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Journal of Materials Science & Technology 2016年第7期32卷 611-616页

作者： Zahra Amirsardari rouhollah mehdinavaz-aghdam Masoud Salavati-Niasari Mohammad Reza Jahannama Institute of Nano Science and Nano Technology University of Kashan. Kashan. Iran Department of Nanotechnology. Space Transportation Research Institute Iranian Space Research Center Tehran lran

The present study focuses on the thermal response of carbon fiber-reinforced phenolic composites, where the matrix has been modified with different reinforcements. Two types of materials, multiwalled carbon nanotubes and zirconium diboride （ZrB2）, were used in a new design of mixture to produce the heat- resistant ablative composite system. The CNT/ZrB2/carbon/phenolic nanocomposite （Z/NT-CR） system corresponding to CNT/carbon/phenolic nanocomposite （NT-CR） showed a reasonable decrease in mass loss and the ablation rate as compared to carbon/phenolic composite （CR）. However, substantial drop in two factors was found for Z/NT-CR as compared to carbon/phenolic and NT-CR. Ablation mechanisms for all three composites were investigated by thermal gravimetric analysis in conjunction with micro- structural studies using a field emission scanning electron microscope. The microstructural studies revealed that CNTs acted as an ablation resistant phase for protection against 2000 ℃, and the conversion from ZrB2 to ZrO2 played an important role as an insulator in the performance of char layer in the ablation resistance.

关键词： Multiwalled carbon nanotubes (MWCNTs)Zirconium diboride nanoparticles (ZrB2)Carbon/phenolic compositeThermal stabilityAblation performance

MRI tracking of human Wharton’s jelly stem cells seeded onto acellular dermal matrix labeled with superparamagnetic iron oxide nanoparticles in burn wounds

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Burns & Trauma 2022年第1期10卷 129-141页

作者： Davood Mehrabani Mehra Nazempour rouhollah mehdinavaz-aghdam Seyedeh-Sara Hashemi Reza Jalli Mahdi Saeedi Moghadam Shahrokh Zare Iman Jamhiri Javad Moayedi Feridoun Karimi-Busheri Stem Cell Technology Research Center Shiraz University of Medical SciencesShirazFars T6G 2E171348-14336Iran Burn and Wound Healing Research Center Shiraz University of Medical SciencesShirazFars 71987-74731Iran Comparative and Experimental Medicine Center Shiraz University of Medical SciencesShirazFars 71348-14336Iran Li Ka Shing Center for Health Research and Innovation University of AlbertaEdmontonAlbertaCanada Department of Biomedical and Tissue Engineering Science and Research BranchIslamic Azad UniversityTehranIran School of Metallurgy and Materials Engineering College of EngineeringUniversity of TehranTehran ***Iran Medical Imaging Research Center Department of RadiologyShiraz University of Medical SciencesShirazFars 71348-14336Iran Department of Biochemistry School of Biotechnology and AgricultureShiraz BranchIslamic Azad UniversityShirazFars 71987-74731Iran Department of Oncology Faculty of MedicineUniversity of AlbertaEdmontonAlbertaT6G 1Z2Canada

Background:In vivo cell tracking after transplantation in regenerative medicine remains an unmet challenge and limits current understanding of the wound healing mechanism through cell-based *** study investigated tracking of human Wharton’s jelly stem cells(hWJSCs)seeded onto an acellular dermal matrix(ADM)and labeled with superparamagnetic iron oxide nanoparti-cles(SPIONs)by magnetic resonance imaging(MRI)in burn ***:The hWJSCs were characterized and assessed for growth kinetics.A total of 30 rats were enrolled in three equal *** 1 underwent scald burn injury left without treatment,the group 2 was treated by an ADM that was prepared from cosmetic surgery skin samples and the group 3 received hWJSCs labeled with SPIONs seeded onto an *** strength was evaluated before and after interventions,real time PCR assessed apoptosis,and Prussian blue staining,scanning electron microscopy(SEM)and MRI were used for the tracking of labeled ***:The hWJSCs exhibited mesenchymal stem cell *** doubling time was 40.1 *** did not show any toxic *** hWJSCs seeded onto an ADM decreased Bax and increased Bcl-2 gene *** of SPIONs within hWJSCs was confirmed by Prussian blue staining,SEM and MRI until day *** was a significant difference between the Young’s moduli of normal skin and the group receiving hWJSCs seeded onto an *** observations and SEM imaging confirmed that MRI is an accurate method to track SPION-labeled hWJSCs in ***:This study showed that SPION labeling coupled with MRI can be used to further understand the fate of stem cells after transplantation in a burn model.

关键词： Wharton’s jelly stem cells Superparamagnetic iron oxide nanoparticles Acellular dermal matrix Magnetic resonance imaging Healing Burn

Studying the effect of surfactant assisted low-salinity water flooding on clay-rich sandstones

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Petroleum 2024年第2期10卷 306-318页

作者： Saeed Khezerloo-ye aghdam Alireza Kazemi Mohammad Ahmadi Department of Petroleum Engineering Amirkabir University of Technology(AUT)TehranIran Department of Petroleum and Chemical Engineering College of EngineeringSultan Qaboos UniversityMuscatOman

Sandstone reservoirs often contain clay particles that can cause damage and reduce permeability during low-salinity water *** this study,the effect of surfactants on fine migration in clay-rich sandstones and its impact on oil recovery was ***,the impact of surfactants on interparticle forces in fine-matrix,fine-fine,and oil-matrix systems was *** results showed that both CTAB(cetyltrimethyl ammonium bromide)and QS(quillaja saponin)cause EDL compaction,weakening the repulsive ***,SDS(sodium dodecyl sulfate)and TX(triton X-100)do not affect the ***,the effect of surfactants on IFT reduction and wettability alteration was experimentally *** surfactants reduced IFT due to the surface excessive concentration *** wettability alteration experiment illustrated that although QS and CTAB compact EDL around oil and matrix particles leading to attraction force augmentation,they both alter wettability through adsorption on matrix and carboxylic groups present in crude oil,*** aqueous solutions were then injected into various clay-rich sandstone sanpacks,which resulted in increased oil ***,the mechanisms leading to enhanced oil recovery variedby surfactant *** increased recovery by 10%through IFT reduction and wettability alteration,while SDS and TX increased recovery by 12%and 9%,respectively,through wettability alteration and extreme fine *** contrast,partial fine migration in the QS flooding experiment reached a recovery increase of 18%.Permeability trends through experiments were also *** CTAB injection,permeability did not reduce,while QS aqueous solution reduced rock permeability to 5 m *** and TX reduced the magnitude of permeability to 2 m *** conclusion,this study demonstrates that surfactants can effectively improve oil recovery in clay-rich sandstones by altering the interparticle forces,reducing IFT,and changing *** results

关键词： Surfactant flooding Smart water Fine migration Recovery factor

Platform Evolution in an Oligo-Miocene Back-arc Basin:An Example from the Central Iran Basin

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 185-206页

作者： Masoud SHARIFI-YAZDI Amirhossein ENAYATI Jamal SALEHI aghdam Mohammad BAHREHVAR Seyed Mustafa REZAEI Department of Geology Faculty of Earth SciencesGeography and AstronomyUniversity of Vienna1090 Vienna.Austria Geology and Geophysics Department Tehran Energy Consultants(TEC Co.)TehranIran School of Geology College of ScienceUniversity of TehranTehranIran Department of Geology Tarbiat Modares UniversityTehranIran

The Qom Formation is the most important hydrocarbon reservoir target in Central *** Qom platform developed in a back-arc basin during the Oligo-Miocene due to the closing of the Tethyan *** formation consists of a variety of carbonate and non-carbonate facies deposited on a platform ranging from supratidal to basin.A combination of tectonic and eustatic events led to some lateral and vertical facies variations in the study *** third-order depositional sequences and related surfaces were identified regarding vertical facies changes in the studied sections of this Oligo-Miocene *** to all results and data,this succession was initially deposited during the Chattian upon a distally steepened ramp of siliciclastic-carbonate composition,including the Bouma ***,from the late Chattian to the Aquitanian,the platform changed into a homoclinal carbonate ramp with a gentle *** respect to tectonic activity,this phase was a calm period during the deposition of the Qom ***,a drowned carbonate platform and a rimmed shelf emerged during the Burdigalian,terminated by the continental deposits of the Upper Red *** all geological characteristics,three main tectono-eustatic evolutionary phases have been recognized in the Qom back-arcbasin.

关键词： carbonate ramp depositional facies submarine fan eustasy basement faults back-arc basin

Interplay between temperature-dependent strengthening mechanisms and mechanical stability in high-performance austenitic stainless steels

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International Journal of Minerals,Metallurgy and Materials 2024年第10期31卷 2182-2188页

作者： Mohammad Javad Sohrabi Hamed Mirzadeh Saeed Sadeghpour Milad Zolfipour aghdam Abdol Reza Geranmayeh Reza Mahmudi School of Metallurgy and Materials Engineering College of EngineeringUniversity of Tehran14395-515 TehranIran Centre for Advanced Steels Research Materials and Mechanical EngineeringUniversity of Oulu90014 OuluFinland Department of Mechanical Engineering College of EngineeringUniversity of Tehran14395-515 TehranIran

The effects of deformation temperature on the transformation-induced plasticity(TRIP)-aided 304L,twinning-induced plasti-city(TWIP)-assisted 316L,and highly alloyed stable 904L austenitic stainless steels were compared for the first time to tune the mechan-ical properties,strengthening mechanisms,and strength-ductility *** this purpose,the scanning electron microscopy(SEM),electron backscattered diffraction(EBSD),X-ray diffraction(XRD),tensile testing,work-hardening analysis,and thermodynamics calcu-lations were *** induced plasticity effects led to a high temperature-dependency of work-hardening behavior in the 304L and 316L stainless *** the deformation temperature increased,the metastable 304L stainless steel showed the sequence of TRIP,TWIP,and weakening of the induced plasticity mechanism;while the disappearance of the TWIP effect in the 316L stainless steel was also ***,the solid-solution strengthening in the 904L superaustenitic stainless steel maintained the tensile properties over a wide temper-ature range,surpassing the performance of 304L and 316L stainless *** this regard,the dependency of the total elongation on the de-formation temperature was less pronounced for the 904L alloy due to the absence of additional plasticity *** results re-vealed the importance of solid-solution strengthening and the associated high friction stress for superior mechanical behavior over a wide temperature range.

关键词： austenitic stainless steels mechanical behavior stacking fault energy metastability mechanical twinning

Techno-economic optimization of a sustainable system to cogenerate power and water for remote areas

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Clean Energy 2023年第3期7卷 602-619页

作者： Sina Akhavan Shams rouhollah Ahmadi School of New Technologies Iran University of Science&TechnologyTehranIran

In this study,a new water and power cogeneration plant,employing photovoltaic(PV)and photovoltaic-thermal(PVT)panels simultaneously,is designed and optimized for a village struggling to provide energy and potable water in *** system includes a solar energy unit to generate clean electricity and heat,and a reverse osmosis unit to produce drinking ***-economic optimization is performed by implementing a genetic algorithm,and a comprehensive water and energy management strategy is designed and presented in detail,expandable for future works.A new method,the logarithmic model,is used to calculate the depth of discharge(DOD)of lithium-ion batteries,which was previously a fixed and predetermined value in previous *** indices,the constraints of the optimization process,are also introduced to measure the reliabilities of different *** effects of the system components on total cost are investigated and a comprehensive sensitivity analysis is performed to find the best solution to increase the penetration of renewable-energy *** results reveal that considering the depth of discharge of batteries and water storage tank capacity as decision variables reduces the system’s life-cycle cost(by 5.1%for changeable DODs).Furthermore,the simultaneous use of PV and PVT panels decreases the life-cycle cost considerably by≤19%compared with the use of only PVT ***,the cost of the battery causes a decrease in the cost of electricity storage and the cost of producing and storing fresh water.

关键词： renewable hybrid system integrated water and power system PV-PVT-RO-battery system genetic algorithm optimization

Simple separation method of Zn(Ⅱ) and Cd(Ⅱ) from brine solution of zinc plant residue and synthetic chloride media using solvent extraction

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Chinese Journal of Chemical Engineering 2020年第4期28卷 1055-1061页

作者： Ali Asghar Balesini aghdam Hossein Yoozbashizadeh Javad Moghaddam Department of Materials Engineering Science and Research BranchIslamic Azad UniversityTehranIran Materials and Metallurgical Engineering Department University of ZanjanZanjanIran

In this work,the possibility of separation of Zn^2+and Cd^2+metal ions from chloride(brine)solutions was *** this purpose,simple solvent extraction(SX)experiments by di-2-ethylhexyl phosphoric acid(D2EHPA)in kerosene as a diluent was performed on synthetic and industrial chloride solution obtained from brine leaching of zinc filter cakes(by-product of zinc hydrometallurgical processing).The optimal conditions for separation were *** zinc extraction efficiency was 99%with negligible co-extraction of ***,a highΔpH0.5 value for Zn(Ⅱ)and Cd(Ⅱ)was ***-IR and slope analysis indicated that ZnClA·3HA and CdClA·3HA species were probably extracted.

关键词： Solvent extraction Brine media Leaching filter cakes Zinc Cadmium

Si_3N_4/Ni nanocomposite formed by electroplating: Effect of average size of nanoparticulates

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Transactions of Nonferrous Metals Society of China 2010年第6期20卷 1017-1023页

作者： M.A.KHAZRAYIE A.R.S.aghdam Department of Materials Engineering Faculty of Engineering Tarbiat Modares University

Properties of Si3N4/Ni electroplated nanocomposite such as corrosion current density after long time immersion,roughness of obtained layer and distribution of nanometric particulates were *** effective factors for fabrication of nanocomposite coatings were fixed for better studying the effect of the average size of *** effects of the different average size of nanometric particulates(ASNP)from submicron scale(less than 1μm)to nanometric scale(less than 10 nm)were *** nanostructures of surfaces were examined by scanning electron microscopy(SEM),transmission electron microscopy(TEM)and atomic force microscopy(AFM).Corrosion rates of the coatings were determined using the Tafel polarization *** is seen that decreasing the ASNP will lead to lower corrosion current densities;however,in some cases,pitting phenomena are *** roughness illustrates a minimum level while the distribution of nanometric particulates is more uniform by decreasing the *** effects of pulsed current on electrodeposition(frequency,duty cycle)and concentration of nanoparticulates in electrodeposition bath on trend of obtained curves have been *** surface methodology was applied for optimizing the effective operating conditions of *** levels studied were frequency range between 1 000 and 9 000 Hz,duty cycle between 10%and 90%and concentration of nanoparticulates of 10-90 g/L.

关键词： corrosion electrodeposition nanocomposite nanostructure nano diamond

Modeling the energy gain reduction due to shadow in flat-plate solar collectors;Application of artificial intelligence

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Artificial Intelligence in Agriculture 2021年第1期5卷 185-195页

作者： Morteza Taki rouhollah Farhadi Department of Agricultural Machinery and Mechanization Engineering Agricultural Sciences and Natural Resources University of KhuzestanP.O.Box:***MollasaniIran

Energy lost due to shadow in the absorber plate of solar collectors can decrease the solar energy *** some studies,mathematical modeling was applied for calculating the energy gain reduction due to shadow in flatplate solar *** this study,ANN method was developed for modeling the energy gain *** Perceptron(MLP)with one hidden layer and a range of neurons(5–30)by two training algorithms(LM and BR)and tangent sigmoid activation function(TanSig)were used by help of K-fold cross validation *** the first section,six set of solar collector dimensions were used(1×1;1×1.5;1×2;1.5×1.5;1.5×2 and 2×2).In the second section all the range of dimensions were used as the *** results of the first section showed thatMLPwith BR training algorithm can predict the energy gain reductionwith minimumMAPE and RMSE in all the *** best results related to(1.5×1.5)dimension that achieved a MAPE of 0.15±0.09%and RMASE of 4.42±2.43 KJm−2 year−1,*** results of the second section indicated that BR is a better training algorithm than *** MAPE and R2 factors for the best topology(5-27-1)were 0.0610±0.0051%and 0.9999±0.0001,*** results of the sensitivity analysis showed that height has the biggest impact on total energy gain reduction due to shadow in flat-plate solar ***,the results of this study indicated that by using ANN and decrease the energy lost,the efficiency of solar collectors can be increased in all applications such as industry and agriculture.

关键词： Multilayer perceptron Optimization Energy Sensitivity analysis

Nonlinear primary resonance analysis of nanoshells including vibrational mode interactions based on the surface elasticity theory

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Applied Mathematics and Mechanics(English Edition) 2020年第2期41卷 233-260页

作者： A.SARAFRAZ S.SAHMANI M.M.aghdam Mechanical Engineering Department Amirkabir University of TechnologyTehran 15875-4413Iran School of Science and Technology The University of GeorgiaTbilisi 0171Georgia

The deviation from the classical elastic characteristics induced by the free surface energy can be considerable for nanostructures due to the high surface to volume ratio. Consequently, this type of size dependency should be accounted for in the mechanical behaviors of nanoscale structures. In the current investigation, the influence of free surface energy on the nonlinear primary resonance of silicon nanoshells under soft harmonic external excitation is studied. In order to obtain more accurate results,the interaction between the first, third, and fifth symmetric vibration modes with the main oscillation mode is taken into consideration. Through the implementation of the Gurtin-Murdoch theory of elasticity into the classical shell theory, a size-dependent shell model is developed incorporating the effect of surface free energy. With the aid of the variational approach, the governing differential equations of motion including both of the cubic and quadratic nonlinearities are derived. Thereafter, the multi-time-scale method is used to achieve an analytical solution for the nonlinear size-dependent problem. The frequency-response and amplitude-response of the soft harmonic excited nanoshells are presented corresponding to different values of shell thickness and surface elastic constants as well as various vibration mode interactions. It is depicted that through consideration of the interaction between the higher symmetric vibration modes and the main oscillation mode, the hardening response of nanoshell changes to the softening one. This pattern is observed corresponding to both of the positive and negative values of the surface elastic constants and the surface residual stress.

关键词： nanostructure nonlinear dynamics surface stress mode interaction multi-time-scale method