Compounds labelled with short-lived beta(+)-emitting radionuclides and some applications in life sciences. The importance of time as a parameter.

Some examples of recent development of the synthesis of compounds labelled with short-lived beta(+)-emitting radionuclides will be discussed with an emphasis on the importance of time in selecting a synthetic strategy. Furthermore the use of such labelled compounds to monitor certain processes in areas within the field of analytical chemistry and in various applications in drug development will be presented.     

Fraunhofer selective diffraction produced by structure elements in sodium vapour

Observations are reported of selective diffraction produced by structure elements in sodium vapour separated from intermediary empty spaces by thin sheets of iron. The phenomena observed can be explained by the phase shifts in sodium vapour due to anomalous dispersion.     

Hydrogen absorption and desorption properties of a novel ScNiAl alloy

A new hydrogen absorbing material has been discovered, ScNiAl, which can store 1.5 wt.% hydrogen reversibly. In this compound, hydrogen absorption is a two-step process; solid solution of hydrogen at temperatures below 180°C and decomposition into ScH₂ and NiAl at higher temperatures. Detailed analysis of the hydrogen absorption/desorption has been performed using in situ synchrotron radiation powder X-ray diffraction and thermal desorption spectroscopy. The apparent activation energy for hydrogen desorption was determined to be 182 kJ/mol and the material is stable during cycling.