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Characteristics of Gold and Its mineralization Style in the Boulon Djounga Eastern Perimeter of Liptako mining Company (Central Southwestern Niger)

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Natural Resources 2024年第1期15卷 28-50页

作者： Gambo Ranaou Noura Kamayé Tourba Karimou dia Hantchi Bouba Hassane moussa Konaté Department of Geology Faculty of Science and Techniques Abdou Moumouni University Niamey Niger Department of Geology Faculty of Science and Techniques Dan Dicko Dankoulodo University Maradi Niger

The Boulon Djounga eastern perimeter is part of the Tiawa operating permit of the Société des mines du Liptako (SmL), located in the central southwestern part of Liptako (Niger). In this study, we used field data, Reverse Circulation (RC) surveys and chemical analyzes of gold to determine the characteristics of gold and its mineralization style. The eastern perimeter of Boulon Djounga is represented by a succession of metabasalts and metasediments both intersected by intrusions of quartz and dolerite dykes, and covered by sandstone and clayey rocks. Gold is present in low contents (0.00 - 0.30 ppm) in the sedimentary cover and in medium (0.30 - 1.00 ppm) or high contents (1.00 - 4.534 ppm) in the metasediments, and in the gray quartz veins and locally in the volcanics. It exists in a disseminated state or in a concentrated state in the surrounding areas in the form of discrete grains associated with sulphurous minerals (pyrite: FeS2, chalcopyrite: CuFeS2 or arsenopyrite: FeAsS). The presence of gold in the quartz veins, and the NE-SW and NW-SE orientations of the ore bodies suggest that the eastern Boulon Djounga gold mineralization would be established during a late magmatic extensive phase.

关键词： Liptako Gold mineralization metasediments-Volcanics Quartz Veins Sulphurous minerals Niger

The role of marine protected areas in sustaining fisheries: The case of the National Park of Banc d’Arguin, mauritania

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Aquaculture and Fisheries 2020年第5期5卷 253-264页

作者： Ewan Trégarot Beyah meissa Didier Gascuel Ousmane Sarr Yeslem El Valy Oumar Hamet Wagne Elimane Abou Kane Abou Cire Bal mohamed Saleck Haidallah Assane Deda Fall abdou daïm.dia Pierre Failler Centre for Blue Governance Portsmouth Business SchoolUniversity of PortsmouthPortsmouthUK Institut mauritanien de Recherches Océanographiques et des Peches(ImROP) NouadhibouMauritania UmR Agrocampus Ouest InraEcologie et SantédesécosystemesUniversitéEuropéenne de BretagneRennesFrance Unitéde Recherche macroéconomie Croissance et Développement(URMCD)Laboratoire EnvironnementSantéet Société(LE2S)Universitéde Nouakchott Al AasriyaNouakchottMauritania

mauritania is characterized by fast-growing fisheries that have developed over the past several decades from low levels of fishing to intense fishing and have led to severe decreases in biomass and severe signs of over*** ensure sustainable fisheries,a primary goal of science-based fisheries policy is to provide an adequate conservation status of marine habitats that are directly,or indirectly,fundamental for the lifecycle of fish populations of commercial *** National Park of Banc d’Arguin has been recognized for its nursery and fish biomass export *** this paper,we present the economic value of the fish provisioning service of marine coastal ecosystems of the protected *** estimated the added value of artisanal fisheries,the spatial distribution of fishing activities,the contribution of the Park to the mauritanian fisheries and the heritage value of artisanal ***,the average added value for artisanal fisheries is about 43 million mRU(1 million euros)over the period 2006–*** mainly benefits to the ship-owners,which generates inequalities and threatens the livelihoods of the *** spatial distribution of fishing activities and associated revenues shows high variability throughout the years,the seasons and the geographic areas,and reveals the high adaptability of Imraguen *** grounds are mostly located close to the shore,associated with seagrass beds,confirming the service of fish provisioning rendered by this ***,the high productivity of seagrass beds contributes to the spill-over of *** contribution of the Park to fishing activities that occur within the mauritanian Exclusive Economic Zone is estimated to 15%,representing an added value creation of 3.2 billion mRU(71 million euros).The heritage value of the fisheries is assessed,through fishers’willingness to accept to stop their fishing activities,at 17.5 million mRU(0.4 million euros).Thus,this paper highlights the

关键词： marine protected areas Fisheries monetary evaluation Ecosystem services West Africa National Park of Banc d’Arguin

multi-Criteria Analysis Using Remote Sensing and GIS: Insight into Groundwater Potential of the Fissured Aquifers in the Liptako Socle (Southwestern Niger)

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Journal of Water Resource and Protection 2021年第11期13卷 881-899页

作者： maman Sani abdou Babaye Karimou dia Hantchi Ibrahim Wagani Boukari Issoufou Ousmane Issoufou Sandao Department of Geology UMR SERMUG Faculty of Science and Techniques Dan Dicko Dankoulodo University Maradi Niger Department of Geology Faculty of Science and Techniques Abdou Moumouni University Niamey Niger

In the basement of southwestern Niger, weathering and fractured zones concentrate most of the groundwater. This study focuses on fractured m.dia and aims to identify areas of productivity in this aquifer to improve the region’s water coverage. The cartographic approach developed made it possible to establish synthetic maps based on multi-criteria analysis. The hydrogeological parameters selected include fracturing data, drainage system, slope and piezometric level as well as shallow and deep lithology. The choice of these criteria is based on their physical meaning but also on the availability of data. The integration of all the criteria in a GIS allowed to generate maps of recharge and potential productivity of fractured aquifers in the area. The validation of these thematic maps with independent data confirms their utility as reference standards for accessibility for future resource exploitation. Like any spatialization tool, potential recharge maps will provide valuable information about areas where infiltration is more important, and help control and manage risk zoning. The upward evacuation effect is even more prominent along the lineaments, faults or fractures: thus, to avoid possible pollution and to locate the future hydraulic structures, the analysis of the potential recharge zones remains necessary. The potential productivity index map, in addition to the very punctual sites identified by the fracturing study, made it possible to define areas of high potential productivity.

关键词： multi-Criteria Analysis Fissured Aquifers Productivity Groundwater Potential Niger

Comparative morphometry of the <i>Sitophilus zeamais</i>motschulsky Populations (Coleoptera: Curculionidae) Infesting Yellow maize in Four West African Countries

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Advances in Entomology 2022年第1期10卷 85-98页

作者： Adiouma Georges Robert Jacques Sarr Cheikh abdou Khadre mbacké dia Tofféne Diome Pape mbacké Sembene Entomology and Acarology Laboratory Animal Biology Department Faculty of Sciences and Techniques Cheikh Anta Diop University of Dakar Dakar Senegal

Sitophilus zeamais is a primary pest of stored maize, which can cause quality and quantity losses. maize is cultivated in several West African countries where different agro-climatic and agro-ecological conditions exi... 详细信息

Sitophilus zeamais is a primary pest of stored maize, which can cause quality and quantity losses. Maize is cultivated in several West African countries where different agro-climatic and agro-ecological conditions exist. These conditions could influence the Sitophilus zeamais morphology. Thus, the purpose of this study is to identify the Sitophilus zeamais morphological groups in the four countries. This was carried out through the morphometric study of 30 male Sitophilus zeamais individuals taken from the yellow maize in each country, by measuring with a binocular magnifying glass, 16 variables of the different tagmas belonging to the insect. Subsequently, statistical analyses were firstly carried out with the raw measurements, such as the principal component analysis, in order to extract the contribution of the variables on each factorial axis and to visualise the correlations between the variables. Taking the case of the transformed measurements, in addition to the principal component analysis, a discriminant factorial analysis was carried out to find out the best factor for gathering individuals according to their morphology, a confusion matrix to summarise the individualdana;">dana;">mily

关键词： morphological Groups Sitophilus zeamais maize

Environmental Factors, Constraints and Risks of Rainwater Runoff in Commune II of maradi (Republic of Niger)

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Open Journal of modern Hydrology 2023年第4期13卷 211-228页

作者： maman Sani abdou Babaye Karimou dia Hantchi abdoulkader moussa Issaka Ousmane Laminou manzo Yahaya Saadou Labo Choukouriya Laouali Sannoussi moussa Konaté Department of Geology Faculty of Science and Techniques Dan Dicko Dankoulodo University Maradi Niger Department of Earth and Environmental Sciences Faculty of Science and Techniques André Salifou University Zinder Niger Department of Rural Engineering and Water & Forests Faculty of Agronomy and Environmental Sciences Dan Dicko Dankoulodo University Maradi Niger Department of Geology Faculty of Science and Techniques Abdou Moumouni University Niamey Niger

The Urban Commune of maradi in Niger experienced increasingly frequent flooding following rainy episodes generating volumes and water flows that are difficult to control in recent years. This study aims to determine the impacts of runoff water in Commune II of maradi City and to assess the role of urban planning in runoff management, as well as the strengths and weaknesses of urban sanitation in maradi. The methodological approach used consisted of: 1) an interpretation of documentary data, 2) gathering information on runoff at several sites in the study area, and 3) interviews and questionnaires with local communities. This approach made it possible to understand the degree of vulnerability of the populations to flooding and then to propose sustainable solutions to reduce the vulnerability of the affected populations, through the implementation of effective urban rainwater management practices (USWmP). The results show that the impacts of runoff are mainly related to the lack of adequate storm water drainage networks in the area, but also to the nature of the habitats. Geomorphological factors such as the nature of the soil, the slope of the terrain and the altitude increase the degree of risk. In addition, the inadequacy and dilapidation of the drainage systems of the canals and above all the anarchic occupation of the land linked to accelerated urbanization are the cause of flooding by stagnation of rainwater. A phenomenon now linked to numerous deteriorations of urban equipment, the runoff of rainwater in the city of maradi carries so many pollutants that municipalities, businesses and individuals should put in place pollution prevention measures.

关键词： Niger Storm Water Impermeable Spaces Urban Runoff Flood Vulnerability

metallogeny and Emplacement Conditions of Continental Terminal 3 (Ct³) Iron Formations of the Niamey Region (Western Niger)

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Open Journal of Geology 2023年第7期13卷 720-739页

作者： Habsatou Ousmane Karimou dia Hantchi Ibrahim abdou Ali Leyla Boubacar Hamidou Aminou abdoulaye maâzou Adiss Kamal Issifou Fatiou moussa Konaté Department of Geology Faculty of Science and Techniques Abdou Moumouni University Niamey Niger Department of Geology Faculty of Science and Techniques Dan Dicko Dankoulodo University Maradi Niger Department of Life and Earth Sciences école Normale Supérieure (ENS) Abdou Moumouni University Niamey Niger Department of Earth Sciences Faculty of Science and Techniques University of Abomey-Calavi Abomey-Calavi Benin

This study aims to characterize the different lithofacies of the Ct3 formation in the Niamey region, and to determine the distribution of major and trace elements, in order to highlight the conditions for the establishment of iron mineralization. A lithological column, synthesizing sections of selected outcrops in the vicinity of Niamey, was produced. The chemical compositions of the selected samples were determined by X-ray fluorescence (XRF) spectrometry. microscopic analysis of the thin sections determined the gœthitic nature of the oolitic iron ore. The oolites show a quartz, limonitic or gœthitic nucleus. Sometimes the nucleus is absent. From a morphoscopic point of view, two types of oolites have been distinguished: spherical-shaped and ellipsoidal-shaped oolites. The oolites are either contiguous or disseminated, as the case may be, in a limonitic to goethitic cement or in a fine sandstone matrix. The larger oolites (pisolites) are relatively friable. They reflect the influence of a relatively turbulent to submerged environment. The hardground of the iron mineralized horizons are covered by quartz grains. They are indicative of a submerged or emergent environment. X-ray fluorescence analysis shows high Fe2O3 contents (50% to 80%) and variable contents of major elements SiO2, Al2O3, TiO2, mnO, mgO, CaO, K2O and P2O5 associated with certain trace elements such as Th, U, V, Y, Zn, Zr and As. The results of the study are an important tool for decision-makers to adopt effective prevention/rem.diation measures for groundwater contamination in the Continental terminal aquifer systems.

关键词： Continental Terminal Iron Ore mineralization Sedimentation Conditions Oolites Gœthites Hardground

Optimization of Electrics Parameters CdS/CdTe Thin Film Solar Cell Using Dielectric model

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World Journal of Condensed matter Physics 2016年第2期6卷 75-86页

作者： Oumar Absatou Niasse mahamadou abdou Tankari Fatou dia Nacire mbengue Amadou diao mamadou Niane moulaye diagne Bassirou Ba Gilles Levebvre Laboratory of Semiconductors and Solar Energy Faculty of Sciences and Technologies University Cheikh Anta Diop of Dakar Dakar Senegal University Paris-Creteil Centre for Studies and Research in Thermal Environment and Systems (CERTES EA 3481) Paris France

Abstract *Corresponding author. In this paper, the electrical properties of heterojunction solar cells thin film n-CdS/p-CdTe from dielectric model have been studied. Based on the expression of the minority, carriers density in the p-CdTe base of solar cell, the photocurrent density and that of the photo voltage are determined according to the cell dimensions, doping levels, the absorption coefficient, the solar irradiance and the temperature, etc. Fitting using mathcad and Origin Lab software on the photocurrent and the photovoltage of the n-CdS/p-CdTe enabled to determine the series, shunt resistance and the maximum power point. The results obtained, in good agreement with experimental results, allow operating simulations for optimizing maximum outputs parameters (Ip, Vp). Thereafter, it is proposed a type of photovoltaic generator module with a good command of the design parameters for better efficiency.

关键词： Solar Cells Heterojunction Series Resistance Shunt Resistance maximum Power Point Irradiation Temperature

Stroke (Cerebrovascular Accident): Epidemiological, Clinical and Evolving Aspects in the Internal medicine Department of the Public Health Establishment 1 (EPS1) of Tivaouane

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Open Journal of Internal medicine 2023年第4期13卷 313-329页

作者： Fulgence abdou Faye Bachir mansour diallo Awa Ba Amina dia Guèye abdou Khadre mbaye Zeinabou marone Adama Berthé Papa Soulèyemane Touré madoky magatte Diop Bernard marcel Diop mamadou mourtalla Ka UFR of Health Sciences Alioune Diop University of Bambey Bambey Senegal Department of Internal medicine Regional Hospital Heinrich Lucké of Diourbel Diourbel Senegal Department of Internal medicine Abdou Aziz Sy Dabakh Hospital Tivaouane Senegal Internal medicine Department Regional Hospital of Thiès Thiès Senegal UFR of Health Sciences Iba Der Thiam University of Thiès Thiès Senegal

Introduction: The frequency, severity, cost of treatment, morbidity and mortality of stroke make it a real public health problem. In industrialized countries, strokes are the leading cause of physical disability in adults, the second leading cause of dementia (after Alzheimer’s disease), and the third leading cause of death (after cancer and cardiovascular disease). It’s also a major cause of depression. The objective of our study was to describe the epidemiological, clinical and evolutionary aspects of stroke in the internal medicine department of Tivaouane Hospital. material and method: This is a retrospective study carried out from January 1, 2015 to December 31, 2018 on the files of patients hospitalized for stroke in the medical department of the EPS1 in Tivaouane. We took into account all the patients who had a brain CT (computed tomography) scan. We collected data related to socio-demographic characteristics, history, risk factors, reasons for admission, clinical signs, paraclinical examinations, as well as evolution. Results: Out of 1999 patients, 206 files of patients with stroke were collected, i.e. a proportion of 10.3%. Our study population had a mean age of 65.53 years [16 - 97 years]. We noted a clear predominance of women (50.5%). The majority of the population came from the outskirts of Tivaouane (56.7%). Risk factors for stroke were dominated by hypertension (90.3%), dyslipidemia (19.4%), previous stroke (18.9%), and diabetes (16%). The clinical signs were dominated by a motor deficit (94.1%), speech disorders (67.4%) and consciousness disorders (47%). Ischemic strokes were predominant (65%) over hemorrhagic strokes (34.5%). The outcome was generally unfavorable with 14.6% total recovery, 58.7% recovery with sequelae and a case fatality of 26.7%. Conclusion: It emerges from this study that strokes still remain a real public health problem. Knowledge of populations of risk factors as well as their proper management is fundamental in primary preventio

关键词： Cerebrovascular Accident Epidemiology Risk Factors Tivaouane EPS1

Epidemiological Profile of Autoimmune Diseases in Thiès, Senegal: About a Descriptive Observational Study over 11 Years in 2 Internal medicine Departments and a Dermatology Department

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Open Journal of Internal medicine 2023年第3期13卷 162-172页

作者： Faye Fulgence abdou Bammo mariama Guèye Amina dia Elame Hugues diallo Bachir Berthé Adama Dioussé Pauline Touré Papa Souleymane Diop madoky magate Diop Bernard marcel Ka mamadou mourtala Training and Research Unit of Health Sciences Alioune Diop University of Bambey Bambey Senegal Training and Research Unit of Health Sciences Iba Der Thiam University Thiès Senegal Department of Internal medicine Regional Hospital Thiès Senegal Department of Dermatology Regional and University Hospital Thiès Senegal Department of Internal medicine Abdou Aziz SyDabakh Hospital Tivaouane Senegal Department of Internal medicine Saint Jean de Dieu of Thiès Hospital Thiès Senegal

Introduction: Autoimmune diseases are characterized by a very large clinical polymorphism that can lead to a diagnostic wandering. So, we aimed to determine their epidemiological profile outside the context of dakar (capital of Senegal) where the technical plateau is more elevated. methodology: We conducted a retrospective descriptive and observational study from January 1, 2007 to December 31, 2017. All patients admitted or followed in outpatient in the Internal medicine departments of the Saint Jean de Dieu and Regional Hospitals of Thiès as well as in the dermatology department of the CHRT (Regional Hospital Center of Thiès), and who met the mAI criteria (autoimmune diseases) have been included. The data were collected on a standardised sheet and analysed by EPI INFO version 7.2. Results: A total of 121 patients were included out of 25951 records i.e a prevalence of 0.46% in internal medicine departments. In dermatology, out of 31973 patients, 95 had mAIS (systemic autoimmune diseases): 0.29% as hospital prevalence. The average age was 40.7 years in internal medicine departments compared to 37.66 years 14.8 years in the dermatology department. Patients aged 30 to 59 years represented 57.89% of the study population. The sex ratio (H/F) was 0.3 in the internal medicine departments compared to 0.17 in the dermatology department. Circumstances of discovery were incidental in 16.52% and clinical in 3.30%. Biermer disease accounted for 29.75% of organ-specific mAI. Concerning systemic presentations, rheumatoid arthritis (RA) was present in 23.14%. Lupus was more representative in dermatology (65.2%) as well as systemic scleroderma (21%), dermatomyositis (6.3%). Cytopenia was found in 105 patients, showing in detail anemia (42.9%);leukopenia (14.8%);thrombocytopenia (2.4%). Autoantibodies were tested in 58 patients (47.9%). Skin histology was contributory in all cases of systemic scleroderma and in 5 cases of lupus. The main therapy prescribed was corticosteroid therapy

关键词： Systemic Autoimmune Diseases Internal medicine Dermatology Senegal