Interpretation of the response of continuous radon monitors to transient radon concentrations.
Continuous monitoring of radon concentrations can yield substantially more information than grab sampling in situations where concentrations vary significantly with time. Although several continuous monitors have been designed, calibration is usually difficult and not completely rigorous. In this work a simple and rigorous method is developed for the calibration and operation of all types of continuous flow-through instruments. Theoretical and experimental verification of the method is provided.
An automatic counter for direct measurements of radon concentration
Abstract Essentially the counter consists of a brass chamber, into which the air to be examined flows continuously at 4 1/min. Within the chamber there is a ZnS(Ag) scintillator, optically coupled with a photomultiplier. The scintillator is coated with a thin film of gold to render it conductive and, between the chamber and the scintillator, a potential of 1000 V is applied. The positive RaA ions are thus electrostatically collected on the scintillator, where their subsequent alpha decays and those of RaC' produce scintillations. The construction and the calibration of the counter is described. The calibration is achieved by admitting into the chamber known amounts of radon grown from a radium chloride solution. Finally, the methods of sampling and measurement for the evaluation of radon atmospheric concentrations are described.
Die Populationsdynamik Von Canthocampt Us Staphylinus (Jurine) (Copepoda, Harpacticoida) Im Litoral Des Bodensees
The population dynamics of Canthocamptus staphylinus in the littoral zone of Lake Constance are described (fig. 2). Adult animals aestivate as cysts. The main part of the population emerges from the cysts in autumn. During the resting stage and the first spell after emerging, mortality is very low (fig. 3). Reproduction, expressed as numbers of ovigerous females, begins in November and reaches its maximum in January. The new generation becomes adult in May/June and encysts without previous reproduction. According to Sarvala (1979) it may be possible, that in littoral populations dormancy is induced by long day periods and temperatures of over 12° C (figs. 1, 2). In the profundal zone C. staphylinus also forms cysts, however, both light and temperature are not likely to induce this stage in depths of over 60 m.