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Journal of Thermal Science 2021年第5期30卷 1625-1642页

作者： Ismail BAKLOUTI zied DRISS National School of Engineers of Monastir University of Monastir5019MonastirTunisia Laboratory of Electromechanical Systems(LASEM) National School of Engineers of SfaxUniversity of Sfax3038SfaxTunisia

The PVT-air solar system simultaneously generates electrical and thermal ***,increasing the cost-effectiveness of the system requires an appropriate choice of key parameters such as mass flow rate and air channel *** this paper,a PVT-air kit of a single module with a 30°slope was used to measure photovoltaic electricity and air heating power in the city of Sfax,***,a computer method was implemented using the ANSYS Fluent 17.0 software and the MATLAB program to analyse the properties of the airflow and to characterise PVT-air yields under different mass flow rates and *** the comparison of numerical and experimental data,the numerical method was validated with a good ***,we have found that increasing of the airflow rate improves the thermal efficiency with a slight change on electrical ***,the reduction in depth shows an improvement on thermal efficiency and a negligible effect on electrical ***,we have presented the thermal and electrical performance of PVT-air as a function of the key parameters with the Hottel-Whillier-Bliss formulation.

关键词： solar energy PVT-air thermal experimental numerical performance

Microstructure and Mechanical Properties of Nano-crystalline Al-8 wt pct Ni Alloy

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Journal of Materials Science & Technology 2006年第5期22卷 605-610页

作者： M.Abou zied Physics Department Faculty of Science South Valley UniversityQena 83511Egypt

Microstructure and mechanical properties of ball-milled Al-8 wt pct Ni ribbon have been investigated by X-ray diffraction （XRD） and continuous Vickers hardness test, respectively. The results indicate that, the main phases of this alloy are α-Al and orthorhombic-Al3Ni. The lattice parameter of α-Al increases with increasing milling time. From the elastic constant of Al, the average contrast factors of the （111）, （200）, （220）, （311） and （222） Bragg＇s reflections for pure edge and pure screw dislocations in fcc crystals with α/2〈110〉{111} slip system were calculated. The average grain size and dislocation parameters as a function Of milling time have been investigated using the modified Williamson-Hall plot and the Warren-Averbach equation, *** attempt has been made to correlate the micro-hardness of milled ribbon with their grain size through the Hall-Patch relationship：HV0.01 = 742.45 〈 D 〉^-1/2 ＋401.55 （kg/mm^2）.

关键词： Aluminum Microstructure Property X-ray diffraction

A Reframed Watermark Extraction Approach Using the ABC Algorithm

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Chinese Journal of Electronics 2021年第4期30卷 736-742页

作者： krIcha Anis kr.cha.zied SAKLY Anis LATIS Lab National School of Engineers of Sousse University of Sousse National School of Engineers of Monastir University of Monastir Higher Institute of Applied Science and Technology of Sousse University of Sousse ESIR Research Unit National School of Engineers of Monastir University of Monastir

The fast development and the rapid spread of information technology have raised the issue of digitalimage copyright protection, which was mostly addressed through robust watermarking. To ensure the survival of the watermark after attacks, most works have been making use of an additional step at the embedding phase,and by so making the scheme unsuitable for real-time implementation. However, to be effective and secure, it is recommended to combine the watermarking algorithm and the capture sensor in one device. In this paper, we brought the extra stage to the detection side. We firstly studied the effect of some signal processing operations on a watermarked image, then we proposed a general model for watermark extraction whose parameters were determined using the artificial bee colony. The efficacy of the proposed method was validated by comparing its robustness with two state-of-art schemes focusing on the watermark extraction.

关键词： Robust watermarking Artificial bee colony(ABC) Adaptive extraction

A Multi-Level Selective Maintenance Strategy Combined to Data Mining Approach for Multi-Component System Subject to Propagated Failures

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Journal of Systems Science and Systems Engineering 2022年第3期31卷 313-337页

作者： Mohamed Ali Kammoun zied Hajej Nidhal Rezg Universite de Lorraine LGIPMF-57000 MetzFrance Ecole poly technique du Groupe Honoris United Universities-Tunisia

In several industrial fields like air transport,energy industry and military domain,maintenance actions are carried out during downtimes in order to maintain the reliability and availability of production *** such a circumstance,selective maintenance strategy is considered the reliable solution for selecting the faulty components to achieve the next mission without *** this paper,a novel multi-level decision making approach based on data mining techniques is investigated to determine an optimal selective maintenance *** the first-level,the age acceleration factor and its impact on the component nominal age are used to establish the local *** first decision making employed K-means clustering algorithm that exploited the historical maintenance *** on the first-level intervention plan,the remaining-levels identify the stochastic dependence among components by relying upon Apriori association rules algorithm,which allows to discover of the failure occurrence *** addition,at each decision making level,an optimization model combined to a set of exclusion rules are called to supply the optimal selective maintenance plan within a reasonable time,minimizing the total maintenance cost under a required reliability *** illustrate the robustness of the proposed strategy,numerical examples and a FMS real study case have been solved.

关键词： Selective maintenance stochastic dependence age acceleration factor data mining flexible manufacturing system

Synthesis of Dy_2O_3 nanoparticles via hydroxide precipitation: effect of calcination temperature

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Journal of Rare Earths 2014年第3期32卷 259-264页

作者： Bahaa M.Abu-zied Abdullah M.Asiri Chemistry Department Faculty of Science King Abdulaziz University Center of Excellence for Advanced Materials Research (CEAMR) King Abdulaziz University Chemistry Department Faculty of Science Assiut University

This work described the preparation of dysprosium oxide, Dy203, nanoparticles using the homogeneous precipitation method. Dy3＋ ions were precipitated using NaOH solution. The obtained product was filtered, dried, and then calcined for 1 h at the temperature range of 300-700 ℃ in static air. The calcination temperature of the Dy-precttrsor was chosen based on its decomposi- tion as indicated by the TGA analysis. The crystalline structure and surface morphology of the calcined solids were studied by X-ray diffraction （XRD）, field emission scanning electron microscopy （FE-SEM）, transmission electron microscopy （TEM） and X-ray pho- toelectron spectroscopy （XPS）. The obtained results revealed that Dy203 with crystallites size of 11-21 nm was formed at 500 ℃. Such value increased to 25-37 nm for the sample calcined at 700 ℃.

关键词： nanocrystalline dysprosium oxide Dy203 precipitation method Dy203 nanoparticles rare earths

Genesis of nanocrystalline Ho_2O_3 via thermal decomposition of holmium acetate: Structure evolution and electrical conductivity properties

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Journal of Rare Earths 2019年第2期37卷 185-192页

作者： Bahaa M.Abu-zied Abdullah M.Asiri Center of Excellence for Advanced Materials Research (CEAMR) King Abdulaziz University Chemistry Department Faculty of Science King Abdulaziz University Chemistry Department Faculty of Science Assiut University

This study focuses on the preparation of nanostructured holmium oxide via the decomposition of holmium acetate precursor utilizing the non-isothermal strategy. Thermogravimetric analysis(TGA) was used to follow up the various thermal events involved in the decomposition process. Dehydration completes approximately at 150℃, which is followed by the decomposition of the anhydrous acetate leading to the formation of holmium oxide. Based on the TGA results the acetate precursor was heated non-isothermally at the temperature range of 150 e700℃. The obtained solids were characterized using powder X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), Fourier transform infrared spectroscopy(FT-IR), field-emission scanning electron microscopy(FE-SEM) and transmission electron microscopy(TEM). It is found that nanocrystalline Ho_2 O_3 starts to form at 500℃ and presents the only phase detected at the 500 e700℃ range. The electrical conductivity of the solids that form at the temperature range of 300 e700℃ was investigated. The obtained values were correlated with the observed structural modifications accompanying the heat treatment. The electrical conductivity of the Ho_2 O_3 samples prepared at 500, 600 and 700℃ reaches the values of 1.92 × 10^(-7), 1.61 × 10^(-7) and 8.33 × 10^(-8) Ω^(-1)cm^(-1) at a measuring temperature of 500℃, respectively. These values are potentially advantageous for high-resistivity devices.

关键词： Nanocrystalline Ho2O3 Thermal decomposition Ho2O3 Holmium oxide Rare earth oxides Nanomaterials

Pseudo-static stability analysis of rock slopes reinforced by passive bolts using the generalized Hoek-Brown criterion

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第4期9卷 659-670页

作者： Mounir Belghali zied Saada Denis Garnier Samir Maghous Laboratoire de Génie Civil ENIT Université de Tunis El Manar Tunis Tunisia Université Paris-Est Laboratoire Navier (UMR8205) ENPC-IFSTTAR-CNRS Marne-la-Vallée France Department of Civil Engineering Federal University of Rio Grande do Sul Av. Osvaldo Aranha 99 Porto Alegre RS 90350-190 Brazil

The stability analysis of passive bolt-reinforced rock slopes under seismic loads is investigated within the framework of the kinematic approach of limit analysis theory.A pseudo-static method is adopted to account for the inertial forces induced in the rock mass by seismic *** strength properties of the rock material are described by a modified Hoek-Brown strength criterion,whereas the passive bolts are modeled as bar-like inclusions that exhibit only resistance to tensile-compressive *** advantage of the ability to compute closed-form expressions for the support functions associated with the modified Hoek-Brown strength criterion,a rotational failure mechanism is implemented to derive rigorous lower bound estimates for the amount of reinforcement strength to prevent slope *** approach is then applied to investigating the effects of relevant geometry,strength and loading parameters in light of a preliminary parametric *** accuracy of the approach is assessed by comparison of the lower bound estimates with finite element limit analysis solutions,thus emphasizing the ability of the approach to properly predict the stability conditions and to capture the essential features of deformation localization ***,the extension of the approach to account for slipping at the interface between reinforcements and surrounding rock mass is outlined.

关键词： Reinforced rock slope Modified Hoek-Brown criterion Seismic loading Limit analysis Rotational failure mechanism

Acute effects of chlorpyryphos-ethyl and secondary treated effluents on acetylcholinesterase and butyrylcholinesterase activities in Carcinus maenas

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Journal of Environmental Sciences 2009年第10期21卷 1467-1472页

作者： Jihene Ghedira Jamel Jebali zied Bouraoui Mohamed Banni Lassaad Chouba Hamadi Boussetta Laboratory of Biochemical and Environmental Toxicology Higher Institute of Agriculture Chott-Mariem 4042 Sousse Tunisia Chemical Laboratory Higher Institute of Marine Sciences and Technology La Goulette Center 2060 Tunisia

The acute effects of commercial formulation of chlorpyrifos-ethyl （Dursban ） and the secondary treated industrial/urban effluent （STIUE） exposure on acetylcholinesterase （ACHE） and butyrylcholinesterase （BuChE） activities in hepatopancreas and gills of Mediterranean crab Carcinus maenas were investigated. After 2 d of exposure to chlorpyriphos-ethyl, the AChE activity was inhibited in both organs at concentrations of 3.12 and 7.82 μg/L, whereas the BuCHE was inhibited only at higher concentration 7.82 μg/L of commercial preparation Dursban~. The exposure of crabs to Dursban （3.12 μg/L） showed a significant decrement of ACHE activity at 24 and 48 h, whereas the BuChE was inhibited only after 24 h and no inhibition for both enzymes was observed after 72 h. Moreover, a significant repression of AChE activity was observed in both organs of C. maenas exposed to 5% of STIUE. Our experiments indicated that the measurement of AChE activity in gills and hepatopancreas of C. maenas would be useful biomarker of organophosphorous （OP） and of neurotoxic effects of STIUE in Tunisia.

关键词： acetylcholinesterase butyrylcholinesterase organophosphorous Dursban secondary treated industrial/urban effluent Carcinus maenas

Fabrication,characterization,and electrical conductivity properties of Pr_6O_(11) nanoparticles

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Journal of Rare Earths 2013年第7期31卷 701-708页

作者： Bahaa M.Abu-zied Youssef A.Mohamed Abdullah M.Asiri Chemistry Department Faculty of ScienceKing Abdulaziz UniversityP.O.Box 80203Jeddah 21589Saudi Arabia Chemistry Department Faculty of ScienceAssiut University71516 AssiutEgypt Center of Excellence for Advanced Materials Research(CEAMR) King Abdulaziz UniversityP.O.Box 80203Jeddah 21589Saudi Arabia

PrrOll nanoparticles were obtained by subsequent thermal decomposition of the as-prepared precipitate formed under ambient temperature and pressure using NaOH as precipitant. The calcination process was affected, for 1 h in static air atmosphere, at 400-700 ℃ temperature range. The different samples were characterized using X-ray diffraction （XRD）, transmission electron microscopy （TEM）, field emission scanning electron microscopy （FE-SEM）, thermogravimetric analysis （TGA）, in situ electrical conductivity, and N2 adsorption/desorption. The obtained results demonstrated that nano-crystalline Pr6O11, with crystallites size of 6-12 nm, started to form at 500 ℃. Such value increased to 20-33 nm for the sample calcined at 700℃. The as-synthesized PrrOll nanoparticles presented high electrical conductivity due to electron hopping between Pr（III）-Pr（IV） pairs.

关键词： nanocrystalline praseodymium oxide Pr6O11 nano structured materials electrical conductivity rare earths

On the Projections of the Mutual Multifractal Rényi Dimensions

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Analysis in Theory and Applications 2021年第4期37卷 572-592页

作者： zied Douzi Bilel Selmi Faculty of Sciences of Monastir Department of Mathematics5000-MonastirTunisia

In this paper,we compare the mutual multifractal Renyi dimensions to the´mutual multifractal Hausdorff and pre-packing *** also provide a relationship between the mutual multifractal Renyi dimensions of orthogonal projections´of a couple of measures(µ,ν)in R^(n).As an application,we study the mutual multifractal analysis of the projections of measures.

关键词： Mutual Hausdorff dimension mutual packing dimension mutual multifractal analysis doubling measures projection.