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Existence and numerical approximation of a solution to frictional contact problem for electro-elastic materials

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Applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 201-219页

作者： Othman Baiz el-Hassan Benkhira rachid Fakhar University Ibn Zohr Lab.ESERFP of OuarzazateMorocco University Moulay Ismail Faculty of SciencesLaboratory MACSESTMBP 3103Toulal-MeknesMorocco University Sultan Moulay Slimane Laboratory LS2MEPolydisciplary Faculty of Khouribga25000 KhouribgaMorocco

In this paper,a frictional contact problem between an electro-elastic body and an electrically conductive foundation is *** contact is modeled by normal compliance with finite penetration and a version of Coulomb’s law of dry friction in which the coefficient of friction depends on the *** addition,the effects of the electrical conductivity of the foundation are taken into *** model leads to a coupled system of the quasi-variational inequality of the elliptic type for the displacement and the nonlinear variational equation for the electric *** existence of a weak solution is proved by using an abstract result for elliptic variational inequalities and a fixed point ***,a finite element approximation of the problem is *** some regularity conditions,an optimal order error estimate of the approximate solution is ***,a successive iteration technique is used to solve the problem numerically and a convergence result is established.

关键词： piezoelectric material frictional contact variational Inequality fixed point process finite element method error estimation iteration method

Tuberculosis among Chronic Hemodialysis Patients: A Senegalese Single Center Experience

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Open Journal of Nephrology 2015年第4期5卷 117-122页

作者： Mouhamadou Moustapha Cisse rachid el kabouss Yaya Kane Sidy Mouhamed Seck Ahmed Tall Lemrabott Maria Faye el Hadji Fary Ka Ansoumana Diatta Abdou Niang Boucar Diouf Nephrology Department of Teaching Hospital Aristide le Dantec Dakar Senegal Department of Nephrology Assane Seck University Ziguinchor Senegal Department of Nephrology Gaston Berger University Saint Louis Senegal

Summary: Tuberculosis is a common infectious disease in chronic hemodialysis due to alteration of the immune system associated with chronic kidney disease. The objectives of this study are to determine the prevalence of tuberculosis in chronic hemodialysis patients and to identify its diagnostic and therapeutic difficulties. Methods and patients: This was a descriptive retrospective study over a period of 20 years (1994-2014). It includes the records of periodic hemodialysis patients in the Nephrology Department of the Aristide Le Dantec University Teaching Hospital in Dakar which clinical symptoms and laboratory favor tuberculosis. Results: Of 258 chronic hemodialysis patients treated in Hospital Aristide Le Dantec hemodialysis center, 29 cases (11.4%) of tuberculosis disease are diagnosed. The mean age is 43.21 ± 12.48 years, and the sex-ratio is 0.8. The median time to onset of tuberculosis after initiation of hemodialysis is 22.86 ± 28.86 months. The diagnosis of tuberculosis is sure only in 17% of cases. Extra-pulmonary sites are found in 79% of cases. The average duration of treatment is 9.39 ± 1.64 months (6 - 13 months). Various treatment protocols are adopted. Mortality is 21%, 50% due to disseminated tuberculosis. Conclusion: The diagnosis of tuberculosis in the chronic hemodialysis patients is often difficult due to the atypical symptoms, the frequency of extra-pulmonary location and the lack of evidence of sure diagnosis.

关键词： Tuberculosis Hemodialysis Dakar

Performance Evaluation of an Evaporative Cooling Pad for Humidification-Dehumidification Desalination

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Fluid Dynamics & Materials Processing 2024年第10期20卷 2323-2335页

作者： Ibtissam el Aouni Hicham Labrim elhoussaine Ouabida Ahmed Ait Errouhi rachid el Bouayadi Driss Zejli Aouatif Saad Advanced Systems Engineering Laboratory National School of Applied SciencesIbn Tofail UniversityKenitra14000Morocco

The perfect combination of renewable energy and desalination technologies is the key to meeting water demands in a cost-effective,efficient and environmentally friendly *** desalination technique by humidificationdehumidification is non-conventional approach suitable for areas with low infrastructure(such as rural and decentralized regions)since it does not require permanent *** this study,this technology is implemented by using solar energy as a source of thermal power.A seawater desalination unit is considered,which consists of a chamber with two evaporators(humidifiers),a wetted porous material made of a corrugated cellulose cardboard and a condenser(dehumidifier).The evaporation system is tested with dry bulb temperature and relative air humidity *** results of numerical simulations indicate that higher inlet air velocities(from 0.75 to 3 m/s)lead to a decrease in theΔT,ΔRH,and *** the air remaining within the evaporator for 30 cm,the temperature differential increases to 5.7°C,accompanied by a 39%rise in relative humidity *** changes result in a significant enhancement in humidification efficiency,achieving a remarkable efficiency level of 78%.However,a wettability value of 630 m^(2)/m^(3)leads to a smaller reduction of these *** the pad thickness,particularly to 0.3 m,improves performance by boostingΔT,ΔRH,and effectiveness,especially for pads with a wettability of 630 m^(2)/m^(3),for which superior performances are predicted by the numerical tests.

关键词： Desalination humidification dehumidification porous material solar energy evaporator

Optimizing solar energy efficiency with an improved hill-climbing maximum power point tracking control approach: hardware implementation

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Clean Energy 2024年第5期8卷 167-176页

作者： Yassine el Alami elmostafa Chetouani Hamza Mokhliss Fatima Ouerradi Mohssin Aoutoul Said Bounouar rachid Bendaoud Ahmed Faize Redouane Rmaily Laboratory of electronics Instrumentation and EnergeticFaculty of SciencesChouaïb Doukkali UniversityB.P 20El JadidaMorocco Laboratory ElectronicsInstrumentation and EnergyExploitation and Processing of Renewable EnergyDepartment of PhysicsFaculty of SciencesUniversity of Chouaïb DoukkaliEl JadidaMorocco STIC Lab. Department of PhysicsChouaïb Doukkali UniversityEl JadidaMorocco Complex Cyber Physical Systems Laboratory National Higher School of Arts and CraftsHassan II UniversityCasablancaMorocco Interdisciplinary Laboratory for Research in Science Educationand TrainingHigher School of Education and Training-BerrechidHassan First UniversityBerrechidMorocco Department of Physics Polydisciplinary FacultyUniversity of Mohamed PremierNadorMorocco

This article implements maximum power point tracking(MPPT)based on the improved hill-climbing algorithm for photovoltaic(PV)systems feeding resistive loads.A direct current-to-direct current boost converter is inserted between the PV system and the load to achieve *** converter is managed using MPPT based on the hill-climbing *** objective of this paper is to optimize the code program to achieve the best compromise between accuracy and rapidity by implementing this algorithm using a *** PV systems are tested under identical meteorological *** the first,an improved hill-climbing MPPT controller is used whereas,in the second,the conventional version is *** experimental results obtained show a signifi-cant enhancement in terms of speed for the improved algorithm with a value of 0.4 s for the response time and 3%for the oscillation power;those values remain satisfactory in terms of precision of the algorithm compared with the conventional system studied and the compared algorithm from the literature.

关键词： DC/DC boost converter hardware implementation improved hill climbing MPPT photovoltaic system

Perspectives and Experiences of Education Stakeholders: A Quantitative Study on the Adoption of Artificial Intelligence in Executive Training Using Structural Equation Modeling

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Intelligent Information Management 2024年第2期16卷 104-120页

作者： el Mostafa Atoubi rachid Jahidi Regional Center for Education and Training Professions (CRMEF) Casablanca Morocco ENCG Settat Hassan 1st University Settat Morocco

The recent increase in the use of artificial intelligence has led to fundamental changes in the development of training and teaching methods for executive education. However, the success of artificial intelligence in regional centers for teaching and training professions will depend on the acceptance of this technology by young executive trainees. This article discusses the potential benefits of adopting AI in executive training institutions in Morocco, specifically focusing on CRMEF Casablanca Settat. Based on the Unified Theory of Acceptance and Use of Technology (UTAUT) (Venkatesh et al., 2003), this study proposes a model to identify the factors influencing the acceptance of artificial intelligence in regional centers for teaching professions and training in Morocco. To achieve this, a structural equation modeling approach was used to quantitatively describe the impact of each factor on AI adoption, utilizing data collected from 173 young executive trainees. The results indicate that perceived ease of use, perceived usefulness, trainer influence, and personal innovativeness influence the intention to use artificial intelligence. Our research provides managers of CRMEFs with a set of practical recommendations to enhance the implementation conditions of an artificial intelligence system. It aims to understand which factors should be considered in designing an artificial intelligence system within regional centers for teaching professions and training (CRMEFs).

关键词： Artificial Intelligence Technology Acceptance Intention to Use UTAUT Model Personal Innovativeness of Young Executive Trainees

Large magnetocaloric effect and magnetic properties of EuRhO_(3)

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Journal of Rare Earths 2024年第9期42卷 1724-1729,I0004页

作者： M.Lassri M.Sajieddine A.elouafi A.el Hachmi S.el Ouahbi R.Moubah Laboratory of Energy and Materials Engineering(LGEM) University of Sultan Moulay SlimaneFaculty of Science and Technology(FST)BP 52323000Béni-MellalMorocco Institute of Applied Physics(IAP)-School of Industrial Management(EMINES) Mohammed Ⅵ Polytechnic UniversityHay Moulay RachidLot 6603150Ben GuerirMorocco National School of Applied Sciences(ENSA) University of Sultan Moulay SlimaneBP 7725000KhouribgaMorocco Laboratory of Mechanics Production and Industrial Engineering(LMPGI)Higher School of Technology of Casablanca(ESTC)University of Hassan Ⅱ CasablancaCasablancaMorocco Laboratory of Radiation on Matter and Instrumentation(LRMI) Faculty of Science and Technology(FST)SettatHassan Ⅰ UniversitySettatMorocco Laboatory of Physics of Advanced Materials and Thermic(LPMAT) Faculty of Science Ain Chock(FSAC)University of Hassan Ⅱ CasablancaCasablancaMorocco

We report on the structural,magnetic,and magnetocaloric properties of EuRhO_(3) *** oxidation states of Eu and Rh ions were studied using X-ray photoelectron spectroscopy(XPS).It is found that the Eu ions are mainly in the divalent oxidation state while the Rh ions have+4 ***_(3) powders are found to be antiferromagnetic with a second order magnetic transition at Neel temperature(T_(N)=2.9 K).Analysis of the magnetic susceptibility versus temperature data in terms of the Curie=Weiss law:(χ=C/(T-θ_(W))) for T>T_(N),yields θ_(W)=-3.1 K and effective magne tic moment μ_(ff)^(exp),which is close to the theoretical value μ_(eff)^(theo).The magnetic entropy change(-Δ_(SM)),was determined by em ploying the thermodynam ic Maxwell's *** μ_0H=5 T and near T_(N),ΔS_(M)^(Max) and relative cooling power(RCP) exhibit large values of 33.7 J/(kg·K) and 238 J/kg,*** large magnitude of-Δ_(SM) and RCP show that the EuRhO_(3) compound could be a potential candidate to be used in cryogenic magnetic refrigeration.

关键词： X-ray photoelectron spectroscopy Cryogenic magnetic refrigeration Magnetic properties Magnetocaloric effect Rare earths

TWO DISJOINT AND INFINITE SETS OF SOLUTIONS FOR AN elLIPTIC EQUATION INVOLVING CRITICAL HARDY-SOBOLEV EXPONENTS

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数学物理学报:B辑英文版 2023年第5期43卷 2061-2074页

作者： Khalid BOUABID rachid ECHARGHAOUI Mohssine el MANSOUR Department of Mathematics Faculty of SciencesIbn Tofail UniversityKenitraB.P.133Morocco

In this paper,by an approximating argument,we obtain two disjoint and infinite sets of solutions for the following elliptic equation with critical Hardy-Sobolev exponents■whereΩis a smooth bounded domain in RN with 0∈?Ωand all the principle curvatures of?Ωat 0 are negative,a∈C1(Ω,R*+),μ>0,02(q+1)/(q-1).By2*:=2N/(N-2)and 2*(s):(2(N-s))/(N-2)we denote the critical Sobolev exponent and Hardy-Sobolev exponent,respectively.

关键词： Laplacien critical Sobolev-Hardy exponent critical Sobolev exponent infinitely many solutions Pohozaev identity

Generation of Different Classes of Multipartite Entanglement Using Cavity-QED

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Communications in Theoretical Physics 2018年第2期69卷 131-136页

作者： Mustapha Ziane rachid el Guerbouz Fatima-Zahra Siyouri Morad el Baz Equipe Sciences de la Matière et du Rayonnement Département de Physique Faculté des sciences Université Mohammed V Av.Ibn Battouta

Using a system of cavity quantum electrodynamics （QED） we present two schemes for multipartite entan- glement generation. In the first scheme, a three-level atom is interacting with three cavities successively. In the second one, two three-level atoms are interacted with a coherent optical cavity. These protocols allow us to generate the six c/asses of tripartite entanglement （GHZ, W, A-B-C, AB-C, C-AB, and B-AC class states） by controling the interaction time between atoms and cavities. Moreover, they allow us to generate entanglement between the cavity fields degrees of freedom （from the first scheme）, and a mixed entanglement between the cavity field degrees of freedom and the atomic degrees of freedom.

关键词： entanglement coherent states cavity QE-D GHZ states W states

pH-indicative Films Based on Chitosan–PVA/Sepiolite and Anthocyanin from Red Cabbage: Application in Milk Packaging

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Journal of Bionic Engineering 2022年第3期19卷 837-851页

作者： Marya Raji Laila el Foujji Mohamed el Mehdi Mekhzoum Mounir el Achaby Hamid Essabir rachid Bouhfid Abou el kacem Qaiss Moroccan Foundation for Advanced Science Innovation and ResearchComposites and Nanocomposites CenterRabat Design CenterRue Mohamed El JazouliMadinat El IrfaneRabat10100Morocco Faculty of Science Laboratoire de Chimie Organique Et HétérocycliqueUniversity Mohammed V in RabatRabat10100Morocco Materials Science and Nano-Engineering Department Mohammed VI Polytechnic UniversityLot 660–Hay Moulay RachidBen Guerir43150Morocco Mechanic Materialsand Composites(MMC)Laboratory of Energy EngineeringMaterials and SystemsNational School of Applied Sciences of AgadirIbn Zohr UniversityAgadir80000Morocco

Biobased smart packaging is been the most interesting research *** this study,pH-sensitive films based on anthocyanin molecules from red cabbage and sepiolite mineral nano-clay as functional additives were *** films were fabricated by casting method of blend polymer Chitosan/Poly(Vinyl Alcohol)at two fillers loading(5wt.%and 10wt.%).The structural,morphological,thermal,optical,hygroscopic,and mechanical properties as well as the pH sensitivity of films were *** thermal properties confirm that the amount of the anthocyanin in sepiolite was around 6.4%.The tensile strength and the young’s modulus of produced composites at 10wt.%sepiolite–anthocyanin content was increased to 8.90 MPa and 163 MPa,*** maximum water absorption that the films may absorb was 12.3%.pH sensitivity analysis showed that the Smart films change the color by changing the pH level,from pink at pH lower than 6 to yellow at pH higher than ***,the developed pH-sensitive films show band gaps in visible light that make them useful for monitoring milk spoilage.

关键词： Smart packaging Anthocyanin Red cabbage pH-sensitive and milk spoilage