This master’s thesis deals with ultra lightweight structural design concept of a lunar habitat. The beginning of the thesis is focused on basic properties of the Moon and different concept designs of lunar habitats and bases. Afterwards the main concept is introduced with defined loads followed by application of loads on the construction and design of main parts of the construction, especially design of an inflatable beam. Thesis is ended by manufacturing technology of an inflatable beam and design concept of main structural nodes.

This master thesis describes design of frame construction of Formula Student car. The objective was to reduce weight and increase the torsional stiffness against to last version of the car. Next objective was to prove advantages of alternative frame. This had been achieved by gradual transformation of standard design of frame to alternative with the usage of FSAE alternative frame rules. The weight was reduced by 20% and torsional stiffness was increased by 34% thanks to FEM simulation and sophisticated changes of alternative frame design.

The aim of the diploma thesis is the proposal of a bridge structure in the direction of Přerov – Lipník in the cadastral territory of the Osek nad Bečvou. A bridge is used to overcome the road III/43612 in km 93,550, the stream Lubeň and a field trip. From tree alternatives is selected a post-tensioned two-beam concrete struction and assessed according to the limit states including an impact of phased construction according to the European standards. Also it is prepared a drawing documentation, an accompanying report and a visualization of the beam.

The aim of the diploma thesis is the proposal of a bridge structure in the direction of Frýdek-Místek - Mosty u Jablunkova. A bridge is used to overcome the local road and Malý javorový stream. From three alternatives is selected a post-tensioned two-beam concrete struction and assessed according to the limit states. It is developed clear and detail drawings and visualization of the bridge.

The subject of this diploma thesis is design and check the steel construction of the office building in Valašské Meziříčí. Floor plan dimensions of building are 55,0 x 30,0 m. The length of building gradually increases with each floor. The building has eight floors. Overall height is 33,6 m. The building ceilings made of composite steel and concrete structure. The construction in both directions is stabilized by vertical bracings. The building adjoins a smaller building with shops. Floor plan dimensions of that building are 31,5 x 21,0 m and building height to the top of the truss girder including cladding is 17,5 m.

Dans le cadre de l'Approche Elargie pour la Fusion conclue entre le Japon et l'Europe, le projet IFMIF (International Fusion Materials Irradiation Facility) a été lancé pour l'étude des futurs matériaux pour la fusion qui devront résister à d'intenses flux de neutrons. Un composant majeur en est son ensemble de deux accélérateurs à très haute puissance (2×5 MW) qui produit le flux de neutrons en bombardant une cible de Lithium avec un faisceau de Deutérium à une énergie de 40 MeV. Vues ces spécifications ambitieuses, une première phase appelée EVEDA (Engineering Validation and Engineering Design Activity) prévoit l'étude et la réalisation d'un accélérateur prototype à l'échelle un jusqu'à 9 MeV au Japon. Le travail de cette thèse concerne le domaine de la Physique des Accélérateurs. Il consiste en des études de dynamique faisceau pour l'accélérateur prototype LIPAc, caractérisé par une intensité et une puissance jamais encore réalisées, exigeant de ce fait des qualités de faisceau exceptionnelles. Les caractéristiques de cet accélérateur, font qu'il requiert de nombreuses études et simulations pour toutes les étapes de sa mise en service. En parallèle, des études de fond sur les interactions coeur-halo et les effets de la charge d'espace dans les accélérateurs intenses, seront aussi menées. En particulier une nouvelle définition du halo d'un faisceau de particules, adaptée à l'étude de ces accélérateurs sera proposée et appliquée. / As part of the Broader Approach to Fusion concluded between Japan and Europe, the IFMIF (International Fusion Materials Irradiation Facility) project was launched for the study of future fusion materials resisting intense neutron fluxes. A major component of it is the couple of twin high power accelerators (2 × 5 MW) which will produce the neutron flux by bombarding a Lithium target with a deuterium beam at an energy of 40 MeV. Considering these ambitious specifications, a first phase called EVEDA (Engineering Validation and Engineering Design Activity) is ongoing to provide the design and construction of an up to scale prototype accelerator to an energy of 9 MeV in Japan. The work of this thesis belongs to the field of Accelerators Physics. It consists of beam dynamics studies for the prototype accelerator LIPAc, characterized by unprecedented current and power, thereby requiring outstanding beam quality. The characteristics of this accelerator, makes many studies and simulations for all stages of its commissioning required. Concurrently, background studies on core-halo interactions and on the effects of space charge on high current beams will also be conducted. In particular a new definition of the halo of a particle beam, adapted to the study of these accelerators will be proposed and implemented.

This thesis addresses the metal nanocluster growth process on prepatterned substrates, the development of atomistic simulation method with respect to an acceleration of the atomistic transition states, and the continuum model of the ion-beam inducing semiconductor surface pattern formation mechanism. Experimentally, highly ordered Ag nanocluster structures have been grown on pre-patterned amorphous SiO2 surfaces by oblique angle physical vapor deposition at room temperature. Despite the small undulation of the rippled surface, the stripe-like Ag nanoclusters are very pronounced, reproducible and well-separated. The first topic is the investigation of this growth process with a continuum theoretical approach to the surface gas condensation as well as an atomistic cluster growth model. The atomistic simulation model is a lattice-based kinetic Monte-Carlo (KMC) method using a combination of a simplified inter-atomic potential and experimental transition barriers taken from the literature. An effective transition event classification method is introduced which allows a boost factor of several thousand compared to a traditional KMC approach, thus allowing experimental time scales to be modeled. The simulation predicts a low sticking probability for the arriving atoms, millisecond order lifetimes for single Ag monomers and about 1 nm square surface migration ranges of Ag monomers. The simulations give excellent reproduction of the experimentally observed nanocluster growth patterns. The second topic specifies the acceleration scheme utilized in the metallic cluster growth model. Concerning the atomistic movements, a classical harmonic transition state theory is considered and applied in discrete lattice cells with hierarchical transition levels. The model results in an effective reduction of KMC simulation steps by utilizing a classification scheme of transition levels for thermally activated atomistic diffusion processes. Thermally activated atomistic movements are considered as local transition events constrained in potential energy wells over certain local time periods. These processes are represented by Markov chains of multi-dimensional Boolean valued functions in three dimensional lattice space. The events inhibited by the barriers under a certain level are regarded as thermal fluctuations of the canonical ensemble and accepted freely. Consequently, the fluctuating system evolution process is implemented as a Markov chain of equivalence class objects. It is shown that the process can be characterized by the acceptance of metastable local transitions. The method is applied to a problem of Au and Ag cluster growth on a rippled surface. The simulation predicts the existence of a morphology dependent transition time limit from a local metastable to stable state for subsequent cluster growth by accretion. The third topic is the formation of ripple structures on ion bombarded semiconductor surfaces treated in the first topic as the prepatterned substrate of the metallic deposition. This intriguing phenomenon has been known since the 1960s and various theoretical approaches have been explored. These previous models are discussed and a new non-linear model is formulated, based on the local atomic flow and associated density change in the near surface region. Within this framework ripple structures are shown to form without the necessity to invoke surface diffusion or large sputtering as important mechanisms. The model can also be extended to the case where sputtering is important and it is shown that in this case, certain "magic" angles can occur at which the ripple patterns are most clearly defined. The results including some analytic solutions of the nonlinear equation of motions are in very good agreement with experimental observation.:1 Introduction: Atomistic Models 1 1.1 Density Functional Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1.1 Schroedinger equation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1.2 Density functional theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.2 Molecular Dynamics Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.2.1 Lagrangian mechanics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.2.2 MD algorithms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 1.3 Lattice Monte Carlo simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 1.3.1 Thermodynamic variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 1.3.2 Metropolis Algorithm and limit theorem . . . . . . . . . . . . . . . . . . . . . 15 1.3.3 Kinetic Monte Carlo Simulation . . . . . . . . . . . . . . . . . . . . . . . . . 18 1.3.4 Imaginary time reaction diffusion . . . . . . . . . . . . . . . . . . . . . . . . . 24 2 Cluster Growth on Pre-patterned Surfaces 29 2.1 Nanocluster growth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 2.1.1 Classical nucleation theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 2.1.2 Cluster growth on substrates . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 2.1.3 Experimental motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 2.2 Local flux and surface ad-monomer diffusion . . . . . . . . . . . . . . . . . . . . . . 35 2.2.1 Surface topography and local flux . . . . . . . . . . . . . . . . . . . . . . . . 35 2.2.2 Surface gas diffusion under inhomogeneous flux . . . . . . . . . . . . . . . . . 37 2.2.3 Surface migration of ad-monomers . . . . . . . . . . . . . . . . . . . . . . . . 40 2.2.4 Simulation vs. experimental gauge . . . . . . . . . . . . . . . . . . . . . . . . 45 2.3 Nucleation models: Surface gas condensation . . . . . . . . . . . . . . . . . . . . . . 46 2.3.1 Simulation setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 2.3.2 Simulation parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 2.3.3 Evolution of sticking probability . . . . . . . . . . . . . . . . . . . . . . . . . 49 2.3.4 Evolution of Ag cluster growth . . . . . . . . . . . . . . . . . . . . . . . . . . 54 2.3.5 Simulation time and system evolution . . . . . . . . . . . . . . . . . . . . . . 57 2.4 Extended cluster growth model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 2.4.1 Modified setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 2.4.2 Simulation result . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 2.4.3 Comparison with experiment . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 2.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 3 A Markov chain model of transition states 63 3.1 Acceleration of thin film growth simulation . . . . . . . . . . . . . . . . . . . . . . . 63 3.2 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 3.3 Transition states of Markov chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 3.3.1 Local transition events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 3.3.2 The Monte-Carlo method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 3.4 Effective transitions of objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 3.4.1 Convergence of the local fluctuation . . . . . . . . . . . . . . . . . . . . . . . 67 3.4.2 The importance of individual local transitions . . . . . . . . . . . . . . . . . . 68 3.4.3 The modified algorithm for effective transition states . . . . . . . . . . . . . . 69 3.5 Cluster growth simulation models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 3.5.1 The configuration energy and migration barriers . . . . . . . . . . . . . . . . 72 3.5.2 Transition events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 3.5.3 Comparison with Experiment . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 3.5.4 Cluster growth stability evaluation . . . . . . . . . . . . . . . . . . . . . . . . 78 3.6 Stability of modified convergence limit . . . . . . . . . . . . . . . . . . . . . . . . . . 80 3.6.1 Acceleration of convergence to Gibbs field . . . . . . . . . . . . . . . . . . . . 80 3.6.2 Relative convergence speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 3.6.3 1D Ag models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 3.6.4 Stability theorem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 3.7 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 4 Ion beam inducing surface pattern formation 89 4.1 Ion-inducing pattern formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 4.1.1 Bradley-Harper equation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 4.1.2 Nonlinear continuum models . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 4.1.3 Other approaches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 4.2 Simulation of surface defects induced by ion beams . . . . . . . . . . . . . . . . . . . 94 4.2.1 MD simulation of single ion impact . . . . . . . . . . . . . . . . . . . . . . . . 94 4.2.2 Monte-Carlo simulations of surface modification . . . . . . . . . . . . . . . . 96 4.2.3 Curvature dependent surface diffusion . . . . . . . . . . . . . . . . . . . . . . 102 4.3 Continuum model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 4.3.1 Equation of motion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 4.3.2 A travelling wave solution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 4.3.3 Lyapunov stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 4.3.4 Comparison with experiment . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 4.3.5 Approximate solutions for other angles . . . . . . . . . . . . . . . . . . . . . . 110 4.4 Contribution of other effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 4.4.1 Surface diffusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 4.4.2 Surface Sputtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 4.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 5 Summary 119 Appendix 123 A The discrete reaction diffusion equation . . . . . . . . . . . . . . . . . . . . . . . . . 123 B The derivation of the solution (2.20) . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 C Contribution of overlapping migration area . . . . . . . . . . . . . . . . . . . . . . . 125 D The RGL potential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 E Stability of the traveling wave solution . . . . . . . . . . . . . . . . . . . . . . . . . . 127

Additive manufacturing (AM) is a technology that inverts the procedure of traditional machining. Instead of starting with a billet of material and removing unwanted parts, the AM manufacturing process starts with an empty workspace and proceeds to fill this workspace with material where it is desired, often in a layer-by-layer fashion. Materials available for AM processing include polymers, concrete, metals, ceramics, paper, photopolymers, and resins. This thesis is concerned with electron beam melting (EBM), which is a powder bed fusion technology that uses an electron beam to selectively melt a feedstock of fine powder to form geometries based on a computer-aided design file input. There are significant differences between EBM and conventional machining. Apart from the process differences, the ability to manufacture extremely complex parts almost as easily as a square block of material gives engineers the freedom to disregard complexity as a cost-driving factor. The engineering benefits of AM also include manufacturing geometries which were previously almost impossible, such as curved internal channels and complex lattice structures. Lattices are lightweight structures comprising a network of thin beams built up by multiplication of a three-dimensional template cell, or unit cell. By altering the dimensions and type of the unit cell, one can tailor the properties of the lattice to give it the desired behavior. Lattices can be made stiff or elastic, brittle or ductile, and even anisotropic, with different properties in different directions. This thesis focuses on alleviating one of the problems with EBM and AM, namely the relatively few materials available for processing. The method is to take a closer look at the widely used stainless steel 316LN, and investigate the possibility of processing 316LN powder via the EBM process into both lattices and solid material. The results show that 316LN is suitable for EBM processing, and a processing window is presented. The results also show that some additional work is needed to optimize the process parameters for increased tensile strength if the EBM-processed material is to match the yield strength of additively laser-processed 316L material. / <p>Vid tidpunkten för framläggningen av avhandlingen var följande delarbete opublicerat: delarbete 3 (inskickat).</p><p>At the time of the defence the following paper was unpublished: paper 3 (submitted).</p>

Seit 1998 werden am Helmholtz-Zentrum Berlin für Materialien und Energie GmbH (HZB) in Kooperation mit der Charité-Universitätsmedizin Berlin Augentumore mit Protonen bestrahlt. Dazu beschleunigt ein Zyklotron, welches hauptsächlich für die Therapie genutzt wird, die Protonen auf eine Energie von 68MeV. Neben dem Therapieplatz existiert auch ein Experimentierplatz zu Forschungszwecken. Die Strahlaufbereitung erfolgt in beiden Anwendungsgebieten primär durch passives Aufstreuen des Strahls mit einer einzelnen Streufolie. Dies führt jedoch zu erheblichen Strahlverlusten, die die erreichbare Strahlintensität bzw. Dosisleistung im Feld limitieren. Ziel dieser Arbeit ist es, einen Bestrahlungsplatz mit aktiver, dreidimensionaler Strahlführung aufzubauen, um eine möglichst effiziente Strahlstromnutzung zu ermöglichen und flexibel auf Anforderungen an das Bestrahlungsfeld eingehen zu können. Zu diesem Zweck wurde ein Modell entwickelt, welches unter Berücksichtigung verschiedener Parameter der Messgeometrie, Strahlcharakteristik und Felderzeugung Strahlprofile berechnet. Dieses Modell wurde im Vergleich mit Monte-Carlo Simulationen und Messungen getestet und verifiziert. Anschließend konnten Untersuchungen zur Positionierung der verwendeten Komponenten durchgeführt sowie deren Einflüsse auf Penumbra, Homogenität und Transmission der Strahlfelder analysiert werden. Es zeigte sich, dass die hohen klinischen Anforderungen für die Anwendung in der Augentumortherapie am HZB erfüllt werden können, sofern stärkere Magnetspulen verwendet werden. Mit Hilfe des Modells wurden für einen optimierten Aufbau Strahlprofile berechnet und charakterisiert. Es konnte so gezeigt werden, dass unter diesen optimierten Bedingungen eine Anwendbarkeit des aktiven Systems in der Augentumortherapie möglich ist. Des Weiteren wurde im Verlauf dieser Arbeit ein statischer Modulator für den Bestrahlungsplatz am HZB entwickelt, mit Hilfe eines 3D-Druckers hergestellt und erfolgreich getestet. / Since 1998, ocular tumours have been irradiated with protons at the Helmholtz- Zentrum Berlin für Materialien und Energie GmbH (HZB) in cooperation with Charité-Universitätsmedizin Berlin. For this purpose a cyclotron is operated which accelerates protons to an energy of 68MeV and is mainly used for therapy purposes. In addition to the therapy station there is also an experimental station for research purposes. In both application areas, beam delivery is primarily achieved by passive scattering using a single scattering foil. However, this leads to considerable beam losses, which in turn limit the maximum beam intensity or dose rate in the irradiation field. The aim of this work is to construct an irradiation setup with active three-dimensional beam delivery in order to enable the most efficient possible use of beam current and to be able to respond flexibly to different irradiation field requirements. Therefore, a model was developed which calculates beam profiles taking into account various parameters of the measurement geometry, beam characteristics and field generation. This model was tested and verified in comparison with Monte Carlo simulations and measurements. Subsequently investigations into the positioning of the components used could be carried out and their influences on penumbra, homogeneity and transmission of the beam fields analysed. It was found that the high clinical requirements in terms of maximum penumbra and field homogeneity for the application in eye tumour therapy at HZB can be met if stronger magnetic coils were used. Model calculations were used to calculate and characterize different beam profiles for an optimized setup. It could be shown that under these optimized conditions an applicability of the active system in eye tumour therapy is possible. Furthermore, a static modulator for the irradiation site at HZB was developed in the course of this work, manufactured using a 3D printer and successfully tested.

I Sverige finns 21 000 broar som Trafikverket förvaltar (Trafikverket, 2018a). Två brotyper som finns är rambro och balkbro. Rambron är en av de vanligaste brotyperna och är uppbyggd som en fast inspänd konstruktion. Brosystemet kallas plattrambro eller balkrambro beroende på om balkarna eller plattan är det bärande elementet. Om bron istället är fritt upplagd på stödkonstruktionen, kallas brosystemet för plattbro eller balkbro (Vägverket, 1996). ZIP-balksbron är uppbyggd som en balkbro med en modell liknande omvända T-balkar som läggs fläns mot fläns. Brosystemet kommer ursprungligen från Spanbeton i Holland och gjorde under år 2019 premiär på den svenska marknaden med ett projekt i Härnösand. Bron har en spännvidd på 20,55 meter bestående av nio ZIP-balkar. Balkarna prefabriceras på Strängbetongs fabrik i Långviksmon utanför Härnösand. Projektet blev klart under hösten 2019. Syfte och mål med examensarbetet var att undersöka skillnader mellan ZIP-balksbron och en traditionell exemplifierad plattrambro. Aspekterna som undersöktes var underhållet hos de två brotyperna, materialåtgång av betong och armering, last av trafik samt att det gjordes en utvärdering av projektet. Resultatet visar att ZIP-balksbron kräver mer underhåll än en plattrambro eftersom balkbroar har övergångskonstruktion och brolager. Den tar även mer tid att inspektera då den innehåller manhål. ZIP-balksbron använder sig av 29,38 % mindre betong på en meter. Armeringsdifferensen mellan broarna är försumbart. Momentet av den vertikala respektive horisontella lasten av trafik är 44,5 % respektive 19,2 % större hos ZIP-balksbron jämfört med plattrambron. Resultatet visar även på ett bra utfört brobygge som kan hänvisas i brolösningen, samt nöjda parter från flera håll. Slutsatsen är att plattrambron är mer fördelaktig att använda ur ett underhållsperspektiv, en balkbro kräver betydligt större underhåll än de driftåtgärder som årligen sker på broar. Men, genom arbetets bevisning använder ZIP-balksbron mindre betong än hos en traditionell plattrambro och har en enkel byggprocess, vilket ökar förtroendet för brolösningen och framförallt för prefabricering inom brobranschen. Trots att brotypen kräver ett större underhåll samt en ökad och mer komplex momentfördelning än hos en plattrambro, kan säkerheten under byggtiden vara en avgörande aspekt vid val av brobyggen i framtiden. / The ZIP-beam bridge is constructed as a beam bridge with inverted T-beams placed with flanges next to each other. The bridge system is originally from Spanbeton in Holland and it is having its premiere on the Swedish market during year 2019 with an ongoing project in Härnösand. The bridge span is 20,55 meters consisted with nine ZIP-beams. The project was finished in august 2019.  The purpose and goal were to examine differences between the ZIP-beam bridge and a traditional slab frame bridge. The aspects to examine was maintence, use of concrete and reinforcement and traffic loads.  The results show that the ZIP-beam bridge requires more maintenance than the slab frame bridge. The ZIP-beam bridge uses 29,38 % less concrete per metre. The use of reinforcement is negligible. The moment force of the horisontal and vertical traffic loads is 44,5 % respective 19,2 % larger at the ZIP-beam bridge. The conclusion of this paper shows that even though the ZIP-beam bridge requires more maintenance and a more complex moment force than a slab frame bridge, the safety during the building time as well as the less amount of concrete used can be a conclusive factor when building bridges in Sweden in the future.