67 research outputs found
Electrolytic determination of phthalates organic pollutants with n nostructured titanium and iron oxides sensors
Magister Scientiae - MScThis work reports the chemical synthesis, characterisation and electrochemical application of titanium dioxide (TiO2) and iron oxide (Fe2O3) nanoparticles in the determination of phthalates. The other part of this work involved electrochemical polymerization of aniline doped with titanium and iron oxide nanoparticles for the sensor platform in the electrolytic determination of phthalates. The TiO2 and Fe2O3 nanoparticles were prepared by sol gel and hydrothermal methods respectively. Particle sizes of 20 nm (TiO2) and 50 nm (Fe2O3) were estimated from transmission electron microscopy (TEM) The other technical methods used in this study for the characterization of the TiO2 and iron oxide Fe2O3 NPs were SEM, XRD and UV- visible spectroscopy. Cyclic voltammetry, square wave voltammetry and electrochemical impedance spectroscopy (EIS) were used to study the electrochemical properties of the nanoparticles. These electrochemical studies of the nanoparticles were performed with a Fe2O3 or TiO2/nafion/glassy carbon membrane electrode in 0.1 M phosphate buffer (pH 7.0) and 0.1 M lithium perchlorate (pH 6.8) under an aerobic condition.South Afric
Evaluating the clinical management of severely malnourished children--a study of two rural district hospitals.
BACKGROUND: Severe malnutrition is an important cause of preventable mortality in most South African hospitals. Work recently done in two rural Eastern Cape hospitals supports the literature which shows that many deaths occur as a result of outdated clinical practices and that improving these practices reduces case fatality rates. Rapid assessment of clinical management in paediatric wards is necessary to highlight areas for improvement. OBJECTIVE: To assess the management of severely malnourished children in two rural district hospitals and to recommend improvements for their care. METHODS: Based on draft World Health Organisation (WHO) guidelines for inpatient care of children with severe malnutrition, data collection instruments were developed in conjunction with the district nutrition team to assess the quality of care given to malnourished children in two Mount Frere hospitals, Eastern Cape. Data were collected through retrospective review of case records, with detailed studies of selected cases, structured observations of the paediatric wards, and interviews with ward sisters and doctors. RESULTS: The combined case fatality rate for severe malnutrition was 32%. Inadequate feeding, poor management of rehydration and infection, lack of resources, and a lack of knowledge and motivation among staff were identified as areas that need attention. CONCLUSION: The clinical management of severely malnourished children can be rapidly assessed to highlight areas for improvement. Involving staff in the assessment process has led to their active involvement in improving the management of malnourished children in their hospitals
Evaluating the clinical management of severely malnourished children- a study of two rural district hospitals
Background. Severe malnutrition is an important cause of preventable mortality in most South African hospitals. Work recently done in two rural Eastern Cape hospitals supports the literature which shows that many deaths occur as a result of outdated clinical practices and that improving these practices reduces case fatality rates. Rapid assessment of clinical management in paediatric wards is necessary to highlight areas for improvement.Objective. To assess the management of severely malnourished children in two rural district hospitals and to recommend improvements for their care.Methods. Based on draft World Health Organisation (WHO) guidelines for inpatient care of children with severe malnutrition, data collection instruments were developed in conjunction with the district nutrition team to assess the quality of care given to malnourished children in two Mount Frere hospitals, Eastern Cape. Data were collected through retrospective review of case records, with detailed studies of selected cases, structured observations of the paediatric wards, and interviews with ward sisters and doctors.Results. The combined case fatality rate for severe malnutrition was 32%. Inadequate feeding, poor management of rehydration and infection, lack of resources, and a lack of knowledge and motivation among staff were identified as areas that need attention.Conclusion. The clinical management of severely malnourished children can be rapidly assessed to highlight areas for improvement. Involving staff in the assessment process has led to their active involvement in improving the management of malnourished children in their hospitals
Chromium Oxide Formation on Nanosecond and Femtosecond Laser Irradiated Thin Chromium Films
Thin coatings of Chromium oxide have been used for applications as absorbing
material in solar cells, as protections for magnetic data recording devices and
as shields in flexible solar cells. Thin coatings of pure chromium were vacuum
deposited on a glass substrate using hot electrons from tungsten filament.
These coatings were then treated with a nanosecond and femtosecond laser in
ambient conditions. The microstructure, morphology and the color of the
coatings treated with laser sources were modified and there was a formation of
an oxide layer due to the heat dissipation on the chromium coating from the
energetic photons. High-resolution scanning electron microscope studies showed
the morphological evolution that are directly correlated with the laser fluence
of both the nanosecond and femtosecond lasers. This morphological evolution was
accompanied by the microstructural change as observed from the x-ray
diffraction patterns, the chromaticity response of the coating was studied by
UV-Vis spectrometer and the response of the coating in the visible region
evolved with the laser fluences. The Rutherford backscattering depth profiling
of the laser treated coatings revealed the diffusion of oxygen atoms in the
coating as a result of laser treatment fluence
An electrochemically active green synthesized polycrystalline NiO/MgO catalyst: Use in photo-catalytic applications
For many years, research scientists have aided communities in their tremendous efforts towards environmental remediation. Due to their high physical and chemical stability, metal oxide nanoparticles (NPs) have been used as metal catalysts to remedy this issue. This article reviews green approaches for the synthesis of metal oxide nanoparticles, in aqueous bio-reductive polyphenols from punica granatum peel extract and the degradation of organic pollutants. The bimetallic nanocomposite of face-centred cubic NiO/MgO pseudocapacitors were successfully prepared via the polyphenols of punica granatum peel extracts. X-ray diffraction spectroscopy (XRD) successfully provide evidence of polycrystalline face-centre cubic nanocomposite (high crystallinity index (Icry) > 1) while revealing their interplanar distance. The spherical and irregular particle distribution of the binary NiO/MgO nanocomposite (at different calcination temperatures) was assessed by high resolution-TEM. FTIR, GC–MS and EDS provided evidence of the proposed mechanism during coordination between polyphenols and metal precursors. The popular “egg box model” is referred to in the case of polyphenols-metal interaction. The unique feature of two consecutive chelation site per repeat that provides a favourable entropic contribution to the inter-chain association is produced by this model governed by electrostatic interactions. Based on the obtained results, new structural models of Ni2+/Mg2+-polyphenols (punicalagin) complexes were proposed. UV–vis and Cyclic voltammetry confirmed the growth and band gap energies of the nanocomposite. NiO/MgO nanocomposite was found to be excellent photocatalysts for the degradation of methylene orange and methylene blue under the illumination of artificial light irradiation. The experiments demonstrated that MB in aqueous solution was more efficiently photo-degraded (87%) than MO (73%) using NiO/MgO nanocomposite as photocatalysts within 10 min of exposure. Conclusively, the nanocomposite was found to be more efficient compared to other reported oxides.ISI & Scopu
Consumer styles inventory in the South African fuel retailing industry
MBA thesisThe fuel retailing industry has stringent legislation which continues to reduce
revenues for the major oil companies. The conservation of the environment has
influenced product changes, which the current refineries, due to their old
infrastructure, are struggling to cope with. Advancement in technology may
spell doom in the future, specifically with the renewed focus on biofuels and
electric cars. Internationally, with deregulation, the major oil companies have
lost market share to big box retailers.
In order to remain relevant and sustainable, the fuel retailing industry has been
compelled to form strategic alliances with big box retailers such as Woolworths,
Pick ‗n Pay, Mugg and Bean, and Food Lover‘s Market, amongst others.
Consequently, the marketing role in this industry has become more complex.
According to Sinkovics et al. (2010), an understanding of consumer decisionmaking
behaviours is critical for marketing activities such as market
segmentation, positioning, and tailoring marketing strategies.
The study used quantitative and qualitative methods to collect data from fuel
retailing customers and dealers. The research instrument was adapted from
Sproles and Kendall‘s (1986) consumer styles inventory (CSI). Four consumer
styles were confirmed as being applicable to the fuel retailing industry: price,
brand loyalty, high quality and location. Fuel remains the main attraction,
however, convenience goods bring a different type of customer, namely females
and young people. Empirically derived factors provided the insights that
mastering speed and convenience, and providing high quality branded
products, can be a competitive advantage
Green Synthesis of CuO-TiO<sub>2</sub> Nanoparticles for the Degradation of Organic Pollutants: Physical, Optical and Electrochemical Properties
CuO-TiO2 nanocomposites were successfully synthesized using the C. benghalensis plant extracts. The effect of the composition of CuO to TiO2 on the morphological, optical, electrochemical, and photodegradation efficiency in the composites was studied. SEM, XRD, UV-vis, FTIR, TGA, BET, and CV were used to characterize these materials. The XRD data reported the tenorite structure of the CuO and the anatase phase of the TiO2. SEM showed the spherical morphologies for all the CuO-TiO2 NPs, and these were also mesoporous in nature, as depicted by BET. The voltammogram of the CuO-TiO2 30/70 electrode showed a higher response current density compared to the other two samples, suggesting a higher specific capacitance. Upon testing the photocatalytic efficiencies of the CuO-TiO2 nanocomposites against methylene blue (MB), ciprofloxacin (CIP), and sulfisoxazole (SSX), the highest degradation of 94% was recorded for SSX using the CuO-TiO2 30/70 nanocomposites. Hydroxyl radicals were the primary species responsible for the photodegradation of SSX, and the material could be reused once. The most active species in the photodegradation of SSX has been identified as OH•. From this study, it can be noted that the CuO-TiO2 nanocomposites were more selective toward the degradation of antibiotics (sulfisoxazole and ciproflaxin) as compared to dyes (methylene blue)
- …