Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 4Citation - Scopus: 4Dayside Episodic Ion Outflow From Martian Magnetic Cusps And/Or Magnetosheath Boundary Motion Associated With Plasma Oscillations(John Wiley and Sons Inc., 2014) Duru, Firdevs; Gurnett, D. A.; Morgan, D. D.; Lundin, R.; Duru, İsmail Hakkı; Winningham, J. D.; Frahm, R. A.The radar sounder on the Mars Express Spacecraft is able to make measurements of electron densities in the Martian ionosphere from both local electron plasma oscillations and remote soundings. A study of thousands of orbits shows that in some cases the electron plasma oscillations disappear and reappear abruptly near the upper boundary of the dayside ionosphere. In some cases, the Analyzer of Space Plasmas and Energetic Atoms (ASPERA-3) data show clear evidence of upwardly accelerated ionospheric ions, on interconnected magnetic field lines. In other cases, ASPERA-3 data show that when the plasma oscillations disappear, the spacecraft is in the magnetosheath and when they return, the ionospheric plasma reappears. These intermittent appearances of plasma suggest the multiple crossings of the magnetosheath boundary. The motion of the boundary or plasma clouds and ionospheric streamers (a relatively narrow strip of plasma attached to the ionosphere) can cause these multiple crossings.Article Boundary Shape and Casimir Energy(IOP Publishing Ltd., 2009) Ahmedov, Hacı; Duru, İsmail HakkıCasimir energy changes are investigated for geometries obtained by small but arbitrary deformations of a given geometry for which the vacuum energy is already known for the massless scalar field. As a specific case, deformation of a spherical shell is studied. From the deformation of the sphere we show that the Casimir energy is a decreasing function of the surface-to-volume ratio. The decreasing rate is higher for less smooth deformations.Article Citation - WoS: 1Citation - Scopus: 1Casimir energies for some single cavities(TUBITAK, 2006) Ahmedov, Hacı; Duru, İsmail HakkıCasimir energies for some single cavities. Casimir energies are discussed for some cavities.Conference Object New Casimir Energy Calculations(World Scientific Publishing Co. Pte Ltd, 2007) Ahmedov, Hadji; Duru, İsmail HakkıNew Casimir energy results for massless scalar field in some 3 -dimensional cavities are presented. We attempted to discuss the correlation between the sign and the magnitude of the energy and the shape of the cavities. Sign of the Casimir energy known to be dependent on the dimension, topology and the shape of the geometry. In this note we present some new exact results for massless scalar fields in three dimensional cavities with the trivial topology. We then compare the known Casimir energy values for several three dimensional cavities. The conclusion we arrived is that the existence of the corners lowers the vacuum energy.