Examinando por Materia "Chemical analysis"

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    Analysis of chemical processes for the synthesis of magnetite for biomedical applications
    (IOP PUBLISHING LTD, 2011-01-01) Baena, J.; Marulanda, J.I.; Universidad EAFIT. Departamento de Ciencias Básicas; Óptica Aplicada
    This article demonstrates the evaluation of wet chemical routes to produce magnetic nanoparticles of iron oxide and surface chemistry characterization by infrared spectroscopy (IR). Its potential use in biomedicine as contrast agents or to deliver drugs in localized medical treatments, which reduce the toxicity associated with cytotoxic drugs, is also evaluated.
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    Ítem
    Analysis of chemical processes for the synthesis of magnetite for biomedical applications
    (IOP PUBLISHING LTD, 2011-01-01) Baena, J.; Marulanda, J.I.; Baena, J.; Marulanda, J.I.; Universidad EAFIT. Departamento de Ciencias; Electromagnetismo Aplicado (Gema)
    This article demonstrates the evaluation of wet chemical routes to produce magnetic nanoparticles of iron oxide and surface chemistry characterization by infrared spectroscopy (IR). Its potential use in biomedicine as contrast agents or to deliver drugs in localized medical treatments, which reduce the toxicity associated with cytotoxic drugs, is also evaluated.
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    Battery State of Charge Estimation Error Comparison Across Different OCV-SOC Curve Approximating Methods
    (Springer Verlag, 2019-01-01) Sanín R.; Fernández-Montoya M.; Garzón-Vargas M.A.; Velásquez-López A.
    Accurate estimation of Rechargeable Batteries Parameters, such as State Of Charge (SOC), contributes to their safety and reliable operation in a wide variety of applications (e.g. automotive, stationary energy storage, medical equipment, among others). Due to variations in environmental and load conditions, battery cells and their instrumentation devices can experience deviations from their standard operation values, leading to an imprecise measurement of State Of Charge (SOC) indicator variables. Then, SOC estimation models are required. These estimations developed through analytical models consider intrinsic battery chemistry variables and operation cycle conditions are taken from charge and discharge testing; where hysteresis phenomena, measurement, and theoretical adjustment errors can be identified over Open Circuit Voltage (OCV)-SOC curves. This study compares the model adjustment errors of several estimation methods, taken from literature to approximate the OCV-SOC curves of a rechargeable battery pack. © 2019, Springer Nature Switzerland AG.
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    Degradación y mineralización de tartrazina mediante electrooxidación. Optimización de las condiciones de operación
    (Centro de Informacion Tecnologica, 2014-01-01) Gilpavas, E.; Dobrosz-Gómez, I.; Gómez-García, M.Á.; Gilpavas, E.; Dobrosz-Gómez, I.; Gómez-García, M.Á.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
    In this work, the operational conditions of the tartrazine electro-oxidation (EO) process were optimized. The batch reactor used has two electrodes: one made of diamond doped with boron and the other one of titanium, working at monopolar configuration. The initial dyestuff concentration (Ci), the current density (i) and the pH were defined as the main factors affecting the EO. Their optimal values were found as follows: Ci=30 ppm, i=5mA/cm2 and pH=6.0. At these conditions, a kinetic analysis was performed in the terms of: the percentage of the dyestuff decolorization (%DC), the percentage of the chemical oxygen demand (%DCOD), and the percentage of the total organic carbon (%TOC). Additionally, the effect of Fe2+ (electro- Fenton process, EF) and Fe2+/UV radiation (electro-photo-Fenton process, EFF) on the studied process were evaluated. The work demonstrates the validity of the hypothesis about the most significant parameters that affect the EO process.
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    Dynamic analysis and performance evaluation of the BIAcore surface plasmon resonance biosensor
    (SPIE-INT SOC OPTICAL ENGINEERING, 2015-01-01) Simon, Laurent; Ospina, Juan; Simon, Laurent; Ospina, Juan; Universidad EAFIT. Departamento de Ciencias; Lógica y Computación
    Solution procedures were proposed to analyze nonlinear mass transport through an optical biosensor. A generalized collocation technique was applied to predict the dynamic behavior of an analyte along the flow chamber as a result of convection, diffusion and chemical reaction. The method estimated the effective time constants for reaching average steady-state concentrations of the free and bound analytes in the cell. When diffusion in the direction of flow was neglected, a closed-form solution, based on double Laplace transforms, was obtained after linearizing the original system. In both models, an increase in the sample diffusion coefficient lowered the effective time constant. This approach may help researchers evaluate the performance of biosensors and meet specific design criteria. © 2015 SPIE.
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    Dynamic analysis of a recirculation system of micro functional fluids for ink-jet applications
    (Springer Verlag, 2017-05-01) Arango, I.; Cañas, M.; Arango, I.; Cañas, M.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Mecatrónica y Diseño de Máquinas
    The rise of ink-jet printing technology has led to numerous studies about functional fluids, which, in most cases, are made to change and improve the chemical and rheological properties. Besides this, there are several patents about the recirculation fluid system that help to prevent settling particles, and thus improving print quality without consequences in the chemical composition of the fluid. This paper presents a dynamic analysis of a recirculation circuit for ink-jet microsystems applications with fluids that contain a particle size of 40 nm to 10 µ m. This analysis integrates multiple mathematical and experimental models, in regard to variables such as: viscosity change with temperature and solid volume fraction, sedimentation, surface tension and flow behavior. As a result, specific values of vacuum pressure for different drop-on-demand print heads with different ink-jet functional fluids, places of probable sedimentation and minimum pickup velocities to remove settled particles are given. © 2017, Springer-Verlag Berlin Heidelberg.