Linear Equations System
Mostrando 1-12 de 193 artigos, teses e dissertações.
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1. 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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2. ANALYTICAL EXPRESSIONS FOR THE CONCENTRATION AND CURRENT IN THE REDUCTION OF HYDROGEN PEROXIDE AT A METAL-DISPERSED CONDUCTING POLYMER FILM
A mathematical model describing the reduction of Hydrogen peroxide (H2O2) to water in a metal dispersed conducting polymer film is discussed. The model is based on a system of reaction-diffusion equations containing a non-linear term related to Michaelis-Menten kinetics of the enzymatic reaction. The approximate analytical expressions corresponding to the co
Quím. Nova. Publicado em: 2020-01
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3. Comparison and Combination of Techniques for Determining the Parameters of a Magnetic Hysteresis Model
Abstract The Jiles-Atherton scalar hysteresis model presents five parameters used to represent the material tested and used to calculate the magnetic losses. This article presents a comparative analysis of the performance of two methods of identifying these parameters. In the first method, the equations of Jiles-Atherton were assembled into a single non-line
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 12/09/2019
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4. STATE ESTIMATION AND TRAJECTORY TRACKING CONTROL FOR A NONLINEAR AND MULTIVARIABLE BIOETHANOL PRODUCTION SYSTEM
ABSTRACT In this paper a controller is proposed based on linear algebra for a fed-batch bioethanol production process. It involves finding feed rate profiles (control actions obtained as a solution of a linear equations system) in order to make the system follow predefined concentration profiles. A neural network states estimation is designed in order to kno
Braz. J. Chem. Eng.. Publicado em: 15/07/2019
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5. Evaluation of the energy extraction of a small-scale wave energy converter
RESUMO Este trabalho tem foco em propostas que podem incentivar o desenvolvimento de dispositivos integrados de pequena escala para atender o desafio global de fornecer energia elétrica a partir de fontes alternativas sem maiores intervenções. O artigo apresenta a avaliação de um dispositivo de extração de energia das ondas em pequena escala que pode
RBRH. Publicado em: 04/04/2019
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6. Liquid-liquid extraction equilibrium for pyruvic acid recovery: experimental data and modeling
ABSTRACT Physical extraction studies of pyruvic acid from dilute aqueous solutions (0.025 kmol·m-3 to 0.200 kmol·m-3) using several pure solvents (tri-n-butylphosphate (TBP), 1-decanol, 1-octanol, toluene, Methyl-isobutylketone (MIBK), and n-heptane) and their binary mixtures are reported in this work. All the batch extraction experiments were carried out
Braz. J. Chem. Eng.. Publicado em: 2017-07
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7. Nonlinear Vibration and Mode Shapes of FG Cylindrical Shells
Abstract The nonlinear vibration and normal mode shapes of FG cylindrical shells are investigated using an efficient analytical method. The equations of motion of the shell are based on the Donnell’s non-linear shallow-shell, and the material is assumed to be gradually changed across the thickness according to the simple power law. The solution is provided
Lat. Am. j. solids struct.. Publicado em: 2017-03
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8. A New Algorithm for Shock Sensor Calculation at Supersonic Speeds on a 3D-Unstructured Grid
ABSTRACT In this paper, 3-Dsupersonic flow around two types of wings is solved using a new algorithm for shock sensor calculation. A dual-time-stepping implicit method with 2nd-order accuracy is used for time integration of the equations. In each real time step, the non-linear system of equations is solved by iterating in pseudo-time, using a multi-step inte
J. Aerosp. Technol. Manag.. Publicado em: 2016-12
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9. Reflection and Refraction of Waves at the Boundary of a Non-Viscous Porous Solid Saturated with Single Fluid and a Porous Solid Saturated with Two Immiscible Fluids
Abstract The phenomenon of reflection and refraction is studied at the welded interface between two different porous solids. One is saturated with single non-viscous fluid and other is saturated with two immiscible viscous fluids. The incidence of Pf, Ps or SV wave through porous solid saturated with non-viscous fluid results in the three reflected waves and
Lat. Am. j. solids struct.. Publicado em: 2016-07
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10. ADVANCED CONTROL OF A COMPLEX CHEMICAL PROCESS
Abstract Three phase catalytic hydrogenation reactors are important reactors with complex behavior due to the interaction among gas, solid and liquid phases with the kinetic, mass and heat transfer mechanisms. A nonlinear distributed parameter model was developed based on mass and energy conservation principles. It consists of balance equations for the gas a
Braz. J. Chem. Eng.. Publicado em: 2016-03
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11. Reflection/refraction at the interface of an elastic solid and a partially saturated porous solid containing liquid filled bound pores and a connected pore space saturated by two-phase fluid
Abstract The phenomena of reflection and refraction of plane waves incident obliquely at a plane interface between uniform elastic solid half-space and porous solid containing liquid filled bound pores and two-phase fluid in connected pores has been analyzed. The amplitude ratios of the reflected and refracted waves to that of the incident wave are calculate
Lat. Am. j. solids struct.. Publicado em: 2015-10
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12. A New Jacobi-based Iterative Method for the Classical Analysis of Structures
Abstract Traditionally, classical methods of structural analysis such as slope-deflection and moment distribution methods (Cross method) are used for primary analysis of structures and also controlling the results of computer programs. The main objective of this paper is to introduce a new method for classical computing and extending it to a matrix formulati
Lat. Am. j. solids struct.. Publicado em: 2015