[en] A report is presented on the preparation of a 57-Co low activity mossbauer source in a stainless steel matrix, which may be used for both demonstration experiments and some simple analysis work. This kind of sources are available in the market and there is not a general agreement on the particular conditions of preparations. Three series of experiments were performed to find out the best conditions to electro deposit 59, 60, 57-Co respectively on a stainless steel foil 25 μM thick and 1 Cm² area. The electrolyte contained Co(NO₃)₂ in a buffer solution to control the ph in the range 8.5< PH<9.5. Several electrodeposition runs were performed during time intervals in the range 20-24 hrs. With current densities from 10 to 50 mA/Cm_². Once the best conditions to electrodeposit 57-Co were found, it was diffused into the stainless steel matrix by annealing at 1100^oC for three hours and then gradually cooled down to room temperature in two hours; all this was done in the presence of an argon flow. Lastly, a 15 μCi 57-Co Mossbauer source in stainless steel matrix was obtained and used to record a series of Mossbauer parameters of this spectra were in close agreement with those given in the literature. (Author)

[en] In this communication the synthesis of the W_0.03RuSe_0.47O_0.3 from the transition metal carbonyl compounds and the chalcogenide in m Xylene, the chemical characterization of the novel material was performed by neutron activation analysis (NAA), using the TRIGA Mark III Reactor from the Nuclear Center of Mexico. The oxygen present in the material was determined by Rutherford Backscattering Spectrometry (RBS). Also the RuSe_5.7 y WSe₂ were synthesized and characterized by NAA. The electro kinetic oxygen reduction behaviour of the W_0.03RuSe_0.47O_0.3 deposited in glassy carbon was investigated in aqueous H₂SO₄ 0.5M. The rotating disk electrode electrochemical technique was used for determining the kinetic parameters: The reaction was of first order which implied that the rate determining step is the transfer of one electron, the Tafel slope was 0.115 V/decade; the electron transfer coefficient found was of 0.5, and the activation energy in the oxygen reduction reaction was 0.47 eV. (Author)

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[en] Vandellos II, following the guidelines GS 01.19 of CSN and RG 1.189 rev. 2, has identified the need to consider a number of local manual actions to be performed by the staff of shift operation and need to be validated according NUREG 1852. The local manual actions include corrective and preventive actions, such as local start and shooting of bombs, checking positions ... According NUREG-1852 these actions must be validated with conditions as similar as possible to those expected, in conjunction with the operating of Vandellos II.

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[en] A brief description of the radioactive wastes problem in Venezuela is presented. The origins of the problem are shown in a squematic form. The requirements for its solution are divided into three parts: information system, control system, radioactive wastes hadling system. A questionnaire summarizing factors to be considered when looking for a solution to the problem in Venezuela is included, as well as conclusions and recomendations for further discussion

[en] It is presented the effect of the reactive and non-reactive sputtering preparation, as well as, the atomic composition on the electrical properties and conduction mechanisms. Depending on the preparation conditions, samples present ohmic, Poole-Frenkel and space charge limited current conduction behaviours, as well as several orders of magnitude in resistivity values. As it is reported, impurities and non-stoichiometry play a very important role in the conduction mechanism and therefore on the thin film resistivity

[en] The biosolids are organic materials, derived from wastewater treatment of domestic and industrial sewage. one of the main problems of wastewater treatment plants is the final destination of the biosolids, their deposit in sanitary fillers, the incineration and land application are the main methods of dispose; the first two methods are expensive, while the last one, is gaining acceptance, because the biosolids are a resource that can be used as supplementary organic fertilizer. furthermore, land application of biosolids can help to improve declined soil fertility in degraded soils, but it can be generated contamination problems. the aims of this study were to investigate the effect of biosolids application on the growth of Jacaranda mimosifolia (Gualanday) and the changes on physical and chemical conditions of a degraded soil. this arboreal specie was planted in a degraded soil amended with biosolids, and was grown in a greenhouse. the treatments corresponded to contents of organic matter in the mixture (soil-biosolid) of 0 %, 2 %, 4 % and 8 %, in a completely randomized design with four treatments and ten replications. monthly samplings were realized to get information about the variables: survival height and diameter of stem, and number of leaves. the dry biomass was evaluated at the end of the study. the physical and chemical analyses were made at the beginning of the experiment and three months later. the chemical analyses included ph, oxidable organic carbon, Al, Ca, Mg, K, Fe, Mn, Cu, Zn, P, S, B, N0₃, NH₄⁺, and the physical analyses included aggregate stability, bulk density, real water retention. the statistical analysis between treatments was realized every month, by analysis of variance and Duncan's multiple range test, using a 95 % confidence level. the treatment with a 2 % of organic matter was not affected the plant growth and was similar with the untreated control. The treatments with a 4 % and 8 % of organic matter caused a lower survival a lower growth in height, diameter, and lesser number of leaves and a lower production of biomass. The high concentration of nutrients found on the soil probably generated toxicity, antagonism and/or synergism problems. the physical soil properties were favored with the addition of biosolids, possibly for its organic matter contents, appearing an increase in the aggregate stability and the humidity retention, and a diminution of the bulk density and the real density

[en] The Northwest region of Mexico has a deficit of potable water, along this necessity is the region growth, which requires of additional energy capacity. The IRIS reactor offers a very suitable source of energy given its modular size of 300 MWe and it can be coupled with a desalination plant to provide the potable water for human consumption, agriculture and industry. The present paper assess the water and energy requirements for the Northwest region of Mexico and how the deployment of the IRIS reactor can satisfy those necessities. The possible sites for deployment of Nuclear Reactors are considered given the seismic constraints and the closeness of the sea for external cooling. And in the other hand, the size of the desalination plant and the type of desalination process are assessed accordingly with the water deficit of the region

No abstract available