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Contribution of electric Tomography, Chemical and Isotopic Tools to the Understanding of the Resilience and Salinization of Wetlands along the Northern Coast of the Cape-Verde Peninsula: The Case of the Retba Lake

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Journal of Geoscience and Environment Protection 2019年第9期7卷 36-57页

作者： Mansour Gueye Abdoul Aziz Gning Mapathé Ndiaye Fatou Diop Ngom Raymond Malou el hadj sow Raphael Sarr Département de Géologie Facultédes Sciences et TechniquesUniversité Cheikh Anta DiopDakarSénégal UFR Sciences de l’Ingénierie Université de ThièsThièsSénégal

On the northern coast of the Cape Verde peninsula, Lake Retba is one of the few depressions that have preserved its water body due to the drought that plagued the Sahel in the 1960s. The aim of this article is to understand the resilience of the lake to the drought. For this purpose, a deep knowledge of interactions between the different components of the hydro-system, namely: lake, dune tablecloth, ponds and ocean is necessary. The use of electrical resistivity tomography (ETR) and chemical and isotopic tools yielded conclusive results. electrical tomography of resistivity (ETR) shows throughout the coastal dune a superposition between fresh and salt water, with even a predominance of salt water at the level of the old canal. The chemistry of the major ions and isotopes confirms this contact between the saltwater bison of the sea and the lake by showing a superposition of the fresh/brackish waters on the salty waters of the bevel, which, in turn, are found in the very salty waters influenced by the lake. This translates a feeding of the lake by the sea through the bevel. At the canal level, this feeding is done, on the surface, by means of ponds whose water characteristics show that they constitute an outcrop of the bevel. The freshwater body of the coastal dune that floats on salt water in the form of a lens also flows into the lake. The feeding of the lake, by the sea through the bevel and the ponds, and by the water table, is therefore effective and attested by all the methods used in this work. It allowed the resilience of the lake against the drought. This inflow of seawater into the lake is at the origin of its salinization and therefore of the salt that settles on the bottom. This study shows that the survival of the lake also depends on safeguarding the ponds located in the north of the lake.

关键词： Tomography Isotope Lake Ponds Aquifer Hydro System Salinization Resilience

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Back Surface Recombination Velocity Dependent of Absorption Coefficient as Applied to Determine Base Optimum Thickness of an n+/p/p+ Silicon Solar Cell

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Energy and Power Engineering 2020年第7期12卷 445-458页

作者： Meimouna Mint Sidi Dede Mamadou Lamine Ba Mamour Amadou Ba Mor Ndiaye Sega Gueye el hadj sow Ibrahima Diatta Masse Samba Diop Mamadou Wade Gregoire Sissoko Laboratory of Semiconductors and Solar Energy Physics Department Faculty of Science and Technology University Cheikh Anta Diop Dakar Senegal Ecole Polytechnique de Thiès (EPT) Thiès Senegal

The monochromatic absorption coefficient of silicon, inducing the light penetration depth into the base of the solar cell, is used to determine the optimum thickness necessary for the production of a large photocurrent. The absorption-generation-diffusion and recombination (bulk and surface) phenomena are taken into account in the excess minority carrier continuity equation. The solution of this equation gives the photocurrent according to absorption and electronic parameters. Then from the obtained short circuit photocurrent expression, excess minority carrier back surface recombination velocity is determined, function of the monochromatic absorption coefficient at a given wavelength. This latter plotted versus base thickness yields the optimum thickness of an n+-p-p+ solar cell, for each wavelength, which is in the range close to the energy band gap of the silicon material. This study provides a tool for improvement solar cell manufacture processes, through the mathematical relationship obtained from the thickness limit according to the absorption coefficient that allows base width optimization.

关键词： Silicon Solar Cell Absorption Coefficient Back Surface Recombination Optimum Thickness

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Toxicology,biosynthesis,bio-control of aflatoxin and new methods of detection

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Asian Pacific Journal of Tropical Biomedicine 2016年第9期6卷 808-814页

作者： Mohamed Amine Gacem Aminata Ould el hadj-Khelil Laboratory of Protection of Ecosystems in Arid and Semi-Arid Area University of Kasdi Merbah Department of Biology Faculty of ScienceUniversity of Amar Tlidji

Mycotoxins and their derivatives since their discoveries and until the present time are behind unspecified economic and medical *** are classified according to their physical–chemical and toxicological characters in the most dangerous row of the *** aflatoxins are in part responsible,of irreversible medical disasters that are not easily manageable such as cancer of the liver and kidneys,and in the other part,of losses in the stored cereal *** on these crucial findings,monitoring of this toxin became imperative in post-harvest food products,during storage,during transformation chain and even during the long phases of *** of this toxin is delivered by detection methods using very advanced technologies to respond in the shortest possible *** addition,the knowledge of factors supporting the biosynthesis of aflatoxins such as the temperature,moisture content,concentration of nitrogen and carbon,and the molecules responsible for the genetic control of the synthesis will be reflected later in the choice of bio-control *** control is currently based on new strategies using the bioactives substances of the plants,the lactic bacteria and some strains of actinomycetes that have good inhibiting activity against aflatoxins with fewer side effects on *** the other hand,this brief review summarizes the results of new studies demonstrating the toxicity of the toxin,new detection methods and bio-control.

关键词： Mycotoxins Aflatoxins Cancer Biosynthesis Bio-controls Detection methods

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Antioxidant antileishmanial cytotoxic and antimicrobial activities of a local plant Myrtus nivellei from Algeria Sahara

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Asian Pacific Journal of Tropical Biomedicine 2017年第8期7卷 702-707页

作者： Farah Ramdane Rym Essid Nadia Fares Dahmane el Ouassis Sana Aziz Mahfoud hadj Mahammed Mohamed Didi Ould hadj Ferid Limam Biogeochemistry Laboratory in Desert Environments Kasdi Merbah University Faculty of Natural and Life Sciences El Oued University Laboratory of Bioactive Substances Biotechnology Center of Borj-Cedria Technopole National Institute of Forest Research Protection Laboratory of Ecosystem in Arid and Semi Arid Zone Kasdi Merbah University

To study the phytochemical constituents and in vitro biological activities of hydromethanolic extract and fractions from Algerian Sahara Myrtus nivellei (M. nivellei) collected in Hoggar region and to identify the active fraction that can act as an alternative of commonly used antibiotics and as antileishmanial or antioxidant *** screening of M. nivellei aerial parts was realised according to the literature. Extract was firstly prepared by using aqueous methanol then fractionated with ethyl acetate and butanol solvents. Total phenolics, tannis and flavonoids, of the hydromethanolic extract and their fractions were determined by Folin-Ciocalteu method as gallic acid equivalents and by aluminium chloride as rutin equivalent respectively. Extract and fractions were tested for their antimicrobial and antiparasital activities against standard bacteria using agar diffusion method and two kinds of leishmania visceral and cutaneous. The antioxidant activities were realized using phosphomolybdenum, FRAP and DPPH *** phytochemical screening exhibited the presence of flavonoids, tannins, saponins, and alkaloids. The experimental results showed that plant extract and fractions were high in phenolic compounds and exhibited an important role as antioxidant, antimicrobial and had a moderate antileishmanial *** observations lead us toward more studies in this field, so that we can get more benefits from our local Algerian medicinal plants.

关键词： Phenolic compounds Flavonoids Antioxidant activity Antimicrobial activity Antileishmanial activity Myrtus nivellei

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Static Analysis of Functionally Graded Sandwich Plates Using an Efficient and Simple Refined Theory

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Chinese Journal of Aeronautics 2011年第4期24卷 432-433页

作者： hadj Henni ABDelAZIZ Hassen Ait ATMANE Ismail MECHAB Lakhdar BOUMIA Abdelouahed TOUNSI Adda Bedia el ABBAS Laboratoire des Matériaux et Hydrologie Université de Sidi Bel Abbes Département de Génie Civil Université Ibn Khaldoun Département de Génie Civil Faculté de Génie Civil et d'Architecture Univesité de Chlef Département de Physique Université de Sidi Bel Abbes

In this paper, a new displacement based high-order shear deformation theory is introduced for the static response of functionally graded sandwich plate. Unlike any other theory, the number of unknown functions involved is only four, as against five in case of other shear deformation theories. The theory presented is variationally consistent, has strong similarity with classical plate theory in many aspects, does not require shear correction factor, and gives rise to transverse shear stress variation such that the transverse shear stresses vary parabolically across the thickness satisfying shear stress free surface conditions. Two common types of functionally graded sandwich plates, namely, the sandwich with fimctionally graded facesheet and homogeneous core and the sandwich with homogeneous facesheet and functionally graded core, are considered. Governing equations are derived from the principle of virtual displacements. The closed-form solution of a simply supported rectangular plate subjected to sinu- soidal loading has been obtained by using the Navier method. The validity of the present theory is investigated by comparing some of the present results with those of the classical, the first-order and the other higher-order theories. It can be concluded that the proposed theory is accurate and simple in solving the static bending behavior of functionally graded sandwich plates.

关键词： functionally graded materials sandwich plates refined plate theory bending Navier solution

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Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry traces the geographical source of Biomphalaria pfeifferi and Bulinus forskali,involved in schistosomiasis transmission

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Infectious Diseases of Poverty 2024年第1期13卷 98-99页

作者： Papa Mouhamadou Gaye EI hadj Ibrahima Ndiaye Souleymane Doucoure Doudou sow Mapenda Gaye Ndiaw Goumballa Carole Cassagne Coralie L'Ollivier Oleg Medianikov Cheikh Sokhna Stephane Ranque Aix-Marseille University IRD AP-HM SSA VITROME Marseille France VITROME International IRD-UCAD Campus Dakar Senegal Hospital-University Institut (IHU) Mediterranée Infection Marseille France Departement of Animal Biology Faculty of Sciences and Techniques UCAD Dakar Senegal Department of Parasitology-Mycology UFR Sciences de la Santé Université Gaston Berger Saint-Louis Senegal

Background Freshwater snails of the genera Bulinus spp.,Biomphalaria spp.,and Oncomelania *** the main intermediate hosts of human and animal *** of these snails has long been based on mor-phological and/or genomic criteria,which have their *** limitations include a lack of precision for the morphological tool and cost and time for the DNA-based ***,Matrix-Assisted Laser Desorp-tion/lonization Time-Of-Flight(MALDI-TOF)mass spectrometry,a new tool used which is routinely in clinical microbi-ology,has emerged in the field of malacology for the identification of freshwater *** study aimed to evaluate the ability of MALDI-TOF MS to identify Biomphalaria pfeifferi and Bulinus forskali snail populations according to their *** This study was conducted on 101 *** and 81 *** snails collected in three distinct geo-graphical areas of Senegal(the North-East,South-East and central part of the country),and supplemented with wild and laboratory *** which had previously been morphologically described were identified by MALDl-TOF MS[identification log score values(LSV)≥1.7],after an initial blind test using the pre-existing *** DNA-based identification,new reference spectra of ***(n=10)and ***(n=5)from the geographical areas were added to the MALDI-TOF spectral *** final blind test against this updated database was per-formed to assess identification at the geographic source *** MALDI-TOF MS correctly identified 92.1%of 101 *** snails and 98.8%of 81 *** *** the final blind test,88%of 166 specimens were correctly identified according to both their species and sampling site,with LSVs ranging from 1.74 to *** geographical source was adequately identified in 90.1%of 91 *** and 85.3%of 75 *** *** Our findings demonstrate that MALDI-TOF MS can identify and differe

关键词： Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry Snail Intermediate host Biomphalaria pfeifferi Bulinus forskali Schistosomiasis Senegal

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<i>Mytilus galloprovincialis</i>as Mussel Watch for Butyltins, Tin, Copper and Zinc Contamination, from Antifouling Paint Particles, in West Algerian Coastal Waters

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Journal of Environmental Protection 2012年第9期3卷 1047-1053页

作者： Zoubida el hadj Zitouni Boutiba Boucif Belbachir Laboratoire de Chimie des Polymères Faculté des Sciences Université d’Oran Oran Algeria. Laboratoire Réseau de Surveillance Environnementale Faculté des Sciences Université d’Oran Oran Algeria

Butyltin compounds (BTs) including tributyltin (TBT) and its degradation product (DBT) and concentrations of heavy metals (Sn, Cu and Zn) were determined in mussels (Mytilus galloprovincialis) collected from some West Algerian harbours. BTs were detected in all the mussels. Quanti?cation of BTs and heavy metals was carried respectively by Gas Chromatography coupled with Mass Spectrometer (GC-MS) and Atomic Absorption Spectrometry, flame AAS. Concentrations of total butyltin (BTs: DBT + TBT) in mussels ranged from 0.49 to 2438 ng/g wet wt. The concentrations (μg/g wet wt) of heavy metals ranged from 0.40 to 3.55 for Sn, 9.62 to 67.03 for Cu, and 87.13 to 731.51 for Zn. Total of tin in mussels ranged from 0.2 to 1054.78 ng/g. Higher concentrations of butyltin compounds were found in mussels collected from Mers el Kebir shipyard, Arzew, a petroleum harbour (industrial), and Beni Saf fishing harbour. This suggested that maritime activities nearby the harbours play a major role as the source of BTs. Indeed, harbour of Arzew is frequented by voluminous tanker. TBT was the predominant compound in mussels collected from almost all the sampling locations;indicate the fresh input of TBT in harbours.

关键词： Organotin Tin Copper Zinc Mytilus galloprovincialis GC-MS AAS

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Characterization of Tunisian marine sediments in Rades and Gabes harbors

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International Journal of Sediment Research 2014年第3期29卷 391-401页

作者： Imen Bel hadj ALI Zoubeir LAFHAJ Mounir BOUASSIDA Imen SAID Ecole Centrale de Lille Villeneuve d'AscqFrance and Ecole Nationale d'Ingenieurs de TunisTunisia Ecole centrale de Lille Villeneuve d'AscqFrance Universite de Tunis el Manar/Ecole Nationale d'Ingenieurs de Tunis/05-UR-11 06 Universite de Tunis el Manar/Ecole Nationale d'Ingenieurs de Tunis/05-UR-1106

The objective of this article is to study the geotechnical and environmental characteristics of sediments dredged from two Tunisian harbors:Rades and *** first harbor represents the main facility place in the national transport *** second one is selected as its sediments present a serious ecological constraint caused by the discharge of wastes into the marine *** sediments are either discarded at sea or landfilled despite their harmful effects on the *** article is divided into three main *** first one presents the material that was carried for Rades and Gabes *** conservation conditions and the used experimental tests are *** characterization includes the determination of the grain size distribution,the water content,the Atterberg limits,the methylene blue value,the specific area,the bulk density,the specific unit weight,the organic and carbonate *** characterization is assessed by the determination of metals concentrations in a leaching *** second section deals with the description and analysis of geotechnical properties of Rades and Gabes harbors’ *** results obtained show that Rades harbor sediments are slightly sandy clayey silts whereas Gabes harbor sediments are silty sands characterized by a highly plastic clay *** of the two sediments don’t exhibit a high organic ***,chemical,mineralogical and environmental properties are presented and then *** experimental results obtained show that Rades and Gabes sediments could be used as a sand substitute in the formulation of a new construction *** harbor sediments are more polluted than Rades harbor sediments.

关键词： Sediments Characterization Geotechnical Environmental Valorization

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electrical Parameters Determination from Base Thickness Optimization in a Silicon Solar Cell under Influence of the Irradiation Energy Flow of Charged Particles

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Energy and Power Engineering 2020年第1期12卷 1-15页

作者： Ousmane sow Mamadou Lamine Ba Mohamed Abderrahim Ould el Moujtaba Youssou Traore el hadji sow Cheikh Tidiane Sarr Masse Samba Diop Grégoire Sissoko University Institute of Technology University of Thiès Thiès Sénégal Laboratory of Semiconductors and Solar Energy Physics Department Faculty of Science and Technology University Cheikh Anta Diop Dakar Senegal Ecole Polytechnique de Thiès Thiès Sénégal

In this work, we study the characteristics I-V and P-V of a silicon solar cell as well as its fill factor, its electrical power from the optimum thickness obtained in the base under variation of the irradiation energy flow of charged particles. The recombination velocity at the junction corresponding to the maximum power point was also deduced.

关键词： Silicon Solar Cell Flow Irradiation Energy Recombination Velocity Optimum Base Thickness

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Correlation between Glomerulopathy and Retinopathy in an African Population of Type 2 Diabetics

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Journal of Diabetes Mellitus 2020年第2期10卷 64-72页

作者： Michel Assane Ndour Jean Pierre Diagne Demba Diedhiou Djiby sow Esperance Ciss Ibrahima Mane Diallo Muriel Diembou el hadj Fary Ka Papa Amadou Ndiaye Anna Sarr Maimouna Ndour Mbaye Department of Internal Medicine Abass Ndao Hospital Center Dakar Sénégal Department of Ophtalmology Abass Ndao Hospital Center Dakar Sénégal Department of Nephrology Aristide Le DantecHospital Center Dakar Sénégal

Introduction: Diabetic microangiopathies are common, but their time to onset in a diabetic patient varies from subject to subject. The aim of our study was to study the correlation between renal and ophthalmic disorders in patients with type 2 diabetes. Patients and methods: This longitudinal, analytical study took place from March 1, 2018 to March 31, 2019 at the Abass Ndao University Hospital Center. It was studying retinal involvement in diabetic patients with glomerulopathy. Results: Of the 100 cases of diabetic glomerulopathy, they are divided into 70 women and 30 men with an average age of 58.2 years. The average duration of diabetes was 6.1 years and their average glycated hemoglobin (HbA1c) was 8.1%. Only 37% of patients had an HbA1c level below 7%. The other cardiovascular risk factors were high blood pressure (HBP) (39%), dyslipidemia (36%), and obesity (15%). Among these patients, diabetic retinopathy was present in 21% of the cases. Retinopathies were more frequent in the group of patients diagnosed with diabetes for less than 6 years (69%) and in patients with chronic renal disease with slightly reduced glomerular filtration rate (GFR) (34%). Conclusion: Our study allowed us to conclude that during the course of type 2 diabetes, the onset of chronic kidney disease does not systematically imply the presence of diabetic retinopathy. It is thus important to make screenings and assessments of systematic complications.

关键词： Diabetic Retinopathy Diabetic Nephropathy Microangiopathy Daka

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