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Thermal explosion of a reactive gas mixture at constant pressure for non-uniform and uniform temperature systems

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Defence Technology（防务技术） 2022年第10期18卷 1842-1851页

作者： Saad A.el-sayed Mechanical Power Engineering Dept.Zagazig University ZagazigAlshrkiaEgypt

In this study,the approximate and exact solutions for the stationary-state of the solids model with neglecting reactant consumption for both non-uniform and uniform temperature systems were applied on gas ignition under a constant pressure *** criticality conditions for a slab,an infinite cylinder,and a sphere are determined and discussed using dimensionless temperatures under constant ambient and surface temperatures for a non-uniform temperature *** solution for a Semenov model with convection heat loss was also *** solution of the Semenov problem for constant volume or density as a solid and constant pressure were *** critical parameterδis calculated and compared with those of frank-Kamenetskii solution *** validation of the calculated ignition temperatures with other exact solution and experimental results were *** relation between critical parameters form Semenov and *** solution was introduced.

关键词： Thermal explosion Approximate solution Critical conditions Distributed and uniform temperature systems

Use of breakthrough experiment to evaluate the performance of hydrogen isotope separation for metal-organic frameworks M-MOf-74(M=Co, Ni, Mg, Zn)

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Science China Chemistry 2020年第7期63卷 881-889页

作者： Yanan Si Wenjing Wang el-sayed M.el-sayed Daqiang Yuan State Key Laboratoty of Structural Chemistry Fujian Institute o f Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China University of the Chinese Academy of Sciences Beijing 100049China Chemical refining Laboratory Refining DepartmentEgyptian Petroleum Research InstituteNasr CityCairoEgypt

The unique adsorption performance of metal-organic frameworks(MOfs) indicates a new direction for gas separation and purification. The low-temperature distillation, as a traditional technique for hydrogen isotope separation, is limited as it is a high energy-and cost-intensive process. Instead of utilizing such a conventional separation route, we use ordered microporous frameworks based on a physical adsorption mechanism to solve the challenge of hydrogen isotope separation. Herein we analyze M-MOf-74(M=Co, Ni, Mg, Zn), featuring a hexagonal channel about 11 ? and high density of open metal sites, for their ability to separate and purify deuterium from the hydrogen isotope mixture by dynamic column breakthrough experiments. Our results show that the combination of the strength of binding sites, density of coordinatively unsaturated metal sites and hydrogen isotope adsorption capacity of materials renders Co-MOf-74 as an optimal adsorbent for the capture of deuterium from hydrogen isotope mixtures in a simulated industrial process.

关键词： hydrogen isotope separation breakthrough experiment MOf-74

Air renewal times and ventilation rate calculations for underground workings using radioactive measurement

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International Journal of Mining Science and Technology 2016年第5期26卷 843-850页

作者： Ayman A.el-Abnoudy sayed f.Hassan Production Sector Nuclear Materials Authority

Potential alpha emitters are of prime concern to the ventilation engineer due to their rapid concentration increasing once radon released in the mine atmosphere, causing tissue irradiation and lung *** of the time based variations of the natural ventilation in tunnels and their relationship to the external parameters contribute to the air circulation assessment. Due to the continuous and high fluctuation of the meteorological conditions affecting the air circulation and intensity through the underground workings, there is a difficulty in the natural ventilation assessment by only the ordinary meteorological measurements. So, in this paper, the possibility of using the radioactive measurements, allowing for the air aging and ventilation quality to be qualified, is investigated through three different underground structures. referring to the most confined structure of them, results show that one structure has a better exchange rate by a factor 1.8 and the other has the best rate by a factor 2.1. This parameter can be linked to the operating costs and size of a future ventilation system.

关键词： Mining ventilation Air circulation radon gas measurement Air aging

Effects of Nickel Distribution on the Strengthening and Toughening of Alumina Ceramics

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Journal of Materials Science & Technology 2008年第5期24卷 723-728页

作者： Mohamed.M.el-sayed Seleman Department of Materials and Metallurgical Eng. Faculty of Petroleum and Mining Eng.Post Code 43721SuezEgypt

Three types of composite materials were designed and fabricated by hot pressing powder blends of alumina with 20 vol. pct nickel particles. The composites differ in the shape, size and distribution of the nickel particles. Composite microstructures are described and measurements of density, hardness, flexure strength, and fracture toughness are reported. The results showed that the fracture strength of the composite with dispersed nickel particles is higher than the other two composites （network microstructure and mixed microstructure） and the alumina matrix. for all the composites studied, tougher materials than the monolithic alumina were produced. The fracture toughness of the composite with a network microstructure is much higher than that of the other composites. The toughening mechanisms were described based on the observation of the fracture surfaces and the crack-particle interactions. Moreover, the parameters for microstructural tailoring of these materials have been deduced. The toughening of the produced composites was explained in light of the interracial bond strength.

关键词： Alumina-nickel composites Nickel morphology Interfacial bonding fracturetoughness flexure strength

fIrST-OrDEr METHODS fOr SOLVING THE OPTIMAL STATIC H∞-SYNTHESIS PrOBLEM

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Journal of Computational Mathematics 2007年第6期25卷 672-689页

作者： el-sayed M.E. Mostafa Department of Mathematics Faculty of Science Alexandria University Alexandria Egypt

In this paper, we consider the static output feedback （SOf） H∞-synthesis problem posed as a nonlinear semi-definite programming （NSDP） problem. Two numerical algorithms are developed to tackle the NSDP problem by solving the corresponding Karush- Kuhn-Tucker first-order necessary optimality conditions iteratively. Numerical results for various benchmark problems illustrating the performance of the proposed methods are given.

关键词： Static output feedback H∞-synthesis Semi-definite programming Nonlinear programming.

electrical Conductivity and Sensitive Characteristics of Ag-Added BaTiO_3-CuO Mixed Oxide for CO_2 Gas Sensing

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Journal of Materials Science & Technology 2011年第1期27卷 35-40页

作者： A.M.el-sayed f.M.Ismail S.M.Yakout Inorganic Chemistry Department National Research CentreTahrir StreetDokki P.C.12622 CairoEgypt

Carbon dioxide gas sensors based on BaTiO3-CuO composite with different concentrations of Ag addition（1,1.5 and 2 wt%） have been prepared by stander ceramic method and sintered at 500 and 700℃ for 5 *** conductivity and gas sensing properties of the prepared samples were *** conductivity measurement was used to characterize the obtained sintered sensor *** was found that electrical conductivity and the sensitivity to CO2 were improved with Ag addition and *** correlation between Ag content at different sintering temperature and sensing characteristics towards CO2 is discussed.

关键词： BaTiO3-CuO composite Ag addition electrical conductivity CO2 sensitive properties

Processing of Ceramic Based Nanocomposite Usingα-Al_2O_3 Powder and feCl_2 Solution as Starting Materials

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Journal of Materials Science & Technology 2007年第6期23卷 837-842页

作者： Mohamed M.el-sayed Seleman Department of Materials and Metallurgical Engineering Faculty of Petroleum and Mining EngineeringPost Code 43721SuezEgypt

Alumina-iron nanocomposite powders were prepared by a two-step process. In the first step, α-Al2O3-feCl2 powder mixture was formed by mixing α-Al2O3 powders with feCl2 solution followed by drying. In the second step, the feCl2 in the dry power mixture was selectively reduced to iron particles. A reduction temperature of 750℃ for 15 min in dry H2 was chosen based on the thermodynamic calculations. The concentration of iron in feCl2 solution was calculated to be 20 vol. pct in the final composite. Two techniques were used to produce composite bulk materials. The Al2O3 nanocomposite powders were divided to two batches. The first batch of the produced mixture was hot pressed at 1400℃ and 27 MPa for 30 min in a graphite die. To study the effect of oxygen on the Al2O3/fe interface bonding and mechanical properties of the composite, the second batch was heat treated in air at 700℃ for 20 min to partially oxidize the iron particles before hot pressing. Characterization of the composites was undertaken by conventional density measurements, X-ray diffractometry （XrD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM） and electron probe micro analysis （EPMA）. The suggested processing route （mixing, reduction and hot pressing） produces ceramic-metal nanocomposite much tougher than the pure Al2O3. The fracture strength of the produced Al2O3/fe nanocomposite is nearly twice that of the pure Al2O3. The presence of spinel phase, feAl204, as thick layer around the fe particles in the Al2O3 matrix has a detrimental effect on interfacial bonding between fe and AI203 and the fracture properties of the composite.

关键词： ferrous chloride reduction Alumina-iron nanocomposite Spinel phase

Classical taxonomy,molecular phylogeny and genetic analysis of the genus Exitianus Ball,1929(Hemiptera:Cicadellidae:Deltocephalinae)from Egypt

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Zoological Systematics 2024年第2期49卷 143-157页

作者： rabab M.el-Hady Ahmed f.el-sayed Survey&Taxonomy Department Plant Protection Research InstituteAgriculture Research CentreGizaEgypt Microbial Genetics Department Biotechnology Research InstituteNational Research CentreGizaEgypt Egypt Center for research and regenerative Medicine(ECrrM) CairoEgypt

Egyptian species of the leafhopper genus Exitianus Ball,1929,***(St?l,1855),***(Distant,1908),and *** ross,1968 are ***,morphological descriptions,and a key for their identification are *** this study,we used molecular techniques to confirm morphological identification and detect phylogeny among the three Exitianus *** partial nucleotide sequences of the amplified products obtained were determined by Macrogen *** nucleotide sequences of 28S rDNA and COX genes of the EGY-ArC-9,EGY-ArC-4,and EGY-ArC-5 were determined by Macrogen Korea,blasted into BLAST at the National Center for Biotechnology Information website(NCBI)and compared with those deposited in the GenBank DNA *** results represented the homology percentage between the partial sequences of the 28S rrNA and COX genes from each species and related species obtained from GenBank DNA *** morphological identifications of the three Exitianus species were confirmed by molecular characterization and sequencing of 28S rDNA and COX genes and identified as ***,***,and ***,their sequences of 28srDNA and COX genes were deposited in GenBank with an accession number(LC670610,LC670607,and OQ196105)for 28srDNA gene and(LC775357,LC775358,and LC775359)for the COX gene.

关键词： Auchenorrhyncha Chaismini taxonomic 28S rDNA phylogenetic

Advance Artificial Intelligence Technique for Designing Double T-Shaped Monopole Antenna

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Computers, Materials & Continua 2021年第12期69卷 2983-2995页

作者： el-sayed M.el-kenawy Hattan f.Abutarboush Ali Wagdy Mohamed Abdelhameed Ibrahim Department of Communications and electronics Delta Higher Institute of Engineering and TechnologyMansoura35111Egypt electrical Engineering Department College of EngineeringTaibah UniversityMedina 42353Saudi Arabia Operations research Department Faculty of Graduate Studies for Statistical ResearchCairo UniversityGiza 12613Egypt Wireless Intelligent Networks Center(WINC) School of Engineering and Applied SciencesNile UniversityGizaEgypt Computer Engineering and Control Systems Department Faculty of EngineeringMansoura UniversityMansoura35516Egypt

Machine learning(ML)has taken the world by a tornado with its prevalent applications in automating ordinary tasks and using turbulent insights throughout scientific research and design *** is a massive area within artificial intelligence(AI)that focuses on obtaining valuable information out of data,explaining why ML has often been related to stats and data *** advanced meta-heuristic optimization algorithm is proposed in this work for the optimization problem of antenna architecture *** algorithm is designed,depending on the hybrid between the Sine Cosine Algorithm(SCA)and the Grey Wolf Optimizer(GWO),to train neural networkbased Multilayer Perceptron(MLP).The proposed optimization algorithm is a practical,versatile,and trustworthy platform to recognize the design parameters in an optimal way for an endorsement double T-shaped monopole *** proposed algorithm likewise shows a comparative and statistical analysis by different curves in addition to the ANOVA and *** offers the superiority and validation stability evaluation of the predicted results to verify the procedures’accuracy.

关键词： Antenna optimization machine learning artificial intelligence multilayer perceptron sine cosine algorithm grey wolf optimizer