スペクトル取得型光学オゾンゾンデ用分光器の感度波長特性

第6回極域科学シンポジウム分野横断型セッション：[IM] 横断　中層大気・熱圏11月17日（火）　国立極地研究所１階交流アトリウ

Study on measuring device arrangement of array-type CdTe detector for BNCT-SPECT

AimTo design the measuring device arrangement of array-type CdTe detector for BNCT-SPECT.BackgroundIn a boron neutron capture therapy, a very serious unsolved problem exists, namely that the treatment effect for BNCT cannot be known during irradiation in real time. Therefore, we have been developing a so-called BNCT-SPECT with a CdTe detector, which can obtain a three-dimensional image for the BNCT treatment effect by measuring 478[[ce:hsp sp="0.25"/]]keV gamma-rays emitted from the excited state of 7Li nucleus created by the 10B(n,α) reaction. However, no practical uses were realized at present, because BNCT-SPECT requires very severe conditions for spatial resolution, measuring time, statistical accuracy and energy resolution.Materials and methodsThe design study was performed with numerical simulations carried out by a 3-dimenaional transport code, MCNP5 considering the detector assembly, irradiation room and even arrangement of arrayed CdTe crystals.ResultsThe estimated count rate of 478[[ce:hsp sp="0.25"/]]keV gamma-rays was sufficiently large being more than the target value of over 1000[[ce:hsp sp="0.25"/]]counts/h. However, the S/N ratio did not meet the target of S/N[[ce:hsp sp="0.25"/]]>[[ce:hsp sp="0.25"/]]1. We confirmed that deterioration of the S/N ratio was caused by the influence of Compton scattering especially due to capture gamma-rays of hydrogen. Theoretical calculations were thereafter carried out to find out whether anti-Compton measurement in an array-type CdTe detector could decrease the noise due to Compton scatterings.ConclusionsThe calculation result showed that the anti-coincidence would possibly increase the S/N ratio. In the next phase, an arrayed detector with two CdTe crystals will be produced to test removal possibility of the anti-coincident event

Production of C

Ethanol conversion to C3+ olefins, especially propylene, using Zr-modified H-ZSM-5 catalysts was investigated. Zr-modification to H-ZSM-5 zeolite could improve the initial yield of C3+ olefins and propylene and could reduce the initial yield of ethylene. In general, catalysts exhibiting the higher initial yield of propylene showed the steeper decrease in propylene yield as the reaction proceeded. However, Zr-modification to H-ZSM-5 could depress the decrease in propylene yield for aqueous ethanol. As cause of catalytic deactivation, carbon deposition on catalyst and framework collapse of zeolite support can be considered. The addition of water to Zr-modified H-ZSM-5 catalyst could depress carbon deposition in some degree, and, as a result, the decrease in propylene yield could be depressed

Análise do comportamento financeiro de alunos inadimplentes de uma instituição de ensino superior: estratégias para a gestão organizacional

In recent years, several companies in the education segment have faced significant challenges related to default, especially during the COVID-19 pandemic. Between 2020 and 2023, the default rate increased from 21.95% to 3.83%, demonstrating the effectiveness of the strategies adopted, such as financial discounts for punctual payments. To overcome this situation, institutions implemented adaptations in their teaching processes and payment system, in line with the National Education Plan (PNE), which aims to improve the quality of education in Brazil. In this study, an investigation was carried out on how consumer behavior analysis strategies from a large company contributed to understanding the motivations and difficulties faced by students. The variation in enrollments reflected the necessary adaptations, with a view to the implementation of 4G Management, which covers financial management, operations, strategy and information technology, contributing to a more efficient administration of resources. In this study, it was identified that future recommendations, such as the periodic review of discount policies and the introduction of more flexible payment plans, can ensure continued success in default management and the institution\u27s financial sustainability.Nos últimos anos, várias empresas do segmento educacional enfrentaram desafios significativos relacionados à inadimplência, especialmente durante a pandemia de COVID-19. Entre 2020 e 2023, a taxa de inadimplência passou de 21,95% para 3,83%, evidenciando a eficácia das estratégias adotadas, como descontos financeiros para pagamentos pontuais. Para contornar essa situação, as instituições implementaram adaptações em seus processos de ensino e no sistema de pagamento, em consonância com o Plano Nacional de Educação (PNE), que visa melhorar a qualidade da educação no Brasil. Neste estudo, foi realizado uma investigação sobre como as estratégias de análise do comportamento do consumidor de uma empresa de grande porte contribuíram para a compreensão das motivações e dificuldades enfrentadas pelos alunos. A variação nas matrículas refletiu as adaptações necessárias, tendo em vista a implementação da Gestão 4G, que abrange gestão financeira, operações, estratégia e tecnologia da informação, contribuiu para uma administração mais eficiente dos recursos. Neste estudo, identificou-se que recomendações futuras como a revisão periódica das políticas de desconto e a introdução de planos de pagamento mais flexíveis, pode assegurar a continuidade do sucesso na gestão da inadimplência e na sustentabilidade financeira da instituição

<ORIGINAL REPORT>X-ray scanning analytical microscopic and scanning electron microscopic studies of an unusual case of dens invaginatus

A mass was extirpated from the region of the maxillary right third molar of a 20 year-old patient. It was proved to be an extreme and unerupted case of dens invaginatus. The clinical and histopathological features have been presented in a previous paper. Ameloblasts and odontoblasts were noted along the surface of enamel or dentin. In the present study, X-ray scanning analytical microscopy (XSAM), a newly developed technique, together with scanning electron microscopy (SEM) was applied for the study of this malformed tooth. SEM study showed a strange arrangement of well-formed enamel and dentin in normal structures. The distribution of calcium (Ca) and phosphorus (P) was clearly observed by the XSAM method. It revealed that the bulk of dentin was composed of two kinds of dentin quite different in mineral content while their SEM appearances were similar. The part of the dentin near the dentinoenamel junction had much higher Ca and P concentrations than the outer parts. In conclusion, the disagreement between the microscopic findings and the XSAM findings suggests the importance of applying various methods in studies to obtain a comprehensive understanding of such malformation. In addition, the present investigation also points out the complexity of the disturbance ranging within the term dens invaginatus