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Effects of the deep rolling process on the surface roughness and properties of an Al-3vol%SiC nanoparticle nanocomposite fabricated by mechanical milling and hot extrusion

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International Journal of Minerals,Metallurgy and Materials 2017年第7期24卷 814-825页

作者： Sajjad Sattari amir Atrian Department of Mechanical Engineering Najafabad Branch Islamic Azad University Najafabad Iran Modem Manufacturing Technologies Research Center Najafabad Branch Islamic Azad University Najafabad lran

Deep rolling is one of the most widely used surface mechanical treatments among several methods used to generate compressive residual stress. This process is usually used for axisymmetric components and can lead to improvements of the surface quality, dimensional accuracy, and mechanical properties. In this study, we deduced the appropriate deep rolling parameters for Al-3vol%Si C nanocomposite samples using roughness and microhardness measurements. The nanocomposite samples were fabricated using a combination of mechanical milling, cold pressing, and hot extrusion techniques. Density measurements indicated acceptable densification of the samples, with no porosity. The results of tensile tests showed that the samples are sufficiently strong for the deep rolling process and also indicated near 50% improvement of tensile strength after incorporating Si C nanoparticle reinforcements. The effects of some important rolling parameters, including the penetration depth, rotation speed, feed rate, and the number of passes, on the surface quality and microhardness were also investigated. The results demonstrated that decreasing the feed rate and increasing the number of passes can lead to greater surface hardness and lower surface roughness.

关键词： deep rolling nanocomposite mechanical milling hot extrusion roughness hardness

Mechanical Properties and Microstructure Evolution of AA1100 Aluminum Sheet Processed by Accumulative Press Bonding Process

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Acta Metallurgica Sinica(English Letters) 2016年第8期29卷 735-741页

作者： amir Mostafapor Vahid Mohammadinia Department of Mechanical Engineering University of Tabriz Department of Mechanical Engineering University of Maragheh

Accumulative press bonding（APB） is a novel variant of severe plastic deformation processes,which is devised to produce materials with ultra-fine *** the present work,the mechanical properties and microstructural evolution of AA1100 alloy,which is produced by APB technique,were *** study of the microstructure of AA1100 alloy was performed by optical *** results revealed that the grain size of the samples decreased to 950 nm after six passes of APB *** yield strength of AA1100 alloy after six passes of the process increased up to 264 MPa,which is three times higher than that of the as-cast material（89 MPa）.After six passes,microhardness values of AA1100 alloy increased from 38 to 61 ***,the results showed that the behavior of variations in mechanical properties is in accordance with the microstructural changes and it can be justified by using the Hall-Patch ***,the rise in the yield strength can be attributed to the reduction in the grain size leading to the strain hardening.

关键词： Severe plastic deformation Accumulative press bonding Mechanical properties Metallurgical properties AA1100 alloy

Ion separation and water purification by applying external electric field on porous graphene membrane

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Nano Research 2018年第4期11卷 2229-2236页

作者： amir Lohrasebi Samaneh Rikhtehgaran Department of Physics University of Isfahan Isfahan 81746-73441 Iran School of Nano Science Institute for Research in Fundamental Sciences (IPM) Tehran 19395-5531 Iran Department of Physics Florida Atlantic University 777 Glades Road Boca Raton FL 33431-0991 USA

Using molecular dynamics （MD） simulations, a porous graphene membrane was exposed to external electric fields to separate positive and negative ions from salt-water and to produce fresh water. It was observed that, by increasing the strength of the applied electric field, ion separation improved noticeably. In addition, to obtain fresh water, the designed system included two graphene membranes, which are exposed to two external electric fields in opposite directions. Ion rejection was found to be greater than 93% for the electric field of 10 mV/A and higher. This atomic-level simulation increases the understanding of electric field effects on desalination using multilayer graphene membranes and can be helpful in designing more efficient membranes.

关键词： desalination nanoporous graphene membrane ion separation molecular dynamicss imulation electric field

Microstructural Evolution of NiTi47.7Cu6.3 Alloy during Hot Deformation

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Journal of Materials Science & Technology 2011年第10期27卷 951-960页

作者： amir Etaati Kamran Dehghani Mining and Metallurgical Eng.Dept. Amirkabir Univ.Tech.

In the present work, the hot workability and microstructural evolution of ***6.3 （at.%） shape memory alloy were investigated by using wedge-rolling test. The wedge specimens were subjected to hot rolling at the temperatures of 700-1000℃. The microstructural evolutions at the strains of 0.05, 0.15, 0.2, 0.25 and 0.3 were then characterized by optical microscopy and scanning electron microscopy （SEM） as well as energy dispersive spectrometry （EDS） technique. Depending on the deformation temperature and strain, the dynamic recrystallization （DRX） could occur, leading to the refining of the microstructure. At low temperatures of 700 and 800℃ there was no sign of DRX at all studied strains. At these temperatures, the formed fine needle-like precipitates pinned the grain boundaries and prevented them from bulging/migration. By contrast, at higher temperatures of 900 and 1000℃, the DRX took place at the critical strains lower than 0.25 and 0.15, respectively. However, at higher temperatures, strain-induced-boundary-migration （SIBM） mechanism resulted in the formation of DRX grains.

关键词： Deformation Wedge rolling test Dynamic recrystallization Ni-rich Nitinol NiTiCu

Targeting late SV40 factor: Is the achilles heel of hepatocarcinogenesis revealed?

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World Journal of Gastroenterology 2012年第46期18卷 6709-6711页

作者： amir Shlomai Institute of Gastroenterology and Liver Diseases Tel-Aviv Sourasky Medical Center and Sackler Faculty of Medicine Tel-Aviv University

Hepatocellular carcinoma (HCC) is a dreadful cancer and a major cause of death among patients with chronic liver disease and cirrhosis. The apparent alterations in a diversity of intracellular pathways found in HCC has set the rational for developing molecular-directed drugs that simultaneously inhibit multiple pathways, such as the multi-kinase inhibitor Sorafenib. However, recently this concept has been challenged by showing that HCC is heavily dependent on a single oncogene designated late SV-40 factor (LSF), a transcription factor that is over-expressed in liver cancer cells and that its expression is strongly correlated with tumor grade and aggressiveness. Furthermore, using an intensive screening for drugs that inhibit LSF activity, Grant et al have found a molecule designated factor quinolinone inhibitor 1 that can specifically block the ability of LSF to bind its target promoters, resulting in a massive death of HCC cells both in vitro and in vivo. The innovative findings of HCC representing "oncogene addiction" to LSF and the ability of a single molecule to block the activity of this oncogene resulting in tumor abolishment are encouraging and provide us with the hope that the "Achilles heel" of HCC has been found.

关键词： Oncogene addiction Hepatocellular carcinoma Late SV40 factor Transcription factor Multikinase inhibit

Neuroprotective potential of traditional Ayurvedic Kadha:age-related neurological disorders:a comprehensive literature review

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Traditional Medicine Research 2024年第9期9卷 51-77页

作者： Sarvin Sadreddini Mohammad Javad Emami Kazemabad Sogand Sheikholeslami Kosar Chitzan-Zadeh Mohammad Taha Kouchaki Midia Rashidi amir Abbas Ghayerin Shahin Sabaghi Ghazal Tavakoli Sepehr Nanbakhsh Tina Mansourian Arefeh Tabashiri Fariba Arbab Mojeni Mohammed Namiq Amin Zahra Taheri Seyed Esmaeil Sedighi Taraneh Tarkashvand Parham amirazodi Mobina Fathi Shirin Yaghoobpoor Niloofar Deravi School of Medicine Tabriz University of Medical SciencesTabriz ***Iran School of Medicine Qom University of Medical SciencesQom ***Iran School of Medicine Hamadan University of Medical SciencesHamadan ***Iran School of Medicine Ahvaz Jundishapur University of Medical SciencesAhvaz ***Iran Faculty of Medicine Tabriz University of Medical SciencesTabriz ***Iran School of Medicine Iran University of Medical SciencesTehran ***Iran School of Medicine Shahid Beheshti University of Medical SciencesTehran ***Iran School of Medicine Mazandaran University of Medical SciencesSari ***Iran School of Medicine Kermanshah University of Medical SciencesKermanshah ***Iran Faculty of Pharmacy Pharmaceutical Sciences BranchIslamic Azad UniversityTehran ***Iran Department of Biology Faculty of SciencePayamNoor UniversityTehran ***Iran Faculty of Medicine Islamic Azad University of Medical ScienceTehran 193951495Iran International Campus Shahid Sadoughi University of Medical SciencesYazd ***Iran

Despite modern medicine’s advancements,age-related neurological diseases like Alzheimer’s disease and Parkinson’s disease remain challenging due to high costs,side effects,and limited ***,a traditional Indian medicine system,offers Kadha tea as a potential herbal *** review explores Kadha’s components(basil(Ocimum basilicum L.),black pepper(Piper nigrum L.),Cinnamon(Cinnamomum verum ***),ginger(Zingiber officinale Roscoe),and raisin(Vitis vinifera L.))and their interaction with various neurological *** suggest Kadha exhibits anti-inflammatory,antioxidant,and antiviral properties,potentially impacting Alzheimer’s disease,Parkinson’s disease,neurotoxicity,neuroinflammation,and brain *** focusing on specific disease mechanisms and Kadha’s intergrade effects,this review aims to elucidate its potential role in managing age-related neurological disorders.

关键词： Ayurveda Kadha neuroprotective neurological disorders traditional medicine

Effects of rotational components of earthquake on seismic response of arch concrete dams

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Earthquake Engineering and Engineering Vibration 2020年第2期19卷 349-362页

作者： amir Javad Moradloo Abbas Naiji Department of Civil Engineering School of EngineeringUniversity of ZanjanZanjan 38791-45371Iran

The present study deals with dynamic analysis of arch concrete dams,taking rotational components of earthquakes into account.A modified methodology was used to evaluate the rotational components of the *** translational components of the earthquake have been used in to obtain the rotational components of the earthquake,based on the intersecting isotropic elastic wave *** rotational components of Taft,Tabas and San-Fernando earthquakes are evaluated based on the translational components of the earthquakes and considering frequency dependencies of incident angle and wave ***,dynamic analyses of Morrow Point Dam are presented to evaluate the effects of combined translational and rotational components on the seismic response of the *** conditions of reservoirs,including full and empty state,are considered in the ***–structure interaction was completely taken into *** was realized that incorporating rotational components increased the maximum compressive and tensile stresses in both empty and full reservoir *** of maximum tensile stresses is very sensitive to the rotational components of the ***,it can be concluded that the segregated effect of the rocking component on the response of concrete dams is more effective than the sole effect of the torsional component.

关键词： rotational components earthquake arch concrete dam seismic analysis fluid-structure interaction

Formation-Containment Control Using Dynamic Event-Triggering Mechanism for Multi-Agent Systems

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IEEE/CAA Journal of Automatica Sinica 2020年第5期7卷 1235-1248页

作者： amir Amini amir Asif Arash Mohammadi Electrical and Computer Engineering Concordia UniversityMontrealQuebec H3G 2W1Canada Concordia Institute for Information System Engineering Concordia UniversityMontrealQuebec H3G 1M8Canada IEEE

The paper proposes a novel approach for formationcontainment control based on a dynamic event-triggering mechanism for multi-agent *** leader-leader and follower-follower communications are reduced by utilizing the distributed dynamic event-triggered *** consider two separate sets of design parameters:one set comprising control and dynamic event-triggering parameters for the leaders and a second set similar to the first one with different values for the *** proposed algorithm includes two novel stages of codesign optimization to simultaneously compute the two sets of *** design optimizations are convex and use the weighted sum approach to enable a structured trade-off between the formation-containment convergence rate and associated *** based on non-holonomic mobile robot multi-agent systems quantify the effectiveness of the proposed approach.

关键词： Co-design convex optimization dynamic event-triggered schemes formation-containment control multi-agent systems

Design of a Bio-inspired Hull Shape for an AUV from Hydrodynamic Stability Point of View through Experiment and Numerical Analysis

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Journal of Bionic Engineering 2018年第6期15卷 950-959页

作者： amir Honaryar Mahmoud Ghiasi Faculty of Marine Technology Amirkabir University of Technology Hafez Avenue 15875-4413 Tehran Iran

The hydrodynamic characteristics and body shape of catfish, Hypostomus, are used to design and develop an Autonomous Under- water Vehicle （AUV） named ZRAUV for subsea pipeline and cable inspection. Among the hydrodynamic characteristics, stability of this bio-inspired AUV, which may be adversely affected by disturbances such as marine currents during inspection process, is taken into consideration and evaluated both numerically and experimentally. Concerning numerical investigation, computational fluid dynamics based on Reynolds Averaged Navier-Stokes equations are applied to compute the hydrodynamic damping derivatives needed for stability analysis. In order to verify the numerical predictions, computations are also performed for the well-known submarine body with a typical axisymmetric hull shape, SUBOFF. Experiments are also carried out for both proposed AUV and a conventional axisymmetric one using self-propulsion tests. Measurements of turning rate in turning circle maneuver are in reasonably good agreement with those of numerical estimations and indicate that the turning rate of conventional bodies like SUBOFF is approximately 3.8 times as great as that of bio-inspired AUV. In other words, the findings reveal that in comparison with common axisymmetric bodies, the proposed AUV with biological hull shape is more stable by about 99%, thus, it is highly suitable for subsea pipeline and cable inspection.

关键词： catfish hydrodynamic stability bio-inspired AUV hull form computational fluid dynamics