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norskFakultet for naturvitenskap og teknologi: Recent submissions
Now showing items 4201-4220 of 5439
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Amplitude and size scaling for interchange motions of plasma filaments
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-12-07)The interchange dynamics and velocity scaling of blob-like plasma filaments are investigated using a two-field reduced fluid model. For incompressible flows due to buoyancy, the maximum velocity is proportional to the square root of the relative amplitude and the square root of its cross-field size. For compressible flows in a non-uniform magnetic field, this square root scaling only holds ... -
Implementing and optimizing a Sparse Matrix-Vector Multiplication with UPC
(Research report; Forskningsrapport, 2016)Programmability and performance-per-watt are the major challenges of the race to Exascale. In this study we focus on Partitioned Global Address Space (PGAS) languages, using UPC as a particular example. This category of parallel languages provides ease of programming as a strong advantage over the classic Message Passing Interface(MPI). PGAS has also advantages compared to classic shared memory ... -
Thermal Properties of SK One Component Polyurethane using Experiments and Multiphysics Simulations
(Conference object; Konferansebidrag, 2016-12-08)This study proposes to determine the thermal conductivity of SK One Component Polyurethane (SKOCP) developed by China Institute of Water Resources & Hydropower Research Beijing IWHR-KHL Co. Ltd. SKOCP provides excellent proof of aging and chemical resistance of this material. It is non-toxic, acts as a good anti-seepage, offers anti-abrasion and good anti-freezing performance. In addition, it has ... -
Study of Acoustics Properties of SK One Component Polyurethane and its Application in Arctic Marine Structures
(Conference object; Konferansebidrag, 2016-12-08)Marine noise reduction tends to be challenging and requires a comprehensive engineering approach. The soundproofing materials for marine noise reduction are usually exposed to high temperatures, potential fluid or oil spills, engine maintenance and a high airflow environment. This work looks into the acoustic proofing properties of a non-toxic material ‘SK One Component Polyurethane’ developed by ... -
Review of Peltier and Resistive Heating Elements through Infrared Imaging
(Conference object; Konferansebidrag, 2016-12-08)The study includes the review of the heating elements to develop the fundamental understanding. The heating elements to be investigated are Peltier and Resistive types. Both have different working principles and they are used in various industrial applications for cooling and heating purposes. The Infrared (IR) wavelength is emitted by each object at a temperature above absolute zero. IR light is ... -
Active Infrared Observation for Ice Detection in Anti/De-Icing Systems for Marine Applications in Arctic Region
(Conference object; Konferansebidrag, 2016-12-08)The number of shipping operations is on the rise in the Arctic region. As a result of these increased activities, significant challenges are being encountered with respect to safety and reliability. One of the challenges is an accretion of ice. The icing on ships and offshore structures is caused by atmospheric sources and sea spray. The sea spray is the main source of icing and is generated by the ... -
Ice Detection of Pure and Saline Ice Using Infrared Signature
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-11-30)The paper shows the possible implementation of an Infrared (IR) ice detection technique. In respect of safety in marine operations, saline ice detection can be significant for automated de-icing systems. Experimentation is performed to observe and detect saline and pure ice samples. The discussed detection mechanism is unique and differs from passive IR detection by introducing the self-heating ... -
Past methane emissions in the earliest Pleistocene on Yermak Plateau, NW Svalbard.
(Master thesis; Mastergradsoppgave, 2016-05-15)Hole 912A (Ocean Drilling Program (ODP) Leg 151) drilled on the Yermak Plateau (eastern Arctic Ocean) is used to investigate past methane emissions in the earliest Pleistocene. Preliminary work showed depleted δ¹³C values at 93-96 meters below sea floor (mbsf), and an increase in methane concentration between 11, 5 and 23 mbsf. A secondary sampling focused on intervals between 10 and 23 mbsf (core ... -
Management of risks - a Paradox?
(Conference object; Konferansebidrag, 2016-11-23) -
Ice Detection Setup Using Infrared and Active Heating
(Conference object; Konferansebidrag, 2015)Considering the cold environment operations, ice accretion can occur at a rapid pace and can adversely affect the operations. In such scenario, ice detection is useful for the ice mitigation and removal upon the marine and offshore structures. Various techniques exist in the literature to detect the icing mainly utilizing its physical or electromagnetic properties. The parameters measured by these ... -
Improving Mechanical Grip of Tyres on Snow and Icy Road Surfaces using Finite Element Method
(Conference object; Konferansebidrag, 2016)Harsh winter conditions are known to be one of the most challenging environments for driving. Although the number of fatal accidents is higher during the summer compared to the winter in Norway (according to Norwegian Highways Authority), the total number of accidents is higher in the winter season. These accidents mainly happen due to loss traction on snowy or icy road surfaces. The loss of traction ... -
Solution of Pure Scattering Radiation Transport Equation using Finite Difference Method
(Conference object; Konferansebidrag, 2016-12)Radiative transfer is the physical phenomenon of energy transfer in the form of electromagnetic radiation. The propagation of radiation through a medium is affected by absorption, emission, and scattering processes. Equations of radiative transfer have application in a wide variety of subjects including optics, astrophysics, atmospheric science, and remote sensing. Analytic solutions to the radiative ... -
Computational Fluid Dynamic Analysis of the Tesla Turbine
(Conference object; Konferansebidrag, 2016-12-08)Serbian-born inventor Nikola Tesla invented the Tesla turbine and patented it in 1913. The Tesla turbine is unique in the sense that it does not have any blades, also referred to as “bladeless turbine”. The working was based on the establishment of the fluid boundary layer. The original Tesla turbine consisted of multiple smooth discs. With the passage of flow, a boundary layer establishes and skin ... -
Study of Materials’ Impact Properties for Arctic Marine Structures
(Conference object; Konferansebidrag, 2016-12)It is well understood that sea ice is one of the biggest problems for the safety and reliability of ships and marine structures operating in the Arctic. Specially designed ships, also known as ‘icebreakers’, are usually used to clear ice to make way for merchant and cruise ships. Even then, the ship’s staff must be extremely careful with speed and steering. Heavy impacts of ice result in fatigue and ... -
Study of Ice Adhesion Behavior of SK One Component Polyurethane
(Conference object; Konferansebidrag, 2016-12)Ice adhesion causes many serious problems such as aircraft accidents, navigational issues on ships, and power loss on wind turbines. These challenges are mainly associated with the acute behavior of ice adhesion. The ice adheres when water seeps into the microscopic pores of the material substrate and freezes, thereby, forming an interlocking mechanism. Therefore, surface roughness has a significant ... -
Marketing structures and strategies of Nordic SME’s: A Norwegian case study
(Conference object; Konferansebidrag, 2016-10-10) -
Wind speed and direction predictions by WRF and WindSim coupling over Nygårdsfjell
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016)In this study, the performance of the mesoscale meteorological Weather Research and Forecast (WRF) model coupled with the microscale computational fluid dynamics based model WindSim is investigated and compared to the performance of WRF alone. The two model set-ups, WRF and WRF-WindSim, have been tested on three high-wind events in February, June and October, over a complex terrain at the ... -
Complete genome sequence of Halomonas sp. R5-57
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016)The marine Arctic isolate Halomonas sp. R5-57 was sequenced as part of a bioprospecting project which aims to discover novel enzymes and organisms from low-temperature environments, with potential uses in biotechnological applications. Phenotypically, Halomonas sp. R5-57 exhibits high salt tolerance over a wide range of temperatures and has extra-cellular hydrolytic activities with several ... -
Interpreting sea surface slicks on the basis of the normalized radar cross-section model using RADARSAT-2 copolarization dual-channel SAR images
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-03-24)A simple automatic multipolarization technique for discrimination of main types of thin oil films (of thickness less than the radio wave skin depth) from natural ones is proposed. It is based on a new multipolarization parameter related to the ratio between the damping in the slick of specially normalized resonant and nonresonant signals calculated using the normalized radar cross-section model ... -
A polarizable continuum model for molecules at spherical diffuse interfaces
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-03-22)We present an extension of the Polarizable Continuum Model (PCM) to simulate solvent effects at diffuse interfaces with spherical symmetry, such as nanodroplets and micelles. We derive the form of the Green’s function for a spatially varying dielectric permittivity with spherical symmetry and exploit the integral equation formalism of the PCM for general dielectric environments to recast the solvation ...
