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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

Size-Dependent Geometrically Nonlinear Free Vibration of First-Order Shear Deformable Piezoelectric-Piezomagnetic Nanobeams Using the Nonlocal Theory

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Advances in Applied Mathematics and Mechanics 2018年第1期10卷 184-208页

作者： Raheb gholami Reza Ansari Department of Mechanical Engineering Lahijan BranchIslamic Azad UniversityP.O.Box 1616LahijanIran Department of Mechanical Engineering University of GuilanP.O.Box 3756RashtIran

This article investigates the geometrically nonlinear free vibration of piezoelectric-piezomagnetic nanobeams subjected to magneto-electro-thermal loading taking into account size effect using the nonlocal elasticity *** this end,the sizedependent nonlinear governing equations of motion and corresponding boundary conditions are derived according to the nonlocal elasticity theory and the first-order shear deformation theory with von K´arm´an-type of kinematic *** effects of size-dependence,shear deformations,rotary inertia,piezoelectric-piezomagnetic coupling,thermal environment and geometrical nonlinearity are taken into *** generalized differential quadrature(GDQ)method in conjunction with the numerical Galerkin method,periodic time differential operators and pseudo arclength continuation method is utilized to compute the nonlinear frequency response of piezoelectric-piezomagnetic *** influences of various parameters such as non-dimensional nonlocal parameter,temperature change,initial applied electric voltage,initial applied magnetic potential,length-to-thickness ratio and different boundary conditions on the geometrically nonlinear free vibration characteristics of piezoelectric-piezomagnetic nanobeams are demonstrated by numerical *** is illustrated that the hardening spring effect increases with increasing the non-dimensional nonlocal parameter,positive initial applied voltage,negative initial applied magnetic potential,temperature rise and decreases with increasing the negative initial applied voltage,positive initial applied magnetic potential and length-tothickness ratio.

关键词： Piezoelectric-piezomagnetic nanobeams geometrically nonlinear free vibration nonlocal elasticity theory size effect magneto-electro-thermal loading

Data-driven failure diagnosis in transmission protection system with multiple events and data anomalies

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Journal of Modern Power Systems and Clean Energy 2019年第4期7卷 767-778页

作者： Amir gholami Anurag K.SRIVASTAVA Shikhar PANDEY Washington State University PullmanUSA

To guarantee a reliable power supply,the expected operation of all the components in the power system is *** protection system is primarily responsible of isolating the faulty section from the healthy part for the *** in protection devices can result in multiple conflicting alarms at the power grid operation center and complex event analysis to manually find the root cause of the observed system *** not handled in time,it may lead to the propagation of the faults/failures to the adjacent transmission lines and *** availability of the synchronized measurements from phasor measurement units(PMUs),real-time system monitoring and automated failure diagnosis are *** multiple adverse events and possible data anomalies,the complexity of the problem will be *** this paper,a PMUbased algorithm is presented and discussed to detect the root cause of the failure in transmission protection system based on the observed state,*** line tripping andbreaker *** failure diagnosis algorithm is further enhanced to come up with the fully functional version of the failure diagnosis tool,which is tailored for the cases in which the PMU anomalies are *** the developed algorithm,the validity of the PMU data is ***,such causes as communication errors or cyber-attacks might lead to the PMU data *** issue is welladdressed in this paper and some major types of anomaly detection methods suitable for PMU data are *** show that the ensemble approach has some distinct advantages in data anomaly detection compared to the previously used standalone ***,the enhanced failure diagnosis method is developed to clean the inaccurate data in case of the anomaly in measured voltage ***,both original and enhanced versions of the tool are tested on 96-bus test system using the real-time OPAL-RT *** results show the accuracy of the enhanced tool and

关键词： Failure diagnosis Transmission protection system Protection mis-operation Phasor measurement unit(PMU) Data anomaly and cleaning Ensemble method

Stochastic Security-constrained Unit Commitment Considering Electric Vehicles, Energy Storage Systems, and Flexible Loads with Renewable Energy Resources

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Journal of Modern Power Systems and Clean Energy 2023年第5期11卷 1405-1414页

作者： Ali gholami Trojani Mahmoud Samiei Moghaddam Javad Mohamadi Baigi Electrical Engineering Department Damghan BranchIslamic Azad UniversityDamghamIran

In this paper, a new formulation for modeling the problem of stochastic security-constrained unit commitment along with optimal charging and discharging of large-scale electric vehicles, energy storage systems, and flexible loads with renewable energy resources is presented. The uncertainty of renewable energy resources is considered as a scenario-based model. In this paper, a multi-objective function which considers the reduction of operation cost, no-load and startup/shutdown costs, unserved load cost, load shifting, carbon emission, optimal charging and discharging of energy storage systems, and power curtailment of renewable energy resources is considered. The proposed formulation is a mixed-integer linear programming(MILP) model, of which the optimal global solution is guaranteed by commercial solvers. To validate the proposed formulation, several cases and networks are considered for analysis, and the results demonstrate the efficiency.

关键词： Electric vehicle energy storage system flexible load renewable energy resource unit commitment

Sonochemical synthesis of photocatalysts and their applications

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Journal of Materials Science & Technology 2022年第28期123卷 243-256页

作者： Kezhen Qi Chunqiang Zhuang Manjie Zhang Peyman gholami Alireza Khataee College of Pharmacy Dali UniversityDali 671000China Beijing Key Lab of Microstructure and Property of Advanced Materials Faculty of Materials and ManufacturingInstitute of Microstructure and Property of Advanced MaterialsBeijing University of TechnologyBeijing 100124China Institute of Catalysis for Energy and Environment College of Chemistry and Chemical EngineeringShenyang Normal UniversityShenyang 110034China Department of Chemistry University of HelsinkiHelsinki 00014Finland Department of Applied Chemistry Faculty of ChemistryResearch Laboratory of Advanced Water and Wastewater Treatment ProcessesUniversity of TabrizTabriz 51666-16471Iran Department of Environmental Engineering Gebze Technical UniversityGebze41400Turkey

Sonochemical synthesis has flourished significantly in the last few decades for the preparation of photocatalysts.A large number of photocatalysts have been prepared through sonochemical *** review highlights the scope of sonochemistry in the preparation of photocatalysts,and their applications in energy production and environmental ***,the sonochemical degradation of pollutants is discussed in *** progress made in sonochemical synthesis and the future perspective for this technique are summarized *** review may create more enthusiasm among researchers to pay extra attention to the sonochemical synthesis of materials and add their useful contribution to the investigation of new materials for photocatalytic and other *** will propel this technique toward commercial sonosynthesis of nanomaterials.

关键词： Sonochemistry Acoustic cavitation Photocatalysis Energy production Environmental remediation

Gas tungsten arc welding of CP-copper to 304 stainless steel using different filler materials

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Transactions of Nonferrous Metals Society of China 2012年第12期22卷 2937-2942页

作者： Sajjad gholami SHIRI Mohsen NAZARZADEH Mahmood SHARIFITABAR Mehdi Shafiee AFARANI Materials Science and Engineering Division School of Engineering University of Sistan and Baluchestan Zahedan Iran Department of Materials Science and Engineering Ferdowsi University of Mashhad Mashhad Iran

The dissimilar joining of CP-copper to 304 stainless steel was performed by gas tungsten arc welding process using different filler materials. The results indicated the formation of defect free joint by using copper filler material. But, the presence of some defects like solidification crack and lack of fusion caused decreasing tensile strength of other joints. In the optimum conditions, the tensile strength of the joint was 96% of the weaker material. Also, this joint was bent till to 180° without any macroscopic defects like separation, tearing or fracture. It was concluded that copper is a new and good candidate for gas tungsten arc welding of copper to 304 stainless steel.

关键词： gas tungsten arc welding CP-copper 304 stainless steel dissimilar joint microstructure mechanical properties

Groundwater quality modeling using self-organizing map(SOM) and geographic information system(GIS) on the Caspian southern coasts

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Journal of Mountain Science 2020年第7期17卷 1724-1734页

作者： Vahid gholami Mohammad Reza KHALEGHI Edris TAGHVAYE SALIMI Department of Range and Watershed Management Faculty of Natural ResourcesUniversity of GuilanRashtIran Department of Range and Watershed Management Torbat-e-Jam BranchIslamic Azad UniversityTorbat-e-JamIran

Groundwater is the main source for water provision in the arid and semi-arid areas such as *** groundwater quality was simulated by using a hybrid model integrating a Self-Organizing Map(SOM)and geographic information system(GIS).SOM and GIS were used as pre-processing and postprocessing tools in the Mazandaran ***,the Ground Water Quality Index(GWQI)and its effective factors were estimated by using digital maps and the secondary *** Solutions software was used for simulating the groundwater *** do this,a model was trained and optimized in the SOM and then the optimized model was *** the next step,the performance of SOM in groundwater quality simulation was confirmed(test stage,Rsqr=0.8,and MSE=0.008).Then,the digital maps of the SOM inputs were converted to raster format in *** the last step,a raster layer was generated by combining the model input layers which comprised the model inputs *** tested SOM was used to simulate GWQI in the sites without the secondary data of the groundwater ***,the groundwater quality map was generated by coupling the results of SOM estimations and GIS *** results revealed that the coupling of SOM and GIS has high performance in the simulation of the groundwater *** to the results,a limited area of the studied plain has groundwater resources with low quality(GWQI>0.04).Therefore,that will be a threat to the life of humans,animals,and vegetative ***,it is necessary to plan for managing the groundwater quality in the Mazandaran plain.

关键词： Simulation GWQI index Optimization Test Groundwater quality map

Precipitation forecasting by large-scale climate indices and machine learning techniques

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Journal of Arid Land 2020年第5期12卷 854-864页

作者： Mehdi gholami ROSTAM Seyyed Javad SADATINEJAD Arash MALEKIAN University of Tehran Tehran ***Iran

Global warming is one of the most complicated challenges of our time causing considerable tension on our societies and on the *** impacts of global warming are felt unprecedentedly in a wide variety of ways from shifting weather patterns that threatens food production,to rising sea levels that deteriorates the risk of catastrophic *** all aspects related to global warming,there is a growing concern on water resource *** field is targeted at preventing future water crisis threatening human *** very first stage in such management is to recognize the prospective climate parameters influencing the future water resource *** prediction models,methods and tools,in this case,have been developed and applied so *** line with trend,the current study intends to compare three optimization algorithms on the platform of a multilayer perceptron(MLP)network to explore any meaningful connection between large-scale climate indices(LSCIs)and precipitation in the capital of Iran,a country which is located in an arid and semi-arid region and suffers from severe water scarcity caused by mismanagement over years and intensified by global *** situation has propelled a great deal of population to immigrate towards more developed cities within the country especially towards ***,the current and future environmental conditions of this city especially its water supply conditions are of great *** tackle this complication an outlook for the future precipitation should be provided and appropriate forecasting trajectories compatible with this region's characteristics should be *** this end,the present study investigates three training methods namely backpropagation(BP),genetic algorithms(GAs),and particle swarm optimization(PSO)algorithms on a MLP *** frameworks distinguished by their input compositions are denoted in this study:Concurrent Model Framework(CMF)and Integrated Model Framework(

关键词： backpropagation genetic algorithms machine learning multilayer perceptron particle swarm optimization Taylor diagram

Effect of microwave pretreatment on grinding and flotation kinetics of copper complex ore

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International Journal of Minerals,Metallurgy and Materials 2021年第12期28卷 1887-1897页

作者： Hamed gholami Bahram Rezai Ahmad Hassanzadeh Akbar Mehdilo Mohammadreza Yarahmadi Department of Mining and Metallurgical Engineering Amirkabir University of TechnologyTehran 158754413Iran Department of Geoscience and Petroleum Faculty of Engineering ScienceNorwegian University of Science and TechnologyNO-7491TrondheimNorway Faculty of Engineering University of Mohaghegh ArdabiliArdabil ***Iran Research and Development Division Sarcheshmeh Copper MineNational Iranian Copper Industries CompanyRafsanjanIran

The present study initially investigates the kinetics of microwave-assisted grinding and flotation in a porphyry copper *** tests were conducted on untreated and microwave-irradiated samples by varying the exposure time from 15 to 150 *** microscopy,energy-dispersive X-ray spectroscopy,and scanning electron microscopy were conducted to determine the mineral liberation and particle surface properties,and to perform mineralogical *** showed that the ore breakage rate constant monotonically increased by increasing the exposure time,particularly for the coarsest fraction size(400μm)due to the creation of thermal stress fractures alongside grain *** irradiation time(>60 s)led to the creation of oxidized and porous surfaces along with a dramatic change in particle morphologies that result in a substantial reduction of chalcopyrite and pyrite flotation rate constants and ultimate *** concluded that MW-pretreated copper ore was ground faster than the untreated variety,but the two types have slightly similar floatabilities.

关键词： grinding microwave copper