Now showing items 461-480 of 541

    • Upgrading technologies for biogas production plants. Overview and life cycle cost analysis of available technologies 

      Brendeløkken, Hanne Wasmuth (Master thesis; Mastergradsoppgave, 2016-06-01)
      An increased focus on waste management has emerged during the last decade. Renewable energy, efficient energy usage and cuts in greenhouse gas emissions are highly prioritized by the EU. The International Energy Agency (IEA) and the World Energy Council estimates that the global energy demand will grow within the next decades. The continuously increasing energy demand, contributes to development of ...
    • Real time estimation of measurement in annular pressure and their relationship with pore and fracture pressure profile 

      Hassan, Syed Yasir (Master thesis; Mastergradsoppgave, 2016-06-01)
      The drilling industry still faces the challenge of acquiring accurate and viable precision of subsurface pressure data. To address this, drilling industry is keen to establish accurate and reliable measurement of pressure in wellbore and to estimate the pore pressure and fracture pressure profile with utmost precision. In any drilling operation, it is important to maintain the annulus pressure ...
    • Utfordringer ved snøkrabbefangst med hensyn på risiko ved operasjoner på sjøen. Kartlegging av risiko og risikoreduserende tiltak 

      Jørgensen, Andreas (Master thesis; Mastergradsoppgave, 2016-05-31)
      Sentrale organer innenfor norsk fiskeri har de siste årene kartlagt spredning av arten ”Chionoecetes Opilio”, snøkrabbe, til norske farvann. Bestanden av snøkrabbe kommer fra russisk side av delelinjen i Barentshavet, og sprer seg vestover til norske territorialfarvann. Norsk havforskningsinstitutt mener at krabben kommer til å etablere seg i Svalbardsonen de kommende år. Krabben anses å være ...
    • Assessing the Risk of Escape from Marine Fish Farms. Improving Data Collection Strategies and Development of Risk Indicators 

      Høyli, Randulf (Master thesis; Mastergradsoppgave, 2016-05-31)
      Marine fish farming is one of Norway’s largest industries and exports. The industry is in rapid development and secures employment for several thousand people, all along the Norwegian coastline. Fish farming is regarded as a relative sustainable method for food production. However, the industry is still prone to certain challenges and problems. Escape of fish, for instance, is one of the industry’s ...
    • Sikkerhetsvurdering av Tromsøysundtunnelen 

      Jensen, Sondre Finjord (Master thesis; Mastergradsoppgave, 2016-05-31)
      Veitunneler er statistisk sett en av de sikreste delene av veinettet, med svært få hendelser sammenlignet med det øvrige nettet. Det er derimot spesielle forhold som i vesentlig grad avviker fra veinettet for øvrig med tanke på brann og rømning. De ulike sikkerhetssystemene i tunnelen er med på å hindre at hendelser oppstår, og redusere konsekvensene hvis ulykken først er ute. Gjennom oppgaven ...
    • The application of unmanned aerial vehicles for snow avalanche search and rescue 

      Albrigtsen, Andreas (Master thesis; Mastergradsoppgave, 2016-06-01)
      Snow avalanches claim in excess of 200 lives annually on a worldwide basis. However, since the invention of the first effective avalanche transceiver, the process of locating victims has remained fundamentally unchanged. Humans as a carrier for locating devices are perceived to be inefficient when moving over rugged avalanche debris, and potentially exposed to excessive risk from secondary avalanches. ...
    • Identification of Challenges and Hazards associated with Cruise Traffic and Evacuation in the Arctic 

      Dalsand, Raymond; Nese, Tord (Master thesis; Mastergradsoppgave, 2016-06-06)
      Arctic cruise tourism is gaining in popularity. There is a need to better understand hazards that are connected with cruise traffic and evacuation in the Arctic. The Polar Code tries to enhance the safety of persons travelling in polar waters by giving functional requirements to life-saving appliances. However, it is unclear what is needed to achieve the required functionality, and how existing ...
    • A fuzzy logic-possibilistic methodology for risk-based inspection (RBI) planning of oil and gas piping subjected to microbiologically Influenced corrosion (MIC) 

      Pokhrel, Marshal (Master thesis; Mastergradsoppgave, 2016-05-31)
      The oil and gas installations are associated with risk due to different degradation mechanisms. Microbial Influenced Corrosion, commonly known as MIC, is one of them. The failures caused by MIC may have significant impacts on health, safety and environment (HSE). Therefore, to avoid failures regular inspection of the assets and maintenance plans need to be executed. With this on mind, engineers try ...
    • Multiphysics investigation of Ice Adhesion over PVC surface 

      Xue, Hui; Khawaja, Hassan Abbas (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 ...
    • Multiphysicsbased Condition Monitoring of Composite Materials 

      Xue, Hui; Sharma, Puneet; Khawaja, Hassan Abbas (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 ...
    • Measuring the Sea Spray Flux using High-Speed Camera 

      Johansen, Jarle André; Edvardsen, Kåre; Sharma, Puneet; Khawaja, Hassan Abbas (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 

      Zhang, Fengying; Xu, Jin; Zhang, Ziying; Meng, Haiying; Wang, Li; Lu, Jinmei; Wang, Wuyi; Kraft, Thomas (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 ...
    • Marine Icing and Anti/De-icing Systems 

      Rashid, Taimur; Khawaja, Hassan Abbas; Edvardsen, Kåre (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 ...
    • Evaluating Visual Saliency Algorithms: Past, Present and Future 

      Sharma, Puneet (Tidsskriftartikkel; Journal article; Peer reviewed, 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 ...
    • Marine stewardship and complexity – How to enhance a better process of risk governance in the Norwegian area of the Arctic Ocean? 

      Nilsen, Aud Solveig; Hammer, Maria (Conference object; Konferansebidrag, 2016-01)
    • Infrared Thermal Signature Evaluation of a Pure Ice Block 

      Rashid, Taimur; Khawaja, Hassan Abbas; Edvardsen, Kåre; Mughal, Umair Najeeb (Conference object; Konferansebidrag, 2015-08-23)
      Marine operations in cold climates are subjected to heavy ice accretion, which can lead to heavy ice loads causing safety concerns. Atmospheric and sea spray icing can cause severe ice accretion on structures. Ice detection over the relatively larger surface area of marine platforms and vessels could be significant for ice mitigation and its removal in cold climates. A thermal ice signature ...
    • Infrared Thermal Signature Evaluation of a Pure and Saline Ice for Marine Operations in Cold Climate 

      Rashid, Taimur; Khawaja, Hassan Abbas; Edvardsen, Kåre; Mughal, Umair Najeeb (Peer reviewed; Journal article; Tidsskriftsartikkel, 2015)
      Marine operations in cold climates are subjected to abundant ice accretion, which can lead to heavy ice loads over larger surface area. For safe and adequate operations on marine vessels over a larger area, remote ice detection and ice mitigation system can be useful. To study this remote ice detection option, lab experimentation was performed to detect the thermal gradient of ice with the infrared ...
    • Multiphysics Simulation of Infrared Signature of an Ice Cube 

      Khawaja, Hassan Abbas; Rashid, Taimur; Eiksund, Oddmar; Brodal, Eivind; Edvardsen, Kåre (Conference object; Konferansebidrag, 2015-12-11)
      This poster presents the Multiphysics numerical methodologies used to simulate the Infrared (IR) signature of an ice cube when taken out of the cold environment (-28 C) and allowed to warm at room temperature conditions by means of natural convection. The ice cube is chosen to simplify the geometry. The cubical geometry can be discretized simply and hence allows easy application of Multiphysics ...
    • 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, ...
    • Prediction of the long-term performance of green liquor dregs as a sealing layer to prevent the formation of acid mine drainage 

      Mäkitalo, Maria; Lu, Jinmei; Maurice, Christian; Öhlander, Björn (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-10-08)
      One of the mining industry's main concerns is the management of waste rock and tailings generated by sulfide ore extraction. Upon exposure of atmospheric oxygen, iron sulfides oxidize generating acidity. Infiltrating water form a metal-rich acidic leachate called acid mine drainage (AMD), that can cause serious environmental problems. Green liquor dregs (GLD) is a material that resists the passage ...