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An experimental investigation of three developmental reading programmes

- Pienaar, P T (Peter Thomas), 1932-

  • Authors: Pienaar, P T (Peter Thomas), 1932-
  • Date: 1970
  • Subjects: Reading (Adult education) Reading comprehension Reading (Elementary)
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:2283 , http://hdl.handle.net/10962/d1007614
  • Description: From Chapter one - 1.1 Genesis: My interest in increasing the efficiency of children's silent reading began in 1958 when I was teaching a Standard 5A of 24 boys and 15 girls in a two-stream Primary School in Rhodesia. the majority of children were able readers and the mean Word Reading Age was 12.7 which, in relation to an average chronological age of 12.3, yeilded an above average Reading Quotient of 103. These children needed lots of reading practice, and in addition to the usual Reading periods I resolved to set aside at least one period a week for Comprehension, as reading for meaning was then called.
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  • Date Issued: 1970

Contributions to the development of the piano sonata : the sonatas of Joseph Haydn, with special reference to their historic position and to the influence of German, Austrian and Italian elements on their form and style

- Heuschneider, Karin

  • Authors: Heuschneider, Karin
  • Date: 1970
  • Subjects: Haydn, Joseph, 1732-1809 Music -- History and criticism -- 18th century Music, influence of -- Germany Music, influence of -- Austria Music, influence of -- Italy
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:2684 , http://hdl.handle.net/10962/d1012264
  • Description: This thesis, which is intended for inclusion in "The Piano Sonatas of the 18th century in Austria" (Vol.3 in the publication series "Contributions the the development of the Piano Sonata") aims to evaluate Haydn's position within the history of the piano sonata. In spite of the widespread popularity of Haydn's sonatas among professional musicians and amateurs, surprisingly little has yet been published regarding the compositional aspects of these works. The main contributions of musicological value were written by Hermann Abert, Karl Geiringer, Walter Georgii and William S.Newman. The recent studies, published as Vol.l and Vol.2 in the above mentioned series, made it possible to trace in much greater detail the various formative factors that influenced the form and style of Haydn's piano sonatas. Moreover, it proved the composer's personal merits not only in the development of this specific genre but also in the creation of 'The International Viennese Language of the High-Classical Period'. The newly gained insight, in turn, should lead to an even higher appreciation of the great master, who utilized the achievements of his predecessors and contemporaries in an original and individual manner and thereby gained a position far superior to that of many other composers.
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  • Date Issued: 1970

Deliberately withheld meaning : aspects of narrative technique in four novels by William Faulkner

- Walters, Paul S

Shakespeare's early comedies: studies in The comedy of errors, The taming of the shrew and The two gentlemen of Verona

- Bryant, Peter

The archetypal fable : an inquiry into the function of traditional symbolism in the poetry of Edwin Muir

- Gillmer, J E

  • Authors: Gillmer, J E
  • Date: 1970
  • Subjects: Muir, Edwin, 1887-1959 -- Criticism and interpretation
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:2297 , http://hdl.handle.net/10962/d1011975
  • Description: Edwin Muir's poetic vision is bound up with that belief in a twofold structure of reality that in European culture has been called Platonist but which is so ancient and widespread that no one can determine its origins. Though no longer fashionable in a time when materialist philosophies flourish and even Christian clerics are busy "de-mythologizing" their faith, it has been the potent source of our greatest poetry and perhaps, as Kathleen Raine believes, of all true poetry. Those who hold this conviction regard the sensible world as the reflection of an "intelligible" or spiritual world which gives meaning and purpose to life, and they see the objects of nature as images that evoke the ideal forms of a divine reality. For poets, as for traditional men, this belief is less a metaphysic than an intuitive way of apprehending and ordering experience, a "learning of the imagination" inherited from ancient and mysterious sources. To Muir it came directly and spontaneously in the symbolic images of dreams, and the fact that he entitled the first version of his autobiography The Story and the Fable testifies to the importance, both for his life and his poetry, of his belief in two corresponding orders of experience. Intro., p. 1-2.
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  • Date Issued: 1970

The classification and phylogeny of the Psocoptera

- Smithers, Courtenay Neville

  • Authors: Smithers, Courtenay Neville
  • Date: 1970
  • Subjects: Psocoptera , Insects -- Classification
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:5884 , http://hdl.handle.net/10962/d1013232
  • Description: This work provides a phylogenetic classification of the insect order PSOCOPTERA. Some of the problems involved, mainly arising from lack of adequate published data, are pointed out and work carried out to overcome them is indicated in a short introductory chapter (Chapter I). This consisted of accummulating data on the genera from published texts and illustrations, adding data from the study of fresh material or material held in collections and compiling generic definitions in adequate detail where possible. Chapter II gives a general description of the Psocoptera together with brief background information on their biology. As considerable changes are proposed in the classification of the order (in Chapter VII) the classification in use at present is set out for comparison to generic level and a brief history of systematic work on the order is given {Chapter III). The data necessary for a discussion of the phylogeny is presented in the series of definitions of genera and suprageneric groups in Chapter IV. Data on fossil forms is given in Chapter V. The principles of phylogenetic study are briefly discussed in Chapter VI and the important question of the relatively primitive or advanced condition of characters in the order is discussed. The monophyly of the order and the relationships between genera are established using Hennig's system and the results are set out in discussion and dendrogram. On the basis of the relationships so established a classification of the order is proposed which is considered to be practical and to reflect evolutionary history of the group. (Chapter. VII.) Comments on the distribution of the Psocoptera are made in Chapter VIII and it is suggested that, despite inadequacy of data, a consideration of the distributions supports the proposed classification in general terms. A general discussion follows and references and figures are included. An appendix provides a practical up-to-date key to the genera of the order.
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  • Date Issued: 1970

The nature and measurement of labour turnover

- Van der Merwe, Roux

  • Authors: Van der Merwe, Roux
  • Date: 1970
  • Subjects: Labor turnover -- South Africa , Industrial relations -- South Africa , Absenteeism (Labor) -- South Africa
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:3385 , http://hdl.handle.net/10962/d1013421
  • Description: From the Introduction, p. 1-2. The main purposes of this study are to examine the methods by which one particular aspect of industrial behaviour, namely that of the worker's final withdrawal from the work situation, can be measured; to offer a more refined technique for the measurement of such withdrawals, and thirdly to attempt to relate this measurable phenomenon of withdrawal, commonly known as Labour Turnover, to the less easily measurable phenomenon of the integration of the individual worker into his working group. Labour Turnover - or the loss, over time, of employees from an employing organisation - is normally regarded as a province of study appropriate to the field of Industrial Psychology, and to its related applied field of Personnel Management. To a large extent, however, (as will be illustrated in Chapter II of this work) the results of such studies have proved inconclusive, and contradictory, and there is little evidence of progress towards a comprehensive understanding of the subject. This is undoubtedly due to the fragmentary nature of most studies in this field. These have generally been limited to the narrow confines of one particular aspect of the phenomenon, and consequently it has not been viewed against a sufficiently broad background.
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  • Date Issued: 1970

A contribution to the biology of warthog (Phacochoerus africanus, Gmelin) in the Sengwa region of Rhodesia

- Cumming, D H M

  • Authors: Cumming, D H M
  • Date: 1971
  • Subjects: Warthog Warthog -- Physiology Warthog -- Ecology
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:5843 , http://hdl.handle.net/10962/d1010740
  • Description: To the AmaZulu a warthog is "inhlovudawana" or "little elephant"; to arrogant hunters it is the "poor man's rhinoceros"; to some writers of encyclopaediae it is a "grotesque and hideous beast"; to stockmen it has long been a carrier of diseases. Injury was added to insult with the discovery that the blood of these self-assured, often comical and certainly engaging animals supports the greater proportion of tsetse flies in the African savannas. Their significance as the primary hosts of Glossina morsitans Westw., the vectors of tryanosomiasis, justified an extended field study of warthog biology. This thesis reports four years of field work on warthogs, together with complementary observations of hand-reared warthogs (and their offspring) which roamed freely in the vicinity of the remote field station on which I live. The Sengwa Research Project, of which this study forms a part, was initiated in 1965 to study relationships between game animals and tsetse flies. One of the main problems investigated in the Sengwa Project is that of "host encounter" (Glasgow, 1961, Bursell, 1970) and how the distribution, abundance and behaviour of game animals may affect their availability to hungry tsetse flies. I have, accordingly, been concerned with discovering how warthog are dispersed in the Sengwa area and have attempted to gain some understanding of the factors, both environmental and social, which may affect or govern their dispersion and possibly population number. Intro. p. 1.
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  • Date Issued: 1971

Creative processes in young children

- Styles, Irene Mavis

  • Authors: Styles, Irene Mavis
  • Date: 1971
  • Subjects: Creative ability in children , Creative thinking
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:3244 , http://hdl.handle.net/10962/d1013327
  • Description: Enthusiasm for developing creativity in the individual has been remarkably widespread - at least in America - over the past twenty-five years or so. The armed services, the arts and sciences, educational institutions, businesses and industries are recognising to a greater and greater extent, the urgent necessity of developing this relatively neglected aspect of people is personalities. Their reasons differ, of course, and usually the welfare of the individual himself is not the main concern. This is perhaps fortunate, as advances made on philanthropic grounds alone have never progressed very rapidly. In business and industry, new ideas are urgently needed for survival - this was especially evident after World War II which was, in the end, really a battle of ideas. The importance of this implication has not decreased with distance in time from that conflagration, indeed, individuals in the armed services are probably the people most deeply involved in and the most concerned with the problem of developing creative thought. "We are in a mortal struggle for the survival of our way of life", writes Guilford. "The need (for developing creativity) is a national crisis" says Anderson*. Intro., p. 1.
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  • Date Issued: 1971

Developmental studies of certain South African Ascostromatic ascomycetes

- Tim, Stephen K-M

  • Authors: Tim, Stephen K-M
  • Date: 1971
  • Subjects: Fungi -- Parasites Ascomycetes Pyrenomycetes -- South Africa
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4245 , http://hdl.handle.net/10962/d1007289
  • Description: From General Introduction: Toward the last half of the nineteenth century, the structure and mode of development of the ascocarp has aroused much interest. De Bary (1887) recognised the fruiting bodies of the Ascomycetes as 'compound sporophores' made up of interwoven hyphae or of pseudoparenchyma consisting of a peripheral layer separate from an inner tissue. These fruiting bodies included the discocarp or apothecium, the pyrenocarp or perithecium and the cleistocarp or cleistothecium. The name, Pyrenomycetes, has been variously applied to a group of Ascomycetes but mainly to the perithecial types, inclusive of the true perithecia and the loculate forms. The perithecium itself was described as a 'cup-shaped discomycetous' sporocarp with margins incurved to form a pyriform structure (de Bary, 1887). The presence or absence of a stroma had been long considered as a basis for the separation of the major groups of the Ascomycetes. Separation on these grounds was found unacceptable as it grouped together clearly unrelated species or separated related ones. As the subdivisions of the pyrenomycetous Ascomycetes are dependent upon the morphological features of the ascocarp, it would be pertinent to discuss the following: a) The Stroma. b) The various forms of ascocarp which mayor may not be associated with such a stroma. i) Perithecia: free or immersed in a stroma. ii) Uni- or multiloculate stromata. c) The centrum, the details associated with the centrum and the use of these details in the taxonomy of the pyrenomycetes.
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  • Date Issued: 1971

Extractives of Leonotis and Euryops species

- Eagle, G A

  • Authors: Eagle, G A
  • Date: 1971
  • Subjects: Stereochemistry Leonotis -- Analysis Euryops -- Analysis Botanical chemistry
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4465 , http://hdl.handle.net/10962/d1011610
  • Description: The isolation and structure determination of dubiin and leonitin, two new diterpenoid acetates from Leonotis dubia and Leonotis leonitis respectively, are discussed. The compounds are diterpenoids of the labdane type and are closely related to marrubiin. The proposed structures are based on chemical and spectral evidence. Dubiin, C₂₂H₃₀0₆̕ contains a tertiary hydroxy- group, a furan ring and a ó-lactone while leonitin, C₂₂H₃₀0₇̕ is a γ - dilactone. at C-20. Both compounds are unusual in being oxygenated The extraction of three Euryops species and the isolation of euryopsol, C₂₂H₃₀0₄̕̕ are also described. A furanoeremophilane structure containing three hydroxy- groups, one of which is at a bridgehead position, is proposed. Euryopsol is the first furanoeremophilanoid with a substituent attached at C-IO
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  • Date Issued: 1971

In community in Christ: a study of theological setting of the sacraments in the New Testament

- Moore, Basil S

  • Authors: Moore, Basil S
  • Date: 1971
  • Subjects: Sacraments Sacraments (Liturgy)
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:1240 , http://hdl.handle.net/10962/d1007688
  • Description: Introduction: Neville Clark has rightly warned against the attempt to approach the theology of the sacraments from a broad and general definition of a 'sacrament' from which we 'read off' a Christian doctrine of the sacraments without paying due regard to the biblical statements. Such an approach could not but obscure the essential differences between the sacraments, and the fact that they stem from historical roots. On the other hand, the specialist treatment of the sacraments which begins by making a detailed analysis of the biblical material fails to do justice to the wholeness of biblical theology and tends to treat the sacraments in isolation not only from each other but also from other aspects of Christian theology with which they are inalienably connected. Bearing in mind the difficulties inherent in both of these approaches, a fresh and more systematic approach is required.
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  • Date Issued: 1971

The novels of André Malraux : a restatement of man's tragic dilemma in contemporary terms

- Greshoff, C J

  • Authors: Greshoff, C J
  • Date: 1971
  • Subjects: Malraux, André, 1901-1976 -- Criticism and interpretation
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:2299 , http://hdl.handle.net/10962/d1012092
  • Description: Writing about Eighteenth Century England, and more particularly about the age of Johnson, Trevelyan gives us an admirable definition of a classical age: It is a "classical age, that is an age of unchallenged assumptions, when the philosophers of the streets such as Dr. Johnson, have ample leisure to moralise on the human scene, in the happy belief that the state of society and the modes of thought to which they are accustomed are not mere passing aspects of an ever shifting kaleidoscope, but permanent habitations, the final outcome of reason and experience. Such an age does not aspire to progress, though it may in fact be progressing; it regards itself not as setting out but as having arrived." To apply this definition of a classical age to the protean Nineteenth Century might, at first glance, seem impossible or at least dangerous. Yet it is only when we see this century - and more particularly the period 1871-1914 - as a truly classical age, as the classical age of the Bourgeoisie, that we can understand the direction and meaning of the revolt during the Twenties and Thirties of which Malraux' work is so representative. Introduction, page 1.
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  • Date Issued: 1971

The Wesleyan Methodist Church in the Transvaal, 1823-1902

- Veysie, Donald Clifford

  • Authors: Veysie, Donald Clifford
  • Date: 1971
  • Subjects: Methodist Church of Southern Africa Methodist Church of Southern Africa -- History Transvaal (South Africa) -- History -- To 1880 Transvaal (South Africa) -- History -- 1880-1910
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:1234 , http://hdl.handle.net/10962/d1007463
  • Description: From Preface: A preliminary survey of the history of the Wesleyan Methodist Church in the Transvaal revealed that the period of the early missions, before the formation of the Transvaal and Swaziland District, required research into the documents of other Districts for the purpose of writing a detailed history. It was therefore decided to confine research to the Documents of the Transvaal and Swaziland District and to write introductory chapters on the period of the early missions. The detailed research for this dissertation begins, therefore, with the creation of the Transvaal and Swaziland District in 1880. The natural point at which to finish appeared, at first, to be the beginning of the Second Transvaal War of Independence, but further research indicated that it would be more useful to conclude with the end of the war in 1902.
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  • Date Issued: 1971

W.H. Auden: a study of his poetry and its critics, 1930-1960

- Millard, Geoffrey Charles

  • Authors: Millard, Geoffrey Charles
  • Date: 1971
  • Subjects: Auden, W. H., (Wystan Hugh), 1907-1973 -- Criticism and interpretation English poetry -- 20th century -- History and criticism
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:2284 , http://hdl.handle.net/10962/d1007629
  • Description: How does a poet fare nowadays at the hands of his critics? This study examines the critical reception Auden received from 1930 to 1960; through a close consideration of a selection of the poems written in this period it will be demonstrated that a considerble discrepency exists between Auden's poetic achievement and. the criticism it received. The main reason for this discrepancy is the lack of attention to individual poems in favour of sweeping surveys of a volume of poetry or the poet's total output. The core of the thesis lies here and the thesis as a whole derives from concern for a poet's reputation during his poetic career.
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  • Date Issued: 1971

A new model of the IO-Controlled Jovian decametric radiation

- Goertz, Christoph K

  • Authors: Goertz, Christoph K
  • Date: 1972
  • Subjects: Jupiter (Planet) Radiation Magnetosphere Ionosphere
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:5521 , http://hdl.handle.net/10962/d1012043
  • Description: Jupiter, the largest planet in the solar system, is not only an emitter of thermal radiation like any other planet. Jupiter also emits relatively high-intensity non-thermal radiation in two bands, the decimetre wavelength range and the decametre wavelength range (5 MHz< f < 40 MHz). The decimetric radiation is believed to be due to synchrotron radiation of electrons trapped in a kind of Jovian "Van Allen belt". This thesis deals almost exclusively with the decametric radiation. Although the decametric radiation has been observed for 15 years since its discovery by Burke and Franklin in 1955, there is no generally accepted theoretical model of its generation to be found in the literature as yet. This is not surprising, as there are many complex and confusing aspects of the radiation. And since our knowledge of the Jovian ionosphere, magnetosphere and magnetic field is very limited indeed, every theoretical model must be based on some more or less well justified assumptions. It is, however, possible to draw some conclusions from the observed properties of the decimetric and decametric radiation. The radiation in both bands is polarized. It has been shown that at least part of the polarization is an intrinsic property of the radiation source at Jupiter, This indicates the existence of a Jovian magnetic field. The magnitude and shape of the magnetic field, however, is open to discussion, although a dipole field does seem to be a good approximation at least for large distances from Jupiter. Intro. p. 1-2.
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  • Date Issued: 1972

A petrological and mineralogical study of peridotite and eclogite xenoliths from certain kimberlite pipes

- Whitfield, Gavin

  • Authors: Whitfield, Gavin
  • Date: 1972
  • Subjects: Petrology Peridotite Mineralogy Kimberlite Igneous rocks -- Inclusions Eclogite
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:5044 , http://hdl.handle.net/10962/d1007690
  • Description: Kimberlite, an ultrabasic diamond-bearing hypabyssal rock-type which has its origin in the Earth's upper mantle, characteristically contains rare, well-rounded xenoliths of peridotite and eclogite. These xenoliths, which undoubtedly originate from some considerable depth below the Earth's surface, possibly represent samples of upper mantle material. They have received much attention from earth scientists and numerous theories as to their origin have been proposed. Forty-two selected peridotite xenoliths from the Bultfontein, Wesselton, Dutoitspan and Roberts Victor kimberlite pipes of the Kimberley area, South Africa, and 24 eclogite xenoliths from the Roberts Victor pipe have been examined in detail using a variety of petrological and mineralogical techniques. The petrologic research comprises conventional petrographic studies, the determination of accurate modal compositions and the presentation of 22 new whole-rock chemical analyses, nine of which are of garnet peridotite, four of spinel peridotite and nine of eclogite, one being a diamondiferous specimen. Detailed mineralogical studies of the constituent minerals of the xenoliths comprises descriptive mineralogy, in most cases an estimation of the compositions of these minerals from the measurement of physical properties, X-ray powder diffraction data and the presentation of 21 new chemical analyses of pure mineral separates. This includes five analyses of clivine, five of orthopyroxene, eight of garnet, one of chrome diopside and two of omphacite. The results of the investigation have shown that the peridotites consist essentially of forsterite and enstatite with minor or trace amounts of one or more of pyrope-rich garnet, chrome diopside, chrome spinel, phlogopite and rarely graphite, and often exhibit features consistent with plastic movement and tectonic deformation. The peridotites are believed to be derived from an ultrabasic upper mantle, which is both chemioally and physically zoned. The eclogite xenoliths, which are composed mainly of pyrope-almandine garnet and omphacitic clinopyroxene and occasionally contain kyanite, corundum and diamond, are not samples of a primary eclogitic upper mantle nor the products of an eclogite fractionation related to kimberlite genesis. Chemically they are not typical of extrusive basalts and probably either represent pockets of partially fractionated basic magma trapped at mantle-level in an eclogite-stable environment or samples of high-grade crustal metamorphic eclogite accidentally incorporated into the Roberts Victor kimberlite.
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  • Date Issued: 1972

A structural investigation of the sulphated polysaccharide of Anathaca dentata (suhr) papenf. and the xylan of Chaetangium erinaceum (turn.) papenf.

- Russell, Irina

  • Authors: Russell, Irina
  • Date: 1972
  • Subjects: Polysaccharides , Marine algae -- Composition
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4494 , http://hdl.handle.net/10962/d1013103
  • Description: Hot-water extraction of Anatheca dentata, a red seaweed belonging to the family Solieriaceae, yielded a mixture of polysaccharides. Fractionation of this mixture with Cetavlon gave a glucomannan as minor component and a highly sulphated major component, which gave D- and L-galactose, D-xylose and small amounts of 3-0 (underscore)-methylgalactose, pyruvic acid and uronic acid on hydrolysis. All subsequent investigations were carried out on the sulphated major component. The sulphate was not labile to alkali, but was removed with methanolic hydrogen chloride. Periodate oxidation of the polysaccharide before and after desulphation indicated that new a-glycol groups were formed during desulphation. All the xylose units in the polymer were cleaved by periodate and this, together with the fact that the major xylose product from methylation analysis of the desulphated polymer was the 2,3, 4-tri-0 (underscore)-methyl derivative, indicated that the xylose occurs as a non-reducing end-group. Methylation of the desulphated polysaccharide revealed the presence of 1,4- and 1,3- linked D- galactose and 1,4- linked L-galactose units in the polymer. D-Glucuronic acid occurred as non-reducing end-groups. Summary, p. 1.
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  • Date Issued: 1972

A structural investigation of the sulphated polysaccharide pachymenia carnos (J. Ag.) J. Ag.

- Farrant, Annette J

  • Authors: Farrant, Annette J
  • Date: 1972
  • Subjects: Polysaccharides Red algae -- Composition
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4470 , http://hdl.handle.net/10962/d1011785
  • Description: The highly sulphated, methylated polysaccharide isolated from Pachymenia Carnosa, a red seaweed, was shown to contain D- galactose, 2-o (underscore) methyl-D- galactose, 6-o (underscore) -methyl- D- galactose and 4-o (underscore)-methylgalactose. The polysaccharide was desulphated with methanolic hydrogen chloride. Methylation of the desulphated polysaccharide revealed that it was composed entirely of (1→73) and (1→4) links in approximately equal amounts. Treatment of the polysaccharide with alkali showed that the majority of the ester sulphate groups were alkali-stable. Partial hydrolysis and acetolysis studies indicated that the polysaccharide was extremely complex, and contained alternate (1→3) and β (1→4) glycosidic linkages. There is evidence for the presence of D-galactose-6-sulphate.
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  • Date Issued: 1972

Diurnal and seasonal variations of the F2 region of the Antarctic ionosphere

- Williams, Morgan Howard

  • Authors: Williams, Morgan Howard
  • Date: 1972
  • Subjects: Harmonic analysis , Ionosphere -- Antarctic Ocean
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:5548 , http://hdl.handle.net/10962/d1013459
  • Description: [From Introduction, p. 2] The first chapter of this thesis deals with an analysis of F2 critical frequency data first for SANAE and then for eleven other Antarctic and sub-Antarctic stations covering the period 1957 to 1969. This shows certain aspects of the F2 behaviour. Some of the results of this chapter have been reported in a paper by Gledhill and Williams. The two most important mechanisms thought to be responsible for the Antarctic f₀F2 behaviour are incoming corpuscular radiation and horizontal neutral winds. These two mechanisms together with two others (the temperature theory of Torr and Torr and the semi-annual variation of neutral atmospheric density) are discussed in detail in part 2 (Chapters 2 to 4) with a view to discovering which aspects of the f₀F2 behaviour over Antarctica can be explained by each theory. An attempt is made in Part 3 (Chapters 5 and 6) to explain the observed behaviour by solving the continuity equation of the ionosphere for high-latitude stations. Finally, besides the critical frequency, another parameter of importance in explaining the behaviour in the F2 region is the height at which the F2 maximum occurs. This quantity cannot be read directly from an ionogram and it is not an easy quantity to determine. In fact the way in which it is usually obtained is by "scaling" the ionogram in question and converting the virtual heights obtained into real heights. In Part 4 (Chapter 7 and 8) an outline is given of the two computer programs which were written to perform this conversion.
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  • Date Issued: 1972
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