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Water Quality on the Basement Areas in Kouba-Adougoul and Its Surroundings, Guera Province, Chad

Journal of Geoscience and Environment Protection 2024年第9期12卷 388-406页

作者： Tekoum Leontine Benadjingar Nguelmbaye jean claude doumnang mbaigane Laboratoire de geologie geomorphologie et de teledetection Dpartement de Gologie Facult de Sciences Exactes et Appliques Universit de NDjamna NDjamena Chad Laboratoire hydro-gosciences et reservoirs Dpartement de Gologie Facult de Sciences Exactes et Appliques Universit de NDjamna NDjamena Chad

Water is an essential element for all forms of life. The quantity and quality of water are a problem in places. In Kouba Adougoul and its surroundings in south guera, water-related health problems are reported. That is why this study focuses on the quality of water in the basement areas, of Kouba Adougoul. Our objective is to contribute to a better understanding of water of human consumption in these areas for this, we carried out a physicochemical and bacteriological control on a number water point. Ten water points were collected during May 2022 for analysis. To achieve this objective, we made the in-situ analysis of physical parameters such as pH, electrical conductivity, and temperature. These measurements were made using the multi-parameter kit. The result shows that, the water temperatures vary from 24.4˚C to 27.4˚C proving that the waters are from deep depths. For the use of these waters, it is necessary to take certain precautions. The pH values varied between 6.15 and 7.78, an average of 6.77 giving some waters an aggressive character. It was low mineralized, with electrical conductivity averages ranging from 182.1 to 2100 μS/cm−1 an average of 586.36 μS/cm−1. For the chemical parameters, it is by hydrometric titration that the content of the ions was determined. The determination of the various coliforms in these waters was carried out by its various methods which led to detecting that the waters of Kouba Adougoul are turbid, and present high proportions of nitrates, iron and ammonium. The presence of pathogenic germs, such as total coliforms and thermo-tolerant coliforms in these waters, has been demonstrated. For their consumption, these waters deserve treatment beforehand. In the study area, the anthropogenic activities are considered the most serious sources of groundwater.

关键词： Environmental Pollution Hydrochemistry Aquifers Crystalline Basement Kouba-Adougoul (Guera-Chad)

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Physico-Chemical Properties of Soils from Diguel and Koudalwa Tchad,and Phytoremediation Potentials of Acasia and Kinkeliba Plants in Removing Cr and Cu from These Soils

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Journal of Environmental Science and Engineering(A) 2024年第5期13卷 165-177页

作者： Dieudonne Caleb Dahaina jean claude doumnang mbaigane Bobet Ouanmini Cornelius Tsamo Department of Chemistry Faculty of Exact and Applied SciencesUniversity of N’DjamenaBP 1027N’DjamenaChad Laboratoire de Géologie Géomorphologie et TélédétectionFacultédes Sciences Exactes et AppliquéesUniversitéde N’DjaménaBP 1027N’DjamenaChad Laboratoire de Chimie Ecole Normale Supérieure de BongorBP 13BongorTchad Department of Chemistry Higher Teachers’Training CollegeUniversity of MarouaP.O.Box 55 MarouaCameroon Department of Agricultural and Environmental Engineering College of TechnologyUniversity of BamendaP.O.BOX 39BambiliCameroon

The aim of this study to investigate the physico-chemical properties of soils from Diguel and Koudalwa Tchad,and phytoremediation potentials of acasia and kinkeliba plants in removing Cr and Cu from these *** was sampled from the tannery plant in Diguel and agricultural land around crude oil activities in *** were characterized by the following properties:pH,(Electrical Conductivity),TDS(Total Dissolved Solids),salinity,bulk density,OM(Organic Matter),nitrate,phosphate,clay,silt,sand,and textural *** acasia and kinkeliba plants were used to decontaminate Cu and Cr from sample soils for 30 days *** bulk density of all the soil samples from Kouldawa was higher compared to Diguil,ranging from 1.421 to 1.64 g/cm^(3)compared to 1.21 to 1.51 g/cm^(3)for *** of the soils in Kouldawa are mineral soils,while those of Diguel are mostly mineral soil with some *** soils are richer in nitrate(577.9 to 2,687.32 mg/kg in Diguel and 33.64 to 197.64 mg/kg in Kouldawa)and phosphate than soils from *** from the studied areas are not saline except for a subsurface soil in Diguel(salinity,4.21;EC,4.280 dS/m;TDS,3,040 mg/L).The highest amount of Cr and Cu removed by acasia is 78%and 53.12%compared to 73.8%and 52.21%by *** soil can be very suitable for agriculture and Kouldawa soils for *** and kinkeliba can be effectively used to decontaminate the studied soils from heavy metal pollution.

关键词： Soil physico-chemical properties phytoremediation heavy metals Tchad.

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Vulnerability Evaluation of Groundwater of N’Djamena City: Contribution of the Parametric Methods GOD and SI

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Journal of Environmental Protection 2021年第7期12卷 472-489页

作者： David Deubalbe Edith Kadjangaba Djimako Bongo Sabine Djimouko jean claude doumnang mbaigane Yaya Mahmout Geology Department Faculty of Exact and Applied Sciences University of N’djamena N’djamena Chad Faculty of Sciences and Techniques University of Doba Doba Chad Higher Normal School of Technology of Sarh Sarh Chad Letters Arts and Human Sciences Faculty University of Moundou Moundou Chad Natural Substances Laboratory Exact and Applied Sciences Faculty University of N’Djamena N’Djamena Chad

The purpose of this work is to study the vulnerability of the Quaternary aquifer that lies beneath the N’Djamena city Chad. The subsoil of N’Djamena city Chad is made up of a multilayered aquifer in which there are two main aquifers located respectively at a depth of about 10 and 60 m, between the two there is an intermediate aquifer at about 30 m depth. It is this latter water table, generally captured by human-powered pumps, that is the subject of this study. Because of anarchic garbage dumping, wastewater discharge, latrines scattered throughout the city, chemical fertilizers and herbicides used on the banks of Chari River and its tributary the Logone for market gardening, the quality of the water in this aquifer is highly threatened. Moreover, it has been noting that the sources of pollution are constantly increasing in conjunction with the growth of the population, so the knowledge and protection of groundwater are necessary. We have therefore carried out a study of intrinsic vulnerability using two mapping methods (GOD and SI), as mapping is recognized as an effective tool for decision support in the case of safeguarding water resources. The results obtained by the GOD method show that 38% of the study area is covered by high vulnerability, 29% by moderate vulnerability, 21% by low vulnerability and 21% by the very low vulnerability. With the SI method, 54% of the study area is covering by low vulnerability and 46% by the low and moderate vulnerability. The coincidence rate of low nitrate values in groundwater with areas of very low and low vulnerability is 91% and 76% for the GOD and SI methods, respectively. Although these observations validated the different maps obtained, the SI approach seems to be the most adequate for vulnerability tracing in our study area.

关键词： Vulnerability GOD SI Groundwater Nitrate N’Djamena City

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Hydrochemical Characterisation and Assessment of the Level of Contamination of Groundwater Collected by Private Waterworks in the Town of Moundou in the South of Chad

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Journal of Geoscience and Environment Protection 2024年第1期12卷 13-32页

作者： Prosper Doumtoudjinodji Elegbede Manou Bernadin jean claude doumnang mbaigane Nguérassem Djoueingue Urbain Agnichola Akilou Socohou Amadou Water and Environment Sciences and Techniques Laboratory National Water Institute (INE) University of Abomey-Calavi Cotonou Benin Geology Geomorphology and Remote Sensing Laboratory University of N’Djaména N’Djamena Chad Applied Hydrology Laboratory National Water Institute (INE) University of Abomey-Calavi Cotonou Benin

Groundwater is the main source of drinking water for large cities in most African countries. In Moundou, for example, the conventional groundwater supply system is failing. To compensate for this state failure, the population is building boreholes and wells, most of which tap the surface water table, generally referred to as the “water table”. The aim of this study is to characterize these waters in order to assess their level of contamination and, by extension, the degree of pollution of the water table. Major elements such as: Chloride (Cl-), Sulfate (SO42-), Nitrate (NO3-), Calcium (Ca2+), magnesium (Mg2+), sodium (Na+) and potassium (K+) were analysed by Liquid Chromatography and the Bicarbonate ion (HCO3-) was determined by the titrimetric method. The methodology applied is based on a combination of hydrochemical techniques and statistical analysis (PCA and CHA). A sampling campaign was carried out during high-water periods. The results of the physico-chemical analyses show mineralization ranging from 7.29 to 3670 μS/cm, with an average of 487.44 μS/cm. The groundwater studied is generally acidic, with a pH ranging from 3.26 to 6.41. Based on their anions, they are classified into four main hydrochemical facies: chloride and sulphate facies, calcium and magnesium facies, sodium and potassium facies and bicarbonate facies. The various correlations between major ions and statistical analyses have enabled us to identify three hydrogeochemical processes involved in water mineralization. The dominant process is silicate hydrolysis, followed by cation exchange, then anthropogenic input, which influences mineralization by polluting the water.

关键词： Drinking Water Groundwater Chemical Pollution Moundou Chad

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Study of a Toposequence of West Mayo-Kani Soils (Far North Cameroon)

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Open Journal of Soil Science 2022年第10期12卷 523-539页

作者： Souoré Irène Basga Simon doumnang mbaigane jean-claude Ngaro M’baïti Management of Water Resources Soils and Environment Department of Earth Sciences Faculty of Sciences University of Ngaoundéré Ngaoundéré Cameroon Institute of Agronomic Research for Development (IRAD) of Garoua Garoua Cameroon Laboratory of Geology Geomorphology and Remote Sensing University of N’Djamena N’Djamena Chad

The soils of Gadas, object of the present study, are identified on the macromorphological, physico-chemical level and the indices of erodibility are related to their physico-chemical properties. The physico-chemical analyzes were carried out by standard methods. The macromorphological analysis of a toposequence made it possible to identify five types of soils: the lithosols which occupy the high zones of the landscape, the colluvial soils (arenosols, regosols) which are located high on the piedmont, alluvial soils (fluvisols) which are located at the bottom of the slope in the alluvial plain and are the most extensive, topomorphic vertisols, and brown soils formed on granite are located either between a colluvial soil and alluvial soil. Physico-chemical analyzes of the soils of Gadas show that these soils are weakly acidic to neutral, sandy to sandy-clayey, saturated, low in nitrogen and organic matter and characterized by average proportions of exchangeable bases. The study of soil erodibility, based on the use of erodibility indices, showed that alluvial soils and brown soils formed on granites are the most susceptible to erosion, whereas vertisols and colluvial soils are the least vulnerable to erosion.

关键词： Far North Cameroon West Mayo-Kani Gadas Soils Erodibility

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The synergy between the payloads on the ASO-S mission

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Research in Astronomy and Astrophysics 2019年第11期19卷 115-126页

作者： jean-claude Vial Institut d’Astrophysique Spatiale University Paris-Sud

This paper addresses the improved science resulting from joint observations performed by the different instruments onboard the Advanced Space-based Solar Observatory(ASO-S)mission along with ancillary instruments on missions flying at the same *** first describes the three major instruments along with their stated *** it presents some basic science issues concerning jointly observed flares,coronal mass ejections(CMEs)and eruptive prominences(EPs).Each physical candidate(magnetic reconnection,instability,hard X-ray emission and magnetic coronal field topology)is discussed in terms of its signature and identification with ASO-S *** importance of Lyαdetection and non-LTE modeling is *** instrumental and science challenges are briefly discussed.

关键词： techniques imagery,polarimetry-Sun eruptions,flares,coronal mass ejections

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Lanthanide-doped nanoscintillators

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Light(Science & Applications) 2022年第10期11卷 2264-2266页

作者： jean-claude Georges Bünzli institute of Chemical Sciences and Engineering Swiss Federal Institute of TechnologyLausanne(EPFL)LausanneSwitzerland Department of Biomedical Engineering Southern University of Science and Technology(SUSTech)ShenzhenChina

Lanthanide-doped nanoscintillators are taking the lead in several important fields including radiation detection,biomedicine,both at the level of diagnosis and therapy,and information encoding.

关键词： diagnosis Lanthanide ill

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G~n filling orbicular N-sided holes using periodic B-spline surfaces

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Science China(Information Sciences) 2011年第7期54卷 1383-1394页

作者： PAUL jean-claude School of Software Tsinghua University Key Laboratory for Information System Security Ministry of Education of China Tsinghua National Laboratory for Information Science and Technology Institute National de Recherche en Informatique et en Automatique

The orbicular N -sided hole filling problem is usually introduced by filleting an end-point of a part with large *** existing methods based on quadrilateral partition or constrained-optimization can rarely generate high-order continuous blending surfaces under these *** paper first reparameterizes the boundary of the specified orbicular N -sided hole to ensure the compatibility of neighboring cross-boundary derivatives on the connecting points,preserving their G n *** we compute the control points of the periodic B-spline surface using the sufficient G n continuity condition on the pole and the algorithm of extending parametric *** method generates single blending surface,which can be converted into standard Bspline surface by adding knots without introducing *** only elevates the degree of the boundary by *** construction method is simple and efficient,without iteration nor large-scale matrix *** achieves G n continuity under compatible *** blending examples underline its feasibility and practicability.

关键词： CAD periodic B-spline surface polar coordinates N -sided hole filling G n continuity

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ON MAXWELL EQUATIONS WITH THE TRANSPARENT BOUNDARY CONDITION

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Journal of Computational Mathematics 2008年第3期26卷 284-296页

作者： Zhiming Chen jean-claude Nédélec LSEC ICMSEC Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China Centre de Mathématiques Appliquées Ecole Polytechnique 91228 Palaiseau Cedex France

In this paper we show the well-posedness and stability of the Maxwell scattering problem with the transparent boundary condition. The proof depends on the well-posedness of the time-harmonic Maxwell scattering problem... 详细信息

关键词： Electromagnetic scattering Well-posedness Stability

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Ontogeny of Drosophila melanogaster female sex-appeal and cuticular hydrocarbons

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Integrative Zoology 2010年第3期5卷 272-282页

作者： Marisa ARIENTI claude ANTONY claude WICKER-THOMAS jean-Paul DELBECQUE jean-Marc JALLON University of Paris South 11 Center of Neurosciences of Paris SouthOrsayFrance Department of Biology Autonoma Metropolitan University-XochimilcoMexico DFMexico EMBL HeidelbergGermany LEGS CNRSGif sur YvetteFrance University of Bordeaux 1 Center of Integrative and Cognitive NeurosciencesTalenceFrance

The chemical communication system in Drosophila melanogaster Meigen,1830 plays a major role in courtship and consists of the male-specific cis-Vaccenyl acetate and sex-specific contact pheromones,cuticular hydrocarbons(CHC),which build up during ontogeny(first 4 days).They replace longer CHCs,common to both sexes and present only after the imaginal eclosion.A detailed quantitative description of the evolution of cuticular unsaturated hydrocarbons with age is presented here for males and females of different *** strains,which have been bred in well controlled *** appear in both sexes at around 12 h,before female *** present paper argues that this is likely linked to the switching on of a new set of ***,which is more abundant in females than in males during this critical period,might control this *** behavioral studies show that whereas female of all ages trigger early mature male courtship steps like wing vibration,only females older than 1 day trigger late courtship steps like attempted *** supports the hypothesis that late male courtship steps might be triggered by the CHCs,which build up after this age,especially female-specific(Z,Z)-7,11-and(Z,Z)-5,9-dienes.

关键词： contact pheromones Drosophila melanogaster ecdysone control ontogeny sex differences

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