Les nouvelles réglementations thermiques, plus strictes, ont rendu nécessaire la prise en compte des transferts de masse dans les parois de bâtiment et leur interaction avec les transferts thermiques, particulièrement dans le cas de celles composées de matériaux poreux très hygroscopiques.Le dispositif expérimental est composé de deux parois montées et testées sur des cellules PASSYS orientables et à l'ambiance intérieure régulée, situées sur le site du CEA-INES au Bourget du Lac. Les parois, à ossature bois et à l'isolation en fibre de bois, ont été testées sous différentes conditions intérieures et extérieures, en fonction respectivement des consignes en température et en humidité, et de l'orientation. Les mesures expérimentales longues d'une année ont mis en évidence l'influence des fluctuations en humidité sur le comportement thermique des parois testées, et inversement de l'influence des températures sur l'humidité dans les parois.Un modèle numérique a été mis en oeuvre afin de simuler les phénomènes observés en conditions expérimentales. Le modèle, développé sur l'outil DYMOLA, a été validé par une comparaison avec d'autres modèles numériques existants, lors d'un benchmark sur des mesures expérimentales en conditions contrôlées. Il a ensuite été simulé les séquences expérimentales en conditions extérieures de ce travail. La comparaison des résultats numériques et expérimentaux ont mis en évidence un concordance des mesures de température, mais une divergence pour les mesures en humidité. Des ajustements paramétriques ont mis en évidence une surestimation de l'inertie hygrique combinée à une sous-estimation de la perméabilité à la vapeur du modèle numérique en comparaison aux séquences expérimentales. Une inadéquation des propriétés des matériaux telles que prises en compte généralement dans les modèles numériques, avec les conditions expérimentales dans lesquelles elles sont relevées est soulignée. / More stringent thermal regulations, made necessary the inclusion of mass transfer in building walls and their interaction with heat transfer, particularly for those composed of porous and highly hygroscopic materials.The experimental device consists of two walls mounted and tested on PASSYS orientable cells, with controlled indoor environment, located on the CEA-INES site in Le Bourget du Lac. The wood framed walls, with a wood fiber insulation were tested under different internal and external conditions, depending respectively on internal monitored temperature and humidity, or orientation. The one-year long experimental measurements have shown the influence of moisture fluctuations on the thermal behavior of the tested walls, and also the influence of temperature on the moisture in the walls.A numerical model was used to simulate the phenomena observed in experimental conditions. The model, developed on DYMOLA was firstly validated by a comparison with other existing numerical models, during a benchmark on experimental measurements under controlled conditions. It was then used to simulate experimental sequences on external conditions of this work. Comparing the numerical and experimental results have shown a correlation of the temperature measurements, but a difference for the moisture measurements. Parametric adjustments showed an overestimation of the Hygric inertia combined with an underestimation of the vapor permeability of the numerical model compared to experimental sequences. A mismatch of material properties such as reflected generally in the numerical models with the experimental conditions in which they are recorded is underlined.

The thesis explores the technical feasibility of an alternative method of decoupling air-conditioning systems function within the context of ecological issues. The system is a variant of dedicated outdoor air systems to separate dehumidification and cooling in air conditioning equipment. The project specifically investigates locating these components within the building envelope. Placement in the envelope moves the systems closer to fresh air and offers architectural expression for components that are normally out of sight. Designers, engineers, building science, mechanical, structural, biologist, and architectural engineers ideally as agents offer beneficial improvement to the system. The reduction in size of components into the building envelope offers risk. The thesis design space uses historical works, biological analogues, and past work to ground the technical understanding of the topic. Specific use of biological inspired design realizes translation from other systems to improve the alternative decoupled air conditioning system. The thesis develops prototype models for lighting analysis and for sensible and latent heat calculations. Psychrometric charts serve as tools to understand the thermodynamic air-conditioning process in conventional direct expansion vapor compression and solar liquid desiccant air conditioning systems. Data, models, and sketches provide tools for improvements to the 'thick' building envelope. Finally, the diagrams translate into functional decompositions for modifications to improve the system. The thesis probes the constraints in the areas of cost, fabrication, and technology that may not yet exist for selective improvement rather than a barrier to development of the thesis.

Atmospheric aerosols are a highly relevant component of the climate system affecting atmospheric radiative transfer and the hydrological cycle. As opposed to other key atmospheric constituents with climatic relevance, atmospheric aerosol particles are highly heterogeneous in time and space with respect to their size, concentration, chemical composition and physical properties. Many aspects of their life cycle are not understood, making them difficult to represent in climate models and hard to control as a pollutant. Aerosol-cloud interactions in particular are infamous as a major source of uncertainty in future climate predictions. Field measurements are an important source of information for the modeling community and can lead to a better understanding of chemical and microphysical processes. In this study, field data from urban, marine, and arid settings are analyzed and the impact of meteorological conditions on the evolution of aerosol particles while in the atmosphere is investigated. Particular attention is given to organic aerosols, which are a poorly understood component of atmospheric aerosols. Local wind characteristics, solar radiation, relative humidity and the presence or absence of clouds and fog are found to be crucial factors in the transport and chemical evolution of aerosol particles. Organic aerosols in particular are found to be heavily impacted by processes in the liquid phase (cloud droplets and aerosol water). The reported measurements serve to improve the process-level understanding of aerosol evolution in different environments and to inform the modeling community by providing realistic values for input parameters and validation of model calculations.

Com o objetivo de se avaliar a relação entre o tempo de fotopolimerização e a alteração dimensional dos cimentos de ionômero de vidro modificados por resina foram analisadas três marcas comerciais deste material: Vitremer (3M/ESPE), Fuji II LC (GC International) e Vitro Fil LC (DFL). Foram confeccionados 60 espécimes no total, sendo 20 para cada marca comercial. Cada corpo-de-prova foi confeccionado em forma de disco, com dimensões de 5mm de diâmetro e 2mm de espessura, com auxílio de uma matriz de PTFE (politetrafluoretileno) vazada no centro, com as dimensões já especificadas. Após a manipulação e inserção do material dentro da cavidade da matriz, e cobertura desta com lâmina de vidro de cada lado, o conjunto foi colocado, durante 15 minutos, dentro de uma caixa de papelão hermeticamente fechada, o que impediu a entrada de luz em seu interior. Dos 20 espécimes confeccionados de cada marca comercial, quatro grupos (n=5) foram formados, variando-se a forma de polimerização com o aparelho de luz halógena Demetron (Dabi-Atlante). O grupo 1 foi fotopolimerizado por 20s, o grupo 2 por 40s, o grupo 3 por 60s, e o grupo 4 não sofreu o processo de fotopolimerização (grupo controle). Cada espécime foi armazenado em um frasco plástico, com 10ml de água destilada, em uma estufa, com temperatura interna de 37ºC. As alterações dimensionais das amostras foram avaliadas nos intervalos de 24 horas, 7 dias e 30 dias de armazenamento. Para o cálculo das alterações volumétricas foi utilizada uma equação física, baseada no princípio hidrostático de Arquimedes, na qual eram obtidas as massas dos espécimes dentro da água e fora dela. Para isso foi utilizada uma balança analítica (AT 261 Delta Range/Mettler Toledo) com aparato de especificação de densidade. As médias dos resultados, em porcentagem da alteração volumétrica, foram submetidas à análise de variância a três critérios seguido pelo teste de Tukey para a averiguação da significância entre os grupos (a=0,05). Os resultados demonstraram que todos os materiais se expandiram após 30 dias. O Vitremer sofreu o menor grau de expansão quando não fotopolimerizado, no entanto, o tempo de fotopolimerização não influenciou o grau de alteração volumétrica, com exceção do Fuji II LC, cuja expansão foi maior após 60s de fotoativação. O Vitro Fil LC teve o volume diminuído entre 7 e 30 dias. Concluiu-se que o tempo de fotopolimerização pode afetar a alteração de volume do cimento de ionômero de vidro modificado por resina, porém não é o único fator relacionado a isto. / This study evaluated the effect of photoativation and storage on the hygroscopic expansion of resin modified glass ionomers (Vitremer-3M/ESPE, Fuji II LC-GC Int., Vitro Fil LC-DFL). . Twenty specimens, 5 +/- 1mm in diameter and 2mm in thickness, were made of each material in a mold of PTFE, . The RMGIC were manipulated according to the manufacturers instructions and inserted into a mold under two glass microscope slides and kept in a darkness box for 15 minutes. Then, the samples were distributed into four groups (n=5): light-cured for 20s, light-cured for 40s, light-cured for 60s and not light-cured (control group). Each sample was storage in distilled water at 37ºC. The measurements of volumetric changes were made in three different times of storage: 24 hours, 7 days and 30 days. Volumetric changes were determined using Archimedes principle, which change in buoyancy of a material in a fluid depends on the volume changes of the material. Measurements were made by an analytic balance with density apparatus (AT 261 Delta Range/Mettler Toledo). Means and standard deviations values were analyzed by three-way analysis of variance and Tukey\'s test to compare significance between the groups (a=0,05). All materials underwent volumetric expansion after 30 days. Vitremer showed the less expansion when no light-cured. The time of light-cure did not influence the volumetric change, except for Fuji II LC, that showed great expansion when activated for 60s. Vitro Fil LC showed some degree of shrinkage after 7 days. This study concluded that photocuring can influence the volumetric change of resin modified glass ionomer cement.

La salissure des modules photovoltaïques (PV) dégrade grandement leurs performances dans les environnements désertiques. Les études précédentes en extérieur ont tendance à trouver de faibles corrélations entre les taux de salissure et les paramètres météorologiques. On pensait que l'une des raisons était le long intervalle de mesure - jours ou semaines - des techniques traditionnelles de mesure des salissures sur le terrain. Dans la présente étude, un «microscope de souillure extérieur» (OSM) a été développé pour mesurer le dépôt et le détachement de particules de poussière individuelles, toutes les 10 minutes, dans des conditions extérieures, de jour comme de nuit. En utilisant une paire d'OSM graissés et non graissés, il était en outre possible de séparer les salissures en trois vitesses de flux de poussière de composants - dépôt, rebondissement immédiat et remise en suspension retardée. Les OSM ont été utilisés pour mesurer les taux de flux dans des expériences sur le terrain à Doha, au Qatar. La nouvelle méthode a révélé des effets explicatifs de paramètres environnementaux qui avaient auparavant été obscurcis par de longs intervalles de mesure des salissures et des taux de flux de poussière confondus. L'OSM pouvait également mesurer l'apparition et la croissance de gouttelettes de condensation microscopiques dans des conditions de terrain et de laboratoire. De telles expériences, ainsi que des mesures isothermes et des analyses de composition, ont démontré que la condensation sur les surfaces sales au terrain d’études était fortement influencée par la présence de matière hygroscopique dans la poussière autre que NaCl. En raison de cette matière, la condensation microscopique peut persister à la surface même si elle est bien supérieure à la température du point de rosée. Les résultats de l'étude suggèrent que la souillure des modules photovoltaïques pourrait être atténuée en tirant parti des variations naturelles des conditions météorologiques au cours de la journée. / Soiling of photovoltaic (PV) modules greatly degrades their performance in desert environments. Previous field studies have tended to find weak correlations between the soiling rate and weather parameters. It was thought that one reason was the long measurement interval — days or weeks — of conventional field soiling measurement techniques. In the present study, an “outdoor soiling microscope” (OSM) was developed able to measure deposition and detachment of individual dust particles, every 10 minutes, in outdoor conditions, day and night. By using a greased and ungreased pair of OSMs, it was further possible to separate soiling into three component dust flux rates — deposition, immediate rebound, and delayed resuspension. OSMs were used to measure flux rates in field experiments in Doha, Qatar. The novel method revealed explanatory effects of environmental parameters that had previously been obscured by limits of conventional long soiling measurement intervals and confounded dust flux rates. The OSM could also measure the onset and growth of microscopic condensation droplets in field and laboratory settings. Such experiments, along with isotherm measurements and composition analysis, demonstrated that condensation on soiled surfaces at the test site was strongly influenced by the presence of hygroscopic matter in the dust other than NaCl. Because of such matter, microscopic condensation could persist on both hydrophilic and hydrophobic surfaces well above the dew-point temperature. Results of the study suggest that soiling of PV modules might be mitigated by taking advantage of natural time-of-day variations in weather conditions.

The contribution of atmospheric aerosols towards radiative forcing has a very high uncertainty due to their short atmospheric lifetime. The aerosol effects are largely controlled by the density, elemental composition, and hygroscopic properties of the aerosol particles. Therefore, we have performed designed new methodology using Scanning Transmission X-ray Microscopy (STXM), Atomic force spectroscopy (AFM), micro-FTIR spectroscopy and Scanning Electron Microscopy (SEM) to quantify these important aerosol properties. Hygroscopic properties are quantified by plotting the mass of water on a single particle basis, calculated from STXM, as a function of relative humidity. Alternatively, micro-FTIR spectra have been used to study the effect of composition of aerosol particles on the hygroscopic properties of NaCl. Moreover, a unique combination of STXM and AFM has been utilized to quantify density and elemental composition of micrometer dimensional particles. This method has also been extended towards exploring mixing state of particles, consisting of heterogeneously mixed inorganic and organic compounds. In addition to these above mentioned properties, the fate of an atmospheric particle is often altered by chemical transformation and that in turn is influenced by the atmospheric RH. Therefore, we have studied an unusual keto-enol tautomerism in malonic acid particles at high RH, which is not observed in bulk. This observation could potentially be utilized to significantly improve the models to estimate Secondary Organic Aerosols (SOA). Using STXM and micro-FTIR technique, RH dependent equilibrium constant of the tautomerism reaction has been quantified as well. Organic nanocrystals capable of undergoing solid state photochemical changes in a single-crystal-to-single-crystal (SCSC) manner have been particularly important in fabricating molecular switches, data storage devices etc. Mechanical properties of these nanomaterials may control its SCSC reactivity. In addition, investigation of mechanical stiffness is important to define allowable limit of stiffness towards device application. Therefore, we studied mechanical properties of series organic nano cocrystals primarily consisting of trans-1,2-bis(4-pyridyl)ethylene and substituted resorcinol using AFM nanoindentation technique. Dependence of mechanical properties and SCSC reactivity on the resorcinol structure is also investigated as well. Moreover, photolithography on the thin film of these organic cocrystals has been performed to demonstrate its applicability as a photoresist.

This dissertation describes two independent studies related to charged aerosols. The first study examines the role of electrical conductivity on the amounts of charge and mass emitted during the break-up of charged droplets via Coulombic fission. The second study examines the hygroscopic behavior of mixed particles. The results from both studies are presented here in detail along with an in-depth discussion of pertinent literature and applications in modern technologies. Charged droplets break-up via a process termed Coulombic fission when their charge density reaches a certain level during which they emit a portion of their charge and mass in the form of progeny microdroplets. Although Rayleigh theory can be used to predict the charge level at which break-ups occur, no equivocal theory exists to predict the amounts of charge or mass emitted or the characteristics of the progenies. Previous investigations have indicated that the electrical conductivity of a charged droplet may determine how much charge and mass are emitted during its break-up via Coulombic fission. To further examine this supposition, charged droplets having known electrical conductivities were observed through multiple break-ups while individually levitated in an electrodynamic balance. The amounts of charge and mass emitted during break-ups were determined using a light scattering technique and changes in the DC null point levitation potentials of the charged droplets. Here, electrical conductivity was found to increase and decrease the amounts of charge and mass emitted, respectively, while having no effect on the charge level at which break-ups occurred. The findings of this investigation have significant bearing in nanoparticle generation and electrospray applications. The hygroscopic behavior of atmospherically relevant inorganic salts is essential to the chemical and radiative processes that occur in Earth’s atmosphere. Furthermore, studies have shown that an immense variety of chemical species exist in the atmosphere which inherently mix to form complex heterogeneous particles with differing morphologies. However, how such materials and particle morphologies affect the hygroscopic behavior of atmospherically relevant inorganic salts remains mostly unknown. Therefore, the effects of water insoluble materials, such as black carbon, on the hygroscopic behavior of inorganic salts were examined. Here, water insoluble solids were found to increase the crystallization relative humidities of atmospherically relevant inorganic salts when internally mixed. Water insoluble liquids however, were found to have no effect on the hygroscopic behavior of atmospherically relevant inorganic salts. The findings of this investigation have significant bearing in atmospheric modeling.

Com o objetivo de se avaliar a relação entre o tempo de fotopolimerização e a alteração dimensional dos cimentos de ionômero de vidro modificados por resina foram analisadas três marcas comerciais deste material: Vitremer (3M/ESPE), Fuji II LC (GC International) e Vitro Fil LC (DFL). Foram confeccionados 60 espécimes no total, sendo 20 para cada marca comercial. Cada corpo-de-prova foi confeccionado em forma de disco, com dimensões de 5mm de diâmetro e 2mm de espessura, com auxílio de uma matriz de PTFE (politetrafluoretileno) vazada no centro, com as dimensões já especificadas. Após a manipulação e inserção do material dentro da cavidade da matriz, e cobertura desta com lâmina de vidro de cada lado, o conjunto foi colocado, durante 15 minutos, dentro de uma caixa de papelão hermeticamente fechada, o que impediu a entrada de luz em seu interior. Dos 20 espécimes confeccionados de cada marca comercial, quatro grupos (n=5) foram formados, variando-se a forma de polimerização com o aparelho de luz halógena Demetron (Dabi-Atlante). O grupo 1 foi fotopolimerizado por 20s, o grupo 2 por 40s, o grupo 3 por 60s, e o grupo 4 não sofreu o processo de fotopolimerização (grupo controle). Cada espécime foi armazenado em um frasco plástico, com 10ml de água destilada, em uma estufa, com temperatura interna de 37ºC. As alterações dimensionais das amostras foram avaliadas nos intervalos de 24 horas, 7 dias e 30 dias de armazenamento. Para o cálculo das alterações volumétricas foi utilizada uma equação física, baseada no princípio hidrostático de Arquimedes, na qual eram obtidas as massas dos espécimes dentro da água e fora dela. Para isso foi utilizada uma balança analítica (AT 261 Delta Range/Mettler Toledo) com aparato de especificação de densidade. As médias dos resultados, em porcentagem da alteração volumétrica, foram submetidas à análise de variância a três critérios seguido pelo teste de Tukey para a averiguação da significância entre os grupos (a=0,05). Os resultados demonstraram que todos os materiais se expandiram após 30 dias. O Vitremer sofreu o menor grau de expansão quando não fotopolimerizado, no entanto, o tempo de fotopolimerização não influenciou o grau de alteração volumétrica, com exceção do Fuji II LC, cuja expansão foi maior após 60s de fotoativação. O Vitro Fil LC teve o volume diminuído entre 7 e 30 dias. Concluiu-se que o tempo de fotopolimerização pode afetar a alteração de volume do cimento de ionômero de vidro modificado por resina, porém não é o único fator relacionado a isto. / This study evaluated the effect of photoativation and storage on the hygroscopic expansion of resin modified glass ionomers (Vitremer-3M/ESPE, Fuji II LC-GC Int., Vitro Fil LC-DFL). . Twenty specimens, 5 +/- 1mm in diameter and 2mm in thickness, were made of each material in a mold of PTFE, . The RMGIC were manipulated according to the manufacturers instructions and inserted into a mold under two glass microscope slides and kept in a darkness box for 15 minutes. Then, the samples were distributed into four groups (n=5): light-cured for 20s, light-cured for 40s, light-cured for 60s and not light-cured (control group). Each sample was storage in distilled water at 37ºC. The measurements of volumetric changes were made in three different times of storage: 24 hours, 7 days and 30 days. Volumetric changes were determined using Archimedes principle, which change in buoyancy of a material in a fluid depends on the volume changes of the material. Measurements were made by an analytic balance with density apparatus (AT 261 Delta Range/Mettler Toledo). Means and standard deviations values were analyzed by three-way analysis of variance and Tukey\'s test to compare significance between the groups (a=0,05). All materials underwent volumetric expansion after 30 days. Vitremer showed the less expansion when no light-cured. The time of light-cure did not influence the volumetric change, except for Fuji II LC, that showed great expansion when activated for 60s. Vitro Fil LC showed some degree of shrinkage after 7 days. This study concluded that photocuring can influence the volumetric change of resin modified glass ionomer cement.

Face à la problématique énergétique du bâtiment et l’impact environnemental lié, il apparait que les enveloppes hygroscopiques sont une piste prometteuse en termes d’amélioration du confort thermique, de qualité de l’air intérieur, de consommation énergétique et de régulation de l'humidité intérieure. Aujourd'hui, on manque de valeurs de référence du comportement hygrothermique transitoire de ce type d’enveloppes. La physique des transferts hydriques dans les matériaux hygroscopiques, aptes à fixer l’humidité, est complexe et rend difficile la modélisation des transferts couplés de chaleur et de masse. Une approche expérimentale et numérique du comportement thermo hydrique des enveloppes hygroscopiques a donc été menée avec une caractérisation multi-échelle. Ainsi, le monitoring de quatre maisons habitées a été sujet de caractérisation au niveau de la première échelle. L’étude à l'échelle du matériau a permis de caractériser les propriétés liées aux transferts de chaleur et de masse. Le couplage thermo-hydrique a fait l'objet d'une étude spécifique à l'échelle de la paroi. Les implémentations différences finies et éléments finis ont abouti à une analyse fine des transferts à l'échelle de cellules-test avec un travail de réduction d'ordre nécessaire pour limiter les temps de calcul. L’accent est mis sur les effets de l’humidité apportés dans les ambiances intérieures afin de valider un outil numérique développé dans ce travail. Les enveloppes hygroscopiques choisies sont composées de matériaux biosourcés tels que le bois massif, le béton de bois, la terre et paille. Les enveloppes de travertin et de plaques de plâtre sont également étudiées. / In front of the building energy issues and environmental impact bound, it appears that the hygroscopic envelopes are a promising track in terms of improving of the thermal comfort, indoor air quality, energy consumption and indoor humidity regulation. Today, we lack reference values of the transient hygrothermal behavior of this envelope type. The physics of moisture transfer in hygroscopic materials (capable to fixing moisture) is complex and makes it difficult modeling of coupled heat and mass transfers. Experimental and numerical approaches of hygrothermal behavior in hygroscopic envelops was therefore conducted with a multi-scale visions. Thus, monitoring of four habited houses was the characterization focus at the first scale. The study on the material scale allowed to characterize the properties related to the heat and mass transfer. The hygrothermal coupling has been the subject of a specific study at a wall scale. Finite differences and finite elements implementations have resulted in a detailed analysis of transfers across cell-test with a reduction work of order required to limit the calculation time. Emphasis is placed on the effects of moisture brought in indoor environments in order to validate a digital tool developed in this work. The selected hygroscopic envelopes are composed of biosourced materials such as massive wood, wood concrete, earth and straw. Envelopes of travertine and plasterboard are also studied.

Since resin composites were first presented to dentistry more than half a century ago, the composition of resin composites has developed significantly. One major change was that the reinforcing filler particles were reduced in size to generate materials of a given filler content that display better physical and mechanical properties. Resin composites may absorb water and chemicals from the surrounding environment but at the same time, composites may release constituents to their surroundings. The physical/mechanical properties of a restorative material provide an indication of how the material will function under stress in the oral environment. The aims of this research were to examine the effects of water at 37°C on the physical and mechanical properties, and the effect of food-simulating solvents of a variety of experimental and contemporary resin composites, on the surface properties. Eight representative resin composites were selected (Exp. VT, BL, NCB, TEC, GSO, XB, VDF and CXD). Due to the recent development of bulk fill materials on the market during the course of this research, the post-cure depth of cure of new bulk fill materials was also investigated. Five representative resin composites were selected: TBF, XB, FBF, VBF and SF. Water sorption and solubility were investigated at 37°C for 150 days. Sorption and solubility are affected by the degree of hydrophilicity of the resin matrix. The bulk fill materials examined showed the lowest water sorption and solubility. Laser scan micrometer (LSM) was used to investigate hygroscopic expansion. The extent of the hygroscopic expansion positively correlated with the amount of water sorption. The effect of water on fracture toughness was also examined. A self-adhesive hydrophilic resin matrix decreased in fracture toughness after 7 days of storage at 37°C. By contrast, the least water absorbed bulk fill material increased in fracture toughness over time. The effect of food-simulating solvents (distilled water, 75% ethanol/water and MEK) on surface micro-hardness, colour stability and gloss retention were investigated. The MEK solvent resulted in the lowest micro-hardness and the greatest colour change (ΔE) for most of the examined composites, while the 75% ethanol/water solution caused the greatest loss in gloss for most of the examined composites. A highly filled nano-composite showed the best result over time, regardless of the condition of storage. Surface micro-hardness profiles were used as an indirect method to assess the depth of cure of bulk fill resin composites. The examined bulk fill resin composites can be cured to an acceptable depth (4 mm).