302 research outputs found
Seasonal Variability of the CO2 System in a Large Coastal Plain Estuary
The Chesapeake Bay, a large coastal plain estuary, has been studied extensively in terms of its water quality, and yet, comparatively less is known about its carbonate system. Here we present discrete observations of dissolved inorganic carbon (DIC) and total alkalinity from four seasonal cruises in 2016–2017. These new observations are used to characterize the regional CO2 system and to construct a DIC budget of the mainstem. In all seasons, elevated DIC concentrations were observed at the mouth of the bay associated with inflowing Atlantic Ocean waters, while minimum concentrations of DIC were associated with fresher waters at the head of the bay. Significant spatial variability of the partial pressure of CO2 was observed throughout the mainstem, with net uptake of atmospheric CO2 during each season in the upper mainstem and weak seasonal outgassing of CO2 near the outflow to the Atlantic Ocean. During the time frame of this study, the Chesapeake Bay mainstem was (1) net autotrophic in the mixed layer (net community production of 0.31‐mol C m−2·year−1) and net heterotrophic throughout the water column (net community production of −0.48‐mol C m−2·year−1), (2) a sink of 0.38‐mol C m−2·year−1 for atmospheric CO2, and (3) significantly seasonally and spatially variable with respect to biologically driven changes in DIC.
DATA available at: https://doi.org/10.25773/rntn‐ez1
High-frequency CO2-system variability over the winter-to-spring transition in a large coastal plain estuary
Understanding the vulnerability of estuarine ecosystems to anthropogenic impacts requires a quantitative assessment of the dynamic drivers of change to the carbonate (CO2) system. Here we present new high‐frequency pH data from a moored sensor. These data are combined with discrete observations to create continuous time series of total dissolved inorganic carbon (TCO2), CO2 partial pressure (pCO2), and carbonate saturation state. We present two deployments over the winter‐to‐spring transition in the lower York River (where it meets the Chesapeake Bay mainstem) in 2016/2017 and 2017/2018. TCO2 budgets with daily resolution are constructed, and contributions from circulation, air‐sea CO2 exchange, and biology are quantified. We find that TCO2 is most strongly influenced by circulation and biological processes; pCO2 and pH also respond strongly to changes in temperature. The system transitions from autotrophic to heterotrophic conditions multiple times during both deployments; the conventional view of a spring bloom and subsequent summer production followed by autumn and winter respiration may not apply to this region. Despite the dominance of respiration in winter and early spring, surface waters were undersaturated with respect to atmospheric CO2 for the majority of both deployments with mean fluxes ranging from −9 to −5 mmol C·m−2·day−1. Deployments a year apart indicate that the seasonal transition in the CO2 system differs significantly from one year to the next and highlights the necessity of sustained monitoring in dynamic nearshore environments
Federalismo cooperativo, financiamento da educação e royalties do petróleo
RESUMO: Este artigo pretende analisar, tendo por consideração o pacto federativo construído na Constituição de 1988, a repartição constitucional de competências legislativas e materiais e os mecanismos de financiamento da educação, como se deu a evolução histórica do tratamento constitucional e legal acerca da propriedade do petróleo e gás natural no Brasil, quais os regimes jurídicos em vigor, as espécies de participações ou receitas governamentais devidas pela sua exploração, como tem se dado a disputa pela definição dos seus beneficiários, e quais são as regras que incidem sobre sua adequada aplicação pelos entes federados.Palavras-chave: Federalismo Cooperativo. Regime de Colaboração. Educação Básica. Financiamento. Royalties. COOPERATIVE FEDERALISM, EDUCATION FINANCING AND ROYALTIES OF OIL. ABSTRACT: This article aims to analyze, taking into consideration the federative pact built in the 1988 Constitution, the constitutional division of legislative and material competences and the financing mechanisms of education, as the historical evolution of the constitutional and legal treatment of oil and natural gas in Brazil, what are the legal regimes in force, the types of stakes or government revenues due for their exploitation, how has the dispute over the definition of their beneficiaries, and what rules apply to their proper application by the federated entities? Keywords: Cooperative Federalism. Collaboration Regime. Basic education. Financing. Royalties. FEDERALISMO COOPERATIVO, FINANCIACIÓN EDUCATIVAY REGALÍAS DE ACEITE. RESUMEN: Este artículo tiene como objetivo analizar, considerando el pacto federativo construido en la Constitución de 1988, la división constitucional de las competencias legislativas y materiales y los mecanismos de financiación de la educación, como la evolución histórica del tratamiento constitucional y legal sobre cuáles son los regímenes legales vigentes, los tipos de tenencias o ingresos del gobierno debido a su exploración, cómo ha surgido la disputa sobre la definición de sus beneficiarios y qué reglas se aplican a su correcta aplicación por entidades federadasPalabras clave: Federalismo cooperativo. Régimen de colaboración. Educación básica. Financiacion Regalías
Educação integral em São João de Meriti: conceitos em desalinho
A Educação Integral em tempo integral é tema atualmente corrente tanto na academia quanto na sociedade civil. Isso se deve, em grande medida, à aprovação da Lei de Diretrizes e Bases da Educação Nacional, que aponta para o progressivo aumento da carga horária diária nas escolas públicas do país. O tema ganhou maior relevância após o ano de 2007, quando do lançamento do Programa Mais Educação, cujo objetivo, em última instância, é melhorar a qualidade da educação pública oferecida. Partindo da ideia de que o conceito de educação em tempo integral está em disputa, buscamos descortinar os conceitos aos quais se referem profissionais da rede municipal do município de São João de Meriti. A análise dos conteúdos das falas dos atores envolvidos na política municipal de educação em tempo integral nos permitiu extrair os elementos que compõem seus imaginários sobre o tema.Palavras chave: Política Pública. Programa Mais Educação. Educação Integral.Comprehensive education in São João de Meriti: unbalanced conceptsAbstractFull-time Comprehensive Education is a current theme both in academia and civil society. This is largely due to the adoption of the Law of Guidelines and Bases of National Education, which indicates progressive increase of the length of the school day in public schools nationwide. The theme became more relevant after 2007 when Mais Educação Program, whose objective is to improve the quality of the education offered throughout the nation’s public school systems, was launched. Based on the idea that Full-time Comprehensive Education is a polysemic concept, we search to uncover the concepts referred by the professionals of education from São João de Meriti. The analysis of the content of the speeches from those involved in the municipal politics of Full-time Education allowed us to extract the elements that made up their minds about the theme.Keywords: Public Policy. Mais Educação Program. Full-time Education
O desenvolvimento educacional e crescimento econômico na Niterói oitocentista
A cidade de Niterói foi alçada à condição de capital da Província do Rio de Janeiro em 1834, deixando a tutela do governo central e experimentando um intenso processo de urbanização e crescimento econômico, o que atraiu uma elite econômica recentemente desenvolvida no país. Neste contexto, desenvolve-se um rico cenário educacional, congregando escolas públicas e privadas, laicas e confessionais, instrução doméstica e coletiva. O objetivo deste ensaio é promover uma análise da Nichteroy no século XIX, a partir de contribuições teóricas e da análise de documentos históricos, relacionando o desenvolvimento econômico e educacional.
Estuarine Dissolved Organic Carbon Flux From Space: With Application to Chesapeake and Delaware Bays
This study uses a neural network model trained with in situ data, combined with satellite data and hydrodynamic model products, to compute the daily estuarine export of dissolved organic carbon (DOC) at the mouths of Chesapeake Bay (CB) and Delaware Bay (DB) from 2007 to 2011. Both bays show large flux variability with highest fluxes in spring and lowest in fall as well as interannual flux variability (0.18 and 0.27 Tg C/year in 2008 and 2010 for CB; 0.04 and 0.09 Tg C/year in 2008 and 2011 for DB). Based on previous estimates of total organic carbon (TOCexp) exported by all Mid‐Atlantic Bight estuaries (1.2 Tg C/year), the DOC export (CB + DB) of 0.3 Tg C/year estimated here corresponds to 25% of the TOCexp. Spatial and temporal covariations of velocity and DOC concentration provide contributions to the flux, with larger spatial influence. Differences in the discharge of fresh water into the bays (74 billion m3/year for CB and 21 billion m3/year for DB) and their geomorphologies are major drivers of the differences in DOC fluxes for these two systems. Terrestrial DOC inputs are similar to the export of DOC at the bay mouths at annual and longer time scales but diverge significantly at shorter time scales (days to months). Future efforts will expand to the Mid‐Atlantic Bight and Gulf of Maine, and its major rivers and estuaries, in combination with coupled terrestrial‐estuarine‐ocean biogeochemical models that include effects of climate change, such as warming and CO2 increase
Challenges in Quantifying Air‐Water Carbon Dioxide Flux Using Estuarine Water Quality Data: Case Study for Chesapeake Bay
Estuaries play an uncertain but potentially important role in the global carbon cycle via CO2 outgassing. The uncertainty mainly stems from the paucity of studies that document the full spatial and temporal variability of estuarine surface water partial pressure of carbon dioxide ( p CO2). Here, we explore the potential of utilizing the abundance of pH data from historical water quality monitoring programs to fill the data void via a case study of the mainstem Chesapeake Bay (eastern United States). We calculate p CO2 and the air‐water CO2 flux at monthly resolution from 1998 to 2018 from tidal fresh to polyhaline waters, paying special attention to the error estimation. The biggest error is due to the pH measurement error, and errors due to the gas transfer velocity, temporal sampling, the alkalinity mixing model, and the organic alkalinity estimation are 72%, 27%, 15%, and 5%, respectively, of the error due to pH. Seasonal, interannual, and spatial variability in the air‐water flux and surface p CO2 is high, and a correlation analysis with oxygen reveals that this variability is driven largely by biological processes. Averaged over 1998–2018, the mainstem bay is a weak net source of CO2 to the atmosphere of 1.2 (1.1, 1.4) mol m−2 yr−1 (best estimate and 95% confidence interval). Our findings suggest that the abundance of historical pH measurements in estuaries around the globe should be mined in order to constrain the large spatial and temporal variability of the CO2 exchange between estuaries and the atmosphere
Progressive failure modelling and ductility demand of steel beam-to-column connections in fire
A numerical procedure has been developed to model the sequences of failure which can occur within steel beam-to-column connections under fire conditions. In this procedure two recent developments, a static-dynamic solution process and a general component-based connection element, have been combined within the software Vulcan in order to track the sequence of local failures of the connections which lead to structural progressive collapse in fire. In particular the procedure developed can be used to investigate the structural behaviour in fire, particularly the ductility and fracture of different parts of the steel-to-steel connections, and the influence of the connections on the progressive collapse resistance of steel frames in fire. In the component-based connection model, a connection is represented as an assembly of "bolt-rows" composed of components representing different zones of mechanical behaviour whose stiffness, strength, ductility and fracture under changing temperatures can be adequately represented for global modelling. The potential numerical instabilities induced by fractures of individual connection's components can be overcome by the use of alternate static and dynamic analyses. The transfer of data between the static and dynamic analyses allows a seamless alternation between these two procedures to take place. Accuracy and stability of the calculations can be ensured in the dynamic phase, provided that the time steps are set sufficiently small. This procedure has the capacity of tracking the sequence of local failures (fractures of connection components, detachment and motion of disengaging beams, etc.) which lead to final collapse. Following an illustrative case study of a two-bay by two-storey frame, the effect of ductility of connections on the collapse resistance of steel frames in fire is demonstrated in two case studies of a generic multi-storey frame. It is shown that the analytical process is an effective tool in tackling the numerical problems associated with the complex structural interactions and discontinuous failures which can affect a steel or composite frame in fire, potentially leading to progressive collapse. It can be seen that both tensile and compressive ductility in the connections make a contribution to the fire resistance of the beams. Preventing the detachment of steel beams in fire can be achieved by inducing greater ductility into their connections. Combined with appropriate component-based connection models, this procedure can be adopted in performance-based fire-resistant design to assess the ductility requirements of steel connections
Reabilitação cognitiva em idosos institucionalizados: um estudo piloto
Este estudo descreve os efeitos da intervenção de terapia ocupacional no desempenho cognitivo, e analisa a influência deste desempenho na capacidade funcional de idosos institucionalizados. Trata-se de um estudo clínico randomizado, descritivo, longitudinal, realizado em uma instituição pública de longa permanência de idosos. Os 12 idosos que participaram do estudo foram divididos em dois grupos: experimental e controle. Para obtenção dos dados, foram utilizados: um questionário com dados sociodemográficos; o Mini-Exame do Estado Mental, o Teste de Fluência Verbal e o Teste do Relógio, para avaliação do desempenho cognitivo; e a Escala de Katz da Atividade de Vida Diária e o Questionário de Atividades Funcionais de Pfeffer, para avaliação da capacidade funcional. Os idosos do grupo experimental foram submetidos a uma intervenção com 23 sessões de reabilitação cognitiva. O grupo que recebeu a intervenção apresentou resultados estatisticamente significativos no desempenho cognitivo, mas não houve resultados estatisticamente significativos no desempenho da capacidade funcional quando comparados com o grupo controle. Conclui-se que a intervenção de terapia ocupacional teve efeitos significativos no desempenho cognitivo de idosos institucionalizados e que, provavelmente, o desempenho na capacidade funcional não foi tão significativo, por se tratar de idosos que, em sua maioria, apresentam limitação motora e dependência instalada
Challenges in Quantifying Air‐Water Carbon Dioxide Flux Using Estuarine Water Quality Data: Case Study for Chesapeake Bay
Estuaries play an uncertain but potentially important role in the global carbon cycle via CO2 outgassing. The uncertainty mainly stems from the paucity of studies that document the full spatial and temporal variability of estuarine surface water partial pressure of carbon dioxide ( pCO2). Here, we explore the potential of utilizing the abundance of pH data from historical water quality monitoring programs to fill the data void via a case study of the mainstem Chesapeake Bay (eastern United States). We calculate pCO2 and the air-water CO2 flux at monthly resolution from 1998 to 2018 from tidal fresh to polyhaline waters, paying special attention to the error estimation. The biggest error is due to the pH measurement error, and errors due to the gas transfer velocity, temporal sampling, the alkalinity mixing model, and the organic alkalinity estimation are 72%, 27%, 15%, and 5%, respectively, of the error due to pH. Seasonal, interannual, and spatial variability in the air-water flux and surface pCO2 is high, and a correlation analysis with oxygen reveals that this variability is driven largely by biological processes. Averaged over 1998–2018, the mainstem bay is a weak net source of CO2 to the atmosphere of 1.2 (1.1, 1.4) mol m−2 yr−1 (best estimate and 95% confidence interval). Our findings suggest that the abundance of historical pH measurements in estuaries around the globe should be mined in order to constrain the large spatial and temporal variability of the CO2 exchange between estuaries and the atmosphere
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