It is possible to simulate an airflow by additives to shoot images and records of such flowing. Additives can be in the form of particles or continuous filaments. A computer evaluation of such data differs depending on the kind of visualization method. This thesis deals with a number of different approaches to determine the airjet shape and airflow velocity in airflow images and records. Exact procedures area sed for these purposes as well as neural networks and genetic algorithms.

Doctor of Philosophy / Department of Mechanical and Nuclear Engineering / M. H. Hosni / B. W. Jones / This dissertation focuses on airflow distribution in the longitudinal direction of a wide-body mockup aircraft cabin, turbulence energy and dissipation rates, and the effect of thermal plumes, generated by passengers, on airflow distribution within the cabin. The mockup cabin utilized for this study mimics a Boeing 767 passenger cabin and includes 11 rows in the longitudinal direction with each row consisting of seven seats. Each seat is occupied by an inflatable manikin which is instrumented with a 10 meters long wire heater generating approximately 100 Watts of distributed sensible heat, representing heat load from a sedentary human being. In order to investigate the fluid dynamics characteristics of the airflow within the cabin, different experimental techniques were implemented. Smoke visualization was used to qualitatively visualize the general airflow pattern inside the cabin. A tracer gas composed mainly of carbon dioxide was used to track the airflow distribution inside the cabin. The tracer gas was released in several locations and then sampled at various locations throughout the mockup cabin. The release and sampling of the tracer gas allowed tracing the airflow inside the cabin using non dispersive infrared sensors. Combining results from different release-sampling scenarios gave better understanding of the chaotic and three-dimensional nature of the airflow behavior inside the cabin. Air speed and turbulence parameters were evaluated using omni-directional probes. Finally, the effect of the heat generated by the thermal manikins on the airflow behavior was investigated. The results from the airflow visualization and the tracer gas were complementary and showed that there were multiple air circulations along the length of the cabin. The dimension of the circulations were controlled by the minimum physical distance inside the cabin. The identified-isotropic turbulence were spread over the full width of the cabin in the front and middle sections of the cabin, whereas, multiple-smaller circulations were identified in the rear section. Cabin sections identified with high speed fluctuations were associated with higher turbulence kinetic energy levels and lower local dissipation rates. These sections served as driving forces to create the circulations identified in the tracer gas experiments. Furthermore, the heat generated by the thermal manikins was shown to significantly impact the behavior of the gaseous flow inside the cabin, the turbulence parameters, and speed fluctuations. Detailed uncertainty analysis was conducted to estimate the uncertainty limits for the measurements taken. The uncertainty estimates obtained for the tracer gas results ranged from ±14% for the test cases with the heated manikins to ±17% with the corresponding unheated manikins cases. The data uncertainty limits for the turbulence parameters were of higher levels due to limitations associated with the omni-directional probes used to measure the speed. With flow repeatability phenomena in same locations inside the mockup cabin during different days reaching up to ±10%, the uncertainty estimates were considered acceptable for these chaotic and highly random airflow conditions within the cabin.

Doctor of Philosophy / Department of Mechanical and Nuclear Engineering / M.H. Hosni / Z.C. Zheng / In order to study the capability of computational methods in investigating the mechanisms associated with disease and contaminants transmission in aircraft cabins, the Computational Fluid Dynamics (CFD) models are used for the simulation of turbulent airflow, tracer gas diffusion, and particle dispersion in a generic aircraft cabin mockup. The CFD models are validated through comparisons of the CFD predictions with the corresponding experimental measurements. It is found that using Large Eddy Simulation (LES) with the Werner-Wengle wall function, one can predict unsteady airflow velocity field with relatively high accuracy. However in the middle region of the cabin mockup, where the recirculation of airflow takes place, the accuracy is not as good as that in other locations. By examining different k-ε models, the current study recommends the use of the RNG k-ε model with the non-equilibrium wall function as a Reynolds Averaged Navier Stokes (RANS) model for predicting the steady-state airflow velocity data. It is also found that changing the cabin air-inlet nozzle height has a significant effect on the flow behavior in the middle and upper part of the cabin, while the flow pattern in the lower part is not affected as much. Through the use of LES and species transport model in simulating tracer gas diffusion, very good agreement between predicted and measured tracer gas concentration data is observed for some monitoring locations, but the agreement level is not uniform for all the sampling point locations. The reasons for the deviations between predictions and measurements for those locations are discussed. The Lagrange-Euler approach is invoked in the particle dispersion simulations. In this approach, the equation of motion for the discrete phase is coupled with the continuous phase governing equations through the calculation of drag and buoyancy forces acting on particles. The continuous phase flow is turbulent and RANS is employed in order to calculate the continuous phase velocity field. A complete study on grid dependence for RANS simulation is performed through a controllable regional mesh refinement scheme. The grid dependence study shows that using unstructured grid with tetrahedral and hybrid elements in the refinement region are more efficient than using structured grid with hexahedral elements. The effect of turbulence on the particle dispersion is taken into account by using a stochastic tracking method (Discrete Random Walk model). One of the significant features of this study is the investigation of the effect of the number of tries on the accuracy of particle concentration predictions when Discrete Random Walk is used to model turbulent distribution of particles. Subsequently, the optimum number of tries to obtain the most accurate predictions is determined. In accordance with the corresponding experimental data, the effect of particle size on particle distribution is also studied and discussed through the simulation of two different sizes of mono-disperse particles in the cabin with straight injection tube, i.e., 3µm and 10µm. Due to the low particle loading, neglecting the effect of particles motion on the continuous phase flow-field seems to be a reasonable, simplifying assumption in running the simulations. However, this assumption is verified through the comparison of the results from 1-way and 2-way coupling simulations. Eventually through the simulations for the particle injection using the cone diffuser, the effects of cabin pressure gradient as well as the particle density on particles dispersion behavior are studied and discussed. In the last part of this dissertation, the turbulent airflow in a full-scale Boeing 767 aircraft cabin mockup with eleven rows of seats and manikins is simulated using steady RANS method. The results of this simulation cannot only be used to study the airflow pattern, but also can be used as the initial condition for running the tracer gas diffusion and particle dispersion simulations in this cabin mockup.

Byggnadssektorn står för 36 % av utsläppen av CO2 till miljön och ungefär 40 % av världens totala energianvändning. Byggnader med större energieffektivitet och hållbarhet har potential att minska: den slutliga energianvändningen, utsläpp av växthusgaser, materialutvinning och användning av dricksvatten. Det är därför viktigt att utföra åtgärder för befintliga och blivande byggnader samt undersöka alternativa byggnadssätt och material som  kan innebära en minskad energianvändning och en begränsning av miljöpåverkan.   Syftet med denna rapport är att undersöka värmeflödesegenskaperna för sexton olika isoleringsmaterial, av vilka fjorton stycken är mindre vanliga i byggnadssammanhang, samt att undersöka hur luftflödet för ett väggparti förbättras av att den lerklinas på en respektive två sidor. Experimenten för värmeflöde utfördes med hjälp av Hotbox-Coldbox metoden. Boxen i studien hade en kammare som kyldes ner och därmed representerade utetemperatur medan den varma temperaturen i lokalen, som boxen stod i, fick representera ett varmt inneklimat. Väggarna undersöktes med hjälp av värmeflödesmätare och temperaturgivare som placerades på väggytorna. Temperaturgivare placerades även upphängd inuti och utanför boxen för att åskådliggöra luftens temperatur inuti boxen och i lokalen.   Samma box användes för lufttäthetsprovningen, då hopmonterad med en fläkt som drog ut luften med ett undertryck ur boxen och skapade en tryckskillnad som innebar att luftflödet genom väggpartiet kunde beräknas med hjälp av en strypfläns.   Den empiriska studiens resultat för värmeflödesmätningen visar och jämför R-värden, lambdavärden (λ) och U-värden för konventionella och alternativa material. De bästa värmeflödesegenskaperna fick cellplasten, följd av mjuk träfiberskiva och klippt halm. Det isoleringsmaterial som presterade sämst i mätningarna var lerhalmen, men då dess dåliga värden troligen härrör från ett konstruktionsfel bör det vara torv som egentligen har sämst värmeisolerande egenskaper.   Resultaten från luftflödesmätningen visar att en vägg med lerklining på båda sidorna av konstruktionen nästan är 2,5 gånger mer lufttät än en vägg med enbart en yta lerklinad och 3,3 gånger bättre än den vägg som inte alls lerklinats.   De slutsatser som kunde dras av arbetet är att en del av de alternativa materialen (klippt halm och mjuk träfiberskiva) har goda möjligheter att agera som substitut för mer konventionella material under förutsättning att det utförs ytterligare forskning av dem. Det som skulle behöva undersökas närmre är, till exempel, deras fuktegenskaper eftersom naturliga material har en högre fuktkänslighet. Vidare bedöms det att lufttätheten förbättras markant av både en- och tvåsidig lerklining, men att den tvåsidiga är att föredra. / The building sector produces 36 % of the CO2 emissions to the environment and claims approximately 40 % of the worlds total energy usage. Buildings have a potential of reducing the net usage of energy, emissions of greenhouse gases, material extraction and usage of drinking water if they were to have a bigger energy efficiency and be more sustainably built. This is why it is of importance to intervene and review alternative ways of constructing buildings and different materials which can result in a reduced energy usage and a limited environmental footprint.   The objectives of this report is to examine the properties of heat flow through sixteen different materials of insulation, fourteen of these are alternative, less conventional. It also investigates how the airflow of a wall will improve by using a technique of wattle and daub on its facade.   The heat flow experiments were conducted with the use of the Hotbox-Coldbox method. The box in the tests had one chamber, which were cooled and thereby representing an outer temperature and the warm temperature in the room surrounding the box represented an inner climate. The walls were studied using heat flow measurers (Hukseflux) and temperature sensors on the inner and outer surfaces of the wall. Temperature sensors were also placed inside and outside the box in order to show the temperature of the air inside the box and in the surrounding room. The same box were used for the investigation of airflow, but then rigged with a fan which blew out the air inside the box. The difference in pressure that was created meant that the airflow through the wall could be calculated by using an orifice plate.   The results of the empirical study visualizes and compares R - values, lambda values (λ) and U - values for conventional and alternative materials. The expanded polystyrene insulation had the best values, followed by the soft board of wood grain and the sheared straw. The material performed the poorest was the straw which was mixed with clay. Though, because its values probably were due to faulty construction of the insulation, the poorest achievement should belong to the peat insulation. The airflow measurement showed a wall with two sides prepared with wattle and daub performed almost 2.5 times better than a wall with only one side prepared and 3.3 times better than a wall with no surface treatment.   Conclusions can be made out of the study that some of the alternative insulation materials (sheared straw and soft board of wood grain) has potential for acting as a substitute for conventional materials, though further research is required. The amount of airflow is deemed to be improved by wattle and daub although it is best if it is applicated on two sides.

Introdução: A respiração oronasal pode impactar adversamente em pacientes com apneia obstrutiva do sono (AOS) pelo aumento da colapsabilidade da via aérea piorando as apneias ou por influenciar os desfechos de tratamento com a pressão positiva continua de vias aéreas (CPAP). Embora os autorrelatos de respiração oronasal sejam comumente utilizados como uma evidência para prescrição da CPAP oronasal, a associação entre o autorrelato e a mensuração objetiva da via preferencial de respiração ainda é desconhecida. Nós hipotetizamos que a respiração oronasal objetivamente mensurada seja mais comum em pacientes com AOS do que em controles, mas que não esteja associada com o autorrelato de respiração oronasal. Os objetivos do presente estudo foram, portanto, determinar: (1) a via preferencial de respiração em controles e pacientes com AOS na vigília e no sono, (2) a concordância entre a via preferencial de respiração mensurada objetivamente e a via preferencial de respiração autorrelatada, e (3) a associação entre a via preferencial de respiração mensurada objetivamente e os sintomas nasais e fatores em pacientes com AOS. Casuística e Método: Foram incluídos 26 indivíduos não tabagistas recrutados na FMUSP (funcionários) e no Ambulatório de Sono do InCor-HCFMUSP (indivíduos com suspeita de AOS). Para o diagnóstico de AOS os indivíduos foram submetidos a uma polissonografia (PSG). A AOS foi definida como índice de apneia-hipopneia (IAH) >= 15 eventos/hora e determinou a alocação dos indivíduos em dois grupos: grupo controle [idade: 40±10 anos, 4 (44%) homens, índice de massa corpórea (IMC): 25±5 kg/m2, IAH: 5±4 eventos/hora] e grupo AOS (idade: 52±14 anos, 10 (59%) homens, IMC: 31±5 kg/m2, IAH: 56 ± 21 eventos/hora). Para avaliar a via preferencial de respiração (nasal ou oronasal) os indivíduos foram submetidos a uma segunda PSG com uso de uma máscara com 2 compartimentos selados (nasal e oral) e conectados a pneumotacógrafos independentes. A via de respiração preferencial foi determinada durante a vígilia que antecedeu o início de sono e durante o sono. Avaliamos dados clínicos e de função pulmonar. Os indivíduos responderam a questionários sobre a percepção da sua via preferencial de respiração, os sintomas nasais (SNOT-20), a sonolência diurna excessiva (Epworth) e a qualidade do sono (Pittsburgh). Resultados: O grupo controle e AOS foram similares no sexo, co-morbidades e uso de medicamentos. Pacientes com AOS eram mais velhos, tinham maior IMC, pressão arterial sistêmica e circunferência do pescoço. A via preferencial de respiração foi similar na vigília e sono. Observamos que os respiradores oronasais foram mais frequentes nos pacientes com AOS se comparados aos controles (65-71% e 0-22%, respectivamente, p < 0,001). Os controles e pacientes com AOS autorrelataram respiração oronasal em 22% e 59% dos casos, respectivamente (p = 0,110). Entretanto, encontramos pobre concordância entre o autorrelato da via de respiração e a via de respiração identificada no grupo controle (Kappa = 0,36) e nenhum concordância nos pacientes com AOS (Kappa = -0,02). Não houve associação entre os sintomas nasais e a respiração oronasal quando considerados todos os indivíduos do estudo (p = ,267). A respiração oronasal foi associada ao aumento do IAH (r = 0,409 e p = 0,038), aumento da idade (r = 0,597 e p = 0,001) e aumento da circunferência do pescoço (r = 0,464 e p = 0,017). Além disso, mudanças na via de respiração após apneias obstrutivas foram incomuns. Conclusões: Em contraste com os controles, os pacientes com AOS sãos frequentemente respiradores oronasais. Contudo, a auto-percepção da via de respiração e de sintomas nasais não prediz medidas objetivas da via preferencial de respiração. Além disso, a respiração oronasal é associada à gravidade da AOS, ao aumento da idade e da circunferência do pescoço / Background: Oronasal breathing may adversely impact obstructive sleep apnea (OSA) patients either by increasing upper airway collapsibility or by influencing CPAP treatment outcomes. Although self-reported oronasal breathing is commonly used as evidence for oronasal CPAP prescription, the association between self-reported and objectively measured preferential breathing route is unknown. We hypothesized that objectively measured oronasal breathing is more common in OSA patients than in controls but is not associated with self-reported breathing route. The aims of this study were, therefore, to determine (1) the preferential breathing route in controls and OSA patients, (2) the agreements between objective analysis of breathing route and self-reports, and (3) the associations between preferential breathing route objectively measure and nasal symptoms and factors in OSA patients. Methods: We included 26 non-smokers enrolled at FMUSP (employees) and Sleep Laboratory at InCor-HCFMUSP (individuals with suspected AOS). For the diagnosis of OSA, the subjects were submitted a full polysomnography (PSG). OSA was defined as apnea-hypopnea index (AHI) >= 15 events/hour and determined the allocation of individuals in two groups: Control group [age: 40 ± 10 years, 4 (44%) men, body mass index (BMI): 25±5 kg/m2, AHI: 5 ± 4 events / hour] and OSA group (age: 52 ± 14 years, 10 (59%) men, BMI: 31±5 kg/m2, mean AHI: 56 ± 21 events / hour). To evaluate the preferential breathing route (nasal or oronasal) the subjects underwent a second overnight PSG with oronasal mask with 2 sealed compartments attached to independent pneumotacographs. The preferential breathing route was determined during wakefulness before sleep and during sleep. We evaluated clinical data and lung function. Subjects answered questionnaires about perceived preferential breathing route, nasal symptoms questionnaires (SNOT-20), excessive daytime sleepiness (Epworth) and sleep quality (Pittsburgh). Results: Controls and OSA patients were similar in sex, co-morbidities and use of medications. OSA patients were older, had higher BMI and blood pressure as larger neck circumference. Breathing pattern awake and asleep was similar. Compare to controls, oronasal breathers was more frequent in OSA patients (0-22% and 65-71%, respectively, p < 0.001). Controls and OSA patients self-reported oronasal breathing in 22% and 59% of cases, respectively (p = 0.110). There were poor agreements between self-reports and objective analysis in controls (Kappa = 0.36) and no agreement in OSA patients (Kappa = -0.02). No associations were found between nasal symptoms and oronasal breathing when all subjects were considered (p = 0.267). Oronasal breathing was associated with OSA severity (r = 0.409 and p = 0.038), increasing age (r = 0.597 and p = 0.001) and higher neck circumference (r = 0.464 and p = 0.017). Additionally, the changes of breathing route were uncommon during obstructive apneas. Conclusions: In contrast to controls, OSA patients are preferentially oronasal breathers. However, self-perception does not predict objectively measured preferential breathing route. Oronasal breathing is associated with OSA severity, increasing age and higher neck circumference

Este trabalho apresenta um estudo sobre o escoamento de ar em dutos com múltiplas saídas que são identificados como caixas sopradoras, quando instalados em máquinas desaguadoras de celulose. Estas caixas auxiliam o processo de secagem conduzindo ar aquecido até um conjunto de orifícios que produzem jatos que são impingidos sobre as folhas de celulose fabricadas. É realizada revisão bibliográfica abordando processos e equipamentos de secagem, com foco no escoamento de ar, métodos para solução numérica de escoamentos, seus modelos e parâmetros, e abordagem semi-empírica para fluxos de ar na saída de dutos. O escoamento do ar no interior da caixa sopradora e nos jatos de saída são estudados através de simulação numérica, e de modelo semi-empírico. São propostas duas alternativas de geometria para estes dutos de modo que se garanta a maior uniformidade possível na vazão e na velocidade média do ar que saí através dos orifícios Na primeira alternativa considera-se que a seção transversal da caixa sopradora se mantém constante. Na segunda se considera que a seção transversal seja reduzida de modo uniforme ao longo da caixa sopradora. Um estudo experimental sobre o comportamento do escoamento de ar para caixas sopradoras em escala reduzida apresenta resultados que possibilitam validar um conjunto de valores numéricos obtidos na simulação e também estabelecer características para o escoamento de modo a atender o processo de secagem. Para cada alternativa são adotadas duas condições de vazão de ar. Os resultados obtidos pela da simulação numérica e modelagem semi-empírica validam um perfil geométrico adequado para que a caixa sopradora produza um conjunto de jatos nas suas saídas com valores de velocidade média. Um dos principais resultados foi obtido para a caixa com 275 orificios, na qual as velocidades médias estiveram dentro do intervalo de 32,5 m/s e 33,1 m/s, que representou um ótimo resultado em termos de balanceamento e uniformidade das vazões de ar. / This study presents an analysis about airflow in ducts with multiple outlets that are identified as blow boxes, when installed in pulp dewatering machines. These boxes work in the drying process leading heated air to a set of nozzles that produce air jets that are impinged against the pulp sheet. It is performed literature review about drying processes and equipment, with a focus on air flow, methods for numerical solution of airflows, their models and parameters, and semi-empirical approach about airflow at the outlets of the duct. The airflow inside the blow box and the output jets are studied by numerical simulation, and semi-empirical model. It is proposed two alternative geometries for these ducts in order to guarantee the greatest possible uniformity in flow rate, and in the average velocity of air jets. In the first alternative is considered that the cross section of the blow box remains constant. In the second one it is considered that the cross section is reduced uniformly along the blow box. An experimental study about the behavior of the airflow in blow boxes, using scaled models, presents results that can validate a set of numerical values obtained in the simulation and also establish characteristics for the drying process. For each alternative two conditions of airflow are adopted. The results obtained through numerical simulation and semi-empirical modeling validates an appropriate geometrical profile for the blow box in order to set the values of average speed within the range required by the drying process. One of the principal results, obtained for the case of boxes with 275 holes, was the average speed within the range of 32,5 m/s and 33,1 m/s, this range represents a great result in tterms of balance and uniformity of air flow.

Introdução: A respiração oronasal pode impactar adversamente em pacientes com apneia obstrutiva do sono (AOS) pelo aumento da colapsabilidade da via aérea piorando as apneias ou por influenciar os desfechos de tratamento com a pressão positiva continua de vias aéreas (CPAP). Embora os autorrelatos de respiração oronasal sejam comumente utilizados como uma evidência para prescrição da CPAP oronasal, a associação entre o autorrelato e a mensuração objetiva da via preferencial de respiração ainda é desconhecida. Nós hipotetizamos que a respiração oronasal objetivamente mensurada seja mais comum em pacientes com AOS do que em controles, mas que não esteja associada com o autorrelato de respiração oronasal. Os objetivos do presente estudo foram, portanto, determinar: (1) a via preferencial de respiração em controles e pacientes com AOS na vigília e no sono, (2) a concordância entre a via preferencial de respiração mensurada objetivamente e a via preferencial de respiração autorrelatada, e (3) a associação entre a via preferencial de respiração mensurada objetivamente e os sintomas nasais e fatores em pacientes com AOS. Casuística e Método: Foram incluídos 26 indivíduos não tabagistas recrutados na FMUSP (funcionários) e no Ambulatório de Sono do InCor-HCFMUSP (indivíduos com suspeita de AOS). Para o diagnóstico de AOS os indivíduos foram submetidos a uma polissonografia (PSG). A AOS foi definida como índice de apneia-hipopneia (IAH) >= 15 eventos/hora e determinou a alocação dos indivíduos em dois grupos: grupo controle [idade: 40±10 anos, 4 (44%) homens, índice de massa corpórea (IMC): 25±5 kg/m2, IAH: 5±4 eventos/hora] e grupo AOS (idade: 52±14 anos, 10 (59%) homens, IMC: 31±5 kg/m2, IAH: 56 ± 21 eventos/hora). Para avaliar a via preferencial de respiração (nasal ou oronasal) os indivíduos foram submetidos a uma segunda PSG com uso de uma máscara com 2 compartimentos selados (nasal e oral) e conectados a pneumotacógrafos independentes. A via de respiração preferencial foi determinada durante a vígilia que antecedeu o início de sono e durante o sono. Avaliamos dados clínicos e de função pulmonar. Os indivíduos responderam a questionários sobre a percepção da sua via preferencial de respiração, os sintomas nasais (SNOT-20), a sonolência diurna excessiva (Epworth) e a qualidade do sono (Pittsburgh). Resultados: O grupo controle e AOS foram similares no sexo, co-morbidades e uso de medicamentos. Pacientes com AOS eram mais velhos, tinham maior IMC, pressão arterial sistêmica e circunferência do pescoço. A via preferencial de respiração foi similar na vigília e sono. Observamos que os respiradores oronasais foram mais frequentes nos pacientes com AOS se comparados aos controles (65-71% e 0-22%, respectivamente, p < 0,001). Os controles e pacientes com AOS autorrelataram respiração oronasal em 22% e 59% dos casos, respectivamente (p = 0,110). Entretanto, encontramos pobre concordância entre o autorrelato da via de respiração e a via de respiração identificada no grupo controle (Kappa = 0,36) e nenhum concordância nos pacientes com AOS (Kappa = -0,02). Não houve associação entre os sintomas nasais e a respiração oronasal quando considerados todos os indivíduos do estudo (p = ,267). A respiração oronasal foi associada ao aumento do IAH (r = 0,409 e p = 0,038), aumento da idade (r = 0,597 e p = 0,001) e aumento da circunferência do pescoço (r = 0,464 e p = 0,017). Além disso, mudanças na via de respiração após apneias obstrutivas foram incomuns. Conclusões: Em contraste com os controles, os pacientes com AOS sãos frequentemente respiradores oronasais. Contudo, a auto-percepção da via de respiração e de sintomas nasais não prediz medidas objetivas da via preferencial de respiração. Além disso, a respiração oronasal é associada à gravidade da AOS, ao aumento da idade e da circunferência do pescoço / Background: Oronasal breathing may adversely impact obstructive sleep apnea (OSA) patients either by increasing upper airway collapsibility or by influencing CPAP treatment outcomes. Although self-reported oronasal breathing is commonly used as evidence for oronasal CPAP prescription, the association between self-reported and objectively measured preferential breathing route is unknown. We hypothesized that objectively measured oronasal breathing is more common in OSA patients than in controls but is not associated with self-reported breathing route. The aims of this study were, therefore, to determine (1) the preferential breathing route in controls and OSA patients, (2) the agreements between objective analysis of breathing route and self-reports, and (3) the associations between preferential breathing route objectively measure and nasal symptoms and factors in OSA patients. Methods: We included 26 non-smokers enrolled at FMUSP (employees) and Sleep Laboratory at InCor-HCFMUSP (individuals with suspected AOS). For the diagnosis of OSA, the subjects were submitted a full polysomnography (PSG). OSA was defined as apnea-hypopnea index (AHI) >= 15 events/hour and determined the allocation of individuals in two groups: Control group [age: 40 ± 10 years, 4 (44%) men, body mass index (BMI): 25±5 kg/m2, AHI: 5 ± 4 events / hour] and OSA group (age: 52 ± 14 years, 10 (59%) men, BMI: 31±5 kg/m2, mean AHI: 56 ± 21 events / hour). To evaluate the preferential breathing route (nasal or oronasal) the subjects underwent a second overnight PSG with oronasal mask with 2 sealed compartments attached to independent pneumotacographs. The preferential breathing route was determined during wakefulness before sleep and during sleep. We evaluated clinical data and lung function. Subjects answered questionnaires about perceived preferential breathing route, nasal symptoms questionnaires (SNOT-20), excessive daytime sleepiness (Epworth) and sleep quality (Pittsburgh). Results: Controls and OSA patients were similar in sex, co-morbidities and use of medications. OSA patients were older, had higher BMI and blood pressure as larger neck circumference. Breathing pattern awake and asleep was similar. Compare to controls, oronasal breathers was more frequent in OSA patients (0-22% and 65-71%, respectively, p < 0.001). Controls and OSA patients self-reported oronasal breathing in 22% and 59% of cases, respectively (p = 0.110). There were poor agreements between self-reports and objective analysis in controls (Kappa = 0.36) and no agreement in OSA patients (Kappa = -0.02). No associations were found between nasal symptoms and oronasal breathing when all subjects were considered (p = 0.267). Oronasal breathing was associated with OSA severity (r = 0.409 and p = 0.038), increasing age (r = 0.597 and p = 0.001) and higher neck circumference (r = 0.464 and p = 0.017). Additionally, the changes of breathing route were uncommon during obstructive apneas. Conclusions: In contrast to controls, OSA patients are preferentially oronasal breathers. However, self-perception does not predict objectively measured preferential breathing route. Oronasal breathing is associated with OSA severity, increasing age and higher neck circumference

Lors des interventions humaines pendant les arrêts de tranche des installations nucléaires d’EDF, on remarque une remise en suspension de certains radionucléides sous forme d’aérosols (1 µm < dp < 10 µm). Dans le cadre d’une augmentation des interventions effectuées de façon simultanée en bâtiment réacteur, il devient important de mieux comprendre la remise en suspension due à l’activité des opérateurs pour adapter leur radioprotection. Le but des travaux de cette thèse est de quantifier la remise en suspension des particules suite à la marche des opérateurs sur un sol faiblement contaminé. Pour cela, la démarche suivie consiste à coupler un modèle de remise en suspension aéraulique avec des calculs numériques d’écoulement sous une chaussure, puis à caractériser expérimentalement certains paramètres d’entrée du modèle (diamètre de particule, forces d’adhésion, mouvement de la chaussure).Le modèle de remise en suspension Rock’n’Roll proposé par Reeks et Hall (2001) a été choisi car il décrit de manière physique ce mécanisme et est basé sur le moment des forces appliquées à une particule. Il nécessite la maîtrise de paramètres d’entrée tels que la vitesse de frottement de l’air, la distribution des forces d’adhésion et le diamètre des particules.Concernant le premier paramètre, des simulations numériques d’écoulement ont été réalisées, à l’aide du code de calcul ANSYS CFX, sous une chaussure de sécurité en mouvement (numérisée par CAO 3D) ; les cartographies des vitesses de frottement obtenues donnent des valeurs de l’ordre de 1 m.s⁻ ¹ pour une vitesse angulaire moyenne de 200 °.s⁻ ¹ .Concernant le deuxième paramètre, des mesures AFM (Atomic Force Microscope) ont été réalisées avec des particules d’alumine ainsi que des particules d’oxyde de cobalt en contact avec des surfaces en époxy représentatives de celles rencontrées dans les installations d’EDF. L’AFM permet d’obtenir la distribution des forces d’adhésion et révèle une valeur moyenne bien plus faible que ce qui peut être calculé de façon théorique en utilisant par exemple le modèle JKR proposé par Johnson et al. (1971). De plus, cette technique, tenant compte des rugosités de surface, montre que plus la taille de la particule augmente, plus la moyenne des forces d’adhésion diminue. Enfin, l’analyse des mesures AFM a permis d’obtenir une corrélation liant la distribution des forces d’adhésion au diamètre des particules, remplaçant celle de Biasi et al. (2001) initialement utilisée dans le modèle Rock’n’Roll et permettant ainsi d’adapter le modèle aux particules et aux revêtements de sol étudiés. Le couplage, effectué dans le code de calcul ANSYS CFX, entre les calculs de vitesses de frottement et le modèle de remise en suspension, a permis de déterminer des taux de remise en suspension théoriques pour le cas d’un cycle unique de marche. Ce couplage a été dans un premier temps validé par une comparaison à l’expérience pour le cas simple d’une plaque en rotation dans un volume contrôlé. En complément, des expériences à l’échelle d’un local ventilé de 30 m³ ont été réalisées en marchant sur un revêtement époxy ensemencé en particules de tailles calibrées (1,1 µm et 3,3 µm). Ces expériences ont permis de mettre en évidence les paramètres influant la remise en suspension des particules, tels que la fréquence de pas et la taille des particules. / In nuclear facilities, during normal operations in controlled areas, workers could be exposed to radioactive aerosols (1 µm < dp < 10 µm). One of the airborne contamination sources is particles that are initially seeded on the floor and could be removed by workers while they are walking. During the outage of EDF nuclear facilities, there is a resuspension of some radionuclides in aerosol form (1 µm < dp < 10 µm). Since the number of co-activity will increase in reactors buildings of EDF, it becomes important to understand particle resuspension due to the activity of the operators to reduce their radiation exposure. The purpose of this Ph.D thesis is to quantify the resuspension of particles due to the progress of operators on a contaminated soil. Thus, the approach is to combine an aerodynamic resuspension model with numerical calculations of flow under a shoe, and then to characterize experimentally some input parameters of the model (particle diameter, adhesion forces, shoes motion).The resuspension model Rock'n'Roll proposed by Reeks and Hall (2001) was chosen because it describes physically the resuspension mechanism and because it is based on the moment of forces applied to a particle. This model requires two input parameters such as friction velocity and adhesion forces distribution applied on each particle.Regarding the first argument, numerical simulations were carried on using the ANSYS CFX software applied to a safety shoe in motion (digitized by 3D CAO); the mapping of friction velocity shows values of about 1 m.s⁻ ¹ for an angular average velocity of 200 °.s⁻ ¹ . As regards the second parameter, AFM (Atomic Force Microscopy) measurements were carried out with alumina and cobalt oxide particles in contact with epoxy surfaces representative of those encountered in EDF power plants. AFM provides the distribution of adhesion forces and reveals a much lower value than what can be calculated theoretically using JKR model (Johnson et al. (1971)). Moreover, this technique, taking into account the surface roughness, shows that adhesion forces decrease while particle diameter increase. Finally, the analysis of AFM measurements gives a correlation linking the distribution of adhesion forces to the particle diameter, replacing the one given by Biasi et al. (2001) originally used in the Rock'n'Roll model and thereby adapt the model to particles and flooring studied in our case.Coupling, performed in ANSYS CFX software, between the calculations of friction velocity and model of particle resuspension, gives theoretical resuspension rate during shoe motion. This coupling was initially validated by comparison to the experience for the simple case of a rotating plate in a controlled volume. Secondly, experiments at the scale of a ventilated room of 30 m³ were performed by walking on an epoxy coating initially seeded by calibrated particle size (1,1 µm and 3,3 µm). These experiments highlight the parameters influencing the suspension of particles, such as step frequency and particle size.

Background: Positive expiratory pressure (PEP) and continuous positive airway pressure (CPAP) are two forms of resistance breathing used in spontaneously breathing patients. With a threshold resistor or a flow resistor, both PEP and CPAP provide a positive (elevated) pressure level during the expiratory phase. With PEP, inspiratory pressure is negative, i.e. lower than ambient air pressure, as during a normal inspiration, but with CPAP, the inspiratory pressure is positive, i.e. higher than ambient air pressure. Methods: This thesis is based on four separate studies in which four different breathing devices, a PEP-bottle (threshold resistor device), a PEP-mask (flow resistor device), a threshold resistor CPAP and a flow resistor device were investigated. Paper I, II and III are based on studies in healthy volunteers. Paper IV is a bench study performed in a hypobaric chamber. Paper I examined differences between two PEP devices, the PEP-bottle and the PEP-mask. Paper II evaluated the performance of a flow resistor CPAP device, (Boussignac CPAP). Paper III investigated the effect of two PEP-devices, a PEP-bottle and a PEP-mask and two CPAP devices, a threshold resistor CPAP and a flow resistor CPAP, on inspiratory capacity (IC). In paper IV, the effect of changes in ambient pressure on preset CPAP levels in two different CPAP devices was compared. Results: With the PEP bottle, both expiration and inspiration began with a zero-flow period during which airway pressure changed rapidly. With the PEP-mask, the zero-flow period was very short and the change in airway pressure almost non-existent (paper I). During normal breathing with the Boussignac CPAP, changes in airway pressure were never large enough to reduce airway pressure below zero. During forced breathing, as airflow increased, both the drop in inspiratory airway pressure and the increase in expiratory airway pressure were potentiated (paper II). IC decreased significantly with three of the breathing devices, the PEP-mask and the two CPAP devices (paper III). With the threshold resistor CPAP, measured pressure levels were close to the preset CPAP level. With the flow resistor CPAP, as the altitude increased CPAP produced pressure levels increased (paper IV). Conclusion: The effect on airway pressure, airflow, IC and the effect of changes in ambient air pressure differ between different kinds of resistance breathing devices. These differences in device performance should be taken into consideration when choosing the optimal resistance breathing device for each patient.

Este trabalho apresenta um estudo sobre o escoamento de ar em dutos com múltiplas saídas que são identificados como caixas sopradoras, quando instalados em máquinas desaguadoras de celulose. Estas caixas auxiliam o processo de secagem conduzindo ar aquecido até um conjunto de orifícios que produzem jatos que são impingidos sobre as folhas de celulose fabricadas. É realizada revisão bibliográfica abordando processos e equipamentos de secagem, com foco no escoamento de ar, métodos para solução numérica de escoamentos, seus modelos e parâmetros, e abordagem semi-empírica para fluxos de ar na saída de dutos. O escoamento do ar no interior da caixa sopradora e nos jatos de saída são estudados através de simulação numérica, e de modelo semi-empírico. São propostas duas alternativas de geometria para estes dutos de modo que se garanta a maior uniformidade possível na vazão e na velocidade média do ar que saí através dos orifícios Na primeira alternativa considera-se que a seção transversal da caixa sopradora se mantém constante. Na segunda se considera que a seção transversal seja reduzida de modo uniforme ao longo da caixa sopradora. Um estudo experimental sobre o comportamento do escoamento de ar para caixas sopradoras em escala reduzida apresenta resultados que possibilitam validar um conjunto de valores numéricos obtidos na simulação e também estabelecer características para o escoamento de modo a atender o processo de secagem. Para cada alternativa são adotadas duas condições de vazão de ar. Os resultados obtidos pela da simulação numérica e modelagem semi-empírica validam um perfil geométrico adequado para que a caixa sopradora produza um conjunto de jatos nas suas saídas com valores de velocidade média. Um dos principais resultados foi obtido para a caixa com 275 orificios, na qual as velocidades médias estiveram dentro do intervalo de 32,5 m/s e 33,1 m/s, que representou um ótimo resultado em termos de balanceamento e uniformidade das vazões de ar. / This study presents an analysis about airflow in ducts with multiple outlets that are identified as blow boxes, when installed in pulp dewatering machines. These boxes work in the drying process leading heated air to a set of nozzles that produce air jets that are impinged against the pulp sheet. It is performed literature review about drying processes and equipment, with a focus on air flow, methods for numerical solution of airflows, their models and parameters, and semi-empirical approach about airflow at the outlets of the duct. The airflow inside the blow box and the output jets are studied by numerical simulation, and semi-empirical model. It is proposed two alternative geometries for these ducts in order to guarantee the greatest possible uniformity in flow rate, and in the average velocity of air jets. In the first alternative is considered that the cross section of the blow box remains constant. In the second one it is considered that the cross section is reduced uniformly along the blow box. An experimental study about the behavior of the airflow in blow boxes, using scaled models, presents results that can validate a set of numerical values obtained in the simulation and also establish characteristics for the drying process. For each alternative two conditions of airflow are adopted. The results obtained through numerical simulation and semi-empirical modeling validates an appropriate geometrical profile for the blow box in order to set the values of average speed within the range required by the drying process. One of the principal results, obtained for the case of boxes with 275 holes, was the average speed within the range of 32,5 m/s and 33,1 m/s, this range represents a great result in tterms of balance and uniformity of air flow.