Radon Potential, Geologic Formations, and Lung Cancer Risk

OBJECTIVE: Exposure to radon is associated with approximately 10% of U.S. lung cancer cases. Geologic rock units have varying concentrations of uranium, producing fluctuating amounts of radon. This exploratory study examined the spatial and statistical associations between radon values and geological formations to illustrate potential population-level lung cancer risk from radon exposure. METHOD: This was a secondary data analysis of observed radon values collected in 1987 from homes (N = 309) in Kentucky and geologic rock formation data from the Kentucky Geological Survey. Radon value locations were plotted on digital geologic maps using ArcGIS and linked to specific geologic map units. Each map unit represented a package of different types of rock (e.g., limestone and/or shale). Log-transformed radon values and geologic formation categories were compared using one-way analysis of variance. RESULTS: Observed radon levels varied significantly by geologic formation category. Of the 14 geologic formation categories in north central Kentucky, four were associated with median radon levels, ranging from 8.10 to 2.75 pCi/L. CONCLUSION: Radon potential maps that account for geologic factors and observed radon values may be superior to using observed radon values only. Knowing radon-prone areas could help target population-based lung cancer prevention interventions given the inequities that exist related to radon

Solar flares with and without SOHO/LASCO coronal mass ejections and type II shocks

We analyse of a set of radio rich (accompanied by type IV or II bursts) solar flares and their association with SOHO/LASCO Coronal Mass Ejections in the period 1998 2000. The intensity, impulsiveness and energetics of these events are investigated. We find that, on the average, flares associated both with type IIs and CMEs are more impulsive and more energetic than flares associated with type IIs only (without CME reported), as well as flares accompanied by type IV continua but not type II shocks. From the last two classes, flares with type II bursts (without CMEs reported) are the shortest in duration and the most impulsive.Comment: Advances in Space Research, Volume 38, Issue 5, p. 1007-101

Photochemically Etched Construction Technology Developed for Digital Xenon Feed Systems

Electric propulsion systems are quickly emerging as attractive options for primary propulsion in low Earth orbit, in geosynchronous orbit, and on interplanetary spacecraft. The driving force behind the acceptance of these systems is the substantial reduction in the propellant mass that can be realized. Unfortunately, system designers are often forced to utilize components designed for chemical propellants in their electric systems. Although functionally acceptable, these relatively large, heavy components are designed for the higher pressures and mass flow rates required by chemical systems. To fully realize the benefits of electric propulsion, researchers must develop components that are optimized for the low flow rates, critical leakage needs, low pressures, and limited budgets of these emerging systems

The Falerii Novi Project

The Falerii Novi Project represents a newly formed archaeological initiative to explore the Roman city of Falerii Novi. The project forms a collaboration of the British School at Rome with a multinational team of partner institutions. Thanks to a rich legacy of geophysical work on both the site and its territory, Falerii Novi presents an exceptional opportunity to advance understanding of urbanism in ancient and medieval Italy. The Falerii Novi Project employs a range of methodologies, integrating continued site-scale survey with new campaigns of stratigraphic excavation, archival research and environmental archaeology. The project aims to present a more expansive and holistic urban history of this key Tiber Valley settlement by focusing on long-run socio-economic processes both within Falerii Novi and as they linked the city to its wider landscape