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Experimental Testing of Cellular Construction Materials Containing Flax Particles

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Fluid Dynamics & Materials Processing 2023年第3期19卷 723-741页

作者： Hamadou-Ali Mohamed benazzouk amar Haïkel Ben Hamed Arash Jamali Laboratoire des Technologies Innovantes(UR-UPJV 3899)-UPJV Amiens80000France Plateforme de Microscopie Electronique-UPJV HUB de l’Energie80039Amiens

The feasibility of a sustainable non-autoclaved cellular concrete,based on flax vegetable co-products,for the production of usable specimen in the lightweight construction field,has been investigated *** produced specimen,containing various volume ratios of flax particles with respect to preformulatd Tradical PF70 lime binder of 0,1,and 2,were lightened by creating a porous structure in the matrix through the addition of 0.3%*** powder(able to react with calcium hydroxide from the binder and result in microscopic air-bubbles).Fresh and hardened specimen properties,including hydration,fresh density,porosity,hardened density,compressive and flexural strengths,toughness energy,and dry thermal conductivity at different temperatures,were assessed for varying flax-to-binder *** have shown that the addition of Aluminum powder leads to restrain the setting time delay of binder-based ***,the hardened material displays a significant decrease in specimen density,thereby resulting in a compressive strength level compatible with that required in the cellular construction materials *** also highlighted the ability of added flax to induce a change in the specimen from brittle to ductile ***,a high degree of thermal insulation can be achieved,which makes the cellular specimen based on flax particle suitable as insulated-bearing walls material.

关键词： Flax particles cellular concrete lightening porous structure physico-mechanical properties thermal conductivity

OPTIMAL CONTROL OF AN M/G/1 RETRIAL QUEUE WITH VACATIONS

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Journal of Systems Science and Systems Engineering 2008年第4期17卷 487-502页

作者： amar AISSANI University of Science & Technology Houari Boumediene BP 32 El Alia Bab-Ez-Zouar 16111Algeria

In this note, we consider an M/G/1 retrial queue with server vacations, when retrial times, service times and vacation times are arbitrary distributed. The distribution of the number of customers in the system in stationary regime is obtained in terms of generating function. Next, we give heavy traffic approximation of such distribution. We show that the system size can be decomposed into two random variables, one of which corresponds to the system size of the ordinary M/G/1 FIFO queue without vacation. Such a stochastic decomposition property is useful for the computation of performance measures of interest. Finally, we solve simple problems of optimal control of vacation and retrial policies.

关键词： Retrial queues vacation optimal control stochastic decomposition ageing distribution heavy traffic

Finite element analysis of slope stability by expanding the mobilized principal stress Mohr's circles-Development, encoding and validation

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第4期14卷 1165-1179页

作者： Djillali amar Bouzid Department of Civil Engineering Faculty of TechnologyUniversity of Blida 1Blida09000Algeria

In recent years,finite element analysis is increasingly being proposed in slope stability problems as a competitive method to traditional limit equilibrium methods(LEMs)which are known for their inherent ***,the application of finite element method(FEM)to slope stability as a strength reduction method(SRM)or as finite element limit analysis(FELA)is not always a success for the drawbacks that characterize both *** increase the performance of finite element analysis in this problem,a new approach is proposed in this *** consists in gradually expanding the mobilized stress Mohr’s circles until the soil failure occurs according to a prescribed non-convergence *** present approach called stress deviator increasing method(SDIM)is considered rigorous for three main ***,it preserves the definition of the factor of safety(FOS)as the ratio of soil shear strength to the mobilized shear ***,it maintains the progressive development of shear stress resulting from the increase in the principal stress deviator on the same plane,on which the shear strength takes ***,by introducing the concept of equivalent stress loading,the resulting trial stresses are checked against the violation of the actual yield criterion formed with the real strength parameters rather than those reduced by a trial *** new numerical procedure was encoded in a Fortran computer code called S^(4)DINA and verified by several *** with other numerical methods such as the SRM,gravity increasing method(GIM)or even FELA by assessing both the FOS and contours of equivalent plastic strains showed promising results.

关键词： Slope stability,Finite element analysis Strength reduction method(SRM),Stress point-based factor of safety(FOS),Limit equilibrium method(LEM),Stress deviator Mohr’s circle,Plastic strain

THE LERAY-SCHAUDER CONDITION FOR 1-SET WEAKLY-CONTRACTIVE AND(ws)-COMPACT OPERATORS

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Acta Mathematica Scientia 2014年第2期34卷 263-273页

作者： Afif BEN amar Department of Mathematics Faculty of Sciences

Abstract The main purpose of this article is to prove a collection of new nxea point theorems for （ws）-compact and so-called 1-set weakly contractive operators under Leray- Schauder boundary condition. We also introduce the concept of semi-closed operator at the origin and obtain a series of new fixed point theorems for such class of operators. As consequences, we get new fixed point existence for （ws）-compact （in particular nonexpansive） self mappings unbounded closed convex subset of Banach spaces. The main condition in our results is formulated in terms of axiomatic measures of weak noncompactness. Later on, we give an application to generalized Hammerstein type integral equations.

关键词： Measure of weak noncompactness weakly condensing and weakly nonexpan-sire (ws)-compact operator fixed point theorems semi-closed at the origin

Are environment-related technologies key to unlock the path towards sustainable development:An econometric analysis

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Geoscience Frontiers 2024年第4期15卷 437-448页

作者： amar Rao Satish Kumar School of Management BML Munjal UniversityGurugramHaryanaIndia Indian Institute of Management Nagpur India

The objective of this study is to investigate the correlation between energy intensity and environmentrelated technology in industrialized *** utilizing panel data from 23 countries over a span of 32 years(1990-2021),this research aims to contribute to the comprehension of the role of green innovation in sustainable *** study employs the Stochastic Impacts by Regression on Population,Affluence,and Technology model while controlling for variables including population growth,gross domestic product in purchasing power parity,Information and Communication Technology capital deepening,renewable energy consumption,and green innovation represented by research and development expenditure on environment-related *** results of the analysis,employing panel unit root tests,cross-sectional dependence tests,and a Method of Moments quantile regression,reveal that green innovation has a positive influence on diminishing energy intensity,with a more substantial impact at higher ***,ICT capital deepening is determined to have a positive and noteworthy effect on reducing energy *** findings of this study offer valuable insights for policymakers in their endeavours to accomplish sustainable development goals.

关键词： Technology Sustainable development Energy intensity Quantile regression

Nonlinear ion-acoustic solitary waves in an electron-positron-ion plasma with relativistic positron beam

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Chinese Physics B 2018年第10期27卷 471-476页

作者： Ridip Sarma amar P Misra Nirab C Adhikary Department of Mathematics University of Science and TechnologyTechno CityKhanaparaBaridua9th MileRi-BhoiMeghalayaIndia Department of Mathematics Siksha BhavanaVisva-Bharati University Physical Sciences Division Institute of Advanced Study in Science and TechnologyVigyan PathPaschim BoragaonGarchukGuwahati-781035AssamIndia

The propagation characteristics of nonlinear ion–acoustic（IA） solitary waves（SWs） are studied in thermal electron–positron–ion plasma considering the effect of relativistic positron beam. Starting from a set of fluid equations and using the reductive perturbation technique, we derive a Korteweg–de Vries（KdV） equation which governs the evolution of weakly nonlinear IA SWs in relativistic beam driven plasmas. The properties of the IA soliton are studied, and it is shown that the presence of relativistic positron beam significantly modifies the characteristics of IA solitons.

关键词： electron-positron-ion plasma relativistic effect ion-acoustic wave homogeneous balance method

CFD simulation of homogeneous reaction characteristics of dehydration of fructose to HMF in micro-channel reactors

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Chinese Journal of Chemical Engineering 2018年第6期26卷 1340-1349页

作者： Xin Zhang Hui Liu amar Samb Guofeng Wang State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology Beijing 100029 China Beijing Key Laboratory of Energy Environmental Catalysis Beijing University of Chemical Technology Beijing 100029 China China Tianchen Engineering Corporation (Beijing Branch) Beijing 100029 China

In this work the applicability of the micro-channel reactor technique to the production of promising platform chemical 5-hydroxymethyl furan(HMF) from fructose in aqueous solution is systemically investigated by performing CFD *** factors including solvents,residence time distribution of reaction mixtures,heat transfer conditions and micro-channel configurations are evaluated in terms of the reaction performance indices,i.e.,conversion of fructose,HMF selectivity and yield.A scale-up method from a single channel to a multiple channel reactor is also *** is demonstrated that:1) at the single channel scale,controlling residence times and temperature distribution of the reaction mixture within the channel is crucial for enhancing the reaction performance,while different channel configurations lead to marginal improvements;2) for the scaling-up of the reaction process,a reactor module containing 15 circular parallel channels could be used as module blocks,which can be stacked one by one to meet the required reactor performance and production *** present results show that micro-reactors are quite suitable for HMF production.

关键词： Fructose dehydration Micro-channel reactor Simulation Optimization

Application of hybrid support vector regression artificial bee colony for prediction of MMP in CO2-EOR process

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Petroleum 2020年第4期6卷 415-422页

作者： Menad Nait amar Noureddine Zeraibi Laboratoire Génie Physique des Hydrocarbures Faculty of Hydrocarbons and ChemistryUniversity M'hamed Bougara of BoumerdesAvenue de l’Indépendance35000BoumerdesAlgeria

Minimum miscibility pressure(MMP)is a key parameter in the successful design of miscible gases injection such as CO2 flooding for enhanced oil recovery process(EOR).MMP is generally determined through experimental tests such as slim tube and rising bubble apparatus(RBA).As these tests are time-consuming and their cost is very expensive,several correlations have been ***,and although the simplicity of these correlations,they suffer from inaccuracies and bad generalization due to the limitation of their ranges of *** paper aims to establish a global model to predict MMP in both pure and impure CO2-crude oil in EOR process by combining support vector regression(SVR)with artificial bee colony(ABC).ABC is used to find best SVR hyper-parameters.201 data collected from authenticated published literature and covering a wide range of variables are considered to develop SVR-ABC pure/impure CO2-crude oil MMP model with following inputs:reservoir temperature(TR),critical temperature of the injection gas(Tc),molecular weight of pentane plus fraction of crude oil(MWC5+)and the ratio of volatile components to intermediate components in crude oil(xvol/xint).Statistical indicators and graphical error analyses show that SVR-ABC MMP model yields excellent results with a low mean absolute percentage error(3.24%)and root mean square error(0.79)and a high coefficient of determination(0.9868).Furthermore,the results reveal that SVR-ABC outperforms either ordinary SVR with trial and error approach or all existing methods considered in this work in the prediction of pure and impure CO2-crude oil ***,the Leverage approach(Williams plot)is done to investigate the realm of prediction capability of the new model and to detect any probable erroneous data points.

关键词： CO2-EOR process CO2-Crude oil minimum miscibility pressure Support vector regression(SVR) Artificial bee colony(ABC)

Attenuation of Rayleigh Surface Waves in a Porous Material

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Chinese Physics Letters 2012年第4期29卷 123-125页

作者： DEBBOUB Salima BOUMAIZA Youcef BOUDOUR amar TAHRAOUI Tarek Laboratory of Materials Elaboration and Analysis Department of PhysicsFaculty of SciencesUniversity of AnnabaP.O.BOX 1223000 AnnabaAlgeria

Using acoustic microscopy at higher frequency,we show the velocity evolutions of surface acoustic waves,in particular Rayleigh waves that depend on porosity for a mesoporous silicon *** velocities are obtained from different V(z) curves,which are determined experimentally at a frequency of *** analysis of V(z) data yields attenuation that is directly dependent on *** the other hand,αN attenuation has been modeled and allows us to investigate its influence on the velocity VR of the propagation for Rayleigh waves.

关键词： layer porosity Porous