Gestión de infraestructura de redes viales y selección de carreteras georreferenciadas mediante matrices de identificación vial, Perú 2021

En el Perú el Sistema Nacional de Carreteras (SINAC), es el conjunto de carreteras con cobertura a nivel del Perú. Éstas deben tener ciertas condiciones en sus niveles de servicios y de seguridad para permitir el flujo de transporte a larga distancia de pasajeros y/o carga, dinamizando las actividades socioeconómicas. Si estas condiciones se interrumpen, la normativa establece que las autoridades competentes deben seleccionar un conjunto prioritario de carreteras para restablecer su operatividad mediante acciones de gestión vial, ejecutadas a través de inversiones públicas. Por otro lado, en las últimas décadas se han identificado diversas situaciones problemáticas que muestran una debilidad en la gestión de carreteras en el Perú. Esto podría suceder cuando las estrategias empleadas en la selección de carreteras no consideran una cobertura geográfica mínima para el transporte, influyendo en las gestiones viales posteriores. La presente investigación tiene como objetivo evaluar la relación entre la estrategia de selección de carreteras georreferenciadas y la gestión de la infraestructura de redes viales en el Perú. Esto permitirá identificar el valor de la estrategia de selección de carreteras en el país para lograr una adecuada gestión vial que restablezca sus niveles de servicios y seguridad

Electron evaporation of carbon using a high density plasma

High-density plasmas are often used either in the preparation of thin films or for the modification of surfaces; nitriding. However, except for collision-driven chemical reactions the electrons present are not used, although electron bombardment heating of the work piece nearly always occurs. Principally it is the ions and neutrals that are utilised for materials processing. By suitable biasing of a conducting source material the electrons can be extracted from a highdensity low-pressure plasma to such an extent that evaporation of this source material can be achieved. Due to the presence of the plasma and the flux of electrons a large proportion of the evaporant is expected to be ionised. We have used this novel arrangement to prepare thin films of carbon using a resonant high-density argon plasma and a water cooled rod of high purity graphite. Multiple substrates were used both outside of, and immersed in, the plasma. We report the characteristics of the plasma (electron temperature and density, the ion energy and flux, and optical emission spectra), the deposition process (the evaporation rate and ion/neutral ratio), and the film properties (IR and UV/Vis absorption spectra, Raman spectra, elemental analysis, hardness and refractive index

Desarrollo de fotocatalizadores basados en TiO2 en forma de película delgada para la degradación de moléculas orgánicas en solución acuosa

En este volumen ademas del capitulo, participo como editora invitadaTiO2 is used in a wide variety of applications, including photocatalysis in the environmental area for surface self-cleaning as well as air and water purification. In order to develop new materials with better photocatalytic response, it has been proposed the modification of TiO2 following different strategies. In this work, the basics of photocatalysis are summarized discussing the advantages of using photocatalysts in thin film form. The results of the preparation and characterization of zinc-modified TiO2 thin films using a novel synthesis route are presented; these indicate that depending on the Zn load incorporated into the film mixtures of TiO2 with Zn titanates are formed. The obtained results in the photocatalytic evaluation of the films in the degradation of the malachite green dye are shown, it was found that the films containing Zn have a better response practically doubling the degradation degree obtained with the sample without Zn. KEYWORDS: photocatalysis, TiO2, thin film, malachite green

Photocatalytic Activity under Simulated Sunlight of Bi-Modified TiO2 Thin Films Obtained by Sol Gel

The synthesis of Bi-modified TiO2 thin films, with different Bi contents, is reported. The obtained materials were characterized by energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy (RS), X-ray diffraction (XRD), photoluminescence (PL), and diffuse reflectance spectroscopy (DRS), in order to obtain information on their chemical composition, vibrational features, and optical properties, respectively. Compositional characterization reveals that the bismuth content can be varied in an easy way from 0.5 to 25.4 at. %. Raman results show that the starting material corresponds to the anatase phase of crystalline TiO2, and Bi addition promotes the formation of bismuth titanates, Bi2Ti2O7 at Bi contents of 10.4 at. % and the Bi4Ti3O12 at Bi contents of 21.5 and 25.4 at. %. Optical measurements reveal that the band gap narrows from 3.3 eV to values as low as 2.7 eV. The photocatalytic activity was tested in the degradation reaction of the Malachite Green carbinol base dye (MG) as a model molecule under simulated sunlight, where the most relevant result is that photocatalytic formulations containing bismuth showed higher catalytic activity than pure TiO2. The higher photocatalytic activity of MG degradation of 67% reached by the photocatalytic formulation of 21.5 at. % of bismuth is attributed to the presence of the crystalline phase perovskite-type bismuth titanate, Bi4Ti3O12.SIEA UAEM 4488 CHT project, CONACyT CB-168827 and CB-24099

Synthesis and characterization of silver vanadates thin films for photocatalytic applications

Silver vanadates thin films were deposited by a hybrid deposition system combining laser ablation and thermal evaporation. A high purity vanadium target was ablated using the third harmonic of a Nd:YAG laser whereas high purity silver pellets were evaporated. The as-deposited thin films were subjected to thermal treatments at 400 °C to obtain crystalline films. For films without Ag amorphous V2O5 thin films were deposited and as the Ag is incorporated in the material different silver vanadates were obtained. The effect of the silver load on the composition, structure, optical properties, surface morphology and photocatalytic response of the deposited films was studied. The film composition, determined by X-ray photoelectron spectroscopy, reveals Ag contents from 5.5 to 18.9 at.%. The crystalline phases formed were identified by micro-Raman Spectroscopy; the results indicate the formation of three silver vanadates depending on the silver content. The morphology was observed using scanning electron microscopy, the filmś surface changes from a smooth surface to belts covering the surface and finally Ag nanoparticles are observed at the higher Ag contens. Optical properties determined from UV–vis reveal the presence of the surface plasmon signal in films containing silver. The films were tested in the photocatalytic degradation of Malachite Green dye reaching maximum degradations degrees close to 53% under solar irradiation. Reactive species trapping experiments suggest that O2 − produced by the O2 reduction via the photogenerated electrons drives the photodegradation mechanismCB-168827 CB-240998 F. Gonzalez-Zavala thanks to CONACyT for the PhD and Beca Mixta grants, and also to the SIEA-UAEM for the beca movilidad para estudios avanzados 2016. E. Rodríguez-Castellón thanks to project CTQ2015-68951-C3-3-R of Ministerio de Economía y Competitividad (Spain) and FEDER funds

Application of the Wigner-Ville distribution for the detection of rotor asymmetries and eccentricity through high-order harmonics

The diagnosis of induction machines through the use of methods based on the study of the startup current has become an issue of special interest. These techniques may provide, in certain situations (unbalanced supply voltages, load torque oscillations, variable load, etc.) and for certain faults (broken bars, eccentricity, stator short circuit, etc.) substantial advantages in comparison with the classical method, based on the Fourier spectrum of the steady-state current. Nevertheless, in the case of rotor asymmetries, these transient-based techniques have been mainly focused on the tracing of the lower sideband harmonic (LSH). In this paper, a wideband diagnosis method is proposed, in which the Wigner-Ville distribution is applied to the detection of eccentricity and other high-order components also introduced by the rotor asymmetry. It is shown that the proposed wide band analysis might help to reach a more reliable diagnosis conclusion in cases in which the tracing of commonly used harmonics may be difficult (inter-bar currents, load torque oscillations, non stationary regimes, etc.). An evaluation of the method is carried out through simulations and laboratory tests. The results show the potential of the tool for the detection and quantification of these components as a basis to diagnose such faults. © 2012 Elsevier B.V

Ag-modified vanadium oxide photocatalytic thin films deposited by a two parallel ablation plasmas configuration

Articulo de colaboracionThe application of a two ablation plasmas configuration to deposit vanadium oxide thin films modified with different amounts of silver is reported. In this configuration, two parallel plasmas are produced ablating simultaneously two different targets, V and Ag, to form the Ag-modified vanadium oxide thin films. The ablation of the vanadium target is performed under constant conditions in all deposits, while the silver produced plasma is varied. The effect of the amount of Ag incorporated in the films on their compositional, morphological, structural, and photocatalytic properties is studied. The results reveal that films with variable Ag content from 0.6 to 17.2 at. % are obtained. Depending on the silver content, the samples show very different surface morphologies from smooth surfaces to acicular structures in films containing Ag. Raman spectra reveal that as the silver content is increased different vanadium oxides coexist and at the highest Ag content a silver vanadate is formed. The photocatalytic activity for the degradation of the Malachite Green dye under simulated solar light is determined. It is found that in general terms, films containing silver show a higher photocatalytic response than V2O5 films aloneCONACYT project CB-24099