Contribuição para a elaboração de um sistema de gestão ambiental dos diques de manutenção e reparo do Arsenal de Marinha do Rio de Janeiro

A Baía de Guanabara, ambiente de localização do Arsenal de Marinha do Rio de Janeiro (AMRJ), sofre com a intensa pressão antrópica, principalmente no aspecto da qualidade das águas. Neste contexto, uma fração considerável da poluição decorre das atividades dos estaleiros, uma vez que a atividade industrial naval no Rio de Janeiro não tem mecanismo de controle de poluição à altura do seu real potencial poluidor. Esta ausência de fiscalização possibilita o lançamento na Baía de resíduos sólidos, esgotos sanitários, efluentes químicos, oleosos e tóxicos, tornando crescente a contaminação dessas águas, margens e mangues. Estes descartes cada vez mais são alvo das exigências ambientais da sociedade e das legislações. Devido a isto, a gestão de efluentes líquidos do Arsenal tornou-se prioritária, para tal, esse estudo foi proposto, tendo iniciado pela análise das oficinas do estaleiro, na qual as operações no dique foram identificadas como uma das mais impactantes do estaleiro. A partir desta constatação, estão apresentadas duas fontes de pesquisas para a redução dos impactos. Na primeira etapa, há o estudo das atividades geradoras de efluentes no dique de reparo, com os objetivos de propor a implantação das diretrizes de melhores práticas de gestão, de minimizar a geração de efluentes líquidos e de contribuir para a adoção de práticas ambientais proativas. Como segunda pesquisa, com base nas tecnologias mundiais, há a proposta de tratamento dos efluentes de um dique, na qual foram identificados os processos que irão atender às necessidades ambientais do estaleiro, com as opções de escolha entre o tratamento parcial, para o descarte na rede pública, ou com o prosseguimento do processo até o seu reúso. As conclusões deste estudo apontam para a implantação da gestão ambiental do dique sistematizada, rigorosa e integrada com a gestão das embarcações, acrescentando-se a isto, as necessidades de incorporação de tecnologias modernas e de sistema de tratamento dos efluentes, propiciando de maneira sustentável que haja a continuação do processo de produção do estaleiro e, ao mesmo tempo, permitindo o retorno da biodiversidade da Baía de Guanabara.

A variational framework for spectral discretization of the density matrix in Kohn Sham density functional theory

Kohn-Sham density functional theory (KSDFT) is currently the main work-horse of quantum mechanical calculations in physics, chemistry, and materials science. From a mechanical engineering perspective, we are interested in studying the role of defects in the mechanical properties in materials. In real materials, defects are typically found at very small concentrations e.g., vacancies occur at parts per million, dislocation density in metals ranges from $10^{10} m^{-2}$ to $10^{15} m^{-2}$, and grain sizes vary from nanometers to micrometers in polycrystalline materials, etc. In order to model materials at realistic defect concentrations using DFT, we would need to work with system sizes beyond millions of atoms. Due to the cubic-scaling computational cost with respect to the number of atoms in conventional DFT implementations, such system sizes are unreachable. Since the early 1990s, there has been a huge interest in developing DFT implementations that have linear-scaling computational cost. A promising approach to achieving linear-scaling cost is to approximate the density matrix in KSDFT. The focus of this thesis is to provide a firm mathematical framework to study the convergence of these approximations. We reformulate the Kohn-Sham density functional theory as a nested variational problem in the density matrix, the electrostatic potential, and a field dual to the electron density. The corresponding functional is linear in the density matrix and thus amenable to spectral representation. Based on this reformulation, we introduce a new approximation scheme, called spectral binning, which does not require smoothing of the occupancy function and thus applies at arbitrarily low temperatures. We proof convergence of the approximate solutions with respect to spectral binning and with respect to an additional spatial discretization of the domain. For a standard one-dimensional benchmark problem, we present numerical experiments for which spectral binning exhibits excellent convergence characteristics and outperforms other linear-scaling methods.

Caracterização ambiental da bacia hidrogáfica do Rio São Domingos a partir da análise geoquímica e isotópica Pb/Pb

A bacia hidrográfica do rio São Domingos constitui uma das sub-bacias do rio Muriaé pertencente ao sistema Paraíba do Sul e, tem seus limites coincidentes com os limites do município de São José de Ubá, sendo este o segundo maior produtor de tomate do estado do Rio de Janeiro, com sua principal fonte econômica baseada na agropecuária. Este tipo de atividade resulta em utilização de produtos químicos nas lavouras e juntamente a ocupação inadequada resulta em modificação das paisagens e da mata nativa, resultando em diversos tipos de impactos no ambiente. Neste estudo foram abordados os impactos relacionados a concentração de metais e sua proveniência através das assinaturas isotópicas Pb/Pb, utilizando para tal o procedimento analítico de lixiviação dos sedimentos de corrente e abertura total de rochas para a obtenção de razões isotópicas e concentrações de metais por ICP-MS. Os resultados mostraram que as contribuições nos sedimentos de corrente se dão a partir de cinco fontes compreendidos no intervalo de assinatura isotópica 206Pb/207Pb 1,1229 e 1,1949, representadas em intervalos bem definidos. Por correlação com as respectivas concentrações se observa que, preferencialmente, existe maior influência das rochas do embasamento, seguido de atividade antrópicas como a urbanização e disposição de lixo doméstico. As maiores concentrações estão associadas ao cobre, chumbo, estrôncio, níquel e zinco. Contudo todas as concentrações de metais obtidas se encontram abaixo da legislação vigente. Desta forma a contaminação antrópica é limitada a regiões de maior densidade populacional e as influências naturais predominam na área da bacia.

Predation and selection in copepod populations of Alpine waters [Translation from: Bollettino di Zoologia 21 541-545, 1954]

Zooplankton was studied in four alpine lakes in Switzerland, France and Italy. The presence the presence of the invertebrate predator Heterocope in three lakes was stated. It is then discussed why in three of these four lakes, the copepod Arctodiaptomus denticornis is present in the absence of Arctodiaptomus bacillifer, and vice versa respectively in the second and first parts of the lacustrine summer.

Alligator Diet in Relation to Alligator Mortality on Lake Griffin, FL

Alligator mississippiensis (American Alligators) demonstrated low hatchrate success and increased adult mortality on Lake Griffin, FL, between 1998 and 2003. Dying Lake Griffin alligators with symptoms of poor motor coordination were reported to show specific neurological impairment and brain lesions. Similar lesions were documented in salmonines that consumed clupeids with high thiaminase levels. Therefore, we investigated the diet of Lake Griffin alligators and compared it with alligator diets from two lakes that exhibited relatively low levels of unexplained alligator mortality to see if consumption of Dorosoma cepedianum (gizzard shad) could be correlated with patterns of mortality. Shad in both lakes Griffin and Apopka had high levels of thiaminase and Lake Apopka alligators were consuming greater amounts of shad relative to Lake Griffin without showing mortality rates similar to Lake Griffin alligators. Therefore, a relationship between shad consumption alone and alligator mortality is not supported.

Proposta de metodologia de projeto de sistemas de disposição oceânica de esgotos sanitários, em localidades de pequeno porte.

O presente trabalho tem por objetivo disponibilizar metodologia para o projeto de tratamento de esgoto sanitário através de disposição oceânica com utilização de emissário submarino, para localidades de pequeno porte. Também apresenta metodologia simplificada para obtenção de alguns dados oceanográficos necessários, na perspectiva de atender aos administradores dessas pequenas prefeituras envolvidas nas questões de atendimento de sua população quanto aos serviços de tratamento dos esgotos sanitários. Esses municípios, por serem pequenos e em país em desenvolvimento, carecem de recursos financeiros para as soluções convencionais de tratamento de esgotos sanitários. O trabalho contém uma revisão da bibliografia técnica relativa ao processo objeto deste estudo, não só referente ao projeto hidráulico como também à estabilidade física da tubulação do emissário assentada no leito do mar. Julgou-se necessário a realização, deste trabalho depois que se verificou que a implantação de emissários submarinos com diâmetros até da ordem de 300 mm, em geral tem seus custos inferiores aos dos sistemas convencionais.

Polyphemus pediculus (L.) (Cladocera) as a possible indicator of water quality

Usually stenobiotic species are used as hydrobiological indicators of the degree of pollution in natural waters. Cladocera are eurybiotic organisms, therefore their role as specific indicators of the water quality is considered to be insignificant. However, considering new methods Cladocera at present are more and more often used as indicators of oligo- and mesosaprobic waters as well as of the presence of considerable amounts of easily degradable organic matter. Work over many years on the biology of Polyphemus pediculus, this striking representative of the order Cladocera, convinced the author of the possibility of using this species not only as an indicator of water purity but also for the estimation of the degree of water pollution as well as of water characteristics such as colour, turbidity, oxgen content and chemical composition. P. pediculus is one of the most common and abundant species of planktonic crustaceans in shallow waters of reservoirs, rivers, lakes, ponds and temporary water bodies.

The scope for biomanipulation in improving water quality

Biomanipulation is a form of biological engineering in which organisms are selectively removed or encouraged to alleviate the symptoms of eutrophication. Most examples involve fish and grazer zooplankton though mussels have also been used. The technique involves continuous management in many deeper lakes and is not a substitute for nutrient control. In some lakes, alterations to the lake environment have given longer-term positive effects. And in some shallow lakes, biomanipulation may be essential, alongside nutrient control, in re- establishing former aquatic-plant-dominated ecosystems which have been lost through severe eutrophication. The emergence of biomanipulation techniques emphasises that lake systems are not simply chemical reactors which respond simply to engineered chemical changes, but very complex and still very imperfectly understood ecosystems which require a yet profounder understanding before they can be restored with certainty.

Using Earth Deformation Caused by Surface Mass Loading to Constrain the Elastic Structure of the Crust and Mantle

Surface mass loads come in many different varieties, including the oceans, atmosphere, rivers, lakes, glaciers, ice caps, and snow fields. The loads migrate over Earth's surface on time scales that range from less than a day to many thousand years. The weights of the shifting loads exert normal forces on Earth's surface. Since the Earth is not perfectly rigid, the applied pressure deforms the shape of the solid Earth in a manner controlled by the material properties of Earth's interior. One of the most prominent types of surface mass loading, ocean tidal loading (OTL), comes from the periodic rise and fall in sea-surface height due to the gravitational influence of celestial objects, such as the moon and sun. Depending on geographic location, the surface displacements induced by OTL typically range from millimeters to several centimeters in amplitude, which may be inferred from Global Navigation and Satellite System (GNSS) measurements with sub-millimeter precision. Spatiotemporal characteristics of observed OTL-induced surface displacements may therefore be exploited to probe Earth structure. In this thesis, I present descriptions of contemporary observational and modeling techniques used to explore Earth's deformation response to OTL and other varieties of surface mass loading. With the aim to extract information about Earth's density and elastic structure from observations of the response to OTL, I investigate the sensitivity of OTL-induced surface displacements to perturbations in the material structure. As a case study, I compute and compare the observed and predicted OTL-induced surface displacements for a network of GNSS receivers across South America. The residuals in three distinct and dominant tidal bands are sub-millimeter in amplitude, indicating that modern ocean-tide and elastic-Earth models well predict the observed displacement response in that region. Nevertheless, the sub-millimeter residuals exhibit regional spatial coherency that cannot be explained entirely by random observational uncertainties and that suggests deficiencies in the forward-model assumptions. In particular, the discrepancies may reveal sensitivities to deviations from spherically symmetric, non-rotating, elastic, and isotropic (SNREI) Earth structure due to the presence of the South American craton.

Efficiency, energy and stoichiometry in pelagic food webs; reciprocal roles of food quality and food quantity

In most lakes, zooplankton production is constrained by food quantity, but frequently high C:P poses an additional constraint on zooplankton production by reducing the carbon transfer efficiency from phytoplankton to zooplankton. This review addresses how the flux of matter and energy in pelagic food webs is regulated by food quantity in terms of C and its stoichiometric quality in terms of C:P. Increased levels of light, CO2 and phosphorus could each increase seston mass and, hence, food quantity for zooplankton, but while light and CO2 each cause increased C:P (i.e. reduced food quality for herbivores), increased P may increase seston mass and its stoichiometric quality by reducing C:P. Development of food quality and food quantity in response to C- or P-enrichments will differ between 'batch-type' lakes (dominated by one major, seasonal input of water and nutrients) and 'continuous-culture' types of lakes with a more steady flow-rate of water and nutrients. The reciprocal role of food quantity and stoichiometric quality will depend strongly on facilitation via grazing and recycling by the grazers, and this effect will be most important in systems with low renewal rates. At high food abundance but low quality, there will be a 'quality starvation' in zooplankton. From a management point of view, stoichiometric theory offers a general tool-kit for understanding the integrated role of C and P in food webs and how food quantity and stoichiometric quality (i.e. C:P) regulate energy flow and trophic efficiency from base to top in food webs.From a management point of view, stoichiometric theory offers a general tool-kit for understanding the integrated role of C and P in food webs and how food quantity and stoichiometric quality (i.e. C:P) regulate energy flow and trophic efficiency from base to top in food webs.

The structure and margins of the Lake Chilwa fisheries in Malawi: a value chain analysis

Small freshwater pelagic fisheries in closed lakes are very important to millions of people in sub-Saharan Africa providing livelihoods and nutritional security. However, returns from these fisheries have been shown to �uctuate in response to climatic variability. In order to understand the impact of these fluctuations on the livelihoods of people dependant on these fisheries, there is a need for information on how the fish value chain is organized and how it functions in response to variation in supplies. The results will feed into strategies that build resilience in fishing households against the uncertainties arising from unstable ecosystems. The Lake Chilwa fishery value chain is composed of fishers, processors, traders, fish transporters, boat owners, owners of fish processing shades, fisheries associations, gear owners, gear makers, firewood sellers, and traders of fishing gear and equipment. The value chain employs many people and local authorities can consider using this information in the design of rural development strategies for employment generation in small-scale fishing communities. The findings from this study have a number of implications for the improvement of the livelihood of fishers and enhancing their capacity to mitigate against the effects of climate change.

Impact of development and dissemination of Integrated Aquaculture-Agriculture (IAA) Technologies in Malawi

Malawi is a small but densely populated country in Southern Africa. Fish is an important part of the nutrition of Malawians, providing essential protein and micronutrients. However, per capita fish consumption has halved over the ten-year period between 1988 to 1998 due to over-fishing in the lakes and doubling of the population since the 1970s, accompanied by an increase in the price of fish. This has worsened access to food insecurity, especially in rural areas, in a country where an estimated 66 per cent of the population consume less than the minimum daily calorie requirement. This paper presents an ex-post impact assessment of the development and dissemination of smallscale integrated aquaculture-agriculture technologies by The WorldFish Center and its national and international partners over more than 15 years in Malawi. The impact study measures the effects of these outputs on the degree of integrated aquaculture-agriculture (IAA) technology adoption and diffusion, the effects on farm income and health of household members, and the welfare effects of increased fish supply on the Malawian economy.

A preliminary study on the feasibility of using fenced brushparks for fish production in Lake Chilwa, Malawi

A study to investigate the feasibility of using fenced brushparks for fish ranching in Lake Chilwa was conducted for five months at the Kachulu Harbor. In a water depth of 1.4 m enclosures constructed from bamboo sticks embedded in the sediment and surrounded by a 13 mm seine net, were filled with three different subrates (Typha, bamboo, and Sesbania branches) and a no substrate enclosure served as a control. Netting materials contributed 57 per cent towards the total cost (US$ 0.24-0.30/m2) of brushpark contruction. Fish productivity was highest in the Typha, bamboo and control treatments and lowest in the Sesbania treatments. The decomposition of substrates did not affect water quality. The results indicate that enclosed brushparks may be a feasible technology for enhancing fish yields and providing alternative income sources to fisherfolk in small lakes and water bodies.

Prospects for fish culture in char areas of Bangladesh

Fish production is considered in the barren chars or sandy land masses created through siltation along river banks and deltas in Bangladesh. The prospects for fish culture in ponds and cages or pen culture in rivers and canals are examined. The socioeconomic implications of fish culture as a livelihood source for communities living in char areas are also discussed.

Qualidade das águas fluviais: estudo de caso da bacia hidrográfica de Jacarepaguá - RJ.

O processo de ocupação urbana da Baixada de Jacarepaguá a partir da década de 1970, promoveu inúmeros impactos ambientais que afetaram, de forma não uniforme, os diferentes grupos sociais, que habitam a região, e afetaram principalmente o meio ambiente, mais especificamente os recursos hídricos. A rápida e intensa ocupação urbana da região, impulsionada pela produção imobiliária, gerou inúmeros problemas ambientais, principalmente devido à precariedade nos serviços de saneamento. Diversos impactos se processam atualmente na rede de drenagem da Baixada de Jacarepaguá, os quais comprometem negativamente a qualidade de vida população que vive na região, assim como, do meio ambiente. Neste trabalho é avaliada a qualidade da água dos principais cursos dágua da bacia hidrográfica de Jacarepaguá, caracterizando o estado atual de degradação dos recursos hídricos da região a partir da análise dos dados referentes aos parâmetros de qualidade das águas, obtidos junto ao órgão ambiental estadual, no período compreendido entre os anos de 2003 e 2008. As variáveis estatísticas dos parâmetros foram determinadas, os resultados foram apresentados através dos gráficos boxplot e sua discussão foi realizada em consoante com a Resolução CONAMA 357/2005. Os cursos dágua da bacia de Jacarepaguá, em destaque aqueles avaliados neste trabalho expressam a degradação pela qual vem sofrendo em virtude das intervenções antrópicas que se projetam na bacia hidrográfica. Nota-se a partir, dos resultados para os parâmetros de qualidade de água avaliados que a poluição nos cursos dágua da baixada de Jacarepaguá que, possivelmente o principal aspecto da poluição hídrica é devido ao despejo de esgotos domésticos nos cursos dágua sem tratamento adequado.