Assessing Fire Damage of Concrete by the Ultrasonic Pulse Technique

1985 ◽  
Vol 7 (2) ◽  
pp. 84 ◽  
Author(s):  
PA Wedding ◽  
H-W Chung ◽  
KS Law
Keyword(s):  
Ultrasonic Pulse ◽  
Fire Damage ◽  
Pulse Technique

Elastic moduli and internal friction in Al2O3-3Y-ZrO2 composites by ultrasonic pulse technique

1995 ◽  
Vol 14 (9) ◽  
pp. 643-645
Author(s):  
T. Ono ◽  
T. Okada ◽  
O. Sakurada ◽  
M. Hashiba ◽  
Y. Nurishi ◽  
...  
Keyword(s):  
Internal Friction ◽  
Elastic Moduli ◽  
Ultrasonic Pulse ◽  
Pulse Technique

scholarly journals Ultrasonic pulse technique for evaluation of mechanical damage in processed coffee beans

2017 ◽  
Vol 38 (5) ◽  
pp. 3007
Author(s):  
Mariana De Oliveira e Silva ◽  
Francisco Carlos Gomes ◽  
Stella Dellyzete Veiga Franco da Rosa
Keyword(s):  
Elastic Modulus ◽  
Stress Wave ◽  
Storage Conditions ◽  
Ultrasonic Pulse ◽  
Coffee Bean ◽  
Pulse Technique ◽  
Indirect Measure ◽  
Coffee Beans ◽  
The Impact ◽  
Non Destructive

The knowledge of the physical characteristics of the coffee bean allows the transition from the conventional storage model in bags to the silo storage, and as an indirect measure of the improvement and conservation of the quality of the stored grain. The elastic modulus allows comparisons on the strength of material. The variations of this occur due to its chemical composition, microstructures and material defects, being able to be used as indicator of the physical integrity of the grain. The ultrasonic pulse technique is an alternative to obtain the elastic modulus in a simple and non-destructive way. In this context, it was proposed the development of a non-destructive methodology that will perform the quality evaluation by determining the elastic modulus of the coffee beans. For this purpose, a reference silo was constructed, reproducing the storage conditions, and the elastic modulus values were determined. The values obtained by the Stress Wave Timer apparatus are between 2.54 and 4.23 MPa, with a maximum load of 8.32 kN, and a calculated vertical pressure of 1,526 kPa. To evaluate the impact of the storage conditions and the loads applied during the non-destructive test, laboratory tests applied in seeds were performed, and the tetrazolium test was the only one able to differentiate the samples. It was concluded that Stress Wave Timer was able to determine the elastic modulus values for the coffee bean mass and could be used as an indicative of the quality.

Longitudinal Waves in Fiber-Reinforced Composite at Low and High Frequency Ranges

1977 ◽  
Vol 44 (3) ◽  
pp. 492-494
Author(s):  
C. H. Yew ◽  
P. N. Jogi
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Ultrasonic Pulse ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Transform Method ◽  
Pulse Technique ◽  
Longitudinal Waves ◽  
Dispersive Effect ◽  
Reinforced Composite

A method for studying the behavior of transient longitudinal waves in fiber-reinforced composites, both in high and low frequency ranges, is presented. The results agree well with the solutions obtained by means of the transform method. The dispersive effect of waves to the interpretation of experimental results is also demonstrated by comparing the results obtained from the ultrasonic pulse technique.

Ultrasonic wave measurements on frozen soils at permafrost temperatures

1976 ◽  
Vol 13 (11) ◽  
pp. 1571-1576 ◽  
Author(s):  
P. J. Kurfurst
Keyword(s):  
Geographical Location ◽  
Uniaxial Stress ◽  
Ultrasonic Pulse ◽  
Frozen Soil ◽  
Stress Conditions ◽  
Seismic Profiles ◽  
Pulse Technique ◽  
Wave Measurements ◽  
Seismic Records ◽  
Ice Content

An ultrasonic pulse technique was used in the laboratory to measure compressional and shear wave velocities on frozen soil samples with various ice contents. Measurements were made on a variety of samples, which differed in type of material, geographical location, and ice content, at temperatures ranging from −7 to +1 °C. Three series of tests were run on specimens from the Norman Wells, Fort Good Hope, and Eureka areas, Northwest Territories. The first series of specimens was tested under uniaxial stress conditions, whereas the measurements for the second and third series were done under triaxial stress conditions. The results measured on samples from the Norman Wells and Eureka areas were compared with the results obtained from shallow seismic profiles shot in the field at the sampled drill sites at the time of drilling. The values of field velocities lie within the range of laboratory measurements, and therefore prove that the laboratory tests provide a measure of control in the interpretation of seismic records.

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