy. The results show that, high purity of nano-hydroxyapatite powders could be obtained at low temperatures, and the crystallinity, crystallite size and Ca/P ratio of the resulting nanoparticles were found to be dependent on the calcination temperature. When Ca/P ratio exceeded 1.75, formation of CaO phase was observed.

关键词： Hydroxyapatite Nano-powder Synthesis Characterization

Flow and heat transfer over hyperbolic stretching sheets

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Applied Mathematics and Mechanics(English Edition) 2012年第4期33卷 445-454页

作者： A. AHMAD S. asghar COMSATS Institute of Information Technology Department of Mathematics King Abdulaziz University

The boundary layer flow and heat transfer analysis of an incompressible viscous fluid for a hyperbolically stretching sheet is presented. The analytical and numer- ical results are obtained by a series expansion method and a local non-similarity （LNS） method, respectively. The analytical and numerical results for the skin friction and the Nusselt number are calculated and compared with each other. The significant observation is that the momentum and the thermal boundary layer thickness decrease as the distance from the leading edge increases. The well-known solution of linear stretching is found as the leading order solution for the hyperbolic stretching.

关键词： hyperbolic stretching sheet boundary layer flow heat transfer seriesexpansion method local non-similarity method

Relative floatability as a criterion for evaluating the separation performance of phosphate from iron

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International Journal of Mining Science and Technology 2017年第3期27卷 451-458页

作者： Azizi asghar Seyyed Alizade Ganji Seyyed Mohammad Department of Mining Petroleum and Geophysics Shahrood University of Technology Shahrood Iran Department of Mining Faculty of Engineering Lorestan University Khorramabad Iran

This work was aimed to study the relative floatability of phosphate flotation by means of kinetic *** relative floatability is important to determine how selectively the phosphate is separated from its impurities. The effects of pulp pH, solid content, reagents dosage(depressant, collector and co-collector) and conditioning time were investigated on the ratio of the modified rate constant of phosphate to the modified rate constant of iron(relative floatability). The results showed that a large dosage of depressant associated with a low value of collector resulted in a better relative floatability. Increasing the co-collector dosage, conditioning time and pH increased the relative floatability up to a certain value and thereafter resulted in diminishing the relative floatability. Meanwhile, the results indicated that increment of solid concentration increased the relative floatability in range investigated. It was also found that that maximum relative floatability(16.05) could be obtained in pulp pH, 9.32, solid percentage, 30,depressant dosage, 440 g/t, collector dosage, 560 g/t, co-collector dosage, 84.63 g/t and conditioning time,9.43 min.

关键词： Phosphate Relative floatability Kinetics Rate constant Separation

Simple separation method of Zn(Ⅱ) and Cd(Ⅱ) from brine solution of zinc plant residue and synthetic chloride media using solvent extraction

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Chinese Journal of Chemical Engineering 2020年第4期28卷 1055-1061页

作者： Ali asghar Balesini Aghdam Hossein Yoozbashizadeh Javad Moghaddam Department of Materials Engineering Science and Research BranchIslamic Azad UniversityTehranIran Materials and Metallurgical Engineering Department University of ZanjanZanjanIran

In this work,the possibility of separation of Zn^2+and Cd^2+metal ions from chloride(brine)solutions was *** this purpose,simple solvent extraction(SX)experiments by di-2-ethylhexyl phosphoric acid(D2EHPA)in kerosene as a diluent was performed on synthetic and industrial chloride solution obtained from brine leaching of zinc filter cakes(by-product of zinc hydrometallurgical processing).The optimal conditions for separation were *** zinc extraction efficiency was 99%with negligible co-extraction of ***,a highΔpH0.5 value for Zn(Ⅱ)and Cd(Ⅱ)was ***-IR and slope analysis indicated that ZnClA·3HA and CdClA·3HA species were probably extracted.

关键词： Solvent extraction Brine media Leaching filter cakes Zinc Cadmium

Generalized thermoelastic interaction in functional graded material with fractional order three-phase lag heat transfer

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Journal of Central South University 2015年第5期22卷 1606-1613页

作者： Ibrahim A.abbas Department of Mathematics Faculty of Science and Arts - Khulais University of Jeddah Nonlinear Analysis and Applied Mathematics Research Group (NAAM) Department of MathematicsKing Abdulaziz University Department of Mathematics Faculty of Science Sohag University

The present work is concerned with the solution of a problem on thermoelastic interactions in a functional graded material due to thermal shock in the context of the fractional order three-phase lag model. The governing equations of fractional order generalized thermoelasticity with three-phase lag model for functionally graded materials(FGM)(i.e., material with spatially varying material properties) are established. The analytical solution in the transform domain is obtained by using the eigenvalue *** inversion of Laplace transform is done numerically. The graphical results indicate that the fractional parameter has significant effects on all the physical quantities. Thus, we can consider the theory of fractional order generalized thermoelasticity an improvement on studying elastic materials.

关键词： three-phase lag model fimctionally graded materials fractional calculus generalized thermoelasticity

Three-dimensional MHD flow over a shrinking sheet: Analytical solution and stability analysis

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Chinese Physics B 2017年第1期26卷 285-289页

作者： Sumaira Afzal Saleem asghar Adeel Ahmad Department of Mathematics COMSATS Institute of Information Technology Department of Mathematics King Abdul Aziz University

The magnetohydrodynamic（MHD） steady and unsteady axisymmetric flows of a viscous fluid over a two-dimensional shrinking sheet are addressed. The mathematical analysis is carried out in the presence of a large magnetic field. The steady state problem results in a singular perturbation problem having an infinite domain singularity. The secular term appearing in the solution is removed and a two-term uniformly valid solution is derived using the Lindstedt–Poincaré technique. This asymptotic solution is validated by comparing it with the numerical solution. The solution for the unsteady problem is also presented analytically in the asymptotic limit of large magnetic field. The results of velocity profile and skin friction are shown graphically to explore the physical features of the flow field. The stability analysis of the unsteady flow is made to validate the asymptotic solution.

关键词： steady and unsteady magnetohydrodynamic flows two-directional shrinking sheet exact and asymptotic solutions stability analysis

Numerical investigation of gas bubble behavior in tapered fluidized beds

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Particuology 2018年第3期16卷 152-164页

作者： Ramin Khodabandehlou Hossein Askaripour asghar Molaei Dehkordi Department of Chemical and Petroleum Engineering Sharif University of Technology P.O. Box 11155-9465 Tehran Iran

In this article, the behavior of gas bubbles in tapered fluidized beds is investigated with the use of a two- fluid model incorporating kinetic theory of granular flow. The effects of various parameters such as apex angle, particle size, and particle density on the size distribution and the rise velocity of gas bubbles were examined. In addition, the simulation results for the bubble fraction and axial velocity of gas bubbles were compared with experimental data reported in the literature and good agreement was observed. As the apex angle was increased, the fraction of gas bubbles with large sizes increased and the fraction of bubbles with small sizes decreased. As the particle size increased, the fraction of gas bubbles with large diameters decreased; however, the fraction of bubbles with medium diameters increased. The obtained results clearly indicate that an increased solid density increased the bubble rise velocity up to a specified height and reduced the velocity at larger heights, in tapered fluidized beds.

关键词： Tapered fluidized beds Apex angle Particle size and density Bubble size distribution Rise velocity of bubbles