The Role of Radioactivities in Astrophysics

I present both a history of radioactivity in astrophysics and an introduction to the major applications of radioactive abundances to astronomy

A Software Architecture for Collaborative Training in Virtual Worlds: F-16 Airplane Engine Maintenance

Abstract. The maintenance of military aircraft is complex and exhaus-tive, requiring an accurate training program. This process is not fault tolerant and requires certification renewal periodically. Furthermore, the process involves many professionals and resources, requiring phases of maintenance and verification of the tasks. Cooperation between profes-sionals in the overall process is essential and requires strong team co-ordination. It is a highly costly process, since aircrafts are scarce and their readiness is essential for missions, and it requires a scheduling ef-fort between all team members and aircrafts. The availability of tools that allow intensive training without aircraft presence is an asset to the maintenance squadrons. Virtual worlds have simulation and collabora-tion capabilities to implement this process. This paper presents a soft-ware architecture developed for training engine maintenance squadrons for certification, using virtual worlds platforms. This architecture is be-ing tested in cooperation with the Portuguese Air Force and an engine maintenance squadron of F-16 aircrafts

The Cambrian System in the Arrowie Basin, Flinders Ranges, South Australia

The lower to ?middle Cambrian rocks (Terreneuvian, Series 2 and possibly Miaolingian) of the Arrowie Basin are exposed superbly in the Flinders Ranges of South Australia. They comprise two major sedimentary packages: a lower carbonate-rich succession (Hawker Group and correlates) and an upper siliciclastic-dominated succession (Billy Creek Formation, Wirrealpa Limestone and Lake Frome Group). These rocks form one of the most complete lower Cambrian (Terreneuvian and Series 2) successions globally. They contain one of the most diverse known early Cambrian biotas in the world, with trilobites, archaeocyaths, bradoriides, brachiopods, some of the earliest known coralomorphs, small shelly fossils, molluscs, hyoliths, acritarchs and trace fossils. Series divisions, based on ranges of shelly fossils and archaeocyath biostratigraphy are currently being established. Ancient reef structures are prominent in several areas. Syndepositional faulting and diapiric activity affected sedimentation in places. The global significance of the region is enhanced by the presence of tuff horizons at some levels, which provide the opportunity to link the biostratigraphic zones with radiometric dates and carbon isotope curves.J. B. Jago, J. G. Gehling, M. J. Betts, G. A. Brock, C. R. Dalgarno, D. C. García-Bellido, P. G. Haslett, S. M. Jacquet, P. D. Kruse, N. R. Langsford, T. J. Mount, J. R. Paterso