Faculty of Natural Sciences: Recent submissions
Now showing items 1961-1980 of 2659
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Contour integral method for European options with jumps
(Elsevier, 2013)We develop an efficient method for pricing European options with jump on a single asset. Our approach is based on the combination of two powerful numerical methods, the spectral domain decomposition method and the Laplace ... -
Human sperm handling in intracytoplasmic sperm injection processes: In vitro studies on mouse oocyte activation, embryo development competence and sperm oxidation–reduction potential
(Wiley, 2018)Polyvinylpyrrolidone (PVP) and hyaluronic acid (HA) are routinely used in handling spermatozoa for intracytoplasmic sperm injection (ICSI). As there are still concerns about possible adverse effects on the embryo, this ... -
Synthesis of zeolites from coal fly ash using mine waters
(Elsevier, 2013)In this study mine waters obtained from coal mining operations in South Africa were used as a substitute for pure water during the synthesis of zeolites from South African coal fly ash. Procedures that had been optimized ... -
Comparison of CO2 capture by ex-situ accelerated carbonation and in in-situ naturally weathered coal fly ash
(Elsevier, 2013)Natural weathering at coal power plants ash dams occurs via processes such as carbonation, dissolution, co-precipitation and fluid transport mechanisms which are responsible for the long-term chemical, physical and geochemical ... -
A fitted numerical method for singularly perturbed parabolic reaction-diffusion problems
(Spring Verlag, 2013)This paper treats a time-dependent singularly perturbed reaction-diffusion problem. We semidiscretize the problem in time by means of the classical backward Euler method. We develop a fitted operator finite difference ... -
Poisoning-tolerant metal hydride materials and their application for hydrogen separation from CO2/CO containing gas mixtures
(Elsevier, 2013)Metal hydride materials offer attractive solutions in addressing problems associated with hydrogen separation and purification from waste flue gases. However, a challenging problem is the deterioration of hydrogen charging ... -
One-pot synthesis and characterization of InP/ZnSe semiconductor nanocrystals
(Elsevier, 2013)We report on the one-pot synthesis of InP/ZnSe quantum dots (QDs) using a precursor-based colloidal synthesis in a noncoordinating solvent environment. The structural and optical studies were carried out on the as-prepared ... -
Application of surface-modified metal hydrides for hydrogen separation from gas mixtures containing carbon dioxide and monoxide
(Elsevier, 2013)Application of surface-modified MH material for H2 separation using temperature/pressure swing absorption–desorption was studied. The substrate alloy had the following composition LaNi3.55Co0.75Al0.4-Mn0.3, and the surface ... -
Characterization and activity test of commercial Ni/Al2O3, Cu/ZnO/Al2O3 and prepared NieCu/Al2O3 catalysts for hydrogen production from methane and methanol fuels
(Elsevier, 2013)In this study, methane and methanol steam reforming reactions over commercial Ni/Al2O3, commercial Cu/ZnO/Al2O3 and prepared NieCu/Al2O3 catalysts were investigated. Methane and methanol steam reforming reactions catalysts ... -
Microwave-assisted methods for the synthesis of pentacyclo[5.4.0.02,6.03,10.05,9]undecylamines
(Elsevier, 2013)Efficient methodologies for the preparation of pentacyclo[5..4.0.02,6.03,10.05,9]undecane (PCU) amine derivatives are described via microwave-assisted synthesis. The obtained results revealed that microwave-assisted synthetic ... -
Mining the Herschel-Astrophysical Terahertz Large Area Survey: submillimetre-selected blazars in equatorial fields
(Oxford University Press, 2013)The Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS) provides an unprecedented opportunity to search for blazars at sub-mm wavelengths. We cross-matched the Faint Images of the Radio Sky at Twenty-cm (FIRST) ... -
Population ecology of Psammobates oculifer in a semi-arid environment
(Taylor & Francis and UNISA Press, 2013)We studied the ecology of Psammobates oculifer over 13 months near Kimberley, South Africa, to ascertain if the population’s life history traits conform to chelonian patterns in arid environments. Capture rates were highest ... -
Extensive recombination detected among beak and feather disease virus isolates from breeding facilities in Poland
(Microbiology Society, 2013)Beak and feather disease virus (BFDV) causes the highly contagious, in some cases fatal, psittacine beak and feather disease in parrots. The European continent has no native parrots, yet in the past has been one of the ... -
Physical properties of spectroscopically confirmed galaxies at Z ≥ 6. I. Basic characteristics of the rest-frame UV continuum and lyman-alpha emission
(American Astronomical Society, 2013)We present deep HST near-IR and Spitzer mid-IR observations of a large sample of spectroscopically- confirmed galaxies at z ≥ 6. The sample consists of 51 Ly-alpha emitters (LAEs) at z ≃ 5.7, 6.5, and 7.0, and 16 Lyman-break ... -
Enhanced drug loading capacity of polypyrrole nanowire network for confrolled drug release
(Elsevier, 2013)For a conducting polymer (CP) based drug release system, drug loading is often accomplished by a doping process, in which drug is incorporated into polymer as dopant. Therefore, the drug loading capacity is relatively low ... -
Pt-Sn/C as a possible methanol-tolerant cathode catalyst for DMFC
(Springer Verlag, 2013)An effective method was developed for preparing highly dispersed nano-sized Pt–Sn/C electrocatalyst synthesised by a modified polyol reduction method. From XRD patterns, the Pt–Sn/C peaks shifted slightly to lower 2θ angles ... -
An overview of the Dwarf Galaxy Survey
(The Astronomical Society of the Pacific, 2013)The Dwarf Galaxy Survey (DGS) program is studying low-metallicity galax- ies using 230h of far-infrared (FIR) and submillimetre (submm) photometric and spectroscopic observations of the Herschel Space Observatory and ... -
Lasiosiphon rigidus, a new species from the Tankwa Karoo and two new combinations in the genus for South Africa
(MDPI, 2013)Thymelaeaceae are well represented in southern Africa, with ± 190 species in nine genera (Bredenkamp & Beyers 2000; Beaumont et al. 2009). Preliminary phylogenetic analyses of nuclear and plastid DNA sequences (Van der ... -
The effect of PtRuIr nanoparticle crystallinity in electrocatalytic methanol oxidation
(MDPI, 2013)Two structural forms of a ternary alloy PtRuIr/C catalyst, one amorphous and one highly crystalline, were synthesized and compared to determine the effect of their respective structures on their activity and stability as ... -
Cardioprotective and anti-hypertensive effects of Prosopis glandulosa in rat models of pre-diabetes
(Clinics Cardive Publishing, 2013)AIM: Obesity and type 2 diabetes present with two debilitating complications, namely, hypertension and heart disease. The dried and ground pods of Prosopis glandulosa (commonly known as the Honey mesquite tree) which is ...