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Recycling Tailings Seepage Water for Diogo Heavy Minerals Mine Sustainability (Northern Senegal)

Journal of Water Resource and Protection 2018年第1期10卷 121-144页

作者： Mouhamat Seck Serigne faye Mark Robertson Michael Rose Department of Geology University Cheikh Anta Diop Dakar Senegal Grande Cote Operations (GCO) Dakar Senegal GEO-ENG Queensland Australia

The sandy Quaternary and the deep Maastrichtian aquifers located in the northern coastal zone of Senegal, from the locality of Kayar in the south to Saint-Louis in the north, constitute the main sources of water supply for urban and local needs as well as mining activities. The Quaternary aquifer that provides the water required for the irrigation of local farmlands, hosts a significant heavy mineral sands deposit currently being mined by the Grande Cote Operations (GCO). As a result of variable rainfall and increased water abstraction, this shallow aquifer has recorded a continuous water level decline since 1970, with potential negative effects on both the social and economic development of the region. The mining of heavy minerals (zircon, ilmenite, leucoxene and rutile) at GCO is realised through conventional dredging techniques that require large volumes of water (up to 60,000 m3/d). The water pumped by the dredge to enable the extraction of the heavy minerals, infiltrates into the shallow aquifer, runs-off into the dredge pond or evaporates. The objective of this study is to evaluate a water balance that enables the provision of a permanent water supply to the dredge pond, whilst minimising the risk of flooding of the cropping depressions adjacent to the mine site or drying out of the farming wells. The hydrodynamic model implemented for this purpose was calibrated and tested during the first year of operation. The Root Mean Squared Error (RMSE) obtained for the calibration is approximately 0.52 m. The predictions indicate a requirement for the system to recover part of the tailings infiltration through dewatering boreholes. The quantity of recycled water is estimated at 16,000 m3/d on average. The model simulations show an additional water requirement, extracted from the deep Maastrichtian aquifer, varying between 23,000 and 28,000 m3/d to achieve the optimum pond water level.

关键词： Mineral Sands Groundwater Modelling Dredge Pond Grande Cote Operations Fe Flow

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Spatiotemporal Analysis of the Effect of Ozone and Fine Particulate on CVD Emergency Room Visits in Harris County, Texas

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Open Journal of Air Pollution 2014年第4期3卷 87-99页

作者： faye Anderson Arch Carson Lawrence Whitehead Keith Burau Texas A & M AgriLIFE Research Center at Beaumont Texas USA

Researchers have reported statistically significant associations between air pollutants and cardiovascular disease (CVD). However, few studies have investigated the acute cardiovascular effects of joint exposure to Ozone (O3) and fine particulate matter (PM2.5) in a location so distinctive like Harris County. The objective of this study was to investigate the association between the joint exposure to O3 and PM2.5, and emergency room diagnosis of CVD, in Harris County, Texas. Data used include all emergency room (ER) visits, and O3 and PM2.5 levels in the same years. Logistic regression modeled the effect of temperature, relative humidity, wind speed, wind, ozone, and fine particulate matter, averaged by day. Three models were estimated for all visits, visits during the months of April and September of 2005 and 2009, and for visits for patients from zip codes that are close to monitoring stations. A 1 μg/m3 increase in PM2.5 was associated with a 0.4% increase in the odds of cardiovascular disease emergency room diagnoses on the same day

关键词： Cardiovascular Disease Air Pollution Emergency Harris County Ozone Particulate Pollution

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Age, Race and Gender Spatiotemporal Disparities of COPD Emergency Room Visits in Houston, Texas

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Occupational Diseases and Environmental Medicine 2015年第1期3卷 1-9页

作者： faye Anderson Arch Carson Lawrence Whitehead Keith Burau Texas A & M AgriLIFE Research Center Beaumont Texas USA

Chronic obstructive pulmonary disease (COPD) is one of the major causes of morbidity and mortality in the United State. The investigation of the continuing increase in its prevalence and mortality has increased attempts to further understand its causes and how to manage it. Understanding the spatial and temporal distribution of COPD emergency room (ER) visits in Harris County (Houston) can guide these efforts in a uniform yet diverse setting like this one. The objectives of this study were to identify the temporal and spatial variations of COPD emergency room visits adjusted by age, gender, ethnicity, day of the week, month, and year, and to estimate the odds ratio of COPD emergency room visits adjusted by the six risk factors. The dataset used were extracted from two resources: ER Utilization Study and Harris County centroid coordinates. Exploratory statistical analyses were conducted to study the spatiotemporal disparities and investigate associations. Logistic regression was performed to estimate the odds ratio of COPD primary diagnosis adjusted for age, race, gender, day of the week, month, and year. The number of COPD ER visits kept increasing from 2004 throughout 2009 but there was a significant increase after the year 2005. Spring and summer had lower visits compared to winter and autumn. Lowest visits were during June and July and higher during December and January. Tuesdays had the highest number of visits compared to the remaining days of the week with Saturdays having had the lowest number of visits. Temporal analyses show the continuous increase in COPD ER visits in Houston as well as the consistent spatial disparities between zip regions. After adjustment for age, race, gender, day of the week, month, and year, there were statistically significant associations between emergency room chronic obstructive pulmonary disease diagnoses in Houston, Texas, with these six predictors.

关键词： COPD Houston Texas Ozone Particulate Matter Logistic Regression

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列线图与机器学习算法预测中老年龋齿的比较研究

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重庆医学 2024年第14期53卷 2130-2137页

作者：赖丽冲韦发烨黄冬妹曹晓莹彭捷冯小玲黄惠桥广西医科大学第二附属医院护理部南宁530007 广西医科大学第一附属医院泌尿外科南宁530021 广西医科大学第二附属医院康复医学科南宁530007 广西医科大学第二附属医院党委办公室南宁530007

目的对比列线图与不同机器学习算法构建中老年人龋齿预测模型的效能。方法采用多阶段分层随机抽样法,选取南宁市、贵港市、崇左市510名中老年人为研究对象,进行问卷调查及口腔检查。采用单因素分析和Lasso回归筛选相关变量,使用多因素lo... 详细信息

目的对比列线图与不同机器学习算法构建中老年人龋齿预测模型的效能。方法采用多阶段分层随机抽样法,选取南宁市、贵港市、崇左市510名中老年人为研究对象,进行问卷调查及口腔检查。采用单因素分析和Lasso回归筛选相关变量,使用多因素logistic回归分析确定最终独立影响因素。基于显著特征,建立列线图预测模型,并运用线性判别分析(LDA)、偏最小二乘算法(PLS)、距离多普勒算法(RDA)、广义线性模型(GLM)、随机森林(RF)、支持向量机(SVM)核函数(SVM-Radial)及SVM线性核函数(SVM-Linear)7种机器学习算法构建7种龋齿风险预测模型。采用受试者工作特征(ROC)曲线下面积(AUC)中位数评价各模型预测性能,以及不同变量筛选方法所构建模型的预测性能。结果中老年人龋齿检出率为71.18%。经过特征筛选后最终保留5个预测因子,分别是年龄(OR=0.945,95%CI:0.917~0.973)、刷牙频率(OR=0.688,95%CI:0.475~0.997)、过去1年是否洗牙(OR=0.303,95%CI:0.103~0.890)、牙存留数(OR=1.062,95%CI:1.038~1.087)和口腔健康评估量表(OHAT)得分(OR=1.363,95%CI:1.234~1.505)。各模型对比结果显示,RF算法所构建的预测模型表现最佳,AUC中位数为0.747,其次为列线图,AUC中位数为0.733。单因素+Lasso+多因素logistic(简称Lasso+logistic)筛选自变量构建预测模型的AUC中位数均高于RF算法筛选自变量构建的预测模型。结论基于Lasso+logistic筛选变量,RF较列线图及其他机器学习算法在中老年龋齿预测中提供了更可靠的预测性能。

关键词：中老年人龋齿预测机器学习列线图

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Case Study: Reviewing Methods of Assessing Community Adaptive Capacity for Jefferson County, Texas

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American Journal of Climate Change 2016年第1期5卷 8-14页

作者： faye Anderson Najla N. J. Al-Thani Center for Advances in Water and Air Quality Lamar University Beaumont Texas USA

With the increased attention on community sustainability and resilience, different poles have developed voicing similarities and/or differences of the two concepts. This study quantifies adaptive capacity of Jefferson County, Texas, one of the coastal communities at the Gulf of Mexico having some of the worse adverse effects. Review of existing methods is presented. Analyses were conducted for the last ten years: from 2005 to 2014. Interestingly, statistical analyses showed that the County’s socio-economic profile or indicators have not changed throughout the ten years, but the environmental, institutional, and infrastructure indicators have. Focusing on one location magnifies the adaptive capacity of Jefferson County, the temporal aspect of both perspectives, and the relevance of existing methods to this community with its peculiarities. Future assessments need to be based on primary data collected through participatory engagement of all stakeholders. This calls for attempts to quantify adaptive capacity using the comparatively more challenging deductive reasoning, which would allow for incorporation of more risks and thus higher readiness.

关键词： Climate Change Resilience Risk Jefferson County Texas Flooding Adaptive Capacity Upper Scale System

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Optimization of Tiger Nut (Cyperus esculentus) Roasting Process Using Response Surface Methodology

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Food and Nutrition Sciences 2022年第10期13卷 811-825页

作者： Bou Ndiaye Alioune Sow Samba faye Oumar Ibn Khatab Cissé Fatou Dieye Papa Guedel faye Mama Sakho Nicolas Cyrille Ayessou Laboratoire Eau Energie Environnement et Procédés Industriels (LE3PI) Ecole Supérieure Polytechnique (ESP) de Dakar Université Cheikh Anta Diop (UCAD) Dakar Sénégal Centre d’Etudes sur la Sécurité Alimentaire et les Molécules Fonctionnelles (CESAM) ESP Dakar Sénégal Ecole Supérieure de Génie Industriel et Biologique (ESGIB) Dakar Sénégal UFR des Sciences Agronomiques de l’Aquaculture et des Technologies Alimentaires (S2ATA) Université Gaston Berger Saint-Louis Sénégal Université du Sine Saloum El Hadj Ibrihima NIASS (USSEIN) Kaolack Sénégal Ecole Nationale Superieure d’Agriculture (ENSA) UIDT Thies Sénégal

Tiger nut (Cyperus esculentus) is an underutilized tuber and a non-conventional oil seed which are known for their biological effect. The transformation of tubers into nutritional and stable flour could be important for West Africa populations. Thus, roasting is a process that improves the biochemical composition of seeds. The purpose of this study was to optimize temperature and roasting time on Tiger nut’s tubers in order to produce high nutritional tiger nut flour. A response surface methodology was used to optimize the roasting process in a temperature range (130°C - 150°C) and in a duration range (20 - 35 min). The data are processed by the software Statgraphic Centurion XVI version 16.2.04. Total polyphenols and flavonoids contents, antioxidant activity, titratable acidity, browning index and Maillard reaction products absorbance were evaluated. A second-order polynomial model was established to predict optimal values, included temperature and time. The contents of polyphenols and flavonoids range respectively from 0.196 to 0.891 g GAE/100g and from 0.022 to 0.051 g CE/100g, the antioxidant activity ranges from 25.21 to 57.09%, titratable acidity varies between 0.193 and 0.472 g/100g, the browning index from 28.42 to 56.20 and the absorbances at 420 nm of Maillard Reactions Products ranged between 0.365 and 0.897. The global desirability was 90%. Roasting had significant effects (p 0.05) on titratable acidity, browning index and antioxidant activity. The optimum roasting conditions were established at the temperature of 147°C for 38 minutes. Experimental values of parameter for flour obtained in optimal condition were proximate to predict values excepted titratable acidity. The model performance is acceptable for this study. The research for the optimal roasting conditions for tiger nut reveals an appropriate temperature and time combination which could improve the biochemical composition with a more attractive color.

关键词： Tiger Nut Roasting Optimization Physicochemical And Biochemical Analyses

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Exploratory Analyses for Water Quality of the Gulf of Mexico Basin, Texas, 2005-2014

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Journal of Geoscience and Environment Protection 2016年第1期4卷 58-63页

作者： faye Anderson Najla N. J. Al-Thani Center for Advances in Water and Air Quality Lamar University Beaumont TX USA

With the increased demand for more water sources, the issues of water quality have become more important. This study presents exploratory data analyses on water quality issues related to the Gulf of Mexico Basin in Texas for the last decade: 2005-2014. Dissolved oxygen, water temperature, specific conductance, PH, transparency, sampling depth and Enterococci observations for the ten years from 2005 to 2014 were analyzed. Statistical testing showed that the observations followed similar distributions between the years. Thus they were combined for each of the variables. Throughout the ten years transparency, water temperature, specific conductance, and Enterococci showed higher variances. Pair-wise correlations were negligible but they had positive spatial autocorrelation. Sampling was constantly conducted in the four months of February, May, August, and November. Water temperature, dissolved oxygen and Enterococci concentrations varied significantly during these four months. Univariate spatial regressions showed that Enterococci is predicted to increase whereas dissolved oxygen, PH, water temperature, specific conductances were predicted to decrease.

关键词： Surface Water Water Quality Gulf of Mexico Basin Texas Multivariate Spatial Stormwater Flooding Community Adaptive Capacity Resilience

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Influence of the Temperature on Coated Bituminous of Road Structures in Senegal (West Africa)

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Open Journal of Civil Engineering 2020年第4期10卷 321-336页

作者： Birame Diouf Adama Dione Papa Sanou faye Khalil Cissé Mechanics and Modeling Laboratory UFR Engineering Sciences University of Thies Thies Senegal Institute of Earth Sciences Cheikh Anta Diop University Dakar Senegal Laboratory of Materials Mechanics and Hydraulics Polytechnic School of Thies Thies Senegal

The Senegalese road network is strongly influenced in the long term by seasonal variations in climate and weather conditions. Indeed, much of the damage is due to these environmental factors. The objective of this paper is to study the behaviour of bituminous structures under the effect of high temperatures. Material samples were taken for a physico-mechanical characterization of the coated components. The results show that Marshall creep (2.87, 3.39, 5, 5.5 mm) and the bitumen penetrability increase with the increasing of temperatures respectively from 34°C to 45°C and from 20°C to 50°C. Marshall Stability drops from 15.81 kN to 11.31 kN for temperatures between 34°C and 45°C. The simulation carried out on Alize-LCPC shows an increase in distortions of traction at the basis of the rolling layer and at the top of the platform if temperatures vary between 34°C and 45°C. This work makes it possible to conform that the bituminous concrete is thermally sensitive and the hypothesis of fixing the constant modulus of the bituminous layers in Senegal for all projects remains unsuitable for a good dimensioning of sustainable road structures. The knowledge of the equivalent regional temperature will make it possible to produce quality pavements with a long lifespan.

关键词： Asphalt Mixes Coated Senegal Thermo Susceptibility Performance Dimensioning

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Base Doping Effects on the Efficiency of Vertical Parallel Junction Solar Cells

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Open Journal of Applied Sciences 2017年第6期7卷 282-290页

作者： Almoustapha Samoura Oumar Sakho Omar faye Aboubaker Chedikh Beye Solid State Physics and Material Science Laboratory Sciences and Technique Faculty Cheikh Anta Diop University Dakar Senegal

In this work, we present a theoretical study of a vertical parallel junction silicon solar cell under monochromatic illumination. The internal quantum efficiency (IQE) and the photovoltaic conversion efficiency are calculated, taking into account the base doping density and illumination wave-length. The main purpose of this work is to show how conversion efficiency depends on internal quantum efficiency and the dependence of the later on the base doping density.

关键词： Vertical Junction Doping Internal Quantum Efficiency (IQE)

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冷战后中国与塞内加尔外交关系的发展

冷战后中国与塞内加尔外交关系的发展

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作者： Abdou Mbar faye（阿布杜）辽宁大学

学位级别：硕士

十年来,中华人民共和国已成为非洲国家的首要合作伙伴。这个重大飞跃带来了巨大的变化,重新配置了撒哈拉以南的权利平衡,给非洲国家以回旋的余地。塞内加尔与中国在1971年正式建立了外交关系,可在那之后根据国家之间没有友谊只有利益的...

十年来,中华人民共和国已成为非洲国家的首要合作伙伴。这个重大飞跃带来了巨大的变化,重新配置了撒哈拉以南的权利平衡,给非洲国家以回旋的余地。塞内加尔与中国在1971年正式建立了外交关系,可在那之后根据国家之间没有友谊只有利益的原则,又切断了这段关系。在与中国决裂的那段时间,塞内加尔与台湾达成了外交关系,但是关于那段“友谊”,我们知道在短短几年后便进入尾声。在历经十一年之后,于2005年,中华人民共和国和塞内加尔重新建立了外交关系。本文论述了中塞两国在新的战略伙伴关系中发展外交关系,换句话说就是外交关系模式的变化。通过经济,金融,政治,军事合作等不同方面的合作,中塞两国重新建立的外交关系使塞内加尔的合作伙伴多元化,西方合作伙伴如法国和美国获得更多自主权。国际关系更具灵活性。中国和塞内加尔的外交关系恢复是塞内加尔当前地缘政治和经济背景的现实和务实视角的一部分。对中国来说,这是一种增加在非洲和国际社会影响力的手段,这要归功于塞内加尔的地理位置及其政治稳定。这是中国巩固和扩大在这一战略地区的存在的重要资产。本文展示了中塞两国外交关系的年表,着重阐述了其合作的来龙去脉。并显示了两国关系的发展,以及对当前国际关系格局及其相关问题的影响。

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