Sökning: "oscillatory currents"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden oscillatory currents.

  1. 1. Some Physical and Environmental Aspects of Shallow Ice Covered Lakes : Emphasis on Lake Vendyurskoe, Karelia, Russia

    Författare :Osama Ali Maher; Avdelningen för Teknisk vattenresurslära; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; convective mixing; dissolved oxygen; heat exchange ice–water; ice cover; oscillatory currents; sediment heat fluxes; water temperature;

    Sammanfattning : The ice cover presence on the surface of a lake insulates the water body from the atmosphere. This prevents or reduces the influence of processes which depend on the exchange between the atmosphere and the water surface. LÄS MER

  3. 2. Calcium signaling in astroglial cells. Noradrenergic effects and regulation

    Författare :Håkan Muyderman; Göteborgs universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Astrocytes; Neurons; Noradrenaline; Glutamate; Fluorometry; Fura-2; Fluo-3; PBFI; Digital imaging; Voltage-patch-clamp; Whole-cell currents; Calcium; Potassium; Intercellular communication; Glutamate release; Neuron-glial interactions.;

    Sammanfattning : Astroglial cells are the most common cell type in the central nervous system and express a wide array of ion channels and neurotransmitter receptors. The cells organize into multicellular networks and exhibit a calcium-based excitability in which receptor-mediated calcium elevations propagate as intercellular waves over considerable distances. LÄS MER

  4. 3. Generation of magnetic fields in plasmas

    Författare :Nitin Shukla; Gert Brodin; Dusan Jovanovic; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Relativistic and non-relativistic plasma outflows are quite ubiquitous in astrophysical scenarios, as well as in laboratory plasmas. The propagation of relativistic and non- relativistic charged particle beams in background plasmas provides return currents in the opposite direction and interactions between the currents then drive several plasma instabilities involving the longitudinal (electrostatic instabilities) and trans- verse (electromagnetic instability) modes. LÄS MER

  5. 4. Studies of individual pancreatic -cells : Electrophysiological analysis of rhythmic behaviour and development of new techniques

    Författare :Staffan Dryselius; Uppsala universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Cell biology; Diabetes; pancreatic beta-cells; insulin release; signal transduction; cytoplasmic calcium; oscillations; patch clamp; ATP-regulated potassium channels; voltage-dependent calcium channels; metabolism; calcium ion; strontium ion; manganese ion; wavelets; de-noising; pattern recognition; superfusion; solution changes; microscopic labelling; Cellbiologi; Cell biology; Cellbiologi; medicinsk cellbiologi; Medical Cell Biology;

    Sammanfattning : The insulin concentration in blood varies periodically, which is believed to prevent down-regulation of the hormone receptors. Loss of the regular insulin oscillations is considered to be an early sign of developing diabetes. LÄS MER

  7. 5. Spin transfer torques and spin dynamics in point contacts and spin-flop tunnel junctions

    Författare :Alexander Konovalenko; Vladislav Korenivski; David W. Abraham; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; spin dynamics; spin transfer torques; point contacts; magnetization dynamics; Physics; Fysik;

    Sammanfattning : The first part of this thesis is an experimental study of the spin-dependent transport in magnetic point contacts. Nano-contacts are produced micromechanically, by bringing a sharpened non-magnetic (N) tip into contact with a ferromagnetic (F) film. LÄS MER