Orientador: Tadeu de Siqueira Barros / Coorientador: Wagner Cotroni Valenti / Banca: Antonio Fernando Monteiro Camargo / Banca: Lúcia Helena Sipaúba Tavares / Banca: Matheus Nicolino Peixoto Henares / Banca: Irineu Bianchini Junior / Resumo: O objetivo deste estudo foi investigar o fluxo de gases do efeito estufa (GEE) em viveiros de criação de organismos aquáticos. Nós testamos se o uso de sistemas multitróficos e multiespaciais (IMTA), povoados com lambari-do-rabo-amarelo (Astyanax lacustris) e camarão-da-amazônia (Macrobrachium amazonicum) numa região tropical, altera o fluxo de gases do efeito estufa em comparação com um sistema de monocultivo de A. lacustris. Nós desenvolvemos um experimento em viveiros de fundo natural com três tratamentos e quatro réplicas: monocultivo (Tetra), IMTA livre (Free IMTA) e IMTA tanque rede (Cage IMTA). O experimento durou 68 dias, entre os meses de novembro e janeiro de 2016. Nós mensuramos os fluxos de dióxido de carbono (CO2), metano (CH4) e óxido nitroso (N2O) por meio das metodologias difusiva e dissolvida. A média dos fluxos na metodologia difusiva foi de -8.93 mg.m-2.h-1 para o CO2, -0.88 mg.m-2.h-1 para o CH4 e 1.78 mg.m-2.h-1 para o N2O. A concentração de CO2 variou de 0.0481 a 0.6668 mg.L-1, CH4 de 0.0003 a 0.0053 mg.L-1 e N2O de 0.0789 a 0.1177 mg.L-1. Nossos resultados indicam variação ao longo do tempo, com maior fluxo de GEE no início do experimento, diminuição ao longo do período de cultivo e tendência de neutralidade com relação a emissão de GEE no final do período experimental. / Abstract: The aim of this study was to investigate Greenhouse Gases (GHG) fluxes in aquaculture ponds. We tested if the use of Integrated Multi Trophic Aquaculture (IMTA) with Yellow tail tetra (Astyanax lacustris) and Amazon River prawn (Macrobrachium amazonicum) in a tropical environment changes the GHG flows in comparation with A. lacustris monoculture. We developed an experiment in earthen ponds with three treatments and four replications: monoculture (Tetra), two species free in the pond (Free IMTA) and fishes in cage and prawns free (Cage IMTA). Experiment ran 68 days between November and January 2016. We measured fluxes of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) with diffusive and dissolved methodologies. Mean of diffusive fluxes was -8.93 mg.m-2 .h-1 for CO2, -0.88 mg.m-2 .h-1 for CH4 e 1.78 mg.m-2 .h-1 for N2O. Concentration of CO2 oscillated between 0.0481 and 0.6668 mg.L-1, CH4: 0.0003 and 0.0053 mg.L-1 e N2O: 0.0789 a 0.1177 mg.L-1 . Our results indicate variations over time, with higher fluxes at the beginning of experiment, decreasing over the growing period and trend of neutrality regarding to the GHG emissions at the end of experimental period. / Doutor

Orientador: João José Caluzi / Banca: Cibelle Celestino Silva / Banca: Deividi Marcio Marques / Banca: Silvia Regina Quijadas Aro Zuliani / Banca: Marcelo Carbone Carneiro / Resumo: As questões ambientais estão cada vez mais sendo discutidas na sociedade. Contudo, de acordo com o autor francês Edgar Morin, para entendê-las em completude, é preciso ter uma mudança de percepção de mundo, buscando religar os pensamentos que foram fragmentados ao longo dos séculos, tanto no contexto social como no educacional. Mudar o pensamento não é um processo trivial e a História da Ciência (HC) pode ser uma boa ferramenta para os estudos da complexidade, possibilitando melhor compreensão sobre as visões contemporâneas da ciência e suas consequências em assuntos amplamente discutidos. Frente aos debates ambientais, foi escolhido como motivação das discussões da presente tese o tema efeito estufa intensificado e suas consequentes alterações no clima. Há pesquisas que relacionam o pensamento complexo com o ensino de ciências e a HC com ensino, mas são quase ausentes as que proponham ou investiguem conexões entre a tríade complexidade, HC e ensino. Diante da suposição de que a HC pode auxiliar a desenvolver o pensamento complexo, o objetivo do trabalho foi identificar a possível relação entre os princípios da complexidade de Edgar Morin e categorias de HC a partir dos estudos do efeito estufa intensificado - na teoria e com estudantes em cursos de formação docente. Foi utilizada a pesquisa qualitativa para o desenvolvimento da tese em duas etapas: a primeira - chamada de estudos teóricos - foi importante para dar base para as discussões na segunda etapa - denominada ativida... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Environmental issues are increasingly being discussed in society. However, according to French author Edgar Morin, in order to understand them in completeness, it is necessary to have a change of world perception, seeking to reconnect the thoughts that have been fragmented over the centuries, both in the social and educational context. Changing thinking is not a trivial process and the History of Science (HS) can be a good tool for studying complexity, enabling a better understanding of contemporary views of science and its consequences on widely discussed subjects. In the face of environmental debates, the intensified greenhouse effect theme and its consequent changes in climate were chosen as motivation of the discussions of this thesis. There is research that links complex thinking with science teaching and HS with teaching, but there are almost no ones who propose or investigate connections between the triad complexity, HS and teaching. Given the assumption that HS can help to develop complex thinking, the objective of this work was to identify the possible relationship between the principles of complexity of Edgar Morin and HS categories from studies of the intensified greenhouse effect - in theory and with students in teacher training courses. Qualitative research was used for the development of the thesis in two stages: the first - called theoretical studies - was important to provide the basis for the discussions of the second stage - called activities with licensees.... (Complete abstract click electronic access below) / Doutor

Academic and political debates over long-run climate policy often invoke “stabilization” of atmospheric concentrations of greenhouse gases (GHGs), but only rarely are non-CO2 greenhouse gases addressed explicitly. Even though the majority of short-term climate policies propose trading between gases on a global warming potential (GWP) basis, discussions of whether CO2 concentrations should be 450, 550, 650, or perhaps as much as 750 ppm leave unstated whether there should be no additional forcing from other GHGs beyond current levels or whether separate concentration targets should be established for each GHG. Here we use an integrated modeling framework to examine multi-gas stabilization in terms of temperature, economic costs, carbon uptake, and other important consequences. We show that there are significant differences in both costs and climate impacts between different "GWP equivalent" policies and demonstrate the importance of non-CO2 GHG reduction on timescales of up to several centuries. / Abstract in HTML and technical report in PDF available on the Massachusetts Institute of Technology Joint Program on the Science and Policy of Global Change website (http://mit.edu/globalchange/www/). / Sarofim was supported in part by a Martin Sustainability Fellowship

Thesis (PhD)--University of South Australia, 2000

Thesis (Ph. D.)--Washington State University, December 2007. / Includes bibliographical references.

Thesis (Ph.D.)--University of Melbourne, Dept. of Agriculture and Food Systems, Institute of Land and Food Resources, 2006. / Typescript. Includes bibliographical references (leaves 219-238).

Thesis (M. Sc.)--University of Hong Kong, 1999. / Includes bibliographical references (leaves 48-65).

Thesis (M. Sc.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 63-69).

Thesis (M. Sc.)--University of Hong Kong, 1996. / Includes bibliographical references (leaf 76-81).

Thesis (M.Sc.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 63-69) Also available in print.