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The purpose of this research is to determine the geochemical and mineralogical similarities of both clay sources from the Tena and Archidona cantons and Cosanga archaeological objects recovered from the upper Napo River basin, Cosanga and Quijos valleys. 22 clay samples and 15 archaeological artifacts were used. The geochemical analyses were performed by atomic absorption spectroscopy (AAS) and energy dispersive X-ray (EDX), while the mineralogical analyses were done by X-ray diffraction (XRD), also using scanning electron microscope (SEM) images. The results showed that both the raw material and the objects came from a homogeneous geological environment, confirming the exchange within the study area. [ABSTRACT FROM AUTHOR]

The objective of this study was to develop ceramic tiles that comply with the Colombian Technical Standard - NTC 919, using agro-industrial banana residues as a feldspar substitute. To this end, test tiles were designed with various mixtures in flours and ashes from the agro-industrial residue and others with the conventional ceramic formula, called PATRON sample. In all the mixtures, the physical-ceramic properties and density were determined. The alternative mixture that showed the best results continued to be analyzed with X-Ray Fluorescence, X-Ray Diffraction and Scanning Electron Microscope. The physical-ceramic properties showed a better suitability in the test tiles prepared with 5% banana peel flour. XRF analyses show a predominance of silica and aluminium, which probably associated with mullite, according to XRD; this was also observed in the microscopic images. The results of the analyses reveal a product with a quality within the NTC 919 standard. [ABSTRACT FROM AUTHOR]

Thin films of Zinc Oxide (ZnO) were grown on glass substrates conductive FTO (Fluorine-doped tin oxide) with a thickness of 400 nm. The hybrid films of ZnO and dye (N719) were grown on FTO conductive glass to a thickness of 600 nm. The growth of hybrid films of ZnO / N719 was made by two steps, cathodic electrodeposition and diping. The effect of increasing the temperature for growth of the hybrid films to 80 °C allows absorption of the dye in the fixed structure of ZnO, completely modifying the ZnO structure of hexagonal wirtzita to be evaluated using the Scanning Electron Microscope (SEM) and X-ray diffraction (XRD). Morphological response study by Scanning Electron Microscope (SEM) showed that it is possible to obtain pores with a diameter <350 nm in the structure of ZnO completely changing its hexagonal shape. The response of optical properties in the hybrid ZnO films / N719, proved to be found two peaks of absorption in the spectrum, 340 nm and 660 nm when a metal-X adheres to the structure of ZnO. [ABSTRACT FROM AUTHOR]

X-Ray Diffraction, Scanning Electron Microscopy, High Resolution Transmission Electron Microscopy studies have been made of TlInS2 layered semiconductor compound to clarify its crystal structure, which has remained ambiguous through several decades. Similarly, in recent studies it has been reported at ambient conditions this semiconductor can crystallize in several polytypes with monoclinic structure, which may be present in the same sample. In this study it was found at ambient temperature TlInS2 crystallized in a monoclinic structure, space group C2/c with lattice parameters a = 8.609 Å, b = 14.904 Å, c = 9.471 Å, ß = 110.44 °, it was not found the presence of more than one polytype in the studied sample. Additionally, the results obtained were compared with other previously derived using an analysis of the vibration modes of the compound by means of Raman spectroscopy. [ABSTRACT FROM AUTHOR]

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Dry powder method is a solid-state processing technique involving constant milling of the initial compounds for later calcination. This technique was used to prepare the compounds presented in this essay, using TiO2 and MgO in diferentes rates. To analyze the resulting compounds' morphology, Scanning electron microscope (SEM) was used. In the images taken from the TiO2 sample, groups of agglomerations and of grains were found. Nevertheless, it maintains a certain round pattern in both groups, in the shape of micrograins of 0.5-1 µm. SEM images from the MgO sample are typically laminar with barely a few microns of width. The comparative studies of their structural and spectral characteristics through X-ray Diffraction (XRD) confirmed the individual structure of each compound and also, new spectral lines are obtained which suggests that titanates were formed during the process. [ABSTRACT FROM AUTHOR]