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Particuology 2017年第5期15卷 61-69页

作者： m. helal uddin Charles J. Coronella Department of Chemical and materials Engineering University of Nevada Reno NV 89557 USA

Numerical simulations of gas-solid fluidized beds based on the kinetic theory of granular flow exhibit a significant dependence on domain discretization. Bubble formation, bubble size and shape all vary greatly with the discretization, and the use of an inappropriate scale resolution leads to inaccurate predictions of fluidization hydrodynamics. In this study, grid-independent solutions of the two fluid model were examined by comparing the bed expansions obtained from numerical simulations with experimental results and empirical predictions, based on bubbling fluidized beds of Geldart B particles. Grid indepen- dence was achieved with a grid resolution equal to 18 times the particle diameter. The simulation results were compared with previously published data for verification purposes. The results of this work should provide a guideline for choosing the appropriate grid size and thereby minimize the time and expense associated with large simulations.

关键词： mesh effectHydrodynamicsComputational fluid dynamicsEuler-Euler method mFIX

A new approach for fuel injection into a solar receiver/ reactor:Numerical and experimental investigation

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Frontiers of Chemical Science and Engineering 2018年第4期12卷 683-696页

作者： m helal uddin Nesrin Ozalp Jens Heylen Cedric Ophoff mechanical and Industrial Engineering Department University of Minnesota DuluthDuluthMN 55812-3042USA mechanical Engineering Department 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 combustion technology. The nozzle design was adapted from a combustion burner and successfully implemented into a solar receiver and studied the influence of the nozzle design on the fluid mixing and temperature distribution inside the solar receiver using a 7 kW solar simulator and nitrogen as working fluid. Finally, a thorough computational fluid dynamics (CFD) analysis was performed and validated against the experimental results. The CFD results showed a variation of the gas flow pattern and gas mixing 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 mixing and recirculation

Gut virome:New key players in the pathogenesis of inflammatory bowel disease

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World Journal of methodology 2025年第2期15卷 27-43页

作者： helal F Hetta Rehab Ahmed Yasmin N Ramadan Hayam Fathy mohammed Khorshid mohamed m mabrouk mai Hashem Department of medical microbiology and Immunology Faculty of MedicineAssiut UniversityAssiut 71515Egypt Division of microbiology Immunology and BiotechnologyFaculty of pharmacyUniversity of TabukTabuk 71491Saudi Arabia Division of microbiology Immunology and BiotechnologyDepartment of Natural Products and Alternative MedicineFaculty of PharmacyUniversity of TabukTabuk 71491Saudi Arabia Department of Internal medicine Division HepatogastroenterologyAssiut UniversityAssiut 71515Egypt Department of Clinical Research Egyptian Developers of Gastroenterology and Endoscopy FoundationCairo 11936Egypt Department of Internal medicine Faculty of Medicine.Tanta UniversityTanta 31527Egypt Department of Tropical medicine Gastroenterology and HepatologyAssiut University HospitalAssiut 71515Egypt

Inflammatory bowel disease(IBD)is a chronic inflammatory illness of the *** the mechanism underlying the pathogenesis of IBD is not fully under-stood,it is believed that a complex combination of host immunological response,environmental exposure,particularly the gut microbiota,and genetic suscept-ibility represents the major *** gut virome is a group of viruses found in great frequency in the gastrointestinal tract of *** gut virome varies greatly among individuals and is influenced by factors including lifestyle,diet,health and disease conditions,geography,and *** majority of research has focused on the significance of gut bacteria in the progression of IBD,although viral populations represent an important component of the *** conducted this review to highlight the viral communities in the gut and their expected roles in the etiopathogenesis of IBD regarding published research to date.

关键词： Inflammatory bowel disease Pathogenesis Gut virome Bacteriophage Eukaryotic viruses

Stability analysis solutions of the nonlinear modified 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 mathematics Department Faculty of ScienceCairo UniversityGizaEgypt mathematics Department Faculty of ScienceTaibah UniversityAl-UlaSaudi Arabia mathematics Department Faculty of ScienceBeni-Suef UniversityEgypt

In the present study,the solitary wave solutions of modified Degasperis-Procesi equation are *** the standard Degasperis-Procesi equation,where multi-peakon solutions arise,the modification caused a change in the characteristic of these peakon solutions and changed it to bell-shaped *** using the extended auxiliary equation method,we deduced some new soliton solutions of the fourthorder nonlinear modified Degasperis-Procesi equation with constant *** solutions include symmetrical,non-symmetrical kink solutions,solitary pattern solutions,weiestrass elliptic function solutions and triangular function *** discuss the stability analysis for these solutions.

关键词： modified Degasperis-Procesi water wave equation Extended auxiliary equation method Solitary wave solutions

Efficacy evaluation of the protein isolated from Peganum harmala seeds as an antioxidant in liver of rats

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Asian Pacific Journal of Tropical medicine 2013年第4期6卷 285-295页

作者： Amel m Soliman helal S Abu-El-Zahab Gamiaa A Alswiai Zoology Department Faculty of ScienceCairo University Zoology Department Faculty of Science

Objective:To evaluate the curative effect of the 132 KD protein isolated from the seeds of Peganum harmala（***） L against carbon tetrachloride（CCl4） induced oxidative stress in ***:Animals were post treated intraperitoneally with 132 KO isolated protein at doses of 4 and 8 mg/kg body weight and bovine serum albumin（BSA）（8 mg/kg body weight） as well as vitamin C（250 mg/kg body weight p.o.） for 7 d after they challenged with CCl4 orally（1 ml/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 aminotransferases（AST,ALT）,alkaline phosphatase（ALP）,lipid profile parameters and liver malondialdehyde（mDA） and decrease in serum total protein,liver superoxide dismutase （SOD）,catalase（CAT）,and reduced glutathione（GSH） levels.132 KD protein treatment of rats post CCl4 intoxication successfully alleviated the toxic effects of CCl4.Conclusions:The isolated protein possessed strong antioxidant activity comparable to that of BSA（negative control） and vitamin C（positive control）.

关键词： Carbon tetrachloride Peganum harmala Oxidative stress 132 KD isolated protein

Simulation 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.Soliman m.m.Abdelrahman A.G.helal F.W.Abdelsalam Accelerators & Ion Sources Department Nuclear Research CenterEgyptian Atomic Energy Authority P.O.Box:13759 InchasAtomic EnergyCairoEgypt

The characteristics of ion beam extraction and focused to a volume as small as possible were investigated with the aid of computer code SImION 3D version 7. This has been used to evaluate the extraction characteristics （accel-decel system） to generate an ion beam with low beam emittance and high brightness. The simulation process can provide a good study for optimizing the extraction and focusing system of the ion beam without any losses and transported to the required target. Also, a study of a simulation model for the extraction system of the ion source was used to describe the possible plasma boundary curvatures during the ion extraction that may be affected by the change in an extraction potential with a constant plasma density meniscus.

关键词： ion beam emittance plasma meniscus space charge argon ion trajectories

mechanical and thermodynamical stability of BiVO4 polymorphs 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 md Nurul Huda Liton H m Tariqul Islam md Al helal md Kamruzzaman Department of Computer Science and Engineering Begum Rokeya University Rangpur Rangpur-5400 Bangladesh Department of Physics Begum Rokeya University Rangpur Rangpur-5400 Bangladesh Department of Chemistry Begum Rokeya University Rangpur Rangpur-5400 Bangladesh Department of Physics and materials Science and Center of Super-Diamond and Advanced Films (COSDAF) City University of Hong Kong Hong Kong SAR China

First principles calculations of structural, electronic, mechanical, and thermodynamic properties of different poly- morphs of BiVO4 are performed using Bender-type plane/wave ultrasoft pseudopotentials within the generalized gradient approximation （GGA） in the flame of density functional theory （DFT）. The calculated structural and electronic properties are consistent with the previous theoretical and experimental 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 mulliken＇s charge analysis, it is observed that only m-BiVO4 has 6s2 Bi lone pair. Bond population analysis indicates that st-BiVO4 shows a more ionic nature and a similar result is obtained from the elastic properties. From the elastic prop- erties, it is observed that st-BiVO4 is more mechanically stable than the others, st-BiVO4 is more ductile and useful for high electro-optical and electro-mechanical coupling devices. Our calculated thermodynamic properties confirm the similar characteristics found from electronic and elastic properties, m-BiVO4 is useful as photocatalysts, solid state electrolyte, and electrode and other polymorphs are applicable in electronic device fabrications.

关键词： BiVO4 crystal structure lone pair mechanical stability

Voltage imbalance mitigation in an active distribution network using decentralized current control

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Protection and Control of modern Power Systems 2023年第2期8卷 68-84页

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

Voltage imbalance(VI)is caused by the difference in connected single-phase load or generation in a low voltage distribution network(DN).VI increase in a smart distribution grid is due to the current practice of increasing single-phase distributed generators such as photovoltaic(PV)*** paper proposes a decentralized control method to mitigate VI using distributed batteries included in smart grid interfaced residential PV *** mitigate VI using the batteries in this way,five challenges must be overcome,i.e.,equalizing all battery stress currents within the DN,mitigating VI in abnormal conditions such as signal loss among bus controllers,being immune from the distorted feedback measurements,minimizing the steady-state error at different loads,and overcoming the insufficient number or capacity of the distributed batteries at the same *** fuzzy logic controllers(FLC)are proposed at each bus to overcome these five tasks based on a decentralized control *** proposed decentralized control based on FLC is compared with centralized control based on a PI *** proposed control method is tested and verified using simulations in the mATLAB/Simulink software,and the results validate the ability of the scheme to alleviate VI on a smart distribution network under both normal and abnormal conditions.

关键词： Fuzzy controller Distributed batteries Decentralized control Voltage imbalance Distributed PV

A Template matching Based Feature Extraction for Activity Recognition

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Computers, materials & Continua 2022年第7期72卷 611-634页

作者： muhammad Hameed Siddiqi helal Alshammari Amjad Ali madallah Alruwaili Yousef Alhwaiti Saad Alanazi m.m.Kamruzzaman College of Computer and Information Sciences Jouf UniversitySakakaAljouf2014Kingdom of Saudi Arabia Department of Computer Science COMSATS University IslamabadLahore CampusPakistan

Human activity recognition(HAR)can play a vital role in the monitoring of human activities,particularly for healthcare conscious *** accuracy of HAR systems is completely reliant on the extraction of prominent *** methods find it very challenging to extract optimal features due to the dynamic nature of activities,thereby reducing recognition *** this paper,we propose a robust feature extraction method for HAR systems based on template ***,in this method,we want to associate a template of an activity frame or sub-frame comprising the corresponding *** this regard,the template is placed on the frame pixels to calculate the equivalent number of pixels in the template correspondent those in the *** process is replicated for the whole frame,and the pixel is directed to the optimum *** best count is estimated to be the pixel where the silhouette(provided via the template)presented inside the *** this way,the feature vector is *** feature vector generation,the hiddenmarkovmodel(Hmm)has been utilized to label the incoming *** utilized different publicly available standard datasets for *** proposed method achieved the best accuracy against existing state-of-the-art systems.

关键词： Activity recognition feature extraction template matching video surveillance

multivariate metal-organic frameworks

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National Science Review 2017年第3期4卷 296-298页

作者： Aasif helal Zain H.Yamani Kyle E.Cordova Omar m.Yaghi Center for Research Excellence in Nanotechnology(CENT) King Fahd University of Petroleum and Minerals Department of Chemistry University of California-Berkeley

Reticular chemistry is founded upon the principles of linking simple organic and inorganic building blocks through strong bonds to form extended,porous and crystalline solids,such as metal-organic frameworks(mOFs)[1].... 详细信息

关键词： mOFs mTV multivariate metal-organic frameworks that for of is were in SBU