Durability Model of Exposed Concrete On-Site Based on Dual Coupling Factors

Author(s):  
Yong Fu ◽  
Hongxia Qiao ◽  
Chenggong Lu ◽  
Theogene Hakuzweyezu ◽  
Fei Guo
Keyword(s):  
1976 ◽  
Vol 8 (2) ◽  
pp. 109-119 ◽  
Author(s):  
B. A. Melandri ◽  
A. Baccarini Melandri

Geophysics ◽  
2021 ◽  
pp. 1-37
Author(s):  
Xinhai Hu ◽  
Wei Guoqi ◽  
Jianyong Song ◽  
Zhifang Yang ◽  
Minghui Lu ◽  
...  

Coupling factors of sources and receivers vary dramatically due to the strong heterogeneity of near surface, which are as important as the model parameters for the inversion success. We propose a full waveform inversion (FWI) scheme that corrects for variable coupling factors while updating the model parameter. A linear inversion is embedded into the scheme to estimate the source and receiver factors and compute the amplitude weights according to the acquisition geometry. After the weights are introduced in the objective function, the inversion falls into the category of separable nonlinear least-squares problems. Hence, we could use the variable projection technique widely used in source estimation problem to invert the model parameter without the knowledge of source and receiver factors. The efficacy of the inversion scheme is demonstrated with two synthetic examples and one real data test.


2005 ◽  
Vol 892 ◽  
Author(s):  
Qianghua Wang ◽  
Jianzeng Xu ◽  
Changhe Huang ◽  
Gregory W Auner

AbstractThis paper reports the fabrication and characterization of micromachined ultrasonic transducers (MUT) based on piezoelectric aluminum nitride (AlN) thin films. The MUT device is composed of an Al/AlN/Al sandwiched structure overlaid on top of a silicon (Si) diaphragm. X-ray diffraction (XRD) scan shows that highly c-axis oriented AlN (002) thin films have been grown on Al/Si(100) substrates. Electrical impedance of the MUT devices is analyzed as a function of frequency. The fundamental resonant frequencies of the devices are found in the range of 65-70 kHz, which are in approximation to the theoretical calculation. The effective coupling factors of the devices are also derived as 0.18.


1976 ◽  
Vol 54 (5) ◽  
pp. 481-487 ◽  
Author(s):  
M. P. Silvanovich ◽  
R. D. Hill

A bean chloroplast coupling factor (CF1) with latent Ca2+-dependent ATPase activity was studied. Immunodiffusion of bean (Phaseolus vulgaris) chloroplast and etioplast coupling factors and spinach coupling factor against antiserum to spinach coupling factor showed partial identity of the bean coupling factor with that of spinach. An immunoelectrophoretic comparison, under dissociating conditions, of bean leaf extracts and spinach extracts containing CF1 subunits (as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis) gave identical results for both extracts. At least six distinct polypeptide species were found. The major species had molecular weights of 42 000, 59 000 and 63 000 daltons. Amino acid analysis of electrophoretically purified bean CF1 gave results similar to those published for spinach CF1.


Author(s):  
Masashi Suzuki ◽  
Shoji Kakio

Abstract Piezoelectricity of YbAlN films has recently been shown to be almost as high as that of ScAlN films. YbAlN film surface acoustic wave (SAW) resonators are expected to have a high coupling factor. We theoretically investigated the propagation characteristics of first-mode Rayleigh SAWs (RSAWs) on Yb0.33Al0.67N film/high-velocity Si, sapphire, AlN, SiC, BN, and diamond substrates. The first-mode RSAWs on the YbAlN layered structures had high coupling factors, higher than those on ScAlN layered structures. An enhancement of the effective coupling factor of the first mode RSAWs was observed in polarity inverted YbAlN film/BN or diamond substrate structures.


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