[en] The alchemists of the Half Age looked for, with pre scientific methods, to transform the lead in gold. Today, thanks to the physics we can understand how the elements are transmuted at level of the one atomic nucleus. (Author)

No abstract available

[en] The generator system of radionuclides more diffused, and used in the world, it is the⁹⁹Mo / ^99m Tc. These use ⁹⁹ Mo, product of fission of the ²³⁵ U of very high specific activity, adsorbed on alumina (0.2% of ⁹⁹ Mo/gram of alumina). An alternative for the production of generators of low activity specifies, via the reaction ⁹⁸ Mo(n, γ) ⁹⁹ Mo, it is based on the use of compounds with molybdates base, as matrices of the generators ⁹⁹ Mo / ^99m Tc. In this work is proposed to develop a generator at base of compounds of magnesium molybdates that could be irradiated after its synthesis, given the short half life of the only radioisotope produced by magnesium: ²⁷ Mg (t_1/2 = 9.46 m). In this work two parameters were studied, fundamental in the preparation of the magnesium molybdates, matrices of the generators ⁹⁹Mo / ^99mTc, and their influence in the efficiency and radionuclide purity: the washing of the gels previous to its irradiation and the molar ratio Mo:Mg. The magnesium molybdates non washing presents bigger efficiencies (72%), but they don't fulfill a smaller percentage to 0.015% of ⁹⁹ Mo, neither with a radiochemical purity of 90%, except when the molar ratio Mo: Mg of 1:1.08 which provide the best results. (Author)

[en] The present book was published on the occasion of the 50 years of the existence of the Institute, from its creation in 1956 like National Commission of Nuclear Energy to 1979 that arises like National Institute of Nuclear Research. The objective of this publication is the one to leave a writing testimony of all the activities that are realized in the National Institute of Nuclear Research and an accessible language within the diverse subjects boarded. Referring subjects to the activities of nuclear physics, radiochemistry, research and development of materials, dosimetry, plasma physics, production of radiopharmaceuticals, tissue sterilization by radiation, food irradiation and other included. (Author)

[en] The zirconium molybdates are gels which are used as cation exchangers in the production of ⁹⁹ Mo/^99m Tc generators. The synthesis method and the characterization of these gels by thermogravimetry, infrared spectroscopy and X-ray diffraction is presented with the purpose of finding which the factors are that influence in the efficiency of the ^99m Tc production. The results show that the quantity of molecular water contained in gel, is possibly the cause of variations of the efficiencies of the ⁹⁹ Mo/^99m Tc generator. (Author)

[en] The present work presents the methodology that was developed for the preparation of one extractant resin with the aim of HDEHP, to separate radio lanthanides with serial atomic numbers. In this case it is exemplified with the separation of the following elements: Gadolinium-161 and the Terbium-161; this last radioisotope it is a beta emitting (β^-) that has a great potential to be used in therapy, also in nuclear medicine and in oncology, this is due to the high penetration power of their β^- particles that can kill to the cancerous cells and to inhibit the growth of the same ones. To be able to separate them it is necessary to appeal to extremely selective separation techniques, since the chemical properties of these elements are very similar. The chromatography is one of the more used analytical tools, this is due to its great sensibility and the selectivity in the compounds separation, in particular the use of the extractive chromatography has shown the feasibility of carrying out this type of separations for this type of elements. The resin with base of HDEHP was absorbed in an inert support under diverse preparation conditions. The extractant properties of the resin, in relation to the elements Gd and Tb (distribution coefficients), its were determined by means of the dynamic method, using as eluent solutions of nitric acid. The Gd-159 was prepared by irradiation of Gd-168 with thermal neutrons and the Tb-161 it is the result of the radioactive decay of the Gd-161 that is produced in turn with the irradiation with neutrons of Gd-160. The coefficients of distribution of Gd and Tb, using the prepared resin under diverse conditions are presented. (Author)

[en] The ^99m Tc is the radioisotope but used in nuclear medicine. Commercially it takes place starting from generators of ⁹⁹ Mo/^99m Tc, composed by a chromatography column padded of aluminium oxide of aluminum, where it is deposited the ⁹⁹ Mo, product of the fission of the ²³⁵ U adsorbed and eluted, by means of a saline solution, in form of ^99m TcO₄^-. The production of ⁹⁹ Mo as a result of the fission, imposes radiochemical separations that generate significant quantities of radioactive waste of medium activity, and inflict elaborated radiochemical manipulation. Due to this, its have been carried out intense investigations to substitute the ⁹⁹ Mo fission product, by chemical compounds that produce ⁹⁹ Mo via the reaction ⁹⁸ Mo(n, γ)⁹⁹ Mo. Presently work intends the use of gels of titanium molybdates like matrices of these generators. Titanium molybdates were synthesized starting from solutions TiCl₃ and ammonium molybdates and it was studied the effect of the final pH of the gels, the concentration of the Ti⁺³ and the influence of the laundry of these on the acting of generators. The best efficiencies and chemical purity, radiochemical and radionuclides of the gels like matrices of generators ⁹⁹ Mo/^99m Tc were gotten with the washed gel, elaborated with the solution of TiCI₃ 0.35M, and to a final pH of 5.9 (Author)

[en] The ^99m Tc, continues being the radionuclide more used in nuclear medicine to world scale. The production of this radioisotope, is carried out by means of generators ⁹⁹ Mo/^99m Tc that get ready commercially with ⁹⁹ Mo of high specific activity, adsorbed in alumina (2 mg ⁹⁹ Mo/g alumina) and that they are elutriated every 23 hours. In an alternative way, it is intended to use gels of titanium molybdates, as matrices of this generators. The gels are synthesized starting from solutions of ammonium molybdates and of titanium tetrachloride in aqueous media. These gels allow to incorporate until 25% of molybdenum in their structure, being been able to use ⁹⁹ Mo of low specific activity that can be obtained starting from the reaction ⁹⁸ Mo (n, γ) ⁹⁹ Mo. With the object of producing generators of medium activity, with the base of gels of titanium molybdates, intends in this work, to study the influence of two synthesis parameters of these gels: the concentration of the titanium solutions and the molar ratio Ti: Mo. The decrease of the concentration of the titanium solution, used during the synthesis of the gels, is converted in an efficiency decrease and radionuclide purity of the generators, as well as an increment so much of the volume of elutriation, as of the pH of the elutriates. The gels that contain an major number of titanium moles, regarding the molybdenum moles, present a greater radionuclide purity, but they diminish their efficiency. The best characteristics for the gels synthesis of titanium molybdates are: a molar ratio 1:1 for Ti and Mo, and to use solutions of titanium whose concentration is near at 1 M. (Author)

[en] The quantification of Tc-99 in spent exchange resins, coming from nuclear power plants, is indispensable to define their administration. The Tc-99 is a pure beta emitter of 210000 years of half-life, volatile and of a high mobility in water and soil. For this reason, the objective of this work is to establish a digestion method of ionic exchange resins containing technetium that retains more than 95% of this radioisotope. Mineralization tests were carried out of a resin Amberlite IRN-150 by means of an oxidation heat, in acid medium, varying the resin mass, the medium volume, the media type, the temperature and the digestion time. The digested samples were analyzed by gas chromatography to estimate the grade of their degradation. The ^99mTc was used as tracer to determine the technetium percentage recovered after mineralizing the resin. The digestion process depends on the temperature and the resin mass. At higher temperature better mineralization of samples and to greater resin mass to a constant temperature, less degradation of the resin. The spectra beta of the ^99mTc and ⁹⁹Tc are presented. (Author)

[en] The more used isotope at the moment in the services of nuclear medicine in the world is the technetium-99m. The ^99m Tc emitts gamma rays of 141 keV and it semi disintegration period is of six hours, given it short half life, to produce it is necessary to order generators that are systems that allow to separate periodically at the ^99mTc of the ⁹⁹ Mo by means of chromatographic techniques. In this work it is sought to evaluate the use of the hydroxyapatite, to separate molybdates ⁹⁹ MoO₄² of pertechnetates ^99mTcO₄^- and to be able to determine if it is feasible their use for to build generators of ^99m Tc. With this purpose preliminary tests to know the likeness of the hydroxyapatite for the molybdates in function of the pH value, in different solutions were carried out: one of NaCl 0.9%, NaCl 2% and CaCl₂ 0.01 M. The obtained results in a NaCl 0.9% solution and at to 2% to different pH values of the solution, shows that the fixation of the molybdate ions (MoO₄^-2) it is worthless to basic pH values of (9-11), as long as in solution of CaCI₂ 0.01 M show a considerable retention of molybdate ions. (Author)