Assessment of Groundwater Physico-Chemical Quality in the Ouémé Delta (Southern-Benin)

Groundwater resources are the main sources of water used to supply drinking water to the population of the Ouémé Delta via the Continental Terminal aquifer. Urbanization, population growth, and agricultural and industrial activities have resulted in a deterioration in the quality of these resources. To assess the quality of the delta’s groundwater and its suitability for human consumption and irrigation, a total of fourteen (14) physico-chemical parameters were analyzed in some forty existing water points between September 2020 and March 2021, using standard water analysis techniques. The values obtained were compared with the potability standards recommended by the World Health Organization (WHO) and the Republic of Benin and were subjected to statistical analysis (principal component analysis (PCA)). In addition, methods for determining the suitability of water for irrigation were used. The results showed that the waters are acidic to slightly neutral and influenced by ambient temperature. In addition, the waters are moderately mineralized, with conductivities (24 - 1205 μS/cm) in line with WHO standards. A comparison of the analytical results of the WHO (2017) and Benin (2001) standards indicates that the majority of the waters studied are of good quality for all the chemical parameters considered. Nevertheless, some samples show levels of nitrates (21%), potassium (14% to 16%), calcium (13%), ammonium (12%), nitrites (8%) and bicarbonates (10%) over their respective standards. The Wilcox and Riverside diagrams indicate that the majority of waters (90%) have excellent suitability for irrigation and no negative effect on soil fertilization.

Hydrochemical Characterisation and Assessment of the Level of Contamination of Groundwater Collected by Private Waterworks in the Town of Moundou in the South of Chad

Groundwater is the main source of drinking water for large cities in most African countries. In Moundou, for example, the conventional groundwater supply system is failing. To compensate for this state failure, the population is building boreholes and wells, most of which tap the surface water table, generally referred to as the “water table”. The aim of this study is to characterize these waters in order to assess their level of contamination and, by extension, the degree of pollution of the water table. Major elements such as: Chloride (Cl-), Sulfate (SO42-), Nitrate (NO3-), Calcium (Ca2+), magnesium (Mg2+), sodium (Na+) and potassium (K+) were analysed by Liquid Chromatography and the Bicarbonate ion (HCO3-) was determined by the titrimetric method. The methodology applied is based on a combination of hydrochemical techniques and statistical analysis (PCA and CHA). A sampling campaign was carried out during high-water periods. The results of the physico-chemical analyses show mineralization ranging from 7.29 to 3670 μS/cm, with an average of 487.44 μS/cm. The groundwater studied is generally acidic, with a pH ranging from 3.26 to 6.41. Based on their anions, they are classified into four main hydrochemical facies: chloride and sulphate facies, calcium and magnesium facies, sodium and potassium facies and bicarbonate facies. The various correlations between major ions and statistical analyses have enabled us to identify three hydrogeochemical processes involved in water mineralization. The dominant process is silicate hydrolysis, followed by cation exchange, then anthropogenic input, which influences mineralization by polluting the water.

Using Extreme Value Theory Approaches to Estimate High Quantiles for Stroke Data

This paper aims to explore the application of Extreme Value Theory (EVT) in estimating the conditional extreme quantile for time-to-event outcomes by examining the functional relationship between ambulatory blood pressure trajectories and clinical outcomes in stroke patients. The study utilizes EVT to analyze the functional connection between ambulatory blood pressure trajectories and clinical outcomes in a sample of 297 stroke patients. The 24-hour ambulatory blood pressure measurement curves for every 15 minutes are considered, acknowledging a censored rate of 40%. The findings reveal that the sample mean excess function exhibits a positive gradient above a specific threshold, confirming the heavy-tailed distribution of data in stroke patients with a positive extreme value index. Consequently, the estimated conditional extreme quantile indicates that stroke patients with higher blood pressure measurements face an elevated risk of recurrent stroke occurrence at an early stage. This research contributes to the understanding of the relationship between ambulatory blood pressure and recurrent stroke, providing valuable insights for clinical considerations and potential interventions in stroke management.

Assessment of the Recent Hydromorphological Features of Nokoue Lake and Its Channels (South-East Benin)

Based on 2022 and 2023 hydrometric data and satellite images (Sentinel 2022, SPOT 2010), this study aims to present the Nokoué Lake and its channels’ re-cent hydromorphological characteristics. Integrating flow, tributary morphology, and topography data determined specific power values along the axes studied. The values obtained range from 2.69 to 12.92 W/m2 for Ouémé River and 2.46 to 10.99 W/m2 for Sô River. The resulting water erosion on banks and bottoms is of linear, areolar, or gully and claw types. Lake bathymetry varies from -0.5 to -2.6 m (low flow period) and -1 to -4 m;in the Ouémé, Sô, and Totchè rivers, it varies from -5 m to -7 m, reaching -10 m at the Cotonou channel entrance (flood period). Bathymetric profiles reveal varied “U”, “V” and “Intermediate” bottom morphologies, influenced by erosion/sedimentation processes and human activities. The flow facies identified are lentic in the northern tributaries and lotic in the Cotonou and Totchè canals. Spatial analysis identified nine (09) thematic classes. In 2022, the surface area of the water body has increased from 274 km2 at low water to 280 km2 at high water, whereas in 2010 (a recent year of exceptional flooding), the surface area was 270 km2 at low water and 277 km2 at high water. Significant changes in land use are observed between 2010 and 2022. The floodplain area decreased slightly, from 421 km2 in 2010 (year of exceptional flooding) to 419 km2 in 2022. The evolution of land use shows a progressive expansion of the urban environment to the detriment of the natural environment. In the medium to long term, this trend could threaten the hydromorphological balance and even the existence of this important lagoon ecosystem.

Structural and Mineralogical Characterization of the Clayey Deposits of Gbédji-Kotovi in Lama Depression, Bénin

The objective of the study was to characterize the clays of the Lama depression in Benin. Macroscopic examination of hand soundings, dynamic penetration test and stratigraphic correlation of water borehole logs, as well as scanning electron microscopy (SEM) combined with energy-dispersive X-ray microanalysis (EDX) method were made on compact or stratified clays. The large grains are embedded in a sintered matrix. The texture is heterogeneous and open, including quartz, carbonates and organic matter. The fine fraction is dominated by mineral paragenesis characterizing Kaolinite-Quartz-Calcite-Gypsum dioctahedral smectites composed of: Oxygen, Silica, Carbon, Aluminum, Iron, Zinc, Titanium and Magnesium. This smectic and regular structure includes coarse grains of the order of 800 μm. The pore diameters vary from 130 μm to 1.14 μm. The inter-particle porosity is poorly developed unlike the inter-aggregate pores larger than 0.05 μm. The texture is laminar and shows elongated turbo static particles with more or less rounded edges and honeycomb particles. Quartz and carbonates induce an increase in heterogeneities which develop mechanical sensitivity and hydraulic conductivity. High contents of silica, iron or aluminum and low contents of calcium and magnesium, as well as the presence of other trace elements suggest an alumino-ferriferous clay resulting from the hydrothermal alteration of the acid granite massif. These heterogeneities promote less tortuous pores or paths, making these clays more permeable. Finally, other stabilization studies and improvements to hydraulic products and binders should favor the use of the studied clay as improved backfill or drilling muds.

Segmentation and Classification of Individual Clouds in Images Captured with Horizon-Aimed Cameras for Nowcasting of Solar Irradiance Absorption

One important aspect of solar energy generation especially in inter-tropical sites is the local variability of clouds. Satellite images do not have temporal resolution enough to nowcast its impacts on solar plants, this monitoring is made by local cameras. However, cloud detection and monitoring are not trivial due to cloud shape dynamics, the camera is a linear and self-adjusting device, with fish-eye lenses generating a flat image that distorts images near the horizon. The present work focuses on cloud identification to predict its effects on solar plants that are distinct for every site’s climatology and geography. We used RASPBERY-PI-based cameras pointed at the horizon to allow observation of clouds’ vertical distribution, not possible with a unique fish-eye lens. A large number of cloud image identification analyses led the researchers to use deep learning methods such as U-net, HRnet, and Detectron. We use transfer learning with weights trained over the “2012 ILSVRC ImageNet” data set and architecture configurations like Resnet, Efficient, and Detectron2. While cloud identification proved a difficult task, we achieved the best results by using Jaccard Coefficient as a validation metric, with the best model being a U-net with Resnet18 using 486 × 648 resolution. This model had an average IoU of 0.6, indicating a satisfactory performance in cloud segmentation. We also observed that the data imbalance affected the overall performance of all models, with the tree class creating a favorable bias. The HRNet model, which works with different resolutions, showed promising results with a more refined segmentation at the pixel level, but it was not necessary to detect the most predominant clouds in the sky. We are currently working on balancing the dataset and mapping out data augmentation transformations for our next experiments. Our ultimate goal is to use such models to predict cloud motion and forecast the impact it will have on solar power generation. The present work has contributed to a better understanding of what techniques work best for cloud identification and paves the way for future studies on the development of a better overall cloud classification model.

Quantification of Carried Sediment Charges through the Outflow in the Basin of Mono River in Benin

The filling of rivers generated by carried solid deposit is a factor for the raising of height of rivers and thus activates the floods and inundations. The quantification of carried solid flow charges through their characterization and the analysis of hydrosedimentary dynamics is the second step of the investigation of the solid flow transport in the Mono river. This study aims to quantify the volume of trapped sediments in function of the variation of the geometry of the shape of sections of the river depending of the slope and the flow rate therefore to evaluate the capacity of transport of eroded solid flows of a watercourse from upstream to downstream. Consequently, the decreasing percentage of deposited alluvium from upstream to downstream is calculated along Mono river. Thus the drawn granulometric curve of sediments and the determinate granulometric characteristics of sediments permit to quantify the carried sediment charges at each chosen section with Engelund-Hansen model in Mono river.

Applications of Enzyme-simulating Copper Complex Catalyst in Low-temperature Scouring/Bleaching of Cotton Knits

An enzyme-stimulating catalyst( PTL) with copper ions( Cu^(2+)) as the activation center and aminophosphonate as ligand was developed and applied in low-temperature scouring/bleaching of cotton knits. The optimal weight ratio of Cu^(2+) to aminophosphonate was 1 ∶75. Via orthodox and single-factor experiments,the most efficient formula for low-temperature scouring/bleaching was composed of 0. 4 g/L high-efficiency degreaser DM-1130,1. 5 g/L PTL,2. 0 g/L sodium hydroxide( NaOH),and 7. 0 g/L 30% hydrogen peroxide( H_2O_2). The PTL could not only increase the whiteness of cotton knits,but also remove pectin to enhance capillary effect.

Geometric Drawing Model of Shape of Water Sections for the Investigation of Solid Flow Transport in the Basin of Mono River in Republic of Benin

The hydrologic and hydraulic changings on the behavior of Mono river are the result of the stress involved by human activities, on one hand and the construction of the dam of Nangbéto and the exploitation of sand in downstream of the dam by the population, between Athiémé and Agbanankin on other hand. That effect had also affected the shape of the sections of the river in the context of climate variability. It shows consequently that area is also a trapping area of sediments eroded in downstream of the dam and is responsible for the trapping of sediments in the river. The slope and the flow rate are the main factors of the real capacity of transport of a watercourse. They also determine the transport of solid flows from upstream to downstream. This drawing model established by taking into account the bathymetry of a transversal section of the Mono river at Athiémé, is the first step of a global investigation of the solid flow transport in the basin of Mono river and the boundary condition for the characterization of its hydro-sedimentary dynamics study. It aims to take into account sections and the used technique which consist to measure on one located section as the representative section of the river at Athiémé, by moving the boat used for bathymetry.

Physico-Chemical Characteristics of Gushing Water Aquifers in the Coastal Sedimentary Basin of Benin (West Africa)

The coastal sedimentary basin in southern Benin consists of monoclinal layers divided into two plateau zones (North and South) which are separated by a longitudinal depression ESE-WNW. The valleys of the main N-S-oriented rivers (Ouémé, Couffo and Mono) set the bondaries of the different plateau of the BSC (Coastal Sedimentary Basin). The present study, based on geology, hydrochemistry, temperature and log data available on boreholes, makes a physico-chemical characterization of the waters of the gushing aquifers of the coastal sedimentary basin of Benin. The gushing water boreholes are shared between the valleys of the main rivers of the BSC. Some of these boreholes are thermal with a water temperature between 38 and 69 degrees Celsius. The hydrogeological correlations established in the BSC in accordance to the North- South direction in the valleys of the main streams (Couffo and Ouémé) reveal that the captured aquifers are sands, marls and limestones that respond either in major discordance (northern zone) or above the sedimentation gaps (southern zone). Chemical analyses have shown that gushing thermal waters are mineralized in the south with a neutral to basic pH and are highly concentrated with bicarbonate, calcium and magnesium ions. In the North, on the other hand, thermal waters are acidic with a pH ranging from 4.8 to 5.9. The acidic nature of the northern waters is influenced by the crystalline base while the southern neutral to basic waters are influenced by the lithological nature (limestone and marl) of the aquifer. The random distribution of thermal water boreholes in the valleys of the main BSC streams is believed to be related to tectonic events.

Assessment of the Pesticides Utilization and the Pesticide Residues Presence in Fresh and Tomato Products for the Tomato Supply Chain in Rwanda

Pesticide residues are either natural or synthetic and are found in most edible products such as fresh fruits, vegetables, meat and other processed products. Excess of these pesticides’ residues is unsafe for consumption due to regulatory measures. Thus, it is beneficial to assess the level of residues of pesticides in the food diet in order to improve the standard of living of the population. This study intends to assess the pesticide usage and residue levels of selected pesticides in fresh tomatoes in the supply chain of Rwanda. The results of the study confirm that there are around 10 brands of pesticides used in Rwanda. 58.97% of the surveyed people around the country are males and 71.79% of farmers apply rockets as the main pesticide. More than 22% of surveyed farmers affirmed to consume the raw or/and unwashed tomatoes. This study revealed that the residues of the active ingredients contained in the pesticides are accumulated in unwashed tomatoes and the quantity of such residues is shown in this study. Deltamethrin was 0.64 ± 0. 009 mg·kg?1 in tomatoes collected in Rusizi district, cypermethrin 1.1435 ± 0. 0375 mg·kg?1 in tomatoes collected from Gisagara District, mancozeb residues was 0.620 ± 0.000 mg·kg?1 in tomatoes collected from Rusizi district. The results of the study also show that pesticide residues are not found in the washed tomatoes. Therefore, the detection of pesticide residues in unwashed tomatoes in some samples indicates the malpractice of residues among farmers in Rwanda. Also, consumers eating the unwashed fresh tomatoes are recommended to wash the tomatoes before use.

Evaluation of Metallic Trace Elements Content (Cadmium, Copper, Zinc and Lead) in the Water of Lake Azili in the Municipality of Zangnanado (Centre-Benin)

This study focuses on the assessment of the level of contamination in metallic trace elements (cadmium, copper, zinc and lead) in the waters of lake Azili in the municipality of Zangnanado. The methodology adopted to achieve these results is the method of molecular absorption spectrophotometry. Four sites were sampled at the beginning of November 2020 (period of the long dry season). The results obtained show that the copper content varies between 1.04 mg/l and 1.67 mg/l. The zinc content between 0.2 mg/l to 0.62 mg/l and those of lead recorded are all above 0.05 mg/l. As for their cadmium concentration, they are all above 0.001 mg/l. These results from water analysis of Azili lake show that the sources of this type contamination of the lake are due on the one hand to human activities (dumps of household waste, use of motorized boats) and others other hand to the contributions of the effluents of the lake carrying pesticides. The water quality of Lake Azili is therefore influenced by these various metallic trace elements found there. These results show that the waters of lake Azili are at their beginning of pollution even if it is not yet alarming at the time of our study. Under these conditions, if nothing is done to mitigate it, the pollution will be critical over time.

Nesfatin-1及其与皮肤疾病

Nesfatin-1是核连蛋白2经激素原转化酶裂解所得蛋白质,在中枢和外周组织均有表达,目前尚未发现在皮肤组织有表达。Nesfatin-1与摄食、肥胖、糖尿病、心血管系统、应激和精神疾病、炎症等相关。其信号通路可能与黑皮质素系统相关,包括黑皮质素3/4受体、促肾上腺皮质激素释放激素、黑素细胞凝集素、阿黑皮素原、神经肽及促炎细胞因子。而这些激素、神经肽及细胞因子在银屑病、白癜风、痤疮及斑秃等应激相关皮肤病中均有表达,且与疾病的发生进展密切相关。故推测Nesfatin-1可能与应激相关皮肤疾病的诱发或进展有直接或间接关系。

伐桩高度对猴耳环人工药材林萌芽更新的影响

为探究不同伐桩高度对猴耳环人工林萌芽更新与生物量积累的影响,于2016年惠州市惠阳区良井镇前锋村,以480 d的猴耳环人工纯林为研究对象,分别采用30、60、90、120 cm的伐桩高度进行采伐,以去枝留顶和去枝截顶2种方式为对照,分析不同伐桩高度对伐桩萌芽率、存活率、萌条数、萌条生长和生物量等的影响。结果表明:伐桩高度120 cm的萌芽点数和萌条数量最多,伐桩高度90 cm的萌条长度和萌条生物量最大,与对照相比,伐桩高度对萌芽率和存活率没有显著影响,但对萌芽点数、萌条数、萌条基径、长度和生物量影响显著;伐桩的萌条数、基径、长度和生物量均随伐桩高度的增加呈现先增加后减少的趋势。总体而言,4种伐桩高度中,90、120 cm的伐桩在萌条数量、基径、长度和生物量方面萌芽更新效果最好。伐桩高度90~120 cm是猴耳环人工药材林适宜的采伐高度,可获得较大的萌芽林生物量。

基于PIM的智慧工厂施工进度管理

智慧工厂施工进度管理具有影响因素多和管理风险大的特点,而PIM技术具有可视化、可模拟、可优化、可关联的特点。文章提出将PIM技术用于智慧工厂施工进度管理中,利用PIM技术搭建三维工厂进度施工模型,完成三维设计成果原生解析及轻量化承载,关联施工进度计划,明确施工活动中的各项参数,通过施工进度沙盘有效反映工程施工进展,实现高效管理施工进度,减少工程延期风险,为智慧工厂相关的智慧化和信息化管理提供参考。

大型炼油装置三剂费用分析

针对某炼化企业三剂单位费用偏高现象,对三剂费用组成进行分解分析,重点分析了费用占比较高的催化裂化装置和加氢精制装置,其中催化裂化装置分析了主催化剂和NaOH溶液的消耗情况。查找出造成单位费用偏高的主要原因是受整体加工工艺的影响和地理位置因素的影响,针对查找出的主要原因,提出了延长加氢催化剂寿命和降低NaOH溶液价格的建议措施。

管道预制设计在工程项目建设期的应用

石油建设行业中管道施工一直是项目中的重难点专业,尤其前期管道二次设计工作,耗费大量人力。为提高施工单位进行管道轴测图二次设计的工作效率和质量,提出通过解析设计IDF/PCF文件,获取管道模型文件以及设计基础数据。通过对模型文件进行二次设计获取施工需要的焊缝信息、材料信息等,并通过自动生成轴测图等功能,提高管道预制设计的效率以及准确性。

施工监理在油气田地面建设与仪表安装中的作用

玉门油田是中国重要油田之一,其在开发石油资源过程中发挥了重要作用。为了进一步提高玉门油田利用率,建设了相应的油气田地面工程,这些工程由于分布范围广,在施工和管理上面临一定困难,不利于玉门油田持续发展。文章针对监理工作在油气田地面建设与储运仪表安装施工过程中的作用展开探讨,指出了当前监理工作面临的不足和存在的问题,并提出了监理工作的工作要点及应对措施。

基于量化评估的细节护理在ICU鼻肠管留置患者中的应用

目的探讨基于量化评估的细节护理在ICU鼻肠管留置患者中的应用价值。方法110例ICU鼻肠管留置患者随机分为两组,对照组采用常规护理,观察组采用基于量化评估的细节护理,比较两组的置管情况、并发症和满意度。结果观察组的置管成功率、置管及管路维护满意度评分均高于对照组,鼻肠管脱管率、并发症发生率均低于对照组,置管操作耗时短于对照组(P<0.05)。结论基于量化评估的细节护理可提高ICU鼻肠管置管的质量及安全性,提高患者的护理满意度。

水电工程经济问题管理信息化研究与应用

基于水电工程建设的特性,施工过程不确定因素较多,导致经济问题繁多,处理工作量较大,在工程建设管理过程中,经济问题管理扮演着非常重要的角色。依托某水电站建设过程管理,从管理手段为切入点,以项目建设单位《变更(索赔)管理办法》为基础,引入信息化手段推动经济问题管理,消除经济问题管理过程中处理不及时、目标不明确、工作效率低、经济问题台账不直观等弊病,有效提升了管理效率和水平。