Acoustic Absorption and Reflection Coefficients in Gases by Supersonic Interferometry

1938 ◽  
Vol 10 (1) ◽  
pp. 88-88 ◽  
Author(s):  
Ray S. Alleman
1945 ◽  
Vol 18 (1) ◽  
pp. 10-19
Author(s):  
Dudley Williams ◽  
Brock Dale

Abstract The transmission spectrum of natural rubber has been studied in the region between 1µ and 15 µ and the effects of linear and radial stretch have been observed. Linear extension greater than 400 per cent of the original length produces an increase in the C—C vibrational frequency. Both linear and radial stretch produce an increase in absorption coefficient and a decrease in reflection coefficient. The changes in absorption and reflection coefficients are greatest at short wave-lengths.


1962 ◽  
Vol 1 (3) ◽  
pp. 369 ◽  
Author(s):  
W. Nazarewicz ◽  
P. Rolland ◽  
E. da Silva ◽  
M. Balkanski

2019 ◽  
Vol 61 (12) ◽  
pp. 2308
Author(s):  
К.И. Рубцова ◽  
М.Д. Силина

A series of samples of gradient-porous silicon structures with crystallographic orientations (100) and (111) by deep anode etching was obtained. Dependences of the rate of deep anodic etching and the depth of the porous layer of the samples on the anode current density are shown. The absorption and reflection coefficients of the samples were investigated by optical spectrometry depending on their crystallographic orientation and the depth of the porous layer. The influence of water solutions on the optical properties of the samples was determined.


Author(s):  
Kittipong Nithiporndecha ◽  
Chatrpol Pakasiri

Background: A compact complex impedance-transforming balun for UHF frequencies, which is based on a coupled-line structure that matched all ports and provided high output port isolation, was designed in this paper. Methods: A lumped component transformation was used to minimize circuit size. The implemented circuit operated at 433 MHz with the reflection coefficients less than -16 dB at all ports, 0.22 dB amplitude balance and 180° phase balance at the output ports. The signal coupling between the output ports was -16.8 dB. The circuit size is small at 0.032λ. Results: Complex impedance-transforming baluns were designed to operate at 433 MHz. The source impedance at port 1 was set at Zs = 12 - j12Ω and the load impedances at port 2 and 3 were set at ZL = 80 + j30Ω. Conclusion: A compact complex impedance-transforming balun at UHF frequency, with all ports matched and high isolations, was designed and illustrated in this paper.


1973 ◽  
Vol 9 (21) ◽  
pp. 495 ◽  
Author(s):  
R. Larosa ◽  
C.F. Vasile ◽  
D.V. Zagardo

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