Analyse expérimentale en entrée et en sortie de l'aspirateur d'une turbine hydraulique de basse chute

Tableau d’honneur de la Faculté des études supérieures et postdoctorales, 2010-2011L'objectif du présent mémoire est de contribuer à la caractérisation de l'écoulement dans l'aspirateur d'une turbine hydraulique de type hélice. Pour y arriver, un anémomètre laser à effet Doppler (LDV) est utilisé dans plusieurs sections de l'aspirateur d'un modèle de cette turbine, maintenu sous plusieurs conditions d'opération, pour créer une base de données de vitesse. La composante radiale en sortie de roue est particulièrement recherchée puisque son acquisition constitue un défi technique au niveau expérimental et que son importance dans l'évolution de l'écoulement est établie. Les résultats principaux font ressortir que la vitesse radiale arbore une grandeur non négligeable en sortie de roue et varie de façon importante suivant les conditions d'opération. L'asymétrie circonférentielle des trois composantes de vitesse est également confirmée dans cette section. L'évolution de l'écoulement dans le coude de l'aspirateur engendre un débalancement du débit sortant à travers les deux pertuis. Finalement, l'écoulement dans l'aspirateur de ce type de turbine est fortement instationnaire, ce qui rend essentielle l'étude des fluctuations qui s'y développent

Extension de bande paramétrique pour les signaux audio de parole et de musique

Dans le domaine du codage audio, l’utilisation d’une extension de bande paramétrique pour encoder les hautes fréquences permet une économie de débit. Contrairement à la majorité des méthodes d'extension de bande qui effectuent leur traitement dans le domaine temporel, le traitement proposé dans ce mémoire s’effectue dans le domaine fréquentiel pour créer une extension de bande audio de 8 à 16 kHz sur les signaux monophoniques de parole et de musique. Le projet de maîtrise étudie plusieurs éléments : les techniques de régénération des hautes fréquences, l'utilisation du cepstre pour le calcul et la représentation de l'enveloppe spectrale, ainsi que des techniques d’amélioration de la dynamique du spectre. Les résultats de tests subjectifs formels montrent un gain sur certaines catégories de signaux par rapport au codec AMR-WB+, lequel est reconnu comme étant un standard international développé à l'Université de Sherbrooke

Les pithoi de Margaritès (Crète)

À l’écart des touristes, quelques potiers crétois fabriquent encore comme autrefois une poterie rustique destinée aux usages domestiques. C’est le cas à Margaritès, en Crète centrale, où il est possible d’observer le façonnage des grands vases de stockage, les pithoi, déjà en usage quinze siècles plus tôt dans la cité antique voisine d’Eleutherna. L’étude conjointe et comparative des deux productions céramiques, l’ancienne et la traditionnelle, nous a ainsi permis de reconstituer les techniques de fabrication des potiers d’autrefois. Elle nous apporte aussi de nombreuses données sur l’économie des villages crétois durant la période, encore peu connue, comprise entre la fin de l’Antiquité et l’occupation vénitienne (VIIe-XIIIe siècles).The pithoi of Margaritès (Crete). Technical data and historical overviewAway from the tourists, Cretan potters still produce traditional crockery for domestic use. It is the case in Margaritès (central Crete) where one can observe the making of huge jars for food storage, called pithoi. These were already in use fifteen centuries ago in the neighbouring antique city of Eleutherna. The joint and comparative study of antique and traditional ceramic productions enabled to reconstitute the techniques fo the ancient potters. Such approach also brought important data on the economy of Cretan villages of this poorly documented historical period spanning from the end of Antiquity and the Venitian occupation (7th-13th centuries).Los pithoi de Margarites (Creta). Datos técnicos y compendio históricoFuera de los circuitos turísticos, unos cuantos alfareros cretenses siguen confeccionando objetos rústicos dedicados a usos domésticos, tal y como se hacía en el pasado. En Margarites (Creta central), es posible observar la fabricación de grandes vasijas destinadas a conservar alimentos, los pithoi, ya empleadas hace quince siglos en Eleutherna, una ciudad antigua próxima a este pueblo. El estudio simultáneo y comparativo de las dos producciones cerámicas —la antigua y la tradicional— ha permitido reconstituir las técnicas de fabricación de los alfareros de la Antigüedad. También nos proporciona numerosos datos acerca de la economía de los pueblos cretenses durante la época —aún poco conocida— comprendida entre el fin de la Antigüedad y la ocupación veneciana

Self-Compassion, Chronic Age-Related Stressors, and Diurnal Cortisol Secretion in Older Adulthood

Background: Many older adults experience chronic age-related stressors (e.g., life regrets or health problems) that are difficult to control and can disturb cortisol regulation. Self-compassion may buffer adverse effects of these stressful experiences on diurnal cortisol secretion in older adulthood. Purpose: To examine whether self-compassion could benefit older adults’ cortisol secretion in the context of chronic and largely uncontrollable age-related stressors. Methods: 233 community- dwelling older adults reported their levels of self-compassion, age-related stressors (regret intensity, physical health problems, and functional disability), and relevant covariates. Diurnal cortisol was measured over 3 days and the average area-under-the-curve (AUC) and slope were calculated. Results: Higher levels of self-compassion were associated with lower daily cortisol levels among older adults who reported higher levels of regret intensity, physical health problems, or functional disability (βs .28). Conclusions: These results suggest that self- compassion may represent an important personal resource that could protect older adults from stress- related biological disturbances resulting from chronic and uncontrollable stressors

Pain catastrophizing and worry about health in generalized anxiety disorder

Because the diagnostic criteria of generalized anxiety disorder (GAD) are not tied to specific worry domains (worry is ‘generalized’), research on the content of worry in GAD is lacking. To our knowledge, no study has addressed vulnerability for specific worry topics in GAD. The goal of the current study, a secondary analysis of data from a clinical trial, is to explore the relationship between pain catastrophizing and worry about health in a sample of 60 adults with primary GAD. All data for this study were collected at pretest, prior to randomization to experimental condition in the larger trial. The hypotheses were that (1) pain catastrophizing would be positively related to the severity of GAD, (2) the relationship between pain catastrophizing and the severity of GAD would not be explained by intolerance of uncertainty and psychological rigidity, and (3) pain catastrophizing would be greater in participants reporting worry about health compared to those not reporting worry about health. All hypotheses were confirmed, suggesting that pain catastrophizing may be a threat-specific vulnerability for health-related worry in GAD. The implications of the current findings include a better understanding of the ideographic content of worry, which could help focus treatment interventions for individuals with GAD

Is 'Cooperative' a Plus factor in market communication ? A franco-Swedish Comparative study of consumer perceptions

Diffusion du document : INRA Station d'Economie et Sociologie rurales 65 rue de Saint-Brieuc 35042 Rennes Cedex (FRA)While what might be termed ethical or 'civic' consumption is no longer reserved to a few isolated eccentrics, the aim of this paper is to set out some first thoughts on the wellfoundedness of developing market communication for agricultural cooperatives based on their specific form of organisation.Based on a consumer suruey conducted jointly in France and Sweden, it sets out to appraise consumer knowledge of and interest in cooperative firms and their activities and to get a clear picture of the image consumers have of these organisations.We first describe the general framework for the study (part 1), then the method employed {part 2). We then set out the results (part 3) and interpret them (part 4)

Associations between daily mood states and brain gray matter volume, resting-state functional connectivity and task-based activity in healthy adults

Numerous studies have shown differences in the functioning in the areas of the frontal-limbic circuitry between depressed patients and controls. However, current knowledge on frontal-limbic neural substrates of individual differences in mood states in everyday life in healthy individuals is scarce. The present study investigates anatomical, resting-state, and functional neural correlates of daily mood states in healthy individuals. We expected to observe associations between mood and the frontal-limbic circuitry and the default-mode network (DMN). A total of 42 healthy adults (19 men, 23 women; 34 ± 1.2 years) regularly followed for behavior and psychosocial functioning since age of 6, underwent a functional magnetic resonance imaging scan, and completed a daily diary of mood states and related cognitions for 5 consecutive days. Results showed that individuals with smaller left hippocampal gray matter volumes experienced more negative mood and rumination in their daily life. Greater resting-state functional connectivity (rsFC) within the DMN, namely between posterior cingulate cortex (PCC) and medial prefrontal cortex regions as well as between PCC and precuneus, was associated with both greater negative and positive mood states in daily life. These rsFC results could be indicative of the role of the DMN regional functioning in emotional arousal, irrespective of valence. Lastly, greater daily positive mood was associated with greater activation in response to negative emotional stimuli in the precentral gyri, previously linked to emotional interference on cognitive control. Altogether, present findings might reflect neural mechanisms underlying daily affect and cognition among healthy individuals