The objective of this study was to develop a research platform using a John Deere 425 Hay Cuber and to evaluate inield densification of grass-based biomass for energy fuel sources. The hay cuber was repaired, modernized, and instrumented to provide a stable test platform on which to quantify and evaluate operating parameters. Bermudagrass was chosen as a model for cubing energy grasses such as Giant miscanthus and switchgrass. Lignin sulfonate binder was added to windrowed bermudagrass at 27.6 kg/tonne (50 lbs/ton) to increase the lignin content to that of energy grasses. The material output from the cuber was collected and separated into cubes and fines to evaluate the effectiveness of densification operations. Bermudagrass treated with binder produced significant regressions that accounted for 83% of variation in production parameters.

This essay explores the effects of urban densification on residents in Bellevuegården, Malmö, focusing on the experiences of tenants and their alignment with municipal planning intentions. Densification advocated for its sustainability benefits, often leads to gentrification and displacement of vulnerable groups. By examining municipal motives and comparing them with tenant experiences, this study sheds light on the discrepancies and challenges arising from densification processes. Through interviews and surveys, the research reveals that densification has varying impacts on residents, including a decline in their daily lives and dissatisfaction with renovations and increased rental costs. The findings underscore the need to understand the direct consequences of densification on residents and to address potential gentrification issues. Furthermore, the study emphasises the importance of considering the impact on local businesses. By delving into these dynamics, this research contributes to a better understanding of the social implications of densification in vulnerable socioeconomic neighbourhoods.

Stockholm is growing very fast and many new housing investments are under construction outside of the city center. Suburbs are getting densifed and readjusted to modern needs as this is where many of us live today and be living in the future. At the same time our society is aging. Sweden today has 1,6 million inhabitants over 64 years old. This number is expected to raise up to 2,7 million in 2060, which means that approximately 1 in 4 people will be aged over 64*. Current urbanization rate of Sweden is oscillating around 85%, therefore the vast majority of Swedish elderly will be living in cities. We are also expected to live and work longer, changing our professions few times during our lifetime. We will have to be fast learners and flexible employees to keep up with technological development and changing job market. We will have to compete with robots and smart technologies in order to keep our positions. This equals being a “lifelong student”, even in the older age. Looking towards the future, where the demographic structure of the society will shift, it is already time to start planning our cities for an aging population, where regardless date of birth everyone can feel important and integral part of our society

Förtätning anses vara eftersträvansvärt och hållbart i dagens stadsbyggnad, i och med de fördelar täthet medför, och i Stockholm syns en trend med områden där det byggs både högre och tätare än tidigare. Även om förtätning innebär fördelar medför det flera utmaningar där avvägningar behöver göras mellan olika kvalitéer. Därför är syftet med denna undersökning att studera utmaningar med förtätning som kan komma att påverka människors välbefinnande ifall de inte prioriteras. Litteraturstudier har utförts för att samla information om kopplingen mellan täthet och välbefinnande samt de studerade utmaningarna kring ljusförhållanden, grönområden och ytor för barn. Dessa utmaningar valdes ut eftersom de var återkommande i den offentliga debatten om förtätning. Därefter utfördes en jämförelse mellan Hagastaden och Liljeholmskajen, vilka båda förtätas genom omexploatering, där både kvalitativa och kvantitativa förtätningsaspekter undersöktes med grund i teorin. Resultaten visade att Liljeholmskajen var tätare än Hagastaden utifrån de kvantitativa måtten på områdesnivå men att Hagastaden var tätare på kvartersnivå. De visade även att liknande strategier använts vid förtätning i båda områdena men att de studerade täthetsmåtten kan förstås på olika sätt. Undersökningen visade dessutom att det är betydande att se till både hårda och mjuka element vid bestämmelse av täthet samt att kvalitativa mått ibland säger mer än kvantitativa. Vidare pekade resultaten i studien på att de undersökta utmaningarna kan påverka välbefinnande negativt om dessa inte hanteras på ett bra sätt i planeringen, där barn riskerar att beröras mest i både Hagastaden och Liljeholmskajen. Studien kom fram till tre kriterier att ta hänsyn till vid avvägningen mellan förtätning och de tre utmaningarna. Dessa kriterier innefattar; att vid förtätning ha en stor skillnad mellan högsta och lägsta våningsantal för att främja goda ljusförhållanden, att vid utformning av grönområden fokusera på varierad natur och vegetation samt att vid ytor för barn fokusera på förskolegårdar, där dessa ska vara tillräckligt stora och inkludera en betydande mängd vegetation. / Densification is considered to be desirable and sustainable in urban planning today, based on the advantages that follow and in Stockholm a current trend can be seen with both higher and more densified blocks. The fact that cities grow more compact is causing challenges which has to be taken in to account in urban planning in order to not jeopardize important qualities. Therefore, the purpose of this paper is to study the challenges that come with densification and how it may affect social well-being. To examine the connection between density and wellbeing, literature studies were performed to collect information. Those studies also included theories about the three challenges that this paper came to focus on, so as light conditions, green spaces and areas made for children. These specific challenges were selected since they were recurrent in the public debate considering densification. Furthermore, a comparison between the former brownfields Hagastaden and Liljeholmskajen was made, which studied both qualitative and quantitative aspects in densification based on the theories. The results in this paper showed that Liljeholmskajen appeared to be more compact than Hagastaden based on the quantitative perspective in the restricted area, but Hagastaden on the other hand was more compact at a block level. Another result proved by the paper was that similar strategies in densification has been used in both areas, but also that the studied dimensions of densification has been practiced in different ways. The study also showed the importance of considering both hard and soft elements when determining density and that the qualities of a built environment can be more important when assessing density over quantity. Furthermore, the paper showed that challenges with densification could have a bad impact on social well-being, if not being considered in urban planning, and that children are the ones most affected by densification in both Hagastaden and Liljeholmskajen. In the discussion, the paper ended up with three criterias which can be included in urban planning in order to encourage social well-being in densified areas. These criterias included; to consider a great difference between the highest and lowest building regarding number of floors to promote good lightning conditions, to include varied nature and vegetation when developing green spaces and when it comes to areas made for children, to focus on the yards belonging to kindergartens, where these should be large enough and include a great amount of vegetation.

Densification is well used in today’s city planning to meet the global urbanisation. Densification brings advantages for social, economic and ecologically sustainable development. However, it can also bring disadvantages, such as loss of open space. This study aims to examine and describe how open spaces manifest in Umeå, a Swedish city undergoing densification. The aim is also to examine how inhabitants perceive and use open space in two cases in Umeå. The study has been carried out through a literature review of relevant theory and relevant planning material, as well as through interviews regarding inhabitants’ perceptions and use of open space. Findings confirm that there is no distinct definition of open space in Sweden, which makes room for interpretation for city planners. In this study open space is defined as land within detailed development plan areas that is free of buildings and that is possible to reside in. The results show that in Umeå the current norm for open spaces within dense building structure is to emphasize quality and availability rather than quantity. Furthermore, the results show that open space manifests differently due to different prerequisites. Open spaces in the city centre are smaller and less green compared to open spaces outside of the city centre.

No description available.

Cities and regions carry with them a baggage of problems stemming from their locality or history, impacting their psychology and development. In Umeå’s case, it is not a problem of geography but a historical event. The fire of 1888 still casts its soot-shadows on the facades of buildings, scaring the extant buildings into retreating from each other, killing densification and turning expansion plans into far-off enclaves on the city outskirts. The project is a targeted intervention confined to the block of Stora Björnen aiming to boldly yet sensibly densify a neglected part of the neighborhood Öst på Stan. The Intervention acts as a benevolent academic enclave to the growing Arts Campus, stemming from an infill development and flowing into the courtyard of the block. Great care is used in fusing the new with the old stylistically. Adhering to local rules in a culturally protected environment while still breaking rules when they can be broken and bringing something new to the neighborhood. The existing barriers and haphazard collection of spaces in the courtyard is rearranged and from it emerges a new block within the block. New paths and relations between buildings emerge, strengthening and inviting more people into the collage that is Öst på Stan. The structure makes room for itself in the block, taking and giving back.

Cette étude de la compaction d’un empilement granulaire par vibrations horizontales a été réalisée dans le cadre d’un partenariat avec le groupe MERSEN pour une application au sable contenu dans ses fusibles. L’objectif scientifique est de développer la compréhension des mécanismes mis en jeu dans un milieu granulaire vibré horizontalement. Deux approches ont été utilisées en parallèle, l’une expérimentale, l’autre par simulation numérique. L’approche expérimentale a été réalisée sur des grains de silice de diamètre moyen 500 m. Un récipient de quelques centimètres est soumis à un mouvement sinusoïdal de fréquence comprise entre 20 et 200 Hz avec des accélérations allant jusqu’à 10 g. Le dispositif instrumenté permet la mesure instantanée de la force et de l’accélération, la vitesse des grains aux parois (PIV) ainsi que la densité globale du milieu. L’approche numérique est basée sur la méthode des éléments discrets (DEM). Des méthodes spécifiques d’analyse des résultats ont été développées pour assurer la comparaison avec l’expérience. Elles permettent d’obtenir des informations qui ne sont pas accessibles expérimentalement comme les densités, vitesses et contraintes locales dans l’ensemble de l’empilement. Dans le cas d’un récipient ouvert, la simulation permet de retrouver les résultats expérimentaux : rouleaux de convections, seuils de comportement, influence de l’accélération… Des résultats originaux ont été établis dans les expériences et les simulations comme une croissance de la vitesse des grains avec la longueur du récipient. La simulation a aussi permis d’obtenir des résultats spécifiques comme l’influence du coefficient de friction sur le sens des rouleaux et la caractérisation des contraintes au sein de l’empilement. L’écoulement des grains à travers des orifices circulaires de différentes dimensions a été également étudié. Le comportement du sable dans un récipient fermé (milieu confiné) a été étudié au cours d’un remplissage progressif. Des différences significatives ont été constatées lorsque le taux de remplissage devient élevé. Des mesures d’accélération et de force sur l’ensemble du dispositif ont permis de définir et de mesurer une masse apparente et l’énergie dissipée par le dispositif. Des modèles descriptifs ont permis de comprendre les comportements observés. Ces résultats sont à l’origine d’un brevet déposé par le groupe MERSEN sur le contrôle du remplissage. / This work on the densification of a granular medium under horizontal vibrations was realised in the context of an industrial study on sand in fuses, undertaken by the firm MERSEN. The scientific purpose is the understanding of the mechanisms involved in horizontally vibrated granular media. Both experiments and computer simulations were used. Experiments were conducted with 500 µm silica grains. Sinusoidal accelerations up to 10 g were applied to a container of a few centimetres using frequencies between 20 and 200 Hz. The experimental device enables instantaneous force, acceleration, grain velocity on the walls (PIV) and mean bulk density to be measured. Discrete element method (DEM) was used for the computer simulations. Specific techniques were developed to analyse the results and compare them with experiments. Computer simulations provided data which are not experimentally available such as local values of density, velocities and stress inside the particle packing. In the case of an open container, simulation results are in good agreement with experimental ones (convection rolls, thresholds, effect of acceleration...). Original results are obtained in both experiments and simulations, such as a grain velocity increase with the container length. Simulation provided specific results such as the effect of friction coefficients on the direction of rotation of convection rolls and the characterization of stress inside the particle packing. The flowability of grains across circular holes of various sizes was also studied. The behaviour of sand in a closed container (confined medium) was studied during a progressive filling. Significant differences were observed when the filling rate becomes high. The dissipated energy and the apparent mass of the vibrated device were defined and measured using acceleration and force measurements. Specific models were built to analyse and understand the observed behaviour. Some results on the filling control were patented by MERSEN.

Le verre de silice (SiO₂) est un des matériaux les plus couramment utilisés dans notre société moderne. Il est notamment employé dans des structures à haut niveau de risque, telles que les verrières d'engins spatiaux ou les protections d'équipements optiques. Cette thèse est effectuée dans le cadre du projet ANR GLASS, qui a pour objectif de faire évoluer les moyens servant à en étudier le comportement sous chargement dynamique (hautes pressions et hautes vitesses de déformations). Elle est focalisée sur l'étude expérimentale de la silice dans ce domaine, afin notamment de permettre un dialogue efficace entre expériences et simulations. Pour cela, la silice est impactée par une impulsion laser de haute puissance, générant une onde de choc qui se propage dans le matériau. Une première étude faite avec des résultats de mesures in situ de la propagation d'ondes de choc dans le verre permet d'obtenir des points de l'équation d'état du matériau. Ensuite, des mesures de spectroscopie Raman sont effectuées sur les échantillons impactés pour observer les modifications permanentes de leur structure atomique. Elles mettent en évidence une densification du matériau et la relaxation thermique du verre dans les zones ayant subi les plus hautes pressions lors du choc. Cet effet est causé par l'importante élévation de température pendant le chargement. Ces résultats montrent une bonne correspondance avec des études numériques effectuées dans le cadre du projet ANR. Enfin, des mesures de microtomographie aux rayons X montrent l'existence de nombreuses fissures à l'intérieur de l'échantillon. Des simulations numériques de peridynamic, une formulation spécialisée dans l'étude de l'endommagement, fournissent un scénario possible pour leur formation. / Fused silica (SiO₂) is one of the most commonly used materials in our modern society. Among other uses, it is the main component of highly critical structures like spacecraft windows or shields for optical equipments. This PhD thesis is done within the context of the ANR GLASS project, whose objective is to model the behavior of silica glass from the atomic cluster to the whole structure under dynamic loading (high pressures and high strain rates). Its main objective is to conduct an experimental study of this material in this loading domain to enable an efficient dialog between experiments and simulations. To this end, samples of fused silica are impacted with high-power laser impulses, generating a shockwave that propagates in the material. A first study is done with in situ results of shockwave propagation in fused silica, giving some data of the equation of state. Subsequently, Raman spectroscopy is used to observe the atomic structure modifications of shocked samples. These measurements show that silica glass is densified in the shocked area, and also that the zones where the highest pressures were applied are subjected to thermal relaxation. This last effect is caused by the important temperature increase during the shock loading. All these results are in accordance with those of numerical simulations performed within the ANR project. Finally, X-Ray microtomography highlight complex fracture patterns inside some of the shocked samples. Numerical simulations using peridynamic formulation, a method specialized to study fracture patterns, provide a possible scenario for the formation and propagation of these cracks.

.La densification du névé en glace est un processus essentiel à comprendre pour interpréter les enregistrements climatiques. Une bonne connaissance des mécanismes permet une datation précise de l'air capturé dans la glace lors de la fermeture des pores. Celle-ci est plus vieille que l'air capturé à cause du transport des gaz dans la colonne de névé plus rapide que la densification de celui-ci. Cette différence d'âge entre la glace et le gaz est généralement appelé le Δage. La densification de la neige consiste en un processus complexe de réarrangement de grains, de frittage et de déformation viscoplastique. Bien que le comportement viscoplastique du cristal de glace soit fortement anisotrope, les modèles de densification actuels ne tiennent pas compte de cette anisotropie. De plus, le caractère granulaire du névé affecte aussi sa densification. La relation entre la fermeture des pores et les mécanismes microstructuraux sous-jacents est encore méconnue. Le but de cette thèse est d'incorporer l'aspect granulaire ainsi que l'anisotropie du cristal de glace dans une approche de modélisation innovante de la densification. Des expériences sur l'indentation viscoplastique de cylindres monocristallins de glace ont été réalisées pour proposer une loi de contact basée sur la théorie de l'indentation, et prenant en compte la déformation préférentielle du cristal de glace sur les plans basaux. Cette loi de contact a été implémentée dans un code utilisant la méthode des éléments discrets pour prédire la densification du névé.La micro-tomographie aux rayons X a été utilisée pour caractériser ex situ le névé polaire en trois dimensions à différentes étapes de la densification (ρ= 0.55-0.88 g/cm3), i.e. pour différentes profondeurs (~23 à 130m). Une étude fine de la fermeture des pores et de différentes caractéristiques morphologiques et physiques a été réalisée pour les sites polaires Dome C et Lock In. Des essais mécaniques ont aussi été réalisés in situ sur du névé extrait de Dome C dans le but de modéliser la densification du névé. Les observations microstructurales des expériences ex situ et in situ révèlent d'importantes différences dues aux vitesses relativement importantes utilisées lors des essais mécaniques. Ces vitesses rapides permettent de découpler la contribution des cinétiques de diffusion de la contribution viscoplastique de la déformation. Les effets de ces contributions sur la morphologie des pores et leurs fermetures sont discutés. Pour caractériser la fermeture des pores, cette thèse propose un indice de connectivité définit par le ratio entre le volume du plus gros pore sur la porosité totale. En effet, cet indice est plus approprié lors de l'utilisation de la tomographie aux rayons X que le ratio de pores fermés pour prédire la densité au close-off. / Densification from firn to ice is an essential phenomenon to understand for the interpretation of the climate record. A good knowledge of this mechanism enables the precise dating of the air embedded in the ice. The step at which the air becomes entrapped is the pore closure (or close-off). Because of gas flow in the firn column, the ice is older than the entrapped air. The difference between ice and gas is generally defined as Δage.Snow densification consists of grain rearrangements, sintering and viscoplastic deformation. Although the viscoplastic behaviour of the ice crystal is strongly anisotropic, densification models do not take into account this anisotropy. Firn also bears some granular characteristics that may affect its densification. The interactions between pore closure and microstructural mechanisms in the firn are still misunderstood.The aim of this PhD thesis is to incorporate both the granular aspect of firn and its anisotropy into an innovating approach of firn densification modelling. The mutual indentation of viscoplastic monocrystalline ice cylinders was experimentally carried out to propose a contact law that is based on indentation theory and that takes into account the preferential viscoplastic deformation on the basal plane. We have integrated this contact law into a DEM (Discrete Element Method) code for the prediction of firn densification.3D X-ray micro-tomography was performed on polar firn at different stages of the densification (ρ= 0.55-0.88 g/cm3) and depths (~23 to 130m). A thorough investigation of pore closure and of different morphological and physical parameters was achieved for the Dome C and the newly drilled Lock In polar sites. In addition to these ex situ analyses, in situ X-ray micro-mechanical experiments were carried out on firn extracted from Dome C in order to model its densification. Ex situ and in situ microstructural observations indicate significant differences that can be explained by the relatively large strain-rates imposed to the firn during in situ tests. These large strain rates allow for a decoupling of the effects of diffusion kinetics and of viscoplastic deformation. Their relative weights on the morphology of pores and on their closure are discussed. To measure pore closure, we propose a connectivity index, which is the ratio of the largest pore volume over the total pore volume. We show that this index is better suited for X-ray tomography analysis than the classic closed porosity ratio to predict the close-off density