Dissertation thesis is focused on the aircraft cooling system optimization. The knowledge of the pressure loss is necessity for design of an optimal system. In the beginning of the thesis, the different designs of piston engine cooling systems are described for both aircrafts and automobiles. Other sections outline the determination of the coolers characteristics and describe the different test sections applicable for the characteristics measurement. The test section built at the Institute of the aerospace engineering is described as well. Practical part of the thesis describes the calibration of the test section. The measurements of the specific coolers were compared with the CFD simulation of two models - the simplified cooler model and cooler element model. Additionally, the measurements were compared with results obtained at specialized coolers testing facility.

Dissertation thesis is focused on the aircraft cooling system optimization. The knowledge of the pressure loss is necessity for design of an optimal system. In the beginning of the thesis, the different designs of piston engine cooling systems are described for both aircrafts and automobiles. Other sections outline the determination of the coolers characteristics and describe the different test sections applicable for the characteristics measurement. The test section built at the Institute of the aerospace engineering is described as well. Practical part of the thesis describes the calibration of the test section. The measurements of the specific coolers were compared with the CFD simulation of two models - the simplified cooler model and cooler element model. Additionally, the measurements were compared with results obtained at specialized coolers testing facility.

Introdução: As doenças cerebrovasculares são consideradas atualmente a segunda principal causa de óbito no mundo e a terceira causa de anos de vida perdidos por mortalidade1,2. A aterosclerose de grandes artérias é uma das principais condições subjacentes associadas ao AVC isquêmico (AVCi) e correlaciona-se com maiores taxas de recorrência. A detecção e a estratificação da estenose extracraniana podem ser feitas através do Doppler, da angiotomografia computadorizada (ATC), da angiorressonância magnética (ARM) e da angiografia intra-arterial digital (AIA), sendo esta última considerada o método padrão-ouro. Objetivo: Avaliar a acurácia diagnóstica e a concordância entre os métodos de ATC, ARM com contraste (AM CC) e AIA na análise da estenose extracraniana. Determinar a frequência e caracterizar a estenose extracraniana em população brasileira sintomática. Metodologia: Foram avaliados retrospectivamente os exames AIA, ATC e ARM, de pacientes adultos sintomáticos admitidos na Unidade de Emergência do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto (UE HCFMRP) no período 03/2014-03/2015, para detecção e estratificação da estenose extracraniana. Foram coletados ainda dados demográficos, clínicos e laboratoriais desses pacientes. Resultados: Observou-se alta acurácia da ATC e da ARM na avaliação de segmentos carotídeos, com sensibilidade de 100% e especificidade variando entre 78% e 100% para estenoses >=50%. Para segmentos vertebrais, observou-se menor acurácia dos métodos, sobretudo da ARM, com valores de sensibilidade e especificidade variando entre 60%-85% e 33-62%, respectivamente, para estenoses >=50%. A prevalência de estenose extracraniana >=50% em nossa população foi de 38,6% e de 23,4% para estenoses >=70%. O segmento vascular mais acometido foi a origem das artérias vertebrais. Os fatores de risco associados a estenose extracraniana foram: sexo masculino, idade avançada, tabagismo e elevada pressão arterial sistólica na admissão. Conclusão: A ATC e ARM representam métodos adequados para investigação de estenoses extracranianas, sobretudo carotídeas. Ambos os métodos, sobretudo a ARM, têm acurácia limitada na avaliação dos óstios vertebrais. / Introduction: Cerebrovascular diseases are considered the second cause of death worldwide and the third cause of years of life lost (YLL)1,2. Large arteries atherosclerosis is one of the main conditions associated with stroke and correlates with higher recurrence rates. Imaging methods such as Doppler, computed tomography angiography (CTA), magnetic resonance angiography (MRA) and intra-arterial angiography (IAA) are available for extra cranial vascular study. Intra-arterial angiography remains the gold standard. Objectives: Evaluate diagnostic accuracy and concordance between CTA, MRA (contrast enhanced) and IAA for extracranial stenosis analysis. Determine frequency and distribution of extra cranial stenosis in a brazilian symptomatic population. Methods: IAA, CTA and MRA exams from adult symptomatic patients admitted between 03/2014 and 03/3015 at the Emergency Unit of Clinics Hospital of Ribeirão Preto\'s School of Medicine were retrospectively reviewed for detection and grading of extra cranial stenosis. Clinical and laboratorial information from patients was obtained. Results: Both CTA and MRA showed high sensitivity (100%) and specificity (78%-100%) in the evaluation of carotid vessels for stenosis >=50%. However, lower sensitivity (60-85%) and specificity (33-62%) were obtained for vertebral segments, Extra cranial stenosis prevalence was 38,6% for stenosis >=50% and 23,4% for stenosis >=70% among our patients. Vertebral artery origins were the most affected segments. Risk factors identified for extra cranial stenosis were: male gender, age, smoking and high systolic blood pressure on admission. Conclusions: CTA and MRA are considered adequate methods for extra cranial stenosis, specially for carotid segments. Both methods have lower accuracy in the investigation of vertebral artery origins.

<p>The substantial advances of coronary CTA have resulted in a boost of use of this new technique in the last several years, which brings a big challenge to radiologists by the increasing number of exams and the large amount of data for each patient. The main goal of this study was to develop a computer tool to facilitate coronary CTA analysis by combining knowledge of medicine and image processing.Firstly, a competing fuzzy connectedness tree algorithm was developed to segment the coronary arteries and extract centerlines for each branch. The new algorithm, which is an extension of the “virtual contrast injection” method, preserves the low density soft tissue around the coronary, which reduces the possibility of introducing false positive stenoses during segmentation.Secondly, this algorithm was implemented in open source software in which multiple visualization techniques were integrated into an intuitive user interface to facilitate user interaction and provide good over¬views of the processing results. Considerable efforts were put on optimizing the computa¬tional speed of the algorithm to meet the clinical requirements.Thirdly, an automatic seeding method, that can automatically remove rib cage and recognize the aortic root, was introduced into the interactive segmentation workflow to further minimize the requirement of user interactivity during post-processing. The automatic procedure is carried out right after the images are received, which saves users time after they open the data. Vessel enhance¬ment and quantitative 2D vessel contour analysis are also included in this new version of the software. In our preliminary experience, visually accurate segmentation results of major branches have been achieved in 74 cases (42 cases reported in paper II and 32 cases in paper III) using our software with limited user interaction. On 128 branches of 32 patients, the average overlap between the centerline created in our software and the manually created reference standard was 96.0%. The average distance between them was 0.38 mm, lower than the mean voxel size. The automatic procedure ran for 3-5 min as a single-thread application in the background. Interactive processing took 3 min in average with the latest version of software. In conclusion, the presented software provides fast and automatic coron¬ary artery segmentation and visualization. The accuracy of the centerline tracking was found to be acceptable when compared to manually created centerlines.</p>

La qualité microbienne de l'air intérieur représente un enjeu sanitaire important, notamment dans le secteur professionnel. Ces travaux de thèse ont permis d'étudier les conditions favorisant le développement des espèces microbiennes collectées sur des médias fibreux utilisés dans des CTA, ainsi que leur réentrainement an aval de la filtration, susceptible de dégrader la qualité de l'air. La première partie de l'étude s'est déroulée en laboratoire à partir de la filtration d'un consortium bactérien - fongique composé de Staphylococcus epidermidis et Penicillium oxalicum. L'influence de trois paramètres a été étudiée sur la croissance microbienne : le taux d'humidité relative (HR) de l'air, la nature du média fibreux, la présence/absence de flux d'air. Les résultats ont révélé notamment que quelles que soient les conditions,S. epidermidis n'arrive pas à croître. En revanche, lorsque l'HR de l'air approche 100%, P. oxalicum se développe sur les filtres et des spores sont relarguées en aval des filtres après une reprise de la filtration. Une seconde partie de l'étude a consisté à travailler avec un aérosol atmosphérique semi urbain. Deux unités de filtration d'air ont fonctionné pendant 5 mois en parallèle. La ventilation d'une des deux unités a été stoppée chaque week-end et redémarrée en début de semaine. Un suivi de la température, de l'humidité de l'air, de la perte de charge des filtres et de la concentration des particules totales dans l'air en amont de la filtration a été assuré tout au long de l'étude. Les concentrations en microorganismes cultivables ont été mesurées chaque semaine en amont et en aval de chaque filtre, notamment au redémarrage de la ventilation. En fonction des variations saisonnières de la concentration des microorganismes, les résultats ont montré en particulier des efficacités de filtration vis-à-vis des particules bactériennes faibles, voire négatives, dans l'unité de filtration fonctionnant en continu.

No description available.

No description available.

Les performances de filtration des filtres de CTA vis-à-vis de particules et d'aérosols microbiens (AM) ont été étudiées ainsi quel'influence des conditions opératoires sur le comportement de microorganismes collectés sur les filtres. A l'échelle du laboratoire, une mini CTA ayant deux étages de filtration en série a été développée et validée pour l'étude de filtres prototypes ayant des géométries industrielles. Trois types de filtres de différentes efficacités ont été considérés : G4, F7 et F9 selon la norme EN 779. Deux configurations de filtres ont été étudiées : 1) G4 plan plissé/F7 à poches et 2) F7/F9 à poches. Les filtres ont été colmatés séquentiellement par des particules d'alumine, qui assurent une fraction minérale, puis du riz microniséqui apporte le champignon Penicillium chrysogenum et assure une fraction organique agissant comme substrat pour les microorganismes. Enfin, un AM composé d'endospores de Bacillus subtilis et de spores d'Aspergillus niger a été nébulisé pour la contamination des filtres. Après colmatage, des périodes de marche/arrêt de la ventilation de différentes durées (10 j ou 6 semaines) ont été simulées. Lors des reprises de la ventilation, des comptages de particules et d'AM en avaldes filtres ont été effectués. Les principaux résultats sont : (i) les filtres placés en 2ème étage présentent un colmatage plus faible que ceux du 1er étage de filtration, (ii) survie de B. subtilis, croissance de P. chrysogenum et décroissance d'A. niger sur les filtres quelle que soit la période d'arrêt de ventilation étudiée, et (iii) lors des reprises de ventilation, il n'a pas été observé de relargage d'AM pour la fraction échantillonnée.D'autre part, deux CTA à pleine échelle ont été étudiées pendant 6 mois. Une CTA ayant deux étages de filtration avec une configuration G4 plan plissé/F7 à poches, traite l'air extérieur et le souffle vers des locaux desservis. L'autre CTA correspond à l'extraction de l'air vicié d'un local pour le rejeter vers l'extérieur. La perte de charge des filtres, l'humidité relative, et la température de l'air ont été suivies en continu. L'efficacité des filtres vis-à-vis des particules et des aérosols microbiens a été mesurée une fois par mois. Une méthodologie originale de suivi mensuel de la concentration des microorganismescollectés sur les filtres a été mise en oeuvre. Les principaux résultats sont : (i) faible évolution de la perte de charge du filtre placé en 2ème étage, (ii) efficacité des filtres G4 comparable à celle des filtres G4 prototypes, (iii) efficacité du filtre F7 plus faible que celle des filtres prototypes, ce qui peut être expliqué par une différence de vitesse de filtration entre les deux échelles, (iv) le filtre G4 de la CTA-extraction contient une concentration de microorganismes 10 fois plus élevée que celle du filtre G4 de la CTA-soufflage après 6 mois de fonctionnement.

Introdução: As doenças cerebrovasculares são consideradas atualmente a segunda principal causa de óbito no mundo e a terceira causa de anos de vida perdidos por mortalidade1,2. A aterosclerose de grandes artérias é uma das principais condições subjacentes associadas ao AVC isquêmico (AVCi) e correlaciona-se com maiores taxas de recorrência. A detecção e a estratificação da estenose extracraniana podem ser feitas através do Doppler, da angiotomografia computadorizada (ATC), da angiorressonância magnética (ARM) e da angiografia intra-arterial digital (AIA), sendo esta última considerada o método padrão-ouro. Objetivo: Avaliar a acurácia diagnóstica e a concordância entre os métodos de ATC, ARM com contraste (AM CC) e AIA na análise da estenose extracraniana. Determinar a frequência e caracterizar a estenose extracraniana em população brasileira sintomática. Metodologia: Foram avaliados retrospectivamente os exames AIA, ATC e ARM, de pacientes adultos sintomáticos admitidos na Unidade de Emergência do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto (UE HCFMRP) no período 03/2014-03/2015, para detecção e estratificação da estenose extracraniana. Foram coletados ainda dados demográficos, clínicos e laboratoriais desses pacientes. Resultados: Observou-se alta acurácia da ATC e da ARM na avaliação de segmentos carotídeos, com sensibilidade de 100% e especificidade variando entre 78% e 100% para estenoses >=50%. Para segmentos vertebrais, observou-se menor acurácia dos métodos, sobretudo da ARM, com valores de sensibilidade e especificidade variando entre 60%-85% e 33-62%, respectivamente, para estenoses >=50%. A prevalência de estenose extracraniana >=50% em nossa população foi de 38,6% e de 23,4% para estenoses >=70%. O segmento vascular mais acometido foi a origem das artérias vertebrais. Os fatores de risco associados a estenose extracraniana foram: sexo masculino, idade avançada, tabagismo e elevada pressão arterial sistólica na admissão. Conclusão: A ATC e ARM representam métodos adequados para investigação de estenoses extracranianas, sobretudo carotídeas. Ambos os métodos, sobretudo a ARM, têm acurácia limitada na avaliação dos óstios vertebrais. / Introduction: Cerebrovascular diseases are considered the second cause of death worldwide and the third cause of years of life lost (YLL)1,2. Large arteries atherosclerosis is one of the main conditions associated with stroke and correlates with higher recurrence rates. Imaging methods such as Doppler, computed tomography angiography (CTA), magnetic resonance angiography (MRA) and intra-arterial angiography (IAA) are available for extra cranial vascular study. Intra-arterial angiography remains the gold standard. Objectives: Evaluate diagnostic accuracy and concordance between CTA, MRA (contrast enhanced) and IAA for extracranial stenosis analysis. Determine frequency and distribution of extra cranial stenosis in a brazilian symptomatic population. Methods: IAA, CTA and MRA exams from adult symptomatic patients admitted between 03/2014 and 03/3015 at the Emergency Unit of Clinics Hospital of Ribeirão Preto\'s School of Medicine were retrospectively reviewed for detection and grading of extra cranial stenosis. Clinical and laboratorial information from patients was obtained. Results: Both CTA and MRA showed high sensitivity (100%) and specificity (78%-100%) in the evaluation of carotid vessels for stenosis >=50%. However, lower sensitivity (60-85%) and specificity (33-62%) were obtained for vertebral segments, Extra cranial stenosis prevalence was 38,6% for stenosis >=50% and 23,4% for stenosis >=70% among our patients. Vertebral artery origins were the most affected segments. Risk factors identified for extra cranial stenosis were: male gender, age, smoking and high systolic blood pressure on admission. Conclusions: CTA and MRA are considered adequate methods for extra cranial stenosis, specially for carotid segments. Both methods have lower accuracy in the investigation of vertebral artery origins.

Actuellement, les polyuréthanes (PUs) sont produits industriellement par polyaddition entre un diisocyanate et un polyol. Le caractère fortement sensibilisant des isocyanates, mettent ces composés sous forte pression réglementaire au niveau européen (REACH) et ont créé le besoin d'obtenir des PUs ne provenant pas d'isocyanates, lesquels sont plus communément appelés Non-Isocyanate PolyUréthanes (NIPUs). Les travaux de cette thèse visent ainsi à établir de nouvelles voies d'accès à des NIPUs. Des pré-polymères téléchéliques ont été synthétisés via la réaction de métathèse. Plusieurs groupements terminaux (jusqu'à 16), réagissant à température ambiante avec une amine primaire, ont été greffés avec succès à ces pré-polymères. La réaction avec plusieurs diamines a conduit à la synthèse de nouveaux matériaux NIPUs entièrement caractérisés. Les stratégies de synthèses développées au cours de ces travaux de thèse ouvrent de nouvelles perspectives quant à l'industrialisation de NIPUs. / Conventional polyurethanes (PUs) involve the use of isocyanates, which are considerably toxic and require phosgene for their manufacture. To tackle environmental issues, it is necessary to elaborate different routes to PUs. In this context, two isocyanate-free strategies towards the preparation of polythiourethanes (PTUs), i.e. non-isocyanate polyurethanes (NIPUs), have being developed. The first way involves the synthesis of α,ω-di(dithiocyclocarbonate) telechelic poly(propylene glycol) (bis(5DTCC)-PPG), poly(tetrahydrofurane diglycidyl ether) (bis(5DTCC)-PTG), upon chemical modification of the corresponding α,ω-diepoxide telechelic polymers (PPG, PTG, respectively) through cycloaddition of carbon disulfide. The second approach involves the ring-opening metathesis polymerization (ROMP), using Grubbs’ 2nd generation ruthenium catalyst, of cycloolefins using 16 differents chain-transfer agents. Bis(5DTCC) telechelic copolyolefins are thus synthesized. Reaction of the end-capping 5DTCC moieties with a diamine by ring-opening polyaddition ultimately affords at room temperature the corresponding NIPTU.