Fakultet for naturvitenskap og teknologi: Nye registreringer
Viser treff 3001-3020 av 5336
-
The Thorpex polar low analysed with AROME-Arctic
(Conference object; Konferansebidrag, 2019-04) -
On local and long-range transported air pollution in Svalbard
(Doctoral thesis; Doktorgradsavhandling, 2019-09-11)Climate change, health of the residents and ecosystems in the Arctic region are impacted by local and long-range transported air pollution. Local emissions in the Arctic are important, but overlooked issue. Despite there have been extensive modelling and measurement studies of long-range transport of short-lived climate forcers to Svalbard, the effect of local emissions from diesel and coal power ... -
Norcorrole as a Delocalized, Antiaromatic System
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-03-19)Nickel norcorrole provides an unusual example of a molecule that is strongly antiaromatic according to the magnetic criterion, but which exhibits, according to high-quality DFT calculations, a symmetric, delocalized structure with no difference in bond length between adjacent C<sub>meso</sub>-C<sub>α</sub> bonds. A fragment molecular orbital analysis suggests that these discordant observations are ... -
Observing Mesospheric Turbulence With Specular Meteor Radars: A Novel Method for Estimating Second-Order Statistics of Wind Velocity
(Journal article; Peer reviewed, 2019-07)There are few observational techniques for measuring the distribution of kinetic energy within the mesosphere with a wide range of spatial and temporal scales. <br>This study describes a method for estimating the three‐dimensional mesospheric wind field correlation function from specular meteor trail echoes. Each radar echo provides a measurement of a one‐dimensional projection of the wind velocity ... -
Novel specular meteor radar systems using coherent MIMO techniques to study the mesosphere and lower thermosphere
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-05)Typical specular meteor radars (SMRs) use one transmitting antenna and at least a five-antenna interferometric configuration on reception to study the mesosphere and lower thermosphere (MLT) region. The interferometric configuration allows the measurement of the angle-of-arrival (AOA) of the detected meteor echoes, which in turn is needed to derive atmospheric parameters (e.g., mean winds, momentum ... -
Antimicrobial activity of amphipathic α,α-disubstituted β-amino amide derivatives against ESBL–CARBA producing multi-resistant bacteria; effect of halogenation, lipophilicity and cationic character
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-06)The rapid emergence and spread of multi-resistant bacteria have created an urgent need for new antimicrobial agents. We report here a series of amphipathic α,α-disubstituted β-amino amide derivatives with activity against 30 multi-resistant clinical isolates of Gram-positive and Gram-negative bacteria, including isolates with extended spectrum β-lactamase – carbapenemase (ESBL-CARBA) production. A ... -
Polyphase kinematic history of transpression along the Mecca Hills segment of the San Andreas fault, southern California
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-09)Miocene–Pliocene sedimentary rocks in the Mecca Hills, southern California, were uplifted and deformed by transpression along a restraining bend in the San Andreas fault trace between the Orocopia and San Bernardino Mountains in Pleistocene time. This paper presents field evidence for three stages of structural evolution of a complex, asymmetric wedge-like flower structure, expressed as: (1) ... -
Group Cohomology and Extensions
(Master thesis; Mastergradsoppgave, 2019-08-31)The goal of this thesis is to classify all extensions where the kernel has order p^s and the cokernel has order p^t, p is a prime, and 1 ≤ s,t ≤ 2. We determine (up to weak congruence) the different combinations of kernel, cokernel and operators, and for each case, calculate the second cohomology group. By comparing resolutions, we get an explicit correspondence between the second cohomology group ... -
A study of the socioeconomic factors influencing migration in Russia
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-03-19)Russia has experienced population decline in years and the economic development in Russia is largely restricted by labor shortage, particularly for the Far North and East region. In order to explore the migration mechanisms, six socioeconomic factors were selected to explore the influences on the net migration. Data from the 82 regions covering four time periods (2000, 2005, 2010 and 2015) was ... -
Excess water storage induced by viscous strain localization during high-pressure shear experiment
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-03-05)Strain localization in viscously deformed rocks commonly results in fine-grained shear zones where massive fluid circulation is regularly observed. Recently attributed to strain-induced pumping, this phenomenon may have major implications for the distribution of ores deposits and rock rheology. However, although grain size reduction and/or creep cavitation have been proposed as important processes, ... -
MOSIDEO/CIRFA Tank Experiments on Behavior and Detection of Oil in Ice
(Conference object; Konferansebidrag, 2019-06)In the Arctic, presence of sea ice presents a challenge to safe and sustainable operations. To optimize planning and minimize impact of inadvertent oil spills, oil-in-ice experiments were performed at the HSVA Arctic Environmental Test Basin (AETB) from 14 March to 4 April 2017. Following an under-ice spill and simulated springtime warming, the microscopic movement and distribution of oil in the sea ... -
Methane-fuelled biofilms predominantly composed of methanotrophic ANME-1 in Arctic gas hydrate-related sediments
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-05)Sedimentary biofilms comprising microbial communities mediating the anaerobic oxidation of methane are rare. Here, we describe two biofilm communities discovered in sediment cores recovered from Arctic cold seep sites (gas hydrate pingos) in the north-western Barents Sea, characterized by steady methane fluxes. We found macroscopically visible biofilms in pockets in the sediment matrix at the depth ... -
A low-cost coastal buoy for ice and metocean measurements
(Conference object; Konferansebidrag, 2019-06)Regionally, an ice cover in fjords of mainland Norway may form and break up repeatedly during winter. Due to relatively high water temperatures, the freeze-up process is expected to be related to freshwater-induced stratification in the fjords in conjunction with low air temperatues. In an attempt to identify the variability of water conditions in the fjords leading up to and during ice cover ... -
Improved maximal strength is not associated with improvements in sprint time or jump height in high-level female football players: a clusterrendomized controlled trial
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-17)<i>Background</i> - Maximal strength increments are reported to result in improvements in sprint speed and jump height in elite male football players. Although similar effects are expected in females, this is yet to be elucidated. The aim of this study was to examine the effect of maximal strength training on sprint speed and jump height in high-level female football players.<p> <p><i>Methods</i> ... -
Radar studies of ionospheric dusty plasma phenomena
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-17)We discuss the influence of charged dust on radar observations in the Earth ionosphere. This region in the upper Earth atmosphere can be described as a partially ionized, low‐temperature plasma. Plasma parameters vary by orders of magnitude spatially and in time. Dust particles influence the charge balance, in some cases dusty plasma condition is met. The polar mesospheric echoes are an example of ... -
Solar Flare Effects on 150-km Echoes Observed Over Jicamarca: WACCM-X Simulations
(Journal article; Tidsskriftartikkel, 2019-09-11)Jicamarca Radio Observatory observations and Whole Atmosphere Community Climate Model with thermosphere‐ionosphere eXtension (WACCM‐X) simulations are used to investigate the effects of the September 7, 2005 X‐17 solar flare on 150‐km echoes, electron densities, and vertical plasma drifts. The solar flare produces a remarkably similar response in the observed 150‐km echoes and simulated electron ... -
Characterization of an intertidal zone metagenome oligoribonuclease and the role of the intermolecular disulfide bond for homodimer formation and nuclease activity
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-17)The gene encoding MG Orn has been identified from a metagenomic library created from the intertidal zone in Svalbard and encodes a protein of 184 amino acid residues. The <i>mg orn</i> gene has been cloned, recombinantly expressed in <i>Escherichia coli</i>, and purified to homogeneity. Biochemical characterization of the enzyme showed that it efficiently degrades short RNA oligonucleotide substrates ... -
Integrated Petrophysical and Seismic interpretation of Norne Field, Norway.
(Master thesis; Mastergradsoppgave, 2014-09-16)The aim of this thesis is to evaluate petrophysical properties and seismic interpretation of main reservoirs of Norne field in Mid Norwegian sea. Petrophysical evaluation helps in getting familiar with reservoir characterization using wireline logs data. The main concentration has been given to evaluate different reservoir properties i.e. porosity, shale volume, water saturation, hydrocarbon saturation, ... -
Extreme Scalability of DFT-based QM/MM MD Simulations Using MiMiC
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-09)We present a highly scalable DFT-based QM/MM implementation developed within MiMiC, a recently introduced multiscale modeling framework that uses a loose-coupling strategy in conjunction with a multiple-program multiple-data (MPMD) approach. The computation of electrostatic QM/MM interactions is parallelized exploiting both distributed- and shared-memory strategies. Here, we use the efficient CPMD ... -
CFD modelling of pollutant transport. Use of ANSYS Workbench® simulating emissions to air from vessel at Port of Breivika.
(Master thesis; Mastergradsoppgave, 2019-05-31)Historically, the Port of Tromsø is well known as the final port before entering the Arctic Sea. Nowadays, there is a noticeable traffic consisting of cruise vessels visiting Port of Tromsø before heading against the Arctic. The vessels transport passengers expecting clean air, midnight sun, northern lights, snow and ice; - and a clean environment. Environmental considerations and air pollution ...