Wave propagation measurements longitudinal

FIG.8-2. Apparatus for longitudinal bulk wave propagation measurements, by echoing longitudinal pulses through a liquid with and without a polymeric sample in the path. (Nolle and Mowry.p ... 

FIG.8-4. Apparatus for longitudinal bulk wave propagation measurements in a viscoelastic liquid, with variable path length. (Mason, Baker, McSkimin, and Heiss. )... 

Fig. 9.15. Longitudinal section of a human molar tooth Rayleigh velocity and attenuation measured using a line-focus-beam lens at 225 MHz (the scales are not the same as in Fig. 9.14). The sketches indicate the approximate measurement angles at which the Rayleigh wave propagation was in the direction of die arrows they are not an accurate representation of die anatomy of tooth enamel (Peck et al. 

The sonic speed used was longitudinal wave speed, measured using a pulse propagation meter (Model 4, H. M. Morgan Co., Cambridge, Mass.). Pulse frequency was 8-10 kHz. Transverse wave velocity was calculated from longitudinal wave velocity using the approximation... 

Fig. 2 Temperature dependences of ultrasonic attenuation for longitudinal waves propagating in ZnSe V along the [110] axis, measured at 270 MHz open circles), 156 MHz (filledcircles), and 52 MHz triangles). A a = a (T) - a (To), To = 16 K. The plot for 52 MHz is shifted downward by 0.7 dB for clarity. Concentration of the dopand = 5.6 X lO cm After Fig. 3 in [3]...

NoNaq"). The shear wave transducer for this sample was a 10 MHz lithium niobate transducer bonded with a cyanoacrylate polyester. For the lower density sample both PZT and quartz transducers operating at nominally 3 to 4 MHz were used for both longitudinal and shear wave propagation. They were bonded with either an alcohol-glycerine-based couplent or phenyl salicylate. The detected ultrasonic echoes were rectified and displayed on an oscilloscope equipped with time-delay circuitry for the transit time measurements. 

To perform measurements of longitudinal wave propagation and damping characteristics, a device designed by Lemaire Langevin (1992) can be used. While the longitudinal wave is... 

FIG. 7-6. Apparatus for measurement of longitudinal wave propagation in fibers. (Tokita. - )... 

Since the subtractions indicated in equations 2 and 3 may cause loss of predsion, it is desirable to measure both M and G in the same experiment with as little manipulation of the apparatus as possible. This can be achieved by propagating both longitudinal and transverse waves through the same sample the velodty and attenuation of the latter provide G and G in accordance with equations 39 and 40 of Chapter 5. Methods for these measurements have been described by Brad-field, Wada,, Kono, and Waterman. In the latter two, the sample in the form of a plate is placed between a transmitting and a receiving transducer as in Fig. 8-2... 

Detailed measurements of the extensional modulus of monofilaments have been made by longitudinal wave-propagation methods, where the relationship of the extensional modulus to molecular orientation and crystallinity has been examined. Early investigations using this technique were made by Hillier and Kolsky [24], Ballou and Smith [25], Nolle [26] and Hamburger [27]. 

For single crystals, the elastic coefficients may be determined by acoustic velocity measurements. For example, it may be shown that the velocity of a longitudinal wave propagating in the [100] direction is given by... 

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