检索结果-南通市图书馆

Thermal Analysis of Melting Occurring Inside a Finned Rectangular Enclosure Equipped with Discrete Pulsed Protruding Heat Sources

在线全文

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2022年第5期18卷 1539-1549页

作者： Brahim Amahan hamid el qarnia Ali el Afif Faculty of Sciences Department of PhysicsLaboratory of Innovation in Sciences Technology and ModelingChouaib Doukkali UniversityEl JadidaMorocco Faculty of Sciences Semlalia Fluid Mechanics and Energetic LaboratoryDepartment of PhysicsCadi Ayyad UniversityMarrakeshMorocco

This paper numerically investigates the effect of the location of a horizontal fin on the melting of a phase change material(PCM)inside a rectangular enclosure heated by multiple discrete pulsed protruding heat *** fin and the phase change material filling the enclosure store the thermal energy extracted from the heat sources,in sensible and latent *** heat sources are assumed to simulate electronic components undergoing a superheating technical *** extracting heat from the electronics,the PCM plays the role of a heat *** analyze the thermal behavior and predict the cooling performance of the proposed cooling system,we derive a nonlinear mathematical model based on mass,momentum and energy conservation *** numerical investigations are conducted to quantify the influence of the fin position on the thermal behavior and the cooling performance of the heat *** include the transient maximum temperature occurring inside the heat sources and the liquid volume.A comparison between our numerical results and experimental data selected from the literature shows a good *** main conclusion is that the presence of the fin leads to a slight increase in the melting time.

关键词： Phase change material melting heat transfer pulsed heating electronics cooling heat storage fin

The Effect of the Fin Length on the Solidification Process in a Rectangular Enclosure with Internal Fins

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2019年第2期15卷 125-137页

作者： Laila Khatra hamid el qarnia Mohammed el Ganaoui Cadi Ayyad University Faculty of Sciences SemlaliaDepartment of PhysicsP.O.2390Fluid Mechanics and Energetic(affiliated to CNRSTURAC 27)MarrakeshMorocco Lorraine University Energetic Laboratory of Longwy(FJV/LERMAB)Henri PoincaréInstitute of LongwyFrance

The aim of the proposed work is to study the solidification process within a rectangular enclosure provided with three internal rectangular fins attached to the left vertical wall of the *** latest is filled with a phase change material(PCM),initially liquid,at a temperature above its melting *** solidification process was initiated by cooling the left wall and fins to a temperature lower than the melting *** order to study and examine the thermal behavior and thermal performance of the proposed system,a mathematical model,based on the conservation equations of mass,momentum and energy was *** governing equations and their associated boundary and initial conditions were next ***,several controlling parameters were *** volume control method was used to discretize the *** resulting algebraic equations were solved *** investigations were carried out to study and examine the effect of the dimensionless fin length on the hydrodynamic and thermal fields of the flow,the dimensionless heat flux,the solidified mass fraction and the dimensionless time of complete solidification.

关键词： Phase change material solidification enthalpy method fins rectangular enclosure

Eco-toxicity and health risk assessment of polycyclic aromatic hydrocarbons in surface sediments of Burullus Lake in Egypt

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Geology 2024年第3期7卷 460-468页

作者： Hanan E Osman Mohamed H E el-Morsy Hazem T Abd el-hamid Department of Biology Faculty of Applied ScienceUmm Al-Qura UniversityMecca 24382Saudi Arabia Deanship of Scientific Research Umm Al-Qura UniversityMakkah 24372Saudi Arabia National Institute of Oceanography and Fisheries(NIOF) Cairo 11865Egypt Botany and Microbiology Department Faculty of ScienceAl-Azhar UniversityCairo 11651Egypt

Polycyclic aromatic hydrocarbons(PAHs)are ubiquitous environmental contaminants of growing concern due to their potential ecological and human health *** study presents a comprehensive assessment of PAHs contamination in the surface sediments of Burullus Lake,a vital and second largest delta lake in *** aim was to evaluate the eco-toxicity and potential health risks associated with the presence of these *** seven sediment samples were collected from various drains in the southern part of Burullus *** extraction method was employed to extract PAHs(16PAHs)from the sediment ***,target compounds were located using *** results showed that samples contained PAHs levels ranging from 0.038×10^(-6)to 0.459×10^(-6),which is considered heavily polluted by the European standard for PAHs ***,there was no apparent source of PAHs in the elKhashah drain or the Brinbal Canal,as HPLC found none of the *** most prevalent compound in sediment samples along the study area was *** diagnostic indices in the present study indicated that the hydrocarbons in the region originated from pyrolytic and man-made sources along the drains of Burullus *** principal component analysis(PCA)and diagnostic ratios revealed that coal combustion and pyrolytic sources were responsible for the PAHs contamination in the surface *** non-carcinogenic risk(HI),which is the product of the HQs for the adult and child populations,respectively,was *** values under 1,therefore,demonstrated that they had no carcinogenic effects on human *** and MEQs in the sediments of Burullus Lake do not have a cancer-causing impact on *** the safety of nearby wildlife,aquatic life,and people,all activities that raise petroleum hydrocarbon levels in Burullus Lake must be adequately regulated and *** to the ecological risk assessment,there is little chance that PAHs will be found

关键词： Polycyclic aromatic hydrocarbons Diagnostic indices Toxicity Delta lake sediment Burullus Lake Human health risk Aquatic ecosystem HPLC Coal combustion

The roles of polysaccharides in tilapia farming:A review

在线全文

学校读者我要写书评

暂无评论

Aquaculture and Fisheries 2024年第1期9卷 20-27页

作者： Zulhisyam Abdul Kari Wendy Wee Noor Khalidah Abdul hamid Mahmoud A.O.Dawood Nik Nur Azwanida Binti Zakaria Lee Seong Wei Department of Agricultural Sciences Faculty of Agro-Based IndustryUniversiti Malaysia KelantanJeli CampusJeliKelantan17600Malaysia Advanced Livestock and Aquaculture Research Group Faculty of Agro-Based IndustryUniversiti Malaysia KelantanJeli CampusJeliKelantan17600Malaysia Center of Fundamental and Continuing Education Universiti Malaysia TerengganuKuala NerusTerengganu21030Malaysia School of Biological Sciences Universiti Sains MalaysiaMindenPulau Pinang11800Malaysia Animal Production Department Faculty of AgricultureKafrelsheikh UniversityKafr El-Sheikh33516Egypt The Center for Applied Research on the Environment and Sustainability The American University in Cairo11835CairoEgypt

Impairment of fish growth and immune system due to stress and disease are major constraints in aquaculture ***,antibiotic was used as prophylactic agent in the health management of aquaculture ***,antibiotic only provide a temporary solution to the problem of disease ***-reliance on antibiotic also has led to the increasing cases of antibiotic resistance among pathogenic bacteria from aquaculture sites and contamination of antibiotic residues into human food ***,prebiotic and symbiotic are therefore suggested as alternatives to prophylactic antibiotic to be used in the aquaculture industry.A potential prophylactic agent is polysaccharide that could be developed into an alternative antibiotic for aquatic *** this review paper,definition,sources,and mode of action of polysaccharide are *** roles of polysaccharides in fish farming with emphasis on growth improvement,immune system enhancement,disease resistance stimulation in tilapia farming,and the effects of polysaccharides on abiotic stressors are summarized and discussed.

关键词： Aquaculture Growth performance Immune response Disease resistance Abiotic stressor Synergistic Polysaccharide

Numerical Study of Greenhouse Nocturnal Heat Losses

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2011年第4期20卷 377-384页

作者： F.Berroug E.K.Lakhal M.el Omari M.Faraji H.el qarnia Laboratoire d'Automatique de l'Environnement et Procédés de Transfert UniversitéCadi AyyadFacultédes Sciences Semlalia-Département de PhysiqueMarrakech-MarocAffiliéau CNRSTURAC 28 Laboratoire de Physique des Materiaux MicroelectroniqueAutomatique et TechniqueDepartement de PhysiquesFaculte des Sciences Ain ChockUniversite Hassan IICasablanca-Maroc

In this study we quantify and analyze different components of nocturnal losses from a heated greenhouse with the presence of vegetation for typical winter weather conditions in Marrakesh-Morocco,using a non linear model,based on the greenhouse heat and mass *** was found that 12% of the total input heat was dissipate as a sensible and latent leakage losses,66% was lost by convective exchange through air-inner *** gain of energy at the inner-cover is dissipated at the outer-cover by radiation(66%)and convection(34%).This results point toward some practical measures to reduce heat losses:increasing air tightness,using covering materials with low-emissivity in the long wave band or putting up an external thermal curtain should provide significant energy savings.

关键词： Greenhouse energy balance heat losses numerical analysis.

Adaptive neural network observer for proton-exchange membrane fuel cell system

在线全文

学校读者我要写书评

暂无评论

Clean Energy 2023年第5期7卷 1078-1090页

作者： Abdelaziz el Aoumari hamid Ouadi Jamal el-Bakkouri Fouad Giri ERERA National School of Arts and CraftsMohammed V UniversityRabatMorocco LESE Lab ENSEMHassan II UniversityCasablancaMorocco Normandie University UNICAENENSICAENLAC14000 CaenFrance

This paper develops an adaptive neural network(NN)observer for proton-exchange membrane fuel cells(PEMFCs).Indeed,information on the oxygen excess ratio(OER)value is crucial to ensure optimal management of the durability and reliability of the *** OER indicator is computed from the mass of oxygen and nitrogen inside the PEMFC ***,the measurement process of both these masses is difficult and *** solve this problem,the design of a PEMFC state observer is ***,the behaviour of the fuel cell system is highly non-linear and its modelling is *** to this constraint,a multilayer perceptron neural network(MLPNN)-based observer is proposed in this paper to estimate the oxygen and nitrogen *** notable advantage of the suggested MLPNN observer is that it does not require a database to train the ***,the weights of the NN are updated in real time using the output *** addition,the observer parameters,namely the learning rate and the damping factor,are online adapted using the optimization tools of extremum ***,the proposed observer stability analysis is performed using the Lyapunov *** observer performances are validated by simulation under MATLAB®/Simulink®.The supremacy of the proposed adaptive MLPNN observer is highlighted by comparison with a fixed-parameter MLPNN observer and a classical high-gain observer(HGO).The mean rela-tive error value of the excess oxygen rate is considered the performance index,which is equal to 1.01%for an adaptive MLPNN and 3.95%and 9.95%for a fixed MLPNN and HGO,***,a robustness test of the proposed observer with respect to measurement noise is performed.

关键词： fuel cell system(PEMFC) multilayer perceptron neural network(MLPNN)observer optimization extremum seeking(ES) oxygen excess ratio(OER)

Hybrid-integer algorithm for a multi-objective optimal home energy management system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Clean Energy 2023年第2期7卷 375-388页

作者： Saad Gheouany hamid Ouadi Saida el Bakali ERERA National School of Arts and CraftsMohammed V UniversityRabatMorocco

Most of the energy produced in the world is consumed by commercial and residential *** the growth in the global economy and world demographics,this energy demand has become increasingly *** has led to higher unit electricity prices,frequent stresses on the main electricity grid and carbon emissions due to inefficient energy *** paper presents an energy-consumption management system based on time-shifting of loads according to the dynamic day-ahead electricity *** simultaneously reduces the electricity bill and the peaks,while maintaining user comfort in terms of the operating waiting time of *** proposed optimization problem is formulated mathematically in terms of multi-objective integer non-linear programming,which involves constraints and consumer *** optimal scheduling,the management problem is solved using the hybridization of the particle swarm optimization algorithm and the branch-and-bound *** techniques are proposed to manage the trade-off between the conflicting *** first technique is the Pareto-optimal solutions classification using supervised learning *** second technique is called the lexicographic *** simulations were performed based on residential building energy consumption,time-of-use pricing(TOU)and critical peak pricing(CPP).The algorithms were implemented in *** results of the current work show that the proposed approach is effective and can reduce the electricity bill and the peak-to-average ratio(PAR)by 28% and 49.32%,respectively,for the TOU tariff rate,and 48.91% and 47.87% for the CPP tariff rate by taking into account the consumer’s comfort level.

关键词： home energy management system smart building coordination of home appliances metaheuristic algorithm day-ahead scheduling multi-objective binary non-linear constraint problem

Day-ahead seasonal solar radiation prediction,combining VMD and STACK algorithms

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Clean Energy 2023年第4期7卷 911-925页

作者： Saida el Bakali Ouadi hamid Saad Gheouany ERERA National School of Arts and CraftsMohammed V UniversityRabatMorocco

This article proposes a method for accurately predicting solar irradiance over a 24-hour horizon to forecast photovoltaic energy generation in a positive-energy *** order to make this prediction,the input data are divided into seasons and preprocessed using the variational mode decomposition(seasonal-VMD)*** VMD method is used for extracting high-bandwidth features from the input data,decomposing them into a finite number of smooth modes and focusing on specific frequency ***,the accuracy of signal extraction using the VMD method can be improved by selecting particular parameters judiciously,which impacts the smoothing and frequency concentration of the extracted *** this regard,the salp swarm algorithm(SSA)is employed to identify the optimal VMD parameters that can be used to enhance extraction *** addition,the obtained residual between the observed solar irradiation data and their decomposed modes is treated to enhance the prediction process.A stacking algorithm(STACK)is used to predict the following 24-hour solar irradiance modes and the residual,which are finally summed to reconstruct the desired *** performances of the proposed prediction method are evaluated using two quantitative evaluation indices:the normalized root mean square percentage error(NRMSPE)and normalized mean absolute percentage error(NMAPE).The proposed model is trained on data collected for three years in Rabat(2019–22).The performance of the proposed model is evaluated by predicting the 24-hour solar irradiance for a different *** proposed approach seasonal-VMD-STACK is compared with two other methods in the case of using VMD-based STACK without season partition and STACK method ***,the proposed method has exhibited stability and proven good results with an NRMSPE of 3.87%and an NMAPE of 1.58%for cloudy days during the test *** results demonstrate that residual preprocessing,seasonal input data partition and appropriate selec

关键词： weather forecasting parametric optimization time series data preprocessing machine learning

ON SelECTIONS OF SET-VALUED EULER-LAGRANGE INCLUSIONS WITH APPLICATIONS

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2020年第4期40卷 1105-1115页

作者： hamid KHODAEI Iz-iddine el-FASSI Bahman HAYAT Faculty of Mathematical Sciences and Statistics Malayer UniversityP.O.Bor 65719-95863MalayerIran Department of Mathematics Faculty of Sciences and TechniquesSidi Mohamed ben Abdellah UniversityB.P.2202FezMoroccc.

We discuss the set-valued dynamics related to the theory of functional *** look for selections of convex set-valued functions satisfying set-valued Euler-Lagrange *** improve and extend upon some of the results in[13,... 详细信息

关键词： set-valued dynamics Euler-Lagrange inclusion composite operator selection