scholarly journals Design and Calibration Tests of an Active Sound Intensity Probe

2008 ◽  
Vol 2008 ◽  
pp. 1-8
Author(s):  
Thomas Kletschkowski ◽  
Delf Sachau
Keyword(s):  
Standing Wave ◽  
Free Field ◽  
Sound Intensity ◽  
Adaptive Controller ◽  
The Novel ◽  
Test Bed ◽  
One Dimensional ◽  
Standing Wave Field ◽  
Cross Spectral Density ◽  
Radiated Sound

The paper presents an active sound intensity probe that can be used for sound source localization in standing wave fields. The probe consists of a sound hard tube that is terminated by a loudspeaker and an integrated pair of microphones. The microphones are used to decompose the standing wave field inside the tube into its incident and reflected part. The latter is cancelled by an adaptive controller that calculates proper driving signals for the loudspeaker. If the open end of the actively controlled tube is placed close to a vibrating surface, the radiated sound intensity can be determined by measuring the cross spectral density between the two microphones. A one-dimensional free field can be realized effectively, as first experiments performed on a simplified test bed have shown. Further tests proved that a prototype of the novel sound intensity probe can be calibrated.

One-dimensional motion of slow atoms in a standing-wave field

1990 ◽  
Vol 42 (7) ◽  
pp. 4032-4036 ◽  
Author(s):  
Y. Z. Wang ◽  
W. Q. Cai ◽  
Y. D. Cheng ◽  
L. Liu ◽  
Y. Luo ◽  
...  
Keyword(s):  
Wave Field ◽  
Standing Wave ◽  
One Dimensional ◽  
Standing Wave Field

scholarly journals Topological correlators and surface defects from equivariant cohomology

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Rodolfo Panerai ◽  
Antonio Pittelli ◽  
Konstantina Polydorou
Keyword(s):  
Quantum Mechanics ◽  
Equivariant Cohomology ◽  
Surface Defects ◽  
Star Product ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Dimensional System ◽  
The Novel ◽  
One Dimensional ◽  
Dual Quantum

Abstract We find a one-dimensional protected subsector of $$ \mathcal{N} $$ N = 4 matter theories on a general class of three-dimensional manifolds. By means of equivariant localization we identify a dual quantum mechanics computing BPS correlators of the original model in three dimensions. Specifically, applying the Atiyah-Bott-Berline-Vergne formula to the original action demonstrates that this localizes on a one-dimensional action with support on the fixed-point submanifold of suitable isometries. We first show that our approach reproduces previous results obtained on S3. Then, we apply it to the novel case of S2× S1 and show that the theory localizes on two noninteracting quantum mechanics with disjoint support. We prove that the BPS operators of such models are naturally associated with a noncom- mutative star product, while their correlation functions are essentially topological. Finally, we couple the three-dimensional theory to general $$ \mathcal{N} $$ N = (2, 2) surface defects and extend the localization computation to capture the full partition function and BPS correlators of the mixed-dimensional system.

scholarly journals Analysis of the effects of acoustic levitation to simulate the microgravity environment on the development of early zebrafish embryos

RSC Advances ◽  
2020 ◽  
Vol 10 (72) ◽  
pp. 44593-44600
Author(s):  
Li Li ◽  
Ning Gu ◽  
Huijuan Dong ◽  
Bingsheng Li ◽  
Kenneth T. V. G.
Keyword(s):  
Wave Field ◽  
Standing Wave ◽  
Development Stage ◽  
Microgravity Environment ◽  
Acoustic Levitation ◽  
Zebrafish Embryos ◽  
Acoustic Standing Wave ◽  
Standing Wave Field

Influence of acoustic standing wave field creating acoustic levitation, on each development stage of early zebrafish embryos has been studied.

Characterization of Ni/C Multilayers with Fluorescence XAFS Experiments at Fixed Standing Wave Field Positions

1996 ◽  
Vol 228-231 ◽  
pp. 511-518 ◽  
Author(s):  
D.C. Meyer ◽  
T. Holz ◽  
R. Krawietz ◽  
K. Richter ◽  
B. Wehner ◽  
...  
Keyword(s):  
Wave Field ◽  
Standing Wave ◽  
Standing Wave Field ◽  
Fluorescence Xafs

Synthesis of New Chalcogenide Materials. The Novel One-Dimensional Semiconductor K4 Ti3 S14

1987 ◽  
Vol 97 ◽  
Author(s):  
Steven A. Sunshine ◽  
Doris Kang ◽  
James A. Ibers
Keyword(s):  
Electrical Conductivity ◽  
Solid State ◽  
Alkali Metal ◽  
The Novel ◽  
Conductivity Measurements ◽  
One Dimensional ◽  
General Utility ◽  
Solid State Materials ◽  
Chalcogenide Materials

ABSTRACTThe use of A2 Q/Q melts (A - alkali metal, Q - S or Se) for the synthesis of new one-dimensional solid-state materials is found to be of general utility and is illustrated here for the synthesis of K4 Ti3 SI4. Reaction of Ti metal with a K2 S/S melt at 375°C for 50 h affords K4 Ti3 SI4. The structure possesses one-dimensional chains of seven and eightcoordinate Ti atoms with each chain isolated from all others by surrounding K atoms. There are six S-S pairs (dave - 2.069(3) Å) so that the compound is one of TiIV and may be described as K4 [Ti3 (S)2 (S2)6]. Electrical conductivity measurements indicate that this material is a semiconductor.

scholarly journals Self-Consistent Solution of the Multi Band Boltzmann, Poisson and Hole-Continuity Equations

VLSI Design ◽  
1998 ◽  
Vol 6 (1-4) ◽  
pp. 257-260
Author(s):  
Surinder P. Singh ◽  
Neil Goldsman ◽  
Isaak D. Mayergoyz
Keyword(s):  
Boltzmann Transport Equation ◽  
The Novel ◽  
Boltzmann Transport ◽  
One Dimensional ◽  
Bipolar Junction Transistor ◽  
Continuity Equations ◽  
The Poisson Equation ◽  
Curvilinear Grid ◽  
Consistent Solution ◽  
Junction Transistor

The Boltzmann transport equation (BTE) for multiple bands is solved by the spherical harmonic approach. The distribution function is obtained for energies greater than 3 eV. The BTE is solved self consistently with the Poisson equation for a one dimensional npn bipolar junction transistor (BJT). The novel features are: the use of boundary fitted curvilinear grid, and Scharfetter Gummel type discretization of the BTE.

Utilizing an Adaptive Controller (Azadi Controller) for Trajectory Planning of PUMA 560 Robot

2011 ◽  
Vol 403-408 ◽  
pp. 4880-4887
Author(s):  
Sassan Azadi
Keyword(s):  
Steady State ◽  
Trajectory Planning ◽  
Positive Feedback ◽  
Fuzzy Controller ◽  
Research Work ◽  
Adaptive Controller ◽  
The Novel ◽  
Transient Responses ◽  
Simulation Results ◽  
Good Substitute

This research work was devoted to present a novel adaptive controller which uses two negative stable feedbacks with a positive unstable positive feedback. The positive feedback causes the plant to do the break, therefore reaching the desired trajectory with tiny overshoots. However, the two other negative feedback gains controls the plant in two other sides of positive feedback, making the system to be stable, and controlling the steady-state, and transient responses. This controller was performed for PUMA-560 trajectory planning, and a comparison was made with a fuzzy controller. The fuzzy controller parameters were obtained according to the PSO technique. The simulation results shows that the novel adaptive controller, having just three parameters, can perform well, and can be a good substitute for many other controllers for complex systems such as robotic path planning.

Acoustics of Sound Production and of Hearing in the Bladder Cicada Cystosoma Saundersii (Westwood)

1978 ◽  
Vol 72 (1) ◽  
pp. 43-55 ◽  
Author(s):  
N.H. FLETCHER ◽  
K. G. HILL
Keyword(s):  
Sound Production ◽  
Abdominal Cavity ◽  
Low Frequency ◽  
Sound Intensity ◽  
Electrical Network ◽  
Directional Hearing ◽  
Hearing Sensitivity ◽  
Physical Mechanisms ◽  
Radiated Sound ◽  
Song Frequency

The male cicada of the species Cystosoma saundersii has a grossly enlarged, hollow abdomen and emits a loud calling song with a fundamental frequency of about 800 Hz. At the song frequency, its hearing is nondirectional. The female of C. saundersii lacks sound producing organs, has no enlargement of the abdomen, but possesses an abdominal air sac and has well developed directional hearing at the frequency of the species' song. Physical mechanisms are proposed that explain these observations in semi-quantitative detail using the standard method of electrical network analogues. The abdomen in the male, with its enclosed air, is found to act as a system resonant at the song frequency, thus contributing a large gain in radiated sound intensity. Coupling between this resonator and the auditory tympana accounts for the observed hearing sensitivity in the male, but destroys directionality. In the female, the abdominal cavity acts in association with the two auditory tympana as part of a phase shift network which results in appreciable directionality of hearing at the unusually low frequency of the male song.

Characterization of a Ni/C multilayer with fluorescence XAFS experiments at fixed standing wave field positions

1995 ◽  
Vol 150 (2) ◽  
pp. 603-612 ◽  
Author(s):  
D. C. Meyer ◽  
Th. Holz ◽  
R. Krawietz ◽  
K. Richter ◽  
B. Wehner ◽  
...  
Keyword(s):  
Wave Field ◽  
Standing Wave ◽  
Standing Wave Field ◽  
Fluorescence Xafs
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