Results 261 to 270 of about 25,442,440 (283)

A transient response model of Pi 2 pulsations

Journal of Geophysical Research: Space Physics, 1982
A transient response model of Pi 2 pulsations due to an enhanced convection in the plasma sheet is presented. A nonlinear Alfvén wave is launched by the enhanced convection electric field. The reflection coefficient at the ionosphere is derived by matching the field‐aligned current of the Alfvén wave to the field‐aligned current from the divergence of ...
Joseph R. Kan, David U. Longenecker, John V. Olson   +2 more
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A Numerical Coincidence and a Candidate Identity: \(14\pi^2 - \pi + 2\)

 Abstract   The fine-structure constant α ≈ 1/137 is one of the most important dimensionless constants in physics. Its origin has been called by Feynman "the most incredible problem in all of theoretical physics." This paper presents a first-principles derivation of the complete closed-form expression for α⁻¹, starting from the postulate system of ...
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Right triangular dihedral f-tilings of the sphere: (a, b, pi/2) and (c, c, pi/2)

2015
The classification of all dihedral f-tilings of the Riemannian sphere S2, whose prototiles are two right triangles with at least one isosceles, is given. The combinatorial structure and the symmetry group of each tiling is also achieved.
Avelino, Catarina Pina, Santos, Altino
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The Variation of Pi 2 Micropulsation Waveform with Time

Radio Science, 1969
Pi 2 micropulsations observed ‘simultaneously’ at two widely separated low‐latitude stations: M'Bour, Senegal, in West Africa, and Makerere, Uganda, in East Africa have been compared. The variation in the waveforms has been measured in terms of an average damping coefficient and the number of excursions taken for events to reach their peak amplitude ...
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Related investigations of pi 2 micropulsations

2011
Related investigations of irregular, nighttime, type Pi 2 micropulsations were undertaken with regards to the source and occurrence of these geomagnetic fluctuations. In particular, the local times of Pi 2's recorded by a global network of stations, during 1964, were determined.
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Propagation of Pi 2 micropulsations through the ionosphere

Journal of Geophysical Research, 1965
Until recently it has been thought that Pi 2 activity was observed simultaneously over the earth's surface [Angenheister, 1912; Grenet et al., 1954]. The first strong evidence that this was not the case was presented by Herron [1964], who observed sizeable phase shifts of the order of seconds between stations separated by hundreds of kilometers along ...
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Latitude effects on the amplitude of Pi 2 micropulsations

Journal of Atmospheric and Terrestrial Physics, 1972
The effect of latitude on the amplitude of Pi 2 micropulsations has been studied using data from Hobart, Brisbane and Lae. Theories of the source mechanism of this class of pulsation are considered and it is shown that the present results favour cavity excitation as the mode of generation.
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Mechanism of certain intramolecular [.pi.2 + .pi.2] cycloadditions

Journal of the American Chemical Society, 1974
Harold Hart, Masayuki Kuzuya
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Pi 2 pulsations: High latitude results

Planetary and Space Science, 1982
Abstract A review of recent experimental results from studies of high latitude Pi 2 pulsations indicates that these pulsations are fundamentally related to the initiation of the auroral breakup and substorm. At high latitudes, the Pi 2's show their peak intensities in the region where the breakup begins and appear to remain in this region after the ...
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Electromagnetic Data from a Raspberry Pi 2

2017
EM data from a Raspberry Pi 2 as the AES-128 cryptographic algorithm was ...
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