Now showing items 1-20 of 697

    • The influence of CaC03 addition and clay binder selection on electricity efficiency and other operational aspects during pre-reduction of pelletised chromite 

      Beukes, J.P.; Neizel, B.W.; Kleynhans, E.L.J.; Van Zyl, P.G.; Dawson, N.F. (2013)
      Production of ferrochrome is an energy intensive process. Pelletised chromite pre-reduction is most likely the ferrochrome production process with the lowest specific electricity consumption, i.e. MWh/t ferrochrome ...
    • Observations of the blazar PKS 2023-07 in flaring state with H.E.S.S. And Fermi-LAT in 2016-2017 and constraints on an intrinsic cut-off 

      Emery, G.; Zacharias, M.; Jankowsky, F.; Lenain, J.-P.; Marais, J.P. (Sissa Medialab, 2019)
      PKS 2023−07 is a flat spectrum radio quasar located at a redshift z = 1.388, farther than any source currently detected at very high energies (E > 100 GeV). At such energies, absorption by the extragalactic background ...
    • Calorimetric neutrino expectations from bright blazar flares 

      Kreter, Michael; Böttcher, Markus; Kadler, Matthias; Krauss, Felicia; Buson, Sara (Sissa Medialab, 2019)
      Blazar jets are extreme environments, in which relativistic proton interactions with an ultraviolet photon field could give rise to photopion production. High-confidence associations of individual high-energy neutrinos ...
    • Search for High-redshift Blazars with Fermi/LAT 

      Kreter, Michael; Böttcher, Markus; Kadler, Matthias; Krauss, Felicia; Buson, Sara (Sissa Medialab, 2019)
      High-redshift blazars (z ≥ 2.5) are one of the most powerful classes of γ-ray sources in the Universe. These objects possess the highest jet powers and luminosities and have black-hole masses often in excess of 109 solar ...
    • Applying Monte Carlo methods to model multi-wavelength emission of RMHD jet simulations. 

      Van der Westhuizen, I.P.; Böttcher, M.; Van Soelen, B.; Meintjes, P.J. (Sissa Medialab, 2019)
      Relativistic jets associated with active galactic nuclei (AGN) produce radiation over a large range of the electromagnetic spectrum. While relativistic magneto-hydrodynamic (RMHD) simulations have become a powerful tool ...
    • GRB observations with H.E.S.S. 

      Piel, Quentin; Böttcher, Markus; Arcaro, Cornelia; Ashkar, Halim; Bissaldi, Elisabetta (Sissa Medialab, 2019)
      Fermi-LAT observations have proven that GeV γ-ray emission is a relatively common feature for many Gamma Ray Bursts (GRB). However the low effective area of space detectors implies low statistics for high-energy photons ...
    • Constraining the environment of neutrino-emitting regions in jets of FSRQs 

      Reimer, Anita; Böttcher, Markus; Buson, Sara; Miceli, Davide (Sissa Medialab, 2019)
      Recently, the gamma-ray blazar TXS 0506+056 has been proposed as the source of neutrino events detected by IceCube in 2014-15 and 2017. This has further pushed the idea of blazar jets being among those cosmic sites where ...
    • Isotope solar modulation with the PAMELA experiment 2019 

      Munini, Riccardo; Aslam, O.P.M.; Bisschoff, D.; Potgieter, M.S. (Sissa Medialab, 2019)
      The satellite-borne PAMELA experiment was launched on the 15th June 2006 from the Baikonur cosmodrome. Since then and until January 2016 PAMELA made high-precision measurements of the charged component of cosmic-rays ...
    • The heliospheric modulation of electrons and positrons over a complete solar cycle 

      Aslam, O.P.M.; Bisschoff, Driaan; Potgieter, Marius S. (Sissa Medialab, 2019)
      The solutions of a comprehensive three-dimensional drift model are compared to PAMELA and AMS-02 spectra of electrons and positrons in order to describe and understand their different modulation down to 1 MeV. This is ...
    • Time dependence of the proton and helium fluxes measured by PAMELA during solar minimum (2006 - 2009) 

      Marcelli, Nadir; Aslam, O.P.M.; Bisschoff, D.; Potgieter, M.S.; Boezio, M. (Sissa Medialab, 2019)
      Precision measurements of the Z = 2 component in the cosmic radiation provide crucial information about both the origin and propagation of the helium nuclei in cosmic rays inside the Galaxy. Moreover, the precise measurement ...
    • The solar modulation of protons and anti-protons 

      Aslam, O.P.M.; Bisschoff, D.; Potgieter, M. (Sissa Medialab, 2019)
      A comprehensive, three-dimensional drift model is used to study the solar modulation of cosmic-ray protons and particularly of anti-protons. Spectra for protons and anti-protons from 10 MeV to 70 GeV are computed based on ...
    • Stellar and dynamical masses of brightest cluster galaxies 

      Loubser, S.I. (Cambridge Univ Press, 2020)
      We investigate the stellar and dynamical mass profiles of 32 brightest cluster galaxies (BCGs, MK = −25.7 to −27.8 mag) in massive clusters (0.05 < z < 0.30), and in particular the rising velocity dispersion profiles of ...
    • Dynamical modelling of brightest cluster galaxies: constraints on the IMF 

      Loubser, S.I. (Cambridge Univ Press, 2020)
      We study the stellar and dynamical masses, as well as the stellar populations, of brightest cluster galaxies (BCGs) located in 32 massive clusters, and for a sub-sample of these use the results to place constraints on the ...
    • Microgrid energy management through levelized cost of energy metric 

      Swanepoel, C.G.; Van Schoor, G.; Uren, K.R.; Rens, A.P.J. (IEEE, 2020)
      The abundance of solar energy in Africa provides the ideal opportunity to mitigate the concerns on price, reliability and voltage quality of electricity supply to end-users. Rooftop PV and local energy storage solutions ...
    • External contextual factors in information security behaviour 

      Snyman, Dirk; Kruger, Hennie A. (SITEPRESS, 2020)
      Human behaviour is often considered to be irrational, difficult to understand, and challenging to manage. This phenomenon has a direct impact on the way in which humans behave when confronted with information security ...
    • DC power quality emulator 

      Jansen van Vuuren, Riekert; Botha, Gerhard (IEEE, 2020)
      Currently, no dc power quality standards exist. The lack of dc power quality (PQ) standards can be addressed by, amongst others, evaluating the impact of PQ deviations on consumer end equipment. A voltage disturbance ...
    • Sunspot identification and tracking with OpenCV 

      Du Toit, Ruben; Drevin, Günther; Maree, Nicolaas; Strauss, Du Toit (IEEE, 2020)
      Space weather forecasting has gained interest over the past five decades since mankind started exploring space and began using highly developed technology. Dangers such as coronal mass ejections (CME) can negatively affect ...
    • An energy-attributed graph approach for the purposes of FDI in a heated two-tank system 

      Uren, Kenneth R.; Van Schoor, George; Auret, Lidia (Elsevier, 2019)
      The focus of this paper is the development of attributed graph representations of industrial processes. In this case energy attributes are used since it serves a data reduction purpose and allows for the consideration of ...
    • Computational cost of an exergy-based fault detection scheme implemented in a commercial process simulator 

      Marais, Henri; Van Schoor, George; Uren, Kenneth R. (Elsevier, 2019)
      Energy-based fault detection and isolation (FDI) schemes show promise in terms of applicability to petrochemical industries and the broader process industries. Model-based FDI schemes offer pronounced advantages over more ...
    • Statistical modelling of an ammonium nitrate fluidised bed granulator for inference measurement 

      Kok, Rudolph L.; Van der Merwe, Abraham F.; Van Schoor, George; Uren, Kenny R. (Elsevier, 2019)
      Fluidised bed granulation is a widely used wet granulation technique. The operation of a fluidised bed granulator (FBG) as well as the quality of the product is strongly influenced by multiple process variables and ...