The response of pure organic crystals to ionising radiations
- Authors: King, J W
- Date: 1953
- Subjects: Inorganic scintillators , Crystals
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5529 , http://hdl.handle.net/10962/d1012641 , Inorganic scintillators , Crystals
- Description: The introduction contains introductory remarks on scintillation counters together with a brief description of the exciton theory believed to be the means of primary energy migration within organic crystals. Part I contains a review of the data published on the reletive responses of different organic crystals and the attempted correlations of these results with the molecular structures of the different phosphors. From data which may be accepted as being both reliable and suitable for comparison it is concluded that theories involving correlations between phosphor efficiencies and molecular structures may be tested only if the efficiency data has (i) been extrapolated to give results for crystals of very small thickness and {ii) been obtained at very low temperatures. Part II contains accurate calculations based on the exciton theory proposed by Birks (1951 ) to account for the response of crystals to different types of ionising radiations. Satisfactory agreement is obta1ned with all the avalable experimental data in the literature. In part III an account is given of the response of organic crystals observed by the author for low-energy ⋉particles, and of the similar behaviour found by Taylor et al, (1951 ) for low-energy electrons. A possible extension of the theory described in part II, allowing for the escape of excitons through the crystal surface is given accounting for this behaviour. An exciton mean free path in anthracene, terphenyl and stilbene of about 3 - 7/u is obtained. Results were obtained with strong ⋉-particle sources which could not be explained. in terms ot normal response of the phosphor used. This effect was inventigatea as described in part IV, and it is shown that photons are produced in air, glass and quartz when these materials are irradiated by ⋉particles. This luminescence was probably responsible for the "scintillations" which Richards and Cole (1951) have ascribed to thin films of various materials. Problems requiring further investigation are indicated.
- Full Text:
- Date Issued: 1953
- Authors: King, J W
- Date: 1953
- Subjects: Inorganic scintillators , Crystals
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5529 , http://hdl.handle.net/10962/d1012641 , Inorganic scintillators , Crystals
- Description: The introduction contains introductory remarks on scintillation counters together with a brief description of the exciton theory believed to be the means of primary energy migration within organic crystals. Part I contains a review of the data published on the reletive responses of different organic crystals and the attempted correlations of these results with the molecular structures of the different phosphors. From data which may be accepted as being both reliable and suitable for comparison it is concluded that theories involving correlations between phosphor efficiencies and molecular structures may be tested only if the efficiency data has (i) been extrapolated to give results for crystals of very small thickness and {ii) been obtained at very low temperatures. Part II contains accurate calculations based on the exciton theory proposed by Birks (1951 ) to account for the response of crystals to different types of ionising radiations. Satisfactory agreement is obta1ned with all the avalable experimental data in the literature. In part III an account is given of the response of organic crystals observed by the author for low-energy ⋉particles, and of the similar behaviour found by Taylor et al, (1951 ) for low-energy electrons. A possible extension of the theory described in part II, allowing for the escape of excitons through the crystal surface is given accounting for this behaviour. An exciton mean free path in anthracene, terphenyl and stilbene of about 3 - 7/u is obtained. Results were obtained with strong ⋉-particle sources which could not be explained. in terms ot normal response of the phosphor used. This effect was inventigatea as described in part IV, and it is shown that photons are produced in air, glass and quartz when these materials are irradiated by ⋉particles. This luminescence was probably responsible for the "scintillations" which Richards and Cole (1951) have ascribed to thin films of various materials. Problems requiring further investigation are indicated.
- Full Text:
- Date Issued: 1953
A preliminary investigation of the structure of green wattle tannin (acacia decurrens willd)
- Authors: Glueck, Leonard David
- Date: 1952
- Subjects: Tannins , Tannin plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4475 , http://hdl.handle.net/10962/d1011988 , Tannins , Tannin plants
- Description: Green wattle tannin extracts were separated by lead salt precipitation into a phenolic tannin fraction and a nontannin fraction. The combustion analysis of the tannin fraction corresponded to an empirical formula C₁₅H₁₄O₆. Methoxy and acetyl values showed four oxygens were hydroxy groups while the residual oxygens could either be ether linked or carbonyl groups. Diazomethane methylation produced a white product of high methoxyl value which indicated that the four hydroxyl groups were phenolic. Chromatography of the lead salt purified tannin showed an indistinct non-fluorescent trail. Ether extraction of the tannin removed the associated Phenolic bodies. The ethereal extract unlike black wattle extracts contained no fisetin and evaporation of the ethereal solutions yielded a gummy non-crystalline residue. Alkaline fusion of the purified tannin produced for the first tlme a variety of acidic and phenolic compounds i.e. resorcinol, pyrogaloll, phloroglucinol β-resorcylic acid, gallic acid and protocatechuic acid. From the high yields of resorcinol (6%) and gallic acid (3%), these units appear to predominate. These degradation productions, coupled with the analytical figures, indicate a possible C₁₅ unit with resorcinol and pyrogallol nuclei as a basis. The non-tannin fraction failed to reveal any compound which might cause the excessive redness in green wattle extracts. Chromatography of this non-tannin fraction showed the presence of sucrose.
- Full Text:
- Date Issued: 1952
- Authors: Glueck, Leonard David
- Date: 1952
- Subjects: Tannins , Tannin plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4475 , http://hdl.handle.net/10962/d1011988 , Tannins , Tannin plants
- Description: Green wattle tannin extracts were separated by lead salt precipitation into a phenolic tannin fraction and a nontannin fraction. The combustion analysis of the tannin fraction corresponded to an empirical formula C₁₅H₁₄O₆. Methoxy and acetyl values showed four oxygens were hydroxy groups while the residual oxygens could either be ether linked or carbonyl groups. Diazomethane methylation produced a white product of high methoxyl value which indicated that the four hydroxyl groups were phenolic. Chromatography of the lead salt purified tannin showed an indistinct non-fluorescent trail. Ether extraction of the tannin removed the associated Phenolic bodies. The ethereal extract unlike black wattle extracts contained no fisetin and evaporation of the ethereal solutions yielded a gummy non-crystalline residue. Alkaline fusion of the purified tannin produced for the first tlme a variety of acidic and phenolic compounds i.e. resorcinol, pyrogaloll, phloroglucinol β-resorcylic acid, gallic acid and protocatechuic acid. From the high yields of resorcinol (6%) and gallic acid (3%), these units appear to predominate. These degradation productions, coupled with the analytical figures, indicate a possible C₁₅ unit with resorcinol and pyrogallol nuclei as a basis. The non-tannin fraction failed to reveal any compound which might cause the excessive redness in green wattle extracts. Chromatography of this non-tannin fraction showed the presence of sucrose.
- Full Text:
- Date Issued: 1952
A study of cation exchange in South African soils
- Authors: Du Toit, A A
- Date: 1952
- Subjects: Soil chemistry , Ion exchange
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4462 , http://hdl.handle.net/10962/d1011506 , Soil chemistry , Ion exchange
- Description: The colloidal fraction is the vital part of a soil. These extremely minute particles determine the nature of the soil and are mainly responsible for its many and varied functions. The most important of these functions is perhaps the ability of the colloids to adsorb and exchange cations, the elements so essential to all organisms as building materials. When pure water is passed through a non-saline. soil, the leachate will contain very few dissolved cations. If, on the other hand, an electrolyte such as a weak solution of sodiun chloride, is passed through the same soil, the leachate will contain considerable quantities of calcium, magnesium and potassiun chlorides as well as much of the original sodium chloride. The number of equivalents of the cations collected will be approximately the same as the number of equivalents of sodium ions added. Sodium ions have displaced some of the calcian, magnesium and potassium ions from the soil. This phenomenon is known as cation exchange. Intro., p. 1.
- Full Text:
- Date Issued: 1952
- Authors: Du Toit, A A
- Date: 1952
- Subjects: Soil chemistry , Ion exchange
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4462 , http://hdl.handle.net/10962/d1011506 , Soil chemistry , Ion exchange
- Description: The colloidal fraction is the vital part of a soil. These extremely minute particles determine the nature of the soil and are mainly responsible for its many and varied functions. The most important of these functions is perhaps the ability of the colloids to adsorb and exchange cations, the elements so essential to all organisms as building materials. When pure water is passed through a non-saline. soil, the leachate will contain very few dissolved cations. If, on the other hand, an electrolyte such as a weak solution of sodiun chloride, is passed through the same soil, the leachate will contain considerable quantities of calcium, magnesium and potassiun chlorides as well as much of the original sodium chloride. The number of equivalents of the cations collected will be approximately the same as the number of equivalents of sodium ions added. Sodium ions have displaced some of the calcian, magnesium and potassium ions from the soil. This phenomenon is known as cation exchange. Intro., p. 1.
- Full Text:
- Date Issued: 1952
Attempted synthesis of a [beta] or [gamma] resorcinyl alcohol
- Authors: Ryding, William Wallace
- Date: 1952
- Subjects: Alcohol -- Synthesis , Resorcinol
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4517 , http://hdl.handle.net/10962/d1014134
- Description: The ultimate objective of this research is the elucidation of the mechanism of the resorcinol-formaldehyde condensation. Whilst a vast literature has been built up about the phenol- formaldehyde condensation, that of resorcinol has received but scant attention, probably because the high reactivity of resorcinol rendered the following of the condensation extremely difficult. The earliest observation concerning the resorcinol-formaldehyde condensation was due to Baeyer who, in 1872, condensed resorcinol with various aldehydes. When the aldehyde was relatively inactive crystalline compounds were obtalned but with acetaldehyde or formaldehyde a resinous product resulted. In 1892 Caro condensed an excess ot resorcinol with formaldehyde in the presence of dilute hydrochloric acid; the product obtained recrystallised from alcohol as white microsoopic crystals, decomposed without melting at 250° and was stated to be bis (2- 4 dihydroxyphenyl) methane ... In decidlng upon the most suitable lines of attack it would seem that a survey of the literature relating to the phenol-formaldehyde concentration which might be expected to be closely related to that of resorcinol, would be of value. Summary of p. 1-5
- Full Text:
- Date Issued: 1952
- Authors: Ryding, William Wallace
- Date: 1952
- Subjects: Alcohol -- Synthesis , Resorcinol
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4517 , http://hdl.handle.net/10962/d1014134
- Description: The ultimate objective of this research is the elucidation of the mechanism of the resorcinol-formaldehyde condensation. Whilst a vast literature has been built up about the phenol- formaldehyde condensation, that of resorcinol has received but scant attention, probably because the high reactivity of resorcinol rendered the following of the condensation extremely difficult. The earliest observation concerning the resorcinol-formaldehyde condensation was due to Baeyer who, in 1872, condensed resorcinol with various aldehydes. When the aldehyde was relatively inactive crystalline compounds were obtalned but with acetaldehyde or formaldehyde a resinous product resulted. In 1892 Caro condensed an excess ot resorcinol with formaldehyde in the presence of dilute hydrochloric acid; the product obtained recrystallised from alcohol as white microsoopic crystals, decomposed without melting at 250° and was stated to be bis (2- 4 dihydroxyphenyl) methane ... In decidlng upon the most suitable lines of attack it would seem that a survey of the literature relating to the phenol-formaldehyde concentration which might be expected to be closely related to that of resorcinol, would be of value. Summary of p. 1-5
- Full Text:
- Date Issued: 1952
Investigation leading to a process for the synthesis of hydrogen sulphide from sulphur and certain lubricating oils derived from petroleum
- Authors: Schauder, H
- Date: 1952
- Subjects: Hydrogen sulfide
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4499 , http://hdl.handle.net/10962/d1013160
- Description: The primary object of the present study was to provide a process adaptable to prevailing South African conditions, for the manufacture of hydrogen sulphide. Such a process would also be suitable for use in other countries where the gas is not obtainable naturally or from refinery operations or as a by-product from other industries. Early in the study it was found that the literature embodying prior work was very scattered in character and had to be sought in many different fields of research. It was therefore decided to make the record of prior work as comprehensive as possible so as to provide, at the same time, a starting point tor future workers on related subjects. Intro., p. 1.
- Full Text:
- Date Issued: 1952
- Authors: Schauder, H
- Date: 1952
- Subjects: Hydrogen sulfide
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4499 , http://hdl.handle.net/10962/d1013160
- Description: The primary object of the present study was to provide a process adaptable to prevailing South African conditions, for the manufacture of hydrogen sulphide. Such a process would also be suitable for use in other countries where the gas is not obtainable naturally or from refinery operations or as a by-product from other industries. Early in the study it was found that the literature embodying prior work was very scattered in character and had to be sought in many different fields of research. It was therefore decided to make the record of prior work as comprehensive as possible so as to provide, at the same time, a starting point tor future workers on related subjects. Intro., p. 1.
- Full Text:
- Date Issued: 1952
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.
- Full Text:
- Date Issued: 1952
- 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.
- Full Text:
- Date Issued: 1952
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.
- Full Text:
- Date Issued: 1952
- 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.
- Full Text:
- Date Issued: 1952
A critical study of assessments made during a trial interview situation
- 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.
- Full Text:
- Date Issued: 1951
- 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.
- Full Text:
- Date Issued: 1951
A socio-economic study of East London, Cape Province, with special reference to the non-European peoples
- 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.
- Full Text:
- Date Issued: 1951
- 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.
- Full Text:
- Date Issued: 1951
East London and its geographical setting
- 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.
- Full Text:
- Date Issued: 1951
- 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.
- Full Text:
- Date Issued: 1951
A study of the E region of the ionosphere
- 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.
- Full Text:
- Date Issued: 1950
- 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.
- Full Text:
- Date Issued: 1950
An investigation of certain complex ions of trivalent chromium by spectrophotometric and other physical methods
- 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.
- Full Text:
- Date Issued: 1950
- 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.
- Full Text:
- Date Issued: 1950
Studies in the plant ecology of Fern Kloof near Grahamstown
- 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.
- Full Text:
- Date Issued: 1950
- 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
A measuring device in spelling
- Authors: Knipe, V H
- Date: 1949
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:21161 , http://hdl.handle.net/10962/6650
- Full Text:
- Date Issued: 1949
- Authors: Knipe, V H
- Date: 1949
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:21161 , http://hdl.handle.net/10962/6650
- Full Text:
- Date Issued: 1949
A standardisation of Professor Spearman’s “A measure of 'intelligence' for use in schools” and a discussion of the methods of factorial analysis as applied to the study of ability
- Authors: Butler, J E
- Date: 1949
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:20970 , http://hdl.handle.net/10962/5740
- Full Text:
- Date Issued: 1949
- Authors: Butler, J E
- Date: 1949
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:20970 , http://hdl.handle.net/10962/5740
- Full Text:
- Date Issued: 1949
The anodic oxidation of calcium lactate : an estimation of the products of electrolysis and an investigation into some of the problems involved
- Authors: Impey, Norman Robert Murray
- Date: 1949
- Subjects: Electrolytic oxidation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4480 , http://hdl.handle.net/10962/d1012556 , Electrolytic oxidation
- Description: The subject of this thesis was chosen originally as a result of a suggestion made by a manufacturer of lactic acid. Lactic acid is made by a fermentation process from molasses and the acid is extracted from the fermentation liquors as calcium lactate. The conversion of the calcium lactate back to lactic acid is a tedious process from an industrial point of view. It was therefore suggested that the conversion may be more easily accomplished by electrolysis. The first experimental work was conducted with this object in view, but it soon became apparent that it was unlikely that lactic acid could be produced in suitable quantities for industrial purposes by this means. There was no reference in the literature to the electrolysis of calcium lactate, and little reference to the electrolysis of lactates in general, and what there was appeared to be conflicting, so it was decided to continue the investigation into the subject in order to determine what are the products of the anodic oxidation of calcium lactate. Intro., p.1.
- Full Text:
- Date Issued: 1949
- Authors: Impey, Norman Robert Murray
- Date: 1949
- Subjects: Electrolytic oxidation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4480 , http://hdl.handle.net/10962/d1012556 , Electrolytic oxidation
- Description: The subject of this thesis was chosen originally as a result of a suggestion made by a manufacturer of lactic acid. Lactic acid is made by a fermentation process from molasses and the acid is extracted from the fermentation liquors as calcium lactate. The conversion of the calcium lactate back to lactic acid is a tedious process from an industrial point of view. It was therefore suggested that the conversion may be more easily accomplished by electrolysis. The first experimental work was conducted with this object in view, but it soon became apparent that it was unlikely that lactic acid could be produced in suitable quantities for industrial purposes by this means. There was no reference in the literature to the electrolysis of calcium lactate, and little reference to the electrolysis of lactates in general, and what there was appeared to be conflicting, so it was decided to continue the investigation into the subject in order to determine what are the products of the anodic oxidation of calcium lactate. Intro., p.1.
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- Date Issued: 1949
The construction of a precision conductance bridge and its application to a study of chromium sulphate complexes
- Authors: Goddard, Errol Desmond
- Date: 1949
- Subjects: Chromium
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4476 , http://hdl.handle.net/10962/d1012038 , Chromium
- Description: A constant temperature room employing the comparatively new method of temperature control by means of a thyratron relay has been constructed. A high precision conductance bridge has been built in a very convenient form. Improvements include the incorporation of a cathode ray oscilloscope as null detector and the inclusion of a very stable oscillator of the phase shift type which is capable of giving a very pure wave form. Tests carried out on a system of degenerative tuning showed the the system is not easily applicable to high gain amplifiers. A new form of conductometric titration cell, employing the dipping type electrodes has been designed with special precautions against possible Parker Effect. A series of tests has been carried out on three types of cell to ascertain the effects of absorption, polarisation and Parker Effect on the accuracy of an ordinary conductometric titration. Conductometric titrations of NaOH solutions of violet and green chromic sulphate has been carried out, and the effect of aging these solutions closely studied. In addition, conductometric titrations of BaCL₂ into the chromic solutions have been made, and the NaOH titrations have been studied potentiometrically as well.
- Full Text:
- Date Issued: 1949
- Authors: Goddard, Errol Desmond
- Date: 1949
- Subjects: Chromium
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4476 , http://hdl.handle.net/10962/d1012038 , Chromium
- Description: A constant temperature room employing the comparatively new method of temperature control by means of a thyratron relay has been constructed. A high precision conductance bridge has been built in a very convenient form. Improvements include the incorporation of a cathode ray oscilloscope as null detector and the inclusion of a very stable oscillator of the phase shift type which is capable of giving a very pure wave form. Tests carried out on a system of degenerative tuning showed the the system is not easily applicable to high gain amplifiers. A new form of conductometric titration cell, employing the dipping type electrodes has been designed with special precautions against possible Parker Effect. A series of tests has been carried out on three types of cell to ascertain the effects of absorption, polarisation and Parker Effect on the accuracy of an ordinary conductometric titration. Conductometric titrations of NaOH solutions of violet and green chromic sulphate has been carried out, and the effect of aging these solutions closely studied. In addition, conductometric titrations of BaCL₂ into the chromic solutions have been made, and the NaOH titrations have been studied potentiometrically as well.
- Full Text:
- Date Issued: 1949
A critical evaluation of the analytical method used for the separation and estimation of copper and nickel
- Authors: Sismey, J E
- Date: 1948
- Subjects: Copper -- Analysis , Nickel -- Analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4519 , http://hdl.handle.net/10962/d1014335
- Description: [From Introduction]. This thesis deals with the determination of copper and nickel both separately and in each other's presence. The work is divided into two sections, one of which treats the subject from the theoretical side while the other contains an account of the practical work performed by the author. In the theoretical section, an attempt is made to summarise the better-known methods for the determination of copper and nickel, and at the same time, to incorporate such improvements, criticism and variations as have appeared in the literature. The subject is so vast that its summary in so short a space must necessarily be incomplete. Yoe and Server, for example, quote 111 references on the subject of the nickel-dimethylglyoxine with other ions. Only a fraction of the literature was available, and space permitted only a fraction of this to be abstracted in the following pages.
- Full Text:
- Date Issued: 1948
- Authors: Sismey, J E
- Date: 1948
- Subjects: Copper -- Analysis , Nickel -- Analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4519 , http://hdl.handle.net/10962/d1014335
- Description: [From Introduction]. This thesis deals with the determination of copper and nickel both separately and in each other's presence. The work is divided into two sections, one of which treats the subject from the theoretical side while the other contains an account of the practical work performed by the author. In the theoretical section, an attempt is made to summarise the better-known methods for the determination of copper and nickel, and at the same time, to incorporate such improvements, criticism and variations as have appeared in the literature. The subject is so vast that its summary in so short a space must necessarily be incomplete. Yoe and Server, for example, quote 111 references on the subject of the nickel-dimethylglyoxine with other ions. Only a fraction of the literature was available, and space permitted only a fraction of this to be abstracted in the following pages.
- Full Text:
- Date Issued: 1948
The economics of state assistance to agriculture with special reference to future policy in South Africa
- Authors: Threlfell, R L
- Date: 1948
- Subjects: Agriculture and state -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1107 , http://hdl.handle.net/10962/d1013399
- Description: [From the Introduction] The argument by which it is shown that, under a system of open competition, prices are determined in a way which secures to consumers a maximum aggregate of satisfaction consonant with the relative security of the means of production is the familiar material of many treatises on economics, and does not need to be repeated here. In Economics (as distinct from Politics) this argument provided in a simple form the logical justification for the advocacy of laissez faire in State policy during the early 19th century even though "it was the actual success of private enterprise and the inefficiency and corruption of Government control that caused laissez faire to be an acceptable policy". No-one, of course, contended that pure competition did in fact characterize the economic relations of the time. Quite the reverse. It was argued that if the hindrances to competition were removed, society as a whole would reap the benefits indicated by the theory.
- Full Text:
- Date Issued: 1948
- Authors: Threlfell, R L
- Date: 1948
- Subjects: Agriculture and state -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1107 , http://hdl.handle.net/10962/d1013399
- Description: [From the Introduction] The argument by which it is shown that, under a system of open competition, prices are determined in a way which secures to consumers a maximum aggregate of satisfaction consonant with the relative security of the means of production is the familiar material of many treatises on economics, and does not need to be repeated here. In Economics (as distinct from Politics) this argument provided in a simple form the logical justification for the advocacy of laissez faire in State policy during the early 19th century even though "it was the actual success of private enterprise and the inefficiency and corruption of Government control that caused laissez faire to be an acceptable policy". No-one, of course, contended that pure competition did in fact characterize the economic relations of the time. Quite the reverse. It was argued that if the hindrances to competition were removed, society as a whole would reap the benefits indicated by the theory.
- Full Text:
- Date Issued: 1948
The oxidation and degradation products of black wattle tannin (Acacia mollissima)
- Authors: Heugh, Richard Anthony
- Date: 1948
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:21169 , http://hdl.handle.net/10962/6706
- Full Text:
- Date Issued: 1948
- Authors: Heugh, Richard Anthony
- Date: 1948
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:21169 , http://hdl.handle.net/10962/6706
- Full Text:
- Date Issued: 1948