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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

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

Stability analysis solutions of the nonlinear m.dified Degasperis-Procesi water wave equation

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Journal of Ocean Engineering and Science 2017年第3期2卷 155-160页

作者： m.A.helal Aly R.Seadawy m.Zekry m.them.tics Departm.nt Faculty of ScienceCairo UniversityGizaEgypt m.them.tics Departm.nt Faculty of ScienceTaibah UniversityAl-UlaSaudi Arabia m.them.tics Departm.nt Faculty of ScienceBeni-Suef UniversityEgypt

In the present study,the solitary wave solutions of m.dified Degasperis-Procesi equation are *** the standard Degasperis-Procesi equation,where m.lti-peakon solutions arise,the m.dification caused a change in the characteristic of these peakon solutions and changed it to bell-shaped *** using the extended auxiliary equation m.thod,we deduced som. new soliton solutions of the fourthorder nonlinear m.dified Degasperis-Procesi equation with constant *** solutions include sym.etrical,non-sym.etrical kink solutions,solitary pattern solutions,weiestrass elliptic function solutions and triangular function *** discuss the stability analysis for these solutions.

关键词： m.dified Degasperis-Procesi water wave equation Extended auxiliary equation m.thod Solitary wave solutions

Voltage im.alance m.tigation in an active distribution network using decentralized current control

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Protection and Control of m.dern Power System. 2023年第2期8卷 68-84页

作者： Ahm.d m.m.Nour Ahm.d A.helal m.gdi m.El-Saadawi Ahm.d Y.Hatata Alexandria Higher Institute of Engineering and Technology(AIET) AlexandriaEgypt Departm.nt of Electrical and Control Engineering Arab Academy for Science and Technology and Maritime TransportAlexandriaEgypt Departm.nt of Electrical Engineering Faculty of EngineeringMansoura UniversityMansouraEgypt Departm.nt of Electrical Engineering College of EngineeringShaqra UniversityShaqraKingdom of Saudi Arabia

Voltage im.alance(VI)is caused by the difference in connected single-phase load or generation in a low voltage distribution network(DN).VI increase in a sm.rt distribution grid is due to the current practice of increasing single-phase distributed generators such as photovoltaic(PV)*** paper proposes a decentralized control m.thod to m.tigate VI using distributed batteries included in sm.rt grid interfaced residential PV *** m.tigate VI using the batteries in this way,five challenges m.st be overcom.,i.e.,equalizing all battery stress currents within the DN,m.tigating VI in abnorm.l conditions such as signal loss am.ng bus controllers,being im.une from.the distorted feedback m.asurem.nts,m.nim.zing the steady-state error at different loads,and overcom.ng the insufficient num.er or capacity of the distributed batteries at the sam. *** fuzzy logic controllers(FLC)are proposed at each bus to overcom. these five tasks based on a decentralized control *** proposed decentralized control based on FLC is com.ared with centralized control based on a PI *** proposed control m.thod is tested and verified using sim.lations in the m.TLAB/Sim.link software,and the results validate the ability of the schem. to alleviate VI on a sm.rt distribution network under both norm.l and abnorm.l conditions.

关键词： Fuzzy controller Distributed batteries Decentralized control Voltage im.alance Distributed PV

Sim.lation of ion beam.extraction and focusing system

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Chinese Physics C 2011年第1期35卷 83-87页

作者： B.A.Solim.n m.m.Abdelrahm.n A.G.helal F.W.Abdelsalam Accelerators & Ion Sources Departm.nt Nuclear Research CenterEgyptian Atomic Energy Authority P.O.Box:13759 InchasAtomic EnergyCairoEgypt

The characteristics of ion beam.extraction and focused to a volum. as sm.ll as possible were investigated with the aid of com.uter code SIm.ON 3D version 7. This has been used to evaluate the extraction characteristics （accel-decel system. to generate an ion beam.with low beam.em.ttance and high brightness. The sim.lation process can provide a good study for optim.zing the extraction and focusing system.of the ion beam.without any losses and transported to the required target. Also, a study of a sim.lation m.del for the extraction system.of the ion source was used to describe the possible plasm. boundary curvatures during the ion extraction that m.y be affected by the change in an extraction potential with a constant plasm. density m.niscus.

关键词： ion beam.em.ttance plasm. m.niscus space charge argon ion trajectories

m.chanical and therm.dynam.cal stability of BiVO4 polym.rphs using first-principles study

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Chinese Physics B 2017年第3期26卷 395-403页

作者： A K m.Farid UI Islam.m. Nurul Huda Liton H m.Tariqul Islam.m. Al helal m. Kam.uzzam.n Departm.nt of Com.uter Science and Engineering Begum Rokeya University Rangpur Rangpur-5400 Bangladesh Departm.nt of Physics Begum Rokeya University Rangpur Rangpur-5400 Bangladesh Departm.nt of Chem.stry Begum Rokeya University Rangpur Rangpur-5400 Bangladesh Departm.nt of Physics and m.terials Science and Center of Super-Diam.nd and Advanced Film. (COSDAF) City University of Hong Kong Hong Kong SAR China

First principles calculations of structural, electronic, m.chanical, and therm.dynam.c properties of different poly- m.rphs of BiVO4 are perform.d using Bender-type plane/wave ultrasoft pseudopotentials within the generalized gradient approxim.tion （GGA） in the flam. of density functional theory （DFT）. The calculated structural and electronic properties are consistent with the previous theoretical and experim.ntal results. The electronic structures reveal that m.BiVO4, op- BiVO4, and st-BiVO4 have indirect band gaps, on the other hand, zt-BiVO4 has a direct band gap. From.the DOS and m.lliken＇s charge analysis, it is observed that only m.BiVO4 has 6s2 Bi lone pair. Bond population analysis indicates that st-BiVO4 shows a m.re ionic nature and a sim.lar result is obtained from.the elastic properties. From.the elastic prop- erties, it is observed that st-BiVO4 is m.re m.chanically stable than the others, st-BiVO4 is m.re ductile and useful for high electro-optical and electro-m.chanical coupling devices. Our calculated therm.dynam.c properties confirm.the sim.lar characteristics found from.electronic and elastic properties, m.BiVO4 is useful as photocatalysts, solid state electrolyte, and electrode and other polym.rphs are applicable in electronic device fabrications.

关键词： BiVO4 crystal structure lone pair m.chanical stability

Efficacy evaluation of the protein isolated from.Peganum.harm.la seeds as an antioxidant in liver of rats

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Asian Pacific Journal of Tropical m.dicine 2013年第4期6卷 285-295页

作者： Am.l m.Solim.n helal S Abu-El-Zahab Gam.aa A Alswiai Zoology Departm.nt Faculty of ScienceCairo University Zoology Departm.nt Faculty of Science

Objective:To evaluate the curative effect of the 132 KD protein isolated from.the seeds of Peganum.harm.la（***） L against carbon tetrachloride（CCl4） induced oxidative stress in ***:Anim.ls were post treated intraperitoneally with 132 KO isolated protein at doses of 4 and 8 m./kg body weight and bovine serum.album.n（BSA）（8 m./kg body weight） as well as vitam.n C（250 m./kg body weight p.o.） for 7 d after they challenged with CCl4 orally（1 m./Ag body weight） in olive oil（50%） for 2 ***:The purified protein from.seeds of *** plant showed in vitro antioxidant activity with DPPH *** of CCl4 induced induction in serum.am.notransferases（AST,ALT）,alkaline phosphatase（ALP）,lipid profile param.ters and liver m.londialdehyde（m.A） and decrease in serum.total protein,liver superoxide dism.tase （SOD）,catalase（CAT）,and reduced glutathione（GSH） levels.132 KD protein treatm.nt of rats post CCl4 intoxication successfully alleviated the toxic effects of CCl4.Conclusions:The isolated protein possessed strong antioxidant activity com.arable to that of BSA（negative control） and vitam.n C（positive control）.

关键词： Carbon tetrachloride Peganum harm.la Oxidative stress 132 KD isolated protein

Oxidative leaching kinetics of m.lybdenum.uranium.ore in H2SO4 using H2O2 as an oxidizing agent

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Frontiers of Chem.cal Science and Engineering 2013年第1期7卷 95-102页

作者： T. A. Lasheen m. E. EI-Ahm.dy H. B. Hassib A. S. helal Nuclear m.terials Authority Cairo Egypt Chem.stry Departm.nt Faculty of Science Cairo University Giza Egypt

The processing of m.lybdenum.uranium.ore in a sulfuric acid solution using hydrogen peroxide as an oxidant has been investigated. The leaching tem.erature, hydrogen peroxide concentration, sulfuric acid concentration, leaching tim., particle size, liquid-to-solid ratio and agitation speed all have significant effects on the process. The optim.m.process operating param.ters were： tem.erature： 95℃; H2O2 concentration： 0.5 m. sulfuric acid concentration： 2.5 m. tim.： 2 h; particle size： 74 gm. liquid-to-solid ratio： 14 ： 1 and agitation speed： 600 rpm. Under these experim.ntal conditions, the extraction efficiency of m.lybdenum.was about 98.4%, and the uranium.extraction efficiency was about 98.7%. The leaching kinetics of m.lybdenum.showed that the reaction rate of the leaching process is controlled by the chem.cal reaction at the particle surface. The leaching process follows the kinetic m.del 1 - （1-X）1/3 = kt with an apparent activation energy of 40.40 kJ/m.le. The tem.erature, concentrations of H202 and H2SO4 and the m.sh size are the m.in factors that influence the leaching rate. The reaction order in H2SO4 was 1.0012 and in H202 it was 1.2544.

关键词： leaching of m.lybdenum leaching of uranium kinetics

A Tem.late m.tching Based Feature Extraction for Activity Recognition

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Com.uters, m.terials & Continua 2022年第7期72卷 611-634页

作者： m.ham.ad Ham.ed Siddiqi helal Alsham.ari Am.ad Ali m.dallah Alruwaili Yousef Alhwaiti Saad Alanazi m.m.Kam.uzzam.n College of Com.uter and Inform.tion Sciences Jouf UniversitySakakaAljouf2014Kingdom of Saudi Arabia Departm.nt of Com.uter Science COMSATS University IslamabadLahore CampusPakistan

Hum.n activity recognition(HAR)can play a vital role in the m.nitoring of hum.n activities,particularly for healthcare conscious *** accuracy of HAR system. is com.letely reliant on the extraction of prom.nent *** m.thods find it very challenging to extract optim.l features due to the dynam.c nature of activities,thereby reducing recognition *** this paper,we propose a robust feature extraction m.thod for HAR system. based on tem.late ***,in this m.thod,we want to associate a tem.late of an activity fram. or sub-fram. com.rising the corresponding *** this regard,the tem.late is placed on the fram. pixels to calculate the equivalent num.er of pixels in the tem.late correspondent those in the *** process is replicated for the whole fram.,and the pixel is directed to the optim.m.*** best count is estim.ted to be the pixel where the silhouette(provided via the tem.late)presented inside the *** this way,the feature vector is *** feature vector generation,the hiddenm.rkovm.del(Hm.)has been utilized to label the incom.ng *** utilized different publicly available standard datasets for *** proposed m.thod achieved the best accuracy against existing state-of-the-art system..

关键词： Activity recognition feature extraction tem.late m.tching video surveillance

Gut virom.:New key players in the pathogenesis of inflam.atory bowel disease

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World Journal of m.thodology 2025年第2期15卷 27-43页

作者： helal F Hetta Rehab Ahm.d Yasm.n N Ram.dan Hayam.Fathy m.ham.ed Khorshid m.ham.d m.m.brouk m.i Hashem Departm.nt of m.dical m.crobiology and Im.unology Faculty of MedicineAssiut UniversityAssiut 71515Egypt Division of m.crobiology Immunology and BiotechnologyFaculty of pharmacyUniversity of TabukTabuk 71491Saudi Arabia Division of m.crobiology Immunology and BiotechnologyDepartment of Natural Products and Alternative MedicineFaculty of PharmacyUniversity of TabukTabuk 71491Saudi Arabia Departm.nt of Internal m.dicine Division HepatogastroenterologyAssiut UniversityAssiut 71515Egypt Departm.nt of Clinical Research Egyptian Developers of Gastroenterology and Endoscopy FoundationCairo 11936Egypt Departm.nt of Internal m.dicine Faculty of Medicine.Tanta UniversityTanta 31527Egypt Departm.nt of Tropical m.dicine Gastroenterology and HepatologyAssiut University HospitalAssiut 71515Egypt

Inflam.atory bowel disease(IBD)is a chronic inflam.atory illness of the *** the m.chanism.underlying the pathogenesis of IBD is not fully under-stood,it is believed that a com.lex com.ination of host im.unological response,environm.ntal exposure,particularly the gut m.crobiota,and genetic suscept-ibility represents the m.jor *** gut virom. is a group of viruses found in great frequency in the gastrointestinal tract of *** gut virom. varies greatly am.ng individuals and is influenced by factors including lifestyle,diet,health and disease conditions,geography,and *** m.jority of research has focused on the significance of gut bacteria in the progression of IBD,although viral populations represent an im.ortant com.onent of the *** conducted this review to highlight the viral com.unities in the gut and their expected roles in the etiopathogenesis of IBD regarding published research to date.

关键词： Inflam.atory bowel disease Pathogenesis Gut virom. Bacteriophage Eukaryotic viruses