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O objetivo desta pesquisa foi investigar a relação linear existente entre a Temperatura de Superfície do Mar (TSM) dos oceanos Pacífico e Atlântico e a vazão do rio Madeira, localizado na parte sul da região Norte do Brasil. A investigação foi feita nas escalas mensal, sazonal e anual, para o período de 1968 a 2009. A hipótese de que alterações climáticas na região Norte do Brasil estariam associadas a episódios de aquecimento e resfriamento dos oceanos globais, já que quando ocorrem têm o potencial de modificar o padrão de precipitação em áreas remotas do globo, foi a motivação central da pesquisa. A pesquisa foi desenvolvida com base em análises estatísticas para os dados de TSM, índices climáticos e a vazão do rio Madeira. Observou-se que a vazão mensal do rio Madeira apresenta correlação linear significativa com áreas específicas dos oceanos Atlântico e Pacífico. No Oceano Atlântico Norte, são significativas as correlações obtidas nos setores tropical (área AT3) e norte (área AT1). O setor subtropical do Atlântico Norte (AT2) apresenta correlações lineares não tão expressivas como suas áreas tropical e norte. O Atlântico Sul não apresenta áreas com correlações lineares significativas com a vazão. As áreas com correlação significativa do Atlântico Norte (AT1) apresentam valores negativos máximos entre -0,6 e -0,4. Os valores de correlação linear entre a vazão mensal do rio Madeira e a TSM do Atlântico (AT2) apresentam um pequeno aumento para os cálculos realizados com defasagem temporal de até nove meses, entre 0,3 a 0,4 para 5 meses de defasagem entre a vazão e a TSM. A TSM do setor oeste do Pacífico tropical apresenta fortes valores negativos de correlação linear com a vazão do rio Madeira, com valores máximos que variam entre -0,7 e -0,4. Tal qual acontece para o Atlântico, as águas superficiais do Pacífico tropical oeste apresentam um pequeno aumento dos valores de correlação linear para defasagens maiores entre a TSM e a vazão. As áreas com forte correlação negativa no setor oeste do Pacífico tropical foram denominadas PA1, no norte, e PA3, no sul. Uma pequena área com correlação significativa e positiva a leste da bacia do Pacífico, junto à costa do Chile, foi denominada PA2. Nesta área os valores máximos de correlação linear entre a vazão mensal e a TSM variam entre 0,2 e 0,4. A análise de correlação linear entre a vazão anual do rio Madeira e índices climáticos indicam que os índices ODP, MEI e OAN são os mais bem correlacionados com a vazão, apresentando valores iguais a 0,89, 0,86 e 0,85, respectivamente. Com base na TSM das áreas bem correlacionadas com a vazão do rio Madeira e nos índices climáticos considerados, foi desenvolvido um modelo estocástico de regressão linear múltipla para a previsão da vazão trimestral com antecedência de um trimestre. A TSM das áreas do setor oeste do Pacífico tropical, PA1, e do Atlântico Norte tropical, AT3, constituíram as variáveis selecionadas para a elaboração do modelo estocástico. O modelo estocástico foi desenvolvido para o início da série temporal considerada, de 1968 a 1988, e apresentou um ajuste linear com coeficiente de determinação igual a 78%. A verificação do modelo foi feita para o final da série, de 1989 a 2009. O erro médio normalizado calculado pela diferença entre os valores de vazão previstos pelo modelo e os observados foi igual a 40%. Desta forma, conclui-se que a vazão trimestral do setor sul da região Norte do Brasil é uma variável que pode ser prevista com base na variabilidade da temperatura das águas superficiais dos oceanos Pacífico e Atlântico. A análise do comportamento atmosférico com base em períodos específicos de anomalias de TSM no Atlântico Norte tropical indica que a ocorrência de TSMs mais altas (baixas) que o normal foram acompanhadas por ventos de leste mais fracos (fortes). Foram analisados os campos atmosféricos médios para os meses chuvosos de novembro a março para as variáveis Velocidade Vertical (Omega) em 500 e 850 hPa, divergência e vorticidade do vento. Os resultados obtidos demonstram que em média, a variabilidade atmosférica foi determinante no que se refere às anomalias apresentadas pela vazão. / The objective of this research was to investigate the linear relation between the sea surface temperature (SST) over Pacific and Atlantic oceans and the outflow of the Madeira river, located at the southern part of the Northern region of Brazil. The investigation considered monthly, seasonal and annual scales, to the period between 1968 to 2009. The consideration about the influence of heating and cooling of oceanic areas over climate around the world constitutes the main hypothesis taken in account in the study. The research was developed based on statistical analysis considering SST, climatic indexes and river outflow data. The monthly outflow for Madeira River shows significant linear correlation to SST at specific areas over Atlantic and Pacific. Over North Atlantic, the linear correlation values are significant at the tropical and north sectors, namely AT3 and AT1, respectively. The subtropical sector of North Atlantic presents positive correlation but not too expressive as the tropical and north areas of Atlantic. South Atlantic does not present significant values of linear correlation with the river outflow. The area with significant correlation over North Atlantic (AT1) presents maximum negative values ranging between -0,6 and -0,4. In general, the greater the interval between river outflow and SST data, greater is the linear correlation values. SST data from the western sector of tropical Pacific presents strong negative correlation with Madeira River outflow data, and shows maximum values ranging between -0,7 and -0,4. The areas to the West of Pacific showing high negative correlation were named PA1 and PA3, to northern and southern sectors, respectively. A small area that shows significant positive linear correlation to the river outflow data, PA2, is located over the eastern side of Pacific basin, very closed to the coast of Chile. In this area, the linear maximum correlation values range between 0,2 and 0,4. Linear correlation analysis between annual river outflow data and climatic indices indicates that PDO, MEI and NAO are those more correlated with the river outflow data, presenting values equal to 0,89, 0,86 e 0,85, respectively. Based on averaged SST and climatic indices well correlated to the Madeira River outflow data, a stochastic model was developed in order to forecast the river outflow in seasonal scale. SST from west of tropical Pacific, PA1, and from tropical North Atlantic, AT3, were selected to build up the stochastic model. The stochastic model was developed considering the first half of the total series, between 1968 and 1988, while the last period was used to validate the model, between 1989 and 2009. The linear adjusting over the first period reach a determining coefficient equal to 78% and the normalized mean error obtained for the second period was equal to 40%. Thus, we conclude that the seasonal outflow for Madeira River is a climatic variable that can be forecast based on the SST variability over specific areas on Pacific and Atlantic oceans. The analysis of atmospheric behavior based on specific periods of SST anomalies in the tropical North Atlantic indicates that the occurrence of SSTs higher (lower) than normal was accompanied by easterly winds weak (strong). We analyzed the average atmospheric fields for the rainy months from November to March for variables Vertical Speed (Omega) at 500 and 850 hPa, divergence and vorticity of the wind. The results show that approximately the atmospheric variability was decisive with regard to the deficiencies presented by the ouflow.

O planejamento da operação energética de sistemas hidrotérmicos de potência tem como objetivo determinar a participação de usinas termoelétricas e hidrelétricas de forma a garantir o suprimento desta energia ao menor custo operacional possível, dentro de restrições técnicas. Alguns fatores tornam a solução desse problema bastante complexa destacando a não linearidade, presente na equação de geração hidráulica; a não separabilidade espacial, devido ao fato da decisão de quanto gerar em uma usina interferir em outra usina do sistema; a separabilidade temporal aditiva, devido a interferência de uma decisão atual em uma decisão futura e, como no caso brasileiro, de grande porte. O objetivo deste trabalho é apresentar uma nova abordagem para o planejamento da operação de sistemas hidrotérmicos de potência, com Programação Dinâmica, de forma que as usinas hidrelétricas possam ser representadas e otimizadas individualmente, completamente desacopladas. Essa aplicação é possível através da utilização de uma função objetivo modificada, considerando-se não apenas os custos, mas também os dados de afluências das usinas imediatamente a jusante. O modelo proposto, como função objetivo modificada, foi aplicado em cascatas de usinas hidrelétricas brasileiras, cujos resultados puderam ser comparados com os comportamentos ótimos obtidos de forma direta, ou seja, com a otimização de todo o sistema em conjunto. Com base nos resultados obtidos, pôde-se observar o bom comportamento do modelo implementado. / The energetic operation planning in hydrothermal power systems aims to determine the participation of hydroelectric power plants and thermoelectric power plants to ensure the supply of electricity at the lowest operating cost possible, between technical constraints. Some factors make the solution of this problem quite complex highlighting the nonlinearity, present in the equation of hydraulic generation, non-spatial separability, due the fact that the decision of the amount of energy generated in a plant interfere in another plants of the system, the additive time separability, because of the interference from an actual decision on a future decision and, as in the Brazilian case, large. The proposal of this work is to present a new approach to hydrothermal power systems, with Dynamic Programming, so that hydroelectric power plants can be represented and optimized individually, completely decoupled. This application is possible through the use of a modified objective function, considering not only costs but also the inflow data immediately on the downstream plants. The proposed model was applied in a Brazilian cascade of hydroelectric plants, comparing the optimal behavior obtained directly, by optimizing the whole system together and the new technique behavior. Based on the results obtained, we can observe the good results of the implemented model.

Introdução: O tratamento alternativo de Redução septal percutânea (RSP) em pacientes com cardiomiopatia hipertrófica obstrutiva é relativamente novo e há poucos trabalhos publicados sobre a evolução tardia. Objetivos: Avaliar nos pacientes com cardiomiopatia hipertrófica obstrutiva sintomáticos e refratários ao tratamento clínico, tratados com RSP, a sobrevida cardíaca e global, qualidade de vida, eventos maiores e as alterações encontradas no eletrocardiograma (ECG), ecocardiograma(ECO) e Holter 24h antes e na evolução tardia de até 15 anos. Método: Foram incluídos pacientes consecutivos que realizaram RSP no Instituto Dante Pazzanese de Cardiologia e no Hospital do Coração de Outubro de 1998 até junho de 2013. Todos os pacientes realizaram exame clínico, ECG e ECO, e a maioria Holter 24h e responderam o questionário DASI antes e pós-RSP. Os dados qualitativos foram descritos em frequências absolutas e relativas e os quantitativos resumidos em médias ± desvios padrão. Para as variáveis quantitativas foram utilizados modelos ANOVA com medidas repetidas, seguidos pelo método de comparações múltiplas de Bonferroni. O nível de significância de 0,05 foi aceito. Resultados: Dos 56 pacientes incluidos, 28 (50%) eram homens, a idade média foi 53,2 ±15,5 anos sendo 2 crianças e 11 (19,6%) tinham coronariopatia. A maioria estava em classe funcional III-IV, o gradiente médio basal por ECO foi 92,8 ± 3,3 mmHg, a espessura do septo 23,9 ± 0,6 e 62,5% tinha insuficiência mitral (IM) moderada. Durante a internação 1 (1,7%)paciente implantou marcapasso. Durante o seguimento de 7,4 ± 4 anos ocorreram 3 implantes de CDI, 2 por prevenção secundaria e 1 marcapasso, 1 nova RSP, 3 cirurgias de miectomias e houve 7 (12,5%) óbitos, apenas 2 de causa cardíaca. O tempo médio de sobrevida, estimado pelo método de Kaplan Meier foi de 13,3 anos (IC95% 12,2 a 14,5 anos), com expectativa de sobrevida de 96,4% em 1 ano, 87,7% em 5 anos e 81,0% a os 12 anos pós-RSP. Houve melhora significativa na qualidade de vida pelo questionário DASI e na classe funcional da NYHA que passou de 3,6 ± 0,5 para 1,2 ± 0,5 no pós-RSP. Na última avaliação do ECO o gradiente 9,37 ± 6,7 mmHg, o septo 12,87 ± 0,98 mm e a IM foi discreta em 90% todos com p < 0,001. Das variáveis analisadas somente o gradiente no estresse, p=0,039 e a massa p=0,024 foram associados a pior prognóstico. Conclusões: A redução septal percutânea mostrou, na evolução tardia com 100% de seguimento, ser uma técnica segura, eficaz em manter os benefícios tardiamente com baixa mortalidade, oferecendo melhora significativa da classe funcional e da qualidade de vida para os pacientes. / Introduction: Percutaneous septal Reduction (PSR) is a relatively new alternative treatment in patients with obstructive hypertrophic cardiomyopathy and there are few published studies on late evolution. Objectives: Evaluate in symptomatic patients with hypertrophic obstructive cardiomyopathy refractory to medical treatment and who underwent PSR, cardiac and overall survival, quality of life, major events and changes found on the electrocardiogram (ECG), echocardiography (ECHO) and Holter 24h before and after PSR during an evolution up to 15 years. Method: Consecutive patients who were submitted to RSP in Dante Pazzanese Institute of Cardiology and Heart Hospital from October 1998 were included. All patients went through clinical, ECG and ECHO examination, and nearly all answered DASI questionnaire, 24-hour Holter monitoring before and after PSR. Qualitative data were described as absolute and relative frequencies and quantitative summarized as means ± standard deviations. ANOVA models were used for quantitative variables with repeated measures, followed by Bonferroni method for multiple comparison. Significance level of 0.05 was accepted. Results: From 56 patients included, 28 (50%) were men , the mean age was 53.2 ± 15.5 years with 2 children and 11 (19.6%) had coronary artery disease . Most were in functional class III - IV from NYHA, the mean baseline ECO gradient was 92.8 ± 3.3 mmHg, the septal thickness 23.9 ± 0.6mm and 62.5 % had moderate mitral regurgitation (MR). During hospitalization 1 (1.7%) patient required permanent pacemaker. During follow-up of 7.4 ± 4 years, 3 patient required ICD implantation, 2 (for secondary prevention), 1 permanent pacemaker, 1 new RSP, 3 myectomy surgery. There were 7 (12.5%) deaths but only 2 of cardiac causes. The median survival time estimated by the Kaplan Meier was 13.3 years (95% CI 12.2 to 14.5 years), with expected survival of 96.4% at 1 year, 87.7% at 5 years and 81.0% at 12 years post-PSR. Significant improvement was seen in quality of life inferred by DASI questionnaire answers and NYHA functional class from 3.6 ± 0.5 to 1.2 ± 0.5. In last evaluation we found statistical significant reduction in ECO gradient 9.37 ± 6.7 mmHg, septum thikness 12.87 ± 0.98 mm and MR was mild in 90 % of patients. Of the variables analyzed only stress gradient (p = 0.039) and mass (p = 0.024) were associated with worse prognosis. Conclusions: The results of this study suggest that percutaneous septal reduction in late evolution with no loses in follow-up, is a safe technique, effective in reducing ventricular gradient and preserving the benefits in long-term evolution with low mortality, offering significant improvement in functional class and quality of life for patients.

Baseado em uma relação simples entre volume de madeira em pé e deflúvio observados em duas microbacias com povoamentos de eucaliptos, este estudo compara os resultado obtido por três modelos de programação linear: (i) um que maximiza o valor total do projeto, com restrições de área e de produção de madeira; e (ii) dois outros modelos que fazem o mesmo com o controle do indicador hidrológico (deflúvio). A hipótese principal do trabalho é que a consideração do indicador hidrológico no planejamento de povoamentos florestais afeta significativamente os regimes de manejo, alterando os planos de colheita e o fluxo de produção de madeira. A área de estudo é constituída por trinta e cinco unidades de gestão, com áreas que variam de 30 ha a 800 ha e diferentes produtividades, totalizando 8007 ha. Regimes de talhadia simples, baseados em dois cortes, diferem entre si apenas pela idade em que a floresta é cortada. O nível de deflúvio e o volume de madeira em pé foram estatisticamente ajustados utilizando um modelo exponencial baseado na coleta de dados na área de estudo. O resultado da relação entre deflúvio e estoque de madeira mostra uma curva que é convexa em relação a origem e negativamente inclinada. Como as áreas de corte raso e florestas novas produzem fluxos de deflúvio elevados, a regularização do mesmo foi incluída como restrição no modelo. Os resultados obtidos permitem concluir que a inclusão das restrições hidrológicas no modelo afetou o manejo, alterou o fluxo de produção de madeira e resultou em valores presente líquidos globais diferentes para cada modelo, confirmando então a principal hipótese do trabalho. A água e a madeira são dois recursos de grande importância e devem ser controlados simultaneamente. As técnicas de programação linear se mostraram eficientes para gerir o manejo desses recursos. / Based on a simple relationship between growing stock and water outflow observed on two watersheds planted with Eucalyptus in Brazil, this study compares the results obtained by three different linear programming formulations: (i) one that maximizes the net present value simply constrained by area and a regulated wood production flow; and (ii) two other models that maximize the net present value constrained by area, a regulated wood production flow, and specific hydrological goals. As one of the hypothesis, it is stated that the inclusion of hydrological constraints in the model will affect significantly the selection of forest regimes, altering the final harvest-scheduling plan and the wood production flow. Thirty-five management units, with areas ranging from 30 ha to 800 ha and different site indexes, form an Eucalyptus plantation project with 8.007 hectares. Simple coppice regimes, based on two clear cuts followed by the complete renewal of the plantation, differ one to another only by the age at which the clear cut is scheduled. Water outflow levels and stock volume levels were statistically adjusted according to an exponential model based on data collected on watersheds in the study area. The resulting relationship between outflow and stock volume shows a curve that is convex to the origin and negatively sloped. Given that clear-cut areas produce highly undesirable water outflows to the watershed, maximum water outflow limits had to be included as constraints in the model. Results obtained by the hydrologically constrained model confirm the hypothesis that the wood production flow is affected by limiting water outflow. The study allowed the attribution of economical values to different levels of limitations in terms of total water production in the watershed. Water and wood, two of the most important assets to a forester, should be managed together. Linear programming modeling techniques, proved to be very efficient when managing such resources.

O planejamento da operação energética de sistemas hidrotérmicos de potência tem como objetivo determinar a participação de usinas termoelétricas e hidrelétricas de forma a garantir o suprimento desta energia ao menor custo operacional possível, dentro de restrições técnicas. Alguns fatores tornam a solução desse problema bastante complexa destacando a não linearidade, presente na equação de geração hidráulica; a não separabilidade espacial, devido ao fato da decisão de quanto gerar em uma usina interferir em outra usina do sistema; a separabilidade temporal aditiva, devido a interferência de uma decisão atual em uma decisão futura e, como no caso brasileiro, de grande porte. O objetivo deste trabalho é apresentar uma nova abordagem para o planejamento da operação de sistemas hidrotérmicos de potência, com Programação Dinâmica, de forma que as usinas hidrelétricas possam ser representadas e otimizadas individualmente, completamente desacopladas. Essa aplicação é possível através da utilização de uma função objetivo modificada, considerando-se não apenas os custos, mas também os dados de afluências das usinas imediatamente a jusante. O modelo proposto, como função objetivo modificada, foi aplicado em cascatas de usinas hidrelétricas brasileiras, cujos resultados puderam ser comparados com os comportamentos ótimos obtidos de forma direta, ou seja, com a otimização de todo o sistema em conjunto. Com base nos resultados obtidos, pôde-se observar o bom comportamento do modelo implementado. / The energetic operation planning in hydrothermal power systems aims to determine the participation of hydroelectric power plants and thermoelectric power plants to ensure the supply of electricity at the lowest operating cost possible, between technical constraints. Some factors make the solution of this problem quite complex highlighting the nonlinearity, present in the equation of hydraulic generation, non-spatial separability, due the fact that the decision of the amount of energy generated in a plant interfere in another plants of the system, the additive time separability, because of the interference from an actual decision on a future decision and, as in the Brazilian case, large. The proposal of this work is to present a new approach to hydrothermal power systems, with Dynamic Programming, so that hydroelectric power plants can be represented and optimized individually, completely decoupled. This application is possible through the use of a modified objective function, considering not only costs but also the inflow data immediately on the downstream plants. The proposed model was applied in a Brazilian cascade of hydroelectric plants, comparing the optimal behavior obtained directly, by optimizing the whole system together and the new technique behavior. Based on the results obtained, we can observe the good results of the implemented model.

Left ventricular (LV) volumes and ejection fraction (EF) are important predictors of cardiac morbidity and mortality. LV volumes provide valuable prognostic information which isparticularly useful in the selection of therapy or determination of the optimal time for surgery. Two-dimensional (2D) echocardiography is the most widely used non-invasive method forassessment of cardiac function, 2D echocardiography has however several limitations inmeasuring LV volumes and EF since the formulas for quantifications are based on geometricalassumptions. Three-dimensional (3D) echocardiography has been available for almost twodecades, although the use of this modality has not gained wide spread acceptance. 3D echocardiography can overcome the above mentioned limitation in LV volume and EF evaluation since it is not based on geometrical assumption. 3D echocardiography has been shownin several studies to be more accurate and reproducible with low inter- and intraobservervariability in comparison to 2D echocardiography regarding the measurements of LV volumesand EF. The overall aim of the thesis was to evaluate the feasibility and accuracy of 3D echocardiography based-methods in the clinical context. In Study I the feasibility of 3D echocardiography was investigated for determination of LV volumes and EF using parasternal, apical and subcostal approaches. The study demonstrated that the apical 3D echocardiography view offers superior visualization. Study II tested the possibility of creating flow-volume loops to differentiate patients with valvular abnormalities from normal subjects. There were significant differences in the pattern from flow-volume loops clearly separating the groups. In Study III the visual estimation, “eyeballing” of EF was evaluated with two- and tri-plane echocardiography in comparison to quantitative 3D echocardiography. The study confirmed that an experienced echocardiographer can, with a high level of agreement estimate EF both with two- and tri-plane echocardiography. Study IV exposed the high accuracy of stroke volume and cardiac output determination using a3D biplane technique by planimetrically tracing the left ventricular outflow tract and indicating that an assumption of circular left ventricular outflow tract is not reliable. In Study V, two 3D echocardiography modalities, single-beat and four-beat ECG-gated 3D echocardiography were evaluated in patients having sinus rhythm and atrial fibrillation. Thesingle-beat technique showed significantly lower inter-and intraobserver variability in LV volumes and EF measurements in patients having atrial fibrillation in comparison to four-beat ECG-gated acquisition due to absence of stitching artifact. All studies demonstrated good results suggesting 3D echocardiography to be a feasible andaccurate method in daily clinical settings. / degree of Medical DoctorQC 20100629

Echocardiography is a well established technique when evaluating the size and function of the heart. One of the most common ways to measure the size of the right ventricle (RV) is to measure the RV outflow tract 1(RVOT1). Several ways to measure RVOT1 are described in the literature.These ways were compared with echocardiography on 27 healthy subjects.The result showed significant differences in RVOT1, depending on the way it was measured, concluding that the same site, method and body positionshould be used when comparing RVOT1 in the same subject over time.One parameter to evaluate the RV diastolic function (RVDF) is to measure the RV isovolumetric relaxation time (RV-IVRT), a sensitive marker ofRV dysfunction. There are different ways to measure this. In this thesis two ways of measuring RV-IVRT and their time intervals were compared in 20 patients examined with echocardiography. There was a significant difference between the two methods indicating that they are not measuring the same interval.Another way to assess the RVDF is to measure the maximal early diastolicvelocity (MDV) in the long-axis direction. MDV can be measured bydifferent methods, hence 29 patients were examined and MDV was measured according to two methods. There was a good correlation but a poor agreement between the two methods meaning that reference values cannot be used interchangeably.Takotsubo cardiomyopathy is characterized by apical wall motion abnormalities without coronary stenosis. The pathology of this condition remains unclear. To evaluate biventricular changes in systolic long-axisfunction and diastolic parameters in the acute phase and after recovery, 13 patients were included and examined with echocardiography at admission and after recovery. The results showed significant biventricular improvementof systolic long-axis function while most diastolic parameters remainedunchanged.

La simulation d’écoulements incompressibles pose de nombreuses difficultés. Une première est la question de savoir comment traiter la contrainte d’incompressibilité et le couplage vitesse/pression afin d’obtenir une solution précise à moindre coût. Pour cela, nous nous intéressons en particulier à deux méthodes de time splitting : la correction de pression et la correction de vitesse. Une seconde difficulté porte sur des conditions limites de sortie. Nous nous intéressons ici à deux d’entre elles : la condition limite de traction et la condition limite d’Orlanski. Après avoir détaillé les difficultés pouvant apparaître lors de l’implémentation des méthodes de time-splitting, nous proposons une nouvelle implémentation de la condition limite de traction qui permet d’améliorer les ordres de convergence obtenus. Nous nous intéressons ensuite à la condition limite d’Orlanski qui nécessite une certaine vitesse d’advection C dans la direction normale à la limite dont nous proposons ici une nouvelle définition. Nos propositions sont confrontées à de multiples écoulements physiques afin de valider leurs comportements : l’écoulement en aval d’une marche descendante, l’écoulement au niveau d’une bifurcation,l’écoulement autour d’un obstacle et des écoulements de Poiseuille-Rayleigh-Bénard. / One of the understudied difficulties in the simulation of incompressible flows is how to treat the incompressibilityconstraint and the velocity/pressure coupling in order to obtain an accurate solution at low computationnalcost. In this context, we develop two methods: pressure-correction and velocity-correction. An anotherdifficulty is due to the boundary conditions. We study here two of them : the traction boundary condition andthe Orlanski boundary condition. After having developed the difficulties that appears when implementing timesplittingmethods, we propose a new way to enforce the traction boundary condition which improves the orderof convergence. Then we propose a new definition of the advective velocity C which is needed for the Orlanskiboundary condition. Our propositions are validated against multiple physical flows: flow over a backward facingstep, flow around a biffurcation, flow around an obstacle and several Poiseuille-Rayleigh-Bénard flows.