Victor Hugo Lara

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UNLABELLED BACKGROUND It is imperative to eliminate bacteria present in water in order to avoid problems in healthy. Escherichia coli and Salmonella typhi bacteria are two common pollutants and they are developing resistance to some of the most used bactericide. Therefore new biocide materials are being tested. Thus, gold nanoparticles are proposed to(More)
Small angle X-ray scattering (SAXS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) have been used to look at enamel from nine premolars, three each from individuals in low, medium and high risk caries groups. Only SAXS was able to detect consistent differences between any of the groups. In enamel from the high caries risk(More)
Samples of polycrystalline calcite were impregnated with solutions of malonic acid of three concentrations (5 x 10(-2), 5 x 10(-3) , and 5 x 10(-4) M) and different pH values (6.00, 7.00, and 8.00). The impregnation was carried out at room temperature to evaluate the adsorption of malonate ion in the calcite surface to optimize the conditions for possible(More)
Layers of a layered double hydroxide, containing aluminum 4-fold coordinated, were partially folded in order to obtain a fibrous hydrotalcite-like compound. The hydrotalcite layers, in the presence of an anionic surfactant (sodium dodecyl sulfate) after hydrothermal treatment for 2 weeks, acquire a mesoporous-like arrangement. The transformation was(More)
The present study discusses the effect of gamma-irradiation on Cs+-exchanged X and A zeolites. The incorporation of Cs+ ions into A and X zeolites was performed using three different cesium salts (chloride, nitrate or acetate). Cs+ ions immobilized into the vitrified zeolites by thermal treatment are located in different sites of the zeolite networks. It is(More)
We explored the affinity of calcite to adsorbed organic molecules as an approach to the conservation of cultural heritage built of marble and limestone. The utilization of phenylmalonic and benzylmalonic acids provided a hydrophobic adsorptive interface, adequate to prevent processes of aqueous weathering. Samples of marble powder (polycrystalline calcite)(More)
Phosphated alumina gels were prepared by the sol-gel method. Gels were aged from 1 to 8 days in air. Gel structure evolution, as time went on, was followed by 27Al magic angle spinning nuclear magnetic resonance, X-ray diffraction, and small-angle X-ray scattering. It is concluded that the aging time is a crucial parameter in the formation of coordinately(More)
Cesium-exchanged A and X zeolites were loaded with cesium acetate species and thermally treated in order to inhibit the mobility of exchangeable cesium cations. The proposed procedure seems to block the cavities channels avoiding the releasing of cesium cations under the leaching conditions. The cesium impregnated species did not induce strong structural(More)
The rehydration process of a calcined MgAl-layered double hydroxide (LDH) with a Mg/Al molar ratio of 3 was systematically analyzed at different temperatures and relative humidity. Qualitative and quantitative experiments were done. In the first set of samples, the temperature or the relative humidity was varied, fixing the second variable. Both adsorption(More)
Maize starch was lime-cooked at 92 °C with 0.0-0.40% w/w Ca(OH)2. Optical micrographs showed that lime disrupted the integrity of insoluble remnants (ghosts) and increased the degree of syneresis of the gelatinized starch dispersions (GSD). The particle size distribution was monomodal, shifting to smaller sizes and narrower distributions with increasing(More)
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