1
artículo
Publicado 2010
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In this work, we study the crystallization and surface morphology of Cu thin films (exposed to environment) growth on SiO2/Si subsstrates. The samples thermally treated using a tubular furnace bet ween temperature range 250-1000ºC during an elapsed time of 3 hours, after was cooling to a rate of 1.4ºC/min. The crystalization process was measured by X-ray difraction (XRD), meanwhile the surface morphology was observed with scanning electron microscopy (SEM). The results was analyzed and permit us to know the temperature dependecy of the dynamics of surface atoms on the Cu/SiO2 system, are the range between 400-500ºC. During the annealing an oxidation process on sample surfaces occur and the presence of Cu silicides are detected.
2
artículo
Publicado 2020
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In the present investigation we present a polysiloxane composite functionalized with silver nanoparticles (NPs-Ag). NPs-Ag was synthesized, by reduction of a silver nitrate solution (AgNO3) with sodium borohydride (NaBH4), the NPs-Ag were characterized by the UVvisible spectrophotometric method, finding that between 400 - 410 nm the typical peak of NPs-Ag by surface plasmon resonance. In the Dynamic Light Scattering (DLS) analysis of the NPs-Ag, a polydisperse distribution was found with two populations of 59.78 nm in 70% and 4.33 nm in 30%. Subsequently, the polysiloxane gel was synthesized by hydrolyzing chlorosilane, using diethyl ether as the solvent, the obtained polysiloxane was characterized by infrared Fourier transform spectrophotometry (FTIR). In the spectrum peaks are observed in the region of 1258.88 cm-1 corresponding to methyl, between 1000 - 1100 cm-1 a peak corresponding ...
3
artículo
Publicado 2024
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The expansion of copper mining on the hyper-arid pacific slope of Southern Peru has precipitated growing concern for scarce water resources in the region. Located in the headwaters of the Torata river, in the department of Moquegua, the Cuajone mine, owned by Southern Copper, provides a unique opportunity in a little-studied region to examine the relative impact of the landscape-scale mining on water resources in the region. Principal component and cluster analyses of the water chemistry data from 16 sites, collected over three seasons during 2017 and 2018, show distinct statistical groupings indicating that, above the settlement of Torata, water geochemistry is a function of chemical weathering processes acting upon underlying geological units, and confirming that the Cuajone mine does not significantly affect water quality in the Torata river. Impact mitigation strategies that firstly ...
4
artículo
Publicado 2024
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The expansion of copper mining on the hyper-arid pacific slope of Southern Peru has precipitated growing concern for scarce water resources in the region. Located in the headwaters of the Torata river, in the department of Moquegua, the Cuajone mine, owned by Southern Copper, provides a unique opportunity in a little-studied region to examine the relative impact of the landscape-scale mining on water resources in the region. Principal component and cluster analyses of the water chemistry data from 16 sites, collected over three seasons during 2017 and 2018, show distinct statistical groupings indicating that, above the settlement of Torata, water geochemistry is a function of chemical weathering processes acting upon underlying geological units, and confirming that the Cuajone mine does not significantly affect water quality in the Torata river. Impact mitigation strategies that firstly ...