Influence of the residual stresses in reshaping operations of large aeronautical parts

Context Large and thick aeronautical parts present distortion after machining because the residual stresses (RS) generated during previous manufacturing steps (heat treatment). Before assembly, distortion is removed manually. It is a time consuming operation and depends exclusively on the skills of a well trained operator. Scientific goals To develop a Reduced Order Model (ROM) for reshaping To evaluate the main parameters during the process and its uncertainty level Industrial goals To study reshaping from a numerical perspective To adapt reshaping simulations to each warped geometry To introduce numerical simulation in order to assist the operato

Análisis y diseño de una wireless lan segura para el enlace entre dos o más edificios en la municipalidad de la ciudad de San Francisco.

Hoy en día el avance científico se ha desarrollado en todos los campos y las necesidades del hombre cada vez son mayores, esto ha obligado a buscar nuevas y mejores formas de Tecnología. Una de ellas es la comunicación entre computadoras, ya sea en áreas locales o zonas con mayor distancia

Diseño de modelo a escala de una grúa torre

El objetivo del presente proyecto es el diseño de una grúa torre a escala reducida empleando como elementos para su estructura exclusivamente palos de helado, con una altura útil de 0,87 m y una longitud de pluma de 0,7m. Su carga máxima en el extremo es de 10 N. Además el diseño de la misma es modular. La metodología utilizada para el dimensionamiento de la grúa distingue dos partes. Por un lado el dimensionamiento y cálculo de la estructura de la grúa con todas las hipótesis de carga necesarias y los coeficientes de seguridad que indica la normativa de aparatos de elevación UNE 58132-2:2000. Por otro lado la selección de todos los accionamientos y elementos que permiten a la grúa darle la función de aparato de elevación. Con el fin de realizar un diseño correcto se han utilizado distintas herramientas CAE y CAD para dimensionar la grúa y sus elementos. El análisis estructural se realizó mediante el software SAP2000 V10, mientras que para los planos de fabricación y montaje se empleó AutoCAD 2002. Esta grúa ha obtenido el 1er premio en 2009 del 1er Concurso Nacional de Grúas con Palos de Helado”, organizado por la Delegación de Estudiantes de la Universidad Carlos III de Madrid, en la categoría Funcionalidad y Estética.Ingeniería Industria

Polipirrol, un buen soporte para electrodos de pilas de combustible de metanol directo (DMFC)

(SPA) El polipirrol es uno de los polímeros conductores más utilizados en la preparación de electrodos debido a su alta actividad catalítica para la oxidación y reducción del metanol. En este trabajo se ha depositado electroquímicamente polipirrol a diferentes potenciales de depósito, Ed, sobre tela de carbón no tejida Freudenberg en medio ácido. Se ha analizado la morfología y la respuesta electroquímica en medio HClO4 y en presencia de HClO4+MeOH antes y después de la síntesis del polipirrol sobre ella. Lastructura de las películas obtenidas se ha estudiado por espectroscopia infrarroja de transformada de Fourier, FTIR. Se observa que el polipirrol mejora las propiedades electroquímicas de la tela de carbón, obteniéndose el mejor resultado para su aplicación como soporte del catalizador en pilas de combustible con la película sintetizada a 1,0V. (ENG) Polypyrrole is one of the most used conducting polymers in electrode building due to its high catalytic activity to the methanol oxidation and reduction. By this motive, polypyrrole has been electrochemically synthesized at constant potential, Ed, on Freudenberg carbon cloth in acid medium. Carbon cloth morphology and electrochemical behaviour in HClO4 and in HClO4+MeOH before and after the polypyrrole eposition have been analysed. The structure of the films was studied by Fourier transform infrared spectroscopy, FTIR. The polypyrrole improves the electrochemical properties of the studied carbon cloth. The biggest charge of the electroactive area is the one synthesized at 1.0V, being the best for its application as catalyst support in fuel cells

La represa como instrumento en una política pública innovadora

La presente propuesta consiste en la tecnificación de una represa tradicional usada para el almacenamiento de las escorrentías estivales propias de los llanos riojanos, destinada a la provisión de agua potable para 1000 habitantes bajo una dotación de 250 l/habitante/día.EEA La RiojaFil: Grande, Andrés. Secretaría de Agricultura Familiar, Campesina e Indígena (SAFCI), La Rioja; ArgentinaFil: Mendez, Carla Rebeca. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Rioja. Agencia de Extensión Rural Chepes; ArgentinaFil: Mena, Ramiro. Municipio Chepes, La Rioja; ArgentinaFil: Pereyra, Diego Iván. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Rioja; Argentin

Departamento Rosario Vera Peñaloza: un camino de organización y articulación popular

EEA La RiojaFil: Llorente, Gonzalo. Cáritas; ArgentinaFil: Moyano, María Ester. Asociación Kölping Argentina; ArgentinaFil: Mena, Ramiro. Asociación de Emprendedores Chepes La Rioja (A.E.Che.La.R.); ArgentinaFil: Mendez, Carla Rebeca. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Rioja. Agencia de Extensión Rural Chepes; Argentin

Electrochemical study of platinum deposited by electron beam evaporation for application as fuel cell electrodes

Platinum is the most used catalyst in electrodes for fuel cells due to its high catalytic activity. Polymer electrolyte and direct methanol fuel cells usually include Pt as catalyst in their electrodes. In order to diminish the cost of such electrodes, different Pt deposition methods that permit lowering the metal load whilst maintaining their electroactivity, are being investigated. In this work, the behaviour of electron beam Pt (e-beam Pt) deposited electrodes for fuel cells is studied. Three different Pt loadings have been investigated. The electrochemical behaviour by cyclic voltammetry in H2SO4, HClO4 and in HClO4+MeOH before and after the Pt deposition on carbon cloth has been analysed. The Pt improves the electrochemical properties of the carbon support used. The electrochemical performance of e-beam Pt deposited electrodes was finally studied in a single direct methanol fuel cell (DMFC) and the obtained results indicate that this is a promising and adequate method to prepare fuel cell electrodes

Electrochemical study of platinum deposited by electron beam evaporation for application as fuel cell electrodes

Platinum is the most used catalyst in electrodes for fuel cells due to its high catalytic activity. Polymer electrolyte and direct methanol fuel cells usually include Pt as catalyst in their electrodes. In order to diminish the cost of such electrodes, different Pt deposition methods that permit lowering the metal load whilst maintaining their electroactivity, are being investigated. In this work, the behaviour of electron beam Pt (e-beam Pt) deposited electrodes for fuel cells is studied. Three different Pt loadings have been investigated. The electrochemical behaviour by cyclic voltammetry in H2SO4, HClO4 and in HClO4+MeOH before and after the Pt deposition on carbon cloth has been analysed. The Pt improves the electrochemical properties of the carbon support used. The electrochemical performance of e-beam Pt deposited electrodes was finally studied in a single direct methanol fuel cell (DMFC) and the obtained results indicate that this is a promising and adequate method to prepare fuel cell electrodes

Synthesis and in vitro antiprotozoal activity of some 2- amino-4-phenyloxazole derivatives

Purpose: To prepare some 2-amino-4-(p-substituted phenyl)-oxazole derivatives and to evaluate their in vitro antiprotozoal activity against Giardia lamblia and Trichomonas vaginalis.Methods: The 2-amino-4-(p-substituted phenyl)-oxazoles (a-g) were synthesized by microwave (MW) irradiation of mixtures of p-substituted 2-bromoacetophenones and urea in dimethylformamide (DMF). All compounds were identified by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy and lowand high-resolution mass spectrometry (HRMS). NMR assignments were made based on heteronuclear single quantum coherence (HSQC) and heteronuclear multiple bond correlation (HMBC) experiments. Each synthesized compound’s melting point was determined. Antiprotozoal activity against Giardia intestinalis and Trichomonas vaginalis was quantified using a rigorous and sensitive subculture method. The commercial drug, metronidazole, was used as positive control. The 50 % inhibitory concentration (IC50) of the antiprotozoal agents for each protozoa was determined.Results: Seven 2-amino-4-(p-substituted phenyl)-oxazoles (a-g) were synthesized. The most active compounds against G. lamblia was 2-amino-4-(p-benzoyloxyphenyl)-oxazole (3d) with an IC50 of 1.17 μM, while compound 3e (2-amino-4-(p-bromophenyl)-oxazole) showed the highest anti-trichomonal activity (IC50, 1.89 μM).Conclusion: The in vitro antigiardial activity of 2-amino-4-(p-benzoyloxyphenyl) oxazole was higher than that exhibited by metronidazole; however, it is necessary increase the number of synthetic derivatives in order to be able to determine their structure-activity relationship.Keywords: Antiprotozoal, 2-Amino-4-phenyl-oxazoles, Giardia lamblia, Trichomonas vaginali