Comparative Study of Solar PV Power Plant Dimensionnement Connected to Network Based on Monofacial and Bifacial Modules

This article presents the results of comparative study of two PV solar modules technologies,namely monofacial and bifacial.This study main objective is to identify conditions and parameters that make it possible to obtain better energy and economic efficiency from one or other of two technologies.The study reason lies in revival observed on bifacial module in recent years where all the major manufacturers of PV solar panels are developing them where in a few years,this technology risks being at the same price as the monofacial solar panel with better efficiency.Economic indicator used is energy levelized cost(LCOE)which is function technology type,energy productivity,annual investment and operation cost.To achieve this,a 3.685 MWc solar PV power plant was dimensioned and simulated under Matlab for a 3.5 ha site with a 2,320,740,602 FCFA budget for monofacial installation,against 1,925,188,640 FCFA for 2.73 MWc bifacial installation.The LCOE comparative analysis of two technologies calculated over a period of 25 years,showed that plant with bifacial panels is more beneficial if bifacial gain is greater than 9%.It has further been found that it is possible to gain up to 40%of invested cost if bifacial gain reaches 45%.Finally,a loss of about 10%of invested cost could be recorded if bifacial gain is less than 9%.

Contribution of poses screen preimpregnated(PSP) installed at openings and eaves of dwellings in the reduction of malaria transmission in the commune of agugus in bnin

Objective:To evaluate the contribution of poses screen pre-impregnated(PSP) installed at openings and eaves of dwellings in the reduction of malaria transmission in the commune of Aguegues in Benin.Methods:The PSP were manufactured from preimpregnated Olyset Net.They were installed at windows,eaves and doors of 70 dwellings.320 children aged 6-59 months were treated and 311 children were recruited in the control zone.Variables measured are:plasmodic index(IP),gametoeyte index,parasite density(PD),fever,hemoglobin,anemia. Results:The global IP was 16.62%with PSP and 72.20%without PSP.Gametoeyte index did not differ significantly between the treated zone(27.8) and the control zone(29.1).The total geometric mean of DP was 309 in the treated zone and 600 in the control zone.Hemoglobin level is 8.7 in the control zone and 9.5 in the treated zone.We noted a predominance of anemia in the control zone compared to the treated zone.Conclusions:The PSP have contributed to a significant reduction in morbidity in the commune of Aguegues.

Influence of Agro Ecology on Rice Varietal Resistance to <i>Sitophilus oryzae</i>(Coleoptera: Curculionidae) and <i>Sitotroga cerealella</i>(Lepidoptera: Gelechiidae) in Benin

The rice weevil, Sitophilus oryzae (L.) and the Angoumois grain moth, Sitotroga cerealella (Oliv.), are serious pests of stored rice in Africa. This study aims to evaluate the influence of growing environments to rice resistance to these pests. Thus, eleven rice varieties including 6 upland NERICA, 2 Oryza glaberrima and 3 O. sativa were grown at four agro ecological zones of Benin. After harvest, samples of 1500 grains of each genotype were infested with 20 adults of S. oryzae (10 males and 10 females) and 1500 additional ones were infested with 50 eggs of S. cerealella. Results showed significant effect of agro ecological zones on pest incidence and on varietal resistance as well. O. glaberrima varieties (TOG 5681 and CG 14) were the most resistant in each location whereas the resistance of NERICA and Sativa varieties varied from tolerant to susceptible according to the growing ecology. This result highlights the impact of growing environment on rice resistance status and will provide the best advice to farmers on how to choose best genetic material according to cropping ecology.

Piezometry of the Aquifer of the Continental Terminal in the Borehole Fields of Godomey and Ouedo for the Delimitation of the Protection Areas around Boreholes of Ouedo

Groundwater is naturally protected against pollution through its filter layer which is the soil. However, the development of human activities, including the use of chemicals, gradually reduces the purifying action of this layer. It is therefore essential to develop strategies for a better management of this precious resource. The general objective of this work is to establish the piezometry of the aquifer of the Continental Terminal in the borehole fields of Godomey and Ouedo to improve the delineation of protection perimeters around the boreholes of Ouedo. The study was conducted using three methods that were the FCR method, the infiltration method and the method of Krijgsman and Lobo-Ferreira. The exploitation of the piezometric map enabled to obtain the hydraulic gradient of 0.165%. The radii of immediate protection’s perimeters (PPI) range from 55.653 m to 99.755 m. The retained close protection’ perimeters (PPR) and remote protection’s perimeters (PPE) have an ellipsoidal shape. Their upstream radii range from 220.72 m to 390 m for PPR and from 356.52 m to 659.52 m for PPE;the downstream radii range from 213.06 m to 387.25 m for PPR, and from 321.28 m to 603.97 m for PPE;the radii perpendicular to the flow direction to the right of each borehole vary from 212.58 m to 381.16 m for PPR, and from 336.11 m to 602.67 m for PPE. Probable risks identified for groundwater contamination in these protection areas are the discharge of domestic waste water, solid wastes and the use of chemical fertilizers and pesticides in farming practices.

Distribution of 26 Metals in the Waters of the Aquatic Ecosystems of the Cotonou Channel and Lake Nokoué, Benin

Metallic elements have various origins: natural and anthropogenic sources as geochemical, marine and atmospheric sources resulting from the fallout of pollutants emitted or dust raised and which are transported by water and air currents. Thus marine, brackish and fresh continental waters may have high metal concentrations. In addition, some essential metals can become toxic above certain concentration values in aquatic environments. The aquatic ecosystems of Cotonou channel and lake Nokoué receive the pollutants charges from the town cities of Cotonou, Abomey-Calavi and town hall of So Ava. The aim of this study is to analyze waters from Eighteen (18) stations identified in the two ecosystems (nine by ecosystem). The concentrations of magnesium (Mg), calcium (Ca), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), selenium (Se), cadmium (Cd), beryllium (Be), aluminum (Al), strontium (Sr), molybdenum (Mo), silver (Ag), tin (Sn), barium (Ba), platinum (Pt), mercury (Hg), thallium (Tl), lead (Pb), thorium (Th) and uranium (U) were measured after acid digestion of the water samples using the inductively coupled plasma source mass spectrometer (ICP-MS). The results of the analyses indicate an unequal distribution of metals in the different ecosystems. However, atypical concentrations were observed at some stations of the lake and the channel. Magnesium, calcium and manganese have very high values in Lake Nokoué respectively at Ganvié market station GAN_M (2990 ± 105 mg/L), Ganvié center, station GAN_C (4991 ± 177 mg/L) and Lake middle station MLak4 (10662 ± 17.03 μg/L). On the other hand, iron, aluminum and strontium have very high concentrations in the Cotonou Channel respectively at Agbato station AGB (5236 ± 103 and 8289 ± 519 μg/L) and at the estuary station EST (6118 ± 68 μg/L). The concentrations were compared to wells and cborehole waters in sixth neighborhood of Cotonou. We have used statistical analyzers such as MANOVA which have made it possible to classify the waters and metals in the ecosystems studied compared to groundwater and Well water waters. We use hierarchical clustering on principal components to identify similarities between stations based on metal concentration with R software packages “FactoMineR” and “factoextra”. In general, we can conclude that most of the metals have an anthropogenic source except strontium and major elements (Ca and Mg) which could respectively provide from marine waters and geochemical sources.

Stabilization of Clay Soil for the Durability of Structures: Case Study of the Soils of the Locality of Zalimé, Commune of Zogbodomey in the Republic of Benin

Structures erected on swelling clay soils are subjected to several stresses which are at the origin of the premature deterioration of the infrastructures. The soils being supports for the works, the improvement of their weak characteristics with cotton fibers will not only increase the bearing capacities of these soils and the resolution of the environmental problem, by eliminating the CO2 produced by the burning of the stems after harvest. The objective of this study is to contribute to the improvement of the characteristics by cotton stalk powder of the swelling clay soils used as the foundation of the infrastructures in order to guarantee their durability. Identification and mechanical parameterization tests were carried out on raw soil samples taken at 1.5 meters deep and on samples improved with cotton stalk powder at different levels (3%, 6% and 10%). The results from the physical tests reveal that the soil studied is very plastic silt. As for the mechanical tests, it appears that by adding 3% cotton stalk powder to dry density which goes from 1.435 t/m3 compared to the control sample with a dry density of 1.50 t/m3;which reflects an improvement in the compaction characteristics of the soil studied. The dry densities are 1.445 t/m3 and 1.29 t/m3 for the samples improved with 6% and 10% cotton stalk powder.