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Mostrando 1-12 de 3360 artigos, teses e dissertações.
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1. Sensitivity analysis of the AquaCrop model for wheat crop in Campos Gerais region, Paraná
ABSTRACT The use of crop modeling can be useful to understand the interactions between the soil-plant-atmosphere system. The objective of this study was to evaluate sensitivity analysis of the AquaCrop model parameters for wheat crop in the Campos Gerais Region. The varietie tested was TBIO Sinuelo in Castro, Ponta Grossa and Itaberá cities. The analyzed pa
Revista Ceres. Publicado em: 2023
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2. A Note on the Well-Posedness of Control Complex Ginzburg-Landau Equations in Zhidkov Spaces
ABSTRACT In this note, we consider the Complex Ginzburg-Landau equations with a bilinear control term in the real line. We prove well-posedness results concerned with the initial value problem for these equations in Zhidkov spaces using splitting methods.
Trends in Computational and Applied Mathematics. Publicado em: 2022
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3. Estimating leaf area of basil cultivars through linear dimensions of leaves
ABSTRACT Ocimum basilicum L. (basil) is an annual herb belonging to the Lamiaceae family that has economic importance for many regions around the world. Thus, ecophysiological studies are needed to assess this species growth and dispersal. This work aimed to obtain equations from regression models that meaningfully estimate the leaf area of basil cultivars u
Revista Ceres. Publicado em: 2022
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4. Radiação térmica e a fórmula de Planck
In this paper, theoretical and experimental research on blackbody thermal radiation is discussed and historically ordered. The main thermal radiation equations following Planck’s revolutionary idea are obtained using the formalism of statistical mechanics. These equations, already well known, are deduced in a very detailed and didactic way in order to faci
Química Nova. Publicado em: 2022
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5. 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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6. A Defected Ground Structure Based on Matryoshka Geometry
Abstract A Defected Ground Structure, DGS, based on matryoshka geometry is described in this paper. The proposed DGS geometry is outlined and initial design equations are presented. Four prototypes, with resonant frequencies 2.17 GHz, 2.44 GHz, 2.99 GHz and 3.73 GHz, were designed, fabricated and characterized, observing a good agreement between measured and
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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7. Semi-analytical Equations for Designing Terahertz Graphene Dipole Antennas on Glass Substrate
Abstract Semi-analytical equations are developed for aiding the process of designing terahertz graphene-based rectangular dipole antennas lying on glass substrates. It directly provides the dipole length required for obtaining resonance at a desired frequency since antenna width and graphene chemical potential are known. By using the finite-difference time-d
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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8. PEDRO DE ALCANTARA LISBOA, QUÍMICO BRASILEIRO DO SÉCULO XIX
The subject of the present article is a Brazilian chemist who lived and worked in the nineteenth century and who is hardly known today. He was the first person in Brazil, still in the first half of the nineteenth century, to write chemical equations in the description of actual reactions, and also the first to use equations in order to perform stoichiometric
Química Nova. Publicado em: 2022
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9. Variational Formulation and A Priori Estimates for the Galerkin Method for a Fractional Diffusion Equation
ABSTRACT In this work we obtain a variational formulation and a priori estimates for approximate solutions of a problem involving fractional diffusion equations.
Trends in Computational and Applied Mathematics. Publicado em: 2022
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10. 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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11. A Numerical Study of Linear Long Water Waves over Variable Topographies using a Conformal Mapping
ABSTRACT In this work we present a numerical study of surface water waves over variable topographies for the linear Euler equations based on a conformal mapping and Fourier transform. We show that in the shallow-water limit the Jacobian of the conformal mapping brings all the topographic effects from the bottom to the free surface. Implementation of the nume
Trends in Computational and Applied Mathematics. Publicado em: 2022
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12. 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