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Effect of Recycling Cycles on the Mechanical and Damping Properties of Flax Fibre Reinforced elium Composite:Experimental and Numerical Studies

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Journal of Renewable Materials 2021年第4期9卷 695-721页

作者： Sami Allagui abderrahim el mahi Jean-Luc Rebiere Moez Beyaoui Anas Bouguecha Mohamed Haddar Acoustics Laboratory of Le Mans University Le Mans UniversityLe Mans72085France Laboratory of Mechanics Modelling and Production National School of Engineering of SfaxSfax3038Tunisia

This manuscript deals with the effects of recycling on the static and dynamic properties of flax fibers reinforced thermoplastic *** corresponding thermoplastic used in this work is elium ***’s the first liquid thermoplastic resin that allows the production of recycled composite parts with promising mechanical *** appeared on the resin market in *** until now,no studies were available concerning how it can be recycled and *** this study,a thermocompression recycling process was investigated and applied to elium *** fiber-reinforced elium composites were produced using a resin infusion process and were subjected to different thermomechanical recycling *** each material,five recycling operations were carried out on the raw material.A total of 10 different materials were investigated and tested by means of tensile and free vibration tests to evaluate the effect of recycling on their *** addition,a finite element model of the dynamic problem was developed to evaluate the loss factor and natural frequencies regarding different *** results obtained show that the failure tensile properties of elium resin as well as flax fiber reinforced composites decrease during recycling ***,recycling induces a rise in the elastic ***,improvement in the dynamic stiffness was observed with recycling *** repeated recycling appeared to have negligible effects on the loss factor of the recycled *** results obtained from the experiment and the numerical analyses were in close agreement.

关键词： Recycling thermoplastic bio-composites thermocompression process tensile properties vibration loss factor

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Gender-Based Analysis of User Reactions to Facebook Posts

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Big Data Mining and Analytics 2024年第1期7卷 75-86页

作者： Yassine el Moudene Jaafar Idrais Rida el Abassi abderrahim Sabour Mathematical Engineering and Computer Science Laboratory Faculty of SciencesIbn Zohr UniversityAgadir 8706Morocco Department of Computer Science Mathematical−High School of Technology Ibn Zohr UniversityAgadir 8706Morocco

Online Social Networks(OSNs)are based on the sharing of different types of information and on various interactions(comments,reactions,and sharing).One of these important actions is the emotional reaction to the *** diversity of reaction types available on Facebook(namely FB)enables users to express their feelings,and its traceability creates and enriches the users’emotional identity in the virtual *** paper is based on the analysis of 119875012 FB reactions(Like,Love,Haha,Wow,Sad,Angry,Thankful,and Pride)made at multiple levels(publications,comments,and sub-comments)to study and classify the users’emotional behavior,visualize the distribution of different types of reactions,and analyze the gender impact on emotion *** of these can be achieved by addressing these research questions:who reacts the most?Which emotion is the most expressed?

关键词： profiling knowledge extraction data mining emotion mining social media data crawling Facebook reactions gender

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Damping Analysis and Failure Mechanism of 3D Printed Bio-Based Sandwich with Auxetic Core under Bending Fatigue Loading

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Journal of Renewable Materials 2021年第3期9卷 569-584页

作者： Khawla Essassi Jean-Luc Rebiere abderrahim el mahi Mohamed Amine Ben Souf Anas Bouguecha Mohamed Haddar Acoustics Laboratory of Mans University(LAUM)-UMR CNRS Le Mans UniversityLe Mans6613France Laboratory of Mechanics Modeling and Production(LA2MP) National School of Engineers of SfaxUniversity of SfaxSfaxTunisia

Meta-sandwich composites with three-dimensional(3D)printed architecture structure are characterized by their high ability to absorb *** this paper,static and fatigue 3-point bending tests are implemented on a 3D printed sandwich composites with a re-entrant honeycomb *** skins,core and whole sandwich are manufactured using the same bio-based material which is polylactic acid with flax fiber *** tests are performed in order to evaluate the durability and the ability of this material to dissipate ***,static tests are conducted to study the bending behaviour of the sandwich beams,as well as to determine the failure parameters and the characteristic used in fatigue ***,fatigue analyses were carried out to determine the fatigue resistance of these *** effects of the core density on the stiffness,hysteresis loop,energy absorption and loss factor,for two loading level,are ***,the behaviour of this sandwich composite with re-entrant honeycomb core is compared with that of sandwiches with different core *** results show that sandwich with high core density dissipate more energy,which results higher loss *** determined properties offer the most sensitive indicators of sandwich composite damage during its *** work aims to determine the static and fatigue properties of this material,thus,study its potential applications in industry.

关键词： Auxetic structure fatigue damping bio-sandwich composite 3D printing

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On stability behaviors of 5D M-theory black objects

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Communications in Theoretical Physics 2024年第5期76卷 94-101页

作者： Adil Belhaj abderrahim Bouhouch Departement de Physique Equipe des Sciences de la matiere et du rayonnementESMaR Faculte des SciencesUniversite Mohammed V de RabatRabatMorocco

Using N=2 supergravity formalism,we investigate certain behaviors of five-dimensional black objects from the compactification of M-theory on a Calabi-Yau *** manifold has been constructed as the intersection of two homogeneous polynomials of degrees(ω+2,1)and(2,1)in a product of two weighted projective spaces given by WP^(4)(ω,1,1,1,1)×P^(1).First,we determine the allowed electric charge regions of the BPS and non BPS black holes obtained by wrapping M2-branes on appropriate two cycles in such a proposed Calabi-Yau *** that,we calculate the entropy of these solutions which takes a maximal value corresponding to ω=1 defining the ordinary projective space P^(4).For generic values of ω,we show that the non BPS states are ***,we conduct a similar study of five-dimensional black *** the allowed magnetic charge regions of the BPS and non BPS black stringy solutions derived from M5-branes on dual divisors,we calculate the tension taking a minimal value for P^(4).By determining the recombination factor,we show that the non-BPS black string states are stable in the allowed regions in the magnetic charge space.

关键词： M-theory Calabi-Yau manifolds black holes black strings stability behaviors

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Graphite Carbone Structure

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Crystal Structure Theory and Applications 2024年第1期12卷 1-10页

作者： Lahbib Abbas Lahcen Bih Khalid Yamni abderrahim elyahyaouy Abdelmalik el Attaoui Zahra Ramzi Materials Membranes and Nanotechnology Laboratory Faculty of Science and Technology Moulay Ismail University Errachidia Morocco Engineering Sciences and Professions Laboratory National School of Arts and Crafts Moulay Ismail University Meknes Morocco Materials Membranes and Nanotechnology Laboratory Chemistry Department Faculty of Sciences Moulay Ismail Univer-sity Meknes Morocco Physics Department Faculty of Sciences Ibn Tofail University Kenitra Morocco Laboratory of Molecular Chemistry Materials and Environment (LCM2E) Multidisciplinary Faculty of Nador Mohamed 1st University Nador Morocco Laboratory of SCiMATOP Chemistry Department Faculty of Sciences Semlalia Cadi Ayyad University Marrakech Morocco

Carbon graphite is a crystalline form of carbon consisting of layers of hexagonal carbon atoms arranged in a two-dimensional “graphene” structure. Graphene layers are stacked on top of each other, forming a three-dimensional structure with a high degree of anisotropy. The carbon atoms within each layer are linked together by strong covalent bonds, creating a strong, stable lattice structure. However, the layers themselves are held together by weak van der Waals forces, enabling them to slide easily over each other. The properties of carbon graphite are highly dependent on the orientation and alignment of the graphene layers. When the layers are aligned parallel to each other, the material exhibits high strength and stiffness along the alignment direction, but is weaker and more flexible in other directions. Carbon graphite is used in a variety of applications where high strength, rigidity and electrical conductivity are required. Some common applications include electrical contacts, electric motor brushes, and as a structural material in aerospace and defense applications. The aim of our work is to describe the structure of graphite, its physical and chemical properties and its applications.

关键词： Graphite Graphene Hexagonal Structure Hardness Rigidity electrical Con-ductivity

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Determination of Latent Heats of Vaporization and Fusion

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Advances in Chemical Engineering and Science 2024年第3期14卷 113-124页

作者： Lahbib Abbas Lahcen Bih Khalid Yamni abderrahim elyahyaouy Abdelmalik el Attaoui Zahra Ramzi Chemistry Department Faculty of Science and Technology Moulay Ismail University Meknes Er-Rachidia Morocco Engineering Sciences and Professions Laboratory National School of Arts and Crafts Moulay Ismail University Meknes Meknes Morocco Materials Membranes and Nanotechnology Chemistry Department Faculty of Sciences Moulay Ismail University Meknes Zitoune Mekns Morocco Physics Department Faculty of Sciences Ibn Tofail University Kenitra Morocco Laboratory of Molecular Chemistry Materials and Environment (LCM2E) Multidisciplinary Faculty of Nador Mohamed 1st University Oujda Nador Morocco Laboratory of SCiMATOP Chemistry Department Faculty of Sciences Semlalia Cadi Ayyad University Marrakech Morocco

Water is the most abundant liquid on the surface of the earth. It is a liquid whose properties are quite surprising, both as a pure liquid and as a solvent. Water is a very cohesive liquid: its melting and vaporization temperatures are very high for a liquid that is neither ionic nor metallic, and whose molar mass is low. Thus, water remains liquid at atmospheric pressure up to 100C while similar molecules such as H2S, H2Se, H2Te for example would give a vaporization temperature close to 80C. This cohesion is in fact ensured by hydrogen bonds between water molecules. This type of bonds between neighboring molecules, hydrogen bonds, is quite often found in chemistry [1] [2]. Any change in the state of aggregation of a substance occurs with the absorption or release of a certain amount of latent heat of transformation. Latent heat of fusion, vaporization or sublimation is the ratio of the energy supplied as heat to the mass of the substance that is melted, vaporized or sublimated. As a result of the reversibility of the processes, the fusion heat is equal to the heat released in the reverse process: crystallization and solidification heat. And likewise the heat of vaporization is equal to the heat of condensation. This equality of heat is often used to determine experimentally either of these quantities. There are two main measurement methods: 1) Direct measurement using the calorimeter, 2) Indirect measure based on the use of the VantHoff relationship. The objective of this work is to measure the latent heat of water vaporization and verify the compatibility of the experimental values with the values given by the tables using the indirect method.

关键词： Latent Heat of Vaporization Latent Heat of Fusion Calorimetry Relationship of Vant’Hoff

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Systematic Method for Constructing Lewis Representations

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Open Journal of Inorganic Chemistry 2024年第1期14卷 1-18页

作者： Lahbib Abbas Lahcen Bih Khalid Yamni abderrahim elyahyaouy Abdelmalik el Attaoui Zahra Ramzi Materials Membranes and Nanotechnology Faculty of Science and Technology Moulay Ismail University Meknes Er-Rachidia Morocco Engineering Sciences and Professions Laboratory National School of Arts and Crafts Moulay Ismail University Meknes Meknes Morocco Materials Membranes and Nanotechnology Chemistry Department Faculty of Sciences Moulay Ismail University Meknes Meknes Morocco Physics Department Faculty of Sciences Ibn Tofail University Kenitra Morocco Laboratory of Molecular Chemistry Materials and Environment (LCM2E) Multidisciplinary Faculty of Nador Mohamed 1st University Oujda Nador Morocco Laboratory of SCiMATOP Chemistry Department Faculty of Sciences Semlalia Cadi Ayyad University Marrakech Morocco

The systematic method for constructing Lewis representations is a method for representing chemical bonds between atoms in a molecule. It uses symbols to represent the valence electrons of the atoms involved in the bond. Using a number of rules in a defined order, it is often better suited to complicated cases than the Lewis representation of atoms. This method allows us to determine the formal charge and oxidation number of each atom in the edifice more efficiently than other methods.

关键词： Systematic Method Lewis Representation Chemical Bond Formal Charge Oxidation Number

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Comparison between seismic analysis of twisting and regular 52-story towers considering soil-structure interaction

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Earthquake Engineering and Engineering Vibration 2024年第3期23卷 663-675页

作者： Mohamed Naguib Abouelsaad Mohammed Shaaban Salah el Bagalaty Mohamed E.el Madawy Structural Engineering Department Faculty of EngineeringMansura UniversityMansoura 35511Egypt Faculty of Engineering Delta University for Science and TechnologyGamasa 35712Egypt

A dynamic analysis of both twisting and regular towers is carried out to determine the results of considering soil-structure interaction(SSI)on high-rise *** addition,the difference between the seismic performance of using twisting towers over regular ones is *** twisting tower is a simulation of the Evolution Tower(Moscow).The towers’skeletons consist of RC elements and rest on a reinforced concrete piled-raft *** soil model is considered as multi-layered with the same soil properties as the zone chosen for the analysis(New Mansoura City,Egypt).The only difference between both towers is their shape in *** whole system is modelled and analyzed in a single step as one full 3D model,which is known as the direct approach in *** analyses are carried out using finite-element software(Midas GTS NX).Dynamic output responses due to three records of seismic loads are proposed and presented in some *** on the results,it is concluded that SSI has a considerable effect on the dynamic response of tall buildings mainly because of the foundation flexibility,as it leads to lengthening the vibration period,increasing the story drift and the base shear for both cases.

关键词： soil-structure interaction seismic analysis twisting towers base shear story drift finite element method Midas GTS NX

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Stability analysis of a time-delayed Van der Pol–Helmholtz–Duffing oscillator in fractal space with a non-perturbative approach

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Communications in Theoretical Physics 2024年第4期76卷 22-31页

作者： Yusry O el-Dib Department of Mathematics Faculty of EducationAin Shams UniversityRoxyCairoEgypt

The time-delayed fractal Van der Pol–Helmholtz–Duffing(VPHD)oscillator is the subject of this paper,which explores its mechanisms and highlights its stability *** time-delayed technologies are currently garnering significant attention,the focus of this research remains crucially relevant.A non-perturbative approach is employed to refine and set the stage for the system under *** innovative methodologies introduced yield an equivalent linear differential equation,mirroring the inherent nonlinearities of the ***,the incorporation of quadratic nonlinearity into the frequency formula represents a cutting-edge *** analytical solution's validity is corroborated using a numerical *** conditions are ascertained through the residual Galerkin ***,it is observed that the delay parameter,in the context of the fractal system,reverses its stabilizing influence,impacting both the amplitude of delayed velocity and the *** analytical solution's precision is underscored by its close alignment with numerical ***,the study reveals that fractal characteristics emulate damping *** its applicability across diverse nonlinear dynamical systems,this non-perturbative approach emerges as a promising avenue for future research.

关键词： Van der Pol-Helmholtz-Duffing oscillator fractal space time-delay non-perturbative approach stability analysis el-Dib's frequency formula

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Nonlinear wave dispersion in monoatomic chains with lumped and distributed masses:discrete and continuum models

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Applied Mathematics and Mechanics(English Edition) 2024年第4期45卷 633-648页

作者： E.GHAVANLOO S.el-BORGI School of Mechanical Engineering Shiraz UniversityShiraz 71963-16548Iran Mechanical Engineering Program Texas A&M University at QatarDoha 23874Qatar

The main objective of this paper is to investigate the influence of inertia of nonlinear springs on the dispersion behavior of discrete monoatomic chains with lumped and distributed *** developed model can represent the wave propagation problem in a non-homogeneous material consisting of heavy inclusions embedded in a *** inclusions are idealized by lumped masses,and the matrix between adjacent inclusions is modeled by a nonlinear spring with distributed ***,the model is capable of depicting the wave propagation in bi-material bars,wherein the first material is represented by a rigid particle and the second one is represented by a nonlinear spring with distributed *** discrete model of the nonlinear monoatomic chain with lumped and distributed masses is first considered,and a closed-form expression of the dispersion relation is obtained by the second-order Lindstedt-Poincare method(LPM).Next,a continuum model for the nonlinear monoatomic chain is derived directly from its discrete lattice model by a suitable continualization *** subsequent use of the second-order method of multiple scales(MMS)facilitates the derivation of the corresponding nonlinear dispersion relation in a closed *** novelties of the present study consist of(i)considering the inertia of nonlinear springs on the dispersion behavior of the discrete mass-spring chains;(ii)developing the second-order LPM for the wave propagation in the discrete chains;and(iii)deriving a continuum model for the nonlinear monoatomic chains with lumped and distributed ***,a parametric study is conducted to examine the effects of the design parameters and the distributed spring mass on the nonlinear dispersion relations and phase velocities obtained from both the discrete and continuum *** parameters include the ratio of the spring mass to the lumped mass,the nonlinear stiffness coefficient of the spring,and the wave amplitude.

关键词： nonlinear mass-spring chain discrete model continuum model LindstedtPoincare method(LPM) method of multiple scales(MMS) dispersion phase velocity

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