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3D FEM simulations and experimental validation of plastic deformation of pure aluminum deformed by ECAP and combination of ECAP and direct extrusion

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Transactions of Nonferrous Metals Society of China 2017年第6期27卷 1338-1352页

作者： mohamed ibrahim Abd EL AAL Mechanical engineering Department College of Engineering Prince Sattam Bin Abdulaziz UniversityWadi Addawasir Kingdom of Saudi Arabia Mechanical Design & Production Department Faculty of Engineering Zagazig University Zagazig Egypt

Rigid-viscoplastic3D finite element simulations(3D FEM)of the equal channel angular pressing(ECAP),thecombination of ECAP+extrusion with different extrusion ratios,and direct extrusion of pure aluminum were performed ***3D FEM simulations were carried out to investigate the load-displacement behavior,the plastic deformationcharacteristics and the effective plastic strain homogeneity of Al-1080deformed by different forming *** simulationresults were validated by microstructure observations,microhardness distribution maps and the correlation between the effectiveplastic strain and the microhardness ***3D FEM simulations were performed successfully with a good agreement with theexperimental *** load-displacement curves and the peak load values of the3D FEM simulations and the experimentalresults were close from each *** microhardness distribution maps were in a good conformity with the effective plastic straincontours and verifying the3D FEM simulations *** ECAP workpiece has a higher degree of deformation homogeneity thanthe other deformation *** microhardness values were calculated based on the average effective plastic *** microhardness values fitted the experimental results *** microstructure observations in the longitudinal andtransverse directions support the3D FEM effective plastic strain and microhardness distributions result in different formingprocesses.

关键词： equal channel angular pressing (ECAP) extrusion finite element method (FEM) microhardness deformation homogeneity microstructure

Using Machine Learning Techniques to Compare Different Resampling Methods in Predicting Insurance Claims Occurrence

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Using Machine Learning Techniques to Compare Different Resam...

作者： mohamed Hanafy Kotb ibrahim 浙江工商大学

学位级别：硕士

Predicting the frequency of insurance claims has become a significant challenge due to the imbalanced datasets since the number of occurring claims is usually Significantly lower than the number of non-occurring *** a result,classification models tend to have a limited ability to predict the occurrence of ***,in this thesis,we’ll use various Resampling Methods to try to solve the imbalanced data problem in the insurance *** developed 84 machine learning models for predicting insurance claims occurrence（（under-sampling,over-sampling,the combination of over-and under-sampling（hybrid）,and SMOTE）×（logistic regression,K-nearest neighbors,na（?）ve bayes,three Decision tree models,three boosting models,two bagging models,SVM,4 neural network,and 5 deep neural network）= 84 models）,and we compared the models’ accuracies,sensitivities,and specificities to comprehend the prediction performance of the built *** dataset contains 81628 claims,each of which is a car insurance *** were5714 claims that occurred and 75914 claims that didn’t *** to the findings,the Ada Boost classifier with oversampling and the hybrid method had the most accurate predictions,with a sensitivity of 92.94%,a specificity of 99.82%,and an accuracy of 99.4%.And with a sensitivity of 92.48%,a specificity of 99.63%,and an accuracy of 99.1%,*** thesis confirmed that when analyzing imbalanced data,the Ada Boost classifier,whether using oversampling or the hybrid process,could generate more accurate models than other models that used in this *** in general,when we applied machine learning models on the different balanced data created by different resampling methods,we can notice that all ML classifiers’ results have improved,and all classes can be predicted,indicating that the classifiers’ performance is satisfactory.

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An Optimal Lempel Ziv Markov Based Microarray Image Compression Algorithm

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Computers, Materials & Continua 2021年第11期69卷 2245-2260页

作者： R.Sowmyalakshmi mohamed ibrahim Waly mohamed Yacin Sikkandar T.Jayasankar Sayed Sayeed Ahmad Rashmi Rani Suresh Chavhan Department of Electronics and Communication Engineering University College of EngineeringBIT CampusAnna UniversityTiruchirappalli620024India Department of Medical Equipment Technology College of Applied Medical SciencesMajmaah UniversityAl Majmaah11952Saudi Arabia Department of Computer Engineering College of Engineering and ComputingAl Ghurair UniversityDubai37374United Arab Emirates Automotive Research Center Vellore Institute of TechnologyVellore632014India Federal University of Piauí Teresina64049-550PIBrazil

In the recent years,microarray technology gained attention for concurrent monitoring of numerous microarray *** remains a major challenge to process,store and transmit such huge volumes of microarray ***,image compression techniques are used in the reduction of number of bits so that it can be stored and the images can be shared *** techniques have been proposed in the past with applications in different *** current research paper presents a novel image compression technique i.e.,optimized Linde–Buzo–Gray(OLBG)with Lempel Ziv Markov Algorithm(LZMA)coding technique called OLBG-LZMA for compressing microarray images without any loss of *** model is generally used in designing a local optimal codebook for image *** construction is treated as an optimizationissue and can be resolved with the help of Grey Wolf Optimization(GWO)*** the codebook is constructed by LBGGWO algorithm,LZMA is employed for the compression of index table and raise its compression efficiency *** were performed on high resolution Tissue Microarray(TMA)image dataset of 50 prostate tissue samples collected from prostate cancer *** compression performance of the proposed coding esd compared with recently proposed *** simulation results infer that OLBG-LZMA coding achieved a significant compression performance compared to other techniques.

关键词： Arithmetic coding dictionary based coding Lempel-Ziv Markov chain algorithm Lempel-Ziv-Welch coding tissue microarray

Resistant Tremors and Unexplained Weight Loss Could Also Be a Sign of HIV

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Neuroscience & Medicine 2015年第3期6卷 81-83页

作者： Mohammed hamdy ibrahim Shivram Kumar Janhavi Sirsat mohamed Khalid Kiran Kumar Department of Neurology GMC Hospital Ajman UAE Gulf Medical University Ajman UAE Department of Internal Medicine GMC Hospital Ajman UAE

This case study is done to show a different type of presentation of a HIV (Human Immunodeficiency Virus) patient. Neurological symptoms in HIV are normally due to Progressive Multifocal Leukoencephalopathy (PML) which is a reactivated infection caused by John Cunningham virus (JC virus). The disease causes fatal demyelination of the central nervous system (CNS). This case presented a 51-year-old Nigerian man who complained of resistant tremors and unexplained weight loss. The patient was suspected to have HIV when a MRI scan revealed T2/FLAIR hyper intensity of white matter which was a sign of PML. HIV ELISA was done and came back with a positive result. PML presenting in the form of tremors is very rare and more research is required to focus on the neurological presentation of HIV.

关键词： Human Immunodeficiency Virus Tremors Progressive Multifocal Leukoencephalopathy

Adiponectin as a therapeutic target for diabetic foot ulcer

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World Journal of Diabetes 2023年第6期14卷 758-782页

作者： Mona mohamed ibrahim Abdalla Jaiprakash Mohanraj Sushela Devi Somanath Department of Physiology Human Biology DivisionSchool of MedicineInternational Medical UniversityKuala Lumpur 57000Malaysia Department of Biochemistry Human Biology DivisionSchool of MedicineInternational Medical UniversityKuala Lumpur 57000Malaysia Department of Microbiology School of MedicineInternational Medical UniversityKuala Lumpur 57000Malaysia

The global burden of diabetic foot ulcers(DFUs)is a significant public health concern,affecting millions of people *** wounds cause considerable suffering and have a high economic ***,there is a need for effective strategies to prevent and treat *** promising therapeutic approach is the use of adiponectin,a hormone primarily produced and secreted by adipose *** has demonstrated anti-inflammatory and antiatherogenic properties,and researchers have suggested its potential therapeutic applications in the treatment of *** have indicated that adiponectin can inhibit the production of pro-inflammatory cytokines,increase the production of vascular endothelial growth factor,a key mediator of angiogenesis,and inhibit the activation of the intrinsic apoptotic ***,adiponectin has been found to possess antioxidant properties and impact glucose metabolism,the immune system,extracellular matrix remodeling,and nerve *** objective of this review is to summarize the current state of research on the potential role of adiponectin in the treatment of DFUs and to identify areas where further research is needed in order to fully understand the effects of adiponectin on DFUs and to establish its safety and efficacy as a treatment for DFUs in the clinical *** will provide a deeper understanding of the underlying mechanisms of DFUs that can aid in the development of new and more effective treatment strategies.

关键词： Diabetic foot ulcer Adiponectin Anti-inflammatory Adipose tissue Antioxidants Wound healing

Co-doped Ni_(3)S_(2) nanosheet array: A high-efficiency electrocatalyst for alkaline seawater oxidation

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Nano Research 2024年第3期17卷 1050-1055页

作者： Meng Yue Xun He Shengjun Sun Yuntong Sun mohamed S.hamdy Mhamed Benaissa Alsamani A.M.Salih Jun Liu Xuping Sun College of Chemistry Chemical Engineering and Materials ScienceShandong Normal UniversityJinan 250014China Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054China Department of Chemistry College of ScienceKing Khalid UniversityP.O.Box 9004Abha 61413Saudi Arabia Department of Chemical Engineering College of EngineeringUniversity of Ha’ilP.O.Box 2440Ha’il 81441Saudi Arabia Department of Otolaryngology-Head&Neck Surgery West China HospitalSichuan UniversityChengdu 610041China

Developing efficient and durable oxygen evolution reaction(OER)catalysts holds great promise for green hydrogen production via seawater electrolysis,but remains a ***,we report a Co-doped Ni_(3)S_(2) nanosheet array on Ni foam(Co-Ni_(3)S_(2)/NF)as a high-efficiency OER electrocatalyst for *** alkaline conditions,Co-Ni_(3)S_(2)/NF requires an overpotential of only 368 mV to drive 100 mA·cm^(–2),superior to Ni_(3)S_(2)/NF(385 mV).Besides,it exhibits at least 50-h continuous electrolysis.

关键词： Co doping Ni_(3)S_(2)nanosheet array oxygen evolution reaction seawater electrolysis electrocatalyst

Applicability and efficacy of a model for prevention of perinatal transmission of hepatitis B virus infection:Single center study in Egypt

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World Journal of Gastroenterology 2014年第45期20卷 17075-17083页

作者： Hanaa M El-Karaksy Lamiaa M Mohsen Doa'a A Saleh Mona S hamdy Noha A Yassin mohamed Farouk mohamed E Salit Mortada H El-Shabrawi Department of Pediatrics Kasr Al-Ainy School of Medicine Cairo University Department of Community Medicine Kasr AlAiny School of Medicine Cairo University Department of Clinical and Chemical Pathology Kasr Al-Ainy School of Medicine Cairo University Department of Obstetrics and Gynecology Kasr Al-Ainy School of Medicine Cairo University

AIM: To identify possible maternal risk factors for hepatitis B virus (HBV) acquisition and assess the efficacy of immunoprophylaxis given to infants born to hepatitis B virus surface antigen (HBsAg) positive mothers.

关键词： Egypt Hepatitis B virus Hepatitis B virus surface antigen positive mothers Immunoprophylaxis Perinatal transmission

Amination of biochar surface from watermelon peel for toxic chromium removal enhancement

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Chinese Journal of Chemical Engineering 2021年第8期34卷 199-222页

作者： mohamed A.El-Nemr ibrahim M.A.Ismail Nabil M.Abdelmonem Ahmed El Nemr Safaa Ragab Department of Chemical Engineering Faculty of EngineeringCairo UniversityGizaEgypt Renewable Energy Program Zewail City of Science and TechnologyEgypt Environmental Division National Institute of Oceanography and FisheriesKayet BeyEl-AnfoushyAlexandriaEgypt

Watermelon peel residues were used to produce a new biochar by dehydration *** new biochar has undergone two methods of chemical modification and the effect of this chemical modification on its ability to adsorb Cr(VI)ions from aqueous solution has been *** biochars,Melon-B,Melon-BO-NH_(2) and Melon-BO-TETA,were made from watermelon peel via dehydration with 50%sulfuric acid to give Melon-B followed by oxidation with ozone and amination using ammonium hydroxide to give Melon-BO-NH_(2) or Triethylenetetramine(TETA)to give *** prepared biochars were characterized by BET,BJH,SEM,FT-IR,TGA,DSC and EDAX *** highest removal percentage of Cr(VI)ions was 69%for Melon-B,98%for Melon-BO-NH_(2) and 99%for Melon-BO-TETA biochars of 100 mg·L^(−1) Cr(VI)ions initial concentration and 1.0 g·L^(−1) adsorbents *** unmodified biochar(Melon-B)and modified biochars(Melon-BO-NH_(2) and Melon-BO-TETA)had maximum adsorption capacities(Q_(m))of 72.46,123.46,and 333.33 mg·g^(−1),*** amination of biochar reduced the pore size of modified biochar,whereas the surface area was *** obtained data of isotherm models were tested using different error function *** Freundlich,Tempkin and Langmuir isotherm models were best fitted to the experimental data of Melon-B,Melon-BO-NH_(2) and Melon-BO-TETA,*** adsorption rate was primarily controlled by pseudo-second–order rate ***,the functional groups interactions are important for adsorption mechanisms and expected to control the adsorption *** adsorption for the Melon-B,Melon-BO-NH_(2) and Melon-BO-TETA could be explained for acid–base interaction and hydrogen bonding interaction.

关键词： Waste treatment Powder technology Citrullus lanatus Hexavalent chromium Biochar amination Adsorption

Geochemistry of island arc assemblage in the Eastern Desert of Egypt and the role of Pan-African magmatism in crustal growth of the Arabian–Nubian Shield:A review

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Acta Geochimica 2024年第3期43卷 588-622页

作者： Abdel-Aal MAbdel-Karim mohamed Mhamdy Adel A.Surour Geology Department Faculty of ScienceZagazig UniversityZagazig 44519Egypt Geology Department Faculty of ScienceTanta UniversityTanta 31527Egypt Department of Geological Sciences Faculty of ScienceNew Galala City 43511Egypt Geology Department Faculty of ScienceCairo UniversityGiza 12613Egypt

Neoproterozoic island arc assemblage of the Arabian–Nubian Shield(ANS)in the Eastern Desert(ED)of Egypt comprises juvenile suites of metavolcanics(MV),large amounts of meta-sedimentary rocks(MS),and voluminous metagabbros-diorites(MGD)and syn-tectonic intrusions of older granitoids(OG).We report here the updates of these four rock units in terms of classification,distribution,chemical characteristics,geodynamic evolution,metamorphism,and *** addition,we discuss these integrated data to elucidate a reasonable and reliable model for crustal evolution in the *** main features of these rock units indicate their relation to each other and the geodynamic environment dominated by early immature oceanic island arcs to primitive continental *** information of the island arc metavolcanic and plutonic rocks(gabbros,diorites,tonalites,and granodiorites)furnish evidence of the genetic *** include proximity and a coeval nature in the field;all protolith magmas are subalkaline in nature following calc-alkaline series with minor tholeiitic affinities;common geochemical signature of the arc rocks and subduction-related magmatism;their similar enrichment in LREEs;and similar major element compositions with mafic melts derived from metasomatized mantle *** volcano-sedimentary and the OG rocks underwent multiphase deformation events whereas the MGD complexes deformed *** on the magmatic,sedimentological,and metamorphic evolutions constrained by geochronological data as well as the progressive evolutionary trend from extensional to compressional regimes,a possible gradual decrease in the subducted slab dip angle is the most infl uential in any geodynamic model for arc assemblage in the ED of Egypt.

关键词： Island arc assemblage Magmatism Crustal growth Neoproterozoic Arabian–Nubian Shield Eastern Desert Egypt