Damping Constant
Mostrando 25-34 de 34 artigos, teses e dissertações.
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25. OTIMIZAÇÃO DE CASCAS SUBMETIDAS A CARREGAMENTO DINÂMICO / OPTIMIZACIÓN DE CASCAS SOMETIDAS A SOBRECARGA DINÁMICA / OPTIMIZATION OF SHELL STRUCTURES UNDER DYNAMIC LOADS
The main goal of this work is to present a methodology and a computer code which allow the designer, by means of optimization techniques, to obtain efficient shapes of plate and shell structures under linear-elastic behavior and dynamic loads. With this objective, it is used the optimization program SHELLD that includes the geometric modeling, the mesh gener
Publicado em: 2000
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26. Efeitos de flutuação do campo magnetico no interferometro de Stern-Gerlach
Spin coherence experiments with particle beams under magnetic fields are investigated taking into account uncontrollable fluctuations. At the same time specific sources for those fluctuations are pointed in terms of characteristic parameters of experimental apparatus. Two kind of fluctuations sources are analyzed: quantum electromagnetic field thermal fluctu
Publicado em: 1998
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27. Effects of synergistic signaling by phytochrome A and cryptochrome1 on circadian clock-regulated catalase expression.
Persistent oscillation in constant conditions is a defining characteristic of circadian rhythms. However, in plants transferred into extended dark conditions, circadian rhythms in mRNA abundance commonly damp in amplitude over two or three cycles to a steady state level of relatively constant, low mRNA abundance. In Arabidopsis, catalase CAT3 mRNA oscillatio
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28. Distortion of non-invasive cardiac pulse curves. A capillary-damped pick-up and a calibration unit forapex cardiograms and other pulse curves.
A calibration unit and a capillary-damped pick-up, of funnel type, intended for apex cardiograms and other non-invasive cardiac pulse curves are presented. The physical properties of a recording system, suitable for non-invasive cardiac diagnostic techniques, are reviewed. In 4 identical recording units consisting of a funnel with and without capillary dampi
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29. From stochastic environments to life histories and back
Environmental stochasticity is known to play an important role in life-history evolution, but most general theory assumes a constant environment. In this paper, we examine life-history evolution in a variable environment, by decomposing average individual fitness (measured by the long-run stochastic growth rate) into contributions from average vital rates an
The Royal Society.
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30. Circadian Nature of a Rhythm Expressed by an Invertaseless Strain of Neurospora crassa1
A new strain of Neurospora crassa which exhibits a rhythm of conidiation when growing along an agar surface in a growth tube is described. The rhythm has been shown to be circadian for it meets the following criteria: A) the period under constant environmental conditions in the dark is about 24 hours (22.7 hours at 25°); B) the period is relatively temperat
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31. Circadian rhythms of melatonin release from individual superfused chicken pineal glands in vitro.
The pineal gland of birds contains one or more circadian oscillators that play a major role in overall temporal organization. We have developed a flow-through culture system for the isolated pineal by which we can measure the release of melatonin continuously from superfused glands over long periods of time. Chicken pineals release melatonin rhythmically, an
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32. Drosophila Free-Running Rhythms Require Intercellular Communication
Robust self-sustained oscillations are a ubiquitous characteristic of circadian rhythms. These include Drosophila locomotor activity rhythms, which persist for weeks in constant darkness (DD). Yet the molecular oscillations that underlie circadian rhythms damp rapidly in many Drosophila tissues. Although much progress has been made in understanding the bioch
Public Library of Science.
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33. Limiting dynamics of high-frequency electromechanical transduction of outer hair cells
High-frequency resolution is one of the salient features of peripheral sound processing in the mammalian cochlea. The sensitivity originates in the active amplification of the travelling wave on the basilar membrane by the outer hair cells (OHCs), where electrically induced mechanical action of the OHC on a cycle-by-cycle basis is believed to be the crucial
The National Academy of Sciences.
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34. A model for amplification of hair-bundle motion by cyclical binding of Ca2+ to mechanoelectrical-transduction channels
Amplification of auditory stimuli by hair cells augments the sensitivity of the vertebrate inner ear. Cell-body contractions of outer hair cells are thought to mediate amplification in the mammalian cochlea. In vertebrates that lack these cells, and perhaps in mammals as well, active movements of hair bundles may underlie amplification. We have evaluated a m
The National Academy of Sciences.