Theory of testing

In principle, the theory used for the presence-absence testing is the same as for counting large numbers of cfp, but differs in its application. Low count materials are characterised by the fact that some capsules contain no organisms. Because the certified value is in reality a fraction of negatives (capsules without bacteria), the fraction of negative isolations in the laboratory will be compared to the certified number of negatives. 

A true fraction of negatives for a laboratory, exists for the studied testing method. To determine this exactly, a very large number of capsules should be analysed. In practice only a small number of capsules can be analysed. With the results of this small number of capsules an estimate, called pi i, of the fraction of negatives for the laboratory can be computed. This / / /, is an estimate of the unknown The estimate, p/,/, is compared to the certified fraction From this comparison, conclusions can be drawn about ii/aft. In practice, the number of positive isolations 

---

USE OE HIGH LEVEL CONTAMINATED CERTIEIED REFERENCE MATERIALS IN MICROBIOLOGY. THEORY OF TESTING THE METHODS ... 

Tocher KD (1950) Extension of the Neyman-Pearson theory of tests to discontinuous variates. Biometrika 37 130-144,... 

J. B. Goodenough and S. L. Gerhart. Toward a theory of test data selection. IEEE Trans, on Software Engineering 1(2) 156-173, June 1975. 

Methods from the theory of LTI-systems are practicable for eddy-current material testing problems. The special role of the impulse response as a characteristic function of the system sensor-material is presented in the theory and for several examples. 

Another phenomenon is so called two-side filling of one-side closed conical capillaries with liquid [5]. On the one hand the more penetrant is trapped by the defect the wider indication will appear. Contrariwise it is almost impossible to extract a penetrant from the completely filled surface defects by dry developer [6]. In this study we propose the theory of the phenomenon. Besides experimental results of the investigation of two-side filling with various penetrants of conical capillaries are presented. Practical recommendations to optimize liquid penetrant testing process are proposed. 

With the reference block method the distance law of a model reflector is established experimentally prior to each ultrasonic test. The reference reflectors, mostly bore holes, are drilled into the reference block at different distances, e.g. ASME block. Prior to the test, the reference reflectors are scanned, and their maximised echo amplitudes are marked on the screen of the flaw detector. Finally all amplitude points are connected by a curve. This Distance Amplitude Curve (DAC) serves as the registration level and exactly shows the amplitude-over-distance behaviour" of the reference reflector for the probe in use. Also the individual characteristics of the material are automatically considered. However, this curve may only be applied for defect evaluation, in case the reference block and the test object are made of the same material and have undergone the same heat treatment. As with the DGS-Method, the value of any defect evaluation does not consider the shape and orientation of the defect. The reference block method is safe and easy to apply, and the operator need not to have a deep understanding about the theory of distance laws. 

F. Bashforth and J. C. Adams, An Attempt to Test the Theories of Capillary Action, University Press, Cambridge, England, 1883. 

Model Networks. Constmction of model networks allows development of quantitative stmcture property relationships and provide the abiUty to test the accuracy of the theories of mbber elasticity (251—254). By definition, model networks have controlled molecular weight between cross-links, controlled cross-link functionahty, and controlled molecular weight distribution of cross-linked chains. Sihcones cross-linked by either condensation or addition reactions are ideally suited for these studies because all of the above parameters can be controlled. A typical condensation-cure model network consists of an a, CO-polydimethylsiloxanediol, tetraethoxysilane (or alkyltrimethoxysilane), and a tin-cure catalyst (255). A typical addition-cure model is composed of a, ffl-vinylpolydimethylsiloxane, tetrakis(dimethylsiloxy)silane, and a platinum-cure catalyst (256—258). 

The techniques, instrumentation and underlying theory of optical microscopy for materials scientists have been well surveyed by Telle and Petzow (1992). One of the last published surveys including metallographic techniques of all kinds, optical and electronic microscopy and also techniques such as microhardness testing, was a fine book by Phillips (1971). 

Thermodynamics and kinetics of phase separation of polymer mixtures have benefited greatly from theories of spinodal decomposition and of classical nucleation. In fact, the best documented tests of the theory of spinodal decomposition have been performed on polymer mixtures. 

Visweswaran, V. and Floudas, C. A. (1990). A global optimization procedure for certain classes of nonconvex NLP s-II. application of theory and test problems. Comput. Chem. Eng, 14(2), 1419-1434. 

Another TSK combination (precolumn -I- PWM -I 6000 -I 5000 -I- 4000 -I-3000) was tested on differences in separation performance between individual narrow distributed samples and mixtures of several narrow distributed samples. The result is summarized in Eig. 16.31 within experimental error the summed chromatograms (theory) of four narrow distributed glucans (dextran) match perfectly with the experimentally determined chromatogram of the mixture. The (theory/experimental) ratio, plotted for quantification of the match, in-... 

---