The objective of this study is to evaluate the quality of underground water according to the standards of Beninese and international drinkability. The choice of watering place centres on daily usages as beverage. The physicochemical and bacteriological parameters have been determined according to the conventional methods. The obtained results show that the studied waters are characterized by an acidic- pH (6.74 – 6.95), a temperature which varies from 27.3°C to 30.4°C, a weak electric conductivity (8.9μS/cm – 588 μS/cm), weak TDS (5mg/L – 270mg/L) and a low potential of reduction-oxidation (202 mV – 344 mV). Besides, the following medium concentrations have been obtained : Sulphate (0.19 mg / L – 36.55 mg / L), Nitrate (4.60 mg / L – 53.28 mg/L), Calcium (0.7 mg/L – 57.46 mg/L), Potassium (0.22 mg/L – 21.02 mg/L), Magnesium (0.01 mg/L – 18.33 mg/L), ammonium (0.02 mg/L – 18.33 mg/L) and Chloride (0.20 mg / L – 55.55 mg/L). Among the studied places, only the well P1 revealed contents in potassium and in nitrate beyond the standards of drinkability. The results of bacteriological analysis confirm the presence in very appreciable numbers of fecal contaminated indicators (Total Coliforms, Fecal Coliforms and Escheriachia-Coli) in the wells except the well P5. Moreover, the Fecal Streptococci have been displayed prominently in the well P6. So at the end of this study, we can deduce that wells studied waters roughly present the serious health risks to the population contrary to the drilling wells and springs water.
This project entitled Design, Sizing and Planning of the works of a reinforced concrete girder bridge was carried out in Tunisia. The objective of this work is based on the determination of the geometrical characteristics and the determination of the cross-cutting coefficient (CCC) for the dimensioning of the various elements of the Apron such as beams, spacer and slab. In this work, we used two methods or (approaches) for the determination of the geometrical characteristics of the beams. The study led to the determination of the various fundamental parameters which are the parameter of bracing and the torsion parameter. The conventional method or approach given by the SETRA references, for which the geometrical characteristics of the different sections were obtained by the following formula:
Bmoy (m2) = B appui C1 + B central C2; C1 and C2 the interpolation coefficients which describe the variation of the section of the beam as a function of the length and when d= 0.5m.
C1 = 1/3 + 4/3Lp = 1/3 + 4/3x21 = 0.3968; C2 = 2/3 - 4/3Lp = 2/3 - 4/3x21 = 0.6032
This for bending inertia and also for torsional inertia. Thus the torsion parameter α = 0.54 and the spacing parameter θ = 1.29.
This work is conducted with women producing shea butter in the regions of Mandoul and Logone Oriental. It aims influence the production processes on the shea butter extraction efficiency. Indeed, these women use two methods to extract shea butter: traditional method that gives butter black and method by manual press that gives butter white. In addition, the traditional method has two variants: use when extracting butter boiled water on the one hand and the water slurry accompanied leaves secondly mango. The butter obtained according to production processes extraction yields are: (44.35 ± 3.513%) for the mechanical press method; (36.11 ± 1.64%) to the traditional method using boiled water and (47.70 ± 0.22) for the traditional method using water boiled over the mango leaves. The values of physico-chemical parameters are analyzed: water content (5.646 ± 0.105%); crude protein (7.2 ± 0.655%); total fat (52.886 ± 1.240%); unsaponifiable (7.25 ± 0.636%); stearic acid (49.526 ± 3.090%); oleic acid (48.716 ± 3.735%); linoleic acid (5.843 ± 0.386%) and linolenic acid (1.653 ± 0.105). The use of mango leaves in the extraction has substantially improved the performance of the butter up to that obtained by the mechanical press. The values of the fatty acids obtained correspond generally to the standards of the Economic and Monetary Union of West Africa (UEMOA) for unrefined shea butter with the exception of the water content is very high compared to the required standards.
Populations located in peri-urban areas are often resigned to using groundwater and surface water as sources of drinking water without, however, worrying about their quality. In order to assess the quality of these waters, a study was carried out in the peri-urban area of Ngoumou. For this study, three sampling stations in the Ebongo stream and three wells were selected. Several physico-chemical variables coupled with biological variables were used to determine the quality of these waters. The analysis of the physicochemical variables reveals that these waters are acid, weakly mineralized and relatively well oxygenated. For biological analyzes, three biological components were used: bacteria, ciliate protozoa and benthic macroinvertebrates. Bacteriological analyzes show that these waters contain bacteria of fecal origin. A total of 698 ciliate individuals belonging to 3 classes, 7 orders and 19 families were harvested. The calculated Shen and Jiang biotic index shows a degradation of water quality from upstream to downstream. Concerning benthic macrofauna, 968 individuals belonging to 3 branches, 4 classes, 7 orders and 25 families were recorded. The Hilsenhoff biotic index reveals that the watercourse is of average to good ecological quality and degrades from upstream to downstream as a result of inputs from runoff and agricultural inputs.
The composition and relative abundance of the benthic diatoms of the rivers of southern Côte d'Ivoire were investigated during three climatic seasons (high dry season, high rainy season and small rainy season) in 43 stations on 28 rivers. Most samples taken from stones were treated with nitric acid. Of the 320 taxa inventoried, the most diverse genera are Nitzschia (43 taxa), Navicula (39 taxa) and Eunotia (33 taxa). The species commonly encountered in the samples vary according to the type of geological substratum. The relative abundances of diatoms of tertiary are significantly different from those of birrimian and granitoid. In addition, Eolimna minima (Grunow) Lange-Bert. is more abundant during the rainy seasons compared to the high dry season whatever the substrate. Several indicator species of pollution were encountered abundantly in the sites studied. The type of geological substratum and the seasons must be taken into account in studies on the distribution of benthic diatoms in Côte d'Ivoire.