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Synthesis of 2-arylbenzimidazoles and 2-arylbenzothiazoles in both room temperature and microwave condition catalyzed by hexamethylenetetramine-bromine complex

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Chinese Chemical Letters 2012年第1期23卷 61-64页

作者： Kaveh khosravi Samira Kazemi Department of Chemistry Faculty of ScienceUniversiy of ArakArak 38/56-8-8349Iran Tehran Shahid tondgoyan Oil Refinery Company TehranIran

One-pot condensation of 2-aminothiophenol or 1,2-phenylenediamine with different aldehydes has been catalyzed by hexamethylenetetramine-bromine（HMTA-Bromine） as new,available and effective catalyst.2-Arylbenzo thiaz... 详细信息

关键词： Benzothiazoles Benzimidazoles One-pot condensation 1 2-Phenylenediamine 2-Aminothiophenol Hexamethylene-tetramine-bromine Microwave condition

Correlation between microstructural features and tensile strength for friction welded joints of AA-7005 aluminum alloy

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Journal of Central South University 2016年第8期23卷 1839-1846页

作者： Seyyed Mostafa Tahsini Ayyub Halvaee Hamed khosravi School of Metallurgy and Materials Engineering College of Engineering University of Tehran Department of Materials Engineering Faculty of Engineering University of Sistan and Baluchestan

Similar friction welded joints of AA-7005 aluminum rods were fabricated using different combinations of process parameters such as friction pressure(1.0, 1.5 and 2.0 MPa) and friction time(10, 15 and 20 s). Interfacial microstructure and formation of intermetallic compounds at the joint interface were evaluated via scanning electron microscopy(SEM) equipped with energy dispersive spectrum(EDS), and optical microscopy(OM). Microstructural observations reveal the formation of intermetallic phases during the welding process which cannot be extruded from the interface. Theses phases influence the tensile strength of the resultant joints. From the tensile characteristics viewpoint, the greatest tensile strength value of 365 MPa is obtained at 1.5 MPa and 15 s. Finally, the role of microstructural features on tensile strength of resultant joints is discussed.

关键词： friction welding AA-7005 aluminum alloy microstructure intermetallics tensile strength

Microstructural characteristics and mechanical properties of Al-2024 alloy processed via a rheocasting route

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International Journal of Minerals,Metallurgy and Materials 2015年第1期22卷 59-67页

作者： Behnam Rahimi Hamed khosravi Mohsen Haddad-Sabzevar Department of Metallurgy and Materials Engineering Faculty of EngineeringFerdowsi University of Mashhad Faculty of Materials Science and Engineering K.N.Toosi University of Technology

This article reports the effects of stirring speed and T6 heat treatment on the microstructure and mechanical properties of Al-2024 alloy synthesized by a rheocasting process. There was a decrease in grain size ofα-Al particles corresponding to an increase in stirring speed. By increasing the stirring speed, however, the globularity of matrix particles first increased and then declined. It was also found that the hardness, compressive strength, and compressive strain increased with the increase of stirring speed. Microstructural studies revealed the presence of nonsoluble Al15（CuFeMn）3Si2 phase in the vicinity of CuAl2 in the rheocast samples. The required time for the solution treatment stage was also influenced by stirring speed;the solution treatment time decreased with the increase in stirring speed. Furthermore, the rheo-cast samples required a longer homogenization period compared to conventionally wrought alloys. Improvements in hardness and compres-sive properties were observed after T6 heat treatment.

关键词： aluminum alloys rheocasting microstructure mechanical properties

Wind Power Revenue Potential: Simulation for Finland

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Energy Engineering 2021年第4期118卷 1111-1133页

作者： Sakarias Paaso Ali khosravi Department of Mechanical Engineering Aalto UniversityEspooFinland

Potential revenue from wind power generation is an important factor to be considered when planning a wind power *** the future,that may become even more important because it is known that wind power generation tends to push electricity wholesale prices ***,it is possible that if a region has plenty of installed wind power capacity,revenue per generated unit of electricity is lower there than could be assumed by looking at the mean electricity wholesale *** this paper,we compare 17 different locations in Finland in terms of revenue from wind power *** is done by simulating hourly generation with three different turbine types at two different hub heights and multiplying that by the hourly electricity spot price for years 2018 and *** revenues differ greatly between locations and turbine types,major factor being technical potential i.e.,the amount of electricity *** between revenues per generated MWh seem to be small,however,the smallest figures being on the western coast where installed capacities are also the largest in Finland.

关键词： Wind power renewable energy resource assessment revenue Finland

Effect of graphene oxide and reduced graphene oxide nanosheets on the microstructure and mechanical properties of mild steel jointing by flux-cored arc welding

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International Journal of Minerals,Metallurgy and Materials 2020年第4期27卷 505-514页

作者： Mohammad khosravi Mohammad Mansouri Ali Gholami Yadollah Yaghoubinezhad Department of Mechanical Engineering Birjand University of Technology BirjandP.O.Box 97175-569235Iran Department of Materials Engineering Birjand University of Technology BirjandP.O.Box 97175-569315Iran

The effect of graphene oxide(GO)and reduced graphene oxide(RGO)nanosheets on the microstructure and mechanical properties of welded joints of mild steel was evaluated by flux-cored arc *** was synthesized by the Hummer’s method and was reduced under hydrothermal conditions at a pressure of 1.1 MPa at 180°C for 12 h.1,3,and 10 mg/mL paste fillers were used in GO and RGO,and applied to the weld *** results clearly showed that by increasing the concentration of RGO up to 10 mg/mL,the tensile strength and hardness of the weld metal were improved by approximately 20.5%and 38.4%,respectively,because the coarse grains were changed into fine *** domain of the nanosheets cluster was 19.85×10^?9 ***,the RGO nanosheets contributed to modifying the mechanical properties of the welded steel,likely due to dislocation pinning.

关键词： graphene oxide reduced graphene oxide flux-cored arc welding steel mechanical properties

Selecting proper sites for underground dam construction using Multi-Attribute Utility Theory in arid and semi-arid regions

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Journal of Mountain Science 2023年第1期20卷 197-208页

作者： Mohammad Hassan SADEGHIRAVESH Hassan khosravi Azam ABOLHASANI Department of Environment College of AgricultureTakestan BranchIslamic Azad UniversityTakestanIran Department of Reclamation of Arid and Mountainous Regions Faculty of Natural ResourcesUniversity of TehranTehranIran

Although the construction of underground dams is one of the best methods to conserve water resources in arid and semi-arid regions,applying efficient methods for the selection of suitable sites for subsurface dam construction remains a *** to the costly and time-consuming methods of site selection for underground dam construction,this study aimed to present a new method using geographic information systems techniques and decision-making *** exclusionary criteria including fault,slope,hypsometry,land use,soil,stream,geology,and chemical properties of groundwater were selected for site selection of dam construction and inappropriate regions were omitted by integration and scoring layers in ArcGIS based on the Boolean ***,appropriate sites were prioritized using the Multi-Attribute Utility *** to the results of the utility coefficient,seven sites were selected as the region for underground dam construction based on all criteria and experts’*** site of Nazarabad dam was the best location for underground dam construction with a utility coefficient of 0.7137 followed by sites of Akhavan with a utility coefficient of 0.4633 and Mirshamsi with a utility coefficient of *** study proposed a new approach for the construction of the subsurface dam at the proper site and help managers and decision-makers achieve sustainable water resources with limited facilities and capital and avoid wasting national capital.

关键词： Prioritization Geographic information system Multi-Attribute decision making Arid region

Effect of Charge, Size and Temperature on Stability of Charged Colloidal Nano Particles

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Chinese Journal of Chemical Physics 2012年第5期25卷 617-624,I0004页

作者： A.Golchoobi A.khosravi H.Modarress A.Ahmadzadeh Facultv of Chemical Engineering.Amirkabir Universty of Technology TehranIran School of Chemical Engineering College of EngineeringUniversity of TehranTehranIran Research and Technology Department Pars Special Economic Energy ZoneAssaluyehIran

Molecular simulation of charged colloidal suspension is performed in NVT canonical ensemble using Monte Carlo method and primitive model. The well-known Derjaguin-Landau-Verwey- Overbeek theory is applied to account for effective interactions between particles. Effect of temperature, valance of micro-ions and the size of colloidal particles on the phase stability of the solution is investigated. The results indicate that the suspension is more stable at higher temperatures. On the other hand, for a more stable suspension to exist, lower micro- ion valance is favorable. For micro-ions of higher charge the number of aggregates and the number of particle in each of aggregate on average is higher. However for the best of our results larger colloidal particle are less stable. Comparing the results with theoretical formula considering the influence of surface curvature shows qualitative consistency.

关键词： Simulation Coagulation Colloidal phenomenon Stability Electrostatic force Dispersion force

Aerodynamic drag reduction of heavy vehicles using append devices by CFD analysis

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Journal of Central South University 2015年第12期22卷 4645-4652页

作者： Mehrdad khosravi Farshid Mosaddeghi Majid Oveisi Ali Khodayari Bavil Young Researches and Elite Club Borujerd BranchIslamic Azad University Faculty of Mechanical Engineering University of Tabriz Lecturer Department of Marine Engineering ChabaharMaritime University Department of Mechanical Engineering Urmia University

Improving vehicle fuel consumption,performance and aerodynamic efficiency by drag reduction especially in heavy vehicles is one of the indispensable issues of automotive *** this work,the effects of adding append devices like deflector and cab vane corner on heavy commercial vehicle drag reduction were *** this purpose,the vehicle body structure was modeled with various supplementary parts at the first ***,computational fluid dynamic(CFD) analysis was utilized for each case to enhance the optimal aerodynamic structure at different longitudinal speeds for heavy commercial *** results show that the most effective supplementary part is deflector,and by adding this part,the drag coefficient is decreased considerably at an optimum *** adding two cab vane corners at both frontal edges of cab,a significant drag reduction is *** vanes and base flaps are simple plates which can be added at the top and side end of container and at the bottom with specific angle respectively to direct the flow and prevent the *** the analysis of airflow and pressure distribution,the results reveal that the cab vane reduces fuel consumption and drag coefficient by up to 20 % receptively using proper deflector ***,by adding all supplementary parts at their optimized positions,41% drag reduction is obtained compared to the simple model.

关键词： aerodynamics computational fluid dynamic(CFD) append device drag reduction fuel consumption

Synthesis of TiO_2 nanoparticles in different thermal conditions and modeling its photocatalytic activity with artificial neural network

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Journal of Environmental Sciences 2012年第4期24卷 750-756页

作者： Fatemeh Ghanbary Nasser Modirshahla Morteza khosravi Mohammad Ali Behnajady Department of Applied Chemistry Faculty of ChemistryNorth Tehran BranchIslamic Azad UniversityTehran***Islamic Republic of Iran Research Laboratory Department of Applied ChemistryTabriz BranchIslamic Azad UniversityTabriz1655Islamic Republic of Iran

Titanium dioxide （TiO2） nanoparticles were prepared by sol gel route. The preparation parameters were optimized in the removal of 4-nitropbenol （4-NP）. All catalysts were analyzed by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. An artificial neural network model （ANN） was developed to predict the photocatalytic removal of 4-NP in the presence of TiOz nanoparticles prepared under desired conditions. The comparison between the predicted results by designed ANN model and the experimental data proved that modeling of the removal process of 4-NP using artificial neural network was a precise method to predict the extent of 4-NP removal under different conditions.

关键词： nanoparticle TiO2 4-nitrophenol photocatalysis neural network modeling