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Static and dynamic stability responses of multilayer functionally graded carbon nanotubes reinforced composite nanoplates via quasi 3D nonlocal strain gradient theory

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Defence Technology（防务技术） 2022年第10期18卷 1778-1809页

作者： ahmed Amine Daikh mohamed sid ahmed houari mohamed Ouejdi Belarbi Salwa A.mohamed mohamed A.Eltaher Laboratoire D'Etude des Structures et de Mecanique des Materiaux Departement de Genie CivilFacultedes Sciences et de La TechnologieUniversite Mustapha Stambouli B.P.305R.P.29000MascaraAlgeria Laboratoire de Genie Energetique et Materiaux LGEMUniversite de BiskraB.P.145R.P07000BiskraAlgeria Department of Engineering Mathematics Zagazig UniversityP.O.Box 44519ZagazigEgypt Faculty of Engineering Mechanical Engineering DepartmentKing Abdulaziz UniversityP.O.Box 80204JeddahSaudi Arabia Faculty of Engineering Mechanical Design and Production DepartmentZagazig UniversityP.O.Box 44519ZagazigEgypt

This manuscript presents the comprehensive study of thickness stretching effects on the free vibration,static stability and bending of multilayer functionally graded(FG)carbon nanotubes reinforced composite(CNTRC)*** nanoscale and microstructure influences are considered through a modified nonlocal strain gradient continuum *** on power-law functions,four different patterns of CNTs distribution are considered in this analysis,a uniform distribution UD,FG-V CNTRC,FG-X CNTRC,and FG-O CNTRC.A 3D kinematic shear deformation theory is proposed to include the stretching influence,which is neglected in classical ***'s principle is applied to derive the governing equations of motion and associated boundary *** solutions are developed based on Galerkin method to solve the governing equilibrium equations based on the generalized higher-order shear deformation theory and the nonlocal strain gradient theory and get the static bending,buckling loads,and natural frequencies of *** with previous works is presented.A detailed parametric analysis is carried out to highlight the impact of thickness stretching,length scale parameter(nonlocal),material scale parameter(gradient),CNTs distribution pattern,geometry of the plate,various boundary conditions and the total number of layers on the stresses,deformation,critical buckling loads and vibration *** new results are also reported in the current study,which will serve as a benchmark for future research.

关键词： 3D shear deformation theory Free vibration Buckling Bending Galerkin method Functionally graded nanotube Nonlocal strain gradient theory

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Improved Manta Ray Foraging Optimizer-based SVM for Feature Selection Problems:A Medical Case Study

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Journal of Bionic Engineering 2024年第1期21卷 409-425页

作者： Adel Got Djaafar Zouache Abdelouahab Moussaoui Laith Abualigah ahmed Alsayat Faculty of informatics University of Science and Technology Houari BoumedieneAlgiersAlgeria LRIA Laboratory University of Science and Technology Houari BoumedieneAlgiersAlgeria Computer Science Department University of Mohamed El Bachir El IbrahimiBordj Bou ArreridjAlgeria Computer Science Department University of Ferhat AbbasSetifAlgeria Computer Science Department Prince Hussein Bin Abdullah Faculty for Information TechnologyAl al-Bayt UniversityMafraq 25113Jordan Department of Computer Science College of Computer and Information SciencesJouf UniversityJoufSaudi Arabia Department of Electrical and Computer Engineering Lebanese American University13-5053ByblosLebanon Hourani Center for Applied Scientific Research Al-Ahliyya Amman UniversityAmman 19328Jordan MEU Research Unit Middle East UniversityAmman 11831Jordan Applied science research center Applied science private universityAmman 11931Jordan School of Computer Sciences Universiti Sains Malaysia11800 PenangMalaysia School of Engineering and Technology Sunway University Malaysia27500 Petaling JayaMalaysia

Support Vector Machine(SVM)has become one of the traditional machine learning algorithms the most used in prediction and classification ***,its behavior strongly depends on some parameters,making tuning these parameters a sensitive step to maintain a good *** the other hand,and as any other classifier,the performance of SVM is also affected by the input set of features used to build the learning model,which makes the selection of relevant features an important task not only to preserve a good classification accuracy but also to reduce the dimensionality of *** this paper,the MRFO+SVM algorithm is introduced by investigating the recent manta ray foraging optimizer to fine-tune the SVM parameters and identify the optimal feature subset *** proposed approach is validated and compared with four SVM-based algorithms over eight benchmarking ***,it is applied to a disease Covid-19 *** experimental results show the high ability of the proposed algorithm to find the appropriate SVM’s parameters,and its acceptable performance to deal with feature selection problem.

关键词： Support vector machine Parameters tuning Feature selection Bioinspired algorithms Manta ray foraging optimizer

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Effect of the Inclination of Baffles on the Power Consumption and Fluid Flows in a Vessel Stirred by a Rushton Turbine

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Chinese Journal of Mechanical Engineering 2017年第4期30卷 1008-1016页

作者： Youcef Kamla mohamed Bouzit houari Ameur Mohammed Ilies Arab Abdessalam Hadjeb Faculty of Mechanical Engineering University of Scienceand Technology USTO-MB1505 E1 M'naouarOranAlgeria Institute of Science and Technology University Center Ahmed Salhi(Ctr-Univ Naama)BP 6645000 NaamaAlgeria

The role of baffles in mechanically stirred tanks is to promote the stability of power drawn by the impeller and to avoid the fluid swirling, thus enhancing mixing. The present paper numerically investigates the baffles effects in a vessel stirred by a Rushton turbine. The geometric factor of interest is the baffle inclination which is varying between 25°, 32.5°, 45°, 70° and 90° at different impeller rotational speeds. The impeller rotational direction has also been varied. The vortex size and power consumption were evaluated for each geometrical configuration. It was found that the best configuration is the baffle inclination by = 70° at a negative angular velocity.

关键词： Stirred tanks Power consumption Baffles Rushton turbine CFD simulation

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Incidence and Risk Factors of Acute Kidney Injury in ICU Patients of Omdurman Teaching Hospital

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Open Journal of Nephrology 2021年第1期11卷 43-57页

作者： Abdel Mumin sid ahmed Nusaiba Hassan mohamed Eltahir Omdurman teaching Hospital Omdurman Khartoum State Sudan

Background: Acute kidney injury (AKI) is a common complication in critically ill patients and it is commonly associated with high mortality and morbidity with adverse short and long term outcome. Objectives: The main objective of this study was to determine the incidence of acute kidney injury in ICU patients in Omdurman teaching hospital, and to assess the risk factors associated with the development of acute kidney injury in a critically ill patient. We also intended to find out the impact of acute kidney injury on ICU outcomes. Methods: In this descriptive prospective, cohort hospital-based study, 211 patients were studied and followed up during admission in ICU from November 2019 until July 2020 in Omdurman teaching hospital. Results: 61 patients of the total 211 patients developed renal impairment during their stay in ICU. 64% (39 patients) were males and 36% (22 patients) were female, mean age was 41 ± 5, renal impairment developed after a mean of 5 days of admission and the most common cause was decreased level of consciousness and severe hypotension, sepsis accounting for 40% of the admission. The outcome in ICU showed that the mortality rate was high up to 41% in patients who developed acute kidney injury, Sepsis accounted for over 96% (24 patients) who have passed away. Conclusions: Development of AKI in ICU is an important risk factor for poor outcomes in critically setting. Prevention is the best method for avoiding AKI, with the early identification and recognition of high-risk patients.

关键词： Acute Kidney Injury ICU Risk Factors Outcome Frequency

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Thermophotovoltaic Emitters Based on a One-Dimensional Metallic-Dielectric Multilayer Nanostructures

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Journal of Electronics Cooling and Thermal Control 2014年第1期4卷 39-48页

作者： Samah G. Babiker Shuai Yong mohamed O. sid-ahmed Xie Ming Department of Engineering Thermophysics School of Energy Science and Engineering Harbin Institute of Technology Harbin China Department of Engineering Thermophysics School of Energy Science and Engineering Harbin Institute of Technology Harbin China Department of Physics Faculty of Education University of the Holy Quran and Islamic Science OmdurmanSudan Department of Physics Faculty of Sciences Sudan University of Science and Technology Khartoum Sudan

In this paper, a one-dimensional multilayer is optimized for potential applications as thermophotovoltaic (TPV) selective emitter. The proposed TPV emitter was fabricated through a magnetron sputtering process by using the radio frequency (RF) magnetron sputtering system. The spectral emittance of the proposed TPV emitter is measured by using spectral transmittance and reflectance measurement system at wavelength from 0.3 μm to 2.5 μm at near-normal incident 8。. The bidirectional reflectance distribution function BRDF is measured by three axis automated scatterometer (TAAS). The effect of the diffraction orders and plane of incidence on the spectral emittance of the proposed TPV emitter is calculated numerically by using the rigorous coupled-wave analysis (RCWA). The emittance spectrum of the proposed TPV selective emitter shows three close to unity emission peaks which are explained by the surface plasmon polariton (SPP), gap plasmon polariton (GPP) and magnetic polariton (MP) excitation. The results show that the proposed emitter has high emittance value in the spectral range of 0.69 emitter, if used as a selective emitter with a low band gap photovoltaic cell (GaSb), would lead to high TPV overall efficiency and high electrical output power.

关键词： Thermophotovoltaic Selective Emitter Rigorous Coupled Wave Analysis (RCWA) A Magnetron

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<i>In Vitro </i>Effects of Oil’s Fatty Acids on T-Cell Function of Obese Men

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Food and Nutrition Sciences 2017年第2期8卷 277-293页

作者： Asmaa Meraou Hafida Merzouk Amel Saidi Amel Medjdoub sid ahmed Merzouk mohamed Bénali Slimane Belbraouet Laboratory of Physiology Physiopathology and Biochemistry of Nutrition Department of Biology Faculty of Natural and Life Sciences Earth and Universe University of Abou-Bekr Belka&#239 d Tlemcen Algeria Laboratory of Biotoxicology Djilali Liabes University Sidi Bel Abbès Algeria Department of Technical Sciences Faculty of Engineering University of Abou-Bekr Belka&#239 d Tlemcen Algeria école de Nutrition Université de Moncton New Brunswick Canada

Background: Dietary fatty acids have important homeostatic functions in regulating the immune response and may exert beneficial effects on immune alterations during obesity. Objective: To assess the in vitro effects of oil fatty acids, different oils (olive, linseed, Nigel, sunflower) were tested on T-lymphocyte proliferation, Th1- and Th2-type cytokine production, and intracellular oxidant/antioxidant status in obese patients. Methods: Peripheral blood lymphocytes were isolated using Histopaque and were in vitro cultured and stimulated by Con A in the presence or absence of the oils. Cell proliferation, interleukin-2, interleukin-4 and interferon-γ (INFγ) secretions and intracellular oxidative status (glutathione (GSH), malondialdehyde (MDA), carbonyl protein levels, catalase activity and micronuclei frequency) were investigated. Results: Abnormalities in lymphocyte function and intracellular oxidative stress were observed in obesity. Linseed oil induced a reduction in T-lymphocyte proliferation and IL-2 production while Nigel oil increased them in both obese and control groups. In addition, Nigel oil enhanced IFNγ and IL-4 secretion. Olive and sunflower oils had no effect on lymphocyte proliferation and cytokine secretion in both groups. Linseed and Nigel oils induced an increase in T cell GSH concentrations and catalase activity with a concomitant decrease in MDA, carbonyl protein contents and micronuclei frequency especially in obese patients. Conclusion: Linseed and Nigel oils had beneficial effects on lymphocyte proliferation, cytokines secretions and redox status, while olive and sunflower oils had no effects on immune cell function in obesity.

关键词： Obesity Lymphocytes Olive Oil Linseed Oil Nigel Oil Sunflower Oil Cytokines Oxidant/Antioxidant Status

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Thermo-mechanical vibration analysis of non-local refined trigonometric shear deformable FG beams

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International Journal of Hydromechatronics 2019年第1期2卷 2-2页

作者： Mouffoki Abderrahmane Aicha Bessaim houari Mohammed sid ahmed Abdelhakim Kaci Tounsi Abdelouahed El Abbas Adda Bedia Laboratoire des Matériaux et Hydrologie Université de Sidi Bel Abbes BP 89 Cité Ben M’hidi Sidi Bel 22000 Algeria Department of Civil Engineering Université Mustapha Stambouli de Mascara Mascara Algeria Département de Génie Civil et de l’hydraulique Université Moulay Tahar de Saida Saida Algeria

In this article, thermo vibration analysis of functionally graded (FG) nanobeams subjected to linear and uniform temperature distribution is studied. The structure is modelled by new efficient shear beam theory considering the effect of shear deformation without shear correction factor. The mentioned theory satisfies the zero boundary traction conditions on the beam surfaces and can be used for transverse shear strains trigonometric distribution. Material properties of the nanostructure are assumed temperature-dependent and FG based on the distribution of power law. The influence of size scale is captured utilising Eringen theory of non-local elasticity.

关键词： Thermo-mechanical vibration refined trigonometric shear deformable FG beams

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3D numerical study and comparison of thermal-flow performance of various annular finne d-tub e designs

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Journal of Ocean Engineering and Science 2023年第3期8卷 294-307页

作者： Farouk Tahrour Hijaz Ahmad houari Ameur Tareq Saeed Hanaa Abu-Zinadah Younes Menni Department of Physics Faculty of SciencesUniversity Mohamed Boudiaf of M’silaM’silaAlgeria Near East University Operational Research Center in HealthcareNear East BoulevardPC:99138 Nicosia/Mersin 10Turkey Section of Mathematics International Telematic University UninettunoCorso Vittorio Emanuele II3900186 RomaItaly Department of Technology University Centre of Naama-Ahmed SalhiP.O.Box 66Naama 45000Algeria Nonlinear Analysis and Applied Mathematics Research Group(NAAM) Mathematics DepartmentKing Abdulaziz UniversityJeddah 21589Saudi Arabia University of Jeddah College of ScienceDepartment of StatisticsJeddahSaudi Arabia

With the increase of heat transfer problems in marine vehicles and submerged power stations in oceans,the search for an efficient finned-tube heat exchanger has become particularly *** purpose of the present investigation is to analyze and compare the thermal exchange and flow characteristics between five different fin designs,namely:a concentric circular finned-tube(CCFT),an eccentric circular finned-tube(ECFT),a perforated circular finned-tube(PCFT),a serrated circular finned-tube(SCFT),and a star-shaped finned-tube(S-SFT).The fin design and spacing impact on the thermal-flow performance of a heat exchanger was computed at Reynolds numbers varying from 4,300 to 15,*** the numerical results,and when the fin spacing has been changed from 2 to 7 mm,an enhancement in the Colburn factor and a reduction in the friction factor and fin performances were observed for all cases under *** criteria were checked to select the most efficient fin design:the performance evaluation criterion P EC,the global performance criterion G PC,and the mass global performance criterion M G *** the value of Reynolds number,the conventional CCFT provided the lowest performance evaluation criterion P EC,while the SCFT gave the highest amount of P *** most significant value of G PC was reached with the ECFT;however,G PC remained almost the same for CCFT,PCFT,SCFT,and *** terms of the mass global performance criterion,the S-SFT provides the highest M Gpc as compared with the full fins of CCFT(41-73%higher)and ECFT(29-54%higher).Thus,the heat exchanger with S-SFT is recommended to be used in the cooling of offshore energy systems.

关键词： Thermal-flow performance Eccentric fins Star-shaped fins Perforated fins Finned-tube designs

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Cartography of Air Pollution in an Industrial City in North-Eastern Algeria by Using Two Indexes： Poleotolerance Index and Atmospheric Purity Index

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Journal of Life Sciences 2014年第1期8卷 95-100页

作者： Djamel Fadel ahmed Soufiane sid Nadla Zga Filali Latreche Abdelkarim Ouamer Ali Institute Agro-Veterinary Taoura Laboratory Life Science and Technology University of Mohamed Cherif Messaadia Route d 'Annaba 41000 Algeria Planning Department Laboratory of Natural Resources and Sustainable Development University of Annaba B.P/12 Annaba 23000 Algeria

Of all the methods of studies on bio-estimation of air pollution by lichen flora, the authors cannot justify a choice of one method over another. Consultation of previous work by researchers has allowed us to compare these methods and to better understand their strengths and limitations. Under the terms of estimating the pollution, these methods are classified into three categories. Some are qualitative, quantitative and others are finally some indirect methods. The methods used to assess the overall air pollution relative value for each station studied. As part of our work, the authors have chosen a quantitative approach based on the combination of two methods. They are based on pollution indices obtained from mathematical formulas based on various parameters related to the lichen flora. They are represented by the I.P. （index poleotolerance） and the I.A.P. （index of atmospheric purity） and these two indices allowed us to map of global air pollution in the city of Skikda and petrochemical industry as well as peri-urban areas （Haddaiek, Hamadi Krouma, Hamrouche Hamoudi, Larbi Ben M＇Hidi）. The authors have identified areas of iso-pollution around different emission centers represented by the largest petrochemical area, traffic and households in urban areas of Skikda, Hamadi Krouma, Hamrouche Hamoudi and Larbi Ben M＇Hidi.

关键词： Bio-diversity bio-indication lichenic flora pollution Algeria.

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