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Acta Metallurgica Sinica(English Letters) 2016年第9期29卷 869-883页

作者： saad b.aziz Mohammad W.Dewan Daniel J.Huggett Muhammad A.Wahab Ayman M.Okeil T.Warren Liao Department of Mechanical and Industrial Engineering Louisiana State University Department of Civil and Environmental Engineering Louisiana State University

Friction stir welding （FSW） is a solid-state joining process, where joint properties largely depend on the amount of heat generation during the welding process. The objective of this paper was to develop a numerical thermomechanical model for FSW of aluminum--copper alloy AA2219 and analyze heat generation during the welding process. The thermomechanical model has been developed utilizing ANSYS APDL. The model was verified by comparing simulated temperature profile of three different weld schedules （i.e., different combinations of weld parameters in real weld situations） from simulation with experimental results. Furthermore, the verified model was used to analyze the effect of different weld parameters on heat generation. Among all the weld parameters, the effect of rotational speed on heat generation is the highest.

关键词： Friction stir welding Frictional dissipation energy Temperature distribution Friction modeling Aluminum alloy

A Fully Coupled Thermomechanical Model of Friction Stir Welding(FSW) and Numerical Studies on Process Parameters of Lightweight Aluminum Alloy Joints

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Acta Metallurgica Sinica(English Letters) 2018年第1期31卷 1-18页

This paper presents a new thermomechanical model of friction stir welding which is capable of simulating the three major steps of friction stir welding （FSW） process, i.e., plunge, dwell, and travel stages. A rate-dependent Johnson- Cook constitutive model is chosen to capture elasto-plastic work deformations during FSW. Two different weld schedules （i.e., plunge rate, rotational speed, and weld speed） are validated by comparing simulated temperature profiles with experimental results. based on this model, the influences of various welding parameters on temperatures and energy generation during the welding process are investigated. Numerical results show that maximum temperature in FSW process increases with the decrease in plunge rate, and the frictional energy increases almost linearly with respect to time for different rotational speeds. Furthermore, low rotational speeds cause inadequate temperature distribution due to low frictional and plastic dissipation energy which eventually results in weld defects. When both the weld speed and rotational speed are increased, the contribution of plastic dissipation energy increases significantly and improved weld quality can be expected.

关键词： Aluminum alloy Friction stir welding Temperature distribution Plastic energy Frictional energy Rate-dependent model Friction modeling

Nanoarchitectured LiMn_2O_4/Graphene/ZnO Composites as Electrodes for Lithium Ion batteries

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Journal of Materials Science & Technology 2014年第5期30卷 427-433页

作者： saad aziz Jianqing Zhao Carrington Cain Ying Wang Department of Mechanical & Industrial Engineering Louisiana State University

LiMn2O4 nanoparticles are facilely synthesized using a sol-gel processing method. Graphene is added to LiMn2O4 electrode aiming at increasing specific capacity and improving rate capability. In order to further improve cycling stability of LiMn2O4/graphene electrode, atomic layer deposition （ALD） is used to deposit ultrathin ZnO coating composed of six ZnO ALD layers and modify the surface of either LiMn2O4/graphene electrode or individual LiMn2O4 particles to form nanoarchitectured LiMn2O4/graphene/ZnO electrodes. both ZnO-ALD-modified LiMn2O4/graphene electrodes demonstrate enhanced cycling performance at 1C, retaining the final discharge capacity above 122 mA h g 1 after 100 electrochemical cycles, which is higher than 115 mA h g-1 of pristine LiMn2O4/graphene electrode and 109 mA h g-1 of bare LiMn2O4 electrode. The improved electrochemical performance of nanoarchitectured LiMn2O4/graphene/ZnO electrodes can be attributed to the cooperative effects from high electronic conductivity of graphene sheets to facilitate electron transportation and effective protection of ZnO ALD coating to restrict Mn dissolution and electrolyte decomposition.

关键词： LiMn2O4/graphene nanocomposite Atomic layer deposition Cathode material Lithium ion battery

On Special Curves According to Darboux Frame in the Three Dimensional Lorentz Space

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Computers, Materials & Continua 2018年第3期54卷 229-249页

作者： H.S.Abdel-aziz M.Khalifa saad Math.Dept. Faculty of ScienceSohag University82524 SohagEgypt. Math.Dept. Faculty of ScienceIslamic University of Madinah170 El MadinahKSA

In the light of great importance of curves and their frames in many differentbranches of science, especially differential geometry as well as geometric properties andthe uses in various fields, we are interested here to study a special kind of curves calledSmarandache curves in Lorentz 3-space. Then, we present some characterizations for thesecurves and calculate their Darboux invariants. Moreover, we classify TP, TU, PU andTPU-Smarandache curves of a spacelike curve according to the causal character of thevector, curve and surface used in the study. besides, we give some of differential geometricproperties and important relations between that curves. Finally, to demonstrate ourtheoretical results a computational example is given with graph.

关键词： Smarandache curves spacelike curve timelike surface Darboux frame

Artificial Fish Swarm for Multi Protein Sequences Alignment in bioinformatics

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Computers, Materials & Continua 2022年第9期72卷 6091-6106页

作者： Medhat A.Tawfeek saad Alanazi A.A.Abd El-aziz Department of Computer Science College of Computer and Information SciencesJouf UniversitySaudi Arabia(KSA Department of Computer Science Faculty of Computers and InformationMenoufia UniversityEgypt Department of Information Systems College of Computer and Information SciencesJouf UniversitySaudi Arabia(KSA) Department of Information Systems and Technology Faculty of Graduates Studies and ResearchCairo UniversityEgypt

The alignment operation between many protein sequences or DNAsequences related to the scientific bioinformatics application is very *** is a trade-off in the objectives in the existing techniques of MultipleSequence Alignment (MSA). The techniques that concern with speed ignoreaccuracy, whereas techniques that concern with accuracy ignore speed. Theterm alignment means to get the similarity in different sequences with highaccuracy. The more growing number of sequences leads to a very complexand complicated problem. because of the emergence;rapid development;anddependence on gene sequencing, sequence alignment has become importantin every biological relationship analysis process. Calculating the numberof similar amino acids is the primary method for proving that there is arelationship between two sequences. The time is a main issue in any alignmenttechnique. In this paper, a more effective MSA method for handling themassive multiple protein sequences alignment maintaining the highest accuracy with less time consumption is proposed. The proposed method dependson Artificial Fish Swarm (AFS) algorithm that can break down the mostchallenges of MSA problems. The AFS is exploited to obtain high accuracyin adequate time. ASF has been increasing popularly in various applicationssuch as artificial intelligence, computer vision, machine learning, and dataintensive application. It basically mimics the behavior of fish trying to getthe food in nature. The proposed mechanisms of AFS that is like preying,swarming, following, moving, and leaping help in increasing the accuracy andconcerning the speed by decreasing execution time. The sense organs that aidthe artificial fishes to collect information and vision from the environmenthelp in concerning the accuracy. These features of the proposed AFS make thealignment operation more efficient and are suitable especially for large-scaledata. The implementation and experimental results put the proposed AFS as afirst choice in th

关键词： Multiple sequence alignment swarm intelligence artificial fish swarm protein sequences

Some Geometric Invariants of Pseudo-Spherical Evolutes in the Hyperbolic 3-Space

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Computers, Materials & Continua 2018年第12期57卷 389-415页

作者： H.S.Abdel-aziz M.Khalifa saad A.A.Abdel-Salam Mathematics Department Faculty of ScienceSohag University82524SohagEgypt Mathematics Department Faculty of ScienceIslamic University of Madinah170 El-MadinahKSA

In this paper,we study the pseudo-spherical evolutes of curves in three dimensional hyperbolic *** use techniques from singularity theory to investigate the singularities of pseudo-spherical evolutes and establish some relationships between singularities of these curves and geometric invariants of curves under the action of the Lorentz ***,we defray with illustration some computational examples in support our main results.

关键词： Pseudo-spherical evolutes evolute curves hyperbolic 3-space

Modern improvement techniques of direct torque control for induction motor drives - a review

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Protection and Control of Modern Power Systems 2019年第1期4卷 138-149页

作者： Najib El Ouanjli aziz Derouich Abdelaziz El Ghzizal saad Motahhir Ali Chebabhi Youness El Mourabit Mohammed Taoussi Laboratory of Production Engineering Energy and Sustainable DevelopmentHigher School of TechnologySidi Mohamed Ben Abdellah UniversityFezMorocco Faculty of Sciences and Technology University of Bordj Bou ArreridjBordj Bou ArreridjAlgeria Laboratory of Systems Integration and Advanced Technologies Faculty of Sciences Dhar El MahrazSidi Mohamed Ben Abdellah UniversityFezMorocco

Conventional direct torque control (DTC) is one of the excellent control strategies available to control the torque of the induction machine (IM). However, the low switching frequency of the DTC causes high ripples in the flux and torque that leads to an acoustic noise which degrades the control performances, especially at low speeds. Many direct torque control techniques were appeared to remedy these problems by focusing specifically on the torque and flux. In this paper, a state of the art review of various modern techniques for improving the performance of DTC control is presented. The objective is to make a critical analysis of these methods in terms of ripples reduction, tracking speed, switching loss, algorithm complexity and parameter sensitivity. Further, it is envisaged that the information presented in this review paper will be a valuable gathering of information for academic and industrial researchers.

关键词： Induction machine Direct torque Control(DTC) Fuzzy logic(FL) Neural network(NN) Sliding mode(SG) Genetic algorithm(GA)

Analytical and finite-element study of optimal strain distribution in various beam shapes for energy harvesting applications

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Acta Mechanica Sinica 2016年第4期32卷 670-683页

作者： b.L.Ooi J.M.Gilbert A.Rashid A.aziz Faculty of Integrative Sciences and Technology Quest International University Perak (QIUP) Faculty of Science and Engineering School of EngineeringUniversity of Hull Center for Automotive Research and Electric Mobility(CAREM) Universiti Teknologi PETRONAS (UTP)

Owing to the increasing demand for harvesting energy from environmental vibration for use in self-powered electronic applications, cantilever-based vibration energy harvesting has attracted considerable interest from various parties and has become one of the most common approaches to converting redundant mechanical energy into electrical energy. As the output voltage produced from a piezoelectric material depends largely on the geometric shape and the size of the beam, there is a need to model and compare the performance of cantilever beams of differing *** paper presents the study of strain distribution in various shapes of cantilever beams, including a convex and concave edge profile elliptical beam that have not yet been discussed in any prior literature. both analytical and finite-element models are derived and the resultant strain distributions in the beam are computed based on a MATLAb solver and ANSYS finite-element analysis tools. An optimum geometry for a vibration-based energy harvesting system is ***, experimental results comparing the power density for triangular and rectangular piezoelectric beams are also presented to validate the findings of the study, and the claim, as suggested in the literature, is verified.

关键词： harvesting triangular elliptical verified normalized piezoelectric cantilever redundant validate rectangular

Incidence, mortality, and risk factors of immunotherapy-associated hepatotoxicity: A nationwide hospitalization analysis

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Liver Research 2021年第1期5卷 28-32页

作者： Simcha Weissman saad Saleem Sachit Sharma Menashe Krupka Faisal Inayat Muhammad aziz James H.Tabibian Department of Medicine Hackensack Meridian Health Palisades Medical CenterNorth BergenNJUSA Department of Medicine Sunrise Hospital and Medical CenterLas VegasNVUSA Department of Medicine University of Toledo Medical CenterToledoOHUSA Department of Medicine Westchester Medical CenterValhallaNYUSA Department of Medicine Allama Iqbal Medical CollegeLahorePakistan Division of Gastroenterology and Hepatology University of Toledo Medical CenterToledoOHUSA Division of Gastroenterology Department of MedicineOlive View-UCLA Medical CenterSylmarCAUSA David Geffen School of Medicine at UCLA Los AngelesCAUSA

background and aims Anti-neoplastic immunotherapy has revolutionized cancer management;however,its safety profile with respect to liver-related injury remains largely ***,we analyzed a United States national database to determine the incidence,mortality,and predictors of hepatotoxicity in the setting of anti-neoplastic *** This was a nationwide retrospective study of hospital encounters from 2011 to 2014 using the National Inpatient Sample(NIS)*** utilized the International Classification of Diseases,Ninth Revision(ICD-9)coding system to identify all adult patients who underwent anti-neoplastic immunotherapy during *** primary outcome was the incidence of hepatotoxicity during the same *** outcomes included in-hospital mortality as well as socioeconomic and ethno-racial predictors of *** were performed using IbM SPSS Statistics *** The sample included 3002 patients who underwent inpatient anti-neoplastic *** incidence of hepatotoxicity was 10.1%,which was significantly higher as compared to a matched inpatient population(adjusted odds ratio(aOR)4.93,95%confidence interval(CI):3.80–6.40,P=0.001).No significant mortality difference was seen in those that developed hepatotoxicity compared to those who did not(aOR 0.47,95%CI:0.03–8.03,P=0.612).Age under 60(aOR 1.56,95%CI:1.23–1.78,P=0.050)and white race(aOR 1.85,95%CI:1.35–2.04,Pbase analysis,we found that anti-neoplastic immunotherapy was associated with a nearly five-fold risk of in-hospital hepatotoxicity as compared to a matched inpatient population,though without an associated mortality ***,younger age and white race were identified as predictors of immunotherapy-associated *** vigilance and prospective investigation of the

关键词： Hepatotoxicity Tumor immunotherapy Liver enzymes Outcomes Risk factors Mortality

Structure and Thermal Parameters of Ni_(20)Pd_(80) Alloy

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Journal of Materials Science & Technology 2009年第2期25卷 208-210页

作者： S. Ahmad A.b. Ziya A. aziz Z.I. Zafar Department of Physics Bahauddin Zakariya University Department of Chemistry Bahauddin Zakariya University

The structure and thermal parameters of Ni20Pd80 alloy were studied by X-ray diffraction（XRD）. The diffraction experiments performed in the temperature range of 308-1100 K revealed that the alloy formed a face centered cubic （fcc） Al-type structure. The temperature dependence of the lattice parameters was investigated by using the bragg line displacement method showing that the lattice parameter increases with the increase of temperature. The mean linear thermal expansion （MLTE（%））, coefficient of thermal expansion （CTE, α）, the characteristic Debye temperature （（θD） and mean square amplitudes of vibration were determined from XRD data. The value of Debye temperature was found to be 253 K. It was found that temperature factor was independent of the static displacements.

关键词： Alloys Structure Thermal parameters X-ray diffraction (XRD)