The endocoprid dung beetles of southern Africa (Coleoptera: Scarabaeidae)
- Davis, Adrian L V (Adrian Louis Victor)
- Authors: Davis, Adrian L V (Adrian Louis Victor)
- Date: 1978
- Subjects: Dung beetles -- Ecology , Dung beetles -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5845 , http://hdl.handle.net/10962/d1011030 , Dung beetles -- Ecology , Dung beetles -- Africa, Southern
- Description: The biology and ecology of the endocoprid dung beetles of the Aethiopian zoogeographic region has been studied in the field and laboratory. Work has centred mainly on Oniticellus planatus and O. formoaus although infomation has also been supplied on O. egregius, O. pictus and Tragiscus dimidiatus. The taxonomy of Onticellus (s.str.) and Tragiscus has been discussed with the recommendation that O. planattus and O. pseudaplanatus be synonymised. It has been suggested that endocoprid distribution is chiefly controlled by temperature, rainfall and the density of suitable large dung masses. On the basis of distribution it has been suggested that the taxonomic status of the subspecies of O. pictus should be reviewed. Endocoprids (genus Oniticellus (s.str.) are found throughout the warmer regions of Africa and Asia. Tragiscus is found only in Africa. Methods are described for monitoring endocoprids in the field, for distinguishing freshly emerged from older specimens, and for breeding endocoprids under laboratory conditions. It has been shown that endocoprids breed within or just beneath large dung masses unlike most other members of the Scarabaeinae which actively bury dung and construct the their broods at depth in the soil. It has been shown that there is a restriction of breeding sites available to endocoprids due to the removal of dung by the Scarabaeinae beetles and the limited space available within dung pads. This has resulted in low endocoprid population numbers, a disadvantage, which has been countered by highly specialised but opportunistic breeding habits. The requirements of dung plasticity have limited the time available for breeding activity by most endocoprids (excluding O. egresius) so that both the reproductive system and the reproductive behaviour (cf. O. planatus) are geared to rapid egg and brood production. Large numbers of follicles are able to be produced over a short period. In the probable absence of feeding, this has possibly been allowed by the involvement of a well developed fat body. The broods are tended by the parent female during larval development and the follicles are gradually resorbed, probably to prevent starvation. Ovarian recovery is rapid once feeding recommences. Behavioural mechanisms have developed which boost the number of broods constructed and the rapidity with which they are produced. The duration of endocoprid colonisation and the timing of arrival at dung is shown to be related to the rate of pad desiccation which is chiefly controlled by temperature and degree of dung removal by other dung beetles. Precipitation may also play a part. Predation by vertebrates and other insects has been noted and a number of mechanisms are described which are probably protective. Two insect parasitoids of O. formosus larvae have been recorded. The potential use of endocoprids in the Australian dung and fly control project has been discussed and it is recommended that their introduction be considered of low priority. It is suggested that the endocoprids evolved from Euoniticellus type ancestors and that their behaviour complex nidification developed in response to harsh environmental factors, chiefly the danger of desiccation and competition for dung with other dung beetles. From a consideration of brood and brood chamber construction it is suggested that O. egresius is a relatively unspecialised endocoprid which may retain dry season aestivation and has not evolved much further than its probable Euoniticellus type ancestor. The broods are coated in clay and abandoned soon after construction. Greater specialisation is shown by O. planatus and O. formosus which exhibit brooding behaviour, increasing longevity, more specialised brood protection, increased potential fecundity and continuous activity throughout the year. O. formosus shows greater specialisation in brood production than O. planatus. Greatest specialisation is found in T. dimidiatus which exhibits a precise brooding period and low egg production. Brood construction is of a similar degree of specialisation to that of O. formosus. Activity is also continuous throughout the year. The comparative biology of the five southern African endocoprids is summarised in Table 35. Summary, p. 129-131.
- Full Text:
- Authors: Davis, Adrian L V (Adrian Louis Victor)
- Date: 1978
- Subjects: Dung beetles -- Ecology , Dung beetles -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5845 , http://hdl.handle.net/10962/d1011030 , Dung beetles -- Ecology , Dung beetles -- Africa, Southern
- Description: The biology and ecology of the endocoprid dung beetles of the Aethiopian zoogeographic region has been studied in the field and laboratory. Work has centred mainly on Oniticellus planatus and O. formoaus although infomation has also been supplied on O. egregius, O. pictus and Tragiscus dimidiatus. The taxonomy of Onticellus (s.str.) and Tragiscus has been discussed with the recommendation that O. planattus and O. pseudaplanatus be synonymised. It has been suggested that endocoprid distribution is chiefly controlled by temperature, rainfall and the density of suitable large dung masses. On the basis of distribution it has been suggested that the taxonomic status of the subspecies of O. pictus should be reviewed. Endocoprids (genus Oniticellus (s.str.) are found throughout the warmer regions of Africa and Asia. Tragiscus is found only in Africa. Methods are described for monitoring endocoprids in the field, for distinguishing freshly emerged from older specimens, and for breeding endocoprids under laboratory conditions. It has been shown that endocoprids breed within or just beneath large dung masses unlike most other members of the Scarabaeinae which actively bury dung and construct the their broods at depth in the soil. It has been shown that there is a restriction of breeding sites available to endocoprids due to the removal of dung by the Scarabaeinae beetles and the limited space available within dung pads. This has resulted in low endocoprid population numbers, a disadvantage, which has been countered by highly specialised but opportunistic breeding habits. The requirements of dung plasticity have limited the time available for breeding activity by most endocoprids (excluding O. egresius) so that both the reproductive system and the reproductive behaviour (cf. O. planatus) are geared to rapid egg and brood production. Large numbers of follicles are able to be produced over a short period. In the probable absence of feeding, this has possibly been allowed by the involvement of a well developed fat body. The broods are tended by the parent female during larval development and the follicles are gradually resorbed, probably to prevent starvation. Ovarian recovery is rapid once feeding recommences. Behavioural mechanisms have developed which boost the number of broods constructed and the rapidity with which they are produced. The duration of endocoprid colonisation and the timing of arrival at dung is shown to be related to the rate of pad desiccation which is chiefly controlled by temperature and degree of dung removal by other dung beetles. Precipitation may also play a part. Predation by vertebrates and other insects has been noted and a number of mechanisms are described which are probably protective. Two insect parasitoids of O. formosus larvae have been recorded. The potential use of endocoprids in the Australian dung and fly control project has been discussed and it is recommended that their introduction be considered of low priority. It is suggested that the endocoprids evolved from Euoniticellus type ancestors and that their behaviour complex nidification developed in response to harsh environmental factors, chiefly the danger of desiccation and competition for dung with other dung beetles. From a consideration of brood and brood chamber construction it is suggested that O. egresius is a relatively unspecialised endocoprid which may retain dry season aestivation and has not evolved much further than its probable Euoniticellus type ancestor. The broods are coated in clay and abandoned soon after construction. Greater specialisation is shown by O. planatus and O. formosus which exhibit brooding behaviour, increasing longevity, more specialised brood protection, increased potential fecundity and continuous activity throughout the year. O. formosus shows greater specialisation in brood production than O. planatus. Greatest specialisation is found in T. dimidiatus which exhibits a precise brooding period and low egg production. Brood construction is of a similar degree of specialisation to that of O. formosus. Activity is also continuous throughout the year. The comparative biology of the five southern African endocoprids is summarised in Table 35. Summary, p. 129-131.
- Full Text:
A study of the distribution of nutrients during the growth of cayenne pineapples under field conditions
- Authors: Fowler, William Mackenzie
- Date: 1977
- Subjects: Plants -- Nutrition , Pineapple -- Crop yields , Growth (Plants) , Field Crops -- Nutrition
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4260 , http://hdl.handle.net/10962/d1011888 , Plants -- Nutrition , Pineapple -- Crop yields , Growth (Plants) , Field Crops -- Nutrition
- Description: The purpose of this study was to determine the uptake and distribution of nutrients during the growth of the Cayenne cultivar of Ananas comosus (L) Merr under field conditions in the Eastern Cape. The study was also done to help explain the apparent drop in the nutrient levels in the basal section of the "D"- leaf of the pineapple plant during the winter months and to determine the best part or parts of the plant to sample in order to measure the nutrient status of the pineapple plant at any stage of its growth. The investigation was conducted by selecting a plot within a production land on two farms in the pineapple growing region of the Eastern Cape. Plants were sampled from each plot at regular intervals from planting of the pineapple tops until the harvesting of the fruit of the first plant crop. Plant growth was measured and the nutrient concentrations in each section of the plant were determined. The total amounts of nutrients for each plant part were calculated and the nutrient uptake was compared and plotted on distribution diagrams.
- Full Text:
- Authors: Fowler, William Mackenzie
- Date: 1977
- Subjects: Plants -- Nutrition , Pineapple -- Crop yields , Growth (Plants) , Field Crops -- Nutrition
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4260 , http://hdl.handle.net/10962/d1011888 , Plants -- Nutrition , Pineapple -- Crop yields , Growth (Plants) , Field Crops -- Nutrition
- Description: The purpose of this study was to determine the uptake and distribution of nutrients during the growth of the Cayenne cultivar of Ananas comosus (L) Merr under field conditions in the Eastern Cape. The study was also done to help explain the apparent drop in the nutrient levels in the basal section of the "D"- leaf of the pineapple plant during the winter months and to determine the best part or parts of the plant to sample in order to measure the nutrient status of the pineapple plant at any stage of its growth. The investigation was conducted by selecting a plot within a production land on two farms in the pineapple growing region of the Eastern Cape. Plants were sampled from each plot at regular intervals from planting of the pineapple tops until the harvesting of the fruit of the first plant crop. Plant growth was measured and the nutrient concentrations in each section of the plant were determined. The total amounts of nutrients for each plant part were calculated and the nutrient uptake was compared and plotted on distribution diagrams.
- Full Text:
A study of the rabbit eye test system to determine the activity of acidic non-steroidal anti-inflammatory agents
- Authors: Wiseman, Ian Charles
- Date: 1977
- Subjects: Nonsteroidal anti-inflammatory agents , Anti-inflammatory agents
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3855 , http://hdl.handle.net/10962/d1013276
- Description: From introduction : "Inflammation per se, has been defined sufficiently to permit a rational approach to the search for drugs that modify this process, but satisfactory animal models for most rheumatoid diseases are not available". (Swingle 1974) In the search for new meaningful procedures for the detection and evaluation of anti-inflammatory drugs, the rabbit eye as a test system was studied.
- Full Text:
- Authors: Wiseman, Ian Charles
- Date: 1977
- Subjects: Nonsteroidal anti-inflammatory agents , Anti-inflammatory agents
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3855 , http://hdl.handle.net/10962/d1013276
- Description: From introduction : "Inflammation per se, has been defined sufficiently to permit a rational approach to the search for drugs that modify this process, but satisfactory animal models for most rheumatoid diseases are not available". (Swingle 1974) In the search for new meaningful procedures for the detection and evaluation of anti-inflammatory drugs, the rabbit eye as a test system was studied.
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An investigation of plant-derived cardiac glycosides as a possible basis for aposematism in the aphidophagous hoverfly Ischiodon aegryptius (Wiedemann) (Diptera: Syrphidae)
- Authors: Malcolm, Stephen Baillie
- Date: 1977
- Subjects: Diptera , Syrphidae , Aphidophagous insects , Predatory animals , Insect-plant relationships , Insect pests -- Biological control , Insects as carriers of disease
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5864 , http://hdl.handle.net/10962/d1012798 , Diptera , Syrphidae , Aphidophagous insects , Predatory animals , Insect-plant relationships , Insect pests -- Biological control , Insects as carriers of disease
- Description: The chemical defences of insects against predators are either passive or aggressive. Passive defence is achieved through crypsis, and aggressive defence is maintained by a conspicuous or 'aposematic' (Poulton, 1890) appearance that advertises some noxious quality of the insect harmful to a predator. Aposematism is mutually beneficial to both the bearer and its predator, whereas crypsis only benefits the prey species. It is therefore not surprising that the fascinating array of chemical defences in insects is both diverse and widespread (Roth and Eisner, 1962). Intro. p. 1.
- Full Text:
- Authors: Malcolm, Stephen Baillie
- Date: 1977
- Subjects: Diptera , Syrphidae , Aphidophagous insects , Predatory animals , Insect-plant relationships , Insect pests -- Biological control , Insects as carriers of disease
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5864 , http://hdl.handle.net/10962/d1012798 , Diptera , Syrphidae , Aphidophagous insects , Predatory animals , Insect-plant relationships , Insect pests -- Biological control , Insects as carriers of disease
- Description: The chemical defences of insects against predators are either passive or aggressive. Passive defence is achieved through crypsis, and aggressive defence is maintained by a conspicuous or 'aposematic' (Poulton, 1890) appearance that advertises some noxious quality of the insect harmful to a predator. Aposematism is mutually beneficial to both the bearer and its predator, whereas crypsis only benefits the prey species. It is therefore not surprising that the fascinating array of chemical defences in insects is both diverse and widespread (Roth and Eisner, 1962). Intro. p. 1.
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Explanation of the geological map of the country east of Kariba
- Authors: Broderick, T J
- Date: 1977
- Subjects: Geology -- Kariba, Lake (Zambia and Zimbabwe) -- Maps , Geology -- Kariba, Lake (Zambia and Zimbabwe)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5075 , http://hdl.handle.net/10962/d1014650
- Description: The area covers part of the western end of the Zambezi Metamorphic Belt as it is known in Rhodesia. Most of the rocks are paragneisses of various ages that have suffered a long and complex history which has taken them into the highest facies of metamorphism and into the realm of granitization. Only the Karoo sediments of the Zambezi Valley are unaffected by these metamorphic events. From the scanty geochronological results obtainable from the north of Rhodesia, the history of this area started more than 2 500 million years ago. In the east and south-east of the mapped area are a group of highly migmatized granitic gneisses which represent a continuation westwards of similar rocks found in the area described in Bulletin 51 by Wiles (1961}. These Urungwe Paragneisses are regarded as forrning the basement on which all other rocks in the area lie, although their relationship with the Basement Complex is unknown. Climatically Kariba is hot and humid. Mean summer temperatures average 30°C (86°F), with temperatures in October that often exceed 40°C (100°F). Away from the Lake the humidity decreases and the increased altitudes above the Escarpment have a cooling effect. The township's mean annual rainfall is 665 millimetres (26,2 inches), most of which falls in the months between November and February. Basically. the area is well timbered but population pressures in the tribal areas, and depredation by elephants elsewhere, have made serious inroads upon the natural vegetation. The gneissic terrain above the Escarpment is characterized by mufuti trees (Brachystegia boehmiz). The baobab (Adansonia digitata) is common in the larger river valleys and in the low-lying area surrounding the lake shore where it occurs together with mopane (Colophospermum mopane) and thick jessie bush. In the river valleys, trees typical of the Zambezi Valley are common and include the tamarind (Tamarindus indica), mumvey (Kigelia africana) and Steculia species. Buffalo beans (Mucuma coriacea) are not uncommon in grassy river-beds. Physiographically, the area can be subdivided into three distinct regions, all of which have a marked geological control. They are- (1) The fault-lined Gwembe trough which has subsequently been inundated by the waters of Lake Kariba to an average altitude of 487 metres (1 600 feet) above sea level since the completion of the dam across the upstream entrance to the Kariba Gorge in 1960. The fiat land that now forms part of the lake shore is underlain by sediments of Karoo age and these, in the mapped area, occupy the Charara and Gachegache Basins, that lie to the north and south respectively of the Msango Range. These fiat-lying areas give way sharply to the gneissic terrain of the Zambezi Metamorphic Belt along the fault-lined Zambezi Escarpment. (2) The northern boundary of the area and the Msango Range are underlain by metasediments of the Makuti Group. The relief is strongly influenced by the regional geological structure of these complexly folded rocks with resistant meta-arkose and quartzite forming the sharp ridges and metapelites occupying the valleys. The ridges and valleys trend eastwards in the Msango Range, but along the northern boundary they trend north-westwards. (3) The linear topographic features of the Makuti Group terrain give way southwards to the older gneisses along an abrupt scarp edge, the base of which is marked by the Tsororo River. This terrain of gneisses is very rugged and highly dissected above the Zambezi Escarpment until it flattens out, at about 900 metres (2 950 feet) above sea level, into the Urungwe Tribal Trust Lands. In the rugged country above the Escarpment, granulites of the Piriwiri Group stand out above the gneisses as steep-sided conical bills. The country rises in a series of fault-lined steps to its highest point, at Nyamangwe trigonometrical beacon, which stands at 1 336 metres (4 382 feet) above sea level.
- Full Text:
- Authors: Broderick, T J
- Date: 1977
- Subjects: Geology -- Kariba, Lake (Zambia and Zimbabwe) -- Maps , Geology -- Kariba, Lake (Zambia and Zimbabwe)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5075 , http://hdl.handle.net/10962/d1014650
- Description: The area covers part of the western end of the Zambezi Metamorphic Belt as it is known in Rhodesia. Most of the rocks are paragneisses of various ages that have suffered a long and complex history which has taken them into the highest facies of metamorphism and into the realm of granitization. Only the Karoo sediments of the Zambezi Valley are unaffected by these metamorphic events. From the scanty geochronological results obtainable from the north of Rhodesia, the history of this area started more than 2 500 million years ago. In the east and south-east of the mapped area are a group of highly migmatized granitic gneisses which represent a continuation westwards of similar rocks found in the area described in Bulletin 51 by Wiles (1961}. These Urungwe Paragneisses are regarded as forrning the basement on which all other rocks in the area lie, although their relationship with the Basement Complex is unknown. Climatically Kariba is hot and humid. Mean summer temperatures average 30°C (86°F), with temperatures in October that often exceed 40°C (100°F). Away from the Lake the humidity decreases and the increased altitudes above the Escarpment have a cooling effect. The township's mean annual rainfall is 665 millimetres (26,2 inches), most of which falls in the months between November and February. Basically. the area is well timbered but population pressures in the tribal areas, and depredation by elephants elsewhere, have made serious inroads upon the natural vegetation. The gneissic terrain above the Escarpment is characterized by mufuti trees (Brachystegia boehmiz). The baobab (Adansonia digitata) is common in the larger river valleys and in the low-lying area surrounding the lake shore where it occurs together with mopane (Colophospermum mopane) and thick jessie bush. In the river valleys, trees typical of the Zambezi Valley are common and include the tamarind (Tamarindus indica), mumvey (Kigelia africana) and Steculia species. Buffalo beans (Mucuma coriacea) are not uncommon in grassy river-beds. Physiographically, the area can be subdivided into three distinct regions, all of which have a marked geological control. They are- (1) The fault-lined Gwembe trough which has subsequently been inundated by the waters of Lake Kariba to an average altitude of 487 metres (1 600 feet) above sea level since the completion of the dam across the upstream entrance to the Kariba Gorge in 1960. The fiat land that now forms part of the lake shore is underlain by sediments of Karoo age and these, in the mapped area, occupy the Charara and Gachegache Basins, that lie to the north and south respectively of the Msango Range. These fiat-lying areas give way sharply to the gneissic terrain of the Zambezi Metamorphic Belt along the fault-lined Zambezi Escarpment. (2) The northern boundary of the area and the Msango Range are underlain by metasediments of the Makuti Group. The relief is strongly influenced by the regional geological structure of these complexly folded rocks with resistant meta-arkose and quartzite forming the sharp ridges and metapelites occupying the valleys. The ridges and valleys trend eastwards in the Msango Range, but along the northern boundary they trend north-westwards. (3) The linear topographic features of the Makuti Group terrain give way southwards to the older gneisses along an abrupt scarp edge, the base of which is marked by the Tsororo River. This terrain of gneisses is very rugged and highly dissected above the Zambezi Escarpment until it flattens out, at about 900 metres (2 950 feet) above sea level, into the Urungwe Tribal Trust Lands. In the rugged country above the Escarpment, granulites of the Piriwiri Group stand out above the gneisses as steep-sided conical bills. The country rises in a series of fault-lined steps to its highest point, at Nyamangwe trigonometrical beacon, which stands at 1 336 metres (4 382 feet) above sea level.
- Full Text:
Instability in the magnetotail
- Authors: English, Daniel Rowe
- Date: 1977
- Subjects: Magnetotails
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5425 , http://hdl.handle.net/10962/d1011764 , Magnetotails
- Description: The magnetic induction field due to the Earth only would, if undisturbed by any outside agency, resemble macroscopically the field due to a magnetic dipole. Hcwever the field is disturbed by the interplanetary magnetic field, of which the most important component is that of the Sun. If the Sun's magnetic field were effectively steady, it would also be a dipole field, and approximately constant in the region within about twenty earth radii from the earth. Also, if we treat the Sun as a dipole, its dipole axis is roughly normal to the ecliptic plane. The Earth, treated as a dipole, has an axis which is inclined to the normal to the ecliptic plane at an angle which varies daily from a few degrees to nearly a third of a right angle. However, in this paper, it is proposed to treat both dipole axes as contra-parallel and effectively normal to the ecliptic plane, so that a general idea of the combined field can be obtained. Then the effect of a steady field due to the Sun, on the Earth's field would be the formation of a "neutral ring" surrounding the Earth; that is, a closed "neutral line", this being a line of points at each of which the net nagnetic induction is zero. As the point of observation passes through this line, the field changes direction. Intro. p. v.
- Full Text:
- Authors: English, Daniel Rowe
- Date: 1977
- Subjects: Magnetotails
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5425 , http://hdl.handle.net/10962/d1011764 , Magnetotails
- Description: The magnetic induction field due to the Earth only would, if undisturbed by any outside agency, resemble macroscopically the field due to a magnetic dipole. Hcwever the field is disturbed by the interplanetary magnetic field, of which the most important component is that of the Sun. If the Sun's magnetic field were effectively steady, it would also be a dipole field, and approximately constant in the region within about twenty earth radii from the earth. Also, if we treat the Sun as a dipole, its dipole axis is roughly normal to the ecliptic plane. The Earth, treated as a dipole, has an axis which is inclined to the normal to the ecliptic plane at an angle which varies daily from a few degrees to nearly a third of a right angle. However, in this paper, it is proposed to treat both dipole axes as contra-parallel and effectively normal to the ecliptic plane, so that a general idea of the combined field can be obtained. Then the effect of a steady field due to the Sun, on the Earth's field would be the formation of a "neutral ring" surrounding the Earth; that is, a closed "neutral line", this being a line of points at each of which the net nagnetic induction is zero. As the point of observation passes through this line, the field changes direction. Intro. p. v.
- Full Text:
Precipitation effects on atmospheric electron densities
- Authors: Huang, Cheryl Yu-Yin
- Date: 1977
- Subjects: Precipitation (Chemistry)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5527 , http://hdl.handle.net/10962/d1012441 , Precipitation (Chemistry)
- Description: In this thesis the effects of precipitated electrons on electron densities in the upper atmosphere are investigated. A method for solving the continuity equation has been developed , and this has been used to calculate electron density profiles under various conditions: daytime equilibrium conditions, with and without additional ionization by precipitated electrons; and nighttime conditions, with and without precinitation . This preliminary study seems to show that certain effects may be attributable to precipitation, and that these effects may be significant at night.
- Full Text:
- Authors: Huang, Cheryl Yu-Yin
- Date: 1977
- Subjects: Precipitation (Chemistry)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5527 , http://hdl.handle.net/10962/d1012441 , Precipitation (Chemistry)
- Description: In this thesis the effects of precipitated electrons on electron densities in the upper atmosphere are investigated. A method for solving the continuity equation has been developed , and this has been used to calculate electron density profiles under various conditions: daytime equilibrium conditions, with and without additional ionization by precipitated electrons; and nighttime conditions, with and without precinitation . This preliminary study seems to show that certain effects may be attributable to precipitation, and that these effects may be significant at night.
- Full Text:
Some aspects of the theory, application, and computation of generalised inverses of matrices
- Authors: Cretchley, Partricia C
- Date: 1977
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/6212 , vital:21063
- Description: The idea of generalising the classical notion of the inverse of a non-singular matrix arose as far back as in 1920, but it was not until the late fifties that the development of the theory gained any impetus. Since then , as is the case in the development of many new concepts , work done in parallel in various parts of the world has resulted in a great deal of untidiness in the literature : confusion over terminology , and even duplication of theory. More recently, however, some attempts have been made to bring together people active in the field of generalised inverses, in order to reach consensus on some aspects of definition and terminology, and to publish more general works on the subject. Towards this purpose, a symposium on the theory and application of generalised inverses of matrices was held in Lubbock, Texas, and its proceedings published in 1968 (see [25] ). A few other works of this nature (see [4], (19a] ) have appeared , but the bulk of the literature still comprises numerous diverse papers offering further ideas on the theoretical properties which these matrices have , and drawing attention to their application in areas of statistics , numerical analysis , filtering , modern control and estimation theory, pattern recognition and many others. This essay offers a look at generalised inverses in the following way: firstly a broad basis and background is established in the first three chapters to provide greater understanding of the motivation for the remaining chapters, where the approach then changes to become far more detailed. Within this general framework, Chapter 1 offers a brief glimpse of the history and development of work in the field. In Chapter 2 some of the most significant properties of these inverses are described, while in Chapters 3 and 4 and 5 attention is given to interesting and remarkable computational algorithms relating to generalised inverses (some well suited to machine processing). The material of Chapters 4 and 5 is largely due to Decell, Stallings and Boullion, and Tanabe, in [6], [24] and [27], respectively, while the source of material for the first three chapters is the literature generally, with Penrose's two papers providing a rough framework for Chapters 1 and 2 (see [17]).
- Full Text:
- Authors: Cretchley, Partricia C
- Date: 1977
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/6212 , vital:21063
- Description: The idea of generalising the classical notion of the inverse of a non-singular matrix arose as far back as in 1920, but it was not until the late fifties that the development of the theory gained any impetus. Since then , as is the case in the development of many new concepts , work done in parallel in various parts of the world has resulted in a great deal of untidiness in the literature : confusion over terminology , and even duplication of theory. More recently, however, some attempts have been made to bring together people active in the field of generalised inverses, in order to reach consensus on some aspects of definition and terminology, and to publish more general works on the subject. Towards this purpose, a symposium on the theory and application of generalised inverses of matrices was held in Lubbock, Texas, and its proceedings published in 1968 (see [25] ). A few other works of this nature (see [4], (19a] ) have appeared , but the bulk of the literature still comprises numerous diverse papers offering further ideas on the theoretical properties which these matrices have , and drawing attention to their application in areas of statistics , numerical analysis , filtering , modern control and estimation theory, pattern recognition and many others. This essay offers a look at generalised inverses in the following way: firstly a broad basis and background is established in the first three chapters to provide greater understanding of the motivation for the remaining chapters, where the approach then changes to become far more detailed. Within this general framework, Chapter 1 offers a brief glimpse of the history and development of work in the field. In Chapter 2 some of the most significant properties of these inverses are described, while in Chapters 3 and 4 and 5 attention is given to interesting and remarkable computational algorithms relating to generalised inverses (some well suited to machine processing). The material of Chapters 4 and 5 is largely due to Decell, Stallings and Boullion, and Tanabe, in [6], [24] and [27], respectively, while the source of material for the first three chapters is the literature generally, with Penrose's two papers providing a rough framework for Chapters 1 and 2 (see [17]).
- Full Text:
The performance of a 22 GHz radio telescope
- Authors: Gaylard, Michael John
- Date: 1977
- Subjects: Radio telescopes , Paraboloid
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5520 , http://hdl.handle.net/10962/d1011946 , Radio telescopes , Paraboloid
- Description: The performance of the Rhodes 22 GHz radio telescope and its improvement are discussed in this thesis. The reflector surfaces of the Cassegrain antenna were surveyed and the surface errors minimised, while the magnitude of thermal and gravitational defomations was calculated. The design and operation of the microwave front end has been improved, and the mixer performance characterised. The continuum and spectral line receivers and their sensitivity are described. The aperture efficiency, which has been raised from 0,47 to 0,57, was deduced from solar and lunar observations and atmospheric attenuation measurements. The antenna beam pattern was also obtained from the observations, with the aid of a computer program, and is compared to that predicted for the telescope.
- Full Text:
- Authors: Gaylard, Michael John
- Date: 1977
- Subjects: Radio telescopes , Paraboloid
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5520 , http://hdl.handle.net/10962/d1011946 , Radio telescopes , Paraboloid
- Description: The performance of the Rhodes 22 GHz radio telescope and its improvement are discussed in this thesis. The reflector surfaces of the Cassegrain antenna were surveyed and the surface errors minimised, while the magnitude of thermal and gravitational defomations was calculated. The design and operation of the microwave front end has been improved, and the mixer performance characterised. The continuum and spectral line receivers and their sensitivity are described. The aperture efficiency, which has been raised from 0,47 to 0,57, was deduced from solar and lunar observations and atmospheric attenuation measurements. The antenna beam pattern was also obtained from the observations, with the aid of a computer program, and is compared to that predicted for the telescope.
- Full Text:
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