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Analytical solution of the low Reynolds third-grade non-Newtonian fluids flow inside rough circular pipes

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Acta Mechanica Sinica 2020年第5期36卷 1018-1030,I0001页

作者： Zohreh Sheidaei Pooria akbarzadeh Faculty of Mechanical and Mechatronics Engineering Shahrood University of TechnologyShahroodIran

The present paper focuses on finding an analytical solution for fully developed third-grade non-Newtonian fluids flows inside rough circular pipes at low Reynolds numbers(Stokes flows).The wall roughness is modeled by two different periodic morphologies based on sinusoidal and triangular *** this study,the relative roughness(ratio of the roughness amplitude to the pipe hydraulic diameter)is selected to be a small value,which is appropriate for the perturbation *** governing parameters including the axial and radial velocity profiles,stream function,wall shear stress,pressure gradient,and friction factor are expressed in analytical formulas and they are compared to the smooth *** effect of the relative roughness,the wall wave number,and the non-Newtonian parameter on the governing parameters are *** results show that modeling the roughness by triangular geometry has a better prediction of pressure drop regarding the basic solution of the smooth pipe.

关键词： Relative roughness Third-grade non-Newtonian fluid Perturbation method Low Reynolds number

POLYROTAXANE WITH π-CONJUGATED PORPHYRIN AND POLYAZOMETHINE SYSTEMS PREPARED FROM A TYPE OF PORPHYRIN-DIALDEHYDE AND COMPLEX OF β-CYCLODEXTRIN WITH 1,4-PHENYLENEDIAMINE

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Chinese Journal of Polymer Science 2013年第1期31卷 139-147页

作者： Raziyeh akbarzadeh Hossein Dehghani Department of Inorganic Chemistry Faculty of ChemistryUniversity of Kashan

The synthesis of 5,15-bis[4-（methoxycarbonyl）phenyl]-10,20-diphenylporphyrin （2） and its reduction to 5,15- bis[4-（hydroxymethyl）phenyl]-10,20-diphenylporphyrin （3）, and so its oxidation to provide 5,15-bis（4-formylphenyl）-10,20- diphenylporphyrin （4） are reported. The copolymer possessing β-cyclodextrin （fl-CD）, n-conjugated porphyrin and polyazomethine systems was synthesized by the polycondensation of porphyrin-dialdehyde monomer （4） and ,β- cyclodextrin/1,4-phenylenediamine complex （5）. The monomers and the copolymer were characterized by UV-Vis, ^1H-NMR and IR spectra. Furthermore, ^1H-NMR and FT-IR spectra confirmed locating the aromatic ring of 1,4-phenylenediamine molecule in the center of β-cyclodextrin cavity.

关键词： Polymer Porphyrin 1,4-Phenylenediamine Imine Cyclodextrin.

Cavitating/non-cavitating flows simulation by third-order finite volume scheme and power-law preconditioning method

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Applied Mathematics and Mechanics(English Edition) 2013年第2期34卷 209-228页

作者： P.akbarzadeh School of Mechanical Engineering Shahrood University of Technology

Equations of steady inviscid and laminar flows are solved by means of a third-order finite volume （FV） scheme. For this purpose, a cell-centered discretization technique is employed. In this technique, the flow parameters at the cell faces are computed using a third-order weighted averages procedure. A fourth-order artificial dissipation is used for stability of the solution. In order to achieve the steady-state situation, four-step Runge-Kutta explicit time integration method is applied. An advanced progressive preconditioning method, named the power-law preconditioning method, is used for faster convergence. In this method, the preconditioning matrix is adjusted automatically from the velocity and/or pressure flow-field by a power-law relation. Attention is directed towards accuracy and convergence of the schemes. The results presented in the paper focus on steady inviscid and laminar flows around sheet-cavitating and fully-wetted bodies including hydrofoils and circular/elliptical cylinder. Excellent agreements are obtained when numerical predictions are compared with other available experimental and numerical results. In addition, it is found that using the power-law preconditioner significantly increases the numerical convergence speed.

关键词： power-law preconditioner finite-volume (FV) scheme third-order accuracy,convergence cavitation hydrofoil

Comparison of effective parameters for copper powder production via electrorefining and electrowinning cells and improvement using DOE methods

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International Journal of Minerals,Metallurgy and Materials 2011年第6期18卷 731-740页

作者： Ebrahim akbarzadeh Sayyed Esmaeil Shakib Department of Materials Science and Metallurgical Engineering Shahid Bahonar University of Kerman

The influences of cupric ion concentration （5-35 g/L）,current density （500-2000 A/m2）,circulation rate of the electrolyte solution （15-120 mL/min）,and temperature （25-60℃） on the physical and chemical properties of copper powders obtained in electrolysis cells were *** industrial processes,electrorefining （ER） cells with a synthetic electrolyte and electrowinning （EW） cells with an original solution of coppermineral leaching,were utilized to produce copper ***,the statistical full factorial method of design of experiments （DOE） was employed to investigate the interaction or the main effects of *** results show that increasing the copper concentration and temperature can increase the grain size,apparent density,and electrical energy *** the other hand,increasing the current density and circulation rate of the electrolyte can decrease *** production process is optimized via DOE to control the interactive and main effects to produce copper powders with favorable properties.

关键词： copper powders electrorefining electrowinning grain size apparent density

Supersymmetry and SWKB Approach to Dirac Equation with Hyperbolic Scarf Potential

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Communications in Theoretical Physics 2016年第7期65卷 49-52页

作者： N.akbarzadeh A.Chenaghlou Department of Physics Faculty of Sciences Sahand University of Technology

By using the supersymmetric quantum mechanics and shape invariance concept, we study the Dirac equation with the hyperbolic Scarf potential and the exact energy spectrum is obtained. Also, we calculate the bound state... 详细信息

关键词： Dirac equation supersymmetric quantum mechanics supersymmetric WKB hyperbolic Scarf potential

A framework for analysis of extended fuzzy logic

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Journal of Zhejiang University-Science C(Computers and Electronics) 2014年第7期15卷 584-591页

作者： Farnaz SABAHI M.-R.akbarzadeh-T Center of Excellence on Soft Computing and Intelligent Information Processing Department of Electrical EngineeringFerdowsi University of Mashhad

We address a framework for the analysis of extended fuzzy logic(FLe) and elaborate mainly the key characteris-tics of FLe by proving several qualification theorems and proposing a new mathematical tool named the A-granule. Specifically, we reveal that within FLe a solution in the presence of incomplete information approaches the one gained by complete infor-mation. It is also proved that the answers and their validities have a structural isomorphism within the same context. This rela-tionship is then used to prove the representation theorem that addresses the rationality of FLe-based reasoning. As a conse-quence of the developed theoretical description of FLe, we assert that in order to solve a problem, having complete information is not a critical need; however, with more information, the answers achieved become more specific. Furthermore, reasoning based on FLe has the advantage of being computationally less expensive in the analysis of a given problem and is faster.

关键词： Extended fuzzy logic Fuzzy logic f-Transformation S-answer Validity

Dynamic task scheduling modeling in unstructured heterogeneous multiprocessor systems

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Journal of Zhejiang University-Science C(Computers and Electronics) 2014年第6期15卷 423-434页

作者： Hamid TABATABAEE Mohammad Reza akbarzadeh-T Naser PARIZ Department of Computer Engineering Islamic Azad University Center of Excellence on Soft Computing and Intelligent Information Processing Ferdowsi University of Mashhad Department of Electrical Engineering Ferdowsi University of Mashhad

An algorithm is proposed for scheduling dependent tasks in time-varying heterogeneous multiprocessor systems, in which computational power and links between processors are allowed to change over time. Link contention is considered in the multiprocessor scheduling problem. A linear switching-state space-modeling paradigm is introduced to enable theoretical analysis from a system engineering perspective. Theoretical analysis of this model shows its robustness against changes in processing power and link failure. The proposed algorithm uses a fuzzy decision-making procedure to handle changes in the multiprocessor system. The efficiency of the proposed algorithm is illustrated by several random experiments and comparison against a recent benchmark approach. The results show up to 18% average improvement in makespan, especially for larger scale systems.

关键词： Dynamic task scheduling Fuzzy logic Genetic algorithms Unstructured environment Linear switching state space

Effect of nodule count and austempering heat treatment on segregation behavior of alloying elements in ductile cast iron

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China Foundry 2016年第3期13卷 217-222页

作者： E.akbarzadeh Chiniforush N.Iranipour S.Yazdani Faculty of Materials Engineering Sahand University of Technology Deakin University Institute for Technology Research and Innovation

The equilibrium partition ratio, k, has been measured for Mn, Mo, Si, Ni and Cu in a ductile iron with composition(wt.%): 3.45 C, 0.25 Mn, 0.25 Mo, 2.45 Si, 0.5Ni and 0.5Cu with different nodule counts obtained from different section sizes of13, 25, 75 mm in the as cast, austenitized(at 870 °C for times 1, 4 and 6 hours) and austempered(at 375 °C for times 1 to 1,440 min) samples. Results show that Mn and Mo segregate positively at cell boundaries, but Si, Ni and Cu concentrate in an inverse manner in the vicinity ofgraphite nodules and there is a depletion ofthese elements at cell boundaries. Segregation curves for Ni and Cu are more smooth than for Si. Carbide formation has been observed at cell boundaries. Based on the results, the partition ratios for all elements decrease with increasing the nodule count. More carbide with coarser morphology has been observed in the microstructure with a lower nodule count. Austenitization for a longer time can decrease partition ratio, but cannot eliminate it entirely. Increasing the austenitization temperature has the same effect. Austenitizing parameters have no significant effect on carbides volume fraction. The kinetics ofaustempering is faster in higher nodule counts and subsequently better mechanical properties including higher ductility, strength and toughness have been observed for all austempering conditions studied.

关键词： segregation ductile iron austenitization austempering

Dry sliding wear of Ni alloyed austempered ductile iron

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China Foundry 2016年第5期13卷 361-367页

作者： E.akbarzadeh Chiniforush M.A.Rahimi S.Yazdani Faculty of Materials Engineering Sahand University of Technology

Measurements of dry sliding wear are presented for ductile irons with composition Fe-3.56C-2.67Si- 0.25Mo-0.5Cu and Ni contents of 0.8 and 1.5 in wt.% with applied loads of 50, 100 and 150 N for austempering temperatures of 270, 320, and 370 ℃ after austenitizing at 870 ℃ for 120 min. The mechanical property measurements show that the grades of the ASTM 897M： 1990 Standard can be satisfied for the selected austempering conditions. The results show that wear resistance is independent of austempedng temperature with an applied load of 50 N, but there is a strong dependence at higher austempering temperatures with applied loads of 100 and 150 N. Observations indicate that wear is due to subsurface fatigue with cracks nucleated at deformed graphite nodules.

关键词： austempered ductile iron wear austenite ausferrite nickel