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Investigation on electron Beam Welded Copper to AISI 316 Stainless Steel Joints

厦门大学学报（自然科学版） 2002年第S1期41卷 90-91页

作者： el-hebeary m.r.megahed h elziady N Faculty of Engineering Cairo UniversityFaculty of Engineering Cairo UniversityFaculty of Engineering Cairo University Giza EgyptGiza EgyptGiza Egypt

Joints of copper and stainless steels are used in a er ospace applications. Production of these joints by fusion welding faces many dif ficulties. This may be due to the differences in their physical, metallurgical a nd mechanical properties. electron Beam Welding (EBW) process has been found to be especially well suited in this area. Selection of the appropriate welding par ameters needs thorough investigations. These parameters include: preheat tempera ture (℃), welding current (I w), focusing current (I F), welding spee d (V), height between the gun and workpiece surface (h), scan width (S w) and shift distance (S). The present work aims firstly, setting the pr oper welding conditions to get sound joint between commercially pure copper (C10 200) and AISI 316 stainless steel plates 8 mm thickness. Secondly, investigate t he effect of electron Beam (EB) shift, single-sided and double-sided welds on the mechanical, metallurgical and chemical properties of the weld bead. Due to t he high difference in thermal conductivity between copper and stainless steel, E lectron Beam (EB) was shifted towards copper with different values. These values were ranged from 0.3 to 0.9 mm in welding without preheating of copper plate an d from 0.1 to 0.4 mm with preheating. Number of joints were welded using variabl e EBW parameters in view to obtain the sound weld bead. These parameters are as follows: gradual reduction I w=51 to 49 mA, I F=845 mA, V=8 mm/sec , h=130 mm, S w=500 μm and S=0.4 mm. The investigation has shown t hat, the copper (C10200) plate must be preheated to get sound welded joint with AISI 316 stainless steel using the EBW process. The tensile fracture in all wel ded samples occurred in copper plate away from the weld bead. This reflects that the weld bead tensile strength is greater than the copper strength. The EB shif t has slight effect on hardness distribution through weld bead. The hardness val ue (h v) reduces in gradual manner from stainless steel hardness to

关键词： AISI Investigation on electron Beam Welded Copper to AISI 316 Stainless Steel Joints

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Complement-dependent neuroinflammation in spinal cord injury:from pathology to therapeutic implications

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Neural regeneration research 2025年第5期20卷 1324-1335页

作者： hassan Saad Bachar el Baba Ali Tfaily Firas Kobeissy Juanmarco Gutierrez Gonzalez Daniel refai Gerald r.rodts Christian mustroph David Gimbel Jonathan Grossberg Daniel L.Barrow matthew F.Gary Ali m.Alawieh Department of Neurosurgery Emory University School of MedicineAtlantaGAUSA Department of Neurology Yale UniversityNew HavenCTUSA Center for Neurotrauma Multiomics&Biomarkers(CNMB)Morehouse School of MedicineAtlantaGAUSA

Spinal cord injury remains a major cause of disability in young adults,and beyond acute decompression and rehabilitation,there are no pharmacological treatments to limit the progression of injury and optimize recovery in this *** the thorough investigation of the complement system in triggering and propagating cerebral neuroinflammation,a similar role for complement in spinal neuroinflammation is a focus of ongoing *** this work,we survey the current literature investigating the role of complement in spinal cord injury including the sources of complement proteins,triggers of complement activation,and role of effector functions in the *** study relevant data demonstrating the different triggers of complement activation after spinal cord injury including direct binding to cellular debris,and or activation via antibody binding to damage-associated molecular *** effector functions of complement have been implicated in spinal cord injury,and we critically evaluate recent studies on the dual role of complement anaphylatoxins in spinal cord injury while emphasizing the lack of pathophysiological understanding of the role of opsonins in spinal cord *** this pathophysiological review,we systematically review the different translational approaches used in preclinical models of spinal cord injury and discuss the challenges for future translation into human *** review emphasizes the need for future studies to dissect the roles of different complement pathways in the pathology of spinal cord injury,to evaluate the phases of involvement of opsonins and anaphylatoxins,and to study the role of complement in white matter degeneration and regeneration using translational strategies to supplement genetic models.

关键词： complement neuroinflammation neuroplasticity regeneration spinal cord injury targeted therapy

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Tribological Characterization of hybrid metal matrix Composites Processed by Powder metallurgy

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Acta metallurgica Sinica(English Letters) 2017年第8期30卷 781-790页

作者： m. megahed m. A. Attia m. Abdelhameed A. G. el-Shafei Department of mechanical Design and Production Engineering Faculty of EngineeringZagazig UniversityP.O.Box 44519ZagazigEgypt

Aluminum （Al）-based aluminum oxide （Al2O3） and silicon carbide （SIC） particles hybrid metal matrix com- posites were processed by powder metallurgy technique, followed by sintering at 500 ℃ and then hot extrusion. The tribological properties of these composites with different weight fractions of Al2O3 and SiC were investigated; extrusion process significantly reduces the extent of porosity after cold compaction and sintering processes. hybridization of the two reinforcements improved hardness and wear resistance of the composites. With an increase in SiC content, hardness was increased and consequently the wear resistance was enhanced also. Scanning electron microscopy observations show a better interfacial bond between matrix and reinforcements and a better distribution of the reinforcements.

关键词： hybrid metal matrix composite Powder metallurgy Abrasive wear hardness Porosity

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Advanced Functional electromagnetic Shielding materials:A review Based on micro‑Nano Structure Interface Control of Biomass Cell Walls

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Nano-micro Letters 2025年第1期17卷 98-134页

作者： Yang Shi mingjun Wu Shengbo Ge Jianzhang Li Anoud Saud Alshammari Jing Luo mohammed A.Amin hua Qiu Jinxuan Jiang Yazeed m.Asiri runzhou huang hua hou Zeinhom m.el‑Bahy Zhanhu Guo Chong Jia Kaimeng Xu Xiangmeng Chen Co‑Innovation Center of Efficient Processing and Utilization of Forest resources College of Materials Science and EngineeringNanjing Forestry UniversityNanjing 210037People’s Republic of China State Key Laboratory of Efficient Production of Forest resourced Beijing Forestry UniversityQinghua East Road 35Haidian DistrictBeijing 100083People’s Republic of China Department of Physics Faculty of Sciences‑ArarNorthern Border UniversityArar 91431Saudi Arabia Department of Chemistry College of ScienceTaif UniversityP.O.Box 1109921944 TaifSaudi Arabia Shaanxi Key Laboratory of macromolecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’anShaanxi 710072People’s Republic of China Integrated Composites Lab Department of Mechanical and Construction EngineeringNorthumbria UniversityNewcastle Upon Tyne NE18STUK College of materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan 030024People’s Republic of China Department of Chemistry Faculty of ScienceAl-Azhar UniversityNasr CityCairo 11884Egypt Yunnan Provincial Key Laboratory of Wood Adhesives and Glued Products International Joint Research Center for Biomass MaterialsSouthwest Forestry UniversityKunming 650224People’s Republic of China School of Science Henan Agricultural UniversityZhengzhou 450002People’s Republic of China

research efforts on electromagnetic interference(EmI)shielding materials have begun to converge on green and sustainable biomass *** materials offer numerous advantages such as being lightweight,porous,and *** to their porous nature,interfacial compatibility,and electrical conductivity,biomass materials hold significant potential as EmI shielding *** concerted efforts on the EmI shielding of biomass materials have been reported,this research area is still relatively new compared to traditional EmI shielding *** particular,a more comprehensive study and summary of the factors influencing biomass EmI shielding materials including the pore structure adjustment,preparation process,and micro-control would be *** preparation methods and characteristics of wood,bamboo,cellulose and lignin in EmI shielding field are critically discussed in this paper,and similar biomass EmI materials are summarized and *** composite methods and fillers of various biomass materials were *** paper also highlights the mechanism of EmI shielding as well as existing prospects and challenges for development trends in this field.

关键词： Biomass materials electromagnetic interference shielding micro-nano structure interface control Conductivity

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Weight Prediction Using the hybrid Stacked-LSTm Food Selection model

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Computer Systems Science & Engineering 2023年第7期46卷 765-781页

作者： Ahmed m.elshewey mahmoud Y.Shams Zahraa Tarek mohamed megahed el-Sayed m.el-kenawy mohamed A.el-dosuky Faculty of Computers and Information Computer Science DepartmentSuez UniversitySuezEgypt Faculty of Artificial Intelligence Kafrelsheikh UniversityKafrelsheikh33511Egypt Faculty of Computers and Information Computer Science DepartmentMansoura University35561Egypt Faculty of Physical Education Track and Field Competitions DepartmentArish UniversityEgypt Delta higher Institute of Engineering and Technology Mansoura35111Egypt Department of Computer Science Arab East CollegesRiyadh13544Saudi Arabia

Food choice motives(i.e.,mood,health,natural content,convenience,sensory appeal,price,familiarities,ethical concerns,and weight control)have an important role in transforming the current food system to ensure the healthiness of people and the sustainability of the *** from several domains have presented several models addressing issues influencing food choice over the ***,a multidisciplinary approach is required to better understand how various aspects interact with one another during the decision-making *** this paper,four Deep Learning(DL)models and one machine Learning(mL)model are utilized to predict the weight in pounds based on food *** Long Short-Term memory(LSTm)model,stacked-LSTm model,Conventional Neural Network(CNN)model,and CNN-LSTm model are the used deep learning *** the applied mL model is the K-Nearest Neighbor(KNN)*** efficiency of the proposed model was determined based on the error rate obtained from the experimental *** findings indicated that mean Absolute Error(mAE)is 0.0087,the mean Square Error(mSE)is 0.00011,the median Absolute Error(medAE)is 0.006,the root mean Square Error(rmSE)is 0.011,and the mean Absolute Percentage Error(mAPE)is ***,the results demonstrated that the stacked LSTm achieved improved results compared with the LSTm,CNN,CNN-LSTm,and KNN regressor.

关键词： Weight prediction machine learning deep learning LSTm CNN KNN

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A new approach for modelling the damped helmholtz oscillator:applications to plasma physics and electronic circuits

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Communications in Theoretical Physics 2021年第3期73卷 119-130页

作者： S A el-Tantawy Alvaro h Salas m r Alharthi Department of Physics Faculty of SciencePort Said UniversityPort Said 42521Egypt research Center for Physics(rCP) Department of PhysicsFaculty of Science and ArtsAl-MikhwahAl-Baha UniversitySaudi Arabia Department of mathematics Universidad National de ColombiaUniversidad National de Colombia-Nubia Campus Derpartment of Mathematics and Statistics FIZMAKO Research GroupColombia Department of mathematics and Statistics College of ScienceTaif UniversityPO Box 11099Taif 21944Saudi Arabia

In this paper,a new approach is devoted to find novel analytical and approximate solutions to the damped quadratic nonlinear helmholtz equation(hE)in terms of the Weiersrtrass elliptic *** exact solution for undamped hE(integrable case)and approximate/semi-analytical solution to the damped hE(non-integrable case)are given for any arbitrary initial *** a special case,the necessary and sufficient condition for the integrability of the damped hE using an elementary approach is *** general,a new ansatz is suggested to find a semi-analytical solution to the non-integrable case in the form of Weierstrass elliptic *** addition,the relation between the Weierstrass and Jacobian elliptic functions solutions to the integrable case will be derived in ***,we will make a comparison between the semi-analytical solution and the approximate numerical solutions via using runge-Kutta fourth-order method,finite difference method,and homotopy perturbation method for the first-two ***,the maximum distance errors between the approximate/semi-analytical solution and the approximate numerical solutions will be *** real applications,the obtained solutions will be devoted to describe the characteristics behavior of the oscillations in rLC series circuits and in various plasma models such as electronegative complex plasma model.

关键词： damped and undamped helmholtz equation Korteweg-de Vries type equation plasma oscillations nonlinear rLC circuits Weierstrass ellliptic function periodical solution

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Nonequivalent Similarity reductions and Exact Solutions for Coupled Burgers-Type Equations

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Communications in Theoretical Physics 2012年第1期57卷 1-4页

作者： m.h.m.moussa r.A.K.Omar rehab m.el-Shiekh h.r.el-melegy Department of mathematics Faculty of EducationAin Shams UniversityHeliopolisCairoEgypt

Using the machinery of Lie group analysis,the nonlinear system of coupled Burgers-type equations is *** the infinitesimal generators in the optimal system of subalgebra of the said Lie algebras,it leads to two nonequivalent similarity transformations by using it we obtain two reductions in the form of system of nonlinear ordinary differential *** search for solutions of these systems by using the G'/G-method has yielded certain exact solutions expressed by rational functions,hyperbolic functions,and trigonometric *** figures are given to show the properties of the solutions.

关键词： symmetry method G/G-method coupled Burgers-type equations exact solutions

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Effect of substitution group on dielectric properties of 4h-pyrano [3,2-c] quinoline derivatives thin films

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Chinese Physics B 2016年第7期25卷 440-449页

作者： h m Zeyada F m el-Taweel m m el-Nahass m m el-Shabaan Department of Physics Faculty of Science Damietta University Department of Chemistry Faculty of Science Damietta University Department of Physics Faculty of Education Ain Shams University

The AC electrical conductivity and dielectrical properties of 2-amino-6-ethyl-5-oxo-4-（3-phenoxyphenyl）-5,6-dihydro-4h-pyrano[3, 2-c]quinoline-3-carbonitrile（Ph-hPQ） and 2-amino-4-（2-chlorophenyl）-6-ethyl-5-oxo-5,6-dihydro-4h-pyrano [3, 2-c] quinoline-3-carbonitrile（Ch-hPQ） thin films were determined in the frequency range of 0.5 k hz–5 mhz and the temperature range of 290–443 K. The AC electrical conduction of both compounds in thin film form is governed by the correlated barrier hopping（CBh） mechanism. Some parameters such as the barrier height, the maximum barrier height, the density of charges, and the hopping distance were determined as functions of temperature and frequency. The phenoxyphenyl group has a greater influence on those parameters than the chlorophenyl group. The AC activation energies were determined at different frequencies and temperatures. The dielectric behaviors of Ph-hPQ and Ch-hPQ were investigated using the impedance spectroscopy technique. The impedance data are presented in Nyquist diagrams for different temperatures. The Ch-hPQ films have higher impedance than the Ph-hPQ films. The real dielectric constant and dielectric loss show a remarkable dependence on the frequency and temperature. The Ph-hPQ has higher dielectric constants than the Ch-hPQ.

关键词： thin films quinoline derivatives dielectrical properties correlated barrier hopping

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Plasma ignition threshold disparity between silver nanoparticle-based target and bulk silver target at different laser wavelengths

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Plasma Science and Technology 2019年第1期21卷 63-71页

作者： A m el ShErBINI m m hAGrASS m r m rIZK E A el-BADAWY Laboratory of Laser and New materials Faculty of Science Cairo University Faculty of Engineering Electrical Engineering Department Alexandria University

Plasma ignition threshold of nanoparticle-based and bulk silver targets was measured in air. The plasma was initiated by a Nd:YAG laser at wavelengths of 355, 532, and 1064 nm. The plasma ignition was monitored utilizing the prominent Ag I line at 546.5 nm. Lower ignition thresholds of the nanoparticle-based silver target were estimated at 0.4?±?0.02, 0.34?±?0.04, and 0.27?±?0.035 J cm^(-2) coupled with the different laser wavelengths, respectively. In contrast, the bulk silver target plasma exhibited an order of magnitude higher ignition threshold. A three orders of magnitude enhanced emission intensity from the nano-based target over the bulk target was achieved at lower levels of laser irradiation. A reduction of the thermal diffusion length of the nanosilver was assumed in order to theoretically predict this reduction in the plasma threshold. In addition, the effect of self-reversal on the resonance lines was taken into consideration.

关键词： NelIBS enhancement nanosilver laser plasma threshold

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Serum homocysteine,lipid profile and BmI as atherosclerotic risk factors in children with numerical chromosomal aberrations

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World Journal of Pediatrics 2022年第6期18卷 443-448页

作者： Eman r.Youness Sherien mel-Daly hanaa reyad Abdallah hala T.el-Bassyouni hisham megahed Azzah A.Khedr marwa elhady Walaa Alsharany Abuelhamd medical Biochemistry Department Medical Research DivisionNational Research CentreGizaEgypt Biological Anthropology Department Medical Research DivisionNational Research CentreGizaEgypt Clinical Genetics Department Human Genetics and Genome Research DivisionNational Research CentreEl-Tahrir StreetPO:12622GizaEgypt human Cytogenetics Department Human Genetics and Genome Research DivisionNational Research CentreGizaEgypt Pediatric Department Faculty of Medicine for GirlsAl-Azhar UniversityCairoEgypt Department of Pediatrics Faculty of MedicineCairo UniversityCairoEgypt

Down syndrome,Turner syndrome,and Klinefelter syndrome are the most common chromosomal disorders *** syndrome is caused by an extra copy of the 21st chromosome and has an incidence of 1 in 800 to 1000 live *** syndrom... 详细信息

关键词： chromosomal Turner Serum

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