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International Journal of Organic Chemistry 2015年第2期5卷 49-56页

作者： saad s. Elmorsy saad shaaban Fathy Eldesoky Ezzat Kandeel Department of Chemistry Faculty of Science Mansoura University Mansoura Egypt

The development of a new silane reagent derived from tetrachlorosilane (TCs) was applied in the present work. TCs-sodium nitrate (NaNO3) binary reagent and zinc chloride (ZnCl2) were reported here as a homogeneous nitrating system. The later was used for the efficient mono nitration, in most cases, with high para-regioselectivity. The nitration proceeded smoothly under mild condition, fairly clean and in good yields. This readily available and inexpensive system is superior to other methods by avoidance of the use of corrosive nitrating reagents and therefore considered to be convenient in terms of risk reduction, economic advantages and environment protection. The present protocol was convenient and applicable to a variety of aromatic hydrocarbons and could be amenable to high throughput synthesis of combinatorial libraries for potential drug development, which needs to be studied as part of future investigations.

关键词： Nitration Regioselectivity sodium Nitrate Tetrachlorosilane

BN-GEPsO:Learning Bayesian Network structure Using Generalized Particle swarm Optimization

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Computers, Materials & Continua 2023年第5期75卷 4217-4229页

作者： Muhammad saad salman Ibrahim M.Almanjahie AmanUllah Yasin Ammara Nawaz Cheema Air University Islamabad44000Pakistan Department of Mathematics College of ScienceKing Khalid UniversityAbha62529Saudi Arabia statistical Research and studies support Unit King Khalid UniversityAbha62529Saudi Arabia

At present Bayesian Networks(BN)are being used widely for demonstrating uncertain knowledge in many disciplines,including biology,computer science,risk analysis,service quality analysis,and *** they suffer from the problem that when the nodes and edges increase,the structure learning difficulty increases and algorithms become *** solve this problem,heuristic optimization algorithms are used,which tend to find a near-optimal answer rather than an exact one,with particle swarm optimization(PsO)being one of *** is a swarm intelligence-based algorithm having basic inspiration from flocks of birds(how they search for food).PsO is employed widely because it is easier to code,converges quickly,and can be parallelized *** use a recently proposed version of PsO called generalized particle swarm optimization(GEPsO)to learn bayesian network *** construct an initial directed acyclic graph(DAG)by using the max-min parent’s children(MMPC)algorithm and cross relative average *** used to create a population for theGEPsO optimization ***,we propose a velocity update procedure to increase the efficiency of the algorithmic search *** of the experiments show that as the complexity of the dataset increases,our algorithm Bayesian network generalized particle swarm optimization(BN-GEPsO)outperforms the PsO algorithm in terms of the Bayesian information criterion(BIC)score.

关键词： Bayesian network structure learning particle swarm optimization

Database Recovery Technique for Mobile Computing:A Game Theory Approach

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Computers, Materials & Continua 2022年第2期70卷 3205-3219页

作者： Magda M.Madbouly Yasser F.Mokhtar saad M.Darwish Institute of Graduate studies and Research Alexandria UniversityAlexandriaEgypt Assistant General Manager IT DepartmentEgyptian Petrochemicals Co.AlexandriaEgypt

Contact between mobile hosts and database servers presents many problems in theMobile Database system(MDs).It is harmed by a variety of causes,including handoff,inadequate capacity,frequent transaction updates,and repeated failures,both of which contribute to serious issues with the information system’s ***,error tolerance technicality allows devices to continue performing their functions in the event of a *** aim of this paper is to identify the optimal recovery approach from among the available state-of-the-art techniques in MDs by employing game *** of the presented recovery protocols are chosen and evaluated in order to determine the most critical factors affecting the recovery mechanism,such as the number of processes,the time required to deliver messages,and the number of messages logged-in ***,using the suggested payout matrix,the game theory strategy is adapted to choose the optimum recovery technique for the specified environmental *** Ns2 simulatorwas used to carry out the tests and apply the chosen recovery *** experiments validate the proposed model’s usefulness in comparison to other methods.

关键词： Mobile computing game theory decision making mobile database recovery

Evaluation of Antioxidants, Total Phenolics and Antimicrobial Activities of Ethyl Acetate Extracts From Fungi Grown on Rice straw

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Journal of Renewable Materials 2019年第7期7卷 667-682页

作者： Bahaa T.shawky Mohammed Nagah Mosad A.Ghareeb Gamal M.El-sherbiny saad A.M.Moghannem Mohamed s.Abdel-Aziz Microbial Chemistry Department National Research CentreDokki-12622CairoEgypt Medicinal Chemistry Department Theodor Bilharz Research InstituteKornaish El-NileWarrak El-HadarImbaba(P.O.30)Giza 12411Egypt Botany and Microbiology Department Faculty of ScienceAzhar UniversityNasr CityCairoEgypt

Rice straw(Rs)collected from Egyptian agricultural environment(Al-Masied village-Alsharqia Governorate-Egypt)was used as substrate for three fungal isolates namely:4b,1Asp,Pleurotus ostreatus NRRL 3501 and mixed culture of(4b,1Asp).Isolates number 4b and 1Asp were identified using the molecular technique(18s rRNA).Isolate 4b and 1Asp,were identified as Trichoderma saturnisporum MN1-EGY and Aspergillus niger MN2-EGY,*** saturnisporum MN1-EGY extract exhibited the highest antimicrobial activity compared to the other fungal *** phenolic,antimicrobial and antioxidant activities were also determined from the ethyl acetate extract of rice straw inoculated by these *** antioxidant scavenging concentration(sC50)values of the tested samples were 88.84,91.45,94.65 and 100.0μg/ml,respectively for Pleurotus sp.,Aspergiluus niger,Aspergiluus niger+Trichoderma sp.,and Trichoderma sp.,after 15 days incubation,compared to ascorbic acid as positive control with sC50 value equal to 8.0μg/*** phenolic contents(TPCs)were maximum in Pleurotus *** and found to be the most polyphenolic enriched sample(380.64 mg GAE/g dry extract)compared to extracts of Aspergiluusniger,Aspergiluus niger+Trichoderma sp.,and Trichoderma sp.(261.89,198.52,and 119.80 mg GAE/g dry extract),*** GC-Ms analysis has been also performed for the promising extracts.

关键词： Rice straw fungi molecular identification antimicrobial antioxidant total phenolics

signature of the 27-day variation in hemispheric sunspot activity and asymmetry during 2010-2015

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Research in Astronomy and Astrophysics 2021年第4期21卷 331-340页

作者： Prithvi Raj singh Ahmad Islam saad Farid Tarun Kumar Pant Abhay Kumar singh Department of Physics Banaras Hindu UniversityVaranasi-221005India Physics and Chemistry Department Faculty of EducationAlexandria UniversityAlexandria-21526Egypt space Physics Laboratory VSSCThiruvananthapuram-695022India

In the present work,we study the time evolution,significance of the N-s asymmetry excesses presented as a function of the solar cycle and prominent rotational periods(~27 d)separately for the northern and southern *** have investigated short-term variations of the hemispheric solar activity(sunspot numbers and sunspot areas)during the time period 2010-2015,which covers the ascending and the maximum phase of solar cycle *** have implemented the Lomb-scargle periodogram and continuous wavelet transform power spectrum techniques to study the time evolution and dominant rotational periods separately for the northern and southern hemispheres,and whole solar *** results showed that the northern hemisphere exhibited longer solar synodic periods than the southern hemisphere,indicating that the northern hemisphere has a lower rotation ***,the northern hemisphere was found to be dominant before transferring to the southern hemisphere during ***,the sunspot areas clearly demonstrated a two-peak structure of solar activity in the northern and southern hemispheres respectively during 2012 and *** statistical significance of the southern hemisphere affirmed enhanced excess during the maximum phase of solar cycle 24.

关键词： sunspots sunspot Area Asymmetry solar Cycle

Direct Interventional Discussion Effectively Improves Awareness and Knowledge about Modern Contraceptive Methods

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Advances in Reproductive sciences 2020年第1期8卷 1-13页

作者： Abdelhaseib s. saad Amr sharafeldeen Departments of Obstetrics & Gynecology Faculty of Medicine Menoufia Universities Al Minufya Egypt Departments of Obstetrics & Gynecology Faculty of Medicine Benha Universities Benha Egypt

Objectives: Determination of influence of direct interview of postpartum women about their awareness and knowledge regarding contraception and modern contraceptive methods. Patients & Methods: 1437 women joined the intervention and underwent evaluation of their knowledge about the concept and methods of contraception. Then, an interview was conducted with each woman to clarify advantages and appropriateness of various contraceptives and the proper time for initiation of contraception. All women were asked to discuss these data with their families and return to give their decision. study outcomes included evaluation of women’s knowledge about contraception and its modalities, frequency of non-users who accepted to use contraception and is considered as success of the intervention and frequency of requesting each modality of contraception. Results: TV programs and discussion with local health provider, relatives or friends are the main sources of knowledge of primiparas. 182 primiparas had good knowledge and chose the appropriate method of contraception during the 1st session of discussion, and 81 primiparas required >2 sessions to choose the method appropriate for them, while 21 primiparas insisted not to use contraception for an acceptance rate of 92.6% among primipara. Among multiparas, 222 multiparas were non-users, but after discussion 133 couples accepted to use contraception. Thus, 396 non-users had accepted to use contraception for an intervention success rate of 78.3%. Collectively 692 women (52.1%) received IUD and 635 women (47.9%) received hormonal contraception;432 orally (32.6%) and 203 parenterally (15.3%). Conclusion: Ignorance, low financial status and cultural beliefs deleteriously affect knowledge about contraception options and its methods, so direct interview is mandatory. The applied intervention succeeded to replenish women’s knowledge about benefits of using contraception. Primiparas had knowledge about contraception but their knowledge about m

关键词： Knowledge Contraception Modern Methods Primiparas Intrauterine Device

Influences of processing parameters and heat treatment on microstructure and mechanical behavior of Ti-6Al-4V fabricated using selective laser melting

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Advances in Manufacturing 2022年第4期10卷 520-540页

作者： Qi-Dong sun Jie sun Kai Guo saad Waqar Jiang-Wei Liu Lei-shuo Wang Key Laboratory of High Efficiency and Clean Mechanical Manufacture National Demonstration Center for Experimental Mechanical Engineering EducationSchool of Mechanical EngineeringShandong UniversityJinan250061People’s Republic of China Research Centre for Aeronautical Component Manufacturing Technology and Equipment Shandong UniversityJinan250061People’s Republic of China school of Energy and Power Engineering Shandong UniversityJinan250061People’s Republic of China school of Mechanical and Power Engineering Zhengzhou UniversityZhengzhou450001People’s Republic of China

selective laser melting(sLM)has provided an alternative to the conventional fabrication techniques for Ti-6Al-4V alloy parts because of its flexibility and ease in creating complex ***,this study investigated the effects of the process parameters and heat treatment on the microstructure and mechanical properties of Ti-6Al-4V fabricated using *** influences of various process parameters on the relative density,tensile properties,impact toughness,and hardness of Ti-6Al-4V alloy parts were *** employing parameter optimization,a high-density high-strength Ti-6Al-4V alloy was fabricated by sLM.A relative density of 99.45%,a tensile strength of 1188 MPa,and an elongation to failure of 9.5%were achieved for the sLM-fabricated Ti-6Al-4V alloy with optimized *** effects of annealing and solution aging heat treatment on the mechanical properties,phase composition,and microstructure of the sLM-fabricated Ti-6Al-4V alloy were also *** ductility of the heat-treated Ti-6Al-4V alloy was *** applying a heat treatment at 850℃ for 2 h,followed by furnace cooling,the elongation to failure and impact toughness were found to be increased from 9.5%to 12.5%,and from 24.13 J/cm^(2)to 47.51 J/cm^(2),respectively.

关键词： selective laser melting(sLM) Ti-6Al-4V alloy Heat treatment Microstructure Mechanical properties

Microbiologically influenced corrosion of 304L stainless steel caused by an alga associated bacterium Halomonas titanicae

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Journal of Materials science & Technology 2020年第2期37卷 200-206页

作者： Yuqiao Dong Yassir Lekbach Zhong Li Dake Xu soumya El Abed saad Ibnsouda Koraichi Fuhui Wang shenyang National Laboratory for Materials science Northeastern UniversityShenyang 110819China Center for Marine Materials Corrosion and Protection College of MaterialsXiamen UniversityXiamen 361005China Laboratory of Microbial Biotechnology Faculty of Science and TechnologySidi Mohamed Ben Abdellah UniversityB.P.2202FezMorocco

Algae are reported to be corrosive,while little is known about the role of the algae associated bacteria in the corrosion *** the present study,Halomonas titanicae was isolated from a culture of an alga strain,spirulina platensis,and identified through 16 s rRNA gene *** behavior of 304L stainless steel(ss)coupons in the presence and absence of *** was characterized by using electrochemical measurements and surface *** results showed that *** significantly accelerated the corrosion rate and decreased the pitting potential of 304L ss in the biotic *** removal of the corrosion products and biofilms,severe pitting corrosion caused by *** was *** largest pit depth after 14 d reached 6.6μm,which was 5.5 times higher than that of the sterile control(1.2μm).This is the first report revealing that an alga associated bacterium can induce microbiologically influenced corrosion(MIC),and a further concern is raised that whether algae play a role in the MIC process.

关键词： Microbiologically influenced corrosion Halomonas titanicae Pitting corrosion

Modulation of the intracellular inhibitory checkpoint sHP-1 enhances the antitumor activity of engineered NK cells

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Cellular & Molecular Immunology 2021年第5期18卷 1314-1316页

作者： Aviad Ben-shmuel Guy Biber Batel sabag Mira Barda-saad The Mina and Everard Goodman Faculty of Life sciences Bar-Ilan UniversityRamat-Gan5290002Israel

Natural killer(NK)cells are innate lymphoid cells(ILCs)that eliminate virally infected and cancerous *** cells directly induce target cell death and release cytokines and chemokines that activate the adaptive arm of t... 详细信息

关键词： killer death lymphoid

由杂多钼酸盐前驱体制备的氧化钼催化剂催化CO_2存在下的异丁烷脱氢(英文)

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催化学报 2012年第9期33卷 1474-1479页

作者： Ahmed AOUIssI Daif ALDHAYAN saad ALKAHTANI Chemistry Department College of ScienceKing Saud University

Molybdenum based oxide catalysts Mo-H,Mo-Fe,Mo-Ce,and Mo-sn were prepared by calcining H3PMo12O40,Fe1.5 PMo 12O40,Ce1.5PMo12O40,and sn1.5 PMo12O40 heteropolyanion precursors at700℃,*** prepared oxides have been characterized and tested for the dehydrogenation of isobutane(IB)to isobutene in the presence of *** effects of temperature,time on stream,and CO2 /IB ratio were *** was found that α-and-MoO3 phases were present in all *** tests showed that increasing the reaction temperature increased both the conversion and isobutene selectivity,whereas increasing the CO2 /IB molar ratio increased the conversion but decreased the selectivity for *** was found to be an effective additive element for the enhancement of catalytic activity compared with Ce and sn.

关键词： isobutane isobutene heteropoly compound mixed oxide carbon dioxide