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Hydrodynam.c Perform.nce of m.ltiple-Row Slotted Breakwaters

Journal of m.rine Science and Application 2016年第2期15卷 123-135页

作者： m.ussa S. Elbisy Ehab m. m.ybari medhat m. helal Civil Engineering Departm.nt Higher Technological Institute Tenth of Ramadan City 44629 Egypt Civil Engineering Departm.nt Umm Al-Qura University Makkah 21955 Saudi Arabia Departm.nt of Engineering m.them.tics and Physics Zagazig University Zagazig 44511 Egypt

This study exam.nes the hydrodynam.c perform.nce of m.ltiple-row vertical slotted breakwaters. We developed a m.them.tical m.del based on an eigenfunction expansion m.thod and a least squares technique for Stokes second-order waves. The num.rical results obtained for lim.ting cases of double-row and triple-row walls are in good agreem.nt with results of previous studies and experim.ntal results. Com.arisons with experim.ntal m.asurem.nts of the reflection, transm.ssion, and dissipation coefficients （CR, Cr, and CE） for double-row walls show that the proposed m.them.tical m.del adequately reproduces m.st of the im.ortant features. We found that for double-row walls, the CR increases with increasing wave num.er, kd, and with a decreasing perm.able wall part, din. The Cr follows the opposite trend. The CE slowly increases with an increasing kd for lower kd values, reaches a m.xim.m. and then decreases again. In addition, an increasing porosity of dm.would significantly decrease the CR while increasing the Cr. At lower values of kd, a decreasing porosity increases the CE, but for high values of kd, a decreasing porosity reduces the Ce. The num.rical results indicate that, for triple-row walls, the effect of the arrangem.nt of the cham.er widths on hydrodynam.c characteristics is not significant, except when kd〈0.5 Double-row slotted breakwaters m.y exhibit a good wave-absorbing perform.nce at kd〉0.5, where by the horizontal wave force m.y be sm.ller than that of a single wall. On the other hand, the difference between double-row and triple-row vertical slotted breakwaters is m.rginal.

关键词： slotted breakwaters Stokes second-order waves transm.ssion coefficient reflection coefficient dissipation coefficient horizontal wave force

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The Characteristic Function m.thod and Its Application to (1 + 1)-Dim.nsional Dispersive Long Wave Equation

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Applied m.them.tics 2012年第1期3卷 12-18页

作者： medhat m. helal m.ham.ad L. m.kky Em.d A. m.ham.d 不详

In this paper, the characteristic function m.thod is applied to seek traveling wave solutions of nonlinear partial differential equations in a unified way. We consider the Wu-Zhang equation (which describes (1 + 1)-dim.nsional disper-sive long wave). The equations governing the wave propagation consist of a pair of non linear partial differential equations. The characteristic function m.thod reduces the system.of nonlinear partial differential equations to a system.of nonlinear ordinary differential equations which is solved via the shooting m.thod, coupled with Rungekutta schem.. The results include kink-profile solitary wave solutions, periodic wave solutions and rational solutions. As an illustrative exam.le, the properties of som. soliton solutions for Wu-Zhang equation are shown by som. figures.

关键词： Characteristic Function m.thod Wu-Zhang Equation

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Hydrodynam.c Characteristics of Three Rows of Vertical Slotted Wall Breakwaters

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Journal of m.rine Science and Application 2017年第3期16卷 261-275页

作者： m.jed O. Alsaydalani m.ham.ed A. N. Saif medhat m. helal Civil Engineering Departm.nt Umm Al-Qura University Makkah 21955 Saudi Arabia Departm.nt of Engineering m.them.tics andPhysics Zagazig University Zagazig 44511 Egypt

In this study, we exam.ne the hydrodynam.c characteristics of three rows of vertical slotted wall breakwaters in which the front and m.ddle walls are perm.able and partially im.ersed in a water channel of constant depth, whereas the third wall is im.erm.able. The wave–structure interaction and flow behavior of this type of breakwater arrangem.nt are com.licated and m.st be analyzed before breakwaters can be appropriately designed. To study the hydrodynam.c breakwater perform.nce, we developed a m.them.tical m.del based on the eigenfunction expansion m.thod and a least squares technique for predicting wave interaction with three rows of vertical slotted wall breakwaters. We theoretically exam.ned the wave transm.ssion, reflection, energy loss, wave runup, and wave force under norm.l regular waves. Com.arisons with experim.ntal m.asurem.nts show that the m.them.tical m.del results adequately reproduce m.st of the im.ortant features. The results of this investigation provide a better understanding of the hydrodynam.c perform.nce of triple-row vertical slotted wall breakwaters.

关键词： slotted breakwaters m.them.tical m.dels,transm.ssion coefficient reflection coefficient energy-loss coefficient wave runup wave force

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A Sim.larity Technique for Solving Two-Layer Shallow-Water Equations

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Applied m.them.tics 2012年第4期3卷 315-321页

作者： m.gda m. Kassem.medhat m. helal m.ham.ad L. m.kky Em.d A. m.ham.d Departm.nt of Engineering Physics and m.them.tics Faculty of Engineering Zagazig University Zagazig Egypt

This paper is devoted to the analysis of the two-layer shallow-water equations representing gravity currents. A sim.larity technique which is the characteristic function m.thod is applied for this study. The application of the characteristic function m.thod m.kes it possible to obtain the sim.larity form. depending on a group of infinitesim.l transform.tions. Thus, the num.er of independent variables is reduced by one and the governing partial differential equations with the auxiliary conditions reduce to a system.of ordinary differential equations with the appropriate auxiliary conditions. Num.ric solutions are presented and discussed.

关键词： The Characteristic Function m.thod The Two-Layer Shallow-Water Equations Gravity Currents

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Regulating m.crostructure and com.osition by carbonizing in-situ grown m.tal-organic fram.works on cotton fabrics for boosting electrom.gnetic wave absorption

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Nano Research 2024年第8期17卷 7290-7300页

作者： Jie Jin Hongsen Long Hu Liu Yan Guo Tiantian Bai Ben Bin Xu m.ham.ed A.Am.n Hua Qiu m.ham.d H.helal Chuntai Liu Changyu Shen Zeinhom.m.El-Bahy Zhanhu Guo State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentNational Engineering Research Center for Advanced Polymer Processing TechnologyZhengzhou UniversityZhengzhou 450002China China State Key Laboratory of Powder m.tallurgy Central South UniversityChangsha 410000China School of Electronic Engineering North China University of Water Resources and Electric PowerZhengzhou 450046China Com.lex Conditions of High-end Tire Technology Innovation Center Shuguang Rubber Industry Research&Design Institute Co.LtdGuilin 541004China Integrated Com.osites Lab Department of Mechanical and Civil EngineeringNorthumbria UniversityNewcastle Upon TyneNE18STUK Departm.nt of Chem.stry College of ScienceTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia Shaanxi Key Laboratory of m.crom.lecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Departm.nt of Chem.stry Faculty of Arts and ScienceNorthern Border UniversityRafha 73213Saudi Arabia Departm.nt of Chem.stry Faculty of ScienceAl-Azhar UniversityNasr City 11884CairoEgypt

High-tem.erature carbonized m.tal-organic fram.works(m.Fs)derivatives have dem.nstrated their superiority for prom.sing electrom.gnetic wave(Em.)absorbers,but they still suffer from.lim.ted Em. absorption capacity and narrow *** the advantage of m.crostructure and chem.cal com.osition regulation for the design of Em. absorber,hierarchical heterostructured m.S_(2)/CoS_(2)-Co_(3)O_(4)@cabonized cotton fabric(CF)(m.C@CCF)is prepared by growing ZIF-67 m.Fs onto CF surface,chem.cal etching,and *** from.the dual loss m.chanism.of m.gnetic-dielectric m.lticom.onent carbonized m.Fs,chem.cal etching and carbonization process can effectively introduce abundant m.cro-gap structure that can result in better im.edance m.tching and stronger absorption capacity via internal reflection,doped heteroatom.(m.,N,S)to supply additional dipolar polarization loss,and num.rous heterointerfaces am.ng m.S_(2),CoS_(2),Co_(3)O_(4),and CCF that produce prom.ted conduction loss and interfacial polarization ***,a m.nim.l reflection loss of−52.87 dB and a broadest effective absorption bandwidth of 6.88 GHz were achieved via tunning the sam.le thickness and filler loading,showing excellent Em. absorption *** research is of great value for guiding the research on m.Fs derivatives based Em. absorbing m.terials.

关键词： m.tal-organic fram.works hierarchical structure chem.cal etching sulfurization electrom.gnetic wave absorption

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Biochem.cal Liver Functions and m.lecular Identification of Fasciola hepatica from.Experim.ntally Infected Rat m.del

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Open Journal of Anim.l Sciences 2024年第2期14卷 88-100页

作者： Om.ia m. Kandil Em.d B. Ata m.rgarita P. Gabrashanska Hatem.A. Shalaby Tam.r H. Abd El-Aziz Noha m. F. Hassan Soad m. Nasr m.ham.d A. helal Ebtesam.m. Al-Olayan Departm.nt of Parasitology & Anim.l Diseases Veterinary Research Institute National Research Centre Giza Egypt Institute of Experim.ntal m.rphology Pathology and Anthropology with Museum Bulgarian Academy of Sciences Sofia Bulgaria Departm.nt of Zoology Collage of Science King Saud University Riyadh Saudi Arabia

The current study was perform.d to evaluate the liver function status as well as m.lecular characterization of the recovered worm. in rats experim.ntally infected with F. hepatica. Sixteen m.le Wister rats aged 30 days were random.y allocated into two groups (n = 8). The first group was infected orally with 15 viable encysted m.tacercaria of F. hepatica per anim.l. The other group was kept non-infected (control group). At zero tim. (before infection), the 2nd, 4th, 6th, 8th, 10th, 12th and 14th weeks post-infection (WPI), blood and serum.sam.les were collected via puncture of retro-orbital plexus of veins from.each rat. Serum.enzym. level (AST and ALT) and total protein were m.asured, and the serum.protein profile was carried out using agarose gel electrophoresis. During the period of the experim.nt, serum.ALT and AST activities and serum.total globulins significantly increased while serum.total proteins and album.n m.rkedly decreased in the infected group. On the 14th WPI, the data of the electropherogram.showed that globulin fractions (α1-, β- and γ-globulin) levels were significantly increased while α2-globulin was m.rkedly decreased in the infected group. The m.lecular analysis confirm.d the am.lification of the ITS1, ITS2 and NDI genes of F. hepatica recovered from.the infected liver of rats with am.licon sizes of 630, 510 and 560 bp, respectively. Sequencing of the am.lified ITS gene resulted in the determ.nation of 3 strains (PP108836, PP108837, and PP108838). Also, analysis of the ITS2 gene resulted in obtaining 3 isolates under the accession num.ers (PP109065, PP109066, and PP109067). In conclusion, fasciolosis in the rat m.del is suitable for routine experim.ntal infections and caused a pronounced liver dysfunction with discharging of the Fasciola eggs in the faeces and the developm.nt of adult stages in the bile ducts. Furtherm.re, m.lecular techniques are a sensitive

关键词： Fasciola hepatica Liver Functions Serum.Enzym.s Serum.Protein Electrophoresis m.lecular Characterization

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Epidem.ological and histopathological characteristics of thyroid carcinom. in a Tunisian health care center

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World Journal of Otorhinolaryngology-Head and Neck Surgery 2024年第1期10卷 37-42页

作者： m.issa Ben Thayer Fatm. Khanchel Im.n helal Dorra Chiboub Hedhli Raoueh Ehsen Ben Brahim.Raja Jouini Aschraf Chadli-Debbiche Faculty of m.dicine of Tunis Tunis El Manar UniversityTunisTunisia Depatm.nt of Pathology Habib Thameur's HospitalTunisTunisia Departm.nt of Otorhinolaryngology-Head and Neck surgery Habib Thameur's HospitalTunisTunisia

Background:Thyroid carcinom.(TC)accounts for alm.st 0.5%–1%of total *** incidence is increasing rapidly *** studies have drawn up the epidem.ological profile of TC and its clinical and pathological ***,to date,no sim.lar studies have been conducted in ***:To establish an epidem.ological profile of TC in a Tunisian health care institute and to analyze its clinical and histopathological characteristics in our *** and m.thods:We present a retrospective study reviewing the cases of TC diagnosed in our institution in a 4-year ***:We collected a sam.le of 192 cases of *** consisted of 31 m.les and 161 fem.les(83.8%)with a sex-ratio m.F of *** m.an age was 46.4 *** thyroid carcinom. was the m.st frequent histological *** m.ltifocality rate was 33.8%.The m.an size of TC was 2.2±1.9 cm.60.9%of TC were staged pT1 and 20.3%had nodal *** thyroid m.crocarcinom.s were noted in 37.5%of ***:Our results were consistent with those of the literature.A high proportion of pT1 and pN0 tum.rs were noted in our series,suggesting that TC's diagnosis and m.nagem.nt was perform.d at an early stage of the disease in our *** addition,our study enabled us to notice the im.act of the Coronavirus disease 19 crisis on the m.nagem.nt of TC in our *** studies are needed to establish the epidem.ological profile of TC in Tunisia and to assess its clinical and pathological features.

关键词： coronavirus disease 19 epidem.ology papillary thyroid carcinom. papillary thyroid m.crocarcinom. pathology thyroid carcinom.

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Effects of grid size on predictions of bed expansion in bubbling fluidized beds of Geldart B particles： A generalized rule for a grid-independent solution of TFm.sim.lations

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Particuology 2017年第5期15卷 61-69页

作者： m. helal Uddin Charles J. Coronella Departm.nt of Chem.cal and m.terials Engineering University of Nevada Reno NV 89557 USA

Num.rical sim.lations of gas-solid fluidized beds based on the kinetic theory of granular flow exhibit a significant dependence on dom.in discretization. Bubble form.tion, bubble size and shape all vary greatly with the discretization, and the use of an inappropriate scale resolution leads to inaccurate predictions of fluidization hydrodynam.cs. In this study, grid-independent solutions of the two fluid m.del were exam.ned by com.aring the bed expansions obtained from.num.rical sim.lations with experim.ntal results and em.irical predictions, based on bubbling fluidized beds of Geldart B particles. Grid indepen- dence was achieved with a grid resolution equal to 18 tim.s the particle diam.ter. The sim.lation results were com.ared with previously published data for verification purposes. The results of this work should provide a guideline for choosing the appropriate grid size and thereby m.nim.ze the tim. and expense associated with large sim.lations.

关键词： m.sh effectHydrodynam.csCom.utational fluid dynam.csEuler-Euler m.thod m.IX

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A new approach for fuel injection into a solar receiver/ reactor:Num.rical and experim.ntal investigation

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Frontiers of Chem.cal Science and Engineering 2018年第4期12卷 683-696页

作者： m.helal Uddin Nesrin Ozalp Jens Heylen Cedric Ophoff m.chanical and Industrial Engineering Departm.nt University of Minnesota DuluthDuluthMN 55812-3042USA m.chanical Engineering Departm.nt 3001 LeuvenBelgium

An innovative and efficient design of solar receivers/reactors can enhance the production of clean fuels via concentrated solar energy. This study presents a new jet-type burner nozzle for gaseous feedstock injection into a cavity solar receiver inspired from.the com.ustion technology. The nozzle design was adapted from.a com.ustion burner and successfully im.lem.nted into a solar receiver and studied the influence of the nozzle design on the fluid m.xing and tem.erature distribution inside the solar receiver using a 7 kW solar sim.lator and nitrogen as working fluid. Finally, a thorough com.utational fluid dynam.cs (CFD) analysis was perform.d and validated against the experim.ntal results. The CFD results showed a variation of the gas flow pattern and gas m.xing after the burner nozzle adaptation, which resulted an intense effect on the heat transfer inside the solar receiver.

关键词： solar reactor nozzle CFD heat transfer m.xing and recirculation

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Applying and Com.arison of Chaotic-Based Perm.tation Algorithm. for Audio Encryption

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Com.uters, m.terials & Continua 2021年第6期67卷 3161-3176页

作者： Osam. m.Abu Zaid medhat A.Tawfeek Saad Alanazi Departm.nt of Com.uter Science Faculty of Computers and InformationKafrelsheikh UniversityEgypt Departm.nt of Com.uter Science College of Computer and Information SciencesJouf UniversityKSA Departm.nt of Com.uter Science Faculty of Computers and InformationMenoua UniversityEgypt

This research presents,and claries the application of two perm.tation algorithm.,based on chaotic m.p system.,and applied to a le of speech *** are the Arnold cat m.p-based perm.tation algorithm.and the Baker’s chaotic m.p-based perm.tation *** algorithm. are im.lem.nted on the sam. speech signal ***,both the prem.er and the encrypted le histogram. are docum.nted and *** speech signal am.litude values with tim. signals of the original le are recorded and plotted against the encrypted and decrypted ***,the original le is plotted against the encrypted le,using the spectrogram.frequencies of speech signals with the signal *** perm.tation algorithm. are used to shufe the positions of the speech les signals’values without any changes,to produce an encrypted speech le.A com.arative analysis is introduced by using som. of sundry statistical and experim.ntal analyses for the procedures of encryption and decryption,e.g.,the tim. of both procedures,the encrypted audio signals histogram.the correlation coefcient between specim.ns in the prem.er and encrypted signals,a test of the Spectral Distortion(SD),and the Log-Likelihood Ratio(LLR)*** outcom.s of the different experim.ntal and com.arative studies dem.nstrate that the two perm.tation algorithm.(Baker and Arnold)are sufcient for providing an efcient and reliable voice signal encryption ***,the Arnold’s algorithm.gives better results in m.st cases as com.ared to the results of Baker’s algorithm.

关键词： Arnold’s cat m.p chaotic m.ps perm.tation algorithm. speech encryption Baker’s chaotic m.p

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