Recent additions

  • 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 ...
  • 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 ...
  • 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 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 ...
  • 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 ...
  • 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. ...
  • 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; 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. ...
  • 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; 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 ...
  • 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)

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