Determining emissivity of thermoelectrode and other materials

Measurement Techniques -     

Standard reference materials for thorium analysis

Reference materials (RMs) are used in analytical measurements for several purposes--to develop and validate analytical measurements, as quality control indicators and for calibration. It is therefore essential that suitable reference materials are available. Because thorium is usually found in very acid-resistant, mineral phases, this becomes even more critical when techniques such as ICP-MS are used, which require complete sample digestion. This paper gives an overview of the reference materials that are currently available for thorium (232Th and other thorium isotopes) in various matrices, sources and indicative costs. The IAEA database is identified as a particularly useful source of information, and the website address is: http://www.iaea.org/programmes/nahunet/e4/nmrm/index.htm A brief summary of the discussion held at the '1st European Workshop on the Analysis of Thorium in Workplace Materials', regarding reference materials, is given at the end of the paper. A general need for new RMs, specifically for workplace materials, was identified as a priority.     

Standard samples and metrological traceability in chemistry

Conceptual and practical problems of ensuring metrological traceability of substance and material composition measurements based on standard samples are examined.     

Standard samples in the quality system for measurements in analytical chemistry

Problems of providing measurement quality in analytical chemistry using reference materials attested under primary methods are considered in this paper. We describe a scheme of establishing the traceability of measurement results in a substance’s chemical composition to SI units, exemplifying it by standard samples attested at FGUP URIM under a primary method—coulonometric titration technique.     

Standard arrangement for the complex measurement of acoustic parameters of materials

Translated from Izmeritel'naya Tekhnika, No. 7, pp. 50–52, July, 1989.     

用环形试样测定软磁材料磁各向异性的研究

采用趋近饱和定律测定了纳米晶合金环形试样有效磁各向异性常数＜K＞.为了对比测量的准确度,同时测试了传统的晶态坡莫合金环形试样的磁晶各向异性.结果表明,用环形试样可以完成对低矫顽力的软磁材料进行磁各向异性的测定.     

Decision theory classification of high-dimensional vectors based on small samples

In this paper, an entirely new procedure for the classification of high-dimensional vectors on the basis of a few training samples is described. The proposed method is based on the Bayesian paradigm and provides posterior probabilities that a new vector belongs to each of the classes, therefore it adapts naturally to any number of classes. The classification technique is based on a small vector which can be viewed as a regression of the new observation onto the space spanned by the training samples, which is similar to Support Vector Machine classification paradigm. This is achieved by employing matrix-variate distributions in classification, which is an entirely new idea.