Radial vibration of a thick-shell hollow piezoceramic sphere

1967 ◽  
Vol 3 (1) ◽  
pp. 13-21 ◽  
Author(s):  
P. W. Drenkow ◽  
C. F. Long
2021 ◽  
Vol 1 (3) ◽  
pp. 263502542110111
Author(s):  
Anthony J. Ignozzi ◽  
Zane Hyde ◽  
Scott E. Dart ◽  
David R. Diduch

Background: Patients who are refractory to initial management of trochlear dysplasia, which consists of bracing and physical therapy, may be candidates for trochleoplasty. Indications: Indications for trochleoplasty include Dejour classification type B or D trochlear dysplasia, supratrochlear spur height ≥7 mm, and a positive J sign on examination. Technique Description: The thick shell sulcus-deepening trochleoplasty technique involves removing the supratrochlear spur by creating a 5-mm–thick osteochondral shell with underlying cavity, dividing the thick shell into medial and lateral leaflets, and securing the leaflets with absorbable sutures. This establishes a new trochlear groove that is flush with the anterior cortex of the femur. Results: A review of 21 studies with length of follow-up from 8.8 months to 15 years found postoperative dislocation was present in 0% to 15% of patients and the patient satisfaction ranged from 81.0% to 94.4%. A prospective study with a minimum 2-year follow-up found no cases of recurrent dislocation, no progression of radiographic arthritis, 84.8% of patients returned to sport, and the patient satisfaction was a 9.1/10. Discussion/Conclusion: Sulcus-deepening trochleoplasty for trochlear dysplasia provides patellar stability and excellent patient satisfaction.


1983 ◽  
Vol 6 ◽  
pp. 648-648
Author(s):  
J.B. Hutchings

IUE has been used to study 11 high luminosity X-ray binaries, of which 3 are in the Magellanic Clouds. In the supergiant systems, X-ray ionisation bubbles have been found in most cases, leading to a greater understanding of the winds and accretion processes. Further studies of precessing objects such as LMC X-4 with IUE and ST are clearly of considerable interest, relating to X-ray heating and blanketing. Detailed studies of the Cyg X-l ionisation bubble may resolve the long standing puzzle of its orbit inclination and masses. UV continua have furnished valuable information on extinction, temperatures and luminosities, and the presence of non-stellar (i.e. disk) luminosity. Here too, more detailed studies are clearly indicated for the future. A unique object of interest is the LMC transient 0538-66 whose UV spectrum has quasarlike lines and luminosity which varies oppositely to the visible. This may be a case of supercritical accretion generating an optically thick shell (“disk”) about the pulsar.


2014 ◽  
Vol 670-671 ◽  
pp. 1153-1158
Author(s):  
Jing Jing Liu ◽  
Lei Qin ◽  
Li Kun Wang ◽  
Chao Zhong ◽  
Bin Zhang ◽  
...  

This paper presents a prototype of a new flextensional transducer with PVDF (Polyvinylidene Fluoride) piezoelectric film instead of metallic shell. Resonance frequency, bandwidth, transmitting voltage response, and horizontal directivity of the flextensional transducer with PVDF piezoelectric film were respectively measured by using laser-scanning vibrometer, and underwater acoustic measurement system. Experimental results showed that the new transducer features effectively conversion from longitudinal vibration of piezoelectric stack into radial vibration of PVDF piezoelectric film.


2006 ◽  
Vol 315-316 ◽  
pp. 641-645 ◽  
Author(s):  
Xin Wei ◽  
Rui Wei Huang ◽  
Shao Hui Lai ◽  
Z.H. Xie

ID (inner-diameter) slicing is widely used in cutting ingots currently. In this paper, the deflection (axial vibration) and vibration (radial vibration) signals in different slicing conditions of the silicon wafers were measured online and analyzed. The effects of the vibration signals on the machining accuracy and surface roughness of sliced wafers were investigated based on the measurement and analysis of the surface roughness, warpage and TTV (total thickness vibration) of the sliced wafers. The results show that the changes of surface roughness, warpage and TTV of the sliced wafers exhibit approximately consistence with the changes of the power spectrums of the acquired vibration signals in different working stage of the blade. The vibration and deflection signals can give evidence of the changes in the cutting forces and blade performance during slicing. The power spectrum of the signals is useful for monitoring the blade wear and tension condition and predicting the surface quality and machining accuracy of the sliced wafers.


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