Ultrasonic high-resolution

Up-to-day reliability requirements as applied to NPP strength maintenance govern development of new generation of computerized systems for in-service inspection. These systems in parallel with capabilities of ordinary ultrasonic techniques allow to reconstruct high resolution image of inner flaw and increase available amount of information. 

BE-3S81 Past film replacement system for high resolution X>ray weld inspection with ultrasonic data fusion Mr M. Erikaen ROBITAS... 

ICP-MS (inductively coupled plasma mass spectrometry) is frequently used for determining ultratrace amounts of technetium [9]. In spite of the high cost of the equipment, this detection method is far superior to other radiometric methods as regards sensitivity. When a double focussing high-resolution system is used (HR-ICP-MS) and an ultrasonic nebulizer is introduced [10], the detection limit is in the order 0.002 mBq. The ICP-MS method has been successfully applied to the determination of environmental "Tc as well as to other long-lived radionuclides of neptunium and plutonium in the environment. 

High resolution transmission electron microscopy (HRTEM) micrographies were performed with a JEOL JEM-3010 microscope operating at 300 kV (Cs= 0.6 mm, point resolution 1.7 A). Images were recorded with CCD camera (MultiScan model 794, Gatan, 1024 x 1024 pixels, pixel size 24 x 24 pm2). The powder samples were mixed in ethanol and then ultrasonicated for 10 min. A drop of the wet sample was placed on a copper grid and then allowed to dry for 10 min before TEM analysis. 

Following the publication of the first edition of Acoustic microscopy, two volumes were published of Advances in acoustic microscopy (Briggs 1995 Briggs and Arnold 1996). In these some of the concepts and applications were further developed, and new topics were introduced. Those two volumes serve as supplements to the second edition the material in them has not been repeated, though in a few places reference has been made to chapters in them. The main addition in this second edition is the chapter on ultrasonic force microscopy and related techniques. We trust that Acoustic microscopy will continue to serve as a helpful resource for further generations of microscopists who wish to image and measure elastic properties at high resolution. 

Planar tomography could be complementarily adopted to indicate cracks and determine their depth propagation with high resolution, while time of flight diffraction (TOFD) has been considered not suitable as a surface crack inspection. Ultrasonic equipment such as phased array technique, on the other hand, allows complete weld inspections, improving, for instance, the separation between back wall and defect indication [10]. 

S. Rauch, M. Motelica-Heino, G. M. Morrison, O. F. X. Donald, Critical assessment of platinum group element determination in road and urban river sediments using ultrasonic nebulization and high resolution ICP-MS, J. Anal. Atom. Spectrom., 15 (2000), 329 D 334. 

As stated above, US secondary responses are obtained under speoific conditions such as resonance, are derived from primary responses suoh as impedanoe or are a fraction of the overall primary response e.g. absorption, refleotion). Measurements made under resonanoe conditions are the basis for resonance ultrasonic spectroscopy (RUS), also known as high-resolution ultrasonic spectroscopy — the latter name was given by the leading manufacturer of RUS instruments. The importanoe of this teohnique warrants disoussion of its basic principles below. 

This equation is also a consequence of Eqs. 9.19 and 9.20. The distance between the piezotransducers, d, can be determined from measurements of (f - f i) for the resonator filled with a liquid of known ultrasonic velocity, c. Based on the simple model for an ideal resonator, Eqs. 9.21 and 9.22 work surprisingly well in real resonators at frequencies that are close to the resonance frequency of the piezotransducer. These equations have been widely used with high-resolution measurements of ultrasonic velocity in liquids. The scope of these equations has been expanded by including empirical correction factors [70]. 

Notwithstanding its significant potential for high-resolution ultrasonic measurements in the analysis of liquids, this technique has for a long time been used mainly by professional ultrasonic laboratories. More widespread use of US for liquid monitoring and analysis has been limited by hindrances such as the following ... 

Ultrasound-based detection is of great interest for the pharmaceutical industry as, in addition to its ability for fast non-destructive analysis and easy adaptation to real process time monitoring in both batch and continuous systems, it has the potential to simultaneously monitor concentrations of both the drug and the excipient in a solution. These possibilities have recently been demonstrated by using a high-resolution ultrasonic spectrometer... 

The details of the structural characteristics of individual constituents in the various carbon deposits were obtained by examination of a number of specimens from each experiment in a JEOL 100 CX transmission electron microscope that was fitted with a high resolution pole piece, capable of 0.18 nm lattice resolution. Suitable transmission specimens were prepared by applying a drop of an ultrasonic dispersion of the deposit in iso-butanol to a carbon support film. In many cases the solid carbon product was found to consist entirely of filamentous structures. Variations in the width of the filaments as a function of both catalyst composition and growth conditions were determined from the measurements of over 300 such structures in each specimen. In certain samples evidence was found for the existence of another type of ca naceous solid, a shell-like deposit in which metal particles appeared to be encapsulated by graphitic platelet structures. Selected area electron diffraction studies were performed to ascertain the overall crystalline order of the carbon filaments and the shell-like materials produced from the various catalyst systems. 

Structural Aspects of Microemulsions. Several investigators have studied the structure of microemulsions using various techniques such as ultracentrifugation, high resolution NMR, spin-spin relaxation time, ultrasonic absorption, p-jump, T-jump, stopped-flow, electrical resistance and viscosity measurements (56-58). The useful compilation of different studies on this subject is found in the books by Robb (68) and Shah and Schechter (69). Several structural models of microemulsions have been proposed and we will discuss only a few important studies here. 

The application of high resolution ultrasonic techniques to CEGB plant... 

THE APPLICATION OF HIGH RESOLUTION ULTRASONIC TECHNIQUES TO CEGB PLANT... 

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