Examinando por Materia "Surface properties"

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    Decolorization and mineralization of Diarylide Yellow 12 (PY12) by photo-Fenton process: the Response Surface Methodology as the optimization tool.
    (IWA PUBLISHING, 2012-01-01) GilPavas, Edison; Dobrosz-Gomez, Izabela; Angel Gomez-Garcia, Miguel; GilPavas, Edison; Dobrosz-Gomez, Izabela; Angel Gomez-Garcia, Miguel; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
    The Response Surface Methodology (RSM) was applied as a tool for the optimization of the operational conditions of the photo-degradation of highly concentrated PY12 wastewater, resulting from a textile industry located in the suburbs of Medellin (Colombia). The Box-Behnken experimental Design (BBD) was chosen for the purpose of response optimization. The photo-Fenton process was carried out in a laboratory-scale batch photo-reactor. A multifactorial experimental design was proposed, including the following variables: the initial dyestuff concentration, the H(2)O(2) and the Fe(+2) concentrations, as well as the UV wavelength radiation. The photo-Fenton process performed at the optimized conditions resulted in ca. 100% of dyestuff decolorization, 92% of COD and 82% of TOC degradation. A kinetic study was accomplished, including the identification of some intermediate compounds generated during the oxidation process. The water biodegradability reached a final DBO(5)/DQO = 0.86 value.
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    Foto-degradación de fenol sobre catalizadores de TiO2 y Mo/TiO2. La metodología de superficie de respuesta como herramienta de optimización
    (Centro de Informacion Tecnologica, 2014-01-01) López-Zamora, S.M.; GilPavas, E.; Gómez-García, M.Á.; Dobrosz-Gómez, I.; López-Zamora, S.M.; GilPavas, E.; Gómez-García, M.Á.; Dobrosz-Gómez, I.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
    In this work, the response surface methodology was applied as a tool for the optimization of the operational conditions of phenol photo-degradation over TiO2 and 2% wt Mo/TiO2 catalysts. A multifactorial experimental design was proposed, including the following variables: phenol initial concentration (Ci), catalyst loading (Cat) and pH. The apparent reaction rate constant and the percentage of phenol degradation were chosen as the response variables. When TiO2 was used as catalyst, the following optimal operational conditions were found: Ci=10ppm, Cat=0.7g/L and pH=8 for both UV and visible light. For 2% wt Mo/TiO2 catalyst, the optimal operating conditions strongly depended on the applied radiation source. Thus, under UV radiation: Ci=10 ppm, Cat=0.7 g/L and pH=8 were found as the optimum conditions. Using visible light, and the following optimized conditions, Ci=10 ppm, Cat=0.1 g/L, pH =3.6, the Mo containing catalyst showed to be the most efficient. Under these conditions, the amount of 2% wt. Mo/TiO2 was 7 times lower than that of unsupported TiO2.
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    Geometrical degeneracy removal by virtual disturbances - An application to surface reconstruction from point slice samples
    (INSTICC-INST SYST TECHNOLOGIES INFORMATION CONTROL & COMMUNICATION, 2008-01-01) Ruiz, Oscar; Vasquez, Eliana; Pena, Sebastian; Granados, Miguel; Universidad EAFIT. Departamento de Ingeniería Mecánica; Laboratorio CAD/CAM/CAE
    In surface reconstruction from slice samples (typical in medical imaging, coordinate measurement machines, stereolithography, etc.) the available methods attack the geometrical and topological properties of the surface. Topological methods classify the transitions occurred in the 2-manifold between two consecutive slices i and i+ 1. Geometrical methods synthesize the surface based on local proximity of the contours in consecutive slices. Superimposed 2D Voronoi Diagrams VDi and VDi+1 for slices i and i + 1, respectively, present topological problems if, for example, a site of VD i lies on an site or an edge of VDi+1. The usual treatment of this problem in literature is to apply a geometrical disturbance to either VDi or VDi+1, thus eliminating the degeneracy. In contrast, this article presents the implementation of a method which identifies the degenerate situation, constructs un-instantiated topological constructs, choses a geometrical instantiation based on a virtual disturbance introduced to the actual configuration. The algorithm was successfully applied to remove non-manifold topologies produced by well known algorithms in surface reconstruction.
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    Optimización de los Costos de Operación del Proceso de Electro-oxidación para una Planta de Tratamiento de Aguas Mediante Análisis Estadístico de Superficie de Respuesta
    (Centro de Informacion Tecnologica, 2016-01-01) GilPavas, E.; Medina, J.; Dobrosz-Gómez, I.; Gómez, M.-A.; GilPavas, E.; Medina, J.; Dobrosz-Gómez, I.; Gómez, M.-A.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
    The statistical optimization of the implementation and operational costs of an electrochemical-oxidation process for treatment of wastewater containing dye Yellow 23 was done. The aim was to optimize the operational parameters for the current density, conductivity, and area of electrodes per unit of volume in order to minimize the net present value (NPV) of the operation while maintaining a defined quality for the treated wastewater. To achieve this, the response surface methodology coupled to the Box-Behnken statistical design was used. The optimal conditions found were: a relationship of treated wastewater volume per area of electrodes of 9.076 mL/cm2, conductivity 4000 µS/cm, and current density 20 mA/cm2. At optimal conditions, the NPV for a 10 year operation is 998636 USD, which corresponds to a cost of 0.68USD/m3 of treated water.