Marisé García Batlle has completed her graduation in Radiochemistry at the Higher Institute of Nuclear Technologies and Applied Sciences in Havana in 2014. She has worked in laboratories of preclinical studies in the clinical research center in Havana and as Assistant Professor at the Institute of Nuclear Technologies and Applied Sciences. She has worked in radio-pharmacy in search of new radio-labeled compounds for treatment of bone diseases. In 2016, she was admitted to the Master\'s degree in Chemical Science in the National University of Mexico, and works in the areas of radioactive contamination under advice of Dr. Navarrete.
All human activity, biomass metabolism and natural event that occur on the surface or inside of the earth occur with emissions of gases, particulate matter, aerosols and others. These are dispersed into the atmosphere, and integrated into the biogeochemical cycles that develop on Earth and can be considered contaminants when they result in risk or damage to persons or property under certain circumstances. During a time period little longer than 60 years , it has been created a radioactive pollution background over the natural one , which started in 1945 and it has been growing up since then, due to several nuclear test, minor nuclear reactors failure and accidents . At present time radioactive contamination is a fact easily proved by radioactive detection from marine sediments, chosen samples in view of the much larger proportion of sea surface on the planet. This short of samples contains appreciable concentration of minerals with natural radioactive isotopes such as 40K. Therefore, the only way to assess the magnitude of radioactive contamination is by comparing it with forever present natural radioactivity. So in this work, radioactivity from fission product 137Cs is compared with that of natural radioisotope 40K as percentage, both found in marine sediments of the Cuban coasts.
N Ouerfelli has a PhD and Habilitation Diploma in Chemistry. He is the Head of Research Project in the Laboratory of Biophysics and Medical Technologies. He has published more than 45 papers in reputed journals on modeling of physicochemical properties in solution.
Ionic self-diffusion coefficients D of the lanthanide trivalent trace ion 153Gd (III) have been determined in supporting aqueous solutions of Gd(NO3)3-HNO3 over a large range of concentration in acidic medium (pH=2.50) at 25°C by the open-end capillary method (O.E.C.M.). The method measures the transportation time of ion across a fixed distance. We optimized the pH in order to avoid the hydrolysis, pairing and complexing trivalent 4f ions. The diffusion data obtained in large range of concentration as well as the physicochemical properties, allow to derive the following information: (i) the limiting value D° at zero ionic strength, as 5.985 10-6 cm2•s-1 for 153Gd (III), (ii) the validity of the Onsager limiting law, (iii) the ionic self-diffusion coefficient as a function of the ionic strength for asymmetrical 3:1 electrolytes in dilute solutions, (iv) a competition between ion-ion interaction and ion-solvent interaction and (v) a more extended law available for an intermediate range of concentration up to 0.114 mol•L-1 and for a concentrated range up to 1.5 mol•L-1. This study contributes to demonstrate similarities transport and structure properties between 153Gd (III) and 244Cm (III) trivalent ions explained by a similar electronic configuration, ionic radius and same hydration number. These properties could also result from a long-range structuration of the concentrated ionic solution.