EXPERIMENTAL TECHNIQUE TO MEASURE THORON GENERATION RATE OF BUILDING MATERIAL SAMPLES USING RAD7 DETECTOR

Thoron (220Rn) is the second most abundant radon isotope in our living environment. In some dwellings it is present in significant amount which calls for its identification and remediation. Indoor thoron originates mainly from building materials. In this work we have developed and tested an experimental technique to measure thoron generation rate in building material samples using RAD7 radon-thoron detector. The mathematical model of the measurement technique provides the thoron concentration response of RAD7 as a function of the sample thickness. For experimental validation of the technique an adobe building material sample was selected for measuring the thoron concentration at nineteen different sample thicknesses. Fitting the parameters of the model to the measurement results, both the generation rate and the diffusion length of thoron was estimated. We have also determined the optimal sample thickness for estimating the thoron generation rate from a single measurement

A model of planning and operation of the national quality systems

The study gives an overall picture about the basis of the statistical process improvements taking into account the Hungarian features. After a theoretical introduction about the variations in the processes the different generations of the quality control are shown. Then the topic of controlled and capable processes is discussed and finally the suggested way in Hungary is explained. The study uses several cases from the Hungarian industrial sector in order to visualize the theoretical statements

Comparative study of X-ray computed tomography and conventional X-ray methods in the diagnosis of swimbladder infection of eel caused by Anguillicola crassus

To date, swimbladder lesions due to Anguillicola crassus infection of the European eel Anguilla anguilla have so far been studied only by conventional X-ray methods. This is the first study to report the use of computerised tomography (CT) for studying lesions induced by anguillicolosis. Of 50 eels caught by electrofishery from Lake Balaton, Hungary, in autumn 2002 and pre-selected by a conventional X-ray method, 22 specimens were examined with a Siemens Somatom Plus S40 spiral CT scanner. Tomograms, radiographs and photographs of 5 of these, showing anguillicolosis-induced swimbladder lesions of varying severity, are presented. Computerised tomograms provide information on the inner structure, air content and wall thickness of the swimbladder as well as on the number of worms it contains. When the swimbladder is not severely affected or not completely filled with worms, computerised tomography provides adequate data on the shape of the swimbladder, thickness of the swimbladder wall and the location of worms in the lumen. However, in more severe cases, i.e. when the swimbladder is tightly packed with worms or contains no air as a result of wallthickening, this method fails to determine the number and location of helminths or the thickness of the swimbladder wall

Shortcomings of the Energy Evaluation Systems in Pigs: a Review

The aim of that review is to present the principles of energy evaluation systems used in pig feeding and to stress out some key consideration when introducing Net Energy (NE) systems and some areas of future research. Based on the relevant literature data it can be stated that despite the mentioned shortcomings of the currently used energy systems, we have to admit that NE and/or Potential Physiological Energy (PPE) are the least inaccurate feed evaluation, therefore they are recommended to use in practical pig production. There is not enough evidence to favor any of these systems. According to our opinion some kind of harmonization would be beneficial, since the European feed market would need a common understanding of energy (feeding) value of compound feeds and feedstuffs. However, according to our view it could be achieved only by the lobby and cooperative action of the European feed manufacturers

Evaluation of polynomials over finite rings via additive combinatorics

We give an improved polynomial bound on the complexity of the equation solvability problem, or more generally, of finding the value sets of polynomials over finite nilpotent rings. Our proof depends on a result in additive combinatorics, which may be of independent interest