Feasibility of Determining Aircraft Certification Noise Levels Using Ground Plane Microphone Measurements

2021 ◽  
Author(s):  
Philippe Bousquet ◽  
Vincent P. Blandeau
Keyword(s):  
Ground Plane ◽  
Noise Levels ◽  
Aircraft Certification

Damage Risk: An Evaluation of the Effects of Exposure to 85 versus 90 dBA of Noise

1976 ◽  
Vol 19 (2) ◽  
pp. 216-224 ◽  
Author(s):  
James T. Yates ◽  
Jerry D. Ramsey ◽  
Jay W. Holland
Keyword(s):  
White Noise ◽  
Statistical Difference ◽  
Noise Exposure ◽  
Threshold Shift ◽  
Temporary Threshold Shift ◽  
Noise Levels ◽  
Potential Damage ◽  
Full Day ◽  
Damage Risk

The purpose of this study was to compare the damage risk of 85 and 90 dBA of white noise for equivalent full-day exposures. The damage risk of the two noise levels was determined by comparing the temporary threshold shift (TTS) of 12 subjects exposed to either 85 or 90 dBA of white noise for equivalent half- and full-day exposures. TTS was determined by comparing the pre- and postexposure binaural audiograms of each subject at 1, 2, 3, 4, 6, and 8 kHz. It was concluded that the potential damage risk, that is, hazardous effect, of 90 dBA is greater than 85 dBA of noise for equivalent full-day exposures. The statistical difference between the overall effects of equivalent exposures to 85 dBA as compared to 90 dBA of noise could not be traced to any one frequency. The damage risk of a full-day exposure to 85 dBA is equivalent to that of a half-day exposure to 90 dBA of noise. Within the limits of this study, TTS t was as effective as TTS 2 for estimating the damage risk of noise exposure.

Radiated Electric Field from a Solar Cell Module Set on the Ground Plane

2010 ◽  
Vol 130 (8) ◽  
pp. 724-732
Author(s):  
Ryosuke Hasegawa ◽  
Mariko Tomisawa ◽  
Masamitsu Tokuda
Keyword(s):  
Solar Cell ◽  
Electric Field ◽  
Ground Plane ◽  
Cell Module ◽  
Solar Cell Module

Simplified Prediction of Ply Steer in Radial Tires

1980 ◽  
Vol 8 (1) ◽  
pp. 3-9 ◽  
Author(s):  
C. W. Bert
Keyword(s):  
Composite Laminate ◽  
Ground Plane ◽  
Lateral Force ◽  
Rolling Contact ◽  
Slip Angle ◽  
Uniform Stress ◽  
Rubber Composite ◽  
Laminate Theory ◽  
Contact Models ◽  
Uniform Stress State

Abstract Ply steer is a rolling contact phenomenon which manifests itself as a lateral force acting at the ground plane of a tire constrained in yaw or a change in slip angle of a tire free to yaw. It has long been known that radial tires generally exhibit greater ply steer than do bias tires. However, the only previously published quantitative analysis of this phenomenon considered the multi-layer cord-rubber composite by means of netting analysis, which is not very accurate at cord angles typical of radial tire belts. A simple, explicit expression is developed herein by combining modern composite laminate theory with two very simple, uniform-stress-state tire-road contact models. The ply-steer results predicted by the resulting expressions are compared with some experimental results and the agreement is found to be reasonably satisfactory.

Determination of the Probability Distribution of the Mean Sound Level

2010 ◽  
Vol 35 (4) ◽  
pp. 543-550 ◽  
Author(s):  
Wojciech Batko ◽  
Bartosz Przysucha
Keyword(s):  
Probability Distribution ◽  
Probability Distribution Function ◽  
Mean Value ◽  
Sound Level ◽  
Function Form ◽  
Noise Levels ◽  
Logarithmic Mean ◽  
The Mean ◽  
Estimation Of Uncertainty

AbstractAssessment of several noise indicators are determined by the logarithmic mean <img src="/fulltext-image.asp?format=htmlnonpaginated&src=P42524002G141TV8_html\05_paper.gif" alt=""/>, from the sum of independent random resultsL1;L2; : : : ;Lnof the sound level, being under testing. The estimation of uncertainty of such averaging requires knowledge of probability distribution of the function form of their calculations. The developed solution, leading to the recurrent determination of the probability distribution function for the estimation of the mean value of noise levels and its variance, is shown in this paper.

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