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Evolution of the Deflection According to Truck Overloading—Comparison between Benkelman Beam Method and FEM of Lateritic Pavements

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Open Journal of Civil Engineering 2018年第4期8卷 478-488页

作者： Fatou Samb Ndiassé Diop Baye Birane thiam Makhaly Ba Laboratoire de Mécanique et de Modélisation UFR Sciences de l’Ingénieur Université de Thiès Thiès Sénégal

The study of the deflection due to the passage of an axle on a pavement structure has the advantage to make possible to pronounce on the portance, the rigidity and the homogeneity of this one. In the case where the allowed axle load is not respected, surface deflection leads to premature deterioration of the roadway. In order to study the evolution of these deformations, deflection measurements were made by using the Benkelman method in the Fatick-Kaolack road in Senegal by varying the axle load with the following values: 10, 13 and 16 tons on three different zones. The results show a linear evolution of the deflection as a function of the axle load. Also, the impact of truck overloading was studied by considering different values of the axle load with comparison to the allowed axle load by using frequent types of vehicle. A numerical simulation of the Cast3M pavement was done first, in the case of an isolated single wheel with a radius of 12.5 cm, then in the case of an equivalent dual wheel with a radius of 18.1 cm for loads of 10 to 19 tons. In the same way, the pavement design software (ALIZE) is used to analyse the variation of the axle load. The results show a linear evolution of the deflection, which corroborates the measurements made in the field and those obtained by Samb (2014) with a slope coefficient equal to 1.7. Nevertheless, the case of an isolated single wheel of 12.5 cm radius is closest to the measurements with a straight line of slope coefficient equal to 1.9.

关键词： Deflection Axle Overload Truck Overloading Cast3M ALIZE FEM Lateritic Gravel

Comparative and Prospective Evaluation of the Carbon Potential of the Mangrove of the Sine-Saloum Delta (Senegal) from 2016 to 2021

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American Journal of Plant Sciences 2023年第9期14卷 994-1008页

作者： Salimata Mouhamad Diop Massamba.thiam Ousmane Ndiaye Saliou Ndiaye Cherif Cisse Ecole Nationale Supérieure d’Agriculture Université Iba Der Thiam de Thiès Thiès Senegal Direction des Eaux et Forêts Chasses et Conservation des Sols Dakar Senegal Association Pour la Promotion des Initiatives Locales Dakar Senegal

With the rupture of the Sangomar spit and climate change, ecosystem functions such as carbon absorption and storage by the Saloum Delta Biosphere Reserve are threatened. Initiatives are carried out as a response to the degradation of the mangrove ecosystem, such as the PRECEMA project. To measure its impact, an assessment of the carbon potential of the mangrove was conducted in 2016 on permanent plots. The present study is part of the monitoring of carbon potential. It aims to contribute to the updating of information on the evaluation of carbon storage potential. The method “afforestation and reforestation of degraded mangrove habitats on a large scale CDM or AR-AM0014 version 04.0” was applied. The mangrove vegetation assessed is dominated by Rhizophora racemosa with 69.9% of the total. With a relatively bushy habit (height = 1.91 m), the height distribution shows a right skewness (Skewness = 2.17;Kurtosis = 4.07) with a tail containing more observations than a normal distribution. The distribution is observed for diameters is skewed with Skewness = 1.5 but Kurtosis = 2.3. Thus the stand is young with an average diameter of 3.90 cm and 79.6% of the trees have a diameter 5 cm. The annual increase in carbon potential of the mangrove has decreased by 80% in 5 years (2016 assessment - 2021 assessment). For a 15-year period, the total carbon stock projected by the model increases globally from 201.396 TeqCO2 in 2011 to 277,318 TeqCO2 in 2026. The projections showed an overall annual stock decrease of 14,164 TeqCO2 (94%). For 2021, the total projected stock (270.289 TeqCO2) is slightly higher than the assessed stock (251.059 TeqCO2), a difference of 7%. Also, the projected annual carbon stock for 2021 (2844 TeqCO2) is higher than the assessed stock (1353 TeqCO2), a gap of 52%.

关键词： Carbon Sequestration Mangrove Forest Sangomar

Zeta Potential of Aggregate and Dynamic Modulus of HMA Estimation Using Aggregate Silica Content

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Open Journal of Civil Engineering 2023年第1期13卷 35-47页

作者： Mouhamed Lamine Chérif Aidara Serigne Touba.thiam Alan Carter Department of Geology Faculty of Science and Technology Cheikh Anta DIOP University of Dakar Dakar Senegal Graduate School of Sustainable Development and Society Iba Der Thiam University Thies Senegal Ecole de Technologie Supérieure de Montréal Montréal Canada

The mineralogical composition of an aggregate influences its adhesion with bitumen and therefore its dynamic modulus. However, few studies have been conducted on this aspect. One of the most used properties to describe the impact of aggregate on the adhesiveness phenomena is the zeta potential. In this study, the first mineralogical and chemical properties were considered through the percentage of silica in the rock source of aggregates and the electric aggregate particles charge zeta. Dynamic modulus values used for regression process are determined from complex modulus test on nine asphalt concretes mix designed with aggregate types (basalt of Diack, quartzite of Bakel and Limestone of Bandia). The results showed that aggregate with high percentage of silica have higher zeta potential than aggregate with low percentage of silica. The development of a zeta potential predictive model showed a strong sensitivity to silica. The results of the complex modulus tests showed that Hot Mixture Asphalt (HMA) mixed with aggregate containing high silica contents gave better results than those mixed with aggregates containing low percentage of silica. The dynamic modulus predictive models of HMA developed shows that it is the properties of bitumen that influence more. However, the effect of silica although low, is very marked at low temperatures and high frequencies.

关键词： Basalt of Diack Quartzite of Bakel Limestone of Bandia Complex Modulus Test Binder-Aggregate Adhesiveness

Multidisciplinary Approach for a Solution to Floods in SampathéDistrict (Thiès-Est, Senegal)

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Journal of Geographic Information System 2020年第6期12卷 663-682页

作者： Mouhamadou Moustapha Mbacké Ndour Alassane thiam Bakary Fall Ibrahima Seye Unité de Formation et de Recherches-Sciences de l’Ingénieur Université of Thiès Thiès Sénégal Centre de Suivi Ecologique Dakar Sénégal Grande Cô te Opération Sa Dakar Sénégal

In recent years (2003), Senegal has been confronted with many urban flooding problems that have become recurrent due to the configuration of its settlement. This is due to galloping population growth, climate change and a lack of planning and rainwater drainage networks. To fix these phenomena, Senegalese government has initiated rainwater drainage programs. In the city of Thiès, particularly in Sampathé district, flooding problem is a reality that is observed during every winter period. It is within this framework that we have proposed a project for the design and dimensioning of a rainwater evacuation network in Sampathé. The network will be integrated into a Geographic Information System for efficient management of project. This study involved identifying flood zones, determining geotechnical characteristics of the soil, and exploiting rainfall data in order to propose a storm water drainage network that will be integrated into a database management system. Thus, we carried out topographical and geotechnical studies, then designed and dimensioned the drainage network, and finally set up a geographic information system. At the end of this project, we designed a sewerage network consisting of two primary pipelines, four secondary pipelines, one tertiary pipeline, ninety-two manholes and a retention basin. To manage the network, we set up a geographic information system to geolocate various elements for rapid intervention in the field in event of a problem, make requests, generate thematic maps, and perform spatial analyses for good decision-making.

关键词： Flood Flooding Sewerage Network Topographic Surveys Geographic Information System Sampathé

Study of HIV Prevalence and Behaviors in Rural Areas of Goudomp Health District (Senegal)

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World Journal of AIDS 2020年第2期10卷 69-79页

作者： Niang Khadim Anne Malick Sarr Assane thiam Ousmane Ndiaye Papa Public Health Department Gaston Berger University (UGB) of Saint-Louis Saint-Louis Senegal Goudomp Health District Sedhiou Region Senegal Obstetrics and Gynecology Department Gaston Berger University (UGB) of Saint-Louis Saint-Louis Senegal

This study aims to determine the factors related to HIV-positive status in people aged 15 to 49 years of age in the commune of Niagha in Goudomp. The study was descriptive and analytically cross-cutting and had taken place in a release of 2018. The data was collected on anonymous questionnaires and then analyzed using R software after entering with Epi 7 software. Bivariate analyses and logistical modelling have been used to investigate the factors associated with HIV status. The sample included 400 people, and a participation rate of 100% was obtained in relation to the administration of the questionnaire. For the detection of HIV infection, 318 people agreed to do so, a proportion of 79.7%. The average age of the respondents was 27.8 years with a standard deviation of 9.1 and extremes of 15 to 49 years. 21.5% of respondents were under 20 years of age, the median was 26 years. With 58.8% of women, the sex ratio (M/F) was 0.7. In this study, 11.5% of respondents did not believe in the existence of HIV infection, 92.0% were sexually active, and 40.5% had sex with casual partners. The main places for casual sex were cultural events (84.0%), weekly markets (53.1%), religious events (27.8%) and during travel (22.8%). Among them, only 20 respondents, or 12.3%, declared that they systematically protect themselves with a condom during these occasional sexual relations. This wearing of condoms was found in 20.7% of singles and 10.7% of married couples having casual sex. In this study, 60.0% of the respondents declared that they had paid for sex, although this practice is not cited in income-generating activities. Non-consensual sex was found in 6.5% of the respondents. In this study, 319 people agreed to be tested for HIV, or 79.7% of the sample. HIV infection was found in 19 people, 6.0% seroprevalence, with 16 cases of HIV 1 infection and three cases of HIV 2 infection. Several risk behaviors were found in this study. However, none of them had a statistically significant

关键词： HIV Risky Behaviors IST Prevalence Senegal

Evaluation of the Influence of Plastic Waste in Improving the Mechanical Characteristics of Asphalt Mixes (Senegal, West Africa)

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Open Journal of Civil Engineering 2023年第3期13卷 517-527页

作者： Adama Dione Papa Sanou Faye Mohamadou Moustapha.thiam Birame Diouf Cheikh Diallo Achim Becker Diodio Diouf Moussa Sow Malick thiam Marème Ba National Hight School of Mining and Geology ex IST UCAD Dakar Senégal Science and Technology Department Iba Der Thiam University Thiès Senegal UFR Engineering Sciences Iba Der Thiam University of Thies Thies Senegal Speciesanalytik Laboratory Dakar Senegal Aventurin Waste ONG Bochum Germany Department of Geology UCAD Dakar Senegal Ecole Supérieure Polytechnique UCAD Dakar Senegal

The recovery of plastic waste has a positive impact on two fronts: The environment, through waste reduction, and the economy, through its use in road construction. This work involves recycling plastic variants such as Polypropylene (PP) 50% and LDPE (Low Density Polyethylene) 50% in proportions of 2% to 8%, incorporated into a 0/14 BBSG. The results of the Marshall test gave stability values ranging from 826 to 1523 kg and creep values from 5.5 to 2.45 mm. The Duriez test gave r/R values ranging from 0.769 to 0.786, with water absorption percentages from 2.24% to 0.69%. The PCG test at 80 gyrations gave void percentages ranging from 11.9% to 5.23%. The rutting test gives a rutting depth percentage that drops at 30,000 cycles from 11.5% to 1.3%. This study shows a considerable increase in the mechanical characteristics of asphalt mixes by adding plastic waste.

关键词： Plastic Waste Marshall Environmental Impact BBSG Recycling

Impact of Non-Compliance of Exposure Classes in Reinforced Concrete Structures

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Open Journal of Civil Engineering 2023年第1期13卷 25-34页

作者： Serigne Touba.thiam Mouhamed Lamine Chérif Aidara Alinté Diatta Graduate School of Sustainable Development and Society Iba Der Thiam University Thies Senegal Department of Geology Faculty of Science and Technology Cheikh Anta DIOP University of Dakar Dakar Senegal Pan-African Polytechnic Institute of Dakar Dakar Senegal

From the National Agency for the Organization and Construction of Infrastructures (ANOCI) program to the Emerging Senegal Plan (PSE), construction in Senegal has improved considerably. However, deficiencies remain in the specification of materials used mainly in hydraulic concrete. They are generally related to the specification of aggregates for alkali reactivity and the choice of exposure classes specified in NF EN 206-1. The purpose of this article is to study the incidence of non-compliance with exposure classes in reinforced concrete structures. To carry out this study, surveys were carried out at several sites (districts) in Dakar (Cité Avion, Touba Ouakam, Cité Asecna, Cité Batrain, Cité Comico, Cité Assemblée and Terme Sud) in order to collect information on the formulation and implementation methods used. The comparison of the various readings carried out made it possible to deduce conclusions and to give recommendations when using standard NF EN 206-1.

关键词： Common Exposure Classes Specific Exposure Classes Concrete Alkali-Reaction

One-Dimensional Study of Thermal Behavior of Typha Panel: Spectroscopy Characterization of Heat Exchange Coefficient on Front Face

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Journal of Sustainable Bioenergy Systems 2020年第2期10卷 52-61页

作者： Sokhna Khadidiatou Ben thiam Alassane Ba Mamadou Babacar Ndiaye Issa Diagne Youssou Traore Seydou Faye Cheikh thiam Pape Touty Traore Ablaye Fame Gregoire Sissoko Ecole Polytechnique de Thiès (EPT) Thiès Senegal University Institute of Technology University of Thiès Thiès Senegal Laboratory of Semiconductors and Solar Energy Physics Department Faculty of Science and Technology University Cheikh Anta Diop Dakar Senegal

Convective heat transfer coefficients, materializing exchanges between solid wall (here typha) and its environment, influence its behavior under excitation pulse. Temperature of wall and its density of flow vary with these coefficients according to its thickness (in depth). This study therefore focuses on the evaluation of convective heat transfer coefficient on front face and the optimal insulation thickness.

关键词： Typha Heat Transfer Coefficients Spectroscopy Optimal Insulation Thickness

Assessment of Hybrid Concentrated Solar Power-Biomass Plant Generation Potential in Sahel: Case Study of Senegal

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Natural Resources 2017年第8期8卷 531-547页

作者： Ababacar thiam Cheikh Mbow Mactar Faye Pascal Stouffs Dorothé Azilinon Efficiency and Energetic Systems Research Group Alioune Diop University Bambey Senegal Laboratoire d’Energétique Appliquée Ecole Supérieure Polytechnique Université Cheikh Anta Diop Dakar Senegal Faculté des Sciences et Technique Université Cheikh Anta Diop Dakar Senegal Latep Université de Pau et des Pays de l’Adour Pau France

Concentrating Solar Power (CSP) is non-existent in Sahel. Such a situation arises from the high investment costs required by these energy infrastructures and from a lack of information on the identification of suitable sites to accommodate them. Conversely, CSP-biomass plants due to lower investment may be an option for CSP penetration in Sahel where Direct Normal Irradiation (DNI) is between 1400 kWh/m2/year and 2000 kWh/m2/year and significant biomass potential. This work presents the results of an identification of suitable sites for hybrid CSP-Biomass in the Sahel, case study of Senegal, taking into account the Direct Normal Irradiation, the availability of water, space and biomass potential. The identified sites have a DNI > 1600 kWh/m2/year. The biogas production capacity is equivalent to 5,096,563 m3/year. The quantity of Typha Australis, invasive plant in Senegal river valley available is estimated at more than 3 million tons. The capacity of electrical energy in this zone is estimated at 6.89 GWe for an installation surface estimated at 275.61 km2. The establishment of CSP/hybrid plants can also contribute to combat the proliferation of Typha Australis.

关键词： Biomass Concentrating Solar Power (CSP) Direct Normal Irradiation (DNI) Hybrid Typha Australis