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mobility of large clusters on a semiconductor surface:Kinetic monte Carlo simulation results

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Chinese Physics B 2016年第1期25卷 580-584页

作者： m Esen A T Ttizemen m Ozdemir Vocational School of Adana Cukurova UniversityAdana O1160Turkey Department of Science and mathematics Education Faculty of EducationCumhuriyet UniversitySivas 58140Turkey Department of Physics Cukurova UniversityAdana 01330Turkey

The mobility of clusters on a semiconductor surface for various values of cluster size is studied as a function of temperature by kinetic monte Carlo method. The cluster resides on the surface of a square grid. Kinetic processes such as the diffusion of single particles on the surface, their attachment and detachment to/from clusters, diffusion of particles along cluster edges are considered. The clusters considered in this study consist of 150-6000 atoms per cluster on average. A statistical probability of motion to each direction is assigned to each particle where a particle with four nearest neighbors is assumed to be immobile. The mobility of a cluster is found from the root mean square displacement of the center of mass of the cluster as a function of time. It is found that the diffusion coefficient of clusters goes as D = A（T）Na where N is the average number of particles in the cluster, A（T） is a temperature-dependent constant and a is a parameter with a value of about -0.64 〈 a 〈 -0.75. The value of a is found to be independent of cluster sizes and temperature values （170-220 K） considered in this study. As the diffusion along the perimeter of the cluster becomes prohibitive, the exponent approaches a value of -0.5. The diffusion coefficient is found to change by one order of magnitude as a function of cluster size.

关键词： diffusion constant cluster mobility monte Carlo method

A study on stochastic longitudinal wave equation in a magneto-electro-elastic annular bar to find the analytical solutions

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Communications in Theoretical Physics 2023年第8期75卷 78-86页

作者： m mamun miah m Ashik Iqbal m S Osman Department of mathematics Khulna University of Engineering and TechnologyKhulna-9203Bangladesh Division of mathematical and Physical Sciences Kanazawa UniversityKakumaKanazawa 920-1192Japan Department of mathematics and Physics Khulna Agricultural UniversityKhulna-9100Bangladesh Department of mathematics Faculty of ScienceCairo UniversityGiza 12613Egypt

In this paper,we set up dynamic solitary perturb solutions of a unidirectional stochastic longitudinal wave equation in a magneto-electro-elastic annular bar by a feasible,useful,and influential method named the dual(G’/G,1/G)-expansion *** software,like mathematica,is used to complete this *** obtained solutions of the proposed equation are classified into trigonometric,hyperbolic,and rational types which play an important role in searching for numerous scientific *** technique employed here is an extension of the(G’/G)-expansion technique for finding all previously discovered *** illustrate our findings more clearly,we provide 2D and 3D charts of the various recovery *** then contrasted our findings with those of past *** graphical illustrations of the acquired solutions are singular periodic solitons and kink solitons which are added at the end of this paper.

关键词： dual(G'/G,1/G)-expansion method stochastic longitudinal wave equation dynamic solitary perturb solutions magneto-electro-elastic annular bar

A practical framework for performance-based reliability analysis of subway stations based on a faultestructure combined system

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Journal of Rock mechanics and Geotechnical Engineering 2023年第6期15卷 1406-1425页

作者： m.Ghorbanzadeh m.Hajihassani m.Kharghani Department of Civil and Environmental Engineering Amirkabir University of TechnologyTehranIran Department of mining Faculty of EngineeringUrmia UniversityUrmiaIran Faculty of Engineering Science and Research BranchIslamic Azad UniversityTehranIran

It is necessary to pay particular attention to the uncertainties that exist in an engineering problem to reduce the risk of seismic damage of infrastructures against natural ***,certain structural performance levels should be satisfied during strong ***,these performance levels have been only well described for aboveground *** study investigates the main uncertainties involved in the performance-based seismic analysis of a multi-story subway *** than 100 pulse-like and no pulse-like ground motions have been *** this regard,an effective framework is presented,based on a set of nonlinear static and dynamic analyses performed by OpenSees *** probabilistic seismic demand models for computing the free-field shear strain of soil and racking ratio of structure are *** models result in less variability compared with existing relations,and make it possible to evaluate a wider range of uncertainties through reliability analysis in Rtx software using the monte Carlo sampling *** work is performed for three different structural performance levels(denoted as PL1ePL3).It is demonstrated that the error terms related to the magnitude and location of earthquake excitations and also the corresponding attenuation relationships have been the most important ***,using a faultestructure model would be inevitable for the reliability analysis of subway *** is found that the higher performance level(***3)has more sensitivity to random variables than the *** this condition,the pulse-like ground motions have a major contribution to the vulnerability of subway stations.

关键词： Seismic hazard Probabilistic models Reliability analysis Subway station

Structural and optical characteristic features of RF sputtered CdS/ZnO thin films

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Chinese Physics B 2020年第8期29卷 204-210页

作者： Ateyyah m Al-Baradi Fatimah A Altowairqi A A Atta Ali Badawi Saud A Algarni Abdulraheem S A Almalki A m Hassanien A Alodhayb A m Kamal m m El-Nahass Department of Physics Faculty of ScienceTaif UniversityTaif 21974Saudi Arabia Department of Physics Faculty of EducationAin Shams UniversityRoxy 11757CairoEgypt Department of Chemistry Faculty of ScienceTaif UniversityTaifSaudi Arabia Department of Physics College of Science and Humanities-Al QuwaiiyahShaqra UniversitySaudi Arabia Research Chair for Tribology Surfaceand Interface SciencesDepartment of Physics and AstronomyCollege of ScienceKing Saud UniversityRiyadh 11451Saudi Arabia Department of Physics and Astronomy College of ScienceKing Saud UniversityRiyadh 11451Saudi Arabia

In this study,CdS/ZnO(2:3 mol%)thin films are successfully deposited on quartz substrates by using the sputtering *** images on the structural and optical characteristic features of CdS/ZnO thin films before and after annealing are *** CdS/ZnO thin films are annealed respectively at temperatures of 373 K,473 K,and 573 K and the structural features are examined by XRD,ATR-FTIR,and *** optical properties of CdS/ZnO thin films such as refractive indices,absorption coefficients,optical band gap energy values,Urbach energy values,lattice dielectric constants,and high frequency dielectric constants are determined from spectrophotometer data recorded over the spectral range of 300 nm-2500 *** parameters are investigated by using a single-oscillator *** spectra of CdS/ZnO thin films show an overall decrease in their intensity peaks after *** third-order nonlinear optical parameter,and nonlinear refractive index are also estimated.

关键词： CdS/ZnO thin films structural&optical properties

Conceptual Design of Glass/Renewable Natural Fibre-Reinforced Polymer Hybrid Composite motorcycle Side Cover

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Journal of Renewable materials 2021年第11期9卷 1973-1989页

作者： m.A.F.A.Wahab S.m.Sapuan m.m.Harussani m.Y.m.Zuhri A.A.Saleh Department of mechanical and manufacturing Engineering Universiti Putra MalaysiaSerdang43400Malaysia Laboratory of Biocomposite Technology Institute of Tropical Forestry and Forest Products(INTROP)Universiti Putra MalaysiaSerdang43400Malaysia Department of mechanical andmanufacturing Engineering Faculty of EngineeringUniversiti Malaysia SarawakKota Samarahan94300Malaysia

This paper presents the development process relating to the conceptual design of glass/renewable natural fibrereinforced polymer hybrid composite motorcycle side *** side cover is a component frequently made from plastic or steel that functions on covering the motorcycle parts,components and systems such as frame,battery,electrical systems and mechanical *** Analysis Systems Techniques(FAST)is used to identify the functions of motorcycle side *** right-side cover of motorcycle model SYm E-Bonus 110 has been physically studied to identify the competitive benchmarking *** functions and competitive benchmarking criteria are then compiled and integrated with the environmental requirements to identify the Product Design Specifications(PDS).The coir fibre has been selected from six identified dominant renewable natural fibre used for automotive component through integration of Ranking method and Quality Based Selection(QBS).Then the polypropylene matrix is selected after shortlisting the existing thermoplastic that is used with coir fibre and has high suitability for injection moulding *** polypropylene matrix is then evaluated using Weighted Evaluation matrix(WEm)by comparing to benchmark material which is Acrylonitrile Butadiene Styrene(ABS).After that,the conceptual design development of glass/renewable coir fibre-reinforced polypropylene motorcycle side cover is carried out using an integrated Theory of Inventive Problem Solving(TRIZ)and morphological Chart,followed by final conceptual design selection using integration of Pugh Scoring method and *** conceptual design development intended on improving the biodegradability to reduce pollution to the ***,the usage of glass/coir fibre-reinforced polypropylene hybrid composite may increase the weight due to higher *** innovative design concepts have been developed and the selected final concept design has the most minimum number of ribs an

关键词： Renewable natural fibre coir fibre hybrid composite conceptual design PDS TRIZ morphological chart QBS FAST diagram WEm natural fibre selection pugh scoring method

Lignite-Derived Humic Acid Effect on Growth of Wheat Plants in Different Soils

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Pedosphere 2011年第1期21卷 124-131页

作者： m.m.TAHIR m.KHURSHID m.Z.KHAN m.K.ABBASI m.H.KAZmI Department of Soil and Environmental Sciences Faculty of AgricultureUniversity of Azad Jammu and Kashmir Land Resource Research Programme National Agriculture Research Centre Department of Agronomy Faculty of AgricultureUniversity of Azad Jammu and Kashmir

Humic acid （HA）, a fairly stable product of decomposed organic matter that consequently accumulates in ecological systems, enhances plant growth by chelating unavailable nutrients and buffering pH. We examined the effect of HA derived from lignite on growth and macronutrient uptake of wheat （Triticum acstivum L.） grown in earthen pots under greenhouse conditions. The soils used in the pot experiment were a calcareous Haplustalf and a non-calcareous Haplustalf collected from Raisalpur and Guliana, respectively, in Punjab Province, Pakistan. The experiment consisted of four treatments with HA levels of 0 （control without HA）, 30, 60, and 90 mg kg^-1 soil designated as HA0, HA1, HA2, and HA3, respectively. In the treatment without HA （HA0）, nitrogen （N）, phosphorus （P）, and potassium （K） were applied at 200, 100, and 125 mg kg^-1 soil, respectively. Significant differences among HA levels were recorded for wheat growth （plant height and shoot weight） and N uptake. On an average of both soils, the largest increases in plant height and shoot fresh and dry weights were found with HA2 （60 mg kg^-1 soil）, being 10%, 25%, and 18%, respectively, as compared to the control without HA （HA0）. Both soils responded positively towards HA application. The wheat growth and N uptake in the non-calcareous soil were higher than those of the calcareous soil. The HA application significantly improved K concentration of the non-calcareous soil and P and NO3-N of the calcareous soil. The highest rate of HA （90 mg kg^-1 soil） had a negative effect on growth and nutrient uptake of wheat as well as nutrient accumulation in soil, whereas the medium dose of HA （60 mg kg^-1 soil） was more efficient in promoting wheat growth.

关键词： calcareous soil NO3-N nutrient uptake plant height soil nutrient

Buckling and large deflection behaviors of radially functionally graded ring-stiffened circular plates with various boundary conditions

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Applied mathematics and mechanics(English Edition) 2016年第9期37卷 1131-1152页

作者： m.E.GOLmAKANI m.EmAmI Department of mechanical Engineering Mashhad BranchIslamic Azad University

The buckling and large deflection behaviors of axis-symmetric radially functionally graded （RFG） ring-stiffened circular plates are investigated by the dynamic relaxation （DR） method combined with the finite difference discretization technique. The material properties of the constituent components of the RFG plate are assumed to vary continuously according to the mori-Tanalka distribution along the radial direction. The nonlinear governing equations are obtained in the incremental form based on the firstorder shear deformation plate theory （FSDT） and the von Karman relations for large deflection. In the buckling analysis, an external in-plane load is applied to the plate in- crementally so that, in each load-step, the incremental form of the governing equations can be solved by a numerical code prepared based on the DR method. After converging the DR code in the first increment, the latter load-step is added to the previous one, and the program is repeated again. The critical buckling load is determined from the compressive load-displacement curve obtained by solving the incremental form of the governing equations. Based on the present incremental form of formulation, a bending analysis can also be conducted if the whole load is applied simultaneously. Finally, a detailed parametric study is carried out to investigate the influences of various boundary conditions, grading indices, thickness-to-radius ratios, stiffener＇s positions and depths on the critical buckling load, and displacements and stresses resulted from the bending analysis. It is observed that the effect of the stiffener on the results is much greater in the functionally graded plate with higher material grading indices. The results also reveal that, by increasing the depth of the stiffer, the values of ascending the critical buckling load are approximately identical for both simply supported and clamped boundary conditions.

关键词： buckling large deflection functionally graded stiffened plate dynamicrelaxation method

Processing investigation and optimization for hybrid thermoplastic composites

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Journal of University of Science and Technology Beijing 2007年第2期14卷 185-189页

作者： m Tufail Department of Industrial & manufacturing Engineering NED University of Engineering & Technology Karachi Pakistan

A thermoplastic based composite material is suitable for automobile and aerospace applications. The recyclability of thermoplastic and clean processing further enhance its use. The only limitation encountered in using this material is its high-melt viscosity. Various techniques have been developed to overcome this problem. Commingled materials are one of such methods adopted for making proper use of thermoplastic. A major problem observed during the use of a commingled material is its de-commingling, wherein, the uniform distribution of fiber and thermoplastic yam gets disturbed and affects the final quality of the composite. The effects of the braiding process on laminate quality were investigated. Flat plaques were produced by braiding the commingled yam, using a 48- carrier braiding machine. The braids （and control woven samples） were subsequently heated and consolidated in a nonisothermal compression molding operation. Prior to the manufacture of the ＇best quality＇ plaques, a series of moldings were produced under different consolidation conditions, to study the dependence of properties on the process variables. This enabled a processing window to be established for each material and helped to separate the respective effects of yam handling, textile processing, and consolidation on laminate properties.

关键词： polypropylene commingled yam braiding consolidation

Influence of Heat Input in Pulsed Current GTAW Process on microstructure and Corrosion Resistance of Duplex Stainless Steel Welds

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Journal of Iron and Steel Research International 2011年第9期18卷 65-69,78页

作者： m Yousefieh m Shamanian A Saatchi Department of materials Engineering Isfahan University of Technology

The high corrosion resistance of duplex stainless steel （DSS） is due to elements such as Cr, mo and N, hut also depends on the microstructure. The best general properties are obtained with approximately equal amounts of austenite and ferrite and the absence of third phases such as σ（sigma） and Cr2N. In the present work the effect of heat input variations on the microstructure and corrosion resistance of a DSS UNS S32760 in artificial sea water media were studied. The corrosion resistance in 3.5 % of NaCl solution was evaluated by potentiostatic polarization tests at room temperature. It is found that the presence of sigma phase and Cr2N decreases the corrosion potential. The specimen with heat input of approximately 0.95 kJ/mm have the best corrosion characteristics, which is the result for the lack of deleterious phases such as sigma and Cr2 N and balanced ferrite austenite proportion.

关键词： steel microstructure corrosion heat input pulse current GTAW