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Your search keyword '"Tauhata, Luiz"' showing total 26 results
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26 results on '"Tauhata, Luiz"'

17. Comparison of Tc activity measurements at LNMRI using SIRTI of the BIPM, a new instrument for comparing short-lived radionuclides.

Author

Cruz, Paulo, Silva, Carlos, Moreira, Denise, Iwahara, Akira, Tauhata, Luiz, S. Loureiro, Jamir, Delgado, José, and Lopes, Ricardo

Subjects
TECHNETIUM isotopes, MAGNETIC resonance imaging, RADIOISOTOPES, NUCLEAR medicine, DIAGNOSTIC imaging, RADIOPHARMACEUTICALS
Abstract

Technetium-Tc is the most widely used radionuclide for obtaining diagnostic imaging in nuclear medicine and its demand is growing every year. In order to provide metrological traceability to producers and end users in Brazil to fulfil nuclear regulatory requirements for radiopharmaceuticals, National Laboratory of Ionizing Radiation Metrology/Institute of Radioprotection and Dosimetry attended, in 2013, an activity comparison measurement of Tc through BIPM Transfer Instrument SIRTI. The measurement results and the degree of equivalence between the key comparison reference value and LNMRI value are presented. The LNMRI result agreed with the measured value by SIRTI within one standard uncertainty. [ABSTRACT FROM AUTHOR]

Published
2015
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23. Calibration of the LNMRI Secondary Standard Ionization Chamber for I capsules used in nuclear medicine.

Author

Chaves, Tainá, Iwahara, Akira, Tauhata, Luiz, Rezende, Eduarda, Correia, Amanda, and Oliveira, Estela

Subjects
MAGNETIC resonance imaging, IONIZATION chambers, NUCLEAR medicine, RADIOISOTOPES, IONIZING radiation, NUCLEAR engineering
Abstract

The radionuclide I has been increasingly used in nuclear medicine therapy procedures. Nowadays, the I source administered to the patient is manufactured in two different geometries: solution and capsules. The purpose of this study is the accurate measurement of the activity present in a I capsule without destroys it. The methodology to determine the capsules activity is to obtain the calibration factor of an IG12 secondary standard activity measurement system based on the IG12 well-type ionization chamber set up at Brazilian national metrology laboratory for ionizing radiation (LNMRI) of institute of radiation protection and dosimetry (IRD).The result obtained, 6.4670 ± 0.0381 × 10 A Bq, is quite similar to the calibration factor of the I solution contained in the standard ampoule geometry, 6.4515 ± 0.0368 × 10 A Bq. After obtaining the calibration factor it was used to measure I therapy capsules in order to check the performance of radionuclide calibrators of some Brazilian nuclear medicine centers. [ABSTRACT FROM AUTHOR]

Published
2012
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24. Fatores de correção volumétrica na medição de atividade de 99mTc e 123I em calibradores de radionuclídeos.

Author

Correia, Amanda Ribeiro, Iwahara, Akira, Tauhata, Luiz, Rezende, Eduarda Alexandre, Chaves, Tainá Olivieri, Oliveira, Antonio Eduardo de, and Oliveira, Estela Maria de

Subjects
RADIOISOTOPES, CORRECTION factors, RADIOPHARMACEUTICALS, IONIZATION chambers, GEIGER-Muller counters, NUCLEAR medicine
Abstract

Copyright of Radiologia Brasileira is the property of Radiologia Brasileira and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2012
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25. Primary activity standardization of 99Tc by three different absolute methods.

Author

da Cruz, Paulo A.L., da Silva, Carlos J., Moreira, Denise S., Iwahara, Akira, Tauhata, Luiz, and Lopes, Ricardo T.

Subjects
*TECHNETIUM, *LIQUID scintillation counting, *COINCIDENCE circuits, *RADIOISOTOPES, *COMPARATIVE studies
Abstract

Abstract: The activity concentration of a solution of 99Tc was absolutely determined by liquid scintillation measurements based on the triple-to double-coincidence ratio method (TDCR) and compared with the results given by 4πβ(LS)-γ(NaI) live-timed anticoincidence (with extending dead-time) and classical 4πβ(PC)-γ(NaI) coincidence counting systems based on using 60Co as the efficiency-tracing radionuclide. The results of anticoincidence and coincidence counting are, respectively, 0.18% and 0.66% higher than the result from TDCR measurements, but they are consistent within uncertainties. [Copyright &y& Elsevier]

Published
2014
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26. A theoretical-experimental approach of the sum-peak method and its applications

Author

Araújo, Miriam Tainá Ferreira de, Delgado, José Ubiratan, Iwahara, Akira, Tauhata, Luiz, Oliveira, Davi Ferreira de, Silva, Carlos José da, and Lopes, Ricardo Tadeu

Subjects
Método pico-soma, Padronização absoluta do 121Te, Padronização absoluta do 60Co, Padronização absoluta do 22Na, Padronização absoluta do 65Zn, ENGENHARIAS::ENGENHARIA NUCLEAR [CNPQ]
Abstract

Submitted by Marlon Silva (marlonviniciuspacheco@gmail.com) on 2021-02-17T14:44:47Z No. of bitstreams: 1 MiriamTainaFerreiraDeAraujo.pdf: 6216413 bytes, checksum: 919e51a574260a2f1b5522b363a518e9 (MD5) Made available in DSpace on 2021-02-17T14:44:47Z (GMT). No. of bitstreams: 1 MiriamTainaFerreiraDeAraujo.pdf: 6216413 bytes, checksum: 919e51a574260a2f1b5522b363a518e9 (MD5) Previous issue date: 2018-10 O método pico-soma tem seu uso destinado à padronização absoluta de radioisótopos emissores de radiação eletromagnética sob regime de coincidência. Desde a época da concepção do método feita em 1963 por Brinkman e colaboradores, a evolução dos aparatos experimentais permitiu melhorias na acurácia da medição de parâmetros de relevância que são utilizados para a obtenção da grandeza atividade por exemplo. Algumas inconsistências teóricas e conceituais foram observadas na proposta original do método, que serão cuidadosamente discutidas e reapresentadas neste trabalho. Portanto, o cerne desta pesquisa consistirá da apresentação de uma abordagem teórica e experimental para o método pico-soma a fim de que as considerações a ele atribuídas reafirmem-no para aplicação em padronizações absolutas, e que com isso o mesmo se torne mais aceito por parte da comunidade científica metrológica. Como consequência destas correções, um estudo detalhado das incertezas associadas ao método, análise crítica da instrumentação utilizada e a apresentação de medições de parâmetros obtidos para vários radionuclídeos foi feita visando à completude do estudo apresentado neste manuscrito. The sum-peak method has its use for the absolute standardization of radioisotopes emitting electromagnetic radiation under a coincidence regime. From the time of the conception of the method made in 1963 by Brinkman et al., the evolution of the experimental apparatus allowed improvements in the accuracy of the measurement of relevance parameters that are used to obtain the activity greatness for example. Some theoretical and conceptual inconsistencies were observed in the original proposal of the method, which will be carefully discussed and re-presented in this work. Therefore, the core of this research will consist of the presentation of a theoretical and experimental approach to the sum-peak method in order that the considerations attributed to it reaffirm it for application in absolute standardizations, and with that the same becomes more accepted by part of the metrological scientific community. As a consequence of these corrections, a detailed study of the uncertainties associated to the method, critical analysis of the instrumentation used and the presentation of measurements of parameters obtained for several radionuclides was done aiming at the completeness of the study presented in this manuscript.

Published
2018

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