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Characterization of aerodynamic performance of wind-lens turbine using high-fidelity CFD simulations

Frontiers in Energy 2022年第4期16卷 661-682页

作者： Islam hAShEM Aida A.hAFIZ mohamed h.mohamed Mechanical Power Engineering Department Faculty of Engineering-MatariaHelwan UniversityCairo 11718Egypt State Key Laboratory of hydroscience and Engineering Department of Energy and Power EngineeringTsinghua UniversityBeijing 100084China Mechanical Engineering Department College of Engineering and Islamic ArchitectureUmm Al-Qura UniversityMakkah5555Saudi Arabia

Wind-lens turbines(WLTs)exhibit the prospect of a higher output power and more suitability for urban areas in comparison to bare wind *** wind-lens typically comprises a diffuser shroud coupled with a flange appended to the exit periphery of the ***-lenses can boost the velocity of the incoming wind through the turbine rotor owing to the creation of a lowpressure zone downstream the flanged *** this paper,the aerodynamic performance of the wind-lens is computationally assessed using high-fidelity transient CFD simulations for shrouds with different profiles,aiming to assess the effect of change of some design parameters such as length,area ratio and flange height of the diffuser shroud on the power *** power coefficient(Cp)is calculated by solving the URANS equations with the aid of the SST k–ω***,comparisons with experimental data for validation are accomplished to prove that the proposed methodology could be able to precisely predict the aerodynamic behavior of the windlens *** results affirm that wind-lens with cycloidal profile yield an augmentation of about 58%increase in power coefficient compared to bare wind turbine of the same rotor *** is also emphasized that diffusers(cycloid type)of small length could achieve a twice increase in power coefficient while maintaining large flange heights.

关键词： shroud diffuser-augmented wind turbine(DAWT) Betz limit aerodynamics computational fluid dynamics(CFD)

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homotopy Analysis Method for Solving Biological Population Model

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Communications in Theoretical Physics 2011年第11期56卷 797-800页

作者： A.A.M.Arafa S.Z.Rida h.mohamed Department of Mathematics Faculty of ScienceSouth Valley University

In this paper,the homotopy analysis method (hAM) is applied to solve generalized biological *** fractional derivatives are described by Caputo's *** method introduces a significant improvementin this field over existing *** obtained using the scheme presented here agree well with the analyticalsolutions and the numerical results presented in Ref.[6].however,the fundamental solutions of these equations stillexhibit useful scaling properties that make them attractive for applications.

关键词： biological populations model fractional calculus homotopy analysis method Mittag-Leffier function

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Enhancing Parkinson’s Disease Diagnosis Accuracy Through Speech Signal Algorithm Modeling

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Computers, Materials & Continua 2022年第2期70卷 2953-2969页

作者： Omar M.El-habbak Abdelrahman M.Abdelalim Nour h.mohamed habiba M.Abd-Elaty Mostafa A.hammouda Yasmeen Y.mohamed Mohanad A.Taifor Ali W.mohamed School of Information Technology and Computer Science Nile UniversityGiza12677Egypt Operations Research Department Faculty of Graduate Studies for Statistical ResearchCairo UniversityGiza12613Egypt Wireless Intelligent Networks Center(WINC) School of Engineering and Applied SciencesNile UniversityGiza12677Egypt

Parkinson’s disease(PD),one of whose symptoms is dysphonia,is a prevalent neurodegenerative *** use of outdated diagnosis techniques,which yield inaccurate and unreliable results,continues to represent an obstacle in early-stage detection and diagnosis for clinical professionals in the medical *** solve this issue,the study proposes using machine learning and deep learning models to analyze processed speech signals of patients’voice *** of these processed speech signals were obtained and experimented on by random forest and logistic regression *** were highly successful,with 90%accuracy produced by the random forest classifier and 81.5%by the logistic regression ***,a deep neural network was implemented to investigate if such variation in method could add to the *** proved to be effective,as the neural network yielded an accuracy of nearly 92%.Such results suggest that it is possible to accurately diagnose early-stage PD through merely testing patients’*** research calls for a revolutionary diagnostic approach in decision support systems,and is the first step in a market-wide implementation of healthcare software dedicated to the aid of clinicians in early diagnosis of PD.

关键词： Early diagnosis logistic regression neural network Parkinson’s disease random forest speech signal processing algorithms

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Molecular and serological prevalence of Toxoplasma gondii in pregnant women and sheep in Egypt

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Asian Pacific Journal of Tropical Medicine 2017年第10期10卷 996-1001页

作者： hany M.Ibrahim Azza h.mohamed Ahmed A.El-Sharaawy hend E.El-Shqanqery Department of Zoology Faculty of ScienceMenoufia UniversityShebin El-KomEgypt Clinical Pathology Unit National Liver InstituteMenoufia UniversityEgypt

Objective: To investigate molecular and serological prevalence of Toxoplasma gondii(***) in pregnant women and sheep in ***: Blood samples collected from healthy 364 pregnant women and 170 sheep were investigated for *** antibodies and parasitemia using highly specific and sensitive surface antigen(TgSAG2) based enzyme linked immunosorbent assay(ELISA)and real time-polymerase chain reaction(RT-PCR).Results: Overall prevalence of *** was 51.76%, 17.65% in sheep, 33.79%, 11.81%in pregnant women, using ELISA and RT-PCR *** differences in *** prevalence were observed on the basis of contact with cats or soil in pregnant women using either RT-PCR or *** pregnant women, a significant increase was detected in aged and those eating under-cooked mutton using simultaneous ELISA/***: Consumption of under-cooked infected mutton is an important source of human infection and the combination of the two assays provide accurate and precise data during infection.

关键词： Toxoplasmosis RT-PCR ELISA Pregnant-women Sheep

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Moringa oleifera leaf ethanol extract ameliorates lead-induced hepato-nephrotoxicity in rabbits

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Asian Pacific Journal of Tropical Biomedicine 2020年第6期10卷 263-272页

作者： Nancy B.mohamed Amira h.mohamed Nashwa A.Abu-Aita Soad M.Nasr Somia A.Nassar Kawkab A.Ahmed Directorate of Veterinary Medicine 3 Teraet El Zomor St.Nasr El DinEl haramGizaEgypt Department of Clinical Pathology Faculty of Veterinary MedicineCairo UniversityGiza12211Egypt Department of Parasitology&Animal Diseases National Research Centre33 Bohouth St.DokkiGiza12622Egypt Department of Laboratory Medical Sciences College of Applied Medical SciencesPrince Sattam bin Abdulaziz UniversitySaudi Arabia Department of Pathology Faculty of Veterinary MedicineCairo UniversityGiza12211Egypt

Objective: To evaluate the effect of Moringa oleifera leaf ethanol extract as an adjunct treatment on lead acetate induced hepatonephrotoxicity in rabbits. Methods: Thirty-six male New Zealand White rabbits were assigned into two main groups. The first group(14 rabbits) served as normal control. The second group(22 rabbits) was administered orally with lead acetate at a dose of 40 mg/kg/day, 5 days/week for 8 weeks. At the 4 th and the 8 th week of treatment, 6 animals(3 animals at each period) of the second group were sacrificed while the remaining animals(16 rabbits) were assigned randomly into 2 subgroups(8 rabbits each): treated and non-treated. The first subgroup was orally given 1 m L phosphate-buffered saline for further 4 weeks while the second subgroup was administered orally with Moringa oleifera leaf ethanol extract at a dose of 400 mg/kg/day for the same period. Blood samples were collected to determine hematological and serum biochemical indices. Tissue specimens were collected from the liver and kidney for evaluation of the oxidant/antioxidant markers and for histopathological ***: Lead acetate exposure decreased the mean body weight gain, hematocrit, hemoglobin, mean corpuscular volume, and lymphocytes count. Moreover, it markedly increased counts of monocytes and platelets, serum enzyme activity, levels of creatinine, total cholesterol, triglycerides, and low-density lipoprotein cholesterol. Malondialdehyde level was markedly increased while the reduced glutathione content was significantly decreased in liver tissue of lead intoxicated-rabbits. histopathological alterations were also noticed in the liver and kidney of lead intoxicated rabbits. Moringa oleifera leaf ethanol extract significantly improved hematological and serum biochemical parameters and histopathological structure of the liver and kidney. Conclusions: Moringa oleifera leaf ethanol extract ameliorates hemato-biochemical and histopathological alterations caused by lead

关键词： Lead toxicity Moringa oleifera Rabbits Liver functions Kidney functions histopathology

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Prenylated flavonoids from Tephrosia apollinea

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Chinese Chemical Letters 2009年第12期20卷 1465-1468页

作者： Ali K.Khalafallah Suleiman A.Suleiman Afifi h.Yousef Nadia A.A.El-kanzi Abou El-hamd h.mohamed Department of Chemistry Faculty of ScienceSouth Valley UniversityAswanEgypt

In continuation of our chemical investigation on some medicinal plants of the genus Tephrosia, re-investigation of the methylenechloride/methanol （1：1） extract of the air-dried aerial part of Tephrosia apollinea afforded a new prenylated flavonoid 1, in addition to an aromatic ester, a sesquiterpene, a lignan and several known prenylated flavonoids. The structures were established by （^1h NMR, ^13C NMR, DEPT, ^1h-^1h COSY, hMQC, hMBC, NOESY and hRMS）. Relative configurations of 9 and 10 were confirmed by X-ray analysis.

关键词： Tephrosia apollinea Leguminosae Prenylated flavonoids

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Syngas cleaning with nano-structured micro-porous ion exchange polymers in biomass gasification using a novel downdraft gasifier

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Journal of Energy Chemistry 2013年第3期22卷 426-435页

作者： Galip Akay C.Andrea Jordan Abdulaziz h.mohamed Process Intensification and Miniaturization Centre School of Chemical Engineering and Advanced MaterialsNewcastle UniversityNewcastle upon TyneNE1 7RUUK ITI Energy Limited Advanced Manufacturing ParkBrunel WayRotherham S60 5WGUK

Sulphonated nano-structured micro-porous ion exchange polymers, known as sulphonated PolyhIPE Polymers （s-PhPs） were used in syngas cleaning to investigate their impact on tar composition, concentration and dew point depression during the gasification of fuel cane bagasse as a model biomass. The results showed that the s-PhPs used as a secondary syngas treatment system, was highly effective at adsorbing and reducing the concentration of all class of tars in syngas by 95%-80% which resulted in tar dew point depression from 90 ~C to 73 ~C. It was shown that tars underwent chemical reactions within s-PhPs, indicating that tar diffusion from syngas was driven by chemical potential. It was also observed that s-PhPs also captured ash forming elements from syngas. The use of s-PhPs in gasification as well as in an integrated thermochemical biorefinery technology is discussed since the tar loaded s-PhPs can be used as natural herbicides in the form of soil additives to enhance the biomass growth and crop yield.

关键词： biorefinery biomass downdraft gasifier gasification PolyhIPE Polymer syngas cleaning tar removal

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Efficient Computation Offloading of IoT-Based Workflows Using Discrete Teaching Learning-Based Optimization

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Computers, Materials & Continua 2022年第11期73卷 3685-3703页

作者： mohamed K.hussein mohamed h.Mousa Department of Computer Science Faculty of Computers and InformaticsSuez Canal UniversityIsmailiaEgypt Department of Information Technology College of Computer Science at AlKamilUniversity of JeddahJeddahSaudi Arabia

As the Internet of Things(IoT)and mobile devices have rapidly proliferated,their computationally intensive applications have developed into complex,concurrent IoT-based workflows involving multiple interdependent *** exploiting its low latency and high bandwidth,mobile edge computing(MEC)has emerged to achieve the high-performance computation offloading of these applications to satisfy the quality-of-service requirements of workflows and *** this study,we propose an offloading strategy for IoT-based workflows in a high-performance MEC *** proposed task-based offloading strategy consists of an optimization problem that includes task dependency,communication costs,workflow constraints,device energy consumption,and the heterogeneous characteristics of the edge *** addition,the optimal placement of workflow tasks is optimized using a discrete teaching learning-based optimization(DTLBO)*** experimental evaluations demonstrate that the proposed offloading strategy is effective at minimizing the energy consumption of mobile devices and reducing the execution times of workflows compared to offloading strategies using different metaheuristics,including particle swarm optimization and ant colony optimization.

关键词： high-performance computing internet of things(IoT) mobile edge computing(MEC) workflows computation offloading teaching learning-based optimization

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Mixed sensitivity h_∞ control for LTI systems with varying time delays

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Journal of Systems Engineering and Electronics 2018年第3期29卷 611-617页

作者： OULD mohamed mohamed vall College of Computer and Information Sciences Al Jouf University

Designing a robust controller for a system with timevarying delays poses a major challenge. In this paper, we propose a method based on mixed sensitivity h∞ for the control of linear time invariant（LTI） systems with varying time delays. The time delay is assumed bounded and the upper bound is known. In the technique we propose, the delay affecting the plant to be controlled is treated as an unmodeled uncertainty（in form of multiplicative uncertainty）. That uncertainty is approximated and then an h∞based controller, for the plant represented by the multiplicative uncertainty and the nominal model, is calculated. The obtained h∞controller is used to control the LTI systems with varying time delays. Simulation examples are given to illustrate the effectiveness of the proposed method.

关键词： linear time invariant(LTI) systems mixed sensitivity h∞ varying time delay unmodeled uncertainty h∞ control

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Low Temperature Growth of Vertically Aligned Carbon Nanotubes via Floating Catalyst Chemical Vapor Deposition Method

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Journal of Materials Science & Technology 2011年第4期27卷 296-300页

作者： M.R.Atiyah D.R.Awang Biak F.Ahmadun I.S.Ahamad F.Mohd Yasin h.mohamed Yusoff Department of Chemical and Environmental Engineering Universiti Putra Malaysia

Synthesis of carbon nanotubes （CNTs） below 600℃ using supporting catalyst chemical vapor deposition method was reported by many research groups. however, the floating catalyst chemical vapor deposition received less attention due to imperfect nanotubes produced. In this work, the effects of varying the preheating temperature on the synthesis of CNT were investigated. The reaction temperature was set at 570℃. The preheating set temperature was varied from 150 to 400℃ at 50℃ interval. Three O-ring shape heating mantels were used as heating source for the preheater. In situ monitoring device was used to observe the temperature profile in the reactor. Benzene and ferrocene were used as the carbon source and catalyst precursor, respectively. Vertically aligned CNTs were synthesized when the preheating temperature was set at 400℃. When the preheating temperature was increased up to 400℃, both the length and the alignment of CNTs produced were improved.

关键词： Vertically aligned carbon nanotubes (CNTs) Floating catalyst Low synthesistemperature Preheating set temperature

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