Ultrasonic wave velocities in the structure II clathrate hydrate THF�17H2O

1984 ◽  
Vol 3 (10) ◽  
pp. 904-906 ◽  
Author(s):  
M. Bathe ◽  
S. Vagle ◽  
G. A. Saunders ◽  
E. F. Lambson
Keyword(s):  
Ultrasonic Wave ◽  
Clathrate Hydrate ◽  
Wave Velocities ◽  
Structure Ii Clathrate Hydrate

Angular Dependent Ultrasonic Wave Velocities in Thin Zircaloy Plate

1991 ◽  
pp. 439-446 ◽  
Author(s):  
S. S. Lee ◽  
B. Y. Ahn ◽  
H. J. Kim ◽  
Y. C. Kim
Keyword(s):  
Ultrasonic Wave ◽  
Wave Velocities

scholarly journals The permeability and elastic moduli of tuff from Campi Flegrei, Italy: implications for ground deformation modelling

Solid Earth ◽  
2014 ◽  
Vol 5 (1) ◽  
pp. 25-44 ◽  
Author(s):  
M. J. Heap ◽  
P. Baud ◽  
P. G. Meredith ◽  
S. Vinciguerra ◽  
T. Reuschlé
Keyword(s):  
Ultrasonic Wave ◽  
Elastic Moduli ◽  
Ground Deformation ◽  
Laboratory Data ◽  
Campi Flegrei ◽  
Pore Collapse ◽  
Campanian Ignimbrite ◽  
Wave Velocities ◽  
Neapolitan Yellow Tuff ◽  
Dynamic Elastic Moduli

Abstract. The accuracy of ground deformation modelling at active volcanoes is a principal requirement in volcanic hazard mitigation. However, the reliability of such models relies on the accuracy of the rock physical property (permeability and elastic moduli) input parameters. Unfortunately, laboratory-derived values on representative rocks are usually rare. To this end we have performed a systematic laboratory study on the influence of pressure and temperature on the permeability and elastic moduli of samples from the two most widespread lithified pyroclastic deposits at the Campi Flegrei volcanic district, Italy. Our data show that the water permeability of Neapolitan Yellow Tuff and a tuff from the Campanian Ignimbrite differ by about 1.5 orders of magnitude. As pressure (depth) increases beyond the critical point for inelastic pore collapse (at an effective pressure of 10–15 MPa, or a depth of about 750 m), permeability and porosity decrease significantly, and ultrasonic wave velocities and dynamic elastic moduli increase significantly. Increasing the thermal stressing temperature increases the permeability and decreases the ultrasonic wave velocities and dynamic elastic moduli of the Neapolitan Yellow Tuff; whereas the tuff from the Campanian Ignimbrite remains unaffected. This difference is due to the presence of thermally unstable zeolites within the Neapolitan Yellow Tuff. For both rocks we also find, under the same pressure conditions, that the dynamic (calculated from ultrasonic wave velocities) and static (calculated from triaxial stress-strain data) elastic moduli differ significantly. The choice of elastic moduli in ground deformation modelling is therefore an important consideration. While we urge that these new laboratory data should be considered in routine ground deformation modelling, we highlight the challenges for ground deformation modelling based on the heterogeneous nature (vertically and laterally) of the rocks that comprise the caldera at Campi Flegrei.

scholarly journals Damage Detection of Asphalt Concrete Using Piezo-Ultrasonic Wave Technology

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 443 ◽  
Author(s):  
Wen-hao Pan ◽  
Xu-dong Sun ◽  
Li-mei Wu ◽  
Kai-kai Yang ◽  
Ning Tang
Keyword(s):  
Damage Detection ◽  
Ultrasonic Wave ◽  
Ultrasonic Velocity ◽  
Asphalt Concrete ◽  
Ultrasonic Waves ◽  
Bending Test ◽  
Measured Velocity ◽  
Three Point Bending ◽  
Wave Technology ◽  
Wave Velocities

Asphalt concrete has been widely used in road engineering as a surface material. Meanwhile, ultrasonic testing technology has also been developed rapidly. Aiming to evaluate the feasibility of the ultrasonic wave method, the present work reports a laboratory investigation on damage detection of asphalt concrete using piezo-ultrasonic wave technology. The gradation of AC-13 was selected and prepared based on the Marshall’s design. The ultrasonic wave velocities of samples were tested with different environmental conditions firstly. After that, the samples were destroyed into two types, one was drilled and the other was grooved. And the ultrasonic wave velocities of pretreated samples were tested again. Furthermore, the relationship between velocity and damaged process was evaluated based on three point bending test. The test results indicated that piezoelectric ultrasonic wave is a promising technology for damage detection of asphalt concrete with considerable benefits. The ultrasonic velocity decreases with the voidage increases. In a saturated water environment, the measured velocity of ultrasonic wave increased. In a dry environment (50 °C), the velocity the ultrasonic waves increased too. After two freeze-thaw cycles, the voidage increased and the ultrasonic velocity decreased gradually. After factitious damage, the wave must travel through or most likely around the damage, the ultrasonic velocity decreased. During the process of three point bending test, the ultrasonic velocity increased firstly and then decreased slowly until it entered into a steady phase. At last the velocity of ultrasonic wave decreased rapidly. In addition, the errors of the results under different test conditions need to be further studied.

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