In this paper, we investigate theoretically a radial n<sup>+</sup>/p silicon solar cell in steady state and monochromatic illumination. The purpose of this work is to analyze the effect of the cell base ra...In this paper, we investigate theoretically a radial n<sup>+</sup>/p silicon solar cell in steady state and monochromatic illumination. The purpose of this work is to analyze the effect of the cell base radius on its electrical parameters. The continuity equation in cylindrical coordinates is established and solved based on Bessel functions and boundaries conditions;this led us to the photovoltage and photocurrent density in the cell. The open circuit voltage and the short circuit current density are then deduced and analyzed considering the base radius. Based on J-V and P-V curves, series and shunt resistances, fill factor and maximum power point are derived and the conversion efficiency of the cell is deduced. We showed that short circuit current density, maximum power, conversion efficiency and shunt resistance decrease with increasing base radius contrary to the open circuit voltage, the fill factor and the series resistance.展开更多
Rice is one of the staple crops in Burkina Faso. However, the local production covers only 47% of the population demands. One of the main reasons of the poor productivity in Burkina Faso is iron toxicity which is rela...Rice is one of the staple crops in Burkina Faso. However, the local production covers only 47% of the population demands. One of the main reasons of the poor productivity in Burkina Faso is iron toxicity which is related mainly to the activity of Iron Reducing Bacteria in the rice field’s ecosystems. In order to control the harmful effects of Iron Reducing Bacterial populations and to improve rice productivity, a pots experiment was conducted at the experimental site of the University Ouaga I Pr. Joseph KI-ZERBO. An iron toxic soil from Kou Valley (West of Burkina Faso) and two rice varieties, BOUAKE-189 and ROK-5, sensitive and tolerant to iron toxicity, respectively, were used for the experiment. The pots were drained for 14 days (D2) and amended with chemical fertilizers (NPK + Urea and NPK + Urea + Ca + Mg + Zn complexes). Control pots without drainage and fertilization (D0/NF) were prepared similarly. The kinetics of Iron Reducing Bacterial populations and ferrous iron content in soil near rice roots were monitored throughout the cultural cycle using MPN and colorimetric methods, respectively. The total iron content was evaluated in rice plant using a spectrometric method. Data obtained were analyzed in relation to drainage and fertilization mode, rice growth stage and rice yield using the Student’s t-test and XLSTAT 2014 statistical software. The experiment showed that the combined application of subsurface drainage and NPK + Urea + Ca + Mg + Zn fertilization, reduced significantly the number of IRB in the soil near rice roots for both rice varieties (p = 0.050 and p = 0.020) increased the leaf tissue tolerance to excess amounts of Fe, and rice yield.展开更多
文摘In this paper, we investigate theoretically a radial n<sup>+</sup>/p silicon solar cell in steady state and monochromatic illumination. The purpose of this work is to analyze the effect of the cell base radius on its electrical parameters. The continuity equation in cylindrical coordinates is established and solved based on Bessel functions and boundaries conditions;this led us to the photovoltage and photocurrent density in the cell. The open circuit voltage and the short circuit current density are then deduced and analyzed considering the base radius. Based on J-V and P-V curves, series and shunt resistances, fill factor and maximum power point are derived and the conversion efficiency of the cell is deduced. We showed that short circuit current density, maximum power, conversion efficiency and shunt resistance decrease with increasing base radius contrary to the open circuit voltage, the fill factor and the series resistance.
文摘Rice is one of the staple crops in Burkina Faso. However, the local production covers only 47% of the population demands. One of the main reasons of the poor productivity in Burkina Faso is iron toxicity which is related mainly to the activity of Iron Reducing Bacteria in the rice field’s ecosystems. In order to control the harmful effects of Iron Reducing Bacterial populations and to improve rice productivity, a pots experiment was conducted at the experimental site of the University Ouaga I Pr. Joseph KI-ZERBO. An iron toxic soil from Kou Valley (West of Burkina Faso) and two rice varieties, BOUAKE-189 and ROK-5, sensitive and tolerant to iron toxicity, respectively, were used for the experiment. The pots were drained for 14 days (D2) and amended with chemical fertilizers (NPK + Urea and NPK + Urea + Ca + Mg + Zn complexes). Control pots without drainage and fertilization (D0/NF) were prepared similarly. The kinetics of Iron Reducing Bacterial populations and ferrous iron content in soil near rice roots were monitored throughout the cultural cycle using MPN and colorimetric methods, respectively. The total iron content was evaluated in rice plant using a spectrometric method. Data obtained were analyzed in relation to drainage and fertilization mode, rice growth stage and rice yield using the Student’s t-test and XLSTAT 2014 statistical software. The experiment showed that the combined application of subsurface drainage and NPK + Urea + Ca + Mg + Zn fertilization, reduced significantly the number of IRB in the soil near rice roots for both rice varieties (p = 0.050 and p = 0.020) increased the leaf tissue tolerance to excess amounts of Fe, and rice yield.
