Equations
Mostrando 13-24 de 3360 artigos, teses e dissertações.
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13. Simulation of Current Pulses and Sound Waves Resulting from Partial Discharges in a Needle-Plane Geometry in Air
Abstract Partial discharges can occur in different types of electric equipment and cause progressive insulation deterioration, so there is interest in monitoring partial discharges for assessing the state of the isolation of an electric system and to predict failures. Techniques to detect partial discharges, such as detecting ultrasonic emission, have been p
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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14. A Finite-Difference Time-Domain Formulation for Modeling Air Ionization Breakdown Streamers
Abstract A numerical model based on the finite-difference time-domain (FDTD) method is developed for calculating discharge currents and fields produced due air ionization between two electrodes. Electric conductivity σ of the ionized channel between two electrodes is calculated using non-linear equations, i.e., σ is obtained using functions of time. The fu
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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15. 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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16. RING CURRENT IN ANTHRACENE AND PHENANTHRENE: CORRECTION TO HÜCKEL PARAMETERS
Excessive degeneracy in the ground state of the π-electron energy levels of anthracene was removed using the Hückel method by correcting the Coulomb integral of the four central carbon atoms. A further correction to the resonance integral was proposed based on the ring-current model, which describes the π-ring current flow along the molecule’s perimeter
Química Nova. Publicado em: 2022
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17. Evaluation of moisture content variation on strength and stiffness properties of Cedrella sp. wood specie
Abstract In order to evaluate the influence of moisture content on wood physical and mechanical properties, the present research analyzed the influence of moisture content variation on Cedrella sp. on 12 strength and stiffness properties, considering 12% moisture content up to Fiber Saturation Point (FSP) were considered. Brazilian Standard consider a correc
REM - International Engineering Journal. Publicado em: 2022
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18. Eco-friendly multivariant green analytical technique for the estimation of ketoconazole by UV spectroscopy in bulk and cream formulation
The pharmaceutical industries are focusing on Green Analytical Chemistry principles like miniaturization, eco-friendly solvent usage, waste recycling, and analyst safety for sustainable results. A simple, eco-friendly sensitive and effective extraction and multivariant green analytical method to estimate ketoconazole in bulk and cream formulation were develo
Química Nova. Publicado em: 2022
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19. Enhancement patterns of adrenal nodules on magnetic resonance imaging
ABSTRACT Objective: To compare enhancement patterns of typical adrenal adenomas, lipid-poor adenomas, and non-adenomas on magnetic resonance imaging (MRI). Materials and Methods: Evaluation of adrenal nodules larger than 1.0 cm, with at least 2-year follow-up, evaluated on MRI in January 2007 and December 2016. Two different protocols were included - upper
International braz j urol. Publicado em: 2022
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20. Influence of conditional cash transfer program on prenatal care and nutrition during pregnancy: NISAMI cohort study
ABSTRACT BACKGROUND: There are few studies on the influence of a cash transfer program on nutritional outcomes from pregnancy. OBJECTIVES: To analyze how a Brazilian conditional cash transfer program (Bolsa Familia Program, BFP) was associated with changes in body mass index (BMI) and food consumption among pregnant women. DESIGN AND SETTING: Cohort study
Sao Paulo Medical Journal. Publicado em: 2022
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21. Countries’ governance and competitiveness: business environment mediating effect
Abstract Purpose The purpose of this study is to analyze how institutional governance and business environment affect countries’ competitiveness and their relative importance. Design/methodology/approach In this paper, the authors analyze how institutional governance and business environment affect countries’ competitiveness, their relative importance
RAUSP Management Journal. Publicado em: 2022
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22. Interdisciplinary Group Intervention on Nutritional Profile, Quality of Life, and Stress During Cardiopulmonary Rehabilitation: A Randomized Clinical Trial
Abstract Background: Participating in therapeutic operative groups with nutritional and psychological interventions might influence the recovery of patients in cardiopulmonary rehabilitation programs. Objective: To evaluate the effectiveness of group interventions on the nutritional profile, stress, and quality of life of patients in cardiopulmonary rehabi
International Journal of Cardiovascular Sciences. Publicado em: 2022
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23. Performance of creatinine-based equations for estimating glomerular filtration rate compared to endogenous creatinine clearance
Resumo Introdução: As diretrizes recomendam a estimativa da taxa de filtração glomerular pelo uso de equações baseadas em creatinina sérica como preditor de doença renal, preferencialmente ajustadas para grupos populacionais locais. Métodos: Estudo transversal que avaliou o desempenho de quatro equações para estimativa da TFG em comparação com
Brazilian Journal of Nephrology. Publicado em: 2022
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24. Finite strip method computer application for buckling analysis of thin-walled structures with arbitrary cross-sections
Abstract The Direct Strength Method (DSM) is a well-known formulation presented in the Brazilian standard ABNT NBR 14762:2010, that estimates the strength capacity of cold-formed steel (CFS) members. However, this formulation requires the elastic critical buckling loads as point of departure, regarding local (L), distortional (D) and global (G) modes, which
REM, Int. Eng. J.. Publicado em: 2021-09