No abstract

This work consisted in the development and characterization of a bioactive coating on Ti6Al4V samples by flame spray projection. A synthetichidroxyapatite powder was used to form the coatings. Oxygen and acetylene gas were used as combustible, and the metallic substrate was Ti6Al4V with a roughness of 0.4 and 2.3 μm. The time process varied from 5 to 60 seconds. The projection distance was of 22 cm.The spray coatings were mechanical tested; in all cases, the results indicated that the coatings were well adhered to the metallic surfaces and the metallic subtracts did not present any degradation of the mechanical properties. In addition, the coatings were immersed in simulated body fluids for 21 days in physiological conditions to evaluate the bioactivity. The results demonstrated that the coatings are potentially bioactive through the formation of a dense and homogeneous apatite layer similar to the bone. Results of X-ray diffraction exhibited evidence of a hidroxyapatite layer and by energy dispersive spectroscopy, a Ca/P ratio of 1.57 was obtained. This is an indication of that the use of flame spray projection to coat Ti6Al4V substrates do not decompose the original hidroxyapatite powder. Compositional analysis of the remnant fluids, made by inductively coupled plasma spectrometry, showed that nonmetallic ions were present in the coatings.

In this work, was considered the thesis that the optic properties of anti-reflecting and the satin-like glasses can improve the efficiency of solar panels that use plastic covertures or conventional glasses as coverage. The infrared radiation that is not turned into electricity with the conventional photovoltaic cells, increments the panel surface temperature, of the supporting structure and of the photovoltaic cells. For above 35oC it is possible that some cells stop converting the visible light in electricity due toparameters dispersion effect, with this, the efficiency of electric generation is diminished. In the electromagnetic spectrum, the wavelength of infrared radiation is since 800nm, the anti-reflecting glasses transmittance is since430 to 680 nm, while the satin-like glassestransmittance issince 500 to 600nm, therefore for thiscause the infrared transmittance is not observed. In this work, it was proved that the use of anti-reflecting glasses and satin-like glasses improves the conventional solar panels efficiency. The results suggest an efficiency of 31.6 % of solar energy conversion with the anti-reflecting glass, and 36% with the satin-like glass, when these were used as cover panel photovoltaic.

The aim of this work was focused on developing a hydrotalcite by chemistry coprecipitation, which one was tested with one agricultural herbicide used in the region of the "Bajío" of the state of Guanajuato in Mexico. The clay was synthesized by a method by chemical precipitation at vacuum, and it was exposed to an herbicide for cultures control. The results showed that the hydrotalcitestructure and the toxic basicity, define their absorption in the hydrotalcite, performance fulfilling a function of soil recuperation.