• 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. ...
    • 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 ...
    • IR Thermography of Steel Specimens undergoing Tensile Tests 

      Stange, Even; Khawaja, Hassan (Conference object, 2018-12-13)
      In this work, the IR thermography was used to study the steel specimens (DIN 50125 Standard) undergoing the tensile tests. The tensile tests were performed using GUNT® Hamburg Universal Material Tester. The tensile specimens were clamped, and the test force was generated using a hand-operated hydraulic system. A dial gauge measured the elongation of the specimens. Using the WP 300.20 system for data ...
    • 25-years Svalbard data record reveals change in long-range transport of sulphur agents to the warming Arctic 

      Dekhtyareva, Alena (Conference object, 2019)
      Current study investigates the 25-years seasonal trend in the concentration of SO2and non-sea salt SO42-and compares observed changes with the evolution in emission of sulphur agents in primary source regions of anthropogenic aerosols and alteration in characteristics of air masses transporting pollutants to Svalbard.
    • Multiphysics Study of Tensile Testing using Infrared thermography 

      Stange, Even; Andleeb, Zahra; Khawaja, Hassan; Moatamedi, Mojtaba (Journal article; Peer reviewed, 2019)
      In this work, the IR thermography was used to study the steel specimens (DIN 50125 Standard) undergoing the tensile tests. The tensile tests were performed using GUNT® Hamburg Universal Material Tester. The tensile specimens were clamped, and the test force was generated using a handoperated hydraulic system. A dial gauge measured the elongation of the specimens. Using the WP 300.20 system for data ...
    • Comparison of Explicit Method of Solution for CFD Euler Problems using MATLAB® and FORTRAN 77 

      Nordli, Anders Samuelsen; Khawaja, Hassan (Journal article; Peer reviewed, 2019)
      This work presents a comparison of an explicit method of solution for an inviscid compressible fluid mechanics problem using Euler equations for two-dimensional internal flows. The same algorithm was implemented in both FORTRAN 77 and MATLAB®. The algorithm includes Runge‒Kutta time marching scheme with smoothing. Both solvers were initialized in the same manner. In addition, it was ensured that ...
    • CFD modelling of pollutant transport from a docked marine vessel: Multiphysics 2019 [poster] 

      Madsen, Synne; Asier, Zubiaga; Khawaja, Hassan; Boiger, Gernot (Conference object; Konferansebidrag, 2019)
      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 ...
    • Fluid-Structure Interaction (FSI) Modelling of Aquaculture Net Cage 

      Myrli, Odd Einar; Khawaja, Hassan (Journal article; Peer reviewed, 2019)
      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. ...
    • Cold Technology Applications of Infrared Thermography (IRT) 

      Khawaja, Hassan (Conference object; Konferansebidrag, 2019)
    • Qualitative visualization of the development of stresses through infrared thermography 

      Stange, Even; Andleeb, Zahra; Khawaja, Hassan (Journal article; Peer reviewed, 2019)
      In this work, the IR thermography was used to study the steel specimens (DIN 50125 Standard) undergoing the tensile tests. The tensile tests were performed using GUNT® Hamburg Universal Material Tester. The tensile specimens were clamped, and the test force was applied using a hand-operated hydraulic system. A dial gauge measured the elongation of the specimens. Using the WP 300.20 system for data ...
    • Towards a Framework for Noctilucent Cloud Analysis 

      Sharma, Puneet; Dalin, Peter; Mann, Ingrid (Journal article; Tidsskriftartikkel; Peer reviewed, 2019)
      In this paper, we present a framework to study the spatial structure of noctilucent clouds formed by ice particles in the upper atmosphere at mid and high latitudes during summer. We studied noctilucent cloud activity in optical images taken from three different locations and under different atmospheric conditions. In order to identify and distinguish noctilucent cloud activity from other objects ...
    • Optimization of the Energy Consumption of a Carbon Capture and Sequestration Related Carbon Dioxide Compression Processes 

      Jackson, Steven; Brodal, Eivind (Journal article; Peer reviewed, 2019-04-26)
      It is likely that the future availability of energy from fossil fuels, such as natural gas, will be influenced by how efficiently the associated CO2 emissions can be mitigated using carbon capture and sequestration (CCS). In turn, understanding how CCS affects the efficient recovery of energy from fossil fuel reserves in different parts of the world requires data on how the performance of each part ...
    • Playing a video game is more than mere procrastination 

      Nordby, Kent; Løkken, Ronny Andre; Pfuhl, Gerit (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-13)
      <i>Background</i>: Procrastination is seen as a severe problem among young people, and many factors have been claimed to be associated with it, playing video games being one of them. One of the reasons why video games might be related to procrastination is their ability to offer instant gratification and feedback, while at the same time offer distractions from less tempting and rewarding tasks. ...
    • Multiphysics Impact Analysis of Carbon Fiber Reinforced Polymer (CFRP) Shell 

      Strand, Cathrine Høgmo; Andleeb, Zahra; Khawaja, Hassan; Moatamedi, Mojtaba (Journal article; Peer reviewed, 2019-07-30)
      With increasing popularity of Carbon Fiber Reinforced Polymer (CFRP) over time, the need for research in the field has increased dramatically. Many industries, i.e. aeronautical, automotive, and marine are opting to install carbon fiber in their structures to account for harsh environments like cold temperatures applications, but the research on the temperature exposure behavior of the materials are ...
    • A comparative study of CO2 heat pump performance for combined space and hot water heating 

      Brodal, Eivind; Jackson, Steven (Journal article; Peer reviewed, 2019-08-20)
      Heat pumps used for combined space and hot water heating are often used in modern energy-efficient buildings. Performance depends on both system design (exchanger sizes, compressor efficiency, etc.) and operating conditions (inlet water temperature, ratio between space and water heating, etc.). Designs using both CO2 and HFCs, such as R410A, are available, but the relative performance of these is ...
    • Performance and Design Study of Optimized LNG Mixed Fluid Cascade Processes 

      Brodal, Eivind; Jackson, Steven; Eiksund, Oddmar (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-26)
      Mixed Fluid Cascade (MFC) processes are often claimed to be one of the most efficient methods to liquefy natural gas. Their performance depends on both operating conditions such as ambient temperature, and system design parameters such as exchanger sizes. The performance of the standard MFC process can be further improved by modifying the design with additional equipment, such as liquid refrigerant ...
    • Optimization of the CO2 Liquefaction Process-Performance Study with Varying Ambient Temperature 

      Jackson, Steven; Brodal, Eivind (Journal article; Peer reviewed, 2019-10-22)
      In carbon capture utilization and storage (CCUS) projects, the transportation of CO2 by ship can be an attractive alternative to transportation using a pipeline, particularly when the distance between the source and usage or storage location is large. However, a challenge associated with this approach is that the energy consumption of the liquefaction process can be significant, which makes the ...
    • Optimization study of heat pumps using refrigerant blends – Ejector versus expansion valve systems 

      Brodal, Eivind; Eiksund, Oddmar (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-11-19)
      This article investigates tap water heating systems to highlight an ongoing debate. Some report that CO2-based transcritical heat pumps with an ejector have the best coefficient of performance (COP), while others report that blend-based refrigerant systems (without an ejector) are better. In the literature, however, these systems are only compared with conventional heat pump designs, and not against ...
    • Best Venue to Disseminate Multiphysics Research 

      Khawaja, Hassan (Conference object; Konferansebidrag, 2019-12)
      Multiphysics analysis has been developed over the recent past to better represent the behaviour of complex processes by the use of simultaneous modelling of a number of systems. This development is driven by the industrial need to further the understanding of real physical phenomena in order to develop and design safer and more efficient products which are environmentally friendly. Such analyses ...
    • Multiphysics study of infrared thermography (IRT) applications 

      Andleeb, Zahra; Ilyas, Muhammad; Khawaja, Hassan; Moatamedi, Mojtaba (Conference object; Konferansebidrag, 2019-12)
      Infrared thermography is the science of detecting infrared energy emitted from an object, converting it to apparent temperature, and producing images of that radiation, called thermograms. Infrared thermography means "beyond red temperature image". IR thermography being a remote non-contact/non-destructive means of testing is perfectly suitable for tests in extreme environments. Also, it is fast, ...