Chaleur Humidité Air dans les maisons à ossature bois (Expérimentation et modélisation)

L évolution actuelle des exigences en termes de performance énergétique des bâtiments a fait apparaître de nouveaux enjeux et problématiques scientifiques, dont ceux liés à l humidité. Cette étude s appuie sur une cellule expérimentale construite sur la technologie des maisons à ossature bois et soumise aux conditions climatiques réelles de Grenoble. L instrumentation de ce bâtiment et le suivi de l évolution en température et en humidité dans les différentes couches de l enveloppe permettent de définir des séquences nécessaires à la validation de modèles numériques. Dans cet objectif, un modèle existant nommé HAM-Tools a été utilisé pour simuler les transferts couplés de chaleur, d air et d humidité à l échelle du bâtiment. La démarche de validation a été décomposée en plusieurs étapes, de manière à cibler des transferts spécifiques et d en améliorer la modélisation. Ces études localisées concernent les transferts couplés de chaleur et de masse à travers les parois solides, la modélisation des transferts de chaleur à travers une lame d air ventilée et enfin la modélisation du renouvellement de l air intérieur en conditions naturelles. Pour estimer la précision globale du modèle, c'est-à-dire à l échelle du bâtiment, une séquence expérimentale a été simulée en prenant en compte l ensemble des transferts couplés simultanément. Les performances du modèle sont discutées à partir des mesures locales, c'est-à-dire dans les parois, puis globales. La bonne concordance entre mesures et résultats de simulation permet de conclure sur la validité et la généricité de la démarche mise en œuvre et les hypothèses de simulation. Plus particulièrement, il est apparu que l outil de modélisation permet de prédire correctement le comportement moyen des parois en humidité et en température. Il est donc envisageable de l utiliser pour simuler et estimer l impact des constituants des parois en termes de durabilité, de performances énergétiques et de confort de l occupant.As energy saving is so important in buildings nowadays, envelopes performances have to be more efficient and have to deal with more obligations, such as moisture accumulation and mould growth. This study relies on an experimental wooden frame house exposed to the natural conditions of Grenoble, France. It has been widely instrumented so the wall s temperature and humidity is monitored at different depths. As a consequence, complete dataset are available and can be used to validate numerical model. In this work, an existing numerical model named HAM-Tolls has been used to simulate the heat, air and moisture coupled transfers at the building scale. The method developed here consists in validating the numerical model step by step, with studying specific transfers separately. The first step deals with heat and mass transfers across the walls. Then, the heat transfers across a ventilated air gap and the air change rate under natural conditions have been studied much in detail. The final step of this works consists in simulating simultaneously every transfer at the building scale. This latest simulation s results were compared both on a local and on a global point of view with the measurements. As they were found to be in good agreement, this allows concluding on the methodology efficiency, the validity of the modelling assumption and gives good hope with extending this methodology to other studies. Specifically, the simulation tool is able to predict correctly the average temperature and humidity content within the walls. Therefore, it should be suitable with estimating the wall components influence on the wall durability, its energy efficiency and its impact on the occupant s thermal comfort.VILLEURBANNE-DOC'INSA-Bib. elec. (692669901) / SudocSudocFranceF

Neurourology and Urodynamics Diagnostic Criteria for Pudendal Neuralgia by Pudendal Nerve Entrapment (Nantes Criteria)

Aims: The diagnosis of pudendal neuralgia by pudendal nerve entrapment syndrome is essentially clinical. There are no pathognomonic criteria, but various clinical features can be suggestive of the diagnosis. We defined criteria that can help to the diagnosis. Materials and Methods: A working party has validated a set of simple diagnostic criteria (Nantes criteria). Results: The five essentials diagnostic criteria are: (1) Pain in the anatomical territory of the pudendal nerve

Démembrement du syndrome douloureux de vessie (intérêt du catalogue mictionnel)

Objectif: analyser les caractéristiques mictionnelles des patients ayant un syndrome douloureux vesical.Méthodes: 54 patients ont prospectivement rempli un calendrier mictionnel avec évaluation des douleurs peri-mictionnelles, et eu une cystoscopie sous anesthésie générale avec description des lésions, et hydrodistension courte. Les groupes "avec" ou "sans" anomalies endoscopiques ont été comparés en utilisant un test T de student. Résultats: des anomalies cystoscopiques significatives ont été mises en évidence chez 33 patients, dont les caractéristiques étaient une pollakiurie plus importante (P=0,03), surtout nocturne (P=0,009), des volumes mictionnels moyens et maximum plus faibles (P=0,01 et P=0,004), des faibles variations des volumes urines (P=0,01) et des douleurs moins importantes après la miction (P=0,04). Conclusion: le catalogue mictionnel permet d'identifier 2 profils cliniques, l'un représentatif d'une pathologie de la paroi vesicale, l'autre d'une hypersensibilité vésicale.RENNES1-BU Santé (352382103) / SudocSudocFranceF

Dynamic coupling between vapour and heat transfer in wall assemblies: Analysis of measurements achieved under real climate

International audienceAn experimental wooden-frame house was designed, instrumented and tested to provide measurements suitable for the study of coupled vapour and heat transfer under real climate conditions. In this paper, six different wall assemblies were tested under complex temperature and humidity boundary conditions over more than 3 years. The main objective is to take advantage of the strong outdoor and indoor stresses to emphasise the dynamic coupling between vapour and heat transfer for different wall assemblies. Measurements showed that the heat flux crossing the vertical walls was significantly influenced when a vapour flow crossed insulating materials with high hygroscopic inertia. To further explain this result, a classical numerical model was selected. It was designed to compute coupled transfer at the building scale. A good agreement was obtained for temperature measurements, while higher differences were observed with humidity measurement. An uncertainty analysis was achieved on both experimental and numerical results. It appeared that the uncertainty of the simulation results was one order of magnitude lower than the experimental uncertainty. Finally, the numerical model was used to break down the coupling of vapour and heat transfers. The latent heat effect occurred as the most sizeable effect, which was consistent with the experimental observations

Procédé de traçabilité de bactéries corrosives dans les systèmes de transport de l’industrie pétrolière

L'invention a pour objet un procédé de détection et/ou de discrimination de microorganismes responsables de la corrosion de matériaux, lesdits matériaux étant en contact avec un échantillon susceptible de contenir au moins un desdits microorganismes

Dynamic coupling between vapour and heat transfer in wall assemblies: Analysis of measurements achieved under real climate

International audienceAn experimental wooden-frame house was designed, instrumented and tested to provide measurements suitable for the study of coupled vapour and heat transfer under real climate conditions. In this paper, six different wall assemblies were tested under complex temperature and humidity boundary conditions over more than 3 years. The main objective is to take advantage of the strong outdoor and indoor stresses to emphasise the dynamic coupling between vapour and heat transfer for different wall assemblies. Measurements showed that the heat flux crossing the vertical walls was significantly influenced when a vapour flow crossed insulating materials with high hygroscopic inertia. To further explain this result, a classical numerical model was selected. It was designed to compute coupled transfer at the building scale. A good agreement was obtained for temperature measurements, while higher differences were observed with humidity measurement. An uncertainty analysis was achieved on both experimental and numerical results. It appeared that the uncertainty of the simulation results was one order of magnitude lower than the experimental uncertainty. Finally, the numerical model was used to break down the coupling of vapour and heat transfers. The latent heat effect occurred as the most sizeable effect, which was consistent with the experimental observations

simulation of coupled heat, air and moisture transfers in an experimental house exposed to natural climate

International audienc

Evidence for a Prognostic Role of Orthostatic Hypertension on Survival in a Very Old Institutionalized PopulationNovelty and Significance

International audienceIn old individuals, regulation of blood pressure during postural changes is impaired. Several studies have assessed the clinical impact of orthostatic hypotension (OHypoT) during the aging process. By contrast, the prevalence and prognostic role of the increase in blood pressure in upright position (orthostatic hypertension, OHyperT) in old adults remain unknown. We investigated the association of OHyperT with cardiovascular morbidity and mortality in a population of old institutionalized subjects. A 2-year follow-up longitudinal study was conducted on 972 subjects (mean age [SD] 88 [5]) from the PARTAGE (Predictive Values of Blood Pressure and Arterial Stiffness in Institutionalized Very Aged Population) study, able to maintain a standing position. OHyperT was defined as an increase in systolic blood pressure ≥20 mm Hg during the first and third minute of standing. Three groups of subjects were compared: orthostatic normotension (n=540), OHypoT (n=157), and OHyperT (n=275). OHyperT prevalence (28%) was higher than OHypoT (16%). Sitting systolic blood pressure was higher in OHypoT compared with orthostatic normotension and OHyperT groups (146 [23] versus 136 [21] and 136 [20] mm Hg, respectively, P<0.001). The OHyperT group was associated with a greater risk of cardiovascular morbidity and mortality than orthostatic normotension (hazard ratio 1.51 [1.09-2.08], P<0.01) and remained unchanged after adjustment for age, sex, sitting systolic blood pressure, and comorbidities. No difference in cardiovascular morbidity and mortality was observed between OHyperT and OHypoT groups. In conclusion, in a old frail population, the increase in systolic blood pressure during upright position occurs frequently and is associated with higher cardiovascular morbidity and mortality independently of sitting blood pressure levels and major comorbidities. Health professional should take into account not only the decrease but also the increase in blood pressure when standing up.URL: http://www.clinicaltrials.gov. Unique identifier: NCT00901355