Top PDF An investigation of the earth's free oscillations

An investigation of the earth's free oscillations

An investigation of the earth's free oscillations

Theoretical phase shift between vertical components at these two stations computed for a moving couple or vertical force with a velocity of 3 kIll/ sec and a length of 1000 kIno Open cir[r]

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The transition to Earth-like torsional oscillations in magnetoconvection simulations

The transition to Earth-like torsional oscillations in magnetoconvection simulations

As is the case with all numerical models of the Earth’s core, the search for TOs is currently hindered by our inability to reach the actual parameter values of the core. The ratio of viscous to Corio- lis forces is tiny in the core and it is not possible to get close to the quasi-magnetostrophic regime for dynamo calculations. Having reached the numerical limits of our code in TJT, a new approach has been necessary to continue our investigation of TOs in sim- ulations and this is the topic of the work presented here. Very long runs are needed to establish the growth and equilibration of a dynamo driven magnetic field. Since we are now confident that numerical dynamos giving a field similar to the geomagnetic field exist in the appropriate region of parameter space, we can make significant computational savings by imposing the dipole compo- nent of the magnetic field at the CMB. The transient field state is then much shorter, and this allows us to reach more Earth- like parameters in this work. Also, magnetoconvection simulations provide the additional benefit of allowing us to vary the imposed magnetic field strength as an input parameter to allow for a sys- tematic exploration of the dependence of TOs on field strength.
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Free oscillations of a fluid sphere in an infinite elastic medium and long period volcanic earthquakes

Free oscillations of a fluid sphere in an infinite elastic medium and long period volcanic earthquakes

This paper focuses on a model based on acoustic reso- nance of a fluid sphere, firstly, because a sphere is one of the simplest shapes in nature and, secondly, because a com- plete description of its characteristic frequencies has never presented. Relating problems have been already solved. For example, free oscillations of a fluid sphere in vacuum have been well studied in an attempt to understand the nature of the Earth’s free oscillations (Aki and Richards, 1980). An- other example is free oscillations of an infinite elastic body, including a vacuum spherical cavity, quoted in one of prob- lems in Landau and Lifshitz (1986). In their formalism, the eigenfrequency of its radial mode is given as a com- plex number whose imaginary part stands for the attenuation (damping) coefficient of the oscillations.
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On forced and free atmospheric oscillations near the 27 day periodicity

On forced and free atmospheric oscillations near the 27 day periodicity

The Whole Atmosphere Community Climate Model was used to investigate the influences of solar fluctuations on zonal wind oscillations. Two simulations were conducted with short-term solar forcing (<35 days) on and off. We found that a 27-day wave is an inherent feature of the atmosphere when the short-term solar forcing is inactive. This internal 27-day oscillation comes along with other periods of the extra-long period wave band (20–40 days) and cannot be linked to the Sun’s rotation period. When the short-term solar variability is part of the forcing, including the solar 27-day periodicity, it affects a wide range of the spectrum of zonal wind. At mid-latitudes, a 10-day wave emerges by the short-term solar forcing, which suggests that indirect and nonlinear interactions are involved. Solar short-term variability seems to generate atmospheric perturbations that interact with modes of the internal wave spectrum or the background mean flow. A robust and clear solar interpretation of these wind oscillations is challeng- ing. However, dynamical responses to short-term solar variability exist and need further investigation.
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Incessant excitation of the Earth’s free oscillations

Incessant excitation of the Earth’s free oscillations

We analyze the MODE channel record in the three year period from March 22, 1993, to December 31, 1995. The data are moving-averaged and resampled at a rate of 10 seconds. The Earth tide components are removed with a least-squares method. We edit 1015 records of a data length of 3 days with a mutual time lag of 1 day. Each record is tapered with a zero-order 4-π prolate taper (Park et al., 1987) and the fast Fourier-transform is applied. We define the spectral intensity as the absolute value of complex coefficient of the Fourier series expansion. The intensity has been corrected for the effect of tapering but not for the effect of filtering. The total of the 1015 spectra are pasted up along the time axis to obtain a spectrogram, which enables us to examine the temporal variation of the spectrum.
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Detection of phase disturbances of free core nutation of the Earth and their concurrence with geomagnetic jerks

Detection of phase disturbances of free core nutation of the Earth and their concurrence with geomagnetic jerks

The Earth rotation possesses a free nutational mode rotat- ing clockwise (retrograde) with the period about 430 side- real days as viewed from the inertial frame. This mode, named as the Free Core Nutation (FCN), appears since the Earth has a rotating and elliptical fluid core (Toomre, 1974). The FCN influences the Earth rotation in two differ- ent ways; (1) modification of forced nutation terms through an indirect response as a non-rigid body, and (2) direct ap- pearance of free oscillation modes. Investigation of the FCN is important in order not only to improve theoretical modeling of the nutations but also to understand nature of the Earth’s interior. For instance, the period of the FCN is closely related to the dynamical ellipticity of the liquid outer core while the quality factor (Q-value) of the FCN is related to the viscosity of the outer (liquid) core and the core-mantle coupling (Sasao et al., 1980; Getino and Fer- randiz, 2000).
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Investigation of Free Liquid Oscillations in a Bounded Basin Representing an Approximate Model of the Sea of Azov

Investigation of Free Liquid Oscillations in a Bounded Basin Representing an Approximate Model of the Sea of Azov

modes by the duration of their periods unambiguously. Wave current maximum velocities of uninodal and binodal seiches of the first ( k ≠ 0 , m = 0 ) and the second ( k = 0 , m ≠ 0 ) types are equal to 0.29 m/s. Wave current maximum velocities of the third type seiches ( k ≠ 0 , m ≠ 0 ) are always lower than the ones of the first and the second type seiches. From all the considered seiches of the third type, the highest wind current velocity, equal to 0.28 m/s, belongs to the seventh mode ( k = 1 , m = 2 ), and the lowest, equal to 0.22 m/s, belongs to the fifth mode ( k = 2 , m = 1 ). Wave current maximum velocities of seiches (( k = 1 , m = 1 ) and ( k = 2 , m = 2 )) (they have an equal number of nodal lines which are transversal both to x and y -axis) are equal to each other and make up 0.26 m/s.
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Investigation of Seiche Oscillations in a Free Entrance Bay

Investigation of Seiche Oscillations in a Free Entrance Bay

Introduction. Most of the seas on the Earth have bays which are used for var- ious purposes: for the construction of ports, beaches and other infrastructure. Therefore, the study of dynamic processes in the bays is of great practical value. Seiches, which are observed both in the basins in general and in certain bays, are one of the common phenomena in the enclosed basins. In the bays seiches cause certain inconveniences and sometimes they are even hazardous for navigation. Such phenomenon as harbor seiche [1, 2] is often associated with these hazards. Harbor seiche is a periodic water mass movement directed from one side to anoth- er. At the same time, anchored and docked ships make rhythmic motions in time with water movement and can break adrift, break the moorings, break their sides against mooring walls, crash into each other suffering significant damage [1, 2].
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Endothelin action in rat liver  Receptors, free Ca2+ oscillations, and activation of glycogenolysis

Endothelin action in rat liver Receptors, free Ca2+ oscillations, and activation of glycogenolysis

High affinity binding sites for endothelin (ET) were identified on rat liver plasma membranes. Binding of 125I-ET-1 with its site was specific, saturable, and time dependent (kobs = 0.019 +/- 0.001 min-1), but dissociation of receptor-bound ligand was minimal. A single class of high affinity binding sites for 125I-ET-1 was identified with an apparent Kd of 32.4 +/- 9.8 pM and a Bmax of 1084 +/- 118 fmol/mg protein. ET-3 and big-ET-1 (1-38) (human) inhibited 125I-ET-1 binding with IC50 values of 1.85 +/- 1.03 nM and 43 +/- 6 nM, respectively. Aequorin measurements of cytosolic free Ca2+ in single, isolated rat hepatocytes showed that ET-1 at subnanomolar concentrations induced a series of repetitive, sustained Ca2+ transients. ET-1 had no effect on cAMP production. Finally, ET-1 caused a rapid and sustained stimulation of glycogenolysis in rat hepatocytes. A 1.8-fold maximal increase in glycogen phosphorylase alpha was observed at 1 pM ET-1, with an EC50 of 0.03 pM. Stimulation of the enzyme was specific for ET-1 since the order of potency of related
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The global variability of diatomaceous earth toxicity: a physicochemical and in vitro investigation

The global variability of diatomaceous earth toxicity: a physicochemical and in vitro investigation

Toxicity of the limited surface cristobalite could be fur- ther dampened by the presence of cation substitutions (Fig. 2), as structural impurities have been hypothesised to decrease the toxic potential of cristobalite in volcanic ash [44]. Treating quartz with aluminium salts or clay extracts has also been shown to reduce its toxicity and haemolytic potential [52–55], and quartz in coal with clay mineral im- purities had lower toxicity than pure, coal-sourced quartz [51]. Therefore, the production of aluminium ions via breakdown of aluminium-rich components of the DE samples could affect the cristobalite exposed at the surface of particles, decreasing the potential toxicity. Conversely, treating quartz with ferric or ferrous iron does not change its toxic potency in vivo [52] and can decrease its haemo- lytic potential [54]. However, Fubini et al. [56] showed iron may increase silica toxicity via production of free
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Using a mobile phone acceleration sensor in physics experiments on free and damped harmonic oscillations

Using a mobile phone acceleration sensor in physics experiments on free and damped harmonic oscillations

the average time step is dt ¼ 0:02 s. Since the oscillations take place along the y axis, the values of the acceleration for the x and z axes remain very close to zero. This application also allows saving the output data to a file, from which the data can be used for further analysis.

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Investigation of the intraseasonal oscillations over a Brazilian equatorial station: a case study

Investigation of the intraseasonal oscillations over a Brazilian equatorial station: a case study

Characteristics of the intraseasonal oscillations (ISO) in the mesosphere and lower thermosphere (MLT) are investigated using meteor radar wind observations from a South American, equatorial station, São João do Cariri (7.4°S, 36.5°W) during 2008. A prominent ISO signature is observed during January-May in the period band approximately 40 to 70 days in the MLT zonal wind. In the lower atmosphere, a dominant ISO is observed in the period band approximately 30 to 60 days in the outgoing longwave radiation (OLR) (a proxy for convection), total columnar water vapor (a proxy for tides), and zonal wind. Considerable high correlation of the ISO between the MLT and lower atmosphere indicates significant dynamical coupling between the lower and middle atmosphere during the observational period. The MLT-ISO shows conspicuous downward propagation of the peak amplitude indicating the role of the dissipating upward propagating waves for its generation. The amplitudes in the zonal wind of the dominant tidal components in the MLT exhibit conspicuous ISO modulation. The eastward propagating waves and tides are surmised to be responsible for communicating the ISO signature from the lower atmosphere to the MLT. The origin of the MLT-ISO is believed to take place in the lower troposphere, below 4 km. The MLT-ISO is believed to be the imprint of the lower atmospheric Madden-Julian oscillation which travels eastward from the Indian Ocean-western Pacific Ocean to the present location.
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THEORETICAL RESEARCH OF DYNAMIC CHARACTERISTICS OF FREE OSCILLATIONS OF A BRIDGE SPAN TYPE 690/7K

THEORETICAL RESEARCH OF DYNAMIC CHARACTERISTICS OF FREE OSCILLATIONS OF A BRIDGE SPAN TYPE 690/7K

Форми деформації поперечного контуру в середині прогінної будови під час влас - них коливань прогінної будови наведені на рис.. Форми деформації поперечного перерізу в середині прогінної[r]

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THE CALCULATION OF THE FREQUENCIES OF THE FREE OSCILLATIONS OF THE METAL ARCH BRIDGES BY FINITE ELEMENT METHOD

THE CALCULATION OF THE FREQUENCIES OF THE FREE OSCILLATIONS OF THE METAL ARCH BRIDGES BY FINITE ELEMENT METHOD

The article provides calculation by the finite elements method of frequencies of own free fluctuations of the metal arch bridge over Staryi Dnepr river in the city of Zaporozhye, and that of the experimental model (an arch with the traffic on top). The calculation chart has been described by the finite elements method. Comparative analy- sis has been performed of the calculation results (FEM) with results of this bridge actual testing, including calcula- tion according to the method proposed by the authors.

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[H986.Ebook] Free Ebook Zetetic Astronomy Earth Not A Globe By Parallax.pdf

[H986.Ebook] Free Ebook Zetetic Astronomy Earth Not A Globe By Parallax.pdf

Zetetic Astronomy: Earth Not A Globe! By Parallax Just how a straightforward suggestion by reading can improve you to be a successful person? Reviewing Zetetic Astronomy: Earth Not A Globe! By Parallax is an extremely simple activity. Yet, exactly how can many people be so lazy to check out? They will certainly favor to spend their leisure time to talking or hanging out. When actually, reviewing Zetetic Astronomy: Earth Not A Globe! By Parallax will certainly give you more opportunities to be effective completed with the hard works.

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Investigation of GSM Signal Variation Dry and Wet Earth Effects

Investigation of GSM Signal Variation Dry and Wet Earth Effects

Figure 4 gives us a conclusion about the effect of wet earth on radio propagation. Increased earth conductivity with heavy rain was assumed that ground reflection contribution would have been increased, but it is not! Actually, this expectation was true, but wet tree caused extra penetration loss is bigger than extra earth reflection gain. This is because that wet earth effect with wet tree obstruction gives us extra losses instead of extra gain.

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Department of Earth and Space Sciences, University of California, s:

Department of Earth and Space Sciences, University of California, s:

Given the magnitude distribution in Figure 1a, should one be surprised that a \char- acteristic" magnitude 6 earthquake occurred in the prediction zone? Using the description given in Michael and Jones (1998), any earthquake over magnitude 5.7 with some rupture in the prediction zone might be counted as a successful prediction. The magnitude distribution says nothing, by itself, about surface rupture, and Michael and Jones don't de ne what is a \characteristic" earthquake, but for discussion let's assume that a characteristic event is a shallow earthquake with its epicenter in the prediction zone and a magnitude in the range 5.7 to 6.3. What is the chance that the next earthquake over 5.7 in the prediction zone after 1966 is a characteristic one? It is just (R-S)/R, where R is the rate of magnitude 5.7 and above, and S is the rate of magnitude 6.3 and above, in the prediction zone. From the maximum-likelihood Gutenberg-Richter line in Figure 1a, R = .0128/yr and S = .0039/yr. Thus the probability that the next event would be \characteristic" is 70%.
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Water Trivia. How much of the earth s surface is water? 80% Of all the earth s water, how much is ocean? 97%

Water Trivia. How much of the earth s surface is water? 80% Of all the earth s water, how much is ocean? 97%

What Sonoran Desert rodent does not have to drink water because it makes water in its kidneys from the carbohydrates in the seeds it east?. Kangaroo rat..[r]

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Clouds have a major impact on the Earth s radiative budget

Clouds have a major impact on the Earth s radiative budget

C louds have a major impact on the Earth’s radiative budget and climate change (1, 2), yet a dearth of microphysical data have been collected within clouds over the Antarctic Plateau. This lack of microphysical data is associated with challenges deploying and operating instrumentation in the world’s harshest, most remote atmospheric environment (3). Clouds have a critical influence on the Antarctic ice sheet’s radiation budget and sur- face mass balance and appear to affect synoptic-scale effects over the Southern Ocean (3–6). Early (1986) airborne lidar measure- ments of cloud properties over the Antarctic Plateau indicated that the clouds consisted entirely of ice crystals (7). Because supercooled water drops are more likely to freeze as the temper- ature approaches the homogenous freezing point, about −37 °C in clouds (8), low-level Antarctic clouds, which are the coldest on Earth, have generally been treated as being all ice in numerical models. However, measurements reported in this article show that supercooled water drops can exist in low-level clouds at −32 °C.
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Contributed Review: A review of the investigation of rare-earth dopant profiles in optical fibers

Contributed Review: A review of the investigation of rare-earth dopant profiles in optical fibers

Rare-earth doped optical fibers have captivated the interest of many researchers around the world across the past three decades. The growth of this research field has been stimulated primarily through their application in optical communications as fiber lasers and amplifiers, although rare-earth doped optical fiber based devices are now finding important uses in many other scientific and industrial areas (for example, medicine, sensing, the military, and material processing). Such wide commercial interest has provided a strong incentive for innovative fiber designs, alternative glass compositions, and novel fabrication processes. A prerequisite for the ongoing progress of this research field is developing the capacity to provide high resolution information about the rare-earth dopant distribu- tion profiles within the optical fibers. This paper constitutes a comprehensive review of the imaging techniques that have been utilized in the analysis of the distribution of the rare-earth ion erbium within the core of optical fibers. Published by AIP Publishing. [http: // dx.doi.org / 10.1063 / 1.4947066]
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