Now showing items 1-20 of 96

    • Active Infrared Observation for Ice Detection in Anti/De-Icing Systems for Marine Applications in Arctic Region 

      Rashid, Taimur; Khawaja, Hassan Abbas (Conference object; Konferansebidrag, 2016-12-08)
      The number of shipping operations is on the rise in the Arctic region. As a result of these increased activities, significant challenges are being encountered with respect to safety and reliability. One of the challenges is an accretion of ice. The icing on ships and offshore structures is caused by atmospheric sources and sea spray. The sea spray is the main source of icing and is generated by the ...
    • Ambient air quality and the effects of air pollutants on otolaryngology in Beijing 

      Zhang, Fengying; Xu, Jin; Zhang, Ziying; Meng, Haiying; Wang, Li; Lu, Jinmei; Wang, Wuyi; Kraft, Thomas (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-07-09)
      Abstract To investigate temporal patterns, pollution concentrations and the health effects of air pollutants in Beijing we carried out time-series analyses on daily concentrations of ambient air pollutants and daily numbers of outpatient visits for otolaryngology over 2 years (2011– 2012) to identify possible health effects of air pollutants. The results showed that PM10 was the major air ...
    • Analytical and Case Studies of a Sandwich Structure using Euler-Bernoulli Beam Equation 

      Xue, Hui; Khawaja, Hassan Abbas (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-11)
      This paper presents analytical and case studies of sandwich structures. In this study, the Euler-Bernoulli beam equation is solved analytically for a four-point bending problem. Appropriate initial and boundary conditions are specified to enclose the problem. In addition, the balance coefficient is calculated and the Rule of Mixtures is applied. The focus of this study is to determine the effective ...
    • Analytical Study of Sandwich Structures using Euler–Bernoulli Beam Equation 

      Xue, Hui; Khawaja, Hassan Abbas (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-01)
      This paper presents an analytical study of sandwich structures. In this study, the Euler–Bernoulli beam equation is solved analytically for a four-point bending problem. Appropriate initial and boundary conditions are specified to enclose the problem. In addition, the balance coefficient is calculated and the Rule of Mixtures is applied. The focus of this study is to determine the effective material ...
    • Anomaly Detection for Environmental Data Using Machine Learning Regression 

      Yuan, Fuqing; Lu, Jinmei (Journal article; Peer reviewed, 2018)
      Environmental data exhibits as huge amount and complex dependency. Utilizing these data to detect anomaly is beneficial to the disaster prevention. Big data approach using the machine learning method has the advantage not requiring the geophysical and geochemical knowledge to detect anomaly. This paper using the popular support vector regression (SVR ) to model the correlation between factors. ...
    • Applicability Extent of 2-D Heat Equation for Numerical Analysis of a Multiphysics Problem 

      Khawaja, Hassan Abbas (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-01)
      This work focuses on thermal problems, solvable using the heat equation. The fundamental question being answered here is: what are the limits of the dimensions that will allow a 3-D thermal problem to be accurately modelled using a 2-D Heat Equation? The presented work solves 2-D and 3-D heat equations using the Finite Difference Method, also known as the Forward-Time Central-Space (FTCS) method, ...
    • Application of a 2-D approximation technique for solving stress analyses problem in FEM 

      Khawaja, Hassan Abbas (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-24)
    • Availability assessment of oil and gas processing plants operating under dynamic Arctic weather conditions 

      Naseri, Masoud; Baraldi, Piero; Compare, Michele; Zio, Enrico (Peer reviewed, 2016-03-19)
      We consider the assessment of the availability of oil and gas processing facilities operating under Arctic conditions. The novelty of the work lies in modelling the time-dependent effects of environmental conditions on the components failure and repair rates. This is done by introducing weather-dependent multiplicative factors, which can be estimated by expert judgements given the scarce data available ...
    • Baseline levels of oxidative stress biomarkers in species from a subtropical estuarine system (Paranaguá Bay, southern Brazil) 

      Sardi Sulvaran, Adriana Eva; Renaud, Paul; Lana, Paulo Da Cunha; Camus, Lionel (Peer reviewed, 2016-08-10)
      Offshore petroleum exploration has increased the risks of oil spills in coastal tropical and subtropical habitats. Monitoring tools are needed to assess and protect environmental health. We determined baseline values of antioxidant biomarkers (CAT, SOD, GPx, GST, MDA) for five ecologically relevant species in a subtropical system in southern Brazil. Regional baseline levels are compared with literature ...
    • Bioremediation Treatment of Hydrocarbon-Contaminated Arctic Soils: Influencing Parameters 

      Naseri, Masoud; Barabadi, Abbas; Barabady, Javad (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)
    • CFD modelling of pressure and shear rate in torsionally vibrating structures using ANSYS CFX and COMSOL Multiphysics 

      Brunner, Daniel; Khawaja, Hassan; Moatamedi, Mojtaba; Boiger, Gernot (Journal article; Tidsskriftartikkel; Peer reviewed, 2018)
      This paper discusses numerical methodologies to simulate micro vibrations on a nontrivial torsionally oscillating structure. The torsional structure is the tip of a viscosity-density sensor using micro vibrations to measure the fluid properties. A 2D transient simulation of the fluid domain surrounding the tip of the sensor has been conducted in ANSYS CFX and COMSOL Multiphysics software. ANSYS CFX ...
    • Coastal Environment, Technology and Innovation in the Arctic (CETIA) 2011-14. 

      Sydnes, Are K. (Conference object; Konferansebidrag, 2012)
    • Column leaching heavy metal from tailings following simulated climate change in the Arctic area of Norway 

      Fu, Shuai; Lu, Jinmei (Journal article; Tidsskriftartikkel; Peer reviewed, 2018)
      This study aimed to assess how the current climate change perspective, with various air temperature (4°C, 10°C, 14°C and 18°C) affected metal releasing from tailings. Heavy metals pollution from tailings leaching are of increasing concern. Column leaching experiment was conducted for 15 weeks to a series of tailings with 20 mm/week water leaching four temperature situations. Leachate chemical physics ...
    • Column leaching test on oxidized and non-oxidized tailings in northern Norway 

      Fu, Shuai; Lu, Jinmei (Journal article; Peer reviewed, 2018)
      Column leaching test was applied for oxide and non-oxide tailings in the Arctic area. Physico-chemical parameters (pH, pe: potential ecolotric, conductivity, TDS: Total dissolved solids, SO4 2−, salinity, Ni, Co, Zn and Mn) were measured to identified the effect of oxidized degree on heavy metals leaching from tailings. Results showed that oxidized tailings contained higher levels of Co and Ni, and ...
    • Computational Fluid Dynamic Analysis of the Tesla Turbine 

      Strand, Cathrine; Eidesen, Hans-Kristian; Khawaja, Hassan Abbas (Conference object; Konferansebidrag, 2016-12-08)
      Serbian-born inventor Nikola Tesla invented the Tesla turbine and patented it in 1913. The Tesla turbine is unique in the sense that it does not have any blades, also referred to as “bladeless turbine”. The working was based on the establishment of the fluid boundary layer. The original Tesla turbine consisted of multiple smooth discs. With the passage of flow, a boundary layer establishes and skin ...
    • Computational Fluid Dynamic Analysis of the Tesla Valve 

      Eidesen, Hans-Kristian; Khawaja, Hassan Abbas (Conference object; Konferansebidrag, 2016-12-08)
      Serbian-born inventor Nikola Tesla invented the Tesla valve (Tesla's Valvular Conduit) and patented it in 1919. The Tesla valve is unique in the sense that it does not have any moving parts, but it can work as a one-way valve. Nikola Tesla invented this unit without advanced mathematical models, nor with the help of modern computing power. The original Tesla valve consisted of a set of cavities and ...
    • Conceptual design of high speed supersonic aircraft: A brief review on SR-71 (Blackbird) aircraft 

      Xue, Hui; Khawaja, Hassan Abbas; Moatamedi, Mojtaba (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)
    • Critical infrastructure resilience: A Nordic model in the making? 

      Pursiainen, Christer Henrik (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-08-19)
      In recent years, there has been a shift in emphasis from critical infrastructure protection to that of resilience. This development reflects the acknowledgment that complete protection can never be guaranteed, and that achieving the desired level of protection is not cost-effective as a rule in relation to the actual threats. This article reviews the responses of four of the five Nordic countries ...
    • Design of a Snow Sledge using Multiphysics Analysis 

      Xue, Hui; Khawaja, Hassan Abbas; Mauseth, Guy Beeri (Conference object; Konferansebidrag, 2014)
    • Determination of Thermal Properties of Fresh Water and Sea Water Ice using Multiphysics Analysis 

      Rashid, Taimur; Khawaja, Hassan Abbas; Edvardsen, Kåre (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-08-29)
      This paper presents a methodology to determine the thermal conductivity of ice using multiphysics analysis. This methodology used a combination of both experimentation and numerical simulation. In the experimental work, an ice block is observed using an infrared camera. The results reveal the variation in temperature over the surface. These results are dependent on two primary heat transfer parameters, ...