Prototypical

C, b.p. 249 C. The prototype of metallocenes, a typical cyclopentadienylide. A sandwich compound. Oxidized to the blue ferricinium cation ((h —CsHjijFe)". ... 

Filters that output noncoherent detector statistics have, in our recent work [1], shown to be very powerful for grain noise suppression in ultrasonics. However, such filters require the operator to carefully specify a transient prototype as a model of the defect echoes which should be detected. Here a new approach is presented, based on the above ideas about perception, which eliminates the need for the operator to manually specify a defect prototype. 

In the work presented here, a slightly different two-parameter transient model has been used. Instead of specifying a center frequency b and the bandwidth parameter a of the amplitude function A(t) = 6 , a simple band pass signal with lower and upper cut off frequencies and fup was employed. This implicitly defined a center frequency / and amplitude function A t). An example of a transient prototype both in the time and frequency domain is found in Figure 1. 

Figure 1 Example of signal prototype in the time and frequency domains.

Within the framework of the ANDES (Automatic Non-Destructive Evaluation System) at TNO Institute of Applied Physics two prototype applications have been developed for automated NDT data interpretation - both using the CBR methodology. 

The SPATE technique is often used to perfonn an experimental validation of the physical behaviour of stressed structures or components. This is the reason why the design activity is usually combined with the SPATE technique used on prototypes in order to provide a good set up of mechanically stressed elements. 

Rapid Prototyping Model of Power Saw Cabinet Part as seen in Figures 6 and 7. Using the Stereolithography technique the part was modelled from a polymere. 

The storage phosphor system was a design prototype developed by AGFA. It consisted of the following components ... 

The IP s were used in combination with appropriate Pb-filters (see 121). For wall thickness inspection we used standard medical IP s (AGFA MDIO), which exhibited an inherent unsharpness of ca. 310 pm. This should be compared with the inherent unsharpness of the film for an Ir-192 exposure which amounts 230 pm 111. For corrosion assessment we used IP prototypes with an inherent unsharpness < 230 pm. 

A prototype is currently under evaluation by our partners in the Raysquins project and first results are very encouraging. 

Several prototypes have been built and give the following characteristics (for 2 mm thick Csl screen) ... 

The prototype of verification system of ultrasonic flaw detector developed is described in the scheme given in figure 2. The verification operators performed with the system are as much automated as possible. The level of automatization is limited by the necessity of human reading of information on flaw detector screen, or other operations as manual adjustment of flaw detector settings. 

As described higher, the VERAPUS prototype system is designed to verify the ultrasonic flaw detectors used for non destructive testing, in the field of periodical amuially performed verifications which are described in CEN projects. 

The CamuS system is intended to be applied mainly in the field of weld inspection, where it is anticipated that the benefits of the analysis and visualisation facilities will be greatest. The specification for the prototype recognised that the system should be applicable to joints where the parent material is between 6mm and 150mm thick, and where the configuration and geometry of the weld preparation are of the types described in prEN1714 (see Figure 2). 

The CamuS system is currently in the form of a laboratory prototype and is undergoing a series of validation tests using an extensive set of test-pieces covering a range of geometries and classes of defect which has been manufactured for the purpose. 

Insofar as Ultrasonic Array probes have come onto the market from several years and are now moving from prototype stages into industrial tools for on-site inspections, methods and tools for acoustic characterization is becoming a real concern. Furthermore, the lack of standards, either national or European, enhances the needs for guidelines proposal. 

A prototype system was manufactured to measure eccentricity values for such tubes in a production line. 

Ultrasonic techniques are an obvious choice for measuring the wall thickness. In the pulse-echo method times between echoes from the outer and inner surface of the tube can be measured and the wall thickness may be calculated, when the ultrasonic velocity of the material is known. In the prototype a computer should capture the measuring data as well as calculate and pre.sent the results. First some fundamental questions was considered and verified by experiments concerning ultrasonic technique (Table I), equipment, transducers and demands for guidance of the tube. 

For the prototype equipment normal immersion inspection in water was selected instead of the delay line solution. 

Measurement at 500 m/min was considered so promising that it was decided to manufacture and test a prototype for the four channel scanning system. In such a system multiplexing of signals from the four transducers to one ultrasonic instrument was a possibility. Alternatively four independent instruments (one for each transducer) could be used in the scanning system. 

The final test of the prototype was performed during actual drawing operation. In Figure 6 an example is shown with all four channels recorded during tube drawing. To see the influence of tube velocity the drawing speed was increased every 30 sec, going from zero to 350 tn/sec. 

Evaluation and calibration. A piece of tube was rotated around its own axis during four channel wall thickness mea.surements (Figure 7). The four traces are not identical A rotation apart as should be expected. The calibrations of the four equipment s from the manufacture was not the same. Especially one of the traces has less dynamic than the other three. Based on these observations a dynamic calibration system was suggested using a tube, which could be rotated around its own axis in the measuring system. The values should be verified using traditional mechanical measurement around the tube circumference. The prototype system was permanently installed in the workshop at the production hall. Experimental work was more difficult under such circumstances so our participation in the development work stopped. 

Putting (A3.2.10) into (A3.2.4) gives the prototype example of what is called the fluctuation-dissipation relation... 

Meier C and Engel V 1995 Pump-probe ionization spectroscopy of a diatomic molecule sodium molecule as a prototype example Femtosecond Chemistry Proc. Berlin Conf Femtosecond Chemistry (Berlin, March 1993) (Weinheim Verlag Chemie)... 

The Landolt reaction (iodate + reductant) is prototypical of an autocatalytic clock reaction. During the induction period, the absence of the feedback species (Irere iodide ion, assumed to have virtually zero initial concentration and fomred from the reactant iodate only via very slow initiation steps) causes the reaction mixture to become kinetically frozen . There is reaction, but the intemiediate species evolve on concentration scales many orders of magnitude less than those of the reactant. The induction period depends on the initial concentrations of the major reactants in a maimer predicted by integrating the overall rate cubic autocatalytic rate law, given in section A3.14.1.1. 

Beeman J W and Haller E E 1994 Ga Ge photooonduotor arrays—design oonsiderations and quantitative analysis of prototype single pixels Infra. Rhys. Technology 25 827-36... 

Cambridge Instruments builds the first commercial SEM 1968 Crewe and colleagues introduce the PEG as electron beam source 1968 Crewe and colleagues build the first STEM prototype 1995 Zach proves the concept of a corrected LVSEM... 

The construction of an aberration-corrected TEM proved to be teclmically more demanding the point resolution of a conventional TEM today is of the order of 1-2 A. Therefore, the aim of a corrected TEM must be to increase the resolution beyond the 1 A barrier. This unplies a great number of additional stability problems, which can only be solved by the most modem technologies. The first corrected TEM prototype was presented by Flaider and coworkers [M]- Eigure BE 17.9 shows the unprovement in image quality and interpretability gained from the correction of the spherical aberration in the case of a materials science sample. 

The H + NO2 OH + NO reaetion provides an exeellent example of the use of laser fluoreseenee deteetion for the elueidation of the dynamies of a ehemieal reaetion. This reaetion is a prototype example of a radieal-radieal reaetion in that the reagents and produets are all open-shell free radieal speeies. Both the hydroxyl and nitrie oxide produets ean be eonveniently deteeted by eleetronie exeitation in the UV at wavelengths near 226 and 308 mn, respeetively. Atlases of rotational line positions for the lowest eleetronie band systems of these... 

The reaction of an atom with a diatomic molecule is the prototype of a chemical reaction. As the dynamics of a number of atom-diatom reactions are being understood in detail, attention is now being turned to the study of the dynamics of reactions involving larger molecules. The reaction of Cl atoms with small aliphatic hydrocarbons is an example of the type of polyatomic reactions which are now being studied [M, 72, 73]. 

The Ar-HCl and Ar-HF complexes became prototypes for the study of intennolecular forces. Holmgren et al [30] produced an empirical potential energy surface for Ar-HCl fitted to the microwave and radiofrequency spectra,... 

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