Invisible radioactivity

Sampling for Airborne Radioactivity

This report examines how to sample airborne radioactivity with minimal complexity and time expenditure, using conventional high-volume samplers in combination with alpha-particle spectrometry. The use of alpha spectrometry provides compensation for radon/thoron decay products collected on the filter paper of the sampler, leading to a seven-fold improvement in measurement sensitivity of artifici...

An Introduction to Radioactivity

Radioactivity in human tissues

The radioactivity in human tissues (lungs) obtained from the dead body of people who died by lung cancer in the region of Ptolemais, Northern Greece, where 16 units of 4 major coal-fired power plants are in operation, was studied. The specific activities of radioactive nuclides searched for in human tissues were not remarkable. The syndrome of lung cancer deaths at that area which showed an inc...

Invisible Obstacles * †

It is proved that one can choose a control function on an arbitrarilly small open subset of the boundary of an obstacle so that the total radiation from this obstacle for a fixed direction of the incident plane wave and for a fixed wave number will be as small as one wishes. The obstacle is called “invisible” in this case.

Invisible Computing

The computer is no longer a tool solely used for enhancing the productivity of organizational tasks. Rather, computing capability now is embedded into our everyday artifacts, enabling our daily activities to become smarter and easier. As a result, the way we interact with computers has radically changed in the past few years: computing is now being designed for activity-oriented users. Thus, as...