Browsing Institutt for fysikk by Title
Now showing items 2632-2650 of 2650
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X-ray absorption, X-ray diffraction and electron microscopy study of spent cobalt based catalyst in semi-commercial scale Fischer-Tropsch synthesis
(Peer reviewed; Journal article, 2014)Calcined, reduced and spent Co-Re/γ-Al2O3 catalysts for Fischer–Tropsch synthesis (FTS) were characterized and compared. Co-K-edge and Re-LIII-edge X-ray absorption near edge structure (XANES), X-ray powder diffraction ... -
X-ray Diffraction and Tomography Studies of Functional Organic Fibres
(Doktoravhandlinger ved NTNU, 1503-8181; 2013:74, Doctoral thesis, 2013)Structural characterisations of materials belong to the primary interests of basic and applied research, since they provide insights into the interactions of molecules and atoms, establish correlations with desired properties ... -
X-ray nanoscopy of a bulk heterojunction
(Journal article; Peer reviewed, 2016)Optimizing the morphology of bulk heterojunctions is known to significantly improve the photovoltaic performance of organic solar cells, but available quantitative imaging techniques are few and have severe limitations. ... -
X-ray Scattering Study of Nanostructured GaSb Surfaces
(Master thesis, 2013)In this thesis the surface structure of a sample consisting of slightly tilted, denselypacked Gallium-Antimonide (GaSb) nanocones, self-assembled through Ion Beam Sputtering(IBS) is investigated with a selection of X-ray ... -
X-ray Studies of Capture, Storage and Release of CO2
(Master thesis, 2012)We show experimentally that CO2 intercalates into the interlayer spaceof the synthetic smectite clay Li-fluorohectorite (LiFh). The intercalationoccurs for a range of conditions in terms of pressure (5 bar to 20 bar) ... -
X-ray Studies of Carbon Dioxide Intercalation in Na-Fluorohectorite Clay at Near-Ambient Conditions
(Journal article, 2012)We show experimentally that gaseous CO2 intercalates into the interlayer space of the synthetic smectite clay Na-fluorohectorite at conditions not too far from ambient. The mean interlayer repetition distance of the clay ... -
XPS and GDOES characterization of porous coating enriched with copper and calcium obtained on tantalum via plasma electrolytic oxidation
(Peer reviewed; Journal article, 2016)XPS and GDOES characterizations of porous coatings on tantalum after Plasma Electrolytic Oxidation (PEO) at 450 V for 3 minutes in electrolyte containing concentrated (85%) phosphoric acid with calcium nitrate and copper ... -
Yb-Doped Fiber Lasers Operating in the Range of 1147-1200 nm
(Chapter, 2012)Pump source brightness and heat production per unit fiber length were found to be the critical parameters for the realized and investigated Yb-doped fiber lasers operating in the range of 1147-1200 nm. -
Yb-Tm energy transfer in Y-codoped fibers
(Chapter, 2013)Experimental investigation of Yb-Tm energy transfer process in Yb/Tm-doped fibers with Y-codoping provided a fairly high energy transfer efficiency of 50 %, making lasers based on these glass fibers attractive for diode-pumping ... -
YDFL Operating in 1150-1200-nm Spectral Domain
(Journal article; Peer reviewed, 2013)A family of high-power Yb-doped fiber lasers operated in the range of 1150–1180 nm with output powers of up to 35 W and optical efficiencies up to 60% is realized. Operation at 1200 nm is also demonstrated. Amplified ... -
Z2 characterization for three-dimensional multiband Hubbard models
(Peer reviewed; Journal article, 2020)We introduce three numerical methods for characterizing the topological phases of three-dimensional multiband Hubbard models based on twisted boundary conditions, Wilson loops, as well as the local topological marker. We ... -
Zernike phase contrast in high-energy x-ray transmission microscopy based on refractive optics
(Journal article; Peer reviewed, 2018)The current work represents the first implementation of Zernike phase contrast for compound refractive lens based x-ray microscopy, and also the first successful Zernike phase contrast experiment at photon energies above ... -
Zero temperature superconductor–edge metal–insulator transition in two-dimensional bosonic systems
(Peer reviewed; Journal article, 2022)Motivated by the recent experimental observation of an intermediate bosonic metallic state in the two-dimensional superconductor-insulator transition at T = 0 , we study an extended Bose-Hubbard model in the limit of a ... -
Zigzag-Shaped Superlattices on the Basis of Graphene Nanoribbons: Structure and Electronic Properties
(Journal article; Peer reviewed, 2016)The paper focuses on superlattices consisting of two coplanar fragments of one-layer graphene nanoribbons that have different width and are connected at an angle. Classification of such superlattices was carried out; their ... -
µSR study of Al-0.67%Mg-0.77%Si alloys
(Journal article; Peer reviewed, 2014)Zero-field muon spin relaxation measurements were carried out with Al-0.67%Mg- 0.77%Si alloys in the temperature range from 20 K to 300 K. Observed relaxation spectra were compared with the relaxation functions calculated ... -
Æther as an Inevitable Consequence of Quantum Gravity
(Peer reviewed; Journal article, 2022)The fact that quantum gravity does not admit an invariant vacuum state has far-reaching consequences for all physics. It points out that space could not be empty, and we return to the notion of an æther. Such a concept ... -
α-Mg primary phase formation and dendritic morphology transition in solidification of a Mg-Nd-Gd-Zn-Zr casting alloy
(Journal article; Peer reviewed, 2016)Microstructure evolution in the commercial Mg-Nd-Gd-Zn-Zr alloy Elektron 21, solidified under nearly isothermal conditions, has been studied via in-situ X-ray radiography. For cooling rates View the MathML source≤0.075 ... -
β- and δ-Al-Fe-Si intermetallic phase, their intergrowth and polytype formation
(Journal article; Peer reviewed, 2019)Crystal structure characteristics of coexisting β and δ phase were investigated in a purely intermetallic Al-Fe-Si alloy and in plate-shaped intermetallic particles formed in a model secondary Al7.1Si1.2Fe0.3Mn alloy. The ... -
β-(1 → 3)(1 → 6)glucan from Schizophyllum commune 227E.32: High yield production via glucose/xylose co-metabolization
(Peer reviewed; Journal article, 2023)A co-metabolization of xylose and glucose by Schizophyllum commune 227E.32 wild mushroom for exopolysaccharide (EPS) production is presented. Cultivations performed with S. commune 227E.32 at different xylose concentrations ...