Acoustics acoustic measurement

Afterwards, the vessels were pressurized according a proof test and a burst test with acoustic emission measurements. Acoustic emission data recorded during these tests are analysed in order to determine assessment criteria. The criteria are mainly based on ... 

Acoustic emission tests Acoustic insulation Acoustic measurements Acoustic microscopy Acoustic spectroscopy Acoustic waves... 

C. M. Harris, ed.. Handbook of Acoustical Measurement and Noise Control, 3rd ed., McGraw-HiU Book Co., Inc., New York, 1991. 

Acoustic Measurements. Measurement of the propagation of ultrasonic acoustic waves has been found useful for determining the viscoelastic properties of thin films of adhesives. In this method, the specimen is clamped between transmitting and receiving transducers. The change in pulse shape between successive reverberation of the pulse is dependent on the viscoelastic properties of the transmitting material. Modulus values can be calculated (267,268). 

This aspect is not included here, but is related to optical flow diagnostics. It is based again on the principle of the optical Doppler effect. Multifunctional equipment is available for noncontact measurements of flow-induced vibration on surfaces of structural elements, for acoustic measurements, and for calibration of accelerometers and vibration transducers. 

A. Yu. Vinogradov and V. A. Khonik, Kinetics of Shear Banding in Bulk Metallic Glasses Monitored by Acoustic Emission Measurments, Phil. Mag., 84, 2147 (2004). 

Ultrasonic acoustic waves, measurement of the propagation of, 21 744 Ultrasonically stimulated drug delivery systems, 9 58, 81... 

After injection starts, but before the granulator reaches normal operating conditions, the airflow drops suddenly for approximately 10-15min. The drop in the airflow can easily be seen in the score plot for the acoustic measurements. The score plot of the process data recorded simultaneously is displayed in Figure 9.16 and does not detect the change. 

There has been some discussion as to whether acoustic signals result from the fracture that occurs when adhesion Is lost at the paint-metal Interface during blistering and cathodic disbonding. In the present study, very sensitive Acoustic Emission measurements have been made In systems exhibiting these types of breakdown. 

In the above I have very briefly sketched the opto-acoustic pollution measurement techniques and described a few examples where the technique has been applied to problems of scientific, industrial, and societal significance. It is clear that these techniques are simple and practical and will play increasing by important roles in pollution monitoring. 

Yamanaka, K. (1983). Surface acoustic wave measurements using an impulsive converging beam. /. Appl, Phys, 54,4323-9. [73,140]... 

L.Baranek, "Acoustic Measurements," Wiley,NY(I949) 6)L.L.Baranek, "Acoustics," McGraw-Hill, NY(1954)... 

One acoustical measure of the direct to reverberant ratio is called the clarity index, and is defined as ... 

There are a large number of subjective attributes of reverberation which have been discussed in the literature. Most of these are monaural attributes directly correlated with acoustical measures that can be derived from the EDR. Consequently, it is convenient to think of the EDR as representative of all the monaural objective measures of a room impulse response. Presumably, the fine details of this shape are irrelevant, particularly in the late response, but no systematic study has been done to determine the resolution required to perceptually reproduce a reverberant response from its EDR. 

Separate from his earlier-described acoustical measurements, Medwin (ref. 31) conducted a direct photographic determination of microbubble populations in coastal ocean waters. His results indicated the presence of several million microbubbles per cubic meter (i.e., >103/liter) within the diameter range of 20 to 100 pm, both at the surface and at a depth of 10 feet in Monterey Marina (ref. 31,33). However, as a result of his technique of illumination, Medwin suggested that his count probably included many non-bubbles (ref. 31). 

H. Medwin, In situ acoustic measurements of bubble populations in coastal ocean waters, J. Geophys. Res. 75 (1970) 599-611. 

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