Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In this work a single column model is implemented, aiming primarily to simulate the Stable Boundary Layer (SBL). The model is composed of prognostic equations for the potential temperature, specific humidity and the wind components. A prognostic equation for the turbulent kinetic energy (TKE) is also used. The turbulent fluxes are approximated from diffusion coefficients that are directly proportional to TKE and to the turbulent mixing length, with a adjustable proportionality factor. To estimate the turbulent mixing lengths, four different parametrizations from the literature are considered. First, a stable case in the Arctic is simulated, then the model is adjusted to reproduce previously published Large Eddy Simulations (LES) results for the same case. After the calibration, the model is validated through a comparison with observed nocturnal data, from tethered balloon soundings performed at a deforested area in the Amazon region, in the months of July and October 2001 and November 2003. The temporal evolution of potential temperature and specific humidity vertical profiles are simulated and compared to the observations from 13 different nights. The performance of the different formulations is evaluated through a statistic analysis for all nights. Potential temperature profiles were better represented by the model than specific humidity ones. In spite being able to reproduce different stability conditions, the model represented the most stable nights better. Finally, the model was coupled to a surface energy budget scheme and for these simulations the initial conditions from the night of 28 July 2001 were used. The scheme was used to evaluate how the simulated atmospheric variables depend on the wind intensity at the top of the vertical domain for the different formulations and with or without the energy budget scheme being added. / Neste trabalho é implementado um Modelo de Coluna Simples, com o intuito de simular a Camada Limite Estável (CLE). O modelo é composto por equações prognósticas para a temperatura potencial, umidade específica e para as componentes horizontais do vento, além de uma equação prognóstica para a energia cinética turbulenta (ECT). Os fluxos turbulentos são aproximados por coeficientes de difusão que são diretamente proporcionais à ECT e ao comprimento de mistura turbulenta, de forma que o coeficiente de proporcionalidade é um fator ajustável. Para estimar os comprimentos de mistura turbulentos são utilizadas quatro diferentes parametrizações encontradas na literatura. Primeiramente, é simulado um caso estável no Ártico, sendo o modelo ajustado de forma a produzir resultados próximos aos da Simulação dos Grandes Turbilhões (LES), obtidos por outros autores para o mesmo caso. Realizados os ajustes, o modelo é validado através da comparação com dados noturnos, obtidos por sondagens de balão cativo realizadas em um sítio experimental localizado numa área desmatada da região Amazônica, nos meses de julho e outubro de 2001 e de novembro de 2003. São simulados os perfis verticais de temperatura potencial e de umidade específica e comparados com as observações de 13 diferentes noites. A avaliação do desempenho das diferentes formulações utilizadas é feita através de uma análise estatística, utilizando dados de todas as noites. Observou-se, que os perfis verticais de temperatura potencial foram melhor representados do que os de umidade específica. Embora o modelo tenha sido capaz de reproduzir as diferentes condições de estabilidade, as noites mais estáveis foram melhor simuladas. Finalmente, é acrescentado um esquema que resolve o balanço de energia em superfície ao modelo, sendo utilizadas para este fim as condições iniciais da noite de 28 de julho de 2001. Este esquema foi utilizado para avaliar como as variáveis atmosféricas simuladas dependem da intensidade do vento no topo do domínio vertical, para as diferentes formulações analisadas e com ou sem a utilização do balanço de superfície.

Made available in DSpace on 2015-05-14T12:09:36Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 5605900 bytes, checksum: 3d25379d8d6eb2b9a5d187b806036974 (MD5) Previous issue date: 2014-05-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This study analyzed the influence of the soil s usage and occupation on the surface temperature variance and on radiation balance in Joao Pessoa city. For that, it was used remote sensing techniques, Geographic Information Systems and SEBAL algorithm. For the soil s usage and occupation classification, and the determination of emissivity, albedo, NDVI, IAF and SAVI were used, and for surface temperature and radiation balance, Landsat 5-TM satellite s images was used, referring to november 5, 1991; August 26, 2006; and October 8, 2010.The usage and occupation of João Pessoa s soil analyses showed that during the years of 1991, 2006 and 2010, the city had a considerable increase of the urban mesh above herbaceous vegetation and bare soil. The surface temperature has shown greater values above urban area and bare soil on the last three years, above all on 1991 which obtained maximum temperature values, with average of 31.4°C above urban area and 31.1°C above bare soil. The radiation balance images and statistic values has shown that the highest values of Rn was founded above arboreal/shrubby vegetation and water for all the years, above all on 2010 when was obtained the highest values of Rn for all soil usages, which the averages were 717.5W/m² above water, and 703.2W/m² above arboreal/shrubby vegetation. The relationship between the albedo of soil usages (urban and herbaceous vegetation) with the temperature and radiation balance, has shown that it was satisfactory, indicating the method efficiency for estimate the quoted parameters with the targets analyzed for João Pessoa city. The temperature and radiation balance results found on this study, obtained through SEBAL and satellite images, allows to conclude that the values has shown match variances with those showed in the literature for similar soil usages / Este trabalho analisou a influência do uso e ocupação do solo na variabilidade da temperatura da superfície e no saldo de radiação na cidade de João Pessoa. Para tanto, foram utilizadas técnicas de sensoriamento remoto, Sistemas de Informações Geográficas e o algoritmo SEBAL. Para a classificação do uso e ocupação do solo e a determinação dos valores de emissividade, albedo, NDVI, IAF, SAVI, temperatura de superfície e saldo de radiação à superfície, foram utilizadas imagens do satélite Landsat 5-TM referente aos dias 5 de novembro de 1991, 26 de agosto de 2006 e 8 de outubro de 2010.A análise do uso e ocupação do solo da cidade de João Pessoa apontou que no decorrer dos anos de 1991, 2006 e 2010 a cidade teve um considerável crescimento da malha urbana sobre áreas de vegetação herbácea e solo exposto. A temperatura da superfície apresentou maiores valores sobre área urbana e solo exposto nos três anos, sobretudo em 1991 que obteve valores máximos de temperatura, com média de 31,4ºC sobre área urbana e de 31,1ºC sobre solo exposto. As imagens do saldo de radiação e os valores estatísticos mostraram que os maiores valores de Rn foram encontrados sobre vegetação arbórea/arbustiva e água para todos os anos, sobretudo em 2010 onde foram obtidos os maiores valores de Rn para todos os usos do solo, cujas médias foram de 717,5W/m² sobre água e 703,2W/m² sobre vegetação arbórea/arbustiva. A relação entre o albedo dos usos do solo (urbano e vegetação herbácea) com a temperatura e o saldo de radiação, mostrou-se satisfatórios, indicando a eficiência do método na estimativa dos parâmetros citados com os alvos analisados para a cidade de João Pessoa. Os resultados de temperatura e saldo de radiação encontrados nesta pesquisa, obtidos através do SEBAL e das imagens de satélite, permitem concluir que os valores apontaram variações condizentes com os apresentados na literatura para usos do solo similares

This diploma thesis deals mainly with utilization of plasma in technological aplications. The introductory part is apllied to the theoretical description of plasma generated by the surfatron. This launcher works with the frequency of 2,45 GHz and it is able to excite the surface wave, that sustains plasma column in a quartz tube. Plasma generated by surfatron was used for modification of surface properties of polyethylen to change its surface energy. By changing of surface energy it was reached of higher hydrophilicity. Plasma generated by surfatron was diagnosed in detail during experiments in a continual regime as well as in a pulse one with a help of a single {--} probe and a double {--} probe Langmuir measurement. In this diploma thesis there is discussed influence of pressure, power and other experimental options.

This thesis consists of two parts and nine chapters. The first part (Part I) presents theoretical studies on non-radiative mode of excitation energy transfer (EET) in donor-acceptor (D-A) systems involving metal nanoparticles. Part I contains four chapters and describes EET in following different D-A systems: (i) dye and a spherical metal nanoparticle of different sizes, (ii) two spherical metal nanoparticles, and (iii) two prolate shaped metal nanoparticles at different relative orientations. Part II provides a detailed study on the origin of photochemical funneling of excitation energy in conjugated polymers like poly-[phenylenevinylene] (PPV) and consists of three chapters. The ninth chapter provides a concluding note. The thesis begins with a basic introduction on Forster resonance energy transfer(FRET), presented in chapter 1. This chapter provides a detail derivation of Forster’s rate expression for a non-radiative process of EET from a donor to an acceptor molecule and discusses the limitations of Forster theory. The chapter highlights the huge success of FRET technique in understanding biological processes assisted by changes in conformations of biopolymers under conditions where Frster theory is valid. The chapter also discusses practical limitations of FRET technique such as use of pre-averaged value of orientation factor and photobleaching of dye molecules. Part I starts with chapter 2 which explains the advantages of using metal nanoparticles over dye molecules in D-A systems. The chapter discusses recent experimental re-ports of excitation energy transfer to nanoparticles, now commonly referred to as nanoparticle surface energy transfer (NSET). Theories describing the process of EET from a dye molecule (dye molecule is assumed to be a point dipole) to a planar metallic surface are discussed. In the case of energy transfer from a donor dye molecule to a planar metallic surface, the distance dependence of the rate of EET is found to vary as 1/d4 where dis a distance from the center of a dye molecule to the metallic surface. This is unlike conven-tional FRET where rate of EET follows 1/R6 distance dependence with R as a distance between the centers of D and A. Also, a recent experimental study by Yun et al [J. Am. Chem. Soc. 127, 3115 (2005)] on energy transfer from a dye molecule to a spherical gold nanoparticle reports that the rate of EET follows 1/d4 distance dependence. The remaining chapters of this part focus on understanding this deviation from the Forster theory in different D-A systems. Chapter 3 describes quantized electro-hydrodynamic approach used to model the plasmonic excitations in metal nanoparticles. The optical absorption frequencies of nanoparticles computed here are subsequently used in chapters 4 and 5 for the calculation of the rate of EET. The chapter discusses the merits and de-merits of electro-hydrodynamic approach in comparison to other available techniques. The electro-hydrodynamic method of calculating the absorption frequencies provide a physically appealing, mathematically simple and numerically tractable approach to the problem and is also at the same time, semi-quantitatively reliable. The optical frequencies obtained as a function of size and aspect ratio of metal nanoparticles are found to be in good agreement with physical predictions. Chapter 4 studies the distance dependence of rate of EET for a D-A system similar to one studied by Yun et al [J. Am. Chem. Soc. 127, 3115 (2005)]. The chapter contains the relevant derivations of the quantities required for computing the interaction matrix elements. The dependence of the rate of EET on R is found surprisingly to be in agreement with Forster theory even at intermediate distances compared to the size of spherical nanoparticles (a). However, the dependence of rate of EET on d is found to vary as 1/dσwith σ=3 - 4 at intermediate distances which is in good agreement with the experimental results of Yun et al. At large values of d, the distance dependence of rate is found to vary as 1/d6 . The chapter discusses the physical basis behind these results. The theory predicts a non-trivial dependence of rate on the size of a nanoparticle which ultimately attains the asymptotic a3 size dependence. The rate of EET is also studied for different orientations of dye molecule. Chapter 5 studies surface plasmon mediated EET between two metal nanoparticles. The rate of EET between two prolate and spherical shaped silver nanoparticles is studied as a function of Rand d. d, in present chapter denotes surface-to-surface separation distance between two nanoparticles. In case of EET between two non-spherical nanoparticles, even at separations larger than the size of the nanoparticle, a significant deviation from 1/R6 dependence is obtained. However, 1/R6 distance dependence of EET rate is found to be robust for spherical nanoparticles over an entire range of separations. The deviation of rate from 1/R6 distance dependence becomes more pronounced with in-crease in the aspect ratio of the nanoparticle. The relative orientation of the nanoparticles is found to markedly influence the R-dependence of EET rate. Interestingly, the relative orientation of nanoparticles effect the d-distance dependence of the rate to a lesser extend in comparison to the R-dependence of the rate. Therefore, we predict that for non-spherical nanoparticles studying EET rate as a function of will provide more conclusive results. The chapter also discusses the size dependence of rate of EET for this particular D-A system. In Part II, excitation energy transfer (EET) in a conjugated polymer is studied. To start with, chapter 6 provides a brief introduction to photophysics of conjugated polymers. The chapter discusses the nature of photoexcitations in these systems and stresses on the influence of polymer’s morphology on the optical properties of conjugated polymers. Chapter 7 describes the theory used for modeling conjugated polymer chain. A polymer chain consists of number of spectroscopic units (chromophores) of varying lengths. The average length of chromophores in conjugated polymer depends on defect concentration. In the present study we treat an excitation generated on each chromophore within “particle-in-a-box” formalism but one that takes into account the electron-hole interactions. The transition dipole moments and the radiative rates are computed for different lengths of chromophores with parameters appropriate for PPV chain. These quantities are used in chapter 8 for calculating the absorption and emission spectra of conjugated polymer chains at different defect concentrations. The main aim of Chapter 8 is to understand the origin of photochemical funneling of excitation energy in conjugated polymers. PPV chain is modeled as a polymer with the length distribution of chromophores given either by a Gaussian or by a Poissonian distribution. We observe that the Poissonian distribution of length segments explains the optical spectra of PPV rather well than the Gaussian distribution. The Pauli’s master equation is employed to describe the excitation energy transfer among different chromophores. The rate of energy transfer is assumed to be given here, as a first approximation, by the well-known Forster expression. The observed excitation population dynamics confirm the photochemical funneling of excitation energy from shorter to longer chromophores of the polymer chain. The calculations show that even in steady state more than one type of chromophore contribute towards the emission spectrum. The observed difference between the calculated emission spectra at equilibrium and in steady state indicates the existence of local domains in a polymer chain within which the non-radiative excitation energy transfer from shorter to longer chromophores take place. These results are found to be in agreement with recent experimental reports. The concluding chapter 9 gives a brief summary of the outcome of the thesis and ends up with suggestion of a few future problems which in current scenario are of great interest.

Povrchy inorganických materiálov, zvlášť kovov alebo kovových oxidov, ktoré sú často charakteristické vysokou povrchovou energiou, sú zvyčajne kontaminované adsorbovanými organickými molekulami. Tieto molekuly majú na povrchy zväčša nepriaznivý vplyv, do značnej miery napríklad ovplyvňujú funkcionalitu a výkonnosť polovodičov a znemožňujú, prípadne sťažujú prevedenie povrchových úprav na povrchoch kovov aj keramík. Taktiež majú nepriaznivý vplyv na priľnavosť. Adsorbované častice spôsobujú znižovanie hydrofilicity povrchu. Hydrofilicita, adhezivita a zmáčavosť povrchu sa veľmi dobre posudzujú prostredníctvom merania kontaktného uhlu. V tejto práci je značná pozornosť venovaná práve meraniu statického kontaktného uhlu. [10] Samotné meranie kontaktného uhlu je možné vykonať rôznymi spôsobmi, v tejto práci bol však použitý najvhodnejší prístup, a to metódou „sessile-drop“, teda pokladanej alebo depozitovanej kvapky na meraný povrch. K meraniu bol využitý klasický „sessile-drop goniometer“, teda aparatúra, ktorá pozostávala z nastaviteľného stojanu na vzorky, nad ktorým bol umiestnený zdroj svetla, a objektívu fotoaparátu, ktorý bol prepojený s kamerou zabudovaného smartfónu. Meranie prebiehalo tak, že kvapka s objemom 3L destilovanej superčistej vody bola depozitovaná na povrch substrátu pomocou mikroinjekčnej striekačky. Cieľom tejto práce bolo nielen stanoviť kontaktné uhly a porovnať ich hodnoty medzi rôznymi typmi materiálov navzájom a po upravách tepelného a/lebo chemického charakteru. Vyhodnotené údaje zachycovali zmeny, ku ktorým došlo na povrchoch daných keramických materiálov pri adsorpcii organických molekúl. Proces tepelnej úpravy (kalcinácia na teplote 800°C, následne pokles na teplotu 600°C, po celkovú dobu 16 hodín) bol aplikovaný na všetkých typoch vzoriek, kde niektoré sa medzi sebou líšili teplotou slinovania. Ihneď po kalcinácii boli vzorky podrobené meraniu kontaktných uhlov, z ktorého jasne vyplynulo, že hydrofilicita a zmáčavosť povrchu sa zvýšila. Tento jav bol pozorovaný na všetkých vzorkách, a na všetkých vzorkách sa hodnoty kontaktného uhlu líšili veľmi významne od hodnoty, ktorá bola získaná v tzv. primárnom meraní. Všetky detailné hodnoty a vyhodnotené výsledky sú posudzované v časti diskusia. Ďalšou úpravou povrchu, ktorá bola vykonaná na vybraných vzorkách, bolo čistenie povrchu etanolom. Proces bol opäť realizovaný na všetkých vzorkách. Potom, ako boli zrealizované všetky merania na kalcinovaných vzorkách, boli všetky tieto vzorky ponorené do etanolu na približne 2 hodiny. Po vybratí vzoriek a ich osušení na vzduchu boli uskutočnené ďalšie merania kontaktných uhlov. Výsledky priniesli opäť rozdielne hodnoty v porovnaní s predchádzajúcimi meraniami a sú rozvinuté v časti diskusia.

In industrial use of paint systems a swift processing is crucial. Another very important issue is to improve the quality of the final coating. This report investigates the film formation process of powder coatings, specially the spreading of individual powder particles. The obtained results can be used to understand and control the film formation process. In this way the desired levelling can be achieved and thus the desired gloss or other surface characteristics that may be required. This means that the method could be used when evaluating different polymer and additive combinations that could be used to change film formation behaviour or curing time for powder coating systems to suit various substrates. It makes it possible to avoid and minimize different surface defects as orange peel or cratering in the powder coated film. We used a reflection optical microscope to better understand the film formation process and especially the spreading of a powder melt on surfaces with various surface energies. The obtained data were: the particle diameter, the area, area ratio and the contact angle of the powder particle as a function of time and temperature. This information can be used to derive the surface tension of any powder melt. In this report we evaluate the dependencies of temperature, heat rate and surface energy for powder coatings on different substrates. The method provides information that can be used to optimize the film formation of a specific powder coating/substrate combination. This method can be used to evaluate the powder spreading and levelling on different substrates from a surface tension point of view. We found, as expected, that the powder flows out on a hydrophilic surface and is inhibited by a hydrophobic. The increase of the area ratio on a hydrophilic surface was about five times as the initial area coverage and on a hydrophobic surface only two times the initial area coverage. The contact angle between the melted powder particle on the different surface types could be calculated. The melt surface tension could be calculated since three substrates surfaces with various surface energies were used. The melt surface tension was found to be about 18.5 mN/m. / Sammanfattning Vid industriell användning av ett färgsystem är det viktigt med en snabb och smidig målningsprocess. En viktig del är att förbättra kvaliteten på den färdiga ytan. Denna rapport undersöker filmbildningsprocessen för pulverfärg, närmare bestämt spridningen av individuella pulverpartiklar. Resultaten från utvärderingen av denna metod kan användas för att bättre förstå och få kontroll över filmbildningsprocessen. Med denna undersökningsmetod kan den önskade utslätningen uppnås och därmed den önskade glansen eller annan yteffekt som kan vara önskvärd. Metoden kan användas för att utvärdera olika polymer- och additivkombinationer som kan användas för att ändra filmbildningens uppförande eller bestämma härdningstiden för en pulverfärg att passa ett visst substrat. Metoden gör det möjligt att förhindra och minska olika ytdefekter såsom apelsinskals- eller kratereffekter i pulverfärgens yta. Ett optiskt reflectionsmikroskop användes för att bättre kunna förstå filmbildningsprocessen och särskilt spridningen av smält pulver på substrat med olika ytenergier. De mätdata vi fick var partikeldiameter, area, areaförändring och kontaktvinkeln för pulverpartiklar som funktion av tid och temperatur. Ur denna information kunde pulversmältans ytenergier härledas. I denna rapport utvärderas pulvrets beroende av temperatur, uppvärmning och ytenergi på olika substrat. Denna metod ger information som kan användas för att optimera filmbildningen av en specifik kombination av pulverfärg och substrat. Denna metod kan också användas för att utvärdera pulverspridning och utjämning av färgfilmen på olika substrat med avseende på ytenergierna. Som förväntat flyter pulvret ut på hydrofila ytor och utflytningen ändras på en hydrofob yta. På en hydrofil yta sprider sig partikeln till fem gånger den ursprungliga arean över substratet och motsvarande två gånger för en hydrofob yta. Kontaktvinkeln mellan en smält pulverpartikel på olika sorters substrat från utförda mätningar beräknas utifrån utförda mätningar. Kontaktvinklar mellan pulver och olika substrat kan användas för att beräkna smältans ytspänning. Smältans ytspänning kan beräknas då experiment gjorts på tre sorters ytor med olika kända ytenergier. Smältans ytspänning var 18,5 mN/m. Slutsatsen är att det går att observera och utvärdera resultaten av utsmältningsförloppet för pulverfärg med denna metod.

Soft matter, here, liquids and polymers, have adaptability to a surrounding geometry. They intrinsically have advantageous characteristics from a mechanical perspective, such as flowing and wetting on surrounding surfaces, giving compliant, conformal and deformable behavior. From the behavior of soft matter for heterogeneous surfaces, compliant structures can be engineered as embedded liquid microstructures or patterned liquid microsystems for emerging compliant microsystems. Recently, skin electronics and soft robotics have been initiated as potential applications that can provide soft interfaces and interactions for a human-machine interface. To meet the design parameters, developing soft material engineering aimed at tuning material properties and smart processing techniques proper to them are to be highly encouraged. As promising candidates, Ga-based liquid alloys and silicone-based elastomers have been widely applied to proof-of-concept compliant structures. In this thesis, the liquid alloy was employed as a soft and stretchable electrical and thermal conductor (resistor), interconnect and filler in an elastomer structure. Printing-based liquid alloy patterning techniques have been developed with a batch-type, parallel processing scheme. As a simple solution, tape transfer masking was combined with a liquid alloy spraying technique, which provides robust processability. Silicone elastomers could be tunable for multi-functional building blocks by liquid or liquid-like soft solid inclusions. The liquid alloy and a polymer additive were introduced to the silicone elastomer by a simple mixing process. Heterogeneous material microstructures in elastomer networks successfully changed mechanical, thermal and surface properties. To realize a compliant microsystem, these ideas have in practice been useful in designing and fabricating soft and stretchable systems. Many different designs of the microsystems have been fabricated with the developed techniques and materials, and successfully evaluated under dynamic conditions. The compliant microsystems work as basic components to build up a whole system with soft materials and a processing technology for our emerging society.

No description available.

Orientador: Rogério Pinto Mota / Resumo: Neste trabalho foram produzidos filmes finos de polímeros a partir da técnica de polimerização a plasma dos monômeros dietilenoglicol dimetil-eter (diglime), 2-metil-2-oxazolina (oxazolina) e da mistura de etilenodiamina (EDA) e o gás acetileno (C2H2), obtidos em baixa pressão. Esses materiais podem possuir um conjunto de características que são necessárias para aplicações na área da biomedicina. Os plasmas foram analisados por meio das técnicas de sonda de Langmuir (LP) e de espectroscopia ótica de emissão (OES). A caracterização dos polímeros foi realizada por meio das técnicas de medidas de ângulo de contato e energia de superfície (AC e ES), microscopia de força atômica (AFM), microscopia confocal (MC) e espectroscopia infravermelha por transformada de Fourier (FTIR). As características dos plasmas foram correlacionadas às propriedades dos polímeros a fim de se obter informações sobre os processos de polimerização, objetivando que o processo de produção de materiais com características desejáveis seja feito de forma controlada. Foram observadas temperaturas eletrônicas de elétrons frios entre 0,2 e 1,6 eV, e as densidades de plasmas foram da ordem de 10^15 m^-3. O comportamento da temperatura eletrônica em função da pressão de operação e da potência aplicada aos plasmas foi relacionado à produção de espécies CH, CO e Hα em plasmas de diglime, CH, CN, CO e NH em plasmas de 2-metil-2-oxazolina e CH, CN e NH em plasmas da mistura de EDA e C2H2. A participação dessas espécies... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Plasma polymers obtained by plasma polymerization of diethyleneglycol dimethyl-ether (diglyme), 2-methyl-2-oxazoline (oxazoline) and the mixture of ethylenediamine (EDA) with acetylene (C2H2) were produced in low pressure conditions. These materials might have a set of essential properties to biomedical applications. The plasmas were analyzed by Langmuir probe technique (LP) and optical emission spectroscopy (OES) techniques. Polymer characterization was performed by contact angle and surface energy analysis (AC and ES), atomic force microscopy (AFM), confocal microscopy (MC) and Fourier transform infrared spectroscopy (FTIR). In order to obtain details of polymerization process, plasma characteristics were correlated to polymers properties in order to control the production of materials with desired characteristics. The cold electron temperatures were observed between 0.2 and 1.6 eV and the plasmas densities about 10-15 m -3 . The electronic temperature behavior was analyzed as a function of operating pressure and applied power. This behavior was linked to production of CH, CO and Hα species in diglyme plasmas, CH, CN, CO and NH in 2- methyl-2-oxazoline plasmas and CN, CH and NH species in plasmas of EDA and C2H2 mixture. The mean roughness investigation, the bonds observed by FTIR technique and the deposition rates revealed the role of these species on polymerization processes. The CO species in diglyme plasmas and CN species in plasmas of EDA and C2H2 mixture were responsi... (Complete abstract click electronic access below) / Doutor

Les infrastructures de transport est essentielle au maintien et à l'expansion des activités sociales et économiques dans les régions circumpolaires. À mesure que le climat se réchauffe, la dégradation du pergélisol sous les remblais a entraîné de graves dommages structuraux à la route, entraînant une augmentation importante des coûts d'entretien et une réduction de la durée de vie des infrastructures. Pendant ce temps, l'advection de chaleur déclenchée par les écoulements d’eau souterrains peut altérer le bilan énergétique du remblai et du pergélisol sous-jacent et modifier le régime thermique des remblais routiers. Cependant, peu de recherches ont été effectuées pour comprendre la synergie entre les processus thermiques de surface et souterrains des remblais routiers des régions froides. L'objectif de cette recherche était de comprendre les interactions thermiques entre l'atmosphère, le remblai routier, les écoulements d’eau et le pergélisol dans le contexte du changement climatique. Cette base, de connaissances est nécessaire pour la conception technique, l'entretien des routes et l'évaluation de la vulnérabilité des infrastructures. Les travaux de recherche ont permis de développer de nouvelles méthodes d'analyse thermique pour caractériser et identifier le rôle de l'advection thermique sur le changement de température d'un remblai routier expérimental au Yukon (Canada) en termes d’intensité, de vitesse et de profondeur de l'impact thermique. Les résultats montrent que l'augmentation de la température due aux flux de chaleur advectifs déclenchés par l’écoulement d'eau peut être jusqu'à deux ordres de grandeur plus rapide qu'en raison du seul réchauffement atmosphérique. La recherche a ensuite présenté un bilan énergétique de surface pour quantifier la quantité d'énergie entrant dans le centre et la pente du remblai avec des épaisseurs et des propriétés de neige variables. Le tout a été appuyé par des observations géothermique de plusieurs années et une grande quantité de données météorologiques. Les résultats illustrent que le bilan énergétique de surface est principalement contrôlé par le rayonnement net et moins par le flux de chaleur sensible. Le flux de chaleur transmis à la pente du remblai diminue de façon exponentielle avec l'augmentation de l'épaisseur de la neige et diminue de façon linéaire avec l’installation du couvert de neige et la longueur de la période d’enneigement. De plus, un modèle de bilan énergétique de surface et un modèle cryohydrologique entièrement couplé ont été développés pour étudier l'impact thermique de l'advection de chaleur associée à l'écoulement de l'eau souterraine sur le dégel du pergélisol et le développement de taliks (c.-à-d. zone perpétuellement non gelée dans les zones de pergélisol). Le modèle couplé a réussi à reproduire la tendance à la hausse du plafond du pergélisol (erreur absolue moyenne <0,2 m) au cours de la période 1997-2018. Les résultats montrent que l'advection de chaleur a fourni une source d'énergie supplémentaire pour accélérer le dégel du pergélisol et a doublé le taux d’augmentation de l’épaisseur de la couche active 0,1 m·a-1 à 0,19 m·a-1, par rapport au scénario où aucun écoulement d'eau ne se produit. Le talik s'est initialement formé et développé en fonction du temps sous l’effet combiné des écoulement d’eau, de l'isolation de la neige, de la construction de la route et du réchauffement climatique. Le débit d'eau souterraine a relié des corps isolés de talik et a amené le remblai de la route dans un état thermique irréversible, en raison de la rétroaction de l'eau liquide (effet de chaleur latente) piégée dans le talik. Ces résultats montrent l'importance de l'advection de chaleur induite par l'écoulement d'eau sur le régime thermique de la sous-couche (c.-à-d. la couche de matériau de remblai) et du sous-sol (c.-à-d. le matériau natif sous un remblai) du remblai lorsque le remblai routier intercepte le drainage local. De plus, les résultats obtenus soulignent la nécessité de coupler les processus thermiques de surface et souterrains dans le but d'évaluer la stabilité thermique des routes subarctiques. / Transportation infrastructure is crucial to maintaining and expanding the social and economic activities in circumpolar regions. As the climate warms, degradation of the permafrost causes severe structural damages to the road embankment, leading to large increases in maintenance costs and reductions in its lifespan. Meanwhile, heat advection triggered by mobile water flow can alter energy balance of the embankment and underlying permafrost and modify the thermal regime of road embankments. However, little research has been done to understand the synergy between surface and subsurface thermal processes of cold region road embankments. The overall goal of this research was to elucidate thermal interactions between the atmosphere, the road embankment, mobile water flow, and permafrost within the context of climate change. This knowledge is needed for engineered design, road maintenance, and infrastructure vulnerability assessment. The research first used new thermal analysis to characterize and identify the role of heat advection on temperature change of an experimental road embankment, Yukon, Canada in terms of magnitude, rate and thermal impact depth. It shows that soil temperature increase due to advective heat fluxes triggered by mobile water flow can be up to two orders of magnitude faster than due to atmospheric warming only. The research then presented a novel surface energy balance to quantify the amount of ground heat flux entering the embankment center and slope with varying snow depth and properties, supported by multi-year thermal and meteorological observations. My results illustrate that the surface energy budget is mainly controlled by net radiation, and less by the sensible heat flux. The ground heat flux released at embankment slope exponentially decreased with the increase of snow depth, and was linearly reduced with earlier snow cover and longer snow-covered period. A fully integrated surface energy balance and cryohydrogeological model was implemented to investigate the thermal impact of heat advection associated with subsurface water flow on permafrost thaw and talik (i.e., perennially unfrozen zone in permafrost areas) development. The integrated model successfully reproduced the observed increasing trend of the active layer depth (mean absolute error < 0.2 m) over the 1997-2018 period. The results show that heat advection provided an additional energy source to expedite permafrost thaw, doubling the increasing rate of permafrost table depth from 0.1 m·a-1 to 0.19 m·a-1, compared with the scenario where no water flow occurs. Talik formation and development occurred over time under the combined effect of subsurface water flow, snow insulation, road construction and climate warming. Subsurface water flow connected isolated talik bodies and triggered an irreversible thermal state for the road embankment, due to a local feedback mechanism (latent heat effect) of trapped, unfrozen water in talik. These findings elucidate the importance of heat advection induced by mobile water flow on the thermal regime of embankment subbase (i.e., a layer of fill material) and subgrade (i.e., the native material under an embankment) when the road embankment intercepts the local drainage. Furthermore, the obtained results emphasize the need to couple surface and subsurface thermal processes to evaluate the thermal stability of sub-Arctic roads.