Sökning: "NATURVETENSKAP Kemi Fysikalisk kemi Spektroskopi"

Visar resultat 1 - 5 av 28 avhandlingar innehållade orden NATURVETENSKAP Kemi Fysikalisk kemi Spektroskopi.

  1. 1. Structure and spectroscopy of bio- and nano-materials from first-principles simulations

    Författare :Weijie Hua; Yi LUO; Mauro Stener; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; soft x-ray spectroscopy; bio- and nano-materials; first-principles simulation; host-guest interaction; generalized energy-based fragmentation; Quantum chemistry; Kvantkemi; Spectroscopy; Spektroskopi; SRA - Molecular Bioscience; SRA - Molekylär biovetenskap;

    Sammanfattning : This thesis is devoted to first-principles simulations of bio- and nano-materials,focusing on various soft x-ray spectra, ground-state energies and structures of isolated largemolecules, bulk materials, and small molecules in ambient solutions. K-edge near-edge x-ray absorption fine structure (NEXAFS) spectra, x-ray emission spectra, andresonant inelastic x-ray scattering spectra of DNA duplexes have been studied by means oftheoretical calculations at the density functional theory level. LÄS MER

  2. 2. Metal Particles – Hazard or Risk? Elaboration and Implementation of a Research Strategy from a Surface and Corrosion Perspective

    Författare :Klara Midander; Inger Odnevall Wallinder; Sannakaisa Virtanen; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; ferro-chromium alloy; metal particles; bioaccessibility; chemical speciation; dermal contact; surface oxide; in-vitro testing; chemical speciation; cu; copper; comet assay; intracellular; ultrafine; in vitro; A549; cytotoxicity; DNA damage; nanoparticles; particle characterization; artificial sweat; nickel release; nickel powder particles; particle loadings; release kinetics; surface area; copper release; powder particles; synthetic body fluids; simulation of interstitial lung conditions; skin contact; metal release; stainless steel; particles; test method; Surface and colloid chemistry; Yt- och kolloidkemi; Analytical chemistry; Analytisk kemi; Spectroscopy; Spektroskopi;

    Sammanfattning : Do metal particles (including particles of pure metals, alloys, metal oxides and compounds) pose a hazard or risk to human health? In the light of this question, this thesis summarizes results from research conducted on metal particles, and describes the elaboration and implementation of an in vitro test methodology to study metal release from particles through corrosion and dissolution processes in synthetic biological media relevant for human exposure through inhalation/ingestion and dermal contact. Bioaccessible metals are defined as the pool of released metals from particles that potentially could be made available for absorption by humans or other organisms. LÄS MER

  3. 3. Drugs and polymers in dissolving solid dispersions : NMR imaging and spectroscopy

    Författare :Carina Dahlberg; István Furó; Anna Millqvist-Fureby; Michael Schuleit; Jadwiga Tritt-Goc; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Physical chemistry; Fysikalisk kemi; Surface and colloid chemistry; Yt- och kolloidkemi; PHARMACY; FARMACI;

    Sammanfattning : The number of poorly water-soluble drug substances in the pharmaceutical pipeline is increasing, and thereby also the need to design effective drug delivery systems providing high bioavailability. One favourable formulation approach is preparation of solid dispersions, where dispersing a poorly water-soluble drug in a water-soluble polymer matrix improves the dissolution behaviour and the bioavailability of the drug. LÄS MER

  4. 4. Molecular Interactions Studied by Electrophoretic and Diffusion NMR

    Författare :Fredrik Hallberg; Peter Stilbs; István Furó; Gareth Morris; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical chemistry; NMR; electrophoretic NMR; Ion pairing; complexation; association; diffusion; pulsed field gradient; Nafion; Spectroscopy; Spektroskopi;

    Sammanfattning : Even though electrophoretic NMR (eNMR) experiments may provide unique chemical information and have been performed for three decades, the technique is still rarely applied, mainly because several experimental sources of artifacts have to be controlled to achieve accurate results. In this thesis, new experimental setups and protocols for accurate and precise eNMR experiments are presented. LÄS MER

  5. 5. Development and Application of a First Principle Molecular Model for Solvent Effects

    Författare :Anders Öhrn; Beräkningskemi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Theoretical chemistry; quantum chemistry; Teoretisk kemi; kvantkemi; magnetisk resonans; Fysikalisk kemi; Physical chemistry; gränsskikt; Ytkemi; Surface and boundary layery chemistry; spektroskopi; egenskaper elektriska; magnetiska och optiska ; supraledare; Kondenserade materiens egenskaper:elektronstruktur; spectroscopy; relaxation; magnetic resonance; supraconductors; magnetic and optical properties; Kemi; Condensed matter:electronic structure; electrical; Solvent model; Solvochromatic shift; Chemistry; Solvent effects; Solvation; Intermolecular interactions; Quantum chemistry; Statistical mechanics;

    Sammanfattning : A considerable part of chemistry in nature and industry, takes place in an environment of other molecules. Reactions, transitions, interactions or other chemical processes are almost always modified by the environment. LÄS MER