2,559 research outputs found
Dr P.J. du Toit : an appreciation
No full textThe articles have been scanned in colour with a HP Scanjet 5590; 300dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.Retirement of Dr. P.J. du Toit as Director of Veterinary Services, Department
of Agriculture, and as Dean of the Faculty of Veterinary Science, University
of Pretoria, Union of South Africa
Impact of market deregulation on the competitiveness of commercial milk producers in East Griqualand: a unit cost ratio (UCR) analysis: 1983-2006
No full textThis study investigates the impact of dairy market deregulation on the competitiveness of milk producers who comprise the East Griqualand (EG) study group in KwaZulu-Natal and the Eastern Cape Province of South Africa. The study uses a microeconomic approach, the unit cost ratio (UCR) method of competitiveness analysis, to assess changes in the relative competitiveness of EG milk producers from 1983 – 2006. Findings of previous research indicate that dairy market deregulation in the 1980s and 1990s caused lower real milk producer prices, increased uncertainty and higher exit rates in the South African dairy industry. Results of the UCR analysis suggest that EG milk producers were not competitive based on the net local price received for milk but were competitive when dairy cattle trading income was included. This suggests that dairy cattle trading income played an important role in enhancing the profitability of EG dairy enterprises in the study period. Further UCR analysis revealed that the top one-third of EG milk producers were relatively competitive from 1983 – 2006 due to higher real milk prices and lower unit costs. A panel data study of individual EG milk producers could be used to identify other important factors affecting milk producer competitiveness over time.dairy market deregulation, East Griqualand milk producers, competitiveness, unit cost ratio analysis, Livestock Production/Industries,
Plan einer Erziehungs-Anstalt
No full text[J. J. Du Toit. D. d. g. W.]Autopsie nach Ex. der ULB Sachsen-AnhaltVorlage des Erscheinungsvermerks: 1775
Plan einer Erziehungs-Anstalt
No full textAm Schluss datiert und unterzeichnet: "Nidau, im Canton Bern. 1775. J.J. Du Toit. D. d. g. W.
Sir Arnold Theiler, Dr P.J. du Toit and Dr G. de Kock
No full textPhoto of Sir Arnold Theiler, Dr P.J. du Toit and Dr G. de Kock taken at Onderstepoort in front of the main buildinghttp://www.ais.up.ac.za/vet/theiler.ht
Rhipicephalus glabroscutatus Du Toit 1941
No full text32. Rhipicephalus glabroscutatus Du Toit, 1941: Afrotropical: 1) South Africa, 2) Lesotho (Walker et al. 2000, Horak et al. 2018, Mahlobo & Zishir 2021). Malhobo & Zishiri (2021) reported the presence of Rhipicephalus glabroscutatus in Lesotho, which is provisionally included within the range of this tick.Published as part of Guglielmone, Alberto A., Nava, Santiago & Robbins, Richard G., 2023, Geographic distribution of the hard ticks (Acari: Ixodida: Ixodidae) of the world by countries and territories, pp. 1-274 in Zootaxa 5251 (1) on page 119, DOI: 10.11646/zootaxa.5251.1.1, http://zenodo.org/record/770419
Radial variation in porosity in annular packed beds
No full textThis paper describes the results of a study of the variation in the radial direction in the porosity of annular packed beds. A comparison is made between the predictions by a number of empirical correlations found in literature, the porosities obtained from physical experiments and the porosities obtained from the analysis of numerically generated packed beds. It is concluded that the numerical annular packed beds can be considered as acceptable representations of the actual annular packed beds. From the comparison between a number of exponential correlations proposed by various authors for the variation in the radial direction in the “averaged” porosity and the numerical results it is recommended that the correlation proposed by Hunt and Tien be used to describe the variation in the radial direction in the porosity. It is, however, also recommended that a further thorough study be conducted to develop a more detailed understanding of the porosity characteristics of annular packed bed
Die strafregtelike aanspreeklikheid van regspersone: lesse uit Kanada
No full textHierdie bydrae ondersoek die grondslag vir die strafregtelike aanspreeklikheid van regspersone in Kanada in 'n poging om moontlike lesse vir die Suid-Afrikaanse reg daaruit te neem. Die Kanadese benadering gee erkenning aan die gefragmenteerde aard van korporatiewe besluitneming én aan die realiteit dat die kollektiewe gedrag van verskeie persone op verskillende vlakke van die korporatiewe hiërargie die misdadige gedrag kan veroorsaak. Voorts hoef die gedrags - en skuldelemente nie aan 'n enkeling toegeskryf te word nie. Die gedrag van die korporatiewe verteenwoordiger kan die handelingselement vorm, terwyl die skuldelement by die bestuur kan lê. Hierdie benadering, hoewel nie volkome 'realisties' van aard nie, verreken tog die aard van moderne regspersone heelwat beter as tradisionele individualistiese benaderings tot die strafregtelike aanspreeklikheid van regspersone. ABSTRACT: This contribution investigates the basis for the criminal liability of juristic persons in Canada in an attempt to gain lessons for South Africa. The Canadian position acknowledges both the fragmented nature of corporate decision-making and the reality that the collective efforts of a number of corporate role players may cause criminal conduct. Furthermore, the conduct and fault elements of corporate criminal misconduct do not have to be found in one individual. The conduct of a representative of the corporate entity may be regarded as the conduct of the corporation, whilst the fault requirement may be found to be the level of management. This approach, although not entirely 'realistic', takes into account the nature of modern corporate entities much better than traditional individualistic approaches to corporate criminal liability
The effect of metacognitive intervention on learner metacognition and achievement in mathematics
No full textEnglish: International and national measures point to the poor mathematics achievement of South African learners. The enhancement of the quality of mathematics education is a key priority of the Department of Basic Education in South Africa. Several studies have found a correlation between learner metacognition and mathematics achievement. Metacognition entails knowledge and regulation of one’s cognitive processes. Previous studies point to the positive effect of metacognitive interventions on learner metacognition and mathematics achievement. The purpose of this study was to investigate the effect of a metacognitive intervention (MI) on learner metacognition and the mathematics achievement of Grade 11 learners in the Free State from a predominantly pragmatic perspective. The MI was developed by combining aspects of a mathematical perspective on De Corte’s (1996) educational learning theory with aspects of previous metacognitive intervention studies in mathematics. A mixed methods research design was employed where qualitative data were embedded within a quasi-experiment. Data were collected from an experimental group (N=25) and a control group (N=24). Quantitative data on learner metacognition were obtained from the Metacognitive Awareness Inventory (MAI), while quantitative data on mathematics achievement were obtained from the learners’ Terms 1 and 4 report marks. Qualitative data were acquired by means of teacher interviews, problem-solving sessions, and learner and teacher perspectives on the MI process. The mixed methods research question investigated the extent to which the findings from the qualitative phase of the study support the findings from the quantitative phase regarding the effect of MI on learner metacognition and mathematics achievement. The quantitative findings indicated that MI had a statistically significant impact on learner metacognition in respect of the MAI total score, the Knowledge of cognition (KC) factor, the Regulation of cognition (RC) factor, and the subscales Declarative knowledge, Planning, and Monitoring. The impact of MI on mathematics achievement was less pronounced, as inferences had to be drawn from the correlation between learner metacognition and mathematics achievement. The quantitative findings showed a statistically significant correlation between KC and mathematics achievement, as well as between Declarative knowledge and mathematics achievement. Since MI had a statistically significant impact on KC and Declarative knowledge, it is concluded that MI also had a positive impact on mathematics achievement. The qualitative findings strongly support the quantitative findings regarding the positive impact of MI on learner metacognition. The quantitative findings in respect of the correlation between learner metacognition and mathematics achievement were only partially supported by the qualitative data. Main recommendations emerging from this study relate to the improvement of learners’ mathematics achievement by enhancing their Declarative knowledge, the enhancement of learners’ problem-solving skills, and the need to implement metacognitive interventions in mathematics particularly in schools where the teachers are inexperienced or underqualified.Afrikaans: Die swak wiskunde-prestasie van Suid-Afrikaanse leerders word deur internasionale en nasionale maatstawwe aangetoon. Die verbetering van die kwaliteit van wiskunde-onderwys is ‘n kernprioriteit van die Departement van Basiese Onderwys in Suid-Afrika.
Verskeie studies het bevind dat daar ‘n korrelasie tussen leerdermetakognisie en wiskunde-prestasie is. Metakognisie behels die kennis en regulering van ‘n persoon se kognitiewe prosesse. Vorige studies dui op die positiewe effek van metakognitiewe intervensies op leerdermetakognisie en wiskunde-prestasie.
Die doel van hierdie studie was om die effek van ‘n metakognisie intervensie (MI) op leerdermetakognisie en die wiskunde-prestasie van Graad 11 leerders in die Vrystaat vanuit ‘n grotendeels pragmatiese wêreldsiening te ondersoek. Die MI is ontwikkel deur aspekte van ‘n wiskundige perspektief op De Corte (1996) se opvoedkundige leerteorie met aspekte van vorige metakognisie-intervensiestudies in wiskunde te kombineer.
‘n Gemengde-metodes navorsingsontwerp is gebruik waar kwalitatiewe data in ‘n kwasi-eksperiment ingebed was. Data is van ‘n eksperimentele groep (N=25) en ‘n kontrole groep (N=24) verkry. Kwantitatiewe data van leerdermetakognisie is verkry uit die “Metacognitive Awareness Inventory” (MAI) terwyl kwantitatiewe data van wiskunde-prestasie uit die Kwartaal 1- en Kwartaal 4 rapportpunte verkry is. Kwalitatiewe data is uit onderhoude met onderwysers, probleemoplossingsessies, en leerder- en onderwyserperspektiewe oor die MI-proses verkry. Die gemengde-metodes navorsingsvraag het die mate ondersoek waartoe die bevindinge van die kwalitatiewe fase van die studie die bevindinge ondersteun van die kwantitatiewe fase met betrekking tot die effek van MI op leerdermetakognisie en wiskunde-prestasie.
Die kwantitatiewe bevindinge het aangedui dat MI ‘n statisties-beduidende impak op leerdermetakognisie gehad het met betrekking tot die totale MAI-telling, die Kennis van kognisie-faktor, die Regulering van kognisie-faktor, en die subskale Verklarende kennis, Beplanning, en Monitering. Die impak van MI op wiskunde-prestasie was minder prominent omdat afleidings gemaak moes word uit die korrelasie tussen leerdermetakognisie en wiskunde-prestasie. Die kwantitatiewe bevindinge het aangetoon dat daar ‘n statisties-beduidende korrelasie tussen Kennis van kognisie en wiskunde-prestasie was, en ook tussen Verklarende kennis en wiskunde-prestasie. Omdat MI ‘n statisties-beduidende impak op Kennis van kognisie en Verklarende kennis gehad het, word die gevolgtrekking gemaak dat MI ook ‘n positiewe impak op wiskunde-prestasie gehad het.
Die kwalitatiewe bevindinge ondersteun tot ‘n groot mate die kwantitatiewe bevindinge wat verband hou met die positiewe impak van MI op leerdermetakognisie. Die kwantitatiewe bevindinge ten opsigte van die korrelasie tussen leerdermetakognisie en wiskundeprestasie was slegs gedeeltelik deur die kwalitatiewe data ondersteun.
Hoofaanbevelings voortspruitend uit hierdie studie het betrekking op die verbetering van leerders se wiskunde-prestasie deur die verbetering van hulle Verklarende kennis, die verbetering van die leerders se probleemoplossingsvaardighede, en die noodsaaklikheid om metakognitiewe intervensies in wiskunde te implementeer veral in skole waar die onderwysers onervare is of onvoldoende gekwalifiseer is
Analysing the porous structure of packed beds of spheres using a semi-analytical approach
No full textIn this paper methodologies are described for the analysis of the porous structure of cylindrical and annular packed beds consisting of spheres when the coordinates and sizes of the spheres are known. Methodologies to determine the overlap between adjacent spheres and between the spheres and the walls of the container; axial variation in the porosity and hydraulic diameter; and the radial variation in the porosity are described. The determination of the overall bulk porosity, as well as the average porosity of selected regions, from the results are also discussed. The methodologies are based on analytical geometry and Simpson's rule is used to perform the numerical integration of the relevant integrals. The validity of the methodologies is demonstrated and the application of the methodologies to analyse the porous structure of selected packed beds is illustrate
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