Viser treff 101-120 av 169

    • 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 ...
    • Conjugate Heat Transfer Model Based on SIMPLE and Coupled Energy and Heat Equations 

      Leyli, Amir Nadem; Andleeb, Zahra; Khawaja, Hassan; Messahel, Ramzi; Kanna, Rajesh; Moatamedi, Mojtaba (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-01-28)
      In this study, a numerical weak coupling strategy for the modeling of a conjugate heat transfer phenomenon is considered. Where the incompressible Navier-Stokes equations are solved using the Semi-Implicit Method for Pressure Linked Equations (SIMPLE) as a first step, and then the heat conduction equation for solid is solved in a second step considering the convective velocity field resulting from ...
    • 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. ...
    • Multiphysics Analysis of Contact Pressure Profile of Airless tires as compared to Conventional Tires 

      Ludvigsen, Søndre; Andleeb, Zahra; Khawaja, Hassan; Moatamedi, Mojtaba; Alzahabi, Basem (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-15)
      The harsh climate of the Arctic has always posed significant challenges to car drivers. The severe loss in traction due to snow and icing on the roads has led to an increased risk of collisions. The purpose of this work is to replace the conventional air-filled tire with a non-pneumatic tire to improve the grip in the Arctic conditions. The grip obtained for tires is determined by the weight of the ...
    • 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 ...
    • 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 ...
    • 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 ...
    • Detection, Identification and Size distribution of micro-plastic particles 

      Varughese, Bindu Sara; Edvardsen, Kåre (Conference object; Konferansebidrag, 2017)
      Pollution by micro-plastic in ecosystems is one of the major problems we are facing now, especially in marine environment. Many studies are going on the detection of different micro substances that pollute our environment. Micro-plastics are among the more frequent pollutants of the sort in aquatic ecosystems. There have been some studies earlier on methodologies to detect and identify micro-plastic ...
    • 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 ...
    • 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.
    • Cold Technology Applications of Infrared Thermography (IRT) 

      Khawaja, Hassan (Conference object; Konferansebidrag, 2019)
    • Multiphysics Study of Infrared Thermography (IRT) Applications 

      Andleeb, Zahra; Malik, Sohail; Hussain, Gulam; Khawaja, Hassan; Roemer, Jakub; Boiger, Gernot; Moatamedi, Mojtaba (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-09-19)
      The paper reviews thermographic and vibrothermography applications such as cold climate operations, determine the temperature profile of steel samples under tensile testing and perform composites Non-Destructive Testing (NDT). This review paper discusses studies, where IR thermography has been used effectively in research and development projects at the UiT The Arctic University of Norway and AGH ...
    • Modelling and Simulation of the HDPE Pyrolysis Process 

      Eidesen, Hans-Kristian; Khawaja, Hassan; Jackson, Steven (Conference object; Konferansebidrag, 2017)
      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. This work aims to describe some of the primary driving reactions ...
    • Fluorescent marking of roads in high-north 

      Khawaja, Hassan; Varughese, Bindu Sara; Edvardsen, Kåre (Conference object; Konferansebidrag, 2017)
      The project objective is to investigate into luminescent coating materials that can be used in marking the roads in high-north. The idea of the project is not entirely new, and efforts have been worldwide to find an energy efficient solution to the street lights. Earlier work conducted in the Netherlands showed quite promising results. However, the challenges include weatherproofing the coat such ...
    • Detection of Cracks and Potholes in Roads using Infrared Thermography 

      Tanveer, Ahmad; Khawaja, Hassan (Conference object, 2017)
      Many remote sensing techniques can be used to identify the cracks/voids on the road surfaces. The given research focuses on applying infrared thermography (IRT). IRT technology can detect features based on the different thermal signature. This method would be an excellent tool for detecting the fracture/cracks. It is because of the reason that the naturally occurring water (rain, snowmelt, etc.) ...
    • A flexible autonomous robotic observatory infrastructure for bentho-pelagic monitoring 

      Aguzzi, Jacopo; Albiez, Jan; Flögel, Sascha; Godø, Olav Rune; Grimsbø, Endre; Marini, Simone; Pfannkuche, Olaf; Rodriguez, Erik; Thomsen, Laurenz; Torkelsen, Terje; Valencia, Javier; López-vázquez, Vanesa; Wehde, Henning; Zhang, Guosong (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-13)
      This paper presents the technological developments and the policy contexts for the project “Autonomous Robotic Sea-Floor Infrastructure for Bentho-Pelagic Monitoring” (ARIM). The development is based on the national experience with robotic component technologies that are combined and merged into a new product for autonomous and integrated ecological deep-sea monitoring. Traditional monitoring is ...
    • Multiphysics Analysis of CFRP Charpy Tests by varying Temperatures 

      Andleeb, Zahra; Strand, Cathrine Høgmo; Malik, Sohail; Hussain, G; Khawaja, Hassan; Boiger, Gernot; Moatamedi, Mojtaba (Journal article; Tidsskriftartikkel; Peer reviewed, 2020)
      Carbon Fiber Reinforced Polymer (CFRP) composites have emerged as a major class of structural materials that have a significant potential use as a substitute for metals in aerospace, marine, automotive, and architecture due to their higher-strength-to-weight-ratio. CFRP is well suited for various applications, but their mechanical properties such as ‘low-velocity impact resistance’ are not well ...