Depositing an antireflection coating on the front surface of solar cells allows a significant reduction in reflection losses. It thus allows an increase in the efficiency of the cells. A modeling of the refractive ind...Depositing an antireflection coating on the front surface of solar cells allows a significant reduction in reflection losses. It thus allows an increase in the efficiency of the cells. A modeling of the refractive indices and the thicknesses of an optimal antireflection coating has been proposed. Thus, the average reflective losses can be reduced to less than 8% and less than 2.4% in a large wavelength range respectively for a single-layer and double-layer anti-reflective coating types. However, the difficulty of finding these model materials (materials with the same refractive index) led us to introduce two notions: the refractive index difference and the thickness difference. These two notions allowed us to compare the reflectivity of the antireflection layer in silicon surface. Thus, the lower the refractive index difference is, the more the material resembles to the ideal material (in refractive index), and thus its reflective losses are minimal. SiNx and SiO2/TiO2 antireflection layers, in the wavelength range between 400 and 1100 nm, have reduced the average reflectivity losses to less than 9% and 2.3% respectively.展开更多
countries in West Africa remain a hotspot for malaria with all age groups at risk.Asymptomatic carriers of Plasmodium spp.are important sources of infections for malaria vectors and thus contribute to the anchoring of...countries in West Africa remain a hotspot for malaria with all age groups at risk.Asymptomatic carriers of Plasmodium spp.are important sources of infections for malaria vectors and thus contribute to the anchoring of the disease in favourable eco-epidemiological settings.The objective of this study was to assess the asymptomatic malaria case rates in Korhogo and Kaedi,two urban areas in northern Côte d’Ivoire and southern Mauritania,respectively.Methods:Cross-sectional surveys were carried out during the rainy season in 2014 and the dry season in 2015 in both settings.During each season,728 households were randomly selected and a household-based questionnaire was implemented to collect demographic and epidemiological data,including of malaria preventive methods used in communities.Finger-prick blood samples were obtained for biological examination using microscopy and rapid diagnostic tests(RDTs).Results:Overall,2672 households and 15858 consenting participants were surveyed.Plasmodium spp.infection was confirmed in 12.4%(n=832)and 0.3%(n=22)of the assessed individuals in Korhogo and Kaedi,respectively.In Korhogo,the prevalence of asymptomatic malaria was 10.5%(95%CI:9.7-11.2)as determined by microscopy and 9.3%(95%CI:8.6-10.0%)when assessed by RDT.In Kaedi,asymptomatic malaria prevalence was 0.2%(95%CI:0.1-0.4%)according to microscopy,while all RDTs performed were negative(n=8372).In Korhogo,asymptomatic malaria infection was significantly associated with age and season,with higher risk within the 5-14 years-old,and during the rainy season.In Kaedi,the risk of asymptomatic malaria infection was associated with season only(higher during the dry season;crude OR(cOR):6.37,95%CI:1.87-21.63).P.falciparum was the predominant species identified in both study sites representing 99.2%(n=825)in Korhogo and 59.1%(n=13)in Kaedi.Gametocytes were observed only in Korhogo and only during the rainy season at 1.3%(95%CI:0.7-2.4%).Conclusions:Our findings show a low prevalence of clinical malaria episodes with a significant proportion of asymptomatic carriers in both urban areas.National policies for malaria infections are focused on treatment of symptomatic cases.Malaria control strategies should be designed for monitoring and managing malaria infections in asymptomatic carriers.Additional measures,including indoor residual spraying,effective use of long-lasting insecticidal nets is strongly needed to reduce the number of Plasmodium spp.infections in Korhogo and Kaedi.展开更多
文摘Depositing an antireflection coating on the front surface of solar cells allows a significant reduction in reflection losses. It thus allows an increase in the efficiency of the cells. A modeling of the refractive indices and the thicknesses of an optimal antireflection coating has been proposed. Thus, the average reflective losses can be reduced to less than 8% and less than 2.4% in a large wavelength range respectively for a single-layer and double-layer anti-reflective coating types. However, the difficulty of finding these model materials (materials with the same refractive index) led us to introduce two notions: the refractive index difference and the thickness difference. These two notions allowed us to compare the reflectivity of the antireflection layer in silicon surface. Thus, the lower the refractive index difference is, the more the material resembles to the ideal material (in refractive index), and thus its reflective losses are minimal. SiNx and SiO2/TiO2 antireflection layers, in the wavelength range between 400 and 1100 nm, have reduced the average reflectivity losses to less than 9% and 2.3% respectively.
基金This project received financial support from the UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases(TDR)and the Canadian International Development Research Centre(IDRC)grant no.NB20283(Dr.Kone Brama)The funders had no role in study design,data collection and analyses,decision to publish,or preparation of the manuscript.
文摘countries in West Africa remain a hotspot for malaria with all age groups at risk.Asymptomatic carriers of Plasmodium spp.are important sources of infections for malaria vectors and thus contribute to the anchoring of the disease in favourable eco-epidemiological settings.The objective of this study was to assess the asymptomatic malaria case rates in Korhogo and Kaedi,two urban areas in northern Côte d’Ivoire and southern Mauritania,respectively.Methods:Cross-sectional surveys were carried out during the rainy season in 2014 and the dry season in 2015 in both settings.During each season,728 households were randomly selected and a household-based questionnaire was implemented to collect demographic and epidemiological data,including of malaria preventive methods used in communities.Finger-prick blood samples were obtained for biological examination using microscopy and rapid diagnostic tests(RDTs).Results:Overall,2672 households and 15858 consenting participants were surveyed.Plasmodium spp.infection was confirmed in 12.4%(n=832)and 0.3%(n=22)of the assessed individuals in Korhogo and Kaedi,respectively.In Korhogo,the prevalence of asymptomatic malaria was 10.5%(95%CI:9.7-11.2)as determined by microscopy and 9.3%(95%CI:8.6-10.0%)when assessed by RDT.In Kaedi,asymptomatic malaria prevalence was 0.2%(95%CI:0.1-0.4%)according to microscopy,while all RDTs performed were negative(n=8372).In Korhogo,asymptomatic malaria infection was significantly associated with age and season,with higher risk within the 5-14 years-old,and during the rainy season.In Kaedi,the risk of asymptomatic malaria infection was associated with season only(higher during the dry season;crude OR(cOR):6.37,95%CI:1.87-21.63).P.falciparum was the predominant species identified in both study sites representing 99.2%(n=825)in Korhogo and 59.1%(n=13)in Kaedi.Gametocytes were observed only in Korhogo and only during the rainy season at 1.3%(95%CI:0.7-2.4%).Conclusions:Our findings show a low prevalence of clinical malaria episodes with a significant proportion of asymptomatic carriers in both urban areas.National policies for malaria infections are focused on treatment of symptomatic cases.Malaria control strategies should be designed for monitoring and managing malaria infections in asymptomatic carriers.Additional measures,including indoor residual spraying,effective use of long-lasting insecticidal nets is strongly needed to reduce the number of Plasmodium spp.infections in Korhogo and Kaedi.
