Viser treff 61-80 av 163

    • Multiphysics based Analysis of Materials for Roads in Cold Regions to Prevent Ice Adhesion and Low-Temperature Crack Developments 

      Andleeb, Zahra; Khawaja, Hassan; Moatamedi, Mojtaba (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-12-12)
      Roads constitute a significant hazard if the effects of wintertime are not handled well. After a heavy snowfall, the most dangerous factor is a slippery surface due to ice adhesion with the asphalt pavement. The ice on roads increases the risk of road accidents and, upon melting, contributes to the formation of Low-Temperature Cracks (LTCs) and potholes. This research explores the physical ...
    • Experimental study on the exposure level of surgical staff to SARS-CoV-2 in operating rooms with mixing ventilation under negative pressure 

      Bi, Yang; Aganovic, Amar; Mathisen, Hans Martin; Cao, Guangyu (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-04-21)
      The purpose of this study was to reveal the exposure level of surgical staff to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from the patient's nose and wound during operations on COVID-19 patients. The tracer gas N<sub>2</sub>O is used to simulate SARS-CoV-2 from the patient's nose and wound. In this study, concentration levels of tracer gas were measured in the breathing zones of ...
    • Zonal modeling of air distribution impact on the long-range airborne transmission risk of SARS-CoV-2 

      Aganovic, Amar; Cao, Guangyu; Kurnitski, Jarek; Melikov, Arsen; Wargocki, Pawel (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-08-28)
      A widely used analytical model to quantitatively assess airborne infection risk is the Wells-Riley model which is limited to complete air mixing in a single zone. However, this assumption tends not to be feasible (or reality) for many situations. This study aimed to extend the Wells-Riley model so that the infection risk can be calculated in spaces where complete mixing is not present. Some more ...
    • Modeling the impact of indoor relative humidity on the infection risk of five respiratory airborne viruses 

      Aganovic, Amar; Bi, Yang; Cao, Guangyu; Kurnitski, Jarek; Wargocki, Pawel (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-07-07)
      With a modified version of the Wells-Riley model, we simulated the size distribution and dynamics of five airborne viruses (measles, influenza, SARS-CoV-2, human rhinovirus, and adenovirus) emitted from a speaking person in a typical residential setting over a relative humidity (RH) range of 20–80% and air temperature of 20–25 °C. Besides the size transformation of virus-containing droplets due to ...
    • Comparison of Deep Learning Models for the Classification of Noctilucent Cloud Images 

      Sapkota, Rajendra; Sharma, Puneet; Mann, Ingrid (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-05-10)
      Optically thin layers of tiny ice particles near the summer mesopause, known as noctilucent clouds, are of significant interest within the aeronomy and climate science communities. Groundbased optical cameras mounted at various locations in the arctic regions collect the dataset during favorable summer times. In this paper, first, we compare the performances of various deep learningbased image ...
    • Multiphysics Perspective of Microspray 

      Khawaja, Hassan (Conference object; Konferansebidrag, 2022-09-22)
    • Finite Element Analysis to determine the impact of Infill density on Mechanical Properties of 3D Printed Materials 

      Andleeb, Zahra; Khawaja, Hassan; Andersen, Kristian; Moatamedi, Mojtaba (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-09-29)
      Additive manufacturing (AM) is the process in which objects are created through the layer-by-layer deposition of material that is controlled by a computer. The infill is the internal structure of the 3D printed model. It determines the strength, weight, cost, time, and overall quality of the part. Ranging from simple lines to more complex geometric shapes, infill patterns can affect a part's ...
    • Measuring Cold Exposure 

      Khawaja, Hassan (Conference object; Konferansebidrag, 2022-08-22)
    • Cost-related analysis of implementing energy-efficient retrofit measures in the residential building sector of a middle-income country – A case study of Bosnia and Herzegovina 

      Kadrić, Džana; Aganovic, Amar; Martinović, Sandra; Delalić, Nijaz; Delalić-Gurda, Berina (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-15)
      This study presents an in-depth analysis of the cost structure when planning EE retrofit measures in the residential sector in Bosnia and Herzegovina. The analysis showed that implementing EE retrofit measures would result in substantial energy savings in single-family houses, however, the specific cost of implementing EE retrofit measures per resident for single-family houses is on average 2.8 ...
    • Statistical Optimization of Pyrolysis Process for Thermal Destruction of Plastic Waste Based on Temperature-Dependent Activation Energies and Pre-Exponential Factors 

      Alqarni, Ali; Un Nabi, Rao Adeel; Althobiani, Faisal; Naz, Yasin; Shukrullah, Shazia; Khawaja, Hassan; Bou-Rabee, Mohammed; Gommosani, Mohammad; Abdushkour, Hesham; Irfan, Muhammad; Mahnashi, Mater (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-08-09)
      The massive increase in disposable plastic globally can be addressed through effective recovery methods, and one of these methods is pyrolysis. R software may be used to statistically model the composition and yield of pyrolysis products, such as oil, gas, and waxes to deduce an effective pyrolysis mechanism. To date, no research reports have been documented employing the Arrhenius equation in R ...
    • HAVFORSKNINGSINSITUTTETS RÅDGIVNING FOR MENNESKESKAPT STØY I HAVET - Kunnskapsgrunnlag, vurderinger og råd for 2022 

      Sivle, Lise Doksæter; Forland, Tonje Nesse; de Jong, Karen; Pedersen, Geir; Zhang, Guosong; Kutti, Tina; McQueen, Kate; Wehde, Henning; Grimsbø, Endre (Research report; Forskningsrapport, 2022)
      Havforskningsinstituttet gir råd for alle operasjoner til havs som involverer bruk av lydkilder som kan påvirke marine økosystemer. Dette inkluderer vitenskapelige undersøkelser, utbygging og sprenging i sjø, seismiske og elektromagnetiske undersøkelser i forbindelse med petroleumsvirksomhet og utbygging og drift av vindkraftanlegg til havs. Denne rapporten er en sammenstilling av tilgjengelig ...
    • Why collaboration is necessary for research in academia? 

      Khawaja, Hassan (Conference object; Konferansebidrag, 2022-05-23)
    • Computational Fluid Dynamics - A Stepping-Stone of MULTIPHYSICS 

      Khawaja, Hassan (Conference object; Konferansebidrag, 2022-07-07)
      Fluids have been around us for as long as we know; they have enabled us to cross the oceans, ride the winds, shorten distances, and much more. Computational Fluid Dynamics (CFD) has extended our understanding of fluids. Even to this day, the analytical solution of fundamental equations of fluid mechanics remains a million-dollar award problem (Clay Mathematics Institute). As engineers, we’ll leave ...
    • Determining Thermal Properties of Polyurethane by Solving the Heat Equation and IR Imaging 

      Eidesen, Hans-Kristian; Andleeb, Zahra; Khawaja, Hassan; Moatamedi, Mojtaba (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-06-27)
      All materials have different and unique thermal properties that determine how the temperature changes when a material is subjected to a temperature difference. This study was intended to investigate the thermal properties of a polymer called Polyurethane, focusing on anti-seepage and anti-abrasion polyurethane. The thermal conductivity and heat transfer coefficient of cold polyurethane specimens ...
    • Dihedral Group D4—A New Feature Extraction Algorithm 

      Sharma, Puneet (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-04-04)
      In this paper, we propose a new feature descriptor for images that is based on the dihedral group D<sub>4</sub>, the symmetry group of the square. The group action of the D<sub>4</sub> elements on a square image region is used to create a vector space that forms the basis for the feature vector. For the evaluation, we employed the Error-Correcting Output Coding (ECOC) algorithm and tested our model ...
    • Multiphysics based Modal and Harmonic Analysis of Axial Turbines 

      Khawaja, Hassan; Andleeb, Zahra; Moatamedi, Mojtaba (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-15)
      The presented work discusses the vibration behavior of an axial turbine, analyzed using the finite element method (FEM) using commercial software ANSYS®. The turbine was modeled as a 2-D plate type of structure discretized with 4-noded shell 63 elements to save computational time. Constraints were applied keeping in view the actual operating conditions. The turbine was modeled with more than one FE ...
    • A systematic review of operating room ventilation 

      Sadrizadeh, Sasan; Aganovic, Amar; Bogdan, Anna; Wang, Cong; Afshari, Alireza; Hartmann, Anne; Croitoru, Cristiana; Khan, Amirul; Kriegel, Martin; Lind, Merethe; Liu, Zhijian; Melikov, Arsen; Mo, Jinhan; Rotheudt, Hansjörg; Yao, Runming; Zhang, Yixian; Abouali, Omid; Langvatn, Håkon; Sköldenberg, Olof; Cao, Guangyu (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-05-18)
      Ventilation systems are the primary way of eliminating airborne pathogenic particles in an operating room (OR). However, such systems can be complex due to factors such as different surgical instruments, diverse room sizes, various staff counts, types of clothing used, different surgical types and duration, medications, and patient conditions. OR ventilation should provide a thermally comfortable ...
    • Thermoelastic Investigation of Carbon-Fiber Reinforced Composites using Drop Weight Impact Test 

      Andleeb, Zahra; Malik, Sohail; Khawaja, Hassan; Nordli, Anders Samuelsen; Antonsen, Ståle; Hussain, Ghulam; Moatamedi, Mojtaba (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-12-28)
      Composite materials are becoming more popular in technological applications due to the significant weight savings and strength these materials offer compared to metallic materials. In many of these practical situations, the structures suffer from drop impact loads. Materials and structures significantly change their behavior when submitted to impact loading conditions as compared to quasi-static ...
    • Multiphysics Analysis of Ice-Polyurethane Adhesion under Flexural Loading using FEM Analysis 

      Eidesen, Hans-Kristian; Andleeb, Zahra; Khawaja, Hassan; Moatamedi, Mojtaba (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-26)
      This paper presents the Finite Element Analysis (FEA) Multiphysics technique, applied to study the strength of ice adhesion between the surface of polyurethane and ice. The theoretical study of this work is based on the Euler-Bernoulli beam theory that is used to solve a four-point bending problem to give the correlation of displacements with load and longitudinal stresses. The physical samples were ...
    • Windtech – A Sensory Device for ‘Cold’ Sensation Measurements 

      Leyli, Amir Nadem; Khawaja, Hassan; Antonsen, Ståle; Swart, Daniel Kristoffer (Journal article; Tidsskriftartikkel, 2021-12-21)
      Windtech device is a novel tool for measuring the sensation of the ‘cold’. Cold poses numerous challenges for industrial operations, human survival, and living convenience. The impact of the cold is not possible to be quantified just based on temperatures; however other factors such as wind speed, humidity, irradiance have to be taken into consideration. Efforts have been made to develop combined ...