Browsing Faculty of Natural and Agricultural Sciences by Title
Now showing items 565-584 of 4825
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Change-point methods for multivariate time-series: paired vectorial observations
(Springer, 2020)We consider paired and two-sample break-detection procedures for vectorial observations and multivariate time series. The new methods involve L2-type criteria based on empirical characteristic functions and are easy to ... -
Changeover-time in psychosocial wellbeing of people living with HIV and people living close to them after an HIV stigma reduction and wellness enhancement community intervention
(Taylor & Francis, 2015)HIV stigma continues to affect the psychosocial wellbeing of people living with HIV (PLWH) and people living close to them (PLC). Literature unequivocally holds the view that HIV stigma and psychosocial wellbeing interact ... -
Changes in abundance of fish-parasitic gnathiid isopods associated with warm-water bleaching events on the northern Great Barrier Reef
(Springer, 2019)Mass coral bleaching events due to rising seawater temperatures are occurring with increasing frequency and are among the most conspicuous consequences of human-induced climate change. While bleaching events have clear ... -
Changes in density and composition of algal assemblages in certain unit processes of two South African water purification plants
(Taylor & Francis, 2014)The water purification plants at Virginia and Bothaville, South Africa, experience problems with cyanobacteria and other algae. Their algal assemblages were studied during 2010 and 2011 to determine the dominant species ... -
Changes in gait and posture as factors of dynamic stability during walking in pregnancy
(Elsevier, 2018)Changes in gait and postural control during pregnancy may lead to increased fall rates during walking relative to non-pregnant women. Due to lack of empirical evidence on balance and postural control in dynamic conditions, ... -
Changes in local free-living parasite populations in response to cleaner manipulation over 12 years
(Springer, 2019)Predation on parasites is an important ecological process, but few experimental studies have examined the long-term impacts on the prey. Cleaner fish prey upon large numbers and selectively feed on the larger individuals ... -
Changes in Perceptions of the Internet’s Influence on Marketing in South Africa since the Late-1990s
(kamla-Raj Enterprises, 2014)The present paper reports on a study that compared senior marketers’ perceptions of the Internet’s influence on marketing in South Africa in 1997 with their perceptions nearly two decades later in 2011. In South Africa, ... -
Changes in soil fertility and Pak choi (Brassica chinensis L.) nutritional content in response to agouti (Dasyprocta leporina Linnaeus, 1758) manure amendment
(The University of the West Indies, 2017)Evaluating agouti manure (AM) as a source of macronutrients for plant production is a precursor to ensuring appropriate land application. Agouti manure was compared to cattle manure (CM) and mineral fertiliser (MF) applied ... -
Changes in the algal composition and water quality of the Sundays River, Karoo, South Africa, from source to estuary
(Taylor & Francis, 2015)A first survey was done on algae present in the Sundays River from its source to its confluence with the sea. Species found in the upstream sections of the river included indicators of good water quality, but the quality ... -
Changes induced by atrazine in Clarias gariepinus provide insight into alterations in ovarian histoarchitecture and direct effects on oogenesis
(Taylor & Francis, 2020)Clarias gariepinus juveniles were exposed to environmentally relevant concentrations of 0 (control), 2.5, 25, 250 and 500 μg L−1 atrazine in a quality-controlled 28-day laboratory procedure. Findings revealed a significant ... -
Changes to the organic functional groups of an inertinite rich medium rank bituminous coal during acid treatment processes
(Elsevier, 2011)A South African inertinite rich medium rank bituminous coal was subjected to a series of acid treatment steps using concentrations of HF and HNO3 ranging between 1.5 and 4 M, temperatures between 65 and 80 °C and reaction ... -
The Chaplygin gas as a model for modified teleparallel gravity?
(Springer, 2019)This paper explores the possibility of treating the exotic Chaplygin-gas (CG) fluid model as some manifestation of an f(T) gravitation. To this end, we use the different cosmological CG equations of state, compare them ... -
Chaplygin-gas solutions of f(R) gravity
(World Scientific Publishing, 2016)We explore exact f(R) gravity solutions that mimic Chaplygin-gas inspired CDM cosmology. Starting with the original, generalized and modified Chaplygin gas equations of state, we reconstruct the forms of f(R) Lagrangians. ... -
Characterisation and liberation of chromium from fine ferrochrome waste materials
(Elsevier, 2014)Three types of generic chromium (Cr)-containing wastes are generated during ferrochrome (FeCr) production, i.e. slag, bag filter dust (BFD) and venturi sludge. Slag is by volume the largest waste; however, fine FeCr waste ... -
Characterisation and photocatalytic assessment of TiO2 nano-polymorphs: influence of crystallite size and influence of thermal treatment on paint coatings and dye fading kinetics
(Elsevier, 2019)A study on the thermal effects on TiO2 rutile and anatase nano-powders was undertaken and displayed some unusual photoactivity and crystal structure properties. Rutile nano-particles with different crystallite sizes were ... -
Characterisation of a polyaromatic PBI blend membrane for SO2 electrolysis
(Elsevier, 2015)The application of a polyaromatic acid–base blend membrane from partially fluorinated and sulfonated aromatic polyether and the polybenzimidazole F6PBI has been investigated for hydrogen production using SO2 electrolysis. ... -
Characterisation of a topotype and other populations of Hemicriconemoides strictathecatus Esser, 1960 (Nematoda: Criconematidae) from Florida with description of H. phoenicis sp. n. from the USA
(Brill Academic Publishers, 2015)The results of morphological and molecular analyses of a Florida topotype and other populations of Hemicriconemoides strictathecatus showed that this sheathoid nematode consists of two morphotypes, both with an average ... -
Characterisation of ambient Total Gaseous Mercury concentrations over the South African Highveld
(Elsevier, 2019)Mercury is considered a ubiquitous, toxic, and global pollutant. In this study, ambient Total Gaseous Mercury (TGM) concentrations over the South African Highveld are characterised. Studies on ambient mercury in this region ... -
Characterisation of Escherichia coli O157 strains from humans, cattle and pigs in the North-West Province, South Africa
(Elsevier Science Limited, 2008)