Image Reconstruction of Blockage in the Continuous and Stepped Pipelines by Noninvasive Acoustic Method

2006 ◽  
Vol 321-323 ◽  
pp. 1640-1643
Author(s):  
Sung Soo Jung ◽  
S.I. Cho ◽  
Young Tae Kim ◽  
C.U. Cheong ◽  
Ho Chul Kim
Keyword(s):  
Image Reconstruction ◽  
Acoustic Waves ◽  
Acoustic Method ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
New Approach ◽  
Resonance Frequencies ◽  
Transmission Pipeline

The image of a semi-circular blockage and location in the uniform and stepped pipe was reconstructed by measuring the eigen-frequency shift of the resonance and anti-resonance frequencies of multi-sine acoustic waves. In this study we have used different boundary conditions from previous works of Wu and Fricke [1] and De Salis and Oldham [2] to determine the blockage cross-sectional area and position. The results agreed with real fractional cross sectional area and position in the both continuous and stepped pipes. New approach showed a better quality of reconstructed image with small ripple number and the false dummy blockage signal was also reduced. The present method of blockage image reconstruction is a noninvasive nondestructive and can meet the integrity evaluation implementation for all types of transmission pipeline

A three-microphone acoustic reflection technique using transmitted acoustic waves in the airway

2013 ◽  
Vol 115 (8) ◽  
pp. 1119-1125 ◽  
Author(s):  
Yuki Fujimoto ◽  
Jyongsu Huang ◽  
Toshiharu Fukunaga ◽  
Ryo Kato ◽  
Mari Higashino ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Cross Sectional Area ◽  
Distance Functions ◽  
Sectional Area ◽  
Wave Tube ◽  
Cross Sectional ◽  
Reflected Waves ◽  
Acoustic Reflection ◽  
Obstructive Sleep ◽  
And Function

The acoustic reflection technique noninvasively measures airway cross-sectional area vs. distance functions and uses a wave tube with a constant cross-sectional area to separate incidental and reflected waves introduced into the mouth or nostril. The accuracy of estimated cross-sectional areas gets worse in the deeper distances due to the nature of marching algorithms, i.e., errors of the estimated areas in the closer distances accumulate to those in the further distances. Here we present a new technique of acoustic reflection from measuring transmitted acoustic waves in the airway with three microphones and without employing a wave tube. Using miniaturized microphones mounted on a catheter, we estimated reflection coefficients among the microphones and separated incidental and reflected waves. A model study showed that the estimated cross-sectional area vs. distance function was coincident with the conventional two-microphone method, and it did not change with altered cross-sectional areas at the microphone position, although the estimated cross-sectional areas are relative values to that at the microphone position. The pharyngeal cross-sectional areas including retropalatal and retroglossal regions and the closing site during sleep was visualized in patients with obstructive sleep apnea. The method can be applicable to larger or smaller bronchi to evaluate the airspace and function in these localized airways.

Intranasal cross-sectional area and quality of life changes following endoscopic transsphenoidal skull base surgery

2015 ◽  
Vol 5 (12) ◽  
pp. 1124-1128 ◽  
Author(s):  
Edward D. McCoul ◽  
Amit S. Patel ◽  
Jeffrey C. Bedrosian ◽  
Vijay K. Anand ◽  
Theodore H. Schwartz
Keyword(s):  
Quality Of Life ◽  
Skull Base ◽  
Skull Base Surgery ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Life Changes ◽  
Cross Sectional

scholarly journals A new nasal acoustic reflection technique to estimate pharyngeal cross-sectional area during sleep

2000 ◽  
Vol 88 (4) ◽  
pp. 1457-1466 ◽  
Author(s):  
J. Huang ◽  
N. Itai ◽  
T. Hoshiba ◽  
T. Fukunaga ◽  
K. Yamanouchi ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Nasal Septum ◽  
Cross Sectional Area ◽  
New Method ◽  
New Technique ◽  
Sectional Area ◽  
Cross Sectional ◽  
Acoustic Reflection ◽  
Nasal Cavities ◽  
Airway Model

The conventional acoustic reflection technique in which acoustic waves are launched through the mouth cannot be applied during sleep, nor can it be applied to the nasopharynx, which is the major site of occlusion in patients with obstructive sleep apnea syndrome. We propose a new technique of nasal acoustic reflection to measure pharyngeal cross-sectional areas including the nasopharynx. The acoustic waves are introduced simultaneously to both nostrils during spontaneous nasal breathing. A new algorithm takes into account the nasal septum with asymmetric nasal cavities on both sides and assumes prior knowledge of the cross-sectional area of the nasal cavities and the position of the nasal septum. This method was tested on an airway model with a septum and on healthy human subjects. The conventional technique gave inaccurate measurements for pharyngeal cross-sectional areas for an airway model with asymmetric branching, whereas the new technique measured them almost perfectly. The oro- and hypopharyngeal cross-sectional area measurements acquired by the new method were not different from those obtained by the conventional method in normal subjects. This new method can be used as a monitor of upper airway dimensions in nocturnal polysomnography.

scholarly journals Association between hip muscle cross-sectional area and hip pain and function in individuals with mild-to-moderate hip osteoarthritis: a cross-sectional study.

2020 ◽  
Author(s):  
Waruna Peiris ◽  
Flavia M Cicuttini ◽  
Maria Constantinou ◽  
Abbas Yaqobi ◽  
Sultana Monira Hussain ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Regression Coefficient ◽  
Hip Osteoarthritis ◽  
Cross Sectional Area ◽  
Hip Pain ◽  
Sectional Area ◽  
Cross Sectional ◽  
Hip Muscle ◽  
And Function

Abstract Objective: To examine the associations between hip muscle cross-sectional area and hip pain and function in community-based individuals with mild-to-moderate hip osteoarthritis. Methods: This study included 27 participants with mild-to-moderate hip osteoarthritis. Cross-sectional area of hip muscles, including psoas major, rectus femoris, gluteus maximus, gluteus medius and minimus, adductor longus and magnus, obturator internus, and obturator externus, were measured from magnetic resonance images. Hip pain and function were evaluated using the Hip Disability and Osteoarthritis Outcome Score (HOOS). Results: After adjusting for age and gender, greater cross-sectional area of adductor longus and magnus was associated with a higher HOOS score in quality of life (regression coefficient 1.4, 95% confidence interval (CI) 0.2-2.7, p=0.02), activity of daily living (regression coefficient 1.3, 95% CI 0.1-2.6, p=0.04) and sport and recreation function (regression coefficient 1.6, 95% CI 0.1-3.0, p=0.04). Greater cross-sectional area of psoas major was associated with a higher quality of life score (regression coefficient 3.6, 95% CI -0.5 to 7.7, p=0.08). The cross-sectional area of hip muscles was not significantly associated with HOOS pain or symptom score. Conclusion: Greater cross-sectional area of hip adductors was associated with better function and quality of life in individuals with mild-to-moderate hip osteoarthritis. Greater cross-sectional area of hip flexors might be associated with better quality of life. These findings, while need to be confirmed in longitudinal studies, suggest that targeting the hip adductor and flexor muscles may improve function and quality of life in those with mild-to-moderate hip osteoarthritis.

Effect of the spatial variation of permeability on air bubble creation and compression

2020 ◽  
Vol 39 (7-8) ◽  
pp. 285-298
Author(s):  
Bouchra Aaboud ◽  
Laurent Bizet ◽  
Abdelghani Saouab ◽  
Yasir Nawab
Keyword(s):  
Cross Sectional Area ◽  
Process Time ◽  
Void Content ◽  
Sectional Area ◽  
Cross Sectional ◽  
Air Bubble ◽  
Bubble Distribution ◽  
Sinusoidal Shape ◽  
Sewing Threads

Tow bundles inside a quasi-unidirectional non-crimp fabric are maintained by sewing threads that induce variation in the bundles’ shape. Indeed, the sewing threads apply a light clamping force that gives a periodical and sinusoidal shape to the tow’s cross-sectional area. This tow cross-sectional area heterogeneity, as a function of position in the fabric, induces a variation of the permeability values. Consequently, while injecting liquid into the fibrous bed, preform's impregnation is influenced as well as the fabric’s void content. The aim of this paper is to consider the effect of tow cross-sectional area heterogeneity on the quality of the manufactured composite part. It leads to reveal the influence of the fibrous reinforcement’s microstructure on the air bubble creation and compression phenomena, especially in terms of process time and the micro and macro air bubble distribution.

scholarly journals A New Approach on Vibrating Horns Design

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Maria Violeta Guiman ◽  
Ioan Călin Roșca
Keyword(s):  
Optimization Design ◽  
Nodal Point ◽  
Optimization Method ◽  
Cross Sectional Area ◽  
Point Of View ◽  
Sectional Area ◽  
Cross Sectional ◽  
New Approach ◽  
Frequency Maximum ◽  
Predicted Values

An optimization method of the vibrating horns is presented considering the smallest action principle and the attached cutting tool mass. The model is based on Webster’s wave propagation equation and as an objective function the minimization of the volume in structural equilibrium conditions was considered. The considered input parameters were working frequency, maximum cross-sectional area, magnification coefficient, and the attached mass. At the end of the study, a new shape function of the horn’s cross section is obtained. The particularity of the new obtained shape is given by the nodal point position that is the same with the position of the maximum cross-sectional area. The obtained horn was analyzed from the modal point of view using theoretical and experimental methods. As theoretical methods, both the state-space method and the finite element method were used. An experimental setup for frequency response function determination was developed using a random input signal. The verification of the magnitude value was done considering a harmonic steady-state signal. The recorded values were compared with the predicted values. The numerical simulations and tests support the validity of the assumptions used in the horns optimization design.

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