O lançamento de águas residuárias contendo compostos nitrogenados tem um importante impacto sobre a saúde e o meio ambiente, tornando necessária a incorporação de processos de remoção desses compostos nos sistemas de tratamento de águas residuárias. Neste trabalho, foram estudadas as condições de operação para promover a remoção conjunta de nitrogênio e matéria orgânica em reator biológico de leito móvel, contínuo, operado sob aeração intermitente, alimentado com água residuária sintética contendo nitrogênio amoniacal (90 a 110 mg/L) e melaço como matéria orgânica (DQO de 450 a 550 mg/L). Foram utilizados dois reatores em escala de bancada, cada um com dois litros de volume útil, contendo diferentes meios suportes para a imobilização da biomassa: matrizes de espuma de poliuretano e anéis plásticos. Na primeira etapa experimental, o reator contendo anéis plásticos apresentou eficiências de remoção de nitrogênio muito baixas. Na segunda etapa, trocou-se o material suporte por matrizes de espuma de poliuretano inoculadas com lodo aeróbio de estação de tratamento de águas residuárias. A partir de então, trabalhou-se com dois reatores de mesma configuração, exceto pelas origens, idades e características dos lodos de inóculo. Inicialmente, a alimentação foi realizada utilizando-se apenas os micronutrientes contidos no melaço. Posteriormente, a composição da água residuária foi alterada, introduzindo-se solução de micronutrientes, pois se concluiu que a instabilidade no processo de nitrificação devia-se ao fato de o melaço comercial apresentar deficiências nutricionais. Como resultado, em condições de estabilidade operacional, foram obtidas eficiências de remoção de DQO superiores a 85%, oxidação total do nitrogênio amoniacal e eficiências de remoção de nitrogênio de aproximadamente 55%. Variações posteriores nas condições de operação, como o aumento do período anóxico (de 1h para 1h15min) e redução do tempo de detenção hidráulica (para valores inferiores a 12 horas), resultaram em melhora no desempenho dos reatores. Os resultados obtidos permitem admitir que as melhores condições de operação não foram atingidas durante o experimento, abrindo a possibilidade para a otimização do processo em pesquisas futuras. Constatou-se que o desenvolvimento das populações microbianas imobilizadas no meio suporte foi diferente do observado na biomassa em suspensão. Verificou-se, também, que a biomassa responsável pela nitrificação e desnitrificação ocorreu predominantemente no meio suporte, enquanto que a biomassa heterotrófica predominou no lodo em suspensão. / The operating conditions for the combined removal of nitrogen and organic matter in moving- bed biological reactor were investigated. Two bench-scale reactors, two liters each, were operated under intermittent aeration and continuously fed with synthetic wastewater containing ammonia nitrogen (90 to 110 mg/L) and molasses as organic carbon source (COD of 450 to 550 mg/L). Each reactor received different moving-bed materials: polyurethane foam matrices and plastic rings, respectively. During the first experimental period, the reactor containing plastic rings maintained very low nitrogen removal efficiencies during large period. For this reason, the moving-bed was replaced by polyurethane foam matrices and the reactor was re-inoculated with aerobic wastewater plant sludge. Thereafter, the two reactors were similar except for the origin, age and characteristics of the inoculum sludge. First, the wastewater micronutrients were just those contained in the carbon source (molasses). After, the synthetic wastewater composition was changed by adding a solution of micronutrients. This procedure was adopted to achieve a stable nitrification process, because commercial molasses is a very poor regarding its micronutrient composition. As a result of the stable conditions prevalence just after adding micronutrients, organic matter (as COD) removal efficiencies were higher than 85% and complete nitrogen ammonia oxidation was achieved. In nitrogen removal efficiencies were approximately 55%. The performance of the reactors improved after the increase of the anoxic period from1h to 1h15min, and reduction of the hydraulic detention time to less than 12 h. The results obtained in the last operating period indicated the optimum operating conditions was not achieved in this experiment, thus opening the possibility of process improvement in further researches. Microbial populations with different characteristics were developed in suspended growth and attached biomass. Nitrification and denitrification bacteria predominated as attached biomass whereas heterotrophic bacteria predominated as suspended growth biomass.

Utilizou-se reator de leito estruturado e aeração intermitente (RLEAI) como pós-tratamento de efluentes de reator UASB tratando esgoto sanitário. O volume total e o tempo de detenção hidráulica (TDH) do reator UASB eram de 11,2 L e 9 horas, respectivamente. O RLEAI possuía volume total de 11,0 L e, devido às hastes cilíndricas verticais de espuma de poliuretano usadas como suporte para a biomassa, o volume útil foi de 9,6 L. Este reator foi operado com um TDH de 12 horas, razão de recirculação igual a 3 e foi alimentado continuamente com efluente do reator UASB. O objetivo deste trabalho foi avaliar a influência do tempo de aeração no desempenho do RLEAI na remoção de matéria orgânica e nitrogênio. O reator foi operado com aeração contínua, e tempos de aeração intermitentes (tempo aerado/não aerado) de 2h/1h, 1h/1h, 0,75h/1,25h, 1h/ h e 1h/3h. Em todas as fases a DQO efluente ao sistema ficou entre 26 e 42 mg.L-1. A fase de aeração contínua foi fundamental para o estabelecimento da comunidade nitrificante no sistema. A oxidação do nitrogênio total (como NTK) para nitrato aumentou de 62% (aeração contínua ) para 82% (aeração intermitente de 1h/2h) devido à alcalinidade gerada pela desnitrificação, estimulada pelo período não aerado. Na fase 1h/3h a oxidação do NTK foi prejudicada pela falta de oxigênio, e a eficiência nesta fase foi de 42%. A maior remoção estável de N-total foi obtida na fase 1h/2h com eficiência de 29%. Foi observado no ensaio em batelada que a velocidade de desnitrificação via nitrato aumentou de 0,90 mg N. g SSV-1.h-1 para 2,55 mg N. g SSV-1.h-1 após aclimatação da biomassa em condições de excesso de matéria orgânica. Concluiu-se que a remoção de N-total foi limitada pela baixa quantidade de matéria orgânica advinda do reator UASB, sendo a relação DQO/N do afluente ao RLEAI de 3,04. A elevada oxidação de NTK e de remoção de matéria orgânica, aliadas à baixa produção sólidos e ao alto tempo de retenção celular (139 dias), mostram que o RLEAI é uma alternativa interessante em comparação às tecnologias praticadas atualmente para pós tratamento de efluentes de reatores anaeróbios. / This study used a structured bed reactor under intermittent aeration for post-treatment of UASB rector treating domestic sewage. The UASB reactor had a total volume of 11.2 L and 9 hours of hydraulic retention time (HRT). The structured bed reactor had a total volume of 11.0 L and working volume of 9.6 L due to the vertical cylindrical rods with polyurethane foam used as a support for the biomass. This reactor was operated whit 12 hours of HRT, recirculation ratio equal to 3 and was continuously fed with effluent from the UASB reactor. The aim of this study was to evaluate the influence of aeration time on RLEAI performance in removal of organic matter and nitrogen. For this the reactor was operated with continuous aeration and intermittent aeration periods (time aerated/ non-aerated) of 2h/1h, 1h/1h, 0.75h/1.25h, 1h/2h e 1h/3h. During all operation time the COD effluent to the system it was between 26 and 42 26 e 42 mg.L-1. The continuous aeration operation was fundamental to the establishment of the nitrifying microorganism community in the system. The TKN oxidation to nitrate increase from 62% (continues aeration) to 82% (intermittent aeration 1h/2h) due to the alkalinity generated by denitrification, that was stimulated by non-aerated period. In the intermittent aeration period of 1h/3h the NTK oxidation was damaged by a lack of oxygen; the efficiency at this stage was 42%. The most stable total nitrogen removal was obtained in 1h/2h aeration period with 29% efficiency. It was observed in the batch test that nitrate denitrification rate increased from 0.90 mg N. g VSS-1.h-1 to 2.55 mg N. g VSS-1.h-1 after acclimation of biomass in conditions of excess organic matter. It was inferred that the removal of total nitrogen was limited by the low amount of organic matter load from the UASB reactor; the COD/N ratio of the influent was 3.04. The high NTK oxidation and high organic matter removal, combined with low solid production and high cell retention time (139 days), leads to the conclusion that the structured bed reactor under intermittent aeration is an interesting alternative compared to the technologies currently applied for post treatment of anaerobic reactors effluent.

INTRODUÇÃO: O termo Síndrome Metabólica denomina um conjunto de fatores de risco cardiovascular associado à resistência à insulina e a um aumento da morbidade e da mortalidade. A síndrome metabólica está relacionada a diversas doenças, especialmente aquelas ligadas à aterosclerose, como a doença arterial periférica. A claudicação intermitente é sintoma característico de um estágio inicial da doença arterial periférica, no qual o conhecimento dos seus fatores predisponentes, entre os quais a síndrome metabólica, torna-se importante para a instituição do tratamento médico adequado, a fim de prevenir ou retardar a progressão da aterosclerose. OBJETIVO: O objetivo deste estudo transversal foi determinar a prevalência da síndrome metabólica em pacientes com claudicação intermitente e sua correlação com a idade, gênero, localização da obstrução arterial e associação com doença arterial coronária sintomática. MÉTODO: Foram estudados 170 pacientes com doença arterial obstrutiva dos membros inferiores de etiologia aterosclerótica cuja única manifestação clínica era dor tipo claudicação intermitente. A idade média foi de 65 anos (33-89 anos). Havia 117 homens (68.8%) com idade média de 65.6 anos (33-84 anos) e 53 mulheres (31.1%) com idade média de 63.7 anos (35-89 anos). RESULTADOS: A síndrome metabólica foi diagnosticada em 98 pacientes (57.6%), 62 homens (63.3%) e 36 mulheres (36.7%). A idade média dos pacientes com síndrome metabólica foi de 63.5 anos, contra 67.0 anos dos pacientes sem síndrome metabólica (P = .027). Considerando os doentes com 65 anos, a síndrome metabólica esteve presente em 46 (48.9%) indivíduos e em 52 (68.4%) pacientes abaixo de 65 anos (P = .011). CONCLUSÕES: A Síndrome Metabólica é uma comorbidade frequente em indivíduos com claudicação intermitente, com prevalência significativamente mais elevada em indivíduos com idade inferior a 65 anos. Não houve associação entre a Síndrome Metabólica e o sexo dos pacientes com claudicação intermitente. Não houve também relação entre a Síndrome metabólica e doença coronariana sintomática na população estudada. A Síndrome Metabólica não afetou nenhum segmento anatômico arterial preferencialmente nos claudicantes / INTRODUCTION: The metabolic syndrome consists in a group of cardiovascular risk factors referring to insulin resistance, associated with increased cardiovascular morbidity and mortality. Metabolic syndrome is correlated to several illnesses, especially those associated with atherosclerosis, like peripheral arterial disease. Intermittent claudication is a symptom of an early stage of peripheral arterial disease, and the precocious diagnosis of metabolic syndrome is important for adequate medical treatment, in order to prevent or delay the progression of atherosclerosis. OBJECTIVES: The aim of this cross-sectional study is to determine the prevalence of the metabolic syndrome in patients with intermittent claudication and its correlation with age, gender, localization of arterial obstruction and association with symptomatic coronary artery disease. METHODS AND RESULTS: There were studied 170 consecutive patients with intermittent claudication, determined by physical examination, which revealed absence or weakness of pulses on the limb or limbs that were limiting deambulation, and an ankle-brachial index 0.9. The mean age was 65 years (33-89 years). There were 117 men (68.8%) with mean age of 65.6 years (33 84 years) and 53 women (31.1%) with mean age of 63.7 years (35 89 years). Metabolic syndrome was diagnosed in 98 patients (57.6%), 62 men (63.3%) and 36 women (36.7%). The mean age of patients with metabolic syndrome was 63.5 years, against 67.0 years of patients without metabolic syndrome (P= .027). Considering patients with 65 years old, the metabolic syndrome was present in 46 (48.9%) individuals and in 52 (68.4%) patients below 65 years old (P= .011). CONCLUSIONS: The metabolic syndrome is frequent among patients with intermittent claudication, with a significant higher prevalence in claudicants < 65 years of age. The metabolic syndrome was not correlated with sex and symptomatic coronary artery disease. The metabolic syndrome did not affect any specific arterial segment in claudicant patients

Orientador: João Batista de Miranda / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-21T06:02:57Z (GMT). No. of bitstreams: 1 Pasqualini_Wagner_D.pdf: 1157517 bytes, checksum: f927ba791a4b318be74e60bad2138135 (MD5) Previous issue date: 2012 / Resumo: Modelo de Estudo: Estudo diagnóstico Transversal de caso controle. Objetivos: comparar pacientes com estenose do canal lombar com indicação de cirurgia e um grupo controle, assintomáticos para esta doença, levando em consideração imagens de ressonância magnética (RM) e o questionário de Oswestry. Material e Método: Vinte e três pacientes com estenose do canal lombar foram comparados com um grupo controle de 17 indivíduos. Todos foram submetidos a RM e responderam ao questionário de Oswestry. Medidas qualitativas foram descritas segundo os grupos com uso de frequências absolutas e relativas e, verificada a existência de associação dessas medidas com uso do teste exato de Fisher. Medidas quantitativas foram descritas e comparadas entre os grupos com uso do teste Mann-Whitney. O teste de Spearman foi utilizado para avaliar a correlação entre os grupos. Resultados: Lombalgia foi a queixa mais frequente nos dois grupos. O índice de Oswestry mostrou média de percentual de invalidez de 45,69% no Grupo Estenose e 11,60% no Grupo Controle. A RM mostrou que a área de secção transversa do saco dural, o diâmetro do canal e a avaliação dos forames e recesso lateral estavam alterados em ambos os grupos. Conclusões: Não houve relação entre o grau de estenose do canal lombar mensurado em exame de RM com o índice de Oswestry em ambos os grupos / Abstract: Study design: Transversal Case-control, diagnostic study. Objectives: To verify the relationship between the degree of lumbar spinal canal stenosis (LCS), as seen in magnetic resonance imaging (MRI), and the severity of disability as seen in the Oswestry Index, in patients with LCS compared to controls without a diagnosed LCS. Methods: Twenty-three patients with a previous diagnosis of LCS were compared with a control group of 17 volunteers. All participants underwent MRI and answered the Oswestry questionnaire. Qualitative data were described according to the groups with the use of absolute and relative frequencies, and the association of these measures was checked by using the Fisher exact test. Quantitative measures were described and compared between groups using the Mann-Whitney test. Spearman's test was used as well. Results: Low back pain was the most frequent complaint in both groups. The Oswestry index showed average percentage of disability of 45.69% in patients with stenosis and 11.60% in the control group. MRI revealed that the dural sac cross-sectional area (DCSA), the diameter of the canal and the evaluation of lateral recesses and foramina were equally changed in both groups. Conclusions: There was no correlation between the degree of lumbar canal stenosis measured on MRI with the Oswestry Disability Index in both groups / Doutorado / Cirurgia / Doutor em Cirurgia

Avloppsreningsverket i Forsmark renar vattnet med aktivt slam i en satsvis biologisk rening (SBR) reaktor samt med våtmarker. Våtmarkerna består av fyra pulskärr och en damm. Pulskärren är utformade som bassänger fyllda med grus som filtermaterial där ytan är bevuxen. Pulskärren beskickas satsvis med 60 m^3 vatten när någon av SBR-reaktorerna töms, vattnet rinner då ut över ytan samtidigt som det perkolerar ner i bädden. När SBR-reaktorn har tömts är hela pulskärret mättat. Tömningen av pulskärret sker genom ett dränerande gruslager i botten och sedan flödar vattnet vidare ut genom ett ställbart dräneringsrör till slutdammen. Pulskärrens uppgift är att stoppa partiklar och att fungera som ett nitrifierande steg ifall verket i framtiden skulle få ökade reningskrav. I detta arbete har pulskärrens funktion som nitrifierare av ammonium undersökts. Detta genom att sammanställa befintliga driftdata från reningsverket, fältstudier samt en litteraturgenomgång. Målet med fältstudien var att mäta halten ammonium, nitrat och totalkväve i vattnet som gick in och ut ur pulskärret för att se hur halterna ändrades. Dessutom mättes temperatur, syrehalt, pH och konduktivitet. Provtagningen genomfördes på två pulskärr med tömningstiderna två respektive fyra timmar. Resultaten visade att ammoniumhalterna halveras i pulskärren. Inkommande ammonium till pulskärren var cirka 3 mg/l under studien men om ammoniumkoncentrationen skulle öka kommer nitrifikationen antagligen ske i liknande utsträckning. Detta då liknande system påvisat sådana resultat. Ökad tömningstid för pulskärren medför ökad nitrifikation, pulskärren bör därför ställas om så att tömning sker under cirka fyra timmar. För att hitta en optimal tömningstid bör vidare undersökningar göras. Forsmarks avloppsreningsverk möter de reningskrav som ställts med marginal. Trots att detta inte var syftet, avskiljs 80 % av inkommande kväve och det kunde konstateras att den största kväveavskiljningen sker i SBR-reaktorn. Kvävereduktionen har uppstått då verket haft låg belastning samtidigt som mycket syre tillsatts till processen. Då rening genom pulskärr sker efter att vattnet passerat genom SBR-reaktorerna borde luftningen kunna minskas för att istället utnyttja pulskärrens nitrifierande egenskaper. Svensk kärnbränslehantering AB har planer på att leda lakvatten till reningsverket för att avskilja kväverester, skulle detta ske kommer flödena över pulskärren att öka. Att den hydrauliska belastningen ökar borde inte utgöra några problem då flödena troligen inte kommer överstiga pulskärrens kapacitetsgränser. I extrema fall kan tömningstiden på pulskärren minskas. / Forsmark wastewater treatment plant treats wastewater using an active sludge process in sequencing batch reactors (SBR:s) and followed by constructed wetlands. The wetlands consist of four intermittent loaded soil filters (ILS:s) and a pond. The ILS:s is designed as pools filled with filter material and with a plant-grown surface. One of the ILS:s fills up with water when one of the SBR reactors is emptied. The water flows out over the surface as it percolates into the bed. When the SBR reactor is emptied, the entire ILS becomes saturated. The ILS then drains through a drainage gravel layer at the bottom and further through an adjustable drainage pipe into the dam. The purpose of the ILS:s is to work as extra filter for removal of the remaining particles and escaping sludge. They have also been thought to act as a nitrifying step if the plant would have tougher cleaning requirements in the future. In this report, the function of the ILS:s as nitrifying steps was investigated by compiling existing operating data from the treatment plant, with conducted field studies and through a literature review. The field study aimed at measuring ammonium, nitrate and total nitrogen in the water at the entering and the outlet in the ILS to see how the different nitrogen concentrations was affected. Temperature, oxygen, pH and electricalconductivity were also measured. The sampling was done on two ILS with different drainage time, two and four hours. The results showed that the ILS:s nitrifies the incoming water with an average efficiency of 50 % depending on the ammonium contentration in the incoming water. An increased drainage time for the ILS seamed to result in better nitrification. Therefore, the ILS:s should be changed to drain for at least four hours. Should the ammonium concentration increase above 3 mg/l the nitrification rate would probably be about the same. Similar systems such as have shown similar nitrification removal but with higher ammonia concentrations. Forsmarks wastewater treatment plant meets the purification requirements imposed on the plant with margin. It is remarkable that, without planning for any nitrogen removal, the removal is about 80 % of incoming nitrogen, most of which is removed in the SBR reactor. Svensk Kärnbränslehantering AB plans to lead leachate to the treatment plant for nitrogen removal. If this plan is fulfilled, the flows through the ILS will increase. This should not be a problem as the total flow trought the ILS will not exceed the capacity limits of the ILS. In case of high flows, the emptying time of the ILS:s can be reduced.

Abstract The purpose of the present study was to gain more insight into the blood oxygen level-dependent (BOLD)-contrast functional MRI (fMRI) in the brain and its connection to EEG, both in global and local scales of their temporal and spatial relations. BOLD signal changes were studied during hyperventilation (HV) induced EEG reactivity of intermittent rhythmic delta activity (IRDA). The BOLD signal in gray matter decreased 30% more in subjects with IRDA (N = 4) than in controls (N = 4), during the first two minutes of HV. This difference disappeared during IRDA in EEG. BOLD signal changes may provide additional information about dynamic hemodynamic changes relative to HV induced EEG reactivity. BOLD signal changes were investigated during sudden deepening of thiopental anesthesia into EEG burst-suppression level in pigs (N = 5). Positive (6–8%) or negative (-3– -8%) group average BOLD signal changes correlated to the thiopental bolus injection were seen. Positive and negative responses covered 1.6% and 2.3% of the brain voxels, respectively. BOLD signal changes in brain are associated with sudden deepening of thiopental anesthesia into EEG burst-suppression level, but they are spatially inconsistent and scarce. Somatosensory BOLD response was studied in brain before and after globally induced methotrexate (MTX) exposition in pigs (N = 4). After the MTX exposure, reduced (from 2–4% to 0–1%) or negative (-2% to -3%) BOLD responses were detected. Somatosensory BOLD-contrast response shows a slight difference in brain before and after globally induced MTX exposition. An experimental epilepsy model for development of simultaneous EEG and BOLD-contrast fMRI in the localization of epilepsy was developed and tested. Dynamic penicillin induced local epilepsy was applied in deep isoflurane anesthesia in pigs (N = 6). Relatively high (10–20%) and localized BOLD signal increase was found. The dynamic penicillin induced focal epilepsy model in deep isoflurane anesthesia with simultaneous EEG and BOLD-contrast fMRI is feasible for the development of these methods for localization of epileptic focus or foci. In conclusion, with careful experimental design and analysis, BOLD-contrast fMRI with EEG provides a potential tool for monitoring and localising functional changes in the brain.

Background: Physiologic functional capacity through maximal oxygen uptake (V̇O2max) can be measured in many different ways depending on sport and qualities needed to be assessed.In handball a demanding 3000 meter (m) running test is used to evaluate V̇O2max. If this test is sport specific or if it could be replaced by a less strenuous test is unknown. Aim: The aim ofthis study was to compare performance on 3000-meter running with predicted V̇O2max from a submaximal treadmill jogging test (SMTJ) and performance of the Yo-Yo intermittentrecovery test 1 (IR1). Methods: Male handball players (n = 12) performed the 3000 m running test, the Submaximal Treadmill Jogging test and the Yo-Yo Intermittent Recovery test level 1. Measurements in seconds (s), ml ∙ kg-1 ∙ min-1 and meters where collected and correlated using Pearson r, interclass correlation. Results: A strong significant linear correlation (p &lt; 0.01) was found between performance in 3000 m running (s) and Yo-Yo IR1 performance (m), r = - 0.724 (r2 = 0.524). A weak, not significant linear correlation (p &gt; 0.05)was found between performance in 3000 m running (s) and predicted V̇O2max from submaximal treadmill test (ml ∙ kg-1 ∙ min-1), r = - 0.309 (r2 = 0.095). Conclusion: According to this study the 3000 m running test could be replaced by the Yo-Yo IR1 test or vice versa in adolescent male handball players. The submaximal treadmill test used in this study had several potential errors in estimating V̇O2max, this is probably the reason why only a weak correlation was found between the SMTJ and the 3000 m running test.

Quand un fluide mouillant visqueux (comme une huile) pénètre un milieu hétérogène tel qu’une fracture, l’interface (entre l’air déplacé et l’huile) développe des corrélations à longue portée menant à une dynamique spatio-temporelle complexe. Dans cette Thèse, nous avons étudié expérimentalement et théoriquement ce processus de transport d’un fluide, appelé imbibition, dans un modèle de fracture ouverte, pertinent dans diverses situations. Notre travail a combiné une étude expérimentale détaillée, avec une analyse précise des données, basées sur des méthodes de physique statistique et non-linéaire. D’abord, la position moyenne de l'interface h(t) est étudiée lors d’expériences de montée capillaire donnant lieu à une nouvelle solution analytique pour h(t). Nous avons ensuite étudié les propriétés d’invariance d’échelle de l’interface et en particulier leur évolution pour des processus d’imbibition forcées, caractérisée par un scénario dit «super-rugueux». Enfin, nous avons étudié et quantifié la dynamique intermittente par avalanches des fronts d’imbibition à partir de l’analyse multi-échelle (spatiales et temporelles) de leurs vitesses. L'ensemble des résultats présentés dans cette Thèse propose une image très générale de la dynamique hors équilibre des fronts d’imbibition se propageant lentement dans des fractures ouvertes. La propagation latérale des fluctuations interfaciales est contrôlée par conservation de la masse locale. L'avancement de l'interface dans la direction de propagation est contrôlé par l’échelle caractéristique du désordre et la vitesse moyenne du front. / The heterogeneous structure of fractured media can lead to complex spatiotemporal fluid invasion dynamics. It thus brings forward challenging fundamental questions in the context of out-of-equilibrium dynamical systems, but also relevant to many processes of interest. The goal of the Thesis is to study the spatio-temporal dynamics of the oil-air interface between displaced air and invading oil, in imbibition through a model open fracture. The research combines exhaustive experimental work with accurate data analysis based on methods of nonlinear statistical physics. The mean postion of the interface h(t) is studied in capillary rise experiments, giving rise to a new analytical solution for h(t). The fluctuations of the interface in forced-flow experiments are analysed in the context of kinetic roughening, characterizing a super-rough scaling scenario. Finally, the burst-like dynamics is studied by analysing the local and global velocities of the front, which are widely distributed and display complex spatio-temporal correlations. We define local and global avalanches whose sizes and durations are also widely distributed, with cutoffs that diverge with the capillary number. Intermittentcy of the global signal is quantified. The ensemble of results presented in this Thesis supports a very general picture of the nonequilibrium dynamics of slowly-driven fronts in open fractures: the lateral propagation of interfacial fluctuations is controlled by local mass conservation, through the lateral correlation length; and the advancement of the interface in the direction of propagation is controlled by the characteristic extent of the disorder d and by the mean front velocity.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study was conducted with the aim of generating information about the tillering process and contribute to the understanding of the defoliation process of Italian ryegrass (Lolium multiflorum Lam) utilized by lambs submitted to different herbage allowances: 6, 8 and 12 kg body weight DM/100 kg. The grazing method was intermittent. Pasture was utilized during 12 days and an accumulated thermal sum of 250 degree-days was the criterion to determine the grazing interval. The experimental design was completely randomized with repeated measures on time, three treatments and two area replication. It was used 35 marked tillers per paddock to determine the intensity and interval of defoliation. Tillering dynamics on the identification and counting of remaining living tiller and new appearance tillers. The intensity of defoliation is greater in 6 and 9% herbage allowances. The interval of defoliation is higher in forage herbage allowance 12%, intermediate in 9% and lower in the 6% offer. The rate appearance, survival and death of tillers, stability index of tillers number are similar for herbage allowances and differ according phenological stages of ryegrass. Different herbage allowances and phenological stages promote variable intensity and interval of defoliation. The advance of phenological stage increases tiller mortality and reduce the interval between defoliation. / Este estudo foi conduzido com o objetivo de gerar informações a respeito do processo de perfilhamento e contribuir com o entendimento do processo de desfolhação do azevém (Lolium multiflorum Lam.) utilizado por cordeiras submetidas a diferentes ofertas de forragem: 6; 8 e 12 kg de MS/100kg de peso corporal. O método de pastejo foi intermitente. O período de ocupação da pastagem foi de 12 dias e o critério para determinar o intervalo entre pastejos foi a soma térmica acumulada de 250 graus-dia. O delineamento experimental foi inteiramente casualizado, com medidas repetidas no tempo, três tratamentos e duas repetições de área. Utilizaram-se 35 perfilhos marcados por parcela para a determinação da intensidade e intervalo de desfolhação. A dinâmica de perfilhamento baseou-se na identificação e na contagem de perfilhos vivos remanescentes e no aparecimento de novos perfilhos. A intensidade de desfolhação foi superior nas ofertas de forragem 6 e 9%. O intervalo de desfolhação foi superior na oferta de forragem 12%, intermediário na oferta 9% e inferior na oferta 6%. As taxas de aparecimento, sobrevivência e mortalidade de perfilhos e o índice de estabilidade da população de perfilhos são similares nas ofertas de forragem e variam em função dos estádios fenológicos do azevém. As diferentes ofertas de forragem e estádios fenológicos promovem intensidade e intervalo de desfolhação variável. O avanço do estádio fenológico aumenta a mortalidade de perfilhos e reduz o intervalo entre desfolhações.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Human activity has been pointed out as the main reason of global warming by effluxes of CO2, N2O and CH4. In the last years, harmful effects of greenhouse gases due to its increase in atmosphere have been arousing interests of scientists into propose mechanisms of mitigation. Flooding rice is responsible for about 12% of CH4 released to atmosphere and therefore, is considerate one of the most important source of this greenhouse gas. There are many factors that control CH4 efflux in irrigated rice fields, which difficult an accurate identification of the responsible mechanisms. However, is known that irrigation regime and selection of rice cultivars affect CH4 efflux and may be managed intending to mitigate it. The objectives of this thesis were: (a) verify the effect of continuous irrigation, intermittent irrigation and intermittent flooding into CH4 efflux of a hapludalf soil cultivated with flooding rice at central region of Rio Grande do Sul State; (b) evaluate CH4 efflux of rice cultivated in greenhouse under different irrigation managements and relate the efflux to agronomic parameters of rice plants; (c) evaluate the irrigation systems over the rice crop and how it affect the electrochemical of soil solution and plant development; (d) evaluate CH4 efflux through cultivars of rice from Rio Grande do Sul and Santa Catarina States and relate it to plant morphological attributes. Intermittent irrigation was efficient to mitigate CH4 efflux in rice cultivations, when the lack of rain did not establish water layers, without having decrease in rice productivity. intermittent flooding management by irrigations, even at saturated soil, decreased the CH4 efflux by 70%. The management of intermittent flooding by irrigations when soil was bellow the field capacity do not cause CH4 efflux, however, this management caused decrease of rice productivity. Irrigation management does affect electrochemical conditions of soil, which are determinant to the CH4 production in soils. The dynamic of efflux of CH4 is similar between cultivars; however, there are differences on potential of CH4 efflux from cultivars of flooding rice. The cultivars Arize 1003, Avaxi Cl, BRS Atalanta, BRS Querência, BRS Taim, Inov Cl, Irga 422 and Irga 424 have showed lower efflux and higher productivities. Morphological characteristics of plants have not explained completely the differences of CH4 effluxes between cultivars. / A atividade antrópica tem sido apontada como a principal causa do aquecimento global pelo efluxo de CO2, N2O e CH4. Nos últimos anos, os efeitos prejudiciais do aumento da concentração atmosférica desses gases têm despertado os cientistas a propor mecanismos de mitigação. A cultura do arroz irrigado por alagamento é responsável por cerca de 12% do efluxo total de CH4 para a atmosfera, sendo considerada uma das principais fontes emissoras desse gás de efeito estufa. Os fatores que controlam o efluxo de CH4 no arroz irrigado são muitos, dificultando identificar com precisão os mecanismos responsáveis pelo seu efluxo. O regime de irrigação e a seleção de cultivares de arroz são fatores que afetam o efluxo de CH4 e podem ser modificados visando mitigar os efluxos para a atmosfera. Os objetivos da tese foram: (a) verificar o efeito do regime de irrigação contínua, intermitente e a banhos no efluxo de CH4 em um Planossolo cultivado com arroz irrigado por alagamento na Depressão Central do Rio Grande do Sul; (b) avaliar o efluxo de CH4 no arroz cultivado em casa de vegetação submetido a diferentes manejos de irrigação e relacionar o efluxo com parâmetros agronômicos da planta de arroz; (c) avaliar os sistemas de manejo de irrigação na cultura do arroz e os efeitos nos atributos eletroquímicos da solução do solo e no desenvolvimento das plantas; (d) avaliar o efluxo de CH4 em cultivares de arroz do RS e SC e relacionar com atributos morfofisiológicos das cultivares; e (e) caracterizar morfologicamente a cultura do arroz e verificar a provável rota de difusão do CH4 do solo até a atmosfera. A prática da irrigação intermitente foi eficiente em mitigar o efluxo de CH4 no cultivo do arroz irrigado quando as condições climáticas permitiram a ausência da lâmina de água durante o cultivo, sem diminuir a produtividade do arroz. O manejo da irrigação intermitente com o realagamento do solo ainda saturado diminuiu a emissão de CH4 em 70%. O manejo intermitente da irrigação com o realagamento do solo abaixo da capacidade de campo não causa efluxo de CH4, porém os efeitos foram negativos sobre a produtividade do arroz. O manejo da irrigação afeta as condições eletroquímicas do solo e são determinantes para a produção de CH4 nos solos. A dinâmica de efluxo de CH4 é semelhante entre as cultivares, porém, existem diferenças no potencial de efluxo de CH4 em cultivares de arroz irrigado por alagamento. As cultivares Arize 1003, Avaxi Cl, BRS Atalanta, BRS Querência, BRS Taim, Inov Cl, Irga 422 e Irga 424 apresentaram menor efluxo de CH4 com a maior produtividade do arroz. As características morfofisiológicas das plantas não explicaram completamente as diferenças de efluxos de CH4 entre as cultivares.