High-voltage insulation organic-inorganic nanocomposites by plasma polymerization

In organic-inorganic nanocomposites, interfacial regions are primarily influenced by the dispersion uniformity of nanoparticles and the strength of interfacial bonds between the nanoparticles and the polymer matrix. The insulating performance of organic-inorganic dielectric nanocomposites is highly influenced by the characteristics of interfacial regions. In this study, we prepare polyethylene oxide (PEO)-like functional layers on silica nanoparticles through plasma polymerization. Epoxy resin/silica nanocomposites are subsequently synthesized with these plasma-polymerized nanoparticles. It is found that plasma at a low power (i.e., 10 W) can significantly increase the concentration of C-O bonds on the surface of silica nanoparticles. This plasma polymerized thin layer can not only improve the dispersion uniformity by increasing the hydrophilicity of the nanoparticles, but also provide anchoring sites to enable the formation of covalent bonds between the organic and inorganic phases. Furthermore, electrical tests reveal improved electrical treeing resistance and decreased dielectric constant of the synthesized nanocomposites, while the dielectric loss of the nanocomposites remains unchanged as compared to the pure epoxy resin.

Del conocimiento y amor del hijo de Dios nuestro Sr. Jesucristo

UANL

Acoplamiento del ciclo humanístico de los seminarios al Bachillerato oficial.

Desde hace algunos años se está generalizando la idea del acoplamiento de los estudios del ciclo humanístico de los seminarios al bachillerato oficial, pero entre los estudios de ambos se está produciendo cada vez más un cierto distanciamiento debido a los planes de estudio del bachillerato orientados hacia la especialización científica y técnica con un total olvido del latín y el griego. En definitiva, este acoplamiento se debe realizar de forma coherente y lógica como se ha realizado en Madrid, teniendo en cuenta que no se puede dar demasiadas pocas clases de latín y griego y que la selección del programa debe centrarse en la calidad de la enseñanza, no en la cantidad.

Modelagem da produção de sedimentos na sub-Bacia Hidrográfica do Riacho Jacaré - SE

The sediment production in river basins is an important aspect for planning the land use. Mathematical models are useful tools for analyzing the problem by providing speed, convenience and flexibility to the simulations of current conditions and future. In this article we evaluate a methodology to simulate the sediment production combining the MUSLE, a hydrologic model (ABC) and a GIS in different scenarios of land use. The models used showed good performance for purposes of planning land use, as well as for agricultural and environmental planning.