Mathematical Equations
Mostrando 1-12 de 425 artigos, teses e dissertações.
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1. 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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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. Leaf area estimation with nondestructive method in cassava
ABSTRACT The objective of this study was to create a single mathematical equation able to estimate the leaf area of different cassava cultivars from one lineal dimension without destroying any plant tissue. Two hundred leaves per cultivar from ten cultivars were used to calibrate the model and more than one hundred leaves per cultivar were used to test its p
Bragantia. Publicado em: 2020-12
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5. IMPORTANCE OF CROP PRODUCTIVITY AND EQUIPMENT LIFETIME IN THE STRATEGIC AND TACTICAL MANAGEMENT OF SUGARCANE HARVESTERS
ABSTRACT Recently, Brazilian agriculture and the mechanization process have been improved and developed, particularly in sugarcane cultivation. The developed processes should adopt suitable management practices in terms of the technical, economic, and operational logistical aspects. As a management tool, the present study aimed to measure the impact of the a
Eng. Agríc.. Publicado em: 2020-10
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6. ESTUDOS DE QSAR PARA SARS-CoV-2
The generation of mathematical models through the quantitative relationship between the chemical structure and the biological activity (QSARs) of compounds was used in this investigation. Mathematical models were generated from compounds available in literature that predicting the biological activity against SARS-CoV-2. The data indicate that the parameters
Quím. Nova. Publicado em: 2020-09
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7. EXTRACTION OF MONOMERS OF HYDROLYSABLE TANNINS FROM PODS OF Libidibia ferrea (Mart. ex Tul.) L. P. QUEIROZ: EFFECTS OF SOLVENT AND AMOUNT OF DRUG USING RESPONSE-SURFACE METHODOLOGY AND DESIRABILITY PROFILE
In this study was evaluated the influence of the extraction factors on the extract’s properties to improve the recovery of high concentrations of the phytochemicals important for the biological activities from pods of Libidibia ferrea (Mart. ex Tul.) L. P. Queiroz. The extracts were obtained by turbo-extraction and a factorial design 32 was used to study t
Quím. Nova. Publicado em: 2020-06
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8. Effect of drying temperature on color and desorption characteristics of oyster mushroom
Abstract Oyster mushroom (Pleurotus ostreatus) slices were dried in a hot air dryer at three temperatures (45, 55 and 65 °C). The sorption isotherm of dried samples in the water activity (aw) range of 0.556-0.970 was also determined at three temperature levels. Moisture desorption isotherms were obtained from changes in water activities of oyster mushroom s
Food Sci. Technol. Publicado em: 2020-03
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9. Dimensionalidade fractal e invariância de escala em circuitos elétricos AC e linhas de transmissão
Resumo A geometria fractal fascina pela capacidade de descrever formas geométricas complexas e que usualmente estão presentes no mundo real . A dimensão fractal ou de Hausdorff d é utilizada para descrever leis de invariância de escala, em que as funções autossimilares seguem uma lei da forma f ( s x ) = s d f ( x ), sendo s o fator de escala. Intim
Rev. Bras. Ensino Fís.. Publicado em: 10/01/2020
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10. 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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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. Praxeologias do Professor: análise comparativa do livro didático no ensino de equações polinomiais do primeiro grau
Resumo O objetivo desse artigo foi analisar, comparativamente, as praxeologias pontuais, em livros didáticos e as praxeologias efetivadas pelos professores em sua prática docente, referentes ao ensino de equações polinomiais do primeiro grau, investigando as relações de conformidade entre eles. A realização deste estudo está fundamentada na ótica d
Bolema. Publicado em: 02/12/2019