Martian planetopause as seen by the plasma wave system onboard Phobos 2

1996 ◽  
Vol 101 (A11) ◽  
pp. 24965-24977 ◽  
Author(s):  
Jean Gabriel Trotignon ◽  
Edik Dubinin ◽  
Réjean Grard ◽  
Stanislav Barabash ◽  
Rickard Lundin
Keyword(s):  
Plasma Wave ◽  
Wave System

The Plasma Wave System on Phobos

1989 ◽  
Vol 22 (10) ◽  
pp. 888-894 ◽  
Author(s):  
R Grard ◽  
D Klinge ◽  
S Klimov ◽  
S Savin ◽  
J G Trotignon
Keyword(s):  
Plasma Wave ◽  
Wave System

Plasma wave system measurements of the Martian bow shock from the Phobos 2 spacecraft

1991 ◽  
Vol 96 (A7) ◽  
pp. 11253 ◽  
Author(s):  
Jean Gabriel Trotignon ◽  
Réjean Grard ◽  
Serguéï Savin
Keyword(s):  
Plasma Wave ◽  
Bow Shock ◽  
Wave System

Position and shape of the Martian bow shock: the Phobos 2 plasma wave system observations

1993 ◽  
Vol 41 (3) ◽  
pp. 189-198 ◽  
Author(s):  
J.G. Trotignon ◽  
R. Grard ◽  
A. Skalsky
Keyword(s):  
Plasma Wave ◽  
Bow Shock ◽  
Wave System

Location of the Martian bow shock measurements by the plasma wave system on Phobos 2

1991 ◽  
Vol 18 (3) ◽  
pp. 365-368 ◽  
Author(s):  
Jean Gabriel Trotignon ◽  
Réjean Grard ◽  
Stanislas Klimov
Keyword(s):  
Plasma Wave ◽  
Bow Shock ◽  
Wave System

The plasma wave system on Phobos

1989 ◽  
Vol 22 (8) ◽  
pp. 656-662 ◽  
Author(s):  
R Grard ◽  
D Klinge ◽  
S Klimov ◽  
S Savin ◽  
J G Trotignon
Keyword(s):  
Plasma Wave ◽  
Wave System

A comparison between the Earth's and Mars' bow shocks detected by the Phobos Plasma-Wave System

1991 ◽  
Vol 39 (1-2) ◽  
pp. 99-112 ◽  
Author(s):  
J.G. Trotignon ◽  
M. Hamelin ◽  
R. Grard ◽  
A. Pedersen ◽  
S. Klimov ◽  
...  
Keyword(s):  
Plasma Wave ◽  
Wave System ◽  
Bow Shocks

Incommensurate modulated phases of the NbxTa1-xTe4 charge density wave system

1992 ◽  
Vol 50 (1) ◽  
pp. 58-59
Author(s):  
S. Ritchie ◽  
J. C. Bennett ◽  
A. Prodan ◽  
F.W. Boswell ◽  
J.M. Corbett
Keyword(s):  
Charge Density ◽  
Charge Density Wave ◽  
Direct Evidence ◽  
Density Wave ◽  
Wave System ◽  
Modulated Phases ◽  
Metal Atoms ◽  
Incommensurate Modulation ◽  
End Members ◽  
Modulation Wave Vector

A continuous sequence of compounds having composition NbxTa1-xTe4; 0 ≤ x ≤ 1 have been studied by electron diffraction and microscopy. Previous studies have shown that the end members of the series, TaTε4 and NbTε4 possess a quasi-one-dimensional character and exhibit charge density wave (CDW) distortions. In these compounds, the subcell structure is tetragonal with axes (a × a × c) and consists of the metal atoms (Nb or Ta) centered within an extended antiprismatic cage of Te atoms. At room temperature, TaTε4 has a commensurate modulation structure with a 2a × 2a × 3c unit cell. In NbTε4, an incommensurate modulation with × ∼ 16c axes is observed. Preliminary studies of the mixed compounds NbxTα1-xTε4 showed a discontinuous jump of the modulation wave vector commensurate to incommensurate when the Nb dopant concentration x, exceeded x ≃ 0.3, In this paper, the nature of the compositional dependence of is studied in greater detail and evidence is presented for a stepwise variation of . This constitutes the first direct evidence for a Devil's staircase in CDW materials.

Trombone Transfer Functions: Comparison Between Frequency-Swept Sine Wave and Human Performer Input

2012 ◽  
Vol 37 (4) ◽  
pp. 447-454
Author(s):  
James W. Beauchamp
Keyword(s):  
Transfer Function ◽  
Transfer Functions ◽  
Cutoff Frequency ◽  
Sine Wave ◽  
Nonlinear Propagation ◽  
Linear Filter ◽  
Wave System ◽  
General Effect ◽  
Filter Characteristic ◽  
High Pass

Abstract Source/filter models have frequently been used to model sound production of the vocal apparatus and musical instruments. Beginning in 1968, in an effort to measure the transfer function (i.e., transmission response or filter characteristic) of a trombone while being played by expert musicians, sound pressure signals from the mouthpiece and the trombone bell output were recorded in an anechoic room and then subjected to harmonic spectrum analysis. Output/input ratios of the signals’ harmonic amplitudes plotted vs. harmonic frequency then became points on the trombone’s transfer function. The first such recordings were made on analog 1/4 inch stereo magnetic tape. In 2000 digital recordings of trombone mouthpiece and anechoic output signals were made that provide a more accurate measurement of the trombone filter characteristic. Results show that the filter is a high-pass type with a cutoff frequency around 1000 Hz. Whereas the characteristic below cutoff is quite stable, above cutoff it is extremely variable, depending on level. In addition, measurements made using a swept-sine-wave system in 1972 verified the high-pass behavior, but they also showed a series of resonances whose minima correspond to the harmonic frequencies which occur under performance conditions. For frequencies below cutoff the two types of measurements corresponded well, but above cutoff there was a considerable difference. The general effect is that output harmonics above cutoff are greater than would be expected from linear filter theory, and this effect becomes stronger as input pressure increases. In the 1990s and early 2000s this nonlinear effect was verified by theory and measurements which showed that nonlinear propagation takes place in the trombone, causing a wave steepening effect at high amplitudes, thus increasing the relative strengths of the upper harmonics.

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