Fakultet for naturvitenskap og teknologi: Recent submissions
Now showing items 3761-3780 of 5327
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Relative generalized hamming weights and extended weight polynomials of almost affine codes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-08-23)This paper is devoted to giving a generalization from linear codes to the larger class of almost affine codes of two different results. One such result is how one can express the relative generalized Hamming weights of a pair of codes in terms of intersection properties between the smallest of these codes and subcodes of the largest code. The other result tells how one can find the extended ... -
Environmental baselines and reconstruction of Atlantic Water inflow in Bjørnøyrenna, SW Barents Sea, since 1800 CE
(Journal article; Tidsskriftartikkel, 2017-10-28)Metal concentrations, sediment properties and benthic foraminiferal assemblages were investigated in sediment cores in the SW Barents Sea, to reconstruct environmental baselines and natural variability of Atlantic Water inflow since 1800 CE. Metal concentrations correspond to no effect levels and do not influence the foraminifera. Increased Hg and Pb was linked to inflow of Atlantic Water. The data ... -
Accurate prediction of emission energies with TD-DFT methods for platinum and iridium OLED materials
(Journal article; Tidsskriftartikkel, 2017-05-02)Accurate prediction of triplet excitation energies for transition metal complexes has proven to be a difficult task when confronted with a variety of metal centers and ligand types. Specifically, phosphorescent transition metal light emitters, typically based on iridium or platinum, often give calculated results of varying accuracy when compared to experimentally determined T1 emission values. ... -
A global multiproxy database for temperature reconstructions of the Common Era
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-07-11)Reproducible climate reconstructions of the Common Era (1 CE to present) are key to placing industrial-era warming into the context of natural climatic variability. Here we present a community-sourced database of temperature-sensitive proxy records from the PAGES2k initiative. The database gathers 692 records from 648 locations, including all continental regions and major ocean basins. The records ... -
A compact portable resonance probe system for in situ measurements of snow conditions
(Master thesis; Mastergradsoppgave, 2018-01-31)A resonance probe for measuring the dielectric properties of snow in terms of the resonance frequency is described and tested. The dielectric properties of snow are closely related to the density and the water content in snow. Having a probe capable of measuring the dielectric properties is therefore a useful tool for anyone working with quantitative descriptions of snow properties. In situ measurements ... -
Are health videos from hospitals, health organizations, and active users available to health consumers? An analysis of diabetes health video ranking in YouTube
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-01-24)Health consumers are increasingly using the Internet to search for health information. The existence of overloaded, inaccurate, obsolete, or simply incorrect health information available on the Internet is a serious obstacle for finding relevant and good-quality data that actually helps patients. Search engines of multimedia Internet platforms are thought to help users to find relevant information ... -
On the potential of hand-held GPS tracking of fjord ice features for remote-sensing validation
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-12-14)Research on young thin sea ice is essential to understand the changes in the Arctic. But it is also the most challenging to investigate, both in situ and from satellites. If satellite remote sensing techniques are developing rapidly, fieldwork remains crucial for the mandatory validation of such data. In April 2016, an Arctic fieldwork campaign was conducted at Kongsfjorden, Svalbard. This campaign ... -
Eurasian ice-sheet dynamics and sensitivity to subglacial hydrology
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-24)Ice-stream dynamics are strongly controlled by processes taking place at the ice/bed interface where subglacial water both lubricates the base and saturates any existing, underlying sediment. Large parts of the former Eurasian ice sheet were underlain by thick sequences of soft, marine sediments and many areas are imprinted with geomorphological features indicative of fast flow and wet basal conditions. ... -
Assessment of offshore wind power potential in the Aegean and Ionian<br> Seas based on high-resolution hindcast model results
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-03-20)In this study long-term wind data obtained from high-resolution hindcast simulations is used to analytically assess offshore wind power potential in the Aegean and Ionian Seas and provide wind climate and wind power potential characteristics at selected locations, where offshore wind farms are at the concept/planning phase. After ensuring the good model performance through detailed validation against ... -
Possible climate preconditioning on submarine landslides along a convergent margin, Nankai Trough (NE Pacific)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-07-25)Submarine landslides are major agents of sediment mass transfer from the shallow to deep sea. Due to their rapid emplacement and tsunamigenic potential, such landslides are significant geohazards for society and off- and on-shore infrastructure. The relationship between climate change and the occurrence of submarine landslides is widely debated. However, there is a lack of continuous long-term ... -
Younger Dryas ice margin retreat triggered by ocean surface warming in central-eastern Baffin Bay
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-10-18)The transition from the last ice age to the present-day interglacial was interrupted by the Younger Dryas (YD) cold period. While many studies exist on this climate event, only few include high-resolution marine records that span the YD. In order to better understand the interactions between ocean, atmosphere and ice sheet stability during the YD, more high-resolution proxy records from the Arctic, ... -
Methane- and dissolved organic carbon-fueled microbial loop supports a tropical subterranean estuary ecosystem
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-28)Subterranean estuaries extend inland into density-stratified coastal carbonate aquifers containing a surprising diversity of endemic animals (mostly crustaceans) within a highly oligotrophic habitat. How complex ecosystems (termed anchialine) thrive in this globally distributed, cryptic environment is poorly understood. Here, we demonstrate that a microbial loop shuttles methane and dissolved organic ... -
RFEA Measurements of High-Energy Electrons in a Helicon Plasma Device with Expanding Magnetic Field
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-01-26)In the inductively coupled plasma of the Njord helicon device we have, for the same parameters as for which an ion beam exists, measured a downstream population of high-energy electrons emerging from the source. Separated measurements of energetic tail electrons was carried out by Retarding Field Energy Analyzer (RFEA) with a grounded entrance grid, operated in an electron collection mode. In a ... -
Derivation of High Spatial Resolution Albedo from UAV Digital Imagery: Application over the Greenland Ice Sheet
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-05-23)Measurements of albedo are a prerequisite for modeling surface melt across the Earth’s cryosphere, yet available satellite products are limited in spatial and/or temporal resolution. Here, we present a practical methodology to obtain centimeter resolution albedo products with accuracies of ±5% using consumer-grade digital camera and unmanned aerial vehicle (UAV) technologies. Our method comprises ... -
β-Octabromo- and β-Octakis(trifluoromethyl)isocorroles: New Sterically Constrained Macrocyclic Ligands
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-05-26)Presented herein is a study of the acid-induced demetalation of two sterically hindered copper corroles, Cu b-octabromomeso-triphenylcorrole (Cu[Br8TPC]) and b-octakis(trifluoromethyl)-meso-tris(p-methoxyphenyl)corrole (Cu[(CF3 )8TpOMePC]). Unlike reductive demetalation, which affords the free-base boctabromocorrole, demetalation of Cu[Br8TPC] under nonreductive conditions (CHCl3 /H2SO4 ) ... -
Ultrasonic measurements of surface defects on flexible circuits using high-frequency focused polymer transducers
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06-12)High frequency transducers made from a layer-by-layer deposition method are investigated as transducers for ultrasonic imaging. Prototypes of adhesive-free transducers with four active elements were made on a high performance PEI (Polyetherimide) substrate with precision milled spherical cavities used to produce focused ultrasonic beams. The transducer prototypes ... -
Dynamically loading mobile/cloud assemblies
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-07-20)Distributed applications that span mobile devices, computing clusters, and cloud services, require robust and flexible mechanisms for dynamically loading code. This paper describes lady: a system that augments the .net platform with a highly reliable mechanism for resolving and loading assemblies, and arranges for safe execution of partially trusted code. Key benefits of lady are the low latency and ... -
Modelling the transport of oil after a proposed oil spill accident in Barents Sea and its environmental impact on Alke species
(Konferansebidrag; Conference object, 2017)Accidental oil spills can have significant effect on the coastal and marine environment. As the oil extraction and exploration activities increase in the Barents Sea, it is of increasingly importance to investigate the potential oil spill incidents associated with these activities. In this study, the transport and fate of oil after a proposed oil spill incident in Barents Sea was modelled by oil ... -
One-Pot Synthesis of a bis-Pocket Corrole through a 14-fold Bromination Reaction.
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-02-14)A one-pot protocol, effecting 14-fold bromination with elemental bromine, has afforded copper β-octabromo-meso-tris (2,6-dibromo-3,5-dimethoxyphenyl) corrole, a new bis-pocket metallocorrole. The Cu complex underwent smooth demetalation under reductive conditions, affording the free corrole ligand, which in turn could be readily complexed to MnIII and AuIII. A single-crystal X-ray structure was ... -
Multiplex visibility graphs to investigate recurrent neural network dynamics
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-03-10)A recurrent neural network (RNN) is a universal approximator of dynamical systems, whose performance often depends on sensitive hyperparameters. Tuning them properly may be difficult and, typically, based on a trial-and-error approach. In this work, we adopt a graph-based framework to interpret and characterize internal dynamics of a class of RNNs called echo state networks (ESNs). We design principled ...