• Non-perturbative flow equations from continuous unitary transformations 

      Kriel, Johannes Nicolaas (Stellenbosch : University of Stellenbosch, 2005-12)
      The goal of this thesis is the development and implementation of a non-perturbative solution method for Wegner’s flow equations. We show that a parameterization of the flowing Hamiltonian in terms of a scalar function ...
    • Noninvasive measurement of dynamic correlations in spin systems 

      Uhrich, Philipp Johann (Stellenbosch : Stellenbosch University, 2017-12)
      ENGLISH ABSTRACT : Dynamic correlations hψ| O1(t1)O2(t2)|ψi of quantum observables are useful quantities for the study of quantum dynamics. Attempts at measuring these correlations are however complicated, due to the ...
    • Nuclear reactions with polarized spin-1/2 beams 

      Hillhouse, G. C. (Gregory Campbell) (Stellenbosch : Stellenbosch University, 1990-03)
      ENGLISH ABSTRACT: The first part of the thesis deals with the subject of polarization in nuclear reactions. The case where the incoming beam is polarized, is emphasized, and the theory is developed for the simple and ...
    • Numerical design of an optical solid-state amplifier 

      Van der Westhuizen, Gysbert Johannes (Stellenbosch : Stellenbosch University, 2007-12)
      Please refer to full text for abstract
    • Numerical modelling of the excitation of polyatomic molecules by femtosecond laser beams 

      De Clercq, Ludwig Erasmus (Stellenbosch : University of Stellenbosch, 2011-03)
      ENGLISH ABSTRACT: The selective excitation of an arbitrary vibrational level of a polyatomic molecule, without passage through an intermediary electronic excited state is demonstrated. This was achieved by simulating the ...
    • On evolutionary algorithms for effective quantum computing 

      Kruger, Markus Gustav (Stellenbosch : Stellenbosch University, 2012-03)
      ENGLISH ABSTRACT: The goal of this thesis is to present evolutionary algorithms, and demonstrate their applicability in quantum computing. As an introduction to evolutionary algorithms, it is applied to the simple but ...
    • One-dimensional fluid model with oscillating, exponentially decaying pair interactions 

      Maziya, Gcina (Stellenbosch : Stellenbosch University, 2015-12)
      ENGLISH ABSTRACT: For a one-dimensional fluid model where the pair interaction potential between the molecules consists of a hard core and an exponential attraction, Kac has shown that the partition function can be ...
    • Optical tweezers for advanced microscopy 

      Erasmus, Anneke (Stellenbosch : Stellenbosch University, 2018-03)
      ENGLISH SUMMARY: The integration of lasers into microscopy has enabled new areas of research and expanded existing ones. Not only can one now image samples to resolutions and contrast unheard of before lasers became ...
    • Optimized discharge excitation techniques for short pulse gas lasers : TEA CO2 laser 

      Kyeyune, Farooq (Stellenbosch : Stellenbosch University, 2013-12)
      ENGLISH ABSTRACT: Transversely excited atmospheric (TEA) CO2 lasers have found numerous established and potential applications in both industry and research. However, the development of laser systems which can meet the ...
    • A path integral approach to the coupled-mode equations with specific reference to optical waveguides 

      Mountfort, Francesca Helen (Stellenbosch : University of Stellenbosch, 2009-03)
      The propagation of electromagnetic radiation in homogeneous or periodically modulated media can be described by the coupled mode equations. The aim of this study was to derive analytical expressions modeling the solutions ...
    • Photoinduced charge dynamics in indoline-dye sensitised solar cells 

      Minda, Iulia (2014-12)
      ENGLISH ABSTRACT: The demand for renewable energy sources has grown out of the humanity’s increasing need for electricity as well as depleting fossil fuel reserves. Organic-dye sensitised solar cells were developed as a ...
    • Point spread function engineering for fluorescence microscopy 

      Holinirina Dina Miora, Ratsimandresy (Stellenbosch : Stellenbosch University, 2018-03)
      ENGLISH SUMMARY: A tool for biological imaging is developed within this work. It consists of engineering the point spread function (PSF) of a fluorescent molecule or a nanoparticle emitter by modulating the phase of the ...
    • Polymer networks at surfaces 

      Vandoolaeghe, Wendy Leigh (Stellenbosch : Stellenbosch University, 2003-03)
      ENGLISH ABSTRACT: In this thesis the formation and properties of a polymer gel on and at a surface are investigated. The gel under investigation is defined as a three-dimensional network of macromolecules that form ...
    • Polymer networks with mobile force-applying crosslinks 

      Mateyisi, Mohau Jacob (Stellenbosch : University of Stellenbosch, 2011-03)
      ENGLISH ABSTRACT: We construct and study a simple model for an active gel of exible polymer filaments crosslinked by a molecular motor cluster that perform reversible work while translating along the filaments. The ...
    • Portable X-ray fluorescence and nuclear microscopy techniques applied to the characterisation of southern African rock art paintings 

      Steyn, Ruan (Stellenbosch : Stellenbosch University, 2014-04)
      ENGLISH ABSTRACT: Non-destructive portable X-ray Fluorescence (pXRF) and Particle Induced X-ray Emission (PIXE) were used to measure the elemental concentration of rock art fragment paintings. For pXRF the Amptek Silicon ...
    • Pre-equilibrium excitation of nuclei in ([rho], [alpha]) and ([rho], 3He) reactions induced by 120, 160 and 200 MeV protons 

      Arendse, Gillian John (Stellenbosch : Stellenbosch University, 1994)
      ENGLISH ABSTRACT: The study of pre-equilibrium reactions induced by medium-energy light ions have become of increasing importance in recent years as they represent the bulk of the measured spectrum. On a nuclear time ...
    • The production of hypernuclei via the weak interaction 

      Van Niekerk, David Douglas (Stellenbosch : University of Stellenbosch, 2007-03)
      In this thesis we present a relativistic formalism for the description of hypernuclei production via the weak interaction. It will be shown that the cross section can be written as the contraction of a leptonic and ...
    • Proton pencil beam kernels as extracted from Geant4 Monte Carlo simulations 

      Chisapi, Maluba Vernon J. (Stellenbosch : Stellenbosch University, 2016-12)
      ENGLISH ABSTRACT : The contribution of primary protons, secondary protons, heavy recoil ions, and other secondary particles to the total energy deposited in water by a proton pencil beam (in the therapeutic energy regime) ...
    • Quantum corrections to the kink-antikink potential 

      Lee, Zander (Stellenbosch : Stellenbosch University, 2017-03)
      ENGLISH ABSTRACT : In quantum field theory vacuum polarization effects may drastically alter the classical properties of non-perturbative field configurations. This is especially the case when comparing the vacuum ...
    • A quantum hall effect without landau levels in a quasi one dimensional system 

      Brand, Janetta Debora (Stellenbosch : Stellenbosch University, 2012-12)
      ENGLISH ABSTRACT: The experimental observation of the quantum Hall effect in a two-dimensional electron gas posed an intriguing question to theorists: Why is the quantization of conductance so precise, given the imperfections ...