Observations of metal-poor Galactic halo stars indicate that the abundance pattern of the (heaviest) neutron-capture elements is consistent with the scaled solar system r-process abundances. Utilizing the radioactive (r-process) element thorium, age determinations have been made for several of these same stars, placing constraints on both Galactic and cosmological age estimates.

The density dependent flow and transport problem in groundwater is solved numerically by means of the mixed finite element scheme for the flow equation and an innovative time-splitting technique for the transport equation. The proposed approach, of global second order convergence, is used for the simulation of the movement of radioactive brines at the Lake Karachai (Russia).

The announcement of the discovery of element 95 was made in 1946 by Seaborg and his associates (1). Like neptunium (element 93), plutonium (element 94), and curium (element 96) this new element, americium, is radioactive and has not been observed in nature in appreciable amounts. During the war an extensive study was made of the metabolic properties of plutonium (2) and several other heavy elem...

Introduction: Various iodine isotopes are undergoing radioactive decay except Iodine-127 (I-127. Iodine I-131 is unsealed radioactive material used in nuclear medicine for both diagnostic and therapeutic procedures in Royal Hospital since 2006. In radiotoxic classification, I-131 is in group 2 element. I-131 is highly reactive element due to its volatilization nature. Currently...

Abstract Due to their rarity and radioactive nature, comparatively little is known about the actinides, particularly those with atomic numbers higher than that of plutonium, compounds. In this work, we describe how transmission electron microscopy can provide comprehensive, safe, cost-effective characterization using only single nanogram amounts highly-radioactive, solid Chlorides rare elements...

Abundance ratios of radioactive to stable neutron-capture elements in very metal-poor stars may be used to estimate the age of our Galaxy. But extracting accurate ages from these data requires continuing work on many fronts: a) identification of more low metallicity stars with neutron-capture element excesses; b) acquisition of the best high resolution stellar spectra; c) improvement in neutron...

The long-lived radioactive element thorium can potentially provide a simple and direct clock to determine the age of our Galaxy. Spectroscopic investigations of thorium in metal-poor stars have yielded some promising initial results. We discuss the major observational and theoretical limitations in thorium cosmochronometry, and point out the ways in which the implied Galactic ages from thorium ...

the present nuclear leakage crisis from japan is a topic to be discussed in present public health. in radiology, the leaked radioactive elements are considered hazard. here, the author briefly reviews and discusses on two important radio-hazard elements in post nuclear power plant crisis, radioactive iodine and radioactive cesium. based on previous similar nuclear crisis in russia, it is eviden...

This paper aims at describing numerical methods developed within the Melodie code to perform 3D saturated flow and transport calculations in the framework of radioactive waste geological repository. The diffusive type terms are discretised by a standard finite-element method and the convective term is treated with a Godunov-type finite-volume approach. The simulation domain is meshed using a st...