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Journal of Modern Physics 2012年第7期3卷 521-528页

作者： Abdelghani Sybous abdelhamid el kaaouachi Jamal Hemine Abdelfattah Narjis Lhoussine Limouny Said Dlimi Rachid Abdia Gerard Biskupski Laboratoire de Physique de la Matière Condensée Faculté des Sciences et Techniques de Mohammadia Département de Physique Mohammedia Morocco Laboratoire de Spectroscopie Hertzienne LSH Batiment P5 Université des Sciences et Technologies de LilleI 59 655 Villeneuve d’Ascq Cedex France Research Group in ESNPS Physics Department University Ibn Zohr Faculty of Sciences B.P 8106 Hay Dakhla Agadir Morocco

We present results of an experimental study of magnetoresistance (MR) in insulating NbSi amorphous alloys sample showing Variable Range Hopping (VRH) conductivity. The MR is found to be negative in a wide range of low temperature (4.2-20 K) and in the range of moderate magnetic fields (0-4 T). We made tentative analysis using three theoretical models which are the model of quantum interference, the model of Zeeman effect and the model of localized magnetic

关键词： NbSi Amorphous Alloys Negative Magnetoresistance Magnetic Field Localized Magnetic moments Quantum Interference

Positive Magnetoresistance in Hydrogenated Amorphous Alloys Silicon Nickel a-Si<sub>1-y</sub>Niy:H at Very Low Temperature with Magnetic Field

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Journal of Modern Physics 2012年第6期3卷 447-450页

作者： Abdelfattah Narjis abdelhamid el kaaouachi Jamal Hemine Abdelghani Sybous Lhoussine Limouny Said Dlimi Rachid Abdia Gerard Buskipski Laboratoire de Physique de la Matière Condensée Département de Physique Faculté des Sciences et Techniques de Mohammadia Mohammedia Morocco Laboratoire de Spectroscopie Hertzienne LSH Université de LilleI Villeneuve d’Ascq Cedex France Research Group ESNPS Physics Department Faculty of Sciences University Ibn Zohr Agadir Morocco

We present results of an experimental study of magnetoresistance phenomenon in an amorphous silicon-nickel alloys a-Si1-yNiy:H:H (where y = 0.23) on the insulating side of the metal-insulator transition (MIT) in presence of magnetic field up to 4.5 T and at very low temperature. The electrical resistivity is found to follow the Efros-Shklovskii Variable Range Hopping regime (ES VRH) with T -1/2. This behaviour indicates the existence of the Coulomb gap (CG) near the Fermi level.

关键词： Amorphous Silicon-Nickel Alloys a-Si1-yNiy:H Variable Range Hopping Conductivity Metal Insulator Transition Positive Magnetoresistance

Variable Range Hopping in Hydrogenated Amorphous Silicon-Nickel Alloys

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Journal of Modern Physics 2012年第7期3卷 517-520页

作者： Abdelfattah Narjis abdelhamid el kaaouachi Abdelghani Sybous Lhoussine Limouny Said Dlimi Abdessadek Aboudihab Jamal Hemine Rachid Abdia Gerard Biskupski Laboratoire de Physique de la Matière Condensée Faculté des Sciences et Techniques de Mohammadia Département de Physique Mohammedia Morocco Laboratoire de Spectroscopie Hertzienne LSH Batiment P5 Université des Sciences et Technologies de LilleI 59 655 Villeneuve d’Ascq Cedex France Research Group ESNPS Physics Department University Ibn Zohr Faculty of Sciences B.P 8106 Hay Dakhla 80000 Agadir Morocco

On the insulating side of the metal-insulator transition (MIT), the study of the effect of low Temperatures T on the electrical transport in amorphous silicon-nickel alloys a-Si1-yNiy:H exhibits that the electrical conductivity follows, at the beginning, the Efros-Shklovskii Variable Range Hopping regime (ES VRH) with T-1/2. This behaviour showed that long range electron-electron interaction reduces the Density Of State of carriers (DOS) at the Fermi level and creates the Coulomb gap (CG). For T higher than a critical value of temperature TC, we obtained the Mott Variable Range Hopping regime with T-1/4, indicating that the DOS becomes almost constant in the vicinity of the Fermi level. The critical temperature TC decreases with nickel content in the alloys.

关键词： Amorphous Silicon-Nickel Alloys a-Si1-yNiy:H Variable Range Hopping Conductivity Transport Phenomenon Metal Insulator Transition

Study of Hygrothermal Behavior of Bio-Sourced Material Treated Ecologically for Improving Thermal Performance of Buildings

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Journal of Renewable Materials 2024年第5期12卷 1007-1027页

作者： Soumia Mounir Miloudia Slaoui Youssef Maaloufa Fatima Zohra el Wardi Yakubu Aminu Dodo Sara Ibn-elhaj abdelhamid Khabbazi National School of Architecture Agadir New Complex Ibn Zohr AgadirHay dakhla80000Morocco EMDD CERNE2DUniversity Mohammed V in RabatEst SaléSaléMedinaMorocco Physics Department LPMAT LaboratoryFaculty of Sciences Ain ChockHassan II UniversityCasablancaMorocco Architectural Engineering Department College of Engineering Najran UniversityNajran66426Saudi Arabia The Centre of Scientific and Engineering Research Najran UniversityNajranSaudi Arabia

Creating sustainable cities is the only way to live in a clean environment,and this problem can be solved by using bio-sourced and recycled *** this purpose,the authors contribute to the valuation of sheep wool waste as an eco-friendly material to be used in *** paper investigates the thermal,hygrothermal,and biological aspects of sheep wool by testing a traditional *** biological method of aerobic mesophilicﬂora has been *** X was used to determine the chemical composition of the materials ***,thermal characterization has been *** thermal conductivity is above 0.046(W·m^(-1)·K^(-1))and the thermal diffusivity is 1.56.10^(-6) m^(2)·s^(-1).Besides,the energy efﬁciency of using sheep wool in buildings was ***,its humidity behavior was evaluated in different aspects in both winter and *** of biological analyses show the efﬁciency of the treatment by removing the majority of the microorgan-isms:the value of yeast and mildew was reduced from 38.10^(2) to 2.10^(2)(UFC·g^(-1)).In addition to that,sheep wool permits obtaining a low thermal transmittance on the scale of the walls and low cooling needs on the scale of the building with a gain of 45%and 52%,respectively.

关键词： Sustainability sheep wool biological treatment hygrothermal wool behavior hot wire method

Childhood asthma biomarkers including zinc: An exploratory crosssectional study

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World Journal of Clinical Pediatrics 2024年第1期13卷 31-40页

作者： Hoda Atef Abdelsattar Ibrahim Mona Mohsen Boles Salep Aziz Hanna Dina Mahmoud Khaled Mohamed abdelhamid el-Khashab Pediatric Clinical Nutrition Unit Faculty of MedicineCairo UniversityCairo 12613Egypt Department of Pediatrics Faculty of MedicineCairo UniversityCairo 12613Egypt Department of Clinical Pathology Faculty of MedicineCairo UniversityCairo 12613Egypt

BACKGROUND Childhood bronchial asthma(BA)is a chronic inflammatory respiratory *** conditions,including zinc deficiency,can affect such allergic *** To outline the difference in serum zinc levels between asthmatic children and healthy *** A cross-sectional study was carried out at Children’s Hospital,Cairo University,investigating serum zinc levels in children with BA(n=40)and healthy children(n=21).Other markers included serum ferritin,iron,hemoglobin(Hb),and immunoglobulin E(IgE)*** t-tests and Mann-Whinny tests were used for *** Kruskal-Wallis test was applied to compare serum ferritin and IgE levels with regard to asthma ***'s rank correlation was performed to explore the relationship between serum ferritin levels and both iron and Hb levels in asthmatic *** Children with BA had higher levels of zinc,yet the difference was not significant(P=0.115).Serum ferritin and IgE levels were significantly higher in asthmatic children(P=0.006 and 0.001,respectively),yet their levels did not differ significantly by severity(P=0.623 and 0.126,respectively).There was a nonsignificant weak correlation between serum ferritin levels and both serum iron and Hb *** Serum zinc levels do not seem to differ between asthmatic children and healthy *** ferritin levels may be a marker of asthma *** IgE levels are not markers of asthma severity.

关键词： Children Asthma Zinc Ferritin

Enhancing Canola Yield and Photosynthesis under Water Stress with Hydrogel Polymers

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Phyton-International Journal of Experimental Botany 2024年第7期93卷 1623-1645页

作者： elham A.Badr Gehan Sh.Bakhoum Mervat Sh.Sadak Ibrahim Al-Ashkar Mohammad Sohidul Islam Ayman el Sabagh Magdi T.abdelhamid Field Crops Research Department National Research CentreCairo12622Egypt Botany Department National Research CentreCairo12622Egypt Plant Production Department College of Food and Agriculture SciencesKing Saud UniversityRiyadh12271Saudi Arabia Department of Agronomy Hajee Mohammad Danesh Science and Technology UniversityDinajpur5200Bangladesh Department of Field Crops Faculty of AgricultureSiirt UniversitySiirt56100Turkey Department of Agronomy Faculty of AgricultureKafrelsheikh UniversityKafrelsheikh33516Egypt Department of Research Centers Montana State UniversityBozemanMT 59717USA

While Egypt’s canola production per unit area has recently grown,productivity remains low,necessitating increased *** are water-absorbent polymer compounds that can optimize irrigation schedules by increasing the soil’s ability to retain ***,twoﬁeld experiments were conducted to examine hydrogel application to sandy soil on canola growth,biochemical aspects,yield,yield traits,and nutritional quality of yielded seeds grown under water deﬁcit stress *** experiments were conducted by arranging a split-plot layout in a randomized complete block design(RCBD)with three times replications of each *** water stress at 75%or 50%of crop evapotranspiration(ETc)lowered chlorophyll a,chlorophyll b,caro-tenoids,and total pigments content,indole-3-acetic acid,plant development,seed yield,and oil and total carbo-hydrates of seed yield,hydrogel treatment enhanced all of the traits mentioned ***,hydrogel enhanced to gather compatible solutes(proline,amino acids,total soluble sugars),phenolics content in leaves,seed protein,and crop water productivity,which increased while the plants were under water *** results revealed that the full irrigation(100%ETc)along with hydrogel compared to water-stressed(50%ETc)led to enhanced seed yield(kg ha^(-1)),Oil(%),and Total carbohydrates(%)of rapeseed by 57.1%,11.1%and 15.7%,***,under water-stressed plots with hydrogel exhibited enhancement by 10.0%,3.2%and 5.1%in seed yield(kg ha^(-1)),oil(%),and total carbohydrates(%)of rapeseed by 57.1%,11.1%and 15.7%,respec-tively compared to *** a result,the use of hydrogel polymer will be a viable and practical solution for increasing agricultural output under water deﬁcit stress situations.

关键词： Hydrogel oil osmolytes rapeseed yield water stress

Modeling environmental sensitivity and risk assessment of PAHs in sediments along two marine coastal areas in Egypt

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Petroleum Research 2024年第1期9卷 125-142页

作者： Muhammad A.el-Alfy National Institute of Oceanography and Fisheries NIOFCairoEgypt

Modeling the environmental sensitivity index(ESI)is vital in the planning and management processes,especially along the coastal *** main objectives of the study were to define the main sources of polycyclic aromatic hydrocarbons(PAHs),establish an ESI model,and measure the risk of PAHs on humans and the environment using various *** methodology of the research involved analyzing PAHs according to the EPA 550 methodology in sediments of the coastline in two important coastline areas in Egypt,namely the Gulf of Suez and the Mediterranean Sea,modeling the sensitivity of PAHs using ArcGIS 10.5 by integrating different physical,biological,and land use/cover factors,identifying the sources,and performing a risk *** sediment samples were collected from each *** produced sensitivity map could explain the highly sensitive areas along the Mediterranean Sea and Gulf of Suez coastlines(especially areas that were near drains'outlets,industrial sites,and sea ports).The highest mean PAH concentrations were Acenaphthylene and Fluorine in the Mediterranean Sea and Suez Gulf,***'s obvious that the individual PAH concentrations were within the ERL,ERM,and Pel threshold limits,indicating no adverse biological *** ratios of BaA/BaA+Chy,Flu/Flu+Py,and Ant/Ant+Phe gave an indication that most PAH sources were petrogenic(63.64%)and others(36.36%)were from petroleum *** principle component analysis(PCA)indicated a diverse correlation among the isomer ratios and LU/LC *** carcinogenic risk values were in the very low category(elines and seawater free of oil spillage act

关键词： Polycyclic aromatic hydrocarbons(PAHs) Modeling Sensitivity Gulf of Suez And Mediterranean sea

Variable range hopping conduction in n-CdSe samples at very low temperature

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Journal of Semiconductors 2015年第12期36卷 14-17页

作者： M Errai A el kaaouachi H el Idrissi Physics Department Ibn Zohr University Faculty of Sciences Laboratoire electronique électrotechnique Automatique et Traitement de l'Information Département Génie ElectriqueFaculté des Sciences et Techniques de Mohammedia Université Hassan Ⅱ Mohammedia Casablanca

We reanalyzed experimental data already published in Friedman J R, Zhang Y, Dai P, et al. Phys Rev B, 1996, 53（15）： 9528. Variable range hopping （VRH） conduction in the insulating three-dimensional n-CdSe samples has been studied over the entire temperature range from 0.03 to 1 K. In the absence of a magnetic field, the low temperature conductivity a of the three samples （A, B and C） obeys the Mott VRH conduction with an appropriate temperature dependence in the prefactor （a = σ0 exp [- （T0/T）]^p with p ≈ 0.25）. This behavior can be explained by a VRH model where the transport occurs by hopping between localized states in the vicinity of the Fermi level, EF, without creation of the Coulomb gap （CG）. On the contrary, no Efros-Shklovskii VRH is observed, suggesting that the density is constant in the vicinity of the EF.

关键词： n-CdSe samples low temperature variable range hopping density of state

electrical properties of ^(70)Ge:Ga near the metal–insulator transition

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Journal of Semiconductors 2015年第6期36卷 1-5页

作者： M Errai A el kaaouachi H el idrissi Laboratoire MSTI Ecole Supérieure de tecchnologie d'Agadir B.P: 33/S University Ibn ZohrFaculty of Sciences AgadirMorocco Laboratoire electronique électrotechnique Automatique et Traitement de l'Information Département Génie Electrique Faculté des Sciences et Techniques de Mohammedia Université Hassan II Mohammedia CasablancaBP 146 Quartier YasminaMohammedia

The results of the metal-insulator transition （MIT） induced by impurity concentration are presented in the case of metallic and insulating samples 70Ge：Ga p-type. The eight samples studied have Ga concentrations N ranging from 1.848 × 1017 to 1.912 × 10^17 cm-3. The conductivity measurements were carried out at low temperature in the range 1 to 0.019 K. We provide physical explanations to explain the behaviors of the temperature dependence of the electrical conductivity in both sides of the MIT. The data are for a 70Ge：Ga sample prepared and reported by Itoh et aL in Ref. [Itoh K M, Watanabe M, Ootuka Y, et al. J Phys Soc Jpn, 2004, 73（1）： 173].

关键词： 70Ge: Ga semiconductor low temperature impurity concentration metal-insulator variable rangehopping conductivity transport properties

A NEW HYBRIDIZED MIXED WEAK GALERKIN METHOD FOR SECOND-ORDER elLIPTIC PROBLEMS

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Journal of Computational Mathematics 2022年第4期40卷 499-516页

作者： abdelhamid Zaghdani Sayed Sayari Miled el Hajji University of Tunis Boulevard du 9 avril 1939 TunisDepartment of MathematicsEnsitTaha Hussein AvenueMontfleuryTunisTunisia Northern Border University Faculty of Arts and ScienceRafhaP.O.840Saudi Arabia Carthage University Isteub2 Rue de l’Artisanat Charguia 22035 TunisTunisia Department of Mathematics Faculty of SciencesUniversity of JeddahSaudi Arabia ENIT-LAMSINBP.371002 Tunis-Belv´ed`ereTunis El Manar UniversityTunisia

In this paper,a new hybridized mixed formulation of weak Galerkin method is studied for a second order elliptic *** method is designed by approximate some operators with discontinuous piecewise polynomials in a shape regular finite element *** discrete inequalities are presented on discontinuous spaces and optimal order error estimations are *** numerical results are reported to show super convergence and confirm the theory of the mixed weak Galerkin method.

关键词： Weak Galerkin Weak gradient Hybridized mixed finite element method Second order elliptic problems