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The Atlantic Meridional Overturning Circulation (AMOC) is a crucial component of the Earth’s climate system due to its fundamental role in the uptake and distribution of important tracers such as heat, carbon, and oxygen. Evaluating changes in AMOC in a warming climate is paramount to understanding the potential influence on global climate. In this study, we utilized outputs produced by the Community Earth System Model for Phase 6 of the Coupled Model Intercomparison Project, in addition to in situ data, to investigate changes in AMOC and the associated physical processes. Two experiments were carried out: a control experiment and an experiment with an annual increase of 1% CO2. Our analysis revealed a significant decrease in AMOC, with the upper branch weakening more than 60% and shallowing more than 600 m, compared to in situ data, leading to a reduction in heat transport to high latitudes in the North Atlantic. This decline was associated with changes in mixed layer depth and buoyancy in high latitudes of the North Atlantic, resulting in the shutdown of deep convection and potentially affecting the formation of North Atlantic Deep Water and Antarctic Bottom Water. Furthermore, the increase in CO2 levels altered the pattern of several parameters and the way they determine the flow of freshwater to the North Atlantic Ocean. Our findings suggest that continued warming may further weaken AMOC, with significant implications for global climate.

Isotopic methods have become an important tool in the study of natural processes and countless applications have proven valuable in several research areas. Geologically, Strontium and Nd isotopic compositions present variations that reflect changes in the geological sources of these elements due to smaller degrees of isotope fractionation than stable isotopes. All data was obtained from academic journals and has been spatialized in a Geographic Information System (GIS), the analysis of which has subsidized the identification where data is more clustered or dispersed. Understanding the distribution of 87Sr/86Sr e εNd(0) in different regions of South America is crucial so, this paper presents 386 data selected, organized, inventoried and arranged in crystalline shields and in sedimentary basins. The latitudinal variation of the isotopic pairs was studied, and this variation is suggestive and corresponds to the intrinsic environmental variations, such temperature and humidity.

Forest fires have global, regional, and local socioeconomic and environmental consequences, with negative effects on ecosystem services, air quality, population health, and other relevant aspects, emphasizing their significance in the context of the United Nations Sustainable Development Goals. The study identified areas in the Rio de Janeiro State (RJS) with varying degrees of susceptibility to fire focis using remote sensing data derived from topographic, anthropogenic, meteorological, and hydrological factors based on seasonality and integrated into geographic information systems. The analytical hierarchy process was used as a method of integration and normalized hierarchy of variables, generating susceptibility maps in the annual, summer, and winter periods in the RJS's hydrographic regions (HR), with the application of the associated chi-square test to records of fire focis from the AQUA satellite, period 2003 to 2017, without methodological variation for data acquisition, whose susceptibility was classified as very low to very high. The results show that the years with the most fire foci in the adopted time series are 2007 and 2014, with a peak in September and a fall from October onwards. According to the susceptibility map, 9% of the RJS is highly susceptible during the annual period, with HR-IX being especially vulnerable. In the summer, 0.2% of RJS is extremely vulnerable, while 32% is highly vulnerable in the winter, with 6402 km

Linear discriminant analysis (LDA) is a mathematically robust multivariate data analysis approach that is sometimes used for surface oil slick signature classification. Our goal is to rank the effectiveness of LDAs to differentiate oil spills from look-alike slicks. We explored multiple combinations of (i) variables (size information, Meteorological-Oceanographic (metoc), geo-location parameters) and (ii) data transformations (non-transformed, cube root, log10). Active and passive satellite-based measurements of RADARSAT, QuikSCAT, AVHRR, SeaWiFS, and MODIS were used. Results from two experiments are reported and discussed: (i) an investigation of 60 combinations of several attributes subjected to the same data transformation and (ii) a survey of 54 other data combinations of three selected variables subjected to different data transformations. In Experiment 1, the best discrimination was reached using ten cube-transformed attributes: ~85% overall accuracy using six pieces of size information, three metoc variables, and one geo-location parameter. In Experiment 2, two combinations of three variables tied as the most effective: ~81% of overall accuracy using area (log transformed), length-to-width ratio (log- or cube-transformed), and number of feature parts (non-transformed). After verifying the classification accuracy of 114 algorithms by comparing with expert interpretations, we concluded that applying different data transformations and accounting for metoc and geo-location attributes optimizes the accuracies of binary classifiers (oil spill vs. look-alike slicks) using the simple LDA technique.

Coastal environments are highly dynamic and sensitive to interference and variations caused by the numerous natural and anthropogenic agents. The northern coast of Northeastern Brazil has undergone intense erosion in recent years. However, the construction of the Pecém Port modified the beach and shoreline features differently from the adjacent areas. This article describes using remote-sensing images integrated with a Geographic Information System to evaluate the sedimentary balance and morphological changes observed in the sandy beach area that was affected by the construction of Pecém Port. Two methods were applied to the RapidEye images to quantify the short-time changes that occurred on the coast. The Digital Shoreline Analysis System method showed that the beach width increased west to the port, which was calculated by the Change Polygon Approach determined by intersecting and uniting polygons to estimate the difference between the areas over time. The short-time analysis results showed changing coastal morphology, demonstrating that the anthropic interventions in the region are transforming significantly the natural elements that make up the region landscape. Between 2011 and 2014, the investigated beach stretch of approximately 3 km suffered an accretion process of more than 102,000 m2 over 3 years. The high spatial resolution of satellite images, digital processing imaging techniques and geostatistical methods were effective in this study, allowing understanding the recent changes in the area.

Ilha Grande Bay is located in Angra dos Reis, Rio de Janeiro State, Brazil. The area is characterized by different land cover, complex topography and proximity to the Atlantic Ocean. These aspects make it susceptible to thermally and dynamically induced atmospheric circulations such as those associated with valley/mountain and land/sea breeze systems, among others. The Almirante Álvaro Alberto Nuclear Complex (CNAAA) is located in this region, with a total of two nuclear power plants (NPPs) in operation in the Brazilian territory, Angra I and Angra II. Therefore, knowledge of local atmospheric circulation has become a matter of national and international security. Considering the importance of the meteorological security tool as a support for licensing, installation, routine operation and nuclear accident mitigation, the main aim of this study is the development of combined strategies of environmental statistical modeling in the analysis of thermally and dynamically driven atmospheric circulations over mountainous and coastal environments. We identified and hierarchized the influence of the thermally and mechanically driven forcing on the wind regime and stability conditions in the coastal atmospheric boundary layer over the complex topography region. A meteorological network of ground-based instruments was used along with physiographic information for the observational characterization of the atmospheric patterns in the spatial and time–frequency domain. The predominant wind directions and intensity are attributed to the combined action of multiscale weather systems, notably, the valley/mountain and continent/ocean breeze circulations, the forced channeling due to valley axis orientation, the influence of the synoptic scale systems and atmospheric thermal tide. The observational investigation of the combined influence of terrain effects and meteorological systems aimed to understand the local atmospheric circulation serves as support for safety protocols of the NPPs, contemplating operation and environmental management. The importance of the study for the adequacy and skill evaluation of computational modeling systems for atmospheric dispersion of pollutants such as radionuclide and conventional contaminants can be also highlighted, in order that such systems are used as tools for environmental planning and managing nuclear operations, particularly those located in regions over mountainous and coastal environments with a heterogeneous atmospheric boundary layer.

Industrial accidents pose risks to the entire environment located in the area of influence of the enterprises, especially when they are affected by the atmospheric dispersion of pollutants emitted, as in the case of a nuclear power plant, where the concern with the evacuation of the population is the main priority in critical situations , which reinforces the implementation of actions to support emergency planning and its management, whose support tools, among them the computational modeling that, based on atmospheric models and geographic information systems, are essential in the decision making process. Thus, based on the Angra dos Reis nuclear complex and the impacts that may affect its surroundings, studies using the integrated use of computational platforms served to evaluate the risks and consequences of a hypothetical accidental event, including the calculation of the thermo- source of nuclear fuel, meteorological characteristics, mechanisms of atmospheric dispersion of pollutants, as well as socio-environmental aspects of the region. Meteorological data (wind regime) characterize the wind field from the WRF model, which subsidized the dispersion of radionuclides calculated in the HYSPLIT, information associated with socioenvironmental data (landslides, population density, etc.), incorporated in a GIS database. The results demonstrate the importance of the integrated use of computational systems as tools that support decision-making, potentializing the application of solutions that contribute to support actions and guidelines of planning and governance in emergency situations.

Our research focuses on refining the ability to discriminate two petrogenic oil-slick categories: the sea surface expression of naturally-occurring oil seeps and man-made oil spills. For that, a long-term RADARSAT-2 dataset (244 scenes imaged between 2008 and 2012) is analyzed to investigate oil slicks (4562) observed in the Gulf of Mexico (Campeche Bay, Mexico). As the scientific literature on the use of satellite-derived measurements to discriminate the oil-slick category is sparse, our research addresses this gap by extending our previous investigations aimed at discriminating seeps from spills. To reveal hidden traits of the available satellite information and to evaluate an existing Oil-Slick Discrimination Algorithm, distinct processing segments methodically inspect the data at several levels: input data repository, data transformation, attribute selection, and multivariate data analysis. Different attribute selection strategies similarly excel at the seep-spill differentiation. The combination of different Oil-Slick Information Descriptors presents comparable discrimination accuracies. Among 8 non-linear transformations, the Logarithm and Cube Root normalizations disclose the most effective discrimination power of almost 70%. Our refined analysis corroborates and consolidates our earlier findings, providing a firmer basis and useful accuracies of the seep-spill discrimination practice using information acquired with space-borne surveillance systems based on Synthetic Aperture Radars.

The aim of this work is to investigate the behavior of volume transport and advective heat flux patterns which are related to the Brazil Current System (BCS) according to the climate change scenarios suggested by the Intergovernmental Panel on Climate Changes. The results deriving from the global model Climate Model version 2.1 (GFDL-CM2.1) for future scenarios of climate change A1FI and B1 and for the scenario that represents the climate in the Twentieth Century (20C3M) have been used in this work. Volume transport and advective heat flux integrated for the whole BCS as well as for each water mass which constitutes the system have been calculated applying these data. Estimates were made for three zonal sections (23ºS, 25ºS and 30ºS) and then were used in the Wavelet Analysis. The performed analysis showed the occurrence of interannual variability for the estimated properties in the region. It also showed that the BCS shows changes in both intensity and variability of these parameters when comparing A1FI and B1 to 20C3M. Results from Wavelet Analysis for the total volume transport and advective heat flux integrated per section show that the period between three and six years prevails in sections 23ºS and 25ºS. The variability in 30ºS however, is significantly higher than eight years. It could also be observed the change of the variability of the total volume transport and heat flux temporal series towards higher frequencies when they are submitted to A1FI and B1 climate changes scenarios.

The spatial and temporal variability of energy exchange in Tropical Instability Waves (TIWs) in the Atlantic Ocean were investigated. A spectral analysis was used to filter the 5-day mean results from Simple Ocean Data Assimilation reanalysis spanning from 1958 to 2008. TIWs were filtered over periods of 15 to 60 days and between wavelengths of 4 and 20 longitude degrees. The main approach of this study was the use of bidirectionally filtered TIW time series as the perturbation fields, and the difference in these time series from the SODA total results was considered to be the basic state for energetics analysis. The main result was that the annual cycle (period of ~ 360 days) was the main source of variability of the waves, and the semi-annual cycle (period of ~ 180 days) was a secondary variation, which indicated that TIWs occurred throughout the year but with intensity that varies seasonally. Barotropic instability acts as the mechanism that feeds and extracts energy to/from TIWs as alternate zonal bands at equatorial Atlantic. Baroclinic instability is the main mechanism that extracts energy from TIWs to the equatorial circulation north of Equator. All TIW patterns of variability were observed at west of ~ 10º W. The present study reveals new evidences regarding TIW variability and suggests that future investigations should include a detailed description of TIW dynamics as part of Atlantic Ocean equatorial circulation

An Exploratory Data Analysis (EDA) aims to use Synthetic Aperture Radar (SAR) measurements for discriminating between two oil slick types observed on the sea surface: naturally-occurring oil seeps versus human-related oil spills—the use of satellite sensors for this task is poorly documented in scientific literature. A long-term RADARSAT dataset (2008–2012) is exploited to investigate oil slicks in Campeche Bay (Gulf of Mexico). Simple Classification Algorithms to distinguish the oil slick type are designed based on standard multivariate data analysis techniques. Various attributes of geometry, shape, and dimension that describe the oil slick Size Information are combined with SAR-derived backscatter coefficients—sigma-(σo), beta-(βo), and gamma-(γo) naught. The combination of several of these characteristics is capable of distinguishing the oil slick type with ~70% of overall accuracy, however, the sole and simple use of two specific oil slick’s Size Information (i.e., area and perimeter) is equally capable of distinguishing seeps from spills. The data mining exercise of our EDA promotes a novel idea bridging petroleum pollution and remote sensing research, thus paving the way to further investigate the satellite synoptic view to express geophysical differences between seeped and spilled oil observed on the sea surface for systematic use.

The knowledge of wind stress variability could represent an important contribution to understand the variability over upper layer ocean volume transports. The South Brazilian Bight (SBB) circulation had been studied by numerous researchers who predominantly attempted to estimate its meridional volume transport. The main objective and contribution of this study is to identify and quantify possible interannual variability in the ocean volume transport in the SBB induced by the sea surface wind stress field. A low resolution ocean global circulation model was implemented to investigate the volume transport variability. The results obtained indicate the occurrence of interannual variability in meridional ocean volume transports along three different zonal sections. These results also indicate the influence of a wind driven large-scale atmospheric process that alters locally the SBB and near-offshore region wind stress field and consequently causes interannual variability in the upper layer ocean volume transports. A strengthening of the southward flow in 25°S and 30°S was observed. The deep layer ocean volume transport in the three monitored sections indicates a potential dominance of other remote ocean processes. A small time lag between the integrated meridional volume transports changes in each monitored zonal section was observed.

Submitted by Jairo Amaro (jairo.amaro@sibi.ufrj.br) on 2019-06-26T18:12:04Z No. of bitstreams: 1 2013_SILVA_v5_p13-23-min.pdf: 732896 bytes, checksum: 87d048232c48dfe9a2eba58b93fd84e1 (MD5) Made available in DSpace on 2019-06-26T18:12:04Z (GMT). No. of bitstreams: 1 2013_SILVA_v5_p13-23-min.pdf: 732896 bytes, checksum: 87d048232c48dfe9a2eba58b93fd84e1 (MD5) Previous issue date: 2013-01-07 Indisponível. The outlook concerning the occurrence of industrial accidents has led to the implementation of response systems based on geoprocessing tools, which are widely adopted in emergency for such ventures, since they have helped and served as a support for decision making, as well as for the preparation of guidelines aimed at managing emergencies. Nuclear power plants, because they constitute types of industrial activities that present dangerous conditions and attention regarding security are characterized as hazardous, especially due to consequences that occurred from large accidents— such as Chernobyl (1986) and Fukushima (2011)—highlighting the importance to its negative impacts, since the occurrence of accidents at nuclear power plants may affect surrounding areas, thus exposing a set of elements that are part of the environmental dynamics that integrates the catchment area where this type of plant is situated. In this way, through an integrated view of the region where the nuclear complex is located in Angra dos Reis City (Rio de Janeiro State) and, also, by aggregating information that portray the geobiophysical reality of its surroundings, several elements were incorporated into a database developed in a virtual environment, in which was produced a geographic information system (GIS) that presents a complex of variables that, once considered, can enhance various analysis in order to support emergency situations and planning, as well as guidelines that help define actions from the occurrence of accidental events at the nuclear plant.

This paper describes the use of Bayesian spatial models to develop the concept of a spatial-temporal mask for the purpose of identifying regions in which before and after drilling effects are most clearly defined and from which the consequences of exposure of macrofauna and meiofauna to the release of drilling discharges can be evaluated over time. To determine the effects of drilling fluids and drill-cuttings on the marine benthic community, it is essential to know not only where discharged materials ended up within the possible impact area, but also the chemical concentrations to which biota were exposed during and after drilling. Barium and light hydrocarbons were used as chemical tracers for water-based and non-aqueous-based fluids in a shallow water site in the Campos Basin, off the coast of Brazil. Since the site showed evidence of exposure to waste material from earlier drilling, the analysis needed to take into account the background concentrations of these compounds. Using the Bayesian models, concentrations at unsampled sites were predicted and regions altered and previously contaminated were identified.

This study evaluates how climate change might affect advective heat and volume transports in the South Atlantic Basin based on Intergovernmental Panel on Climate Change (IPCC) A1FI and B1 climate change scenarios projections. Using the Climatic Model 2.1 (CM2.1) results that were developed by the Geophysical Fluid Dynamics Laboratory (GFDL), integrated on the water column, analyses were conducted through two meridional sections and one zonal section of the study area (between 25◦S-70◦S and 70◦W-20◦E). The annual mean time series were analyzed using historical 100-year climate change scenarios. The analyses of the climate change experiment parameters were compared with those of the H2 climate scenario. The volume transport (VT) through the water column weakened of about 5% in average and the advective heat transport (HT) increased of about 22% at the Drake and Africa-Antarctic (AF-AA) passages at the end of the experiments. For the zonal section at 25◦S, direction oscillations were observed in the integrated VT through the water column due to velocity intensity variations of the water masses and a decrease of about 22% in the HT was observed. Thus, it was observed a decrease in the water and heat supplies at 25◦S due to the Drake and AF-AA VT behavior, which may alter deep circulation patterns.Keywords: water column analysis, advective heat transport, flow direction, Drake Passage, Africa-Antarctic passage.RESUMO. Baseado nas projeções dos cenários de mudanças climáticas A1FI e B1 do Painel Intergovernamental de Mudanc¸as Climáticas (IPCC), esse estudo avalia como as mudanças climáticas podem impactar os transportes advectivos de calor e volume na bacia do Atlântico Sul. Através de resultados gerados pelo Modelo Climático 2.1 (CM2.1) desenvolvido pelo Geophysical Fluid Dynamics Laboratory (GFDL), foram feitas análises através de duas seções meridionais e uma seção zonal na área de estudo (entre 25◦S-70◦S e 70◦W-20◦E) integradas na coluna d’água. Foram analisados campos prognósticos médios anuais referentes a experimentos com 100 anos de duração. As análises dos parâmetros dos experimentos de mudanças climáticas foram realizadas em comparação com o experimento clima (H2). O transporte de volume (TV) integrado na coluna d’água enfraqueceu aproximadamente 5%, enquanto o transporte advectivo de calor (TC) aumentou em torno de 22% no Drake e na Passagem África-Antártida (AF-AA) ao final dos experimentos. Para a seção em 25◦S, foram observadas oscilações de direção do fluxo devido a variações na intensidade das velocidades das massas d’água com um enfraquecimento médio de 22% para o TC. Adicionalmente, foi observada uma diminuição no suprimento de água em 25◦S devido ao comportamento do TV das demais seções, o que pode alterar os padrões de circulação profunda.Palavras-chave: análise na coluna d’água, transporte advectivo de calor, direção do fluxo, Passagem de Drake, passagem África-Antártida.

A new a posteriori error estimate for finite element stress analysis is proposed. This engineering approach is characterized by using local reference systems that allows establishing which stress components must be continuous and which may not be continuous at interfaces between two elements. It is shown that, for a 3D analysis, only three stress components are sufficient to evaluate the stress error, and for a 2D analysis only two stress components are needed. Some 2D examples are considered and excellent results are obtained for both homogenous and heterogeneous materials.

Stabilized finite element formulations and post-processing techniques are presented for Darcy flow and miscible displacement problems. In these techniques all primary unknowns are approximated in space by standard equal-order interpolations. We presented a review of the main mathematical results, including convergence estimates for global post-processing to solve the pressure–velocity problem and for the stabilized solution of the complete set of coupled partial differential equations in both space–time and semi-discrete frameworks. Demonstration problems are solved to show that we obtained numerically high rates of convergence than those predicted, achieving good accuracy in the solution of monophasic flow problems in adverse conditions.

Interface finite elements have been used in many geotechnical and engineering applications. Essentially, these elements must allow relative displacements between two bodies in contact, or separated by a thin material layer. Frequently, interface elements behave as linear elastic bodies up to a limiting stress state. This linear behavior of interfaces is very important, because it will establish when the slip and/or separation occurs, causing stress redistribution over the mesh. In this paper, the mechanical behavior of interface elements is discussed. It is shown that the kinematic inconsistency pointed by Kaliakin and Li [Comp. Geotech. 17 (1995) 225] for the element proposed by Goodman et al. [ASCE J. Soil Mech. Fdns. Div. 99 (1968) 637] also occurs for other interface models, and new interface elements for 2D and 3D analyses without kinematic inconsistencies are proposed.

Submitted by Jairo Amaro (jairo.amaro@sibi.ufrj.br) on 2019-07-01T16:41:27Z No. of bitstreams: 1 2012_PIMENTEL_IJEP_v48_p194-min.pdf: 1562131 bytes, checksum: 35aba882011922b521faa6b2d28e34ae (MD5) Made available in DSpace on 2019-07-01T16:41:27Z (GMT). No. of bitstreams: 1 2012_PIMENTEL_IJEP_v48_p194-min.pdf: 1562131 bytes, checksum: 35aba882011922b521faa6b2d28e34ae (MD5) Previous issue date: 2012-10-11 Indisponível. This work presents the results of a photochemical modelling system composed of MM5-SMOKE-CMAQ on Brazilian Amazonia area, been a pioneered implementation task. These results focus on the biogenic and biomass burning emissions and the impact of these emissions on regional air quality. Global and local anthropogenic emissions data, satellite-derived biomass burning inventories, and biogenic emissions calculated with MEGAN model were used to estimate emissions over the domain. The goal is the development of air quality model input data for CMAQ. Results are consistent with O3 formation theory and CO hotspot concentration matches with the geographic area of biomass burning.

Nuclear power is a very important option that meets the global needs for power generation. But nuclear plants’ operation involves high safety requirements, due to all the potential risks involved. Nuclear power plants (NPP) must be operated under safety conditions in all stages, since its start up, and during all the process. For this reason, control desks and rooms must be designed in such a way operators can take all the procedures safely, with a good overview of all variable indicators and easy access to actuator controls. Also, operators must see alarms indication in a way they can easily identify any abnormal conditions and bring the NPP back to normal operation. These matters have been taken into account through the years in NPP control desks and rooms design, through ergonomics or human factors evaluations, to help design safer NPP control systems (Hollnagel, 1985; Pikaar, 1990; ANSI ANS-3.5, 1993; Foley et al., 1998; Feher, 1999). Operator training routines used to be carried out in full-scope simulators that resembled real control desks with high fidelity. Then, a new concept emerged, using control systems simulators based on synoptic windows interface, with NPP dynamics computer-based simulation system. These later usually include all the dynamics involved in a NPP operation. All variables are affected by operators’ actions in the synoptic windows-based interface, with responses to their actions readily presented on screen. Although the high fidelity in the NPP dynamics simulations, synoptic windows-based interfaces does not resemble much real NPP control desks, since operators have to deal with graphical diagrams on computer screens. Virtual reality technology help NPP operation simulation, since it enables virtual control desks (VCD) prototyping, thus adding to NPP dynamics computer simulation the design of control desks with high visual fidelity with real ones. Operators can now take advantage of both the online simulation capabilities of NPP dynamics computer-based simulation systems, with a more suitable interface such as VCDs, which resemble more closely the real

Realizaram-se avaliações climatológicas, sazonais e diárias, da estabilidade atmosférica na região da Central Nuclear Almirante Álvaro Alberto (CNAAA), Angra dos Reis - RJ. A climatológica foi baseada no critério de Pasquill-Gifford (P-G) para um período de 26 anos (1980-2006) e a sazonal-diária pelos números de Richardson Global (RiB) e de Froude (Fr) - estudo de caso (2002-05). O Fr foi usado na caracterização do escoamento da região. O critério de P-G mostrou que as classes predominantes foram D, E e F (no período noturno e diurno). Avaliaram-se as classes predominantes com a direção e velocidade do vento, os setores mais freqüentes foram S, SSW, SSE no período diurno e N, NNE, NNW e E no noturno. Quanto à velocidade verificou-se que a classe D foi mais veloz, e as classes E e F menos velozes, em qualquer período. As maiores velocidades foram coincidentes com a brisa marítima. Baseado no RiB, a condição estaticamente estável prevaleceu em comparação às demais, sendo de 79%, seguida da instável (17%) e neutra (4%). O Fr indicou que o escoamento na CNAAA foi caracterizado por regime de vento fraco, com forte estabilidade e ar estagnado. A maior parte das ocorrências (63%) foi para Fr inferior a 0,1, seguida de poucas ocorrências nas categorias Fr igual a 1,0 (8%) e superior a 1,7 (12%). Os critérios utilizados na caracterização da estabilidade na região e na análise do regime de escoamento indicaram a baixa capacidade da atmosfera para a dispersão de poluentes, devido à predominância da condição estável e do regime de bloqueio. The atmospheric stability over the nuclear power plant Almirante Álvaro Alberto (CNAAA), Angra dos Reis - RJ, Brazil, was analyzed at climatological, seasonal, and daily scales. The climatologic analysis was based on the Pasquill-Gifford (P-G) for a long-term series of 26 years (1980 - 2006), while the seasonal/daily was performed using the Global Richardson number, RiB, and the Froude number, Fr, (case study 2002-2005). The Froude number was used for the regional flow characterization. According to the P-G criteria, the dominant classes were D, E and F (for diurnal and nocturnal periods). The most frequent sectors of wind direction were S, SSW, SSE in diurnal period and N, NNE, NNW and E in nocturnal. The highest wind velocities were observed for class D while the lowest values were observed for classes E and F, for both periods. The highest wind velocities were correlated to the occurrence of sea breeze. Based on RiB, the dominant stratification regime was stable (for 79% of the time), followed by unstable (17%) and neutral (4%). According to Fr, the flow around CNAAA was characterized by low wind velocities, strong stability and stagnant air. The Fr was lesser than 0.1 during 63% of the time, equal to 1 for 8% of the time and greater than 1.7 during 12% of the time. The criteria used in the determination of the stability and flow characteristics of this region indicated the lower dispersion capacity of the local atmosphere due to the prevalence of stable stratification regimes and blocking conditions.

Monitoring the volume and heat transports around the world oceans is of fundamental importance in the study of the climate system, its variability, and possible changes. The application of an Oceanic General Circulation Model for climatic studies needs that its dynamic and thermodynamic fields are in equilibrium. The time spent by the model to reach this equilibrium is called spin-up time. This work presents some results obtained from the application of the Modular Ocean Model version 4.0 initialized with temperature, salinity, velocity and sea surface height data already in equilibrium from an ocean data assimilation experiment conducted by Geophysical Fluid Dynamics Laboratory (GFDL). The use of this dataset as initial condition aimed to diminish the spin-up time of the oceanic model. The model was integrated for seven years. Volume and heat transports in different sections around the world oceans showed to be in good agreement with the literature. The results showed a well defined seasonal cycle starting at the second integration year, also some important dynamic and thermodynamic aspects of the Global Ocean Circulation, as the great conveyor belt, are well reproduced. The obtained results could constitute an important data source to be used as initial and boundary conditions in regional ocean model experiments as well as for long integration runs in order to study oceanic climate variability. O monitoramento dos transportes de volume e calor nos oceanos é de fundamental importância para o estudo do sistema climático, sua variabilidade e possíveis mudanças. A aplicação de Modelos de Circulação Global dos Oceanos em estudos climáticos necessita que os dados dinâmicos e termodinâmicos gerados pelos mesmos se encontrem em equilíbrio. Esse trabalho apresenta alguns resultados obtidos a partir da aplicação do Modular Ocean Model , em sua versão 4.0, inicializado com campos de temperatura, salinidade, velocidade e elevação da superfície livre em equilíbrio, oriundos do experimento de assimilação de dados oceânicos conduzido pelo Geophysical Fluid Dynamics Laboratory (GFDL). O uso desse conjunto de dados objetivou a diminuição do tempo de "spin-up" do modelo oceânico utilizado. O modelo foi integrado por sete anos, ao fim dos quais foram estimados transportes de volume e calor em diferentes seções ao redor do globo. Tais estimativas demonstraram boa concordância com valores estimados em trabalhos anteriores. Os resultados demonstraram a ocorrência de um ciclo sazonal oceânico bem definido a partir do segundo ano de integração do modelo, assim como importantes aspectos da circulação oceânica global como o "conveyor belt", os giros subtropicais oceânicos e o escoamento associado à Corrente Circumpolar Antártica. O experimento realizado demonstrou a importância desse modelo como fonte de dados a ser utilizado como condições iniciais e de contorno em modelos regionais de circulação oceânica, assim como para longas integrações a serem aplicadas em estudos de variabilidade e mudanças climáticas.

Some macular pathology produces degeneration, which causes a perception loss in specific areas of the visual field. In this case, people visualize “blind spots” that hide part of the images captured by the impaired eye. The goal of this paper is to present an image distortion system that explores the Virtual Reality technology potential. To implement it we developed a system that is able to obtain the data generated by the visual field exam, and decode it. A camera captured the real images and the Convex Hull algorithm and Isoperimetric Mapping were used to identify the spots limits generating a divergent distortion in the images situated inside of the blind spot. The modified images can be visualized in a Virtual Reality head mounted display with eye tracking. This system offers opportunities to people with this visual problem to get a general perception of the covered area, reducing the visual loss.

El objetivo del actual trabajo es definir de forma preliminar los grupos que componen la Corteza Laterítico Niquelíferas Cobaltíferas del Yacimiento Punta Gorda en Cuba, mediante redes neuronales aplicadas a un conjunto de registros radioactivos de pozo de acuerdo a una clasificación geológica previamente determinada. Se realiza además la evaluación del contenido de Níquel en cada uno de los grupos definidos aplicando también redes neuronales.

The mass balance study for the generated, migrated and accumulated petroleum constitutes an important tool for quantification of the petroleum systems providing indication for the comprehension of the oil distribution in a studied basin, whether it is a very explored province or a frontier area. This thesis has established a methodology for a mass balance construction in a petroleum system on a real case study. It is not only interested on the quantification of its charges and losses, but equally in its compositional aspects. The known hydrocarbon accumulation were used as a criteria for calibration of the mass balance parameters. It was chosen the Reconcavo basin, located at the Northeastern part of Brazil to this study. The basin is an aborted rift created during the fragmentation of the Gondwana supercontinent, during Lower Cretaceous. The quite known stage of exploration of the Reconcavo basin has contributed to the reduction of uncertainties concerning charges and losses, important issues to the definition of mass balance. The large number of parameters that influence the mass balance were then calibrated on a precise way. For its acquisition it was used a geochemical protocol involving the kinetic-compositional description of the Tauá and Gomo Members (Candeias Formation), the main source rocks of the basin. A restoration law of Total Organic Carbon (TOC) was obtained through the results of the thermogravimetric experiments and also by Rock-Eval analysis. A second part of this work integrated these geochemical results in a sequential scheme of petroleum system modelings (1D, 2D and 3D). A thermal history calibration apart from the maturation data was used to obtain the source term. Later on, generation, expulsion and migration were modeled. These results provided the elements of mass balance for the Reconcavo basin showing that 8% of the expelled oil from the source rocks was accumulated, 16% was lost at the porous framework of the non-reservoir rocks and 76% left the system laterally or through exsudation, during its geological evolution., Etablir un bilan de masses entre la génération, la migration et l'accumulation du pétrole est un processus important pour quantifier des systèmes pétroliers. Ce bilan donne en effet des indications sur la répartition du pètrole dans un bassin sédimentaire, que ce soit une province très explorée ou un secteur d'exploration frontière. Cette thèse a établi la méthodologie pour approcher un bilan de masses d'un système pétrolier sur un cas réel. Elle a non seulement quantifié les termes sources et les pertes, mais s'est également intéressée aux aspects compositionnels. Les accumulations connues ont pour cela servi de données de calibration des paramètres influant le bilan. Dans cette optique, le cas d'étude choisi est le bassin de Recôncavo au Nord-Est du Brésil. Il s'agit d'un rift avorté qui a été formé pendant la fragmentation du Gondwana, au cours de le Crétacé Inférieur. Le stade mature de l'exploration de ce bassin a contribué à réduire les incertitudes sur les pertes et les charges, points essentiels d'une définition de bilan de matière. Les nombreux paramètres qui influencent le bilan ont pu être calibrés de façon précise. Pour procéder au bilan, on a d'abord effectué des analyses géochimiques pour la description cinétique compositionnelle des membres Tauá et Gomo (Fm. Candeias), les roches mères principales de ce bassin. Une loi de restauration du carbone organique total (COT) a été obtenue en résultat des expériences thermogravimétriques et de l'analyse Rock-Eval. Une deuxième partie de ce travail a intégré les résultats de géochimie dans un schéma séquentiel de modélisation de systèmes pétroliers en 1D,2D et 3D. Une calibration du régime thermique au cours du temps géologique indépendante des données de maturité a servi de guide pour le terme source. Puis la genèse, l'expulsion et la migration ont été modélisées. Ces résultats ont fourni les éléments du bilan de masses sur ce bassin, qui montre que seulement 8% des hydrocarbures expulsés des roches-mères ont été piégés, 16% sont perdus dans le réseau poreux non réservoir et 76% sont sortis du système latéralement ou par exsudation au cours de son évolution.

COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR Apresenta-se neste trabalho a implementação de um método adaptativo de refinamento automático de malhas de Elementos de Finitos. O método aplica-se a problemas planos de elasticidade linear. Elementos triangulares e quadrilaterais (lineares e quadráticos) são utilizados. Estimativas de erro a-posteriori são obtidas através do estimador de erro proposto por Zienkiewicz-Zhu, empregando-se uma técnica de recuperação da solução numérica fornecida pelo MEF (superconvergent patch recovery technique). A metodologia da adaptação da malha emprega o conceito de remalhamento do domínio na forma proposta por Peraire e Zhu para malhas de elementos triangulares e quadrilaterais, respectivamente. Implementa-se um esquema de localização de singularidades presentes no domínio baseado no conceito de concentração da energia de deformação. O uso deste esquema combinado com a metodologia de adaptação permite um processo automático sem intervenção do usuário durante os ciclos de refinamento da malha. Para demonstrar-se a performance do método são analisados três problemas: uma viga curta em balanço sob carregamento distribuído, uma placa quadrada com furo quadrado e uma placa quadrada com dupla trinca. This work presentes the theory and the implementation techniques for na automatic h-adaptive procedure of finite elemento mesh refinements. Themetodology is applied to plane problems inlinear elasticity using triangular and quadrilateral shape elements with linear and quadratic lagrangian interpolation functions. Solution errors are a-posteriori evaluated using the Zienkiewicz- Zhu error estimator based on numerical solutions recovered from the finite element method solution – superconvergent patch recovery technique. For the mesh adaptivity of triangular and quadrilateral elements the remeshing concepts proposed by. Peraire and Zhu employed, respectively. The presence of solution singularities and their intensity is identified throughout the finite cloment mesh from the evaluation of the strain energy concentration, considering the numerical solution obtained. This scheme combined with adaptivity methodology allows for fully automatic procedure of mesh refinement/derefinement at the cycle of solution searching. Three examples are considered to demonstrate the procedure ability in handling elasticity problems: a cantiliver short beam under transverse distributed loading, a square plate with a middle square hole under inplace traction distributed loading and a double notch square plate under in plane distributed loading.