Sökning: "Rajeev Ahuja"

Visar resultat 1 - 5 av 37 avhandlingar innehållade orden Rajeev Ahuja.

  1. 1. Understanding Physical Reality via Virtual Experiments

    Författare :Sergiu Arapan; Rajeev Ahuja; Börje Johansson; Chris Pickard; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; density functional theory; ab initio calculations; electronic structure; lattice dynamics; high-pressure phase transitions; high-temperature phase transitions; incommensurate structures; Condensed matter physics; Kondenserade materiens fysik;

    Sammanfattning : In this thesis I have studied some problems of condensed matter at high pressures and temperatures by means of numerical simulations based on Density Functional Theory (DFT).The stability of MgCO3 and CaCO3 carbonates at the Earth's mantle conditions may play an important role in the global carbon cycle through the subduction of the oceanic crust. LÄS MER

  2. 2. Energy Storage Materials: Insights From ab Initio Theory : Diffusion, Structure, Thermodynamics and Design

    Författare :Rafael Barros Neves de Araújo; Rajeev Ahuja; Graeme Henkelman; Uppsala universitet; []
    Nyckelord :Density Functional Theory; Defects Diffusion; Thermodynamics and Batteries.;

    Sammanfattning : The development of science and technology have provided a lifestyle completely dependent on energy consumption. Devices such as computers and mobile phones are good examples of how our daily life depends on electric energy. LÄS MER

  3. 3. Materials Modelling for Energy Harvesting : From Conversion to Application through Storage

    Författare :Amitava Banerjee; Rajeev Ahuja; Gunnar Niklasson; Sudip Chakraborty; Tejs Vegge; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Materials Modelling; DFT; Energy Materials; Photocatalysis; HER and OER; Hybrid Perovskite Solar Cells; Stability; Thermodynamics and Kinetics in Na-ion battery; Organic Crystal Battery;

    Sammanfattning : In this Ph.D. thesis, ab initio density functional theory along with molecular dynamics and global optimization methods are used to unveil and understand the structures and properties of energy relevant materials. In this connection, the following applications are considered: i. LÄS MER

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

    Författare :Andreas Blomqvist; Rajeev Ahuja; Christopher Wolverton; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; 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

  5. 5. Atomic Scale Modelling in Photoelectrocatalysis : Towards the Development of Efficient Materials for Solar Fuel Production

    Författare :Giane B. Damas; Carlos Moyses Araujo; Rajeev Ahuja; Clas Persson; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Photocatalytic hydrogen production; polymeric materials; donor-acceptor architecture; small molecules; density functional theory; hydrogen binding free energies; exciton binding energies; electrocatalysis; carbon dioxide conversion; formic acid production; Sn-based electrodes; Tin oxides; Ru-complexes; Metal Organic Frameworks; carbon dioxide capture.;

    Sammanfattning : Using sunlight to produce valuable chemicals has been pointed out as an interesting alternative to deal with the well-known environmental problem related to the use of fossil fuels for energy generation. Thus, it is crucial for this field the development of novel photocatalysts that could drive the uphill reactions with high efficiency while presenting low price and toxicity. LÄS MER