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Journal of magnesium and Alloys 2022年第4期10卷 938-955页

作者： m.Kasaeian-Naeini m.sedighi R.Hashemi School of mechanical Engineering Iran University of Science and TechnologyTehranIran

The use of magnesium in orthopedic and cardiovascular applications has been widely attracted by diminishing the risk of abnormal interaction of the implant with the body tissue and eliminating the second surgery to remove it from the ***,the fast degradation rate and generally inhomogeneous corrosion subsequently caused a decline in the mechanical strength of mg during the healing *** researches have been conducted on the influences of various severe plastic deformation(SPD)processes on magnesium bioalloys and *** paper strives to summarize the various SPD techniques used to achieve magnesium with an ultrafine-grained(UFG)***,the effects of various severe plastic deformation methods on magnesium microstructure,mechanical properties,and corrosion behavior have been ***,this review intends to clarify the different potentials of applying SPD processes to the magnesium alloys and composites to augment their usage in biomedical applications.

关键词： magnesium Severe plastic deformation Biodegradable implant mechanical properties Corrosion

Effect of stiffeners on crashworthiness of square aluminium columns considering damage evolution

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Journal of Central South University 2013年第3期20卷 599-607页

作者： H.R.Allahbakhsh m.Shariati m.sedighi mechanical Department Damghan BranchIslamic Azad UniversityDamghan 36716-39998Iran mechanical Department Ferdowsi University of MashhadMashhad 91779-48974Iran

Combining the optimization and FEm technology,crashworthiness of aluminum extrusions was studied for an automobile safety *** effects of longitudinal stiffeners on the crushing of stiffened square columns were studied considering the damage *** numerical analysis was carried out by ABAQUS ***,the collapse behavior of aluminum extrusion damage was validated by comparing against solution published in ***,in order to find more efficient and lighter crush absorber and achieving minimum peak crushing force,response surface methodology(RSm) has been applied for optimizing the aluminum extrusion tube.

关键词： damage response surface methodology (RSm) crashworthiness stiffener

A multi-mechanistic approach to the oil recovery study of a family of amphiphilic polysaccharides

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Petroleum Research 2024年第2期9卷 238-249页

作者： Funsho Afolabi Syed mmahmood Lunech mario Nur Asyraf md Akhir Bennett Tackie-Otoo hamid Sharifigaliuk Center of Research in Enhanced Oil Recovery Universiti Teknologi PETRONASSeri IskandarMalaysia Center for Subsurface Imaging Universiti Teknologi PETRONASSeri IskandarMalaysia Research Institute of Petroleum Industry(RIPI) TehranIran

Chemical enhanced oil recovery(cEOR)remains one of the most potent tertiary recovery ***,it is expensive and rarely environmentally ***-based amphiphilic polymers have been suggested as an alternative to eradicating the challenges of conventional cEOR because of cost-effectiveness,and ***,few in-depth studies exist in the literature to investigate the prospects of these materials.A new family of amphiphilic polysaccharides was synthesized by hydrophobic modification of cellulose sulphate,and the EOR functionalities were *** novel biopolymers exhibited the ability to alter rock wetting *** terms of recovery,one of the variants of the synthesized bio amphiphilic polymer(D-I)was able to reduce residual oil saturation to 12%at harsh conditions of 60,000 ppm salinity at 75℃.micromodel visual analysis revealed that the performance of the novel materials was due to the combination of mobility control,IFT lowering and emulsification,wettability alteration,and *** a performance commensurate to that of a commercial hydrophobically modified polymer,it can be said that the novel amphiphilic polysaccharides can stand as a viable cEOR agent for oilfield applications.

关键词： Bio-based polymers Amphiphilic polysaccharides EOR Cellulose sulphate Environmental sustainability

Static and Dynamic Pull-In Instability of Nano-Beams Resting on Elastic Foundation Based on the Nonlocal Elasticity Theory

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Chinese Journal of mechanical Engineering 2017年第2期30卷 385-397页

作者： hamid m.sedighi ASHKAN Sheikhanzadeh mechanical Engineering Department Faculty of EngineeringShahid Chamran University of Ahvaz Departmentof mechanical Engineering Najafabad BranchIslamic Azad Univesity

This paper provides the static and dynamic pullin behavior of nano-beams resting on the elastic foundation based on the nonlocal theory which is able to capture the size effects for structures in micron and sub-micron scales. For this purpose, the governing equation of motion and the boundary conditions are driven using a variational approach. This formulation includes the influences of fringing field and intermolecular forces such as Casimir and van der Waals forces. The differential quadrature （DQ） method is employed as a high-order approximation to discretize the governing nonlinear differential equation, yielding more accurate results with a Considerably smaller number of grid points. In addition, a powerful analytical method called parameter expansion method （PEm） is utilized to compute the dynamic solution and frequency-amplitude relationship. It is illustrated that the first two terms in series expansions are sufficient to produce an acceptable solution of the mentioned structure. Finally, the effects of basic parameters on static and dynamic pull-in insta- bility and natural frequency are studied.

关键词： Static and dynamic pull·in voltages Size dependent Nonlocal theory Euler·Bernoulli beam model Differential quadrature method Parameter Expansion method

Kaoline-based catalyst for a high stability desulfurization of sour heavy naphtha in a three-phase oscillatory baffled reactor

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Particuology 2024年第1期84卷 249-260页

作者： Hassan m.Hmood Saba A.Gheni Safaa m.R.Ahmed mudheher m.Ali hamid Yonis Saleh mohammed H.mohammed Awad E.mohammed marwan A.mahomood Hiba R.mohammed Ahmed A.Hassan Adam Harvey North Refineries Company Ministry of OilIraq Chemical Engineering Department Tikrit UniversityIraq ministry of Oil Iraq AL-Hawija Technical Institute Northern Technical UniversityMoselIraq School of Engineering Newcastle UniversityUK

To meet the rapidly increasing demand for energy and the dramatic depletion of conventional crude oil,it is imperative to utilize sour *** no coke being produced,oxidative desulfurization(ODS)of naphtha lowers its sulfur content and average molecular *** this article,we outline a method for heavy naphtha non-extractive ODS using a very stable *** technique involves the use of a solid catalyst with oxygen gas as the *** necessitated relatively high mixing intensities;hence a three-phase Oscillatory Baffled Reactor(OBR)was *** catalyst was based on the zeolite ZSm-5,prepared from natural kaolin by a series of delamination and activation steps and impregnated with Fe.A TiO2 nanolayer was applied,using the sol-gel method,to prevent rapid *** reactor performance was evaluated to minimize the sulfur content in the naphtha *** to the protective coating,the sulfur conversion stabilized at 90%.The results of this work establish the use of natural clay-based catalysts in a continuous,three-phase ODS,particularly with regard to proving long-term *** also showed that modest ODS can be achieved using an environmentally friendly oxidant,at mild operating conditions,whilst maintaining stability.

关键词： Natural kaoline Desulfurization Three-phase Oscillatory baffled reactor

Security and Privacy Challenges in SDN-Enabled IoT Systems: Causes, Proposed Solutions,and Future Directions

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Computers, materials & Continua 2024年第8期80卷 2511-2533页

作者： Ahmad Rahdari Ahmad Jalili mehdi Esnaashari mehdi Gheisari Alisa A.Vorobeva Zhaoxi Fang Panjun Sun Viktoriia m.Korzhuk Ilya Popov Zongda Wu hamid Tahaei Institute of Artificial Intelligence Shaoxing UniversityShaoxing312000China Department of Computer Engineering Gonbad Kavous UniversityGonbad-e Kavus49717-99151Iran Faculty of Computer Engineering K.N.Toosi University of TechnologyTehran196976-4499Iran Department of Computer Science and Engineering Saveetha School of EngineeringSaveetha Institute of Medical and Technical SciencesChennai602105India Secure Information Technologies Department National Research University ITMOSt.Petersburg197101Russia School of Electrical and Computer Engineering Shiraz UniversityShiraz71946–84334Iran Department of Computer Science and Engineering Islamic Azad UniversityDamavand***Iran Department of R&D Shenzhen BKD Co.Ltd.Shenzhen518000China

Software-Defined Networking(SDN)represents a significant paradigm shift in network architecture,separating network logic from the underlying forwarding devices to enhance flexibility and centralize ***-rently,the Internet of Things(IoT)connects numerous devices to the Internet,enabling autonomous interactions with minimal human ***,implementing and managing an SDN-IoT system is inherently complex,particularly for those with limited resources,as the dynamic and distributed nature of IoT infrastructures creates security and privacy challenges during SDN *** findings of this study underscore the primary security and privacy challenges across application,control,and data planes.A comprehensive review evaluates the root causes of these challenges and the defense techniques employed in prior works to establish sufficient secrecy and privacy *** investigations have explored cutting-edge methods,such as leveraging blockchain for transaction recording to enhance security and privacy,along with applying machine learning and deep learning approaches to identify and mitigate the impacts of Denial of Service(DoS)and Distributed DoS(DDoS)***,the analysis indicates that encryption and hashing techniques are prevalent in the data plane,whereas access control and certificate authorization are prominently considered in the control plane,and authentication is commonly employed within the application ***,this paper outlines future directions,offering insights into potential strategies and technological advancements aimed at fostering a more secure and privacy-conscious SDN-based IoT ecosystem.

关键词： Security privacy-preserving software-defined network internet of things

Designing of ECAP parameters based on strain distribution uniformity

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Progress in Natural Science:materials International 2012年第5期22卷 452-460页

作者： F.Djavanroodi B.Omranpour m.Ebrahimi m.sedighi Department of mechanical Engineering Iran University of Science and TechnologyTehranIran

Equal Channel Angular Pressing(ECAP) is currently one of the most popular methods for fabricating Ultra-Fine Grained(UFG) *** this work,ECAP process has been performed on commercial pure aluminum up to 8 passes by route *** verification of FEm work,the influences of four die channel angles,three outer corner angles and pass number up to 8 have been analyzed to investigate strain distribution behavior of ECAPed *** methods for quantifying the strain homogeneity namely inhomogeneity index(Ci) and standard deviation(S.D.) are *** is shown that Ci is not a good candidate for examining the strain distribution ***,it is suggested that designing of ECAP die geometry to achieve optimum strain distribution homogeneity is more suitable than the optimum effective strain *** best strain distribution uniformity in the transverse plane is obtained with Ф=60° and Ψ=15° and for the bulk of the sample,Ф=120° and Ψ=15° or 60°,gives the highest strain dispersal uniformity.

关键词： ECAP FEm Die design Strain distribution

Seroprevalence Survey of HIV and Hepatitis B Virus and Behavioral Characteristics among Heavy Truck Drivers along Port Sudan-Khartoum Highways

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Open Journal of medical microbiology 2024年第1期14卷 11-22页

作者： Sara S. Osman Adam A. mattar Omnia m. hamid Faculty of Public Health Alzaiem Alazhari University Khartoum Sudan Faculty of medical Laboratory Sciences University of Medical Sciences & Technology Khartoum Sudan

The prevalence of human immunodeficiency virus (AIDS) and hepatitis B virus among heavy truck drivers and their assistants has been well documented globally in correlation with their behavioral characteristics. The present study aimed to screen for human immunodeficiency virus (HIV), hepatitis B virus (HBV), and behavioral characteristics among heavy truck drivers in Port Sudan. A cross-sectional study was conducted on 274 heavy truck drivers and their assistants who used the highway Port Sudan-Khartoum in Port Sudan city during 2019-2021. Data on behavioral characteristics and substance use habits were collected using a structured questionnaire, and an ELISA test was used to screen for HIV and HBV infections in the study participants. The chi-square test, odds ratio, and confidence intervals were used to find the association between behavioral characteristics and seropositive HIV/HBV. Of the 274 enrolled participants, the seroprevalence rates of HIV were 2.7% and HBV was 23.7%. Ninety-four (34.3%) of them had a history of high-risk sexual behavior outside of marriage;only two (0.7%) used condoms;14.2% of participants reported alcohol use;and 1.1% reported drug use. Univariate analysis revealed that having a sex history outside of marriage with ≥1 sex partner and never using a condom with a spouse or casual partner were significant risk factors for HIV and HBV among drivers. Fortunately, we found that most of the drivers reported low alcohol and drug use. Concerning this study, the seroprevalence of HIV and HBV is highly associated with a history of having sex outside of marriage and sexual behavior among truck drivers and assistances. Additional studies are needed to further investigate other STIs and behavioral characteristics associated with factors in truck drivers/assistance in different truck stop regions in Sudan.

关键词： Sexual Transmitted Infection Port Sudan Truck Drivers/Assistance

应变路径对AA1050铝板力学性能、成形极限曲线及织构演化影响的实验研究

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中南大学学报:英文版 2023年第8期30卷 2472-2484页

作者： A.ROUZBEH S.m.ATIFEH m.sedighi R.HASHEmI School of mechanical Engineering Iran University of Science&TechnologyNarmak ***Iran

实验研究了应变路径变化对AA1050铝合金力学性能、成形性能和成形极限的影响。讨论了以单向、反向和交叉轧制的三种不同方式的应变路径。对比了三种轧制方式在20%和40%轧制比下的晶粒尺寸、硬度、应力-应变曲线和成形极限。结果表明,交... 详细信息

实验研究了应变路径变化对AA1050铝合金力学性能、成形性能和成形极限的影响。讨论了以单向、反向和交叉轧制的三种不同方式的应变路径。对比了三种轧制方式在20%和40%轧制比下的晶粒尺寸、硬度、应力-应变曲线和成形极限。结果表明,交叉轧制试样的晶粒尺寸小于其他方式轧制试样的晶粒尺寸;单向和交叉轧制试样的强度和伸长率均高于反向轧制方式的,单向和交叉轧制试样的硬度等于或大于反向轧制试样的;此外,交叉轧制使试样的各向异性减小,R趋近于1。试样的成形极限在交叉轧制方式下明显提高,在40%轧制比下,交叉轧制的FLC_(0)为0.113,单向轧制的FLC_(0)为0.09,反向轧制的FLC_(0)为0.081。单向和反向轧制的成形极限与加载路径的相关。

关键词：应变路径成形性轧制方向织构演变铝合金板

Straightforward method for Nonlinear Oscillators

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Journal of Donghua University(English Edition) 2023年第1期40卷 105-109页

作者：吕国娟何吉欢何春辉 sedighi hamid m School of Science Xi’an University of Architecture and TechnologyXi’an 710055China School of mathematics and Information Science Henan Polytechnic UniversityJiaozuo 454003China National Engineering Laboratory for modern Silk College of Textile and ClothingEngineeringSoochow UniversitySuzhou 215021China School of Civil Engineering Xi’an University of Architecture and TechnologyXi’an 710055China Faculty of Engineering Shahid Chamran University of AhvazAhvaz61357-43337Iran

It is challenging to predict the frequency property of a nonlinear vibration system conveniently and ***,an invalid or physically irrelevant result might be obtained by some advanced ***,predicting the frequency lacks an expedient and efficient *** challenge is addressed by developing a straightforward and effective frequency formulation that reliably predicts the frequency-amplitude *** study provides a one-step approach which can fast determine the periodic properties of any conservative oscillators and also provides a reference for other similar studies.

关键词： He's frequency formulation Duffing oscillator nonlinear oscillator