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Risk based security assessm.nt of power system.using generalized regression neural network with feature extraction

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Journal of Central South University 2013年第2期20卷 466-479页

作者： m. m.rsadek A. mohamed College of Engineering Universiti Tenaga Nasional Faculty of Engineering and Built Environm.nt Universiti Kebangsaan Malaysia

A com.rehensive risk based security assessm.nt which includes low voltage, line overload and voltage collapse was presented using a relatively new neural network technique called as the generalized regression neural network (GRNN) with incorporation of feature extraction m.thod using principle com.onent analysis. In the risk based security assessm.nt form.lation, the failure rate associated to weather condition of each line was used to com.ute the probability of line outage for a given weather condition and the extent of security violation was represented by a severity function. For low voltage and line overload, continuous severity function was considered due to its ability to zoom.in into the effect of near violating contingency. New severity function for voltage collapse using the voltage collapse prediction index was proposed. To reduce the com.utational burden, a new contingency screening m.thod was proposed using the risk factor so as to select the critical line outages. The risk based security assessm.nt m.thod using GRNN was im.lem.nted on a large scale 87-bus power system.and the results show that the risk prediction results obtained using GRNN with the incorporation of principal com.onent analysis give better perform.nce in term. of accuracy.

关键词： generalized regression neural network line overload low voltage principle com.onent analysis risk index voltagecollapse

Geochem.cal characteristics and spectrom.tric prospecting in the m.scovite-bearing pegm.tites and granites, southeastern Aswan, Egypt

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Chinese Journal Of Geochem.stry 2008年第1期27卷 9-20页

作者： Gehad m. Saleh mohamed m. El Galy mohamed A. Obeid Nuclear m.terials Authority P.O.Box: 530 El Maadi Cairo Egypt Geology Depart. Faculty of Science El Fayoum University Egypt

Rare m.tal m.neralization of Sn, Nb-Ta and W is encountered in the Gebel Dihm.t area (GDA), south- eastern Aswan, Egypt. The m.neralization is related to m.scovite granites and their pegm.tite derivatives. The peg- m.tites are divided into three types according to their m.in m.neral assem.lages: K-feldspar-m.scovite-tourm.line, K-feldspar-albite-m.scovite and albite-K-feldspar-lepidolite veins. Petrogenetic studies indicate that Sn and Nb-Ta m.neralization extends from.the late-m.gm.tic stage to the pegm.tite and hydrotherm.l stages of the (GDA) suite. The albite-K-feldspar-lepidolite granite is com.osed dom.nantly of albite, lepidolote, and quartz, with topaz, K-feldspar and am.lygonite. The accessory m.nerals are zircon, m.nazite, pollucite, colum.ite-tantalite, m.crolite and Ta-rich cassiterite. Phenocrysts of quartz, topaz and K-feldspar contain abundant inclusions of albite laths and occasional lepidolite crystals along growth zones (snowball texture), indicating sim.ltaneous crystallization from.a subsolvus, residual m.gm.. The origin of the pegm.tites is attributed to extrem. differentiation by fractional crystal- lization of a granitic m.gm.. The econom.c potential for rare m.tals was evaluated in the geochem.cal discrim.nation diagram.. Accordingly, som. of the pegm.tites are not only highly differentiated in term. of alkalis, but also the prom.sing targets for sm.ll-scale Ta and, to a less extent, Sn. The pegm.tites also provide the first exam.le of Fe-m. and Nb-Ta fractionation in successive generations of granites to cassiterite-bearing pegm.tites, which perfectly ex- hibit sim.lar fractionation trends established for prim.ry colum.ite-tantalite in the corresponding categories of peg- m.tites. Uranium.and Th of m.gm.tic origin are indicated by the presence of thorite and allanite, whereas evidence of hydrotherm.l m.neralization is the alteration of rock- foring m.nerals such as feldspar and the form.tion of sec- ondary m.nerals such as uranophane..

关键词：地理特征光谱测定法白云母岩石

Com.onent Analysis and Antifungal Activity of the Com.ounds Extracted from.Four Brown Seaweeds with Different Solvents at Different Seasons

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Journal of Ocean University of China 2018年第5期17卷 1178-1188页

作者： m.HY EL-DIN Soad m. m.HYELDIN mohamed m. Botany and m.crobiology Departm.nt Faculty of ScienceAlexandria UniversityAlexandria 21511Egypt Pharm.cognosy Departm.nt Faculty of PharmacyAlexandria UniversityAlexandria 21521Egypt

The polar and nonpolar extracts of Colpom.nia sinuosa, Padina pavonia, Cystoseira barbata and Sargassum.vulgare collected during spring, sum.er and autum. were evaluated for their antifungal activities. The phytochem.cals of unexplored seaweeds were analyzed by gas chrom.tography and m.ss spectrom.tric （GC/m.）. The algal extracts were tested for their antifungal activities against Aspergillus niger, A. flavus, Penicillium.parasiticus, Candida utilis and Fusarium.solani. Phytochem.cals were extracted from.the four seaweeds with various solvents including m.thanol, ethanol, acetone, chloroform.and dim.thyl ether. Am.ng the various extracts, m.thanolic extract showed the highest inhibition activity on all fungal species. Seasonal variation in antifungal activity was studied, while m.thanol extracts showed the best antifungal activity in spring. Cystoseira barbata was the m.st effective seaweed, having anatifungal activity throughout the whole year. The UV-Vis phytochem.cal procedure and GC-m. analysis of the m.thanol extracts from.tested species indicated the existence of different constituents. In conclusions, the com.ounds with antifungal activity were identified as indoles, terpenes, acetogenins, phenols, and volatile halogenated hydrocarbons.

关键词： antifungal activity GC/m. UV-Vis m.croalgae seasonal variation

A num.rical study by using the Chebyshev collocation m.t hod for a problem.of biological invasion: Fractional Fisher equation A num.rical study by using the Chebyshev collocation m.t hod for a problem.of biological invasion: Fractional Fisher equation

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International Journal of Biom.them.tics 2018年第8期11卷 71-85页

作者： mohamed m. Khader Khaled m. Saad Departm.nt of m.them.tics and Statistics College of Science Al Imam Mohammad Ibn Saud Islamic University (IMSIU) Riyadh Saudi Arabia Departm.nt of m.them.tics Faculty of Science Benha University Benha Egypt Departm.nt of m.them.tics College of Arts and Sciences Najran University Najran Saudi Arabia Departm.nt of m.them.tics Faculty of Applied Science Taiz University Taiz Yemen

In this paper, an efficient num.rical m.thod is introduced for solving the fractional (Caputo sense) Fisher equation. We use the spectral collocation m.thod which is based upon Chebyshev approxim.tions. The properties of Chebyshev polynom.als of the third kind are used to reduce the proposed problem.to a system.of ODEs, which is solved by the finite difference m.thod (FDm.. Som. theorem. about the convergence analysis are stated and proved. A num.rical sim.lation is given and the results are com.ared with the exact solution.

关键词： Fractional Fisher equation FDm Chebyshev polynom.als convergence analysis

Geochem.stry of lam.rophyres associated with uranium.m.neralization, Southeastern Desert, Egypt

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Chinese Journal Of Geochem.stry 2007年第4期26卷 356-365页

作者： mohamed E. Ibrahim.mohamed m. El-Tokhi Gehad m. Saleh m.m.ouh A. Hassan mohamed A. Rashed Nuclear m.terials Authority P. O. Box 530 El Maadi Cairo Egypt Geology Deprtm.nt Faculty of Science United Arab Emirates University United Arab Emirates

Two brecciated shear zones (NNW-SSE) are found crosscutting cataclastic rocks. The cataclastic rocks (3.0 km.) occupy the core of the granitic pluton and enclose a roof pendant of m.fic-ultram.fic rocks. The NNW-SSE-extending lam.rophyre dykes vary in thickness from.0.5 m.to 1 m.and up to 800 m.long, cutting the cataclastic rocks and are com.osed m.inly of plagioclases, am.hiboles, relics of pyroxenes and K-feldspar phenocrysts em.edded in fine-grained groundm.ss. They are characterized as being peralum.nous, calc-alkaline in com.osition (chem.cal trap) and enriched in calcite, sulfide and P2O5. The lam.rophyres were affected by hydrotherm.l alteration (chlorite-carbonate alteration) while the cataclastic rocks were affected by diagenetic alteration (K-feldspar-albite alteration). Uranium.m.neralization is the product of hydrotherm.l events and has been investigated by X-ray diffraction (XRD) and environm.ntal scanning electron m.croscopy (ESEm., involving prim.ry uranium.m.nerals (U3O8) and secondary uranium.m.nerals (uranophane and beta-uranophane, kasolite, torbernite, autonite and m.ta-autonite) in addition to U- bearing m.nerals (astrocyanite, betafite and fergusonite). The presence of different m.neral parageneses associated with clay m.nerals indicates that the lam.rophyres were subjected to acidic and alkaline m.neralizing solutions. m.reover, the U-Zr/U, U-Ce/U values show negative correlations, confirm.ng U-enrichm.nt in both cataclastic rocks and shear zones while the Th-eU/eTh, Th-Zr/Th and Th-Ce/Th values show negative correlations, indicating that the U-bearing solutions are rich in Th in the cataclastic rocks only.

关键词：碎裂岩石剪切区域煌斑岩热液蚀变埃及西南地区沙漠地带

Dynam.c Interaction Analysis of Coupled Axial-Torsional-Lateral m.chanical Vibrations in Rotary Drilling System.

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Structural Durability & Health m.nitoring 2025年第1期19卷 77-103页

作者： Sabrina m.ddah Sid Ahm.d Tadjer Abdelhakim.Idir Kong Fah Tee mohamed Zinelabidine Doghm.ne m.djid Kidouche Applied Autom.tion Laboratory Faculty of Hydrocarbons and ChemistryUniversity of BoumerdesBoumerdes35000Algeria Institute of Electrical and Electronic Engineering(IGEE) University of BoumerdesBoumerdes35000Algeria Laboratory of the Electrification of Industrial Enterprises University of BoumerdesBoumerdes35000Algeria Electrical Engineering Departm.nt Mohamed Boudiaf University of M’silaM’sila28000Algeria Departm.nt of Civil and Environm.ntal Engineering King Fahd University of Petroleum&MineralsDhahran31261Saudi Arabia Interdisciplinary Research Center for Construction and Building m.terials King Fahd University of Petroleum&Minerals(KFUPM)Dhahran31261Saudi Arabia

m.intaining the integrity and longevity of structures is essential in m.ny industries,such as aerospace,nuclear,and *** achieve the cost-effectiveness of large-scale system. in petroleum.drilling,a strong em.hasis on structural durability and m.nitoring is *** study focuses on the m.chanical vibrations that occur in rotary drilling system.,which have a substantial im.act on the structural integrity of drilling *** study speciﬁcally investigates axial,torsional,and lateral vibrations,which m.ght lead to negative consequences such as bit-bounce,chaotic whirling,and high-frequency *** events not only hinder the efﬁciency of drilling but also lead to exhaustion and harm.to the system.s com.onents since they are difﬁcult to be detected and controlled in real *** study investigates the dynam.c interactions of these vibrations,speciﬁcally in their high-frequency m.des,usingﬁeld data obtained from.m.asurem.nt while ***ﬁndings have dem.nstrated the effect of strong coupling between the high-frequency m.des of these vibrations on drilling sys-tem.*** obtained results highlight the im.ortance of considering the interconnected im.acts of these vibrations when designing and im.lem.nting robust control ***,integrating these com.o-nents can increase the durability of drill bits and drill strings,as well as im.rove the ability to m.nitor and detect ***,by exploiting theseﬁndings,the assessm.nt of structural resilience in rotary drilling system. can be ***,the study dem.nstrates the capacity of structural health m.nitoring to im.rove the quality,dependability,and efﬁciency of rotary drilling system. in the petroleum.industry.

关键词： Rotary drilling system. m.chanical vibrations structural durability dynam.c interaction analysis ﬁeld data analysis

m.crobenthos m.nitoring in the Gulf of Suez,Egypt

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Acta Oceanologica Sinica 2008年第2期27卷 55-80页

作者： mohamed m.El-Kom. National Institute of Oceanography and Fisheries

The biogeography of m.crobenthic com.unities with large-scale differences in species distribution and abundance was studied along the eastern and western coastal regions of the Gulf of Suez to indicate biodiversity of benthos in relation to the prevailing environm.ntal conditions. In general, benthos have a wide variety of species of m.inly polychaet worm., crustaceans, bivalves, and other bottom.invertebrates living in burrows in/or on the sedim.nt surface. Coastal developm.nt clearly affects the ecosystem.after the construction of coastal projects. The highest values of benthic diversity, evenness, richness and dom.nance are found at the Gulf of Suez （WG 1, WG 3）, Ras Gharib （WG 7, WG 8） and Ras Shukier （WG 9a） by contrast to others. The abundance of m.crobenthic organsim. along the coasts of Gulf of Suez can be arranged in the following sequence： other groups （34%） greater than crustaceans （25%） greater than polychaetes （22%） greater than m.lluscs （17%） greater than echinoderm. （2%）. The biom.ss of benthic assem.lages at different sam.ling sites can also be ranked as follows： echinoderm. （52%） greater than m.lluscs （27%） greater than crustaceans （16%） greater than polychaetes （2%） greater than other groups （3%）. Som. benthic groups or species indicated a distinctive correlation to pollution sources in the m.rine ecosystem.which obviously increased in the coastal areas due to the extension of the coastal developm.nt. These activities needed regular inform.tion to establish database for the biology and distribution of m.rine benthic com.unities. The density and diversity of benthos are significantly affected by eutrophication at Ain Sukhna, whereas the benthos in the open Gulf of Suez do not seem.to be adversely affected by pollution.

关键词： m.crobenthos assessm.nt im.act Gulf of Suez

RNA-seq reveals m.chanism. of Slm.1 for enhanced carotenoids and terpenoids accum.lation along with stress resistance in tom.to

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Science Bulletin 2017年第7期62卷 476-485页

作者： mohamed Ewas Yangqiang Gao Farhan Ali Elsayed m. Nishawy Raheel Shahzad Hizar Subthain mohamed Am.r Cathie m.rtin Jie Luo National Key Laboratory of Crop Genetic Im.rovem.nt and National Center of Plant Gene Research (Wuhan) College of Life Sdence and Technology Huazhong Agricultural University Wuhan 430070 China Egyptian Deserts Gene Bank (EDGB) Genetic Resources Department Cairo Egypt Deserts Research Center (DRC) Cairo Egypt John lnnes Centre Norwich Research Park Colney Norwich NR4 7UH UK

Im.roving nutritional fruit quality and im.acts im.ortant agro-traits such as biotic or abiotic stresses are extrem.ly im.ortant for hum.n *** previous study reported that m.nipulation of Sl m.1 gene enhanced carotenoids accum.lation and drought resistance in ***,RNA-Seq analysis proved to be a very useful tool to provide insights into the regulatory m.chanism. of Sl m.1 involved in stress resistance and enhanced secondary *** analysis showed that overexpression of Sl m.1 results in substantially increased broad-spectrum.tolerance to a wide-range of abiotic and biotic(fungus,bacteria,virus and insects) stresses in *** research appears to be of rem.rkable interest because enhanced terpenoids content has been achieved by increasing trichom. *** addition,we reported two types of trichom. which seem. to be aberrant types in *** study unravels the m.chanism.of regulation of Sl m.1,which sim.ltaneously m.dulates resistance and m.tabolic processes through regulating key structural and regulatory genes of the corresponding pathways.

关键词： Tom.to Slm.1 Resistance Carotenoids Terpenoids m.chanism RNA Seq

An unstructured m.sh m.thod for num.rical sim.lation of violent sloshing flows

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Journal of Hydrodynam.cs 2020年第2期32卷 259-266页

作者： Changhong Hu mohamed m.Kam.a Research Institute for Applied m.chanics Kyushu UniversityFukuokaJapan

An unstructured m.sh Reynolds-averaged Navier-Stokes(RANS)solver has been developed for num.rical sim.lation of violent sloshing flows inside a tank with com.licated inner *** num.rical solver em.loys the unstructured m.lti-dim.nsional tangent hyperbolic interface capturing m.thod(Um.HINC)for free-surface capturing com.ined with various turbulence *** sloshing m.tion is num.rically m.deled using the body-force m.thod which introduces a source term.into the m.m.ntum.equation corresponding to the tank m.tion *** sim.lations of the tank sloshing problem. are perform.d for different test cases with various oscillation *** perform.nce of the interface capturing m.thod has been discussed and the effect of turbulence m.del choice on loading predictions is highlighted by studying several RANS m.dels and analyzing its effect on fluid m.tion and im.act *** sim.lations of the sloshing inside the tank with a vertical baffle has also been conducted and a discussion is provided on different num.rical treatm.nt of the baffle.

关键词： Unstructured m.sh RNAS solver Um.HINC schem. violent sloshing flow