Browsing by Author "Coetzee, C."

Now showing 1 - 5 of 5
  • Thumbnail Image
    Item
    An ancient example of literary blackmail
    (Stellenbosch University, Department of Ancient Studies, 2018) Coetzee, C.
    ENGLISH ABSTRACT: Towards the end of his life and especially after his exile in 58-57 BC, Cicero’s publication program accelerated. While he aimed to promote his own glory, he had to do so in an environment where writing about oneself attracted censure. This article explores some of the ways in which Cicero tries to overcome this limitation. These include writing about himself indirectly, defending artists in court, soliciting historians to include his role as consul in their works and even attempts at public literary blackmail, specifically towards his prolific contemporary, Marcus Terentius Varro.
  • Thumbnail Image
    Item
    Investigation of thiol levels in young commercial South African Sauvignon Blanc and Chenin Blanc wines using propiolate derivatization and GC-MS/MS
    (South African Society for Enology and Viticulture, 2018) Coetzee, C.; Schulze, A.; Mokwena, L.; Du Toit, W. J.; Buica, A. S.
    In this work, the ethyl propiolate method for analysing thiols in white wine by GC-MS, originally proposed by Herbst-Johnstone et al.) (2013), has been adapted to GC-MS/MS and has been validated. The method performance has shown improvement in terms of sensitivity (limit of detection, LOD) and of the number of compounds measured. In addition to 3-mercaptohexanol (3MH), 3-mercaptohexyl acetate (3MHA), and 4-mercapto-4-methylpentan-2-one (4MMP), the adapted method can also measure 2-furanmethanethiol (FMT) and makes use of a commercially-available internal standard (IS), 4-methoxy-2-methyl-2-butanethiol (4M2M2B, IS). The proposed method was applied to determine thiol levels in young commercial South African Sauvignon and Chenin Blanc wines. The samples (n=20 for each cultivar) were chosen according to a high frequency of the typical descriptors associated with this class of impact compounds. 3MH was found at 178-904 ng/L and 99-1124 ng/L, and 3MHA at 23-151 ng/L and 5-253 ng/L in Sauvignon and Chenin Blanc respectively. 4MMP was present in Sauvignon Blanc in concentrations up to 21.9 ng/L, but in none of the Chenin Blanc samples.
  • Thumbnail Image
    Item
    Motoriese ontwikkeling en selfkonsep by laerskool seuns : 'n intervensie studie
    (Stellenbosch : Stellenbosch University, 2004-03) Coetzee, C.; Hendry, J. A.; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Interdisciplinary Health Sciences. Centre for Rehabilitation Studies.
    ENGLISH ABSTRACT: The modern child forms part of a computerised television generation with little exposure to physical activities. Contributing factors such as violence, the increased prevalence of single parents, smaller playgrounds and increased pressure to succeed contribute to an increase in motor development problems in children. Various studies (Skinner & Piek, 2001; Losse, Henderson, Elliman, Hall, Knight & Jongmans, 1991) found a correlation between motor developmental problems and a poor self-concept. This implies a negative cycle because poor motor development has a negative influence on selfconcept and individuals with a poor self-concept do not have the nerve to take part in activities that will improve their motor skills. Objective The objective of this study was to determine whether a positive correlation could be drawn between motor problems and self-concept in nine- to 10 year old boys, as well as to determine whether a motor developmental program that stretches over a period of eight weeks will make a significant difference to nine- to ten year old boys. Another objective of this study was to apply the results of this study in such a way that it could be used to perform preventative rehabilitation programs in order to decrease the prevalence of motor problems. METHODS An intervention study was used. Two schools from similar sosio-economic backgrounds were identified and 20 boys between the ages of nine and ten year were randomly appointed as subjects. Vredelust Primary was chosen as the experimental group and Parow East Primary as the control group. Both groups were evaluated according to motor abilities and self-concept during a pre-test session. After completion of these evaluations, the experimental group followed an eight-week motor development programme (thus eight hours). Both groups' motor abilities and self-concept were re-evaluated and all results were calculated in Microsoft Excell under the supervision of the Statistics Department of the University of Stellenbosch. RESULTS The experimental group improved significantly with regard to motor abilities, while the control group did not show a significant change in motor skills. Both groups did not have significant changes over the eight weeks with regard to self-concept. Although not statistical significant the experimental group's mean with regard to self-concept did improve, while the control group's selfconcept showed a slight decreased when compared to the mean. CONCLUSION In conclusion, the statement can be made that motor development programmes that stretch over eight weeks will have a significant influence on nine- to 10 year old boys' motor abilities. The influence of this improvement on self-concept could not be accurately determined.
  • Thumbnail Image
    Item
    Research note: the use of SO2 to bind acetaldehyde in wine : sensory implications
    (South African Society for Enology and Viticulture, 2018) Coetzee, C.; Buica, A. S.; Du Toit, W. J.
    It is thought that the formation of hydroxysulphonate when sulphur dioxide is added to wine containing free acetaldehyde negates the sensory impact of the latter compound, but little research has been done on this. Descriptive analyses were employed using a trained sensory panel to assess the sensory effect of sulphur dioxide and acetaldehyde as single compounds and in combination in model wine. The addition of acetaldehyde or sulphur dioxide as singular compounds led to large increase in especially the green apple or sulphur descriptors respectively. When these two compounds were added in equimolar concentrations, the green apple description decreased drastically; however, a prominent sulphur description was still noted. It thus seems that hydroxysulphonate also has a sulphur-like aroma. The hydroxysulphonate did not influence the perception of a prominent ester, isoamyl acetate, in model wine. A low pH influences the perception of sulphur when sulphur dioxide is present on its own, but this is not the case with hydroxysulphonate. The implications of these results for wine production are discussed further.
  • Thumbnail Image
    Item
    The use of SO2 to bind acetaldehyde in wine : sensory implications
    (South African Society for Enology and Viticulture, 2018) Coetzee, C.; Buica, A.; Du Toit, W. J.
    It is thought that the formation of hydroxysulphonate when sulphur dioxide is added to wine containing free acetaldehyde negates the sensory impact of the latter compound, but little research has been done on this. Descriptive analyses were employed using a trained sensory panel to assess the sensory effect of sulphur dioxide and acetaldehyde as single compounds and in combination in model wine. The addition of acetaldehyde or sulphur dioxide as singular compounds led to large increase in especially the green apple or sulphur descriptors respectively. When these two compounds were added in equimolar concentrations, the green apple description decreased drastically; however, a prominent sulphur description was still noted. It thus seems that hydroxysulphonate also has a sulphur-like aroma. The hydroxysulphonate did not influence the perception of a prominent ester, isoamyl acetate, in model wine. A low pH influences the perception of sulphur when sulphur dioxide is present on its own, but this is not the case with hydroxysulphonate. The implications of these results for wine production are discussed further.