Calculation of precision in isotope dilution experiments.
Abstract Equations are derived for the composite error of isotope dilution measurements in three types of experiment viz. simple dilution, saturation analysis (sub-stoichiometric dilution) and adsorbed ion measurement; the latter two yielding equations of the same form. Errors for each type are derived in terms of radiometric errors, chemical errors and a factor related to the extent of isotope dilution. In general, dilution is the most critical factor which controls error; chemical errors are usually less important than radiometric errors. A nomogram for calculating dilution errors is given.
The accuracy of isotope dilution methods.
BS>The accuracy of quantitative analyses by various isotope dilution methods is discussed. The most favorable amounts of dilution are derived under the assumption that the relative error, delta S/S, in measuring a specific activity, S, is independent of S. (auth)
An Internet-based Real-time Heavy Rainfall Display System
A new storm warning system, which can be accessed through the Internet and by cellular phones is described. At the time of a heavy rainfall for disaster prevention, it is important that every resident understand how heavy is that rainfall. A real-time heavy rainfall display system designed for all of Japan provides such information (http://www.disaster-i.net/rain/). In that system values for 1-hour precipitation, 24-hour accumulated precipitation, etc. are displayed at every observatory. Advantages are that not only the latest observations but differences from the historical highest records can be seen. Almost all information is displayed by characters so that users have easy access to the system even when the communication network is crowded. Access date for the six months after the system opened shows that the average daily number of accesses of the top page was 306, and the largest number 3078. The maximum number for daily access to all the pages was about 21,500. This is about 2% of the number obtained on the same day for a similar system operated by the Ministry of Land, Infrastructure and Transport (http://www.river.go.jp/).