Uran in Wässern

The study presents 172 measurements of the uranium²³⁸U and²³⁴U isotopes in ground water and 21 measurements of these substances in the rivers of Eastern Germany. The uranium concentration in the ground water ranged from under 0.1 mBq/l to over 1000 mBg/l with a mean of 12 mBq/l. The respective activity relationships of²³⁴U/²³⁸U ranged from 0.85 to 12.6 with a mean of 1.66. A comparison of these values with those in the literature demonstrates an agreement with more recent measurements obtained from water in Thuringia and Saxony which were seen to have a mean value of 19 mBq/l. The activity relationships of²³⁴U/²³⁸U which were seen to be substantially over the equilibrial value of 1.0 and which were found in a quite high proportion of the samples must be taken into consideration when evaluating these. The measurements of river water demonstrated values for the Elbe river which are related to the periods of extensive uranium mining in Saxony and Thuringia. Measurements performed in the catchment regions going into the Baltic Sea revealed substantially higher values than would be expected from the distribution of uranium in these areas. A number of reasons are discussed here in an attempt to explain these findings.     

High-sensitivity luminescence spectrometry: Progress in archaeological and geological dating

This study was supported by the Bundesministerium für Forschung und Technologie (BMFT), core program Einsatz neuer Technologien in den Geisteswissenschaften.     

Radioluminescence Dating: A New Tool for Quaternary Geology and Archaeology

 Natural minerals, such as widespread quartz and feldspars, have physical properties which enable them to be used as radiation dosimeters. The underlying luminescence phenomena have made it possible in recent decades to determine the age of a variety of materials important for quaternary geochronometry and archaeochronometry. We present a new luminescence dating method based on radioluminescence measurements of potassium feldspar. For the first time we have been able to investigate the light-emitting transition of electrons from the conduction band to an optically sensitive electron trap. Many advantages can be derived from such direct measurements of the metastable electron density in this particular trap, which produces the age-dependent signal. The method can be used to date the last light exposure of feldspar grains within a range of a few hundred to more than 200,000 years. Examples are presented of age determination of various waterlaid quaternary sands. The results of a basic study of feldspar radioluminescence also shed light on effects not sufficiently understood in conventional dating by luminescence techniques, especially in infrared optically stimulated luminescence dating of feldspar. Received: 6 August 1998 / Accepted in revised form: 14 April 1999     

A performance-based tabular approach for joint systematic improvement of risk control and resilience applied to telecommunication grid,gas network,and ultrasound localization system

Environment Systems and Decisions - Organizational and technical approaches have proven successful in increasing the performance and preventing risks at socio-technical systems at all scales....     

Assessing public opinion regarding potential ATV-related policies

Problem

States with laws regarding ATV use and safety have lower mortality and injury rates than states with few or no restrictions. Our objective was to assess the attitudes of registered Ohio voters concerning potential legislation regarding ATV use and safety to determine the feasibility of its enactment.

Method

A statewide telephone survey of 838 registered Ohio voters was conducted and results were weighted by region to accurately represent all Ohio voters.

Results

Registered voters were in favor of restricting the use of ATVs by children < 16 years (81%), prohibiting passengers on ATVs (81%), requiring helmets (78%), and requiring all ATV owners and users to take a safety class (77%). ATV riders indicated that a mandatory helmet law would increase helmet use.

Impact on Industry

Assessing public opinion regarding public health and safety laws is a critical first step when considering legislation to improve ATV safety.