Examinando por Materia "Closed form solutions"

Mostrando 1 - 3 de 3
  • No hay miniatura disponible
    Ítem
    Closed-form solutions for drug transport through controlled-release devices in two and three dimensions
    (Wiley, 2015-04-01) Ospina, Juan Fernando; Laurent, Simon; Ospina, Juan Fernando; Laurent, Simon; Universidad EAFIT. Departamento de Ciencias; Lógica y Computación
    Provides solutions for two- and three-dimensional linear models of controlled-release systems Real-world applications are taken from used to help illustrate the methods in Cartesian, cylindrical and spherical coordinate systems Covers the modeling of drug-delivery systems and provides mathematical tools to evaluate and build controlled-release devices Includes classical and analytical techniques to solve boundary-value problems involving two- and three-dimensional partial differential equations Provides detailed examples, case studies and step-by-step analytical solutions to relevant problems using popular computational software. © 2016 by John Wiley & Sons, Inc. All rights reserved.
  • No hay miniatura disponible
    Ítem
    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.
  • No hay miniatura disponible
    Ítem
    Two-dimensional description of absorption in humans after dermal exposure to volatile organic compounds
    (TAYLOR & FRANCIS INC, 2017-06-03) Simon, Laurent; Ospina, Juan; Simon, Laurent; Ospina, Juan; Universidad EAFIT. Departamento de Ciencias; Lógica y Computación
    A two-dimensional diffusion model was developed to predict the absorption of chemicals in humans following dermal contact. A firstorder evaporation rate equation was applied to the skin surface while a perfect-sink boundary condition was imposed at the stratum corneum/viable epidermis interface. Initially, there was a certain amount of the substance present within the stratum corneum at the end of the exposure period. Laplace transform techniques were implemented to solve the governing equations and to derive an expression for the time elapsed before reaching 90% of the final amount of chemical absorbed by the body. This index was 0.43, 2.67, 6.91, and 36.9 h for ethanol, diphenylamine, p-nitroaniline, and benzyl butyl-phthalate, respectively. Simulations show that surface evaporation is important for highly volatile compounds. A large fraction of the amount of poorly volatile compounds, available in the skin after exposure, was absorbed into the bloodstream. © Taylor & Francis Group, LLC.