Browsing Faculty of Natural and Agricultural Sciences by Title
Now showing items 743-762 of 4825
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A comparison of four sputum pre-extraction preparation methods for identifying and characterising Mycobacterium tuberculosis using GCxGC-TOFMS metabolomics
(Elsevier, 2012)In many pulmonary diseases, sputum is a valuable sample material for use in disease characterisation and diagnostics. However, due to its high viscosity and uneven consistency (lumpiness), it is difficult to obtain ... -
Comparison of ionically and ionical-covalently cross-linked polyaromatic membranes for SO2 electrolysis
(Elsevier, 2014)It has been shown that hydrogen, which can be used for energy storage, can be produced efficiently by the membrane based Hybrid Sulfur (HyS) process. During the HyS electrolysis step, SO2 and H2O are converted to H2 and ... -
A comparison of low and high activity precatalysts: do the calculated energy barriers during the self-metathesis reaction of 1-octene correlate with the precatalyst metathesis activity?
(Wiley, 2014)The self-metathesis reaction of 1-octene with several wellknown Grubbs-type precatalysts and the new Z-selective Grubbs precatalyst were studied with molecular modeling. The obtained Gibbs-free energy values for all the ... -
A comparison of methods for incubating zooplankton diapausing eggs from sediment of endorheic pans in the Free State, South Africa
(Taylor & Francis, 2014)Determining the composition of zooplankton in endorheic pans can be challenging, and live sampling of these microcrustaceans does not give a true indication of their species diversity and abundance. The incubation of ... -
A comparison of microbial community function and structure in rehabilitated asbestos and coal discard sites
(Springer, 2012)Previous studies have made some progress with the use of microbial community properties as assessment criteria for rehabilitation success of postmining areas. Currently, there is a need for reference ranges of specific ... -
A comparison of mollusc diversity between the relatively pristine Marico River and the impacted Crocodile River, two major tributaries of the Limpopo River, South Africa
(Water Research Commission, 2016)A study of the freshwater mollusc diversity was conducted at selected sites in the relatively pristine Marico River and the impacted Crocodile River, the major tributaries of the Limpopo River. Four surveys were conducted, ... -
A comparison of outer electron radiation belt dropouts during solar wind stream interface and magnetic cloud driven storms
(Springer, 2017)Energetic electrons are trapped in the Earth’s radiation belts which occupy a toroidal region between 3 and 7 R E above the Earth’s surface. Rapid loss of electrons from the radiation belts is known as dropouts. The ... -
Comparison of physical properties of oxidative sintered pellets produced with UG2 or metallurgicalgrade South African chromite: a case study
(SAIMM, 2015)The physical properties of oxidative sintered pellets produced from typical South African UG2 ore are compared with the physical properties of pellets produced with conventional South African metallurgical-grade chromite ore ... -
Comparison of phytoplankton assemblages in two differentially polluted streams in the Middle Vaal Catchment, South Africa
(Elsevier, 2019)Phytoplankton is an important role player in the ecology of rivers and streams, and sensitive to changes in water quality. This study aimed to determine how pollution influenced phytoplankton composition in two streams and ... -
A comparison of risk aggregation estimates using copulas and Fleishman distributions
(Taylor & Francis, 2017)Determining banks’ expected losses (EL) is straightforward because they are calculated using a linear combination of credit risk-related measures. Non-linear metrics, like economic capital (EC), pose considerable ... -
Comparison of sampling methodologies and estimation of population parameters for a temporary fish ectoparasite
(Elsevier, 2016)Characterizing spatio-temporal variation in the density of organisms in a community is a crucial part of ecological study. However, doing so for small, motile, cryptic species presents multiple challenges, especially where ... -
A comparison of singular spectrum analysis forecasting methods to forecast South African tourism arrivals data
(Bureau for Economic Research and the Graduate School of Business, University of Stellenbosch., 2015)Singular spectrum analysis (SSA) has been shown to be a powerful non-parametric time series method by which a time series is unfolded into a Hankel structured matrix. Time series structures are then extracted by direct ... -
Comparison of sintering and compressive strength tendencies of a model coal mineral mixture heat-treated in inert and oxidizing atmospheres
(Elsevier, 2011)The chemical interactions responsible for sintering in a coal mineral mixture were investigated in air and in N2. A mineral mixture was made up by mixing kaolin, pyrite, quartz, calcite, hydromagnesite, FeCO3 and anatase ... -
A comparison of surface NO2 mixing ratios and total column observations at a South African site
(SASAS, 2014)The total column density nitrogen dioxide (NO2) retrievals collated by a ground-based sun-tracking spectrometer (Pandora/GSFC) and the satellite-borne (Aura) Ozone Monitoring Instrument (OMI) were compared to the volume ... -
A comparison of the cardiometabolic profile of black South Africans with suspected non-alcoholic fatty liver disease (NAFLD) and excessive alcohol use
(Elsevier, 2015)Excessive alcohol use and non–alcoholic fatty liver disease (NAFLD) are putative cardiovascular disease risk factors. In order to ease the identification of these conditions on primary health care level, we aimed to determine ... -
Comparison of the damage potential and yield loss of the rice root–knot nematode, Meloidogyne graminicola, on lowland and upland rice varieties from Myanmar
(Russian Academy of Sciences, 2015)In Asia, the rice root-knot nematode, Meloidogyne graminicola, is an important pathogen of Asian rice (Oryza sativa) in most rice producing countries including Myanmar. In the first part of our study, the damage potential ... -
Comparison of the dietary bioavailability of copper sulphate and copper oxide nanomaterials inex vivogut sacs of rainbow trout: effects of low pH and amino acids in the lumen
(RSC, 2020)Diet is an important exposure pathway of engineered nanomaterials (ENMs) in fish, but the long duration of in vivo toxicity tests is a barrier to hazard assessment. This study used ex vivo gut sacs from rainbow trout ... -
A comparison of the effect of two intervention regimes on coronary prone executives in the South African colliery industry
(The South African Society of Occupational Medicine, 2012)Corporate environment presently realises the importance of health promotion strategies to ensure health and productivity. In this pre-test-post-test quasi-experimental study, the effect of two intervention strategies ... -
Comparison of the lipid composition of three adipose tissue types of male and female wild nile crocodiles (Crocodylus niloticus)
(Taylor & Francis, 2014)We describe and compare the fatty acid composition of three different adipose tissue types, namely, abdominal, tail, and steatotheca (an abdominal fat body) tissues of healthy wild Nile Crocodiles (Crocodylus niloticus). ...