Nanoestructured TiO2 solar cells modified with MgO (TiO2-MgO) were assembled and characterized; they were sensitized with N791 dye. The MgO modification of the TiO2 films was performed using suspensions with different concentrations of Mg(OH)2 prepared from magnesium nitrate in aqueous solution. One drop of the suspension was placed on top of the film and then was sintered at 530 °C during 30 min. Unsealed cells and sealed cells were obtained, the latter achieved an efficiency of 4.4%, representing an increase of 69% compared to the unmodified sealed cells, which showed an efficiency of 2.6%. Solar efficiency measurements were also performed in darkness and under illumination. It was found that the efficiency diminished 19% in darkness after 22 days, but under illumination diminished 76 % in two days. 

Se comparó la función visual de dos aves terrestres Charadriiformes: la dara (Burhinus bistriatusWagler 1829), de hábitos de crepusculares y nocturnos, y el alcaraván (Vanellus chilensis L. 1758), primordialmente diurnos y ocasionalmente nocturnos, utilizando electrorretinogramas (ERG), mediante análisis morfológicos y electrofisiológicos de sus retinas. Dado que las daras tienen los ojos relativamente más grandes y mayor actividad nocturna que los alcaravanes se esperarían que tuvieran una retina más sensible bajo condiciones de escasa iluminación. Las aves fueron anestesiadas para obtener los electrorretinogramas bajo condiciones escotópicas y fotópicas y luego sacrificadas para el análisis histológico de la retina. A todas las intensidades luminosas probadas, las ondas b escotópicas fueron siempre de mayor amplitud en B. bistriatus que en V. chilensis; no obstante, la ...