Now showing items 11-30 of 98

    • CFD modelling of pressure and shear rate in torsionally vibrating structures using ANSYS CFX and COMSOL Multiphysics 

      Brunner, Daniel; Khawaja, Hassan; Moatamedi, Mojtaba; Boiger, Gernot (Journal article; Tidsskriftartikkel; Peer reviewed, 2018)
      This paper discusses numerical methodologies to simulate micro vibrations on a nontrivial torsionally oscillating structure. The torsional structure is the tip of a viscosity-density sensor using micro vibrations to measure the fluid properties. A 2D transient simulation of the fluid domain surrounding the tip of the sensor has been conducted in ANSYS CFX and COMSOL Multiphysics software. ANSYS CFX ...
    • Coastal Environment, Technology and Innovation in the Arctic (CETIA) 2011-14. 

      Sydnes, Are K. (Conference object; Konferansebidrag, 2012)
    • Column leaching heavy metal from tailings following simulated climate change in the Arctic area of Norway 

      Fu, Shuai; Lu, Jinmei (Journal article; Tidsskriftartikkel; Peer reviewed, 2018)
      This study aimed to assess how the current climate change perspective, with various air temperature (4°C, 10°C, 14°C and 18°C) affected metal releasing from tailings. Heavy metals pollution from tailings leaching are of increasing concern. Column leaching experiment was conducted for 15 weeks to a series of tailings with 20 mm/week water leaching four temperature situations. Leachate chemical physics ...
    • Column leaching test on oxidized and non-oxidized tailings in northern Norway 

      Fu, Shuai; Lu, Jinmei (Journal article; Peer reviewed, 2018)
      Column leaching test was applied for oxide and non-oxide tailings in the Arctic area. Physico-chemical parameters (pH, pe: potential ecolotric, conductivity, TDS: Total dissolved solids, SO4 2−, salinity, Ni, Co, Zn and Mn) were measured to identified the effect of oxidized degree on heavy metals leaching from tailings. Results showed that oxidized tailings contained higher levels of Co and Ni, and ...
    • Computational Fluid Dynamic Analysis of the Tesla Turbine 

      Strand, Cathrine; Eidesen, Hans-Kristian; Khawaja, Hassan Abbas (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 ...
    • Computational Fluid Dynamic Analysis of the Tesla Valve 

      Eidesen, Hans-Kristian; Khawaja, Hassan Abbas (Conference object; Konferansebidrag, 2016-12-08)
      Serbian-born inventor Nikola Tesla invented the Tesla valve (Tesla's Valvular Conduit) and patented it in 1919. The Tesla valve is unique in the sense that it does not have any moving parts, but it can work as a one-way valve. Nikola Tesla invented this unit without advanced mathematical models, nor with the help of modern computing power. The original Tesla valve consisted of a set of cavities and ...
    • Conceptual design of high speed supersonic aircraft: A brief review on SR-71 (Blackbird) aircraft 

      Xue, Hui; Khawaja, Hassan Abbas; Moatamedi, Mojtaba (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)
    • Critical infrastructure resilience: A Nordic model in the making? 

      Pursiainen, Christer Henrik (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-08-19)
      In recent years, there has been a shift in emphasis from critical infrastructure protection to that of resilience. This development reflects the acknowledgment that complete protection can never be guaranteed, and that achieving the desired level of protection is not cost-effective as a rule in relation to the actual threats. This article reviews the responses of four of the five Nordic countries ...
    • Design of a Snow Sledge using Multiphysics Analysis 

      Xue, Hui; Khawaja, Hassan Abbas; Mauseth, Guy Beeri (Conference object; Konferansebidrag, 2014)
    • Determination of Thermal Properties of Fresh Water and Sea Water Ice using Multiphysics Analysis 

      Rashid, Taimur; Khawaja, Hassan Abbas; Edvardsen, Kåre (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-08-29)
      This paper presents a methodology to determine the thermal conductivity of ice using multiphysics analysis. This methodology used a combination of both experimentation and numerical simulation. In the experimental work, an ice block is observed using an infrared camera. The results reveal the variation in temperature over the surface. These results are dependent on two primary heat transfer parameters, ...
    • Development of strategic asset management planning in the petroleum industry 

      Kusumawardhani, Mayang; Markeset, Tore; Kumar, Rajesh (Tidsskriftsartikkel; Journal article; Tidsskriftartikkel; Peer reviewed, 2017)
      <i>Purpose</i> – Due to the certain risk carried in offshore petroleum installations, the integrity of these installations needs to be maintained at all times. Thus, asset integrity management (AIM) needs to be formulated and monitored to achieve the integrity objective. The purpose of this paper is to study the practices and progression of strategic AIM planning in the petroleum industry. ...
    • Dynamic spare parts transportation model for Arctic production facility 

      Ayele, Yonas Zewdu; Barabadi, Abbas; Barabady, Javad (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, ...
    • The effect of drinking water quality on the health and longevity of people-A case study in Mayang, Hunan province, China 

      Lu, Jinmei; Yuan, Fuqing (Peer reviewed; Bokkapittel; Chapter, 2017)
      Drinking water is an important source for trace elements intake into human body. Thus, the drinking water quality has a great impact on people's health and longevity. This study aims to study the relationship between drinking water quality and human health and longevity. A longevity county Mayang in Hunan province, China was chosen as the study area. The drinking water and hair of local centenarians ...
    • The effect of temperature and precipitation on the leaching of contaminants from Ballangen tailings deposit, Norway 

      Lu, Jinmei; Yuan, Fuqing (Journal article; Peer reviewed, 2019)
      Leaching and transport of contaminants from tailings deposit is a highly complex interacting system affected by a suite of environmental factors, among which temperature and precipitation rates linked to climate change are two important parameters. The climate change in the Nordic region is more drastic than other regions. In this study, a laboratory batch leaching experiment was performed on the ...
    • Endurance Test on Carbon Film Fixed Resistor under Escalated Voltage Stress 

      Yuan, Fuqing; Lu, Jinmei (Journal article; Peer reviewed; Tidsskriftartikkel, 2018)
      Film fixed resistor is a basic unit in the electronic devices. As it is less frequently failed than other units such as capacitor, the reliability and robustness of it are less concerned both in the academics and in the industries. This paper investigates the endurance of the carbon film fixed resistor. The resistance shift and life of it under the escalated voltage stress level are the aim. A PCB ...
    • Evaluating Visual Saliency Algorithms: Past, Present and Future 

      Sharma, Puneet (Tidsskriftartikkel; Peer reviewed; Journal article, 2015-09-01)
      With the introduction of compressed sensing (CS) theory, investigation into exploiting sparseness and optimizing compressive sensing performance has ensued. Compressed sensing is highly applicable to images, which naturally have sparse representations. Improvements in the area of image denoising have resulted from the combination of highly-directional transforms with shrinkage and thresholding ...
    • An expert-based approach to production performance analysis of oil and gas facilities considering time-independent Arctic operating conditions 

      Naseri, Masoud; Barabady, Javad (Journal article; Tidsskriftartikkel, 2016-03)
      The availability and throughput of offshore oil and gas plants operating in the Arctic are adversely influenced by the harsh environmental conditions. One of the major challenges in quantifying such effects is lack of adequate life data. The data collected in normal-climate regions cannot effectively reflect the negative effects of harsh Arctic operating conditions on the reliability, availability, ...
    • Failure intensity of offshore power plants under varying maintenance policies 

      Perera, Lokukaluge Prasad; Machado, Mario M.; Valland, Anders; Manguinho, Diego A.P. (Journal article; Peer reviewed; Tidsskriftartikkel, 2019-01-06)
      System reliability of an offshore power plant with several gas turbine engines is analyzed in this study to understand the failure intensity of a selected gas turbine engines under varying maintenance activities. A set of event data of a selected gas turbine engine is considered to identify system failure intensity levels, where unknown maintenance actions were implemented (i.e. various repairs ...
    • Finite element analysis of human femur bone 

      Mughal, Uzair; Khawaja, Hassan Abbas; Moatamedi, Mojtaba (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-08-04)
      An effort is made to analyse the stresses experienced by the human femur. In order to achieve these results a CAD model was developed by using the 3-D scanning of generic human femur for an individual of 70 kg weight (approx. averaged adult weight). The marrow cavity has been approximated as a hollow cylinder. The FEM model was built using solid tetrahedral element (20-noded 186 structural ...
    • Group Based Asymmetry – A Fast Saliency Algorithm 

      Sharma, Puneet; Eiksund, Oddmar (Chapter; Bokkapittel, 2015-12-18)
      In this paper, we propose a saliency model that makes two major changes in a latest state-of-the-art model known as group based asymmetry. First, based on the properties of the dihedral group D4 we simplify the asymmetry calculations associated with the measurement of saliency. This results is an algorithm which reduces the number of calculations by at-least half that makes it the fastest among the ...