The current study presents the characterization of three types of materials after exposure to solar UV radiation. The selection of the materials is related to socio-economic aspects and rural activities in the northwe...The current study presents the characterization of three types of materials after exposure to solar UV radiation. The selection of the materials is related to socio-economic aspects and rural activities in the northwest of Argentina (a.k.a. NOA). The objective was to establish a time parameter that allows estimating the durability of the materials according to their use. One of the materials is used as a protective cover (polyethylene film) of greenhouses, which are used for crop cultivation in the area. Another material is used in photovoltaic modules (PVMs), which are used to supply energy in isolated areas and the third material is sunscreen used by people that are exposed to UV radiation during rural activities. Degradation or deterioration of the materials was monitored using different spectroscopic assays: infrared was used to detect any structural changes in the material, X-rays were used for possible changes in the crystalline structure of the material, and spectral transmittance as this property is likely to be affected by changes in the structure of the material. The results showed that degradation of polyethylene seems to be related to the diminution in transparency and the loss of mechanical resistance with increasing exposure time. The decrease in transparency of one of the layers of a PVM caused a considerable decrease in the energy generated, whereas the sunscreens with a low sun protection factor (SPF) rapidly lost their protective properties and changed their photostability properties. Our results revealed a relationship between relative transmittance loss and exposure timse, which allows estimating the stability of different materials.展开更多
More than 10% of the population in Salta is regarded as rural. Many rural areas suffer a shortage of energy, and consequently, possibilities of social and economic development of the inhabitants become reduced. The ac...More than 10% of the population in Salta is regarded as rural. Many rural areas suffer a shortage of energy, and consequently, possibilities of social and economic development of the inhabitants become reduced. The activation of renewable energy sources in these areas presents inhabitants the advantages to generate their own energy. Dispersed rural communities create small electricity demands that are not considered by suppliers, because they are not profitable. Although thus far, feasibility analyses to install photovoltaic or thermal solar collectors are based on technical reasons, it seems more convenient that, in the future, projects for the installation of technology based on renewable energy should consider social indicators. As a preliminary step to field work is proposed in this paper using an equation that allows us to obtain a value of＂social index＂. With this analysis and the current survey accompanied by the local people, knowledge will be obtained of the real needs of these rural communities. The results show that there is a variation that would allow a classification or ordering of localities. To validate the results obtained is proposed as the next step to perform field work in each of the localities.展开更多
文摘The current study presents the characterization of three types of materials after exposure to solar UV radiation. The selection of the materials is related to socio-economic aspects and rural activities in the northwest of Argentina (a.k.a. NOA). The objective was to establish a time parameter that allows estimating the durability of the materials according to their use. One of the materials is used as a protective cover (polyethylene film) of greenhouses, which are used for crop cultivation in the area. Another material is used in photovoltaic modules (PVMs), which are used to supply energy in isolated areas and the third material is sunscreen used by people that are exposed to UV radiation during rural activities. Degradation or deterioration of the materials was monitored using different spectroscopic assays: infrared was used to detect any structural changes in the material, X-rays were used for possible changes in the crystalline structure of the material, and spectral transmittance as this property is likely to be affected by changes in the structure of the material. The results showed that degradation of polyethylene seems to be related to the diminution in transparency and the loss of mechanical resistance with increasing exposure time. The decrease in transparency of one of the layers of a PVM caused a considerable decrease in the energy generated, whereas the sunscreens with a low sun protection factor (SPF) rapidly lost their protective properties and changed their photostability properties. Our results revealed a relationship between relative transmittance loss and exposure timse, which allows estimating the stability of different materials.
文摘More than 10% of the population in Salta is regarded as rural. Many rural areas suffer a shortage of energy, and consequently, possibilities of social and economic development of the inhabitants become reduced. The activation of renewable energy sources in these areas presents inhabitants the advantages to generate their own energy. Dispersed rural communities create small electricity demands that are not considered by suppliers, because they are not profitable. Although thus far, feasibility analyses to install photovoltaic or thermal solar collectors are based on technical reasons, it seems more convenient that, in the future, projects for the installation of technology based on renewable energy should consider social indicators. As a preliminary step to field work is proposed in this paper using an equation that allows us to obtain a value of＂social index＂. With this analysis and the current survey accompanied by the local people, knowledge will be obtained of the real needs of these rural communities. The results show that there is a variation that would allow a classification or ordering of localities. To validate the results obtained is proposed as the next step to perform field work in each of the localities.
