OBJECTIVE The efficiency of rotary, manual and ultrasonic root canal instrumentation techniques was investigated in proximally flattened root canals. MATERIAL AND METHODS Forty human mandibular left and right central incisors, lateral incisors and premolars were used. The pulp tissue was removed and the root canals were filled with red die. Teeth were instrumented using three techniques: (i) ...

Ultrasonic polar scans are based on the recording of the reflected or transmitted amplitude of sound, impinging a fiber reinforced composite from every possible angle of incidence. The mechanical anisotropy of such materials makes the reflection coefficient direction dependent, whence an ultrasonic polar scan forms a fingerprint of the investigated material. Such scans have already proved to be...

nano zno/ montmorillonite composite were prepared by sol gel method under ultrasonic irradiation from directly mixing montmorillonite nano clay into zinc gel. the zn(ch3coo)2.2h2o and montmorillonite nano clay was used as precursor. the zinc acetate was dissolved in di water and, nh3 (aq) solution was dropped into the zinc solution until ph 9 consequently the zinc gel was produced. the montmori...

Intramedullary nail internal fixation is the most prevalent method of treatment of fracture. The study on hole testing and localization of intramedullary nail is one of the most important research topics in present-day orthopedic medicine. This paper gives a new method for hole testing of intramedullary nail based on ultrasonic sensor. Considering the disadvantage, ultrasonic attenuates too fas...

Amongst a number of NDE methods Ultrasonics has been a tool of choice to inspect, since the likely defects and important material properties are most easily, and inexpensively, uncovered in ultrasonic NDE. Due to physical constraints of accessing the other side of the structure and the immeasurability of transmitted signal (like cardiovascular imaging), ultrasonic reflection technique has great...

Integrated (IUTs) and flexible ultrasonic transducers (FUTs) are presented for NDT at high temperatures. These transducers are made of sol-gel sprayed piezoelectric thick (> 40μm) ceramic films. The ceramic materials are lead-zirconate-titanate, bismuth titanate and lithium niobate which are for thickness measurement up to 150°C, 400°C and 800°C, respectively. The IUT can be also deposited onto...

A layer-by-layer deposition method for producing dual-layer ultrasonic transducers from piezoelectric copolymers has been developed. The method uses a combination of customized and standard processing to obtain 2D array transducers with electrical connection of the individual elements routed directly to the rear of the substrate. A numerical model was implemented to study basic parameters effec...

Recently, the Al2O3–TiO2–ZrO2 system has found valuable applications, particularly, as a support for NOx storage–reduction (NSR) catalysts. Nanocomposite powders were prepared from the co-precipitation method in inorganic precursors. The behaviors of mixed oxide nanoparticles under ultrasonic irradiation, such as dispersion, and crushing were studied. Phase transformations, crystallite size, an...

Scan conversion is an important ultrasonic processing stage that maps the acquired polar coordinate data to Cartesian coordinates for display. This requires computationally expensive square root and arctangent calculations for geometric transformation. Previously, we developed an algorithm for implementing scan conversion for gray-scale images using precomputed lookup tables. In a clinical sett...

Ultrasonic arrays are now used routinely for the inspection of engineering structures in order to maintain their integrity and assess their performance. Such inspections are usually optimised manually using empirical measurements and parametric studies which are laborious, time-consuming, and may not result in an optimal approach. In this paper, a general framework for the optimisation of ultra...