Synthesis and Characterization of CoMo/Al2O3-MgO-(X) catalysts doped with alkaline oxides (K, Li)

CoMo catalysts were prepared using Al2O3-MgO-(X) hybrid supports, where X = K2O or Li2O. The textural, structural and acid-base properties of these materials were characterized by several techniques. The catalysts were preliminarily evaluated in the hydrodesulfurization (HDS), hydrogenation (HYD) and hydrocracking (HCK) model reactions. The aims of this work are to identify the effect of the addition of an alkaline oxide (either K2O or Li2O) to the Lewis acid sites in the CoMo/Al2O3-MgO formulation; and on the other hand, to establish a relationship between the acidity and the catalytic performance (hydrogenation function). The results obtained from the pyridine thermodesorption analysis and the n-butyl amine titration techniques show that the incorporation of an alkaline oxide to the CoMo/Al2O3-MgO formulation causes a slight decrease in the total number of acid sites (TNAS) with respect to Al2O3 and the Al2O3-MgO hybrid supports. Both the enhanced textural and structural stability of the CoMo/Al2O3-MgO-(X) catalytic formulations, which could be probably attributed to the incorporation of Li or K cations to the MgO framework, stabilizing it, can also be observed. As for the catalytic performance, the CoMo/Al2O3-MgO-(X) catalysts containing either Li2O or K2O, show a decrease in both the HYD and HYC conversions; however, the formulation containing Li2O shows the best catalytic behavior due to both the low n-octane yield and the low hydrocracking activity

Relevant changes in the properties of Co(Ni)Mo/Al2O3 HDS catalysts modified by small amounts of SiO2

The changes in hydrodesulfurization activity, selectivity, dispersion, sulfidation, and extent of promotion of Co(Ni)Mo catalysts were investigated when the alumina support surface is modified by grafting 4 wt% silica. Adding SiO2 eliminates the most reactive hydroxyl groups on the alumina surface (IR band at 3775 cm 1) decreasing the possibility of generating tetrahedral Mo species difficult to sulfide in favor of octahedral ones capable of contributing to the sulfided active phase. The catalysts were evaluated in the hydrodesulfurization of 4,6-dimethyldibenzothiophene. Incorporating SiO2 to alumina increases the hydrogenation rate constant and therefore the global hydrodesulfurization rate of 4,6-dimethyldibenzothiophene and enhances the promotion of Mo by Co (or Ni). The global sulfidation of Ni is not affected by the addition of silica but the sulfidation of cobalt is significantly improved. The extent of promotion of the NiMo/Al2O3 and NiMo/SiO2/ Al2O3 catalysts was greater than the one achieved in their Co-promoted counterpartsCB-168827, beca posdoctoral otorgada por CONACyT al Dr. Adolfo Romero Galarza from DGAPA-UNAM, project PAPIIT-IN-113015. We thank Mariela Bravo-Sanchez (Universidad de Guadalajara) for her discussion about the XPS results, Ivan Puente for the TEM work, and Alberto Herrera-Gómez (CINVESTAV-Unidad Querétaro, Mexico) for providing computer program AANALYZER version 1.2

New perspectives into Gluconobacter-catalysed biotransformations

Different from other aerobic microorganisms that oxidise carbon sources to water and carbon dioxide, Gluconobacter catalyses the incomplete oxidation of various substrates with regio- and stereoselectivity. This ability, as well as its capacity to release the resulting products into the reaction media, place Gluconobacter as a privileged member of a non-model microorganism class that may boost industrial biotechnology. Knowledge of new technologies applied to Gluconobacter has been piling up in recent years. Advancements in its genetic modification, application of immobilisation tools and careful designs of the transformations, have improved productivities and stabilities of Gluconobacter strains or enabled new bioconversions for the production of valuable marketable chemicals. In this work, the latest advancements applied to Gluconobacter-catalysed biotransformations are summarised with a special focus on recent available tools to improve them. From genetic and metabolic engineering to bioreactor design, the most recent works on the topic are analysed in depth to provide a comprehensive resource not only for scientists and technologists working on/with Gluconobacter, but for the general biotechnologist

Quantification of the sulfidation extent of Mo in CoMo HDS catalyst through XPS

Background removal in X-ray photoelectron spectroscopy (XPS) spectra was carried out in Co–Mo hydrodesulfurization (HDS) catalysts supported alumina using traditional and recent methods. The sulfidation extent, expressed by the XPS area ratio AMo3d-MoS2/AMo3d-Total, which is a fundamental parameter in the performance of a hydrodesulfurization catalyst, was obtained using different methodologies. The methods include the use of the background active approach, in which the background is optimized during peak-fitting. The method allows for the use of several types of backgrounds, which proved crucial for fitting the Mo 3d-S 2s and the S 2p–Si 2p regions. Both regions contain two overlapped elements, making fundamental a distinction between them. In these cases, a slope background subtraction was used in conjunction with the Shirley-Vegh-Salvi-Castle (SVSC) method to have a clear distinction between the different strengths of backgrounds arising from the overlapped peaks Mo 3d-S 2s and S 2p–Si 2p. From the resulting fitting, the relative percentage (% rel.) of each species present in Mo and S in the catalyst CoMoAl was obtained. The results were compared with those obtained using the static (traditional) approach. With these results, the sulfidation extent, an important parameter in the performance of the HDS catalyst was determined.Adolfo-Romero Galarza thanks Consejo Nacional de Ciencia y Tecnologia (CONACyT), Mexico for their postdoctoral fellowship (ID. 1908/2010C ) . We acknowledge financial support from Direccion General de Asuntos del Personal Academico ( DGAPA) Mexico, UNAM , project PAPIIT-IN-113015 . The authors appreciate the support provided by Gustavo Gomez-Sosa (CINVESTAV-Qro.) for the acquisition of the XPS data and Alberto Herrera-Gómez (CINVESTAV-Unidad Queretaro, Mexico) for engaging in useful discussion regarding the spectra fitting and for providing computer program AANALYZER version 1.2

Caracterización de los movimientos de ladera en la vía Méndez – Limón en la parroquia Yunganza/El Rosario. km 16-39

La presente investigación propone: caracterizar los movimientos de ladera de mayor magnitud resultantes de la relación entre los factores condicionantes y detonantes, expresados en un modelo digital en la vía Méndez - Limón en la parroquia Yunganza/El Rosario km 16 – 39, cantón Limón Indanza, provincia de Morona Santiago; se empleó el método de la descripción de los movimientos de ladera para determinar la relación entre los factores condicionantes y detonantes. Los factores condicionantes: material plástico débil, material sensible, material meteorizado, material fallado por corte, material fisurado o agrietado, orientación desfavorable de las discontinuidades y geometría del terreno; datos obtenidos del levantamiento de campo. Los factores detonantes: lluvias intensas y movimientos tectónicos, recopilados de la estación meteorológica del cantón, de la Norma Ecuatoriana de la Construcción 2014 y de los datos estructurales recopilados en campo. Los resultados de los ensayos realizados en laboratorio de los deslizamientos tienen los siguientes tipos de suelos, según el sistema de clasificación SUCS. Los tipos de suelos son: Tipo SM-SC: Suelo limoso y arcilloso, Tipo GM-GW: Gravas limosas y bien graduadas, Tipo SM: suelo areno limoso, Tipo SC Suelo areno arcilloso. Se realizaron los mapas: inventario de los movimientos de ladera, geológico estructural y de pendientes, que contribuyeron para la elaboración del modelo digital de los movimientos de ladera. Se concluye que la vía se localiza en un área donde se producen deslizamientos constantes y el factor detonante de mayor injerencia son las precipitaciones intensas que registran mayor incremento en los meses de abril, mayo, junio, julio y diciembre. Se recomienda formular propuestas de control y mitigación de los movimientos de ladera de acuerdo al modelo digital. Palabras clave: MOVIMIENTOS DE LADERA - FACTORES CONDICIONANTES - FACTORES DETONANTES - MODELO DIGITAL.This research proposes to typify the movements of the highest hillside in the Mendez-Limon road in the Yunganza El Rosario town, 16.39, Limon Indanza village, Morona Santiago Province as a result of the relationship among the conditions and the detonating factors expressed in a digital model. Identify the hillside movements; the descriptive method was applied to determine the triggers and conditioning factors relationship conditioning factors such as: weak plastic material, sensitive material. Weathered material, fault material by cut, split and cracked material, unfavorable discontinuity in the surface and geometry of the land, these data were obtained through a field survey. The data about the triggers such as heavy rain, tectonic movements were collected from the weather station of the village, the construction Ecuadorian Regulation of 2014 and the structured field data. The results of the test developed in the lab about the landslides present the following types of soil: sM-sc, clay and loam soil, GM-Gw: silty and well calibrated gravel SM type: muddy and sandy soil, sc type: sandy-clayey soil The maps, structural geology and slope movements of the hillside records were developed, this data contributed to the creation of the digital model for the hillside movements. It is concluded that the road located in an area where there are constant landslides and the trigger factor is the heavy rain which increase in April, May, June, July, and December. It is recommended to keep a record and hillside motion mitigation by using the digital model. Key words: SLOPE MOVEMENTS, CONDITIONING FACTORS, TRIGGERS, DIGITAL MODE

Factores asociados al abandono de la lactancia materna exclusiva en madres que acuden a un Centro de Salud, Lima 2024

El objetivo de la investigación fue determinar los factores asociados al abandono de la lactancia materna exclusiva en madres que acuden a un centro de salud Lima 2024. Material y métodos: Estudio con enfoque cuantitativo de diseño no experimental, nivel descriptivo y corte transversal. Con una población de 162 madres y la muestra fue de 50 madres. Como Instrumento se utilizó un cuestionario con una serie de 25 preguntas asociadas al abandono de la lactancia materna exclusiva. Los resultados muestran que el 56%de madres abandonaron la lactancia materna exclusiva, de los factores demográficos con respecto al grado de instrucción. Es un factor influyente para el abandono de la lactancia materna exclusiva, con respecto a los factores biológicos el 26% representaron mayor relevancia en la poca producción de leche materna. Así mismo se demostró que las progenitoras presentaban dolor en los pezones a la hora de amantar a sus bebes por grietas, ambos indicadores muestran ser factores de riesgo para el abandono de la lactancia materna exclusiva, con respecto a los factores socioeconómicos el 64% no cuentan con el apoyo familiar, así mismo la investigación mostro que el 58% no cuentan con un ingreso económico que cubra sus necesidades, ambos indicadores muestran ser factores de riesgo para el abandono de la lactancia materna exclusiva .sin embargo los factores culturales con un 98% los indicadores resultaron presente en su mayoría en los ítems siguientes: la leche materna exclusiva fortalece el vínculo madre e hijo, la leche materna en el proceso de la lactancia materna exclusiva cubre las necesidades del lactante menor de 6 meses, la lactancia materna protege al bebé de muchas enfermedades, La calidad de leche varía según la madre, lo cual se resultó ser un factor riesgoso para que la madre abandone la lactancia materna exclusiva . en conclusión, los factores que influyen directamente al abandono de la lactancia materna exclusiva fueron los factores demográficos, los factores biológicos, los factores socioeconómicos y los factores culturales

Plan de manejo ambiental de la Cuenca baja del Río Ambato tramo comprendido de la quebrada Jarupana a la quebrada Seca

The purpose of this thesis is to carry out an environmental management plan in order to provide alternatives for the conservation of the natural resources of the Basin Baja del Río Ambato, and thus be able to counteract and minimize the impacts negative environmental impacts that have been caused in recent years by different Anthropogenic activities on the Ambato River. In order to carry out this study, a line survey was first carried out basis in order to be able to evaluate in detail the environmental performance of this project, including the description of the physical, biotic and socioeconomic environment existing, identification and evaluation of environmental impacts, determination of compliance with current environmental regulations, among others important aspects for the project area. Once the main environmental impacts have been determined and evaluated, proceeded to conduct an investigation to determine measures and plans for action against the main problems facing the Lower River Basin Ambato Finally, the conclusions reached are presented once the research, also describes a schedule of action and its main actors, as well as the relevant recommendations to make the proposals in this research work.El propósito de esta tesis es realizar un plan de manejo ambiental con el fin de proporcionar alternativas de conservación de los recursos naturales de la Cuenca Baja del Río Ambato, y así poder contrarrestar y minimizar los impactos ambientales negativos que se han ocasionando en los últimos años por las distintas actividades antropogénicas en el río Ambato. Para poder realizar este estudio primero se realizó un levantamiento de una línea base con la finalidad de poder evaluar detalladamente el desempeño ambiental de este proyecto, incluyendo la descripción del medio físico, biótico y socioeconómico existente, identificación y evaluación de impactos ambientales, la determinación de cumplimientos de las normas ambientales vigentes, entre otros aspectos importantes para la zona del proyecto. Una vez determinados y evaluados los principales impactos ambientales se procedió a realizar una investigación para determinar medidas y planes de actuación frente a los principales problemas que enfrenta la Cuenca Baja del Río Ambato. Finalmente, se presentan las conclusiones a las que se llegó una vez finalizada la investigación, además se describe un cronograma de actuación y sus principales actores, así como las recomendaciones pertinentes para realizar las propuestas en este trabajo de investigación

Enfoques y controversias sobre la prima de riesgo de mercado

En el presente trabajo se abordan temas enfocados al estudio de la prima de riesgo de mercado considerando la siguiente estructura: En primera instancia desarrollaremos los antecedentes vinculados a la prima de Riesgo de Mercado y los modelos que utilizan esta variable para el cálculo de rendimientos futuros. En el segundo lugar, abordaremos los enfoques relacionados a la Prima de Riesgo de Mercado, donde detallaremos en orden cronológico las diferentes teorías que han ido emergiendo a lo largo del tiempo tales como el teorema de portafolios de Markowitz, el modelo CAPM de Sharpe, entre otros. Seguidamente estudiaremos los métodos aplicados para el cálculo de la Prima de Riesgo de Mercado y las variables que se utilizan. Ahondaremos en los criterios de autores que están a favor del cálculo de la prima de riesgo de mercado tales como Ibbotson y Goetzmann (2005), Gordon y Shapiro (1956), Damodaran (2015) y posteriormente analizamos la elección del aspecto de la prima de riesgo de mercado basado en mercados futuros. Asimismo, presentamos la controversia, en la cual hacemos mención al enfoque de Pablo Fernández, quien tiene una opinión distinta sobre el tema principal. Finalmente, precisamos nuestras conclusiones respecto del método que se debe utilizar para estimar la prima de riesgo de mercado.In this paper, we will address issues focused on the study of the market risk premium considering the following structure: In the first instance, we will develop the antecedents linked to the Market Risk premium and the models that use this variable to calculate future returns. In the second we will detail the approaches related to the Market Risk Premium, where we will detail in chronological order the different theories that have been emerging over time such as the Markowitz portfolio theorem, the Sharpe CAPM model among others. Next, we will study the methods applied to calculate the Market Risk Premium and the variables that are used. We will delve into the criteria of authors who are in favor of calculating the market risk premium such as Ibbotsson, Gordon and Shapiro, Damodaran and then analyze the choice of the aspect of the market risk premium based on future markets. Likewise, we present the controversy where we mention the approach of Pablo Fernández who has a different opinion on the main topic. Finally, we need our conclusions regarding the method that should be used to estimate the market risk premium.Trabajo de Suficiencia Profesiona

Las estrategias de conservación del medio ambiente en el aprendizaje del área ciencia y ambiente en estudiantes del tercer grado de primaria en la I.E 7096 Villa El Salvador

La presente investigación, que lleva por título “Las estrategias de conservación del medio ambiente en el aprendizaje del área ciencia y ambiente en estudiantes del tercer grado de primaria en la I.E 7096 Villa El Salvador, 2013”, tiene como objetivo determinar la influencia de las estrategias de conservación del medio ambiente en el aprendizaje del área ciencia y ambiente en estudiantes del tercer grado de primaria. La metodología utilizada responde a un tipo aplicada, diseño cuasi experimental, método experimental y se aplicó una prueba de ciencia y ambiente. Luego de haber realizado el procesamiento de los datos recogidos en el cuestionario, se llegó a la siguiente conclusión: La aplicación de estrategias de conservación del medio ambiente influyó significativamente el aprendizaje del área ciencia y ambiente en los estudiantes del tercer grado de primaria de la Institución Educativa 7096 de Villa el Salvador, 2013, habiendo obtenido como resultados en el post test, un valor en la prueba U de Mann-Whitney=6,283 y un pvalor= 0,000

Oxygen transport membranes in a biomass/coal combined strategy for reducing CO2 emissions: Permeation study of selected membranes under different CO2-rich atmospheres

[EN] This contribution introduces how the integration of biomass as fuel in power plants would balance CO2 emissions and the related role of oxygen transport membranes (OTM) on it. CO2 capture techniques could be introduced to minimize CO2 emissions at the cost of a substantial energy penalty in the overall process. Among the different approaches, the use of pure O2 and/or N2-free oxidation gases for combustion and/or for gasification leads to promising energy efficiencies. Ceramic OTM membranes could be successfully integrated in such thermal processes, which enable to increase the net plant efficiency when CO2 capture is implemented. Further, this work reviews how selected ceramic materials and membrane architectures behave under CO2 containing atmospheres at high temperatures above 700 °C. These conditions have been selected for checking the viability of these membrane compositions and configurations to fit in an oxy-co-gasification process, involving coal and biomass. The tested asymmetric membranes present competitive oxygen fluxes in the range 0.6 1.2 ml min−1 cm−2 when using CO2 as (inlet) sweep gas at 850 °C (optimal membrane operation conditions in oxy-fuel power plant) and stable oxygen production up to 100 h of continuous operation in similar conditions. Specifically, La0.6Sr0.4Co0.2Fe0.8O3−ä and NiFe2O4 Ce0.8Tb0.2O2−ä composite materials showed the best results for oxygen permeation and time stability under CO2-rich atmospheres.Financial support by the Spanish Government (ENE2011-24761 and SEV-2012-0267 grants), by the EU through FP7 GREEN-CC Project (GA 608524), and by the Helmholtz Association of German Research Centers through the Helmholtz Portfolio MEM-BRAIN is gratefully acknowledged.García Fayos, J.; Vert Belenguer, VB.; Balaguer Ramírez, M.; Solis Díaz, C.; Gaudillere, CC.; Serra Alfaro, JM. (2015). Oxygen transport membranes in a biomass/coal combined strategy for reducing CO2 emissions: Permeation study of selected membranes under different CO2-rich atmospheres. Catalysis Today. 257(2):221-228. https://doi.org/10.1016/j.cattod.2015.04.019S221228257