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A critical study of the curcumin method for the determination of boron in plant material

  • Authors: Davidson, Raymond John
  • Date: 1958
  • Subjects: Plants -- Nutrition , Boron , Turmeric
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4458 , http://hdl.handle.net/10962/d1011003
  • Description: Methods for the determination of boron are reviewed. A thorough investigation of the curcumin method was undertaken. Factors such as spectral absorption, boron volatilisation and the effects of pH, the stability of reagents and colour solutions, the drying of reaction products and the interference from certain elements, were investigated. A study of the efficiency of extracting boron from plant material using an ashing procedure is presented. The modified curcumin method for the determination of boron in plant material is described. The statistical accuracy and precision of the modified method is presented. The modified method was used to determine the boron content in citrus and pineapple leaf samples obtained from various parts of the Eastern Cape.
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A statistical study of the errors involved in the sampling and chemical analysis of soils and plants, with particular reference to citrus and pineapples

  • Authors: Steyn, Willem Johannes Abraham
  • Date: 1958
  • Subjects: Soil chemistry , Plants -- Analysis , Soils -- Analysis
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4506 , http://hdl.handle.net/10962/d1013291
  • Description: 1. Accurate and reproducible methods for the determination of N and acid- extractable P in soils are described. The variations in N, P, and K found by intensive sampling of three different soil types are presented. 3. Suggestions for the adequate sampling of soils for various purposes arc given. 4. A study is presented of the preparative stages in leaf analysis (washing, drying, grinding and storage) as applied to citrus and pineapple leaf material. Likely errors are pointed out and procedures whereby these may be minimised are described. 5. A reliable wet-ashing procedure for obtaining leaf solutions is described. 6. Accurate and reproducible methods for the determination of total N, P,. K, Ca, Mg, Na, Fe, Mn, Zn and Cu in citrus and pineapple leaves are presented. 7. It is shown that diurnal variations in nutrient concentrations occur in citrus and pineapple leaves. 8. The variations in N, P, K, Ca, Mg, Na, Fe, Mn, Zn and Cu, occurring from tree to tree in 3 different Navel orange blocks are presented. It is shown that if all these elements are to be represented . to within 10% of the mean values on a 19 : 1 probability level, all the trees in the blocks would have to be sampled. Reasonable sampling procedures for various purposes are suggested. 9. The variations in N, P, K, Ca, Mg, Fe, Mn, Zn and Cu, occurring in 3 different Cayenne pineapple plantations are presented and described. Suitable sampling procedures are suggested.
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Acacia Karoo enormous thorns

Aloe ferox - King William's Town

  • Authors: Skead, C J (Cuthbert John)
  • Date: 1958
  • Subjects: Aloe -- South Africa -- Eastern Cape -- Photographs , Trees -- South Africa -- Photographs
  • Language: English
  • Type: mixed material , photographs , landscape photographs
  • Identifier: http://hdl.handle.net/10962/72501 , vital:30073
  • Description: Caption: "Aloe ferox inflorescence burnt by frost on slopes of Karburie River at Peninsula far near Gray's Halt, KWT district, June 1958. Only the heads of a certain stage of development were affected. The fulls open and the sprouting ones were undamaged."
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Aloe ferox - King William's Town

  • Authors: Skead, C J (Cuthbert John)
  • Date: 1958
  • Subjects: Aloe -- South Africa -- Eastern Cape -- Photographs , Trees -- South Africa -- Photographs
  • Language: English
  • Type: mixed material , photographs , landscape photographs
  • Identifier: http://hdl.handle.net/10962/72524 , vital:30080
  • Description: Caption: "Aloe ferox inflorescence burnt by frost on slopes of Karburie River at Peninsula far near Gray's Halt, KWT district, June 1958. The head on the right is affected but not the others. It was a most exceptional spell of frost in an otherwise mild winter."
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An investigation of isolated bursts of solar radio noise

  • Authors: Shuter, William Leslie Hazlewood
  • Date: 1958
  • Subjects: Solar physics -- Research , Solar radio emission
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5539 , http://hdl.handle.net/10962/d1013216
  • Description: The literature on isolated bursts and possible mechanisms of origin has been critically reviewed, and observations point to a mechanism involving omission of electromagnetc radiation from plasma oscillations in the solar corona excited by outward travelling disturbances. Solar noise observations on 125 Mc./s. recorded at Rhodes University during the period November 26 1957 - February 6 1958 have been analysed by the author for isolated bursts, and these observations show the same general features reported by previous investigators. In interpretation of these records particular attention has been devoted to two aspects of isolated bursts; namely the preponderance on single frequency records of double-humped bursts, and the shape of isolated burst profiles. The authors suggests that a probable explanation of double-humped bursts observed on any frequency f is that the first hump represents omission at or near the level of zero refractive index for f radiation, and that the second hump corresponds to harmonic omission at the f/2 level. Source velocities may be calculated from the time delay between the peaks and an average value of 2 x 10⁴ km./sec. was obtained from an analysis of 21 double-humped bursts. This value is in very good agreement with that deduced by Wild (1950b) from the rate of frequency drift of peak intensity of isolated bursts. Simple isolated bursts had decay profiles which are approximatley exponential in shape, and this is usually interpreted in terms of the natural decay of plasma oscillations in the medium of origin. The author has verified that the exponential function is a good fit to the observed decay profiles, but shows that a relation of the form I - ¹/n (superscript) ⋉ t (where I is intensity and t is time) fits just as well. An alternative model is suggested which would lead to an exponential-like decay profile which is not determined by the natural decay of plasma oscillations. The work concludes with some suggestions for further research.
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Contributions to the biology, anatomy and physiology of Opisthophthalmus Latimanus & other scorpions

  • Authors: Alexander, Anne Joy
  • Date: 1958
  • Subjects: Scorpions -- South Africa , Scorpions -- Anatomy , Scorpions -- Physiology
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:5891 , http://hdl.handle.net/10962/d1013375
  • Description: [From Introduction] For many years the problem of interrelationships within the Arthropoda and, indeed, the origin of the Phylum itself have been of interest to many zoologists. It was felt, for reasons which will be given later, that one of the studies which might throw some light on this matter is that of the neuromuscular physiology of arachnid appendages. Consequently it was proposed that the work which is reported here should be primarily concerned with this problem. As in so many cases involving live animals, both the experimental subjects and the experimenter gradually managed to change the direction in which work was proceeding and the result is that only a preliminary attack has been made on the original problem, while most of the material submitted here deals either with functional anatomy or with biological-cum-behavioural characteristics of the experimental animal. Thus it was found that to develop experimental preparations for neuro-muscular studies, it was necessary to work out the anatomy of the muscles and nerves of the appendages used; but this it is not enough. For these nerves and muscles are part of a functional complex which operates as a unit and have therefore to be studied in relation to the structures that they move. Considerations at this level, in fact, carried the study to the plane of functional anatomy. Furthermore it was recognised that even the comprehension of a limb as a functional complex cannot be acquired in isolation. All structures have an evolutionary history and in any consideration of functional anatomy this history must be taken into account - even if the consideration requires extension to the problem of the origin of the group immediately under study.
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Correlation of the feeding habits, jaw musculature and type of teeth of some South African golden moles

  • Authors: Thelejane, Thomas Sohl
  • Date: 1958
  • Subjects: Moles (Animals) -- Food , Insectivores (Mammals)
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5892 , http://hdl.handle.net/10962/d1013385
  • Description: The jaw musculature and its innervation in the Chrysochloridae studied is typicaly mammalian except that the m. temporalis occupies the whole of the orbito-temporal fossa. The antemolar teeth are specialized, while the molars are simple and primitive. Normally the diet of Golden Moles consists of earthworms, insects in all stages of development and millipedes. The firm implantation of the antemolar teeth can be correlated with their function of catching the prey, while the molars are adapted for a worm-like diet. The available evidence indicates that the genera Bematiscus and Chrysospalax are more primitive than the other Golden Moles. Since Golden Moles feed on insects in all stares of development and millipedes, they can be considered as being of economic importance.
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Erythrina caffra

Erythrina caffra

Erythrina caffra

Erythrina caffra

Erythrina caffra - kaffirboom

Erythrina caffra - Kaffirboom

Erythrina caffra - Kaffirboom

Ficus sansibarica - Wild Fig

Freedom in the thought of John Locke and John Stuart Mill

  • Authors: Omer-Cooper, John David
  • Date: 1958
  • Subjects: Locke, John, 1632-1704 , Mill, John Stuart, 1806-1873 , Liberty , Ethics , Free thought , Autonomy (Psychology)
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:2746 , http://hdl.handle.net/10962/d1012989
  • Description: Recent history has abundantly justified J. S. Mlll's theory that the power of soclety over the indivldual is llkely to increase without limlt If lt was not prevented. One of the most obvlous phenomena of our times has been the rise of the so-called totalltarlan systems of government; states that treat the lndlvldual as a being wlth no other end but the servlce of the state and which are prepared to use the advanced technlques which modern scientific research has made available to them to mould the individual as the perfect tool of the system.
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Grahamstown: a socio-ecological study of a small South African Town

  • Authors: Watts, Hilstan Lett
  • Date: 1958
  • Subjects: Grahamstown (South Africa) -- Buildings , Grahamstown (South Africa) -- History , Grahamstown (South Africa) -- Social conditions , Grahamstown (South Africa) -- Economic conditions
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:3386 , http://hdl.handle.net/10962/d1013424
  • Description: Little is known at present about the development, structure, and functions of small towns in the Union of South Africa, and there is a need to fill this gap in our knowledge. A study has been made of Grahamstown, a small South African town. This study is monographic and intensive in character, and heuristic in aim. Ad hoc hypotheses have been formulated on the basis of the findings of the study, and these must be tested by subsequent studies of other small towns. Grahamstown, the subject of the study, was chosen largely for reasons of convenience, and also because of its interesting development. It is suggested that in many ways the town is possibly a typical small town, but at this stage we cannot know if this is so. Only the white population of the town was investigated, as it was necessary to limit research to manageable proportions, and in addition several studies have already been made of the non-white populations of the town. The analysis has been described as socio-ecological, as basically the methodological approach used is an attempt to wed the methods of the urban demographer and the social ecologist. Time and space are used as the two co-ordinates for the analysis, so that both a social historical and an ecological-demographic analysis of the town have been made. The historical analysis of the development and functions of Grahamstown relies heavily on material collected from the early newspapers of the town. Grahamstown, once the most important town in the Eastern Cape Province, known as the ''Emporium" and ''Metropolis" of the Eastern Cape, and the most progressive town in the Colony, is to-day a small static town with, on the whole, relatively restricted influence. This fundamental change in the historical development of the town, hitherto unexplained, is the result of the changes in the socioecological make-up of the region around the town. Founded in 1812 as a strategic outpost on the frontier of the Colony, Grahamstown dominated a wide region; as the gateway to and the supply centre for, the frontier, the town flourished and reigned supreme. From the mid 19th Century onwards the region began to change to a developed one, with the frontier more and more inland. Grahamstown, no longer a strategic outpost in a frontier region, lost its dominant ecological position to Port Elizabeth, the natural supply base for, and gateway to, the new settled region. As one town among many in the new settled region, Grahamstown gradually lost many of its former functions, and began to stagnate. The town is to-day mainly known for its important educational function. This function, a relic from the days of the town's zenith, has saved the town from complete stagnation. The town is what it is to-day largely because of the socio-ecological regional influences which have operated on it since its foundation. To-day Grahamstown is located within the Port Elizabeth metropolitan district. The town is the centre of a wide variety of regional services of an ad hoc type, and the modal region served seems to be that settled by the 1820 Settlers - basically the town is mainly a supply centre for its surrounding rural areas. The demographic structure of the town reveals a static population. Growth of the white population has been practically static since about 1880, and the age structure is that of a stationary population. Particularly noticeable is the under-representation of the young working group in the population, and it is suggested that due to the lack of economic opportunities in the town, the young workers of the town, especially the unmarried males, migrate to larger urban areas to seek employment, and advancement. The sex-ratio of the population shows an excess of females, and this may be due to migration out of an excess of young males, and possibly migration in of older spinsters. Retired persons definitely migrate to the town to settle. The town, a predominantly English speaking one, has practically no industries, and so the population contains a majority of workers engaged in professional, administrative, and commercial activities. This stresses the service and supply functions of the town. The ecological analysis delineated various natural areas and zones in the town. The pattern approximates to patterns revealed by studies of American towns. Although the areas involved were relatively small, ecological differentiation was marked. The spatial distribution of demographic and other social phenomena was studied in detail. The results of the study have allowed several ad hoc hypotheses concerning the development, functions, and structures of small towns in South Africa to be formulated. These may be tested by subsequent studies, and so ultimately knowledge and theories about our small towns may be built up.
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Harpephyllum caffrum - Kaffir plum

Kaffir plum

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