A 22 GHz water maser radiometer
- Authors: Nunn, Brian J
- Date: 1975
- Subjects: Masers , Radiometers
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5535 , http://hdl.handle.net/10962/d1012987
- Description: This thesis describes the properties of interstellar water maser sources, and other sources near 22 GHz. Calculations based on manufacturer's specifications of the 22 GHz mixer, which was to be used in a water radiometer, and on the size antenna aperture of the proposed antenna aperture, show the viability of constructing such a radiometer for spectral line and continuum work. Various sections of the radiometer were constructed, including the Cassegrain feed system and its support, an intermediate frequency amplifier and buffer, a timing control unit, and a data processor. These units are part of the radiometer, which is almost ready for observations of sources.
- Full Text:
- Date Issued: 1975
- Authors: Nunn, Brian J
- Date: 1975
- Subjects: Masers , Radiometers
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5535 , http://hdl.handle.net/10962/d1012987
- Description: This thesis describes the properties of interstellar water maser sources, and other sources near 22 GHz. Calculations based on manufacturer's specifications of the 22 GHz mixer, which was to be used in a water radiometer, and on the size antenna aperture of the proposed antenna aperture, show the viability of constructing such a radiometer for spectral line and continuum work. Various sections of the radiometer were constructed, including the Cassegrain feed system and its support, an intermediate frequency amplifier and buffer, a timing control unit, and a data processor. These units are part of the radiometer, which is almost ready for observations of sources.
- Full Text:
- Date Issued: 1975
A computer analysis of some of the Harrison metrics
- Authors: Sadler, Christopher John
- Date: 1975
- Subjects: Computer science -- Mathematics , Software measurement
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5427 , http://hdl.handle.net/10962/d1013151
- Description: In his paper B.K.Harrison concludes with the observation that his "solutions ... are presented as raw material for further research in General Relativity". In the same spirit, the present work started out as an attempt to process that raw material in a production-line powered by a computer. Harrison's solutions uould be fed in at one end, and the finished product, as yet undecided, would appear at the other. In the event, however, the project became more like an exercise in quality control, to continue the analogy. A search was made for algebraic criteria which would distinguish between those solutions which were acceptable for further analysis with particular regard to Gravitational radiation, and those which were not. Regrettably, no criteria could be found which characterised radiative solutions unequivocally, and, at the same time, lent themselves to a computer approach. The result is that the discussion of radiative solutions has had to be relegated to an appendix (Appendix 1), while the main body of the work is concerned with the determination of those quantities (the Newman-Penrose scalars) which would seem to be the foundation of any future computer-based analysis of gravitational radiation. Chapter 1 is an account of the underlying mathematical formulation, defining the terms, concepts and processes involved. In Chapter 2 the transformation of some of the ideas of Chapter 1 into computer software is presented. Chapter 3 is concerned with the specific metrics (the Harrison metrics) and the extent to which they have heen processed. The project has leaned heavily on papers by Harrison for the "raw material", by D' Inverno and Russell Clark, who pioneered the techniques and classified the Harrison metrics, and by Sachs for the treatment of gravitational radiation. However, the analysis of diagonal metrics, the special tetrad of Chapter 2 and the results in Appendix 2 are new.
- Full Text:
- Date Issued: 1975
- Authors: Sadler, Christopher John
- Date: 1975
- Subjects: Computer science -- Mathematics , Software measurement
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5427 , http://hdl.handle.net/10962/d1013151
- Description: In his paper B.K.Harrison concludes with the observation that his "solutions ... are presented as raw material for further research in General Relativity". In the same spirit, the present work started out as an attempt to process that raw material in a production-line powered by a computer. Harrison's solutions uould be fed in at one end, and the finished product, as yet undecided, would appear at the other. In the event, however, the project became more like an exercise in quality control, to continue the analogy. A search was made for algebraic criteria which would distinguish between those solutions which were acceptable for further analysis with particular regard to Gravitational radiation, and those which were not. Regrettably, no criteria could be found which characterised radiative solutions unequivocally, and, at the same time, lent themselves to a computer approach. The result is that the discussion of radiative solutions has had to be relegated to an appendix (Appendix 1), while the main body of the work is concerned with the determination of those quantities (the Newman-Penrose scalars) which would seem to be the foundation of any future computer-based analysis of gravitational radiation. Chapter 1 is an account of the underlying mathematical formulation, defining the terms, concepts and processes involved. In Chapter 2 the transformation of some of the ideas of Chapter 1 into computer software is presented. Chapter 3 is concerned with the specific metrics (the Harrison metrics) and the extent to which they have heen processed. The project has leaned heavily on papers by Harrison for the "raw material", by D' Inverno and Russell Clark, who pioneered the techniques and classified the Harrison metrics, and by Sachs for the treatment of gravitational radiation. However, the analysis of diagonal metrics, the special tetrad of Chapter 2 and the results in Appendix 2 are new.
- Full Text:
- Date Issued: 1975
Remarks on formalized arithmetic and subsystems thereof
- Brink, C
- Authors: Brink, C
- Date: 1975
- Subjects: Gödel, Kurt , Logic, Symbolic and mathematical , Semantics (Philosophy) , Arithmetic -- Foundations , Number theory
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5424 , http://hdl.handle.net/10962/d1009752 , Gödel, Kurt , Logic, Symbolic and mathematical , Semantics (Philosophy) , Arithmetic -- Foundations , Number theory
- Description: In a famous paper of 1931, Gödel proved that any formalization of elementary Arithmetic is incomplete, in the sense that it contains statements which are neither provable nor disprovable. Some two years before this, Presburger proved that a mutilated system of Arithmetic, employing only addition but not multiplication, is complete. This essay is partly an exposition of a system such as Presburger's, and partly an attempt to gain insight into the source of the incompleteness of Arithmetic, by linking Presburger's result with Gödel's.
- Full Text:
- Date Issued: 1975
- Authors: Brink, C
- Date: 1975
- Subjects: Gödel, Kurt , Logic, Symbolic and mathematical , Semantics (Philosophy) , Arithmetic -- Foundations , Number theory
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5424 , http://hdl.handle.net/10962/d1009752 , Gödel, Kurt , Logic, Symbolic and mathematical , Semantics (Philosophy) , Arithmetic -- Foundations , Number theory
- Description: In a famous paper of 1931, Gödel proved that any formalization of elementary Arithmetic is incomplete, in the sense that it contains statements which are neither provable nor disprovable. Some two years before this, Presburger proved that a mutilated system of Arithmetic, employing only addition but not multiplication, is complete. This essay is partly an exposition of a system such as Presburger's, and partly an attempt to gain insight into the source of the incompleteness of Arithmetic, by linking Presburger's result with Gödel's.
- Full Text:
- Date Issued: 1975
The agricultural development of the 1820 settlement down to 1846
- Authors: Webb, Arthur (Arthur C M)
- Date: 1975
- Subjects: Agriculture -- South Africa -- Eastern Cape -- History Agricultural colonies -- South Africa -- Eastern Cape British settlers of 1820 (South Africa) Cape of Good Hope (South Africa) -- History -- 1795-1872
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:1060 , http://hdl.handle.net/10962/d1007519
- Description: Preface: The arrival of the 1820 Settlers in South Africa and their impact on the political and social life of the Cape Colony has been well covered by historical research. This work is an attempt to illuminate yet another area in which their impact was felt. The failure of the settlement scheme under which these people were introduced into the colony has tended to detract from the importance which agriculture played in the early years of their residence in South Africa. The failure of the first crops may well have ended the attempts by many to establish themselves on the land but for others it was the beginning of a process of adaptation to the agricultural conditions of a new country. In this they were remarkably successful and within a decade the English farming community of the eastern frontier was prospering. The theme of this work traces the progress of these farmers through the initial period of crop failures, which condemned the settlement in the eyes of many, and through the ensuing years and later misfortune, the Sixth Frontier war of 1834-35. Both these setbacks were very significant in moulding the development of agriculture as practised by these farmers. In the past, historians have tended to over-estimate the reverse suffered by these farmers during this frontier war. The seemingly paradoxical questions raised by the rapid recovery of this community after the war have been left largely unanswered. Some attempt is made in the pages which follow to shed new light on this issue. In the first three chapters of this work the letters written by Thomas Philipps to his family in Britain form the chief source of information. Much of this correspondence has already found wider publication in a volume edited by Arthur Keppel-Jones, but there are significant omissions, particularly with regard to Philipps' commentary on agricultural matters. Unfortunately, this series of letters ends in 1830, and the chief sources for the latter period of this work are the various entries made) on agricultural matters, in the Graham's Town Journal, together with the farm diary of James Collett, another frontier farmer. From these, and various other works, it has been possible to trace the major developments of this farming community.
- Full Text:
- Date Issued: 1975
- Authors: Webb, Arthur (Arthur C M)
- Date: 1975
- Subjects: Agriculture -- South Africa -- Eastern Cape -- History Agricultural colonies -- South Africa -- Eastern Cape British settlers of 1820 (South Africa) Cape of Good Hope (South Africa) -- History -- 1795-1872
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:1060 , http://hdl.handle.net/10962/d1007519
- Description: Preface: The arrival of the 1820 Settlers in South Africa and their impact on the political and social life of the Cape Colony has been well covered by historical research. This work is an attempt to illuminate yet another area in which their impact was felt. The failure of the settlement scheme under which these people were introduced into the colony has tended to detract from the importance which agriculture played in the early years of their residence in South Africa. The failure of the first crops may well have ended the attempts by many to establish themselves on the land but for others it was the beginning of a process of adaptation to the agricultural conditions of a new country. In this they were remarkably successful and within a decade the English farming community of the eastern frontier was prospering. The theme of this work traces the progress of these farmers through the initial period of crop failures, which condemned the settlement in the eyes of many, and through the ensuing years and later misfortune, the Sixth Frontier war of 1834-35. Both these setbacks were very significant in moulding the development of agriculture as practised by these farmers. In the past, historians have tended to over-estimate the reverse suffered by these farmers during this frontier war. The seemingly paradoxical questions raised by the rapid recovery of this community after the war have been left largely unanswered. Some attempt is made in the pages which follow to shed new light on this issue. In the first three chapters of this work the letters written by Thomas Philipps to his family in Britain form the chief source of information. Much of this correspondence has already found wider publication in a volume edited by Arthur Keppel-Jones, but there are significant omissions, particularly with regard to Philipps' commentary on agricultural matters. Unfortunately, this series of letters ends in 1830, and the chief sources for the latter period of this work are the various entries made) on agricultural matters, in the Graham's Town Journal, together with the farm diary of James Collett, another frontier farmer. From these, and various other works, it has been possible to trace the major developments of this farming community.
- Full Text:
- Date Issued: 1975
The development of a morphometric model for the estimation of mean annual sediment yield in ungauged catchments of South African river systems
- Authors: Roberts, Peter J T
- Date: 1975
- Subjects: Sedimentation and deposition -- South Africa -- Mathematical models
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4876 , http://hdl.handle.net/10962/d1013062
- Description: Hydrologists are regularly faced with the unenviable task of having to predict the magnitude and frequency of phenomena such as floods and droughts; and rates of erosion. If long records are available for analysis the hydrologist is able to base his predictions on the premise that the pattern of variation that has been observed in the past will persist in the future. The confidence that can be placed in any estimate consequently depends to a large extent on the length of time over which the phenomena have been measured at the problem site. Unfortunately the availability of adequate records tends to be the exception rather than the rule and in areas where there is inadequate data, it is necessary to resort to the hazardous procedure of transferring information from the gauged to the ungauged catchments. The transfer of information is accomplished by using empirical methods based on regionalised parameters, but the uncertainties involved together with the economic implications that could arise from a poor estimate, prompt the hydrologist to use as many methods as possible. The need for empirical methods of estimating mean annual sediment yield in ungauged catchments was first appreciated by the author when he was involved in the estimation of design floods and sediment accumulation at sites for proposed reservoirs. Empirical methods of estimating sediment yield are frequently used in an engineering context, but little attention has been given to the catchment surface from which the sediment supply is derived. It is perhaps in this often neglected field of research that the physical geographer can make a contribution. The principal aim of the thesis, more fully discussed in Chapter I, was the development of a morphometric model which could be used to estimate mean annual sediment yield in ungauged catchments in South Africa. The data used in the development of the model were drawn from the catchments, described in Appendix A, that cover a wide range of climate and topography. A description of the approaches adopted by other researchers for the development of empirical models of estimating sediment yield which forms the background to the model has been included as Appendix B. The model was first developed in an elementary form as the focus of a research project which was documented in the form of three reports of research in progress (Roberts, 1973 a, b and c). Analysis of the pattern of variation of suspended sediment yield provided a better understanding of factors affecting sediment yield and supported the selection of the prediction variable (Horton's P ratio) which was used in the model. The concepts of network topology were utilised to gain insight into the environmental factors controlling both the P ratio and sediment yield. Reasons for the high correlation between the P ratio and sediment yield are suggested but it is felt that further research should be focused on this aspect. In order not to break the continuity and development of the steps taken in the derivation of the model details of the calculations are collected in Appendices C, D and E. While many of the figures and tables presented in the thesis appeared in technical notes prepared entirely by the author for the Department of Water Affairs, the views expressed in the thesis do not in any way, either explicitly or by implication, represent any official view or policy of the Department of Water Affairs.
- Full Text:
- Date Issued: 1975
- Authors: Roberts, Peter J T
- Date: 1975
- Subjects: Sedimentation and deposition -- South Africa -- Mathematical models
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4876 , http://hdl.handle.net/10962/d1013062
- Description: Hydrologists are regularly faced with the unenviable task of having to predict the magnitude and frequency of phenomena such as floods and droughts; and rates of erosion. If long records are available for analysis the hydrologist is able to base his predictions on the premise that the pattern of variation that has been observed in the past will persist in the future. The confidence that can be placed in any estimate consequently depends to a large extent on the length of time over which the phenomena have been measured at the problem site. Unfortunately the availability of adequate records tends to be the exception rather than the rule and in areas where there is inadequate data, it is necessary to resort to the hazardous procedure of transferring information from the gauged to the ungauged catchments. The transfer of information is accomplished by using empirical methods based on regionalised parameters, but the uncertainties involved together with the economic implications that could arise from a poor estimate, prompt the hydrologist to use as many methods as possible. The need for empirical methods of estimating mean annual sediment yield in ungauged catchments was first appreciated by the author when he was involved in the estimation of design floods and sediment accumulation at sites for proposed reservoirs. Empirical methods of estimating sediment yield are frequently used in an engineering context, but little attention has been given to the catchment surface from which the sediment supply is derived. It is perhaps in this often neglected field of research that the physical geographer can make a contribution. The principal aim of the thesis, more fully discussed in Chapter I, was the development of a morphometric model which could be used to estimate mean annual sediment yield in ungauged catchments in South Africa. The data used in the development of the model were drawn from the catchments, described in Appendix A, that cover a wide range of climate and topography. A description of the approaches adopted by other researchers for the development of empirical models of estimating sediment yield which forms the background to the model has been included as Appendix B. The model was first developed in an elementary form as the focus of a research project which was documented in the form of three reports of research in progress (Roberts, 1973 a, b and c). Analysis of the pattern of variation of suspended sediment yield provided a better understanding of factors affecting sediment yield and supported the selection of the prediction variable (Horton's P ratio) which was used in the model. The concepts of network topology were utilised to gain insight into the environmental factors controlling both the P ratio and sediment yield. Reasons for the high correlation between the P ratio and sediment yield are suggested but it is felt that further research should be focused on this aspect. In order not to break the continuity and development of the steps taken in the derivation of the model details of the calculations are collected in Appendices C, D and E. While many of the figures and tables presented in the thesis appeared in technical notes prepared entirely by the author for the Department of Water Affairs, the views expressed in the thesis do not in any way, either explicitly or by implication, represent any official view or policy of the Department of Water Affairs.
- Full Text:
- Date Issued: 1975
The genus Sisyphus Latr. (coleoptera : scarabaeidae) in Southern Africa
- Authors: Paschalidis, Karen Margaret
- Date: 1975
- Subjects: Beetles -- Africa, Southern , Scarabaeidae -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5872 , http://hdl.handle.net/10962/d1013000
- Description: 1. Twenty four species of the genus Sisyphus known in southern Africa are listed with their synonyms and their taxonomy is discussed. 2. A key to the adults of 23 of these species is given. 3. The known distribution of 23 species and seasonal occurrence of 19 species are illustrated and briefly discussed. 4. The general biology of the genus Sisyphus is discussed and the major behavioural and biological differences between the two subgenera Sisyphus and Neosisyphus are given. 5. The laboratory and field investigation into variations in behaviour and biology in eight species occurring in the Mkuzi Game Reserve, with regards to interspecific competition, is presented. 6. The known possible natural enemies of Sisyphus are mentioned and the extent of competition from other genera, based on field and laboratory observations, is outlined. 7. Summary tables of all data with a final tabulated evaluation of the suitability of species for introduction into Australia is given. 8. Nine species have been highly recommended for Australia. Six more species could be considered but most of these still need further investigation. The remaining nine species were found to be unsuitable for transfer to Australia.
- Full Text:
- Date Issued: 1975
- Authors: Paschalidis, Karen Margaret
- Date: 1975
- Subjects: Beetles -- Africa, Southern , Scarabaeidae -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5872 , http://hdl.handle.net/10962/d1013000
- Description: 1. Twenty four species of the genus Sisyphus known in southern Africa are listed with their synonyms and their taxonomy is discussed. 2. A key to the adults of 23 of these species is given. 3. The known distribution of 23 species and seasonal occurrence of 19 species are illustrated and briefly discussed. 4. The general biology of the genus Sisyphus is discussed and the major behavioural and biological differences between the two subgenera Sisyphus and Neosisyphus are given. 5. The laboratory and field investigation into variations in behaviour and biology in eight species occurring in the Mkuzi Game Reserve, with regards to interspecific competition, is presented. 6. The known possible natural enemies of Sisyphus are mentioned and the extent of competition from other genera, based on field and laboratory observations, is outlined. 7. Summary tables of all data with a final tabulated evaluation of the suitability of species for introduction into Australia is given. 8. Nine species have been highly recommended for Australia. Six more species could be considered but most of these still need further investigation. The remaining nine species were found to be unsuitable for transfer to Australia.
- Full Text:
- Date Issued: 1975
Twistors in curved space
- Ward, R S (Richard Samuel), 1951-
- Authors: Ward, R S (Richard Samuel), 1951-
- Date: 1975
- Subjects: Twistor theory , Space and time
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5429 , http://hdl.handle.net/10962/d1013472
- Description: From the Introduction, p. 1. During the past decade, the theory of twistors has been introduced and developed, primarily by Professor Roger Penrose, as part of a long-term program aimed at resolving certain difficulties in present-day physical theory. These difficulties include, firstly, the problem of combining quantum mechanics and general relativity, and, secondly, the question of whether the concept of a continuum is at all relevant to physics. Most models of space-time used in general relativity employ the idea of a manifold consisting of a continuum of points. This feature of the models has often been criticised, on the grounds that physical observations are essentially discrete in nature; for reasons that are mathematical, rather than physical, the gaps between these observations are filled in a continuous fashion (see, for example, Schrodinger (I), pp.26-31). Although analysis (in its generally accepted form) demands that quantities should take on a continuous range of values, physics, as such,does not make such a demand. The situation in quantum mechanics is not all that much better since, although some quantities such as angular momentum can only take on certain discrete values, one still has to deal with the complex continuum of probability amplitudes. From this point of view it would be desirable to have all physical laws expressed in terms of combinatorial mathematics, rather than in terms of (standard) analysis.
- Full Text:
- Date Issued: 1975
- Authors: Ward, R S (Richard Samuel), 1951-
- Date: 1975
- Subjects: Twistor theory , Space and time
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5429 , http://hdl.handle.net/10962/d1013472
- Description: From the Introduction, p. 1. During the past decade, the theory of twistors has been introduced and developed, primarily by Professor Roger Penrose, as part of a long-term program aimed at resolving certain difficulties in present-day physical theory. These difficulties include, firstly, the problem of combining quantum mechanics and general relativity, and, secondly, the question of whether the concept of a continuum is at all relevant to physics. Most models of space-time used in general relativity employ the idea of a manifold consisting of a continuum of points. This feature of the models has often been criticised, on the grounds that physical observations are essentially discrete in nature; for reasons that are mathematical, rather than physical, the gaps between these observations are filled in a continuous fashion (see, for example, Schrodinger (I), pp.26-31). Although analysis (in its generally accepted form) demands that quantities should take on a continuous range of values, physics, as such,does not make such a demand. The situation in quantum mechanics is not all that much better since, although some quantities such as angular momentum can only take on certain discrete values, one still has to deal with the complex continuum of probability amplitudes. From this point of view it would be desirable to have all physical laws expressed in terms of combinatorial mathematics, rather than in terms of (standard) analysis.
- Full Text:
- Date Issued: 1975
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