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  • A comparison of the energy consumption for CO2 compression process alternatives 

    Jackson, Steven; Brodal, Eivind (Journal article; Peer reviewed; Tidsskriftartikkel, 2018)
    The efficient transportation of large volumes of CO2 generally requires pipelines that will operate above the critical pressure of CO2. Since most capture processes release CO2 at low pressure, compression of CO2 from the point of capture to pipeline will generally be required. The compression duty can be achieved using conventional multi-stage compressors or using newer shockwave type compressors. ...
  • On Context, Issues, and Pitfalls of Expert Judgement Process in Risk Assessment of Arctic Offshore Installations and Operations 

    Naseri, Masoud; Barabadi, Abbas (Journal article; Tidsskriftartikkel; Peer reviewed, 2018)
    Decisions to be made in the Arctic offshore operations rely extensively on risk assessment outputs, which require a great deal of historical data and information. However, at the current stage of operating in the Arctic offshore – compared to normal-climate regions – such data is scarce due to the limited industrial activities to date. Lack of data on the probability of the occurrence of an unwanted ...
  • Multi-dimensional Hardy type inequalities in Hölder spaces 

    Burtseva, Evgeniya; Lundberg, Staffan; Persson, Lars Erik; Samko, Natasha (Journal article; Tidsskriftartikkel; Peer reviewed, 2018)
    Most Hardy type inequalities concern boundedness of the Hardy type operators in Lebesgue spaces. In this paper we prove some new multi-dimensional Hardy type inequalities in Hölder spaces.
  • Fluid solid interaction simulation of CFRP shell structure 

    Khawaja, Hassan Abbas; Messahel, Ramzi; Souli, Mhmed; Al-Bahkali, Essam; Moatamedi, Mojtaba (Journal article; Tidsskriftartikkel; Peer reviewed, 2017)
    This work attempts to model the dynamic behavior of Carbon Fiber Reinforced Polymer (CFRP) shell structure subjected to water shock wave to improve the results presented in the study by Khawaja et al., 2014. In the previous study, the real physical problem was simplified by decoupling the fluid and the structural phenomena, applying the recorded experimental fluid pressure load to the CFRP shell ...
  • Semi-Implicit Method for Pressure-Linked Equations (SIMPLE) – solution in MATLAB® 

    Khawaja, Hassan; Moatamedi, Mojtaba (Journal article; Tidsskriftartikkel; Peer reviewed, 2018)
    This work presents a method for the solution of fundamental governing equations of computational fluid dynamics (CFD) using the Semi-Implicit Method for Pressure-Linked Equations (SIMPLE) in MATLAB®. The fundamental governing equations of fluid mechanics are based on three laws of conservation, referred to as the law of conservation of mass, the law of conservation of momentum and the law of ...
  • Review of Low-Temperature Crack (LTC) Developments in Asphalt Pavements 

    Khawaja, Hassan; Tanveer, Ahmad (Journal article; Tidsskriftartikkel; Peer reviewed, 2018)
    The article presents a review of low-temperature crack (LTC) developments in asphalt pavements commonly observed in regions affected by cold weather. The cold weather contributes significantly towards the development of these low-temperature cracks (LTCs). Since the 1960s, many studies have been published, proposing various cracking mechanisms. The simplistic reason for the development of cracks in ...
  • Validation of air ventilation in tunnels, using experiments and computational fluid dynamics 

    Myrvang, Torgeir; Khawaja, Hassan (Journal article; Tidsskriftartikkel; Peer reviewed, 2018)
    The study presented in this paper concerns the ventilation system inside tunnels. The ventilation system is responsible for the removal of exhaust gases produced by vehicles and for providing a clear view throughout the tunnels in routine operations and in the event of fire. The ventilation system has several stages, which are equipped with one or more fans and can be activated together or separately. ...
  • Effect of seasonal mesoscale and microscale meteorological conditions in Ny-Ålesund on results of monitoring of long-range transported pollution 

    Dekhtyareva, Alena; Holmén, Kim; Maturilli, Marion; Hermansen, Ove; Graversen, Rune (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-06)
    Ny-Ålesund is an international research settlement where the thermodynamics and chemical composition of the air are monitored. The present work investigates the effects of micrometeorological conditions, mesoscale dynamics and local air pollution on the data collected at two different locations around the village. Daily filter measurements of sulphur dioxide and non-sea salt sulphate from the temporary ...
  • Measuring Thickness of Marine Ice Using IR Thermography 

    Rashid, Taimur; Khawaja, Hassan; Edvardsen, Kåre (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-04)
    <p>There are several challenges to operating in a cold climate. Marine icing is one of them, and its mitigation is vital for marine operations.</p> <p>The presented work is a laboratory-scale setup to measure marine ice thickness. The developed methodology can be applied towards de-/anti-icing setups. The method described is based on measuring the average surface temperatures of the marine ice. ...
  • Ship-icing prediction methods applied in operational weather forecasting 

    Samuelsen, Eirik Mikal (Journal article; Peer reviewed; Tidsskriftartikkel, 2017-10-11)
    Sea-spray wetting of ships operating in cold environments imposes a great safety risk, due to icing. For this reason, marine-icing warnings have been a part of operational weather forecasting for the last five decades, yet verification of such warnings has only been done sparingly. This article evaluates different ship-icing methods applied in operational weather forecasting. The methods are tested ...
  • Scenario-based approaches for handling uncertainty in MPC for power system frequency control 

    Ersdal, Anne Mai; Imsland, Lars Struen (Journal article; Peer reviewed; Tidsskriftartikkel, 2017)
    A stochastic nonlinear model predictive controller (SNMPC) is designed for automatic generator control of a proxy of the Nordic power system, and it is compared with a multi-stage nonlinear model predictive controller (MNMPC). Both controllers are scenario based, but originate in two different disturbance modeling paradigms; stochastic and deterministic. A simulation study indicates that the two ...
  • Study Of Wind Chill Effect and Thermal Insulation Using Infrared Imaging 

    Ahmad, Tanveer; Khawaja, Hassan (Conference object; Konferansebidrag, 2017)
    Tanveer Ahmad presented his findings on using Infrared Imaging to identify the wind chill-effect and insulation of winter clothing. He showed qualitatively that IR can detect the effects of wind chill and conducted experiments to obtain data with a view to establishing metrics which can be used to assess the effectiveness of survival gear. An unusual item that cropped up during the presentation was ...
  • Monitoring of nitrogen oxides at Svalbard: measurements in Adventdalen 

    Dekhtyareva, Alena; Holmén, Kim; Hermanson, Mark H (Conference object; Konferansebidrag, 2017)
  • Affordances for capturing and re-enacting expert performance with wearables 

    Guest, Will; Wild, Fridolin; Vovk, Alla; Fominykh, Mikhail; Limbu, Bibeg; Klemke, Roland; Sharma, Puneet; Karjalainen, Jaakko; Smith, Carl; Rasool, Jazz; Aswat, Soyeb; Helin, Kaj; Di Mitri, Daniele; Schneider, Jan (Journal article; Peer reviewed; Tidsskriftartikkel, 2017-09-05)
    The WEKIT.one prototype is a platform for immersive procedural training with wearable sensors and Augmented Reality. Focusing on capture and re-enactment of human expertise, this work looks at the unique affordances of suitable hard- and software technologies. The practical challenges of interpreting expertise, using suitable sensors for its capture and specifying the means to describe and display ...
  • Simulation of the HDPE Pyrolysis Process 

    Eidesen, Hans-Kristian; Khawaja, Hassan; Jackson, Steven (Journal article; Peer reviewed; Tidsskriftartikkel, 2018)
    Pyrolysis is a thermochemical decomposition of organic compounds such as High-density polyethylene (HDPE) plastics. The product of the HDPE pyrolysis is usually diesel with other wastes (such as carbon black, etc.). A pyrolysis reaction is essentially a decomposition reaction performed at elevated temperatures in the absence of oxygen. There are many other complex reactions taking place in pyrolysis, ...
  • Solution of Pure Scattering Radiation Transport Equation (RTE) Using Finite Difference Method (FDM) 

    Khawaja, Hassan Abbas (Peer reviewed; Bokkapittel; Book; Bok; Chapter, 2017-05-19)
    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. Radiative Transfer Equation (RTE) have been applied in a many subjects including optics, astrophysics, atmospheric science, remote sensing, etc. Analytic solutions for RTE exist for simple cases, ...
  • Ice Detection Experimentation Setup Using Infrared and Active Heating 

    Rashid, Taimur; Khawaja, Hassan Abbas; Edvardsen, Kåre (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-07-24)
    The paper shows the possible implementation of Infrared (IR) ice detection technique. The experimental setup is implemented keeping in view of the marine icing phenomena over the ships and offshore structures. The detection mechanism is unique from the passive IR detection by introducing the active heating concept. The intervention of the active heating information inside the IR ice detection system ...
  • Sound waves in fluidized bed using CFD–DEM simulations 

    Khawaja, Hassan Abbas (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-10-16)
    The speed of sound waves is investigated using CFD-DEM numerical simulations. Appropriate initial and boundary conditions are applied to capture the phenomenon. The effect of varying the height of the bed is also studied. The results of the simulations matched those from literature. The pressure and particle velocity profiles from the simulation showed the oscillatory behavior. Functions (based on ...
  • Transient Model of an RSW System with CO2 Refrigeration – A Study of Overall Performance 

    Brodal, Eivind; Jackson, Steven; Eiksund, Oddmar (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-07)
    Refrigerated seawater (RSW) cooling using CO2 based refrigeration is a relatively new technology that shows promising performance in cold climates. For being a refrigerant CO2 has a low global warming potential (GWP) and is therefore recognized as an environmentally friendly alternative if the unit is competitive on energy efficiency. However, RSW systems with CO2 have a significant reduction in ...
  • State-of-the-art techniques in crack detection and utilizing innovative materials for the repair and maintenance of roads 

    Khawaja, Hassan (Conference object; Konferansebidrag, 2017)
    This work is looking into the issue of repairing and maintaining the roads using innovative materials in the Arctic region. We have conducted preliminary studies at UiT The Arctic University of Norway and found a suitable material that has potential to be applied on roads cracks or even coat the entire road. This is an ongoing work and has two main sections: 1) To investigate the suitable techniques ...

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