A study of the fluorescence excitation spectrum of crystalline anthracene
- Authors: Driver, Adrian Stanford
- Date: 1960
- Subjects: Fluorimetry , Anthracene crystals -- Spectra
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5518 , http://hdl.handle.net/10962/d1011463 , Fluorimetry , Anthracene crystals -- Spectra
- Description: The work described in this thesis was performed at the Physics Department, Rhodes University during 1958 and 1959 under the supervision of Professor J.A. Gledhill. Use was made of a vacuum ultra-violet spectrograph which had been constructed in the Physics Department (1.1) and modifications to be described were made to this instrument. The instrument was used for studying the effects of oxygen on the fluorescence excitation spectrum of Anthracene.
- Full Text:
- Date Issued: 1960
- Authors: Driver, Adrian Stanford
- Date: 1960
- Subjects: Fluorimetry , Anthracene crystals -- Spectra
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5518 , http://hdl.handle.net/10962/d1011463 , Fluorimetry , Anthracene crystals -- Spectra
- Description: The work described in this thesis was performed at the Physics Department, Rhodes University during 1958 and 1959 under the supervision of Professor J.A. Gledhill. Use was made of a vacuum ultra-violet spectrograph which had been constructed in the Physics Department (1.1) and modifications to be described were made to this instrument. The instrument was used for studying the effects of oxygen on the fluorescence excitation spectrum of Anthracene.
- Full Text:
- Date Issued: 1960
An investigation of the profiles of bursts of solar radio noise
- Wild, Peter Anthony Thornton
- Authors: Wild, Peter Anthony Thornton
- Date: 1960
- Subjects: Solar radio emission , Radio noise , Solar noise storms , Radio astronomy
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5551 , http://hdl.handle.net/10962/d1013504
- Description: [Summary] Chapter I . The general characteristics of solar radiation at metre wavelengths are described, with reference to data published in the literature. A brief description of some aspects of solar physics relevant to the study of solar noise is given, and the literature relating to the correlation of radio effects with solar disturbances is reviewed. Chapter II. A concise description of the apparatus constructed for the continuous recording of the flux density of solar radio noise at a frequency of 300 Mc/s is given, with some mention of difficulties experienced, and how these were overcome. Full circuit diagrams of electronic apparatus, and illustrative photographs, are supplied. Chapter III. The development of theories of the origin and propagation of solar noise radiation is historically reviewed and the success of each theory in explaining or predicting observed phenomena, is assessed. A working model is chosen from among these theories, and reasons for its adoption are given. Chapter IV. Observations made by the author of solar radiation at a frequency of 300 Mc/s are described, together with a description of the objects and methods, of analysis of the records. Chapter V. Phenomena observed by the author are compared with those observed by other workers. It is concluded that storm bursts are caused by transients similar to those producing Type II and Type ITI bursts, and a model for the production of storm bursts is tentatively suggested. Chapter VI. Suggestions for further research, including suggestions for methods of testing the author's conclusions, are made.
- Full Text:
- Date Issued: 1960
- Authors: Wild, Peter Anthony Thornton
- Date: 1960
- Subjects: Solar radio emission , Radio noise , Solar noise storms , Radio astronomy
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5551 , http://hdl.handle.net/10962/d1013504
- Description: [Summary] Chapter I . The general characteristics of solar radiation at metre wavelengths are described, with reference to data published in the literature. A brief description of some aspects of solar physics relevant to the study of solar noise is given, and the literature relating to the correlation of radio effects with solar disturbances is reviewed. Chapter II. A concise description of the apparatus constructed for the continuous recording of the flux density of solar radio noise at a frequency of 300 Mc/s is given, with some mention of difficulties experienced, and how these were overcome. Full circuit diagrams of electronic apparatus, and illustrative photographs, are supplied. Chapter III. The development of theories of the origin and propagation of solar noise radiation is historically reviewed and the success of each theory in explaining or predicting observed phenomena, is assessed. A working model is chosen from among these theories, and reasons for its adoption are given. Chapter IV. Observations made by the author of solar radiation at a frequency of 300 Mc/s are described, together with a description of the objects and methods, of analysis of the records. Chapter V. Phenomena observed by the author are compared with those observed by other workers. It is concluded that storm bursts are caused by transients similar to those producing Type II and Type ITI bursts, and a model for the production of storm bursts is tentatively suggested. Chapter VI. Suggestions for further research, including suggestions for methods of testing the author's conclusions, are made.
- Full Text:
- Date Issued: 1960
Some aspects of the chemistry of zirconium compounds relating to their combination with collagen
- Williams-Wynn, David Ernest Arthur
- Authors: Williams-Wynn, David Ernest Arthur
- Date: 1960
- Subjects: Zirconium compounds , Collagen
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4513 , http://hdl.handle.net/10962/d1013456
- Description: [Summary] Some properties of zirconium compounds in aqueous solution have been determined using physico-chemical techniques. Zirconium oxychloride was used as the source of zirconium in all detailed investigations; zirconium sulphate was used in a few cases for comparative purposes. The Stokes diaphragm cell method has been used to determine the diffusion coefficient of zirconium in hydrochloric acid solution. It was found that the diffusion coefficient fell progressively with time, a limiting value being reached 4 to 5 weeks after dissolving the salt, and it was demonstrated that particles in the aged solutions were more homogeneous than in freshly prepared solutions. The limiting values were concentration dependent; dilute solutions had a lower diffusion coefficient than the more concentrated solutions when measured at the natural pH. In the presence of added acid the rate of diffusion was increased until a limiting value was reached in 0.5 M acid. The addition of alkali or complexing acids reduced the rate of diffusion.
- Full Text:
- Date Issued: 1960
- Authors: Williams-Wynn, David Ernest Arthur
- Date: 1960
- Subjects: Zirconium compounds , Collagen
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4513 , http://hdl.handle.net/10962/d1013456
- Description: [Summary] Some properties of zirconium compounds in aqueous solution have been determined using physico-chemical techniques. Zirconium oxychloride was used as the source of zirconium in all detailed investigations; zirconium sulphate was used in a few cases for comparative purposes. The Stokes diaphragm cell method has been used to determine the diffusion coefficient of zirconium in hydrochloric acid solution. It was found that the diffusion coefficient fell progressively with time, a limiting value being reached 4 to 5 weeks after dissolving the salt, and it was demonstrated that particles in the aged solutions were more homogeneous than in freshly prepared solutions. The limiting values were concentration dependent; dilute solutions had a lower diffusion coefficient than the more concentrated solutions when measured at the natural pH. In the presence of added acid the rate of diffusion was increased until a limiting value was reached in 0.5 M acid. The addition of alkali or complexing acids reduced the rate of diffusion.
- Full Text:
- Date Issued: 1960
The contribution of the Anglican church to education in the Cape
- Authors: Rawlins, G E
- Date: 1960
- Subjects: Church and education -- South Africa , Church of England -- Education -- South Africa , Education -- South Africa -- Cape of Good Hope
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1978 , http://hdl.handle.net/10962/d1013055
- Description: In his "Onderwys in Kaapland, 1652 - 1939", Dr. P.S. du Toit makes special references to the educational work of the Anglican Church, indicating that there is some contribution. This attitude has as its aim to expose more of the reef of which the outcrops receive attention by Dr. du Toit ... much can happen between 1807 and 1829, and some of what did is described in these pages. One of Dr. du Toit's interests is the effect of the attempt to make English and instruction in English the basis of all education. Chap. 1, p. 1.
- Full Text:
- Date Issued: 1960
- Authors: Rawlins, G E
- Date: 1960
- Subjects: Church and education -- South Africa , Church of England -- Education -- South Africa , Education -- South Africa -- Cape of Good Hope
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1978 , http://hdl.handle.net/10962/d1013055
- Description: In his "Onderwys in Kaapland, 1652 - 1939", Dr. P.S. du Toit makes special references to the educational work of the Anglican Church, indicating that there is some contribution. This attitude has as its aim to expose more of the reef of which the outcrops receive attention by Dr. du Toit ... much can happen between 1807 and 1829, and some of what did is described in these pages. One of Dr. du Toit's interests is the effect of the attempt to make English and instruction in English the basis of all education. Chap. 1, p. 1.
- Full Text:
- Date Issued: 1960
The diary of C. L. Stretch - a critical edition and appraisal
- Authors: Crankshaw, Grahame Bruce
- Date: 1960
- Subjects: Stretch, Charles Lennox, 1797-1882 , South Africa -- History -- Frontier Wars, 1811-1878 , Treaties -- Interpretation and construction
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2535 , http://hdl.handle.net/10962/d1002387 , Stretch, Charles Lennox, 1797-1882 , South Africa -- History -- Frontier Wars, 1811-1878 , Treaties -- Interpretation and construction
- Description: In the investigation of the Diary and its validity as evidence, the origin and structure of the treaty System, and the functioning of the treaties, in both their original form and subsequent modification, has been examined, with special reference to Stretch and the Gaika tribes.
- Full Text:
- Date Issued: 1960
- Authors: Crankshaw, Grahame Bruce
- Date: 1960
- Subjects: Stretch, Charles Lennox, 1797-1882 , South Africa -- History -- Frontier Wars, 1811-1878 , Treaties -- Interpretation and construction
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2535 , http://hdl.handle.net/10962/d1002387 , Stretch, Charles Lennox, 1797-1882 , South Africa -- History -- Frontier Wars, 1811-1878 , Treaties -- Interpretation and construction
- Description: In the investigation of the Diary and its validity as evidence, the origin and structure of the treaty System, and the functioning of the treaties, in both their original form and subsequent modification, has been examined, with special reference to Stretch and the Gaika tribes.
- Full Text:
- Date Issued: 1960
The thermal decomposition of silver oxide
- Authors: Herley, Patrick James
- Date: 1960
- Subjects: Silver oxide -- Thermal properties , Decomposition (Chemistry)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4525 , http://hdl.handle.net/10962/d1015017
- Description: [From Introduction]. The thermal decomposition of solids is characterized by the formation and growth of nuclei at sites on the surface of the solid or within the crystal lattice. Such nuclear formation is favoured by disorganisation of the crystal either by mechanical damage, or by the presence of impurities. Disorganisation results in positions which have a high thermodynamic instability. The nuclei are likely to be formed initially at the corners and the edges of the crystal since these are more prone to damage. Careful handling and storage in vacuo often leads to a large reduction in their number, while deliberate scratching of the surface facilitates their production. The number of potential sites for nuclear formation is also increased by pre-irradiation with ultra-violet light, though there are indications that a different type of nucleus may be produced. Nucleation can be facilitated by pre-irradiation with electrons, neutrons, X-rays, gamma-rays and atomic particles. The nature of the nuclei is not always clearly defined, but it is generally accepted that they are composed of solid reaction products e.g. in the decomposition of barium azide and silver oxalate, nuclei of metallic barium and silver, respectively, are formed.
- Full Text:
- Date Issued: 1960
- Authors: Herley, Patrick James
- Date: 1960
- Subjects: Silver oxide -- Thermal properties , Decomposition (Chemistry)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4525 , http://hdl.handle.net/10962/d1015017
- Description: [From Introduction]. The thermal decomposition of solids is characterized by the formation and growth of nuclei at sites on the surface of the solid or within the crystal lattice. Such nuclear formation is favoured by disorganisation of the crystal either by mechanical damage, or by the presence of impurities. Disorganisation results in positions which have a high thermodynamic instability. The nuclei are likely to be formed initially at the corners and the edges of the crystal since these are more prone to damage. Careful handling and storage in vacuo often leads to a large reduction in their number, while deliberate scratching of the surface facilitates their production. The number of potential sites for nuclear formation is also increased by pre-irradiation with ultra-violet light, though there are indications that a different type of nucleus may be produced. Nucleation can be facilitated by pre-irradiation with electrons, neutrons, X-rays, gamma-rays and atomic particles. The nature of the nuclei is not always clearly defined, but it is generally accepted that they are composed of solid reaction products e.g. in the decomposition of barium azide and silver oxalate, nuclei of metallic barium and silver, respectively, are formed.
- Full Text:
- Date Issued: 1960
A quantitative investigation of the absorption of certain cations by whole plants and plant tissues
- Cresswell, Christopher Frederick
- Authors: Cresswell, Christopher Frederick
- Date: 1959 , 2014-07-24
- Subjects: Cations -- Absorption and adsorption , Plant tissues
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4262 , http://hdl.handle.net/10962/d1013335
- Description: Introduction: Part 1. Greenhouse studies were conducted to investigate the absorption of sodium, potassium, calcium and magnesium by lemon seedlings. The plants were grown in controlled nutrient solutions and analysis of the plant material was made to determine the relationship between the four cations in the different plant organs. Results of the experiment may be summarized as follows:- The occurrence of leaf burn appeared to be associated with a low calcium content, together with a high sodium, potassium or sodium + potassium content. The development of the seedlings was shown to be markedly influenced by the level of calcium supply and to a much lesser degree by the level of potassium supplied. The concentration of sodium, potassium, calcium and magnesium in the stem and leaf varied with position of the tissues on the main axis. The level of sodium was found to influence the distribution of sodium in the leaves, and the sodium content of the leaf, stem and root tissues gave a good reflection of the level of sodium supplied. The effect of the sodium treatment on the uptake of potassium appeared to be dependent on the calcium content of the tissues. Sodium treatment was found not to affect the leaf calcium content. In the stem and root tissues the calcium content was reduced when the calcium level in the nutrient medium was low, and increased the calcium content of these two tissues at the higher level of calcium supply. The sodium supply was shown to reduce the leaf magnesium only slightly, and its affect on the magnesium content of the stem and root tissues was shown to be dependent on the level of calcium supplied. The potassium content of the leaves, stems and roots increased when the supply of potassium was raised. Increasing the potassium level in the nutrient supply was found to cause a very slight reduction in the sodium content of the leaf, but did not affect the sodium content of the stem and root. Potassium did not affect the calcium content of the leaves and increased the stem calcium when sodium was not present in the nutrient media in high concentrations. In the roots potassium only increase the calcium content at the upper level of calcium supply. The magnesium content of the leaf and stem tissues was reduced as the potassium supply was increased. In the roots the general trend was for the magnesium content to increase when the level of potassium treatment was raised. The calcium content of all the plant parts increased with a rise in the calcium supply, the stem and root tissues having a greater percentage increase than the leaves. The sodium content of the plant tissue was reduced as the level of calcium supply was raised. The leaf potassium content decreased with a higher calcium level of supply. In the stem and roots the potassium content was increased by doubling the calcium supply. The calcium treatment had no influence on the magnesium content of the foliage, but in the stem and root tissues a decrease in magnesium content resulted from an increase in the calcium supply. Part II Potato tuber tissue and carrot root tissue were used as experimental material in the investigation of sodium9 potassium9 and calcium uptake by storage tissue. It was shown that when the tissue disks are transferred from distilled water to a solution of salts there is a rapid initial uptake of cation which is neither particularly selective, nor related to metabolism, but dependent on the external concentration. On the other hand, the prolonged active accumulation of cation exhibits selectivity. Potassium absorption by potato tuber tissue was shown to be stimulated by sodium9 whereas the potassium and calcium absorption by carrot root tissue was shown to be reduced by sodium. Similarly the sodium absorption by the carrot root tissue was reduced by potassium, thus suggesting that the cations compete with one another for the same absorption mechanism.
- Full Text:
- Date Issued: 1959
- Authors: Cresswell, Christopher Frederick
- Date: 1959 , 2014-07-24
- Subjects: Cations -- Absorption and adsorption , Plant tissues
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4262 , http://hdl.handle.net/10962/d1013335
- Description: Introduction: Part 1. Greenhouse studies were conducted to investigate the absorption of sodium, potassium, calcium and magnesium by lemon seedlings. The plants were grown in controlled nutrient solutions and analysis of the plant material was made to determine the relationship between the four cations in the different plant organs. Results of the experiment may be summarized as follows:- The occurrence of leaf burn appeared to be associated with a low calcium content, together with a high sodium, potassium or sodium + potassium content. The development of the seedlings was shown to be markedly influenced by the level of calcium supply and to a much lesser degree by the level of potassium supplied. The concentration of sodium, potassium, calcium and magnesium in the stem and leaf varied with position of the tissues on the main axis. The level of sodium was found to influence the distribution of sodium in the leaves, and the sodium content of the leaf, stem and root tissues gave a good reflection of the level of sodium supplied. The effect of the sodium treatment on the uptake of potassium appeared to be dependent on the calcium content of the tissues. Sodium treatment was found not to affect the leaf calcium content. In the stem and root tissues the calcium content was reduced when the calcium level in the nutrient medium was low, and increased the calcium content of these two tissues at the higher level of calcium supply. The sodium supply was shown to reduce the leaf magnesium only slightly, and its affect on the magnesium content of the stem and root tissues was shown to be dependent on the level of calcium supplied. The potassium content of the leaves, stems and roots increased when the supply of potassium was raised. Increasing the potassium level in the nutrient supply was found to cause a very slight reduction in the sodium content of the leaf, but did not affect the sodium content of the stem and root. Potassium did not affect the calcium content of the leaves and increased the stem calcium when sodium was not present in the nutrient media in high concentrations. In the roots potassium only increase the calcium content at the upper level of calcium supply. The magnesium content of the leaf and stem tissues was reduced as the potassium supply was increased. In the roots the general trend was for the magnesium content to increase when the level of potassium treatment was raised. The calcium content of all the plant parts increased with a rise in the calcium supply, the stem and root tissues having a greater percentage increase than the leaves. The sodium content of the plant tissue was reduced as the level of calcium supply was raised. The leaf potassium content decreased with a higher calcium level of supply. In the stem and roots the potassium content was increased by doubling the calcium supply. The calcium treatment had no influence on the magnesium content of the foliage, but in the stem and root tissues a decrease in magnesium content resulted from an increase in the calcium supply. Part II Potato tuber tissue and carrot root tissue were used as experimental material in the investigation of sodium9 potassium9 and calcium uptake by storage tissue. It was shown that when the tissue disks are transferred from distilled water to a solution of salts there is a rapid initial uptake of cation which is neither particularly selective, nor related to metabolism, but dependent on the external concentration. On the other hand, the prolonged active accumulation of cation exhibits selectivity. Potassium absorption by potato tuber tissue was shown to be stimulated by sodium9 whereas the potassium and calcium absorption by carrot root tissue was shown to be reduced by sodium. Similarly the sodium absorption by the carrot root tissue was reduced by potassium, thus suggesting that the cations compete with one another for the same absorption mechanism.
- Full Text:
- Date Issued: 1959
A study of the biology of the Jameson reservoir near Grahamstown, Cape Province
- Authors: Darbyshire, John Frederick
- Date: 1959
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/6784 , vital:21179
- Description: 1. This thesis is an ecological study of a South African water storage reservoir and it’s tributary streams. 2. A brief description of the reservoir, the surrounding vegetation, superficial geological strata, soils and early history of the reservoir is given in Chapter I. 3. The surrounding vegetation is discussed in some detail in Chapter II. The zonation of the plants and the influence of water upon it are discussed. 4. The results of the regular investigations of the physicochemical environment are presented in Appendix 1 and the salient points noted in Chapter III. 5. The species of algae collected are listed in Appendix 2 and in Chapter IV are discussed in relation to habitat and abundance. 6. The animals are dealt with in a similar manner in Chapter V. Under 'Discussion and Conclusions' in Chapter VI an attempt is made to review the findings and discuss their significance.
- Full Text:
- Date Issued: 1959
- Authors: Darbyshire, John Frederick
- Date: 1959
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/6784 , vital:21179
- Description: 1. This thesis is an ecological study of a South African water storage reservoir and it’s tributary streams. 2. A brief description of the reservoir, the surrounding vegetation, superficial geological strata, soils and early history of the reservoir is given in Chapter I. 3. The surrounding vegetation is discussed in some detail in Chapter II. The zonation of the plants and the influence of water upon it are discussed. 4. The results of the regular investigations of the physicochemical environment are presented in Appendix 1 and the salient points noted in Chapter III. 5. The species of algae collected are listed in Appendix 2 and in Chapter IV are discussed in relation to habitat and abundance. 6. The animals are dealt with in a similar manner in Chapter V. Under 'Discussion and Conclusions' in Chapter VI an attempt is made to review the findings and discuss their significance.
- Full Text:
- Date Issued: 1959
A study of the heroine in certain Victorian novels
- Authors: Addecott, Grahame John
- Date: 1959
- Subjects: English fiction -- 19th century -- History and criticism , Heroines in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2319 , http://hdl.handle.net/10962/d1013374
- Description: During the reign of Queen Victoria was seen the gradual emergence of the emancipated woman. The idea that women were innocent beings who must be kept from real knowledge of the world died hard, however, and to the end of the era there were many who repudiated the very concept of emancipation whether in literature or life. Coupled with the chivalrous, idealistic concept of womanhood was Victorian respectability, and it is not surprising that in the earlier Victorian novels we see clearly the idealistic concept of women and the effects of the cult of respectability. To illustrate my theme, of the gradual change in the concept of the novel which naturally kept pace, more or less, with the progress the emancipation of women was making, I have chosen one novel from each of seven great Victorian novelists whose works span the whale era. The only exception I have made is with Charlotte Bronte. In her case the heroines of two of her novels are discussed mainly because she is the first Victorian novelist to sound a note of protest against the then conventional concept of the heroine.
- Full Text:
- Date Issued: 1959
- Authors: Addecott, Grahame John
- Date: 1959
- Subjects: English fiction -- 19th century -- History and criticism , Heroines in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2319 , http://hdl.handle.net/10962/d1013374
- Description: During the reign of Queen Victoria was seen the gradual emergence of the emancipated woman. The idea that women were innocent beings who must be kept from real knowledge of the world died hard, however, and to the end of the era there were many who repudiated the very concept of emancipation whether in literature or life. Coupled with the chivalrous, idealistic concept of womanhood was Victorian respectability, and it is not surprising that in the earlier Victorian novels we see clearly the idealistic concept of women and the effects of the cult of respectability. To illustrate my theme, of the gradual change in the concept of the novel which naturally kept pace, more or less, with the progress the emancipation of women was making, I have chosen one novel from each of seven great Victorian novelists whose works span the whale era. The only exception I have made is with Charlotte Bronte. In her case the heroines of two of her novels are discussed mainly because she is the first Victorian novelist to sound a note of protest against the then conventional concept of the heroine.
- Full Text:
- Date Issued: 1959
A study of the predators and parasites of Planococcus citri (Risso) (Homoptera) on vines in the Western Cape Province, South Africa
- Authors: Whitehead, Vincent Booth
- Date: 1959
- Subjects: Hemiptera , Parasites , Insect pests -- Biological control , Grapes -- Diseases and pests
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5896 , http://hdl.handle.net/10962/d1013425
- Description: [Introduction] In the Western Cape Province the mealybug, Planococcus citri (Risso), was first reported on vines in 1930 by Joubert (1943a). By 1935 this mealybug had spread to the Hex River Valley, and subsequently to all the main table grape producing areas of the Western Cape Province. At present Pl. citri is the most important insect pest of the table grape industry and can, if not effectively controlled, result in a loss of at least five per cent of the export table grape crop (Kriegler, 1954). Some preliminary work on the natural enemies of Pl. citri on vines was carried out by Stubbings in 1948, but no further work of this nature has been undertaken in this area since then. The fact that the natural enemies can be an effective check to this mealybug on vines in the Western Cape Province has been known for a number of years (Potgieter, 1937; Hattingh, 1943; Joubert, 1943a; Myburgh, 1951). The present work is an attempt to obtain some basic knowlege of the population fluctuations of the insects concerned in this biological control. Surveys undertaken have shown that there is a complex of primary, secondary and possibly tertiary Hynenopterous parasites associated with Pl. citri. The presence of hyperparasites reduces the efficiency of the primary parasitic Hymenoptera. The usefulness of these primary parasites is further reduced as they only occur in effective numbers for a short period of the year. On the other hand, although attacked by some parasites, the numerous coccinellids found preying on Pl. citri are of more importance in reducing the mealybug populations, as they are present on the vines in effective numbers for the greater part of the year.
- Full Text:
- Date Issued: 1959
- Authors: Whitehead, Vincent Booth
- Date: 1959
- Subjects: Hemiptera , Parasites , Insect pests -- Biological control , Grapes -- Diseases and pests
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5896 , http://hdl.handle.net/10962/d1013425
- Description: [Introduction] In the Western Cape Province the mealybug, Planococcus citri (Risso), was first reported on vines in 1930 by Joubert (1943a). By 1935 this mealybug had spread to the Hex River Valley, and subsequently to all the main table grape producing areas of the Western Cape Province. At present Pl. citri is the most important insect pest of the table grape industry and can, if not effectively controlled, result in a loss of at least five per cent of the export table grape crop (Kriegler, 1954). Some preliminary work on the natural enemies of Pl. citri on vines was carried out by Stubbings in 1948, but no further work of this nature has been undertaken in this area since then. The fact that the natural enemies can be an effective check to this mealybug on vines in the Western Cape Province has been known for a number of years (Potgieter, 1937; Hattingh, 1943; Joubert, 1943a; Myburgh, 1951). The present work is an attempt to obtain some basic knowlege of the population fluctuations of the insects concerned in this biological control. Surveys undertaken have shown that there is a complex of primary, secondary and possibly tertiary Hynenopterous parasites associated with Pl. citri. The presence of hyperparasites reduces the efficiency of the primary parasitic Hymenoptera. The usefulness of these primary parasites is further reduced as they only occur in effective numbers for a short period of the year. On the other hand, although attacked by some parasites, the numerous coccinellids found preying on Pl. citri are of more importance in reducing the mealybug populations, as they are present on the vines in effective numbers for the greater part of the year.
- Full Text:
- Date Issued: 1959
A study of the relationship between the poetry and criticism of Ezra Pound 1908-1920
- De Villiers, André Rex Wepener
- Authors: De Villiers, André Rex Wepener
- Date: 1959
- Subjects: Pound, Ezra, 1885-1972 -- Criticism and interpretation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2317 , http://hdl.handle.net/10962/d1013320
- Description: From the preface: The purpose of this thesis is exposition rather than criticism. Pound's position in the hierarchy of the 'New Criticism' would provide an extremely interesting subject; but I have rather tried to outline; the standards which he has laid down as being central in the technics of good poetry and to show how closely he has adhered to them in his own verse. I have limited the period to be discussed because all of the essential principles which he employs in his writing after 1920 are discernible in the body of his work published before that date.
- Full Text:
- Date Issued: 1959
- Authors: De Villiers, André Rex Wepener
- Date: 1959
- Subjects: Pound, Ezra, 1885-1972 -- Criticism and interpretation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2317 , http://hdl.handle.net/10962/d1013320
- Description: From the preface: The purpose of this thesis is exposition rather than criticism. Pound's position in the hierarchy of the 'New Criticism' would provide an extremely interesting subject; but I have rather tried to outline; the standards which he has laid down as being central in the technics of good poetry and to show how closely he has adhered to them in his own verse. I have limited the period to be discussed because all of the essential principles which he employs in his writing after 1920 are discernible in the body of his work published before that date.
- Full Text:
- Date Issued: 1959
The economic geography of the Union's chicory Industry : past and present
- Authors: Young, Bruce Stratton
- Date: 1959
- Subjects: Chicory -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:4882 , http://hdl.handle.net/10962/d1013438
- Description: The motivating force behind this survey and study of a branch of the Union's agricultural industry has been the conviction that detailed case studies of economic activities and their influences on the map of the country are the essential foundation stones on which mature scholars may build a perceptive and valuable economic geography of the Union.
- Full Text:
- Date Issued: 1959
- Authors: Young, Bruce Stratton
- Date: 1959
- Subjects: Chicory -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:4882 , http://hdl.handle.net/10962/d1013438
- Description: The motivating force behind this survey and study of a branch of the Union's agricultural industry has been the conviction that detailed case studies of economic activities and their influences on the map of the country are the essential foundation stones on which mature scholars may build a perceptive and valuable economic geography of the Union.
- Full Text:
- Date Issued: 1959
The historical development of geography as a subject in the schools of the Cape Province (1772-1951)
- Authors: Knox, John Charles
- Date: 1959
- Subjects: Geography -- Study and teaching -- South Africa -- Cape of Good Hope
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1974 , http://hdl.handle.net/10962/d1012702 , Geography -- Study and teaching -- South Africa -- Cape of Good Hope
- Description: As the title indicates, this is a study of the historical emergence of geography as a subject in Cape schools, and covers the period 1772-1951. The account is not merely descriptive and factual, for wherever possible an attempt is made to assess the nature and scope of the geography which was taught at different periods in relation to modern, authoritative ideas concerning the pedagogic application of the subject in the school. The work as a whole is predominantly concerned with the historical development of geography in the secondary school. However, in the initial four chapters the slight and insubstantial nature of the available data precludes the possibility of differentiating between geoeraphy of primary standard and that of secondary standard, and in these early chapters all references to the subject are consequently generalized. In Chapter 5, which deals with the period during which Langham Dale was Superintendent-Genera l of Education, geography of secondary standard becomes distinguishable from that of primary standard for the first time, and from this point onwards the two are differentiated to the fullest extent possible, and the former is chiefly emphasized. The entire study is presented against a broad background of relevant, educational developments of a general nature.
- Full Text:
- Date Issued: 1959
The historical development of geography as a subject in the schools of the Cape Province (1772-1951)
- Authors: Knox, John Charles
- Date: 1959
- Subjects: Geography -- Study and teaching -- South Africa -- Cape of Good Hope
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1974 , http://hdl.handle.net/10962/d1012702 , Geography -- Study and teaching -- South Africa -- Cape of Good Hope
- Description: As the title indicates, this is a study of the historical emergence of geography as a subject in Cape schools, and covers the period 1772-1951. The account is not merely descriptive and factual, for wherever possible an attempt is made to assess the nature and scope of the geography which was taught at different periods in relation to modern, authoritative ideas concerning the pedagogic application of the subject in the school. The work as a whole is predominantly concerned with the historical development of geography in the secondary school. However, in the initial four chapters the slight and insubstantial nature of the available data precludes the possibility of differentiating between geoeraphy of primary standard and that of secondary standard, and in these early chapters all references to the subject are consequently generalized. In Chapter 5, which deals with the period during which Langham Dale was Superintendent-Genera l of Education, geography of secondary standard becomes distinguishable from that of primary standard for the first time, and from this point onwards the two are differentiated to the fullest extent possible, and the former is chiefly emphasized. The entire study is presented against a broad background of relevant, educational developments of a general nature.
- Full Text:
- Date Issued: 1959
The solubility of mercurous chloride in water at 25°C
- Authors: Clur, Dennis Alwin
- Date: 1959
- Subjects: Mercury compounds -- Solubility , Mercuric chloride
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4522 , http://hdl.handle.net/10962/d1014705
- Description: [From Introduction]. In 1955, Dry and Gledhill, both formerly of this Department, published their paper on the Solubility of Mercurous Chloride in Water at 25°0, and it was originally intended that this thesis should be an extension of the study to cover the temperature range from 5 t o 55°0. A preliminary investigation at 25°0, however, failed to yield results which were consistent with their findings, even though their apparatus and experimental technique were used. In an effort to resolve these difficulties their method of saturating the calomel in the conductance cell was thoroughly investigated, and as this procedure was found to be responsible, it was necessary to evolve an entirely new approach. The technique finally adopted was to saturate the mercurous chloride solutions by mechanical stirring in siliconed vessels and to carry out the conductance, pH, and total mercury concentration measurements on the filter ed solution. This method gave good results, and was free from the many extrapolations prevalent in the original procedure.
- Full Text:
- Date Issued: 1959
- Authors: Clur, Dennis Alwin
- Date: 1959
- Subjects: Mercury compounds -- Solubility , Mercuric chloride
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4522 , http://hdl.handle.net/10962/d1014705
- Description: [From Introduction]. In 1955, Dry and Gledhill, both formerly of this Department, published their paper on the Solubility of Mercurous Chloride in Water at 25°0, and it was originally intended that this thesis should be an extension of the study to cover the temperature range from 5 t o 55°0. A preliminary investigation at 25°0, however, failed to yield results which were consistent with their findings, even though their apparatus and experimental technique were used. In an effort to resolve these difficulties their method of saturating the calomel in the conductance cell was thoroughly investigated, and as this procedure was found to be responsible, it was necessary to evolve an entirely new approach. The technique finally adopted was to saturate the mercurous chloride solutions by mechanical stirring in siliconed vessels and to carry out the conductance, pH, and total mercury concentration measurements on the filter ed solution. This method gave good results, and was free from the many extrapolations prevalent in the original procedure.
- Full Text:
- Date Issued: 1959
The sorption of Hydrochloric Acid and Potassium Hydroxide by mohair and wool
- Bamford, Graeme Reginald Ernest
- Authors: Bamford, Graeme Reginald Ernest
- Date: 1959
- Subjects: Hydrochloric acid -- Absorption and adsorption , Hydroxides -- Absorption and adsorption , Wool , Mohair
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4452 , http://hdl.handle.net/10962/d1009503
- Description: The main object of the present investigation has been to establish a titration curve for mohair keratin and to compare it with similar data for wool, to determine whether the differences in physical and chemical properties could be attributed in any way to the acidic and basic character of these fibres. As shown in subsequent discussion such measurements provide extremely useful information regarding the chemical structure of proteins in general, and in the technical fields involving processes such as wool scouring, carbonizing and dyeing. The study has been extended to include certain modified wools, i.e. photochemically damaged, and oxidized keratin. The most successful contribution to the titration data of wool keratin is the work of Steinhardt and Harris and subsequent authors have tended to adopt their procedures without modification. In the present study attempts have been made to obtain a clearer understanding of the fundamental processes. New techniques and analytical methods have been introduced to improve the accuracy of the measurements.
- Full Text:
- Date Issued: 1959
- Authors: Bamford, Graeme Reginald Ernest
- Date: 1959
- Subjects: Hydrochloric acid -- Absorption and adsorption , Hydroxides -- Absorption and adsorption , Wool , Mohair
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4452 , http://hdl.handle.net/10962/d1009503
- Description: The main object of the present investigation has been to establish a titration curve for mohair keratin and to compare it with similar data for wool, to determine whether the differences in physical and chemical properties could be attributed in any way to the acidic and basic character of these fibres. As shown in subsequent discussion such measurements provide extremely useful information regarding the chemical structure of proteins in general, and in the technical fields involving processes such as wool scouring, carbonizing and dyeing. The study has been extended to include certain modified wools, i.e. photochemically damaged, and oxidized keratin. The most successful contribution to the titration data of wool keratin is the work of Steinhardt and Harris and subsequent authors have tended to adopt their procedures without modification. In the present study attempts have been made to obtain a clearer understanding of the fundamental processes. New techniques and analytical methods have been introduced to improve the accuracy of the measurements.
- Full Text:
- Date Issued: 1959
The thermal decomposition of irradiated silver permanganate
- Authors: Sole, Michael John
- Date: 1959
- Subjects: Decomposition (Chemistry) , Irradiation , Permanganates , Silver compounds , Metals -- Thermal properties
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4502 , http://hdl.handle.net/10962/d1013265
- Description: The thermal decomposition of silver permanganate, pre-irradiated in BEPO and in a ⁶°C₀ Ϫ 'hot spot' has been investigated in the temperature range 100 - 125°C. The results are similar to those for irradiated KMn0₄ and the mechanism proposed for the latter is again suggested. The activation energy for the migration of point defects over the induction period is 1.03 ev. The decompositions of unirradiated and irradiated crystals differ in that the latter undergo physical disintegration over the acceleratory period. X-ray studies immediately prior to disintegration show strain and fragmentation in the irradiated crystal. An explanation involving the annealing of point defects at dislocation is advanced to explain the changes produced in the p/t plots with increased dosage, and fixed decomposition temperature. Summary, p. 94.
- Full Text:
- Date Issued: 1959
- Authors: Sole, Michael John
- Date: 1959
- Subjects: Decomposition (Chemistry) , Irradiation , Permanganates , Silver compounds , Metals -- Thermal properties
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4502 , http://hdl.handle.net/10962/d1013265
- Description: The thermal decomposition of silver permanganate, pre-irradiated in BEPO and in a ⁶°C₀ Ϫ 'hot spot' has been investigated in the temperature range 100 - 125°C. The results are similar to those for irradiated KMn0₄ and the mechanism proposed for the latter is again suggested. The activation energy for the migration of point defects over the induction period is 1.03 ev. The decompositions of unirradiated and irradiated crystals differ in that the latter undergo physical disintegration over the acceleratory period. X-ray studies immediately prior to disintegration show strain and fragmentation in the irradiated crystal. An explanation involving the annealing of point defects at dislocation is advanced to explain the changes produced in the p/t plots with increased dosage, and fixed decomposition temperature. Summary, p. 94.
- Full Text:
- Date Issued: 1959
A critical study of the curcumin method for the determination of boron in plant material
- Authors: Davidson, R J
- 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.
- Full Text:
- Date Issued: 1958
- Authors: Davidson, R J
- 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.
- Full Text:
- Date Issued: 1958
An investigation of isolated bursts of solar radio noise
- Shuter, William Leslie Hazlewood
- 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.
- Full Text:
- Date Issued: 1958
- 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.
- Full Text:
- Date Issued: 1958
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.
- Full Text:
- Date Issued: 1958
- 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.
- Full Text:
- Date Issued: 1958
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.
- Full Text:
- Date Issued: 1958
- 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.
- Full Text:
- Date Issued: 1958