392 research outputs found

    Combinatorial Synthesis and High-Throughput Analysis of Halide Perovskite Materials for Thin-Film Optoelectronic Devices

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    Metallhalogenid-Perowskite (MHP) haben sich als hervorragende Materialklasse im Bereich der Optoelektronik erwiesen, obwohl die Degradation der hĂ€ufig verwendeten organischen Komponenten ihre LangzeitstabilitĂ€t begrenzt. Um schnell stabile Alternativen zu finden, ist eine Parallelisierung des Prozesses der Materialentwicklung durch kombinatorische Synthese und Hochdurchsatzanalyse erforderlich. In dieser Arbeit wird dies durch die Entwicklung, Implementierung und Validierung zweier komplementĂ€rer Methoden fĂŒr die kombinatorische Synthese realisiert. Zum einen wurde die lösungsmittelbasierte Methode des kombinatorischen Tintenstrahldrucks weiterentwickelt, indem ein neuer Algorithmus fĂŒr eine verbesserte Tintenmischung bereitgestellt und validiert wurde. Zum anderen wurde die Synthese von CsyPb1-y(BrxI1-x)2-y-Doppelgradientenschichten durch Co-Verdampfung erreicht. Kombinatorische Bibliotheken, die durch diese beiden Methoden hergestellt wurden, wurden fĂŒr die Hochdurchsatzuntersuchung der strukturellen und optischen Eigenschaften der anorganischen CsyPb1-y(BrxI1-x)2-y-MHP verwendet. Dies ermöglichte die schnelle Erstellung vollstĂ€ndiger Phasendiagramme fĂŒr DĂŒnnfilme des CsPb(BrxI1-x)3-Mischkristalls, die zeigen, dass die Zugabe von Br die halbleitende Perowskitphase stabilisiert und niedrigere Verarbeitungstemperaturen ermöglicht. DarĂŒber hinaus wurden CsyPb1-y(BrxI1-x)2-y-Bibliotheken mit automatisierten, kontaktlosen optischen Raster-Messungen untersucht, die eine schnelle Sichtung von ĂŒber 3400 Zusammensetzungen ermöglichten. Dies ermöglichte die Bewertung des photovoltaischen Potenzials von CsyPb1-y(BrxI1-x)2-y ĂŒber einen sehr breiten Bereich von Zusammensetzungen. Das höchste Wirkungsgradpotenzial wurde fĂŒr stöchiometrische Zusammensetzungen gefunden, wobei ein Überschuss an Pb oder Cs zu erhöhten Verlusten durch nichtstrahlende Rekombination fĂŒhrt. Diese Ergebnisse liefern wichtige Erkenntnisse fĂŒr die weitere Entwicklung von anorganischen MHP-Bauelementen.To keep up with the increasing need for specialized materials, a parallelization of the materials discovery process is needed through combinatorial synthesis and high-throughput analysis. The acceleration of materials discovery is especially of interest in the area of optoelectronics where metal halide perovskites (MHPs) have proven to be an excellent material class and have achieved impressive performance in photovoltaic devices among other applications. However, the degradation of the frequently employed organic components contributes to limiting the long-term stability of MHP devices. In this work, accelerated materials discovery is addressed through the development, implementation, and validation of two complementary methods for combinatorial synthesis. Firstly, the solution-based method of combinatorial inkjet printing was further developed by providing and validating a new algorithm for improved ink mixing. Secondly, the vapor-based synthesis of double-gradient CsyPb1-y(BrxI1-x)2-y was achieved by co-evaporation. Combinatorial libraries created by both methods were used for the high-throughput investigation of the structural and optical properties of the inorganic CsyPb1-y(BrxI1-x)2-y MHPs. This enabled the fast construction of complete phase diagrams for thin-films of the CsPb(BrxI1-x)3 solid solution which show that the addition of Br stabilizes the semiconducting perovskite phase and allows for lower processing temperatures. Additionally, CsyPb1-y(BrxI1-x)2-y libraries were investigated by automized, contact-less, optical mapping measurements, enabling the rapid screening of over 3400 compositions. This enabled the assessment of the photovoltaic potential of CsyPb1-y(BrxI1-x)2-y over a very broad compositional range. The maximum efficiency potential was found for stoichiometric compositions, with excess of Pb or Cs causing increased losses by non-radiative recombination. These results provide vital knowledge for further development of inorganic MHP devices

    What Bounds A-Legality?

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    This comment discusses Hans Lindahl’s central idea of a-legality. It begins by positioning the idea of a-legality in the literature on the constituent power of the people, showing how it ad-vances the discussion at hand. Having done that, it raises two questions regarding the conceptu-al and normative significance of the politics of a-legality. Is a-legality contingent on a certain form of consciousness, or a certain form of government? And, what is the basis of the normative recommendation that legal collectives ought to respond to a-legality with collective self-restraint? The aim of both questions is to identify what bounds Lindahl’s idea of a-legality

    The rites in the mysteries of Dionysus: the birth of the drama

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    The Greek drama can be apprehended as an extended ritual, originating in the ceremonies of the Dionysus cult. In particular, tragedy derived its origin from the sacrifice of goats and the hymns which were sung on that occasion. Tragedia means "song of the male goat" and these hymns later developed into choruses and eventually into tragedy, in the sense of a solemn and purifying drama. The presence of the god Dionysus is evident in the history and development of the Greek drama at the beginning of the fifth century B.C. and its sudden decline 150 years later. Its rise seems to correspond with the Greek polis, where questions of justice and divine law in conflict with the individual were obviously a matter of discussion and where the drama had individual and collective catharsis (purifying) in mind

    The role of banking sector performance for renewable energy consumption

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    Renewable energy has in recent years become an important component of world energy consumption since it holds the characteristics of decreasing carbon oxide emissions while at the same time being able to meet the future increase in energy demand. To secure future universal access to modern energy, large investments in renewable energy technology are required. For these investments, financing needs to be assured which puts the banking sector at the front position when determining renewable energy consumption. To determine the drivers of renewable energy, researchers have investigated the role of both growth and financial development in relation to renewable energy consumption. The literature is however limited as no one has previously studied the role that the commercial banking sector holds for renewable energy consumption. This thesis estimates the impact of five banking sector performance variables (return on asset, market capitalisation, asset quality, managerial inefficiency and financial stability) on renewable energy consumption for a global panel consisting of 124 countries over the period 1998-2012 by using a two-step system-GMM panel model. It also considers three homogenous subpanels which are constructed based on the income group classification of sample countries (high-, middle-, and low-income countries). The results show statistical significant effects of banking sector performance on renewable energy consumption for the global panel as well as for the three income groups. For high income countries, an increase in bank size together with improved asset quality and managerial efficiency have positive effects on renewable energy consumption. For middle and low income countries, a high return on asset, an increase in bank size and financial stability are positive determinants of renewable energy consumption. The results in this thesis highlights the importance of a well-functioning bank sector to achieve the investment in renewable energy needed to meet future energy demand simultaneously as decreasing CO2 emissions.VĂ€rlden stĂ„r inför stora utmaningar gĂ€llande att sĂ€kra global tillgĂ„ng till modern energi. Samtidigt krĂ€ver alarmerande rapporter om klimatets allt sĂ€mre tillstĂ„nd en omedelbar minskning av koldioxidutslĂ€ppen. Detta har medfört att förnybar energi vuxit till en allt viktigare energikĂ€lla och konsensus rĂ„der kring att det krĂ€vs en snabb energiomstĂ€llning frĂ„n fossila brĂ€nslen till förnybar energi. För att kunna sĂ€kra en sĂ„dan omstĂ€llning krĂ€vs stora investeringar, vilka i sin tur krĂ€ver finansiering. Behovet av tillgĂ„ng till finansiering skapar intresse kring banksektorns roll för att kunna öka andelen energikonsumtion frĂ„n förnybara kĂ€llor. Studier har undersökt förnybar energikonsumtion bĂ„de i relation till tillvĂ€xt och finansiell utveckling. Ingen har dock tidigare studerat banksektorns inverkan pĂ„ hur mycket av energikonsumtionen som bestĂ„r av förnybar energi. Denna uppsats syftar till att undersöka hur banksektorn pĂ„verkar konsumtion av förnybar energi genom att estimera fem variabler (avkastning pĂ„ investeringar, marknadskapitalisering, kvalitĂ©t pĂ„ tillgĂ„ngar, bankens styrning samt finansiella sektorns tillstĂ„nd) relaterade till bankers- och banksektorns prestation. I studien anvĂ€nds paneldata med observationer för 124 lĂ€nder mellan Ă„ren 1998 - 2012). Den ekonometriska metod som anvĂ€nds Ă€r system-GMM (”system general method of moments”) och flertalet tester (CD-test och Unit root-test) utförs för att sĂ€kerstĂ€lla resultatens trovĂ€rdighet. Datat delas Ă€ven in i tre subgrupper baserat pĂ„ lĂ€ndernas inkomstklassificering. Hög-, medel- och lĂ„ginkomstlĂ€nder analyseras separat för att kunna urskilja policyrelevanta skillnader mellan grupperna. Uppsatsen kommer fram till att banksektorns prestation har en statistisk signifikant betydelse för konsumtionen av förnybar energi globalt sĂ„vĂ€l som för+ de tre inkomstgrupperna. NĂ€r banker innehar större marknadsandelar pĂ„verkas andelen energi som konsumeras frĂ„n förnybara kĂ€llor positivt för alla grupper. Ökad avkastning pĂ„ investeringar samt förbĂ€ttrat finansiellt klimat pĂ„verkar andelen förnybar energi i medel- och lĂ„ginkomstlĂ€nder positivt men verkar inte ha nĂ„gon effekt pĂ„ förnybar energikonsumtion i höginkomstlĂ€nder. Studien visar att ökad kvalitĂ©t pĂ„ tillgĂ„ngar pĂ„verkar andelen förnybar energi positivt i höginkomstlĂ€nder sĂ„vĂ€l som globalt, medan andelen förnybar energi i medel- och lĂ„ginkomstlĂ€nder pĂ„verkas negativt. DĂ„ bankers interna styrning förbĂ€ttras ökar andelen energi som konsumeras frĂ„n förnybara kĂ€llor i höginkomstlĂ€nder samt globalt. Sammantaget visar studien att en vĂ€lfungerande banksektor spelar en betydande roll i omstĂ€llningen frĂ„n fossila brĂ€nslen till förnybar energi

    Virkesgripen

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    The aim of this study was to investigate and describe conceptions that been used when people talks about grapples and to put together parameters that the customers sees as important when they chose a grapple from Hultdins. Every year Hultdins manufacturer and sells about 3500 grapples around the world. With so many users its difficult to oblige everyone. To get an apprehension of what kind of grapple the operators wanted a formula with 18 questions was made. For the interviews 20 forestmachineoperators were choicest who had experience from Hultdins grapples, a lot of them also had experience from other grappleproducers and constructions. The study showed that it is the durability the users give priority to. A lot of operators use the grapple to move stones, stumps, etc. to get an even and faster main haul road. That is a big problem because the grapple is not made for that kind of use and the life is reduced. The operators were asked about the grapples qualities during work with timber. Many operators thought that the qualities would improve if the grapple claws were made rounder and wider. If the grapples claws were rounder they also thought that the grapple should get much less stones, moss and soil with it when the grapple is closed to pick up logs from the ground. Other qualities and factors like color and long lubrication intervals, etc. weren't anything the operators cared about. Out on the market Hultdins is well known for all the robust and simple products they designed. During year 2006 Hultdins introduce a further development of the SuperGrip, SuperGrip 2. The construction is a bit different from the previous SuperGrip, the grapples claws is made rounder and also wider even the construction is more vigorous. They also developed an extra size of grapple that operators who perform forwarding both in thinning and final felling will appreciate. The conclusion of this report is that Hultdins made the right decisions when they developed Super Grip 2.Syftet med detta examensarbete har varit att reda ut och beskriva begrepp som anvÀnds nÀr man pratar virkesgripar och att sammanstÀlla vilka parametrar som kunderna anser vara viktigast nÀr man vÀljer en virkesgrip frÄn Hultdins. Varje Är tillverkar och sÀljer Hultdins ca 3000 virkesgripar över hela vÀrlden. Med sÄ mÄnga anvÀndare Àr det svÄrt att tillmötesgÄ samtliga anvÀndare. För att fÄ en uppfattning om vad skotarförare vill ha för sorts grip sammanstÀlldes ett intervjuunderlag med frÄgor till 20 maskinförare. MÄnga av dessa förare hade tidigare erfarenhet frÄn andra fabrikat och modeller av gripar. Hultdins som ute hos förarna Àr kÀnt för att robusta och enkla produkter kom under 2006 med en vidareutveckling av SuperGripen, SuperGrip II. SuperGrip II har en kraftigare konstruktion och ytterligare en storleksmodell, SGII 300 har Àven tagits fram. Slutsatserna man kan dra av de resultat som framkommit i studierna Àr att man har satsat rÀtt vid utvecklingen av den nya gripen

    Stefan Olsson. 2016. GĂ­sl: givande och tagande av gisslan som rituell handling i fredsprocesser under vikingatiden

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    I den fornnordiska mytologin krigar tvÄ gudaslÀkter mot varandra, men kommer till sist överens om att sluta fred. För att sÀkra freden utvÀxlar man gisslan, vilket innebÀr att de mytomspunna vanerna Njord, Frey och Freyja införlivas i gudarnas krets. Mindre lyckligt gick det för asarnas gisslan, dÀr den vise Mimer dödades och hans huvud skickades tillbaka till Oden. SistnÀmnda episod ligger nÀra det moderna gisslan­tagandet som ofta kan leda till en tragisk utgÄng. PÄ medeltiden var gisslanutlÀmnandet strÀngt reglerat genom ömsesidiga utfÀstelser pÄ vilka fredsförhandlingar följde. Stefan Olsson har i sin avhandling behandlat processen noggrant med hjÀlpa av exempel frÄn Norden, England, Skottland, Irland, Frankrike och de baltiska lÀnderna
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