UTN- FRC -Producción Académica de Investigación y Desarrollo
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Item Multiple-wall carbon nanotubes obtained with mesoporous material decorated with caria-zirconia.(Univesidsad Tecnológica Nacional, 2020) Rodríguez , Miguel Angel; Anunziata , Oscar Alfredo; Beltramone, Andrea Raquel; Juárez , Juliana María; Juárez , Juliana María; Anunziata , Oscar AlfredoIn this work, Ceria-Zirconia on ordered Santa Barbara mesoporous silica (Ce-Zr-SBA-15), has been used directly as a catalyst for the synthesis of carbon nanotubes (CNTs) through Chemical Vapor Deposition (CVD). In addition to cerium oxide, it contains zirconium oxide nano crystallites, which act as catalysts for carbon nanostructures. The catalytic performance of this material was evaluated for the decomposi- tion of ethanol at 900 °C, with N2 flow. The carbon decomposed from absolute ethanol diffuses through the surface of the nanostructured catalytic material and precipitates in the form of MWCNT structures, which could be identified by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM), showing average diameters of 30–35 nm.Item H2 storage using Zr-CMK-3 developed by a new synthesis method.(Univesidsad Tecnológica Nacional, 2021) Juárez , Juliana María; Venosta , Lisandro; Anunziata, Oscar Alfredo; Gómez Costa , Marcos Bruno; Anunziata, Oscar AlfredoOne of the biggest problems in using hydrogen as an alternative fuel is that its storage must be safe and portable. This work addresses a new direct synthesis technique used to obtain a novel mesoporous carbon (CMK-3) modified with zirconium oxide. This novel material shows promise for hydrogen adsorption and storage application for energy harvesting. Zirconium oxide (Zr-CMK-3) material is achieved through successful synthesis and characterized by XRD, SEM,Raman, BET, UV-Vis-DRS, XPS and TEM analyses. Zr-CMK-3 signifi- cantly improved H2 storage performance (reaching at 77 K and 10 bar 4.6 wt%) comparedto the pristine CMK-3. The novel material is favorable for H2 uptake by using weak bonding (physisorption). A hydrogen uptake mechanistic approach is proposed and the role of the Zr+4 cation in hydrogen adsorption is discussed.Item Synthesis and characteristics of CMK-3 modified with magnetite nanoparticles for application in hydrogen storage.(Univesidsad Tecnológica Nacional, 2020) Venosta, Lisandro; Juárez , Juliana María; Anunziata , Oscar Alfredo; Bercoff, Paula; Gómez Costa , Marcos Bruno; Anunziata , Oscar Alfredo; Juárez , Juliana María: In this work, we report the synthesis and characterization of iron oxide nanoparticles supported in nanostructured carbon (CMK-3). This material is promising in the application of hydrogen adsorption for energy storage. The material with iron oxide nano particles (Fe-CMK-3) was successfully synthesized and characterized by X-ray diffraction, textural properties analysis, transmission and scanning electron microsco py, X-ray photoelectron spectroscopy, and magnetiza tion studies. A large amount of the iron incorporated as iron oxide nanoparticles was in the magnetite phase. The incorporation of magnetite on the CMK-3 carbon surface significantly improved the storage capacity of hydrogen (4.45 wt% at 77 K and 10 bar) compared with the CMK-3 framework alone (2.20 wt% at 77 K and 10 bar). The synthesized material is promising for hy drogen adsorption by weak bond forces (physisorption). A hydrogen adsorption mechanism was proposed in which the nanoparticles of magnetite have an important role.Item Sulfated/Zr-containing mesoporous carbons: a promising nanostructured catalytic material.(Univesidsad Tecnológica Nacional, 2021) Anunziata , Oscar Alfredo; Martínez , María LauraIn this work, we report the successful preparation of a promising material with acidic properties from starch-derived mesoporous carbon (SMC), functionalized with sulfated zirconia (SZr-SMC). The process of assembling P123, starch, zirconia, and silicon produces ordered mesoporous carbon modified with Zr. Reaction time and temperature are essential to avoid the appearance of poorly assembled or unsightly structures, reducing the surface area and the size of the pores. SZr SMC has a surface area of approximately 1300 m2/g, and a total pore volume of 0.94 cm3/g, composed mainly of mesoporous with an average pore size of 3.5 nm. The composition of the surface and the chemical states of the elements did not reveal ZrO2 as isolated clusters. Ammonia thermodesorption studies indicated that, SZr-SMC retains 2.49 mmol/g of NH3 at very high temperature, exhibiting a strong acidity. According to the data collected by infrared spectroscopy (FTIR), of pyridine desorbed at various temperatures, the total number of acidic sites was 2.36 mmol/g, and the distribution in weak- medium, strong, and super acidic sites was determined. The activity in the methylation of aniline and isopropanol dehydration indicated that the acid sites are strong, and have not redox properties. A new and promising catalyticmaterial based onmesoporous carbons modified with sulfated Zr is developed, which opens a wide range of acid-catalyzed reactions applied to industrial and medical processes.Item HaP/SBA-3 Nanostructured Composite to Remove Fluoride Effectively from Contaminated Water.(Univesidsad Tecnológica Nacional, 2021) Cussa, Jorgelina; López , Claudia; Anunziata, Oscar Alfredo; Anunziata, Oscar AlfredoHighly ordered pore mesoporous silica composites, like SBA-3 and hydroxyapatite (HaP) nanocrystals, characterized by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and textural properties, were successfully applied to remove fluoride from contaminated water. The proposed procedure to prepare HaP/SBA-3 wassuccessful, which acts as supports to anchor the HaP crystals, in nanometer-scale (<2nm), with higher fluoride retention from contaminated water. The free OH- groups of HaP nanocrystals, within the host, facilitated the high-performance fluoride trapping. The fluoride retention activity was much higher than that of pure HaP and the composites HaP/SBA-15 and HaP/MCM-41.Item Euro Theoretical study of acetylation of ethanol catalyzed by Mn2+ ions(Journal of Clinical & Experimental Toxicology, 2020) Caglieri, SilvanaA theoretical study of acetylation of ethanol catalyzed by Mn 2+ ions from the analysis of intermediate of the reaction was carried out. The study of acetylation of alcohols is of great interest by the utility of its products of reaction and is one of the most frequently used transformations in organic synthesis as it provides an efficient means for protecting hydroxyl groups in a synthetic process. Acetylation of alcohols is a nucleophilic substitution reaction. This reaction can be catalyzed by Lewis acid, metallic ion. In reaction mechanism, the metallic ion formed a complex with the oxygen of the acetic anhydride carbonyl, facilitating the polarization of the same and the successive addition of alcohol at the position to form a tetrahedral intermediate, determining step of the rate of the reaction. Experimental studies were carried out and agreed that this reaction takes place with the formation of a tetrahedral intermediate. In the present theoretical work were investigated the structure and energy of the tetrahedral intermediate of the reaction catalyzed by Mn 2+ ions. Geometries of all species involved in the acetylation were made and identified. All of the geometry optimizations were performed by the method at the DFT/B3LYP level of theory and were adopted the 6-31+G* basis sets. Energies were calculated using the Mechanics-UFF method. Following the same procedure it was identified the geometric parameters and energy of reaction intermediate. The calculations show 65.39 kcal/mol of energy for the tetrahedral intermediate and the energy of activation for the reaction was 26.29 kcal/mol. Acetylation is one of the most significant responses in natural blend since acetyl gatherings can be advantageously used to secure a wide scope of utilitarian gatherings including alcohols, amines, phenols, and thiols, among others .Acetylation with acyl halides or corrosive anhydrides has been accounted for utilizing either homogeneous or heterogeneous corrosive impetuses or on the other hand base impetuses .In this manner, a wide scope of homogeneous progress metal based or on the other hand organocatalysts have been created for the acetylation of alcohols utilizing RuCl3 , CeCl3 ,ZrCl4 , La(NO3)·6H2O, Al(OTf)3 ,AgOTf Co(II)salen complex NiCl2 Moreover, acetylation has additionally been accounted for with a progression of heterogeneous impetuses, for example, ionic fluids. Ethanol utilization is as of now the fourth most noteworthy preventable reason for death in the United States and is an extreme general wellbeing concern. Besides, ethanol is a huge hepatotoxicant and oxidative pressure assumes a focal job in the pathogenesis of alcoholic liver illness (ALD) Oxidative pressure is characterized as an unevenness between ace oxidants and enemies of oxidants, coming about in dysregulated redox flagging and control. This persevering oxidative unevenness can adjust redox delicate pathways and can bring about harm to cell macromolecules, including lipids, proteins and DNA, when receptive oxygen species are in abundance Explaining cell systems of adjusted hepatic redox homeostasis because of ethanol digestion is fundamental to understanding the commencement and movement of ALD.Item Aplicación y modificación de un modelo matemático de infiltración con redistribución de humedad del suelo(2021) Jorquera, Eliana; Weber, Juan Francisco; Reyna, SantiagoDentro del ciclo hidrológico el proceso de infiltración es aquel mediante el cual el agua precipitada ingresa en la matriz del suelo. Se presenta la evolución del difundido método de infiltración de Green y Ampt (GA) hasta llegar al modelo MGAR (Green y Ampt con Redistribución Modificado) desarrollado en la Universidad de Florida que modifica GA para considerar la recuperación de la capacidad de infiltración estimando la redistribución de humedad y el movimiento del agua en el interior del suelo cuando la intensidad de la lluvia es menor a la conductividad hidráulica saturada del suelo (hiato de lluvia). Además se presenta MGAR-E que incorpora a MGAR la evaporación del agua encharcada en la superficie del suelo en los hiatos de lluvia. Se comparan los resultados de GA, MGAR, y MGAR-E.Item Parámetros de modelos de infiltración en suelos de la ciudad de Córdoba, Argentina(-, 2021) Weber, Juan FranciscoEn trabajos ingenieriles vinculados al diseño y cálculo de obras de desagüe pluvial urbano, el proyectista se ve en la obligación, a la hora de cuantificar los caudales de aporte, a considerar dos tipos de superficies en las cuencas: las impermeables y las permeables. En relación a éstas, se han impuesto en la práctica un conjunto de modelos de uso generalizado a la hora de cuantificar la fracción de la precipitación de escurrimiento directo, y por tanto, la fracción infiltrada. Lamentablemente, existen grandes dificultades a la hora de disponer de datos medidos de infiltración en áreas permeables urbanas en la República Argentina. En la ciudad de Córdoba, por ejemplo, recién se encara una tarea sistemática de producción de información experimental al respecto a partir del trabajo de Weber et al (2005), a través una campaña de obtención de datos experimentales de infiltración en suelos de la ciudad de Córdoba, a través de la técnica del infiltrómetro de doble anillo. Las limitaciones de este procedimiento llevaron al desarrollo de un simulador de lluvia portátil para una mejor caracterización del proceso.Item Avances en la modelación de la producción de sedimentos de cuencas torrenciales(2020) Moreno, Miqueas; Weber, Juan Francisco; García, Carlos MarceloLos modelos hidrológicos distribuidos son aquellos en los cuales se permite que los parámetros varíen espacialmente dentro de la cuenca. Esto posibilita el cálculo no sólo de la respuesta de toda la cuenca sino también la respuesta de las sub-cuencas individuales. Sin embargo, para que los resultados del modelado distribuido sean significativos, la calidad y la cantidad de datos disponibles deben ser proporcionados con gran nivel de detalle (Ponce En este trabajo se presentan los avances en la generación de los modelos de cuenca de los ríos Ambato, Sijan, Saujil y Los Nogales. Estos conforman la base para la posterior implementación del modelo hidrosedimentológico distribuido T-REX. La región de estudio se encuentra en la zona sur de la provincia de Catamarca, dividida por la Sierra de Ambato. Sobre la ladera oeste de la misma, se sitúan las cuencas de los ríos Sijan y Saujil pertenecientes al departamento de Pomán y sobre la este, las cuencas de los ríos Ambato y Los Nogales pertenecientes al departamento de AmbatoItem Modelación matemática distribuida del impacto hidrológico- ambiental de los incendios en la zona serrana de la provincia de Córdoba(2020) Stehli, Pablo T.; Weber, Juan FranciscoLos incendios en la cobertura vegetal son causados por el hombre o por la naturaleza. Sus efectos se observan en distintos niveles, siendo las serranías y el pie de monte las áreas más susceptibles de ser afectadas por la erosión, cuando el suelo ha sufrido ese disturbio (Rodríguez et al, 2005). En este trabajo se presentan los resultados de la modelación matemática distribuida del impacto hidrológico-ambiental que ocasionan los incendios en una cuenca en el área serrana de la provincia de Córdoba contrastándolos con las mediciones de campo disponibles.