Nonlinear Analysis
Mostrando 1-12 de 889 artigos, teses e dissertações.
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1. Numerical Analysis and Approximate Travelling Wave Solutions for a Higher Order Internal Wave System
ABSTRACT In this work we focus on the numerical solution of a higher order bidirectional nonlinear model of Boussinesq type involving a nonlocal operator. Based on a von Neumann stability analysis for the linearized problem, an efficient and stable scheme for the nonlinear system is proposed. Our method is based on a numerical scheme known from the literatur
Trends in Computational and Applied Mathematics. Publicado em: 2022
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2. Finite element computational development for thermo-mechanical analysis of plane steel structures exposed to fire
Abstract This article presents a numerical formulation based on finite element procedures for application in nonlinear thermo-mechanical analyses of steel planar structures under fire condition. The mechanical properties of structural elements degrade when subjected to high temperatures, resulting in significant reductions in strength and stiffness. Under th
REM - International Engineering Journal. Publicado em: 2022
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3. 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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4. Sulfonylurea resistance in Amaranthus hybridus from southern Brazil
ABSTRACT Amaranthus hybridus is a C4 broadleaf species widely spread across Brazilian agricultural territory. Recently, several herbicide resistance reports have been documented in southern Brazil, including the reports for enolpyruvilshikymate-3-phosphate (EPSPS)- and acetolactate-synthase (ALS)- inhibitors. The objective of this study was to confirm the ex
Revista Ceres. Publicado em: 2022
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5. Numerical formulation for nonlinear analysis of concrete and steel shells with deformable connections
Abstract A two-dimensional interface finite element capable of associating flat shell elements positioned one above the other was developed. The implemented interface element can physically simulate the contact between the flat shell elements and connect the reference planes of the shell elements above and below it. The formulation presented allows considera
REM, Int. Eng. J.. Publicado em: 2021-09
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6. Linear and Nonlinear Heart Rate Variability Analysis in Gonadal Dysgenesis (Swyer Syndrome): A Case Report
Abstract Swyer syndrome is one of the disorders of sexual differentiation. Previous studies have demonstrated increased sympathetic activity with heart rate variability (HRV) analysis with decreasing estradiol levels. One patient presented a pure 46, XY gonadal dysgenesis with female phenotype. Cardiac autonomic modulation was assessed through HRV analysis w
Int. J. Cardiovasc. Sci.. Publicado em: 2021-08
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7. Compatibility by a Nonisothermal Kinetic Study of Azathioprine Associated with Usual Excipients in the Product Quality Review Process
Azathioprine is an immunosuppressive drug for several inflammatory disorders. Due to its clinical relevance, to explore the solid-state properties for excipient compatibility in the product quality review process is essential. Fourier transform infrared spectroscopy, powder X-ray diffraction and thermal analysis (thermogravimetry/derivative thermogravimetry
J. Braz. Chem. Soc.. Publicado em: 2021-03
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8. A Parametric Study of Inductive SWIPT Systems Assisted by Metamaterial Using Virtual Magnetic TL-Based Channel Modeling
Abstract This paper presents a general methodology based on the description of the inductive channel as virtual magnetic transmission-lines (VMGTLs). In comparison with other existing methods, VMGTL approach presents a better physical insight of the channel behavior since the model correctly preserves the energy flow between the transmitting and receiving co
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2021-03
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9. RAPID DETECTION OF VITAMIN C CONTENT IN FRUITS AND VEGETABLES USING A DIGITAL CAMERA AND COLOR REACTION
In this study, we propose a novel method to determine the vitamin C content in fruits and vegetables. The proposed method exploits the image and data processing abilities of computers by coupling a digital camera and a color reaction. An image acquisition device was developed to collect the image information of the solution to be measured after the color rea
Quím. Nova. Publicado em: 2020-12
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10. Optimization of geometrically nonlinear truss structures under dynamic loading
Abstract The goal of this article is to present the formulation of the optimization problem of truss structures with geometric nonlinearity under dynamic loads and provide examples of this problem. The formulated optimization problem aims to determine the cross-sectional area of the bars that minimizes the weight of the structure, imposing constraints on nod
REM, Int. Eng. J.. Publicado em: 2020-09
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11. Analysis and Optimization of Ultra-Low-Power Rectifier with High Efficiency for Applications in Wireless Power Transmission and Energy Harvesting
Abstract The system capable of harvesting RF energy from the environment through an antenna and converting it into direct current energy to deliver to a load is known as rectenna. The rectifier circuit is an important part of the rectenna and its modeling is arduous since it employs a non-linear device working at extremely low power levels. In addition, ther
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-03
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12. MULTILEVEL NONLINEAR MIXED-EFFECTS MODEL AND MACHINE LEARNING FOR PREDICTING THE VOLUME OF Eucalyptus SPP. TREES
ABSTRACT Volumetric equations is one of the main tools for quantifying forest stand production, and is the basis for sustainable management of forest plantations. This study aimed to assess the quality of the volumetric estimation of Eucalyptus spp. trees using a mixed-effects model, artificial neural network (ANN) and support-vector machine (SVM). The datab
CERNE. Publicado em: 2020-03