RESUMO
The technical and scientific basis for the measurement of indoor 222Rn concentration using an E-PERM (Electret passive environmental radon monitor) has been described in our earlier work. The purpose of this paper is to describe further development of a practical and convenient system that can be used routinely for indoor 222Rn measurement. The ion chamber is now made of electrically conducting plastic to minimize the response from natural gamma radiation. A spring-loaded shutter method is used to cover and uncover the electret from outside the chamber. The electret voltage reader has been modified to improve the accuracy and the ease in operation. The calibration, performance, error analysis, and lower limits of detection for these standardized versions of E-PERMs are also described.
Assuntos
Poluentes Radioativos do Ar/análise , Poluentes Atmosféricos/análise , Habitação , Monitoramento de Radiação/instrumentação , Radônio/análiseRESUMO
Conflict between school systems and their communities is part of American history. Much of the conflict is symbolic, the school being the stage for the acting out of deeper clashes. Several hundred teachers in the north Florida area were polled in 1977 and 1978 to identify areas of conflict between schools and community. The issue which evoked the greatest dissension was the question of responsibility for the children of the new American underclass. Data were tabulated and analyzed in the light of historical patterns developed by the author, and the conclusion drawn that school-community conflict will persist with regard to the teaching of underclass children because the public has no clear perception about who is responsible.