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Simulation of the Hygrothermal Behavior of a Building Envelope Based on Phase Change Materials and a Bio-Based Concrete

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Fluid Dynamics & Materials Processing 2022年第5期18卷 1483-1494页

作者： Dongxia Wu mourad Rahim Wendong Li Mohammed El Ganaoui Rachid Bennacer University of Lorraine LERMABIUT H Poincaréde LongwyLongwy54400France University of Paris-Saclay ENS Paris-SaclayCNRSLMTGif-sur-Yvette91190France

Phase Change Materials(PCMs)have high thermal inertia,and hemp concrete(HC),a bio-based concrete,has strong hygroscopic *** previous studies,PCM has been extensively combined with many materials,however,most of these studies focused on thermal properties while neglecting hygroscopic *** this study,the two materials have been combined into a building envelope and the related hygrothermal properties have been *** particular,numerical studies have been performed to investigate the temperature and relative humidity behavior inside the HC,and the effect of adding PCM on the hygrothermal behavior of the *** results show that there is a high coupling between temperature and relative humidity inside the HC,since the relative humidity changes on the second and third days are different,with values of 8%and 4%,***,the variation of relative humidity with temperature indicates the dominant influence of temperature on relative humidity *** the presence of PCM,the temperature variation inside the HC is damped due to the high thermal inertia of the PCM,which also leads to suppression of moisture evaporation and thus damping of relative humidity *** the second and third days,the temperature changes at the central position are reduced by 4.6%and 5.1%,compared to the quarter *** the relative humidity change,the reductions are 5.3%and 5.4%on the second and third days,***,PCM,with high thermal inertia,acts as a temperature damper and has the potential to increase the moisture buffering capacity inside the *** makes it possible for such a combined envelope to have both thermal and hygric inertia.

关键词： Phase change material(PCM) bio-based concrete passive building envelope heat and moisture transfer hygrothermal performance

Experimental investigation of hygrothermal behavior of wooden-frame house under real climate conditions

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Energy and Built Environment 2023年第1期4卷 122-129页

作者： mourad Rahim Rabah Djedjig Dongxia Wu Rachid Bennacer Mohammed EL Ganaoui University of Lorraine LERMABIUT H Poincaréde Longwy168 Rue de LorraineCosnes et Romain54400 LongwyFrance University of Paris-Saclay ENS Paris-SaclayCNRSLMT91190 Gif-sur-YvetteFrance

This paper deals with the experimental investigation of hygrothermal behavior of wooden-frame building *** experiment was based on in-situ monitoring of a full size experimental monozone house built at the University of *** in temperature and relative humidity inside and outside the envelope were logged simultaneously with local meteorological *** showed the high coupling between temperature and relative humidity variations within the envelope *** overall hygrothermal response of the wall highlighted an interesting hygrothermal dynamic behavior of the envelope which may contribute to mitigate variations of relative humidity inside the ***,relative humidity evolves within a range of values that can lead to mold growth at a certain position which may alter wooden envelope life.

关键词： 3 hygrothermal behavior Heat and mass transfer Wood Bio-based building envelope

Effect of Hole Configuration on Heat Transfer through a Hollow Block Subjected to Solar Flux

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Fluid Dynamics & Materials Processing 2022年第5期18卷 1339-1348页

作者： mourad Najjaoui Thami Ait-Taleb Abdelhalim Abdelbaki Zaki Zrikem Hassan Chaib Polydiscilinary Faculty of Ouarzazate Ibn Zohr UniversityOuarzazate638Morocco Faculty of Sciences Semlalia Cadi Ayyad UniversityMarrakesh2390Morocco

In this paper,some effort is provided to optimize the geometry of a concrete hollow brick(used in the construction of building roofs)in order to increase the related thermal resistance,thereby reducing energy *** analysis is conducted for three different configurations of the hollow concrete *** of conduction,natural convection and thermal radiation phenomena is ***,the flows are assumed to be laminar and two-dimensional for the whole range of parameters *** conservation equations are solved by a finite difference method based on the control volumes approach and the SIMPLE algorithm for velocity-pressure *** results show that the aspect ratio affects neither the nature of the fluid flow nor the number of convective ***,the extension of the circulation cells increases with this ***,the cavities with a large aspect ratio lead to significant reductions in the heat transfer through the hollow block,these reductions reaching approximately 14%.

关键词： Heat transfers coupled hollow block solar flux aspect ratio control volumes

Predicting Students’Final Performance Using Artificial Neural Networks

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Big Data Mining and Analytics 2022年第4期5卷 294-301页

作者： Tarik Ahajjam Mohammed Moutaib Haidar Aissa mourad Azrour Yousef Farhaoui Mohammed Fattah Department of Computer Science Faculty of Sciences and TechniquesMoulay Ismail UniversityErrachidia 52000Morocco IMAGE Laboratory Moulay Ismail UniversityMeknes 50000Morocco

Artificial Intelligence(AI)is based on algorithms that allow machines to make decisions for *** technology enhances the users’experience in various *** studies have been conducted in the field of education to solve the problem of student orientation and performance using various Machine Learning(ML)*** main goal of this article is to predict Moroccan students’performance in the region of Guelmim Oued Noun using an intelligent system based on neural networks,one of the best data mining techniques that provided us with the best results.

关键词： data science Artificial Intelligence(AI) Machine Learning(ML) neural networks prediction recommendation high school data analysis

Coupled Conductive-Convective-Radiative Heat Transfer in Hollow Blocks with Two Air Cells in the Vertical Direction Subjected to an Incident Solar Flux

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Fluid Dynamics & Materials Processing 2022年第5期18卷 1399-1407页

作者： mourad Najjaoui Thami Ait-taleb Abdelhalim Abdelbaki Zaki Zrikem Hassan Chaib Polydiscilinary Faculty of Ouarzazate Ibn Zohr UniversityOuarzazateMorocco Faculty of Sciences Semlalia Cadi Ayyad UniversityMarrakeshMorocco

This work presents the results of a set of steady-state numerical simulations about heat transfer in hollow blocks in the presence of coupled natural convection,conduction and *** with two air cells deep in the vertical direction and three identical cavities in the horizontal direction are considered(typically used for building ceilings).Moreover,their outside horizontal surface is subjected to an incident solar flux and outdoor environment temperature while the inside surface is exposed to typical indoor environment *** flows are considered laminar and two-dimensional over the whole range of parameters *** conservation equations are solved by means of a finite difference method based on the control volumes approach,relying on the SIMPLE algorithm for what concerns the coupling of pressure and *** effects of the number of cells in the horizontal direction and the thermal conductivity on the heat transfer through the alveolar structure have been *** results show that the number of holes has a significant impact on the value of the overall heat flux through the considered structure.

关键词： Numerical simulation heat transfer coupled hollow concrete block control volumes approach

Joint Optimal Power Source Sizing and Data Collection Trip Planning for Advanced Metering Infrastructure Enabled by Unmanned Aerial Vehicles

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Journal of Modern Power Systems and Clean Energy 2022年第5期10卷 1337-1348页

作者： Haiam Shahin Mostafa F.Shaaban Mahmoud H.Ismail Hebat-Allah M.mourad Ahmed Khattab Department of Electronics and Communications Engineering Facultyof EngineeringCairo UniversityGiza 12613Egypt IEEE Department of Electrical Engineering American University of SharjahPOBox 26666SharjahThe United Arab Emirates

The use of unmanned aerial vehicles(UAVs) in the collection of data from wireless devices, sensor nodes, and the Internet of Things(IoT) devices has recently received significant attention. In this paper, we investigate the data collection process from a set of smart meters in advanced metering infrastructure(AMI) enabled by UAVs. The objective is to minimize the total annual cost of the electric utility by jointly optimizing the number of UAVs, their power source sizing, the charging locations as well as the data collection trip planning. This is achieved while considering the energy budgets of batteries of UAVs and the required amount of collected data. The problem is formulated as a mixed-integer nonlinear programming(MINLP), which is decoupled into two sub-problems where a candidate UAV and a number of buildings are first grouped into trips via genetic algorithms(GAs), and then the optimum trip path is found using a traveling salesman problem(TSP) branch and bound algorithm. Simulation results show that the battery capacity or the number of UAVs increases as the coverage area or the density increases.

关键词： Advanced metering infrastructure unmanned aerial vehicle power source sizing trip planning genetic algorithm

Ion Beam Figuring System for Synchrotron X-Ray Mirrors Achieving Sub-0.2-µrad and Sub-0.5-nm Root Mean Square

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Nanomanufacturing and Metrology 2023年第3期6卷 1-11页

作者： Tianyi Wang Lei Huang Yi Zhu Stefano Giorgio Philip Boccabella Nathalie Bouet mourad Idir Brookhaven National Laboratory National Synchrotron Light Source II(NSLS-II)PO Box 5000UptonNY11973USA

Optics with high-precision height and slope are increasingly desired in numerous industrial *** instance,Kirkpatrick-Baez(KB)mirrors play an important role in synchrotron X-ray applications.A KB system is composed of two aspherical,grazing-incidence mirrors used to focus an X-ray *** fabrication of KB mirrors is challenging due to the aspherical departure of the mirror surfaces from base geometries and the high-quality requirements for slope and height *** this paper,we present the process of manufacturing an elliptical cylinder KB mirror using our in-house-developed ion beam figuring(IBF)and metrology ***,the key aspects of figuring and finishing processes with IBF are illustrated in *** effect of positioning error on the convergence of the residual slope error is highlighted and ***,inspection and cross-validation using different metrology instruments are performed and used as the final validation of the *** confirm that relative to the requested off-axis ellipse,the mirror has achieved 0.15-μrad root mean square(RMS)and 0.36-nm RMS residual slope and height errors,respectively,while maintaining the initial 0.3-nm RMS microroughness.

关键词： Ion beam figuring Kirkpatrick-Baez Synchrotron X-ray mirrors Stitching interferometry Optical fabrication Optical metrology

Energy Decay for the Elastic Wave Equation with A Local Time-dependent Nonlinear Damping

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Acta Mathematica Sinica,English Series 2008年第7期24卷 1175-1192页

作者： mourad BELLASSOUED Faculty of Sciences of Bizerte Department of Mathematics7021 Jarzouna BizerteTunisia

In this paper, we shall investigate the decay property of the solutions to the initial-boundary value problem for the elastic wave equation with a local time-dependent nonlinear damping. We give some decay rate of the energy when the damping term is effective only in a neighborhood of a suitable subset of the boundary. The results obtained in this paper extend, in particular, the known results for the scalar wave equation.

关键词： stabilization energy decay rate elasticity system

Temperature and Thickness Effects on Electrical Properties of InP Films Deposited by Spray Pyrolysis

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Chinese Physics Letters 2009年第1期26卷 260-263页

作者： Refik Kayah Mehmet An Mustafa Oztas Metin bedir Funda Aksoy Department of Physics Arts and Sciences Faculty Nigde University Nigde Turkey Department of Physics Arts and Sciences Faculty Erciyes University Kayseri Turkey Department if Physics and Engineering Engineering Faculty Gaziantep University Gaziantep Turkey

InP film samples are prepared by spray pyrolysis technique using aqueous solutions of InCl3 and Na2HPO4, which are atomized with compressed air as carrier gas onto glass substrates at 500° C with different thicknesses of the films. The structural properties of the samples are determined by x-ray diffraction （XRD）. It is found that the crystal structure of the InP films is polycrystalline hexagonal. The orientations of all the obtained films are along the c-axis perpendicular to the substrate. The electrical measurements of the samples are obtained by dc four-probe technique on rectangular-shape samples. The effects of temperature on the electrical properties of the InP films are studied in detail.

关键词： THIN-FILMS BEAM EPITAXY SOLAR-CELLS GROWTH-RATE DEPENDENCE