Confirmation

The data from Table 7.4 are presented graphically in Fig. 7.11. The optimal is at 10°C, confirming the initial value used for this problem in Chap. 6. 

During loading and unloading of crude oil tankers, the specific gravity of the crude is measured to confirm it meets the specifications for the case where payment is made on a barrel basis, or when the volume is converted into weight if the transaction is based on a price per ton (Hayward et al., 1980). 

The initial condition for the dry gas is outside the two-phase envelope, and is to the right of the critical point, confirming that the fluid initially exists as a single phase gas. As the reservoir is produced, the pressure drops under isothermal conditions, as indicated by the vertical line. Since the initial temperature is higher than the maximum temperature of the two-phase envelope (the cricondotherm - typically less than 0°C for a dry gas) the reservoir conditions of temperature and pressure never fall inside the two phase region, indicating that the composition and phase of the fluid in the reservoir remains constant. 

The gradients may be caloulated from surface fluid densities, or may be directly measured by downhole pressure measurements using the repeat formation testing tool (RFT). The interfaces predicted can be used to confirm wireline measurements of fluid contact. 

The number and shape of the grid blocks in the model depend upon the objectives of the simulation. A 100 grid block model may be sufficient to confirm rate dependent processes described in the previous section, but a full field simulation to be used to optimise well locations and perforation intervals for a large field may contain up to 100,000 grid blocks. The larger the model, the more time consuming to build, and slower to run on the computer. 

Fluid samples will be taken using downhole sample bombs or the MDT tool in selected development wells to confirm the PVT properties assumed in the development plan, and to check for areal and vertical variations in the reservoir. In long hydrocarbon columns (say 1000 ft) it is common to observe vertical variation of fluid properties due to gravity segregation. 

Reservoir pressure is measured in selected wells using either permanent or nonpermanent bottom hole pressure gauges or wireline tools in new wells (RFT, MDT, see Section 5.3.5) to determine the profile of the pressure depletion in the reservoir. The pressures indicate the continuity of the reservoir, and the connectivity of sand layers and are used in material balance calculations and in the reservoir simulation model to confirm the volume of the fluids in the reservoir and the natural influx of water from the aquifer. The following example shows an RFT pressure plot from a development well in a field which has been producing for some time. 

In order to confirm the capability of acoustic emission to detect the evolution of a defect during a pneumatic test, a vessel with a lack of thickness due to the action of corrosion was pressurized pneumatically until burst. 

No emission during holds was observed but the concentration of events in clusters and the high level of amplitude of events confirmed the results of the proof test. After 20 bars, the bottom of the vessel around the defect became silent and activity is observed in the high part of the vessel near welds. 

Preliminary in-field applications have also confirmed the successful long-term performance of the AEBIL instrumentation in power plant environment. 

The results obtained with the two methods confirm the measured data with a good precision, with less computational time for the specialised code than the general code. This validation on three representative test bloeks can lead to many applications of modelling of the thin-skin regime. 

Note that while the ToF information is relatively consistent, the amplitude is varying considerably between the measurement points. This confirms the uncertainty related to the amplitude information which, in this works serves only to locate the area in which the measurements should be taken typically measurements are limited to within the range of signal amplitudes in excess of 30% of the peak value. 

The estimated VSS and EPD allow for the observation of the tip diffraction effects (phase inversion - Atp = 180° - for the direct and mirror diffraction echoes) for all selected Ascan signals. This proves the plane nature of the OSD and confirm our initial hypothesis. 

In Dynamic Spatial Reconstructor at the expense of use 2D matrix of detectors there was the opportunity to use a divergent cone beam of source emission. This system had a number of lacks. In particular the number of projections is rigidly limited by the number of x-ray sources. The dispersion of source emission results in errors of data collected.. However the system confirmed basic advantages of application of conic beams and 2D matrices of detectors for collecting information about 3D object. 

The fundamental confirmation of the theory of focusing laser radiation may be formulated in the following way [3,4] ... 

By increasing the probe diameter, we bring down tlie impedance point along the impedance curve with the same way as the electrical frequency or conductivity. We will describe only one type of probes, namely, the probe with ferritic circular section that we could qualify as punctual with an optimal sensibility. In order to satisfy these conditions, tests will be made to confirm these results by ... 

As a conclusion to this experiment and in order to optimize the sensibility of tire probe it is necessary that the coil shall be on the edge of the ferrite. The results obtained confirm the probe stability. 

This paper is structured as follows in section 2, we recall the statement of the forward problem. We remind the numerical model which relates the contrast function with the observed data. Then, we compare the measurements performed with the experimental probe with predictive data which come from the model. This comparison is used, firstly, to validate the forward problem. In section 4, the solution of the associated inverse problem is described through a Bayesian approach. We derive, in particular, an appropriate criteria which must be optimized in order to reconstruct simulated flaws. Some results of flaw reconstructions from simulated data are presented. These results confirm the capability of the inversion method. The section 5 ends with giving some tasks we have already thought of. 

High-current betatrons experiments confirm the wide practical possibilities of use of these installations for radiative control of the articles and materials with big thickness. 

Fig. 4 illustrates the time-dependence of the length of top s water column in conical capillary of the dimensions R = 15 pm and lo =310 pm at temperature T = 22°C. Experimental data for the top s column are approximated by the formula (11). The value of A is selected under the requirement to ensure optimum correlation between experimental and theoretical data. It gives Ae =3,810 J. One can see that there is satisfactory correlation between experimental and theoretical dependencies. Moreover, the value Ae has the same order of magnitude as Hamaker constant Ah. But just Ah describes one of the main components of disjoining pressure IT [13]. It confirms the rightness of our physical arguments, described above, to explain the mechanism of two-side liquid penetration into dead-end capillaries. 

One more experimental result, which is important for PT is as follows. Only polar liquids fill conical capillaries from both sides. We used various penetrants to fill conical defects Pion , LZh-6A , LZhT , LUM-9 etc. It was established that only the penetrants containing polar liquid as the basic liquid component (various alcohols, water and others) manifest two-side filling phenomenon. This result gives one more confirmation of the physical mechanism of the phenomenon, based on liquid film flow, because the disjoining pressure strongly depends just on the polarity of a liquid. 

For coloured product family selection is made on nickel-chromium specimen of 30 pm, but for fluorescent product family selection is made on nickel-chromium specimen of 10 pm. Tests made on real defects confirm these results. 

It can be concluded, that indications with lengths of more than about 1.5 mm can be detected with high probability (100%). This confirms with the recommended smallest acceptance level (optimum conditions) of 1.5 mm (registration level) in various product standards (e g. as [10]). It is self evident that smaller indications (1 = 0.6 mm) will be detected too, but the correlations explained above, clearely indicates a decreasing probability of detection with decreasing length of indications. 

However this is not sufficient to give the customer confidence that a satisfactory quality of NDT will be provided. It is necessary to have a system of quality management and to confirm the effectiveness of its functioning. 

In doing this the problems may arise if one person alone manages several processes, i.e. if his activity embraces a number of functions (as may be especially typical for NDT). It is better if each process is assigned to a specialist responsible for it. For example, persons responsible for the technical state of NDT equipment, for metrological confirmation of NDT facilities, for standards on testing, for NDT results registration, etc. 

The accredited laboratory must confirm that all the equipment used in NDT implementation is tested with regular intervals in compliance with relevant state standards. 

Attestation of the test procedure is realized with the aim to confirm both the correctness of the choice of method and NDT facilities and fullness of requirements included in the test procedure. Attestation ensures reliability of testing results with required accuracy. 

The measuren.cnts are performed on a sample made from Inconell IN 718 placed at our disposal by Me oren- und Turbinen-Union Miinchen GmbH (MTU). The sample is of disk shape and has a curved side and a flat side, see also fig. 6. On the curved side MTU had detected a segregation reaching to the surface but with unknown depth. It had been detected by segregation etching and its existence was confirmed by eddy current testing. Both methods are successful only in such a special case where the segregation extends to the surface. 

Most important is the following Fig. 7c shows that the segregation can be detected also from that side where it does not extent to the surface. This confirms that the material is transparent for this kind of susceptibility measurements. That means, that also segregations can be detected, which are in the volume and do not extent to the surface. 

For each tube, the analyst carefully examines the complete eddy current record. Any indication above the detection threshold that did not lead to a confirmed computer diagnostic is manually examined. 

The results of the review exercise described above confirmed that all shipyards do not have the same attitude towards quality. Whilst the results presented by most of the yards visited were reasonably consistent at 0.5 - 4.5 % repair rate regardless of NDE method, the results from other yards were less satisfactory. The exercise showed that in some yards repair rates were regularly in excess of 10% and that repair rates for radiography tended to be higher than those for ultrasonics. 

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