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...

A six-coordinated iron(II) complex, t-Fe(tzpy)2(NCS)2 (tzpy = 3(2-pyridyl)[1,2,3]triazolo[1,5-a]pyridine), undergoes a graduate spin transition from a paramagnetic high spin state (T2, S = 2, HS-1) above 200K to a diamagnetic low spin state (A1, S = 0, LS-1) below 75 K according to the magnetic measurement. The crystal structures of both HS-1 and LS-1 are studied at 298 and 40K respectively. Si...

background: the concentrations of radionuclides like 226ra, 232th and 40k and the dose rate are measured in igneous and metamorphic rock formations in and around chickmagalur. a total of 236 samples from 13 different locations around study area were analyzed. materials and methods: the activity concentrations of the three radioactive elements were determined for mean period of 25000 s using hpg...

background: the sources of radioactivity in the environment have natural, terrestrial and extraterrestrial, and anthropogenic origins. plants may get radioactive nuclides in two ways: (i) by the deposition of radioactive fallout, (ii) by absorption from the soil. materials and methods: the concentrations of the natural radionuclides (226ra, 228ra, 40k) and the artificial radionuclide (137cs) in...

We have developed specially designed semiconductor devices for the measurement of thermal conductance in suspended nanostructures. By means of a novel subtractive comparison, we are able to deduce the phonon thermal conductance of individual nanoscale beams of different geometry and dopant profiles. The separate roles of important phonon scattering mechanisms are analyzed and a quantitative est...

We study the widths of interspecies Feshbach resonances in a mixture of the fermionic quantum gases 6Li and 40K. We develop a model to calculate the width and position of all available Feshbach resonances for a system. Using the model, we select the optimal resonance to study the {6}Li/{40}K mixture. Experimentally, we obtain the asymmetric Fano line shape of the interspecies elastic cross sect...

background: many radioactive compounds may be released into the environment and hence into the drinking water supplies due to the human activities. radionuclides can also enter the food chain if the contaminated water is used for drinking or irrigation purposes. objective: to estimate the annual effective dose of natural radioactive materials like 226ra and 40k in drinking water of wells in zan...

natural background radiation is the main source of human exposure to radioactive material. soils naturally have radioactive mineral contents. the aim of this study is to determine natural ((238) u, (232) th, (40) k) and artificial ((137) cs) radioactivity levels in wheat and corn fields of eilam province.hpge detector was used to measure the concentration activity of (238) u and (232) th series...

The fundamental goal of this study is to measure the level radioactivity in soil area around Al-Hadbaa cement plant, also evaluate radiological hazard radionuclide, gamma-spectroscopy with an HPGe detector crystal diameter 70.6 mm and length 70 has been used estimate specific activity natural radionuclides 226Ra, 232Th, 40K, artificial 137Cs fifteen samples collected. results show that average ...