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UV/Vis Characterization and Fate of Organic Amendment Fractions in a Dune Soil in Dakar, Senegal

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Pedosphere 2015年第3期25卷 372-385页

作者： Silwan DAOUK Mohammad HASSOUNA Anne gueye-GIRARDET Seydou NIANG Hans-Rudolf PFEIFER Institute of Earth Sciences Faculty of Geosciences and Environment(FGSE)University of Lausanne Laboratory of Wastewater Treatment Fundamental Institute of North Africa (IFAN)Cheikh Anta Diop University of Dakar

The application of organic amendments on soils poor in organic matter(OM) can improve long-term soil fertility, but may also enhance the mineralization of native soil organic matter. Three organic amendments, compost, sewage sludge and horse manure, used by urban market gardeners in Dakar, Senegal were analyzed for their OM maturity. Their fate was evaluated in a 45-d agronomic trial in a sandy Arenosol with lettuce. In each case, water-extractable organic matter(WEOM) and humic-like substances(HLS)were isolated from raw amendments and amended soils, and characterized using ultraviolet-visible(UV/Vis) spectroscopy. Results highlighted the general more aromatic character of HLS and WEOM fractions extracted from compost compared to the other two amendments. When applied to soils, however, these differences were not clearly observed. The aromaticity and humification degree of the labile fraction(WEOM) increased with depth in the first 30 cm for all amendments. This indicated the high lixiviation rates that fresh OM underwent in the studied sandy soil. Finally, a statistical analysis of the results was able to discriminate between surface and deeper horizons and between amended- and non-amended soil samples. Spectroscopic indices showed indeed strong increase/decrease with depth linked with the mineralization/humification processes that the fresh OM from amendments underwent during the 45 d of the agronomic trial. This study highlights the potential of spectroscopic techniques to study agricultural amendment organic matter fractions and their fate in soils.

关键词： absorbance spectroscopy compost fluorescence spectroscopy horse manure humic-like substances sewage sludge,water-extractable organic matter

Type 2 diabetes in a Senegalese rural area

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World Journal of Diabetes 2017年第7期8卷 351-357页

作者： Priscilla Duboz Gilles Boetsch Lamine gueye Enguerran Macia UMI 3189 Environnement Santé Sociétés CNRS/Université Cheikh Anta Diop/Université Gaston Berger/USTTB/CNRST International Human-Environment Observatory Tessekere Faculté de Médecine de Dakar Université Cheikh Anta Diop UMI 3189 Environnement Santé Sociétés CNRS/Université Cheikh Anta Diop/Université Gaston Berger/USTTB/CNRST Faculté de Médecine de Dakar Université Cheikh Anta Diop

AIM To estimate the prevalence of diabetes in the rural population of Tessekere(Senegal) and investigate associated risk factors. METHODS Data from a 2015 survey of 500 individuals age 20 and over representative of the population of the municipality of Tessekere were used. Sociodemographic characteristics, health related variables, capillary whole blood glucose, and weight and height measurements of individuals were collected during face-to-face interviews. Statistical analyses used were bivariate tests and binary logistic *** The percentage of individuals having impaired fasting glucose(IFG) is 6.6%. Those with fasting blood glucose(FBG) levels ≥ 126 mg/dL and/or currently being treated for diabetes is 4.2%. Only mean body mass index(BMI) is significantly higher among diabetic individuals and among those having FBG levels ≥ 110 mg/dL. After adjustment for sex, age, educational level, BMI and hypertension, only BMIis associated with diabetes. CONCLUSION Prevalence of diabetes and IFG in our study correspond to the high range of rural sub-Saharan Africa prevalence. Diabetes is thus becoming a pressing public health concern, even in rural areas. But the risk factors identified in Tessekere suggest that the diabetes epidemic is still in the early stages, such that concerted action would make it possible to contain the devastating impact of this chronic condition.

关键词： Anthropology Epidemiology Sub-Saharan Africa Diabetes

Characterization of the Omni-Processor Sewage Sludge Ash for Reuse as Construction Material

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Fluid Dynamics & Materials Processing 2022年第6期18卷 1581-1593页

作者： Prince Momar gueye Siham Kamali-Bernard Dame Keinde Fabrice Bernard Vincent Sambou LE3PI of E S P-UCAD DakarSenegal LGCGM of INSA of Rennes RennesFrance

Omni Processors(OP)are machines which use sludge as a fuel to generate electricity and clean water,but create ash at the same *** the present study,fly ash and bottom ash are investigated as materials for potential reuse in the construction ***,the granular size,density and Blaine finesse are ***,the chemical composition and microstructure are obtained by means of X-ray fluorescence and Scanning Electron Microscopy-Energy Dispersive Spectroscopy(SEM-EDS),***,ashes reactivity is determined by two chemical methods(modified Chapelle test,bound water content R3)and a mechanical method(pozzolanic activity index).The characterization results indicate two material types:fly ash similar to cement and bottom ash similar to fine ***’s why the mortars mechanical strength with fly ash 0%-30%is better than that with bottom ash at the same *** ash slightly decreases the mechanical strength of mortars while bottom ash induces a much more significant decrease.

关键词： Characterization Omni-processor fly Ash bottom ash

Radio Frequency Quadrupole for Bunching Electron Beam: Electromagnetic Field, Particle Velocity Range, and Accuracy at 10 GHz

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Journal of Electromagnetic Analysis and Applications 2023年第1期15卷 1-11页

作者： Serigne Bira gueye Department of Physics Faculty of Sciences and Techniques Cheikh Anta Diop University Dakar Senegal

The Radio Frequency Quadrupole (RFQ) accelerator invented by Kapchinskii and Tepliakov can focus, bunch, and accelerate charged-particle beams simultaneously. Typically, it operates at frequencies up to 500 MHz, for low particle velocities ( β ). The first attempt to design cylindrical RFQ for electrons in the GHz region was done using 3 GHz at Frascati in 1990. In this paper, an analytical approximation of the electromagnetic field is given, and linearized in the beam region for a rectangular Electron Radio Frequency Quadrupole (ERFQ). The differences between the proton-RFQ and the electron-RFQ are discussed. Then, it will be shown that contrary to the quadrupoles for protons or heavy-ions, the ERFQ is suited for electron velocities in the range 0.5 - 0.7 c, and possible applications are given. Finally, it is illustrated, with numerical field computations that this approach gives sufficient accuracy at 10 GHz.

关键词： Electron RF Quadrupole Buncher Linear Accelerator Linac Beam Injector

The Exact Formulation of the Inverse of the Tridiagonal Matrix for Solving the 1D Poisson Equation with the Finite Difference Method

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Journal of Electromagnetic Analysis and Applications 2014年第10期6卷 303-308页

作者： Serigne Bira gueye Département de Physique Faculté des Sciences et Techniques Université Cheikh Anta Diop Dakar-Fann Sénégal

A new method for solving the 1D Poisson equation is presented using the finite difference method. This method is based on the exact formulation of the inverse of the tridiagonal matrix associated with the Laplacian. This is the first time that the inverse of this remarkable matrix is determined directly and exactly. Thus, solving 1D Poisson equation becomes very accurate and extremely fast. This method is a very important tool for physics and engineering where the Poisson equation appears very often in the description of certain phenomena.

关键词： 1D Poisson Equation Finite Difference Method Tridiagonal Matrix Inversion Thomas Algorithm Gaussian Elimination Potential Problem

Semi-Analytical Solution of the 1D Helmholtz Equation, Obtained from Inversion of Symmetric Tridiagonal Matrix

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Journal of Electromagnetic Analysis and Applications 2014年第14期6卷 425-438页

作者： Serigne Bira gueye Département de Physique Faculté des Sciences et Techniques Université Cheikh Anta Diop Dakar-Fann Sénégal

An interesting semi-analytic solution is given for the Helmholtz equation. This solution is obtained from a rigorous discussion of the regularity and the inversion of the tridiagonal symmetric matrix. Then, applications are given, showing very good accuracy. This work provides also the analytical inverse of the skew-symmetric tridiagonal matrix.

关键词： Helmholtz Equation Tridiagonal Matrix Linear Homogeneous Recurrence Relation

基底支撑刚度梯度变化对石墨烯层间摩擦力的影响

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物理学报 2019年第1期68卷 210-219页

作者：董赟段早琦陶毅 gueye Birahima 张艳陈云飞东南大学机械工程学院江苏省微纳生物医疗器械设计与制造重点实验室南京211189 兰州理工大学机电工程学院兰州730050

基于纳米摩擦能耗理论,利用分子动力学方法建立了公度接触下支撑刚度梯度变化的石墨烯层间摩擦力模型,分析了基底质心刚度和支撑刚度梯度变化对基底和薄片各接触区摩擦能耗的贡献.结果表明:软边界区始终贡献驱动力;硬边界区贡献的摩擦... 详细信息

基于纳米摩擦能耗理论,利用分子动力学方法建立了公度接触下支撑刚度梯度变化的石墨烯层间摩擦力模型,分析了基底质心刚度和支撑刚度梯度变化对基底和薄片各接触区摩擦能耗的贡献.结果表明:软边界区始终贡献驱动力;硬边界区贡献的摩擦力最大,且随着支撑刚度的增大,硬边界区对总摩擦的贡献比也越高.各接触区的摩擦力是薄片和基底之间的褶皱势和接触区产生的法向变形差两部分的共同作用.前者是公度接触下阻碍滑移的界面势垒和刚度梯度方向上不同刚度支撑原子热振动引起的势梯度;后者是接触边界过渡区两侧原子的非对称变形和自由度约束突变引起的非平衡边界势垒相耦合的结果.本文对研究公度接触下刚度梯度支撑的纳米器件的相对运动规律有指导意义.

关键词：分子动力学纳米摩擦公度接触刚度梯度

Exact Inversion of Pentadiagonal Matrix for Semi-Analytic Solution of 2D Poisson Equation

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Journal of Modern Physics 2022年第12期13卷 1525-1529页

作者： Serigne Bira gueye Department of Physics Faculty of Sciences and Techniques Cheikh Anta Diop University Dakar-Fann Senegal

This work essentially consists in inverting in an exact, explicit, and original way the pentadiagonal Toeplitz matrix or tridiagonal block matrix resulting from the discretization of the two-dimensional Laplace operator. This method is an algorithm facilitating the resolution of a large number of problems governed by PDEs involving the Laplacian in two dimensions. It guarantees high precision and high efficiency in solving various differential equations.

关键词： Block Matrix Pentadiagonal Matrix 2D Laplacian Toeplitz Matrix Inversion

Prevalence and Associated Factors of Diabetic Kidney Disease in Senegalese Patients: A Cross-Sectional Study in Saint-Louis

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Open Journal of Nephrology 2020年第1期10卷 23-33页

作者： Sidy Mohamed Seck Dominique Doupa Seraphin Ahou Serigne gueye Macia Engerran Lamine gueye Internal Medicine-Nephrology Department Faculty of Health Sciences University Gaston Berger Saint-Louis Senegal UMI 3189 Environnement santé sociétés (CNRS/UCAD/Université de Bamako/CNRST Burkina-Faso) Faculté de Médecine de Pharmacie et d’Odontostomatologie Dakar Senegal Nephrology Department Faculty of Health Sciences University of Parakou Parakou Benin Nephrology and Hemodialysis Department CH Cahors Cahors France

Introduction: Diabetes is a leading cause of chronic kidney disease in the world. During the next decade, its burden is expected to increase in Africa with potential complications such as chronic kidney disease. However, epidemiology and risk factors of diabetic kidney disease are poorly described at population level. This study aimed to determine prevalence of diabetic kidney disease (DKD) in adult diabetics living in Saint-Louis, northern Senegal. Methods: A cross-sectional study including diabetic patients followed-up aged ≥18 years during a five-year period (2013-2018) in Saint-Louis. Clinical and biological parameters were collected during annual community-based mass screening. Diabetes was defined as fasting blood glucose ≥ 1.26 g/L confirmed by a second lab dosage. DKD was defined as persistence of albuminuria ≥ 30 mg/24h and/or estimated glomerular filtration rate (eGFR) 2. Data were analyzed with Stata 12.0. Results: We included a total of 1310 diabetic patients among whom 3.7% (95% CI = 1.4% - 9.8%) presented DKD. Their mean age was 46.2 ± 11.8 years and sex-ratio was 0.7. Micro-albuminuria and macro-albuminuria were present respectively in 59.2% and 18.4% of patients with DKD and half of them had a normal eGFR. Before the survey 89.8% of patients with DKD were not aware of their renal disease and only four of them had seen a nephrologist. After multivariate analysis, age (OR = 1.5;95% CI = 1.1 - 3.4), duration of diabetes (OR = 1.2;95% CI = 1.6 - 4.4) and hypertension (OR = 2.5;95% CI = 1.4 - 4.6) were associated with the presence of DKD in diabetic patients while no significant association was not found with gender, blood glucose level, smoking and familial history. Conclusion: DKD is a frequent complication in diabetic adult population living in Saint-Louis. Early detection and management should be promoted in order to prevent progression to end-stage renal disease.

关键词： Diabetes Kidney Disease Epidemiology Saint-Louis