Examinando por Materia "Titanium"
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Ítem The Box-Benkhen experimental design for the optimization of the electrocatalytic treatment of wastewaters with high concentrations of phenol and organic matter.(IWA PUBLISHING, 2009-01-01) GilPavas, Edison; Betancourt, Alejandra; Angulo, Monica; Dobrosz-Gomez, Izabela; Angel Gomez-Garcia, Miguel; GilPavas, Edison; Betancourt, Alejandra; Angulo, Monica; Dobrosz-Gomez, Izabela; Angel Gomez-Garcia, Miguel; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)In this work, the Box-Benkhen experimental Design (BBD) was applied for the optimization of the parameters of the electrocatalytic degradation of wastewaters resulting from a phenolic resins industry placed in the suburbs of Medellin (Colombia). The direct and the oxidant assisted electro-oxidation experiments were carried out in a laboratory scale batch cell reactor, with monopolar configuration, and electrodes made of graphite (anode) and titanium (cathode). A multifactorial experimental design was proposed, including the following experimental variables: initial phenol concentration, conductivity, and pH. The direct electro-oxidation process allowed to reach ca. 88% of phenol degradation, 38% of mineralization (TOC), 52% of Chemical Oxygen Demand (COD) degradation, and an increase in water biodegradability of 13%. The synergetic effect of the electro-oxidation process and the respective oxidant agent (Fenton reactant, potassium permanganate, or sodium persulfate) let to a significant increase in the rate of the degradation process. At the optimized variables values, it was possible to reach ca. 99% of phenol degradation, 80% of TOC and 88% of COD degradation. A kinetic study was accomplished, which included the identification of the intermediate compounds generated during the oxidation process.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 Dislocation density based flow stress model applied to the PFEM simulation of orthogonal cutting processes of Ti-6Al-4V(MDPI AG, 2020-01-01) Rodríguez, J.M.; Larsson, S.; Carbonell, J.M.; Jonsén, P.; Rodríguez, J.M.; Larsson, S.; Carbonell, J.M.; Jonsén, P.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Mecatrónica y Diseño de MáquinasMachining of metals is an essential operation in the manufacturing industry. Chip formation in metal cutting is associated with large plastic strains, large deformations, high strain rates and high temperatures, mainly located in the primary and in the secondary shear zones. During the last decades, there has been significant progress in numerical methods and constitutive modeling for machining operations. In this work, the Particle Finite Element Method (PFEM) together with a dislocation density (DD) constitutive model are introduced to simulate the machining of Ti-6Al-4V. The work includes a study of two constitutive models for the titanium material, the physically based plasticity DD model and the phenomenology based Johnson-Cook model. Both constitutive models were implemented into an in-house PFEM software and setup to simulate deformation behaviour of titanium Ti6Al4V during an orthogonal cutting process. Validation show that numerical and experimental results are in agreement for different cutting speeds and feeds. The dislocation density model, although it needs more thorough calibration, shows an excellent match with the results. This paper shows that the combination of PFEM together with a dislocation density constitutive model is an excellent candidate for future numerical simulations of mechanical cutting. © 2020 by the authors.Ítem Lagrangian model for predicting the dynamic behavior of cohesive particles in a fluidized confined environment(Universidad EAFIT, 2013) Posada Noreña, Juliana; García Ruíz, Manuel JulioTitanium dioxide, TiO2, is one of the most important raw materials in the paint production process; also TiO2 is classified as a Geldart C solid type, and it makes its storage and handling more than important not only because of its importance to the process but also because of its complicated nature -- Most common problems encountered handling and storing TiO2 come from the cohesive nature of the solid, which benefits the formation of agglomerates leading to clogging in pipes and storage vessels -- Attempting to simulate TiO2’s handling and storage, a Lagrangian particle simulation began by using a Discrete Element Model -- Understanding the interactions and forces acting on solids when they are dispersed in a gas and then stored, and the agglomerate formation due to cohesive forces were the main purposes of this work -- The particle motion under the influence of gravity and a fluid in motion was simulated with the BBO equation for each of the particles -- The wall-particle collisions were simulated with the equations for exchange of momentum and energy; the particle-particle collisions were simulated with the hard sphere model using as well the equations for exchange of momentum and energy and the agglomerate formation considered the collision model and a cohesion parameter -- Three hypotheses were proposed for the analysis of the interactions acting on the particles and their behavior was compared with results from various authors to conclude on the final validation of the DEM here proposedÍtem Multifactorial optimization of the decolorisation parameters of wastewaters resulting from dyeing flowers.(IWA PUBLISHING, 2009-01-01) Gil Pavas, Edison; Angel Gomez-Garcia, Miguel; Gil Pavas, Edison; Angel Gomez-Garcia, Miguel; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)This work deals with the treatment of the wastewaters resulting from the process of dyeing flowers. In some local cases for growing flowers near to Medellin (Colombia), wastewater color was found to be one of the main problems in meeting local effluent standards. Wastewaters were treated by photodegradation process (which includes photocatalysis) to achieve the degradation of dyes mixture and organic matter in the wastewater. A multifactorial experimental design was proposed, including as experimental factors the following variables: pH, and the concentration of both catalyst (TiO(2)) and hydrogen peroxide (H(2)O(2)). According to the obtained results, at the optimized variables values, it is possible to reach a 99% reduction of dyes, a 76.9% of mineralization (TOC) and a final biodegradability of 0.834. Kinetic analysis allows proposing a pseudo first order reaction for the reduction, the mineralization, and the biodegradation processes.Ítem Síntesis y caracterización de películas delgadas de Reb2 en Co-deposición con Ti mediante la técnica Magentrón Sputtering(Universidad EAFIT, 2023) Ruiz Daza, Carolina Rocío; Arroyave Franco, Mauricio; Palacio Espinosa, Claudia ConstanzaUsing the reactive magnetron sputtering technique, Rhenium Boride films in co-deposition with Titanium were grown on steel substrates at 100°C. To improve the adhesion of the coating a stack of twelve Ti/TiN bilayers was grown using a reactive atmosphere of argon and nitrogen with a ratio Ar/N2=40/1.4 sccm meanwhile, radio frequency power, negative bias voltage, working pressure, and temperature of 100°C were fixed in the experiments to produce the (ReB2):Ti. A design of experiments with a fraction-factorial style was made with four inputs and two outputs with 3 different levels. A matrix of procedures was defined for a total of 9 experiments. The titanium target was powered with 30 and 60 watts during the co-deposition with ReB2 to evaluate the content of titanium at different ratios. Structural and compositional measurements were carried out using SEM, XRD, and XPS to confirm the formation of (ReB2):Ti and AFM analysis to measure the thickness and observe the morphology of samples. Furthermore, mechanical properties were measured with nano hardness equipment, showing that the addition of titanium to ReB2 coating has a significant improvement on the chemical stability of ReB2 on steel and preserves mechanical properties of hardness and high Young’s module, which makes the material suitable for applications in the mechanical industry reaching hardness around 20 GPa.