Natural precious opals consist of silica nanoparticles of uniform diameter organised in a periodic three-dimensional structure. The physical structure of the material produces the perceived colour by a process of light diffraction. The modification of light by the physical structure of the material is also known as structural colour. This is a different process from how most surface colours are produced where light is more usually absorbed by dye and/or pigment molecules. Desirable aesthetic qualities could be achieved if the structural colours produced by natural opals could be replicated in the form of a film or a coating on textile substrates. The work presented investigates how to produce structurally coloured textiles using surface applications of uniform spherical silica nanoparticles (USSNPs). A novel one-step solvent varying (SV) technique has been developed to synthesise USSNPs with particle diameters in a controlled size range. Using suspensions containing USSNPs, structurally coloured artificial opal (AO) films have been fabricated by self-assembly using a process of natural gravity sedimentation. The sedimentation of a particular particle size range of USSNPs (from which a coloured film was produced), onto the surface of fabrics, produced a structurally coloured fabric. By controlling the mean particle diameter a wide range of spectral colours from red to blue was obtained. The light fastness properties of the coloured textiles were investigated. A further surface modification of USSNPs was performed by adding vinyl functional groups to improve the mechanical strength of the structural colour. This work suggested a novel approach to colouring textile materials without using traditional dyes and/or pigments.

This thesis was written in collaboration with the department of electrical engineering at Uppsala University. It evaluates and tests the potentials and limitations of using the OPAL-RT simulator as a tool for designing and developing control strategies used in microgrids with a high penetration of distributed energy resources. As the world gradually transitions to a more decentralized power system with less conventional power production, new strategies to ensure reliable and robust power transmission and distribution must be developed.    The objectives of this thesis were to develop a model of a microgrid that can be used as a base for developing control strategies to limit slow voltage variations in microgrids with high penetration of distributed energy resources. When a template model and strategy for conducting this type of research had been developed the thesis started to focus on the Real-Time simulator. The power system part of the microgrid was converted into a Real-Time compatible model and was allocated to be run on one of the CPU cores of the simulator. In an iterative process, the power system was built and run on the simulator to get results concerning the size of the power system that can be simulated using the CPU cores where the limiting factor is the computational power of the cores. Since the power electronics found in the inverter part of the voltage source converter is operating at a very high switching frequency the inverter must be simulated on the simulator's FPGA. The last objective was to integrate the CPU model and the FPGA model into one model where two different time steps were used.  The results show that one CPU can simulate the 18-bus power system developed during this thesis. It is also assessed that the CPU is capable of simulating a considerably bigger system if no calculations or control strategies are present in the system. The FPGA is functioning and can simulate high-frequency switching power electronics in Real Time.    The conclusions are that Real Time simulators in general as well as the OPAL-RT simulator studied here at Uppsala University will be of great importance for the continuation of research connected to control strategies.

This research centers on the fabrication, characterization, and engineering of inverse opal scaffolds, a novel class of three-dimensional (3D) porous scaffolds made of biocompatible and biodegradable polymers, for applications in tissue engineering and regenerative medicine. The unique features of an inverse opal scaffold include a highly ordered array of pores, uniform and finely tunable pore sizes, high interconnectivity, and great reproducibility. The first part of this work focuses on the fabrication and functionalization of inverse opal scaffolds based on poly(D,L-lactic-co-glycolic acid) (PLGA), a biodegradable material approved by the U.S. Food and Drug Administration (FDA). The advantages of the PLGA inverse opal scaffolds are also demonstrated by comparing with their counterparts with spherical but non-uniform pores and poor interconnectivity. The second part of this work shows two examples where the PLGA inverse opal scaffolds were successfully used as a well-defined system to investigate the effect of pore size of a 3D porous scaffold on the behavior of cell and tissue growth. Specifically, I have demonstrated that i) the differentiation of progenitor cells in vitro was dependent on the pore size of PLGA-based scaffolds and the behavior of the cells was determined by the size of individual pores where the cells resided in, and ii) the neovascularization process in vivo could be directly manipulated by controlling a combination of pore and window sizes when they were applied to a mouse model. The last part of this work deals with the novel application of photoacoustic microscopy (PAM), a volumetric imaging modality recently developed, to tissue engineering and regenerative medicine, in the context of non-invasive imaging and quantification of cells and tissues grown in PLGA inverse opal scaffolds, both in vitro and in vivo. Furthermore, the capability of PAM to monitor and quantitatively analyze the degradation of the scaffolds themselves was also demonstrated.

Gruppenbildung gilt gemeinhin als soziales Phänomen. Doch mit der Evolution sozialer Software im Internet und dem einhergehenden reziproken Interaktionismus von Individuen in Online-Communities werden Kollaborationsstrukturen und Verhaltensmuster innerhalb virtueller Wissensräume sichtbarer denn je. Wie entsteht nun Kollaboration? Und welche Formen der Kollaboration gibt es? Welche Einflussfaktoren sind im Aufbau und Wachstum digitaler Wissensnetzwerke ausschlaggebend, um erfolgreich Information und Wissen verteilen zu können? Diese Fallstudie zeigt erste Einblicke in die Organisationsstruktur virtueller Wissensgemeinschaften anhand der Untersuchung des Wissen- und Lernportals OPAL. Dabei werden Theorien und Modelle aus den Handlungsfeldern der Kommunikationsund Bildungsforschung zu Grunde gelegt und mit dem soziologischen Paradigma der sozialen Netzwerktheorie verbunden.

There is an ever increasing demand of electricity and to meet this demand, installation of new transmission and distribution lines is required. This task requires a significant investment and consent from the respective authorities. An alternative is to utilize maximum capability of the existing lines. Static line ratings are based on a conservative estimate, which means that on most occasions, the actual capacity of lines is much higher than the static line ratings. In order to provide a solution to this problem, this thesis introduces an approach that has been developed to utilize real time weather conditions, conductor sag data and the actual line loading of the conductor from PMU to provide dynamic line ratings for active distribution networks. The application has been developed in LabVIEW environment which provides a user friendly front panel where real-time ampacity can be seen as a waveform while being compared to the actual line loading.  The developed application has been tested on the reference grid created for IDE4L project. The ampacity calculation method introduced here makes use of real-time data available through a real-time simulator in SmarTS lab at KTH, Sweden. / Det är ett ökande behov av elektricitet och för att möta detta behövet, installation av nya transmission och distributionsledningar behövs. Denna utbyggnad kräver ett stort engagemang och förståelse från ansvariga grupper. Ett alternativ är att utnyttja max-kapaciteten på redan befintliga ledningar. Installerade ledningar har räknats på ett konservativt sätt, vilket innebär att det vid vissa tillfällen går att öka belastingen på på dessa. För att ge en lösning på detta problem, introducerar den här avhandlingen en metod för att använda realtids-väderdata, tabeller för ledningarnas utvidgning och realtids-belastningsdata från PMU för att framställa dynamisk data för aktiva distributions-nätverk. Applikationen har utvecklas i LabVIEW-miljön som har ett användarvänligt GUI, där “Real-time ampacity” kan ses som en vågform medans den jämförs mot den faktiska belastningen på ledningen.  Den utvecklade appliktionen har testats på referens-miljön som skapts för IDE4L projektet. “Ampacity calculation metoden” som introduceras här använder sig av realtidsdata som görs tillgänglig igenom en realtids-simulator i SmarTSlab på Kungliga Tekniska Högskolan i Sverige.

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Zum ersten Mal an der TU Bergakademie Freiberg wurde im Wintersemester 2012/13 eine klassische Präsenzvorlesung in ein umfassendes handlungsorientiertes Blended-Learning-Szenario (Methode: Flipped Classroom; Tools: OPAL-Kurs mit Wiki, Forum etc.) transformiert und evaluiert. Im folgenden Beitrag werden die Ergebnisse des Pilotversuchs vorgestellt und aus Sicht der beteiligten Akteure kritisch diskutiert.

Zum ersten Mal an der TU Bergakademie Freiberg wurde im Wintersemester 2012/13 eine klassische Präsenzvorlesung in ein umfassendes handlungsorientiertes Blended-Learning-Szenario (Methode: Flipped Classroom; Tools: OPAL-Kurs mit Wiki, Forum etc.) transformiert und evaluiert. Im folgenden Beitrag werden die Ergebnisse des Pilotversuchs vorgestellt und aus Sicht der beteiligten Akteure kritisch diskutiert.

L’auto-assemblage de particules colloïdales est une technique polyvalente qui permet la fabrication de cristaux colloïdaux à de grandes échelles. Le but de notre étude est de développer des processus fiables et reproductibles pour fabriquer des matériaux photoniques et plasmoniques pouvant être incorporés au sein de différents dispositifs.Des opales inverses en dioxyde de titane composées d’un nombre précis de couches ont été intégrées au sein de cellules solaires à colorant «tout solide», ce qui a entraîné une amélioration des performances allant jusqu'à105%. Des surfaces d'ornano structurées présentant une absorption omnidirectionnelle et totale de la lumière ont été fabriquées par dépôt électrolytique d'or à travers une monocouche de particules de polystyrène. En outre, des surfaces d'or très rugueuses présentant des propriétés anti-réfléchissantes ont également été élaborées. En modulant la taille des interstices entre les particules de polystyrène, il a été possible de fabriquer par électrodéposition séquentielle des nanopiliers d’or de différentes longueurs. Enfin, l'utilisation d'une monocouche non compacte de particules comme moule a permis la réalisation de métamatériaux de type fishnet / The bottom-up self-assembly of colloidal particles is a versatile technique that allows the fabrication of large areas of colloidal crystals. The purpose of the present study is to develop highly reliable and reproducible process routes to fabricate nanostructured photonic and plasmonic materials that can be incorporated into different devices. Titania inverse opals with precise control of the layer thickness have been successfully incorporated into solid state DSSCs which showed improved performance of up to 105 %. Nanostructured gold surfaces that exhibited omnidirectional total light absorption have been fabricated by controlled electrodeposition of gold through colloidal monolayers of polystyrenebeads. In addition, very rough gold surfaces that showed anti-reflective properties were also made. By tuning the pore size of the colloidal monolayer, plasmonic gold nanopillarswith different lengths were fabricated by a sequential electrodeposition process. Using a non close-packed monolayer of PS beadscombined with electrodeposition,fishnet metamaterialswere fabricated.

名古屋大学年代測定総合研究センターシンポジウム報告