JOAO PEDRO DE OLIVEIRA FLORES
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Artigo IPEN-doc 30602 Re-characterization of pneumatic station irradiation position of IEA-R1 reactor for use in k0 - INAA method2024 - FLORES, J.P.O.; SEMMLER, R.; DIAS, M.S.; KOSKINAS, M.F.; MOREIRA, D.S.; YAMAZAKI, I.M.; SILVA, P.S.C.; MAIHARA, V.A.Artigo IPEN-doc 27914 Calibration of the short irradiation facility for k0 - NAA implementation at the IEA-R1 reactor2021 - OLIVEIRA, J.P.; SILVA, P.S.C.; SEMMLER, R.; DIAS, M.S.; KOSKINAS, M.F.; MOREIRA, D.S.; YAMAZAKI, I.M.The short irradiation facility of the IEA-R1 nuclear research reactor at IPEN, São Paulo, Brazil, has been used for short irradiation of samples for the purpose of determining the concentration of elements of these samples through the use of the instrumental neutron activation analysis technique. With the aim of determine precisely the reactor parameters α and f, for implementing the k0-NAA method at the Neutron Activation Analysis Laboratory (LAN), was used the bare triple method. In this method, a set of three neutron flux monitors were irradiated without Cd-cover. The efficiency curve of the gamma-ray spectrometer used was determined by measuring calibrated radioactive sources at the commonly used counting geometries. The results for the parameters α and f were respectively 0.0384±0.0016 and 35.67±0.26. This value of f shows that the neutrons in the irradiation position are well thermalized. The variation of these parameters was studied with time and the reproducibility was verified.Artigo IPEN-doc 26150 Calibration of the short irradiation facility for K0 − NAA implementation at the IEA-R1 Reactor2019 - OLIVEIRA, J.P.; SILVA, P.S.C.; SEMMLER, R.The short irradiation facility of the IEA-R1 nuclear research reactor at IPEN, S~ao Paulo, Brazil, has been used for short irradiation of samples for the purpose of determining the concentration of elements of these samples through the use of the instrumental neutron activation analysis technique. With the aim of implementing the k0-NAA method at the Neutron Activation Analysis Laboratory (LAN), the reactor parameters and f were obtained using the bare triple method. In this method, a set of three neutron ux monitors were irradiated without Cd-cover. The e ciency curve of the gamma-ray spectrometer used were determined by measuring calibrated radioactive sources at the usually utilized counting geometries. The results obtained for the parameters and f were respectively 0:0384 0:0016 and 35:67 0:26. The obtained value of f shows that the neutrons in the irradiation position are well thermalized, in other words, the value of f, means that thermal neutron ux is 35 times higher than epithermal neutron ux. It means that this irradiation position is well thermalized. The variation of these parameters was studied with time and the reproducibility was veri ed.Artigo IPEN-doc 25002 Preparación de muestras del médio ambiente para análisis por médio de técnicas cromatograficas2017 - VEGA, O.; LOPES, P.R.; AMARAL, P.O.; GONSCHOROWSKI, G.; OLIVEIRA, J.P.; FABBRO, R.; MESQUITA, K.A.; GIMENEZ, M.P.; REDIGOLO, M.Este artículo explora la ciencia de la preparación de muestras para matrices sólidas, líquidos y gases, utilizados en el laboratorio del Centro de Química y Medio Ambiente del IPEN. Extracción de neonicotinoides del agua por LLE (Liquid-Liquid Extraction), extracción de hidrocarburos aromáticos policíclicos (PAHs) del agua atraves de DLLME (Dispersive liquid - liquid micro extraction) y el uso de extracción en fase sólida SPE (Solid Phase Extraction) para el análisis de hormonas en agua son descritos. Limites de detección que utilizan estas técnicas son descritas en este trabajo.Resumo IPEN-doc 24547 Characterization of neutron spectrum at the short irradiation facility of the IEA-R1 reactor using the bare triple monitor method2017 - FLORES, J.P.O.; SEMMLER, R.The neutron spectrum parameters were determined in the short irradiation facility of the IEA-R1 reactor of IPEN. The neutron spectrum parameters are: the epithermal neutron flux shape factor ( ) approximated by a 1=E1+ distribution and the thermal to epithermal neutron flux ratio (f ). According to the HOGDAHL formalism, the k0-NAA method uses the following input parameters: the full energy peak detection efficiency ("p), and nuclear data on Q0 (ratio of resonance integral I0 to thermal neutron cross-section 0) and k0 factors. The and f parameters depend on each irradiation facility and "p depends on each counting facility. In the HOGDAHL formalism the reactor neutron spectrum parameters ( and f ) can be obtained using three methods: Cd-ratio, Cd-covered and bare triple monitors. In this work and f were determined by the bare triple monitor method. In this method, a set of three neutron flux monitors are irradiated without Cd-cover. The efficiency curves of the gamma-ray spectrometer used were determined by measuring calibrated radioactive sources at the usually utilized counting geometries.Resumo IPEN-doc 23484 Caracterização do fluxo de nêutrons epitérmicos do reator IEA-R1 utilizando o método bare triple monitor para o uso em análise por ativação2017 - FLORES, JOAO P. de O.; SEMMLER, RENATOResumo IPEN-doc 23778 Protein crosslinking by high energy irradiation - towards the development of size-controlled biocompatible nanocarriers2016 - VARCA, G.H.; MOHAMED, L.B.; FAZOLIN, G.N.; OLIVEIRA, J.P.; BATISTA, J.G.; LUGAO, A.B.Protein and peptide based delivery systems are on the spotlight considering their unique properties specially related to site specific delivery and high biocompatibility despite other biopharmaceutical advantages. Following the recent success of the so-called NAB platform, most of the attention has been driven towards the development of cosolvent -free or crosslinker-free technologies capable of producing protein nanoparticles with a specific size or shape, in the seek for better or preferential tumor uptake and low or negligible toxicity among other features. Within this context irradiation stands a tool capable of promoting protein crosslinking and sterilization of the systems simultaneously, in which combined or not with other techniques may allow the design of nanocarriers without the need of monomers or toxic crosslinkers. This research details the use of high energy irradiation towards the design of size-controlled protein-based nanocarriers for drug delivery. The albumin or papain based nanocarriers were designed by combining desolvation/solvation techniques followed by gamma irradiation or gamma irradiation alone. Sizecontrolled nanocarriers were manufactured up to 80 nm, as determined by dynamic light scattering, depending upon the protein or the presence of cosolvent. Nanocarrier morphology was evaluated by transmission electron microscopy, and protein crosslinking was evaluated by means of bityrosine formation using fluorescence measurements. Final applications of the developed systems comprise relevant potential for the delivery of radiopharmaceuticals or chemotherapic agents.Resumo IPEN-doc 22925 Caracterização do fluxo de nêutrons epitérmicos do reator IEA-R1 utilizando o método bare triple monitor para o uso em análise por ativação2016 - FLORES, JOAO P. DE O.; SEMMLER, RENATOResumo IPEN-doc 21403 Effective dose assessment due to Aguas de Lindoia water ingestion2015 - SILVA, P.S.C.; SAUEIA, C.H.R.; OLIVEIRA, J.P.; LAZZERINI, F.T.