Sökning: "echo"

Visar resultat 31 - 35 av 191 avhandlingar innehållade ordet echo.

1. 31. Hydrology and Bed Topography of the Greenland Ice Sheet : Last known surroundings

   Författare :Katrin Lindbäck; Rickard Pettersson; Francisco Navarro; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; climate change; Greenland Ice Sheet; radio-echo sounding; digital elevation models; ice thickness; bed topography; spectral analysis; roughness; subglacial hydrology; water piracy; englacial features; drainage catchments; meltwater runoff; ice dynamics; klimatförändringar; Grönlands inlandsis; markbaserad radar; digitala höjdmodeller; istjocklek; bottentopografi; spektralanalys; subglacial hydrologi; englaciala strukturer; avrinningsområden; isdynamik;

   Sammanfattning : The increased temperatures in the Arctic accelerate the loss of land based ice stored in glaciers. The Greenland Ice Sheet is the largest ice mass in the Northern Hemisphere and holds ~10% of all the freshwater on Earth, equivalent to ~7 metres of global sea level rise. LÄS MER

3. 32. Trees, Queues and Alcohols

   Författare :Per Sillrén; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Raman Scattering; Neutron Diffraction; Alcohols; EPSR; Quasi Elastic Neutron Scattering; Neutron Spin Echo; Monte Carlo Simulation; Hydrogen Bonded Liquids;

   Sammanfattning : Hydrogen bonded (H-bonded) materials, such as water, alcohols, sugars, and even DNA, are extremely important for biology, as well as chemical industry. Alcohols are used as solvents in paints, in perfumes, as cleaners, anti-freezers, or as an alternative to petrol in combustion engines. LÄS MER

4. 33. Media Echo Chambers: Selective Exposure and Confirmation Bias in Media Use, and its Consequences for Political Polarization

   Författare :Peter Dahlgren; Göteborgs universitet; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; selective exposure; confirmation bias; political polarization; affective polarization; ideological polarization; political attitudes; political preferences;

   Sammanfattning : The new digital media landscape has created a high-choice media environment that has made it easier for people to find news and information that support their political beliefs and attitudes, and avoid news and information that challenge those beliefs or attitudes. How does this affect people’s selection of content and political polarization in the long run? This thesis investigates the relationship between different political preferences (political party, political interest and ideological leaning) and selective media use over time among the Swedish population, and whether this selectivity leads to political polarization (ideological polarization and affective polarization). LÄS MER

5. 34. Nuclear Magnetic Relaxation Dispersion and Pulsed-Gradient Spin Echo Studies of Biomolecular Solutions and Amphiphilic Liquid Crystals

   Författare :Haukur Jóhannesson; Biofysikalisk kemi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stretched dispersion; DNA hydration; solvent dynamics; NMRD; Random flight simulation; PGSE; Diffusion; Nematic phase; NMR; Amphiphilic liquid crystals; Physical chemistry; Fysikalisk kemi;

   Sammanfattning : Biomolecular solutions and amphiphilic liquid crystals are studied by Nuclear Magnetic Resonance Dispersion (NMRD) and Pulsed-Gradient Spin Echo (PGSE) respectively. A random-flight simulation is performed to obtain the obstructing factors for self-diffusion of small molecules in macrofluids. LÄS MER

7. 35. Formation and Dynamics of Molecular Excitons and their Fingerprints in Nonlinear Optical Spectroscopy

   Författare :Pär Kjellberg; Kemisk fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; supraledare; magnetisk resonans; spektroskopi; Physical chemistry; Fysikalisk kemi; Photochemistry; Fotokemi; Kondenserade materiens egenskaper:elektronstruktur; magnetiska och optiska ; egenskaper elektriska; supraconductors; magnetic resonance; relaxation; spectroscopy; Fysik; Chemistry; Kemi; Condensed matter:electronic structure; electrical; Physics; Redfield relaxation theory ; Inhomogeneous broadening ; Time-dependent density functional theory ; Conjugated polymers ; Three-pulse photon echo ; Molecular excitons ; magnetic and optical properties; Nonlinear spectroscopy ;

   Sammanfattning : An efficient transfer of energy in molecular systems has proven to be of fundamental importance both in nature and industrial applications. The ability of molecules to work together forming collective excitations, so-called excitons, plays a key role in for example the extraordinary fast energy transfer involved in the first steps of photosynthesis. LÄS MER