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Improving the Stability of the Inflatable Soil of Diamniadio by Using Typha Australis in Order to Value It in Partitioning Wall

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Journal of Building Construction and Planning Research 2020年第4期8卷 273-284页

作者： Ahmadou diop Macodou Thiam mamadou Babacar Ndiaye Oumar Diallo Harouna mamadou Bal Salif Gaye Laboratory of Materials and Energetics (LME) University Institute of Technology (IUT) Thiès Senegal

The construction industry in Senegal is experiencing an upsurge in the development of residential housing units and administrative buildings within the new Diamniadio municipality, an area located just about 35 km from the capital city of Dakar. Laboratory oedometer or expansive-index tests, however, show poor density and compromised shear strength in the soil samples within the area -posing serious construction problems due to significant volume changes (swellings) that occur when subjected to moisture, thus, bringing into question the structural performance integrity of the soil, and the financial implications of substitute soil types used to compensate for its poor tensile strength. By way, the companies collect the soil of this location (Diamniadio) and throw it to make pile or micro-pile (pious) for their structures. This article demonstrates how we can value the soil of Diamniadio and the Typha Australis in residential building with a reasonable cost. Typha Australis is a plant generally luxuriant within the northern and central belts of Senegal but also known for its negative ecological impacts on the agricultural production of rice. The valorisation of the soil of Diamniadio will pass by the ability to increase its stability or to decrease its shrinkage/swelling rate. When we achieve it, the soil associate with Typha Australis will be used for small bricks which can be useful for partition wall and so the soil will not be ever thrown as a non-useful material. Tests results of soil specimens extracted from the site show a shrinkage rate of 29.19% with estimated cracking depths of 3.5 cm. But by adding gradually Typha Australis, the shrinkage rate will pass from 29.19% to 5.13% with the material treats with 10% by mass of Typha Australis. Moreover, the crackings in the cylindrical specimen disappear. That shows the increase of the stability;thus the composition will be used for building bricks. However, the densities will also be affected by the presence of Ty

关键词： Buildings Clay Cracking Fine Particle Shrinkage Rate Stabilization Typha Australis Valorisation

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Solar Controller with Automatic Search Technology for the Maximum Power Point with Autonomy Display

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Energy and Power Engineering 2022年第9期14卷 509-522页

作者： mamadou Sall Ousmane Sow Sega Gueye Gora diop Lemrabott Habiboullah mamadou Wade Gregoire Sissoko Ecole Polytechnique de Thiè s Thi&egrave s S&eacute né gal Institut Universitaire de Technologie. Université Iba Der THIAM de Thi&egrave s S&eacute né gal Groupe International de Recherche en Energie Renouvelable(GIRER) Dakar S&eacute né gal Ecole Supérieure Multinationale de Té lé communication Dakar S&eacute né gal

In our work, we have been interested in conducting technological research on the use of photovoltaic energy for lighting. In fact, we have produced a stand-alone photovoltaic system with automatic search for the maximum power point, consisting of a photovoltaic module, a solar regulator, a storage battery and a digital control by microcontroller. The solar field is connected to the input of the regulator and the battery to its output. When the battery voltage is lower than the regulation voltage, the controller operates the photovoltaic generator at maximum power Pmpp and transfers this power to the output. In addition to the protection function, this regulator ensures tracking of the maximum power point (MPPT) and allows the photovoltaic generator to deliver its power whatever the variation of climatic conditions (sunshine and temperature). The main role of the solar regulator is the continuous monitoring of the state of charge of the battery to ensure its protection against overcharging and excessive discharging, the coupling and decoupling of the user as well as its maintenance. The principle of operation is based on controlling a DC-DC converter by a rectangular “PWM” signal generated by a PIC16F874 microcontroller which also controls the entire system. The results of simulation after realization were presented to illustrate the operation of the regulator by curves.

关键词： Index Terms-Battery Charge/Discharge Regulator PIC16FC874

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Trend and Return Level Analysis of Extreme Rainfalls in Senegal

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Journal of Water Resource and Protection 2022年第3期14卷 221-237页

作者： mamadou Sarr Mahamat Adoum Moussa El Hadji Deme Bouya diop Laboratoire des Sciences de l’Atmosphère et des Océans Matériaux-Energies-Dispositifs (LSAOMED) Université Gaston Berger Saint-Louis Sénégal Ecole Nationale Supérieur des TIC (ENASTIC) N’Djamena Tchad Laboratoire d’Etudes et de Recherches en Statistique et Développement (LERSTAD) Université Gaston Berger Saint-Louis Sénégal

In recent years, Senegal has been confronted with increasingly frequent and damaging extreme events. In the context of climate change, we conducted this study to characterize the trends of rainfall extremes in Senegal. In this work, we used daily rainfall data from 27 stations in Senegal from the period 1951 to 2005 (55 years). To study their linear trends, non-stationary extreme value models with time as a covariate are fitted to evaluate them. Our results indicate a decreasing trend of extreme rainfalls at most of the stations except for 5 stations. However, the decreasing trends are only significant for two stations (Thiès and Kidira), however, this can only be taken as information that climate change may have already impacted extreme rainfalls. For the 20-year and 30-year return periods, the results show that they have undergone changes, in fact for almost all stations, the trends in return periods are decreasing.

关键词： Climate Change Extreme Rainfall Rain Trend Return Level Senegal

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Development and Application of Water Quality Index (WQI) for the Evaluation of the Physico-Chemical Quality of Groundwater in Gold Mining Areas of Southeastern Senegal

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Journal of Water Resource and Protection 2023年第2期15卷 33-50页

作者： Mor diop Ibrahima Mall El Hadji mamadou Sonko Tidiane diop Liengsy Badji Cheikh Mbow Environmental Sciences Institute (ISE) Cheikh Anta Diop University Dakar Senegal Amadou Mahtar Mbow University of Diamniadio (UAM) Dakar Senegal Department of Chemical Cheikh Anta Diop University Dakar Senegal Faculty of Medicine Pharmacy and Dentistry Cheikh Anta Diop University Dakar Senegal

Water is the most essential requirement for life. It provides a variety of purposes such as a source of water supply for drinking, domestic and industrial use, irrigated agriculture, livestock, and mining activities. Evaluating the status of water quality from traditional approaches does not guarantee the whole overview of the water quality situation. Therefore, developing a tool that can convert multiple parameters data into information that is understandable by both technical and non-technical personnel is vital. In this context, the purpose of this paper was to develop, calculate, and apply a water quality index for assessing the suitability (for drinking purposes) of groundwater in the gold mining areas in south-eastern Senegal. The development of this index based on WHO water quality guidelines followed the five standards steps i.e., parameters selection, sub-index formation, parameters weighting and sub-index aggregation and evaluation. Finally, the WQI summarized twelve key water quality parameters into 05 simple terms (excellent, good, medium, poor, and very poor) which is more relevant for reporting to managers and the public in a consistent manner. Thus, it was observed in the study area, that the water quality indexes in artisanal and industrial mining areas are either poor or very poor while in the reference stations (where there are no mining activities) WQI are either good or excellent. This situation was attributed to the effects of mining activities in such zones which contribute to the pollution of groundwater with heavy metals, nitrates, and suspended solids.

关键词： Water Quality Index Groundwater Gold Mining Pollution Heavy Metals

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Dust Source, Vertical Profile and Climate Impact by RegCM3 Regional Climate Model over West Africa during 2006

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Atmospheric and Climate Sciences 2020年第2期10卷 206-219页

作者： Dialo diop Demba Ndao Niang mamadou Simina Drame Abdoulaye Ba Département de Physique Faculté des Sciences et Techniques Université Cheikh Anta Diop de Dakar Dakar Sénégal Laboratoire de Physique de l’atmosphère et de l’Océan Siméon Fongang Université Cheikh Anta Diop Dakar Sénégal

This study aims to evaluate dust impact on climate parameters over the Sahel region by RegCM3 regional model during 2006. Indeed, aerosols are one of the main uncertainties in climate models. The aerosol optical depth (AOD) derived from RegCM3 model has been validated with various observed datasets. The aerosol sources are identified over North Algeria and East of Sahel (Bodele depression). Discrepancies are noted when considering dust temporal and spatial distribution. Dust season extends between March and October, with two peaks of AOD recorded in March (spring) and June (summer). The dust vertical distribution showed that the mineral aerosol layer is located between 850 hPa and 300 hPa (1.5 km to 7 km). The RegCM3 model simulates fairly well the transport in the upper layers, especially in the Saharan Air Layer (SAL) during the summer. However, RegCM3 simulates poorly the transport and sedimentation of particles in the lower layers (below 2 km). The investigation of dust radiative impact shows a general cooling. The maximum of radiative forcing is located around 18°N - 20°N, with values of about -80 W/m2 in June - August (JJA) and -40 W/m2 at the surface during March - May (MAM). This study also showed the indirect effect of dust with a decrease in precipitation about -0.7 mm/day around 15 - 20°N during the rainy season.

关键词： Dust RegCM3 Sahel Lidar AERONET Temperature Rainfall West Africa

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Profile of Autoimmune Polyendocrinopathies at the Medical Clinic II of the Abass Ndao Hospital: About 40 Cases

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Open Journal of Internal Medicine 2024年第1期14卷 74-82页

作者： Michel Assane Ndour Djiby Sow Mouhamed Dieng Ibrahima Mané Diallo Boundia Djiba Mélaine Honorine Olympio Julie Borges Preira Muriel Diembou Fatou Kiné Gadji Fama Ndiaye El Hadj mamadou Moussa Thioye Charles Halim Demba Diédhiou Anna Sarr Maïmouna Ndour Mbaye Abass Ndao Hospital Internal Medicine Department Cheikh Anta Diop University Dakar Senegal Aristide Le Dantec Hospital Internal Medicine Department Cheikh Anta Diop University Dakar Senegal

Introduction: Autoimmune polyendocrinopathies (AP) represent a group of rare concomitant pathologies, making them underdiagnosed. The objective was to study their profile at the Medical Clinic II of the Abass Ndao Hospital. Patients and Methods: This was an observational, descriptive and analytical study, lasting 24 months, from January 1, 2020 to December 31, 2022. We assessed the epidemiological, clinical and paraclinical characteristics of the patients and classified the APs found. Results: We included 40 patients divided into type III (38 cases) and IV (2 cases). A female predominance was noted with a sex ratio of 0.21. The mean age was 38.6 years. A family history of component diseases of autoimmune polyendocrine syndrome (APS) was found in 62.5%. Goiter (80%) was the main clinical sign present. All 38 patients with ISAP-3 had autoimmune thyroiditis, including 29 cases of Graves’ disease (72.5%) and 9 cases of Hashimoto’s thyroiditis (22.5%). They were associated with either type 1 diabetes (57.9%), Biermer’s disease (21.1%), vitiligo + alopecia (18.4%), lupus (2.6%). The 2 patients with AP-4 had Biermer’s disease associated with either Addison’s disease or type 1 diabetes. Management depended on the pathologies present and their possible complications. The immunological phenomena were also controlled. Conclusion: This series is globally similar to the literature. The polymorphous character of the clinical pictures requires a better collaboration between specialists leading to a clinical and holistic synthesis.

关键词： APS Biermer Graves’ Disease Hashimoto’s Addison’s Vitiligo Senegal

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Establishment of Local Diagnostic Reference Levels in Conventional Radiography: A Pilot Study in Dakar, Senegal

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World Journal of Nuclear Science and Technology 2022年第1期12卷 28-42页

作者： Adji Yaram diop Magatte Diagne Ndeye Arame Boye Faye mamadou Moustapha Dieng Cheikh Anta diop University of Dakar Dakar Senegal Aristide Le Dantec Hospital Joliot Curie Institute of Cancer Dakar Senegal Nuclear Radiation Protection and Safety Authority Dakar Senegal

Diagnostic Reference Levels (DRLs) are indicators that allow assessing the quality of equipment and procedures from the point of view of the doses delivered to patients and subsequently initiate corrective actions if necessary. The purpose of this study is to encourage health professionals to investigate patient radiation doses and to determine whether those doses comply with the principles of radiation protection in medical fields so as to improve practices by reducing patient exposure without reducing clinical effectiveness. To perform this work, we have investigated patient doses for different radiological examinations from six (6) medical centers in Dakar, including the following nine routine types: chest (PA), abdomen (AP), pelvis (AP), cervical spine (AP), lumbar spine (AP, Lat), hip (AP), thoracic spine (AP, Lat). Three types of data were collected, i.e., X-ray tube machine data, patient data and output measurements. The data were analyzed statistically and the median, minimum, maximum, and third quartile values were calculated and displayed throughout boxplots graphs for all exams and medical centers. The two sigma range (95% confidence interval) was also checked. Comparison of third quartiles of Entrance Surface Dose (ESD) and Dose Area Product (DAP) by type of examination with recommended international DRLs was performed. The third quartile of ESD for pelvis (AP) and thoracic spine (AP) was up to 16% and 38% higher, respectively than their corresponding DRLs in the European Commission Report RP 180 Part 2. For all exams, except thoracic spine (lat), the third quartiles of the dose area product were higher than the corresponding DRLs in the above report. The source of dose variability between medical centers was related to many parameters such as poor radiographic techniques, lack of modern X-ray machines and adequately documented radiation protection practices. The results show the need to develop protocols for dose measurement as well as to carry

关键词： Entrance Surface Dose Diagnostic Radiology Dose Area Product Optimization X-Rays

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Assessment of a Database Management System in a Mammogram Unit of a Radiologic Department in Fann Teaching Hospital (Senegal)

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International Journal of Medical Physics, Clinical Engineering and Radiation Oncology 2017年第4期6卷 401-409页

作者： Mamour Gueye Awa Sadikh Badiane Sokhna Ba diop mamadou Ly Mame Diarra Ndiaye Gueye Abdoulaye Dione diop Abdoulaye Ndoye diop Marame Fall Gynecologic and Obstetric Clinic Aristide Le Dantec Teaching Hospital Dakar Senegal Department or Radiology Fann Teaching Hospital Dakar Senegal

Objectives: To evaluate a medical data management system of a mammogram unit in a department of Radiology. Methods: This is a qualitative and quantitative assessment study in Fann Teaching Hospital between April 2014 and June 2015 one year after its implementation. The quantitative component consisted of the audit of the database to determine the socio-demographic characteristics of patients and the results of mammograms. The qualitative component assessed users’ experience. For analysis, quantitative data were extracted and transferred to Microsoft Excel. For scale variables, we calculated the averages and extremes. For qualitative variables, we established percentages. Results: During the study period, 433 patients underwent mammograms. The average age of patients was 48 years. The completion rate maintained above 85% was below 26% in the first two months of use. As to the completeness given examinations, it was still above 83%. The results of mammogram examinations were normal in the majority of cases: 96% for the right breast and 95.2% for the left breast. All users had a favourable opinion about the database. The reasons were better work organization, comprehensiveness, accessibility and standardization of information about the patient and especially the immediate availability of statistics. For 60% of these health professionals, complaints related to the use of the software were the time-consuming of filling data. Conclusion: This study mainly describes the perception of health professionals on the computerization of radiological examinations. It offers some advantages, proposes improvements and opens avenues for reflection on the globalization of the computerization of patient records in Radiology.

关键词： Electronic Medical Records Database Mammogram Radiology Dakar

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Modelling of Photovoltaic Modules Optical Losses Due to Saharan Dust Deposition in Dakar, Senegal, West Africa

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Smart Grid and Renewable Energy 2020年第7期11卷 89-102页

作者： Dialo diop mamadou Simina Drame Moussa Diallo David Malec Dominique Mary Philippe Guillot Groupe des Laboratoires de Physique des Solides des Sciences des Matériaux (GLPSSM) Département de Physique Faculté des Sciences et Techniques (FST) Université Cheikh Anta Diop Dakar Sénégal Laboratoire de Physique de l’Atmosphère et de l’Océan Siméon Fongang Université Cheikh Anta Diop Dakar Sénégal Department of Computer Science Polytechnic Institute (ESP) Université Cheikh Anta Diop Dakar Sénégal Laboratoire Plasma et Conversion d’Energie (LAPLACE) Université de Toulouse UPS INPT CNRS Toulouse France Equipe Diagnostics de Plasmas Hors Equilibre (DPHE) Université de Toulouse INU Champollion Albi France

This study aims to evaluate the optical losses of photovoltaic modules due to Saharan dust deposition in Dakar, Senegal, West Africa. For this purpose, an air-dust-glass system is modeled to simulate optical losses in transmittance and reflectance. To do this, we have collected dust samples from Photo-Voltaic (PV) surface in Dakar area (14°42'N latitude, 17°28'W longitude), Senegal. X-ray fluorescence reveals that silicon (Si), iron (Fe), calcium (Ca) and potassium (K) mainly composed these dust samples. Then, dust refractive indices obtained from an ellipsometer were used as an input to be used in the model. Simulations show that for radiation (at normal incidence) arriving on a dust layer of 30 μm-thick (corresponding to a dust deposit of 1.63 g/m2), 79% of the visible spectrum is transmitted; 19% is reflected and 2% is absorbed. Overall, the transmittance decreases by more than 50% as of dust layer of 70 μm-thick corresponding to a dust deposit of 3.3 g/m2.

关键词： Dust Characterization Modeling Ellipsometry PV Transmittance Solar Panel Spin Coating X-Ray Fluorescence

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Solar Photocatalysis of A Pesticide in A Tubular Reactor on Titaniferous Sand as A New Semi-Conductor

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Advances in Chemical Engineering and Science 2023年第2期13卷 119-131页

作者： El Hadji Moussa diop Kalidou Ba mamadou Faye Alpha Ousmane Toure Falilou Mbacké Sambe Water Energy Environment and Industrial Processes Laboratory (LE3PI) Higher Polytechnic/Cheikh Anta Diop University Dakar Senegal School of Industrial and Biological Engineering Dakar Senegal

This present study comes in addition to overcome the problems of separation of fine particles of TiO2 in heterogeneous photocatalysis after treatment. It aims to show the potential for using titaniferous sand as a new semiconductor under solar irradiation. The photocatalytic efficiency of this titaniferous sand was tested on a pesticide (Azadirachtin). A tubular photocatalytic reactor with recirculation of the polluting solution was designed for the elimination of the pesticide in an aqueous solution. Before its use as a photocatalyst, the titaniferous sand has undergone a specific treatment that consists of calcination at 600℃ followed by extraction of the calcined natural organic materials, which can interfere with the measurement of analytical parameters such as COD. The titaniferous sand was also characterized by X-ray fluorescence spectroscopy (XRF). XRF analyses have shown that TiO2 is predominant in the titaniferous sand with a percentage that has been estimated at 46.34%. The influence of various experimental parameters such as the flow rate of the polluting solution, the concentration of titaniferous sand, the presence of oxygen and the intensity of the overall rate of sunshine, was studied to optimize the photocatalytic degradation of the pesticide. The results showed that the highest removal rate (70%) was observed under the following conditions: a pH of 6, a titaniferous sand concentration of 150 g/L, a flow rate of 0.3 mL/min, and a sunshine rate of 354 W/m2 and in the presence of atmospheric oxygen. Under these experimental conditions, the rate of photodegradation of the pesticide follows the pseudo first order kinetic model of Langmuir Hinshelwood with a coefficient of determination R2 of 0.9869 and an apparent rate constant of 0.0029 min-1. The results clearly demonstrated the potential of titaniferous sand as a photocatalyst sensitive to sunlight for the effective removal of pesticides in the aq

关键词： Solar Energy Heterogeneous Photocatalysis Sand Titaniferous Titanium Dioxide Pesticide

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