R K Theory
Mostrando 1-12 de 73 artigos, teses e dissertações.
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1. Nonlinear numerical analysis of composite slabs with steel decking
Resumo O comportamento das lajes mistas é governado pelo cisalhamento longitudinal na interface entre o aço e o concreto, que é desenvolvido em lajes sob flexão simples. O método m-k e o método da interação parcial, utilizados no cálculo da resistência ao cisalhamento na interface aço-concreto de lajes mistas, são baseados em ensaios experimentai
Rev. IBRACON Estrut. Mater.. Publicado em: 11/11/2019
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2. EXTRACTION OF BIOACTIVE COMPOUNDS OF LEAVES OF Duguetia furfuracea (ANNONACEAE) USING GREEN AND ORGANIC SOLVENTS
ABSTRACT Duguetia furfuracea (Annonaceae) is a shrub found in the Brazilian Cerrado that is used in popular medicine as an antirheumatic, for wound healing, treatment of kidney pain and against pediculosis. The aim of this study was to analyze the extraction of leaves of Duguetia furfuracea, using supercritical CO2, ethanol and hexane as solvents. For the su
Braz. J. Chem. Eng.. Publicado em: 15/07/2019
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3. Modeling of stem form and volume through machine learning
Abstract Taper functions and volume equations are essential for estimation of the individual volume, which have consolidated theory. On the other hand, mathematical innovation is dynamic, and may improve the forestry modeling. The objective was analyzing the accuracy of machine learning (ML) techniques in relation to a volumetric model and a taper function f
An. Acad. Bras. Ciênc.. Publicado em: 18/10/2018
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4. Vibration Analysis of a Cylindrical Sandwich Panel with Flexible Core Using an Improved Higher-Order Theory
Abstract This paper deals with free vibration analysis of thick cylindrical composite sandwich panels with simply supported boundary conditions based on a new improved higher-order sandwich panel theory. The formulation used the third-order polynomial description for the displacement fields of thick composite face sheets and for the displacement fields in th
Lat. Am. j. solids struct.. Publicado em: 2017-03
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5. Parametric resonance in concrete beam-columns
A dynamic instability, called parametric resonance, is exhibited by undampedelastic beam-columns when under the action of pulsating axial force. The scope of the existing theory of parametric resonance is restricted to physically linear beam-columns undergoing finite lateral displacements. In this Paper, the dynamic behaviour of physically nonlinear elastic
Lat. Am. j. solids struct.. Publicado em: 2014-11
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6. Stability of concrete beam-columns under follower forces
An axial follower force acting on the free end of a beam-column is known to remain tangential to its elastica at that point. Elastic beam-columns exhibit infinitely high buckling resistance to static compressive follower load. Loss of their dynamic stability is known to occur at critical follower loads, by flutter characterized by vanishing lateral displacem
Lat. Am. j. solids struct.. Publicado em: 2014-10
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7. Improved high-order bending analysis of double curved sandwich panels subjected to multiple loading conditions
For the first time, the bending analysis of a double curved sandwich panel was presented which was subjected to point load, uniform distributed load on a patch, and harmonic distributed loads and was based on a new improved higher order sandwich panel theory. Since the cross-sectional warping was accurately modeled by this theory, it did not require any shea
Lat. Am. j. solids struct.. Publicado em: 2014
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8. Studies on the adsorption behavior of CO2-CH4 mixtures using activated carbon
Separation of CO2 from CO2-CH4 mixtures is an important issue in natural gas and biogas purification. The design of such separation processes depends on the knowledge of the behavior of multicomponent adsorption, particularly that of CO2-CH4 mixtures. In this study, we present a series of experimental binary equilibrium isotherms for CO2-CH4 mixtures on an a
Braz. J. Chem. Eng.. Publicado em: 2013-12
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9. Crescimento e propriedades vibracionais de cristais a base de Ãxidos / Growth and Vibrational Properties of Oxide Crystals
In this work we used different experimental techniques to study four different series of inorganic oxide crystals, namely: (i) congruent lithium isotope niobate (C7LN), (ii) rare-earth doped mixed vanadates ((Nd,Yb):YxGd1-x(VO4)); (iii) alkali metal doped and pure calcium barium niobates (CaxBa1-xNb2O6); and (iv) potassium tantalite niobate (KTa1-xNbxO3). Be
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 16/03/2012
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10. Nanotubos de carbono como nanoadsorventes na remoção de corantes sintéticos de soluções aquosos : um estudo experimental e teórico
Este trabalho teve como objetivo investigar a adsorção de corantes têxteis (Vermelho Reativo 194 e Azul de Prociona MX-R) em nanotubos de carbono (NTC) em meio aquoso. Para tanto, empregou-se nanotubos de carbono de paredes múltiplas (NTCPM) e carvão ativo (CA) em pó, ambos comerciais, na remoção do corante têxtil Vermelho Reativo 194 e nanotubos de
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2012
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11. Construção de separadores globalmente suaves para conjuntos de pontos no R2 e geração de base mínima / Construction of globally smooth separators for sets of points in R2 and generation of minimum basis
Esta tese tem duas partes relativamente independentes. A primeira estuda o problema de construir uma curva suave (C1) que separa dois conjuntos de pontos do plano. Especificamente, a curva é definida por uma equação implícita F(x, y) = 0 onde F é uma spline polinomial de grau 2 com continuidade adequada. O objetivo é determinar uma única cônica se po
Publicado em: 2011
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12. Comparative vibrational spectra of pilosine and epiisopilosine crystals
This paper describes the study of two alkaloids extracted from Pilocarpus Microphyllus (Rutaceae): pilosine and epiisopilosine. These substances have potential application in the treatment of several diseases. In this work FT-Raman and the FT-IR spectra of pilosine and epiisopilosine were investigated at 300 K. Vibrational wavenumber and wave vector have bee
Brazilian Journal of Physics. Publicado em: 2010-06