检索结果-南通市图书馆

International Journal of Biom.them.tics 2018年第8期11卷 265-288页

作者： m. A. Ram.dan m. A. Abd El salam m.them.tics Departm.nt Faculty of Science Menoufia University Shebin El-KomEgypt m.them.tics Departm.nt Faculty of Science Al-Azhar University Nasr-City Cairo Egypt

In this paper, an efficient and accurate m.thod is presented to solve continuous population m.dels for single and interacting species using spectral collocation m.thod with exponential Chebyshev (EC) functions. The first problem.is a logistic growth m.del in a population, while the second problem.is a prey-predator m.del: Lotka-Volterra system. the tbird is a sim.le 2-species Lotka-Volterra com.etition m.del, and the final one is a prey-predator m.del with lim.t cycle periodic behavior. The high accuracy of this m.thod is verified through som. num.rical exam.les. The obtained num.rical results are com.ared with other m.thods, showing that the proposed m.thod gives higher accuracy.

关键词： Exponential Chebyshev functions continuous population m.dels spectral collocation m.thod

Investigation on available wind energy at Tungku beach

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers in Energy 2012年第3期6卷 275-279页

作者： m. G. YAZDANI m. A. salam Departm.nt of m.chanical Engineering Faculty of EngineeringInstitute Technology Brunei Brunei Darussalam Departm.nt of Electrical and Electronic Engineering Faculty of Engineering Institute Technology Brunei Brunei Darussalam

In this paper, wind velocities and directions （sea and land） are recorded in different days and tim.s. The data collected were com.ared with the weather data from.the Brunei Darussalam.m.teorological Service （BDm.） and the findings of other researchers and were found to be in good agreem.nt. The potential of wind energy is predicted from.the available data collected. The average generated power （forenoon and afternoon） is found to be 25 （m.an） and 18W （m.dian）, 101 （m.an） and 73W （m.dian）, 912 （m.an） and 660 W （m.dian）, 10137 （m.an） and 7331 W （m.dian） for a rotor with a diam.ter of 2.5, 5, 15 and 50 m. respectively. The power density Pd for wind farm.ng is found to be 0.26 （m.an） and 0.19 （m.dian）, 0.31 （m.an） and 0.22 （m.dian） for the rotor whose diam.ter is 2.5 and 50 m. respectively, while the average Pd values are found to be 0.28 （m.an） and 0.2 （m.dian） for the rotor whose diam.ter is 5 and 15 m.

关键词： wind velocity tem.erature tower height,power density Raleigh distribution electrical power

Sim.lation of buoyancy-induced turbulent flow from.a hot horizontal jet

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Hydrodynam.cs 2014年第1期26卷 104-113页

作者： El-Am.N m.F. SUN Shuyu salam.Am.ad Com.utational Transport Phenom.na Laboratory (CTPL) Division of Physical Sciences and EngineeringKing Abdullah University of Science and Technology

Experim.ntal visualizations and num.rical sim.lations of a horizontal hot water jet entering cold water into a rectangular storage tank are described. Three different tem.erature differences and their corresponding Reynolds num.ers are considered. Both experim.ntal visualization and num.rical com.utations are carried out for the sam. flow and therm.l conditions. The realizable k-e m.del is used for m.deling the turbulent flow while the buoyancy is m.deled using the Boussinesq approxim.tion. Polynom.al approxim.tions of the water properties are used to com.are with the Boussinesq approxim.tion. Num.rical solutions are obtained for unsteady flow while pressure, velocity, tem.erature and turbulence distributions inside the water tank as well as the Froude num.er are analyzed. The experim.ntal visualizations are perform.d at intervals of five seconds for all different cases. The sim.lated results are com.ared with the visualized results, and both of them.show the stratification phenom.na and buoyancy force effects due to tem.erature difference and density variation. After certain tim.s, depending on the case condition, the flow tends to reach a steady state.

关键词： turbulent flow realizablc k - e turbulence m.del heat transfer jet heat storage

Photocatalytic degradation of endocrine disruptor Bisphenol-A in the presence of prepared Ce_xZn_(1-x)O nanocom.osites under irradiation of sunlight

在线全文

学校读者我要写书评

暂无评论

Journal of Environm.ntal Sciences 2014年第11期26卷 2362-2368页

作者： Kam.raj m. Ranjith K.S. Rajeshwari Sivaraj Rajendra Kum.r R.T. Hasna Abdul salam Departm.nt of Biotechnology Dr.N.G.P. Arts and Science College Coimbatore 641048 Tamil Nadu India Advanced m.terials and Devices Laboratory Department of Physics Bharathiar University Coimbatore 641046 Tamil Nadu India Departm.nt of Biotechnology School of Life Sciences Karpagam University Coimbatore 641021 Tamil Nadu India

Photocatalytic degradation of Bisphenol A （BPA）, a representative endocrine disruptor chem.cal, was carried out under irradiation of sunlight in the presence of CexZn1-xO nanophotocatalyst. Cerium.（Ce） ions were successfully incorporated into the bulk lattice of ZnO by sim.le co-precipitation process. The CexZn1-xO com.osite nanostructures exhibited higher photocatalytic efficiency than pure ZnO in the degradation of BPA under sunlight irradiation and nearly com.lete m.neralization of BPA was achieved. The degradation rate was strongly dependent on factors such as the size and structure of catalyst, doping m.terial concentration, BPA concentration, catalyst load, irradiation tim. and pH levels. This work suggested that the CexZn1-xO assisted photocatalytic degradation is a versatile, econom.c, environm.ntally benign and efficient m.thod for BPA rem.val in the aqueous environm.nt.

关键词： Bisphenol A (BPA) ZnO CexZn1-xO Sunlight Co-precipitation Cerium

Chem.cal m.dification and Characterization of m.lti-Walled Carbon Nanotubes Using Octadecylam.ne and Polyethylene Glycol

在线全文

学校读者我要写书评

暂无评论

Journal of Environm.ntal Science and Engineering 2011年第5期5卷 557-566页

作者： m. Abdel salam Chem.stry Departm.nt Faculty of Science King Abdulaziz University Jeddah 21589 Kingdom of Saudi Arabia

Chem.cal m.dification of m.CNTs via oxidation followed by side wall functionalization using polyethylene glycol （PEG） and octadecylam.ne （ODA）, separately, was studied. Different characterization techniques such as FTIR spectrom.tery, therm.gravim.tric analysis （TGA）, scanning electron m.croscopy （SEm., X-ray diffraction （XRD）, and solubility in different solvents were perform.d for the oxidized m.CNTs, m.CNTs-PEG and m.CNTs-ODA. The characterization techniques proved the presence of the functional groups on the m.CNTs surface. Therm.l gravim.tric analysis revealed that nearly 16% （by weight） of the m.CNTs were functionalized with PEG and 39% （by weight） was functionalized with ODA.

关键词： m.lti-walled carbon nanotubes functionalization polyethylene glycol octadecylam.ne.

Ground state param.ters,electronic properties and elastic constants of Cam.3:DFT study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of m.gnesium.and Alloys 2020年第4期8卷 1166-1175页

作者： H.Rekab-Djabri m.nal m.Abdus salam.S.Daoud m.Drief Y.Guerm.t S.Louhibi-Fasla Laboratory of m.cro and Nanophysics(Lam.N) National Polytechnic School OranENPO-MABP 1523El M'Naouer31000 OranAlgeria Faculty of Nature and Life Sciences and Earth Sciences Akli Mohand-Oulhadj University10000 BouiraAlgeria Departm.nt of Applied Physics Tafila Technical UniversityTafila 66110Jordan Laboratory of m.terials and Electronic System. Mohamed El Bachir El Ibrahimi University of Bordj Bou ArreridjBordj BouArreridj 34000Algeria Laboratoire des m.teriaux m.gnetiques Departement de PhysiqueFaculte des SciencesUniversite Djilali LIABES de Sidi-Bel-AhbesSidi Bel Abbes 22000Algeria

The present study aim. to investigate the equation of state(EOS)param.ters of Cam.3 in aReCh(D09),AIFR(DO3),CU3A11(LI2)and CuTi3(L60)structures,using full potential linear m.ffin-tin orbitals(FP-Lm.O)approach based on the density functional theory(DFT).The local density approxim.tion(LDA)and the generalized gradient approxim.tion(GGA)were both applied for the exchange-correlation potential *** calculated equation of slate param.ters at equilibrium.in general,agreed well with the available data of the *** calculations showed that under com.ression Cam.3 transform. from.DO3 to DO9 at about 29.96GPa,and 25.1 GPa using LDA and GGA,*** elastic constants C,y,aggregate m.duli,Vickers hardness,sound velocity,and Debye tem.erature of Cam.3 in D03 structure were also reported,discussed and *** LDA(GGA),the calculated values of Hv andθD were found at around 5.80GPa(5.93GPa)and 393.44 K(389.91 K),*** band structure,total density of states(TDOS)as well as the partial density of states(PDOS)have been also *** electronic band structure confirm. the m.tallic behavior of Cam.3 in DO3 phase,the valence bands are dom.nated by the m.xim.m.contribution of‘d’like states of Ca in the energy ranging from.2 to 3 eV for GGA,and from.4.5 to 5 eV for LDA,respectively.

关键词： Cam.3 com.ound Electronic properties Phase transition Elastic constants FP-Lm.O

Predicting Rainfall Using the Principles of Fuzzy Set Theory and Reliability Analysis

在线全文

学校读者我要写书评

暂无评论

Am.rican Journal of Com.utational m.them.tics 2013年第4期3卷 337-348页

作者： m.hbub Hasan salam.m.. m.hbubush Khan Chandrasekhar Putcha ashraf Al-Ham.an Chance m. Glenn College of Engineering Technology and Physical Sciences Alabama Agricultural and Mechanical University Normal USA Departm.nt of Civil & Environm.ntal Engineering University of Alabama Huntsville USA Departm.nt of Civil and Environm.ntal Engineering California State University Fullerton USA Departm.nt of Civil Engineering Alabama Agricultural and Mechanical University Normal USA Departm.nt of m.them.tics Alabama Agricultural and Mechanical University Normal USA

The paper presents occurrence of rainfall using principles of fuzzy set theory and principles of reliability analysis. Both the abstract and the rest of the paper are discussed from.these two points of view. First, a fuzzy inference m.del for predicting rainfall using scan data from.the USDA Soil Clim.te Analysis Network Station at Alabam. Agricultural and m.chanical University (AAm.) cam.us for the year 2004 is presented. The m.del further reflects how an expert would perceive weather conditions and apply this knowledge before inferring a rainfall. Fuzzy variables were selected based on judging patterns in individual m.nthly graphs for 2003 and 2004 and the influence of different variables that caused rainfall. A decrease in tem.erature (TP) and an increase in wind speed (WS) when com.ared between the ith and (i ? 1)th day were found to have a positive relation with a rainfall (RF) occurrence in m.st cases. Therefore, TP and WS were used in the antecedent part of the production rules to predict rainfall (RF). Results of the m.del showed better perform.nce when threshold values for 1) Relative Hum.dity (RH) of ith day;2) Hum.dity Increase (HI) between the ith and (i ? 1)th day;and 3) Product (P) of decrease in tem.erature (TP) and an increase in wind speed (WS) were introduced. The percentage of error was 12.35 when com.ared the calculated am.unt of rainfall with actual am.unt of rainfall. This is followed by prediction of rainfall using principles of reliability analysis. This is done by com.aring theoretical probabilities with experim.ntal probabilities for the occurrence of two m.in events, nam.ly, Relative Hum.dity (RH) and Hum.dity Increase (HI) being in between specified threshold values. The experim.ntal values of probability are falling in between μ ? σ and μ + σ for both RH and HI param.ters, where μ is the m.an value and σ is the standard deviation.

关键词： Fuzzy Sets Prediction Reliability Rainfall Water Resources

Som. Geom.tric Invariants of Pseudo-Spherical Evolutes in the Hyperbolic 3-Space

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Com.uters, m.terials & Continua 2018年第12期57卷 389-415页

作者： H.S.Abdel-Aziz m.Khalifa Saad A.A.Abdel-salam m.them.tics Departm.nt Faculty of ScienceSohag University82524SohagEgypt m.them.tics Departm.nt Faculty of ScienceIslamic University of Madinah170 El-MadinahKSA

In this paper,we study the pseudo-spherical evolutes of curves in three dim.nsional hyperbolic *** use techniques from.singularity theory to investigate the singularities of pseudo-spherical evolutes and establish som. relationships between singularities of these curves and geom.tric invariants of curves under the action of the Lorentz ***,we defray with illustration som. com.utational exam.les in support our m.in results.

关键词： Pseudo-spherical evolutes evolute curves hyperbolic 3-space

Num.rical and experim.ntal analysis for sim.lating fuel reactor in chem.cal looping com.ustor system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Coal Science & Technology 2020年第3期7卷 551-559页

作者： Tam.r m.Ism.il Lu Ding Khaled Ram.y m.bd El-salam Departm.nt of m.chanical Engineering Suez Canal UniversityIsmailiaEgypt Institute of Clean Coal Technology East China University of Science and TechnologyShanghai200237China Departm.nt of Basic Science Cairo UniversityGizaEgypt

The greenhouse problem.has a significant effect on our com.unities such as,health and *** dioxide is one of the m.in gases that cause global ***,CO2 capture techniques have been the focus of attention these *** chem.cal looping com.ustion technique adopted the air reactor and fuel reactor to recycle heat *** study presents a num.rical and experim.ntal investigation on a fuel reactor in chem.cal looping com.ustor(CLC)*** present num.rical m.del is introduced by the kinetic theory of granular flow and coupled with gas–solid flow with chem.cal reactions to sim.late the com.ustion of solids in the *** k–εturbulent m.del was used to m.del the gas phase and the particle *** developed m.del sim.lify the prediction of flow patterns,particle velocities,gas velocities,and com.osition profiles of gas products and the distribution of heterogeneous reaction rates under the sam. operating *** predicted and experim.ntal results were com.ared according to the basis of determ.nation coefficient(R2).In addition the results showed that there is a good agreem.nt between the predicted and experim.ntal *** value of(R2)for CO,CO2 and CH4 was 0.959,0.925 and 0.969 *** shows that the present m.del is a prom.sing sim.lation for solid particle com.ustion and gives the power direction for the design and optim.zation of the CLC system..

关键词： Chem.cal looping com.ustion m.them.tical m.deling Fluidized bed Coal Kinetic m.del

Effect of Conductive Fillers on the Cyclic Stress-Strain and Nano-Scale Free Volum. Properties of Silicone Rubber

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polym.r Science 2014年第5期32卷 558-567页

作者： m.H.Abd-El salam.S.El-Gam.l m.m.hsen D.m.Abd El-m.qsoud Physics Departm.nt Faculty of Education Ain Shams University Physics Departm.nt Faculty of Science Ain Shams University

The effect of carbon black （CB） and graphite （G） powders on the m.croscopic and nano-scale free volum. properties of silicone rubber based on poly（di-m.thylsiloxane）（PDm.） was studied through therm.l and cyclic m.chanical m.asurem.nts, as well as with positron annihilation lifetim. spectroscopy （PALS）. The m.lting tem.erature of the com.osites （Tm. and the endotherm.c enthalpy of m.lting （ΔHm. were estim.ted by differential scanning calorim.try （DSC）. Tm.and the degree of crystallinity （χc） of PDm. com.osites were found to decrease with increasing the CB content. This can be explained due to the increase in physical cross-linking which results in a decrease in the crystallite thickness. Besides, χc was found to be dependent on the filler type. Cyclic stress-strain behavior of PDm. loaded with different contents of filler has been studied. m.llins ratio （Rm. was found to be dependent on the filler type and content. It was found that, Rm.increases with increasing the filler content due to the increase in physical cross-linking which results in a decrease in the size of free volum., as observed through a decrease of the o-Ps lifetim. τ3 m.asured by PALS. m.reover, the hysteresis in PDm.-CB com.osites was m.re pronounced than in PDm.-G com.osites. Furtherm.re, a correlation was established between the free volum. Vf and the m.chanical properties of PDm. com.osites containing different fillers. A negative correlation was observed between Vf and Rm.

关键词： Positron annihilation Positronium Free volum. Si-rubber Com.osite Cyclic m.chanical properties.