ダブルショー実験でのθ13測定の改良及び異なるベースラインでの原子炉ニュートリノ振動による有効Δm312の初めての測定

Tohoku University末包文彦課

Double Chooz and a history of reactor θ<inf>13</inf> experiments

This is a contribution paper from the Double Chooz (DC) experiment to the special issue of Nuclear Physics B on the topics of neutrino oscillations, celebrating the recent Nobel prize to Profs. T. Kajita and A.B. McDonald. DC is a reactor neutrino experiment which measures the last neutrino mixing angle θ13. The DC group presented an indication of disappearance of the reactor neutrinos at a baseline of ∼1 km for the first time in 2011 and is improving the measurement of θ13. DC is a pioneering experiment of this research field. In accordance with the nature of this special issue, physics and history of the reactor-θ13 experiments, as well as the Double Chooz experiment and its neutrino oscillation analyses, are reviewed

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Study of the sensitivity of the neutrino's detector of the ANGRA Project to the effects of the nuclear fuel burn-up

Orientador: Ernesto KempDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb WataghinResumo: Reatores nucleares constituem uma profusa fonte de antineutrinos, cujo espectro é determinado pelos decaimentos beta dos isótopos radioativos presentes no combustível nuclear. À medida que o combustível é consumido, sua composição isotópica é alterada, com reflexos diretos no espectro de antineutrinos. Desta forma, investigamos neste trabalho a viabilidade de um detector de neutrinos monitorar o reator de uma usina nuclear, sabendo seu estado de atividade. Também investigamos a evolução temporal da resposta do detector à queima gradual do combustível nuclear. Assim, determinamos o tempo necessário de coleta de dados para identificarmos que o combustível nuclear evoluiu para outra composição, para vários níveis de confiança, com relação ao início de operação da usina. Estes resultados fazem da detecção de antineutrinos de reatores nucleares uma ferramenta adicional para a verificação de salvaguardas nuclearesAbstract: Nuclear reactors are a profuse neutrino source, which spectrum is determined by the beta decay of the fissile isotopes in the nuclear fuel. While the fuel is consumed, the isotopic composition changes, resulting in trends on the neutrino spectrum. So, we investigated in this work the viability of monitoring a reactor of a nuclear power plant with a neutrino detector, knowing its state of activity. We also investigated the temporal evolution of the response time of the detector in function of the gradual burn of the fuel. Therefore, with some confidence levels, we determined the needed time of data taking to identify fuel changes, in a PWR power plant, related to the beginning of operation. Consequently, these results make the detection of antineutrinos of nuclear reactors an additional method to nuclear safeguardsMestradoFísica das Particulas Elementares e CamposMestre em Físic

Núcleos de Ensino da Unesp: artigos 2013: volume 2: metodologias de ensino e a apropriação de conhecimento pelos alunos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP