La modification de la structure des matériaux par Détente Instantanée Contrôlée (DIC), implique nécessairement un processus d’autovaporisation instantanée en conditions thermodynamiques extrêmes de surchauffe du liquide. Les divers processus DIC de modification de la structure par expansion contrôlée, d’extraction et de refroidissement instantané sont d’un intérêt particulier. Les conditions opératoires et les caractéristiques spécifiques du produit interagissent mutuellement pour aboutir au meilleur résultat, principalement en termes de texture. Les modifications des caractéristiques structurelles généralement traduites par des taux d’expansion du produit, dépendent donc des conditions opératoires et des propriétés thermiques et rhéologiques de la matière. De nombreuses études initiales ont montré l’intérêt de déterminer l’évolution des divers processus à travers un suivi et un enregistrement instantané des images, des températures et de la pression à l’échelle de 1000 unités par seconde ; il a ainsi été indispensable de mettre en opération une caméra ultra rapide à 1000 images / s, des capteurs de température et de pression à temps de réponse de l’ordre du ms, placés dans le réacteur et au sein du produit. Une analyse fondamentale a prouvé l’importance de la thermodynamique, du transfert et de la problématique d’expansion pendant le traitement. L’analyse des expériences est réalisée par la détermination des taux d’expansion, surfacique et volumique, de la durée du processus d’expansion proprement dite, de l’analyse des caractéristiques micro-structurelles par MEB, mais principalement par la détermination de la température de transition vitreuse, de la différence de température minimale et d’ébullition, et du taux d’échange de chaleur. Plusieurs produits ont été étudiés (fromage, tofu, pomme, pomme de terre, carotte et banane). Des essais préliminaires adéquats ont permis d’identifier les domaines de variation des paramètres opératoires et d’adopter la méthode des plans d’expériences rota tables à cinq niveaux pour quantifier les diverses réponses nécessaires. / The structural modification of materials by the process of instant controlled pressure drop (DIC), is mainly based on the instant autovaporization process in very far from thermodynamic equilibrium conditions. The structure modification process and the volume evolution strictly depend on DIC operational parameters and the product characteristics mutually interacting to achieve the objective in terms of texture.The change in the structural characteristics of the product is generally revealed through the expansion rates of the product ; it depends on the operating conditions. This study will use a snapshot taken by a high speed video camera 1000 fps, coupled with 1 ms response temperature and pressure sensors, placed in the treatment vessel and inside the product. A fundamental analysis has proved the importance of thermodynamics, the transfer and the specific problematic of expansion during treatment. Study was carried out by determining the3D expansion ratio, the 2D surface expansion ratio, and the volumetric expansion ratio, as well as the durations of expansion just after pressure drops, the analysis of SEM micro-structural characteristics, the different glass transition temperatures Tg, the differences between lowest product and reactor temperatures and boiling temperature, and the heat exchange rate. Various products were considered (cheese, tofu, apple, potato, carrot and banana). The preliminary tests with each have led us to identify the relevant operating parameter ranges. Different fundamental conclusions and industrial application could be thus defined.

Alkali-kiselsyrareaktionen (AKR) är en kemisk reaktion som medför att spänningar uppstår i betongen då den bildade silikatgelen expanderar. Reaktionen kräver tillräcklig hög alkalihalt, reaktiv ballast samt vatten. På grund av de AKR-inducerade spänningarna är det av intresse att få kunskap i hur reaktionen påverkar betongens böjmomentkapacitet, förankring samt skjuvnings- och genomstansningskapacitet. För att besvara frågeställningen har därför en omfattande litteraturinventering tillsammans med tre kompletterande intervjuer utförts. Resultat som har erhållits, påvisar att två huvudsakliga effekter fås av AKR. Utöver en reducerad hållfasthet på grund av expansioner och sprickbildningar, erhålls även en gynnsam förspänningseffekt när armering motverkar expansioner. Med hänsyn till dessa huvudeffekter påverkas betongs bärighet i olika stor utsträckning beroende på expansionens storlek samt armeringens läge och typ i tvärsnittet. Resultaten tyder på att draghållfastheten reduceras till 40 % medan tryckhållfastheten reduceras till 60 % vid 5 mm/m expansion. För böjkapaciteten har ingen större reduktion uppmäts då expansioner understiger 6 mm/m. Emellertid har en reduktion på 25 % observerats vid expansioner större än 6 mm/m. Skjuvkapaciteten i AKR-skadad betong beror till stor del av byglars närvaro samt expansionens omfattning. I balkar utan byglar reduceras skjuvkapaciteten med 15-25 % för slät armering och 20-30 % för räfflad armering. Genomstansningskapaciteten i ett dubbelarmerat betongtvärsnitt reduceras obetydande till dess att expansionen överstiger 6 mm/m varpå en mer påtaglig reduktion fås. Hållfastheten för vidhäftning minskar med ca 40 % då täckande betongskikt understiger 1.5Æ och/eller att inga byglar är närvarande. Om byglar är närvarande samt om täckande betongskikt överstiger 4Æ visas inga tecken på försämrad vidhäftningshållfasthet. Utöver en minskad bärighet, öppnar AKR upp betong och skapar gynnsammare förutsättningar för rost-och frostangrepp. / Alkali-silica reaction (ASR) is a chemical reaction that causes stresses in concrete when the produced alkali silica gel expands. The reaction requires sufficiently high alkali content, reactive aggregates and water. Due to ASR-induced stresses it is of interest to gain insight in how ASR affects the concrete’s bending capacity, anchoring together with shear- and punching shear capacity. An extensive literature review was therefore carried out together with three complementary interviews in order to answer the question at issue. Obtained results show two main effects of ASR. In addition to a reduced strength because of cracking and expansion, an advantageous pre-stress is gained due to restraint to expansion. Thus, the load-carrying capacity of concrete is affected in various extents depending on the size of expansion and location and type of the reinforcement. The results indicate that the tensile strength is reduced to 40 % whereas the compressive strength is reduced to 60 % at 5 mm/m expansions. While expansions lesser than 6 mm/m has not shown a greater reduction of the bending capacity, a reduction of 25 % has been observed in concrete with expansions greater than 6 mm/m. The shear capacity of an ASR-affected concrete structure depends mainly on the presence of links and the extent of expansions. In beams without links, shear capacity is reduced to 15-25 % for smooth bars and 20-30 % for ribbed bars. The punching strength of a concrete structure reinforced in both faces is not reduced until expansions exceed 6 mm/m, whereas a more significant reduction is obtained. The bond strength decreases by about 40 % if the concrete cover is less than 1.5 Æ and/or if no links are present. Meanwhile if links are present and if concrete cover is more than 4Æ, no signs of reduction of the bond strength has been observed. Additionally, to a reduced load-carrying capacity, ASR also opens up the concrete and consequently creates beneficial circumstances for corrosion and frost attacks.

In this thesis, we provide convergent numerical solutions to non-linear forward-BSDEs (Backward Stochastic Differential Equations). Applications in mathematical finance, financial economics and financial econometrics are discussed. Numerical examples show the effectiveness of our methods.

A material’s Coefficient of Thermal Expansion (CTE) is a valuable physical property, particularly for structural fiber reinforced composites that are routinely used in satellite/aerospace applications. Satellite space structures are routinely designed with a high degree of dimensional and thermal stability. Designing and verifying for near zero CTE performance is a common design requirement. The CTE is routinely a physical property with known values for common materials. However, the strength, stiffness and CTE properties on a multi-ply graphite fiber reinforced laminate composite can be tailored to specific engineering requirements. Because of this, a method of verification (testing) is routinely performed to ensure these requirements are met.

Agroekologi är ett jordbrukskoncept baserat på kunskap från ursprungsbefolkning och bönder som syftar till att uppnå hållbara, motståndskraftiga och stabila jordbrukssystem utan externa insatser. Konceptet syftar även till att stärka landsbygdssamhällen och skapa produktiva jordbrukssystem för att säkra livsmedelstillgången världen över. Agroekologi utmanar konventionell odling och exportorienterad livsmedelsproduktion där ekonomisk lönsamhet ofta prioriteras på bekostnad av sociala och ekologiska aspekter. Syftet med denna studie är att undersöka hinder och förutsättningar för en agroekologisk expansion i sydamerikanska länder då dessa länder besitter värdefulla ekosystem som i dagsläget hotas av konventionellt jordbruk. För att uppfylla målen med studien utfördes expertintervjuer samt litterära studier av expertgranskade artiklar. Resultatet av studien visar bland annat att samhälleliga aktörer såsom stat, forskningsinstitutioner, sociala rörelser, bönder och konsumenter har viktiga roller när det gäller agroekologisk expansion, samt att en tydlig kommunikation mellan dessa aktörer är nödvändig. En generell slutsats är att en hållbar omställning inom jordbruket är komplex och svår att genomföra, delvis på grund av de starka nyliberala diskurser som existerar inom stat och näringsliv och försvårar ett främjande av sociala och ekologiska frågor. / Agroecology is an agricultural concept based on indigenous and peasant knowledge, which strives to achieve sustainable, resilient and reliable agricultural systems without external inputs. The concept also aims to strengthen rural communities and create productive agricultural systems in order to achieve food sovereignty across the world. Agroecology challenges conventional farming and export-oriented food production which often prioritizes profitability with little regard to ecological and social aspects. The purpose of this study is to investigate the obstacles and possibilities for an agroecological expansion in South American countries, since these countries possess valuable ecosystems that are currently threatened by conventional agriculture. In order to fulfill the goals of this study, literary studies of peer-reviewed articles as well as expert interviews were conducted. The results show that societal actors such as governments, research institutions, social movements, farmers and consumers have important roles in the expansion of agroecology, and that a clear articulation between these actors is necessary. A general conclusion of the study is that a sustainable transition within the agricultural sector is complex and would be difficult to achieve, partly because of the strong neoliberalist discourses that exist within governments and businesses and prevent the promotion of social and ecological issues.

This thesis aims at using novel machine learning techniques to test the dynamics of the Universe via the cosmological redshift-distance test. Currently, one of the most outstanding questions in cosmology is the physical cause of the accelerating cosmic expansion observed with supernovae. Simultaneously, tensions in measurements of the Hubble expansion parameter $H_0$ are emerging. Measuring the Universe expansion with next generation galaxy imaging surveys, such as provided by the Vera Rubin Observatory, offers the opportunity to discover new physics governing the Universe dynamics. In this thesis, with the long-term goal to unravel these peculiarities, we create a deep generative model in the form of a convolutional variational auto-encoder (VAE), trained with a "Variational Mixture of Posteriors" prior (VampPrior) and high-resolution galaxy images from the simulation project \texttt{TNG-50}. Our model is able to learn a prior on the visual features of galaxies and can generate synthetic galaxy images which preserve the coarse features (shape, size, inclination, and surface brightness profile), but not finer morphological features, such as spiral arms. The generative model for galaxy images is applicable to uses outside the scope of this thesis and is thus a contribution in itself. We next implement a cosmological pinhole camera model, taking angular diameter changes with redshift into account, to forward simulate the actual observation on a telescope detector. Building upon the hypothesis that certain features of galaxies should be of proper physical sizes, we use probabilistic triangulation to find the comoving distance $r(z,\Omega)$ to these in a flat ($K=0$) Universe. Using a sample of high-resolution galaxy images from redshifts $z\in[0.05,0.5]$ from \texttt{TNG-50}, we demonstrate that the implemented Bayesian inference approach successfully estimates $r(z)$ within $1\sigma$-error ($\Delta r_{\text{est}} = 140$ $(580)$ Mpc for $z=0.05$ $(0.5)$). Including the surface brightness attenuation and utilizing the avalanche of upcoming galaxy images could significantly lower the uncertainties. This thesis thus shows a promising path forward utilizing novel machine learning techniques and massive next-generation imaging data to improve and generalize the traditional cosmological angular-diameter test, which in turn has the potential to increase our understanding of the Universe. / Denna avhandling syftar till att använda nya maskininlärningstekniker för att testa universums dynamik via det kosmologiska rödförskjutningsavståndstestet. För närvarande är en av de mest framstående frågorna inom kosmologi den fysiska orsaken till den accelererande kosmiska expansionen som observerats med supernovor. Samtidigt uppstår spänningar i mätningar av Hubble-expansionsparametern $H_0$. Att mäta universums expansion med nästa generations galaxundersökningar, såsom de som ska genomföras av Vera Rubin Observatory, ger möjlighet att upptäcka ny fysik som styr universums dynamik. I den andan skapar vi i den här avhandlingen en djup generativ modell i form av en "convolutional variational auto-encoder" (VAE), tränad med en "Variational Mixture of Posteriors" prior (VampPrior) och högupplösta galaxbilder från simuleringsprojektet \texttt{TNG-50}. Vår modell kan lära sig en "prior" om galaxernas visuella egenskaper och kan generera syntetiska galaxbilder som bevarar de grova dragen (form, storlek, lutning och ytans ljusprofil), men inte finare morfologiska egenskaper, såsom spiralarmar. Den generativa modellen för galaxbilder är tillämplig på användningar som inte omfattas av denna avhandling och är därmed ett bidrag i sig. Därefter implementerar vi en kosmologisk hålkameramodell, med vilken hänsyn till förändringar i vinkelstorleken med rödförskjutning tas, för att framåt-simulera den faktiska observationen på en teleskopdetektor. Med utgångspunkt från hypotesen att galaxer i grunden borde ha gemensamma egenskaper med liknande fysiska storlekar, använder vi probabilistisk triangulering för att hitta avståndet (s.k. "comoving distance") $ r (z, \Omega) $ till dessa i ett platt ($ K = 0 $) universum. Med hjälp av ett urval av högupplösta galaxbilder från rödförskjutningar $ z \in [0.05,0.5] $ från \texttt {TNG-50} visar vi att den implementerade "Bayesian inference"-metoden framgångsrikt uppskattar $ r (z) $ inom $ 1 \sigma $ felmarginaler ($ \Delta r _ {\text{est}} = 140 $ $ (580) $ Mpc för $ z = 0,05 $ $ (0,5) $). Att inkludera dämpning i ytljusstyrka med rödförskjutning och att använda den massiva mängd av kommande galaxbilder skulle kunna minska den erhållna osäkerheten betydligt. Denna avhandling visar således en lovande väg framåt med nya maskininlärningstekniker och kommande enorma mängder av galaxbilder för att förbättra och generalisera det traditionella kosmologiska vinkeldiametertestet, vilket i sin tur har potentialen att öka vår förståelse om universum.

Syftet med undersökningen är att beskriva de konsekvenser som Bolidens expansion av sin gruvverksamhet fått för de boende i byarna Liikavaara och Sakajärvi, både före och under processen. En kvalitativ fallstudie har använts som metod för att granska materialet. Undersökningen bygger till stor del på semistrukturerade intervjuer som källa. Resultatet visade att livet i byarna innan gruvans expansion har påverkats av Aitikgruvan då både buller och damning varit ett problem. Med expansionen har det medfört att de boende tvingats att flytta och anpassa sig till nya förhållanden. Processen har för det mesta kantas av negativa upplevelser då den skapat känslor av sorg och besvikelse. / The purpose of this study is to describe the consequences that Boliden’s expansion of its mining operation had on people in the villages of Liikavaara and Sakajärvi, both before and during the process. A qualitative case study has been used as a method to process the material. The investigation is mostly based on semi-structured interviews as a source. The result showed that life in the villages before the expansion has been affected by the Aitik mine. With the expansion, the people have been forced to move and adapt to new changes. The process has mostly result in negative experiences and created feelings of sadness and disappointment.

This thesis deals with the applications of graph theory towards the electrical distribution networks that transmit electricity from the generators that produce it and the consumers that use it. Specifically, we establish the substation and bus network as graph theoretical models for this major piece of electrical infrastructure. We also generate substation and bus networks for a wide range of existing data from both synthetic and real grids and show several properties of these graphs, such as density, degeneracy, and planarity. We also motivate future research into the definition of a graph family containing bus and substation networks and the classification of that family as having polynomial expansion.

Background: Maxillary expansion has long been used in children and adolescents for transverse discrepancies and dental crowding. With age, the mid-palatal suture becomes increasingly mature, requiring heavy, rapid force in order to achieve skeletal expansion. As an individual grows into adulthood, it has been demonstrated that a skeletally anchored expander can be used in order to achieve successful sutural separation. The side effects between these two types of expanders, including dental tipping with relative extrusion of buccal segments and clockwise mandibular rotation, have been demonstrated to have differences in their degrees of severity. However, most of the studies have evaluated the effects immediately following the expansion and not through a prolonged period in which growth may occur. The purpose of the present study was to investigate long-term skeletal differences in two types of expansion (RPE vs MARPE) on a growing population. Methods: This retrospective study included 39 adolescent subjects (mean age = 13.8 years) who had received maxillary expansion (20 RPE, 19 MARPE) with subsequent completion of orthodontic treatment. Initial and final CBCTs were used to analyze cephalometric and transversal changes between the two groups. Transverse measurements were repeated two weeks apart to test intra-observer reliability. Results: Cephalometric analysis demonstrated no significant differences in changes of FMA (p = 0.549) or MP-SN (p = 0.722) between the two groups following expansion and completion of orthodontic treatment. There were statistically significant differences in transverse changes between the two groups, with the MARPE group displaying more skeletal expansion. Conclusions: The results of the present study suggest that skeletally anchored expander - MARPE and conventional expander have similar skeletal effects in adolescents.

[pt] Hoje em dia, é crescente a utilização de expansores de pele, visando criar um excesso de pele localizado, com o qual pode-se corrigir imperfeições encontradas na pele de um paciente. Este processo, envolve um implante de uma bolsa de silicone sob a pele, sendo enchida vagarosamente, através da injeção de uma solução fluida salina. Obviamente, a pele se expande no mesmo formato da forma da bolsa implantada. Em estudos prévios já realizados, as propriedades viscoelásticas da pele expandida foram ignoradas. O objetivo deste trabalho, é modelar a pele expandida por um expansor axissimétrico e inicializar os estudos para expansores sem simetria, como um material viscoelástico, isotrópico e homogêneo. Para este fim, é utilizado o método dos elementos finitos. Na análise de elementos finitos, é usado um modelo viscoelástico linear, com três diferentes tipos de elementos, casca, membrana e elementos sólidos, procurando o melhor elemento para descrever o modelo. É realizado também, um estudo paramétrico, variando a espessura dos elementos e comparando seus resultados. Para a análise por elementos finitos, é utilizado o programa ABAQUS, sendo o método validado através de resultados numéricos já obtidos. No futuro, nossa intenção é modelar expansores de forma não axissimétricas e aplicar nosso trabalho em experimentos in- vivo. / [en] Nowadays, soft tissue expanders are being increasingly, used to create local skin flaps which can cover relatively large tissue defects. This involves inserting a silicon-rubber balloon (prosthesis) in its collapsed state under the subcutaneous tissue of the patient, closing the incision, and then inflating the balloon slowly with a saline fluid through a one way valve. The valve is part of the balloon prosthesis. Obviously, the skin expands in the form of a dome in unison with the balloon underneath it. In preliminary studies designed to evaluate the behavior of skin created by soft tissue expansion, the viscoelastic proprieties of skin were ignored. The objective of the present work is model skin as an isotropic homogeneous viscoelastic material using the finite element method for large deformation in axisymmetric expanders. In finite element analysis we are using a linear viscoelastic model with three different kinds of elements, solid, shell and membrane, looking for the best element to describe the model. We are also making a parametric study, varying the thickness of the elements and comparing the results. To develop this finite element analysis, we are using the ABAQUS program . The methods have been validated using results from previous experimental works . In the future, we intend to model non-axisymmetric expanders and apply this work to in-vivo experiments. / [es] En la actualidad, la utilización de expansores de piel está en franco crecimiento. El objetivo de esta utilización es crear un exceso de piel localizado, con el cual se pueden corregir imperfecciones encontradas en la piel de un paciente. Este proceso consiste en el implante de una bolsa de silicone bajo la piel, a través de la injección de una solución fluida salina. Obviamente, la piel se expande en el mismo formato de la forma de la bolsa implantada. En estudios previos, se ignoraron las propriedades viscoelásticas de la piel expandida. El objetivo de este trabajo es modelar la piel expandida por un expansor axisimétrico e inicializar los estudios para expansores sin simetría, como un material viscoelástico, isotrópico y homogéneo. Para este fin, se utiliza el método de los elementos finitos. En el análisis de elementos finitos, se utiliza un modelo viscoelástico lineal, con tres tipos diferentes de elementos, casca, membrana y elementos sólidos, buscando el mejor elemento para descrivir el modelo. Se realiza también un estudo paronétrico, variando la espesura de los elementos y comparando sus resultados. Para el análisis por elementos finitos, se utiliza el programa ABAQUS, y el método es evaluado a través de resultados numéricos obtenidos con anterioridad. En el futuro, nuestra intención es modelar expansores de forma no axisimétricas y aplicar nuestro trabajo en experimentos in- vivo.