Search for dissertations about: "transient processes"

Showing result 1 - 5 of 264 swedish dissertations containing the words transient processes.

  2. 1. Secondary Electromagnetic Radiation Generated by HF Pumping of the Ionosphere

    Author : Lars Norin; Bo Thidé; Savely M. Grach; Bengt Gustafsson; James W. LaBelle; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; space physics; ionospheric modification experiments; plasma turbulence; stimulated electromagnetic emission; ionospheric irregularities; radio waves; parametric processes; thermal parametric instability; transient dynamics; wave-wave interactions; Physics; Fysik;

    Abstract : Electromagnetic waves can be used to transmit information over long distances and are therefore often employed for communication purposes. The electromagnetic waves are reflected off material objects on their paths and interact with the medium through which they propagate. READ MORE

  4. 2. Shining Light on Molecules : Electron Transfer Processes in Model Systems for Solar Energy Conversion Investigated by Transient Absorption Spectroscopy

    Author : Jens Föhlinger; Leif Hammarström; Davidsson Jan; Benjamin Dietzek; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; photophysics; photoinduced electron transfer; transient absorption spectroscopy; laser spectroscopy; solar energy conversion; p-type DSSCs; Charge separation; recombination; mesoporous NiO;

    Abstract : In the recent years, solar energy conversion has attracted a huge research interest due to the potential application for limiting the greenhouse effect. In many solar cells and solar fuel cells, understanding of charge transfer (CT) and recombination is important for future improvement of the overall efficiency. READ MORE

  5. 3. Palladium(II)-Catalysed Heck and Addition Reactions : Exploring Decarboxylative and Desulfitative Processes

    Author : Bobo Skillinghaug; Mats Larhed; Antonio de la Hoz Ayuso; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Palladium; catalysis; palladium II catalysis; synthesis; Heck; carboxylic acid; sulfinic acid; sodium sulfinate; nitrile; styrene; ketone; aryl ketone; electrospray ionization mass spectrometry; density functional theory; microwave heating; continuous flow; Chemistry with specialization in Organic Chemistry; Kemi med inriktning mot organisk kemi;

    Abstract : Palladium complexes have the ability to catalyse cross-coupling of two organic moieties through the formation of transient metal-carbon bonds, thus bringing them closer to each other to facilitate the formation of a new bond. Palladium-catalysed coupling reactions are one of the most important carbon-carbon forming reactions available to organic chemists and many of these reactions rely on the reactivity of aryl-palladium complexes. READ MORE

  6. 4. Retarded sorption in wood : experimental study, analyses and modeling

    Author : Håkan Håkansson; Institutionen för arkitektur och byggd miljö; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Building construction; transient; non-linear model; swelling-shrinkage; latent heat effect; history-dependent sorption; anomalous sorption; non-Fickian; retarded sorption; measurements; moisture; wood; Byggnadsteknik;

    Abstract : Models of moisture flow processes in wood are normally based on a Fickian approach. In many instances, there are considerable discrepancies between modelling and experimental results. It is shown in this thesis that a major cause for these discrepancies is a so-called retarded sorption which is not accounted for in conventional theories. READ MORE

  7. 5. Investigation of electrochemical properties and performance of stimulation/sensing electrodes for pacemaker applications

    Author : Anna Norlin; Jinshan Pan; Dieter Scharnweber; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physical chemistry; pacemaker electrode; interfacial property; biomaterial; electrostimulation charge transfer mechanism; electrochemical impedance spectroscopy; transient processes; plasma electrolysis anodisation; porous niobium oxide; ruthenium oxide; nano-porous carbon; iridium oxide; titanium nitride; platinum; surface roughness; porous electrode; pacing impedance; electrode polarisation; Fysikalisk kemi; Physical chemistry; Fysikalisk kemi;

    Abstract : People suffering from certain types of arrhythmia may benefit from the implantation of a cardiac pacemaker. Pacemakers artificially stimulate the heart by applying short electrical pulses to the cardiac tissue to restore and maintain a steady heart rhythm. By adjusting the pulse delivery rate the heart is stimulated to beat at desired pace. READ MORE