Use of HPGe gamma-ray spectrometry to assess the isotopic compositiion of uranium in soils

Gamma-ray spectrometry was used to determine uranium activity and investigate the presence of depleted uranium in soil samples collected from camping sites of the Greek expeditionary force in Kosovo. Assessment of 238U concentrations was based on measurements of the 63.3 keV and 92.38 keV emissions of its first daughter nuclide, 234Th. To determine the isotopic ratio of 238U/235U, secular equilibrium along the two radioactive series was first ensured and thereby the contribution of 235U under the 186 keV peak was deduced. The uranium activity in the samples varied from 48 to 112 Bq kg(-1), whereas the activity ratio of 238U/235U averaged 23.1+/-4.3.     

ICAROS: An Integrated Computational Environment for the Assimilation of Environmental Data and Models for Urban and Regional Air Quality

Integrated environmental management in urban areas is nowadaysconsidered a sine qua non objective of Community and nationalenvironmental and development policies. A large amount ofscientific information on the state of the environment is nowavailable from a large pool of data sources. This work presentsan innovative method for integration of these data sources andeffective coupling of environmental information with appropriatemodels and decision-support tools. State-of-the-art Earthobservation techniques, ground-based air quality measurements,atmospheric transport and chemical modelling, and multi-criteriadecision-aid systems are used in an integrated information fusionenvironment in support of environmental and health impactassessment and decision-making at the urban and regional scales. Results of the pilot application of the method in the area ofLombardy in Northern Italy demonstrate the validity andusefulness of this novel approach.     

Numerical Study of the Indoor Environmental Conditions of a Large Athletic Hall Using the CFD Code PHOENICS

This study investigates, experimentally and numerically, the environmental conditions prevailing in a large mechanically ventilated athletic hall, with the aid of the computational fluid dynamics code PHOENICS. The indoor space of the building was simulated in the PHOENICS environment and the model results were validated against experimental data collected during a 10-day campaign in the hall. The measurements included airflow characteristics and pollutants concentrations at different locations of the indoor space, as well as surface temperatures of the indoor materials. Having obtained good agreement between experimental and numerical results, different scenarios were applied in the model to investigate the environmental conditions prevailing in the hall under different ventilation and occupational conditions. These regard air-conditioning, heating, and cooling modes, as well as empty and full hall during an athletic event. The airflow, temperature, and CO₂ concentration fields were studied and results revealed dynamic behavior of the fields, significantly altering with the different considered cases. The airflow patterns were characterized by distinct vortices of various sizes, originating from the ceiling air inlet fans of the heating–ventilating–air conditioning system, while temperature and pollution stratification were evident, indicating ineffective performance of the ventilation system.