Now showing items 421-440 of 541

    • Spatiotemporal patterns of particulate matter (PM) and associations between PM and mortality in Shenzhen, China 

      Zhang, Fengying; Liu, Xiaojian; Zhou, Lei; Yu, Yong; Wang, Li; Lu, Jinmei; Wang, Wuyi; Krafft, Thomas (Peer reviewed; Journal article; Tidsskriftsartikkel, 2016-03-02)
      Background: Most studies on air pollution exposure and its associations with human health in China have focused on the heavily polluted industrial areas and/or mega-cities, and studies on cities with comparatively low air pollutant concentrations are still rare. Only a few studies have attempted to analyse particulate matter (PM) for the vibrant economic centre Shenzhen in the Pearl River Delta. ...
    • Human reliability assessment (HRA) in maintenance of production process: A case study 

      Aalipour, Mojgan; Ayele, Yonas Zewdu; Barabadi, Abbas (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-04-02)
      Human reliability makes a considerable contribution to the maintenance performance, safety, and cost-efficiency of any production process. To improve human reliability, the causes of human errors should be identified and the probability of human errors should be quantified. Analysis of human error is very case-specific; the context of the field should be taken into account. The aim of this study is ...
    • 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, ...
    • 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 ...
    • Wind Chill Effect in Cold Climate: Study of Wind Chill Effect Using Infrared Imaging 

      Ahmad, Tanveer (Research report; Forskningsrapport, 2016)
      Wind chill factor is explained as the cooling sensation due to the exposure of wind temperature environment. The wind chill factor depends on air temperature, wind velocity and humidity. Wind chill poses serious health risks. Various wind chill index models are given in literature. In order to understand the wind chill effect, it is important to understand the phenomenon of heat transfer. There are ...
    • 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 ...
    • Shock Tube. Detail overview of equipment and instruments in the shock tube experimental setup 

      Khawaja, Hassan Abbas; Kapaya, Juma; Moatamedi, Mojtaba (Book; Bok, 2015)
      The shock tube is a device in which a normal shock wave is produced by the interaction of fluids at significantly high-pressure difference. The shock tube is comprised of two sections known as driver and driven sections. These two sections are interacted with the high-speed valve or a bursting disc. When the interaction happens, a shock wave forms almost instantaneously and propagates into the driven ...
    • 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 ...
    • Thermal Properties of SK One Component Polyurethane using Experiments and Multiphysics Simulations 

      Ahmad, Tanveer; Xue, Hui; Khawaja, Hassan Abbas; Sun, Zhiheng; Linmei, Nie; Moatamedi, Mojtaba (Conference object; Konferansebidrag, 2016-12-08)
      This study proposes to determine the thermal conductivity of SK One Component Polyurethane (SKOCP) developed by China Institute of Water Resources & Hydropower Research Beijing IWHR-KHL Co. Ltd. SKOCP provides excellent proof of aging and chemical resistance of this material. It is non-toxic, acts as a good anti-seepage, offers anti-abrasion and good anti-freezing performance. In addition, it has ...
    • Study of Acoustics Properties of SK One Component Polyurethane and its Application in Arctic Marine Structures 

      Xue, Hui; Khawaja, Hassan Abbas; Moatamedi, Mojtaba; Sun, Zhiheng; Souli, Mhmed (Conference object; Konferansebidrag, 2016-12-08)
      Marine noise reduction tends to be challenging and requires a comprehensive engineering approach. The soundproofing materials for marine noise reduction are usually exposed to high temperatures, potential fluid or oil spills, engine maintenance and a high airflow environment. This work looks into the acoustic proofing properties of a non-toxic material ‘SK One Component Polyurethane’ developed by ...
    • Review of Peltier and Resistive Heating Elements through Infrared Imaging 

      Taimur, Madiha; Rashid, Taimur; Khawaja, Hassan Abbas (Conference object; Konferansebidrag, 2016-12-08)
      The study includes the review of the heating elements to develop the fundamental understanding. The heating elements to be investigated are Peltier and Resistive types. Both have different working principles and they are used in various industrial applications for cooling and heating purposes. The Infrared (IR) wavelength is emitted by each object at a temperature above absolute zero. IR light is ...
    • 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 ...
    • Ice Detection of Pure and Saline Ice Using Infrared Signature 

      Rashid, Taimur; Khawaja, Hassan Abbas; Edvardsen, Kåre (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-11-30)
      The paper shows the possible implementation of an Infrared (IR) ice detection technique. In respect of safety in marine operations, saline ice detection can be significant for automated de-icing systems. Experimentation is performed to observe and detect saline and pure ice samples. The discussed detection mechanism is unique and differs from passive IR detection by introducing the self-heating ...
    • Management of risks - a Paradox? 

      Nilsen, Aud Solveig; Leonhardsen, Mette (Conference object; Konferansebidrag, 2016-11-23)
    • Ice Detection Setup Using Infrared and Active Heating 

      Rashid, Taimur; Khawaja, Hassan Abbas; Edvardsen, Kåre (Conference object; Konferansebidrag, 2015)
      Considering the cold environment operations, ice accretion can occur at a rapid pace and can adversely affect the operations. In such scenario, ice detection is useful for the ice mitigation and removal upon the marine and offshore structures. Various techniques exist in the literature to detect the icing mainly utilizing its physical or electromagnetic properties. The parameters measured by these ...
    • Improving Mechanical Grip of Tyres on Snow and Icy Road Surfaces using Finite Element Method 

      Ludvigsen, Sondre; Khawaja, Hassan Abbas (Conference object; Konferansebidrag, 2016)
      Harsh winter conditions are known to be one of the most challenging environments for driving. Although the number of fatal accidents is higher during the summer compared to the winter in Norway (according to Norwegian Highways Authority), the total number of accidents is higher in the winter season. These accidents mainly happen due to loss traction on snowy or icy road surfaces. The loss of traction ...
    • Solution of Pure Scattering Radiation Transport Equation using Finite Difference Method 

      Khawaja, Hassan Abbas (Conference object; Konferansebidrag, 2016-12)
      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 processes. Equations of radiative transfer have application in a wide variety of subjects including optics, astrophysics, atmospheric science, and remote sensing. Analytic solutions to the radiative ...
    • 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 ...
    • Study of Materials’ Impact Properties for Arctic Marine Structures 

      Xue, Hui; Khawaja, Hassan Abbas; Moatamedi, Mojtaba; Kwon, Young; Sun, Zhiheng (Conference object; Konferansebidrag, 2016-12)
      It is well understood that sea ice is one of the biggest problems for the safety and reliability of ships and marine structures operating in the Arctic. Specially designed ships, also known as ‘icebreakers’, are usually used to clear ice to make way for merchant and cruise ships. Even then, the ship’s staff must be extremely careful with speed and steering. Heavy impacts of ice result in fatigue and ...
    • Study of Ice Adhesion Behavior of SK One Component Polyurethane 

      Xue, Hui; Khawaja, Hassan Abbas; Moatamedi, Mojtaba; Sun, Zhiheng (Conference object; Konferansebidrag, 2016-12)
      Ice adhesion causes many serious problems such as aircraft accidents, navigational issues on ships, and power loss on wind turbines. These challenges are mainly associated with the acute behavior of ice adhesion. The ice adheres when water seeps into the microscopic pores of the material substrate and freezes, thereby, forming an interlocking mechanism. Therefore, surface roughness has a significant ...