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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.
11

Hydraulic characteristics of embedded circular culverts

Magura, Christopher Ryan 14 September 2007 (has links)
This report details a physical modeling study to investigate the flow characteristics of circular corrugated structural plate (CSP) culverts with 10% embedment and projecting end inlets using a 0.62 m diameter corrugated metal pipe under a range of flows (0.064 m3/s to 0.254 m3/s) and slopes (0%, 0.5% and 1.0%). An automated sampling system was used to record detailed velocity measurements at cross-sections along the length of the model. The velocity data was then used to develop isovel plots and observations were made regarding the effect of water depth, average velocity, boundary roughness and inlet configuration on the velocity structure. Other key aspects examined include the distribution of shear velocity and equivalent sand roughness, Manning’s roughness, an evaluation of composite roughness calculation methods, secondary currents, area-velocity relationships, the effect of embedment on maximum discharge and a simulation of model results using HECRAS. Recommendations are presented to focus future research. / October 2007
12

Hydraulic characteristics of embedded circular culverts

Magura, Christopher Ryan 14 September 2007 (has links)
This report details a physical modeling study to investigate the flow characteristics of circular corrugated structural plate (CSP) culverts with 10% embedment and projecting end inlets using a 0.62 m diameter corrugated metal pipe under a range of flows (0.064 m3/s to 0.254 m3/s) and slopes (0%, 0.5% and 1.0%). An automated sampling system was used to record detailed velocity measurements at cross-sections along the length of the model. The velocity data was then used to develop isovel plots and observations were made regarding the effect of water depth, average velocity, boundary roughness and inlet configuration on the velocity structure. Other key aspects examined include the distribution of shear velocity and equivalent sand roughness, Manning’s roughness, an evaluation of composite roughness calculation methods, secondary currents, area-velocity relationships, the effect of embedment on maximum discharge and a simulation of model results using HECRAS. Recommendations are presented to focus future research.
13

Hydraulic characteristics of embedded circular culverts

Magura, Christopher Ryan 14 September 2007 (has links)
This report details a physical modeling study to investigate the flow characteristics of circular corrugated structural plate (CSP) culverts with 10% embedment and projecting end inlets using a 0.62 m diameter corrugated metal pipe under a range of flows (0.064 m3/s to 0.254 m3/s) and slopes (0%, 0.5% and 1.0%). An automated sampling system was used to record detailed velocity measurements at cross-sections along the length of the model. The velocity data was then used to develop isovel plots and observations were made regarding the effect of water depth, average velocity, boundary roughness and inlet configuration on the velocity structure. Other key aspects examined include the distribution of shear velocity and equivalent sand roughness, Manning’s roughness, an evaluation of composite roughness calculation methods, secondary currents, area-velocity relationships, the effect of embedment on maximum discharge and a simulation of model results using HECRAS. Recommendations are presented to focus future research.
14

Dieta e fatores ambientais associados aos tumores de cérebro em adultos: um estudo caso-controle no Rio de Janeiro / Diet and environmental factors associated to the tumors of brain in adults

Pereira, Rosângela Alves January 2000 (has links)
Made available in DSpace on 2012-09-05T18:24:04Z (GMT). No. of bitstreams: 2 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) 63.pdf: 3121932 bytes, checksum: e6c67c8e43db434e50d45a260a22021e (MD5) Previous issue date: 2000 / Os tumores do cérebro vêm ganhando importância devido ao aparente aumento da sua incidência e por sua alta letalidade. Nao está, ainda, esclarecido se a elevaçao das taxas de tumores cerebrais é reflexo da modificaçao do risco de desenvolver a doença, ou se é conseqüência da melhoria dos métodos de diagnóstico, porque, apesar dos avanços na pesquisa epidemiológica e de genética molecular, a etiologia dos tumores de cérebro permanece desconhecida. A investigaçao da associaçao entre fatores da dieta e tumores de cérebro tem considerado os compostos N-nitroso como favorecedores do desenvolvimento desses tumores e as vitaminas C e E atuando como protetores. Desenvolve-se na Regiao Metropolitana do Rio de Janeiro um estudo caso-controle de base hospitalar com o objetivo de determinar a magnitude da associaçao entre fatores de risco ambientais e os tumores de cérebro em adultos. Sao definidos como casos indivíduos de 30-65 anos, residentes na mesma regiao, internados em hospitais específicos com tumor primário de cérebro. Os controles sao indivíduos internados nas mesmas instituiçoes, pareados por sexo e freqüencia de idade, residentes na mesma área, excluídos os que tiverem diagnóstico de câncer ou de nosologias que tenham os componentes da dieta entre os seus fatores de risco. Para a obtençao dos dados utiliza-se um questionário com questoes referentes à exposiçao a fatores de risco diversos como campos eletromagnéticos, exposiçoes ocupacionais, radiaçao ionizante; defensivos agrícolas, contato com animais, uso de aco, álcool e medicamentos, antecedents familiares de câncer, história de traumatismo craniano e os padroes de alimentaçao na adolescência e no ano anterior ao diagnóstico. Explora algumas questoes mais relevantes que emergem no estudo da epidemiologia dos tumores de cérebro, particularmente, os métodos empregados na avaliaçao do papel que os fatores da dieta exercem no desenvolvimento destes tumores.
15

O uso do amianto e avaliaçäo de impacto na saúde / The use of the amianthus and impact evaluation in the health

Menezes, Marco Antônio Carneiro January 2001 (has links)
Made available in DSpace on 2012-09-06T01:12:09Z (GMT). No. of bitstreams: 2 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) 229.pdf: 2676574 bytes, checksum: 475aa6f6338da10569c40365566c9cfd (MD5) Previous issue date: 2001 / O amianto é uma substância reconhecidamente cancerígena, largamente utilizada no país como matéria-prima em diversos ramos da indústria. A experiência do seu uso no Brasil, exemplifica o problema da importaçäo de tecnologia e processos perigosos para uso em grande escala, sem um estudo de impacto à saúde. Um estudo de estimativa de casos divulgado pela ECO/OPS-OMS, indica que do período atual até o ano de 2010, o Estados Unidos teräo 1,6 milhöes de mortes relacionadas a trabalhadores expostos ao amianto. Nossa realidade vem revelando os inúmeros casos de adoecimento e mortes, causados pelo uso desta substância, e atualmente no país, discute-se o custo benefício do seu uso e os diversos setores da sociedade debatem o uso controlado ou o banimento. O atual estágio do desenvolvimento tecnológico, a pressäo social e questöes de ordem político/econômica, apontam a substituiçäo do amianto por outras fibras como uma realidade. Para subsidiar estas discussöes e a tomada de decisäo, é importante dar visibilidade a realidade brasileira quanto aos agravos a saúde e ao meio ambiente e, a determinaçäo do nível de risco e prevalência das doenças causadas pelo uso desta substância. Aplica a metodologia para avaliaçäo e gerenciamento de riscos-EPA/OMS e a adequaçäo proposta por Landrigan, 1999, para calcular o risco relativo, nos processos de remoçäo e setor de fiaçäo na indústria têxtil.
16

Untersuchung der Dynamik von Resistenzvarianten des Hepatitis-B-Virus unter Drittlinientherapie mit Tenofovir mittels Tiefenpyrosequenzierung bei Patienten mit chronischer Hepatitis-B-Virusinfektion mit Schwerpunkt auf den Adefovir-Resistenzvarianten und Verlauf der HBV-Quasispezies

Bock, Julia Friederike 30 March 2017 (has links) (PDF)
Eine Monotherapie mit Tenofovir disoproxil fumarate (TDF) stellt eine hoch effiziente Therapie-option für multipel vorbehandelte Patienten mit chronischer Hepatitis-B-Virusinfektion (HBV) dar. Eine Resistenz gegen TDF wurde bislang nicht beschrieben, jedoch wird ein möglicher negativer Einfluss von Adefovir dipivoxil (ADV)-Resistenzvarianten auf die TDF-Ansprechrate diskutiert. Diese retrospektive Kohortenstudie untersucht die Dynamik von Nukleos(t)id-Analoga (NA)-Resistenzvarianten im HBV-Polymerasegen mit Fokus auf ADV-Resistenzvarianten bei 18 chronisch HBV-infizierten Patienten mit Therapieversagen auf eine vorangegangene Lamivudin (LAM)- und ADV-Therapie, sowie nur partiellem Therapieansprechen auf eine TDF-Monotherapie. Zur Detektion von NA-Resistenzvarianten wird eine HBV-Genomsequenzierung mit Tiefenpyrosequenzierung (Genome Sequencer FLX, Roche Diagnostics, Germany) (UDPS), direkte Sequenzierung (TRUGENETM HBV Genotyping Kit, OpenGeneTM DNA Sequencing Sys-tem, Siemens Healthcare Diagnostic, USA) (TG) und Line Probe Assay (INNO-LiPa DRv2 und v3, Innogenetics, Belgium) (INNO-LiPA) durchgeführt. Unter TDF kommt es zu einer quantitati-ven Shift zugunsten der ADV-Resistenzvarianten mit konstant bleibendem Anteil und deutlich höher persistierender Virämie zu Monat 12 im Vergleich zu Patienten ohne ADV-Resistenzvarianten. Vor allem werden die Varianten rtA181V und rtN236T selektiert, jedoch nicht die Variante rtA181T. Die absolute Anzahl der LAM-Resistenzvarianten hingegen halbiert sich. Varianten mit einem initial per UDPS detektierten Anteil von >20% der patientenspezifi-schen HBV-Population werden meist selektiert und nehmen im Verlauf den Hauptanteil der Quasispezies ein. UDPS stellte ein potentes Medium der Detektion, Identifikation und Quantifi-zierung von HBV-Varianten dar und ist INNO-LiPa und TG überlegen. Es ergibt sich kein Hin-weis auf TDF-Resistenzvarianten, jedoch zeigt das Vorliegen von ADV-Resistenzvarianten ei-nen tendentiell negativen Einfluss auf die virale Kinetik. Weitere größere Langzeitstudien sind zur Bestätigung dieser Beobachtung notwendig. / Tenofovir disoproxil fumarate (TDF) is a highly efficient treatment option for nucleos(t)ide analogue (NA) pre-treated patients with chronic hepatitis B virus (HBV) infection. Little is known about the reasons for persistent virus replication in some rare cases. As of today, no TDF resistance variants have been identified, but a possible linkage to Adefovir dipivoxil (ADV) resistance associated variants negatively influencing HBV-DNA suppression by TDF has been suspected, based on the similarity of the chemical structure. In this retrospective cohort study the dynamics of NA resistance variants in the HBV polymerase gene with focus on ADV resistance variants were assessed. For this, we have chosen a cohort including patients with multiple failures to treatment with different NAs. Thus, data of 18 patients with previous treatment failure to LAM and ADV was analysed, showing a persistent viremia (HBV-DNA >35 copies/mL) despite switch to TDF monotherapy (median HBV-DNA at month 12 3,5±0,8 (2,1-4,9) log10 copies/mL). Sequencing analysis was performed with ultra-deep pyrosequencing (UDPS) (Genome Sequencer FLX, 454 Life Science, Roche Diagnostic, Branford, CT), direct sequencing (TG) (TRUGENETM HBV Genotyping Kit, OpenGeneTM DNA Sequencing System, Siemens Healthcare Diagnostic, USA) and line probe assay (INNO-LiPA) (INNO-LiPa DRv2/v3, Innogenetics, Belgium). Using TDF monotherapy, a quantitative shift in favour to ADV resistance variants was observed in this cohort. The percentage of substitutions conferring resistance to ADV at baseline (BL) and at the time of the last sequencing endpoint (EP) of the HBV genome remained constant (BL 35%, 13/37, EP 36%, 9/25). The variants rtA181V and rtN236T were mostly selected, whereas rtA181T was not selected. The total amount of substitutions conferring resistance to Lamivudin (LAM) showed a strong decline, however remained the majority part of all NA resistance variants (BL 51% (19/37), EP 40% (10/25)). The percentage of ETV resistance variants increased slightly (BL 14% (5/37), EP 24% (6/25)). Known ADV, Lam and ETV resistance variants emerged in variable abundance (1,0-99,6%) of quasispecies during TDF therapy. A homogenization of HBV quasispecies took place. Especially mutations occurring in higher abundance (>20% of viral population) were mostly selected (BL 51% (19/37), EP 80% (20/25)). No new HBV variants with possible association to resistance against TDF were identified, but patients with ADV resistance variants showed the highest HBV-DNA level at month 12 of TDF therapy (median HBV-DNA 3,57±0,72 (2,14-3,96) log10 copies/mL, not significant). A negative influence of ADV resistance variants on viral suppression with TDF monotherapy may be assumed, however more long-term studies are needed to confirm the role of ADV resistance variants in TDF therapy. UDPS is a potent medium for detection, identification and quantification of dominant to low level variants in HBV-DNA. It is superior to direct sequencing and line probe assay in the detection of variants.
17

L'impact de la rugosité et du niveau d'eau sur les courants secondaires en rivière naturelle

Nicol, Patrick January 2015 (has links)
Ce mémoire traite de l’étude des écoulements en rivière naturelle. Plus précisément, l’impact de la granulométrie du lit des rivières, ainsi que de la profondeur d’eau sur la génération de courants secondaires y est analysé. Les courants secondaires sont causés par les effets de cisaillement ainsi que de la turbulence. Cependant, les structures d’écoulement telles que les courants secondaires peuvent être affectés par une multitude de facteurs et la majorité des recherches actuelles sur le domaine sont effectuées en laboratoire. Le but de ce projet est donc d’observer les courants secondaires en milieu naturel. Un vélocimètre acoustique Doppler (ADV) a été utilisé afin de déterminer les profils de vitesse in situ de différentes sections de rivières. Le lit de la rivière a été échantillonné afin d’en déterminer la granulométrie. Différentes bases théoriques sont explorées afin d’interpréter les profils de vitesse obtenus. La base théorique choisie est en mesure de décrire les processus physiques de la rivière naturelle ainsi que de permettre la caractérisation des phénomènes de courants secondaires. Selon les recherches effectuées, nous croyons que la granulométrie a un impact sur la structure des courants secondaire puisque ceux-ci dépendent de la rugosité du lit de la rivière. Or, la taille et la forme des grains du lit de la rivière ont certainement un impact sur la rugosité du fond de la rivière. Les effets anthropogéniques sur l’environnement, notamment sur les cours d’eau, sont de plus en plus reconnus. Afin de bien comprendre et mitiger les impacts dus à l’aménagement de notre environnement, il devient nécessaire de caractériser les processus physiques des rivières. Les courants secondaires sont liés à la résistance à l’écoulement des rivières et ont donc un impact considérable sur le comportement de celles-ci.
18

政黨電視競選廣告政治符號之研究:1991∼2000

羅時宜, Luo, Shih Yi Unknown Date (has links)
自1989年解除動員戡亂時期以來,台灣社會歷經快速的變遷,政治上,中央民代改選、二二八官方事件報告的出爐、廢國大、開放直轄市市長民選、第一次的台灣省長大規模地區的選舉、也是最後一次;1996年第一次的民選總統,李登輝高票當選,台灣本土意識的高漲,凍省,宋楚瑜出走國民黨獨自參選,直至2000年第二屆的總統副總統選舉,民進黨陳水扁的勝選,形成台灣有史以來第一次政黨輪替;本土化的興起、去中國化的爭議;而競選傳播上,報紙、電視競選廣告的相繼開放、候選人商品化、call in、政論節目的熱潮,選民與媒體多元聲音呈現,1989年至今的台灣變遷不僅快速、多元、更是驚人。 本研究使用內容分析法,探討1991年至2000年國民黨與民進黨具國家認同符號之電視競選廣告,其訊息策略以及政治符號的變化與趨勢;採用『國家』、『台灣』以及『中國』三面向為主要的切入點。 本文研究結果與發現歸納為下列十點: (一) 兩黨均以形象塑造傳達國家認同意識 (二) 民進黨擅長負面攻擊以形塑對手國家認同之『謬誤』 (三) 民進黨與『標榜自己愛台』訊息高度連結;但國民黨標榜『自己愛中華民國』,也同樣『愛台灣』 (四) 國民黨以『中華民國』與民進黨『台灣』認同的競爭 (五) 長期觀察國民黨國家認同模稜兩可 (六) 國民黨形塑多元民族認同,民進黨形塑單一民族認同 (七) 國民黨之『中國』符號為正向,民進黨之『中國』符號為負向 (八) 不同年代國家認同、土地認同、民族認同明顯不同,但歷年『愛台』訊息逐年上升 (九) 單一選區:隱性訴求獨立;複數選區:顯性訴求獨立 形象塑造類型在高層次選舉類型的高使用比例 (十) 長期觀察『台灣』符號成為主流
19

Le transport des sédiments, les structures sédimentaires et la stabilité dans les cours d'eau de morphologie en step-pool

Lamarre, Hélène January 2006 (has links)
Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.
20

Um estudo dos adv?rbios -mente sob a teoria da argumenta??o na l?ngua

Figueredo, F?bio Castilhos 16 January 2009 (has links)
Made available in DSpace on 2015-04-14T13:37:45Z (GMT). No. of bitstreams: 1 410384.pdf: 2652775 bytes, checksum: 411984a13fb6ac771bb4b52ce4a0ba76 (MD5) Previous issue date: 2009-01-16 / Neste trabalho de disserta??o de mestrado, com o objetivo de investigar uma instru??o que abranja as poss?veis ocorr?ncias para o uso de adv?rbios com sufixo mente, ser?o analisados diferentes textos, buscando entender seu sentido constru?do pelo locutor. Prop?e-se estas an?lises sob a perspectiva da Teoria da Argumenta??o na L?ngua (TAL). Essa teoria, proposta por Oswald Ducrot, observa que a argumenta??o est? na pr?pria l?ngua e isto lhe ? fun??o primordial. Baseada em preceitos estruturalistas, a Teoria da Argumenta??o na L?ngua vem sendo reformulada ao longo dos anos: foi desenvolvida inicialmente a Forma Standard (1? fase); em um segundo momento sofreu uma reestrutura??o, tornando-se a Forma Recente, em 1988 (2? fase); est? atualmente em sua 3? fase, a Teoria dos Blocos Sem?nticos (TBS), desenvolvida em parceria com Marion Carel. De acordo com a TBS, os encadeamentos argumentativos permitem entender os sentidos dos enunciados propostos, pois s?o um modo de abordar a argumenta??o atrav?s de dois segmentos determinados. Esses encadeamentos podem ser normativos (com conectores donc, DC, ou portanto) ou transgressivos (com conectores pourtant, PT, ou no entanto).

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