A key challenge for three dimensional (3D) integrated circuits (ICs) is thermal management. There are two main thermal challenges in typical 3D ICs. First, in the homogeneous integration with multiple high-power tiers, an effective cooling solution that scales with the number of dice in the stack is needed. Second, in the heterogeneous integration, an effective thermal isolation solution is needed to ‘protect’ the low-power tier from the high-power tier. This research focuses to address these two thermal challenges through hybrid microfluidic cooling and thermal isolation technologies. Within-tier microfluidic cooling is proposed and demonstrated to cool a stack with multiple high-power tiers. Electrical thermal co-analysis is performed to understand the trade-offs between through silicon via (TSV) parasitics and heat sink performance. A TSV-compatible micropin-fin heat sink is designed, fabricated and thermally characterized in a single tier, and benchmarked with a conventional air-cooled heat sink. The designed heat sink has a thermal resistance of 0.269 K·cm2/W at a flow rate of 70 mL/min. High aspect ratios TSVs (18:1) are integrated in the micropin-fins. Within-tier microfluidic cooling is then implemented in 3D stacks to emulate different heating scenarios, such as memory-on-processor and processor-on-processor. Air gap and mechanically flexible interconnects (MFIs) are proposed for the first time to decrease the vertical thermal coupling between high-power (e.g. processor) and low-power tiers (e.g. memory or nanophotonics). A two-tier testbed with the proposed thermal isolation technology is designed, fabricated and tested. Compared with conventional 3D integration approach, thermal isolation technology helps reduce the temperature at a fixed location in the low-tier by 12.9 °C. The resistance of a single MFI is measured to be 46.49 mΩ.

Cette thèse a été consacrée à l’étude du Si poreux comme matériaux à faible conductivité thermique (k) pour application aux dispositifs thermoélectriques à base de Si. D’autres paramètres thermoélectriques, comme par exemple le coefficient Seebeck de ce matériau, ont été également étudiés.Si poreux est un matériau complexe composé de nanostructures de Si séparées de vide. Quand la porosité est élevée, sa conductivité thermique est bien inférieure à celle de Si cristallin. Nous avons étudié la conductivité thermique de Si poreux de différentes morphologies et porosités dans la gamme de températures 4.2-350K. Les mesures à T<20K sont les premières dans la bibliographie et ont montré une saturation de k en fonction de T pour ces températures. A des températures supérieures à 20K, k augmente régulièrement avec la température. La dépendance de température de k de Si poreux a été interprétée en considérant des modèles théoriques, basées sur la nature “fractal” de Si poreux. Nous avons calculé la dimension fractale de Si poreux par des images de microscopie électronique à balayage (SEM) et l’algorithme de “box counting”.Deux méthodes différentes ont été utilisées pour mesurer k: la méthode à courant direct (dc) combinée avec une analyse FEM et la méthode 3ω. Nous avons proposé deux approches améliorées pour extraire k du signal de potentiel 3ω en fonction de la fréquence. La première considère l’accord des résultats expérimentaux avec la solution asymptotique intégrale de la formule de Cahill, et la seconde fait une analyse des résultats expérimentaux en solvant l’équation temporelle de transfert de chaleur par des éléments finis. Plus précise est la méthode 3ω combinée avec des éléments finis. Les résultats correspondants sont en bon accord avec ceux obtenus par la méthode dc.Nous avons aussi étudié le Si poreux comme matériau thermoélectrique. Dans ce cas, le Si poreux peut être intéressant si il a une faible porosité, car le matériau à haute porosité est très résistive. Dans ce but, nous avons déterminé le coefficient Seebeck (S) des membranes de Si poreux de différentes porosités dans la gamme 40-84%, en utilisant un dispositif de mesure spécialement développé à cet effet. Pour des échantillons de porosité 51%, la valeur de coefficient S est de 1mV/K, bien supérieure à celle le Si cristallin. La dépendance de S de la porosité n’est pas monotone, et ceci est attribué à une combinaison des effets de filtrage d’énergie, des collisions des phonons et interactions phonon-porteurs électriques. Les résultats obtenus sont basées sur des mesures de photoluminescence (PL) et observations microscopiques à transmission (TEM). Nous avons enfin conclue que, malgré le coefficient S très élevé, le Si poreux n’est pas adéquat comme matériau thermoélectrique à cause de sa faible conductivité électrique, qui diminue en augmentant la porosité à cause de la résultante déplétion de porteurs.Nous avons aussi étudié des films minces polycristallins dopés avec du Bore. Ces films sont très intéressants comme matériaux thermoélectrique, car ils sont compatibles avec les procédés de fabrication des circuits intégrés de Si. Leur performance thermoélectrique est améliorée par diminution de la taille des grains. Des films minces polycristallins d’épaisseur entre 100 et 500nm ont été étudiés. Tous leurs paramètres thermoélectriques ont été mesurés et nous avons trouvé que le facteur de performance thermoélectrique zT augmente d’un facteur 3 en diminuant l’épaisseur de 500 à 100nm ceci étant attribué à la diminution de la taille des grains dans les films, conduisant à zT = 0.033, qui est la meilleure valeur reporté dans la littérature.Ce résultat compétitif augmente le potentiel d’utilisation des films polycristallins dans des dispositifs thermoélectriques efficaces, compatibles à la technologie de Si. / This thesis is devoted to the thermal conductivity and other thermoelectric properties of porous silicon (PSi) and thin polycrystalline Si films (thickness: 100-500 nm).PSi is a complex material composed of a Si skeleton of interconnected nanowires and dots, separated by voids. When it is highly porous, its thermal conductivity is very low, even below that of the amorphous Si. This makes it a good material for use as a thermal isolation platform on the Si wafer. In addition, its Seebeck coefficient is much higher than that of bulk c-Si.We studied k of PSi layers with different morphologies and porosities, in the temperature range 4.2-350K. The measurements below 20K are the first reported in the literature. A plateau-like dependence on temperature was observed for T below 20K, while above this temperature a monotonic increase with T is observed. The observed behaviour was interpreted using known theoretical models, based mainly on the fractal nature of PSi. PSi was characterized as a fractal material by calculating its fractal dimension using SEM images and the box counting algorithm.Two different methods were used to determine porous Si thermal conductivity: the DC method combined with FEM analysis and the 3ω method. Concerning the 3ω method, two improved approaches were proposed for extracting k from the 3ω voltage as a function of frequency: the first uses a fitting of the experimental data to the asymptotic solution of the Cahill’s integral formula, and the second is based on the analysis of the experimental data by combining them with a solution of the transient heat transfer equation using FEM analysis. The results in this second case were more accurate and in very good agreement with the DC method.We also measured the Seebeck coefficient (S) of PSi membranes with porosities 40-84% using a home-built setup, which was fabricated, calibrated and tested within this thesis. A value as high as 1mV/K was obtained for the 51% porosity sample. An anomalous porosity dependence of S was obtained, which was attributed to the interplay between energy filtering, phonon scattering and phonon drag effects. The results were explained by combining them with PL and TEM measurements, used for the determination of nanocrystal sizes. We concluded that, despite of the extremely low k and the high S of PSi, the material with the studied high porosities is not adequate for use as a “good thermoelectric” material, because of its significantly low electrical conductivity, which decreases with increasing porosity, resulting from carrier depletion during formation.We also studied the thermoelectric properties of thin, boron-doped, polycrystalline silicon films, which are much more attractive for use as Si-based thermoelectrics than porous Si. Their thermoelectric performance is improved by decreasing film thickness, due to a decrease in polysilicon grain size. Thin films with thickness between 100-500nm were investigated. We measured their thermal conductivity, resistivity and Seebeck coefficient and extracted their thermoelectric figure of merit, which showed threefold increase by reducing film thickness down to 100nm. A value as high as 0.033 was achieved, which is the highest reported in the literature so far for boron-doped polysilicon films at room temperature. This increase is attributed to a decrease in the grain size of the material. The obtained value shows the interest of nanocrystalline Si films for integration in efficient Si-based thermoelectric generators, compatible with CMOS processing.

Made available in DSpace on 2014-12-17T14:57:51Z (GMT). No. of bitstreams: 1 ElmoTLCF_TESE.pdf: 5043931 bytes, checksum: 055ef9454dc04669cebfe47f8a31509b (MD5) Previous issue date: 2011-07-22 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The process of recycling has been stimulated by the markets for several reasons, mainly on economical and environmental. Several products have been developed from recycled materials that already exist as well as several residues have been studied in different forms of applications. The greater majority of the applications for thermal insulation in the domestic, commercial and industrial systems have been elaborated in the temperature ranges between low to medium reaching up to 180oC. Many materials such as glass wool, rock wool, polystyrene are being used which are aggressive to the environment. Such materials in spite of the effectiveness in the retention of heat flow, they cost more and when discarded take several years to be absorbed by the nature. This way, in order to adapt to a world politics concerning the preservation of the environment, the present study was intended to develop a material composed of natural/biodegradable materials and industrial residues. The development of such a product in the form of a composite material based on tyre scrapes and latex for thermal insulation is presented in this research work. Thermal and physical properties of the tire scrapes as well as latex were studied in order to use them as raw materials for the manufacture of the intended composite to be applied as a thermal insulator in hot and cold systems varying between 0?C and 200oC, respectively. Composite blankets were manufactured manually, in weight proportions of 1:1 (50:50%); 1:2 (33:67%) and 2:1 (67:33%) (tire scrapes: latex) respectively. Physical, mechanical and thermal properties of the composites were analyzed to obtain data about the viability of using the composite as a thermal insulator. The analyses carried out were based on standards ABNT, ASTM and UL. The maximum temperature obtained for the composite as a thermal insulator was 200?C, which meets the range of applications that could be used as a thermal insulator in domestic as well as industrial purposes. The experimental results prove that the composite can be used as a thermal insulator on heated or cooled surface / A reciclagem tem sido muito estimulada pelo mercado. J? existem v?rios produtos que s?o produzidos com materiais reciclados e v?rios res?duos t?m sido estudados nas mais diversas formas de aplica??es. A grande maioria das aplica??es de isolamento t?rmico em sistemas dom?sticos, comerciais e industriais na faixa de baixas e m?dias temperaturas (at? 180?C), utilizam materiais agressivos ? natureza tais como: l? de vidro, l? de rocha, poliuretano, poliestireno. Tais materiais, apesar da efic?cia na reten??o do fluxo de calor, t?m custo elevado e quando descartados demoram anos para serem absorvidos pela natureza. Dessa forma, tentando adequar-se a uma pol?tica mundial acerca da preserva??o do meio ambiente, foi realizado um estudo com o intuito de desenvolver um isolante t?rmico composto de materiais naturais/biodegrad?veis e rejeitos industriais. Com isso, esta pesquisa apresenta o desenvolvimento de um material comp?sito a base de raspas de pneu e l?tex para isolamento t?rmico. Para isso, analisou-se as propriedades t?rmicas e f?sicas da raspa de pneu e do l?tex visando a utiliza??o como mat?ria-prima para fabrica??o do comp?sito a ser aplicado como isolante t?rmico em sistemas quentes (at? 200?C) e frios (0?C). Atrav?s de processos manuais, foram fabricadas mantas do comp?sito nas propor??es em peso de 1:1 (50:50%); 1:2 (33:67%) e 2:1 (67:33%) (raspa de pneu : l?tex) respectivamente. Foram analisadas propriedades f?sicas e t?rmicas dos comp?sitos com intuito de obter dados sobre a viabilidade de uso como isolante t?rmico. As an?lises foram fundamentadas em normas ABNT, ASTM e UL. O limite de temperatura de trabalho obtido para o comp?sito foi de 200?C, que se encontra na faixa de aplica??es que abrangem desde o uso domestico at? o industrial. Os resultados obtidos experimentalmente comprovaram que o comp?sito, pode ser utilizado para fins de isolamento t?rmico tanto em superf?cies aquecidas como resfriadas

The diploma thesis deals with the energy audit of the kindergarten building Špálova in Ostrava, according to order No. 480/2012 Sb. as amended. It is divided into three parts. The first part deals with the project of photovoltaic power plants in the energy audit, the second part analyzes the calculation procedures in the design of energy-saving measures and the third part completes the energy audit according to the requirements of the above-mentioned decree.

El calentamiento global es un tema que genera mucha preocupación en la población mundial. Siendo el cambio climático una de las consecuencias que se perciben en las diversas partes del mundo. La manifestación de este cambio ha ocasionado que se propongan diversas técnicas o métodos que permitan mitigar o controlar relativamente las temperaturas extremas, entre estos métodos ingenieriles se propone al plástico como componente del concreto para aislar las temperaturas externas. Ese estudio desarrolla una investigación experimental de la influencia del tereftalato de polietileno (PET), al ser incluido en la mezcla de concreto, en el logro del confort térmico que se pudiese llegar a obtener, al combinarlo con una innovadora adaptación del sistema trombe en la construcción de una vivienda. Para ello, se asumirán especificaciones de investigaciones realizadas, con respecto a la elaboración e inclusión del PET, que permiten concluir indirectamente la mejora del aislamiento térmico sin dejar de cumplir las restricciones estructurales. Asimismo, se explicó a detalle, la forma en la que se adoptó e innovo el sistema de muros trombe al construir el techo de un prototipo de la vivienda. Los resultados muestran que la técnica empleada en el presente estudio permitió mejorar considerablemente la eficiencia térmica en el prototipo de la vivienda. / Global warming is a topic of great concern to the world population. Being climate change one of the consequences perceived in various parts of the world. The manifestation of this change has caused various techniques or methods to be proposed to mitigate or relatively control extreme temperatures. Among these engineering methods, plastic is proposed as a component of concrete to isolate external temperatures. This study develops an experimental investigation of the influence of polyethylene terephthalate (PET), when it is included in the concrete mix, in achieving the thermal comfort that could be obtained, when combined with an innovative adaptation of the trombe system in the construction of a house. For this, specifications of investigations carried out, with respect to the preparation and inclusion of PET, will be assumed, which allow indirectly to conclude the improvement of thermal insulation while still complying with structural restrictions. Likewise, the way in which the trombe system was adopted and innovated when building the roof of a prototype of the house was explained in detail. The results show that the technique used in the present study considerably improved the thermal efficiency of the prototype of the house. / Tesis

Tanto en el Perú como en otras partes del mundo, el adobe es uno de los materiales de construcción más utilizados en la construcción de viviendas en las zonas rurales debido a su bajo costo y accesibilidad. Sin embargo, las viviendas en dichos entornos son, lamentablemente, llevadas a cabo con procedimientos constructivos empíricos y erróneos; provocando, entre muchos factores, que su comportamiento térmico no sea idóneo a las bajas temperaturas que presentan dichas zonas rurales en temporadas de friaje excesivo. Sin embargo, existe un mineral denominado diatomita que abunda en numerosos yacimientos en la cercanía de la cordillera de los Andes y que posee grandes propiedades térmicas, lo que lo convierte en un gran aislante térmico capaz de suplir la falencia de los bloques de adobe convencionales originarios de la zona. Por ello, esta investigación busca evaluar el comportamiento térmico de bloques de adobe adicionados con diatomita en comparación a los convencionales con el fin de mejorar el aislamiento térmico de las viviendas rurales que usan dichos bloques como principal material de construcción mediante la reducción del coeficiente de conductividad térmica. Dicho esto, en primer lugar, se determinó tanto el lugar de estudio como las principales propiedades de los materiales extraídos de dicha zona. Posteriormente, se estimó teóricamente el porcentaje de reducción de la conductividad térmica para diferentes porcentajes de diatomita con el análisis de otras investigaciones. Luego, con los porcentajes de reducción obtenidos se procedido a calcular los coeficientes de conductividad térmica y otros parámetros para las diferentes muestras de adobe con diferentes porcentajes de diatomita (0%, 10% y 20%). Por último, los datos calculados se ingresaron al software ECOTECT junto a una data climatológica de la zona de estudio para realizar el análisis térmico y compararlos con los resultados obtenidos de los bloques de adobe originarios de la zona de estudio, lo cual nos permite verificar si la diatomita mejoró el comportamiento térmico del adobe. De este modo, se obtuvo que en la condición más adversa (día más frio del año) la muestra con 20% de diatomita tuvo una mejora de temperatura del 23.18% en comparación con el adobe empírico. / In both Peru and other parts of the world, adobe bricks are one of the most used construction materials applied in rural areas due to its low cost and great accessibility. Houses in these environments are, unfortunately, carried out with empirical and erroneous construction procedures; causing, among many factors, that its thermal behaviour is not ideal at the low temperatures that these rural areas present in seasons of excessive cold. However, there is a mineral known as diatomite, whose abundance in numerous deposits in the vicinity of the Andes mountain range is quite notorious, this mineral has great thermal properties, making it a great thermal insulator capable of filling the gap of common adobe blocks originating in the area. Therefore, this research seeks to evaluate the thermal behaviour of an adobe brick added with powdered diatomite compared to a traditional adobe brick, in order to improve the thermal insulation of homes by reducing the coefficient of thermal conductivity and improving its internal temperatures. Therefore, firstly, both the ideal study location and the main properties of the materials extracted from said area were determined. Subsequently, the percentage reduction in thermal conductivity for different percentages of diatomite was theoretically estimated with the analysis of other investigations. Then, with the reduction percentages obtained, the thermal conductivity coefficients and other parameters were calculated for the different adobe samples with different percentages of diatomite (0%, 10% and 20% diatomite). Finally, the calculated data was entered into the ECOTECT software together with a climatological data from the study area to carry out the thermal analysis and compare them with the results obtained from the empirical adobe bricks and verify if the diatomite improved the thermal behaviour of the adobe. In this way, it was obtained that in the most adverse condition (coldest day of the year) the sample with 20% diatomite had a temperature improvement of 23.18% compared to empirical adobe. / Tesis

Denna studie är ett examensarbete utfört under sista året av tre på Sportteknologiprogrammet vid Mittuniversitetet i Östersund. Syftet med studien är att ge det svenska klädföretaget Didriksons svar på frågan om vilken av de vadderingar använda i deras produktion besitter bäst isoleringsförmåga och vilka faktorer som kan påverka den. Målet var att kunna presentera ett fullgott resultat från alla studier för Didriksons som de senare förhoppningsvis kan ha hjälp utav i sin fortsatta produktutveckling. För att besvara frågan har tester av 9 likvärdiga jackor tillverkade med olika isoleringsmaterial och konstruktionsprinciper utförts i laboratorium, bland annat i kylkammaren på Nationellt Vintersportcentrum tillsammans med vindtunneln och textillaboratoriet på Sports Tech Research Centre vid Mittuniversitetet i Östersund. Testerna har inte följt någon standard utan är utvecklade tillsammans med studenten, Didriksons och personer med expertis inom området vid universitetet. Undersökningen har visat att den jacka som hade den bästa isoleringsförmågan var den isolerad med syntetiskt dun. Studien har också påvisat att så kallade cold spots, i form av sömmar, dragkedjor och andra attiraljer som på något sätt stör vadderingen, har stor påverkan på isoleringsförmågan. Jackor med samma typ av isolering men med olika mängd av cold spots har presterat bäst respektive sämst i testerna. De olika vadderingarna har även undersökts i laboratorium för att se dess vindtäthet och analysera dess mikrostruktur, allt för att skapa förståelse för materialens olika egenskaper. / This study is a thesis during the last semester of three years at the SportsTechnology program at the Mid Sweden University in Östersund. Theaim of the study is to give the swedish clothing brand Didriksons ananswer to the question of which padding used in their production thathas the best thermal insulation properties and which factors that mayhave an impact on it. The goal for this study is to present a satisfactoryresult for Didriksons from all the executed tests combined which laterhopefully will help them within their product development. To answerthat question, nine equal jackets with different isolation materials andways of construction have been tested in various laboratories such as thecold chamber at National Wintersport Centre and the wind tunnel atSports Tech Research Centre all within the Mid Sweden University. Thetests have not been according to any ISO-standards or such, but hasbeen produced by the student together with Didriksons and researcherswith expertise within the subject at the university. Studies showed thatthe jacket with the best thermal isolation property was the onefabricated with synthetic down. The study also showed that so calledcold spots, stiches, zippers and so on, may affect the padding whichresults in a big negative impact to the thermal isolation, especially whenthe garment is exposed to wind. Jackets with the same type of paddingbut different amounts of cold spots have delivered the best and theworst results during the tests. The different paddings have also beeninvestigated in laboratories to see how they withstand wind and toanalyze their micro structure. All this to get a better understanding ofthe materials and its various properties.

Cette thèse s'inscrit dans une démarche de maîtrise de l'énergie dans le secteur du bâtiment. Elle a pour but d'utiliser des solutions passives pour atteindre de hautes performances énergétiques. Une des solutions proposée, est l'utilisation de Matériaux à Changements de Phase (MCP) dans les parois. Les matériaux à formes stabilisée solide-liquide, sont utilisés pour stocker l'énergie thermique sous forme de chaleur latente. Le but de l'étude est de mettre en évidence l'impact réel des MCP en terme de complément d'isolation thermique et de proposer un modèle thermique pour prédire son impact sur le champ de température et par conséquent, sur le confort thermique. Une séquence expérimentale en environnement naturel et à grande échelle a été menée à l'île de La Réunion, où le climat est tropical et humide, avec un fort taux d'ensoleillement. Le rayonnement solaire étant important, il est nécessaire de minimiser les sollicitations solaires sur l'ensemble du bâtiment et en particulier la toiture, qui constitue la surface la plus exposée. La présence de lames d'airs au niveau de la toiture, qualifie celle-ci de complexe. Il est alors nécessaire de proposer une modélisation adaptée. Le modèle est couplé à un code de simulation thermique du bâtiment (ISOLAB) et permet de prédire d'une part, les profils de températures de chacune des surfaces constituant l'enveloppe du bâtiment, et d'autre part, d'évaluer l'impact des MCP sur le confort thermique pour différentes configurations. Selon une méthodologie, alliant Modélisation, Expérimentation et Validation (MEV), la démarche a permis de valider l'expérimentation dédiée et d'évaluer la capacité du modèle à prédire l'ensemble des données issues de l'expérimentation. / This Ph.D thesis focusses on energy control in buildings in order to reach high energetic performances by the use of passive means. One of the proposed solution is based on the use of Phase Change Materials (PCMs). Located into walls, PCMs allow to stock thermal energy into latent heat. The aim of the study is thus to put in evidence PCMs actual impacts on the thermal field of a building and its role as thermal insulation. For these considerations, a thermal model has been developed and validated. An experimental device has been set-up for the collection of data in field environment and for a human scale. The measurement sequence has been conducted at Reunion Island, for a hot and humid tropical climate. For the determination of the thermal behaviour of a commplex wall included PCMs, we proposed a generic model, able to predict many configurations. The model has been implemented in a multizone building simulation code (ISOLAB), for the prediction of wall temperature profiles and PCMs impact on the thermal comfort. Following a combined metholodogy, including modelling and experimentation for validation, we were able to validate the model for actual conditions and to evaluate the model's prediction accuracy.

Dissertation focuses on the verification of construction family houses made of concrete shell block with internal thermal insulation system. The construction technology is transferred to the Czech Republic from France. The work focuses on building envelope. The suitability of implementation is assessed on the basis of verification selected thermal technical requirements placed on building envelope. Requirements are specified by legislation in force in the ČR. The verification was performed by using software simulations and measurements on realized buildings. Critical areas of construction technology were identified on the basis software simulations and measurements on site. It was suggested solution, in which critical areas comply the thermal technical requirements. The building envelope was checked also using the thermography imaging on site. Continuous measurement of interior temperature was used to evaluate thermal comfort in the room. In the completed buildings was tested airtightness of the building envelope, which revealed other critical areas of the building envelope. Critical areas are necessary to solve with sufficient care. The economic cost of implementing each variants of exterior walls made of concrete shell block with internal thermal insulation were compared with the economic costs of implementing external walls made of burnt clay hollow blocks and made of burnt clay hollow blocks with external thermal insulation system ETICS. Subsequently, the economic return was calculated for individual variants of external walls made of concrete shell blocks with internal thermal insulation. From the environmental viewpoint was made comparison of production greenhouse gas CO2 and SO2 (cause acid rains) during the life cycle of the individual variations of exterior walls made of concrete shell blocks with system of internal thermal insulation, exterior walls made of burnt clay hollow blocks and burnt clay hollow blocks with external thermal insulation syst