Oscillations
Mostrando 37-48 de 1048 artigos, teses e dissertações.
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37. Seasonal variation in gas exchange by plants of Erythroxylum simonis Plowman
ABSTRACT Erythroxylum simonisis an understory species found in Northeast Brazil. Due to its shaded habitat,E. simonisis subjected to seasonal oscillations of the environment, to which it must respond ecophysiologically. The objective of this study was to evaluate the effects of seasonality on the ecophysiology ofE. simonis in a fragment of Seasonal Semidecid
Acta Bot. Bras.. Publicado em: 15/02/2018
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38. Corrosion Resistance Evaluation of HVOF Produced Hydroxyapatite and TiO2-hydroxyapatite Coatings in Hanks' Solution
The electrochemical behavior of HVOF produced hydroxyapatite (HA) and 80HA-20TiO2 coatings were investigated using electrochemical techniques in natural aerated Hanks' solution in the presence and absence of bovine serum albumin (BSA) for 30 days. All samples presented open circuit potential oscillations, which were associated to the porous nature of the coa
Mat. Res.. Publicado em: 22/01/2018
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39. Modelización lineal de un sistema masa-resorte real
On university introductory courses, while studying the frequency of free oscillations of a vertical spring-mass system in the case of negligible dissipative forces and massless spring, such a frequency can be simply calculated as the square root of the relationship between the local gravity and the spring elongation. However, when an actual spring is used, t
Rev. Bras. Ensino Fís.. Publicado em: 28/09/2017
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40. Paleodistribution of Neotropical species of Erythroxylum (Erythroxylaceae) in humid and dry environments
ABSTRACT Variation in environmental conditions during the Quaternary period served as important filters for the maintenance of vegetation types and for determining the composition of the current biota. We analyzed oscillations in the distributions of different vegetation types in Brazil during the Quaternary period using species of the genus Erythroxylum (Er
Acta Bot. Bras.. Publicado em: 21/09/2017
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41. Fourier analysis of nonlinear pendulum oscillations
Since the times of Galileo, it is well-known that a simple pendulum oscillates harmonically for any sufficiently small angular amplitude. Beyond this regime and in absence of dissipative forces, the pendulum period increases with amplitude and then it becomes a nonlinear system. Here in this work, we make use of Fourier series to investigate the transition f
Rev. Bras. Ensino Fís.. Publicado em: 20/07/2017
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42. Limit growth of ice crystals under different temperature oscillations levels in nile Tilapia
Abstract The degenerative effect of temperature fluctuations during storage time is a critical condition that needs to be quantitatively characterized in products where drip losses are appreciable. In this work, real storage conditions were reproduced using freezers modified to cause 3 levels of temperature fluctuation (± 0, ± 3, ± 5; ± 7) during storage
Food Sci. Technol. Publicado em: 20/03/2017
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43. Variabilidad de Baja Frecuencia de la Persistencia de la Temperatura en el Sudeste de Sudamérica
Abstract Eight reference stations in south-eastern South America are analysed to derive the auto-covariance and auto-correlations of maximum and minimum temperature. Through the analysis are observed oscillations of periods between 18 and 25 years in the series studied. These periodicities show changes over time, especially in the 1950-1970 period. The excep
Rev. bras. meteorol.. Publicado em: 2017-03
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44. APPLICATION OF OPTICAL METHOD IN MEASURING MECHANICAL VIBRATIONS IN A CANTILEVER BEAM
ABSTRACT The pertinent literature discloses a family of optical profile measuring techniques highlighting the moiré methods. The Moiré technique is based on the interference of two superimposed optical grids which produce fringe patterns which can be processed to analyze the DYNAMIC MEASUREMENT IN MATERIALS mechanical behavior. The goal of this research is
Eng. Agríc.. Publicado em: 2017-02
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45. Viscoelastic Substrates Effects on the Elimination or Reduction of the Sandwich Structures Oscillations Based on the Kelvin-Voigt Model
Abstract Effects of viscoelastic substrates on the sandwich structures oscillations are examined in this paper. In this regard, dynamic response of sandwich annular panels with FG polar orthotropic face sheets resting on viscoelastic substrate is presented. Young’s modulus in the radial and circumferential direction, shear modulus and density of each face
Lat. Am. j. solids struct.. Publicado em: 2017
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46. A New Algorithm for Shock Sensor Calculation at Supersonic Speeds on a 3D-Unstructured Grid
ABSTRACT In this paper, 3-Dsupersonic flow around two types of wings is solved using a new algorithm for shock sensor calculation. A dual-time-stepping implicit method with 2nd-order accuracy is used for time integration of the equations. In each real time step, the non-linear system of equations is solved by iterating in pseudo-time, using a multi-step inte
J. Aerosp. Technol. Manag.. Publicado em: 2016-12
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47. Numerical Study of Reduced Frequency Effect on Longitudinal Stability Derivatives of Airfoil under Pitching and Plunging Oscillations
ABSTRACT In this study, incompressible, unsteady and turbulent flow over an airfoil with pitching and plunging oscillations is numerically studied in order to investigate the effect of reduced frequency on stability derivatives of oscillating airfoil. Linear k – ε model called Launder-Sharma and Rhie and Chow model are used for turbulence modeling and ove
J. Aerosp. Technol. Manag.. Publicado em: 2016-09
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48. Experimental Investigation on Limit Cycle Wing Rock Effect on Wing Body Configuration Induced by Forebody Vortices
ABSTRACT The purpose of this paper is to present the aerodynamic and flow characteristics of a slender body with a 30° swept wing configuration undergoing a limit cycle oscillation using a synchronous measurement and control technique of wing rock/particle image velocimetry/dynamic pressure associated with the time history of the wing rock motion. The exper
J. Aerosp. Technol. Manag.. Publicado em: 2016-09