Spelling suggestions: "subject:"highly"" "subject:"lighly""
461 |
Caracterização das atividades para melhoria da adesão à TARV em serviços de saúde do SUS no Estado de São Paulo / HAART adherence support provided by HIV/AIDS outpatient clinics in Sao Paulo state, BrazilCaraciolo, Joselita Maria de Magalhães 08 July 2010 (has links)
Introdução: O emprego da terapia antirretroviral (TARV) proporcionou dramático impacto na mortalidade por aids e aumento na sobrevida. Entretanto, esse panorama depende da manutenção de altas taxas de adesão ao tratamento medicamentoso. A relevância da adesão tem sido reconhecida pelo Programa Nacional de DST e Aids desde o final dos anos 1990. Em que pese o destaque que o plano propositivo do Programa tem dado para a questão, ainda não dispõe de estudo atualizado sobre o número e tipo das atividades que estão em curso nos serviços. Este estudo teve por objetivo descrever as atividades de adesão em curso nos serviços de HIV/aids do Estado de São Paulo. Métodos: Foi enviado um questionário semi-estruturado para todos os 179 ambulatórios de HIV/aids do Estado, com perguntas sobre o tipo de serviço, pessoas sob TARV, formas e frequências de avaliação de adesão, atividades desenvolvidas (individuais, coletivas e para grupos específicos) e parcerias com organizações não governamentais. Para testar associação entre variáveis categóricas utilizou-se o teste Qui-quadrado de Pearson ou os testes exato de Fisher ou teste da razão de verossimilhanças, no nível de significância de p<0,05. A análise de agrupamento foi utilizada para investigar cada uma das associações de cada resposta com as variáveis: tamanho do município, tipo e tamanho das clínicas. Resultados: 136 dos ambulatório (76%) responderam à pesquisa. Quase todos (96,3%) relataram incentivar a adesão na prática clínica, predominantemente nas consultas de médicos (94,1%) e enfermeiros (67,6%). A maioria (78,7%) relatou avaliar a adesão através de registros da farmácia. Grupos (38,2%) e palestras (28,7%) foram as atividades de grupo mais conduzidas. A análise de agrupamento identificou três grupos de ambulatórios, dois deles muito distintos. Grupo 1 (27 ambulatórios) foi composto predominantemente por unidades de saúde básica, com menos de 100 pacientes, apresentaram a menor freqüência de avaliação da adesão e menos atividades individuais e em grupo. Grupo 2 (51 ambulatórios) foi constituído principalmente por ambulatórios especializados em HIV/aids, com mais de 500 pacientes, com maior freqüência de avaliação da adesão, maior participação de psicólogos, assistentes sociais e farmacêuticos e mais atividades individuais e em grupo. Grupo 3 (56 ambulatórios) foi composto em sua maioria por ambulatórios de especialidades e de médio porte, com a maioria das atividades semelhantes ao Grupo 2, exceto pela ausência de atividades para grupos específicos e menos envolvimento multidisciplinar. Conclusão: Dado o amplo reconhecimento da importância da adesão por parte das clínicas, ainda há poucas atividades específicas de adesão no Estado. As clínicas maiores e mais especializadas tendem a oferecer mais atividades individuais e em grupo, utilizando abordagens multidisciplinares. Maior atenção deve ser dada para a descentralização do atendimento às pessoas vivendo com HIV para assegurar cuidados de qualidade mais homogêneos em toda a rede ambulatorial. / Introduction: The use of antiretroviral therapy (HAART) has provided dramatic impact on AIDS mortality and improved survival. However, this scenario depends on maintaining high rates of adherence to HAART. The relevance of adherence has been recognized by the National STD/AIDS Program since the late 1990s. Despite the emphasis that the Program has given to the issue, there have been no study to date on the number and type of activities that are underway in the services. This study aimed to describe the HAART adherence support activities in Sao Paulo State HIV/AIDS clinics. Methods: We sent a semi structured questionnaire to all 179 HIV/AIDS clinics with questions about type of clinic, people on HAART, adherence assessment, activities (individual, group and for specific groups). To test association between categorical variables used the chi-square test or Fisher exact test or likelihood ratio test at a significance level of p <0.05. Cluster analysis was used to investigate each association of each answer with the variables: municipality size, type and size of the clinics. Results: 136 clinics (76%) answered the survey. Almost all (96.3%) reported encouraging adherence in clinical practice, particularly in the medical (94.1%) and nurse (67.6%) visits. Most (78,7%), reported assessing adherence by pharmaceutical records. Groups (38.2%) and lectures (28.7%) were the group activities most developed. Cluster analysis identified three groups of clinics; two of them were too different. Group 1 (27 clinics) was predominately composed by primary care clinics, with less than 100 patients, the lowest frequency of assessing adherence and fewer individual and group activities. Group 2 (51 clinics) predominately composed by HIV specialized clinics specializing, HIV/AIDS, with more than 500 patients, assessing adherence more frequently, with greater involvement of psychologists, social workers and pharmacists developing more individual and group activities. Group 3 (56 clinics) was predominately composed by medium size specialized clinics, with majority of activities similar to Group 2, except by the absence of activities to specific groups and less multidisciplinary involvement. Conclusion: Given the broad recognition of the adherence importance by the clinics, there are still few specific adherence activities. The larger and more specialized clinics tend to provide more individual and group activities, using multidisciplinary approaches. Greater attention should be given to the decentralization of care offered to people living with HIV to ensure more homogeneous quality care across the ambulatory network.
|
462 |
Alterações metabólicas associadas ao uso de medicamento antirretroviral em pessoas vivendo com HIV/AIDS: caracterização e desenvolvimento de algoritmos inteligentes aplicados à sua identificação e previsão / Metabolic changes associated with use of antiretroviral drugs in people living with HIV/AIDS: characterization and development of intelligent algorithms applied to identification and predictionCassenote, Alex Jones Flores 28 September 2017 (has links)
Introdução: com o advento da terapia antirretroviral altamente ativa observou-se um profundo impacto na história natural da infecção pelo HIV. O emprego de combinações terapêuticas contendo drogas de diferentes classes promove importante e sustentada supressão na replicação viral, levando à restauração imunológica e, consequentemente, eleva a sobrevida e a qualidade de vida das pessoas que vivem com HIV (PVH). Objetivos: a presente proposta visa analisar e caracterizar as alterações endocrinológicas e metabólicas associadas ao uso de medicamentos antirretrovirais em PVH e desenvolver algoritmos computacionais inteligentes visando sua identificação e previsão. Métodos: Trata-se de uma coorte ambidirecional de PVH, que iniciaram o uso de TARV entre 1º. de janeiro de 2003 e 31 de dezembro de 2013, com seguimento até dezembro de 2014. Recortes metodológicos foram empregados para, (1) avaliar a qualidade da base de dados, (2) estimar a densidade de incidência de alterações lipídicas e glicídicas na coorte, (3) identificar fatores associados à incidência de diabetes mellitus, e (4) desenvolver um algoritmo para predição de novos casos de diabetes mellitus. O primeiro recorte utilizou as estatísticas de kappa e coeficiente de correlação para medidas qualitativas e quantitativas de LTCD4+ e carga viral do HIV; o segundo usou estatísticas de incidência acumulada com intervalo de confiança de 95% com emprego do método de reamostragem de bootstrap e determinação da densidade de incidência por 1.000 pessoas ano usando, com cálculo de intervalo de confiança de 95% projetado com distribuição de Poisson; o terceiro utilizou a regressão de Cox e um modelo hierarquizado para estudar os fatores que influenciam no tempo até a ocorrência de diabetes mellitus e, o quarto, empregou metodologia para estruturação do sistema especialista fuzzy Sugeno, a curva ROC para estudar a acurácia do modelo comparada aos outros fatores. Resultados: 8.007 pacientes foram considerados elegíveis no primeiro recorte. A correlação geral observada para a menor contagem de LTCD4+ antes de TARV foi 0,970 (p < 0,001). Os coeficientes gerais de concordância para medidas qualitativas de contagens de LTCD4+ e para CV foram, respectivamente, 0,932 (p < 0,001) e -0,996 (p < 0,001). No caso do segundo e terceiro recorte, foram considerados 6.724 pacientes. As alterações metabólicas mais comuns foram a hipertrigliceridemia isolada 84,3 por 1000 pessoas-ano (IC95% 81,1-87,6), seguida por baixas concentrações de HDL-colesterol (HDL-c) 48,5 por 1.000 pessoas-ano (IC95% 46,1-51,1) e diabetes mellitus 17,3 por 1.000 pessoas-ano (IC95% 15,8-18,8). As variáveis mais fortemente associadas à incidência de DM foram idade 40 --| 50 anos HR 1,7 (IC95%1,4-2,1) e >= 50 anos HR 2,4 (IC95%1,9-3,1), obesidade HR 2,1 (IC95%1,6- 2,8), razão triglicerídeos:HDL-c >= 3,5 HR 1,8 (IC95%1,51-2,2) e hiperglicemia HR 2,6 (IC95%1,7-2,5). O sistema fuzzy Sugeno teve acurácia (AUC) de 0,811 (IC95% 0,772- 0,851). Conclusões: as análises indicaram alta correlação (quantitativa) e concordância (qualitativa) entre Coorte Brasil de HIV/AIDS e o sistema informatizado SISCEL; diabetes mellitus e outros alterações metabólicas foram comuns na coorte Brasil de HIV/AIDS; a exposição a estavudina (d4T) mostrou-se fator de risco para diabetes mellitus; e o algoritmo linguístico fuzzy foi capaz de predizer novos casos de diabetes mellitus com acurácia superior à dos fatores de risco convencionais / Introduction: with the advent of highly active antiretroviral therapy (ART) a profound impact on the natural history of HIV infection was observed. The use of combined therapeutic regimens containing antiretroviral drugs of different classes promotes important and sustained suppression of viral replication, leading to immune restauration and increases survival and the quality of life of people living with HIV (PLWH). Objectives: This study aims to analyze and characterize the endocrinological and metabolic changes associated with the use of antiretroviral drugs in PLWH and to develop intelligent computational algorithms for their identification and prediction. Methods: this is an ambidirectional cohort of PLWH, who were started on ART between January 1, 2003 and December 31, 2013, with follow-up through December 31, 2014. Our methodological approaches aimed at (1) assessing the quality of the database, (2) estimating the incidence density of lipid and glucose changes, (3) identifying factors associated with incident diabetes mellitus, and (4) developing an algorithm for prediction of incident diabetes mellitus. For the first approach we used the kappa and correlation coefficient statistics for qualitative and quantitative measures of LTCD4 + and HIV viral load (VL); for the second we used cumulative incidence statistics with a 95% confidence interval, by means of bootstrap resampling and calculation of incidence density per 1,000 person-years with a 95% confidence interval based on the Poisson distribution; for the third we used Cox regression and a hierarchical model to investigate factors that influenced time until incidence of diabetes mellitus and, for the fourth, we used in addition to structuring the Sugeno fuzzy expert system, the ROC curve to assess the accuracy of the model as compared to other factors. Results: 8,007 patients were considered eligible for the first approach; overall observed correlation for the lower LTCD4+ count before ART was 0.970 (p < 0.001) and the general agreement coefficient for qualitative measures of LTCD4 + counts and HIV VL were 0.932 (p < 0.001) and -0.996 (p < 0.001), respectively. For the second and third approaches, 6,724 patients were considered. The most common metabolic alterations were hypertriglyceridemia, 84.3 per 1,000 person-years (95% CI 81.1-87.6), followed by low HDL-cholesterol (HDL-c) 48.5 per 1,000 person-years (95% CI 46.1-51.1) and diabetes mellitus 17.3 per 1,000 person-years (95% CI 15.8-18.8). Most strongly associated factors with incident DM were age 40 - | 50 years HR 1.7 (95%CI 1.4-2.1) and age >= 50 years HR 2.4 (95%CI 1.9-3.1), obesity HR 2.1 (95% CI 1.6-2.8), triglyceride:HDL-c ratio >= 3.5 HR 1.8 (95% CI 1.51-2.2) and hyperglycemia HR 2.6 (95% CI 1.7-2.5). The Sugeno fuzzy system had an accuracy (AUC) of 0.811 (IC95% 0,772-0,851). Conclusions: the analyses indicated a high correlation (quantitative) and agreement (qualitative) between Brazil\'s HIV/AIDS Cohort Study and SISCEL databases; diabetes mellitus and other metabolic alterations were common in the Brazil cohort of HIV / AIDS; exposure to stavudine (d4T) was a risk factor for incident diabetes mellitus; and the fuzzy linguistic algorithm could predict new cases of diabetes mellitus with a higher accuracy than conventional risk factors
|
463 |
Grau de saturação de fósforo em solos tropicais altamente intemperizados / Degree of phosphorus saturation in highly weathered tropical soilsCampos, Murilo de 28 August 2014 (has links)
O fósforo (P) é um elemento essencial para o desenvolvimento das plantas e precisa ser suprido em quantidades adequadas para obtenção de altas produtividades das culturas agrícolas. O conteúdo de P no solo e consequente perda deste para as águas superficiais são importantes fatores relacionados a eutrofização de ambientes aquáticos. Nesse trabalho foi obtido o Grau de saturação de P (GSP) em 29 solos tropicais altamente intemperizados e seus valores foram correlacionados com atributos químicos, físicos e mineralógicos dos solos. Antes de calcular o GSP, foram determinados parâmetros como Índice de sorção de P (ISP), Capacidade de sorção de P (CSP) e fator de escala ?. Os solos foram divididos em grupos, e os solos de cada grupo receberam doses diferenciadas de P para obtenção do ISP devido a variação na capacidade de adsorção,. As doses utilizadas foram 200, 500, 1000, 1500 e 3000 mg L-1 de P. Os períodos de reação avaliados foram 1, 3, 7, 21, 42, e 84 d. A porcentagem média de P adsorvida no final do período de contato (84 d) variou de 23% a 49% do P adicionado inicialmente. Os Latossolos, os Gleissolos e os Nitossolos apresentaram os maiores valores de ISP, enquanto os Argissolos e os Neossolos tiveram os menores valores. Os maiores valores foram encontrados nos solos com elevados teores de argila, matéria orgânica (MO) e óxidos cristalinos e mal cristalizados de Fe e de Al. O ISP foi maior no final do período de contato (84 d), o que realça a influência do tempo na adsorção do P. O fator de escala ? e o GSP foram calculados em todos os períodos de contato. Os valores de ? aumentaram e os de GSP diminuíram em função do tempo devido à maior interação do P com o solo. Os menores valores de GSP foram obtidos nos solos com alta capacidade de adsorção de P, ao passo que os maiores valores de GSP foram dos solos com menor capacidade de adsorção. O maior GSP (31%) foi obtido no Neossolo Litólico. O valor limite de GSP considerado nesse trabalho foi 23%. As relações entre GSP, CSP, ISP e alguns atributos dos solos foram abordadas por meio da análise de componentes principais. Com o agrupamento de todos os solos, os teores de óxido mal cristalizado de alumínio (Alox), argila, MO e de óxido cristalino de alumínio (AlDCB) foram os que melhor se correlacionaram com o ISP e a CSP. Avaliando somente os Latossolos, os teores de argila e de óxidos cristalinos e mal cristalizados de ferro e de alumínio (Feox, FeDCB, AlDCB e Alox) representaram os componentes principais ligados à adsorção de P. Com a adição dos demais solos, os teores de fósforo extraídos por solução ácida de oxalato de amônio (Pox), Alox, argila e MO formaram os componentes principais para ISP e CSP. O GSP não correlacionou significativamente com nenhum dos atributos. A partir do dendograma, os solos foram separados em dois grupos. O grupo I foi composto por solos pouco suscetíveis a perdas de P em função dos valores de CSP e de GSP. Já o grupo II reuniu os solos mais suscetíveis. Equações de regressão linear múltipla foram utilizadas na predição do ISP e CSP e duas delas obtiveram um alto coeficiente de determinação (R2 = 0,94 para ambas), podendo ser utilizadas para estimar a CSP e o ISP nos solos. / Phosphorus (P) is an essential element for plant growth and must be supplied in adequate quantities to the growers obtain high yields of agricultural crops. The content of P in the soil and its loss to surface water are important factors related to eutrophication of aquatic environments. In this study, we obtained the degree of P saturation (DPS) in 29 highly weathered tropical soils, and their values were correlated with chemical, physical and mineralogical soil attributes. Before calculating the DPS, parameters such as P sorption index (PSI), P sorption capacity (PSC) and the scaling factor ? were obtained. Because of the variation in the soils` ability to adsorb P, they were divided into groups, and the soils from each group received different P rates for obtaining the PSI. The rates were 200, 500, 1000, 1500 and 3000 mg L-1 of P. The periods of reaction evaluated were 1, 3, 7, 21, 42, and 84 d. The average percentage of P adsorbed at the end of the contact period (84 d) ranged from 23% to 49% of P added initially. The Oxisols, the Gleysols and the Alfisols showed the highest values of PSI, while the Ultisols and Entisols had the lowest values. The highest values were found in soils with high clay contents of organic matter (OM) and crystalline and poorly crystalline Fe and Al oxides. ISP was higher at the end of the contact period (84 d), which highlights the influence of weathering on P adsorption by soils. The scale factor ? and the DPS were calculated for all periods of contact. The values of ? increased while DPS decreased as a function of time because of the greater interaction of P with the soil. The lowest values of GSP were obtained in soils with high P adsorption capacity, whereas the highest values of DPS were obtained in soils with lower adsorption capacity. The largest DPS (31%) was obtained in the Typic Udorthent. The limit value of DPS considered in this study was 23%. Correlations between DPS, PSC, PSI and some soil attributes were addressed by principal component analysis. By grouping all soils, the levels of poorly crystalline aluminum (Alox), clay, OM and crystalline aluminum oxide (AlDCB) were the atributes best correlated with both PSI and PSC. When evaluating only the Oxisols, it was observed that the contents of clay and crystalline and poorly crystalline iron and aluminum oxides (Feox, FeDCB, AlDCB and Alox) represented the main components related to the adsorption of P. When the other soils were added, the contents of P extracted by an acid ammonium oxalate solution (Pox), Alox, MO and clay composed the main components for PSC and PSI. DPS did not correlate significantly with any of the attributes. From the dendrogram, the soils were separated into two groups: group I, consisted of soils with little susceptiblity to P loss based on the PSC and DPS, and group II, that met the more susceptible soils for P losses. Multiple linear regression equations were used to predict PSI and PSC, and two of them had a high determination coefficient (R2 = 0.94 for both). So, they can be used to estimate the PSC and PSI at the soils.
|
464 |
Spektroskopische Untersuchungen hochgeladener Krypton-Ionen im Röntgen-BereichFuchs, Tino 23 June 2000 (has links)
Diese Dissertation widmet sich der spektroskopischen Untersuchung verschiedener Aspekte der Strahlungsemis\-sion hochgeladener Krypton-Ionen mit Relevanz für die Fusionsforschung. Die Experimente hierzu erfolgten an der Berliner Elektronenstrahl-Ionenfalle (EBIT). Der erste Teil der Arbeit hat die Messung kanalspezifischer Wirkungsquerschnitte für die dielektronische Rekombination (DR) der KL$n$-Resonanzserie ($n$=2, \ldots, 5) von Helium- bis Kohlenstoff-ähnlichen Kr-Ionen ($\mbox{Kr}^{(34\, \ldots\,30)+}$) zum Inhalt, die relativ zum Wirkungsquerschnitt der nichtresonanten strahlenden Rekombination (RR) bestimmt wurden. Die Anpassung der Anregungskurven durch eine Modellfunktion aus berechneten Resonanzst ärken ermöglichte den Vergleich mit theoretischen DR-Wirkungsquerschnitten. Es zeigt sich, dass Vorhersagen des HULLAC-Atomstrukturcodes für die Resonanz\-st"ar\-ken der Kr-Ionen durch das Experiment innerhalb der Me"sunsicherheiten best"a\-tigt werden. Darüber hinaus wurde auch die Relaxation der einfach angeregten Ionen nach erfolgtem DR-Stabilisierungsübergang analysiert. Die zur Auswertung der DR-Anre\-gungs\-kurven angewandte Technik eröffnet gleichzeitig eine spektroskopische Methode für die Bestimmung der relativen Konzentration hochgeladener Ionen in EBIT. Die Messung der Strahlungskühlungsrate von Krypton, die den zweiten inhaltlichen Schwerpunkt der Dissertation darstellt, wäre ohne diese in situ Diagnostik der Ladungbilanz nicht möglich gewesen. Hier wurde die Ionenfalle so eingestellt, dass sich eine Ladungsverteilung herausbildet, die dem Ionisationsgleichgewicht eines Plasmas bei einer Temperatur von etwa $5\;\mbox{keV}$ entspricht. Die Bestimmung der Strahlungsk"uhlungsrate profitierte von dem Potential einer EBIT, die gefangenen Ionen mit Elektronenenergien aus einem weiten Bereich abzutasten und einzelne Strahlunsprozesse selektiv anzuregen. Die Röntgenemission verschiedener Strahlungskanäle, wie Bremsstrahlung, strahlende Rekombination, dielektronische Rekombination und Linienstrahlung nach direkter Anregung wurde separat erfaßt. Hieraus konnten erstmals kanalspezifische Strahlungskühlungsraten bestimmt werden. Es stellte sich heraus, dass der dominante Beitrag zur Strahlungskühlungsrate durch die direkt angeregte Linienstr ahlung des L-Schalen-Spektrums zustande kommt, die etwa 75\% der gesamten Verlustleistung ausmacht. Beim Vergleich der totalen Strahlungsverlustleistung mit Vorhersagen der Theorie sind Abweichungen festzustellen. Die berechneten Werte sind je nach Modell um einen Faktor 1.5 - 2.0 kleiner als das Ergebnis der Messung. Dieser Unterschied liegt außerhalb der experimentellen Unsicherheit von maximal 30\%. / This thesis deals with the spectroscopic investigation of various aspects of the x-ray emission of highly charged krypton ions with relevance for fusion research. The experiments have been performed at the Berlin electron beam ion trap (EBIT). One part of the work was devoted to the measurement of channel-specific cross sections for dielectronic recombination (DR) via the KL$n$ ($n$=2, \ldots, 5) resonance series of He- to C-like krypton ions ($\mbox{Kr}^{(34\, \ldots\,30)+}$). The DR cross sections were determined relative to the cross section for non-resonant radiative recombination (RR). A fit procedure was used to compare the measured data with theoretical calculations. Predictions of the HULLAC atomic structure code are confirmed within the experimental uncertainties. Additionally, the radiative relaxation mechanism following the stabilizing transition in the DR process was analyzed. The approach used to obtain the DR excitation function opens up a spectroscopic method to determine the relative abundance of the highly charged ions in the trap. This in situ diagnostic of the charge state balance allowed for the measurement of the radiative cooling rates of krypton being the second focus of the thesis. For this purpose EBIT was tuned to a charge state distribution approaching the ionization balance of a plasma at a temperature of about $5\;\mbox{keV}$. EBIT's capability to sample a wide range of electron-beam energies and distinguish between different radiation channels was utilized to determine the cooling rate. The x-ray emission from the various plasma radiation channels, like bremsstrahlung, radiative recombination, dielectronic recombination, and line radiation following electron-impact excitation was analyzed. For the first time, channel-specific cooling rates could be obtained from these data. It was found, that the dominant contribution to the cooling rate is made up by the directly excited x-rays of the L-shell spectra of krypton, producing more than 75\% of the total radiation loss. A difference with theoretical calculations is noted for the total cooling rate. The predicted values are lower by a factor of 1.5 - 2.0, depending on the theoretical model. This discrepancy is clearly beyond the experimental uncertainty of 30\% at maximum.
|
465 |
Modelos constitutivos para materiais hiperelásticos: estudo e implementação computacional / Constitutive models for hyperelastic materials: study and computational implementationPascon, João Paulo 01 April 2008 (has links)
O objetivo central deste trabalho é implementar modelos constitutivos hiperelásticos não lineares em um código computacional que faz análise não linear geométrica de cascas. São necessários, para este propósito, conceitos sobre álgebras linear e tensorial, cinemática, deformação, tensão, balanços, princípios variacionais, métodos numéricos e hiperelasticidade. Tal programa usa a formulação Lagrangiana posicional, o método dos elementos finitos, o princípio dos trabalhos virtuais e o método iterativo de Newton-Raphson para solução das equações não lineares. O elemento finito de casca possui dez nós, sete parâmetros por nó e variação linear da deformação ao longo da espessura. Para dedução dos novos modelos usou-se a decomposição multiplicativa do gradiente da função mudança de configuração, o tensor deformação de Green-Lagrange e o tensor da tensão de Piola-Kirchhoff de segunda espécie. O código desenvolvido foi usado em simulações de diversos exemplos e apresentou boa precisão na análise mecânica de polímeros naturais altamente deformáveis. A ocorrência do fenômeno travamento não se manifestou nas análises realizadas. A presente pesquisa confirmou outros trabalhos, reforçou a necessidade de se usar modelos hiperelásticos não lineares para simular o comportamento mecânico de polímeros naturais e apresentou resultados condizentes com dados experimentais existentes na literatura científica e às respectivas soluções analíticas. / The main objective of this work is to implement nonlinear hyperelastic constitutive models in a computational code of geometrically nonlinear analysis of shells. For this purpose, concepts of linear and tensor algebras, kinematics, strain, stress, balances, variational principles, numerical methods and hyperelasticity are necessary. Such program uses the positional Lagrangian formulation, the finite element method, the principle of virtual work and the iterative method of Newton-Raphson for the solution of the nonlinear equations. The shell finite element has ten nodes, seven parameters per node and presents linear variation of the strain along the thickness. To achieve the new constitutive models the multiplicative decomposition of the deformation gradient, the Green-Lagrange strain tensor and the second Piola-Kirchhoff stress tensor are used. The developed code is tested for simulations of various examples and presents good accuracy in the mechanical analysis of highly deformable natural rubber. The locking phenomena didn\'t appear in the proposed analysis. The present research confirms other works, corroborates the need of using nonlinear hyperelastic models to simulate the mechanical behavior of natural rubber and presents suitable results when compared to existent experimental data of the scientific literature and to the respective analytical solutions.
|
466 |
Modélisation, conception et commande de robots manipulateurs flexibles. Application au lancement et à la récupération de drones à voilure fixe depuis un navire faisant route / Modeling, design and control of flexible robot manipulators - Applied to UAV launch and recovery from a moving shipSolatges, Thomas 12 July 2018 (has links)
Les robots manipulateurs sont généralement des machines rigides, conçues pour que leurflexibilité ne perturbe pas leurs mouvements. En effet, des flexibilités mécaniques importantesdans la structure d’un système introduisent des degrés de liberté supplémentaires dont le comportementest complexe et difficile à maîtriser. Cependant, la réduction de la masse d’un systèmeest bénéfique du point de vue des coûts, de la performance énergétique, de la sécurité et des performancesdynamiques. Afin de faciliter l’accès aux nombreux avantages d’une structure légèremalgré la présence de fortes flexibilités, cette thèse porte sur la modélisation, la conception et lacommande de robots manipulateurs flexibles. Elle est motivée par le projet YAKA, dont l’applicationest le lancement et la récupération de drones à voilure fixe depuis un navire faisant route.Cette application nécessite une importante dynamique sur un vaste espace de travail, bien au-delàdes spécifications des robots rigides classiques. Les outils de modélisation, de conception et decommande proposés prennent en compte la flexibilité des segments et des articulations, pour unnombre quelconque de degrés de liberté et de segments flexibles. Le modèle dynamique flexibleest obtenu par le formalisme de Lagrange, les poutres flexibles sont représentées par le modèled’Euler-Bernoulli. Le schéma de commande proposé se décompose en une inversion de modèledynamique rigide et un bloc de précommande par Input Shaping adapté aux robots manipulateursflexibles. Les outils de conception proposés permettent de baser le processus de conceptionsur des performances prédites du système complet muni de ses actionneurs et de son contrôleuravec une simulation réaliste. Les validations expérimentales effectuées sur le robot YAKA permettentde valider la pertinence de la démarche suivie. Les résultats du projet YAKA confirment lafaisabilité de la mise en oeuvre d’un robot flexible de grande envergure et à forte dynamique dansun contexte industriel, en particulier pour le lancement et la récupération d’un drone à voilurefixe depuis un navire faisant route. / Robot manipulators are generally stiff machines, designed in a way that flexibility does not affecttheir movements. Indeed, significant flexibility introduces additional degrees of freedom witha complex behavior. However, reducing the mass of a system allows for costs, performance, andsafety improvements. In order to allow those benefits despite important flexibility, this thesis focuseson modeling, design and control of flexible robot manipulators. It is motivated by the YAKAproject, which aims at developing a robot to launch and recover fixed wing UAVs from a movingship. It implies reaching very high dynamics on a large workspace, way beyond the specificationsof common rigid robots. The proposed tools for modeling, design and control allow for taking intoaccount both joint and link flexibility, for any number of degrees of freedom and flexible links.The elastodynamic model is obtained with Lagrange principle, each flexible link being representedwith one ormany Euler-Bernouilli beams. The proposed control scheme uses a nonlinear rigiddynamic inversion and extends classical Input Shaping techniques to flexible robot manipulators.The proposed design tools allow for performance prediction of the system including its actuatorsand controllers thanks to a realistic simulation. Experiments conducted with the YAKA robot validatedthe proposed approach. The results of the YAKA project confirmed the feasibility of usinga large scale, highly dynamic flexible robot in an industrial context, in particular for UAVs launchand recovery operations from amoving ship.
|
467 |
Avaliação do questionário WebAd-Q como ferramenta de monitoramento da adesão ao tratamento antirretroviral nos serviços do SUS / Evaluation of the questionnaire WebAd-Q as a tool to monitor adherence to antiretroviral therapy in Brazilian public health care servicesVale, Felipe Campos do 26 November 2014 (has links)
Objetivo: Apresentar o desenvolvimento, a validação e a aplicação do Questionário Qualiaids de Monitoramento da Adesão ao Tratamento Antirretroviral ou Web Adherence Qualiaids Questionnaire (WebAd-Q), um instrumento de autorrelato para monitorar a adesão de pacientes sob tratamento em serviços públicos de HIV no Brasil. Métodos: O WebAd-Q contém três perguntas sobre horário, medicamentos e doses tomadas na última semana. Foi construído a partir de entrevistas e grupos focais com 38 pacientes. Após pilotada, sua versão eletrônica teve a validade testada em estudo para o qual foram convidados 90 pacientes maiores de 18 anos, sob terapia antirretroviral (TARV) há pelo menos três meses. Os pacientes foram orientados a utilizar frascos com monitoramento eletrônico por 60 dias. O questionário foi respondido no sexagésimo dia por duas vezes, com intervalo mínimo de uma hora. A adesão foi também mensurada por contagem de comprimidos e entrevista de autorrelato. A carga viral de cada paciente foi obtida nos registros do serviço. Analisou-se a concordância entre as respostas ao WebAd-Q, a correlação com carga viral e a associação com outras medidas de adesão. Após o estudo de validação, o WebAd-Q foi empregado em uma pesquisa nacional para medir a adesão dos pacientes à TARV nos serviços de HIV/aids do SUS. Foram sorteados 55 serviços de diversas características institucionais de todo o país. Após o convite aos serviços, o WebAd-Q foi instalado em computadores e respondido por pacientes eleitos sistematicamente conforme chegada aos serviços. Resultados: Entre os 90 pacientes convidados, 75 (83,3%) responderam o WebAd-Q. Não foram relatadas dificuldades em responder ao questionário. O tempo médio de resposta foi 5,8 minutos. O conjunto das três questões do WebAd-Q obteve uma concordância de 88%, com Kappa de 0,74 (IC95% 0,56 - 0,92, p < 0,0001). A correlação da escala de não adesão do WebAd-Q e a carga viral foi de 0,42 (p < 0,0001). A questão 2 (medicamentos) teve o melhor desempenho, associando-se com todas as outras medidas, com exceção da contagem de comprimidos para 60 dias. Na aplicação nacional, ao todo 2424 pacientes responderam ao WebAd-Q. Todos conseguiram completar o questionário sem dificuldades. O sistema eletrônico apresentou poucas falhas e o questionário foi bem recebido por pacientes e pelos profissionais dos serviços. Conclusões: O WebAd-Q atendeu a todos os quesitos considerados relevantes para a validação de questionários, foi bem entendido por pacientes, obteve uma boa concordância, apresentou uma correlação moderada com a carga viral e associação com as medidas concorrentes. Portanto, mostrou propriedades satisfatórias para o monitoramento da adesão em serviços de HIV / Objective: To present the development, validation and application of the Web Adherence Qualiaids Questionnaire (WebAd-Q), a tool to monitor self-reported adherence among patients receiving care in Brazilian public HIV healthcare facilities. Methods: The WebAd-Q contains three questions regarding dosing time, drugs and doses taken on the last week. It was developed through interviews and focus groups with 38 patients. After piloted, the electronic version was submitted to statistical validity with 90 adult patients receiving antiretroviral therapy for at least three months. Patients were instructed to use event monitoring bottles for 60 days. The WebAd-Q was completed at the 60th day. Adherence was also measured by pill counting and self-report interview. Viral load was obtained from patient records. Concordance was analyzed, as well as correlations with viral load and associations between adherence measures and the WebAd-Q. After the validation study, the WebAd-Q was submitted to a national survey to measure adherence to antiretroviral therapy in HIV facilities from the Brazilian health system. Fifty-five sites were selected among different institutional characteristics. At these sites, the WebAd-Q was installed in computers and completed by patients chosen systematically as they arrived at the facilities. Results: Among 90 patients invited to participate in the study, 75 (83.3%) completed the WebAd-Q. No difficulties to answer the questionnaire were reported. Mean answer time for the WebAd-Q was 5.8 minutes. The three questions presented a concordance of 88% and Kappa of 0.74 (IC95% 0.56 - 0.92, p < 0.0001). The correlation obtained with viral load was 0.42 (p < 0.0001). The question regarding drugs taken had a better performance, with significant associations with all other adherence measures, except for pill counting for 60 days. At the application study, 2424 patients completed the questionnaire without difficulties. The electronic system presented few glitches and the questionnaire was welcomed by patients and healthcare professionals. Conclusions: The WebAd-Q complied with all aspects considered relevant for the validation of self-reported questionnaires. It was well understood by patients and presented a good concordance, moderate correlation with viral load and association when compared to concurrent adherence measures. Therefore, the questionnaire adequate proprieties to monitor adherence in HIV healthcare facilities
|
468 |
Comportamento eletroquímico de nitrofuranos em eletrodos de diamante dopado com boro-modelo para o mecanismo de ação de nitrocompostos com atividades antichagásica / Electrochemical behaviour of nitrofurans on highly boron doped diamond Electrodes-model for the action mechanism of the nitrocompounds with antichagasic activityJulião, Murilo Sérgio da Silva 09 March 2007 (has links)
O comportamento eletroquímico do Nitrofural (NFZ) foi estudado em eletrodos de pasta de carbono, carbono vítreo e diamante altamente dopado com boro (EDADB) em tampão Britton-Robinson (BR) usando a voltametria cíclica. Os melhores resultados foram obtidos em EDADB, no qual foi possível estabilizar o radical aniônico (R-NO2•‾) em meio predominantemente aquoso, como também estudar a interação entre o R-NO2•‾ a glutationa (GSH), a L-cisteína (Cis) e o O2. Somente na superfície do EDADB, o NFZ foi diretamente reduzido à amina derivada (R-NH2) no intervalo de 2,02 ≤ pH ≤ 4,03 num processo envolvendo seis (6,0 ± 0,4) elétrons e seis prótons. Na faixa de 7,04 ≤ pH ≤ 12 e meio predominantemente aquoso, a etapa de redução desmembrou-se em seus dois componentes: a redução do NFZ ao nitro radical aniônico (R-NO2•‾) e posterior redução deste ao derivado hidroxilamínico (R-NHOH) em processos envolvendo um e três (3,1 ± 0,1) elétrons respectivamente. No sentido anódico da varredura dos voltamogramas cíclicos registrados em pH 8,06, observou-se a oxidação da hidroxilamina ao derivado nitroso (R-NO), num processo envolvendo 2 (1,7 ± 0,2) elétrons e 2 prótons. Além disto, um novo pico de oxidação não relatado na literatura em qualquer material de eletrodo foi detectado em pH ≤ 8,06, que foi observado não importando se o NFZ havia sido previamente reduzido ou não. O cálculo do número de elétrons, n, envolvido em cada etapa eletroquímica foi satisfatoriamente estimado usando-se a equação de Randles-Sevcik. Na presença de [Tiol] ≤ 3,7 x 10-2 mol L-1, o NFZ é reduzido ao aduto R-NO-Tiol em um processo eletroquímico envolvendo dois elétrons e dois prótons. Por outro lado, o O2 atua como um aceptor de R-NO2•‾ e a constante de equilíbrio para a transferência monoeletrônica do R-NO2•‾ para o oxigênio, kO2, é 60. O processo é catalítico e pode ser utilizado para a determinação analítica de NFZ na faixa de 9,9 x 10-7 ≤ [NFZ] ≤ 1,1 x 10-5 mol L-1 em pH 8,06, com sensibilidade amperométrica de 2,2 x 104 µA L mol-1 cm-2 e limite de detecção de 3,4 x 10-7 mol L-1. Os parâmetros analíticos foram similares aqueles obtidos em pH 4,0 usando a redução direta do NFZ à respectiva amina derivada em um processo envolvendo seis elétrons e seis prótons. A caracterização do processo de redução total do NFZ em meio aquoso e velocidades de varredura relativamente baixas, 100 mV s-1, somente foi possível devido às características superficiais intrínsecas do EDADB, o qual estabiliza o radical livre, R-NO2•‾, permitindo trabalhar numa ampla janela de potencial, sem haver perda do sinal de oxidação do R-NO2•‾. / The electrochemical behaviour of nitrofural (NFZ) at carbon paste, glassy carbon and highly boron doped diamond (HBDD) electrodes was studied in Britton- Robinson (BR) buffer using cyclic voltammetry. The best results were obtained at HBDD electrodes, in which it was possible to stabilize the radical anion (R-NO2•‾) in predominantly aqueous medium as well as to study the interaction between the radical anion and glutathione (GSH), L-cysteine (Cys), and O2. Only at HBDD surface, NFZ was directly reduced to the amine derivative (R-NH2) in the pH range of 2.02 to 4.03 in a process involving six (6.0 ± 0.4) electrons and six protons. In the range of pH 7.04 to 12 and, predominantly aqueous medium, the reduction step split into its two components: the reduction of NFZ to the nitro radical anion (R-NO2•‾) and reduction of R-NO2•‾ to hydroxylamine derivative (R--NHOH) in processes involving one and three (3.1 ± 0.1) electrons respectively. On the anodic scan of the cyclic voltammograms and at pH 8.06, it was observed the oxidation of the hydroxylamine to the nitroso derivative (R-NO), in a process involving 2 (1.7 ± 0.2) electrons and 2 protons. In addition and unreported in the literature on any electrode material, was the detection of a new oxidation peak at pH > 8.06, which was observed regardless of whether NFZ had been previously reduced or not. The calculation of n, number of electrons, involved in each electrochemical step was satisfactorily accomplished using the Randles-Sevcik equation. In presence of [Thiol] ≤ 3.7 x 10-2 mol L-1 NFZ is directly reduced to R-NO---Thiol adducts in an electrochemical process involving two electrons and two protons. On the other side, O2 acts as a R-NO2•‾ scavenger and the equilibrium constant for the electron transfer from nitro radical to oxygen, kO2, is 60. The process is catalytic and can be used to the analytical determination of NFZ in the range of 9.9 x 10-7 ≤ [NFZ] ≤ 1.1 x 10-5 mol L-1 at pH 8.0, with amperometric sensitivity of 2.2 x 104 µA L mol-1 cm-2 and detection limit of 3.4 x 10-7 mol L-1. The analytical parameters were similar to those obtained at pH 4.03 using the direct reduction of NFZ to the respective amine derivative in a process involving six electrons and six protons. The characterization of NFZ global reduction process in aqueous medium and at relative low scan rate, 100 mVs-1, was only possible due the intrinsic superficial characteristics of the HBDD electrode, which stabilize the R-NO2•‾ free radical, allowing to work in a large potential window, without losing the R-NO2•‾ oxidation signal.
|
469 |
Search for the supersymmetric partner of the top quark and measurements of cluster properties in the silicon strip tracker of the CMS experiment at Run 2 / Recherche du partenaire supersymétrique du quark top et mesure des propriétés des dépôts dans le trajectographe à pistes de silicium de l’expérience CMS au Run 2Jansova, Markéta 27 September 2018 (has links)
Cette thèse présente trois études différentes basées sur les données de CMS du Run 2. Les deux premières sont des mesures des propriétés des amas dans le trajectographe à pistes de silicium de CMS, liées respectivement aux particules hautement ionisantes (HIP) et au partage de charge entre les pistes voisines (également appelé diaphonie). Le dernier sujet abordé dans ce document est la recherche du partenaire supersymétrique du quark top, appelé stop. Une augmentation de l’inefficacité de reconstruction des hits dans le trajectographe à pistes de silicium de CMS a été observée au cours des années 2015 et 2016. Les particules hautement ionisantes ont été identifiées comme une cause possible de ces inefficacités. Cette thèse apporte des résultats qualitatifs et quantitatifs sur l’effet HIP et sa probabilité. Le HIP n’était pas la source la plus importante d’inefficacité et, une fois la source identifiée et corrigée, les nouvelles données révèlent qu’après cette correction, le HIP représente à présent la principale source d’inefficacité. La seconde étude présentée porte sur les conditions utilisées dans la simulation du trajectographe par CMS afin de fournir des résultats réalistes. Ces conditions changent avec les conditions de fonctionnement du trajectographe et évoluent avec le vieillissement du trajectographe résultant des dommages causés par le rayonnement. Nous avons constaté que les paramètres de diaphonie obsolètes avaient une grande incidence sur la forme de l’amas. Dans cette thèse, les paramètres ont été réévalués et il a été confirmé que les nouveaux paramètres améliorent grandement l’accord des amas entre données et simulation. La dernière partie décrit en profondeur la recherche de stop en utilisant les données collectées en 2016 (correspondant à ∫L = 35.9 fb−1) avec un lepton dans l’état final. Aucun excès n’a été observé par rapport aux prédictions attendues par le modèle standard et les résultats ont été interprétés en terme de limites d’exclusion sur des modèles simplifiés. / This thesis presents three different studies based on the CMS Run 2 data. The first two are measurements of the cluster properties in the CMS silicon strip tracker related respectively to the highly ionizing particles (HIP) and the charge sharing among neighboring strips (also known as cross talk). The last topic discussed in this document is the search for the supersymmetric partner of the top quark, called the stop. An increase in the hit inefficiency of the CMS silicon strip tracker was observed during the years 2015 and 2016. The highly ionizing particles were identified as a possible cause of these inefficiencies. This thesis brings qualitative and quantitative results on the HIP effect and its probability. The HIP was found not to be the largest source of inefficiency at that time and once the source was identified and fixed, the new data revealed that after this fix the HIP now represents the major source of the hit inefficiency. The second study presented in this thesis focuses on the conditions plugged in CMS tracker simulation in order to provide realistic results. These conditions change with the tracker operating conditions and also evolve with tracker ageing resulting from the radiation damage. We identified that the outdated cross talk parameters largely impact the cluster width and seed charge. In this thesis the parameters were remeasured and it was confirmed that the new parameters largely improve the agreement of clusters between data and simulation. The last part describes deeply the stop analysis using data recorded in 2016 (corresponding to ∫L =35.9 fb−1) with single lepton in the final state. No excess was observed in the full 2016 data (∫L = 35.9 fb−1) with respect to the standard model background predictions and therefore exclusion limits in terms of simplified model spectra were derived.
|
470 |
Ebullition nucléée sur des surfaces ultra-polies : Influence de la topographie et du revêtement sur le phénomène de nucléation / Nucleate boiling on ultra-smooth surfaces : Influence of topography and coating on the nucleation phenomenonAl Masri, Mostafa 07 July 2017 (has links)
Une étude expérimentale est menée afin de comprendre le phénomène de nucléation lors de l'ébullition. Cette étude est menée sur des surfaces polies miroir ou ultra-polies en aluminium, l’acétone étant le fluide de travail. L'analyse est réalisée en fonction de la topographie de la surface liée au degré de polissage et en fonction du revêtement de la surface dans le but de modifier sa mouillabilité. L’étude a mis en avant trois catégories de comportement, fonctions de l’état de surface : les surfaces nano lisses, les surfaces nano lisses avec défauts et les surfaces rugueuses. Les bonnes caractéristiques obtenues avec des échantillons nano lisses comportant des défauts aléatoirement répartis ont conduit à la réalisation d’échantillons nano lisses avec des défauts de position et de taille contrôlés. Les résultats obtenus avec ces derniers échantillons présentent les meilleures performances. Une amélioration supérieure à un facteur deux par rapport aux surfaces rugueuses est observée, ce qui représente un gain substantiel. Bien qu’il soit le fondement de la plupart des modèles théoriques, le nucléus à l’origine de la formation d’une bulle n’a jamais été observé expérimentalement car sa taille dépasse la capacité des moyens de mesure traditionnels. Dans ce mémoire, une méthode optique - basée sur la résonnance de plasmons sur des surfaces comportant un réseau de diffraction - est utilisée dans le but d’étudier ce phénomène. Les expériences mettent en évidence la capacité de cette méthode à mesurer la variation de la température pariétale de l’échantillon avant le déclenchement de l’ébullition. Les mesures de résonance plasmon montrent qu’il n’y a pas de modification de la densité du fluide au voisinage de la paroi pour des surchauffes proches du déclenchement de l’ébullition. La nucléation est trop rapide pour être mesurée. Cependant, des premiers nuclei de condensation ont été détectés par cette méthode, ce qui constitue un résultat très prometteur. / An experimental study was conducted in order to understand the phenomenon of nucleation in boiling. This study was done on smooth surface or ultra-smooth surface made of aluminum, the working fluid is acetone. The analysis was realized as a function of the topography of the sample, roughness level, and as a function of nanocoating of the surface in order to modify the wettability. The study classed the sample in three categories, depending on the surface condition: the ultra-smooth surface, the ultra-smooth surface with defect and the rough surface. The good characteristics were obtained for the ultra-smooth sample with randomly distributed defects led to the fabrication of ultra-smooth sample with controlled artificial cavity. The results obtained with these latter samples present the best performances. A two-fold improvement over rough surfaces is observed, representing a substantial gain. Although it is the foundation of most theoretical models, the nucleus at the origin of the formation of a bubble has never been observed experimentally because its size exceeds the capacity of the traditional means of measurement. In this memory, an optical method - based on the resonance of plasmons on surfaces with a diffraction grating - is used to study this phenomenon. The experiments demonstrate the ability of this method to measure the temperature variation in the wall of the sample before boiling. Plasmon resonance measurements show that there is no change in the density of the fluid near the wall for overheating close to the boiling point. The nucleation is too fast to be measured. However, first nuclei of condensation were detected by this method, which is a very promising result.
|
Page generated in 0.0372 seconds