'N strategie vir melkproduksie in die winterreënstreek van Suid-Afrika

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Digestibility studies with Prosopis juliflora (mesquite thorn) pods

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Activity budgets of male Maccoa ducks

The behaviour of breeding and non-breeding male maccoa ducks (Oxywa maccoa) was studied in South Africa. Individual ducks were observed continuously from sunrise to sunset in the wild, and all ritualized and non-ritualized behaviour was recorded. Diurnal time budgets of territorial and non-territorial males were translated into energy budgets, showing relative time and energy expenditures for resting, foraging, preening and bathing, territorial defence and courtship activities. A territorial male spent one-third of the daytime on active behaviour associated with reproduction. Territorial males averaged 297 displays per fifteen-hour day, or about one display every three minutes. Active defence of territory occupied 15 per cent of a male's time budget, adding an estimated 20 per cent to the energy a non-breeding male spent on self-maintenance. Active courtship of females occupied IS per cent of a male's time budget, adding 18 per cent to the energy a non-breeding male spent on self-maintenance. The increase in time spent on reproductive behaviour over that of a non-breeding male is achieved mainly through decrease of time allocated to resting in the budget of the non-breeder. Territorial males increased energy expenditure by a factor of 1,3, but devoted the same portion of time as non-breeders to actual feeding (21 per cent). Energy and time-saving strategies were associated with territorial defence and courtship, contributing towards optimization of time and energy budgeting

Injection of coal fly ash slurry in deep saline formations for improved CO2 confinement : a theoretical concept

98% of South Africa‟s total CO2 geological storage capacity is in the form of deep saline formations located off-shore, while the remaining 2% is situated on-shore. Such formations may not have a similar proven sealing capacity to that of depleted gas and oil reservoirs, and the country must give due consideration to every theoretically conceivable option for CO2 storage. This paper discusses a theoretical concept whereby coal fly ash slurries, composed of homogeneously-sized ultra-fine particles with adequate shear-thinning Newtonian rheological properties when suspended in water, could be injected in deep saline formations, alongside CO2, to engineer a „mineral curtain‟ that could act as a barrier preventing unwanted CO2 migration outside the boundary layers of the reservoir. The resulting pressure build-up could be managed by extracting the brine from the formations, which could then be used to produce fresh water for local communities deprived of drinking water.South African Centre for Carbon Capture and Storage and the Mining Qualifications Authority of South Africahttp://www.elsevier.com/locate/ijggchb201

Heartwater : past, present and future : proceedings of a workshop held at Berg en Dal, Kruger National Park, on 8-16 September 1986

The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Nuutste ontwikkelinge in kennis oor die mineraalmetabolisme en mineraalversorging van herkouers

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Exercising 'Race' through the coronation physical training competition

During the last decade of the 19 th and first two decades of the 20 th century, the Cape Colony education authorities employed an instructional method known as physical training or physical training drill. This investigation expands on two previous studies that explored the Coronation Physical Training Competition (1902-1906). The low number of entries indicates that the Education Department was not serious in drawing a mass of learners to the competition. This article investigates the racial considerations behind this. The competition was organised in a post South African War (1899-1902) period where the education authorities asserted British racial superiority through their concern with race. The Coronation Physical Training Competition fitted into this agenda. Despite betrayal by the English during the post South African War negotiations, Black political movements and individuals continued seeking means to prove themselves loyal subjects of the King. Black schools therefore had no problem with competing in the Coronation Competition as second-class citizens. The education authorities held two Coronation competitions under the same banner. The competition was not only divided racially but differed in quality, favouring Whites

Die vitamin A-status van beeste of Elsenburg

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Mass density of oat hay and lucernee hay as a feed evaluation characteristics

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Nasionale beplanning en koördinering van veekundige navorsing in Suid-Afrika

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