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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

Influence of ECAP as grain refinement technique on microstructure evolution, mechanical properties and corrosion behavior of pure aluminum

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Transactions of Nonferrous Metals Society of China 2015年第12期25卷 3865-3876页

作者： mohamed ibrahim abd el aal M.M.SADAWY Mechanical Design and Production Department Faculty of Engineering Zagazig University Mining and Petroleum Engineering Department Al-Azhar University

Pure aluminum samples were processed by equal channel angular pressing（ECAP） up to 10 passes at room temperature. The effects of the ECAP number of passes on the microstructure evolution, the mechanical properties, deformation homogeneity and corrosion behavior of the processed samples were fully investigated. The imposed strain resulted in an obvious reduction in the grain size from 390 μm before ECAP down to 1.8, 0.4, and 0.3 μm after ECAP up to 2, 4 and 10 passes, respectively. The microhardness, deformation homogeneity and tensile strength were increased while the elongation decreased with the increase of ECAP number of passes. Immersion tests, open circuit potential, Tafel polarization, cyclic polarization and potentiostatic measurements in 3.5% Na Cl solution revealed an obvious improvement in the corrosion resistance of ECAP processed samples compared with the as-cast sample. The increase of the number of passes can be used successfully in producing ultra-fine grained（UFG） bulk pure aluminum sample with a high misorientation angle, reasonably high mechanical properties and corrosion resistance.

关键词： equal channel angular pressing(ECAP) microstructure mechanical properties corrosion resistance passive film pitting

Effect of different metal sulfate precursors on structural and catalytic performance of zirconia in dehydration of methanol to dimethyl ether

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燃料化学学报 2018年第1期46卷 67-74页

作者： abd el-Aziz A.Said mohamed abd el-aal Chemistry Department Faculty of ScienceAssiut University71516 AssiutEgypt

ZrO_2 was treated with 10% SO_4^(2-) from different metal sulfate precursors for methanol dehydration to dimethyl *** the samples exhibited tetragonal phase and no diffraction peaks corresponding to metal sulfates or metal oxides were *** FT-IR results revealed that there were different interactions between sulfate and ZrO_2,and this had a great effect on the surface area of the *** catalytic activity was measured over the catalysts in the temperature range of 100-300 ℃.The results revealed that sulfated zirconia with CuSO_4·5 H_2O and Al_2(SO_4)_3·16 H_2O showed the best catalytic *** maximum yield of DME ≈87% was obtained over CuSZ at a reaction temperature of 275 ℃.Moreover,the catalytic activity of the catalysts was correlated well with their surface acidity that measured by dehydration of isopropanol.

关键词： MSO 4/ZrO2 甲醇脱水 DME

Wireless Sensor Networks Routing Attacks Prevention with Blockchain and Deep Neural Network

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Computers, Materials & Continua 2022年第3期70卷 6127-6140页

作者： mohamed Ali ibrahim A.abd el-Moghith mohamed N.el-Derini Saad M.Darwish Higher Institute for Tourism Hotels and ComputerAl-SeyoufAlexandria21533Egypt Department of Information Technology Institute of Graduate Studies and ResearchAlexandria University21526Egypt Department of Computer and Systems Engineering Faculty of EngineeringAlexandria UniversityAlexandria21544Egypt

Routing is a key function inWireless Sensor Networks(WSNs)since it facilitates data transfer to base *** attacks have the potential to destroy and degrade the functionality ofWSNs.A trustworthy routing system is essential for routing security andWSN *** methods have been implemented to build trust between routing nodes,including the use of cryptographic methods and centralized ***,the majority of routing techniques are unworkable in reality due to the difficulty of properly identifying untrusted routing node *** the moment,there is no effective way to avoid malicious node *** a consequence of these concerns,this paper proposes a trusted routing technique that combines blockchain infrastructure,deep neural networks,and Markov Decision Processes(MDPs)to improve the security and efficiency of WSN *** authenticate the transmission process,the suggested methodology makes use of a Proof of Authority(PoA)mechanism inside the blockchain *** validation group required for proofing is chosen using a deep learning approach that prioritizes each node’s *** are then utilized to determine the suitable next-hop as a forwarding node capable of securely transmitting *** to testing data,our routing system outperforms current routing algorithms in a 50%malicious node routing scenario.

关键词： Wireless sensor networks trusted routing deep neural network blockchain markov decision

The vitreomacular interface in different types of agerelated macular degeneration

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International Journal of Ophthalmology(English edition) 2017年第2期10卷 246-253页

作者： mohamed abd elM onaem el-Hifnawy Hisham Ali ibrahim Amir Ramadan Gomaa mohamed A elmasry Ophthalmology Department Alexandria University Faculty of MedicineKhartoum SquareAzaritaAlexandria 21526Egypt

AIM： To evaluate the vitreomacular interface in cases with wet age-related macular degeneration（AMD） and to compare them to eyes with dry AMD and normal ***： This was a cross-sectional comparative study that included 87 eyes with wet AMD,42 eyes with dry AMD and 40 eyes without AMD as a control *** coherence tomography（OCT） examination was performed for all patients to assess the vitreomacular ***： In the wet AMD group,34.5% of cases had vitreomacular adhesion（VMA）.Only 14.3% of dry AMD cases and 10% of control cases had *** was a significant difference between the control group and the wet AMD group（P=0.004） as well as the dry and wet AMD group（P=0.017）.There was also a significant difference between the incidence of VMA in patients with subretinal choroidal neovascularization（CNV,type 1） and intraretinal CNV（type 2 or type 3）（P=0.020）.CONCLUSION： There is an association between posterior vitreous attachment and *** is also an increased incidence of VMA with intra-retinal CNV.

关键词： age-related macular degeneration vitreomacular interface optical coherence tomography macula

Determination of a novel ACE inhibitor in the presence of alkaline and oxidative degradation products using smart spectrophotometric and chemometric methods

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Journal of Pharmaceutical Analysis 2014年第2期4卷 132-143页

作者： Maha abdel-Monem Hegazy Maya Shaaban Eissa Osama ibrahim abd el-Sattar mohamed mohamed abd el-Kawy Analytical Chemistry Department Faculty of PharmacyCairo UniversityCairoEgypt Analytical Chemistry Department Faculty of PharmacyEgyptian Russian UniversityCairoEgypt National Organization of Drug Control and Research GizaEgypt

Simple, accurate, sensitive and validated UV spectrophotometric and chemometric methods were developed for the determination of imidapril hydrochloride （IMD） in the presence of both its alkaline （AKN） and oxidative （OXI） degradation products and in its pharmaceutical formulation. Method A is the fourth derivative spectra （D4） which allows the determination of IMD in the presence of both AKN and OXD, in pure form and in tablets by measuring the peak amplitude at 243.0 nm. Methods B, C and D, manipulating ratio spectra, were also developed. Method B is the double divisor-ratio difference spectrophotometric one （DD-RD） by computing the difference between the amplitudes of IMD ratio spectra at 232 and 256.3 nm. Method C is the double divisor-first derivative of ratio spectra method （DD-DR1） at 243.2 nm, while method D is the mean centering of ratio spectra （MCR） at 288.0 nm. Methods A, B, C and D could successfully determine IMD in a concentration range of 4.0-32.0 mg/mL. Methods E and F are principal component regression （PCR） and partial least-squares （PLS）, respectively, for the simultaneous determination of IMD in the presence of both AKN and OXI, in pure form and in its tablets. The developed methods have the advantage of simultaneous determination of the cited components without any pre-treatment. The accuracy, precision and linearity ranges of the developed methods were determined. The results obtained were statistically compared with those of a reported HPLC method, and there was no significant difference between the proposed methods and the reported method regarding both accuracy and precision.

关键词： Double divisor-ratio difference Double divisor-ratio derivative Mean centering of ratio spectra Chemometry Imidapril hydrochloride

Structural Development of Northwest Saudi Arabia Using Aeromagnetic and Seismological Data

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Journal of Earth Science 2016年第6期27卷 998-1007页

作者： mohamed Fnais elkhedr ibrahim Essam abd el-Motaal Kamal abdelrahman abdelmaguid Al-Heniedi Khaled Al-Kahtany Department of Geology and Geophysics King Saud University Riyadh 36002 KSA Department of Geology Faculty of Science Mansoura University Mansoura 21345 Egypt Department of Geology Faculty of Science Al-Azhar University Cairo 11435 Egypt Department of Seismology National Research Institute of Astronomy and Geophysics Cairo 11435 Egypt

High resolution aeromagnetic and seismological data constrained by field-based structural investigations have been used to map and delineate the structural elements that affected and shaped the Midyan area in the northwest part of Saudi Arabia. The area was divided into four major domains defined by NNE, NNW, NW and ENE trending faults identified by trends, patterns and intensity of magnetic anomalies. The ENE trending left-lateral strike-slip faults intersected by NNE trending faults are the predominant tectonic features in the Gulf of Aqaba coastal area and stop at the boundary of a central domain characterized by complexity in the pattern and intensity of magnetic anomalies, that may be attributed to heterogeneity of basement rocks containing complex igneous rock suites including diorite, gabbro, ultramafic and alkali granitic rocks. This domain is characterized by the presence of narrow linear magnetic anomalies that extend for kilometers in an NNW direction, indicating dikes intruded through NNW trending faults. These dikes become WNW-oriented near their northern termination by transfer of movement to WNW-oriented faults marking the northern termination of the Red Sea rift. It is believed that this fault zone is still experiencing neotectonic activity, as evident from recorded seismicity. The aeromagnetic structural resuits coincide with fault plane solutions for the largest earthquakes, confirming aeromagnetic interpreted trends and illustrating mixed mechanisms between extensional and strike-slip faulting. Thus the study area displays different mechanisms associated with different tectonic trends which show clearly in the structural patterns of the area.

关键词： aeromagnetism seismicity neotectonics Midyan area Saudi Arabia.

Power frequency AC voltage measurement based on double wound Rogowski coil

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High Voltage 2017年第2期2卷 129-135页

作者： mohamed E.ibrahim Amr M.abd-elhady High Voltage and Dielectric Materials Lab. Faculty of EngineeringMenoufia UniversityShebin El_Kom 32511Egypt

This study presents a technique for power frequency AC voltage *** proposed technique utilises a capacitor having a low capacitance in addition to a double wound Rogowski *** technique depends on capacitor current measurement using the double wound Rogowski *** voltage across the capacitor that connected in parallel with the system at which AC voltage is intended to be measured is *** proposed technique is experimentally evaluated by designing the measurement system and using a digital signal processing board for the reconstruction ***,the experimental results based on Rogowski coil measurements are compared with those obtained from reference ***,the obtained results validate the efficacy of the proposed technique in power frequency AC voltage measurement.

关键词： Rogowski double capacitance

Improved RC6 Block Cipher Based on Data Dependent Rotations

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Computers, Materials & Continua 2022年第1期70卷 1921-1934页

作者： Osama S.Faragallah ibrahim F.elashry Ahmed AlGhamdi Walid el-Shafai S.el-Rabaie Fathi E.abd el-Samie Hala S.el-sayed mohamed A.elaskily Department of Information Technology College of Computers and Information TechnologyTaif UniversityP.O.Box 11099Taif21944Saudi Arabia Department of electrical Communications Faculty of EngineeringKafrelsheikh UniversityKafrelsheikhEgypt Department of Computer Engineering College of Computers and Information TechnologyTaif UniversityP.O.Box 11099Taif21944Saudi Arabia Department of electronics and electrical Communications Faculty of Electronic EngineeringMenoufia UniversityMenouf32952Egypt Department of electrical Engineering Faculty of EngineeringMenoufia UniversityShebin El-Kom32511Egypt Department of Informatics Electronic Research Institute(ERI)CairoEgypt

This paper introduces an Improved RC6(IRC6)cipher for data encryption based on data-dependent *** proposed scheme is designed with the potential of meeting the needs of the Advanced Encryption Standard(AES).Four parameters are used to characterize the proposed *** parameters are the size of the word(w)in bits,the number of rounds(r),the length of the secret key(b)in bytes,and the size of the block(L)in *** main feature of IRC6 is the variable number of working registers instead of just four registers as in RC6,resulting in a variable block size for plaintext and *** IRC6 cipher is designed to improve the robustness against attacks by increasing the diffusion for each round and providing greater security with fewer *** effectiveness of the proposed IRC6 scheme is verified against theoretical *** proposed IRC6 scheme depends on full diffusion and confusion mechanisms regardless of the utilized block *** proposed IRC6 scheme saves 70%of the encryption time and 64%of the decryption time of *** simulation results prove that the IRC6 achieves a better encryption/decryption time compared to the ***,the proposed IRC6 is anticipated to fulfill the market needs and system security requirements.

关键词： Cryptography block cipher RC6,IRC6,AES