Self-concept as a measure of success in the military environment
- Authors: Besener, Paul Robert
- Date: 1987
- Subjects: Self-perception , Control , Recruits , Soldiers , Military , National service , South Africa , Pupils , Learners , Guidance , School curriculum
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: vital:1363 , http://hdl.handle.net/10962/d1001429
- Description: This piece of research is an attempt to evaluate the relationship between military 'success' and the psychological preparedness of recruits in terms of their self-concepts and locus of control orientations. The new recruit is forced to adapt to the military environment which will, in turn, attempt to change him into an effective soldier. It was noticed by the researcher, who was involved in military training at the time, that a number of recruits, even some with seemingly limited potential, coped well, while others who seemed to have the ability failed to cope adequately. Recruits completed questionnaires which provided the researcher with biographical data and background information. In addition, the Bledsoe Self-Concept Scale and the Nowicki and Strickland Locus of Control Scale were used in order to determine their self-concepts and locus of control orientations respectively, prior to the beginning of national service. Detailed unstructured interviews were also conducted with a sample of military personnel, to provide another basis for gathering data and for clarifying some of the issues involved. Briefly, the chief conclusion of this researcher is that a significant majority of 'successful' recruits in the military environment have a positive self-concept and an internal locus of control. On the basis of the above finding, it is suggested that there is a need to guide pupils about certain aspects of military life before they begin their National Service. There would seem to be a need for this guidance to be incorporated into the school curriculum, together with such practical aspects as cadets, shooting, etc. There is a shortage of this kind of research on the military situation in South Africa, and it is suggested that numerous issues in this field need to be researched for the benefit of future conscripts and the military alike.
- Full Text:
- Date Issued: 1987
- Authors: Besener, Paul Robert
- Date: 1987
- Subjects: Self-perception , Control , Recruits , Soldiers , Military , National service , South Africa , Pupils , Learners , Guidance , School curriculum
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: vital:1363 , http://hdl.handle.net/10962/d1001429
- Description: This piece of research is an attempt to evaluate the relationship between military 'success' and the psychological preparedness of recruits in terms of their self-concepts and locus of control orientations. The new recruit is forced to adapt to the military environment which will, in turn, attempt to change him into an effective soldier. It was noticed by the researcher, who was involved in military training at the time, that a number of recruits, even some with seemingly limited potential, coped well, while others who seemed to have the ability failed to cope adequately. Recruits completed questionnaires which provided the researcher with biographical data and background information. In addition, the Bledsoe Self-Concept Scale and the Nowicki and Strickland Locus of Control Scale were used in order to determine their self-concepts and locus of control orientations respectively, prior to the beginning of national service. Detailed unstructured interviews were also conducted with a sample of military personnel, to provide another basis for gathering data and for clarifying some of the issues involved. Briefly, the chief conclusion of this researcher is that a significant majority of 'successful' recruits in the military environment have a positive self-concept and an internal locus of control. On the basis of the above finding, it is suggested that there is a need to guide pupils about certain aspects of military life before they begin their National Service. There would seem to be a need for this guidance to be incorporated into the school curriculum, together with such practical aspects as cadets, shooting, etc. There is a shortage of this kind of research on the military situation in South Africa, and it is suggested that numerous issues in this field need to be researched for the benefit of future conscripts and the military alike.
- Full Text:
- Date Issued: 1987
Competition and segmentation : an analysis of wage determination and labour adjustments in manufacturing industry
- Authors: McCartan, Patrick John
- Date: 1986
- Subjects: Labour supply , Labour market , Competition , South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:927 , http://hdl.handle.net/10962/d1001453
- Description: The thesis itself proceeds according to the following outline. Chapter One is concerned with the neoclassical theory of the labour market. Three particular models are surveyed all of which attempt to explain wage differentials and labour adjustments within a competitive equilibrium framework. The basic model of the labour market which rests upon the marginal productivity theory of labour demand, the utility-maximising approach to labour supply and the competitive theory of market equilibrium is dealt with first.This is followed by an outline of human capital theory which emphasises the crucial role played by education and training in determining individual earnings . Finally, attention is focused on disequilibrium wage models of adjustment which account for wage dispersion in terms of the amount and quality of information available to transactors in the labour market.(Introduction, p. 3-4)
- Full Text:
- Date Issued: 1986
- Authors: McCartan, Patrick John
- Date: 1986
- Subjects: Labour supply , Labour market , Competition , South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:927 , http://hdl.handle.net/10962/d1001453
- Description: The thesis itself proceeds according to the following outline. Chapter One is concerned with the neoclassical theory of the labour market. Three particular models are surveyed all of which attempt to explain wage differentials and labour adjustments within a competitive equilibrium framework. The basic model of the labour market which rests upon the marginal productivity theory of labour demand, the utility-maximising approach to labour supply and the competitive theory of market equilibrium is dealt with first.This is followed by an outline of human capital theory which emphasises the crucial role played by education and training in determining individual earnings . Finally, attention is focused on disequilibrium wage models of adjustment which account for wage dispersion in terms of the amount and quality of information available to transactors in the labour market.(Introduction, p. 3-4)
- Full Text:
- Date Issued: 1986
Graphicacy and the third dimension: an investigation into the problem of poor performance in relief mapwork in South African secondary schools
- Burton, Michael St. John Whitehead
- Authors: Burton, Michael St. John Whitehead
- Date: 1986
- Subjects: Graphicacy , Maps , Map reading , Visualisation , Geography , Secondary education , South Africa , Pupils , Learners , Teachers
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: vital:1358 , http://hdl.handle.net/10962/d1001424
- Description: Three-dimensional graphicacy is the part of map work that appears to be the most problematIcal. Bartz (1970) says that thinking and visualising in three-dimensional space is difficult enough, but trying to derive notions in three-dimensions, when you have only seen them as they are represented in distorted two-dimensional fashion, is even more difficult. Yet pupils of geography are required to learn such three-dimensional concepts from the two-dimensional distorted map presentations. The geography teacher has an important educational role to play in promoting graphicacy and Balchin (1965), who coined the term, felt that it should be an essential underpinning of an integrated education. The problem is that children perform badly, teachers are not successfully imparting three-dimensional graphicacy skills and as Board and Taylor (1977) indicate, for some time now it has been fashionable to dismiss maps as being irrelevant or useless in geographical research. This thesis attempts to analyse this reported malady, the problems are exposed and solutions offered. Investigation of the literature, with the aim of clarifying the problems involved, follows four leads. These are the part played by the map as a mode of communication, the physical processes involved in mapwork revealed by work in the realm of neurophysiology, the process of visualisation in the field of perception and psychology, and finally the stage of conceptual development of the mapworker. The state of affairs in South Africa is disclosed by an analysis of teacher-directed literature, of examination syllabuses, of text-book treatment of three-dimensional mapwork in South Africa and overseas, of past examination questions, and finally of teachers' views. Experimental exercises have been executed in an attempt to link the key findings of published research to the local scene. Conclusions are then drawn, and recommendations made for improving three-dimensional graphicacy in South African secondary schools.
- Full Text:
- Date Issued: 1986
- Authors: Burton, Michael St. John Whitehead
- Date: 1986
- Subjects: Graphicacy , Maps , Map reading , Visualisation , Geography , Secondary education , South Africa , Pupils , Learners , Teachers
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: vital:1358 , http://hdl.handle.net/10962/d1001424
- Description: Three-dimensional graphicacy is the part of map work that appears to be the most problematIcal. Bartz (1970) says that thinking and visualising in three-dimensional space is difficult enough, but trying to derive notions in three-dimensions, when you have only seen them as they are represented in distorted two-dimensional fashion, is even more difficult. Yet pupils of geography are required to learn such three-dimensional concepts from the two-dimensional distorted map presentations. The geography teacher has an important educational role to play in promoting graphicacy and Balchin (1965), who coined the term, felt that it should be an essential underpinning of an integrated education. The problem is that children perform badly, teachers are not successfully imparting three-dimensional graphicacy skills and as Board and Taylor (1977) indicate, for some time now it has been fashionable to dismiss maps as being irrelevant or useless in geographical research. This thesis attempts to analyse this reported malady, the problems are exposed and solutions offered. Investigation of the literature, with the aim of clarifying the problems involved, follows four leads. These are the part played by the map as a mode of communication, the physical processes involved in mapwork revealed by work in the realm of neurophysiology, the process of visualisation in the field of perception and psychology, and finally the stage of conceptual development of the mapworker. The state of affairs in South Africa is disclosed by an analysis of teacher-directed literature, of examination syllabuses, of text-book treatment of three-dimensional mapwork in South Africa and overseas, of past examination questions, and finally of teachers' views. Experimental exercises have been executed in an attempt to link the key findings of published research to the local scene. Conclusions are then drawn, and recommendations made for improving three-dimensional graphicacy in South African secondary schools.
- Full Text:
- Date Issued: 1986
The petrogenesis of the volcanic rocks of the Witwatersrand triad in the Klerksdorp area, Transvaal
- Authors: Bowen, Michael Peter
- Date: 1985
- Subjects: Volcanic rocks , Witwatersrand triad , Klerksdorp , Transvaal , Northwest Province , South Africa , Chemical analysis , Magma , Geology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4909 , http://hdl.handle.net/10962/d1001569
- Description: Several hundred chemical analyses of early Proterozoic lavas of the Witwatersrand triad (incorporating the Dominion Group, Witwatersrand Supergroup and Ventersdorp Supergroup) in the Klerksdorp area, have revealed the presence of various distinct magma types. These essentially correspond to formally defined lithostratigraphic units, but several inconsistencies have necessitated the use of informal nomenclature. The lavas have been regionally metamorphosed to low-grade, greenschist facies assemblages. Original igneous textures are preserved, despite a metamorphic overprint. Metamorphism has resulted in a certain degree of random chemical remobilization. Ba, Sr, Rb, K₂0, Na₂0 and CaO have been highly mobile, and their usefulness in petrogenetic modelling is extremely limited. In contrast, Zr, Nb, Y, LREE's, Cr, Ni, Ti0₂ P₂0₅ and Al₂0₃ have remained immobile. Ti/Zr and Ti/P ratios together constitute efficient discriminating variables for characterizing the different magma types. Lava compositions range from primitive Mg-rich tholeiites to rhyolites, the bulk being tholeiitic andesites. Al₂0₃ contents do not exceed 15%, a feature which reflects the tholeiitic, as opposed to calcalkaline, character of these lavas. Two magma-types are present within the Dominion Group, which is a typical example of bimodal volcanism. The Dominion basic lavas are overlain by the Dominion acid porphyries, with a limited amount of interfingering. The basic lava suite is highly fractionated, with compositions ranging from Mg-, Cr- and Ni-rich tholeiites (close to primary mantle melts) to evolved tholeiitic andesites. The most primitive liquids evolved by 45% fractional crystallization of hornblende, followed by a further 70% crystallization of an orthopyroxene-plagioclase assemblage containing up to 3% sulphides. The Dominion porphyries are rhyolitic, display very limited compositional variation, and probably represent a crustal melt related to the same magmatic event which produced the basic lavas. The only lavas from the Witwatersrand Supergroup present in the Klerksdorp area are those of the Crown Formation (Jeppestown amygdaloid). These are tholeiitic dacites which display extremely limited compositional variation, and are unrelated to any of the other magmas of the Witwatersrand triad. The Ventersdorp Supergroup comprises 4 magma-types: The Kliprivierberg Group lavas at the base are subdivisible into 3 sub-types on the basis of Zr contents. (Zr>11Oppm) are the most evolved. They are tholeiitic andesites which display fairly limited compositional variation. It is likely that more evolved compositions are present in other areas where the porphyritic lavas which characterize this unit are better developed. The overlying Orkney lavas are characterized by 110ppm>Zr>90ppm. They are tholeiitic andesites of similar composition to the Alberton lavas, but have lower incompatible element levels, higher siderophile element levels, and are of extremely uniform composition. The uppermost Loraine/Edenville lavas range from magnesian tholeiites to tholeiitic andesites. They are distinguished by Zr< 90ppm, and contain the most primitive magmas af the Witwatersrand triad, with up to 17,5% MgO, 2600ppm Cr, 600ppm Ni and M-values up to 77. The most primitive liquids evolved by 38% fractional crystallization of orthopyroxene ∓ chromite, followed by 35% fractional crystallization of an extract containing clinopyroxene and plagioclase. The absence of olivine precipitation is a result of the inherently high Si0₂ content of the magma. The Loraine/Edenville, Orkney and Alberton lavas do not lie on a common liquid line of descent, but are probably consanguinous. The Platberg Group overlies the Kliprivierberg Group, and has a coarse-clastic sedimentary unit, the Kameeldoorns Formation, at the base. Three petrographically distinct porphyritic lava sequences overlie the Kameeldoorns Formation, namely the informal "Goedgenoeg formation", the Makwassie quartz-feldspar porphyries and the Rietgat Formation. Despite petrographic differences, the Goedgenoeg and Rietgat lavas are chemically indistinguishable and thus form a single magma-type. The Makwassie porphyries are dacitic in composition with a high proportion of feldspar and quartz phenocrysts. Rational variation trends are attributed to a nett loss of Si0₂ during secondary alteration. The porphyries are probably of crustal origin. The Goedgenoeg/Rietgat lavas display unusual chemistry and a broad, irrational compositional spectrum. They contain very high incompatible element levels, high nonnative quartz, as well as high MgO, M-values, Cr and Ni relative to the other tholeiitic andesites of the Witwatersrand triad. It is tentatively suggested that they are hybrid magmas containing both crust and mantle components, the former possibly represented by the Makwassie porphyries. Field evidence suggests that Platberg volcanism commenced directly after Klipriviersberg volcanism ceased, and was accompanied by a period of enhanced tectonic activity. The Platberg lavas thus probably reflect a crustal melting cycle associated with the Klipriviersberg magmatic event. The Allanridge lavas are the youngest rocks of the Witwatersrand triad. They are separated from the Platberg Group by a unit of flat-lying sediments, the Bothaville Formation, which was deposited after an extended period of peneplanation. The Allanridge lavas form a separate magma-type. They are tholeiitic andesites of similar composition to the Alberton lavas, but have higher incompatible element levels and are not consanguinous. The compositional similarities amongst the basic magma-types of the Witwatersrand triad suggests that all were generated in an hydrous mantle. Interelement ratio differences between the various magma-types nevertheless support the concept that the mantle was chemically heterogeneous during the early Proterozoic.
- Full Text:
- Date Issued: 1985
- Authors: Bowen, Michael Peter
- Date: 1985
- Subjects: Volcanic rocks , Witwatersrand triad , Klerksdorp , Transvaal , Northwest Province , South Africa , Chemical analysis , Magma , Geology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4909 , http://hdl.handle.net/10962/d1001569
- Description: Several hundred chemical analyses of early Proterozoic lavas of the Witwatersrand triad (incorporating the Dominion Group, Witwatersrand Supergroup and Ventersdorp Supergroup) in the Klerksdorp area, have revealed the presence of various distinct magma types. These essentially correspond to formally defined lithostratigraphic units, but several inconsistencies have necessitated the use of informal nomenclature. The lavas have been regionally metamorphosed to low-grade, greenschist facies assemblages. Original igneous textures are preserved, despite a metamorphic overprint. Metamorphism has resulted in a certain degree of random chemical remobilization. Ba, Sr, Rb, K₂0, Na₂0 and CaO have been highly mobile, and their usefulness in petrogenetic modelling is extremely limited. In contrast, Zr, Nb, Y, LREE's, Cr, Ni, Ti0₂ P₂0₅ and Al₂0₃ have remained immobile. Ti/Zr and Ti/P ratios together constitute efficient discriminating variables for characterizing the different magma types. Lava compositions range from primitive Mg-rich tholeiites to rhyolites, the bulk being tholeiitic andesites. Al₂0₃ contents do not exceed 15%, a feature which reflects the tholeiitic, as opposed to calcalkaline, character of these lavas. Two magma-types are present within the Dominion Group, which is a typical example of bimodal volcanism. The Dominion basic lavas are overlain by the Dominion acid porphyries, with a limited amount of interfingering. The basic lava suite is highly fractionated, with compositions ranging from Mg-, Cr- and Ni-rich tholeiites (close to primary mantle melts) to evolved tholeiitic andesites. The most primitive liquids evolved by 45% fractional crystallization of hornblende, followed by a further 70% crystallization of an orthopyroxene-plagioclase assemblage containing up to 3% sulphides. The Dominion porphyries are rhyolitic, display very limited compositional variation, and probably represent a crustal melt related to the same magmatic event which produced the basic lavas. The only lavas from the Witwatersrand Supergroup present in the Klerksdorp area are those of the Crown Formation (Jeppestown amygdaloid). These are tholeiitic dacites which display extremely limited compositional variation, and are unrelated to any of the other magmas of the Witwatersrand triad. The Ventersdorp Supergroup comprises 4 magma-types: The Kliprivierberg Group lavas at the base are subdivisible into 3 sub-types on the basis of Zr contents. (Zr>11Oppm) are the most evolved. They are tholeiitic andesites which display fairly limited compositional variation. It is likely that more evolved compositions are present in other areas where the porphyritic lavas which characterize this unit are better developed. The overlying Orkney lavas are characterized by 110ppm>Zr>90ppm. They are tholeiitic andesites of similar composition to the Alberton lavas, but have lower incompatible element levels, higher siderophile element levels, and are of extremely uniform composition. The uppermost Loraine/Edenville lavas range from magnesian tholeiites to tholeiitic andesites. They are distinguished by Zr< 90ppm, and contain the most primitive magmas af the Witwatersrand triad, with up to 17,5% MgO, 2600ppm Cr, 600ppm Ni and M-values up to 77. The most primitive liquids evolved by 38% fractional crystallization of orthopyroxene ∓ chromite, followed by 35% fractional crystallization of an extract containing clinopyroxene and plagioclase. The absence of olivine precipitation is a result of the inherently high Si0₂ content of the magma. The Loraine/Edenville, Orkney and Alberton lavas do not lie on a common liquid line of descent, but are probably consanguinous. The Platberg Group overlies the Kliprivierberg Group, and has a coarse-clastic sedimentary unit, the Kameeldoorns Formation, at the base. Three petrographically distinct porphyritic lava sequences overlie the Kameeldoorns Formation, namely the informal "Goedgenoeg formation", the Makwassie quartz-feldspar porphyries and the Rietgat Formation. Despite petrographic differences, the Goedgenoeg and Rietgat lavas are chemically indistinguishable and thus form a single magma-type. The Makwassie porphyries are dacitic in composition with a high proportion of feldspar and quartz phenocrysts. Rational variation trends are attributed to a nett loss of Si0₂ during secondary alteration. The porphyries are probably of crustal origin. The Goedgenoeg/Rietgat lavas display unusual chemistry and a broad, irrational compositional spectrum. They contain very high incompatible element levels, high nonnative quartz, as well as high MgO, M-values, Cr and Ni relative to the other tholeiitic andesites of the Witwatersrand triad. It is tentatively suggested that they are hybrid magmas containing both crust and mantle components, the former possibly represented by the Makwassie porphyries. Field evidence suggests that Platberg volcanism commenced directly after Klipriviersberg volcanism ceased, and was accompanied by a period of enhanced tectonic activity. The Platberg lavas thus probably reflect a crustal melting cycle associated with the Klipriviersberg magmatic event. The Allanridge lavas are the youngest rocks of the Witwatersrand triad. They are separated from the Platberg Group by a unit of flat-lying sediments, the Bothaville Formation, which was deposited after an extended period of peneplanation. The Allanridge lavas form a separate magma-type. They are tholeiitic andesites of similar composition to the Alberton lavas, but have higher incompatible element levels and are not consanguinous. The compositional similarities amongst the basic magma-types of the Witwatersrand triad suggests that all were generated in an hydrous mantle. Interelement ratio differences between the various magma-types nevertheless support the concept that the mantle was chemically heterogeneous during the early Proterozoic.
- Full Text:
- Date Issued: 1985
A comparison of the performance of selected conceptual models of the rainfall-runoff process in semi-arid catchments near Grahamstown
- Authors: Roberts, Peter J T
- Date: 1979
- Subjects: Runoff , Rainfall , South Africa , Grahamstown
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4798 , http://hdl.handle.net/10962/d1001898
- Description: A comparison of the performance of selected conceptual models of the rainfall-runoff process forms the central theme of this study and the comparison was conducted with three major objectives in mind. The first objective was to develop a conceptual model that could be used by practising hydrologists for the refinement and extension of historical streamflow records. The major requirements of the model were that it should be simple in structure and easy to operate and yet be flexible in terms of complexity of structure and input requirements as well as producing output at a level of accuracy that is competitive with that of the more complex models presently available. A comparison of the performance of the required model with that of other models formed an integral part of the development process. The second objective of the comparative study was to contribute to current knowledge of the criteria used in the selection of a suitable model for a particular application. There are, at present, no reliable guidelines to assist the hydrologist in selecting a suitable model from the wide range of models available and a comparative study would indicate the merits of various forms of model structure. The third objective is associated with the problems that arise when no streamflow data are available for model calibration. One approach is to calibrate the model in a nearby gauged catchment that the hydrologist regards as being 'hydrologically similar' and transferring the model parameter values to the ungauged catchment. Little is known about the feasibility of this parameter transfer process or about the choice of a model for such an application. The third objective was to test the feasibility of the parameter transfer process and to make use of the comparison of model performance to determine the model characteristics that are most suitable for the purpose
- Full Text:
- Date Issued: 1979
- Authors: Roberts, Peter J T
- Date: 1979
- Subjects: Runoff , Rainfall , South Africa , Grahamstown
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4798 , http://hdl.handle.net/10962/d1001898
- Description: A comparison of the performance of selected conceptual models of the rainfall-runoff process forms the central theme of this study and the comparison was conducted with three major objectives in mind. The first objective was to develop a conceptual model that could be used by practising hydrologists for the refinement and extension of historical streamflow records. The major requirements of the model were that it should be simple in structure and easy to operate and yet be flexible in terms of complexity of structure and input requirements as well as producing output at a level of accuracy that is competitive with that of the more complex models presently available. A comparison of the performance of the required model with that of other models formed an integral part of the development process. The second objective of the comparative study was to contribute to current knowledge of the criteria used in the selection of a suitable model for a particular application. There are, at present, no reliable guidelines to assist the hydrologist in selecting a suitable model from the wide range of models available and a comparative study would indicate the merits of various forms of model structure. The third objective is associated with the problems that arise when no streamflow data are available for model calibration. One approach is to calibrate the model in a nearby gauged catchment that the hydrologist regards as being 'hydrologically similar' and transferring the model parameter values to the ungauged catchment. Little is known about the feasibility of this parameter transfer process or about the choice of a model for such an application. The third objective was to test the feasibility of the parameter transfer process and to make use of the comparison of model performance to determine the model characteristics that are most suitable for the purpose
- Full Text:
- Date Issued: 1979
An examination of the spatial variation of surficial sediment characteristics in the Howison's Poort Reservoir
- Authors: Weaver, Alex van Breda
- Date: 1979
- Subjects: Howison's Poort Reservoir , South Africa , Sedimentation and deposition
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:4790 , http://hdl.handle.net/10962/d1001890
- Description: From Introduction: Lakes, estuaries and man-made water impoundments can be considered as intervening basins which provide for the temporary storage both of sediment and of water. Because of the potential energy of soil in elevated positions and because of the kinetic energy of water flowing under the influence of gravity, eroded material is eventually transported to the lowest possible level, i.e. the ocean deeps, or some intervening basin. This denudation process may be compared with Newton’s second law of thermodynamics which states that each system tends to move in the direction of lowest energy. Sedimentation in intervening basins may be seen as part of the natural process of landscape evolution. The rates at which sedimentation occurs may be strongly influenced by the activities of man.
- Full Text:
- Date Issued: 1979
- Authors: Weaver, Alex van Breda
- Date: 1979
- Subjects: Howison's Poort Reservoir , South Africa , Sedimentation and deposition
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:4790 , http://hdl.handle.net/10962/d1001890
- Description: From Introduction: Lakes, estuaries and man-made water impoundments can be considered as intervening basins which provide for the temporary storage both of sediment and of water. Because of the potential energy of soil in elevated positions and because of the kinetic energy of water flowing under the influence of gravity, eroded material is eventually transported to the lowest possible level, i.e. the ocean deeps, or some intervening basin. This denudation process may be compared with Newton’s second law of thermodynamics which states that each system tends to move in the direction of lowest energy. Sedimentation in intervening basins may be seen as part of the natural process of landscape evolution. The rates at which sedimentation occurs may be strongly influenced by the activities of man.
- Full Text:
- Date Issued: 1979
Dispersal of the cochineal insect Dactylopius Austrinus de Lotto (Homoptera : Dactylopiidae)
- Authors: Gunn, Brian Howard
- Date: 1979
- Subjects: Cochineal insect--South Africa , Cochineal insects , Biological control , Jointed cactus , South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5596 , http://hdl.handle.net/10962/d1002046
- Description: Dispersal of the cochineal insect Dactylopius austrinus De Lotto, introduced into South Africa in 1932 as a biological control agent against jointed cactus Opuntia aurantiaca Lindley, was investigated. Zimmermann et al. (l974) suggested that the apparent failure of this insect to control jointed cactus infestations is due to limited dispersal of the first instar nymphs (hereafter referred to as crawlers). Studies on crawler morphology have shown a clear sexual dimorphism in the pattern and development of filaments on the head, thorax and abdomen of male and female crawlers. This enabled differentiation between the sexes with respect to terminal velocities, behaviour and survival of crawlers which have shown that the crawlers, especially the females, are well adapted to dispersal. Long filaments on the head, thorax and abdomen of the female crawlers, that are restricted to dispersal in the crawler stage (as later instars are sessile) and a behaviour directed towards "take-off" enhance the potential for dispersal. The more sedentary males, with long filaments restricted to the abdomen, are able to disperse as winged adults. The principal factors influencing the timing of dispersal and number of crawlers blown from the host plant are wind and temperature; the latter determining the number of crawlers moving on the host plant. Dispersal is confined to the period between 06h00 and 20h00 and it was possible to correlate the pattern of crawler dispersal with wind patterns. The general equation of Taylor (1978) provided an adequate description of horizontal distribution of D.austrinus crawlers in all directions. Wind dispersal of the apterous crawlers is restricted by the low height of jointed cactus plants. Horizontal distribution is limited (generally less than 10 m) although a small proportion of crawlers carried vertically upwards by turbulence or convection currents are sufficiently hardy to survive long range displacement. It is suggested that the small size of the host plant will also reduce effective colonization as the canopy area provides a small target for the wind-blown crawlers. The limitation on dispersal due to the low height of the host plant suggested a system for artificially enhancing crawler dispersal from elevated towers in the field. Evaluation of this system confirmed that it would be practical to augment or introduce cochineal into jointed cactus infestations to enhance the biocontrol potential of this insect. This offers an alternative to chemical control, that has so far failed to control the spread of jointed cactus despite an intensive and expensive herbicide program
- Full Text:
- Date Issued: 1979
- Authors: Gunn, Brian Howard
- Date: 1979
- Subjects: Cochineal insect--South Africa , Cochineal insects , Biological control , Jointed cactus , South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5596 , http://hdl.handle.net/10962/d1002046
- Description: Dispersal of the cochineal insect Dactylopius austrinus De Lotto, introduced into South Africa in 1932 as a biological control agent against jointed cactus Opuntia aurantiaca Lindley, was investigated. Zimmermann et al. (l974) suggested that the apparent failure of this insect to control jointed cactus infestations is due to limited dispersal of the first instar nymphs (hereafter referred to as crawlers). Studies on crawler morphology have shown a clear sexual dimorphism in the pattern and development of filaments on the head, thorax and abdomen of male and female crawlers. This enabled differentiation between the sexes with respect to terminal velocities, behaviour and survival of crawlers which have shown that the crawlers, especially the females, are well adapted to dispersal. Long filaments on the head, thorax and abdomen of the female crawlers, that are restricted to dispersal in the crawler stage (as later instars are sessile) and a behaviour directed towards "take-off" enhance the potential for dispersal. The more sedentary males, with long filaments restricted to the abdomen, are able to disperse as winged adults. The principal factors influencing the timing of dispersal and number of crawlers blown from the host plant are wind and temperature; the latter determining the number of crawlers moving on the host plant. Dispersal is confined to the period between 06h00 and 20h00 and it was possible to correlate the pattern of crawler dispersal with wind patterns. The general equation of Taylor (1978) provided an adequate description of horizontal distribution of D.austrinus crawlers in all directions. Wind dispersal of the apterous crawlers is restricted by the low height of jointed cactus plants. Horizontal distribution is limited (generally less than 10 m) although a small proportion of crawlers carried vertically upwards by turbulence or convection currents are sufficiently hardy to survive long range displacement. It is suggested that the small size of the host plant will also reduce effective colonization as the canopy area provides a small target for the wind-blown crawlers. The limitation on dispersal due to the low height of the host plant suggested a system for artificially enhancing crawler dispersal from elevated towers in the field. Evaluation of this system confirmed that it would be practical to augment or introduce cochineal into jointed cactus infestations to enhance the biocontrol potential of this insect. This offers an alternative to chemical control, that has so far failed to control the spread of jointed cactus despite an intensive and expensive herbicide program
- Full Text:
- Date Issued: 1979
The geochemistry and petrology of the Karoo andesites and associated basalts of the north-eastern Cape Province
- Authors: Rumble, Keith Christopher
- Date: 1979 , 2013-02-11
- Subjects: Basalt , South Africa , Cape of Good Hope , Geochemistry , Petrology , Andesite
- Language: English
- Type: Thesis , Masters , M.Sc
- Identifier: vital:4902 , http://hdl.handle.net/10962/d1001562
- Description: New geochemical data consisting of major and 15 trace element analyses are presented for 41 rocks from three andesitic and associated basaltic rock occurrences in the North Eastern Cape Province. These include the Pronksberg, Belmore and Roodehoek localities. Field evidence suggests that the three andesites were emplaced during the early stages of Karoo volcanicity. Geochemical variations within the Pronksberg and Roodehoek andesite are small, manifesting the undifferentiated nature of the magmas. Variations within the Belmore andesite are interpreted as representing fractionation of orthopyroxene, accompanied by only minor plagioclase fractionation. Differences in trace element concentrations and inter-element ratios between the andesites and associated basalts of the Pronksberg and Belmore volcanic suites precludes the possibility of the two rock types being genetically related. Geochemical differences constrain the possibility of the three andesites being cogenetic. Magmatic processes resulting in their formation are, however, thought to be similar. The differences in chemistry between the Pronksberg Basalt (High K Type) and Pronksberg Basalt (Drumbo Type) are interpreted as representing the combined influence of weathering, the presence of amygdales and the within-flow variations of alkali elements on the Pronksberg Basalt (High K Type). Similarities in petrography and chemistry justifies a correlation of the Pronksberg Basalt (Drumbo Type) with the Drumbo Basalt Member in the Barkly East area. Data for the Drumbo Basalt (This study) in the Barkly East area confirms and complements previously presented data. Normative chemistry and strontium isotope data indicate a process involving crustal assimilation or melting of crustal rocks as being the most likely explanation for the genesis of the Karoo andesites , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Date Issued: 1979
- Authors: Rumble, Keith Christopher
- Date: 1979 , 2013-02-11
- Subjects: Basalt , South Africa , Cape of Good Hope , Geochemistry , Petrology , Andesite
- Language: English
- Type: Thesis , Masters , M.Sc
- Identifier: vital:4902 , http://hdl.handle.net/10962/d1001562
- Description: New geochemical data consisting of major and 15 trace element analyses are presented for 41 rocks from three andesitic and associated basaltic rock occurrences in the North Eastern Cape Province. These include the Pronksberg, Belmore and Roodehoek localities. Field evidence suggests that the three andesites were emplaced during the early stages of Karoo volcanicity. Geochemical variations within the Pronksberg and Roodehoek andesite are small, manifesting the undifferentiated nature of the magmas. Variations within the Belmore andesite are interpreted as representing fractionation of orthopyroxene, accompanied by only minor plagioclase fractionation. Differences in trace element concentrations and inter-element ratios between the andesites and associated basalts of the Pronksberg and Belmore volcanic suites precludes the possibility of the two rock types being genetically related. Geochemical differences constrain the possibility of the three andesites being cogenetic. Magmatic processes resulting in their formation are, however, thought to be similar. The differences in chemistry between the Pronksberg Basalt (High K Type) and Pronksberg Basalt (Drumbo Type) are interpreted as representing the combined influence of weathering, the presence of amygdales and the within-flow variations of alkali elements on the Pronksberg Basalt (High K Type). Similarities in petrography and chemistry justifies a correlation of the Pronksberg Basalt (Drumbo Type) with the Drumbo Basalt Member in the Barkly East area. Data for the Drumbo Basalt (This study) in the Barkly East area confirms and complements previously presented data. Normative chemistry and strontium isotope data indicate a process involving crustal assimilation or melting of crustal rocks as being the most likely explanation for the genesis of the Karoo andesites , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Date Issued: 1979
Transcending the culture of poverty in a Black South African township
- Authors: Wilsworth, Mercia Joan
- Date: 1979
- Subjects: Black people , South Africa , Grahamstown , Economic conditions
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2085 , http://hdl.handle.net/10962/d1001602
- Full Text:
- Date Issued: 1979
- Authors: Wilsworth, Mercia Joan
- Date: 1979
- Subjects: Black people , South Africa , Grahamstown , Economic conditions
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2085 , http://hdl.handle.net/10962/d1001602
- Full Text:
- Date Issued: 1979
Plan of Graham's Town
- Authors: Lewcock, E
- Date: 1962
- Subjects: Grahamstown (South Africa) -- Maps Maps , Streets -- South Africa -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/57798 , vital:26990 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP485 , MP485
- Description: "Plan probably drawn 1824. Copied by E. Lewcock, Sept. 1962. Original in Albany Museum, Courtesy Surveyor-General."
- Full Text: false
- Date Issued: 1962
- Authors: Lewcock, E
- Date: 1962
- Subjects: Grahamstown (South Africa) -- Maps Maps , Streets -- South Africa -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/57798 , vital:26990 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP485 , MP485
- Description: "Plan probably drawn 1824. Copied by E. Lewcock, Sept. 1962. Original in Albany Museum, Courtesy Surveyor-General."
- Full Text: false
- Date Issued: 1962
Contour plan of Grahamstown
- Authors: AWM , Hodge, WA
- Date: 1934
- Subjects: Grahamstown (South Africa) -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/68301 , vital:29236 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP407 , MP407
- Description: Contour plan of Grahamstown, 1934. Drawn by A.W.M. ; signed by W.A. Hodge, City Engineer. "War time regulations: this plan must not be removed from college premises under any circumstances" signed by E H Wied.
- Full Text: false
- Date Issued: 1934
- Authors: AWM , Hodge, WA
- Date: 1934
- Subjects: Grahamstown (South Africa) -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/68301 , vital:29236 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP407 , MP407
- Description: Contour plan of Grahamstown, 1934. Drawn by A.W.M. ; signed by W.A. Hodge, City Engineer. "War time regulations: this plan must not be removed from college premises under any circumstances" signed by E H Wied.
- Full Text: false
- Date Issued: 1934
Plan of the subdivisions of Featherstone's Kloof originally called Kowiefontein showing the portion it is proposed to sell
- Authors: AWM , Hodge, WA
- Date: 1934
- Subjects: Land subdivision - South Africa -- Eastern Cape -- Maps Maps , Featherstone Kloof (Eastern Cape, South Africa) -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/54849 , vital:26621 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP1462 , MP1462
- Description: Drawn by A.W.M. ; signed by W.A. Hodge, City Engineer.
- Full Text: false
- Date Issued: 1934
- Authors: AWM , Hodge, WA
- Date: 1934
- Subjects: Land subdivision - South Africa -- Eastern Cape -- Maps Maps , Featherstone Kloof (Eastern Cape, South Africa) -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/54849 , vital:26621 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP1462 , MP1462
- Description: Drawn by A.W.M. ; signed by W.A. Hodge, City Engineer.
- Full Text: false
- Date Issued: 1934
Map of the Great Fish River Irrigation Board (as per government proclamation no. 63 of 1920 : showing the areas under minor boards and private schemes)
- South Africa.Irrigation Department, Great Fish River Irrigation Board
- Authors: South Africa.Irrigation Department , Great Fish River Irrigation Board
- Date: 1926
- Subjects: South Africa -- History -- Frontier Wars, 1811-1878 -- Maps Maps , Irrigation -- South Africa -- Cradock -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/57113 , vital:26847 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP577 , MP577
- Description: Map of the Great Fish River Irrigation Board. C.H. Hughes, circle engineer; A.D. Lewis, Director of Irrigation.
- Full Text: false
- Date Issued: 1926
- Authors: South Africa.Irrigation Department , Great Fish River Irrigation Board
- Date: 1926
- Subjects: South Africa -- History -- Frontier Wars, 1811-1878 -- Maps Maps , Irrigation -- South Africa -- Cradock -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/57113 , vital:26847 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP577 , MP577
- Description: Map of the Great Fish River Irrigation Board. C.H. Hughes, circle engineer; A.D. Lewis, Director of Irrigation.
- Full Text: false
- Date Issued: 1926
Plan of the Diocese of St John's, Kaffraria
- Date: 1915
- Subjects: Missions -- South Africa -- Kaffraria -- Geography -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/57014 , vital:26838 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP438 , MP438
- Full Text: false
- Date Issued: 1915
- Date: 1915
- Subjects: Missions -- South Africa -- Kaffraria -- Geography -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/57014 , vital:26838 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP438 , MP438
- Full Text: false
- Date Issued: 1915
Plan of proposed buildings for the Inter State Native College (later Fort Hare University)
- Date: 1908
- Subjects: University of Fort Hare -- History -- Maps Maps , Fort Hare (South Africa) -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/57487 , vital:26954 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP1487 , MP1487
- Full Text: false
- Date Issued: 1908
- Date: 1908
- Subjects: University of Fort Hare -- History -- Maps Maps , Fort Hare (South Africa) -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/57487 , vital:26954 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP1487 , MP1487
- Full Text: false
- Date Issued: 1908
Divisional map of Vryburg
- Authors: Fleming, J
- Date: 1907
- Subjects: Vryburg (South Africa) -- Maps , Scale 2,000 Cape roods = 1 inch , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/55001 , vital:26644 , Original map held by Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa , MP104
- Full Text: false
- Date Issued: 1907
- Authors: Fleming, J
- Date: 1907
- Subjects: Vryburg (South Africa) -- Maps , Scale 2,000 Cape roods = 1 inch , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/55001 , vital:26644 , Original map held by Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa , MP104
- Full Text: false
- Date Issued: 1907
Sketch of general plan of Lovedale property
- Authors: Preston, F
- Date: 1907
- Subjects: Cape of Good Hope (Colony) -- Maps Maps , Lovedale (South Africa) -- Maps Maps , Lovedale Institution -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/54990 , vital:26643 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP100 , MP100
- Full Text: false
- Date Issued: 1907
- Authors: Preston, F
- Date: 1907
- Subjects: Cape of Good Hope (Colony) -- Maps Maps , Lovedale (South Africa) -- Maps Maps , Lovedale Institution -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/54990 , vital:26643 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP100 , MP100
- Full Text: false
- Date Issued: 1907
Divisional Map of Komgha
- Great Britain. Army. Quarter Master General's Department
- Authors: Great Britain. Army. Quarter Master General's Department
- Date: 1902
- Subjects: Komga (South Africa) -- Administrative and political divisions -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/54940 , vital:26638 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa , MP595
- Full Text: false
- Date Issued: 1902
- Authors: Great Britain. Army. Quarter Master General's Department
- Date: 1902
- Subjects: Komga (South Africa) -- Administrative and political divisions -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/54940 , vital:26638 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa , MP595
- Full Text: false
- Date Issued: 1902
General plan of East London harbour, South Africa
- Date: 1901
- Subjects: East London (South Africa) -- Maps Maps , Harbors -- South Africa -- East London -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/57316 , vital:26872 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP492 , MP492
- Full Text: false
- Date Issued: 1901
- Date: 1901
- Subjects: East London (South Africa) -- Maps Maps , Harbors -- South Africa -- East London -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/57316 , vital:26872 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP492 , MP492
- Full Text: false
- Date Issued: 1901
Transkei
- Great Britain. Army. Field Intelligence Department, Casgrain, P H du P
- Authors: Great Britain. Army. Field Intelligence Department , Casgrain, P H du P
- Date: 1901
- Subjects: South African War, 1899-1902 -- Maps Maps , Transkei (South Africa) -- Maps Maps , Eastern Cape (South Africa) -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/57336 , vital:26874 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP568 , MP568
- Description: This map forms part of the Imperial map of the Cape Colony. , "South Africa having never been properly surveyed, this map must necessarily contain many inaccuracies." The map shows main roads, branch roads, farm roads, rivers, hills, pans, railways, telegraph lines, farm names, farm boundaries, divisional boundaries, outspans and homesteads in the Transkei region.Compiled and lithographed by Mapping Section, F.I.D., Cape Town, under the superintendence of P.H. du P. Casgrain from farm surveys and all other available information.
- Full Text: false
- Date Issued: 1901
- Authors: Great Britain. Army. Field Intelligence Department , Casgrain, P H du P
- Date: 1901
- Subjects: South African War, 1899-1902 -- Maps Maps , Transkei (South Africa) -- Maps Maps , Eastern Cape (South Africa) -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/57336 , vital:26874 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP568 , MP568
- Description: This map forms part of the Imperial map of the Cape Colony. , "South Africa having never been properly surveyed, this map must necessarily contain many inaccuracies." The map shows main roads, branch roads, farm roads, rivers, hills, pans, railways, telegraph lines, farm names, farm boundaries, divisional boundaries, outspans and homesteads in the Transkei region.Compiled and lithographed by Mapping Section, F.I.D., Cape Town, under the superintendence of P.H. du P. Casgrain from farm surveys and all other available information.
- Full Text: false
- Date Issued: 1901