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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Caracterização e pré-tratamento de lodo de fossas e de tanques sépticos / Characterization and treatment of sludge originated from septic tanks

Nayara Batista Borges 27 November 2009 (has links)
Fossas e tanques sépticos são sistemas de pequeno porte utilizados para tratamento parcial do esgoto sanitário produzido nas áreas urbana e rural, quando não beneficiados por sistema de esgotamento sanitário. Tal utilização se justifica principalmente por ser tecnologia que não exige muita dedicação operacional e ser de simples implantação. Apesar da vasta utilização dessas unidades no Brasil, há pouca informação sobre a caracterização, as condições de coleta, transporte, tratamento e destino final de resíduo (lodo) produzido nesses sistemas. Nesse sentido, o presente trabalho tem como objetivo a caracterização do lodo produzido nessas unidades; e, também, a concepção, o desenvolvimento e a avaliação de uma unidade piloto para pré-tratamento de lodo de fossas e tanques sépticos. Essa unidade, constituída por grade, desarenador e flotador, foi instalada no Campus da Universidade de São Paulo, junto da Estação de Tratamento de Esgoto do Campus - área 1, e vista à remoção de sólidos grosseiros, areia e materiais flutuantes, antes de seu lançamento na Estação de Tratamento de Esgoto do Campus. Foi feita a caracterização do lodo de tanques sépticos coletado in situ e do lodo proveniente dos caminhões limpa-fossas, descarregando em tanque pulmão de 15000 litros. A caracterização do lodo proveniente dos caminhões limpa-fossas foi realizada em duas campanhas (coletas), sendo uma feita na primeira visita ao local pré-definido, e outra realizada aproximadamente seis meses após a primeira coleta. Com intuito de aprimorar o método de análise das amostras do lodo in situ, com finalidade de melhor fragmentar o material particulado, foi testado o uso de ultrassom. Também, foi realizada a caracterização do lodo de fossas e tanques sépticos na Central de Recebimento de Resíduos na cidade de Campinas-SP - SANASA - Sociedade de Abastecimento de Água e Saneamento AS. Para tanto, foram coletadas amostras compostas de lodo descarregado por 24 caminhões. Foi feito teste complementar, com a finalidade de estudar a degradação do lodo flotado por processos anaeróbio e aeróbio. Mediante essas caracterizações pode-se constatar a grande heterogeneidade da composição do lodo e a elevada carga orgânica, que devem ser ponderados com relação a impactos no meio ambiente e em Estações de Tratamento de Esgoto. Contudo, nota-se a importância do pré-tratamento desse lodo antes de ser lançado em ETEs. A unidade piloto foi operada com diferentes taxas de aplicação superficial (80; 110; 140 e 200 \'M POT.3\'/\'M POT.2\'.dia), quando foram obtidas remoções de 91,7% de sólidos suspensos; 89,3% de DQO e 81,9% de óleos e graxas. Pelos resultados obtidos foi demonstrada a eficiência do sistema de flotação na remoção de óleos e graxas e dos sólidos suspensos. A digestão aeróbia do lodo flotado mostrou-se eficiente quando foi aplicado inócuo com período de aeração superior a 20 dias, sendo que foram obtidas eficiências de 88,3% e 90% para remoção de DQO e de óleos e graxas, respectivamente. / Septic tanks are small structures used for partial treatment of wastewater produced from urban and rural areas. It utilization is justify mainly by simplicity of construction and for being a technology that requires low operational dedication. Although it is a technology vastly used in Brazil, there is not much information about the characteristics of the waste dumped in there, and the conditions of collection, transport, and final destination of the sludge generated in the system. The objective of this research was characterize the sludge originated from septic tanks and to design, construct and evaluate a treatment unit model to be used for prior treatment of the sludge generated in those septic tanks. This unit, composed by a sieve, a degritter, and a flotation device, was assembled in the São Paulo University Campus, near the area 1 from the campus Wasterwater Treatment Plant (WWTP). It had the purpose to remove har solid particle, sand and the floating material before their entry in the Wasterwater Treatment Plant. Was made to characterize the sludge septic tank collected in situ and the sludge originated from the Septic Pumper Truck, unloaded into a tank of 15000 L. Furthermore, the characterization of the sludge originated from the Septic Pumper Truck was performed twice, once in the material collected in the first visit to the defined location and the other in the material collected about six months after the first collection. The use of ultrasound was tested to ameliorate the fragmentation of the particulate material and to improve the method of analysis of the sludge in situ. Additionally, it was characterized the sludge from septic tanks in the Waste Reception Center from the city of Campinas, São Paulo State - SANASA - Society of Water Supply and Sanitation in composite samples collected from 24 trucks during the unloading. Septic Pumper Truck in th Waste Receptation Center. A complementing test was performed in order to text the degradation of the floated sludge by anaerobic and aerobic processes. The characterizations revealed a great heterogeneity in the composition of the sludge and the high organic content, which should be taken in consideration regarding the impacts in the environment and in the WWTP. This underlines the importance of treatment of the sludge prior to discharging into the WWTP. The pilot plant was managed to work at different rates of surface sludge application (80, 110, 140 and 200 \'M POT.3\'/\'M POT.2\'.day). The 110 \'M POT.3\'/\'M POT.2\'.day rate displayed the highest efficiency with the removal of 91.7% of suspended solids, 89.3% of the chemical oxygen demand, and 81 9% of oils and waxes. The results showed the efficiency of the flotation system in the removal of suspended solids, oil and greases. The aerobic digestion of the floated material was efficient when it received inoculation with aeration period greater than 20 days, which allowed CDO the removal of 88.3% and 90% of oil and greases.
82

Identification of Chiari Malformation Type I Brain Morphology and Biomechanics: A Multi-Faceted Approach to Determine Diagnostic and Treatment Criteria

Eppelheimer, Maggie S. 25 August 2020 (has links)
No description available.
83

La ventilation nasale du nouveau-né : études cliniques d'anomalies congénitales, modélisations numériques de l'écoulement et du réchauffement de l'air / Neonatal nasal breathing : clinical studies of congenital abnormalities, numerical modeling of airflow and air-conditioning

Moreddu, Éric 07 December 2018 (has links)
La ventilation nasale est vitale pour le nouveau-né, respirateur nasal exclusif. Le tiers antérieur des fosses nasales peut être modifié par une sténose congénitale de l’orifice piriforme, tandis leur partie postérieure peut être fermée par une atrésie choanale uni ou bilatérale ou par des lésions du nasopharynx.Les simulations numériques permettent d’analyser l’écoulement et le conditionnement de l’air en contournant les limites techniques et éthiques rencontrées in vivo. Devant la rareté des données dans la littérature, une étude de faisabilité a été nécessaire et concluante : les modèles numériques sont qualitativement proches de la réalité. Un travail sur les conditions physiologiques chez le nouveau-né a ensuite été réalisé, avec une méthodologie retravaillée. La reconstruction tridimensionnelle des fosses nasales est possible dès la naissance. La création d’une sphère centrée sur la pointe du nez, éloignant le domaine d’entrée de la zone d’intérêt, a permis d’analyser le rôle du tiers antérieur des fosses nasales.La valve nasale joue un rôle majeur en inspiration : perte de charge, accélération, guidage des flux et réchauffement de l’air. Les trois quarts du réchauffement ont lieu en amont du cornet inférieur. Une obstruction nasale entraîne une réduction des vitesses et une augmentation des températures de l'air. La simulation de l’inspiration d’air à 0°C a permis de constater que les fosses nasales permettent d’amortir les effets du refroidissement de l’air extérieur.Ce travail constitue une première approche de la physiologie de la ventilation nasale du nouveau-né par modélisation numérique, indispensable à la compréhension de la pathologie nasale néonatale. / Nasal breathing is essential for the newborn, exclusive nasal breather. The anterior third of the nasal fossae may be modified by a congenital stenosis of the pyriform aperture, while their posterior part may be closed by unilateral or bilateral choanal atresia.Numerical simulations are a good means to analyze airflow and air-conditioning: they circumvent the technical and ethical limits encountered in vivo. Given the rarity of available data in the literature, a feasibility study was necessary and was conclusive: numerical models are qualitatively close to reality. A work on the physiological conditions in newborns was conducted, using refined methodology. The three-dimensional reconstruction of the nasal fossae is possible from birth. The creation of a sphere centered on the tip of the nose, moving the boundary conditions away from the area of interest, made it possible to analyze the role of the anterior third od the nasal fossae.The nasal valve plays a major in inspiration: it is a zone of pressure loss, acceleration, flow guidance and air warming. Three-fourths of the warming takes place upstream the inferior turbinate. A partial nasal obstruction modifies these results with lower velocities and higher temperature of the air. The simulation of the inspiration of cold air (0°C) has shown that the nasal fossae can dampen, without canceling, the effects of air cooling. This work is a first approach to the physiology of nasal ventilation of the newborn by numerical modeling, which is essential to the understanding of neonatal nasal pathology.

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