Author:Van Niekerk, DR; Barnard, EDate:Sep 2010The authors present an initial investigation into the acoustic realisation of tone in continuous utterances in Sepedi (a language in the Southern Bantu family). An analytic model for the generation of appropriate pitch contours given an ...Read more
Author:Naidoo, Darryl; Forbes, A; Aït-Ameur, K; Fromager, MDate:Jan 2011A method of decomposing a dual-directional laser beam into a forward propagating field and a backward propagating field for an apertured plano-concave cavity is presented. An intra-cavity aperture is a simple method of laser beam shaping as ...Read more
Author:Ngcobo, Sandile; Ait-Ameur, K; Forbes, ADate:Aug 2012This work deals with the generation of symmetrical high order Laguerre Gaussian modes. These high order Laguerre-Gaussian beams are generated by forcing the laser using an annular binary Diffractive Optical Element whose geometry is in ...Read more
Author:Naidoo, Darryl; Aït-Ameur, K; Brunel, M; Forbes, ADate:2012In this paper we demonstrate experimentally the intra-cavity generation of a coherent superposition of Laguerre–Gaussian modes of zero radial order but opposite azimuthal order. The superposition is created with a simple intra-cavity stop ...Read more
Author:Naidoo, Darryl; Litvin, I; Laskin, A; Forbes, ADate:Feb 2014We explore an intra-cavity beam shaping approach to generate a Gaussian distribution by the metamorphosis of a Gaussian beam into a flat-top distribution on opposing mirrors. The concept is tested external to the cavity through the use of two ...Read more
Author:Naidoo, Darryl; Aït-Ameur, K; Forbes, ADate:Aug 2011In this paper the authors explore vortex beams and in particular the generation of single LG0l modes and superpositions thereof. Vortex beams carry orbital angular momentum (OAM) and this intrinsic property makes them prevalent in transferring ...Read more
Author:Litvin, IA; Khilo, NA; Forbes, A; Belyi, VNDate:Aug 2009In this paper the researchers report on two resonator systems for producing LDBLBs with arbitrary initial parameters. First resonator system is based on doublet of divergence and convergence lenses with spherical aberration. Second resonator ...Read more
Author:Litvin, IA; Loveday, Philip W; Long, Craig S; Kazak, NS; Belyi, V; Forbes, ADate:Aug 2008There are many applications in which a laser beam with a flat–top intensity profile would be ideal, as compared to a laser beam with a non–uniform energy distribution. Standard stable optical resonators will unfortunately not generate such a ...Read more
Author:Mthunzi-Kufa, Patience; Lee, WM; Riches, AC; Brown, CTA; Gunn-Moore, FJ; Dholakia, KDate:May 2010Optical micromanipulation of transparent microparticles such as cellularmaterials relies upon the application of optical forces that are crucially dependent on the refractive index contrast between the particle and the surrounding medium. We ...Read more
Author:Wesley-Smith, J; Berjak, P; Pammenter, NW; Walters, Chavon RDate:Mar 2014Cryopreservation is the only long-term conservation strategy available for germplasm of recalcitrant-seeded species. Efforts to cryopreserve this form of germplasm are hampered by potentially lethal intracellular freezing events; thus, it is ...Read more
Author:Kwezi, Lusisizwe; Wheeler, JI; Marondedze, C; Gehring, C; Irving, HRDate:Feb 2018Signal modulation is important for the growth and development of plants and this process is mediated by a number of factors including physiological growth regulators and their associated signal transduction pathways. Protein kinases play a ...Read more
Author:Botha, N; Kok, S; Inglis, HMDate:Jul 2012Glaucoma is the second leading cause of irreversible blindness. The primary indicator for glaucoma is an elevated intraocular pressure, which is estimated by means of contact or non-contact tonometry. However, these techniques do not accurately ...Read more
Author:Litvin, IA; Forbes, ADate:Aug 2009In this paper the authors present the analytical and numerical analyses of two new resonator systems for generating flat–top–like beams. Both approaches lead to closed form expressions for the required cavity optics, but differ substantially ...Read more
Author:Litvin, IA; Khilo, NA; Forbes, A; Belyi, VNDate:Feb 2010The authors report on two resonator systems for producing Bessel–like beams with longitudinally dependent cone angles (LDBLBs). Such beams have extended propagation distances as compared to conventional Bessel– Gauss beams, with a far field ...Read more
Author:Rens, GB; Varzinczak, IJDate:Dec 2009The authors are developing a new logic (DyMoDeL) for reasoning about dynamic agents with stochastic action, partial observation, knowledge-of and degree-of-belief-in a state of affairs. Development of the syntax and semantics is almost complete, ...Read more
Author:Bopape, Mary-Jane M; Engelbrecht, FDate:Sep 2011A nonhydrostatic sigma coordinate model (NSM) is currently being developed at the Council for Scientific and Industrial Research (CSIR), using the equation set of Engelbrecht et. al. (2007), for purposes of simulating weather at spatial ...Read more
Author:Pattinson, T; Majozi, TDate:2009A novel operational policy, the Process Intermediate Storage operational policy, is introduced and used to synthesize, schedule and design multipurpose batch plants. The model is based on the State Sequence Network and non-uniform discretization ...Read more
Author:Casini, G; Meyer, T; Moodley, K; Sattler, U; Varzinczak, IDate:Oct 2015In recent years, various approaches have been developed for representing and reasoning with exceptions in OWL. The price one pays for such capabilities, in terms of practical performance, is an important factor that is yet to be quantified ...Read more
Author:Van Niekerk, Cornelia W; Pieterse, Amy; Le Roux, AlizeDate:Jan 2020The Green Book is not a book, but a novel, practical online planning tool to support the adaptation of South African settlements to the impacts of climatic changes and severe events. It provides evidence of current and future (2050) climate ...Read more
Author:Stavropoulos, CCDate:Sep 1977The telemetering of information over long distances from unattended environmental monitoring equipment at remote sites can be difficult to carry out using conventional high frequency radio communication. This is because of the need to change ...Read more