Com o crescente aumento dos problemas ambientais relacionados à emissão de poluentes, normas cada vez mais rigorosas estão sendo implementadas para diminuir a emissão de gases nocivos provenientes da queima de hidrocarbonetos em motores de combustão interna. Um importante fator que influencia na geração de gases poluentes em motores é o comportamento do escoamento no cilindro, desde o início da admissão até a fase de combustão. O presente trabalho realiza um estudo numérico com validação experimental do escoamento no motor Honda GX35, considerando diversas aberturas de válvula fixas e diferenças de pressão para gerar o escoamento. A validação da metodologia numérica é realizada através da comparação dos resultados do coeficiente de descarga para todas as aberturas de válvula utilizadas. A medição da vazão de ar na metodologia experimental é realizada com um anemômetro de filme quente de aplicação automotiva, calibrado para as condições do teste. Já a metodologia numérica utiliza dois modelos de turbulência, k-ω SST e k-ε standard. Os resultados numéricos apresentaram boa concordância com os experimentais para ambos os modelos adotados, quanto ao coeficiente de descarga. Entretanto, a diferença de comportamento do escoamento no interior do cilindro é elevada, pois o modelo k-ω SST é capaz de captar a oscilação transiente do jato que se forma na saída da válvula, inexistente no k-ε standard. O comportamento transiente causa uma significativa variação da vorticidade média em um plano perpendicular ao cilindro, com o escoamento trocando de direção principal de rotação em alguns instantes. Dados numéricos médios e de variação ao longo do tempo para swirl e tumble também são apresentados e discutidos. Ao analisar a oscilação da vazão mássica na fronteira de saída do domínio, frequências de aproximadamente 1300 Hz são captadas. Tais frequências são confrontadas com resultados experimentais obtidos pelo presente grupo de pesquisa para medições de oscilação de pressão no coletor de admissão do mesmo motor. O desvio percentual relativo para a frequência de oscilação é de 0,3%, o que demonstra a correta predição, tanto do fenômeno de desprendimento de vórtice quanto do coeficiente de descarga obtido através do modelo de turbulência k-ω SST. / With the increasing environmental problems concerning pollutant emissions, stringent standards have been applied in order to decrease harmful gases produced by the hydrocarbons combustion in internal combustion engines. The flow behaviour within the cylinder is an important factor that affects the emission’s formation in engines, since the intake stroke until the combustion. This work performs a numerical study with experimental validation of fluid flow at Honda GX35 engine, considering different fixed valve lifts and suction pressures to generate the flow. The validation of the numerical methodology is made through the discharge coefficient and flow pattern comparisons for all valve lifts utilized. The mass flow rate in the intake system is measured with an automotive hot film anemometer, calibrated for the test’s conditions. Regarding the computational solution for the turbulent air flow, two turbulence models were utilized: SST k-ω and k-ε standard. Although the numerical results presented a good agreement with the experimental data concerning the discharge coeficient, the flow pattern comparisons presented a high discrepancy among the models utilized. The SST k-ω model is capable to capture the transient behaviour of the jet formed in the valve exit, constituting the main difference between them. The transient oscillation causes a significant difference of mean vorticity in a cylinder section plane, with the bulk flow changing its main rotation along the time. The averaged and transient numerical data of swirl and tumble are presented and discussed. In the frequency analysis of the numerical mass flow rate oscillations, obtained at the outlet boundary, presented an average value about 1300 Hz. Such frequencies, when compared with experimental results obtained by the present research group for the pulsating pressure waves into the intake duct of the same engine, had a relative percentage deviation of 0.3%. The agreement between the results using the SST k-ω model reveals the correct prediction of vortex shedding frequency and discharge coefficient.

Com o crescente aumento dos problemas ambientais relacionados à emissão de poluentes, normas cada vez mais rigorosas estão sendo implementadas para diminuir a emissão de gases nocivos provenientes da queima de hidrocarbonetos em motores de combustão interna. Um importante fator que influencia na geração de gases poluentes em motores é o comportamento do escoamento no cilindro, desde o início da admissão até a fase de combustão. O presente trabalho realiza um estudo numérico com validação experimental do escoamento no motor Honda GX35, considerando diversas aberturas de válvula fixas e diferenças de pressão para gerar o escoamento. A validação da metodologia numérica é realizada através da comparação dos resultados do coeficiente de descarga para todas as aberturas de válvula utilizadas. A medição da vazão de ar na metodologia experimental é realizada com um anemômetro de filme quente de aplicação automotiva, calibrado para as condições do teste. Já a metodologia numérica utiliza dois modelos de turbulência, k-ω SST e k-ε standard. Os resultados numéricos apresentaram boa concordância com os experimentais para ambos os modelos adotados, quanto ao coeficiente de descarga. Entretanto, a diferença de comportamento do escoamento no interior do cilindro é elevada, pois o modelo k-ω SST é capaz de captar a oscilação transiente do jato que se forma na saída da válvula, inexistente no k-ε standard. O comportamento transiente causa uma significativa variação da vorticidade média em um plano perpendicular ao cilindro, com o escoamento trocando de direção principal de rotação em alguns instantes. Dados numéricos médios e de variação ao longo do tempo para swirl e tumble também são apresentados e discutidos. Ao analisar a oscilação da vazão mássica na fronteira de saída do domínio, frequências de aproximadamente 1300 Hz são captadas. Tais frequências são confrontadas com resultados experimentais obtidos pelo presente grupo de pesquisa para medições de oscilação de pressão no coletor de admissão do mesmo motor. O desvio percentual relativo para a frequência de oscilação é de 0,3%, o que demonstra a correta predição, tanto do fenômeno de desprendimento de vórtice quanto do coeficiente de descarga obtido através do modelo de turbulência k-ω SST. / With the increasing environmental problems concerning pollutant emissions, stringent standards have been applied in order to decrease harmful gases produced by the hydrocarbons combustion in internal combustion engines. The flow behaviour within the cylinder is an important factor that affects the emission’s formation in engines, since the intake stroke until the combustion. This work performs a numerical study with experimental validation of fluid flow at Honda GX35 engine, considering different fixed valve lifts and suction pressures to generate the flow. The validation of the numerical methodology is made through the discharge coefficient and flow pattern comparisons for all valve lifts utilized. The mass flow rate in the intake system is measured with an automotive hot film anemometer, calibrated for the test’s conditions. Regarding the computational solution for the turbulent air flow, two turbulence models were utilized: SST k-ω and k-ε standard. Although the numerical results presented a good agreement with the experimental data concerning the discharge coeficient, the flow pattern comparisons presented a high discrepancy among the models utilized. The SST k-ω model is capable to capture the transient behaviour of the jet formed in the valve exit, constituting the main difference between them. The transient oscillation causes a significant difference of mean vorticity in a cylinder section plane, with the bulk flow changing its main rotation along the time. The averaged and transient numerical data of swirl and tumble are presented and discussed. In the frequency analysis of the numerical mass flow rate oscillations, obtained at the outlet boundary, presented an average value about 1300 Hz. Such frequencies, when compared with experimental results obtained by the present research group for the pulsating pressure waves into the intake duct of the same engine, had a relative percentage deviation of 0.3%. The agreement between the results using the SST k-ω model reveals the correct prediction of vortex shedding frequency and discharge coefficient.

The aim of this work is to create a computational model of radial industrial tumble dryers, to calculate and identify the amount of air that flows through the inside of the drum itself. The calculation will be performed via computational fluid dynamics (CFD). Furthermore, compile transient balance model of mentioned dryers. Perform simulation balance model and compare the results of simulations with experimental measurements. By comparing the experimental data and simulation to determine the degrees of freedom of balance model and evaluate their impact on the assembled transient model. For a better understanding of the drying process, there is constructed a system of differential equations describing heat and moisture within the material being dried on a simple model. In the section devoted to the computational analysis of fluid flow is analyzed existing geometry of the drum, which has a major impact on the flow of air inside the drum itself. Following describes how to simplify its complex geometry entering the computational fluid dynamics. Then, there is carried out a simulation of fluid flow inside the tumble dryers using MRF and Sliding Mesh models. Finally, there is an analysis of the data obtained and determined the average amount of air flowing through the drum itself. On the contrary, the aim of the work is not to create another text tool for students engaged in CFD theme.

Throughout recent years, computer based programs has been applied to solve and analyze industrial problems. One of these developed programs is the Computational Fluid Dynamics (CFD) program. The purpose of implementing CFD analysis is to solve complex flow behavior which is not possible with ordinary calculus. The extensive application of CFD in the industry is a result of improved commercial CFD codes  in terms of more advance partial differential equations (PDE) describing various physical phenomena, CAD and mesh-grid generating tools and improved graphical user interfaces (GUI). Today, CFD usage has extended to fields such as aerodynamic, chemical process engineering, biomedical engineering and drying technology. As there is an on-going expansion of CFD usages in the industry, certain issues need to be addressed as they are frequently encountered. The general demand for simulation of larger control volumes and more advanced flow processes result in extensive requirement of computer resources. Numerous complex flow topics today require computer cluster networks which are not accessible for every company. The second issue is the implementation of commercial CFD codes in minor industrial companies is utilized as a black box based on the knowledge on fluid mechanic theory. A vital part of the simulation process is the evaluation of data through visual analysis of flow patterns, analysis on the sensitivity of the mesh grid, investigation of quantitative parameters such as pressure loss, velocity, turbulence intensity etc. Moreover, increased partnerships between industry and the academic world involving various CFD based design processes generally yields to a verbal communication interface which is a crucial step in the process given the fact of the level of dependency between both sides. The aim of this thesis is to present methods of CFD analysis based on these issues. In paper I, a heuristically determined design process of the geometry near the front trap door of an internal duct system was achieved by implementing the CFD code COMSOL MultiPhysics as a communication tool. The design process was established by two counterparts in the project in which CFD calculations and geometry modifications were conducted separately. Two design criteria presenting the pressure drop in duct and the outflow uniformity was used to assess geometry modifications conducted by a CAD-engineer. The geometry modifications were based on visual results of the flow patterns. The geometry modifications confirmed an improvement in the geometry as the pressure drop was reduced with 23% and the uniformity was increased with 3%. In paper II, volume-averaged equations were implemented in a tube-fin heat exchanger in order to simulate airflow. Focus was on achieving a correct volume flow rate and pressure drop (V-p) correlation. The volume averaged model (VAM) is regarded as a porous medium in which the arrangement of fins and tube bundles are replaced with volume-averaged equations. Hence, the computational time was reduced significantly for the VAM model. Moreover, experimental results of the (V-p) correlation showed good agreement with the VAM model.

In the first study, three different transport systems for bacteria were evaluated. The CLSI M40-A guideline was used to monitor the maintenance of both mono- and polymicrobial samples during a simulated transportation at room temperature that lasted 0-48 h. All systems were able to maintain the viability of all organisms for 24 h, but none of them could support all tested species after 48 h.  The most difficult species to recover was Neisseria gonorrhoeae, and in polymicrobial samples overgrowth was an observed problem. The aim of the second study was to study the presence of TSST-1 and three other important toxin genes in invasive isolates of Staphylococcus aureus collected during the years 2000-2012 at two tertiary hospitals. The genes encoding the staphylococcal toxins were detected by PCR, and whole-genome sequencing was used for analyzing the genetic relatedness between isolates. The results showed that the most common toxin was TSST-1, and isolates positive for this toxin exhibited a clear clonality independent of year and hospital. The typical patient was a male aged 55-74 years and with a bone or a joint infection. The third study was a clinical study of the effect of silver-based wound dressings on the bacterial flora in chronic leg ulcers. Phenotypic and genetic silver-resistance were investigated before and after topical silver treatment, by determining the silver nitrate MICs and by detecting sil genes with PCR. The silver-based dressings had a limited effect on primary wound pathogens, and the activity of silver nitrate on S. aureus was mainly bacteriostatic. A silver-resistant Enterobacter cloacae strain was identified after only three weeks of treatment, and cephalosporin-resistant members of the Enterobacteriaceae family were relatively prone to developed silver-resistance after silver exposure in vitro. The last study was undertaken in order to develop an easy-to-use method for simulating the laundering process of hospital textiles, and apply the method when evaluating the decontaminating efficacy of two different washing temperatures. The laundering process took place at professional laundries, and Enterococcus faecium was used as a bioindicator. The results showed that a lowering of the washing temperature from 70°C to 60°C did not affect the decontamination efficacy; the washing cycle alone reduced the number of bacteria with 3-5 log10 CFU, whereas the following tumble drying reduced the bacterial numbers with another 3-4 log10 CFU, yielding the same final result independent of the washing temperature. To ensure that sufficient textile hygiene is maintained, the whole laundering process needs to be monitored. The general conclusion is that all developmental work in the bacterial field requires time and a large strain collection.

V rámci této práce byla provedena komplexní analýza elektricky vyhřívané bubnové sušičky prádla s cílem identifikovat možnosti optimalizace její konstrukce vedoucí ke zlepšení přestupu tepla. Pro řešení byl zvolen postup využívající výpočtovou dynamiku tekutin (CFD). K dosažení dostatečně detailního popisu zadaného problému byl využit komerční software Fluent společně se speciálně vyvinutým modelem přenosu tepla.

This thesis is devided into two parts. First part is a bibliographic search and speaks about maths modeling, simulations, a MATLAB Simulink programme, and a laundy process. Second part deals with a math model of an industrial laundry. In this part, there is a detailed descripton of the model and how the model was created.

Leken betraktas som en grundläggande och avgörande del av barnkulturen, och det framhävs både i förskolans läroplan och forskning som en betydelsefull faktor för barns utveckling och lärande. Inom förskoleverksamheten uppkommer och främjas bråklekar regelbundet som en del av barnens lek. Studiens syfte är till att undersöka bråklek bland förskolebarn och dess betydelse för deras utveckling. Frågeställningar som besvaras är hur bråkleker 1–3 åringar respektive 3–5 åringar och vilka lekstämningar och sociala lekregler som framträder i bråkleken. Vi har valt att utgå ifrån en kvalitativ metod och utfört deltagande observationer på två olika förskolor i en större stad för att studera barnens bråklekar i förskolan. Vi observerade barnens bråklekar under alla möjliga situationer och hade en rik data som vi sedan bearbetade utifrån ett hermeneutiskt synsätt. Resultatet av vår studie visar att bråklek kan ha flera fördelaktiga effekter på barns utveckling. Bland annat att det kan hjälpa barn att lära sig sociala lekregler, utveckla förmågan att anpassa sin styrka och förstå vad som är en lämplig nivå av fysisk kontakt, att den kan hjälpa barn att hantera aggression i en trygg och kontrollerad miljö och till och med lära sig att respektera andras gränser och att ta hänsyn till sina kamrater. Sammanfattningsvis visar denna studie att bråklek kan ha flera fördelaktiga effekter på barns utveckling som kommer att vara till nytta för dem senare i livet.

In this current study, discussions were conducted in three focus groups with preschool teachers. In each focus group, two preschool teachers from two municipal preschools in a medium-sized city participated. The purpose of the research was to create a basic knowledge of how rough-and-tumble play (R&T) are perceived, interpreted and handled by preschool teachers. The cultural-historical theory of Vygotsky is used as a theoretical basis for this study. The results show that among preschool teachers there is a tendency to allow this kind of play in a limited form. The results also highlight the preschool teachers' insecurity in relation to children's rough-and-tumble plays. That uncertainty can take place because R&T games require a balance between being allowed, restricted and forbidden during a game. Furthermore, preschool teachers' awareness of the connection between their experiences and the approaches described about R&T plays are demonstrated. A lack of preschool teachers' consensus on R&T games also emerged in the study. / I den aktuella studien genomfördes diskussioner i tre fokusgrupper med förskollärare. I varje fokusgrupp deltog två förskollärare från två kommunala förskolor i en mellanstor stad. Forskningssyftet var att skapa en grundläggande kunskap om hur bråklekar uppfattas, tolkas och hanteras av förskollärare. Den kulturhistoriska teorin av Vygotskij användes som en teoretisk grund för den här studien. Resultatet visar att det bland förskollärare finns en tendens att tillåta bråklekar i en begränsad form. I resultatet lyfts även förskollärares osäkerhet gentemot barns bråklekar. Den osäkerheten kan uppkomma eftersom bråklekar kräver en balans mellan att vara tillåten, begränsad och förbjuden under en lek. Vidare påvisas förskollärares medvetenhet om en koppling mellan deras erfarenheter och de föreställningar som beskrivs kring bråklekar. En brist på förskollärares samsyn kring bråklekar framkom i studien.

Les pères s’impliquent aujourd’hui davantage qu’auparavant auprès de leurs enfants. À l’âge préscolaire, les jeux physiques (incluant les jeux de bataille) sont une caractéristique distinctive du style paternel d’interaction. Quelques études tendent à suggérer un lien entre ce type de jeu et l’adaptation sociale des enfants. Cependant,des contradictions se dégagent de la littérature, notamment quant au lien entre la quantité de jeu physique père-enfant et des mesures d’adaptation sociale, quant aux différentes opérationnalisations de la qualité du jeu physique, ainsi qu’en ce qui a trait au genre de l’enfant. Il y a également un débat entourant le degré optimal de contrôle ou de mutualité) au cours du jeu, de même qu’un nombre très limité d’études sur le lien entre le jeu physique père-enfant et l’anxiété/retrait. Dans ce contexte de divergences entre les chercheurs, la présente thèse vise quatre objectifs, soit : 1)vérifier si la quantité de jeux de bataille père-enfant est liée à l’adaptation sociale des enfants d’âge préscolaire (via des mesures de compétence sociale, d’agressivité/irritabilité, d’agression physique et d’anxiété/retrait); 2) tester si des mesures de mutualité ou de contrôle modèrent la relation entre la quantité de jeux de bataille père-enfant et les mesures d’adaptation sociale; 3) explorer le rôle potentiel d’autres indices de qualité du jeu de bataille; 4) clarifier le rôle du genre de l’enfant. L’échantillon est composé de 100 dyades père-enfant de Montréal et les environs. Les résultats des analyses corrélationnelles suggèrent que la fréquence et la durée de jeu de bataille ne sont pas reliées directement à l’adaptation sociale des enfants et mettent en lumière des variables qui pourraient jouer un rôle modérateur. Les régressions pour modèles modérateurs indiquent que la mutualité père-enfant dans les initiations au jeu de bataille et la peur exprimée par l’enfant au cours de ce type de jeu modèrent la relation entre la durée des jeux de bataille et la compétence sociale de l’enfant d’âge préscolaire. La mutualité modère également le lien entre la durée du jeu et l’agressivité/irritabilité de l’enfant. Les initiations autoritaires faites par le père modèrent le lien entre la durée du jeu et les agressions physiques, alors qu’aucune variable ne modère le lien entre la durée du jeu et l’anxiété/retrait des enfants. Les analyses post-hoc donnent davantage d’informations sur la nature des liens de modération. Bien que les pères rapportent ne pas faire davantage de jeux de bataille, ni jouer plus longtemps à se batailler avec leurs garçons qu’avec leurs filles, trois modèles modérateurs sur quatre demeurent significatifs uniquement pour les garçons. Ces données sont interprétées à la lumière des théories éthologique et développementale. Il est suggéré que plutôt que de traiter l’agression et la compétence sociale comme des variables opposées de l’adaptation, une mesure de compétition permettrait peut-être de réconcilier les deux mondes. / Today’s fathers are increasingly more involved with their children. During the preschool years, rough-and-tumble-play (RTP; including play-fighting) is a significant aspect of paternal interaction style. A few studies suggest that this type of play is linked to children’s social adaptation. However, many contradictions remain in the current literature, particularly concerning the link between the quantity of father-child RTP and social adaptation measures, RTP quality indicators and their measurement, and gender differences. There is also a debate regarding the optimal control level (or mutuality) during play. Moreover, very few studies have investigated the link between father-child RTP and children’s anxiety/withdrawal. The current thesis has four objectives: 1) to verify the presence of a link between father-child play-fighting quantity and preschooler’s social adaptation measures (i.e., social competency, aggressiveness/irritability, physical aggression and anxiety/withdrawal); 2) to verify if mutuality or control measures moderate the relationship between father-child play-fighting quantity and social adaptation; 3) to explore the potential role of other play-fighting quality cues; 4) to clarify the role of child gender. The sample consists of 100 father-child dyads from the Montreal region. Correlational analyses suggest that the frequency and duration of play-fighting are not directly linked to children social adaptation. The regressions for moderation models indicate that father-child mutuality in play-fighting initiations, as well as the fear expressed by the child during play, moderate the relationship between playfighting duration and the preschooler’s social competency. Mutuality also moderates the link between play duration and child aggressiveness/irritability. Although fathers do not report a higher frequency or duration of play-fighting according to their children’s gender, post-hoc analyses show that three out of four moderating models are significant only for the boys. iv The data is interpreted according to evolutionary and developmental theories. It is argued that a measure of competition could shed light on the relationship between aggressiveness and social competency in social adaptation, and that these two variables may not systematically be opposed as it is commonly perceived in RTP literature.