Nondestructive experimental method

Ellipsometry is a high-precision optical characterization technique, the potential of which has not yet been sufficiently exploited in polymer science. It is a rapid and nondestructive experimental method for the analysis of surfaces and thin films. Besides the determination of film thickness with high sensitivity ( 0.1 nm), optical parameters related to material properties can also be evaluated [1]. The facts that ellipsometric measurements can be performed under any ambient conditions, and require no special sample preparation procedures, provide a definite advantage over other surface science techniques [2—4]. 

Neutrons provide a unique, nondestructive probe for determining residual stress in materials. Traditionally, laboratory-based X-ray generators were used, but because of the generally small penetration depth, only limited information is available nondestructively. Bruno et al. have used the D1A two-axis diffractometer at the ILL to analyze the interface residual stress in Mo-coated steel gear wheels. This work was used to develop a new experimental method for similar studies. 

An objective evaluation of the methods on the basis of literature data is hardly possible, because of differences in experimental conditions, sample, amount of sample available, and measurement time. Therefore, the detection limit values stated in the literature given in Tables 1-4 should be considered, at best, approximate. But it is clear that there is no single instrumental technique that meets all the analytical requirements. For example, some methods may be applicable over only a limited concentration range, may be subject to matrix effects or spectral interferences, or have a limited availability. Also, sometimes nondestructive fast methods are needed. The choice of an instrumental method depends on the material to be analyzed and the type of analysis required. 

The disadvantage of ellipsometry is undoubtedly that it does not represent a direct analytical method, but attempts to match functional relationships as well as possible to the experimental data by the development of models [93]. On the other hand, ellipsometry is one of the few nondestructive analytical methods that allows measurement of the monolayer or submonolayer. However, even when a microspot" of measuring light is used, it represents several square millimeters in area. In this surface area, the product nd (optical film thickness) is averaged laterally. 

The aim of this work was to increase the nuclear safety of the VVER-440 by improving fission product limitation systems (barriers) and implementing special nondestructive spectroscopic methods for the testing of structural materials (mostly steels). All theoretical and experimental studies performed were done to improve the deterministic approach to defence in depth for the VVER-440. Defence in depth is an extremely important principle for assuring nuclear safety in nuclear power plants, and this work focused on the barrier system through which this principle is achieved ... 

IQiowledge of parameters such as reactivity ratios, is necessary for synthesis of polymer based resists, and an accurate method of analysis should be useful in various areas associated with resist development such as quality control. Raman spectroscopy provides a convenient, absolute, nondestructive method for compositional analysis of polymer systems which, if an internal standard is present, does not require standards of known composition or ancillary calibration curves. The accuracy, with appropriate selection of experimental conditions such as slit width and integration time, is limited only by the instrumentation. 

Although the high sensitivity of activation analysis is perhaps its most striking advantage, there are a number of other favorable aspects as well. Activation analysis is basically a multielemental technique. Many elements in the sample will become radioactive during the irradiation and if each of these elements can be isolated chemically or instrumentally, their abundances may be determined simultaneously. Activation analysis can be a nondestructive method of analysis. Numerous tests have shown that with careful experimental manipulation, activation analysis is an accurate ( 1% accuracy) and precise ( 5% precision) method of measuring elemental concentrations. 

This sensitivity is, of course, the precision of the measurement based on signal noise considerations, and it does not reflect the absolute accuracy of the measurement. As with other noncontact, nondestructive methods, the thermal-wave technique provides an indirect measure of the geometric film thickness, and absolute accuracy must rely on either an accurate knowledge of the relevant physical parameters, or, as is common with the other methods, the use of calibration standards. In analyzing the data presented here we have used a rather complete (and complex) theoretical model to explain our experimental data, and thereby... 

Reflectance-based optical characterization techniques offer the advantages of high energy resolution and sensitivity to both macrostructural and microstructural effects while nondestructively providing real-time information with the sample in any transparent ambient. Experimental and analytical methods are discussed, and examples are given to illustrate representative applications to problems of current interest in semiconductor technology. 

If the method contribution to the total experimental CV (CVgx) or Cl is known e.g. nondestructive testing, then the inhomogeneity of the material for the tested sample size can be determined. If inhomogeneity can be demonstrated for a given sample size, several conclusions can be drawn ... 

Fourier transform infrared difference spectroscopy has enormous potential. It represents a nondestructive method working at the molecular level, so the amount of material required is relatively small (40-100 fig). This enables its combination with other techniques in molecular biology. More theoretical and experimental advances are indeed possible. A theoretical means for interpreting the observed small changes of the amide I bands needs to be developed. The practical realization of the method of site-directed labeling (i.e., the incorporation of one labeled amino acid at a specific site) would represent a major breakthrough. 

NDE methods have the advantage that they cause no harm to the specimen thus the same part can be nondestructively retested or subsequently tested destructively. However, NDE only reveals the location and severity of flaws. The experimenter must judge the importance of each particular flaw. Some times, the importance of a defect is obvious (harmless, or likely to shorten service lifetime, or likely to cause catastrophic failure) otherwise, experimental stress analysis will quantify the severity of the flaw. The defects that are relevant to the strength of short/long fiber RPs are as follows ... 

Optical MathOdS. Optical methods involve directing polarized monochromatic light toward the solid-liquid interface and measuring a response, eg the polarity or intensity of reflected or emitted light. Various schemes have been proposed, as described below, and these allow for the determination of adsorbed-layer thickness, density, and composition as well as information on internal conformation. Principal advantages of optical experimental probes include nondestructiveness and the capability of continuous, real-time measurements. 

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