Browsing NTNU Open by Author "Hågenvik, Hans Olaf"

Now showing items 1-10 of 10

    • Analysis of active and passive metamaterials 

      Hågenvik, Hans Olaf (Doctoral theses at NTNU;2019:158, Doctoral thesis, 2019)
      Metamaterials are composite materials acting as effectively continuous media, which are capable of realizing entirely new phenomena such as negative refraction and transformation optics. This class of new materials may ...

    • Applying the ProdRisk- SHOP simulator for investment decisions 

      Mo, Birger; Hågenvik, Hans Olaf (HydroCen Report;19, Research report, 2020)
      The report describes status for the ProdRisk-SHOP simulator developed in HydroCen WP 3.3. Development of the simulator was motivated by the need for a tool that can calculate future production revenue for different investment ...

    • Boundary Conditions and Fresnel Equations for Weakly Spatially Dispersive Media 

      Jansen, Erlend Grøndahl (Master thesis, 2017)
      Although usually negligible for natural materials for optical and lower frequencies, spatial dispersion is a significant effect for metamaterials. In this thesis the electromagnetics of such media are investigated using a ...

    • Dielectric media considered as vacuum with sources 

      Hågenvik, Hans Olaf; Bløtekjær, Kjell; Skaar, Johannes (Journal article; Peer reviewed, 2017)
      Conventional textbook treatments on electromagnetic wave propagation consider the induced charge and current densities as “bound” and therefore absorb them into a refractive index. In principle, it must also be possible ...

    • FDTD simulations of novel gain media 

      Hågenvik, Hans Olaf (Master thesis, 2014)
      Fourier-Laplace analysis of gain media predicts the existence of novel types of media. In particular it predicts the existence of media refracting positively and negatively at the same time, so-called simultaneous refraction. ...

    • Four definitions of magnetic permeability for periodic metamaterials 

      Skaar, Johannes; Hågenvik, Hans Olaf; Dirdal, Christopher Andrew (Journal article; Peer reviewed, 2019)
      We state and compare four different definitions of magnetic permeability for periodic, artificial media, or metamaterials. The connections among them, and properties in general, are discussed in detail, including causality, ...

    • Higher order multipoles in metamaterial homogenization 

      Dirdal, Christopher Andrew; Hågenvik, Hans Olaf; Haave, Haakon Aamodt; Skaar, Johannes (Journal article; Peer reviewed, 2018)
      The higher order multipoles above the electric quadrupole are commonly neglected in metamaterial homogenization. We show that they nevertheless can be significant when the second-order spatial dispersive effects, such as ...

    • Homogenizing metamaterials by the plane wave expansion method 

      Haave, Haakon Aamot (Master thesis, 2017)
      Increasingly complex metamaterial structures has revitalized the interest in homogenization and effective medium theories, with the intention of finding better ways to model and understand their electromagnetic complexity. ...

    • Hydropower Scheduling with State-Dependent Discharge Constraints: An SDDP Approach 

      Helseth, Arild; Mo, Birger; Hågenvik, Hans Olaf; Schäffer, Linn Emelie (Peer reviewed; Journal article, 2022)
      Environmental constraints in hydropower systems serve to ensure sustainable use of water resources. Through accurate treatment in hydropower scheduling, one seeks to respect such constraints in the planning phase while ...

    • Magnetic permeability in Fresnel’s equation 

      Hågenvik, Hans Olaf; Skaar, Johannes (Journal article; Peer reviewed, 2019)
      Magnetic permeabilities derived for infinite, periodic media are used in the Fresnel equation to calculate the reflection from corresponding semi-infinite media. By comparison to finite-difference time-domain (FDTD) ...