Browsing Faculty of Natural Sciences by Title
Now showing items 1698-1717 of 2571
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Optical-faint, far-infrared-bright Herschel sources in the CANDELS fields: Ultra-luminous infrared galaxies at z > 1 and the effect of source blending
(American Astronomical Society, 2014)The Herschel very wide-field surveys have charted hundreds of square degrees in multiple far-IR (FIR) bands. While the Sloan Digital Sky Survey (SDSS) is currently the best resource for optical counterpart identifications ... -
The optically selected 1.4-GHz quasar luminosity function below 1 mJy
(Oxford University Press, 2020)We present the radio luminosity function (RLF) of optically selected quasars below 1 mJy, constructed by applying a Bayesian-fitting stacking technique to objects well below the nominal radio flux density limit. We test ... -
Optimal design of combined two-tank latent and metal hydrides-based thermochemical heat storage systems for high-temperature waste heat recovery
(Multidisciplinary Digital Publishing Institute (MDPI), 2020)The integration of thermal energy storage systems (TES) in waste-heat recovery applications shows great potential for energy efficiency improvement. In this study, a 2D mathematical model is formulated to analyze the ... -
An optimal portfolio and capital management strategy for basel III compliant commercial banks
(Hindawi Publishing Corporation, 2014)We model a Basel III compliant commercial bank that operates in a financial market consisting of a treasury security, a marketable security, and a loan and we regard the interest rate in the market as being stochastic. We ... -
Optimal strategy for controlling the spread of HIV/AIDS disease: A case study of South Africa
(Taylor and Francis Group, 2012)HIV/AIDS disease continues to spread alarmingly despite the huge amounts of resources invested infighting it. There is a need to integrate the series of control measures available to ensure a consistentreduction ... -
Optimisation of electrophoretic deposition parameters for gas diffusion electrodes in high temperature polymer electrolyte membrane fuel cells
(Elsevier, 2013)Electrophoretic deposition (EPD) method was used to fabricate gas diffusion electrodes (GDEs) for high temperature polymer electrolyte membrane fuel cells (HT PEMFC). Parameters related to the catalyst suspension and the ... -
Optimisation of SlotTime for a single-radio Mid-Range Multi-hop Wireless Mesh Network
(Telkom SA, 2014)This paper presents the business context and results of an optimisation exercise for a single-radio mid-range multi-hop wireless mesh network for the provision of VoIP services. This WiFi mesh network physically covers 30 ... -
Optimization of gas diffusion electrode for polybenzimidazole-based high temperature proton exchange membrane fuel cell: Evaluation of polymer binders in catalyst layer
(Elsevier, 2013)Gas diffusion electrodes (GDEs) prepared with various polymer binders in their catalyst layers (CLs) were investigated to optimize the performance of phosphoric acid doped polybenzimidazole (PBI)-based high temperature ... -
Optimization of the observing cadence for the Rubin observatory legacy survey of space and time: A pioneering process of community-focused experimental design
(IOP Publishing, 2022)Vera C. Rubin Observatory is a ground-based astronomical facility under construction, a joint project of the National Science Foundation and the U.S. Department of Energy, designed to conduct a multipurpose 10 yr ... -
Opto-electronic properties of anodized TiO2 nanotube arrays investigated using electron energy loss spectroscopy
(sciencedirect, 2019)A study of the nanoscale crystallinity of anodized TiO2 nanotubes is reported with the aim of demonstrating its influence on the localized optical and electronic properties of the structure. By employing scanning transmission ... -
Oral colonization of Gram-negative anaerobes as a risk factor for preterm birth
(Landes Bioscience, 2011)Preterm birth significantly impacts on neonatal morbidity and mortality and is apparently increasing worldwide. Several studies have attempted to define a causative role for periodontal disease in adverse pregnancy ... -
Oral health status and treatment needs of pregnant women attending antenatal clinics in KwaZulu-Natal, South Africa
(Hindawi, 2019)During pregnancy, the oral cavity is characterised by an acidic environment and an inflammatory response brought about by vomiting and changes in hormonal levels, respectively, thereby increasing the mother’s risk of ... -
The orbital periods of aa dor and ny vir
(Oxford University Press, 2011)New timings of eclipses made between 2000 and 2010 are presented for two binary systems with hot subdwarf primary stars. In the case of AA Dor, an sdOB star with a very cool secondary, the period is found to be constant ... -
Organic nanostructured materials for sustainable application in next generation solar cells
(MPDI, 2021)Meeting our current energy demands requires a reliable and efficient renewable energy source that will bring balance between power generation and energy consumption. Organic photovoltaic cells (OPVs), perovskite solar ... -
The organisation of urban agriculture in Cape Town, South Africa: A social capital perspective
(Taylor & Francis, 2018)This article explores urban agriculture in Cape Town and its organisational forms. Based on a literature review of peerreviewed articles and grey literature, it examines the state of linkages among urban farmers and various ... -
An orientation bias in observations of submillimetre galaxies
(Monthly Notices of the Royal Astronomical Society, 2021)Recent high-resolution interferometric images of submillimetre galaxies (SMGs) reveal fascinatingly complex morphologies. This raises a number of questions: how does the relative orientation of a galaxy affect its observed ... -
The origin and evolution of Lyα blobs in cosmological galaxy formation simulations
(IOP Publishing Ltd, 2021)High-redshift Lyα blobs (LABs) are an enigmatic class of objects that have been the subject of numerous observational and theoretical investigations. It is of particular interest to determine the dominant power sources for ... -
The origin of radio emission in broad absorption line quasars: Results from the Lofar Two-metre Sky Survey (Corrigendum)
(EDP Sciences, 2020)We report an erratum in Morabito et al. (2019, A&A, 622, A15). When calculating radio powers from observed flux densities, the wrong sign convention was used. This resulted in an underestimation of the radio powers by a ... -
The origin of the dust extinction curve in milky way-like galaxies
(Oxford University Press, 2021)We develop a cosmological model for the evolution of dust grains in galaxies with a distribution of sizes in order to understand the origin of the Milky Way dust extinction curve. Our model considers the formation of active ... -
Origin, Migration, and Reproduction of Indigenous Domestic Animals with Special Reference to Their Sperm Quality
(MDPI, 2022): Indigenous domestic animals such as cattle, sheep, goats, pigs, and chickens have a natural resistance to endo- and ecto-parasites and are tolerant in terms of harsh environmental conditions. These species orginated ...