Experimental characterization of air-saturated porous material via low-frequencies ultrasonic transmitted waves

2021 ◽  
Vol 33 (3) ◽  
pp. 037102
Author(s):  
Mustapha Sadouki
Keyword(s):  
Porous Material ◽  
Experimental Characterization ◽  
Low Frequencies ◽  
Transmitted Waves

scholarly journals Experimental Characterization of 2 × 2 Electronically Reconfigurable 1 Bit Unit Cells for a Beamforming Transmitarray at X Band

2021 ◽  
Vol 21 (2) ◽  
pp. 153-160
Author(s):  
Biswarup Rana ◽  
In-Gon Lee ◽  
Ic-Pyo Hong
Keyword(s):  
Phase Shifter ◽  
Unit Cell ◽  
Experimental Characterization ◽  
Waveguide Transition ◽  
Transmitted Waves ◽  
X Band ◽  
Unit Cells ◽  
New Type ◽  
Good Agreement

This paper proposes a reconfigurable unit cell for a transmitarray operating at the X band. The unit cell consists of an active patch, a passive patch, and a phase shifter. The active patch has two PIN diodes that change the phase of 180° of the transmitted waves. The passive and active patches both have circular slots to enhance the bandwidth of the transmitted wave. We also propose a new type of experimental characterization technique to measure the performance of the unit cells at the X band without fabricating the entire transmitarray. Instead of a 1 unit cell as described in the literature, we propose 2 × 2 unit cells to measure the performance of unit cells using the X band waveguide. The waveguide consists of a WR-90 section and a rectangular to square waveguide transition section that can be fit to our proposed structure. A good agreement between simulated and measured results was found.

Experimental Evaluation of the Acoustic Impedance of Different Ground Types by Sound Propagation in Open-Air Environments

2014 ◽  
Vol 902 ◽  
pp. 185-191 ◽  
Author(s):  
Rafael A.C. Laranja ◽  
Vander M. Budel ◽  
Heraldo J. Amorim ◽  
Mario R. Sobczyk S.
Keyword(s):  
Experimental Evaluation ◽  
Sound Propagation ◽  
Theoretical Background ◽  
Experimental Characterization ◽  
Urban Centers ◽  
Absorption Properties ◽  
Low Frequencies ◽  
Experimental Procedure ◽  
Ground Types

This work presents an experimental characterization of three types of ground commonly found in urban centers regarding their absorption properties with respect to sound propagation: asphalt, grassland and soil. A brief theoretical background is presented, and the experimental procedure is discussed in detail. With basis on experimental results, it is concluded that grassland ground is mostly absorbent for all tested frequencies, whereas asphalt and soil are reflexive for low frequencies and absorbent for high ones.

Random pseudo promptings applied to the thermal characterization of a wet porous material

1999 ◽  
Vol 6 (1) ◽  
pp. 101-108 ◽  
Author(s):  
E. Delacre ◽  
D. Defer ◽  
E. Antczak ◽  
B. Duthoit
Keyword(s):  
Porous Material ◽  
Thermal Characterization

Experimental Characterization of the Reliability of 3-Terminal Dual-Damascene Copper Interconnect Trees

2002 ◽  
Vol 716 ◽  
Author(s):  
C. L. Gan ◽  
C. V. Thompson ◽  
K. L. Pey ◽  
W. K. Choi ◽  
F. Wei ◽  
...  
Keyword(s):  
Stress Conditions ◽  
Experimental Characterization ◽  
Contact Lines ◽  
Tree Structures ◽  
Similar Test ◽  
Dual Damascene ◽  
Copper Interconnect ◽  
Test Conditions

AbstractElectromigration experiments have been carried out on simple Cu dual-damascene interconnect tree structures consisting of straight via-to-via (or contact-to-contact) lines with an extra via in the middle of the line. As with Al-based interconnects, the reliability of a segment in this tree strongly depends on the stress conditions of the connected segment. Beyond this, there are important differences in the results obtained under similar test conditions for Al-based and Cu-based interconnect trees. These differences are thought to be associated with variations in the architectural schemes of the two metallizations. The absence of a conducting electromigrationresistant overlayer in Cu technology, and the possibility of liner rupture at stressed vias lead to significant differences in tree reliabilities in Cu compared to Al.

Experimental Characterization of Mechanical Behavior of Cord-Rubber Composites

1982 ◽  
Vol 10 (1) ◽  
pp. 37-54 ◽  
Author(s):  
M. Kumar ◽  
C. W. Bert
Keyword(s):  
Response Characteristic ◽  
Cord Compression ◽  
Complete Characterization ◽  
Strain Response ◽  
Strain Gages ◽  
Experimental Characterization ◽  
Rubber Composites ◽  
Stress Strain ◽  
Strain Data

Abstract Unidirectional cord-rubber specimens in the form of tensile coupons and sandwich beams were used. Using specimens with the cords oriented at 0°, 45°, and 90° to the loading direction and appropriate data reduction, we were able to obtain complete characterization for the in-plane stress-strain response of single-ply, unidirectional cord-rubber composites. All strains were measured by means of liquid mercury strain gages, for which the nonlinear strain response characteristic was obtained by calibration. Stress-strain data were obtained for the cases of both cord tension and cord compression. Materials investigated were aramid-rubber, polyester-rubber, and steel-rubber.

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