Browsing by Author "Burger, A."

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    Experimental evaluation of a Ranque-Hilsch vortex tube as a particle separator
    (South African Institution of Mechanical Engineering, 2012) Burger, A.; Dobson, R. T.
    The Pebble Bed Modular Reactor (PBMR) is a Generation IV graphite-moderated helium cooled nuclear reactor developed in South Africa from the German Arbeitsgemeinschaft Versuchreaktor (AVR). After decommissioning of the AVR plant, radioactive isotopes of silver 44Ag110 as well as graphite particles were found in the primary helium coolant loop of the reactor. Hence the main objective of this work was to evaluate the efficiency of the Ranque-Hilsch vortex tube (RHVT) as a separation device for removing graphite particles from a helium coolant stream. This objective was accomplished by designing and building an experimental test apparatus and measuring the particle separation efficiency of the RHVT under different operating conditions. It was found that the RHVT is a very efficient particle separator, which may, however, not easily be incorporated into the PBMR system.
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    Presentation and outcome of culture-confirmed isoniazid-resistant rifampicin-susceptible tuberculosis in children
    (International Union Against Tuberculosis and Lung Disease, 2016) Garcia-Prats, Anthony J.; Du Plessis, L.; Draper, H. R.; Burger, A.; Seddon, J. A.; Zimri, K.; Hesseling, Anneke C.; Schaaf, H. Simon
    Setting: Isoniazid-resistant rifampicin-susceptible (HRRS) tuberculosis (TB) is the most prevalent form of drug-resistant TB globally, and may be a risk factor for poor outcomes. HRRS-TB in children has been poorly described. Objective: To characterize the clinical presentation, treatment, and clinical and microbiological outcomes, and factors associated with poor outcomes among children with culture-confirmed HRRS-TB. Design: Retrospective hospital-based cohort study. Results: Of the 72 children included, median age 50.1 months (IQR 21.5-102.5), 42% were male. Forty-four (51%) had a potential source case; only 13 were confirmed HRRS-TB. Twelve of 66 tested (17%) were HIV-infected, and 36 of 60 (60%) with pulmonary TB had severe disease. Seventy had treatment data; median total duration was 11.3 months (IQR 9-12.3); 25 (36%) initiated treatment with a 3-drug intensive phase; 52 (74%) received a fluoroquinolone. Of 63 with known outcome, 55 (88%) had a favourable outcome; 1 died and 3 had treatment failure. Ten had positive follow-up cultures at ≥2 months after starting treatment (17% of all PTB and 27% of those with follow-up culture data); older age (p=0.008), previous TB treatment (p=0.023) and severe PTB (p=0.018) were associated with failure to culture-convert at ≥2 months. Conclusions: Although overall outcomes were good, prolonged culture positivity and cases of treatment failure emphasize the need for additional attention to clinical management of children with HRRS-TB.