Plant Acoustic Responses Concept and Significance

2021 ◽  
pp. 11-21
Author(s):  
Gayathri Rajasekharan ◽  
K. Nandini
Keyword(s):  
Acoustic Responses

scholarly journals Comparison and Validation of Acoustic Response Models for Wind Noise Reduction Pipe Arrays

2017 ◽  
Vol 34 (2) ◽  
pp. 401-414 ◽  
Author(s):  
Julien Marty ◽  
Stéphane Denis ◽  
Thomas Gabrielson ◽  
Milton Garcés ◽  
David Brown
Keyword(s):  
Noise Reduction ◽  
Acoustic Response ◽  
Detection Capability ◽  
Wind Noise ◽  
Response Models ◽  
Operational Conditions ◽  
Measurement Systems ◽  
International Monitoring ◽  
Wind Noise Reduction ◽  
Acoustic Responses

AbstractThe detection capability of the infrasound component of the International Monitoring System (IMS) is tightly linked to the performance of its wind noise reduction systems. The wind noise reduction solution implemented at all IMS infrasound measurement systems consists of a spatial distribution of air inlets connected to the infrasound sensor through a network of pipes. This system, usually referred to as “pipe array,” has proven its efficiency in operational conditions. The objective of this paper is to present the results of the comparison and validation of three distinct acoustic response models for pipe arrays. The characteristics of the models and the results obtained for a defined set of pipe array configurations are described. A field experiment using a newly developed infrasound generator, dedicated to the validation of these models, is then presented. The comparison between the modeled and empirical acoustic responses shows that two of the three models can be confidently used to estimate pipe array acoustic responses. This study paves the way to the deconvolution of IMS infrasound data from pipe array responses and to the optimization of pipe array design to IMS applications.

Third Order Nonlinear Optical Responses of Metallophthalocyanines in Films and Solutions

1992 ◽  
Vol 247 ◽  
Author(s):  
Roger J. Reeves ◽  
Richard C. Powell ◽  
Warren T. Ford ◽  
Young H. Chang ◽  
Weiming Zhu
Keyword(s):  
Excited State Absorption ◽  
Third Order ◽  
Incident Intensity ◽  
Optical Responses ◽  
A Value ◽  
Fast Electronic ◽  
Probe Spectroscopy ◽  
Acoustic Responses ◽  
532 Nm ◽  
Pulse Probe

ABSTRACTDihydrogen, copper, platinum, and lead octakis(2-ethylhexyloxy)phthalocyanines (Pc's) were studied in polystyrene films at 532 nm and in chloroform solutions at 1064 nm by picosecond degenerate four wave mixing. Resonant χ(3) values of Pc's at 532 nm (a local minimum in the absorption spectrum) at a time coincident with the 20 psec pump pulses were as high as 104 times that of CS2 by extrapolation of the response from 1 wt % PtPc in polystyrene film to a value for pure PtPc. Delay of the probe pulse as long as 3 nsec revealed acoustic responses stronger than the fast electronic responses. The films showed the expected quadratic dependence of the instantaneous reflectivity on incident intensity only for a decade of magnitude of intensity, 100–1000 MW/cm2, with the output saturating at higher intensities. Excited state absorption at 532 nm was detected in the film samples by pulse-probe spectroscopy and was shown to be a factor in the saturation observed in the NLO signals. Nonresonant χ(3) values at 1064 nm were as high as 120 times that of CS2 from measured responses of 1 wt % chloroform solutions of Pc's. Time delay of the probe revealed both fast electronic and slower acoustic responses at 1064 nm too.

Acoustic Responses of Vestibular Afferents in a Model of Superior Canal Dehiscence

2004 ◽  
Vol 25 (3) ◽  
pp. 345-352 ◽  
Author(s):  
John P. Carey ◽  
Timo P. Hirvonen ◽  
Timothy E. Hullar ◽  
Lloyd B. Minor
Keyword(s):  
Superior Canal Dehiscence ◽  
Vestibular Afferents ◽  
Acoustic Responses ◽  
Canal Dehiscence

Three-dimensional hydroelasciticity analysis of acoustic responses of ship structures

2010 ◽  
Vol 22 (S1) ◽  
pp. 802-809 ◽  
Author(s):  
Ming-song Zhou ◽  
You-sheng Wu ◽  
Yong-lin Ye
Keyword(s):  
Three Dimensional ◽  
Ship Structures ◽  
Acoustic Responses

Prediction of High Frequency Sonic Boom Noise Transmission Into Buildings Using a Hybrid Analytical-Ray Tracing Approach

2012 ◽  
Author(s):  
Joseph M. Corcoran ◽  
Marcel C. Remillieux ◽  
Ricardo A. Burdisso
Keyword(s):  
Ray Tracing ◽  
High Frequency ◽  
Acoustic Radiation ◽  
Low Frequency ◽  
Sonic Boom ◽  
Acoustic Transmission ◽  
Frequency Method ◽  
Low Frequencies ◽  
Sonic Booms ◽  
Acoustic Responses

As part of the effort to renew commercial supersonic flight, a predictive numerical tool to compute sonic boom transmission into buildings is under development. Due to the computational limitations of typical numerical methods used at low frequencies (e.g. Finite Element Method), it is necessary to develop a separate approach for the calculation of acoustic transmission and interior radiation at high frequencies. The high frequency approach can then later be combined with a low frequency method to obtain full frequency vibro-acoustic responses of buildings. An analytical method used for the computation of high frequency acoustic transmission through typical building partitions is presented in this paper. Each partition is taken in isolation and assumed to be infinite in dimension. Using the fact that a sonic boom generated far from the structure will approximate plane wave incidence, efficient analytical solutions for the vibration and acoustic radiation of different types of partitions are developed. This is linked to a commercial ray tracing code to compute the high frequency interior acoustic response and for auralization of transmitted sonic booms. Acoustic and vibration results of this high frequency tool are compared to experimental data for a few example cases demonstrating its efficiency and accuracy.

Acoustic responses of Baleen whales to low‐frequency, man‐made sounds

1999 ◽  
Vol 106 (4) ◽  
pp. 2279-2280 ◽  
Author(s):  
Christopher W. Clark ◽  
Peter L. Tyack ◽  
William T. Ellison
Keyword(s):  
Low Frequency ◽  
Baleen Whales ◽  
Acoustic Responses

Numerical simulation of Sector Bond log and improved cement bond image

Geophysics ◽  
2012 ◽  
Vol 77 (4) ◽  
pp. D95-D104 ◽  
Author(s):  
Ruo-Long Song ◽  
Jin-Xia Liu ◽  
Chun-Hui Hou ◽  
Ke-Xie Wang
Keyword(s):  
Numerical Simulation ◽  
Finite Difference ◽  
Field Data ◽  
New Approach ◽  
Channel Size ◽  
Well Production ◽  
Well Completion ◽  
Bond Evaluation ◽  
Potential Channels ◽  
Acoustic Responses

The two principal functions of a primary cement job are to provide support for the casing and to provide hydraulic isolation between zones. A poor cement job may cause many issues during the well production. Therefore, cement bond evaluation is very important in well completion. The Sector Bond log (SBL) has been widely used for cement bond evaluation for years. The SBL tool has eight pairs of directional transmitter-receivers, which are equally distributed in azimuth and used for identifying channels and channel azimuths. To better understand SBL, using a parallel 3D finite difference algorithm, we numerically simulated acoustic responses of the SBL under a variety of cement bond scenarios and investigated the sensitivity of the integral amplitudes to channel size and its azimuth. We further developed a new approach to image potential channels in cement annulus using the integral amplitudes. The comparisons between conventional SBL images and the reprocessed ones using the new approach showed significant improvement on both synthetic and field data.

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