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Effect of Notch Location on Fatigue Life Prediction of Strength Mismatched HSLA Steel Weldments

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Journal of Materials Science & Technology 2004年第2期20卷 129-135页

作者： S.Ravi V.Balasubramanian S.Nemat nasser Department of Manufacturing Engineering Annamalai University Annamalainagar-608 002. Tamil Nadu IndiaDepartment of Manufacturing Engineering Annamalai University Annamalainagar-608 002. Tamil Nadu IndiaCentre of Excellence for Advanced Materials University of California at San Diego La Jolla CA 92093-0416 USA

Welding of high strength low alloy steels (HSLA) involves usage of low, even and high strength filler materials (electrodes) than the parent material depending on the application of the welded structures and the availability of the filler material. In the present investigation, the fatigue crack growth behaviour of weld metal (WM) and heat affected zone (HAZ) regions of under matched (UM), equal matched (EM) and over matched (OM) joints has been studied. The base material used in this investigation is HSLA-80 steel of weldable grade. Shielded metal arc welding (SMAW) process has been used to fabricate the butt joints. Centre cracked tension (CCT) specimen has been used to evaluate the fatigue crack growth behaviour of the welded joints. Fatigue crack growth experiments have been conducted using servo hydraulic controlled fatigue testing machine at constant amplitude loading (R=0).A method has been proposed to predict the fatigue life of HSLA steel welds using fracture mechanics approach by incorporating influences of mismatch ratio (MMR) and notch location.

关键词： Shielded metal arc welding High strength low alloy steel Mismatch ratio Notch location Fatigue crack growth Fatigue life

Characterization of low-purity clays for geopolymer binder formulation

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International Journal of Minerals,Metallurgy and Materials 2014年第6期21卷 609-619页

作者： nasser Y.Mostafa Q.Mohsen A.El-maghraby Materials and Corrosion Lab (MCL) Department of Chemistry Faculty of Science Taif University Department of Chemistry Faculty of Science Suez Canal University Refractory & Ceramics Department National Research CenterDokki 12622 Cairo Egypt

The production of geopolymer binders from low-purity clays was investigated. Three low-purity clays were calcined at 750℃ for 4 h. The calcined clays were chemically activated by the alkaline solutions of NaOH and Na2SiO3. The compressive strength was measured as a function of curing time at room temperature and 85℃. The results were compared with those of a pure kaolin sample. An amorphous aluminosilicate polymer was formed in all binders at both processing temperatures. The results show that, the mechanical properties depend on the type and amount of active aluminum silicates in the starting clay material, the impurities, and the processing temperature.

关键词： geopolymers microstructure X-ray diffraction compressive strength clay

Non-alcoholic steatohepatitis or metabolic-associated fatty liver:time to change

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Hepatobiliary Surgery and Nutrition 2021年第1期10卷 123-125页

作者： Gamal Shiha nasser Mousa Egyptian Liver Research Institute and Hospital(ELRIAH) MansouraEgypt Hepatology and Gastroenterology Unit Internal Medicine Department Tropical Medicine Department Faculty of MedicineMansoura UniversityMansouraEgypt

Non-alcoholic fatty liver disease(NAFLD)is a range of liver disease characterized by the occurrence of steatosis in greater than 5%of hepatocytes of people who drink tiny or no *** comprises,a benign non-alcoholic fatty liver(NAFL),and the more serious non-alcoholic steatohepatitis(NASH)described by steatosis,hepatocellular ballooning,lobular inflammation and lastly cirrhosis(1).

关键词： balloon NAFLD liver

Visual inspection of aircraft skin:Automated pixel-level defect detection by instance segmentation

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Chinese Journal of Aeronautics 2022年第10期35卷 254-264页

作者： Meng DING Boer WU Juan XU Abdul nasser KASULE Hongfu ZUO College of Civil Aviation Nanjing University of Aeronautics and AstronauticsNanjing 210016China Key Laboratory of Civil Aircraft Health Monitoring and Intelligent Maintenance of CAAC Nanjing 210016China

Skin defect inspection is one of the most significant tasks in the conventional process of aircraft *** paper proposes a vision-based method of pixel-level defect detection,which is based on the Mask Scoring ***,an attention mechanism and a feature fusion module are introduced,to improve feature ***,a new classifier head—consisting of four convolutional layers and a fully connected layer—is proposed,to reduce the influence of information around the area of the ***,to evaluate the proposed method,a dataset of aircraft skin defects was constructed,containing 276 images with a resolution of 960×720 *** results show that the proposed classifier head improves the detection and segmentation accuracy,for aircraft skin defect inspection,more effectively than the attention mechanism and feature fusion *** with the Mask R-CNN and Mask Scoring R-CNN,the proposed method increased the segmentation precision by approximately 21%and 19.59%,*** results demonstrate that the proposed method performs favorably against the other two methods of pixellevel aircraft skin defect detection.

关键词： Aircraft skin Automatic non-destructive testing Defect inspection Instance segmentation Machine vision

Oncogenic BRAF^(V600E) induces microglial proliferation through extracellular signal-regulated kinase and neuronal death through c-Jun N-terminal kinase

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Neural Regeneration Research 2023年第7期18卷 1613-1622页

作者： Qing Ye Pranay Srivastava nasser Al-Kuwari Xiqun Chen Department of Neurology Massachusetts General HospitalHarvard Medical SchoolCharlestownMAUSA Department of Neurology Longhua HospitalShanghai University of Traditional Chinese MedicineShanghaiChina Aligning Science Across Parkinson’s(ASAP)Collaborative Research Network Chevy ChaseMDUSA

Activating V600E in v-Raf murine sarcoma viral oncogene homolog B(BRAF)is a common driver mutation in cancers of multiple tissue origins,including melanoma and ***^(V600E) has also been implicated in *** present study aims to characterize BRAF^(V600E) during cell death and proliferation of three major cell types of the central nervous system:neurons,astrocytes,and *** primary cultures(primary cortical mixed culture)and cell lines of glial cells(BV2)and neurons(SH-SY5Y)were ***^(V600E) and BRAF^(WT) expression was mediated by lentivirus or *** of downstream effectors(extracellular signal-regulated kinase 1/2 and JNK1/2)were achieved by *** astrocytes and microglia,BRAF^(V600E) induces cell proliferation,and the proliferative effect in microglia is mediated by activated extracellular signal-regulated kinase,but not c-Jun N-terminal *** medium from BRAF^(V600E)-expressing microglia induced neuronal *** neuronal cells,BRAF^(V600E) directly induces neuronal death,through c-Jun N-terminal kinase but not extracellular signal-regulated *** further show that BRAF-related genes are enriched in pathways in patients with Parkinson’s *** study identifies distinct consequences mediated by distinct downstream effectors in dividing glial cells and in neurons following the same BRAF mutational activation and a causal link between BRAF-activated microglia and neuronal cell death that does not require physical *** provides insight into a possibly important role of BRAF in neurodegeneration as a result of either dysregulated BRAF in neurons or its impact on glial cells.

关键词： astrocytes cell death cell proliferation inflammation microglia mutation neurons v-Raf murine sarcoma viral oncogene homolog B(BRAF)

A direct power control of a DFIG based-WECS during symmetrical voltage dips

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Protection and Control of Modern Power Systems 2020年第1期5卷 36-47页

作者： Sara Mensou Ahmed Essadki Tamou nasser Badr Bououlid Idrissi Research Center of Engineering and Health Sciences and Technologies from ENSET Mohammed V UniversityRabatMorocco Research Center of Engineering and Health Sciences and Technologies from ENSIAS Mohammed V UniversityRabatMorocco Electromechanical Engineering Department of ENSAM Moulay Ismaïl UniversityMeknèsMorocco.

The Wind Energy Conversion System(WECS)based Doubly Fed Induction Generator(DFIG)has experienced a rapid development in the world,which leads to an increasing insertion of this source of energy in the electrical *** sudden and temporary drop of voltage at the network can affect the operation of the DFIG;the voltage dips produce high peak currents on the stator and rotor circuits,without protection,the rotor side converter(RSC)will suffer also from over-current limit,consequently,the RSC may even be destroyed and the generator be *** this paper a new Direct Power Control(DPC)method was developed,in order to control the stator powers and help the operation of the aero-generator during the faults grid;by injecting the reactive power into the network to contribute to the return of voltage,and set the active power to the optimum value to suppress the high peak *** DPC method was designed using the nonlinear Backstepping(BS)controller associated with the Lyapunov function to ensure the stability and robustness of the system.A comparison study was undertaken to verify the robustness and effectiveness of the DPC-BS to that of the classical vector control(VC)using Proportional-Integral(PI)*** were simulated under the Simulink®software.

关键词： Wind energy Doubly-fed induction aero-generator Voltage dips DPC strategy Backstepping technique Lyapunov function

Generation of sodium hypochlorite (NaOCl) from sodium chloride solution using C/PbO_2 and Pb/PbO_2 electrodes

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International Journal of Minerals,Metallurgy and Materials 2012年第6期19卷 561-566页

作者： nasser Abu Ghalwa Hassan Tamos Mohamed ElAskalni Abed Rhman El Agha Chemistry Department Al-Azhar University of GazaP.O.Box 1277Palestine

Two modified electrodes （Pb/PbO2 and C/PbO2） were prepared by electrodepositing a lead oxide layer on lead and carbon sub- strates. These modified electrodes were used as anodes for the generation of sodium hypochlorite （NaOC1） from sodium chloride solution. Different operating conditions and factors affecting the treatment process of NaOC1 generation, including current density, pH values, con- ductive electrolytes, and electrolysis time, were studied and optimized. By comparison the C/PbO2 electrode shows a higher efficiency than the Pb/PbO2 electrode for the generation of NaOC1.

关键词： sodium hypochlorite sodium chloride lead oxide electrodeposition electrodes

Regularized machine learning through constraint swarm and evolutionary computation applied to regression problems

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International Journal of Intelligent Computing and Cybernetics 2014年第4期7卷 346-381页

作者： Ahmad Mozaffari nasser Lashgarian Azad Alireza Fathi Systems Design Engineering Department University of WaterlooWaterlooCanada Department of Mechanical Engineering University of TechnologyBabolIran

Purpose–The purpose of this paper is to demonstrate the applicability of swarm and evolutionary techniques for regularized machine ***,by defining a proper penalty function,regularization laws are embedded into the structure of common least square solutions to increase the numerical stability,sparsity,accuracy and robustness of regression *** regularization techniques have been proposed so far which have their own advantages and *** efforts have been made to find fast and accurate deterministic solvers to handle those regularization ***,the proposed numerical and deterministic approaches need certain knowledge of mathematical programming,and also do not guarantee the global optimality of the obtained *** this research,the authors propose the use of constraint swarm and evolutionary techniques to cope with demanding requirements of regularized extreme learning machine(ELM).Design/methodology/approach–To implement the required tools for comparative numerical study,three steps are *** considered algorithms contain both classical and swarm and evolutionary *** the classical regularization techniques,Lasso regularization,Tikhonov regularization,cascade Lasso-Tikhonov regularization,and elastic net are *** swarm and evolutionary-based regularization,an efficient constraint handling technique known as self-adaptive penalty function constraint handling is considered,and its algorithmic structure is modified so that it can efficiently perform the regularized *** well-known metaheuristics are considered to check the generalization capability of the proposed *** test the efficacy of the proposed constraint evolutionary-based regularization technique,a wide range of regression problems are ***,the proposed framework is applied to a real-life identification problem,*** the dominant factors affecting the hydrocarbon emissions of an automotive eng

关键词： Evolutionary computation Function approximation Hybrid systems

Effect of the degree of template removal from mesoporous silicate materials on their adsorption of heavy oil from aqueous solution

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Frontiers of Chemical Science and Engineering 2014年第4期8卷 488-497页

作者： Farouq TWAIQ M.S. nasser Sagheer A. ONAIZI Faculty of Engineering Computing and Science Swinbume University of Technology Kuching 93350 Malaysia Gas Processing Center College of Engineering Qatar University Doha P. O. Box 2713 Qatar School of Chemical Engineering and Advanced Materials Newcastle University Singapore 599489 Singapore School of Chemical Engineering and Advanced Materials Newcastle University Newcastle upon Tyne NE1 7RU UK

The key aim of this study is to evaluate the adsorption of heavy oil from aqueous solutions with different oil contents over mesoporous silicate materials having different surfactant template contents. The meso- porous silicate materials have been synthesized from tetraethylorthosilicate as a silica precursor and cetyltri- methylammonium bromide as a template using the sol-gel technique. Four samples were prepared by （1） totally removing the template using the calcination process, （2） partially removing the template via ethanol extraction, （3） partially removing the template via water extraction, and （4） keeping the template as synthesized, respectively. These four samples have been characterized using X-ray diffraction, nitrogen adsorption, thermal gravimetric ana- lysis and Fourier transformed infrared. The effect of the degree of template removal of these mesoporous materials for the oil removal has been investigated. The oil removal is inversely proportional to the surfactant content in the mesoporous material, being highest for the calcined sample but lowest for the as-synthesized sample. The kinetic of oil adsorption over the calcined material has been also studied and the data obtained fit well a second-order model.

关键词： adsorption heavy oil mesoporous silicatematerial kinetics template removal