Now showing items 21-40 of 83

    • Solution of Pure Scattering Radiation Transport Equation (RTE) Using Finite Difference Method (FDM) 

      Khawaja, Hassan Abbas (Conference object; Konferansebidrag, 2017-06)
      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, ...
    • 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; Tidsskriftartikkel; Peer reviewed, 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 ...
    • Ship-icing prediction methods applied in operational weather forecasting 

      Samuelsen, Eirik Mikal (Journal article; Tidsskriftartikkel; Peer reviewed, 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 ...
    • Sound waves in fluidized bed using CFD–DEM simulations 

      Khawaja, Hassan Abbas (Journal article; Peer reviewed; Tidsskriftartikkel, 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 ...
    • 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 ...
    • Simulation of the HDPE Pyrolysis Process 

      Eidesen, Hans-Kristian; Khawaja, Hassan; Jackson, Steven (Journal article; Tidsskriftartikkel; Peer reviewed, 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, ...
    • Validation of air ventilation in tunnels, using experiments and computational fluid dynamics 

      Myrvang, Torgeir; Khawaja, Hassan (Journal article; Peer reviewed; Tidsskriftartikkel, 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. ...
    • 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 ...
    • 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.
    • 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. ...
    • Solution of Pure Scattering Radiation Transport Equation (RTE) using Finite Difference Method (FDM) (poster) 

      Khawaja, Hassan; Moatamedi, Mojtaba (Conference object; Konferansebidrag, 2018)
      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 atmospheric science, astrophysics, nuclear, optics, remote sensing, etc. Analytic solutions for RTE exist for simple ...
    • Sound waves in fluidized bed using CFD–DEM simulations 

      Khawaja, Hassan (Conference object; Konferansebidrag, 2018)
      The seminar is about modelling sound waves in a fluidized bed using CFD–DEM numerical simulations. The presented case includes the application of appropriate initial and boundary conditions to reproduce bed phenomena and the effect of varying the bed height. The results of the simulations matched those from the literature. The pressure and particle velocity profiles obtained feature oscillatory ...
    • IR THERMOGRAPHY in Multiphysics Applications 

      Khawaja, Hassan (Conference object; Konferansebidrag, 2018)
      It is seen that Infrared (IR) thermography is becoming one of the very popular and effective methods in the industry as well as research and development sectors. IR thermography being a remote non-contact/non-destructive means of testing is perfectly suitable for tests in extreme environments. In addition, it is fast, reliable and detailed. Due to the advantages offered by IR thermography, it is ...
    • Is Thorium a Viable Nuclear Fuel? [poster] 

      Khawaja, Hassan; Moatamedi, Mojtaba; Tehrani, Ali (Conference object; Konferansebidrag, 2018)
      Thorium was discovered in 1829 by the Norwegian mineralogist Morten Thrane Esmark and identified by the Swedish chemist Jöns Jacob Berzelius, who named it after Thor, the Norse god of thunder. Thorium is more abundant in nature than Uranium. It is fertile rather than fissile, and can only be used as a fuel in conjunction with a fissile material such as recycled plutonium. Thorium fuels can breed ...
    • Infrared Thermography (IRT) of Conjugate Heat Transfer (CHT) Problem and Comparison with Multiphysics Model 

      Khawaja, Hassan; Moatamedi, Mojtaba; Alzahabi, Basem (Conference object; Konferansebidrag, 2018)
      This work presents a problem undergoing conjugate heat transfer (CHT). Conjugate heat transfer problems are common is domestic heating/cooling, industrial heat exchangers, cooling of electronics (e.g. PC fans). It is to be noted that in conjugate heat transfer problems, the convection part of the heat transfer is dominated. In the given study, a hypothetical case is built where a heat source (a ...
    • CFD modelling of pollutant transport 

      Madsen, Synne; Khawaja, Hassan (Conference object; Konferansebidrag, 2018)
      With the increase of the human activities in the Arctic, including land and sea, is resulting in higher release of pollutants to the environment. These pollutants can be categorised as gases released in the air such as carbon dioxide, sulphur dioxide, NOx, etc., and waste released in seas such as chemical toxins, microplastic, etc. This work presents a computational fluid dynamics (CFD) study ...
    • Influence of seasonal mesoscale and microscale meteorological conditions in Svalbard on results of monitoring of long-range transported pollution [poster] 

      Dekhtyareva, Alena; Holmén, Kim; Maturilli, Marion; Hermansen, Ove; Graversen, Rune (Conference object; Konferansebidrag, 2018)
      The Zeppelin Observatory is an atmospheric monitoring station located on the northwest coast of Spitzbergen island, in the Svalbard archipelago. The station provides background air composition, meteorological and climatological data for numerous research projects. The observatory is located on a mountain ridge in a region with complex topography that affects local atmospheric circulation ...
    • Fluid-Structure Interaction (FSI) of Aquaculture Net Cages [poster} 

      Myrli, Odd Einar; Khawaja, Hassan (Conference object; Konferansebidrag, 2018)
      The number of good sites in less exposed locations for aquaculture farming is limited. Trends are now that the fish cages are increasing in both width and depth as well as more weather-exposed locations, are taken into use. As the net cages continue to increase in size, so does the material costs. The design of the sea cages should be modified for safe and reliable use in remote offshore locations. ...