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ON THE sTABiLiTY OF THE REsiDUAL-FREE BUBBLEs FOR THE NAViER-sTOKEs EQUATiONs

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Acta Mathematica scientia 2005年第4期25卷 715-730页

作者： ali i.Nesliturk Department of Mathematics Izmir Institute of Technology P.O. Box 35430 Izmir Turkey

This paper considers the Calerkin finite element method for the incompressible Navier-stokes equations in two dimensions, where the finite-dimensional spaces employed consist of piecewise polynomials enriched with residual-free bubble （RFB） functions. The stability features of the residual-free bubble functions for the linearized Navier-stokes equations are analyzed in this work. it is shown that the enrichment of the velocity space by bubble functions stabilizes the numerical method for any value of the viscosity parameter for triangular elements and for values of the viscosity parameter in the vanishing limit case for quadrilateral elements.

关键词： Galerkin finite element method incompressible Navier-stokes equations stability

Dynamics of Humic substance-Complexed Copper and Copper Leaching During Composting of Chicken Manure

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Pedosphere 2010年第2期20卷 245-251页

作者： A.s.ali College of Resource and Environment Northwest A & F University

Chicken manure was composted for 110 d to evaluate changes in organic carbon (C) and humic substance-complexed copper (Hs-Cu) extracted with water,sodium hydroxide (NaOH),and sodium pyrophosphate and sodium hydroxide mixture (Na 4 P 2 O 7-NaOH).The average Hs-Cu content from the Na 4 P 2 O 7-NaOH extraction accounted for 46.8% of the total Cu in the compost,followed by those from the NaOH and water extractions,which accounted for 34.5% and 6% of the total Cu in the compost,***-Na 4 P 2 O 7-extractable Hs-Cu increased throughout the composting ***-extractable Hs-Cu increased during the first 50 d of composting and then leveled ***-extractable Hs-Cu enhanced during the first 21 d and then ***-extractable Hs-Cu was not correlated to NaOH-or NaOH-Na 4 P 2 O 7-extractable organic *** average amount of Cu leached from the compost was about 20% of the total Cu in the chicken manure and Cu leaching increased during the first 35 d of composting and then *** of Cu was significantly correlated to the concentrations of Hs-Cu extracted with NaOH and water,but was not correlated to the concentration of Hs-Cu extracted with NaOH-Na 4 P 2 O ***,NaOH-and water-extractable Hs-Cu were relatively labile and NaOH-Na 4 P 2 O 7-extractable Hs-Cu was relatively *** process after rapid decomposition could result in low potential of Cu leaching because of formation of more NaOH-Na 4 P 2 O 7-extractable Hs-Cu.

关键词： humic substance leaching organic carbon

Effects of a structurally related substance on the crystallization of paracetamol

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Frontiers of Chemical science and Engineering 2013年第1期7卷 79-87页

作者： ali sALEEMi i.i. ONYEMELUKWE Zoltan NAGY Department of Chemical Engineering Loughborough University Loughborough LE11 3TU UK school of Chemical Engineering Purdue University West Lafayette Ind. 47907 USA

Paracetamol （PCM） was crystallized from an isopropanol （iPA） solution containing various small amounts of metacetamol as an additive. The effect on the nucleation kinetics was studied by measuring the induction time to nucleation and the metastable zone width using focused beam reflectance measurements （FBRM） and attenuated total reflectance （ATR-UV/Vis） spectroscopy. Both the induction time and the metastable zone width were expressed as functions of the additive concentration. small amounts ofmetacetamol （1-4 tool-%） were found to cause significant inhibition to the nucleation by extending both the induction time and the metastable zone width. A progressive change in the morphology of the paracetamol crystals from tabular to columnar habit was observed with increasing metacetamol concentration. The solvent also had a significant effect on the size of the paracetamol crystals as smaller crystals were obtained in iPA than in aqueous solution. The dissolution rate of paracetamol was improved by the incorporation of metacetamol with 4 tool-% having the most effect. A supersaturation control （ssC） approach was implemented for the PCM-iPA system with and without metacetamol in an attempt to control and obtain larger metacetamol-doped paraeetamol crystals.

关键词： acetaminophen metacetamol crystallization metastable zone width induction time supersaturation control

Prediction of Hub Corner stall Characteristics of a Highly Loaded Low speed single stage Fan

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Journal of Thermal science 2011年第2期20卷 106-114页

作者： s. Farhan ali Hashmi school of Power and Energy 127 YouYi Xilu Northwestern Polytechincal University

in this paper a numerical investigation has been presented on the stall mechanism of a highly loaded single stage Low speed Fan designed for the research test facility to be installed at North Western Polytechnic University (NWPU) Xi’an, China. The results presented are for the design point, near stall and just stall operating conditions at design speed. Design point studies have been found to be an indicative of stall area. Unsteady method of domain scaling has been used to compute the results at near stall and just stall conditions. it has been found that unlike the conventional tip leakage flow of the rotor, stator hub section is mainly responsible for the stall of the fan. The flow mechanism has been discussed with correlation to the design variables and previous investigations. Commercial CFD code NUMECA FiNE/Turbo has been used for computations; results have been compared with results obtained from commercial CFD code ANsYs-CFX. The loss prediction of latter code is conservative than the former. The stall mechanism predicted by both codes is analogous.

关键词： Low stage reaction stall Rotor hub corner separation stator hub corner separation 3D flow separation

New ordered MAX phase Mo_2 TiAlC_2: Elastic and electronic properties from first-principles

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Chinese Physics B 2016年第10期25卷 323-329页

作者： M A Hadi M s ali Department of Physics University of Rajshahi Department of Physics Pabna University of Science and Technology

First-principles computation on the basis of density functional theory(DFT) is executed with the CAsTEP code to explore the structural, elastic, and electronic properties along with Debye temperature and theoretical Vickers’ hardness of newly discovered ordered MAX phase carbide Mo2TiAlC2. The computed structural parameters are very reasonable compared with the experimental results. The mechanical stability is verified by using the computed elastic constants. The brittleness of the compound is indicated by both the Poisson’s and Pugh’s ratios. The new MAX phase is capable of resisting the pressure and tension and also has the clear directional bonding between atoms. The compound shows significant elastic anisotropy. The Debye temperature estimated from elastic moduli(B, G) is found to be 413.6 K. The electronic structure indicates that the bonding nature of Mo2TiAlC2is a mixture of covalent and metallic with few ionic characters. The electron charge density map shows a strong directional Mo–C–Mo covalent bonding associated with a relatively weak Ti–C *** calculated Fermi surface is due to the low-dispersive Mo 4d-like bands, which makes the compound a conductive *** hardness of the compound is also evaluated and a high value of 9.01 GPa is an indication of its strong covalent bonding.

关键词： new ordered MAX phase density functional theory calculations Debye temperature Vickers hardness

Femtosecond laser induced nanostructuring of zirconium in liquid confined environment

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Chinese Physics B 2017年第1期26卷 310-319页

作者： Nisar ali shazia Bashir Umm-i-Kalsoom M.shahid Rafique Narjis Begum Wolfgang Husinsky ali Ajami Chandra s.R.Natahala Laser Laboratories Institute for Applied Physics Vienna University of Technology 1040 Vienna Austria Department of Basic sciences and Humanities University of Engineering and Technology Lahore Faisalabad Campus Faisalabad Pakistan Laser Laboratories Centre for Advanced Studies m Physics GC University 1-Church Road Lahore Pakistan Department of Physics GC University Kachehri Road Lahore Pakistan Department of Physics Riphah International University Islamahad (Lahore Campus) Lahore Pakistan Department of Physics University of Engineering and Technology Lahore Pakistan Department of Physics COMSATS Institute of Information Technology Islamabad Pakistan

The surface, structural, and mechanical properties of zirconium after irradiation with Ti： sapphire laser（800 nm, 30 fs,1 k Hz） have been investigated. The zirconium targets were exposed for a varying number of laser pulses ranging from 500 to 2000 at a fixed fluence of 3.6 J/cm^2 corresponding to an intensity of 1.2×10^14W/cm^2 in ambient environments of deionized water and propanol. A scanning electron microscope（sEM） was employed to investigate the surface morphology of the irradiated zirconium. The sEM analysis shows the formation of various kinds of features including nanoscale laser induced periodic surface structures（LiPss）, sponge like surface structure, flakes, conical structures, droplets, pores, and cavities. The energy dispersive x-ray spectroscopy（EDs） analysis exhibits the variation in chemical composition along with an enhanced diffusion of oxygen under both ambient conditions. The crystal structure and phase analyses of the exposed targets were explored by x-ray diffraction（XRD） and Raman spectroscopy techniques, respectively. The XRD analysis confirms the presence of various phases of zirconium hydride and zirconia after ablation in both de-ionized water and propanol. However, excessive hydrides are formed in the case of propanol. The Raman analysis supports the EDs and XRD results. it also reveals the presence of oxides（zirconia） after irradiation in both de-ionized water and propanol *** chemical reactivity of zirconium was significantly improved in the presence of liquids which were accountable for the growth of novel phases and modification in the chemical composition of the irradiated Zr. A nanohardness tester was employed to measure the nanohardness of the laser treated targets. The initial increase and then decrease in nanohardness was observed with an increase in the number of laser pulses in the de-ionized water environment. in the case of propanol,a continuous decrease in hardness was observed.

关键词： ambient environments periodic structure crystallinity synthesis

structural and Mechanistic studies of γ-Fe2O3 Nanoparticle as Capecitabine Drug Nanocarrier

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Chinese Journal of structural Chemistry 2018年第3期37卷 375-382页

作者： ETEBARi Nasfin MORsali ali BEYRAMABADi s.ali Department of Chemistry Mashhad BranchIslamic Azad UniversityMashhadIran&Research Center for Animal Development Applied Biology Mashhad BranchIslamic Azad UniversitG Mashhad 917568Iran

Using density functional theory,noncovalent interactions and four mechanisms of covalent functionalization of capecitabine anticancer drug onto γ-Fe2O3 nanoparticles have been *** molecular descriptors of noncovalent configurations were *** was specified that binding of capecitabine onto γ-Fe2O3 nanoparticles is thermodynamically *** and the gap of energy between LUMO and HOMO of capecitabine are higher than the noncovalent configurations,showing the reactivity of capecitabine increases in the presence of γ-Fe2O3 *** can bond to γ-Fe2O3 nanoparticles through OH（k1 mechanism）,NH（k2 mechanism）,CO（k3 mechanism） and F（k4 mechanism） *** activation energies,activation enthalpies and activation Gibbs free energies of these reactions were *** was specified that the k1 and k2 mechanisms are under thermodynamic control and k3 and k4 under kinetic *** results could be generalized to other similar drugs.

关键词： γ-Fe2O3 nanoparticles capecitabine density functional theory noncovalent and covalent functionalization mechanism

Thermophoresis and concentration effects in a fourth grade peristaltic flow with convective walls

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Journal of Central south University 2017年第7期24卷 1654-1662页

作者： ali Aamir Asghar s Awais M Department of Mathematics COMSATS Institute of Information TechnologyAttock 43600Pakistan Department of Mathematics COMSATS Institute of Information TechnologyIslamabad 44000Pakistan Department of Mathematics King Abdulaziz UniversityJeddah 21432Saudi Arabia

in this investigation,we have studied the peristaltic fluid flow in an asymmetric channel with convective *** grade fluid model has been utilized in view of the fact that the results of all other differential type models can be deduced as the special *** effects of heat and mass transfer are *** thermophoresis effects occur in the energy *** heat and mass boundary conditions have been given special *** wave length and low Reynolds number approximations are utilized for the *** analytic solutions for the velocity,temperature and concentration profiles are calculated using perturbation technique and elaborated in the form of graphical observations for various physical quantities.

关键词： fourth grade fluid convective boundary conditions pumping and trapping peristalsis

Daily variation of radon gas and its short-lived progeny concentration near ground level and estimation of aerosol residence time

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Chinese Physics B 2016年第5期25卷 111-118页

作者： M Mohery A M Abdallah A ali s s Baz Physics Department Faculty of Science University of Jeddah Physics Department Faculty of Science Sohag University Astronomy Department Faculty of Science King Abdulaziz University Astronomy Department Faculty of Science Cairo University Physics Department Girls Faculty of Science King Abdulaziz University

Atmospheric concentrations of radon（^（222）Rn） gas and its short-lived progenies^（218）Po,^（214）Pb, and^（214）Po were continuously monitored every four hours at the ground level in Jeddah city, Kingdom of saudi Arabia. The measurements were performed three times every week, starting from November 2014 to October 2015. A method of electrostatic precipitation of positively charged^（218）Po and ^（214）Po by a positive voltage was applied for determining^（222）Rn gas concentration. The short-lived^（222）Rn progeny concentration was determined by using a filter holder connected with the alpha-spectrometric technique. The meteorological parameters（relative air humidity, air temperature, and wind speed） were determined during the measurements of^（222）Rn and its progeny concentrations.^（222）Rn gas as well as its short-lived progeny concentration display a daily and seasonal variation with high values in the night and early morning hours as compared to low values at noon and in the afternoon. The observed monthly atmospheric concentrations showed a seasonal trend with the highest values in the autumn/winter season and the lowest values in the spring/summer season. Moreover, and in parallel with alphaspectrometric measurements, a single filter-holder was used to collect air samples. The deposited activities of^（214）Pb and the long-lived^（222）Rn daughter ^（210）Pb on the filter were measured with the gamma spectrometric technique. The measured activity concentrations of^（214）Pb by both techniques were found to be relatively equal largely. The highest mean seasonally activity concentrations of ^（210）Pb were observed in the autumn/winter season while the lowest mean were observed in the spring/summer season. The mean residence time（MRT） of aerosol particles in the atmospheric air could be estimated from the activity ratios of ^（210）Pb/^（214）Pb.

关键词： daily variation radon progeny concentration meteorological variables