Reproduction de : Thèse de doctorat : Mécanique des solides, des matériaux, des structures et des surfaces : Poitiers : 2008. / Titre provenant de l'écran-titre. Bibliogr. 99 réf.

Reproduction de : Doctorat d'Etat : Physique : Metz : 1988. / 1988METZ001S.

Thèse de doctorat : Génie civil - hydrosystèmes - géotechnique : INPL : 2008. / Titre provenant de l'écran-titre.

Th. doct.--Paris--École centrale, 1995. / Bibliogr. p. 171-176. Résumé en français et en anglais.

Th. univ.--Méd.--Reims, 1980. N°: 202.

Made available in DSpace on 2014-06-11T19:29:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-08-25Bitstream added on 2014-06-13T21:00:19Z : No. of bitstreams: 1 portocarrerosanchez_c_me_botfm.pdf: 410152 bytes, checksum: 7c21ba36fbce5cc498fe42900b430f52 (MD5) / Fundação de Ensino e Pesquisa em Ciências da Saúde (FEPECS) / A taxa de sucesso de ovulação com uso do citrato de clomifene é excelente, alcançando valores entre 80% e 85%, porém a taxa de gravidez é de apenas 20% a 40%. Quando o citrato de clomifene é usado como indutor de ovulação, em mulheres portadoras de síndrome dos ovários policísticos, a literatura não define qual o momento ideal de ruptura folicular que se correlaciona com sucesso de gravidez. Identificar o diâmetro de ruptura folicular de pacientes com síndrome de ovários policísticos (SOP) estimuladas com citrato de clomifeno que melhor se correlacione com ocorrência de gravidez. Estudo corte transversal realizado entre janeiro a dezembro de 2010, que incluiu 104 pacientes com ciclos ovulatórios após uso de citrato de clomifeno, acompanhadas com ultrassonografia até determinar-se o diâmetro de ruptura folicular, que foi posteriormente correlacionado com a ocorrência ou não de gravidez. Para o estudo da associação entre as variáveis aplicou-se o teste do qui-quadrado e para as variáveis quantitativas a análise de variância seguida do método de Tukey ou teste t de Student, com valor de p <0,05. No grupo de pacientes com ruptura folicular com menos de 25 mm (n: 54) a taxa de gravidez foi de 35,2% e no grupo com ruptura folicular com mais de 25 mm (50) essa taxa foi de 34%, sem diferencia estatística significativa. Quando relacionamos aleatoriamente os diferentes diâmetros de ruptura folicular com a ocorrência de gravidez também não houve diferença significativa. O presente estudo permitiu concluir que, a taxa de gravidez de mulheres portadoras de síndrome dos ovários policísticos estimuladas com citrato de clomifene, não tem correlação com o diâmetro de ruptura folicular / The success rate of ovulation using clomiphene citrate is excellent, reaching values between 80% and 85%, but the pregnancy rate is only 20% to 40%. When clomiphene citrate is used to induce ovulation in women with polycystic ovary syndrome (PCOS), the literature does not define what the optimal timing of follicular rupture that correlates with successful pregnancy is. To identify the diameter of follicular rupture in patients with PCOS stimulated with clomiphene citrate that best correlates with the occurrence of pregnancy. Cross-sectional study conducted between January and December 2010, which included 104 patients with ovulatory cycles after the use of clomiphene citrate, followed by ultrasound to determine the diameter of follicular rupture, which was later correlated with the occurrence of pregnancy or not. To the study of the association between variables the chi-square test for quantitative variables and the analysis of variance followed by Tukey’s method or Student’s t test, with p <0.05 was applied. In patients with follicular rupture less than 25mm (n = 54) the pregnancy rate was 35.2%, in the group with follicular rupture with more than 25mm (50) this rate was 34%, no statistically significant difference was found. When relating the different diameters of randomly follicular rupture with the occurrence of pregnancy there was no significant difference. This study concluded that the pregnancy rate of women with PCOS stimulated with clomiphene citrate does not correlate with the diameter of follicular rupture

Submitted by Marcele Costal de Castro (costalcastro@gmail.com) on 2017-09-06T13:30:34Z No. of bitstreams: 0 / Made available in DSpace on 2017-09-06T13:30:34Z (GMT). No. of bitstreams: 0 Previous issue date: 1984-05 / This work is concerned with the application of the finite element method to the study of creep brittle rupture of structural components. In the formulation material behavior is described by an elastocreep model in which the total strain rates are assumed to be the sum of elastic and creep components. The elastic strain rates are given by Hooke’s law while the creep strain rates and the damage rates are espressed by the multiaxial form of the Kachanov-Rabotnov equations proposed by Leckie and Hayhurst. The incremental equations of motion are derived from the principle of virtual work using an updated Lagrangian formulation which accounts for geometric effects due to large displacements, large rotations and deformation dependent loadings. The finite element incremental equations are developed according to a displacement-based formulation. Isoparametric elements with quadratic shape functions are employed for the domain discretization and simple numerical procedures are developed to deal with the presence of partially and/or fully ruptured elements in the mesh. For integration of the creep strain rate equations a family of implicit time marching schemes is developed which can be regarded as Runge-Kutta methods of second order. The integration of the coupled damage rate equations is performed using a first order predictor-corrector scheme with automatic time step length control. For material nonlinear problems only, a substructuring technique is employed in conjunction with the time integration algorithms. Selected numerical applications are presented and discussed in detail. Comparison with alternative numerical, analytical and/or experimental results is made whenever possible.

To determine the current clinical practices of perinatologists regarding the management of premature rupture of membranes (PROM), 1,041 perinatologists were surveyed by multiple choice questionnaire with regard to induction of labor, use of antibiotics, tocolytic agents, and corticosteroids following uncomplicated PROM occurring between 19 and 36 weeks. The response rate was 51% (557/ 1,041). There was a consensus on expectant management of preterm PROM, except (1) where fetal lungs are found mature between 33 and 35 weeks gestation (51% induction vs. 44% expectant) and (2) at 19-22 weeks (71% undecided). During the expectant management the majority does not at any time use antibiotics, tocolytic agents, or corticosteroids. No uniform protocol has yet evolved for the management of preterm PROM, especially (1) between 33 and 35 weeks with mature fetal lungs, and (2) at 19-22 weeks gestation.

Un barrage est une structure qui est construite sur une rivière pour contrôler l'eau. L'un des types de barrages est un barrage en remblai. Les deux principaux types de barrages en remblai sont les barrages en terre et les barrages en enrochement, selon les matériaux utilisés dans la construction du barrage. La rupture de barrage est l'un des problèmes les plus importants de la structure des barrages. De nombreux facteurs sont à l'origine de la rupture d'un barrage. Le débordement est l'une des principales causes de rupture de barrage. Le développement de la brèche dans le barrage peut causer des dommages irréparables. La rupture de remblai a récemment attiré plus d'attention en raison de l'importance de ce problème. Cette recherche a étudié la rupture d'un barrage en remblai en raison d'un débordement. Cinq essais expérimentaux réalisés en dispositif à flume au laboratoire de l'Université Laval. Un modèle a été construit avec du till romaine 3 (T₁), un modèle a été construit avec du sable pur (T₂) et trois modèles ont été construits avec des mélanges sable-argile (T₃, T₄ et T₅). Le développement de l'érosion pour différents matériaux observé lors des essais de rupture de remblai et l'analyse des résultats sont décrits dans cette recherche. / A dam is a structure that is built across a river to control water. One of the types of dams is an embankment dam. The two principal types of embankment dams are earth dams and rock-fill dams, depending on the materials used in construction of the dam. Dam failure is one of the most important problems in dam structure. There are many factors that causes of dam failure. Overtopping is one of the main causes of dam failure. Development of the breach in the dam can cause irreparable damage. Embankment breaching has recently drawn more attention due to importance of this issue. This research studied breaching of embankment dam due to overtopping. Five experimental tests carried out in flume device in laboratory of Laval University. One model was constructed of till of romaine 3 (T₁), one model was constructed of pure sand (T₂) and three models were built of sand-clay mixtures (T₃, T₄ and T₅). The erosion development for different materials observed during embankment breaching tests and the analysis of the results are described in this research.

La surverse est un phénomène qui survient lorsque le niveau du réservoir dépasse celui de la crête du barrage permettant à l'eau de s'écouler sur la face aval de l'ouvrage de retenue. Lorsque ce dernier est composé de sol, l'écoulement initie le processus d'érosion superficielle qui peut mener à la rupture du barrage. L'objectif principal de cette étude est d'étudier la rupture par surverse des barrages en remblai à l'échelle du laboratoire en utilisant la technologie LiDAR. Pour atteindre cet objectif, un canal expérimental a été développé, à l'intérieur duquel un modèle physique d'un barrage en remblai à l'échelle du laboratoire est construit. Ce montage expérimental permet de reproduire la rupture d'un barrage en remblai due à la surverse tout en contrôlant les conditions hydrauliques et géotechniques. Le canal expérimental a également permis de mesurer les paramètres essentiels à l'étude de la surverse. En effet, l'évolution temporelle du débit d'eau s'échappant du réservoir, ainsi que le niveau du réservoir ont pu être mesuré. De plus, le LiDAR a permis d'obtenir des images en 3D du barrage pour chaque seconde de l'essai de surverse. Ensuite, la technologie LSPIV (Large Scale Particle Image Velocimetry) a été intégrée au montage expérimental dans le but d'estimer la vitesse de l'eau s'écoulant sur la face aval de l'ouvrage qui servirait à calculer la force de cisaillement appliquée sur les grains de sol. Pour continuer, des sols dont la proportion de kaolin et de sable varie ont été utilisés pour la construction des barrages, et différents chargements hydrauliques ont été appliqués, afin d'en déterminer l'effet sur le processus d'érosion qui survient lors de la surverse. Afin de traiter les données expérimentales recueillies lors de cette étude à partir du LiDAR, il a fallu développer une méthodologie d'analyses. Cette dernière a permis de calculer les volumes de sol érodé, les taux d'érosion et l'évolution de la brèche dans le temps. En se basant sur ces données, un modèle de prédiction du temps de rupture des barrages en remblai soumis à une surverse est proposé, visant à devenir un outil de conception dans l'avenir. / Overtopping occurs when the reservoir level exceeds the crest level of the dam, allowing water to flow over the downstream face of the retaining structure. When the structure is composed of soil, this flow initiates a surface erosion process that can lead to dam failure. The main objective of this study is to investigate embankment dam overtopping on a laboratory scale using LiDAR technology. To achieve this objective, an experimental channel has been developed, within which a physical model of a laboratory-scale embankment dam is constructed. This experimental setup allows the simulation of the embankment dam failure due to overtopping while controlling hydraulic and geotechnical conditions. The experimental channel also facilitated the measurement of essential parameters for studying overtopping. This includes the temporal evolution of outflows and the reservoir level. Additionally, LiDAR was used to capture 3D images of the dam every second during the overtopping test. Furthermore, LSPIV (Large Scale Particle Image Velocimetry) technology was integrated into the experimental setup to estimate the velocity of water flowing over the downstream face of the structure. This velocity data could be used to calculate the shear force applied to the soil grains. Moreover, soils with varying proportions of kaolin and sand were used in dam construction and different hydraulics loads have been applied, to assess their effect on the erosion process during overtopping. To process the experimental data collected using LiDAR, an analysis methodology was developed. This methodology facilitated the calculation of eroded soil volumes, erosion rates, and the evolution of the breach over time. Based on these data, a model for predicting the failure time of embankment dams subjected to overtopping was proposed with the aim of becoming a design tool in the future.