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Abstract  

Continuous measurements of concentrations of radon and radon decay products, and equilibrium factor were carried out in the indoor air of 12 schools at the beginning of 2000. Average values of the parameters measured, obtained during working time only and during the whole period, were compared and applied to calculate exposure of a person breathing in this air. Results of short-term continuous measurements are proposed to be used to correct the exposure, generally based on the radon concentration obtained by etched track detectors, and the justification of applying this procedure is discussed.

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The problem of the actual rock mass temperature poses considerable difficulties in practical mining engineering. So far, measurements have been made with the use of thermistor thermometers. These do not provide infallible data on temperature, particular as concerns a certain distance from a rib into the rock mass, and they do not allow continuous data logging. Accordingly, a device has been designed and made for measuring the rock mass temperature, together with a thermal probe.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: Tadeusz Przylibski, Jakub Bartak, Elżbieta Kochowska, Lidia Fijałkowska-Lichwa, Krzysztof Kozak, and Jadwiga Mazur

Abstract  

The article presents new Polish probes SRDN-3, developed at the Institute of Nuclear Chemistry and Technology in Warsaw, equipped with a semi-conductor detector used for continuous measurements of 222Rn activity concentration. Due to a relatively high lower detection limit, the device is dedicated for use in underground spaces—caves, adits, mines, tourist routes in strongholds, pyramids, etc. Its structure allows for difficult conditions in which the device is transported to the measurement site, as well as hard operating conditions caused chiefly by large ambient relative humidity, reaching up to 100%. The authors present calibration results of these appliances, as well as the results of their work in a cave and an adit in the Sudetes (SW Poland). After almost 2 years of working in difficult conditions, the probes displayed high reliability. No defects of the semi-conductor detectors or the electronics were observed, which ensured problem-free communication of the probe-programmer-PC set. Thanks to this, the authors have a 2 year stock of data, recorded hourly by five probes, at their disposal. The only element that did not withstand the test of extreme operating conditions was one of the combined relative humidity and temperature sensors. No powering problems were observed either, and the batteries were replaced once a year, before the winter season. Also the programmer functioned faultlessly, enabling data transmission to a PC, which, being much more sensitive to operating conditions, had been placed away from the site of probe exposure. After using more sensitive temperature, relative humidity and pressure sensors, SRDN-3 probes will certainly prove an excellent tool for microclimate measurements (including measurement of air-atmosphere exchange) in caves and other underground sites. Even nowadays they are already a satisfactory tool for monitoring 222Rn concentration in underground spaces.

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Soil texture is an important input parameter for many soil hydraulic pedotransfer functions (PTFs) of the day. Common soil particle-size classes are required to be able to uniformly determine the texture of soils. However, it is not always possible - due to different national classification systems - and much valuable information is disregarded while either deriving or applying PTFs. One way to get common particle-size class information is to interpolate the particle-size distribution (PSD) curve. Advanced interpolation solutions are becoming available, but there is always uncertainty associated with these techniques. Another possibility is to measure all PSD curves in such a way that it is compatible to the commonly used classification systems. A new automated measurement technique is introduced that can easily provide PSD data compatible to any (and all) of the existing national and international classification systems at the same time, without the burden of extra labour. A computerized measurement system has been developed to record density changes in a settling-tube system in any discretional (small) time steps, which in turn allows the derivation of a quasi-continuous PSD curve. The measurement is based on areometry (Stokes-law), thus the system is compatible to the most commonly applied settling-tube measurements. The new evaluation method of measured values takes into consideration the density changes along the areometer-body so it avoids the problem of reference point determination. The theory and setup of the system are explained and measurement examples are given. The presented comparative measurements show good correspondence with conventional settling-tube results, and the reproducibility of the measurement shows to be very high. This technique does not require more sample preparation than past methods. The automated reading requires less manpower to perform the measurement - which also reduces human error sources. However, it provides very detailed PSD data that has advantages, like revealing multi-modality in the particle-size distribution or providing data that complies with any of the classification systems.

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Abstract  

A six month survey of radon, radon progeny and condensation nuclei (CN) has been conducted in an Australian tourist cave. The measurements have been made continuously at two sites within the cave: one a small chamber with a high air exchange rate close to one entrance and connected to several other entrances by complex passages; the other a large chamber with a low air exchange rate 1 km from the nearest entrance. The measurements form a basis for evaluation of the accuracy with which dose due to radon can be determined for different monitoring strategies. It is shown that the estimate of dose based on the measurement of radon concentration and recommendations in ICPR-65, is low by a factor of 1.3 at the well ventilated site and 1.5 at the site with a low air exchange rate and low CN. At each site the weekly average equilibrium factor and unattached fraction were steady, leading to the possibility of establishing a cave system average of these factors. However, given the technical diffuculties involved, it may not be practicable to make enough unattached fraction measurements to fully represent the cave system. Therefore it may be necessary to use a conservative approach to the dosimetry and add 50% to values determined by the ICRP-65 conversion convention.

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the Department of Meteorology and Water Management of the University of Pannonia Georgikon Faculty (Keszthely). This data set is special because few stations in Hungary have continuous measurements over more than 140 years with detailed historical

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Abstract  

The determination of uranium in solutions and sorbents by measurement of absorption of soft gamma-rays is described. The use of 22 keV gamma-rays of109Cd enbled us to improve the sensitivity of the determination for nearly an order of magnitude when compared to the measurements using241Am source. The application to the continuous measurement of uranium concentration in pilot-plant streams and of concentration profiles of uranium sorbed on columns of ion exchangers is described.

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Summary  

Meteorological and radon concentration data referring to a measurement campaign carried out in Urbino, Central Italy, are reported and discussed. This study presents a method allowing monitoring of the vertical atmospheric stability using continuous measurements of radon gas near ground. In particular radon evidences the presence of temperature inversion such as the formation of the nocturnal stable layer and gives information on the vertical turbulence and the motion of air masses. This technique is very useful in describing the temporal evolution of the pollutants in the atmosphere.

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Abstract  

Since October 1983, the Niigata Prefectural Government has been carrying out the continuous measurements of gamma-emitting radionuclides in the environment around the Kashiwazaki Kariwa nuclear power station by environmental radiation monitoring telemetry system. Continuous measurements of gamma-ray spectra have been established since April 1996. As a result, the contribution of various radionuclides has been gradually clarified in the variations of the gamma-ray dose rate. In this paper, the energy spectrum of the incident gamma-ray to NaI(Tl) scintillation detector was obtained by the unfolding method using a response matrix, and the variations of the energy spectrum observed in the precipitation and snow were investigated. The increase in the dose rate in precipitation originated from the increase in the flux density of gamma-ray from 214Bi and 214Pb, daughter nuclide of 222Rn, which fell down with the precipitation. On the other hand, the reduction in the dose rate in the snowy period was confirmed due to the shielding effect of a part of gamma-rays from the natural radioactive nuclides by the snow layer, in coincidence with the decrease of the flux density in 40K and 208Tl.

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In Hungary there are borehole tiltmeters used for monitoring tectonic movements and landslides. These investigations need long time continuous measurements. The Model 722A tiltmeters of Applied Geomechanics Inc. are fastened to the ground by tamped sand in the borehole.  In some cases the boreholes become untight  and it was thought that in this case the ground water seeping into the borehole could loosen the tamped sand causing a bad coupling between the tiltmeter and the ground. It was proved by laboratory test that the ground water and the variation of its level does not change the coupling of the instrument to the ground. In this paper the description of the test made at the Geodetic and Geophysical Research Institute of the Hungarian Academy of Sciences and the results of the measurements are given.

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