Differential Equations
Mostrando 1-12 de 608 artigos, teses e dissertações.
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1. Strong Stability Preserving Runge-Kutta Methods Applied to Water Hammer Problem
ABSTRACT The characteristic method of lines is the most used numerical method applied to the water hammer problem. It transforms a system of partial differential equations involving the independent variables time and space in two ordinary differential equations along the characteristics curves and then solve it numerically. This approach, although showing gr
Trends in Computational and Applied Mathematics. Publicado em: 2022
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2. A Nodal-iterative Technique for Criticality Calculations in Multigroup Neutron Diffusion Models
ABSTRACT In this work, a nodal and iterative technique to evaluate the effective multiplication factor as well as the neutron flux, in multigroup diffusion problems, is presented. An iterative scheme, similar to the source iteration method, is implemented to decouple the system of differential equations which is the fundamental mathematical model. Then, anal
Trends in Computational and Applied Mathematics. Publicado em: 2022
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3. Modeling and Computer Simulation of Viscoelastic Crypt Deformation
ABSTRACT Colorectal cancer morphogenesis begins at the cellular level from cell mutations in the intestinal epithelium cavities called crypts. These mutations lead to a pressure difference in the epithelium crypt walls, which can cause deformation and generate visible abnormalities in the epithelium. The geometrical modeling of these crypts and the mathemati
Trends in Computational and Applied Mathematics. Publicado em: 2022
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4. A Mathematical Model for Accessing Dengue Hemorrhagic Fever in Infants
ABSTRACT A mathematical model was developed to describe the dynamics of the primary infection of dengue virus in infants who were born to a mother immune to some serotype of the dengue virus. The model is given by a system of nonlinear ordinary differential equations with time-dependent variables for the number of dengue virus antibodies of the infant transf
Trends in Computational and Applied Mathematics. Publicado em: 2022
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5. Meshless Methods for Computation of Overhead Transmission Lines Electromagnetic Fields
Abstract The meshless element-free Galerkin method (EFGM) is used to solve partial differential equations responsible for obtaining the electromagnetic fields generated by a transmission line. For this purpose, a 2D model based in a real transmission line is constructed and simulated. The results obtained by EFGM have good accuracy and they are compared agai
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2021-06
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6. Glass transition and sorption properties of Köftür: a dehydrated fruit-based product
Abstract This study was conducted to determine the glass transition temperature (Tg) using Differential Scanning Calorimetry (DSC) and sorption characteristics of köftür, a dehydrated fruit-based product. Tg of was found to be 24.5 °C ± 0.30. Sorption isotherms were determined at 5, 15 and 25 °C using nine different salt solutions. The data were then ap
Food Sci. Technol. Publicado em: 2020-12
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7. Two-dimensional beams in rectangular coordinates using the radial point interpolation method
Abstract The three-dimensional Theory of Elasticity equations lead to a complex solution for most problems in engineering. Therefore, the solutions are typically developed for reduced systems, usually symmetrical or two-dimensional. In this context, computational resources allow the reduction of these simplifications. The most recognized methods of algebraic
REM, Int. Eng. J.. Publicado em: 2020-03
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8. Large Displacement Static Analysis of Composite Elliptic Panels of Revolution having Variable Thickness and Resting on Winkler-Pasternak Elastic Foundation
Abstract Nonlinear static response of laminated composite Elliptic Panels of Revolution Structure(s) (EPRS) having variable thickness resting on Winkler-Pasternak (W-P) Elastic Foundation is investigated in this article. Generalized Differential Quadrature (GDQ) method is utilized to obtain the numerical solution of EPRS. The first-order shear deformation th
Lat. Am. j. solids struct.. Publicado em: 20/12/2019
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9. A METHODOLOGY TO OBTAIN ANALYTICAL MODELS THAT REDUCE THE COMPUTATIONAL COMPLEXITY FACED IN REAL TIME IMPLEMENTATION OF NMPC CONTROLLERS
Abstract Model Predictive Control, MPC and NMPC, and real-time optimization, RTO and D-RTO, are known to help plant operability through the mitigation of impacts caused by external disturbances. However, the usage of these tools in industry requires overcoming some challenges, for instance: accurate models of the process, particularly in regard to nonlineari
Braz. J. Chem. Eng.. Publicado em: 09/12/2019
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10. Exact and inexact differentials in the early development of mechanics and thermodynamics
Abstract We give an account and a critical analysis of the use of exact and inexact differentials in the early development of mechanics and thermodynamics, and the emergence of differential calculus and how it was applied to solve some mechanical problems, such as those related to the cycloidal pendulum. The Lagrange equations of motions are presented in the
Rev. Bras. Ensino Fís.. Publicado em: 02/12/2019
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11. Apropriação Linguística e Significado em Atividades de Modelagem Matemática
Resumo Neste artigo dirigimos nossa atenção para os diferentes jogos de linguagem associados ao desenvolvimento de atividades de Modelagem Matemática e os significados constituídos pelos alunos no interior destes jogos de linguagem em relação a equações diferenciais ordinárias de primeira ordem. A pesquisa está fundamentada na Modelagem Matemática
Bolema. Publicado em: 02/12/2019
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12. Computational algorithm for stability analysis of distribution networks with distributed generation
Abstract With the insertion of distributed generation in distribution networks, security analysis becomes crucial, in islanded operation or when the system is connected to the grid. Dynamic stability analyses are necessary in order to achieve minimum levels of security and reliability. Such analyses are obtained through the solution of the algebraic-differen
Braz. arch. biol. technol.. Publicado em: 25/11/2019