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.Lima NorteEscuela de PosgradoGestión de Políticas PublicasDesarrollo sostenible, emprendimientos y responsabilidad social.Desarrollo económico, empleo y emprendimientoTrabajo decente y crecimiento económic

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

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

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

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

Advanced Oxidation Processes II: Removal of Pharmaceuticals by Photocatalysis

In this chapter, basic concepts of advanced oxidation processes (AOP) are cited, such as photolysis, photocatalysis, and semiconductors used as photocatalysts. This is important since the wastewater pollution with drugs, coming from domestic use, hospitals, and industry is not only an environmental problem but social too. Pharmaceutical case study is shown to exemplify the photocatalytic degradation of different drugs contained in wastewater taken directly from some currents in the pharmaceutical industry, such as diclofenac, acetaminophen, naproxen, and ibuprofen, using modified TiO2 catalysts with different tin contents.CONACy

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

Two-dimensional carbon nanostructures obtained by laser ablation in liquid: effect of an ultrasonic field

en este articulo se detallan procedimientos de síntesis de materiales novedosos obtenidos por ablación láserThe ablation of a carbon target immersed in deionized water, in absence and in presence of ultrasonic waves is reported, and the differences investigated. The obtained nanostructures are characterized by transmission electron microscopy, Raman spectroscopy and photoluminescence. Transmission electron images reveal that the produced carbon nanostructures, with and without ultrasonic excitation, are graphene-like sheets with improved quality in the first case. Samples prepared with ultrasounds show graphene layers with large sizes (several microns) and regular shapes, whereas the samples prepared without ultrasounds show smaller sizes and irregular shapes; additionally, some dispersed quasi-spherical nanoparticles are observed in the samples prepared without ultrasound. Photoluminescence measurements of the obtained nanostructures reveal emission in the blue spectral region.conacy

Photodegradation of pharmaceutical drugs using Sn-modified TiO2 powders under visible ligth irradiation

Sn-modified TiO2 powders with different amounts of tin (0, 2.4, 5.1 and 7.2 at.%) were obtained by the surfactant-assisted technique using Pluronic P123 as template. The synthesis procedure favors the formation of a mixture anatase/rutile at annealing temperatures as low as 350 C. The incorporation and further increase of the tin content promotes the transformation of anatase to rutile phase allowing to vary the anatase to rutile ratio in a controlled way, reaching the rutile phase the 96% of the mixture at a Sn content of 7.2 at.%. The synthesized materials were tested in the photocatalytic degradation of the NSAIDs, diclofenac, ibuprofen and paracetamol present in real wastewaters to evaluate their catalytic performance under visible light. The obtained results seem to indicate a certain kind of selectivity or affinity for degradation of each specific drug with a catalyst.The authors thank UAEM for the financial support through the project 3458 CHT. Thanks also to the staff of the SIEA-UAEM for their help and technical support. This work was partially supported by CONACYT, under the project CB-168827

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