Examinando por Materia "Aluminum"
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Ítem Cálculo de propiedades estructurales, electrónicas y topológicas del Al2TiO5 usando DTF(Universidad EAFIT, 2015) Duarte Ruíz, Daniel; David Caro, Jorge León; Vélez Ruíz, Mario ElkinÍtem Digital material laboratory: Wave propagation effects in open-cell aluminium foams(PERGAMON-ELSEVIER SCIENCE LTD, 2012-09-01) Saenger, E. H.; Uribe, D.; Jaenicke, R.; Ruiz, O.; Steeb, H.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Laboratorio CAD/CAM/CAEThis paper is concerned with numerical wave propagation effects in highly porous media using digitized images of aluminium foam. Starting point is a virtual material laboratory approach. The aluminium foam microstructure is imaged by 3D X-ray tomography. Effective velocities for the fluid-saturated media are derived by dynamic wave propagation simulations. We apply a displacement-stress rotated staggered finite-difference grid technique to solve the elastodynamic wave equation. The used setup is similar to laboratory ultrasound measurements and computed results are in agreement with our experimental data. Theoretical investigations allow to quantify the influence of the interaction of foam and fluid during wave propagation. Together with simulations using an artificial dense foam we are able to determine the tortuosity of aluminium foam. © 2012 Elsevier Ltd. All rights reserved.Ítem Diseño conceptual de una planta para la producción de Sulfato de Aluminio a partir de Bauxita(Universidad EAFIT, 2014) Velásquez Velásquez, Susana; Vélez Martínez, Daniel; Acosta Maya, Diego AndrésEn el presente estudio se planteó el diseño conceptual para la producción de cristales de sulfato de aluminio a partir de bauxita -- Para ello se planteó inicialmente un diseño de experimentos factorial fraccionado para determinar la conversión de ácido sulfúrico que se alcanza durante la digestión ácida, teniendo en cuenta los factores de temperatura, agitación, tiempo de reacción, relación alúmina-ácido y relación sólido líquido, encontrando que los factores más significativos en la conversión de ácido sulfúrico son el tiempo de reacción, la relación alúmina ácido y la relación sólido líquido, donde los dos primeros presentan un efecto positivo y la última un efecto negativo -- De acuerdo a los resultados obtenidos en el primer diseño de experimentos se llevó a cabo un diseño de superficie de respuesta Box-Behnken, para encontrar la mayor conversión que se podía alcanzar dentro de la región de operabilidad propuesta -- La corrida que presentó una conversión de ácido sulfúrico de 94.8%, la mayor alcanzada, se logró bajo las condiciones de 90°C de temperatura, una agitación de 500 rpm, una mol de alúmina por cada 5 de ácido sulfúrico, 4 horas de reacción y una relación sólido-líquido de 1 g de bauxita por cada 9 gramos de solución de agua y ácido sulfúrico -- Se presentan las especificaciones de diseño para la planta propuesta, su ubicación y características del entorno, condiciones del mercado y demanda esperada en el sector y su crecimiento potencial -- Por último se presenta el diseño conceptual, donde se encuentran los diagramas de proceso, hojas de especificación de equipos, análisis económico, entre otrosÍtem Estudio de factibilidad para la instalación de una planta de fabricación de hidroxicloruro de aluminio (ACH) a partir de aluminio reciclado en Perú(Universidad EAFIT, 2024) Contreras Peña, Andrés Felipe; Velásquez Motta, Didier; Pérez Restrepo, Camilo AlbertoÍtem Selección de parámetros en herramientas de soldadura por fricción y agitación : una aplicación de la cópula no paramétrica y aprendizaje de máquina(Universidad EAFIT, 2023) Hoyos Cano, Leidy Marcela; Laniado Rodas, Henry; Hoyos Pulgarín, ElizabethÍtem Structural diagnosis of rail vehicles and method for redesign(Polish Society of Technical Diagnostics, 2014-01-01) Aristizabal, M.; Barbosa, J.L.; Betancur, G.R.; Castañeda, L.F.; Zóltowski, B.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)Structures of rail vehicles are designed for a useful structural life of 30 years. However, structural problems which reduce the mechanical performance of the structure might appear due to normal operation conditions, in some cases, make it unsuitable for a safe operation. This document presents the structural diagnosis of a metro system and the method for the redesign of structural elements of rail vehicles that was derived from this diagnosis, so that the structural performance of both the element and the whole structure is improved. It is based on the European standards related with aluminium and railway applications, and considers the necessary aspects to produce a safe solution for the final design.Ítem Synthesis of Alumina Thin Films Using Reactive Magnetron Sputtering Method(IOP PUBLISHING LTD, 2017-06-13) Angarita G.; Palacio C.; Trujillo M.; Arroyave M.; Angarita G.; Palacio C.; Trujillo M.; Arroyave M.; Universidad EAFIT. Departamento de Ciencias; Electromagnetismo Aplicado (Gema)Alumina (Al2O3) thin films were deposited on Si (100) by Magnetron Sputtering in reactive conditions between an aluminium target and oxygen 99.99% pure. The plasma was formed employing Argon with an R.F power of 100 W, the dwelling time was 3 hours. 4 samples were produced with temperatures between 350 and 400 °C in the substrate by using an oxygen flow of 2 and 8 sccm, the remaining parameters of the process were fixed. The coatings and substrates were characterized using Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and Energy Dispersive Spectroscopy (EDS) in order to compare their properties before and after deposition. The films thicknesses were between 47 and 70 nm. The results show that at high oxygen flow the alumina structure prevails in the coatings while at lower oxygen flow only aluminum is deposited in the coatings. It was shown that the temperature increases grain size and roughness while decreasing the thicknesses of the coatings. © Published under licence by IOP Publishing Ltd.Ítem Test results. EMIR optomechanics(SPIE-INT SOC OPTICAL ENGINEERING, 2005-08-30) Barrera, S.; González, C.; Manescau, A.; Abreu, D.; Becerril, S.; Correa, S.; Fragoso, A.; Pérez, J.; Redondo, P.; Restrepo, R.; Saavedra, P.; Sánchez, V.; Tenegi, F.; Garzón, F.; Patrón, J.; Universidad EAFIT. Departamento de Ciencias Básicas; Óptica AplicadaEMIR is a NIR multiobject spectrograph with imaging capabilities to be used at the GTC. The first collimator lens in EMIR, made of Fused Silica, has an outer diameter of 490 mm, and a weight of 265 N, which make it one of the largest Fused Silica lenses ever mounted to work under cryogenic conditions. The results of the various tests being done at the IAC (with two different lens dummies) in order to validate a mounting design concept for this lens, are presented here. The radial support concept tested consists of three contact areas around the lens, one of which is a PTFE block, preloaded by coil springs and the other two are fixed supports made of Aluminum and PTFE, dimensioned in order to keep lens centered both at room temperature and under operation conditions.Ítem Thermal and permeability properties of metal Aluminum foams for functional applications(Pontificia Universidad Javeriana, 2017-01-01) Fernández-Morales, P.; Cano-Montoya, C.A.; Pérez-Mesa, J.A.; Navacerrada, M.Á.; Universidad EAFIT. Departamento de Geología; Ciencias del MarTo determine the coefficients of permeability and thermal conductivity of aluminum metal foams, thermal transference and pressure drop tests were carried out. Metal foam samples measuring 50 mm in diameter and 20 mm in thickness with pore sizes ranging between 0.5 and 2.0 mm were used for both tests. An adaptation in a fluid flow system was made to perform the pressure drop tests, and Darcy’s law was used to calculate the permeability values. A thermal box test and Fourier’s law were used to obtain the conductivity coefficients. The results showed that the pore size has an important influence on the values of permeability and thermal conductivity. Finally, the results were compared with those reported by other researchers and were found to be consistent with those found in previous work. Our interest is to enhance knowledge regarding aluminum metal foams and show their potential use in applications that involve fluid flow and heat transfer. © 2017, Pontificia Universidad Javeriana. All rights reserved.Ítem Treatment of automotive industry oily wastewater by electrocoagulation: statistical optimization of the operational parameters.(IWA PUBLISHING, 2009-11-01) GilPavas, Edison; Molina-Tirado, Kevin; Angel Gomez-Garcia, Miguel; GilPavas, Edison; Molina-Tirado, Kevin; Angel Gomez-Garcia, Miguel; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)An electrocoagulation process was used for the treatment of oily wastewater generated from an automotive industry in Medellin (Colombia). An electrochemical cell consisting of four parallel electrodes (Fe and Al) in bipolar configuration was implemented. A multifactorial experimental design was used for evaluating the influence of several parameters including: type and arrangement of electrodes, pH, and current density. Oil and grease removal was defined as the response variable for the statistical analysis. Additionally, the BOD(5), COD, and TOC were monitored during the treatment process. According to the results, at the optimum parameter values (current density = 4.3 mA/cm(2), distance between electrodes = 1.5 cm, Fe as anode, and pH = 12) it was possible to reach a c.a. 95% oils removal, COD and mineralization of 87.4% and 70.6%, respectively. A final biodegradability (BOD(5)/COD) of 0.54 was reached.