Fakultet for naturvitenskap og teknologi: Nye registreringer
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Effects of Geomagnetic Disturbances on Offshore Magnetic Directional Wellbore Positioning in the Northern Auroral Zone
(Doctoral thesis; Doktorgradsavhandling, 2016-01-29)This thesis focuses on how disturbances in the geomagnetic field, offshore northern Norway, may affect the accuracy of magnetic directional wellbore surveying. The topics discussed are, however, applicable to the entire northern auroral zone. Suggestions on how to manage the effect of increased geomagnetic activity on magnetic directional wellbore survey operations in and near the auroral zone are ... -
Properties and distribution of a metallo-β-lactamase (ALI-1) from the fish pathogen Aliivibrio salmonicida LFI1238
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015)Objectives. To characterize the chromosome-encoded metallo-β-lactamase (MBL) from the psychrophilic, marine fish-pathogenic bacterium Aliivibrio salmonicida LFI1238 and check for the presence of the gene in other Aliivibrio isolates both connected to the fish-farming industry and from the environment. Methods. The MBL gene was cloned and intracellularly expressed in Escherichia coli. Kinetic ... -
Ligand noninnocence in FeNO corroles: insights from β-octabromocorrole complexes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-30)The first FeNO octabromocorroles have been synthesized including four β-octabromo-meso-tris(p-X-phenyl)corrole derivatives Fe[Br8TpXPC](NO) (X = CF3, H, CH3, OCH3) and the β-octabromo-meso-tris(pentafluorophenyl)corrole complex, Fe[Br8TPFPC](NO). The last complex, which proved amenable to single-crystal X-ray structure determination, exhibits the geometry parameters: Fe–N(O) 1.643(8) Å, N–O 1.158(9) ... -
COPD in primary lung cancer patients: prevalence and mortality
(Journal article; Peer reviewed; Tidsskriftartikkel, 2016-03-23)Background: Previous studies have relied on international spirometry criteria to diagnose COPD in patients with lung cancer without considering the effect lung cancer might have on spirometric results. The aim of this study was to examine the prevalence of COPD and emphysema at the time of primary lung cancer diagnosis and to examine factors associated with survival. Materials and methods: Medical ... -
A generalization of weight polynomials to matroids
(Tidsskriftartikkel; Journal article; Peer reviewed, 2015-11-11)Generalizing polynomials previously studied in the context of linear codes, we define weight polynomials and an enumerator for a matroid M. Our main result is that these polynomials are determined by Betti numbers associated with N0-graded minimal free resolutions of the Stanley-Reisner ideals of M and so-called elongations of M. Generalizing Greene’s the- orem from coding theory, we show that ... -
Multiphysics investigation of Ice Adhesion over PVC surface
(Conference object; Konferansebidrag, 2015-12-10)This work investigates the ice over a PVC (polyvinyl chloride also known as ‘PVC’) surface as a two-layer laminate model. In this study, ice was frozen over a PVC surface and allowed to adhere. The built samples were tested experimentally in a four-point loading setup. The experimental results contain strain data gathered through data acquisition system using LabView® software. The data was collected ... -
Late summer sea ice segmentation with multi-polarisation SAR features in C- and X-band
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-09-01)In this study we investigate the potential of sea ice segmentation by C- and X-band multi-polarisation synthetic aperture radar (SAR) features during late summer. Five high-resolution satellite SAR scenes were recorded in the Fram Strait covering iceberg- fast first-year and old sea ice during a week with air temperatures varying around zero degrees Celsius. In situ data consisting of sea ice ... -
Sensitive on-chip methane detection with a cryptophane-A cladded Mach-Zehnder interferometer
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-24)We report a methane sensor based on an integrated Mach-Zehnder interferometer, which is cladded by a styrene-acrylonitrile film incorporating cryptophane-A. Cryptophane-A is a supramolecular compound able to selectively trap methane, and its presence in the cladding leads to a 17-fold sensitivity enhancement. Our approach, based on 3 cm-long low-loss Si3N4 rib waveguides, results in a detection limit ... -
Multiphysicsbased Condition Monitoring of Composite Materials
(Conference object; Konferansebidrag, 2015-12-10)Composites are increasingly being used in products such as: automobiles, bridges, boats, drillships, offshore platforms, aircrafts and satellites. The increased usage of these composite materials and the fact that the conditions pertaining to their failure are not fully understood makes it imperative to develop condition monitoring systems for composite structures. <br>In this work, we present a ... -
Optical transport, lifting and trapping of micro-particles by planar waveguides
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-03-03)Optical waveguides can be used to trap and transport micro-particles. The particles are held close to the waveguide surface by the evanescent field and propelled forward. We propose a new technique to lift and trap particles above the surface of the waveguides. This is made possible by a gap between two opposing, planar waveguides. The field emitted from each of the waveguide ends diverge fast, away ... -
Measuring the Sea Spray Flux using High-Speed Camera
(Conference object; Konferansebidrag, 2015-12-10)The sea spray contains water droplets that are produced due to sea waves that collide with the marine structures as well as the breaking of waves due to the strong winds. Similarly, fog and precipitation at sea level may contribute to the phenomenon of sea spray containing water droplets of minuscule sizes. Wind characteristics (speed and direction) also has a direct influence on the speed of water ... -
Ambient air quality and the effects of air pollutants on otolaryngology in Beijing
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-07-09)Abstract To investigate temporal patterns, pollution concentrations and the health effects of air pollutants in Beijing we carried out time-series analyses on daily concentrations of ambient air pollutants and daily numbers of outpatient visits for otolaryngology over 2 years (2011– 2012) to identify possible health effects of air pollutants. The results showed that PM10 was the major air ... -
How does relativity affect magnetically induced currents?
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-07-23)Magnetically induced probability currents in molecules are studied in relativistic theory. Spin–orbit coupling (SOC) enhances the curvature and gives rise to a previously unobserved current cusp in AuH or small bulge-like distortions in HgH2 at the proton positions. The origin of this curvature is magnetically induced spin-density arising from SOC in the relativistic description. -
A generalization of Kung’s theorem
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-10-01)We give a generalization of Kung’s theorem on critical exponents of linear codes over a finite field, in terms of sums of extended weight polynomials of linear codes. For all i=k+1,…,ni=k+1,…,n, we give an upper bound on the smallest integer m such that there exist m codewords whose union of supports has cardinality at least i. -
Enforcing Privacy Policies with Meta-Code
(Konferansebidrag; Conference object, 2015)This paper proposes a mechanism for expressing and enforcing security policies for shared data. Security policies are expressed as stateful meta-code operations; meta-code can express a broad class of policies, including access-based policies, use-based policies, obligations, and sticky policies with declassification. The meta-code is interposed in the filesystem access path to ensure policy ... -
Submarine landform assemblages and sedimentary processes related to glacier surging in Kongsfjorden, Svalbard
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-21)High-resolution swath-bathymetry data from inner Kongsfjorden, Svalbard, reveal characteristic landform assemblages formed during and after surges of tidewater glaciers, and provide new insights into the dynamics of surging glaciers. Glacier front oscillations and overriding related to surge activity lead to the formation of overridden moraines, glacial lineations of two types, terminal moraines, ... -
Stanley-Reisner resolution of constant weight linear codes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014-08)Given a constant weight linear code, we investigate its weight hierarchy and the Stanley–Reisner resolution of its associated matroid regarded as a simplicial complex. We also exhibit conditions on the higher weights sufficient to conclude that the code is of constant weight. -
Betti numbers associated to the facet ideal of a matroid
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-01-06)To a matroid M with n edges, we associate the so-called facet ideal F(M)⊂k[x1,…,xn] , generated by monomials corresponding to bases of M. We show that when M is a graph, the Betti numbers related to an ℕ0-graded minimal free resolution of F(M) are determined by the Betti numbers related to the blocks of M. Similarly, we show that the higher weight hierarchy of M is determined by the weight hierarchies ... -
Marine Icing and Anti/De-icing Systems
(Conference object; Konferansebidrag, 2015-12-10)Shipping operations are on the rise in the Arctic region. Due to these increased activities, maritime transport operations are encountering significant challenges with respect to the safety and reliability. These shipping operations are comprised of commercial vessels such as oil tankers, container ships, fishing vessels, tourism cruises, research and offshore exploration vessels and icebreakers In ... -
Bioprospecting around Arctic islands: Marine bacteria as rich source of biocatalysts
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-12-11)We have investigated the biotechnological potential of Arctic marine bacteria for their ability to produce a broad spectrum of cold-active enzymes. Marine bacteria exhibiting these features are of great interest for both fundamental research and industrial applications. Macrobiota water and sediment samples have been collected during 2010 and 2011expeditions around the Lofoten and Svalbard islands. ...