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New composite boards with low-thermal conductivity produced from a mixture of powder Typha leaves and a binder as gum arabic have been developed. The goal of this paper was to investigate the effect of binder content on compressive strength and thermal properties of typha panels. The results showed that the panels with a binder content of 33.33–50 % had the thermal conductivity values ranging from 0.055 to 0.083 W.m-1.K-1, which was close to that of many natural insulating materials. The compressive strength values obtained were comparable to those of the lime – hemp concrete. This study showed that typha possesses interesting capacities of insulating and its combination with gum arabic contributes to the improvement of thermal comfort, to the reduction of the energy consumption as well as to the emissions of CO2.

New composite boards with low-thermal conductivity produced from a mixture of powder Typha leaves and a binder as gum arabic have been developed. The goal of this paper was to investigate the effect of binder content on compressive strength and thermal properties of typha panels. The results showed that the panels with a binder content of 33.33–50 % had the thermal conductivity values ranging from 0.055 to 0.083 W.m-1.K-1, which was close to that of many natural insulating materials. The compressive strength values obtained were comparable to those of the lime – hemp concrete. This study showed that typha possesses interesting capacities of insulating and its combination with gum arabic contributes to the improvement of thermal comfort, to the reduction of the energy consumption as well as to the emissions of CO2.

This paper explores the monitoring and evaluation system of the Millennium Villages Project in Potou, rural Senegal. It specifically focuses on the first evaluation report undertaken in 2009 after three years of intervention to assess the impacts of the project on communities in Potou. Theory of change, causal attribution, scaling-up, use of evaluation, and learning are the key issues that are addressed throughout the paper. Interviews with beneficiaries and project staff as well as the analysis of the project’s evaluation report revealed that the project has created many positive impacts in the communities of Potou. However, unintended negative results have been observed in the sectors of education, health, and agriculture. Given the weaknesses that have been identified in the evaluation method, this paper suggests some strategies to strengthen the methodology of future evaluations, thus allowing for distinct attribution of the impacts to the project. Consilience, No 9 (2013): Issue Nine: 2013

This paper explores the monitoring and evaluation system of the Millennium Villages Project in Potou, rural Senegal. It specifically focuses on the first evaluation report undertaken in 2009 after three years of intervention to assess the impacts of the project on communities in Potou. Theory of change, causal attribution, scaling-up, use of evaluation, and learning are the key issues that are addressed throughout the paper. Interviews with beneficiaries and project staff as well as the analysis of the project’s evaluation report revealed that the project has created many positive impacts in the communities of Potou. However, unintended negative results have been observed in the sectors of education, health, and agriculture. Given the weaknesses that have been identified in the evaluation method, this paper suggests some strategies to strengthen the methodology of future evaluations, thus allowing for distinct attribution of the impacts to the project. Consilience, No 9 (2013): Issue Nine: 2013

In this work, recent advances in various silicon nanostructures used in crystalline silicon solar cells for antireflection and light trapping are reviewed. Simulations and optimizations are also performed for the most relevant of these nanostructures. The results showed that nanocones and nanoparaboloids outperform nanopillars and give almost the same antireflective performance, reducing the average reflectance of the crystalline silicon surface below 2% in the wavelength range 300-1100 nm and under normal incidence. This reflectance is also found to stay below 4% for angles of incidence lower than 60° and for the averaged s and p light polarization. As a result, short-circuit current densities of 41.62 and 41.96 mA/cm², can be expected for a silicon solar cell decorated with these two nanostructures, respectively. Finally, we described the formation of silicon nanocones via nanowires by metal assisted chemical etching.

In this work, recent advances in various silicon nanostructures used in crystalline silicon solar cells for antireflection and light trapping are reviewed. Simulations and optimizations are also performed for the most relevant of these nanostructures. The results showed that nanocones and nanoparaboloids outperform nanopillars and give almost the same antireflective performance, reducing the average reflectance of the crystalline silicon surface below 2% in the wavelength range 300-1100 nm and under normal incidence. This reflectance is also found to stay below 4% for angles of incidence lower than 60° and for the averaged s and p light polarization. As a result, short-circuit current densities of 41.62 and 41.96 mA/cm², can be expected for a silicon solar cell decorated with these two nanostructures, respectively. Finally, we described the formation of silicon nanocones via nanowires by metal assisted chemical etching.

This paper presents a model for short-term forecasting of solar potential on a horizontal surface. This study is carried out in to the context of valuing of energy production from photovoltaic solar sources in the Sahelian zone. In this study, Autoregressive Moving Average (ARMA) process is applied to predict global solar potential upon 24 hours ahead. The ARMA (p, q) is based on finding optimum parameters p and q to better fit considered variable (sunshine). Data used for the model calibrating are measured at the station of Ecole Supérieure Polytechnique of Dakar. Records are hourly and range from October 2016 to September 2017. The choice of this model is justified by its robustness and its applicability on several scales through the world. Simulation is done using the RStudio software. The Akaike information criterion shows that ARMA (29, 0) gives the best representation of the data. We then applied a white noise test to validate the process. It confirms that the noise is of white type with zero mean, variance of 1.252 and P-value of about 26% for a significant level of 5%.Verification of the model is doneby analyzing some statistical performance criteria such the RMSE =0.629 (root mean squared error), the R² = 0.963 (Coefficient of determination), the MAE=0.528 (Mean Absolut Error) and the MBE=0.012 (Mean BiasError). Statistics criteria show that the ARMA (29,0) is reliable; then, can help to improve planning of photovoltaic solar power plants production in the Sahelian zone.