Applied Social Science / Education

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Browsing Applied Social Science / Education by Subject "CEA/IEA-MS4SSA"

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    Rotifers in the Niger River, Niger: diversity and abundance in relation to environmental parameters
    (African Journal of Aquatic Science, 2021-01-26) Adamou, H Souley; Alhou, B; Tackx, M
    A first study of the rotifers of the Niger River in Niger is reported here. Two surveys took place under contrasting hydrological conditions: low-water level (16 April to 8 May 2018) and high-water level (1 to 15 February 2019). Zooplankton and physico-chemical parameters were sampled at eight stations spread over 520 km from Ayorou to Gaya. In total, 32 taxa were identified, including 26 at species level. During the low-water sampling, Polyarthra sp. (31%), Brachionus caudatus (23%), Synchaeta longipes (11%), Keratella tropica (7%) and Filinia longiseta (5%) were the most abundant, whereas Brachionus quadridentatu s (26%), Lecane hastata (25%), Keratella cochlearis (9%), Keratella lunaris (5%), Hexarthra sp. (3%) were dominant during the high-water sampling. The mean abundance of rotifers ranged between 14 × 103 ind. m−3 during the high-water sampling and 244 × 103 ind. m−3 during the low-water sampling. The highest diversity was observed in the three stations located upstream from the city of Niamey. The results reflect the difference in environmental parameters between the downstream and upstream Niamey stations. RDA analyses showed that the main environmental factors explaining the distribution of rotifers were dissolved oxygen, orthophosphate and nitrate concentrations.
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    Study of Mass and Energy Yields of an Agroforestry Residues Carbonizer
    (International Journal of Engineering Trends and Technology, 2021-11) Nouhou, Doulla Seydou; Ali, Aboubacar; Ibrahim, Harouna Gado
    Energy recovery from processing wastes of agricultural products is a solution to their management issues and a means of energy production. In addition, it contributes to the reduction of deforestation. The objective of this study is to develop a method of agroforestry residues carbonization. The residues used to consist of the shell of the doum palm (hyphaenethebaica) and the rice husk. Carbonization is in partial combustion, and the device used is a metal furnace made up of three (3) stages. The peaks of temperatures, mass and energy yields, and the quality of the coal (fixed carbon rate) were determined at each stage of the carbonized. The mass yields obtained for stages 3, 2, and 1 are 66.41%, 42.60%, and 21.57% for the shell of the doum palm and 46.94%, 67.19% 24.83% for the rice husk. The energy yields are 82.41%, 57.05%, and 30.97% for the shell of the doum palm and 56.1%, 74.58%, and 26.66% for the rice husk. The coal quality (fixed carbon rate) for the same stages 3, 2, and 1 is 35.32%, 44.42%, and 52.32% for the shell of the doum palm and 32.55%, 30, 43%, and 30.75% for the rice husk. The cycle time is 9.03h for the shell of the doum palm against 11.22h for the rice husk. This study shows that the shell of the doum palm produces better quality charcoal compared to the rice husk and that the charcoal obtained at stage 1 ( ) can be used not only for gasification but also for direct home use.