The natural radioactivities of five characteristic igneous rocks of the eastern foreland of the Opava Mountains (Eastern Sudetes, Poland), obtained in the laboratory and under in situ conditions, are presented. The activity concentrations of 232Th, 238U, and 40K were measured using an HPGe gamma-ray spectrometry system. The ranges of the activity concentrations of 232Th were 7-71 Bq kg-1 in the...

Changing precipitation patterns are projected to reduce snowpack storage and late summer stream flows in mountain headwaters of the western United States. Ecosystems, agriculture, municipalities depend on flow streams supplying water front. Therefore, improved understanding groundwater contributions is increasingly important. In this work, we use 87Sr/86Sr ratios 234U/238U activity ([234U/238U]...

Eddies play a critical role in regulating the biological pump by pumping new nutrients to the euphotic zone. However, the effects of cyclonic eddies on particle export are not well understood. Here, biogenic silica (BSi) and particulate organic carbon (POC) exports were examined inside and outside a decaying cyclonic eddy using 234Th-238U disequilibria in the tropical South China Sea. For the e...

Radiometric investigation in a rainforest of the Golfo Dulce region of southern Costa Rica has shown the presence of the anthropogenic radionuclides caesium-137, strontium-90 and the plutonium isotopes 238, 239 and 240 along with the naturally occurring radionuclides 7Be, 40K, 238U and 232Th, and respective progenies. 137Cs, 90Sr and Pu can be attributed to global fallout; no other sources coul...

The ratio 3He/4He (R) plays a central role in models of mantle evolution that propose an undegassed lower mantle, rich in the primordial isotope 3He. A large primordial volatile-rich reservoir, a feature of recent models, is inconsistent with high-temperature accretion and with estimates of crustal and bulk Earth chemistry. High R can alternatively reflect high integrated 3He/(U+Th) ratios or l...

background: natural radioactivity, though natural requires concentration monitoring, especially for the health/ environmental checks of the populace. materials and methods: the activity concentrations of 40k, 238u and 232th in the waters from wells with depths ranging between 141.0 - 214.0 feet were randomly sampled and determined from 20 locations in ago-iwoye town in south western, nigeria. r...

background: the presence of radionuclides in the soil, measures need to be taken to minimize the radiation dose to humans. it is mostly gamma-emitting radionuclides that contribute to the radiation dose in long term behavior of these radionuclides in soil may determine the extent to which such countermeasures need to be applied. materials and methods: the activity concentration of these radionu...

The study of the isotopic fractionation of endogen elements and toxic heavy metals in living organisms for biomedical applications, and for metabolic and toxicological studies, is a cutting-edge research topic. This paper shows that human neuroblastoma cells incorporated small amounts of uranium (U) after exposure to 10 µM natural U, with preferential uptake of the 235U isotope with regard to 2...