527 research outputs found

    Melão Tupã: origem e melhoramento genético.

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    bitstream/CNPAT-2010/7912/1/Dc-055.pd

    Protocolo para desenvolvimento de marcadores microssatélites.

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    bitstream/CENARGEN/24380/1/ct020.pd

    A new FSA approach for in situ γ\gamma-ray spectroscopy

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    An increasing demand of environmental radioactivity monitoring comes both from the scientific community and from the society. This requires accurate, reliable and fast response preferably from portable radiation detectors. Thanks to recent improvements in the technology, γ\gamma-spectroscopy with sodium iodide scintillators has been proved to be an excellent tool for in-situ measurements for the identification and quantitative determination of γ\gamma-ray emitting radioisotopes, reducing time and costs. Both for geological and civil purposes not only 40^{40}K, 238^{238}U, and 232^{232}Th have to be measured, but there is also a growing interest to determine the abundances of anthropic elements, like 137^{137}Cs and 131^{131}I, which are used to monitor the effect of nuclear accidents or other human activities. The Full Spectrum Analysis (FSA) approach has been chosen to analyze the γ\gamma-spectra. The Non Negative Least Square (NNLS) and the energy calibration adjustment have been implemented in this method for the first time in order to correct the intrinsic problem related with the χ2\chi ^2 minimization which could lead to artifacts and non physical results in the analysis. A new calibration procedure has been developed for the FSA method by using in situ γ\gamma-spectra instead of calibration pad spectra. Finally, the new method has been validated by acquiring γ\gamma-spectra with a 10.16 cm x 10.16 cm sodium iodide detector in 80 different sites in the Ombrone basin, in Tuscany. The results from the FSA method have been compared with the laboratory measurements by using HPGe detectors on soil samples collected in the different sites, showing a satisfactory agreement between them. In particular, the 137^{137}Cs isotopes has been implemented in the analysis since it has been found not negligible during the in-situ measurements.Comment: accepted by Science of Total Environment: 8 pages, 10 figures, 3 table

    Preliminary results for the characterization of the radiological levels of rocks in Tuscany Region.

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    The environmental background levels of natural radiation due to the nuclides in rocks vary in significant amounts that depend on the geological and geomorphological features of a territory. The main source of terrestrial gamma-ray radiation exposure to humans is from 238U, 232Th decay chains and 40K decay. This paper reports a part of the results of the Research Project “Measurement of natural radioactivity and mapping of the radioisotope abundances of Tuscany Region”, which started at August 2008 and it is supported by founds of Tuscany Region. The aim of this project is to realize the thematic maps of radioactivity content and in particular of the abundances of eU1, eTh1 and 40K. These goals will be achieved by integrating the information from measurements on samples in laboratory with in-situ investigations and airborne surveys. The Legnaro National Laboratory (LNL) is the national leader for the design and realization of high-resolution gamma-ray spectrometers, portable and massive NaI(Tl) detectors. The MCA_Rad gamma-ray spectrometry system was designed and built up at LNL for measuring large amount of samples with a minimum attendance: these features fit perfectly with the requirements of this project. This system is able to measure any type of materials (solid, liquid, gas), and due to the high efficiency and its geometric symmetry, absolute activity measurements are possible with systematic errors below 5%. http://www.fe.infn.it/u/mantovani/CV/Proceedings/Bezzon_10b.pd

    Estudo da divergência genética de linhagens de melão do tipo Pele de Sapo, utilizando marcadores SSR.

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    Uma forma eficiente de auxiliar os programs de melhoramento genético de melão é a análise da variabilidade genética de genitores por meio de marcadores moleculares, pois detectam dissimilaridades entre diferentes acessos em nível de DNA

    Glossario de biotecnologia vegetal.

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