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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

Implications of regional identity for neural stem and progenitor cell transplantation in the injured or diseased nervous system

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Neural Regeneration Research 2024年第4期19卷 715-716页

作者： Prakruthi amar Kumar Jennifer N.Dulin Department of Biology Texas A&M UniversityCollege Station Texas A&M Institute for Neuroscience Texas A&M UniversityCollege Station

Neural stem and progenitor cell(NSPC)transpla ntation has emerged as a promising therapeutic strategy for replacing lost neuronal populations and repairing damaged neural circuits following nervous system injury and disease.A great deal of experimental work has investigated the biology of NSPC grafting in preclinical animal models;more recently.

关键词： neural system injured

Antenatal Noninvasive Fetal Electrocardiography:A Literature Review

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Maternal-Fetal Medicine 2024年第3期6卷 178-189页

作者： Claire Pegorie Becky Liu Basky Thilaganathan amar Bhide Department of Obstetrics and Gynaecology St George’s University Hospitals NHS Foundation TrustLondon SW170QTUnited Kingdom Vascular Biology Research Centre Molecular and Clinical Sciences Research InstituteSt George’s University of LondonLondon SW170QTUnited Kingdom

Fetal heart rate(FHR)monitoring is one of the central parts of obstetric ***-based technologies such as cardiotocography(CTG)remain the most common method for FHR *** CTG’s limitations,including subjective interpretation,high interobserver variability,and the need for skilled professionals,led to the development of computerized CTG(cCTG).While cCTG demonstrated advantages,its superiority over visual interpretation remains *** has prompted the exploration of alternatives like noninvasive fetal electrocardiography(NIFECG).This review explores the landscape of antenatal FHR monitoring and the need for remote FHR monitoring in a patient-centered care ***,FHR monitoring needs to evolve from the traditional approach to incorporate artificial intelligence and machine *** review underscores the importance of aligning fetal monitoring with modern healthcare,leveraging artificial intelligence algorithms for accurate assessments,and enhancing patient *** physiology of FHR variability(FHRV)is explained emphasizing its significance in assessing fetal *** measures of FHRV and their relevance are *** delves into the promising realm of NIFECG,detailing its history and recent technological *** potential advantages of NIFECG are objective FHR assessment,beat-to-beat variability,patient comfort,remote prolonged use,and less signal loss with increased maternal body mass *** its promise,challenges such as signal loss must be *** clinical application of NIFECG,its correlation with cCTG measures,and ongoing technological advancements are *** conclusion,this review explores the evolution of antenatal FHR monitoring,emphasizing the potential of NIFECG in providing reliable,home-based monitoring *** research directions are outlined,urging longitudinal studies and evidence generation to establish NIFECG’s role in enhancing fetal well-being assess

关键词： Ambulatory monitoring Noninvasive fetal electrocardiography Fetal heart-rate monitoring Fetal heart rate variability

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

High-speed silicon photonic electro-optic Kerr modulation

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Photonics Research 2024年第1期12卷 51-60页

作者： JONATHAN PELTIER WEIWEI ZHANG LEOPOLD VIROT CHRISTIAN LAFFORGUE LUCAS DENIEL DELPHINE MARRIS-MORINI GUY AUBIN FARAH amar DENH TRAN XINGZHAO YAN CALLUM G.LITTLEJOHNS CARLOS ALONSO-RAMOS KE LI DAVID J.THOMSON GRAHAM REED LAURENT VIVIEN University Paris-Saclay CNRSCentre for Nanoscience and Nanotechnology(C2N)Palaiseau 91120France University Grenoble Alpes CEALETIGrenoble 38000France Optoelectronics Research Centre Zepler Institute for Photonics and NanoelectronicsFaculty of Engineering and Physical SciencesUniversity of SouthamptonSouthampton SO171BJUK

Silicon-based electro-optic modulators contribute to easing the integration of high-speed and low-power consumption circuits for classical optical communications and data *** the plasma dispersion modulation,an alternative solution in silicon is to exploit the DC Kerr effect,which generates an equivalent linear electro-optical effect enabled by applying a large DC electric *** some theoretical and experimental studies have shown its existence in silicon,limited contributions relative to plasma dispersion have been achieved in high-speed modulation so *** paper presents high-speed optical modulation based on the DC Kerr effect in silicon PIN *** contributions of both plasma dispersion and Kerr effects have been analyzed in different waveguide configurations,and we demonstrated that the Kerr induced modulation is dominant when a high external DC electric field is applied in PIN ***-speed optical modulation response is analyzed,and eye diagrams up to 80 Gbit/s in NRZ format are obtained under a *** of 30 *** work paves the way to exploit the Kerr effect to generate high-speed Pockels-like optical modulation.

关键词： waveguide dispersion effect

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

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

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)