[en] The management of radioactive wastes considers many stages. The first one is the segregation of them in the place where they are produced and the last stage is their final disposal. However, the technical options for radioisotopes are different due to the very different characteristics that they have. One of the biggest problems in the case of the disposal of radium-226 is its half-life equivalent to 1600 years. The disposal of this kind of radioisotope produces technical, environmental and economic problems. In general, countries where are being considered radium-226 as radioactive wastes has considered their conditioning in an adequate way and then their respective storage. The final disposal has not been defined. Based on an agreement between Peru and the United States of America it has been possible the repatriation of a number of sources of radium-226 which were stored in the Nuclear Research Center of RACSO. In the present work is described all the technical aspects in relation to the repatriation of this kind of radioactive wastes. (orig.)

[en] The annual report of the results of the environmental radiation monitoring program developed in 2009 is presented, including also historical data to provide a frame of reference. This document is a continuation of the Environmental Radiation Monitoring Program developed by the Peruvian Institute of Nuclear Energy (IPEN) since 1990 and shows information on environmental radioactivity levels in the country available for public and private organisms as well as for general public. This paper briefly describes the main features of the environmental radiation monitoring programs in the Peruvian territory their results obtained from the surveillance campaign of 2009. It also shows the temporal radiological projection values more representatives in the recent years. (orig.)

[en] The analysis of the bony pieces of the skeleton attributed to the conquer Francisco Pizarro was continued, with the quantitative determinations of the elements Calcium (Ca), Iron (Fe), Copper (Cu), Zinc (Zn), Strontium (Sr) and Lead (Pb) evidence graphically the strong contamination by contact with Pb of the pieces of the head and the punctual contamination of some other pieces, with this same element by handling; besides the contamination by Cu in the pieces pertaining to the extremities has been determined. Finally by means of statistical evaluations of the elements Ca, Cu, Zn and Sr the type of diet of the individual in study is determined. (orig.)

[en] In this work the preparation of nanoparticles of magnetite by methods of precipitation in inverse microemulsions and the conventional method 'Chemical Co-precipitation' is reported. Magnetite nanoparticles were characterized by X-ray diffraction, Moessbauer spectroscopy and vibrating sample magnetometer (VSM). The results showed that the nanoparticles obtained by the method of precipitation in inverse microemulsion showed a superparamagnetic behavior and had a particle average diameter of 9 nm, while by the conventional method 'Chemical Co-precipitation' were 17 nm. In addition, other benefits observed in the application of the method of precipitation in inverse microemulsion with regard to the conventional method is that it allowed obtaining spheroidal magnetite nanoparticles, monodisperse and with magnetic and chemical properties which might have better results in medical applications. (author)

[en] A module for the automatic extraction of volume from 0.05 mL to 1 mL has been developed using a 3D printer, using as base material acrylonitrile butadiene styrene (ABS). The design allows automation of the input and ejection eluate "9"9"m Tc in the generator prototype "9"9Mo/"9"9"mTc processes; use in other systems is feasible due to its high degree of versatility, depending on the selection of the main components: precision syringe and multi-way solenoid valve. An accuracy equivalent to commercial equipment has been obtained, but at lower cost. This article describes the mechanical design, design calculations of the movement mechanism, electronics and automatic syringe dispenser control. (authors).

[en] The aim of this study was to determine background levels of natural and artificial radionuclides in Peruvian hakes, collected in the Pacific coast of Peru, as a mechanism to establish a biomonitoring model for human radiation exposure resulting from the ingestion of this species. The concentration range overall dry weight of beta activity was between 39 and 79 Bq/kg; for K-40, the range was between 66 and 116 Bq/kg and for Cs-137, the range was between 0.0 and 0.4 Bq/kg. No detectable levels of Co-60, Cs-134 and Ra-226 were found. The dose derived from K-40 was negligible. Data show that Peruvian hakes do not represent a public health risk because of their intake as food. (author).

[en] Six microbial strains called 'Culti-loops' (A. brasiliensis, B. subtilis, C. albicans, P. aeruginosa, S. aureus and E. coli) were used to verify the efficiency of the culture media, however, USP indicates to use less than 100 cfu / strain; to achieve it increasing dilutions were performed for each strain and according to the obtained results that grew from 1 x 10"4 to 30 x 10"6 cfu / strain and by means of calculation, volumes were determined (µL), seeded in culture medium for each of the listed microorganisms. Practical values were determined and according to the results, a dilution value of less than 100 cfu was obtained for each strain. (authors).

[en] Some dye-sensitized solar cells were prepared using TiO₂ modified with CuO (TiO₂-CuO) like a working electrode. P25 commercial powder and small amounts of CuO powder were used in preparing the modified coating. The coating was deposited following doctor Blade method, on a conductive substrate SnO₂:F, which was previously deposited on a TiO₂ blocking layer by spray pyrolysis technique. For sensitization of the coating, a ruthenium complex, cis-bis (isothiocyanate) bis (2,2'bipiridil-4,4'dicarboxilato) ruthenium (II) ammonium bistetrabutil, also known as N719, was used. The CuO powder was structurally characterized by X-ray diffraction and its morphology was studied by scanning electron microscopy. The functional groups of TiO₂ and CuO were studied by infrared spectroscopy. The oxidation and reduction cycles of Cu were shown by cyclic voltammetry. Through incident photon to current conversion efficiency measures, and solar efficiency measures, it was found that the modified films TiO₂-CuO with 0,33 % CuO displayed values of 57 and 2 %, respectively, which were higher than those prepared from TiO₂, which were 52 % and 1,7 %, respectively.

[en] The objective of the present study has been to extract and isolate the alkaloids from leaves of Croton baillonianus, corresponding to the methanolic extract by exclusion chromatography with Sephadex LH-20 followed by a purification by high performance liquid chromatography, obtaining six alkaloids. Two low polarity alkaloid and two glycoside alkaloids were analyzed by Electronic System impact mass spectrometry; these alkaloids belong to bencylisoquinolinic type; the study has connection to the determination of its antioxidant, antiulcerose and cytotoxic properties. (author).

[en] In copper oxide superconductor materials the internal charge transference between the superconducting planes of CuO₂ and the charge reservoir blocks, it is a key factor that controls the superconducting critical temperature. The superconducting planes of CuO₂ are not planes in a strict sense, the position of the Cu(2) atom and the O(2) and O(3) oxygen atoms are not lying in a same plane, the change of its positions are closely related to atomic replacements in the superconducting planes of CuO₂ or in the charge reservoir blocks. Therefore, we correlates the substitutions effects in the canonical unit cell of YBa₂Cu₃O₇ with regard to length and angle bond variation of copper and oxygen atoms with the superconducting critical temperature obtained by Rietveld refinement of X-ray diffraction patterns in polycrystalline powder samples, such as: SmBa₂Cu₃O₇, [Y0,90,Pr0,10]Ba₂Cu₃O₇, [Ca,La]Ba₂Cu₃O₇ and YBa₂Cu₃O₇. (author)