Examinando por Materia "Color"

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    Ítem
    El poder de la forma y el color : percepción de naturalidad en los snacks de chocolate
    (Universidad EAFIT, 2023) Abreu Domínguez, Manuela; Rendón Vélez, Elizabeth; Rendón Vélez, Elizabeth
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    Evaluation between methods for the color measurement in holograms by using a CMOS-RGB camera and a spectrometer
    (SPIE, 2013-07-22) Palacios Ortega, Natalith; Velásquez Prieto, Daniel; Universidad EAFIT. Departamento de Ciencias Básicas; Óptica Aplicada
    Many models and methods commonly used in colorimetry have been incorporated to the study and knowledge of the colorimetric properties in the reflection color holograms; these methods have reported the possibilities of color reproduction in holograms. One method is based in calculating the color differences between the CIE-L*a*b* coordinates of the original object compared to the same values obtained for the reconstructed hologram; these values are calculated through the measurement of the spectral composition of the light in the reproduced hologram which are made with spectrometers. Other methods are based in the use of cameras for the color measurement, although, they are not commonly used for that ending in holography. This work presents the results of a comparative study between the use of spectrometers and RGB digital cameras for the color measurement in holograms. The diffraction efficiency of the holograms for a GretagMacbeth Colorchecker samples is measured through a spectrometer and their CIE-L*a*b* coordinates are calculated; the color differences are also calculated by taking as theoretical values the coordinates of the original object. A similar procedure is made by capturing the reconstructed images of the hologram through a CMOSRGB camera, which requires a linearizing and characterizing procedure. The RGB coordinates of the original object are compared with the RGB coordinates of the reproduced hologram too. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
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    Monocolor and color holography of pre-Hispanic Colombian goldwork: A way of Colombian heritage appropriation
    (SPIE-INT SOC OPTICAL ENGINEERING, 2018-01-01) Madrid Sánchez, A.; Giraldo, L.M.; Velásquez Prieto, D.; Universidad EAFIT. Departamento de Ciencias Básicas; Óptica Aplicada
    Optically indistinguishable copies of 3D real objects or holograms are known to be suitable to replace exhibited artistic pieces in museums. In this paper, we discuss holography as an alternative to protect, share and preserve finely crafted gold pieces belonging to the indigenous treasure inherited by Colombians. We present high diffraction efficiency monocolor and color holograms of native goldwork. As reference objects and proof of concept, we use replicas of the renowned and emblematic Poporo Quimbaya, pre-Hispanic gold pendants and anthropomorphic gold pieces. We report experimental details to deal with different types of commercial holographic recording materials, as for example, PFG-03M and PFG- 03C silver halides or C-RT20 photopolymers. And its general feasibility for reproducing high-quality holograms suitable for museum exhibitions or traveling art-collections. Copyright © 2018 SPIE. Downloading of the abstract is permitted for personal use only.
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    Natural User Interface for color selection in conceptual design phase
    (Springer-Verlag France, 2017-02-01) Arbeláez-Estrada, J.C.; Osorio-Gómez, G.; Universidad EAFIT. Departamento de Ingeniería de Diseño; Ingeniería de Diseño (GRID)
    In most of the surrounding discrete products, style plays a very important role. Specifically, color has a great impact in the visual perception, and its meaning can vary depending on the context where the product is located. Anyway, there are not dedicated applications devoted to support designers during this activity of color selection in the conceptual stage of the product design process. In this way, this paper presents the development and evaluation of a software platform that allows the user to choose a scheme of colors of a product concept using a Natural User Interface (NUI) in a 3D scanned context. In addition, the NUI was validated and evaluated with a case study oriented to compare the scheme of colors, for a conceptual product, selected by product designers, an expert panel and the target user in order to prove that this interface can enhance the process of color selection during the concept stage of the product design process, with regards to a traditional selection process with images and user profile. © 2015, Springer-Verlag France.
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    Optimization and toxicity assessment of a combined electrocoagulation, H2O2/Fe2+/UV and activated carbon adsorption for textile wastewater treatment
    (Elsevier, 2019-02-15) GilPavas, E; Dobrosz-Gomez, I; Gomez-Garcia, MA; GilPavas, E; Dobrosz-Gomez, I; Gomez-Garcia, MA; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
    In this study, the potential application of sequential Electrocoagulation + Fenton (F) or Photo-Fenton (PF) + Active carbon adsorption (EC + F/PF + AC) processes were analyzed as alternatives for the treatment of an industrial textile wastewater resulting from an industrial facility located in Medellín (Colombia). In order to maximize the organic matter degradation, each step of the treatment was optimized using the Response Surface Methodology. At first, the optimal performance of EC was achieved with Fe electrodes operating at pH = 7, jEC = 10 mA/cm2 and 60 rpm, during 10 min of electrolysis. At these conditions, EC let to remove 94% of the dye's color, 56% of the COD and 54% of the TOC. Next, sequentially applied Fenton or photo-Fenton process (i.e., EC + F/PF), operating at the optimized conditions (pH = 4.3, [Fe2+] = 1.1 mM, [H2O2] = 9.7 mM, stirring velocity = 100 rpm and reaction time = 60 min.), improved the quality of the treated effluent. The EC + F let to achieve total color reduction, as well as COD and TOC removals of 72 and 75%, respectively. The EC + PF reached 100% of color, 76% of COD and 78% of TOC reductions. The EC + F/PF processes were more efficient than EC in elimination of low molecular weight (<5 kDa) compounds from wastewater. Moreover, the BOD5/COD ratio increased from 0.21 to 0.42 and from 0.21 to 0.46 using EC + F and EC + PF processes, respectively. However, EC + F/PF were not fully effective for the removal of acute toxicity to Artemia salina: 20% and 60% of reduction in toxicity using EC + F and EC + PF, respectively, comparing to very toxic (100%) raw textile wastewater. Thus, activated carbon adsorption was applied as an additional step to complete the treatment. After AC adsorption, the acute toxicity decreased to 10% and 0% using EC + F and EC + PF, respectively. The total operational costs, including chemical reagents, electrodes, energy consumption and sludge disposal, were of 1.65 USD/m3 and 2.3 USD/m3 for EC + F and EC + PF, respectively. © 2018 Elsevier B.V.
  • No hay miniatura disponible
    Ítem
    Optimization and toxicity assessment of a combined electrocoagulation, H2O2/Fe2+/UV and activated carbon adsorption for textile wastewater treatment
    (Elsevier, 2019-02-15) GilPavas, E; Dobrosz-Gomez, I; Gomez-Garcia, MA; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
    In this study, the potential application of sequential Electrocoagulation + Fenton (F) or Photo-Fenton (PF) + Active carbon adsorption (EC + F/PF + AC) processes were analyzed as alternatives for the treatment of an industrial textile wastewater resulting from an industrial facility located in Medellín (Colombia). In order to maximize the organic matter degradation, each step of the treatment was optimized using the Response Surface Methodology. At first, the optimal performance of EC was achieved with Fe electrodes operating at pH = 7, jEC = 10 mA/cm2 and 60 rpm, during 10 min of electrolysis. At these conditions, EC let to remove 94% of the dye's color, 56% of the COD and 54% of the TOC. Next, sequentially applied Fenton or photo-Fenton process (i.e., EC + F/PF), operating at the optimized conditions (pH = 4.3, [Fe2+] = 1.1 mM, [H2O2] = 9.7 mM, stirring velocity = 100 rpm and reaction time = 60 min.), improved the quality of the treated effluent. The EC + F let to achieve total color reduction, as well as COD and TOC removals of 72 and 75%, respectively. The EC + PF reached 100% of color, 76% of COD and 78% of TOC reductions. The EC + F/PF processes were more efficient than EC in elimination of low molecular weight (<5 kDa) compounds from wastewater. Moreover, the BOD5/COD ratio increased from 0.21 to 0.42 and from 0.21 to 0.46 using EC + F and EC + PF processes, respectively. However, EC + F/PF were not fully effective for the removal of acute toxicity to Artemia salina: 20% and 60% of reduction in toxicity using EC + F and EC + PF, respectively, comparing to very toxic (100%) raw textile wastewater. Thus, activated carbon adsorption was applied as an additional step to complete the treatment. After AC adsorption, the acute toxicity decreased to 10% and 0% using EC + F and EC + PF, respectively. The total operational costs, including chemical reagents, electrodes, energy consumption and sludge disposal, were of 1.65 USD/m3 and 2.3 USD/m3 for EC + F and EC + PF, respectively. © 2018 Elsevier B.V.