At late phases the powering of supernova light curves is often provided by the decay of radioactive elements synthesized in the explosions. This is unambiguously revealed when the light curve decline follows the half life time of the decaying elements, and the bolometric luminosity then directly provides the mass of ejected radioactive material. I will focus on the best observed element, Ni, an...

This research aims to monitor the trace elements content (Cr, Cu, Pb, Cd, Ag, Al, Mn, Mg, Zn and Fe) in the tissues of the muscle and liver of silver carp (H. molitrix ) and stone moroko (P. parva) from Zarivar Wetland in western Iran. This research was cross-sectional. The research specimen was fish caught from Zarivar Wetland. Metal concentration analysis was carried out utilizing an ICP. Fin...

Very soon after the discovery of radioactivity, measurements of the heavy radioactive elements existing in nature were undertaken to determine the age of rocks (Rutherford 1904), but only when Professor Willard Libby in an evening lecture during the first United Nations Conference on the Peaceful Uses of Atomic Energy in Geneva in 1955 described how he and his research team had evolved the carb...

The distribution of radioactivity in fish bodies had been made clearly by our observations on•gShunkotsu Maru•h. It was also observed that the radioactivity in one organ of a fish was quite different from that of another.. However, the radioactive elements contained in fish bodies were left un-identified. The present work was undertaken to meet the urgent necessity of identification of the radi...

In this article I review the main methods for determining the age of the Universe. I describe how to determine the age of the oldest known systems at z = 0, the system of galactic globular clusters, using different techniques. I also describe how to date the Universe using the decay of radioactive elements (Cosmochronology). Finally, I focus on how to determine the age of the Universe at differ...