Heat transfer experiments were done on a flat plate to study the effect of internal counter-flow backside cooling on adiabatic film cooling effectiveness and heat transfer coefficient. In addition, the effects of density ratio (DR), blowing ratio (BR), diagonal length over diameter (L/D) ratio, and Reynolds number were studied using this new configuration. The results are compared to a conventional plenum fed case. Data were collected up to X/D =23 where X=0 at the holes, an S/D = 1.65 and L/D=1,2. Testing was done at low L/D ratios since short holes are normally found in double wall cooling applications in turbine components. A DR of 2 was used in order to simulate engine-like conditions and this was compared to a DR of 0.92 since relevant research is done at similar low DR. The BR range of 0.5 to 1.5 was chosen to simulate turbine conditions as well. In addition, previous research shows that peak effectiveness is found within this range. Infrared (IR) thermography was used to capture temperature contours on the surface of interest and the images were calibrated using a thermocouple and data analyzed through MATLAB software. A heated secondary fluid was used as 'coolant' in the present study. A steady state heat transfer model was used to perform the data reduction procedure. Results show that backside cooling configuration has a higher adiabatic film cooling effectiveness when compared to plenum fed configurations at the same conditions. In addition, the trend for effectiveness with varying BR is reversed when compared with traditional plenum fed cases. Yarn flow visualization tests show that flow exiting the holes in the backside cooling configuration is significantly different when compared to flow exiting the plenum fed holes. We hypothesize that backside cooling configuration has flow exiting the holes in various directions, including laterally, and behaving similar to slot film cooling, explaining the differences in trends. Increasing DR at constant BR shows an increase in adiabatic effectiveness and HTC in both backside cooling and plenum fed configurations due to the decreased momentum of the coolant, making film attachment to the surface more probable. The effects of L/D ratio in this study were negligible since both ratios used were small. This shows that the coolant flow is still underdeveloped at both L/D ratios. The study also showed that increasing turbulence through increasing Reynolds number decreased adiabatic effectiveness. / MS / Gas turbine engines are used for multiple applications for power (power plants) or thrust (aircraft propulsion). Engine efficiency is correlated with higher working temperatures, which exceed the melting points of the materials being used. Therefore, more efficient cooling techniques are needed in order to protect the engine turbine components, such as blades and vanes. Relatively cooler air is bypassed from the compressor to the turbine section to cool the turbine components from the high temperatures. The air flows through the turbine components and out through machined holes referred to as film cooling holes. A protective layer, or film, protects the external region of the blade or vane. Previous research has found that the geometry of the airfoils used and the flow conditions play a major role in heat transfer. Most of the relevant research use a model that contains one-sided heat transfer. The present study focuses on combined backside and film cooling heat transfer, with different geometries and flow conditions, using a steady-state model for the data reduction procedure.

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<p>Granskande av ritningar, tidsplaner och kalkyler för referensprojektet Hus N i Växjö har hjälpt oss kartlägga skalväggars för- och nackdelar. Från intervjuer har vi sedan kunnat se liknelser och skillnader om vad olika yrkesfolk i samma bransch tycker, sedan därifrån dragit slutsatser. Det är inte alltid enkelt att avgöra vilken byggnadsmetod som är att föredra för att projektet ska vara kostnadseffektivt, prefabricerat eller platsbyggd. Faktorer som byggnadens konstruktion, årstid, arbetsmiljö, resurser, tid och kostnad ska ta hänsyns till.</p><p>Genom att planera bättre, öka förtillverkningen, skapa en bättre samverkan mellan byggherrar, konsulter, entreprenörer, underentreprenörer och materialleverantörer, så anser man allmänt att man kan öka industrialiseringen av byggandet. Då man kan få kortare byggtider och lägre totalkostnader.</p><p><p><p> </p></p></p> / <p>Checking of blueprints, time plans and calculations for the reference project house-N in Växjö have helped us to map double walls' advantages and disadvantages. From interviews, we have seen similarities and difference what different people in same sector think, and how they make their conclusions. It is not always simple to decide the preferable building method in order to make the project cost-effective, prefabricated or suite-built. Factors such as the building's frame, season, work environment, resources, time and cost take considerations' to.</p><p>Through better planning, increase of prefabrication and achieving a better collaboration between developers, consultants, contractors, subcontractors and material suppliers, it is generally considered that it may increase the industrialization of the building. Then procurement of shorter construction times and lower overall costs can be achieved </p>

Granskande av ritningar, tidsplaner och kalkyler för referensprojektet Hus N i Växjö har hjälpt oss kartlägga skalväggars för- och nackdelar. Från intervjuer har vi sedan kunnat se liknelser och skillnader om vad olika yrkesfolk i samma bransch tycker, sedan därifrån dragit slutsatser. Det är inte alltid enkelt att avgöra vilken byggnadsmetod som är att föredra för att projektet ska vara kostnadseffektivt, prefabricerat eller platsbyggd. Faktorer som byggnadens konstruktion, årstid, arbetsmiljö, resurser, tid och kostnad ska ta hänsyns till. Genom att planera bättre, öka förtillverkningen, skapa en bättre samverkan mellan byggherrar, konsulter, entreprenörer, underentreprenörer och materialleverantörer, så anser man allmänt att man kan öka industrialiseringen av byggandet. Då man kan få kortare byggtider och lägre totalkostnader. / Checking of blueprints, time plans and calculations for the reference project house-N in Växjö have helped us to map double walls' advantages and disadvantages. From interviews, we have seen similarities and difference what different people in same sector think, and how they make their conclusions. It is not always simple to decide the preferable building method in order to make the project cost-effective, prefabricated or suite-built. Factors such as the building's frame, season, work environment, resources, time and cost take considerations' to. Through better planning, increase of prefabrication and achieving a better collaboration between developers, consultants, contractors, subcontractors and material suppliers, it is generally considered that it may increase the industrialization of the building. Then procurement of shorter construction times and lower overall costs can be achieved

Measurement of all the mechanical properties of carbon nanotubes is extremely difficult because of its small size. In the present work, all the five transverse isotropic properties of single wall carbon nanotubes (SWCNTs) and double wall carbon nanotubes are estimated through molecular structural mechanics for different chirality, length and assumed thickness. Armchair, zigzag & chiral SWCNTs and polychiral DWCNTs are considered for the analysis. Longitudinal and lateral Young’s modulus; longitudinal and lateral Poisson’s ratio and shear modulus are estimated for 1080 SWCNTs and 1170 polychiral DWCNTs. Effect of temperature on all the properties of SWCNT are investigated. Modal characterization of SWCNT is carried out in base fixed condition and different mode shapes viz. axial, torsion and bending mode shapes are identified based on the effective mass. Once the transverse isotropic properties of SWCNTs are estimated, these are used to estimate the transverse isotropic properties of nanocomposites embedded with SWCNT agglomerates. During the manufacturing of nanocomposite, SWCNT agglomerates are formed due to sticking of number of SWCNTs. Parametric studies are carried out to see the effect of SWCNT length on the properties of nanocomposite. Empirical formulae for all the transverse isotropic properties of SWCNT at room temperature and elevated temperature; frequency of SWCNT are derived. Empirical formulae for polychiral DWCNT transverse isotropic properties are estimated. Input for these empirical formulae are the length, chirality and assumed thickness. Empirical formulae were also derived for nanocomposite embedded with different number of SWCNTs having different chirality. The derived empirical formulae were validated with available analytical and experimental results for some sample cases.

Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-06-07T17:57:54Z No. of bitstreams: 1 JoseEdilsonSilva.pdf: 1819277 bytes, checksum: 391131ff8e28cc1636472453e9b94fd8 (MD5) / Made available in DSpace on 2017-06-07T17:57:54Z (GMT). No. of bitstreams: 1 JoseEdilsonSilva.pdf: 1819277 bytes, checksum: 391131ff8e28cc1636472453e9b94fd8 (MD5) Previous issue date: 2009-11-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico e Tecnológico do Maranhão (FAPEMA) / In this work we studied the adsorption and the encapsulation of the amino acid lysine with the double wall carbon nanotube (DWCNT) (8,0)@(17,0). This study is of interest for applications technological, because it allows to analyze the carbon nanotubes in di erent atmospheres and also to give it the speci c functions with biological goals. To treat with details the properties structural and electronics of the considered system, we used one theoretical approach based on calculations of rst principles making use of the density functional theory with the approach of the generalized gradient to describe the exchange and correlation term. The calculations were accomplished using the program SIESTA. When the system reached the expected convergence, the analysis of electronic properties through the structure of the band and density of states showed signi cant changes in behavior of system. System (8,0)@(17,0) DWCNT with lysine interacting on the outer wall begins to show character metallic, while the system with the lysine encapsulated energy gap is 0.30 eV to 0.19 eV. Also the degenerate levels of the system pure lose the degeneration when amino acid lysine is adsorbed and also encapsulated in DWCNT. To check the stability of these systems, we calculate the binding energy, which has a value of -1.63 eV indicating that this system is highly stable, while the (8,0)@(17,0) DWCNT with lysine encapsulated has a binding energy of the order of 3.24 eV, indicating the low stability. / Neste trabalho estudamos a adsorção e o encapsulamento do aminoácido lisina com o nanotubo de carbono de camada dupla (DWCNT) (8,0)@(17,0). Este estudo é de interesse para aplicações tecnológicas, pois permite analisar os nanotubos de carbono em diferentes ambientes e também dar-lhe funções específicas com metas biológicas. Para tratar com detalhes as propriedades estruturais e eletrônica do sistema considerado, utilizamos uma abordagem teórica baseada em cálculos de primeiros princípios, fazendo uso da teoria do funcional da densidade com a aproximação do gradiente generalizado para o termo de troca e correlação. Os cálculos foram realizados usando o programa SIESTA. Quando o sistema atingiu a convergência esperada, a análise das propriedades eletrônicas através da estrutura de banda e da densidade de estado mostraram mudan ças significativas no comportamento do sistema. O sistema DWCNT (8,0)@(17,0) com a lisina interagindo na parede externa passa a apresentar caráter metálico, enquanto que o sistema com a lisina encapsulada a energia do gap passa de 0.30 eV para 0.19 eV. Também os níveis degenerados do sistema puro perdem a degenerescência quando o aminoácido lisina é adsorvido e também encapsulado ao DWCNT. Para veri ficar a estabilidade destes sistemas, calculamos a energia de ligação, a qual apresenta um valor de -1.63 eV indicando que este sistema é altamente estável, enquanto que o DWCNT (8,0)@(17,0) com a lisina encapsulada tem uma energia de ligação da ordem de 3.24 eV, indicando a baixa estabilidade.

La perméabilité de la peau ne permet pas la diffusion passive de grandes molécules, comme l'insuline ou encore les plasmides d'ADN, au travers de l'épiderme dans le but d'atteindre les vaisseaux sanguins. Cela est uniquement possible pour des molécules de plus petite taille comme la nicotine par exemple. Il existe différentes voies alternatives (électrique, mécanique, thermique) de délivrance transdermique permettant d'éviter l'utilisation de la seringue d'injection, qui pourraient améliorer la qualité de vie des patients atteints de maladies comme le diabète. Ces méthodes incluent par exemple les micro-aiguilles, l'électro-perméabilisation, et l'iontophorèse. L'électroperméabilisation permet, via l'application d'un champ électrique, d'augmenter momentanément la perméabilité de la peau et par conséquent de permettre le passage transdermique de molécules de haut poids moléculaire. L'objectif de ces travaux de thèse était de concevoir et de réaliser un patch nanocomposite à base de nanotubes de carbone permettant de stocker, mais également de relarguer un médicament lorsque qu'il est soumis à une électrostimulation. Pour ce faire, différents polymères ainsi que différentes techniques de mise en forme ont été explorées et développées pour permettre de démontrer la faisabilité de notre approche. Les études ont permis de proposer et de développer un hydrogel nanocomposite biocompatible comportant une matrice polymère agarose et contenant de nanotubes de carbone biparois dans le but d'améliorer les propriétés à la fois électriques et mécanique du matériau. Nous en avons étudié les différentes caractéristiques telles que la microstructure, la capacité de stockage et de relargage, ainsi que les propriétés électriques. Dans le contexte général de précaution en relation avec la mise en œuvre de nanoparticules, et sur la base de travaux antérieurs démontrant l'innocuité des nanotubes utilisés lorsqu'ils ne sont pas en contact direct avec des cellules. Nous avons aussi démontré qu'il n'y a pas de relargage des nanotubes dans des conditions extrêmes (sans électrostimulation) de température en milieu sueur artificielle. L'avancée de ces travaux a permis d'effectuer les premiers tests de délivrance transdermique ex-vivo sur peau de souris et a démontré ainsi la faisabilité et l'intérêt d'utiliser les nanotubes de carbones biparois dans une matrice en polymère pour la délivrance transdermique électrostimulée de molécules de masse molaire de l'ordre de celle de l'insuline. Cette thèse en co-direction alliant la Science des Matériaux (CIRIMAT) et la Science du Vivant (IPBS) a réuni différentes compétences lui donnant un véritable contexte interdisciplinaire. Elle s'est intégrée dans un projet de plus grande ampleur associant la Sociologie et le Droit (Défi Nano CNRS), centré sur le cas du diabète. Ceci a permis de démontrer l'intérêt de développer un tel dispositif (du point de vue des médecins et des patients), mais aussi en nous orientant vers un dispositif médical afin d'éviter de futurs écueils juridiques en termes d'application. / The permeability of skin does not allow the passive diffusion across epidermis to reach blood vessels for large molecular weight molecules such as insulin or DNA plasmids. This is possible only for small molecules such as nicotine, for example. Alternative routes of transdermal delivery exist (thermal, electrical, mechanical) that avoid injections and improve the quality of life of patients suffering of diseases like diabetes. These methods known as "Transdermal Drug Delivery" (TDD) technologies, include for example electroporation, iontophoresis and micro needles. In particular, electropermeabilisation is known to temporarily increase the permeability of the skin, consequently allowing transdermal passage of molecules of high molecular weight. The aim of this work was to conceive and elaborate an innovative needle-free device for transdermal drug delivery, made of a nanocomposite material containing carbon nanotubes to improve both electrical and mechanical properties of the biocompatible polymer matrix. This nanocomposite device aims at permeabilising the skin and delivering drug molecules simultaneously when electrically stimulated. To reach this goal, we investigated different biocompatible polymers and shaping processes, finally demonstrating the feasibility of the fabrication of such a device. We have developed a bio-sourced and biocompatible nanocomposite hydrogel with an agarose matrix and containing double-walled carbon nanotubes, and characterized it in terms of microstructure, storage and release capacity, as well as electrical properties. In the general context of precaution in relation to the implementation of nanoparticles, and on the basis of previous work demonstrating the safety of nanotubes used when they are not in direct contact with cells, we have also demonstrated that there is no release of the nanotubes under extreme conditions of temperature (without electrostimulation) in an artificial sweat medium. Finally, we have demonstrated the feasibility of its first use as a TDD system using an ex vivo mouse skin model. These results provide good evidence that the use of double-walled carbon nanotubes makes possible the transdermal delivery of large molecules with a molecular weight similar to insulin with such a nanomaterial. This thesis was in co-direction, combining Materials Science (CIRIMAT) and Life Science (IPBS) in order to gather different skills, giving it a real interdisciplinary context. Moreover, this work was integrated into a larger project (CNRS, "Nano challenge"), also including Sociology and Law, focusing on diabetes. This has demonstrated the actual demand for such a device from both the medical doctors and the patients, but also directed our work towards a medical device thanks from the juridical point of view.

Les structures à double paroi sont largement utilisées dans la lutte contre les nuisances sonores et vibratoires en raison de leur supériorité en terme d'isolation acoustique sur les parois simples. Parmi les exemples typiques on peut citer les doubles vitrages, le fuselage des avions, les véhicules, etc. Dans ce contexte, nous nous sommes intéressés à l'étude expérimentale et numérique du comportement vibroacoustique des doubles parois feuilletées. Le système étudié est composé de deux plaques sandwichs à cœur viscoélastique séparées par une cavité remplie d'air. Nous avons développé un modèle éléments finis basé sur une formulation variationnelle impliquant le déplacement en tout point de la structure et la pression acoustique dans la cavité d'air. Due aux propriétés mécaniques complexes du matériau viscoélastique utilisé dans le cœur des panneaux, cette formulation est complexe et dépend de la fréquence. La résolution de ce modèle par les méthodes directes a un coût numérique exorbitant. Nous avons réussi à développer un modèle d'ordre réduit à faible coût numérique capable de prédire la transmission sonore quelque soit le domaine fréquentiel d'étude. Ce modèle, basé sur la méthode de superposition modale, nécessite le calcul des modes découplés solide et acoustique du système. Les modes solides sont les modes réels et non amortis des panneaux sandwich sans charge de pression acoustique à l'interface fluide-structure, tandis que les modes acoustiques sont les modes de la cavité acoustique avec des conditions aux limites de parois rigides à l'interface fluide-structure. Pour valider notre modèle numérique, nous avons réalisé des mesures expérimentales de vitrages simples, feuilletés et doubles selon la norme ISO 140. Cette norme concerne la mesure de l'isolement acoustique des immeubles et des éléments de construction. Les comparaisons entre les résultats numériques et expérimentaux montrent une assez bonne corrélation entre les deux approches. / Double-wall structures are widely used in noise control due to their superiority over single-leaf structures in providing better acoustic insulation. Typical examples include double glazed windows, fuselage of airplanes, vehicles, etc. In this context, we are interested in experimental and numerical study of the vibro-acoustic behavior of double-wall sandwich panels with viscoelastic core coupled to an acoustic enclosure. A finite element formulation is derived from a variational principle involving structural displacement and acoustic pressure in the fluid cavity. Since the elasticity modulus of the viscoelastic core is complex and frequency dependent, this formulation is complex and nonlinear. Therefore, the direct solution of this problem can be considered only for small model sizes. We successfully developed a reduced order-model to predict the sound transmission in any frequency range at a lower numerical cost. This model, based on a normal mode expansion, requires the computation of the uncoupled structural and acoustic modes. The uncoupled structural modes are the real and undamped modes of the sandwich panels without fluid pressure loading at fluid-structure interface, whereas the uncoupled acoustic modes are the cavity modes with rigid wall boundary conditions at the fluid-structure interface. Our numerical model is validated by means of experiments realized on simple, double and laminated glazing according to ISO 140 standards. This standard concerns the measurement of sound insulation in buildings and of building elements. The numerical predictions agree reasonably well with experiments.

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