4,867 research outputs found
Group Analysis Method For Fission Track Thermochronology
No full textA methodology to obtain ages and thermal histories of sets of apatite samples from localities with geologically compatible characteristics is described. A methodology exploring the fact that samples with similar geological characteristics should present the same thermal history is proposed. This approach can contribute for the obtainment of more conclusive results by analysing fewer samples than it is necessary when the samples are individually analysed. In order to determine the ages, we use the absolute neutron dosimetry through thin films of natural uranium along with λf = 8.46 × 10- 17 a- 1. As an example of application of the proposed methodology, we analyse samples collected in a Brazilian region, São Francisco Craton, which experienced low tectonic activity. © 2008 Elsevier Ltd. All rights reserved.43SUPPL.1S163S168Barbarand, J., Hurford, T., Carter, A., Compositional and structural control of fission-track annealing in apatite (2003) Chem. Geol., 198, pp. 107-137Bevington, P.R., (1969) Data Reduction and Error Analysis for the Physical Sciences, , Mc Graw-Hill, New YorkBigazzi, G., Hadler, J.C., Iunes, P.J., Osorio, A.M., Muscovite SSNTD: detection efficiency for fission fragments (1991) Radiat. Meas., 19, pp. 451-452Bigazzi, G., Guedes, S., Hadler, J.C., Iunes, P.J., Oddone, M., Osorio, A.M., Paulo, S.R., Zúniga, A., Potentialities and practical limitations of an absolute neutron dosimetry using thin films of uranium and thorium applied to the Fission Track Method (1999) Radiat. Meas., 31, pp. 651-656Carlson, W.D., Mechanisms and kinetics of apatite fission-track annealing (1990) Am. Mineral., 75, pp. 1120-1139Carlson, W.D., Donelick, R.A., Ketcham, R.A., Variability of apatite fission-track annealing kinetics I: experimental results (1999) Am. Mineral., 84, pp. 1213-1223Crowley, K.D., Cameron, M., Shaefer, R.L., Experimental studies of annealing of etched fission tracks in fluor apatite (1991) Geochim. Cosmochim. Acta, 55, pp. 1449-1465Fleischer, R.L., Hart, H.R., Fission track dating techniques and problem (1972) Calibration of Humanoid Evolution, pp. 135-170. , Bishop W.W., Miller J.A., and Cole S. (Eds), Scottish Academic Press, EdinburgFleisher, R.L., Price, P.B., Charged particle tracks in glass (1963) J. Appl. Phys., 34, pp. 2903-2904Franco, A.O.B., Hackspacher, P.C., Godoy, D.F., Ribeiro, L.F.B., Guedes, S., História térmica do Maciço Alcalino de Poços de Caldas (SP/MG) e adjacências através da análise de datação por traços de fissão em apatitas (2005) Rev. Bras. Geociênc., 35, pp. 351-358Gleadow, A.J.W., Fission track dating methods: what are the real alternatives? (1981) Nucl. Tracks, 5, pp. 3-14Green, P.F., Duddy, I.R., Gleadow, A.J.W., Tingate, P.R., Laslett, G.M., Thermal annealing of fission tracks in apatite, 1. The qualitative description (1986) Chem. Geol. Isot. Geosci. Sect., 59, pp. 237-253Green, P.F., Duddy, I.R., Laslett, G.M., Hegarty, K.A., Gleadow, A.J.W., Lovering, J.F., Thermal annealing of fission tracks in apatite 4. Quantitave modeling techniques and extension to geological time scale (1989) Chem. Geol. Isot. Geosci. Sect., 79, pp. 155-182Guedes, S., Hadler, J.C., Iunes, P.J., Paulo, S.R., Zúñiga, A., The spontaneous fission decay constant of 238U using SSNTD (2000) J. Radioanal. Nucl. Chem., 245, pp. 441-442Guedes, S., Hadler, J.C., Iunes, P.J., Zúñiga, A., Tello, C.A., Paulo, S.R., The use of the U (n, f) reaction dosimetry in the determination of the λf value through fission-track techniques (2003) Nucl. Instrum. Methods A, 496, pp. 215-221Guedes, S., Hadler, J.C., Iunes, P.J., Oliveira, K.M.G., Kakazu, M.H., Sarkis, J.E.S., Paulo, S.R., Tello, C.A., Spontaneous-fission decay constant of 238U measured by nuclear track techniques without neutron irradiation (2003) J. Radioanal. Nucl. Chem., 258, pp. 117-122Guedes, S., Hadler, J.C., Iunes, P.J., Tello, C.A., Kinetic model for the relationship between confined fission-track length shortening and fission-track age reduction in minerals (2004) Nucl. Instrum. Methods B, 217, pp. 627-636Guedes, S., Hadler, J.C., Iunes, P.J., Oliveira, K.M.G., Moreira, P.A.F.P., Tello, C.A., Kinetic model for the annealing of fission tracks in zircon (2005) Radiat. Meas., 40, pp. 517-521Guedes, S., Hadler, J.C., Oliveira, K.M.G., Moreira, P.A.F.P., Iunes, P.J., Tello, C.A., Kinetic model for the annealing of fission tracks in minerals and its application to apatite (2006) Radiat. Meas., 41, pp. 392-398Guedes, S., Curvo, E.A.C., Tello, C.A., Hadler, J.C., Iunes, P.J., Paulo, S.R., Palissari, R., On the annealing of fission tracks in randomly oriented grains of apatite (2007) Nucl. Instrum. Methods B., 256, pp. 683-692Hadler, J.C., Paulo, S.R., Iunes, P.J., Tello, C.A., Balestrieri, M.L., Bigazzi, G., Curvo, E.A.C., Hackspacher, P.C., A PC compatible Brazilian software for obtaining thermal histories using apatite fission track analysis (2001) Radiat. Meas., 34, pp. 149-154Hadler, J.C., Bigazzi, G., Guedes, S., Iunes, P.J., Oddone, M., Tello, C.A., Paulo, S.R., Spontaneous 238U fission half-life measurements based on fission-track techniques (2003) J. Radioanal. Nucl. Chem., 256, pp. 155-157Harman, R., Gallagher, K., Brown, R., Raza, A., Bizzi, L., Accelerated denudation and tectonic/geomorphic reactivation of the cratons of northeast Brazil during the Late Cretaceous (1998) J. Geophys. Res., 103, pp. 27091-27105Holden, N.E., Hoffman, D.C., Spontaneous fission half-lives for ground-state nuclides (Technical Report) (2000) Pure Appl. Chem., 72, pp. 1525-1562Hurford, A.J., Standardization of fission track dating calibration: recommendation by the fission track working group of the I. U.G.S. Subcommission on Geochronology (1990) Chem. Geol. Isot. Geosci. Sect., 80, pp. 171-178Iunes, P.J., Hadler, J.C., Bigazzi, G., Tello, C.A., Guedes, S., Paulo, S.R., Durango apatite fission-track dating using length-based age corrections and neutron fluence measurements by thorium thin films and natural U-doped glasses calibrated through natural uranium thin films (2002) Chem. Geol., 187, pp. 201-211Iunes, P.J., Bigazzi, G., Hadler, J.C., Tello, C.A., Guedes, S., Paulo, S.R., Balestrieri, M.L., Zúñiga, A., The Th/U ratio in minerals by a fission track technique: application to some reference samples in order to estimate the influence of Th in fission-track dating (2002) Radiat. Meas., 35, pp. 195-201Iunes, P.J., Hadler, J.C., Bigazzi, G., Guedes, S., Zúñiga, A., Paulo, S.R., Tello, C.A., Uranium and thorium film calibrations by particle track techniques (2004) J. Radioanal. Nucl. Chem., 262, pp. 461-468Iwano, H., Danhara, T., A re-investigation of the geometry factors for fission-track dating of apatite, sphene and zircon (1998) Advances in Fission-Track Geochronology, pp. 47-66. , Van den haute P., and De Corte F. (Eds), Kluwer Academic Publishers, DordrechtJonckheere, R., On the densities of etchable fission tracks in a mineral and co-irradiated external detector with reference to fission-track dating of minerals (2003) Chem. Geol., 200, pp. 41-58Ketcham, R.A., Donelick, R.A., Carlson, W.D., Variability of apatite fission-track annealing kinetics III: extrapolation to geological time scales (1999) Am. Mineral., 84, pp. 1224-1234Laslett, G.M., Galbraith, R.F., Statistical modeling of thermal annealing of fission tracks in apatite (1996) Geochim. Cosmochim. Acta, 60, pp. 5117-5131Laslett, G.M., Green, P.F., Duddy, I.R., Gleadow, A.J.W., Thermal annealing of fission tracks in apatite 2. The quantitative analysis (1987) Chem. Geol. Isot. Geosci. Sect., 65, pp. 1-13Lutz, T.M., Omar, G., An inverse method of modeling thermal histories from apatite fission-track it dates (1991) Earth Planet. Sci. Lett., 104, pp. 181-195Nóbrega, M.A., Sá, J.M., Bezerra, F.H.R., Hadler, J.C., Iunes, P.J., Guedes, S., Tello, C.A., Lima-Filho, F.P., The use of apatite fission track thermochronology to constrain fault movements and sedimentary basin evolution in northeastern Brazil (2005) Radiat. Meas., 39, pp. 627-633Osório, A.M., Iunes, P.J., Bigazzi, G., Hadler, J.C., Laurenzi, M.A., Norelli, P., Tello, C.A., Paulo, S.R., Fission-track dating of Macusanite glasses with plateau and size correction methods (2003) Radiat. Meas., 36, pp. 407-412Price, P.B., Walker, R.M., Fossil tracks of charged particles in mica and the age of the minerals (1963) J. Geophys. Res., 68, pp. 4847-4862Silva, A.B., Liberal, G.S., Grossi Sad, J.H., Issa Filho, A., Rodrigues, C.S., Riftel, B.F., Geologia e petrologia do complexo Angico dos Dias (Bahia, Brazil), uma assiciação carbonatítica precanbriana (1988) Geochimica Bras., 2 (1), pp. 81-108Storzer, D., Poupeau, G., Ages-plateaux de minéraux et verres par la méthode des traçes de fission (1973) C. R. Acad. Sci. Paris D, 276, pp. 137-139Storzer, D., Wagner, G.A., Correction of thermally lowered fission track ages of tektites (1969) Earth Planet. Sci. Lett., 5, pp. 463-468Tello, C.A., Hadler, J.C., Iunes, P.J., Guedes, S., Hackspacher, P.C., Ribeiro, L.F.B., Paulo, S.R., Osorio, A.M., Thermochronology of the South American platform in the state of São Paulo, Brazil, through apatite fission tracks (2005) Radiat. Meas., 39, pp. 635-640Tello, C.A., Palissari, R., Hadler, J.C., Iunes, P.J., Guedes, S., Curvo, E.A.C., Paulo, S.R., Annealing experiments on induced fission tracks in apatite: measurements of horizontal-confined track lengths and track densities in basal sections and randomly oriented grains (2006) Am. Mineral, 91, pp. 252-260Wagner, G., Van den haute, P., (1992) Fission Track Dating, , Kluwer Academic Publishers, Dordrecht, The Netherlands 285pYoshioka, T., Tsuruta, T., Iwano, H., Danhara, T., Spontaneous fission decay constant of 238U determined by SSNTD method using CR-39 and DAP plates (2005) Nucl. Instrum. Methods Phys. A, 555, pp. 386-39
J.C. Steyn Collection index
No full textThis index describes the J. C. Steyn collection which includes background material for 3 biographies by J.C. (Jaap) Steyn namely N.P. van Wyk Louw, P.J. Cillié and MER (M.E. Rothman). Prof. J.C. Steyn (1939-) is an educationist, linguist and author. Correspondence ; clippings ; photographs ; book reviews ; articles ; speeches ; varia compiled in 23 pamphlet boxes
On Energy Absorption Effects In Uranium And Thorium Thin Films
No full textThe use of U and Th thin films, attached to detectors of fission tracks, allows determining the neutron fluence in nuclear reactors. In principle, the parameters involved in neutron fluence determinations through U and Th thin films that might be influenced by effects related with fission fragments and α particle energy absorption are: (i) the detection efficiency of nuclear emulsions for α particles, (ii) the detection efficiency of muscovite mica for fission fragments from thin films, ε{lunate}F and (iii) the detection efficiency of nuclear emulsions for fission fragments, used to estimate ε{lunate}F. Fission fragments are more ionizing than α particles and are more influenced by energy absorption. We show that fission fragment energy absorption effects are negligible in case of U and Th thin films employed in neutron fluence determinations for fission-track (FT) dating. © 2008.43SUPPL.1S334S336Bigazzi, G., Hadler, J.C., Iunes, P.J., Osorio, A.M., Muscovite SSNTD: detection efficiency for fission fragments (1991) Nucl. Tracks Radiat. Meas., 19, pp. 451-452Bigazzi, G., Guedes, S., Hadler, J.C., Iunes, P.J., Oddone, M., Osorio, A.M., Paulo, S.R., Zúniga, A., Potentialities and practical limitations of an absolute neutron dosimetry using thin films of uranium and thorium applied to the fission track method (1999) Radiat. Meas., 31, pp. 651-656Hadler, J.C., 1979. Estudos sobre Traços Anômalos Observados em Emulsões Carregadas com Urânio. Master Thesis, Universidade Estadual de Campinas, Campinas SP, BrazilHadler, J.C., Iunes, P.J., Mello, T.C.W.P., Navia, L.M.S., Paulo, S.R., On the nuclear emulsion detection efficiency for alpha particles and fission fragments (1996) Radiat. Meas., 26, pp. 169-171Iunes, P.J., Hadler, J.C., Bigazzi, G., Tello, C.A., Guedes, S., Paulo, S.R., Durango apatite fission-track dating using length-based age corrections and neutron fluence measurements by thorium thin films and natural U-doped glasses calibrated through natural uranium thin films (2002) Chem. Geol., 187, pp. 201-211Iunes, P.J., Hadler, J.C., Bigazzi, G., Guedes, S., Zúñiga, A., Paulo, S.R., Tello, C.A., Uranium and thorium film calibrations by particle track techniques (2004) J. Radioanal. Nucl. Chem., 262, pp. 461-468Iunes, P.J., Bigazzi, G., Hadler, J.C., Laurenzi, M.A., Balestrieri, M.L., Norelli, P., Osório, A.M., Curvo, E.A.C., U and Th thin film neutron dosimetry for fission-track dating: application to the age standard Moldavite (2005) Radiat. Meas., 39, pp. 665-668Osório, A.M., Iunes, P.J., Bigazzi, G., Hadler, J.C., Laurenzi, M.A., Norelli, P., Tello, C.A., Paulo, S.R., Fission-track dating of macusanite glasses with plateau and size correction methods (2003) Radiat. Meas., 36, pp. 407-412Segrè, E., Wiegand, C., Stopping power of various substances for fission fragments (1946) Phys. Rev., 70, pp. 808-81
Cr-39 Alpha Particle Spectrometry For The Separation Of The Radon Decay Product 214po From The Thoron Decay Product 212po
No full textIn this work, it is presented an experimental assembly based on electric capture of radionuclides in order to discriminate the alpha activity of 214Po (radon decay product) from 212Po (thoron decay product) one. The alpha activity was registered with CR-39 analyzing etch pit diameters and optical density. This discrimination may allow for the estimation of the relative contribution of the alpha activity due to thoron decay products compared to the total activity due to radon decay products. © 2010 Elsevier Ltd. All rights reserved.457823826Abreu, S.F., Recursos Minerais do Brasil (1962) MIC - Instituto Nacional de Tecnologia, 2, p. 633. , Rio de JaneiroFromm, M., Membrey, F., Chambaudet, A., Saouli, R., Proton and alpha track profiles in CR-39 during etching and their implications on track etching models (1991) Nucl. Tracks Radiat. Meas., 19, pp. 163-168Fromm, M., Membrey, F., Rahamany, A.E., Chambaudet, A., Principle of light-ions micromapping and dosimetry using a CR-39 polymeric detector - Modelized and experimental uncertainties (1993) Nucl. Tracks Radiat. Meas., 21, pp. 357-365Hadler, J.C., Iunes, P.J., Osorio, A.M., Paulo, S.R., Relationship between track size and energy for alpha particles in CR-39 (1991) Nucl. Tracks Radiat. Meas., 19, pp. 313-317Hadler, J.C., Paulo, S.R., Indoor radon daughter contamination monitoring - The absolute efficiency of CR-39 taking into account the plate-out effect and environmental-conditions (1994) Radiat. Prot. Dosimetry, 51, pp. 283-296Lederer, C.M., Shirley, V.M., (1978) Table of Isotopes, Seventh, p. 1523. , ed. Wiley-interscience, New York, USA(1983) Ministério Das Minas E Energia, Secretaria Geral, Levantamento de Recursos Naturais, 32, p. 261. , Projeto RadamBrasilSantos, N.F., Hadler, J.C., Iunes, P.J., Guedes, S., Paulo, S.R., CR-39 detectors calibration using a beehive collimator (2005) Radiat. Meas., 39, pp. 661-664Somogyi, G., Hunyadi, I., Hafez, A.F., Espinosa, G., A new possibility for highresolution spectroscopy of nuclear-particles entering CR-39 at selected dip angles (1984) Nucl. Tracks Radiat. Meas., 8, pp. 163-166Ziegler, J.F., (2006) SRIM 2006, 2. , http://www.srim.or
Product Innovation Knowledge Transfer for Developing Countries: Towards a systematic Transfer Approach
No full textThe transfer of knowledge on product innovation to small- and medium-sized enterprises and local knowledge institutions in developing countries is expected to be one of the key drivers for competiveness and economical growth, and a part of the solution to environmental and social challenge. In that respect, this PhD study focuses on how the process of the current knowledge transfer takes place and how it can be improved. A combination of literature review and empirical research has resulted into a conceptual framework to describe the complex and dynamic process of product innovation knowledge transfer to developing countries. In order to improve this process, a systematic approach has been developed and operationalized by a needs assessment tool and a design manual: The UNEP Design for Sustainability for Developing Economies (D4S-DE) Manual (www.d4s-de.org). Both tools have been tested in practice by practitioners and have been evaluated by an academic review board.Design EngineeringIndustrial Design Engineerin
Where do we draw lines: professional relationship boundaries and the child and youth care practitioner
No full textThe question of professional relationship boundaries is a poignant one, in light of the many boundary grey-zones that are created by the variety of young people’s needs, practice settings and professional relationship contexts within the field of child and youth care. In order to support practitioners’ development of critical thought and awareness of professional boundaries, this paper applies a professional relationship boundaries conceptual framework to child and youth care work, and the literature is consulted to explore the impacts of boundary violations, influences on individual’s boundaries, cues to indicate blurring boundaries, and key strategies to maintain balanced boundaries
Radon Surveys In Brazil Using Cr-39
No full textIn this work results of two radon daughters survey in Brazil are presented and discussed. Some methodological problems concerning the first survey are pointed out which were corrected for the second survey in order to make a realistic long-term measurement of radon decay products in the air. The technique employed in both surveys was the alpha-spectroscopy using CR-39. The reliability of this technique as well as the results of the second survey are discussed, which indicate a poor correlation between radon and its decay products in the air at the researched dwellings. © 2005 Elsevier Ltd. All rights reserved.396657660Guedes, S., Hadler Neto, J.C., Iunes, P.J., Navia, L.M.S., Neman, R.S., Paulo, S.R., Rodrigues, V.C., Zuniga, A., Indoor radon and radon daughters survey at Campinas, Brazil using CR-39: First results (1999) Radiat. Meas., 31, pp. 287-290Hadler Neto, J.C., Paulo, S.R., Indoor radon daughters contamination monitoring: The absolute efficiency of CR-39 taking into account the plate-out effect and environmental conditions (1994) Radiat. Prot. Dosim., 51, pp. 283-296Hadler Neto, J.C., Iunes, P.J., Osório Araya, A.M., Paulo, S.R., Relationship between track size and energy for alpha particles in CR-39 (1991) Nucl. Tracks Radiat. Meas., 19, pp. 313-317Magalhães, M.H., Amaral, E.C.S., Sachett, I., Rochedo, E.R.R., Radon-222 in Brazil: An outline of indoor and outdoor measurements (2003) J. Environ. Radioactivity, 67, pp. 131-143Malanca, A., Gaidolfi, M., Environmental radon in some Brazilian towns and mines (1997) Radiat. Prot. Dosim., 69, pp. 211-216Neman, R., (2000) Medida Da Contaminação Radioativa Do Ar Ambiental Por radônio-222 E Filhos Em Residências De Campinas-SP, , Brasil. Master Thesis, Universidade Estadual de Campinas (in Portuguese)Neman, R.S., Schmitman, I.D., Hadler Neto, J.C., Iunes, P.J., Paulo, S.R., Guedes, S., Measurement of indoor 222Rn using CR-39 under a thin film geometry (2001) Radiat. Meas., 34, pp. 145-148Nikolaev, V.A., Ilić, R., Etched track radiometers in radon measurements: A review (1999) Radiat. Meas., 31, pp. 1-1
Boron Thin Films And Cr-39 Detectors In Bnct: A Method To Measure The 10b(n,α)7li Reaction Rate
No full textThe working principle of the Boron Neutron Capture Therapy (BNCT) is the selective delivery of a greater amount of boron to the tumor cells than to the healthy ones, followed by the neutron irradiation that will induce the emission of α-particles and recoil 7Li nuclei through the 10B(n,α)7Li reaction. The objective of this work is to present a setup composed of a boron thin film coupled with CR-39. Alpha and 7Li particle coming from the boron films are used to quantify neutron boron reaction and are detected by CR-39. The nuclei compounding of this detector, H, C and O, will undergo fast neutrons reactions, which will be detected in the CR-39 itself. In this way, the 10B(n,α) 7Li reaction and the contribution of fast neutrons to the flux can be determined at the same time. These measurements are essential for treatment planning as well as for studies of the biodistribution of 10B-carrier drugs and tissue microdosimetry. The boron films were deposited on stainless steel substrates through the sputtering technique and irradiated with thermal neutrons at the reactor IEA-R1 located at IPEN, São Paulo/SP, Brazil. Here we show the first results on the characterization of these thin films and calibration of the proposed setup. © 2012 Elsevier Ltd. All rights reserved.50181186Altieri, S., Bortolussi, S., Bruschi, P., Chiari, P., Fossati, F., Stella, S., Prati, U., Pinelli, T., Neutron autoradiography imaging of selective boron uptake in human metastatic tumours (2008) Appl. Radiat. Isot., 66, pp. 1850-1855Barth, R., Coderre, J.A., Vicente, M.G.H., Blue, T.E., Boron neutron capture therapy of cancer: Current status and future prospects (2005) Clin. Cancer Res., 11, pp. 3987-4002Behrisch, R., (1981) Sputtering by Particle Bombardment I: Physical Sputtering of Single-Element Solids, , Springer Berlin 3540105212Bigazzi, G., Hadler, J.C., Iunes, P.J., Mineral dating by the fission track method: Neutron dosimetry by thin film of natural uranium (1993) Revista de Física Aplicada e Instrumentação, 8, pp. 13-23Bigazzi, G., Hadler, J.C., Iunes, P.J., Mello, T.C.W.P., Navia, L.M.S., Paulo, S.R., Zúñiga, A., Employment of thin thorium films in fission track neutron dosimetry (1995) Braz. J. Phys., pp. 246-251Bigazzi, G., Hadler, J.C., Iunes, P.J., Oddone, M., Paulo, S.R., Zúñiga, A., Absolute thermal neutron fluence determination by thin film of natural uranium (1995) Nucl. Instrum. Meth. Phys. Res., 352 A, pp. 588-591Bigazzi, G., Guedes, S., Hadler, J.C., Iunes, P.J., Oddone, M., Osorio, A.M., Paulo, S.R., Zúñiga, A., Potentialities and practical limitations of an absolute neutron dosimetry using thin films of uranium and thorium applied to the Fission Track Method (1999) Radiat. Meas., 31, pp. 651-656Coderre, J.A., Morris, G.M., The radiation biology of boron neutron capture therapy (1999) Radiat. Res., 151, pp. 1-18Deevband, M.R., Abdolmaleki, P., Kardan, M.R., Khosravi, H.R., Taheri, M., An investigation on the response of PADC detectors to neutrons (2011) Appl. Radiat. Isot., 69, pp. 340-345Durham, J.S., Blue, T.E., Wehring, B.W., Ragheb, M.H., Blue, J.W., Microdosimetry in fast-neutron therapy by automatic readout of CR-39 solid state nuclear track detectors (1989) Nuc. Instr. Meth. Phys. Res., 36 B, pp. 319-331Quantification and reporting of low-dose and other heterogeneous exposures (2011) J. ICRU, 11, pp. 1-77Iunes, P.J., Hadler, J.C., Bigazzi, G., Guedes, S., Zúñiga, A., Paulo, S.R., Tello, S.C.A., Uranium and thorium thin film calibrations by particle track techniques (2004) J. Radioanalytical Nucl. Chem., 262, pp. 461-468Smilgys, B., Guedes, S., Hadler, J.C., Coelho, P.R.P., Alencar, I., Soares, C.J., Salim, L.A., Manufacturing of boron thin films for the measurement of the 10B(n,α)7Li reaction in BNCT (2011) Proc. Sci., , XXXIV BWN
Thermochronology Of The South American Platform In The State Of São Paulo, Brazil, Through Apatite Fission Tracks
No full textThe fission-track method (FTM) in apatite was applied to 45 samples collected in the Serra da Mantiqueira (Mantiqueira mountain range), the Serra do Mar (Mar mountain range), regions next to these mountain ranges and the coastal region between Ubatuba and Santos in the State of São Paulo, Brazil, to study the thermochronology of the South American Platform in southeast Brazil and its influence on Santos and Campos basins. The data presented in this work complement the previously presented data on the same region (Tello Saenz et al., 2003. J. S. Am. Earth Sci. 15, 765-774) with 31 new samples analyzed. The weighted mean of the corrected ages from high Mantiqueira (around 1000 m), (121±6)Ma, coincides with the South Atlantic opening. The fact that its thermal history starts at a relatively low temperature (∼80°C) suggests that the age of ∼120Ma would be the formation age of Serra da Mantiqueira due to a rapid pulse, in which tracks had no time to be retained at the closure temperature, that is ∼120°C. The Serra do Mar presents a more complicated thermal history, with several reactivations indicated by the changes in the slope of its cooling curve. The thermal histories obtained in the regions next to these mountain ranges are compatible with the results mentioned above. The Santos Basin has unconformities that agree with changes in the slope thermal histories of the studied region. © 2005 Elsevier Ltd. All rights reserved.396635640Almeida, F.F.M., Carneiro, C.D.R., Origem e evolução da Serra do Mar (1998) Rev. Bras. Geociência, 28, pp. 135-150Amaral, G., Born, H., Hadler Neto, J.C., Iunes, P.J., Kawashita, K., Machado Jr., D.L., Oliveira, E.P., Tello Saenz, C.A., Fission track analysis of apatites from São Francisco craton and mesozoic alcaline-carbonatite complexes from central and southeastern Brazil (1997) J. S. Am. Earth Sci., 10, pp. 285-294Fleischer, R.L., Hart, H.R., Fission track dating: Techniques and problems (1972) Proceedings of Burg Wartenstein Conference on Calibration of Hominoid Evolution, pp. 135-170. , W.W. Bishop D.A. Miller S. Colle Scottish Academic Press EdinburghGuedes, S., Hackspacher, P., Hadler Neto, J.C., Iunes, P.J., Paulo, S.R., Ribeiro, L.F.B., Tello Saenz, C.A., Constraints on the evolution and thermal history of the continental platform of southeast Brazil, São Paulo state, using Fission Track Analyses (AFTA) (2000) Rev. Bras. Geociências, 30, pp. 107-109Guedes, S., Hadler Neto, J.C., Iunes, P.J., Paulo, S.R., Zuñiga, A., The spontaneous fission decay constant of 238U using SSNTD (2000) J. Radioanal. Nucl. Chem., 245, pp. 441-442Guedes, S.O., Hadler Neto, J.C., Iunes, P.J., Zuñiga, A.G., Tello Saenz, C.A., Paulo, S.R., The use of the U(n,f) reaction dosimetry in the determination of the λf value through fission-track techniques (2003) Nucl. Instrum. Meth. A, 496, pp. 215-221Guedes, S., Hadler Neto, J.C., Sarkis, J.E.S., Oliveira, K.M.G., Kakazu, M.H., Iunes, P.J., Saiki, M., Paulo, S.R., Spontaneous-fission decay constant of 238U measured by nuclear techniques without neutron irradiation (2003) J. Radioanal. Nucl. Chem., 258, pp. 117-122Hadler Neto, J.C., Paulo, S.R., Iunes, P.J., Tello Saenz, C.A., Balestrieri, M.L., Bigazzi, G., Curvo, E.A.C., Hackspacher, P., A PC compatible Brazilian software for obtaining thermal histories using apatite fission track analysis (2001) Radiat. Meas., 34, pp. 149-154Hadler Neto, J.C., Bigazzi, G., Guedes, S., Iunes, P.J., Oddone, M., Tello Saenz, C.A., Paulo, S.R., Spontaneous U-238 fission half-life measurements based on fission track techniques (2003) J. Radioanal. Nucl. Chem., 256, pp. 155-157Holden, N.E., Hoffman, D.C., Spontaneous fission half-lives ground-state nuclides (Technical report) (2000) Pure Appl. Chem., 72, pp. 1525-1562Iunes, P.J., Hadler Neto, J.C., Bigazzi, G., Tello Saenz, C.A., Guedes, S.O., Paulo, S.R., Durango apatite fission-track dating using length-based age corrections and neutron fluence measurements by thorium thin films and natural U-doped glasses calibrated through natural uranium thin films (2002) Chem. Geol., 187, pp. 201-211Laslett, G.M., Green, P.F., Duddy, I.R., Gleadow, J.W.A., Thermal annealing of fission tracks in apatite 2. The quantitative analysis (1987) Chem. Geol., 65, pp. 1-13Lutz, T.M., Omar, G., An inverse method of modeling thermal histories from apatite fission-track dates (1991) Earth Planet. Sci. Lett., 104, pp. 181-195Pereira, M.J., Feijó, F.J., Bacia de Santos (1994) Bol. Geociências Petrobrás, 8, pp. 219-234Tello Saenz, C.A., Hackspacher, P., Hadler Neto, J.C., Iunes, P.J., Guedes, S.O., Paulo, S.R., Ribeiro, L.F.B., Recognition of Cretaceus, Paleocene and Neogene Tectonic reactivation, through apatite fission-track analysis, in Precambrian areas of the Southeast Brazil: Association with the South Atlantic Ocean opening (2003) J. S. Am. Earth Sci., 15, pp. 765-774Tello Saenz, C.A., Hadler Neto, J.C., Iunes, P.J., Guedes, S., Paulo, S.R., Annealing experiments on induced fission tracks in apatite: I. Measurements of horizontal-confined-track lengths and track densities in basal sections and randomly oriented grains (2004) Am. Mineral., , submitte
Comparison Between Thorium And Uranium Fission Track Diameters In Glass
No full textComparisons between diameters of uranium and thorium neutron induced fission tracks in glass made possible to test indirectly the hypothesis that observation efficiency of spontaneous 238U and induced 235U fission tracks may be considered the same. The sources of fission fragments were uranium and thorium thin films irradiated with neutrons with and without Cd-cover. After irradiation, the glasses were etched for 50 s by HF 24% at 15 {ring operator} C followed by another etching for 30 s in same conditions. Diameters were measured after each chemical etching. Only tracks presenting a ratio between the longer and shorter diameters lesser than 1.1 have been analyzed. The results indicates the hypothesis is valid. © 2008 Elsevier Ltd. All rights reserved.43SUPPL.1S329S333Bigazzi, G., Hadler, J.C., Iunes, P.J., Osório, A.M., Fission track DS / DI measurement in artificial glass at conditions free from fading and radiation (1991) Nucl. Instrum. Methods B, 53, pp. 67-70Iunes, P.J., Hadler, J.C., Bigazzi, G., Tello, C.A., Guedes, S.O., Paulo, S.R., Durango apatite fission-track dating using length-based age corrections and neutron fluence measurements by thorium thin films and natural U-doped glasses calibrated through natural uranium thin films (2002) Chem. Geol., 187, pp. 201-211Tagami, T., Nishimura, S., Neutron dosimetry and fission-track age calibration: insights from intercalibration of uranium and thorium glass dosimeters (1992) Chem. Geol., 102, pp. 277-296Wagner, G.A., Van den haute, P., (1992) Fission-track dating, , Kluwer Academics Publisher, LondonWahl, J.S., Energy distributions of fragments from fission of 235U, 238U and 239Pu by fast neutrons (1954) Phys. Rev., 95, pp. 126-13
- …
