Frequency dependence of ultrasonic backscattering in cancellous bone: Autocorrelation model and experimental results

2000 ◽  
Vol 108 (5) ◽  
pp. 2403-2411 ◽  
Author(s):  
S. Chaffaı̈ ◽  
V. Roberjot ◽  
F. Peyrin ◽  
G. Berger ◽  
P. Laugier
Keyword(s):  
Frequency Dependence ◽  
Cancellous Bone ◽  
Experimental Results ◽  
Ultrasonic Backscattering

scholarly journals Characterization of percolation behavior in conductor–dielectric 0-3 composites

2014 ◽  
Vol 04 (04) ◽  
pp. 1450035 ◽  
Author(s):  
Lin Zhang ◽  
Patrick Bass ◽  
Zhi-Min Dang ◽  
Z.-Y. Cheng
Keyword(s):  
Dielectric Constant ◽  
Percolation Threshold ◽  
Frequency Dependence ◽  
Experimental Results ◽  
Effective Dielectric Constant ◽  
Filler Concentration ◽  
Percolation Behavior ◽  
The Matrix ◽  
The Relationship

The equation ε eff ∝ (ϕc - ϕ)-s which shows the relationship between effective dielectric constant (εeff) and the filler concentration (φ), is widely used to determine the percolation behavior and obtain parameters, such as percolation threshold φc and the power constant s in conductor–dielectric composites (CDCs). Six different systems of CDCs were used to check the expression by fitting experimental results. It is found that the equation can fit the experimental results at any frequency. However, it is found that the fitting constants do not reflect the real percolation behavior of the composites. It is found that the dielectric constant is strongly dependent on the frequency, which is mainly due to the fact that the frequency dependence of the dielectric constant for the composites close to φc is almost independent of the matrix.

Experimental Results of Autogenous Cancellous Bone Chips Transplanted into the Canine Frontal Sinus Cavity

1974 ◽  
Vol 83 (17_suppl) ◽  
pp. 1-15 ◽  
Author(s):  
Allan L. Abramson ◽  
Robert L. Eason ◽  
William H. Pryor ◽  
Eugene J. Messer
Keyword(s):  
Cancellous Bone ◽  
Frontal Sinus ◽  
Experimental Results ◽  
Variable Amount ◽  
Cystic Formation ◽  
Partial Filling ◽  
Sinus Cavity ◽  
Sinus Mucosa

Autogenous marrow-cancellous bone chips were transplanted into 36 canine frontal sinus cavities and studied over variable postoperative periods by radiographic and histologic methods. Cysts lined with frontal sinus mucosa were noted to enlarge progressively between three and 26 weeks. Cysts which originated from the ectoturbinate scroll frequently went on to communicate with the nasofrontal duct (neocavitation). If no cystic formation developed, this loosely packed autograft eventually was transformed into organized cancellous bone, thus obliterating the sinus cavity. When external frontal contour was evaluated, good results were obtained when the cavity was completely filled with cancellous autograft. If partial filling of the sinus cavity was performed, a variable amount of depression was noted.

Analysis of frequency dependence of ultrasonic backscatter coefficient in cancellous bone

2008 ◽  
Vol 124 (6) ◽  
pp. 4083-4090 ◽  
Author(s):  
Dean Ta ◽  
Weiqi Wang ◽  
Kai Huang ◽  
Yuanyuan Wang ◽  
Lawrence H. Le
Keyword(s):  
Frequency Dependence ◽  
Cancellous Bone ◽  
Backscatter Coefficient ◽  
Ultrasonic Backscatter

Contribution to the Dielectric Behavior of Relaxers from the Surface of Nano-Order Cluster in the Materials

1997 ◽  
Vol 492 ◽  
Author(s):  
Z. -Y. Cheng ◽  
Aqiang Guo ◽  
R. S. Katiyar
Keyword(s):  
Dielectric Constant ◽  
Relaxation Time ◽  
Frequency Dependence ◽  
Relaxor Ferroelectrics ◽  
Dielectric Behavior ◽  
Experimental Results ◽  
Time Analysis ◽  
Resonance Process

ABSTRACTBased on the analysis of the dielectric behavior of relaxor ferroelectrics, it is assumed that the material has two polarization processes. Thus, a formula, which can fit the experimental results very well, is proposed to describe the temperature and frequency dependence of the dielectric constant. The fitted results show that there is a resonance process in the material and the peak of the dielectric constant is determined with both the relaxation and resonance processes. The relaxation time analysis shows that the peak of the dielectric constant indeed consists of two parts.

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