Fakultet for naturvitenskap og teknologi: Nye registreringer
Viser treff 4441-4460 av 5442
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Prediction of the long-term performance of green liquor dregs as a sealing layer to prevent the formation of acid mine drainage
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-10-08)One of the mining industry's main concerns is the management of waste rock and tailings generated by sulfide ore extraction. Upon exposure of atmospheric oxygen, iron sulfides oxidize generating acidity. Infiltrating water form a metal-rich acidic leachate called acid mine drainage (AMD), that can cause serious environmental problems. Green liquor dregs (GLD) is a material that resists the passage ... -
Dynamic spare parts transportation model for Arctic production facility
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-09-14)Timely delivery of the required spare parts plays an important role in meeting the availability target and reducing the downtime of production facilities. Spare parts logistics is affected in complex ways while operating in the Arctic, since the area is sparsely populated and has insufficient infrastructure. It is also greatly affected by the distinctive operational environment of the region, ... -
Real-space numerical grid methods in quantum chemistry
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-03) -
On the Relationship between PMSE Strength and Particle Precipitation
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-06)We have studied the relationship between particle precipitation and PMSE strength on days where we observe PMSE layers both with the EISCAT VHF and UHF radars. The UHF observations of the ionization and its variation, above the PMSE layer, is used as a measure of precipitation. Variations of the precipitation is compared with variations of the PMSE strengths observed with both radars. Although ... -
Shipping oil from the Russian Arctic: Past experiences and future prospects
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-06)Transport of oil from Russian Arctic ports to Western markets was insignificant prior to 2002. In 2002, there was a major surge, with 5 million tonnes delivered westwards through the Barents Sea. By 2004, this had increased to 12 million tonnes. Since then, annual volumes have been on levels between 9 and 15 million tonnes. In the near future, the flow of oil cargo in the Arctic may rise ... -
Network analysis of geomagnetic substorms using the SuperMAG database of ground-based magnetometer stations
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-09-26)The overall morphology and dynamics of magnetospheric substorms is well established in terms of the observed qualitative auroral features seen in ground-based magnetometers. This paper focuses on the quantitative characterization of substorm dynamics captured by ground-based magnetometer stations. We present the first analysis of substorms using dynamical networks obtained from the full available ... -
Application of a 2-D approximation technique for solving stress analyses problem in FEM
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-24) -
Preliminary Assessment of Remote Wind Sites
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-08)Wind energy is becoming a reliable and affordable source of clean energy and is rapidly expanding to remote places around the world. A crucial input for wind farming prospect is the assessment of potential wind sites. Sites, especially remotely located, often do not have a wind resource map and thus lack credible historical records of wind resources. Measurement campaigns to map these sites are ... -
Change in turbopause altitude at 52 and 70° N
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-02-26)The turbopause is the demarcation between atmospheric mixing by turbulence (below) and molecular diffusion (above). When studying concentrations of trace species in the atmosphere, and particularly long-term change, it may be important to understand processes present, together with their temporal evolution that may be responsible for redistribution of atmospheric constituents. The general ... -
Review of the phenomenon of fluidization and its numerical modelling techniques
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-24) -
Marine icing observed on KV Nordkapp during a cold air outbreak with a developing polar low in the Barents sea.
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-06)Marine icing is a phenomenon that may occur for temperatures below subfreezing where sea spray either is lofted from the sea surface or being generated by waves interacting with a ship or a structure. On a voyage from Tromsø to the waters east of Bjørnøya late February 1987, the Norwegian Coast Guard vessel KV Nordkapp experienced heavy icing due to a polar low that raged over these waters during ... -
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. ... -
Degradation of oil products in a soil from a Russian Barents hot‑spot during electrodialytic remediation
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-02-24)A highly oil-polluted soil from Krasnoe in North-West Russia was used to investigate the degradation of organic pollutants during electrodialytic remediation. Removal efficiencies were up to 70 % for total hydrocarbons (THC) and up to 65 % for polyaromatic hydrocarbons (PAH). Relatively more of the lighter PAH compounds and THC fractions were degraded. A principal component analysis (PCA) revealed ... -
Klimakrisen og økonomisk politikk
(Chronicle; Kronikk, 2015-11-14) -
Note: Derivation of two-photon circular dichroism - Addendum to "two-photon circular dichroism" [J. Chem. Phys. 62, 1006 (1975)]
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-09-02)This addendum shows the detailed derivation of the fundamental equations for two-photon circular dichroism which are given in a very condensed form in the original publication [I. Tinoco, J. Chem. Phys. 62, 1006 (1975)]. In addition, some minor errors are corrected and some of the derivations in the original publication are commented. -
Structure determination of uracil-DNA N-glycosylase from Deinococcus radiodurans in complex with DNA
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-10-01) -
Wavelet formulation of the polarizable continuum model. II. Use of piecewise bilinear boundary elements
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-07-27)The simplicity of dielectric continuum models has made them a standard tool in almost any Quantum Chemistry (QC) package. Despite being intuitive from a physical point of view, the actual electrostatic problem at the cavity boundary is challenging: the underlying boundary integral equations depend on singular, long-range operators. The parametrization of the cavity boundary should be molecular- ... -
Complete genome sequence of Vibrio anguillarum strain NB10, a virulent isolate from the Gulf of Bothnia
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-09-02)Vibrio anguillarum causes a fatal hemorrhagic septicemia in marine fish that leads to great economical losses in aquaculture world-wide. Vibrio anguillarum strain NB10 serotype O1 is a Gram-negative, motile, curved rod-shaped bacterium, isolated from a diseased fish on the Swedish coast of the Gulf of Bothnia, and is slightly halophilic. Strain NB10 is a virulent isolate that readily colonizes ... -
Bivalve shell horizons in seafloor pockmarks of the last glacial-interglacial transition suggest a thousand years of methane emissions in the Arctic Ocean
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-05)We studied discrete bivalve shell horizons in two gravity cores from seafloor pockmarks on the Vestnesa Ridge (1200 m water depth) and western Svalbard (798000 N, 068550 W) to provide insight into the temporal and spatial dynamics of seabed methane seeps. The shell beds, dominated by two genera of the family Vesicomyidae: Phreagena s.l. and Isorropodon sp., were 20–30 cm thick and centered at ... -
Molecular quantum mechanical gradients within the polarizable embedding approach-Application to the internal vibrational Stark shift of acetophenone
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-01-21)We present an implementation of analytical quantum mechanical molecular gradients within the polarizable embedding (PE) model to allow for efficient geometry optimizations and vibrational analysis of molecules embedded in large, geometrically frozen environments. We consider a variational ansatz for the quantum region, covering (multiconfigurational) self-consistent-field and Kohn–Sham density ...