101 research outputs found

    Upwelling regime off the Cabo Frio region in Brazil and impact on acoustic propagation

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    This work introduces a description of the complex upwelling regime off the Cabo Frio region in Brazil and shows that ocean modeling, based on the feature-oriented regional modeling system (FORMS) technique, can produce reliable predictions of sound speed fields for the corresponding shallow water environment. This work also shows, through the development of simulations, that the upwelling regime can be responsible for the creation of shadow coastal zones, in which the detection probability is too low for an acoustic source to be detected. The development of the FORMS technique and its validation with real data, for the particular region of coastal upwelling off Cabo Frio, reveals the possibility of a sustainable and reliable forecast system for the corresponding (variable in space and time) underwater acoustic environment. (C) 2018 Acoustical Society of AmericaBrazilian Navy; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)/Ciencias Sem Fronteiras [400671/2014-0]; European Union [OAEX-230855]; Fundacao de Amparo a Pesquisa (FAPERJ) [E-26/110.327/2012

    Observational Characterization of the Downward Atmospheric Longwave Radiation at the Surface in the City of SĂŁo Paulo

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    This work describes the seasonal and diurnal variations of downward longwave atmospheric irradiance (LW) at the surface in São Paulo, Brazil, using 5-min-averaged values of LW, air temperature, relative humidity, and solar radiation observed continuously and simultaneously from 1997 to 2006 on a micrometeorological platform, located at the top of a 4-story building. An objective procedure, including 2-step filtering and dome emission effect correction, was used to evaluate the quality of the 9-yr-long LW dataset. The comparison between LW values observed and yielded by the Surface Radiation Budget project shows spatial and temporal agreement, indicating that monthly and annual average values of LW observed in one point of São Paulo can be used as representative of the entire metropolitan region of São Paulo. The maximum monthly averaged value of the LW is observed during summer (389 ± 14 W m-2; January), and the minimum is observed during winter (332 ± 12 W m-2; July). The effective emissivity follows the LW and shows a maximum in summer (0.907 ± 0.032; January) and a minimum in winter (0.818 ± 0.029; June). The mean cloud effect, identified objectively by comparing the monthly averaged values of the LW during clear-sky days and all-sky conditions, intensified the monthly average LW by about 32.0 ± 3.5 W m-2 and the atmospheric effective emissivity by about 0.088 ± 0.024. In August, the driest month of the year in São Paulo, the diurnal evolution of the LW shows a minimum (325 ± 11 W m-2) at 0900 LT and a maximum (345 ± 12 W m-2) at 1800 LT, which lags behind (by 4 h) the maximum diurnal variation of the screen temperature. The diurnal evolution of effective emissivity shows a minimum (0.781 ± 0.027) during daytime and a maximum (0.842 ± 0.030) during nighttime. The diurnal evolution of all-sky condition and clear-sky day differences in the effective emissivity remain relatively constant (7% ± 1%), indicating that clouds do not change the emissivity diurnal pattern. The relationship between effective emissivity and screen air temperature and between effective emissivity and water vapor is complex. During the night, when the planetary boundary layer is shallower, the effective emissivity can be estimated by screen parameters. During the day, the relationship between effective emissivity and screen parameters varies from place to place and depends on the planetary boundary layer process. Because the empirical expressions do not contain enough information about the diurnal variation of the vertical stratification of air temperature and moisture in São Paulo, they are likely to fail in reproducing the diurnal variation of the surface emissivity. The most accurate way to estimate the LW for clear-sky conditions in São Paulo is to use an expression derived from a purely empirical approach

    A influência da frente térmica da ressurgência costeira de cabo frio na perda do sinal acústico: um estudo numérico

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    Este trabalho avaliou a perda do sinal acústico na presença do gradiente térmico formado pela ressurgência costeira de Cabo Frio – RJ. Para tanto, utilizou-se de um modelo numérico hidrodinâmico para construir a estrutura termohalina da ressurgência. Essa estrutura foi implementada como parâmetro de entrada em um modelo acústico e utilizada como base de propagação do som. Após este procedimento, foram simulados sinais acústicos em dois cenários distintos, um deles representando uma situação de ressurgência intensa, e outro na qual a ascenção da água de fundo não ocorria. A comparação entre esses dois cenários mostrou que a pluma de ressurgência atua como uma barreira à propagação do som, visto que no cenário sem ressurgência um mesmo sinal acústico alcançou distâncias maiores. Neste sentido, especula-se que o gradiente térmico promovido pela ressurgência costeira possa prejudicar a detecção de alvos submarinos

    Transfer-Expanded Graphs for On-Demand Multimodal Transit Systems

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    This paper considers a generalization of the network design problem for On-Demand Multimodal Transit Systems (ODMTS). An ODMTS consists of a selection of hubs served by high frequency buses, and passengers are connected to the hubs by on-demand shuttles which serve the first and last miles. This paper generalizes prior work by including three additional elements that are critical in practice. First, different frequencies are allowed throughout the network. Second, additional modes of transit (e.g., rail) are included. Third, a limit on the number of transfers per passenger is introduced. Adding a constraint to limit the number of transfers has a significant negative impact on existing Benders decomposition approaches as it introduces non-convexity in the subproblem. Instead, this paper enforces the limit through transfer-expanded graphs, i.e., layered graphs in which each layer corresponds to a certain number of transfers. A real-world case study is presented for which the generalized ODMTS design problem is solved for the city of Atlanta. The results demonstrate that exploiting the problem structure through transfer-expanded graphs results in significant computational improvements.Comment: 9 pages, 4 figure

    Ministros de Economía, burocracia y política económica en el desarrollismo brasileño (1930-1964)

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    The aim of this article is to explain the existence, between 1930 and 1964, of a developmental economic policy patter in Brazil, despite the strong political instability that characterized the period. The thread of the analysis is institutionalist. We tried to find the institutional locus where the stability of economic policy occurred. Firstly, we revealed that this was not the Ministry of Economy. In the following, we show that the agents of the economic bureaucracy are the ones responsible for maintaining the economic policy pattern during those years. Data on economy ministers and the economic bureaucracy were collected from various sources, but especially from Dicionário Histórico Biográfico Brasileiro, by CPDOC.El objetivo de este artículo es explicar la existencia, entre los años 1930 y 1964, de un padrón de política económica desarrollista en Brasil, a pesar de la fuerte instabilidad política que caracterizó el período. El hilo conductor del análisis es institucionalista. Intentamos encontrar el locus institucional donde se producía la estabilidad de la política económica. Primeramente, revelamos que este no era el Ministerio de la Economía. A continuación, mostramos que los agentes de la burocracia económica son los responsables por mantener el padrón de política económica durante aquellos años. Los datos sobre ministros de Economía y sobre la burocracia económica fueron colectados a partir de fuentes diversas, pero especialmente del Dicionário Histórico Biográfico Brasileiro del CPDOC

    Social Licence to Operate e settore petrolifero nell\u2019Amazzonia ecuadoriana: un approccio geografico

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    Gli obiettivi di sostenibilit\ue0 al 2030 del settore del oil & gas indicano come prioritario l\u2019impegno delle compagnie petrolifere nella promozione dello sviluppo sostenibile delle comunit\ue0 presenti nei territori in cui esse operano. In questo modo l\u2019impresa pu\uf2 raggiungere pi\uf9 facilmente la cosiddetta Social Licence to Operate (SLO), ovvero il livello di accettazione delle attivit\ue0 di un\u2019impresa da parte delle comunit\ue0 locali. L\u2019obiettivo di questa ricerca, \ue8 sviluppare e testare un modello per misurare il livello di SLO di una compagnia petrolifera, analizzando in modo critico l\u2019applicazione di questo strumento nell\u2019Amazzonia ecuadoriana. L\u2019area di studio \ue8 il Blocco 10, gestito dalla compagnia petrolifera italiana Agip Oil Ecuador, filiale di Eni. Si tratta di un importante hotspot di biodiversit\ue0 popolato da diverse etnie indigene. La ricerca impiega un approccio geografico abbinato a metodi quali-quantitativi per esaminare le percezioni dei locali in merito agli impatti socio-ambientali delle operazioni dell\u2019impresa, elementi chiave nella definizione della SLO in un territorio. L\u2019assenza di informazioni geografiche precise dell\u2019area di studio \ue8 stata compensata mediante strumenti di Participatory GIS coinvolgendo le comunit\ue0 locali. Infine, l\u2019analisi GIS dei risultati sulle percezioni delle popolazioni permetter\ue0 di comprendere meglio le relazioni spaziali dei conflitti socio-ambientali e degli elementi critici della SLO nel territorio studiato

    Brazil in the Era of Fascism: The “New State” of Getúlio Vargas

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    The New State established in Brazil by Getúlio Vargas (1937–1945) is the most important case of the institutionalisation of a dictatorship of the fascism era in Latin America. During this time, an impressive spectrum of authoritarian regimes was established, some of which were very instable and poorly institutionalised, while others were more consolidated. Roger Griffin coined the concept of para-fascism for some of them, and the “New State” of Getúlio Vargas in Brazil is a paradigmatic case. In this essay, we analyse the processes of institutional reform in 1930s Brazil paying particular attention to how domestic political actors look at institutional models of fascism and corporatism.info:eu-repo/semantics/publishedVersio
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