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Total synthesis of tubastrine and 3-dehydroxy tubastrine by microwave-assisted cross-coupling reactions
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-09-03)
The first syntheses of tubastrine and 3-dehydroxy tubastrine are described. The target compounds were prepared in four consecutive steps from commercially available starting materials. The central scaffold was formed by a microwave-assisted C–N cross-coupling reaction between 1,3-bis(<i>tert</i>-butoxycarbonyl)-guanidine and (<i>E</i>)-((4-(2-iodovinyl)-1,2-phenylene)bis(oxy))bis(<i>tert</i>-butyl ...
Iron/Brønsted Acid Catalyzed Asymmetric Hydrogenation: Mechanism and Selectivity-Determining Interactions
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-06-03)
Hydrogenation catalysts involving abundant base metals such as cobalt or iron are promising alternatives to precious metal systems. Despite rapid progress in this field, base metal catalysts do not yet achieve the activity and selectivity levels of their precious metal counterparts. Rational improvement of base metal complexes is facilitated by detailed knowledge about their mechanisms and ...
Experimental and four-component relativistic DFT studies of tungsten carbonyl complexes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-07-24)
We present a theoretical and experimental study of the structure and nuclear magnetic resonance (NMR) parameters of the pentacarbonyltungsten complexes of η<sup>1</sup>-2-(trimethylstannyl)-4,5-dimethylphosphinine, η<sup>2</sup>-norbornene, and imidazolidine-2-thione. The three complexes have a pseudo-octahedral molecular structure with the six ligands bonded to the tungsten atom. The η<sup>1</sup ...
Applying Multivariate Analysis to Developing Electrodialytic Remediation of Harbour Sediments from Arctic Locations
(Doctoral thesis; Doktorgradsavhandling, 2015-03-13)
Electrodialytic remediation (EDR) is a method for removing pollutants from different materials achieved by acidification and transport processes induced by application of an electric field of low intensity. In the thesis, EDR was shown to be a reliable technology for removal of heavy metals, PAH, PCB and TBT from harbour sediments. The final concentrations of heavy metals met the background criteria ...
Role of subsea permafrost and gas hydrate in postglacial Arctic methane releases
(Doctoral thesis; Doktorgradsavhandling, 2015-09-18)
Greenhouse gas methane is contained as gas hydrate, an icy structure, under the seabed in enormous amounts of Arctic regions. West Svalbard continental margin, which we investigated here, is one of these regions. Also, in the Russian Kara Sea the subsea permafrost is acting as a cap for the gas to be released in the future. But continuous expulsions of methane have been already observed in both ...
Palaeoceanography of the Barents Sea continental margin, north of Nordaustlandet, Svalbard, during the last 74 ka
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-07-17)
We investigated gravity core HH11‐09GC from 488 m water depth at the northern Svalbard margin in order to reconstruct changes in Atlantic Water (AW) inflow to the Arctic Ocean. The study was based on the distribution patterns of benthic and planktic foraminifera, benthic and planktic oxygen and carbon isotopes, lithology and physical properties of the sediments. The core contains sediments from ...
An unsupervised method for equivalent number of looks estimation in complex SAR scenes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-12)
This paper introduces a novel unsupervised estimator of equivalent number of looks (ENL) that can be applied to an arbitrary image. It avoids the assumption that homogeneous speckle will dominate the investigated image that is followed by current unsupervised ENL estimators but not always valid, especially for the complex SAR scenes with high mixture and texture. Incorporating the statistical ...
Carbon Nanotube Spectrally Selective Solar Absorbers
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015)
The use of multi-walled carbon nanotubes (MWCNTs) as spectrally selective solar thermal absorbers (SSA)
in solar thermal collectors is presented in this paper. CNT layers were coated by electrophoretic deposition
(EPD) on aluminum substrates. Stable aqueous CNT suspensions consisted of multi-walled CNTs, DI water
and surfactant was used for EPD. The deposited samples were heat treated in a tube ...
CFD-DEM and Experimental Study of Bubbling in a Fluidized Bed
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-12)
In this study, phenomenon of bubbling is investigated using CFD-DEM and
experiments. A CFD-DEM simulation is setup to model the fluidized beds of different
sizes. Geldart D particles of 1.2 mm diameter and 1000 Kg/m3 density are modelled. Study revealed different types of fluidization regimes as stated in the literature. An experimental setup is built to obtain the results for the comparison. ...
An optimised method for electrodialytic removal of heavy metals from harbour sediments
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-08-10)
A 2-compartment electrodialytic cell set-up for treatment of solid materials has in many
respects proven superior to other types of cells in removing heavy metals from sediments.
Most notably, remediation times were shorter, energy consumption was lower and higher
removal efficiencies were observed. By employing multivariate modelling and investigating
additional experimental variables, the ...