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Some comparative studies of the fauna in soils developed under natural forest, pine and bluegum

- Watts, John Christopher David

Authors: Watts, John Christopher David
Date: 1952
Subjects: Soil science , Forest ecology , Soil animals
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:5895 , http://hdl.handle.net/10962/d1013423
Description: [From Introduction] It has been said that, "If a nation saves its trees, the trees will save the nation." The truth of this assertion is apparent in many parts of the world today. In South Africa, fires and demands in the past for timber have led to extensive depletion of the Natural Forests. In many cases, natural revegetation has been slow to develop and deterioration of the soil has resulted. The desire to replace the tree cover and at the same time to meet an increasing internal demand for timber, has led to widespread planting of Pine and Bluegum. It is probable that more trees have now been planted than were destroyed in the past. The silviculturist however, who develops a pure stand on land which previously supported the mixed stand, should anticipate a change in soil properties as a natural accompaniment of such an undertaking. The nature of this change is the primum mobile of the present comparative study. The forest soils studied were taken in the Cape Province in the following areas:- Grahamstown; Amatola Mountains, District Alice; Witte-els-Bosch, District Humansdorp, during the course of a year. The physical and chemical properties, and the faunal composition of the soil samples were examined in relation to the different tree covers. Because of the necessity of taking large numbers of samples and thorough examination of these to arrive at a definite conclusion, the work is necessarily incomplete. It is felt however that the results obtained justify a further study of this aspect of soil biology.
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Date Issued: 1952

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The distribution, importance and biology of the important cotton pests of Moc̦ambique

- Da Silva Barbosa, António Jorge

Authors: Da Silva Barbosa, António Jorge
Date: 1952
Subjects: Cotton -- Diseases and pests -- Moc̦ambique
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:5844 , http://hdl.handle.net/10962/d1010977 , Cotton -- Diseases and pests -- Moc̦ambique
Description: Up to the second half of the eighteenth century the most important fibres in the world were wool, flax and silk. But the Industrial Revolution in England, together with the invention of the Cotton gin by Whitney in 1793, soon gave cotton the first place amongst all the important fibers in world's textile industry. Although some attempts were made, both in Angola and Mozambique to cultivate cotton since remote days -- as far back as the American Civil War, when market prices suffered an important rise no serious efforts were made to grow this crop before the proclamation of the Portuguese Republic in 1910, when some definite legislation was passed to encourage the development of this culture.
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Date Issued: 1952

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A critical study of assessments made during a trial interview situation

- Pons, A L

Authors: Pons, A L
Date: 1951
Subjects: Interviewing
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:3226 , http://hdl.handle.net/10962/d1013040
Description: At the end of 1948 the National Institute for Personnel Research (N.I.P.R.) organised a series of testing procedures for the selection of administrative trainees for a large industrial organisation. The fruitful results obtained by the British War Office and the Civil Service selection Boards in the application of approved techniques for similar purposes supplied the basis on which the battery of tests was constructed. While having regard for this established approach as well as the controlling influence imposed by the stipulations of the contract, the N.I.P.R. was able to devise a battery which provided scope for its specific interest in research. Intro., p. 1.
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Date Issued: 1951

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A socio-economic study of East London, Cape Province, with special reference to the non-European peoples

- Bettison, D G

Authors: Bettison, D G
Date: 1951
Subjects: East London (South Africa) -- Social conditions , East London (South Africa) -- Economic conditions , Rural-urban migration -- South Africa
Language: English
Type: Thesis , Masters , MA
Identifier: vital:3387 , http://hdl.handle.net/10962/d1013496
Description: From Forward: The development of gold mines in the Orange Free State is likely to be to modern East London what Kaffir Wars were to old East London. "The Fighting Port", as it is commonly called, is the nearest harbour to these mines and is linked by good rail, road and air facilities. A wide variety of industry is already established. Development is likely to be rapid. At present the City contains over 80,000 persons, and with the addition of peri-urban suburbs has doubled its population in just over fifteen years. In the past is has claimed to be the healthiest holiday resort in the Union. This year a City-wide campaign has been organised to fight tuberculosis, as the City's statistics indicate that it has one of the highest rates of anywhere in the world. Within twelve years two government sided commissions of enquiry have sat in the City and reported on the administration and living conditions of the city's African populaton. Extremely strong adjectives have been used to describe, and drastic recommendations made to improve the socio-economic and general conditions of the African people. Under the holiday atmosphere of the City lies a very serious, complex, and potentially dangerous human problem.
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Date Issued: 1951

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East London and its geographical setting

- Moult, Frank Leslie

Authors: Moult, Frank Leslie
Date: 1951
Subjects: East London (South Africa) -- Geography
Language: English
Type: Thesis , Masters , MA
Identifier: vital:4874 , http://hdl.handle.net/10962/d1012908
Description: Along the South African coast between Cape Town and Durban, a distance of 822 miles, are the two major ports, Port Elizabeth and East London. These two ports, rivals in some ways, have histories that are closely linked. Their harbours have been built at two of the most favourable spots along a coastline poorly endowed with natural harbours. East London, the fourth harbour of the Union of South Africa, is the only river port of any consequence, and had to win the mechanical fight against nature and the fight against prejudice that contended that her position was too close to a troublesome frontier. After a hundred years of growth, East London is a mature town, with the residential and industrial areas clearly defined. Her expansion will be along the lines of planned zoning. (2) Her population in 1950 was 910,195 of which 43,195 were European and 39,698 Native. Besides being a port, East London is a prominent holiday resort and, of recent years, is developing as an industrial town. A striking feature is the clean aspect of the town. Those two "miracles" of South Africa, the discovery of diamonds and the discovery of gold, stimulated the growth of East London; especially the discovery of diamonds since Kimberley was about 450 miles from this, its nearest harbour. But the river mouth at East London had very little natural advantage over the other river mouths along the coast. There was at the Buffalo Mouth no outstanding, decisive merit. In many matters, such as the railway, the bridge, the water supply, there was doubt, uncertainty and bickering, with subsequent decisions to shelve the latter or make use of a temporary expedient, because there were many mediocre alternatives but none which was supremely suitable. In 1852, Bishop Gray wrote, "East London ... .has as few natural advantages as any place I have seen claiming to be a port. I could have walked across the river without getting wet above the knee." Intro., p. i-ii.
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Date Issued: 1951

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A study of the E region of the ionosphere

- Barnard, A J

Authors: Barnard, A J
Date: 1950
Subjects: Ionosphere -- Research
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:5549 , http://hdl.handle.net/10962/d1013464
Description: After a brief historical introduction, the apparatus used in the investigation of the ionosphere in Grahamstown, is described with special reference to the recording equipment, which consists essentially of a camera focussed on the screen of a C.R.O. with z-axis deflection. The equations of the magneto-ionic theory are quoted. The basic formulae of the theories of layer formation in an isothermal (Chapman's),and linear temperature gradient (Gledhill and Szendrei) atmosphere are also quoted.
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Date Issued: 1950

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A study on white leather tannage

- Williams-Wynn, D A

Authors: Williams-Wynn, D A
Date: 1950
Subjects: Uncatalogued
Language: English
Type: Diploma theses , text
Identifier: http://hdl.handle.net/10962/193713 , vital:45389
Description: As has been noted in the previous section little or no complex formation occurs with either formate or acetate except possibly above pH 9*0 or so. These anions do not stabilise the aluminium solutions to precipitation - they may* however, be of value in controlling pH, as solutions of these salts buffer strongly in the region pH 4 to 5. The other salts, lactate, tartrate and citrate all show tendencies to complex formation though the degree to which this occurs varies with the anion. The complexes formed by lactate at high pH must be very unstable because on the addition of acid the pH corresponds to the calculated blank. Below pH 9.0 however, the curves deviate quite considerably showing that more acid must be added to reach a certain pH value than is required by the blank. This means complex formation has occurred with loss of -COGH groups. In this system too, buffering is apparent. The same is true of tartrate but this salt is not as efficient a buffering agent. This is probably due to the fact that the excess tartrate is not available as a buffer as it is precipitated as the acid salt which is only sparingly soluble. Citrate on the other hand must form very stable complexes, the effect of which is apparent at even very high pH values. In other words, addition of strong acid liberates free -GOGH groups which are immediately incorporated in the complex. This evidently does not occur with lactate or tartrate until lower pH values are reached. The ratio of lactate and citrate to aluminium appears to have some influence on the degree of masking as greater complex formation is found to occur at the higher ratio levels. Tartrate on the other hand apparently has a fixed complex forming capacity between 1 and 4 mols/mol aluminium, since the same deviation from the blank was observed irrespective of which ratio of the masking agent to aluminium, was employed. However, at ratios of less than 1 mol tartrate/mol aluminium, deviations from the blank were reduced and less stabilisation occurs as evidenced by the formation of precipitates containing aluminium under these conditions. In view of these facts it may be suggested that 1 mol tartrate combines with 1 mol aluminium to form a complex containing equimolar proportions of aluminium and tartrate. The effect of boiling apart from one or two exceptions always has the same effect, i.e. a shift to the acid side of the curve. Free acid must have been liberated which is an indication that olation might have occurred. In the lactate and citrate series dilution appears to reduce the complex forming capacity of these ions but tartrate is unaffected. Thus it would appear that the tartrate complex is more stable than those formed by lactate. Citrate stabilises aluminium solutions with fewer equivalents than tartrate, but the complex does not contain a constant ratio of masking agent to aluminium further quantities of tartrate cannot enter the complex even in the presence of large excess of the anion probably due to the effect of steric hindrance. , Thesis (Dip) -- Leather Industries Research Institute, 1950
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Date Issued: 1950

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An investigation of certain complex ions of trivalent chromium by spectrophotometric and other physical methods

- Burley, Ralph Walter

Authors: Burley, Ralph Walter
Date: 1950
Subjects: Chromium
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:4521 , http://hdl.handle.net/10962/d1014675
Description: Although chromium coordination compounds are of considerable technological importance, they have been subjected to few thorough investigations since Werner's original experlments, in spite of the fact that we now possess a number of accurate physical methods, not available in Werner's time for the study of coordination complexes, The object of the work described in this thesis was to obtain further information on the chemistry of complex chromium(III) ions with special reference to the dioxalato-diaquochromiate system, [Cr(C₂0₄)₂(H₂0)₂]. For this purpose; spectrophotometric and potentlometrlc measurements were combined to yield information on a number of topics, The spectrophotometric investigations consisted in measuring the absorption spectra of the potassium salts of the complexes under consideration and in observing the changes in light absorption which occur during their formatlon and decomposition. The instrument used was a Beckmann Quartz Spectrophotometer model du. More than than twelve new absorption spectra were measured in this work and in conjunction with the spectra of other chromium and cobalt complexes reported by earlier workers, these are used to review the position of spectrophotometry as a method of investigating chromium complexes. The reasons for the shapes of the absorption spectra are discussed and it is concluded that spectrophotometry is useful for observing the progress of reactions involving complex ions and for analysing solutions, but that more fundamental data cannot be expected from the absorption curves.
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Date Issued: 1950

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Studies in the plant ecology of Fern Kloof near Grahamstown

- Seagrief, S C

Authors: Seagrief, S C
Date: 1950
Subjects: Plant communities -- South Africa -- Eastern Cape , Plant ecology -- South Africa -- Eastern Cape , Plants -- South Africa -- Eastern Cape , Forest ecology -- South Africa -- Eastern Cape
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:4267 , http://hdl.handle.net/10962/d1014299
Description: The area studied at Fern Kloof, near Grahamstown, consists of a strip of vegetation approximately 260 yds. long and 50 yds. wide, in which there are two communities: 1) indigenous forest 2) exotic Pine forest (which has only one tree species Pinus pinaster). Throughout the thesis this species is referred to as the pine. The object of the investigation has been to determine whether these communities are natural or not. This has involved a study of the floristic composition, the life forms and the structure of the plant communities. In addition, various soil and environmental factors have been studied.
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Date Issued: 1950

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