Thesis (Ph.D.)--Mechanical Engineering, Georgia Institute of Technology, 2008. / Committee Co-Chair: Minami Yoda, Co-Advisor; Committee Co-Chair: Said I. Abdel-Khalik; Committee Member: Donald R. Webster; Committee Member: Narayanan M. Komerath; Committee Member: S. Mostafa Ghiaasiaan; Committee Member: Yogendra Joshi

Made available in DSpace on 2014-06-11T19:32:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-08Bitstream added on 2014-06-13T20:44:25Z : No. of bitstreams: 1 sampaio_rl_dr_jabo.pdf: 843789 bytes, checksum: 21b909eb74cfc7533c9acade3faba6b0 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Avaliaram-se 144 bovinos mestiços não castrados, manejados em lotação intermitente em pastagem de Brachiaria brizantha, com o objetivo de avaliar o efeito no desempenho de bovinos de corte de diferentes níveis de suplementação da dieta (baixo, médio e alto) nas estações de seca e de águas, durante fase de recria, e diferentes sistemas de terminação (no pasto ou confinamento), além de verificar o efeito de planos nutricionais crescente, contínuo e decrescente nas características físicas e químicas da carcaça desses animais. Na transição entre as etapas avaliadas durante a fase recria (seca e águas), cada grupo de animal avaliado na seca foi dividido em 3 subgrupos sendo 1/3 de cada distribuído nos tratamentos das águas. Na fase de terminação cada grupo avaliado durante a recria foi dividido, sendo metade terminado no pasto e a outra metade em confinamento. Os animais foram abatidos ao atingirem 500 kg de peso corporal. Tanto na seca quanto nas águas o desempenho se elevou com o aumento do nível nutricional do suplemento. Na terminação obteve-se ganho médio diário da ordem de 1,476 kg/dia e 0,731 kg/dia no confinamento e no pasto, respectivamente. Ao abate não foi observado diferença no rendimento de carcaça, porém, animais terminados em confinamento apresentaram espessura de gordura subcutânea (4,46 mm) superior aos animais terminados no pasto (2,06 mm) / 144 unregistered half-breed cattle, managed in a rotational stocking in pasture of Brachiara brizantha, were evaluated with the purpose of diagnosing the effects on the performance of beef cattle from different levels of diet supplementation (low, medium, high), at dry and wet seasons, during the growing phase, in different ending systems (pasture or confinement), besides checking the effects of increasing, continuous and decreasing nutritional plans on the physical and chemical characteristics of the carcass of those animals. In the transition between the steps rated during the growing phase (wet and dry seasons), each animal group of the dry season was divided in three subgroups, being a third part of it distributed in the water treatments. At the ending phase, each group evaluated in the period of growing was divided in two endings: the first at pasture whereas the second at confinement. The animals were slaughtered when they achieved 500kg of corporal weight. Both in dry and wet seasons, the performance rose with the raise of the supplement’s nutritional level. At the end, the daily average gain obtained was from the order of 1.476 kg/day and 0.731 kg/day in confinement and pasture, respectively. It was not noticed any difference in the income of carcass at the slaughter, although animals that ended in confinement showed a subcutaneous grease thick (4.46 mm) superior to the animals that ended in pasture (2.,06 mm)

Made available in DSpace on 2014-06-11T19:32:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-07Bitstream added on 2014-06-13T20:24:29Z : No. of bitstreams: 1 bonagurio_s_dr_botfmvz.pdf: 1804420 bytes, checksum: 9db1235e1aa2ef0e33f2bce2025b1f7f (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / O experimento teve como objetivo avaliar o efeito da suplementação da ovelha 30 dias antes do parto, a idade à desmama (45 ou 60 dias) de cordeiros machos e o sistema de terminação em confinamento (com dieta completa ou somente feno) e em pasto, sobre perfil de ácidos graxos do tecido muscular. As dietas fornecidas aos animais foram formuladas segundo as recomendações do NRC (1985). O perfil de ácidos graxos foi feito no músculo Tríceps brachii. Os parâmetros de abate foram 30 kg de peso vivo ou 150 dias de idade. Os cordeiros terminados no confinamento, alimentados com feno, foram abatidos pela idade e os demais cordeiros pelo peso vivo. Os ácidos graxos C15:0, C16:0, C17:0, C16:1, C18:1 e C18:3 diferiram entre os sistemas de terminação dos cordeiros. Os cordeiros da dieta completa tiveram maiores valores de C16:0, C16:1 e C18:1, e os cordeiros alimentados com feno e do pasto maiores teores de C18:3. A dieta dos cordeiros alterou o perfil de ácidos graxos. / The objective of this work was to evaluate the effect of sheep supplementation 30 days before parturition, age of male lambs at weaning (45 or 60 days old) and termination system in confinement (with full diet or hay only) and in pasture over the fatty acid profile of the muscle tissue. The diets provided to the animals were formulated as recommended by NRC (1985). The fatty acid profile was performed on Tríceps brachii muscle. Slaughter parameters were 30 kg of live weight or 150 days old. Lambs terminated in confinement, fed with hay, were slaughtered by age and the remaining ones, by live weight. Fatty acids C15:0, C16:0, C17:0, C16:1, C18:1 and C18:3 were different between lambs termination systems. Lambs fed with full diet presented higher C16:0, C16:1 and C18:1 values and the ones fed with hay and grass presented higher C18:3 values. Lambs diet affected the fatty acid profile.

Epoxy intumescent coatings are fire protection systems for steel structural elements that are widely used in applications that protection from severe hydrocarbon fires is required, such as oil and gas facilities. These polymer coatings react upon heating and expand into a thick porous char layer that insulates the protected steel element. In the typical fire scenarios for these applications, the intumescent coatings must resist very high heat fluxes and highly erosive forces from ignited pressurised gases. Hence, continuous fibre reinforcement is embedded in the thick epoxy coating during installation, so as to ensure the integrity of the weak intumesced char during fire exposure. This reinforcement is typically in the form of a bidirectional carbon and/or glass fibre mesh, thus under normal service conditions a fibre-reinforced intumescent coating (FRIC) is essentially a lightly fibre-reinforced polymer (FRP) composite material. This thesis examines the impacts of embedded high strength fibres on the tensile behaviour of epoxy intumescent materials in their unreacted state prior to fire exposure, and the potential enhancements that arise in the structural performance of elements protected with FRICs. An experimental programme is presented comprising tensile coupon tests of unreacted intumescent epoxies, reinforced with different fibre meshes at various fibre volume fractions. It is demonstrated that the tensile properties of FRICs can be enhanced considerably by including increasing amounts of carbon fibre reinforcement aligned in the principal loading direction, which can be tailored in the desired orientation on the coated structural members to enhance their load carrying capacity and/or deformability. An experimental study is presented on coated intact and artificially damaged I-beams (simulating steel losses from corrosion) tested in bending, demonstrating that FRICs can enhance the flexural response of the beams after yielding of steel, until the tensile rupture of the coatings. An analytical procedure for predicting the flexural behaviour of the coated beams is discussed and validated against the obtained test results, whereas a parametric analysis is performed based on this analytical model to assess the effect of various parameters on the strengthening efficiency of FRICs. The results of this analysis demonstrate that it is feasible to increase the flexural load capacity of thin sections considerably utilising the flexural strength gains from FRICs. Finally, a novel application is proposed in this thesis for FRICs as a potential system for structural strengthening or retrofitting reinforced concrete and concrete-encased steel columns by lateral confinement. An experimental study is presented on the axial compressive behaviour of short, plain concrete and concrete-encased structural steel columns that are wrapped in the hoop direction with FRICs. The results clearly show that epoxy intumescent coatings reinforced with a carbon fibre mesh of suitable weight can provide lateral confinement to the concrete core resisting its lateral dilation, thus resulting in considerable enhancements of the axial strength and deformability of concrete. The observed strengthening performance of the composite protective coatings is found to be at least as good as that of FRP wraps consisting of the same fibre reinforcement mesh and a conventional, non-intumescent epoxy resin. The predictive ability of existing design-oriented FRP confinement models is compared against the experimental results, and is found to be reasonably precise in predicting the peak strength of the tested columns, hence existing models appear to be suitable for design and analysis of column strengthening schemes with the proposed novel FRIC system. The research presented herein shows clearly that FRICs have a strong potential as alternative systems for consideration in the field of structural strengthening and rehabilitation, since they can provide substantial enhancements in the load carrying capacity for both applications considered. At the same time FRICs can thermally protect the underlying structural elements in the event of a fire, by intumescing and charring, thus potentially eliminating the need for additional passive fire protection that is common with conventional fire-rated FRP wrapping systems. Although this thesis provides a proof-of-concept for use of the proposed novel FRICs as structural strengthening materials, considerable additional research is particularly required to study their fire protection performance when applied to concrete substrates, to make use of the proposed hybrid functionality with confidence.

Background: The human ability to adapt to extreme environments is fascinating. Research into this adaptation has been lacking in Arctic isolated teams because it has concentrated on Antarctic teams. The hazards of the poles often confine the researchers indoors with their colleagues, reducing their privacy. This deployment also limits their contact with loved ones at home. Subsequently, over the course of polar night, rates of anxiety, depression, irritability and sleep disturbance increase (Suedfeld & Palinkas, 2008). Often, the teams complain of cognitive impairments. The High Arctic’s distinctive feature is the polar bear. The presence of bears requires Arctic research station teams to handle fire arms for their personal safety. It also means that fire arms – which are highly restricted in the Antarctic – are ever-present and easily accessible at Arctic stations. This poses a unique psychological challenge for these teams which has not been well-researched. Methodology: This thesis is an original contribution to science in that it employs a mixed-methods approach combining phenomenological interviews, cognitive testing and mental health assessment via questionnaires with a team spending a year at the Polish Polar Station, Hornsund, Svalbard. The participants were ten of the eleven winter team members who spent the year between July 2015 and June 2016 at Hornsund (“Explorers”) and an age-/gender-/education-matched control group (“Controls”). They filled in the Symptom Checklist-90-Revised and the Profile of Mood States-Brief Version in July, September, January, April and June of that year. Cognitive testing was completed in September, January and June; it comprised the Figural Learning and Memory Test, the Sustained Attention to Response Task (SART), the elevator tasks of the Test of Everyday Attention (TEA) and the Raven Standard Progressive Matrices. The interviews took place at the same time as the cognitive testing. Results: The results showed that the most stressful time reported in the questionnaires was April 2016, just after the winter isolation had ended and the sun had risen again. The Explorers reported little subjective complaints about their cognition but they performed near-ceiling on the TEA while scoring far below their Controls on the SART. This implies a dichotomy between sustained attention and inhibition in the Explorers. Their lived experiences were shaped by a struggle to adapt to the other team members rather than by struggling to adapt to the hazardous environment. The environment was perceived as awe-inspiring. Over time, the Explorers shifted their view of the team from informal colleagues to a family which they did not choose to be a member of and then, to friends. Unanimously, other people were seen as the most difficult aspect of the mission. Conclusions: This thesis provides unique insight into a non-Anglo-Saxon Arctic wintering team: the conclusions suggest that participants should receive social training to get along better and be emotionally prepared. The findings can be implemented by my research partner, the Institute of Geophysics (Warsaw) to better select and prepare their future expeditions to Hornsund. Some of the insights such as the nature of the interpersonal stressors may be applicable to space missions.

Les liquides sont capables, comme les solides, de supporter des forces de traction. Ils sont alors à pression négative (c'est-à-dire en tension), dans un état qui est métastable. Le retour vers un état stable à pression positive peut se faire par la nucléation d'une bulle, un processus appelé cavitation. Dans cette thèse nous nous intéressons aux propriétés de la cavitation en milieu confiné, avec un accent particulier sur la dynamique des bulles. Ce sujet est motivé par l'étude du transport de l'eau dans les arbres dont une partie (la sève montante) se fait sous tension, dans des canaux micrométriques. La cavitation entraîne alors l'embolie des éléments conducteurs de sève, c'est-à-dire leur remplissage par du gaz. Une grande partie du manuscrit est consacrée à l'étude de la cavitation dans un milieu modèle, où de l'eau est confinée dans des inclusions sphériques micrométriques au sein d'un hydrogel. L'évaporation passive de l'eau à travers le gel permet de générer des pressions négatives, et la cavitation peut se produire spontanément ou être déclenchée à l'aide d'un laser. Nous résolvons la dynamique subséquente de la bulle à l'aide de diverses méthodes (caméra time-lapse ou caméra rapide, diffusion de la lumière, strobophotographie laser ...) et montrons qu'après une séquence inertielle ultra-rapide, la bulle atteint un état d'équilibre temporaire, puis grossit de manière quasi-statique sous l'effet des flux d'eau dans l'hydrogel, provoquant "l'embolie" de l'inclusion. Une place importante est accordée à un chapitre de théorie qui explore d'une part les propriétés thermodynamiques d'un liquide confiné à pression négative, et d'autre part la dynamique aux temps courts de bulles de cavitation dans de tels systèmes. Nous proposons ainsi une équation de Rayleigh-Plesset modifiée qui rend compte de l'accélération importante des oscillations radiales des bulles que nous avons observée expérimentalement. La compressibilité du liquide et l'élasticité du confinement sont des éléments-clés de ce modèle. Enfin, nous discutons l'application des résultats précédents dans le contexte des arbres, tout en proposant une nouvelle méthode expérimentale qui permet un suivi optique du processus d'embolie. Nous présentons quelques résultats obtenus sur des échantillons de pin sylvestre. / Liquids can sustain traction forces, as solids do. In this case, they are at negative pressure (that is, under tension), in a metastable state. Nucleation of a bubble can occur, leading the system back to a stable state : this process is called cavitation. In this PhD work, we are interested in the properties of cavitation in a confined liquid, with a particular emphasis on bubble dynamics. This study is motivated by the context of water transport in plants : ascending sap is indeed under tension, in natural micro-channels. Cavitation then leads to embolism, i. e. the gas-filling of these channels. A significant part of the manuscript is devoted to the study of cavitation in a model system : spherical inclusions of water are embedded in a hydrogel, and passive evaporation of water through the gel allows the generation of negative pressures. Cavitation can then happen spontaneously or be triggered with a laser. We resolve the subsequent dynamics of the bubble, using several methods (fast or time-lapse camera, light scattering, laser strobe photography ...), showing that after a first ultra-fast inertial step, the bubble reaches a temporary equilibrium. Then, it slowly grows due to fluxes in the hydrogel, leading to full embolism of the inclusion. A theoretical chapter follows. First, the thermodynamical properties of a confined liquid under negative pressure are investigated. In a second part, we focus on the dynamics of cavitation bubbles in such systems, at short time scales. We derive a modified Rayleigh-Plesset equation which accounts for the experimentally observed ultra-fast radial oscillations of the bubbles. Liquid compressibility and confinement elasticity are key ingredients in this model. Last, the applicability of the previous results in the context of trees is discussed. A new method to directly study embolism in trees by optical means is also presented, and applied to Scots pine samples.

161f. / Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2013-04-08T17:43:56Z No. of bitstreams: 3 maristelaribeiropt3.pdf: 1208442 bytes, checksum: 15bb8a1e20e49d86bfa3184ac486111d (MD5) maristelaribeiropt2.pdf: 1161467 bytes, checksum: e9eb2bca16b91eb599f192720110c47b (MD5) maristelaribeiropt1.pdf: 1054407 bytes, checksum: b52b36bd7a229755eeaa4c6cd208239d (MD5) / Approved for entry into archive by Lêda Costa(lmrcosta@ufba.br) on 2013-04-18T12:36:10Z (GMT) No. of bitstreams: 3 maristelaribeiropt3.pdf: 1208442 bytes, checksum: 15bb8a1e20e49d86bfa3184ac486111d (MD5) maristelaribeiropt2.pdf: 1161467 bytes, checksum: e9eb2bca16b91eb599f192720110c47b (MD5) maristelaribeiropt1.pdf: 1054407 bytes, checksum: b52b36bd7a229755eeaa4c6cd208239d (MD5) / Made available in DSpace on 2013-04-18T12:36:10Z (GMT). No. of bitstreams: 3 maristelaribeiropt3.pdf: 1208442 bytes, checksum: 15bb8a1e20e49d86bfa3184ac486111d (MD5) maristelaribeiropt2.pdf: 1161467 bytes, checksum: e9eb2bca16b91eb599f192720110c47b (MD5) maristelaribeiropt1.pdf: 1054407 bytes, checksum: b52b36bd7a229755eeaa4c6cd208239d (MD5) Previous issue date: 2005 / Esta dissertação, que visa à reflexão de algumas demandas do processo criativo, aborda as ações deflagradas num curto período de intensa ocupação com a criação em si e suas implicações, provenientes de uma fase de construção poética, vivenciada durante o Mestrado em Artes Visuais. Nesse período, em que se fez presente o diálogo poético com as experimentações derivadas das linguagens visuais – práticas híbridas e mistas –, foram descritos os procedimentos realizados em consonância com os conceitos de multiplicidade, modulação e reprodução, tais como a reprografia, o transfer, a imagem digital, além de outros mecanismos advindos da técnica fotográfica. A metodologia adotada para o incremento da pesquisa, está amparada na Poiética, ou seja, na ciência e filosofia da criação que aborda todo o processo de criação. O conteúdo desenvolvido no presente trabalho pretende, dentre outras coisas, gerar a reflexão sobre a problemática que envolve a mulher na contemporaneidade. São discutidos os conceitos cristalizados, abrigados em antigos costumes e tradições, e observadas as condições em que tais conceitos são forjados nos mais variados níveis da ideologia dominante. Após o exame de questões como gênero, exclusão, abandono e relação de menos-valia, são apontadas algumas possibilidades de sensibilização das condições sociais e existenciais do feminino. / Salvador

Esta dissertação tem por objetivo compreender de que maneira os estudantes de graduação em Educação Física relatam suas experiências com a clausura durante o estágio em saúde mental no Hospital Psiquiátrico São Pedro (HPSP). Fundamentase nos aportes teóricos produzidos a partir do movimento em prol da da Luta Antimanicomial e da Reforma Psiquiátrica, bem como busca inspiração analítica nos princípios da desinstitucionalização da loucura. A pesquisa é de corte qualitativo com metodologia centrada na análise documental proposta por André Cellard (2008; 2012) e incrementada pelo relato da experiência da própria pesquisadora in loco. A operacionalização da investigação contou com duas etapas desenvolvidas entre os meses de outubro de 2015 e abril de 2016. A primeira, refere-se à experiência de dois meses ininterruptos da pesquisadora no estágio de familiarização dentro dos serviços de saúde mental oferecidos pelo Hospital Psiquiátrico São Pedro. A segunda, emerge da análise documental sobre os relatórios de estágio em saúde mental dos estudantes de Educação Física que realizaram seus estágios nesta mesma instituição. A partir da análise dos relatos, foi possível notar que o estágio em saúde mental foi tratado mais na perspectiva de cumprimento de uma demanda de familiarização com o HPSP do que de um movimento de estranhamento à manutenção do controle e confinamento dos sujeitos nos dias de hoje. Pelo que pude perceber nas entrelinhas dos relatos, os estagiários veem a Educação Física mais como uma ferramenta de contenção, presa às demandas orgânicas do cuidado, do que um espaço para reflexões sobre os serviços substitutivos e a aposta na reinserção social do sujeito. Em conclusão, penso que para aprofundar os efeitos da Reforma Psiquiátrica é preciso também pôr em marcha um movimento "antiestágio- manicomial". / This research aims to understand how the graduate students in Physical Education report their experiences with the patients’ confinement during the internship in mental health at São Pedro Psychiatric Hospital (HPSP). The study is based on the theoretical contributions made from the movement for the Anti-Asylum and the Psychiatric Reform, and search analytical inspiration in the principles of deinstitutionalization.The research was based on qualitative cutting with its methodology centered on document analysis proposed by André Cellard (2008; 2012), and also, improved by the experience of the researcher on the spot. The investigation had two stages developed between the months of October 2015 and April 2016. The first refers to two months of continuous experience researcher had at the familiarization stage within the mental health services offered by the Psychiatric Hospital St. Pedro. The second emerges from the documentary analysis of internship reports on mental health of Physical Education students who conducted their internships at the same institution.From the analysis of the reports, it was noticeable that the internship in mental health has been treated more from the perspective of demand compliance to the familiarization with HPSP than a movement of estrangement to control maintenance and confinement of patients in these days. In these demands the internship in Physical Education also appeared as a containment tool, trapped in a care organic logic. It is possible to tell that the internship ends incorporating asylum features, leaving little space for reflection on the substitutive services and its commitment to social reintegration of the patients. In conclusion, I believe that stop deepen the effects of psychiatric reform is necessary to set also in motion a movement "anti-asylum-internship".

Este estudo teve como objetivo contribuir com as informações ecológicas e paleoecológicas geradas para a Baía de Guanabara com base na distribuição das assembléias de foraminíferos bentônicos. Para tal foram coletadas 30 amostras de sedimento superficial, ao longo de três perfis distribuídos pela baía e um testemunho (BG28) de 6 m de comprimento retirado próximo a Ilha do Governador. Nas amostras superficiais foram identificados 30 gêneros e 52 espécies das quais as espécies mais constantes foram Amonia tepida e Bolivina translucens que apresentaram a maior constância. Espécies de habitat de plataforma foram identificadas em diversas estações indicando uma boa eficiência no transporte das correntes de fundo para dentro da baía. Das estações superficiais analisadas, 10 localizadas ao redor da Ilha do Governador não continham testas de foraminíferos, possivelmente como resultado da acidificação do sedimento causado pelo derrame de óleo ocorrido em 2000. O índice de confinamento associado às análises de agrupamento e ao DCA indicaram a presença de três setores ambientais influenciadas por COT e granulometria. O primeiro setor entre Copacabana-Itatipú e Aeroporto Santos Dumont Ilha de Boa Viagem foi o ambiente marinho, o segundo setor entre o Aeroporto Santos Dumont - Ilha de Boa Viagem e Ilha do Governador Ilha de Paquetá Litoral de São Gonçalo pode se classificado como um ambiente de estuário inferior ou baía com grande influência marinha e o terceiro setor entre a Ilha do Governador Ilha de Paquetá Litoral de São Gonçalo e fundo da baía como o ambiente mais confinado. No testemunho foram feitas 7 datações indicando uma idade de aproximadamente 5180 40 anos BP. As datações também mostraram que nos últimos anos a taxa de sedimentação aumentou muito podendo estar relacionada com o período de colonização européia. Foram encontradas 18 gêneros e 30 espécies de foraminíferos das quais a espécie mais constante foi a Ammonia tepida seguida pela Buliminella elegantissima. O padrão de distribuição dessas espécies ocorreu com a maior abundância de B. elegantissima nas porções mais inferiores do testemunho e uma abundância maior de A. tepida nas porções mais superiores. Os índices de confinamento junto com as análises de agrupamento e com as curvas de isótopos mostraram que houve poucas oscilações no aporte de água marinha naquela região. As análises dos isótopos de C13 e C14 e O16 e O18 não seguiram um padrão inverso comum em outros estudos, possivelmente influenciado pela proximidade da costa. As análises de agrupamentos indicaram que nos últimos 5180 anos BP a baía não sofreu grandes variações ambientais, ou seja, a região oeste da baía mesmo apresentando alterações ao longo dos anos não foi suficiente para modificar as características de confinamento. As análises nos padrões de distribuição das assembléias de foraminíferos demonstraram ser eficientes ferramentas na caracterização ambiental e paleoambiental da Baía de Guanabara. / This study aimed to contribute with ecological and paleoecological informations generated in the Guanabara Bay based on the distribution of benthic foraminifera assemblages. In this study were collected 30 samples of surface sediments along three transect distributed in the bay and one core of 6 m length extracted near to Ilha do Governador. In the surface samples were identified 30 genera and 52 species which the most constant species were Ammonia tepida e Bolivina translucens exhibit the major constancy. Marine species were identified in several stations indicating good efficiency of tidal landward transport. In the surface stations analyzed, 10 located around Ilha do Governador doesn`t contain foraminifera tests, perhaps as a result of sediment acidification caused by oil spill occurred at year 2000. The confinement index associated to cluster analysis and DCA indicated the presence of three influenced environmental sectors by COT and grain size. The first section between Copacabana Itaipú and Santos Dumont airport Ilha de Boa Viagem was the marine environment, the second section between Santos Dumont airport Ilha de Boa Viagem and Ilha do Governador Ilha de Paquetá São Gonçalo coast can be classified like a inferior estuarine environment or bay with great marine influence and a third section between Ilha do Governador Ilha de Paquetá São Gonçalo coast and the inner of the bay as the most confined environment. In the core were done 7 dating indicating an age approximately 518040 years BP. The dating also reveal that in the last years the sedimentation rate increase and could be related with the European colonization period. Were found 18 genera and 30 species of foraminifera which the most constant specie was Ammonia tepida followed by Buliminella elegantissima. The distribution pattern of this species occurred with higher abundance of B. elegantissima in most inferior portions from the core and major abundance of A. tepida in most superior portions. The confinement index combined with cluster analysis and isotopes curves showed that was a few oscillations in the input of marine water in that region. Isotope analysis of C13/C14 and O16/O18 doens`t followed usual inverse pattern in other studies, possibly influenced by the proximity with the coast. The cluster analysis indicated that in the last 5180 years BP the bay didn`t suffer large environmental variations, that means the west region of the bay even presenting modification through the years it was not sufficient to modify the characteristics of the confinement. Analysis in the distribution pattern of foraminiferal assemblages demonstrated to be efficient tools to the environmental and paleoenvironmental characterization of Guanabara Bay.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In this work we studied the properties of confined water by graphene sheets via Classical Molecular Dynamics. The main objective of this dissertation is to understand how the structural and dynamic properties of confined water can be changed due to the geometric confinement, including the density profile, formation of layering, the average number of hydrogen bonds and the diffusion process of water molecules. The confinement geometry is formed by two graphene sheets aligned parallel with respect to one another separated by a distance "d". Both the distance "d" as the system temperature were varied to obtain different degrees of confinement and thermodynamic conditions. Values used were d=7, 9, 11, 15, 20, 25 and 30Å and T=280, 300 and 320K. Furthermore, all simulations were carried out with GROMACS (GROningen Machine for Chemical Simulations) code in a NVT ensemble (particle number, volume and pressure are kept constant) and using SPC/E (Simple Point Charge/Extend) water model. For these systems have been found that confinement induces the formation of layers of water molecules and the number of layers depend on the degree of confinement. Due to this structure, we analyzed the average number of hydrogen bonds with water molecules and these molecules in the respective diffusion layers (central and near the confining walls). It was concluded that the formation of layers is directly related to the breaking of hydrogen bonds. / Neste trabalho estudamos as propriedades da água confinada por folhas de grafeno via Dinâmica Molecular Clássica. O principal objetivo dessa dissertação é compreender como as propriedades dinâmicas e estruturais da água confinada podem ser alteradas devido ao confinamento geométrico, entre elas o perfil da densidade, a formação de camadas, o número médio de ligações de hidrogênio e o processo difusivo das moléculas de água. A geometria confinante foi construída através de duas folhas de grafeno alinhadas paralelamente uma em relação a outra separadas por uma distância "d". Tanto a distância "d" como a temperatura do sistema foram variadas de modo a obtermos diferentes graus de confinamento e condições termodinâmicas. Os valores utilizados foram d=7, 9, 11, 15, 20, 25 e 30Å e T=280, 300 e 320K. Além disso, todas as simulações foram realizadas com o código computacional GROMACS (do inglês GROningen Machine for Chemical Simulations) em um ensemble NVT (ensemble onde o número de partículas, volume e pressão são mantidos constantes) usando o modelo de água SPC/E (do inglês Simple Point Charge/Extend). Para esses sistemas foi encontrado que o confinamento induz a formação de camadas de moléculas de água e o número de camadas dependem do grau de confinamento. Devido a esta estruturação, foi analisado o número médio de ligações de hidrogênio por moléculas de água e a difusão dessas moléculas nas respectivas camadas (central e próximas as paredes confinantes). Concluiu-se que a formação de camadas está diretamente relacionado com a quebra das ligações de hidrogênio.