In this work, a model based on single particle plus pairing residual interaction was used to study the low-lying excited states of the 193Ir nucleus. In this model, the deformation parameters in equilibrium were obtained by minimizing the total energy calculated by the Strutinsky prescription; the macroscopic contribution to the potential was taken from the Liquid Droplet Model, with the shell and paring corrections used as as microscopic contributions. The nuclear shape was described using the Cassinian ovoids as base figures; the single particle energy spectra and wave functions for protons and neutrons were calculated in a deformed Woods-Saxon potential, where the parameters for neutrons were obtained from the literature and the parameters for protons were adjusted in order to describe the main sequence of angular momentum and parity of the bandheads, as well as the proton binding energy of 193Ir. The residual pairing interaction was calculated using the BCS prescription with Lipkin-Nogami approximation. The results obtained for the first three bandheads (the 3/2+ ground state, the 1/2+ excited state at E ~ 73keV and the the 11/2- isomeric state at E ~ 80keV) showed a very good agreement, but the model so far greatly overestimated the energy of the next bandhead, a 7/2- at E ~ 299keV.

The beta decay of 155Sm (T1/2 ~ 22min) has been investigated by gamma spectroscopy measurements. The single and coincidence spectra were taken using HPGe detectors with high energy resolution. The energy and relative intensities of 42 gamma-rays have been determined, most of them with a better precision than previously. The gamma-transitions at 205.7keV and 224.8keV were observed for the first time and 40 of them were confirmed and 39 of them placed in the decay scheme. The present results, together with the results of earlier studies, allows to confirm the energy levels, in the energy range 0.05-1.6MeV, as well as the assignments of spin for most of them.

The absolute neutron activation analysis (ANAA) technique was used for the determination of some elements on body organs, such as, kidney, heart, muscles and spleen of small-sized animals used on experiments in health area. The advantages and limitations of using this nuclear methodology were discussed.

The population and the mode of decay of the low-lying excited levels of 193Ir have been investigated by single and <FONT FACE=Symbol>gg</FONT> coincidence spectroscopy using 192Os enriched to 99% and several HPGe detectors. From singles spectra analysis the energies of 71 gamma rays have been determined with a better overall precision than previously, 17 of them for the first time. The energies at 1043.244(15) and 1316.628(18)keV , observed for the first time in this work, as well as some preliminary coincidence relationships, suggest that the end point energy Qbetamax(<FONT FACE=Symbol>»</FONT>1.14MeV) must be further investigated.