Periodic Motions
Mostrando 1-12 de 12 artigos, teses e dissertações.
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1. Near the resonance behavior of a periodicaly forced partially dissipative three-degrees-of-freedom mechanical system
Abstract In this paper, a nonlinear three-degrees-of-freedom dynamical system consisting of a variable-length pendulum mass attached by a massless spring to the forced slider is investigated. Numerical solution is preceded by application of Euler-Lagrange equation. Various techniques like time histories, phase planes, Poincaré maps and resonance plots are
Lat. Am. j. solids struct.. Publicado em: 14/06/2018
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2. Análise de movimentos periódicos em sistemas bi-linear com folga simétrica
O presente trabalho apresenta a modelagem matemática de um sistema vibracional com excitação harmônica da base. Esse tipo de sistema tem sido estudado por vários pesquisadores que exploraram muitos aspectos da dinâmica global. No entanto, na grande parte dos sistemas estudados, o sistema era modelado para uma característica de vibroimpacto. No sistema
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 27/03/2012
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3. Nonlinear dynamics of a SMA large-scale space structure
Large-scale structures are of special interest of aerospace applications, especially the ones involving smart materials. This paper deals with an archetypal system with two degrees of freedom that resembles the use of SMA elements as vibration isolation systems on a sparse aperture satellite array. The system has SMA elements in two perpendicular directions
J. Braz. Soc. Mech. Sci. & Eng.. Publicado em: 2012
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4. Movimentos sob atração focal em campos vetoriais planares / Motions under focal attraction in planar vector fields
In this work, we develop the article On the motion under focal attraction in a rotating medium, of J. Sotomayor, which deals with a bidimensional differential system that model the following Biological problem: in a shallow recipient with circular section, with liquid in, spinning with angular speed ω, there are platyhelminthes, flatworms organisms, the
Publicado em: 2008
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5. Determination of molecular motion in membranes using periodic pattern photobleaching.
The lateral diffusion of a fluorescent phospholipid probe in oriented multibilayers of dimyristoylphosphatidylcholine has been measured by observing the redistribution of fluorescence after photobleaching of the membranes in a periodic pattern of parallel stripes. The diffusion constant D of the fluorescent lipid was found to vary between 1.5 X 10(-11) cm2/s
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6. Periodicity in the isotope chemistry of hydrogen
Periodicities and regularities are established among the deuterium to protium isotopic reduced partition function ratios, ln(s/s′)f, of 39 diatomic and 19 polyatomic hydrides. It is shown that ln(s/s′)f for diatomic hydrides can be correlated with the position in the periodic table of the element X in the hydride HX. A similar analysis is made for the co
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7. Anisotropic molecular motion on cell surfaces.
Photobleaching in a two-dimensional periodic pattern has been used to characterize the motion of succinylconcanavalin A receptors on the surfaces of mouse fibroblasts. These receptors were found to exhibit anisotropic two-dimensional diffusion in adherent cells having parallel stress fibers. Diffusion coefficients of the order of 10(-11) cm2/sec and 10(-12)
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8. Bifurcation Theory and the Type Numbers of Marston Morse
Let H be a real Hilbert space and f(x,λ) be a C2 operator mapping a small neighborhood U of (x0,λ0) ε (H × R1) into itself. We investigate the solutions of the equation f(x,λ) = 0 near a solution (x0,λ0), assuming that f(x,λ) is a gradient mapping and 0 < dim Ker fx(x0,λ0) < ∞. In particular, we show that the type numbers of Marston Morse for an is
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9. The 1,800-year oceanic tidal cycle: A possible cause of rapid climate change
Variations in solar irradiance are widely believed to explain climatic change on 20,000- to 100,000-year time-scales in accordance with the Milankovitch theory of the ice ages, but there is no conclusive evidence that variable irradiance can be the cause of abrupt fluctuations in climate on time-scales as short as 1,000 years. We propose that such abrup
The National Academy of Sciences.
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10. “Waves” vs. “particles” in the atmosphere's phase space: A pathway to long-range forecasting?
Thirty years ago, E. N. Lorenz provided some approximate limits to atmospheric predictability. The details—in space and time—of atmospheric flow fields are lost after about 10 days. Certain gross flow features recur, however, after times of the order of 10–50 days, giving hope for their prediction. Over the last two decades, numerous attempts have been
National Academy of Sciences.
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11. The respiratory activity of human levator costae muscles and its modification by posture.
The activation of the levator costae, a set of axial muscles inserted between each rib and the vertebra immediately rostral, has been studied electromyographically in a human subject, standing upright, with head erect ('neutral' posture). Caudal levator costae muscles (T9, and T10) are active during eupnoea. Periodic activity in phase with inspiration occurs
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12. Drag force acting on a neuromast in the fish lateral line trunk canal. I. Numerical modelling of external–internal flow coupling
Fishes use a complex, multi-branched, mechanoreceptive organ called the lateral line to detect the motion of water in their immediate surroundings. This study is concerned with a subset of that organ referred to as the lateral line trunk canal (LLTC). The LLTC consists of a long tube no more than a few millimetres in diameter embedded immediately under the s
The Royal Society.