Scielo RSS <![CDATA[Superficies y vacĂ­o]]> http://www.scielo.org.mx/rss.php?pid=1665-352120180004&lang=es vol. 31 num. 4 lang. es <![CDATA[SciELO Logo]]> http://www.scielo.org.mx/img/en/fbpelogp.gif http://www.scielo.org.mx <![CDATA[Study of the behavior of short chains in print paper subjected to a natural aging]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1665-35212018000400001&lng=es&nrm=iso&tlng=es Abstract: Degradation of paper through time can be measured by monitoring the intensity changes in the band located at 620 nm of its emission fluorescence spectra. The behavior of this band is closely related to the structural stability of the short cellulose chains. A fast degradation of these cellulose chains, mainly lignin, translates in the rapid denaturation of paper occurring at its first aging state. This work proposes a method to reincorporate short cellulose chains in the structure of aged paper through its immersion during 24 h in a solution based on ethyl alcohol and extracts of wood pieces. Results of fluorescence spectra measurements indicate that the short cellulose chains in the solution get embedded in the old paper, making the shape and intensity of the fluorescence emission spectra peaks of new and old paper almost indistinguishable. This behavior provides a desirable approach to analyze, preserve and restore aged paper documents. <![CDATA[Deposition of SnO<sub>2</sub> buffer layer onto commercial conducting glass to be used in thin films solar cells technology]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1665-35212018000400002&lng=es&nrm=iso&tlng=es Abstract: In this work the influence of the deposition of SnO2 buffer layer on the optical, electrical and morphological properties of commercial conducting glasses is presented. Previously the transparent conducting oxide (TCO) were studied in order to determine which is the most appropriate in solar cell applications. The SnO2 thin films were deposited onto glass and commercial conducting glass by pneumatic spray pyrolysis (PSP) and magnetron sputtering techniques and characterized optically and electrically. TCO/buffer bi-layers configuration were processed and characterized through a modified well-known Haccke figure of merit. The results are discussed in terms of considering the usefulness or otherwise of this configuration, depending on the morphological quality of commercial conductive glass in the processing of second-generation solar cells in thin film technology.