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Effect of CuO Addition on the Sintering Behavior and electrical Conductivity of 3Y-TZP

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Journal of Materials Science & Technology 2007年第1期23卷 131-134页

作者： Ahmed A.Hassan omar Abdelal A. S.M.el-Hout Dept. of Metallurgy Nuclear Research CenterAtomic Energy AuthorityCairoEgypt

Yttria stabilized tetragonal zirconia polycrystals （3Y-TZP） doped with CuO was prepared, to get two compositions, 0.3 and 1 mole fraction CuO, respectively. The dilatometric study of the samples showed sintering to be improved for the samples doped with 0.3 mole fraction CuO, and to be deteriorated for the samples doped with 1 mole fraction CuO. The 1 mole fraction CuO doped 3Y-TZP showed higher tetragonal/monoclinic phase transformation which was accompanied by grain growth. The electrical conductivity decreased with the addition of CuO.

关键词： Y2O3 Sintering aids electrical conductivity Fuel cells

Assessment of Indoor and Outdoor Radon Levels in South Lebanon

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International Journal of Disaster Risk Science 2014年第3期5卷 214-226页

作者： Mohammed A.Kobeissi omar el Samad Khaled Zahraman Ibrahim Rachidi Lebanese Atomic Energy Commission National Council for Scientific ResearchRiad ElsolhBeirutLebanon Department of Physics Faculty of Sciences(I)The Lebanese UniversityHadethBeirutLebanon

The presence of high indoor radon concentrations,Cx,is a major concern of the public *** of indoor radon in South Lebanon have been achieved using CR-39 *** ranged between 30 and 122 Bq m-3 in one of the major towns in the area and are compared with measured atmospheric air *** seasonal variation of Cxindoors has been observed,although 90%of the obtained indoor Cxmeasurements are below 100 Bq *** homes produced Cxreadings above the permissible *** showed that the ventilation effect played a major factor in reducing radon concentration levels *** assessment has been *** effective doses of radon varied from 1.01±0.10 to 8.65±0.50 m Sv a-1 in six homes in one of the four cases *** dosage values are above the permitted limit of 2.5 m Sv *** types of granite contained in the studied homes were identified and their contributions to radon levels indoors were calculated.

关键词： Building materials CR-39 Effective dose Granite exhalation rate Lebanon Radon risk assessment

Impacts of climate change on water quantity, water salinity, food security, and socioeconomy in Egypt

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Water Science and Engineering 2021年第1期14卷 17-27页

作者： Mohie el Din Mohamed omar Ahmed Moustafa Ahmed Moussa Reinhard Hinkelmann National Water Research Center Fum Ismailiya CanalShoubra El-Kheima 13411Egypt International Center for Agricultural Research in the Dry Areas Cairo 2416Egypt Nile Research Institute(NRI) National Water Research CenterEl-Qanater 13621Egypt Department of Water Engineering Technische Universit€at Berlin(TU Berlin)Campus El GounaEl Gouna 84513Egypt

Climate change might have direct impacts on water quantity in Egypt and lead to indirect effects on Mediterranean saltwater intrusion to groundwater,which exposes agriculture to *** study investigated impacts of climate change on agriculture,with particular regard to food security and socioeconomy,and quantified the effectiveness of cropping pattern adaptation measures by integrating three mathematical *** BlueM model was used for hydrological simulations of Nasser Lake under flooding scenarios to predict the water supply from the High Aswan *** water and salinity balance(WB-SAL)model was adopted to estimate the water salinity in the Nile *** simulated results from the BlueM and WB-SAL models were integrated with the agricultural simulation model for Egypt(ASME)to project cropping patterns,food security,and socioeconomy throughout the *** results showed that future climate change will directly affect the total crop area;crop areas for 13 crop types;the self-sufficiency of wheat,rice,cereal,and maize supplies;and socioeconomic *** proposed cropping pattern adaptation measures focus on fixing the crop areas of rice and orchards and providing half of the population with lentils,maize,onion,vegetables,milk,and *** adaptation measures have the potential to promote food security without causing deterioration of the socioeconomic ***,water availability has much more significant effects on food security and socioeconomy than cropping pattern adaptation measures ***,the country should rationalize water use efficiency and increase water supply.©2021 Hohai *** and hosting by elsevier *** is an open access article under the CC BY-NC-ND license(http://***/licenses/by-nc-nd/4.0/).

关键词： Climate change Water quantity Salinity Cropping pattern adaptation measures Food security Socioeconomy

Comparative study of energetic potential from anaerobic digestion and direct combustion of date palm wastes

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Clean Energy 2023年第4期7卷 747-754页

作者： Nabila Lahboubi omar Kerrou Brahim Sarh Toufik Boushaki Veronica Belandria Yasser el Khattabi Hassan el Bari Laboratory of electronic Systems Information ProcessingMechanics and EnergeticsFaculty of Sciences KenitraUniversity Ibn Tofail KenitraKenitraMorocco Institute of Combustion AerothermalReactivity and Environment(ICARE)-CNRS UPR302145071 Orléans Cedex 2France

This work aims to evaluate the technical and environmental feasibility of converting date palm waste from a Moroccan oasis into *** this study,two different scenarios were *** first proposed scenario is the valorization of the date palm substrates using direct combustion(thermochemical conversion)to produce *** second proposed scenario is the valorization of the substrates using combined anaerobic digestion of the substrate and direct combustion of the *** this study,two different date palm wastes are:empty fruit bunch(EFB)and palm leaflet(PL).The experimental lower heating values of the digestates studied are 12.93 and 12.71 MJ/kg,*** results show that using Scenario 1,the estimated output energies for the EFB and PL waste were 1.13 and 1.17 MWh,*** Scenario 2,the EFB and PL output energies were 1.27 and 1.39 MWh,*** study revealed that the combined process is possible as an alternative way to produce ***,combining anaerobic digestion and direct combustion of lignocellulosic waste can contribute to reducing greenhouse gas emissions.

关键词： biomass date palm waste energy direct combustion anaerobic digestion digestate

Apatite Fission-Track Datings on Hercynian Granites from Rehamna and Jebilet Massifs(Western Meseta,Morocco):Paleogeographic Implications and Interpretation of AFT Age Discrepancies

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地学前缘 2009年第S1期16卷 217-218页

作者： omar Saddiqi Fatima Zahra el Haimer Hassan Ⅱ University CasablancaMoroccoFaculty of Sciences Laboratoire Géosciences Faculté des SciencesUniversite Hassan Ⅱ An Chock

This work is based on apatite fission-track analysis of samples(mostly granites)from the basement of the Cretaceous-Tertiary Phosphate and Ganntour Plateaus, exposed in the Jebilet and Rehamna massifs (Western Meseta,... 详细信息

关键词： thermochronology fission track apatite exhumation Rehamna Jebilet Western Meseta Morocco

Cellular and molecular aspects of gastric cancer

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World Journal of Gastroenterology 2006年第19期12卷 2979-2990页

作者： Malcolm G Smith Georgina L Hold Eiichi Tahara Emad M el-omar Department of Medicine and Therapeutics Aberdeen University ForesterhillAberdeen AB25 2ZDScotlandUnited Kingdom

Gastric cancer remains a global killer with a shifting burden from the developed to the developing world. The cancer develops along a multistage process that is defined by distinct histological and pathophysiological phases. Several genetic and epigenetic alterations mediate the transition from one stage to another and these include mutations in oncogenes, tumour suppressor genes and cell cycle and mismatch repair genes. The most significant advance in the fight against gastric caner came with the recognition of the role of Helicobacter pylori （H pylori） as the most important acquired aetiological agent for this cancer. Recent work has focussed on elucidating the complex host/microbial interactions that underlie the neoplastic process. There is now considerable insight into the pathogenesis of this cancer and the prospect of preventing and eradicating the disease has become a reality. Perhaps more importantly, the study of H pylori-induced gastric carcinogenesis offers a paradigm for understanding more complex human cancers. In this review, we examine the molecular and cellular events that underlie Hpyloriinduced gastric cancer.

关键词： Gastric cancer Helicobacter pylori Hostmicrobial interactions Inflammation Molecular mechanisms Host genetics

Numerical Investigation and Optimization of a Flat Plate Solar Collector Operating with Cu/CuO/Al_(2)O_(3)–Water Nanofluids

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Transactions of Tianjin University 2021年第1期27卷 64-76页

作者： Youssef Belkassmi Kamal Gueraoui Lahoucine el maimouni Najem Hassanain omar Tata ERMAM Polydisciplinary Faculty of OuarzazateIbn Zohr UniversityBox 638OuarzazateMorocco MSME Faculty of SciencesMohammed-V UniversityRabatMorocco Group of Semiconductors and Environmental Sensor Technologies-Energy Research Center Faculty of ScienceMohammed-V UniversityB.P.1014RabatMorocco GEMS Laboratory ENSAIbn Zohr UniversityB.P.1136AgadirMorocco

Nanofluids are a potential alternative to significantly improving the performance of heat transfer applications. In this work, a numerical analysis to examine the eff ect of dispersing copper(Cu), copper oxide(CuO), and aluminum(Al2O3) nanoparticles in pure water on the performance of a flat plate solar collector(FPSC) and a numerical model was proposed. The influence of the nanofluid type on the thermal efficiency was critically investigated and discussed. The eff ect of the mass flow rate on the performance was also analyzed and discussed. Based on correlations of the thermophysical properties of nanofluids, a sensitivity analysis was used to analyze the impact of the nanoparticles on the base fluid. The results indicate that the performance of the FPSC with Cu/water nanofluid was better than that of FPSCs using CuO/water or Al2O3/water nanofluids. When the mass flow rate of the nanofluids was 8.0 L/min, the efficiency of the FPSC was much greater than those at the flow rates of 5.0 L/min and 2.0 L/min. Mean enhancements in thermal efficiency of 4.44%, 4.27%, and 4.21% were observed when 2.0 L/min was applied using Cu/water, Cu O/water, and Al2O3/water nanofluids, respectively. Improvements in thermal efficiency of 2.76%, 2.53%, and 2.47% occurred when 8.0 L/min was applied.

关键词： Flat plate solar collector Solar energy Thermal efficiency Nanofluids Al_2O_3/water Cu/water CuO/water

Polyester-supported Chitosan-Poly(vinylidene fluoride)-Inorganic-Oxide-Nanoparticles Composites with Improved Flame Retardancy and Thermal Stability

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Chinese Journal of Polymer Science 2020年第1期38卷 84-91,I0007页

作者： Ahmed Abed Nabil Bouazizi Stephane Giraud Ahmida el Achari Christine Campagne Olivier Thoumire Reddad el Moznine omar Cherkaoui Julien Vieillard Abdelkrim Azzouz ENSAIT GEMTEX-Laboratoire de Genie et Materiaux TextilesF-59000 LilleFrance Laboratory LPMC Faculty of Science El JadidaChouaib Doukkali UniversityEl JadidaMorocco Laboratory REMTEX ESITHRouted'EI Jadidakm8BP 7731-OulfaCasablancaMorocco Normandie Univ. UNIROUENCNRSPBS(UMR 6270)55 rue Saint Germain27000 EvreuxFrance Normandie Univ. UNI ROUENINSA RouenCNRSCOBRA(UMR 6014)55 rue Saint Germain27000 EvreuxFrance Nanoqam Department of ChemistryUniversity of Quebec at MontrealQCCanada

Polyester(PET) was pre-activated by atmospheric air plasma and coated by various inorganic oxide nanoparticles(MOx) such as titanium dioxide(TiO2), zinc oxide(ZnO), and silicon oxide(SiO2), using poly(vinylidene fluoride)(PVDF) and chitosan(CT) as binders. The resulting PET-PVDF-MOx-CT composites were thermally compressed and then characterized by scanning electron microscopy, Fourier infrared spectroscopy, thermal gravimetric analysis, and flame retardancy(FR) ability tests. PET modifications resulted in more thermally stable and less harmful composites with weaker hazardous gas release. This was explained in terms of structure compaction that blocks pyrolysis gas *** incorporation was found to reduce the material susceptibility to oxidation. This judicious procedure also allowed improving flame retardancy ability, by lengthening the combustion delay and slowing the flame propagation. Chitosan also turned out to contribute to a possible synergy with the other polymers present in the synthesized materials. These results provide valuable data that allow understanding the FR phenomena and envisaging low-cost high FR materials from biodegradable raw materials.

关键词： Polyester nonwovens Composite PVDF Flame retardancy Material oxides Chitosan

VISCOMETRIC STUDY OF POLY(METHYL METHACRYLATE) AND POLYSTYRENE BLENDS IN DIFFERENT SOLVENTS

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Chinese Journal of Polymer Science 2003年第1期21卷 15-19页

作者： omar Melad Rajai Baraka Jamil K.J.Salem Hani Hilles Awni el-Khazandar Department of Chemistry AL-Azhar University P.O. Box 1277 GAZA PalestineDepartment of Chemistry AL-Azhar University P.O. Box 1277 GAZA PalestineDepartment of Chemistry AL-Azhar University P.O. Box 1277 GAZA PalestineDepartment of Chemistry AL-Azhar University P.O. Box 1277 GAZA PalestineDepartment of Chemistry AL-Azhar University P.O. Box 1277 GAZA Palestine

The intermolecular interaction between poly(methyl methacrylate) (PMMA) and polystyrene (PS) intetrahydrofuran (THF) and N,N'-dimethyl formamide (DMF) solvents was studied at 28℃ using a dilute solution viscometrymethod. Solvent is believed to play a key role in characterizing the viscosity behavior of the polymer solution. The intrinsicviscosity and viscosity interaction parameter were experimentally measured for the binary (solvent/polymer) and for theternary systems in two solvents. The compatibility of the polymer mixture was discussed in terms of the sign of △b_m. Theresults show that the compatibility of PMMA/PS blend in DMF is larger than that in THF.

关键词： Viscometry Compatibility PMMA/PS blend