Viser treff 141-160 av 1010

    • Homogenization of Non-Autonomous Operators of Convolution Type in Periodic Media<sup>∗</sup> 

      Piatnitski, Andrei; Zhizhina, Elena (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-23)
      The paper deals with periodic homogenization problem for a para\-bo\-lic equation whose elliptic part is a convolution type operator with rapidly oscillating coefficients. It is assumed that the coefficients are rapidly oscillating periodic functions both in spatial and temporal variables and that the scaling is diffusive that is the scaling factor of the temporal variable is equal to the square of ...
    • Assessing shielding material Performance: Benchmarking of Monte Carlo codes for oil shale and Basalt-Boron fiber concretes Hando Tohver a,* , Andrius Slavickas b , Maryna Holiuk c , Andrejs Krasn¸ i 

      Tohver, Hando; Motlep, Riho; Krasnikovs, Andrejs; Novakova, Iveta; Gulik, Volodymyr; Slavickas, Andrius; Holiuk, Maryna; Vaišnoras, Mindaugas (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-12-12)
      Cement-based concretes are commonly used for managing radioactive waste due to their low cost and radiation shielding properties. However, the potential of using oil shale ash as an additive in waste packaging material has been overlooked. This study focuses on benchmarking and developing a Monte Carlo based modeling methodology using multiple transport codes (MCNP, SERPENT, SCALE, OpenMC, and ...
    • Well-posedness of heat and wave equations generated by Rubin’s q-difference operator in Sobolev spaces 

      Shaimardan, Serikbol; Persson, Lars-Erik; Tokmagambetov, Niyaz (Journal article; Tidsskriftartikkel; Peer reviewed, 2023)
      In this paper, we investigate difference-differential operators of parabolic and hyperbolic types. Namely, we considern on-homogenous heat and wave equations for Rubin’s difference operator. Wellposedness results are obtained in appropriate Sobolev type spaces. In particular, we prove that the heat and wave equations generated by Rubin’s difference operator have unique solutions. We even show that ...
    • Line Balancing Problem with Multi-Manned Workstations and Resource Constraints: The Case of Electronics Waste Disassembly 

      Yin-Yann, Chen; Pourhejazy, Pourya; Liu, Tzu-Ning (Journal article; Tidsskriftartikkel, 2023-12-14)
      The increasing public awareness of environmental protection and the scarcity of rare earth elements have made closed-loop supply chains a necessity in many sectors. In particular, recycling components and parts from end-of-life consumer electronics have drawn the attention of both academics and practitioners. Disassembly line balancing improves the resource efficiency of recycling operations. This ...
    • A Qualitative Comparison of ANSYS and OpenFOAM results for Carbon dioxide Plume Transport 

      Madsen, Synne; Andleeb, Zahra; Khawaja, Hassan Abbas; Boiger, Gernot; Moatamedi, Mojtaba (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-12-02)
      This research presents Computational Fluid Dynamics (CFD) simulations in ANSYS® illustrating emissions of to the air. The CFD simulations is employed to study plume transport in urban environment, i.e., Breivika port in the city of Tromsø. The case study presents a two-phase model considering specific wind strength and direction in the city of Tromsø. Geographical coordinates, temperature, and wind ...
    • Refinements of Bennett type inequalities 

      Oguntuase, James A; Persson, Lars-Erik; Adeleke, EO (Journal article; Tidsskriftartikkel; Peer reviewed, 2023)
      In this paper we discuss, complement and improve some Bennett type inequalities. In particular,we prove a new refinement of a Bennett type inequality using super quadracity argument.
    • Some new multidimensional Cochran-Lee and Hardy type inequalities 

      Yimer, Markos Fisseha; Persson, Lars-Erik; Ayele, Tsegaye Gedif (Journal article; Tidsskriftartikkel; Peer reviewed, 2023)
      A multidimensional Cochran-Lee operator is introduced and investigated in the frame of Hardy-type inequalities with parameters 0<p⩽q<∞. Moreover, for the case p=q and power weights even the sharp constant is derived, thus generalizing the original Cochran-Lee inequality to a multidimensional setting. As applications both several known but also new inequalities are pointed out.
    • Some new restricted maximal operators of Fejér means of Walsh–Fourier series 

      Baramidze, Davit; Baramidze, Lasha; Persson, Lars-Erik; Tephnadze, George (Journal article; Tidsskriftartikkel, 2023-09-12)
      In this paper, we derive the maximal subspace of natural numbers { <i>n<sub>k</sub></i> : <i>k</i> &#8805; 0 }, such that the restricted maximal operator, defined by sup<sub><i>k</i>&#8712;&#8469;</sub> | &sigma;<i><sub>n<sub>k</sub></sub>F</i> | on this subspace of Fejér means of Walsh–Fourier series is bounded from the martingale Hardy space <i>H</i><sub>1/2</sub> to the Lebesgue space ...
    • Multiphysics: Paving the Future of Engineering 

      Khawaja, Hassan Abbas (Conference object; Konferansebidrag, 2023-12)
      The landscape of engineering is undergoing a transformative evolution, and at its forefront is the paradigm of multiphysics—a revolutionary approach that integrates and simulates multiple physical phenomena within a single computational framework. This abstract explores the significance of multiphysics in shaping the future of engineering and its profound impact on innovation, efficiency, and ...
    • Investigating RANS Turbulence Models for Predicting Airflow Dispersion in Enclosed Environments: Numerical Simulation and Experimental Validation 

      Owolabi, Jibola Obafemi; Dhar, Sushmit; Muhammed, Manaf; Khawaja, Hassan Abbas; Aganovic, Amar; Virk, Muhammad Shakeel (Conference object; Konferansebidrag, 2023-12)
      The dispersion of respiratory aerosol particles in enclosed environments poses a significant challenge to understanding the transmission of airborne infectious diseases, mainly due to the influence of turbulence on the propagation of aerosol particles. Turbulence, with its complex and chaotic nature, is a prevailing phenomenon in a fluid flow. Four widely used Reynolds-Averaged Navier-Stokes (RANS) ...
    • Multiphysics Study of Thermal Properties of Neoprene and Natural Rubber for Wetsuit Applications 

      Busvold, Mads; Khawaja, Hassan Abbas (Conference object; Konferansebidrag, 2023-12)
      Surfers daring the harshest waves, including the frigid arctic waters of Norway, rely on wetsuits for extended cold-water sessions. Understanding the thermal behavior of wetsuit materials is crucial for enhancing surfers' comfort and safety. In this study, we investigate the thermal properties of neoprene and natural rubber, the primary materials used in wetsuit construction, with a focus on conductive ...
    • The International Conference of Multiphysics 2024 

      Khawaja, Hassan Abbas (Conference object; Konferansebidrag, 2023-12)
      The objective of The International Conference of Multiphysics is to share and explore findings on mathematical advances, numerical modelling and experimental validation of theoretical and practical systems in a wide range of applications. The scope of the conference is to address the latest advances in theoretical developments, numerical modelling and industrial application which will promote ...
    • The International Journal of Multiphysics (2023) 

      Khawaja, Hassan Abbas (Conference object; Konferansebidrag, 2023-12)
      The International Journal of Multiphysics publishes peer-reviewed original research articles, review papers and communications in the broadly defined field of Multiphysics. The emphasis of this journal is on the theoretical development, numerical modelling and experimental investigations that underpin Multiphysics studies. The scope of the journal is to address the latest advances in theoretical ...
    • Investigating Ice Nucleation and Heat Transfer Dynamics in Supercooled Liquid Water Using Thermography 

      Khawaja, Hassan Abbas; Keshavarzi, Samaneh; Muhammed, Manaf; Yousuf, Adeel; Virk, Muhammad Shakeel; Harvey, Derek; Momen, Gelareh (Conference object; Konferansebidrag, 2023-12)
      This study delves into the intricate interplay of thermography, ice nucleation, and heat transfer during the phase change from supercooled liquid water to crystallized ice. The phenomena of ice nucleation and its subsequent growth have paramount importance in various fields, including cold climate engineering, atmospheric science, cryopreservation, and refrigeration systems. Our research aims to ...
    • A CFD Study of Preventing Snow Accumulations on Roofs using Airflows 

      Sjøveian, Andreas; Andleeb, Zahra; Khawaja, Hassan Abbas; Moatamedi, Mojtaba (Conference object; Konferansebidrag, 2023-12)
      Today, there is an abundance of roof designs for buildings, each possessing distinct characteristics when subjected to snowy and cold conditions. Snow buildup on roofs poses various risks, including structural damage and personal injuries. Snow loads can lead to severe building damage or even collapse. The presence of intricate roof shapes and valleys exacerbates the potential harm caused by snow. ...
    • Current source Inverter for fuel cell Application 

      Hamad, Zainab (Master thesis; Mastergradsoppgave, 2023-08-14)
      In recent years, the scientific renaissance has turned towards alternative energy. Scientific research and dissertations of all degrees, doctoral, Master, and even bachelor's degrees include. Green energy and alternative solution to protect the environment from increasing pollution. Different inverters have been used to increase the potential for power resulting from devices that do not have the ...
    • Investigation of ballast water conditions using remote sensing. Suspended Particulate Matter Characterization in Emden Sea Port 

      Taña i Viñeta, Pau (Master thesis; Mastergradsoppgave, 2023-05-22)
      This thesis investigates the use of remote sensing techniques to study the conditions of ballast water in the northwestern port of Emden, Germany. Sentinel-2 data of the seaport has been collected and used in order to retrieve the suspended particulate matter (SPM), evaluating its distribution and checking for any time or spatial periodicity over the past 5 years. The aim of the study is to provide ...
    • Optimization of industrial power grid of Narvik 

      Khan, Md Nafis Ul Hoq (Master thesis; Mastergradsoppgave, 2023-05-22)
      The objective of this study is to review a comprehensive plan for optimization framework for the industrial power grid. Few factors considered such as power generation, transmission, distribution, energy storage solutions, cost development. The aim targets an overview of planning and optimization for a hydrogen production plant in Narvik region. It will improve the overall efficiency, stability, ...
    • Energy Conversion and Control of Hydrogen Fuel Cell Based Electric Transport 

      Subedi, Jhalak Nath (Master thesis; Mastergradsoppgave, 2023-05-22)
      The research investigates the effective utilization of hydrogen fuel cells in electric transport applications, addressing the challenges associated with power generation, energy storage, and control. By implementing the MPPT Perturb and Observe (P&O) technique, the thesis aims to optimize the power output of the fuel cell system, ensuring maximum efficiency and performance. To enhance the overall ...
    • A Study of Dynamic Wind Effects on High-Rise Building with Tube-in Tube System in Norway 

      Pham, Son Hoang; Abujayyab, Abdelrahman Bassam (Master thesis; Mastergradsoppgave, 2023-05-15)
      According to a new high-rise strategy, Norway is expected to have more tall buildings. However, due to a lack of knowledge and experience in high-rise technology, the country has not built many such structures yet. To address this issue, a study was conducted to analyze the response of a high-rise building to dynamic wind load, considering the low seismic activity in the region. The study is divided ...