210Pb in forage consumed by dairy cows.

The aim of this research was to determine (210)Pb concentrations in forage from farms located in the municipalities of Pedra and Venturosa, in the Brazilian state of Pernambuco, where rolled blocks of mafic rock with a high percentage of U(3)O(8) were found. The concentrations of (210)Pb varied from 2 to 503 Bq kg(-1) in the forage dry matter samples evaluated. Due to the elevated levels of (210)Pb in the forage samples, it is concluded that this radionuclide is highly available to be ingested by dairy cows and this could represent a hazard to the human population due to possible milk contamination.

Pb-210 in rock and soils of the semi-arid agreste region of Pernambuco, Brazil.

The aim of this research was to determine (210)Pb concentrations in rocks and soils of farms located in the municipalities of Pedra and Venturosa. In these farms, rolled blocks of mafic rock with a high percentage of U(3)O(8) were found. The concentrations of (210)Pb varied from 3.2 to 201 kBq kg(-1) in rock samples and from 195 to 86,400 Bq kg(-1) in soil samples. The high levels of radioactivity found in the samples, indicate the need to conduct more detailed studies to evaluate the risk of radionuclide ingestion due to milk consumption by the population in the state of Pernambuco.

Analysis of the energetic parameters of a theta pinch.

This work is devoted to study experimentally the performance of a theta pinch when the number of capacitors and turns of magnetic coil and the diameter of the glass tube are changed. To model the theta pinch a simple RLC circuit is used and the measurement of energy transmission from the bank of capacitors to the plasma is made using few experimental resources. In this work it was analyzed more than 2500 curves with a nonlinear procedure. Our results show that it is possible to design an optimized theta pinch making the appropriated choice of energetic parameters and therefore to reduce the stress of the system.