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SYNTHESIS AND CHARACTERIZATION OF ORGANOSOLUBLE POLYAMIDES FROM QUINOXALINE BASED DIAMINE

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Chinese Journal of Polymer Science 2010年第2期28卷 147-155页

作者： hossein Mighani Mousa Ghaemy Department of Chemistry University of Golestan Department of Chemistry University of Mazandaran

Aromatic/aliphatic polyamides were synthesized from a diamine monomer, 2,3-bis-p-aminophenylquinoxaline （IV）, based on quinoxaline and various dicarboxylic acids of aliphatic, aromatic and heterocyclic. The diamine and polyamides were characterized by elemental analysis, FTIR and IH-NMR. The solubility of the polyamides was affected by the quinoxaline and heterocyclic groups in the polymer chain. They were all soluble in common organic solvents such as dimethylsulfoxide （DMSO）, N,N-dimethylformamide （DMF） and N-methylpyrolidone （NMP）. The polyamides showed inherent viscosity in the range of 0.25-0.3 dL/g in DMSO at 25℃ and good thermal stability with the char yields in the range of 65%-82% at 600℃ in nitrogen.

关键词： Quinoxaline Polyamides Solubility Thermal stability

Thermo-structural analysis on evaluating effects of friction and transient heat transfer on performance of gears in high-precision assemblies

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Journal of Central South University 2017年第1期24卷 71-80页

作者： hossein Golbakhshi Moslem Namjoo Department of Mechanical Engineering of Biosystems University of JiroftJiroft 78671-61167Iran

The high precision assemblies with considerable radial interference should be accompanied by heating and cooling ***,the mechanical properties of metals are greatly affected by thermal ***,for evaluating the stress distribution and distortion of teeth profiles in a gear/shaft assembly,a transient thermal analysis is necessary for finding the change in mechanical *** friction on the contact surface is another important parameter in interaction of the gear with the *** the gear stress and deformation fields for several modes of heat transfer and friction coefficients showed that the maximum radial or tangential stresses on contact surface of the joint may have more than 8%increase by increasing friction coefficient;while the intensity of heat transfer at cooling stage has lower effect on stress distribution.

关键词： friction coefficient transient heat transfer stress field distortion of teeth concurrent analyses

Fabrication of phosphor bronze/Al two-phase material by recycling phosphor bronze chips using hot extrusion process and investigation of their microstructural and mechanical properties

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International Journal of Minerals,Metallurgy and Materials 2020年第6期27卷 809-817页

作者： Majid hosseini Mohammad hossein Paydar Department of Materials Science and Engineering School of EngineeringShiraz UniversityShiraz 71964-84334Iran

Despite the existence of conventional methods for recycling chips,solid-state techniques have become popular,whereby waste metals are directly recycled into consolidated products with the desired shapes and *** investigated the feasibility of recycling phosphor bronze chips through a hot extrusion process using aluminum powder as a metal binder for the fabrication of a metal-fiber-reinforced aluminum matrix *** do so,mixtures containing 20 vol%–50 vol%of chips were prepared,cold-compacted,and *** quality of the consolidated samples was evaluated by determining the density of the fabricated composites and studying their *** addition,we performed tensile and hardness tests to evaluate the mechanical properties of the fabricated *** also analyzed the fracture surfaces of the samples to study the fracture mechanism as a function of the volume fraction of phosphor bronze chips in the fabricated *** results indicated that the most effective consolidation occurred in the sample containing 20 vol%of chips extruded at 465℃in which the chips serve as ideal fibers for improving the mechanical properties,especially the ultimate tensile strength,in comparison with those of Al matrixes that contain no chips but are produced under the same conditions.

关键词： recycling hot extrusion metal–metal composite phosphor bronze chips aluminum powder

An Alternative Technique for Compounding and Fabrication of Lithium Ion Conductive PVB Films with Enhanced Thermal Properties and Electrochromic Performance

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Chinese Journal of Polymer Science 2022年第10期40卷 1213-1222,I0009页

作者： Mohammad hossein Azarian Jatuphorn Wootthikanokkhan Materials Technology Program School of EnergyEnvironment and MaterialsKing Mongkut's University of Technology ThonburiBangkok 10140Thailand

This research concerns the development of lithium ions conductive electrolyte from poly(vinyl butyral)(PVB)resin for use as a special interlayer film in electrochromic *** obtain the final PVB film with high ionic conductivity and thermal stability,a masterbatch was firstly prepared by mixing of PVB resin with lithium salt(LiClO_(4))and additives in an aqueous ethanol *** this,the dried masterbatch were converted into final films by an extrusion *** this study,PVB film with the highest ionic conductivity value of 4.85×10^(-6) was obtained when the masterbatch was diluted with the neat PVB resin at the weight ratio of 2:1 in the extruder prior to *** results from cyclic voltammetry over 100 cycles,showed that performance of the electrochromic device(ITO/WO_(3)/PVB electrolyte/ITO)fabricated by using the above PVB film is stable and *** overall,this work demonstrates that ion conductive PVB films with compromised ionic conductivity and thermal stability can be prepared via an extrusion process without the need to modify chemical structure of *** was carried out through the masterbatch approach,by introducing (LiClO_(4)) salts into the plasticized PVB via a solution mixing process prior to converting it into a final film via the extrusion process.

关键词： Ionic conductivity Poly(vinyl butyral) Masterbatch mixing Solid polymer electrolyte Electrochromic glass Safety glass

A magnetic adsorbent based on salicylic acid-immobilized magnetite nano-particles for pre-concentration of Cd(II) ions

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Frontiers of Chemical Science and Engineering 2021年第2期15卷 450-459页

作者： hossein Abdolmohammad-Zadeh Arezu Salimi Analytical Spectroscopy Research Lab Department of ChemistryFaculty of SciencesAzarbaijan Shahid Madani UniversityTabriz ***Iran

In this research,an eco-friendly magnetic adsorbent based on Fe_(3)O_(4)/salicylic acid nanocomposite was fabricated using a facile one-pot co-precipitation *** crystalline and morphological characterization of the prepared nanocomposite was performed by field emission scanning electron microscopy,X-ray diffraction,and Fourier transform infrared *** nanocomposite was employed as a magnetic solid-phase extraction agent for separation of Cd(II)ions from synthetic *** experimental factors affecting the extraction efficiency were investigated and *** elution with acetic acid(pH 3.5),the pre-concentrated analyte was quantified by flame atomic absorption *** optimal conditions,a linear calibration graph was achieved in the concentration range of 0.2–30 ng·mL^(−1) with a determination coefficient(R^(2))of *** detection limit,the enhancement factor,inter-and intra-day relative standard deviations(for six consecutive extractions at the concentration level of 10 ng·mL^(−1))were 0.04 ng·mL^(−1),100,2.38%and 1.52%,*** evaluate the accuracy of the method,a certified reference material(NIST SRM 1643e)was analyzed,and there was a good agreement between the certified and the measured *** was successfully utilized to determine cadmium in industrial wastewater samples and the attained relative recovery values were between 96.8%and 103.2%.

关键词： cadmium magnetic solid-phase extraction Fe_(3)O_(4)nanoparticles Fe_(3)O_(4)/salicylic acid nanocomposite flame atomic absorption spectrometry

SINGULAR SPECTRUM ANALYSIS:METHODOLOGY AND APPLICATION TO ECONOMICS DATA

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Journal of Systems Science & Complexity 2009年第3期22卷 372-394页

作者： hossein HASSANI Anatoly ZHIGLJAVSKY Institute for Trade Studies and Research (ITSR) Centre for Optimisation and Its Applications School of Mathematics Centre for Optimization and Its Applications School of Mathematics

This paper describes the methodology of singular spectrum analysis (SSA) and demonstratethat it is a powerful method of time series analysis and forecasting,particulary for economic time *** authors consider the application of SSA to the analysis and forecasting of the Iranian nationalaccounts data as provided by the Central Bank of the Islamic Republic of Iran.

关键词： Economic time series forecasting Iranian national accounts SSA.

Finding buckling points for nonlinear structures by dynamic relaxation scheme

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Frontiers of Structural and Civil Engineering 2020年第1期14卷 23-61页

作者： Mohammad REZAIEE-PAJAND hossein ESTIRI Civil Engineering Department Ferdowsi University of MashhadMashhad 91775-1111Iran

Dynamic Relaxation Method(DRM)is an explicit approach for solving the simultaneous systems of *** this tactic,the fictitious mass and damping are added to the static governing equations,and an artificial dynamic system is *** using DRM for nonlinear analysis,the structural static equilibrium path is *** outcome is extremely valuable,since it leads to the behavior of *** the finding related to the structural static path are the critical and buckling points for nonlinear *** this paper,a new way for calculating the load factor is proposed by setting the external work *** the dynamic relaxation scheme with external work technique has not been formulated so *** all incremental-iterative methods,the load factor increment sign should be determinated by extra *** sign leads to increase or decrease of the load *** is worth emphasizing that sign of the load factor increment changes at the load limit ***,the sign determinations are required in the common work control *** disadvantages are eliminated in the proposed *** fact,the suggested load factor depends only on the Dynamic Relaxation(DR)fictitious ***,all DR calculations are performed via vector ***,the load factor is calculated only by one formula,and it has the same relation in the all solution *** contrast to the arc length techniques,which requires the sign determined,the proposed scheme does not need any sign *** is shown that author’s technique is quicker than the other dynamic relaxation *** prove the capability and efficiency of the presented scheme,several numerical tests are *** results indicate that the suggested approach can trace the complex structural static paths,even in the snap-back and snap-through parts.

关键词： load factor external work dynamic relaxation static equilibrium path large displacement

Supersonic flow over a pitching delta wing using surface pressure measurements and numerical simulations

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Chinese Journal of Aeronautics 2018年第1期31卷 65-78页

作者： Mostafa HADIDOOLABI hossein ANSARIAN Aerospace Engineering Department Malek Ashtar University of Technology

Experimental and numerical methods were applied to investigating high subsonic and supersonic flows over a 60°swept delta wing in fixed state and pitching oscillation. Static pressure coefficient distributions over the wing leeward surface and the hysteresis loops of pressure coefficient versus angle of attack at the sensor locations were obtained by wind tunnel tests. Similar results were obtained by numerical simulations which agreed well with the experiments. Flow structure around the wing was also demonstrated by the numerical simulation. Effects of Mach number and angle of attack on pressure distribution curves in static tests were investigated. Effects of various oscillation parameters including Mach number, mean angle of attack, pitching amplitude and frequency on hysteresis loops were investigated in dynamic tests and the associated physical mechanisms were discussed. Vortex breakdown phenomenon over the wing was identified at high angles of attack using the pressure coefficient curves and hysteresis loops, and its effects on the flow features were discussed.

关键词： Delta wing Hysteresis loop Pitching oscillation Supersonic flow Vortex breakdown

Finite element simulation for elastic dislocation of the North-Tehran fault:The effects of geologic layering and slip distribution for the segment located in Karaj

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Frontiers of Structural and Civil Engineering 2022年第4期16卷 533-549页

作者： Pooya ZAKIAN hossein ASADI HAYEH Department of Civil Engineering Faculty of EngineeringArak UniversityArak 38156-88349Iran

The present study uses the finite element method for simulating the crustal deformation due to the dislocation of a segment of the North-Tehran fault located in the Karaj metropolis *** this regard,a geological map of Karaj that includes the fault segment is utilized in order to create the geometry of finite element ***,finite element analysis of homogeneous counterpart of the fault’s domain with two different sections was performed,and the results were compared to those of Okada’s analytical *** fault was modeled with the existing heterogeneity of the domain having been *** influences of both uniform and non-uniform slip distributions were ***,three levels of simplification for geometric creation of geological layers’boundaries were defined in order to evaluate the effects of the geometric complexity of the geological layering on the displacement responses obtained with the finite element *** addition to the assessment of slip distribution,layering complexity and heterogeneity,the results demonstrate both the capability and usefulness of the proposed models in the dislocation analysis for the Karaj segment of North-Tehran fault.

关键词： finite element method fault dislocation slip distribution the North-Tehran fault heterogeneity geological layering