Sökning: "Diffusion system"

Visar resultat 1 - 5 av 590 avhandlingar innehållade orden Diffusion system.

  1. 1. Insights into Materials Properties from Ab Initio Theory : Diffusion, Adsorption, Catalysis & Structure

    Författare :Andreas Blomqvist; Rajeev Ahuja; Christopher Wolverton; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Density functional theory; Molecular dynamics; Diffusion; Catalysis; Adsorption; Random structure search; Hydrogen-storage materials; Phase-change materials; Defects and diffusion; Defekter och diffusion; Surfaces and interfaces; Ytor och mellanytor; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : In this thesis, density functional theory (DFT) calculations and DFT based ab initio molecular dynamics simulations have been employed in order to gain insights into materials properties like diffusion, adsorption, catalysis, and structure. In transition metals, absorbed hydrogen atoms self-trap due to localization of metal d-electrons. LÄS MER

  2. 2. Inducing large-scale diffusion of innovation : An integrated actor- and system-level approach

    Författare :Ingrid Mignon; Anna Bergek; Johanna Nählinder; Volker Hoffmann; Linköpings universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Innovation; large-scale diffusion; adopters; actor; system; drivers; challenges; motives; strategies; policies; renewable electricity; technology; intermediaries;

    Sammanfattning : In order for the innovation process to be successful, not only do innovations need to be developed and reached the market, but, once they are available for users, they have to spread on a large scale. In the innovation literature, a complete explanation is lacking of why some innovations reach a phase of large-scale diffusion faster than others, including both actor- and system-level components. LÄS MER

  3. 3. Developing novel diffusion MRI methods for comprehensive analysis of restricted and anisotropic self-diffusion system

    Författare :Hong Jiang; Fysikalisk kemi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; MRI; diffusion; tissue microstructure; heterogeneity; diffusion encoding; q-vector; ;

    Sammanfattning : Diffusion MRI is a non-invasive imaging technique used to study the microstructural properties of biological tissues by observing the self-diffusion of water molecules. Traditional diffusion MRI methods, based on the pulsed gradient spin-echo sequence, employ magnetic field gradients to encode information about translational motion. LÄS MER

  4. 4. Hydrogen in nano-sized metals : Diffusion and hysteresis effects

    Författare :Wen Huang; Björgvin Hjörvarsson; Max Wolff; Gavin Walker; Uppsala universitet; []
    Nyckelord :Hydrogen; diffusion; hysteresis; optical technique; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : Metal hydrides can be used as hydrogen storage materials for fuel cells and batteries, and as sensors for detecting hydrogen gas. The use of metal hydrides for hydrogen storage can be hindered by poor kinetics and low capacity. Moreover, poor sensitivity, long recovery and response time, limit the applications of metal hydrides as hydrogen sensors. LÄS MER

  5. 5. Exploring the Role of Business Models in Large-Scale Diffusion of Solar Photovoltaics - A study of demand-side solar firms in Sweden

    Författare :Amanda Bankel; Chalmers tekniska högskola; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; firm; innovation; sustainability; Sweden; photovoltaic; business model; diffusion; solar; system; policy;

    Sammanfattning : A rapid and large-scale diffusion of renewable energy technologies, like solar photovoltaics (PV), is crucial to slow down climate change. Research on technology diffusion explains that the rate and scale at which a new technology diffuses in society is influenced by the actors, networks, and institutions that make up its innovation system. LÄS MER