JOÃO AUGUSTO MOURA

JOÃO AUGUSTO MOURA

(Fonte: Lattes)

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Possui graduação em Tecnologia em saúde pela Faculdade de Tecnologia de Sorocaba (2005). Mestrado em Tecnologia Nuclear pela Universidade de São Paulo (2009). Doutorado em Tecnologia Nuclear pela Universidade de São Paulo (2015). Tem experiência na área de Tecnologia Nuclear, com ênfase em produção de fontes para radioterapia. Atualmente trabalha em pesquisa e desenvolvimento no Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP). (Texto extraído do Currículo Lattes em 8 maio 2023)

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Improvements in the quality control of iridium-192 wire used in brachytherapy
2011 - COSTA, OSVALDO L.; ZEITUNI, CARLOS A.; ROSTELATO, MARIA E.C.M.; MOURA, JOÃO A.; FEHER, ANSELMO; MOURA, EDUARDO S.; SOUZA, CARLA D.; SOMESSARI, SAMIR L.
Brachytherapy is a method used in the treatment of cancerous tumors by ionizing radiation produced by sources introduced into the tumor area, this method seeks a more direct attack to the tumor, thereby maximizing the radiation dose to diseased tissue while minimizing the dose to healthy tissues (1). One of the radionuclides used in brachytherapy is iridium-192. The Radiation Technology Center (CTR) of the Nuclear and Energy Research Institute (IPEN) has produced commercially, since 1998, iridium-192 wires used in low dose rate (LDR) brachytherapy (2). To produce this radionuclide, firstly a iridium-platinum wire is irradiated in the nuclear reactor IEA-R1 for 30 hours with a neutron flux of 5 x 1013 ncm-2s-1, the wire is left to decay by 30 days to remove the main contaminants and then goes through a quality control before being sent to the hospital. In this quality control is checked the radiation homogeneity along each centimeter of the wire (3). To implement this procedure is used a device consisting of an ionization chamber surrounded by a lead shield with a small 1 cm wide slit, linked to the ionization chamber is a voltage source and a Keithley 617 electrometer, 2 minutes is the range used to measure the charge by the electrometer. The iridium wire is considered in accordance when there is no variation greater than 5% between the average measures and the maximum and minimum values. However, due to design features of the measurement system, the wire may appear to the detector through the slit in larger sizes than the ideal, improperly influencing the final quality control. This paper calculates the difference in size of these variations in profile and their influence on the final count, it compares the actual values obtained and describes the improvements made in quality control procedures that provided more accurate measurement data, analyzes the results and suggests changes in devices aimed at further improving the quality control of iridium-192 wires produced at IPEN and used in hospitals in Brazil.
Development of an automated system for the operation of an electron beam accelerator
2019 - SOMESSARI, S.L.; MOURA, J.A.; CALVO, W.A.P.
Electron beam accelerators are used in many applications, such as basic physical research, chemistry, medicine, molecular biology, microelectronics, agriculture and industry, among others. The majority of the accelerators have electrons from a hot tungsten filament and their energy is increased as it passes through an electric field in the vacuum chamber. For industrial purposes, the most common model is Dynamitron®. At IPEN-CNEN/SP, there is an electron beam accelerator Dynamitron® Type (Manufactured by RDI - Radiation Dynamics Inc., 1978) model DC1500/25/4. The technology applied was available in the 60´s and 70´s, but, nowadays is obsolete. Moreover, there are not original spare parts for this equipment any longer. The aim of this work is to develop a nationalized automated operation system for the accelerator, to replace the old equipment and allow extending the useful life of the accelerator for around ten years.
Development of an automated system for the operation of an electrom beam acellerator
2017 - SOMESSARI, SAMIR L.; MOURA, JOAO A.; CALVO, WILSON A.P.
Electron beam accelerators are used in many applications, such as basic physical research, chemistry, medicine, molecular biology, microelectronics, agriculture and industry, among others. The majority of the accelerators have electrons from a hot tungsten filament and their energy is increased as it passes through an electric field in the vacuum chamber. For industrial purposes, the most common model is Dynamitrons®. At IPEN-CNEN/SP, there is an electron beam accelerator Dynamitron® Type (Manufactured by RDI- Radiation Dynamics Inc., 1978) model DC1500/25/4. The technology applied was available in the 60´s and 70´s, but, nowadays is obsolete. Moreover, there are not original spare parts for this equipment any longer. The aim of this work is to develop a nationalized automated operation system for the accelerator, to replace the old equipment.
Theoretical, manufacturing and clinical application aspects of a prostate brachytherapy I-125 source in Brazil
2012 - ZEITUNI, CARLOS A.; SOUZA, CARLA D.; MOURA, EDUARDO S.; SAKURABA, ROBERTO K.; ROSTELATO, MARIA E.C.M.; FEHER, ANSELMO; MOURA, JOAO A.; SOMESSARI, SAMIR; COSTA, OSVALDO L.
Influence of the profile of iridium-192 wire in measurements of quality control for use in brachytherapy
2013 - COSTA, OSVALDO L.; ZEITUNI, CARLOS A.; ROSTELATO, MARIA E.C.M.; MOURA, JOAO A.; FEHER, ANSELMO; MOURA, EDUARDO S.; SOUZA, CARLA D.; SOMESSARI, SAMIR L.; PELEIAS JUNIOR, FERNANDO S.; MATTOS, FABIO R.
Leakage test evaluation used for qualification of iodine-125 seeds sealing
2009 - FEHER, ANSELMO; ROSTELATO, MARIA E.C.M.; ZEITUNI, CARLOS A.; CALVO, WILSON A.P.; SOMESSARI, SAMIR L.; MOURA, JOAO A.; SOUZA, CARLA D.; RELA, PAULO R.
Development of an encapsulation method using plasma arc welding to produce iodine-125 seeds for brachytherapy
2011 - FEHER, ANSELMO; CALVO, WILSON A.P.; ROSTELATO, MARIA E.C.M.; ZEITUNI, CARLOS A.; SOMESSARI, SAMIR L.; COSTA, OSVALDO L.; MOURA, JOAO A.; MOURA, EDUARDO S.; SOUZA, CARLA D.; RELA, PAULO R.
Automation system for quality control in manufacture of iodine-125 sealed sources used in brachytherapy
2011 - SOMESSARI, SAMIR L.; FEHER, ANSELMO; SPRENGER, FRANCISCO E.; ROSTELATO, MARIA E.C.M.; MOURA, JOAO A.; COSTA, OSVALDO L.; CALVO, WILSON A.P.
A study about the measurement method of the homogeneity of radioactivity along an iridium-192 wire used in brachytherapy
2014 - COSTA, OSVALDO L.; CALVO, WILSON A.P.; ZEITUNI, CARLOS A.; ROSTELATO, MARIA E.C.M.; MOURA, JOAO A.; FEHER, ANSELMO; SOUZA, CARLA D.; SOMESSARI, SAMIR L.
The Nuclear and Energy Research Institute has produced, since 1998, iridium-192 wires used in low dose rate brachytherapy. In the paper the authors studied the influence of wire profile on the homogeneity distribution of radioactivity of iridium-192 along the wire. The authors propose the improvements in the quality control procedure that will provide more accurate measurement data and suggest changes in control devices.
Leakage test evaluation used for qualification of iodine-125 seeds sealing
2011 - FEHER, ANSELMO; ROSTELATO, MARIA E.C.M.; ZEITUNI, CARLOS A.; CALVO, WILSON A.P.; SOMESSARI, SAMIR L.; MOURA, JOAO A.; MOURA, EDUARDO S.; SOUZA, CARLA D.; RELA, PAULO R.