Películas de óxido de Ti policristalino fueron depositadas empleando DC "sputtering" reactivo con magnetron de platos de Ti en una atmósfera de O2+Ar sobre láminas de vidrio pre-cubiertas con ITO (óxido de indio dopado con estaño). Las fases anatasa y rutilo se obtuvieron por calentamiento del sustrato durante el depósito de las películas la eficiencia en la conversión foton-incidente-corriente (denominado "IPCE" de la expresión inglesa Incident Photon-to-Current Eficiency) se estudió en función de diferentes parámetros de preparación, tales como la temperatura del sustrato, el espesor de la película y la relación de flujos O/A r. la fotorespuesta se midió usando un sistema de tres electrodos empleando un electrolito acuoso de O.1 M de KI, que fue purgado con nitrógeno. El espectro de la fotorespuesta se obtuvo en un rango de longitud de onda entre 280 y 400 nm. Se enco...

Se obtuvieron películas delgadas electrocrómicas de niquel y óxido de empleándose la técnica de rociado pirolítico. Las películas de óxido de niquel fueron obtenidas de dos formas. Una empleando soluciones alcohólicas de Ni(NO3)26H2O, y otra usando soluciones acuosas Ni(NO3)26H2O adicionando pequeñas cantidades de Co(NO3)26H2O. La temperatura de depósito para ambos casos fue de 3000C. Ambas muestran un electrocromismo pronunciado; particularmente en el segundo caso cuando la proporción Ni(NO3)2Co(NO3)2 es de 90:10 se obtiene un cambio de la transmisión 50% en el rango visible. Las películas de oxido de tungsteno-fósforo se obtuvieron a partir de un sol de WO, al cual se le añadió acido fosfórico. El sol fue preparado por intercambio iónico de Na2WO42H2O en una resina fuertemente acida. La temperatura de depósito fue 4300C. Se observo un incremento significativo de la ...

Some dye-sensitized solar cells were prepared using TiO2 modified with CuO (TiO2-CuO) like a working electrode. P25 commercial powder and small amounts of CuO powder were used in preparing the modified coating. The coating was deposited following doctor Blade method, on a conductive substrate SnO2:F, which was previously deposited on a TiO2 blocking layer by spray pyrolysis technique. For sensitization of the coating, a ruthenium complex, cis-bis (isothiocyanate) bis (2,2'bipiridil-4,4'dicarboxilato) ruthenium (II) ammonium bistetrabutil, also known as N719, was used. The CuO powder was structurally characterized by X-ray diffraction and its morphology was studied by scanning electron microscopy. The functional groups of TiO2 and CuO were studied by infrared spectroscopy. The oxidation and reduction cycles of Cu were shown by cyclic voltammetry. Through incident photon to current convers...

Sensitized solar cells working electrodes of titania (TiO2) nanoparticles were modified with nickel oxide (NiO), which were synthesized from nickel chloride (NiCl2.6H2O). The deposit of the working electrode was performed by Doctor. Blade technique and the sensitization process was performed using commercial dye: Di-tetrabutylammonium cis-bis (isothiocyanato) bis (2,2'-bipyridyl-4,4 '-dicarboxylato) ruthenium (II), also known as N719. The structural and morphological characterization of the working electrodes was performed by X-ray diffraction and scanning electron microscopy, respectively. The photoelectrochemical characterization of the working electrodes and solar cells was performed by measuring the Incident Photon to Current Efficiency (IPCE) and the current-voltage, respectively. Ni concentration in the TiO2 powder was 125 ppm as determinated by atomic absorption. Efficiency m...

An appropriate treatment of the problems that people, living in high Andean rural areas, have during the winter months with their cold houses, passes through a correct bioclimatic approach. This is demonstrated with the involvement of the Centre for Renewable Energy and the Faculty of Science of the National University of Engineering (UNI) in San Francisco de Raymina community (SFR) in Ayacucho. In this community a bioclimatic house has been built, allowing a thermal comfort of the occupants. This work has been done applying clearly and correctly bioclimatic concepts, some of which are presented in this article, as well as part of the experience of UNI in SFR community.

Un adecuado tratamiento a la problemática que las viviendas rurales altoandinas atraviesan durante los meses de invierno, pasa por un acertado enfoque bioclimático. Así lo demuestra la intervención de la Universidad Nacional de Ingeniería, por medio del Centro de Energías Renovables (CER-UNI) y la Facultad de Ciencias, en la Comunidad San Francisco de Raymina (SFR), Ayacucho. En esta Comunidad se ha construido una vivienda bioclimática, mediante la cual se ha alcanzado un bienestar térmico a sus ocupantes. Este trabajo ha pasado por claramente establecer y, acertadamente, aplicar los conceptos bioclimáticos, algunos de los cuales son presentados en el presente artículo, así también como parte de la experiencia de la UNI en la Comunidad SFR.

Un adecuado tratamiento a la problemática que las viviendas rurales altoandinas atraviesan durante los meses de invierno, pasa por un acertado enfoque bioclimático. Así lo demuestra la intervención de la Universidad Nacional de Ingeniería, por medio del Centro de Energías Renovables (CER-UNI) y la Facultad de Ciencias, en la Comunidad San Francisco de Raymina (SFR), Ayacucho. En esta Comunidad se ha construido una vivienda bioclimática, mediante la cual se ha alcanzado un bienestar térmico a sus ocupantes. Este trabajo ha pasado por claramente establecer y, acertadamente, aplicar los conceptos bioclimáticos, algunos de los cuales son presentados en el presente artículo, así también como parte de la experiencia de la UNI en la Comunidad SFR.

  Zinc peroxide (ZnO2) nanoparticles were synthesized by sol-gel technique. The chemicals used for the synthesis were zinc acetate di-hydrate (Zn(CH3COO)2.2H2O) and hydrogen peroxide (H2O2) at 30% under UV radiation. The structure of the ZnO2 nanoparticles was characterized by X-ray diffraction. While the morphology and the cluster size, were determined using scanning electron microscopy. For a preliminary evaluation of the bactericidal properties of the ZnO2, the material was exposed to Bacillus subtilis (ATCC 6051), Escherichia coli (ATCC 25922) y Staphylococcus aureus (ATCC 25923) and it was found that the material has notorious antibacterial activity. 

El peróxido de zinc (ZnO2) fue sintetizado en forma de nanopartículas por medio de la ruta sol-gel. Para la síntesis se empleó acetato de zinc di-hidratado (Zn(CH3COO)2.2H2O) y peróxido de hidrogeno (H2O2) al 30% asistido de radiación UV. Las nanopartículas de ZnO2 obtenidas fueron caracterizadas estructuralmente mediante la técnica de difracción de rayos-X. Mientras que el estudio de la morfología y tamaño de conglomerados cristalinos, se realizó por microscopía electrónica de barrido. Para explorar las propiedades bactericidas del ZnO2, se realizaron pruebas preliminares en las que se enfrentó este material a las cepas: Bacillus subtilis (ATCC 6051), Escherichia coli (ATCC 25922) y Staphylococcus aureus (ATCC 25923), y se observó que las nanopartículas presentan una notoria propiedad bactericida.

This paper presents a rural exemplar house built in San Francisco de Raymina (a high Andean village 3700 masl) in southern Peru that integrates passive and sustainable solar heating techniques. A climatic analysis of this village was carried out using measurements of meteorological parameters recorded throughout a whole year. The annually averaged temperature, relative humidity and horizontal daily solar energy were 8.3 °C, 73.1% and 5.2 kWh/m2, respectively. The temperatures outside and inside the most rural dwellings are almost the same, so they do not offer any protection specially, during nights when the temperature can reach values below zero. The thermal behavior of the house was modeled with the m2m tool, and an experimental validation was carried out. With the use of m2m, it was possible to create an energy balance during the month of June 2014 (the winter cold and dry season) t...

Textiles functionalized with cupric oxide (CuO) nanoparticles have become a promising option to prevent the spread of diseases due to their antimicrobial properties, which strongly depend on the structure and morphology of the nanoparticles and the method used for the functionalization process. This article presents a review of work focused on textiles functionalized with CuO nanoparticles, which were classified into two groups, namely, in situ and ex situ. Moreover, the analyzed bacterial strains, the resistance of the antimicrobial properties of textiles to washing processes, and their cytotoxicity were identified. Finally, the possible antimicrobial mechanisms that could develop in Gram-positive and Gram-negative bacteria were described.

El peróxido de zinc (ZnO2) fue sintetizado en forma de nanopartículas por medio de la ruta sol-gel. Para la síntesis se empleó acetato de zinc di-hidratado (Zn(CH3COO)2.2H2O) y peróxido de hidrogeno (H2O2) al 30% asistido de radiación UV. Las nanopartículas de ZnO2 obtenidas fueron caracterizadas estructuralmente mediante la técnica de difracción de rayos-X. Mientras que el estudio de la morfología y tamaño de conglomerados cristalinos, se realizó por microscopía electrónica de barrido.

Activated carbons and activated carbons modified with ZnO nanoparticles were prepared mixing agricultural wastes like corn cob or red mombin seed with the activating chemical agent, ZnCl2, in a weight ratio 1:1 or with ZnCl2 and zinc acetate in a weight ratio 1:1:0.5 in aqueous medium, respectively. Pellets were obtained from this slurry and were dried before being carbonized. The resulting material was repeatedly washed with a solution of HCl 0,5 M and abundant distilled water to finally be dried at 100°C for 12 h in the form of pellets, which were crushed and sieved to a size smaller than 0,25 mm. A Field Emission Scanning Electron Microscope was used to characterize the different morphologies of the ZnO nanoparticles on the surface of the obtained activated carbon which depended of the raw material used to produce the activated carbon, however in both samples the presence of ZnO was ...

The application of nanotechnology has gained importance in the finishing of textile products, imparting them functional properties, which are achieved without affecting the textile. A novel method was developed for the in situ growth of CuO nanoparticles (NPs) onto cotton textiles by the exhaust dyeing method. For functionalised textiles, a constant sodium hydroxide concentration (0.4 g l(-1)) and different percentages of on-weight-fabric (% owf) of copper acetate were used. The textiles were microbiologically evaluated, the laundering durability was assessed and their UV protection factor (UPF) was determined. In addition, their CIE L*a*b* colour coordinates and colour strength (K/S) were studied. The results determined that NPs on the textile were CuO and were distributed randomly on the cotton fibre surface. The functionalised textiles with CuO NPs had percentages of bacterial reducti...