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Architecture and landscape design : an investigation into the harmonising of these two aspects of design as exemplified by the collaboration of Gertrude Jekyll and Sir Edwin Landseer Lutyens

- Judge, Stephen Michael

Authors: Judge, Stephen Michael
Date: 1996
Subjects: Lutyens, Edwin Landseer, Sir, 1869-1944 Jekyll, Gertrude, 1843-1932 Gardens -- Design Architecture, British
Language: English
Type: Thesis , Masters , MFA
Identifier: vital:2405 , http://hdl.handle.net/10962/d1002201
Description: Sir Edwin Lutyens and Miss Gertrude Jekyll were part of the 'Art's and Crafts' movement, which advocated the use of local techniques and materials. They grew up separately, both in the Surrey country-side and both among creative people. Jekyll later worked with Edward Hudson (the author of 'Country Life') who persuaded her to be a garden designer . Lutyens was inspired first by the architecture of Surrey (mostly that of Norman Shaw), then by his friend, Herbert Baker, at architectural school, and lastly, by his long - time partner Jekyll. Munstead Wood, Surrey, England, was the partners' first project and it embodies nearly all of their ideals; the natural and indigenous use of flowers and plants, with an ordered colour scheme ; graded colour schemes without discord; the use of entirely local materials ; the sole use of local craftsmen and local techniques; a garden of 'rooms'; the intergration of architecture and garden design. A revival of interest in the partners work has helped to recreate some of the lost gardens of Jekyll. This interest has in turn put a spotlight on the ideals employed by the partners. Their wide influence has also produced many great buildings and gardens, most notably through the work of Sir Herbert Baker in South Africa. The Union Buildings are a perfect example of Baker's work, and much of it has the stamp of Lutyens' style and ideals. Through my own interest in Lutyens and Jekyll I have created my own Jekyll-style border in Grahamstown, Eastern Cape, to try and prove that her ideals can be translated into climates other than that of England. In this experiment, I succeeded in using indigenous South African plants and flowers with a colour scheme in the style of Jekyll, proving that the ideals to which she aspired could be applied in other countries.
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Date Issued: 1996

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Asleep in a glass coffin: fairy tales as illuminating attitudes to women in the novels of Charles Dickens

- Daly, Robyn Anne

Authors: Daly, Robyn Anne
Date: 1996
Subjects: Dickens, Charles, 1812-1870 -- Criticism and interpretation Dickens, Charles, 1812-1870 -- Folklore Dickens, Charles, 1812-1870 -- Characters Women Dickens, Charles, 1812-1870 -- Symbolism Fairy tales -- History and criticism
Language: English
Type: Thesis , Masters , MA
Identifier: vital:2227 , http://hdl.handle.net/10962/d1002270
Description: The field of research of this thesis covers three main areas: the novels of Charles Dickens; fairy tales and storytelling; and notions of women as reflected in feminist literary theory. A reading of selected novels by Dickens provides the primary source. That he copiously drew on fairy tales has been explored in such notable works as Harry Stone's, but the thesis concentrates on Dickens 's propensity in his creation of female protagonists to give them a voice which is vivified through fairy tale. The analysis of fairy story through narrative theory and feminist literary theory functions as the basis of an exploration of the role female narrative voices play in a reading of the novels which reveals a more sympathetic vision of the feminine than has been observed hitherto. The context of this study is Victorian attitudes to women and that modem criticism has not sufficiently acknowledged Dickens's insight into of the condition of women; much of this is discovered through an examination of his use of fairy tale wherein the woman is bearer of imaginative and emotional capacities magically bestowed. The research aims to counter the view of Dickens's novels as being sexist, through the iIluminatory characteristics of fairy tale. Dickens activates his women characters by means of their often being tellers of tales replete with fairy tale imagery, and their tales are almost always seminal to the novelist's moral purpose.
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Date Issued: 1996

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Aspects of nutrition of the swordtail fish, Xiphophorus Helleri, (Family : Poeciliidae) under intensive culture conditions

- Kruger, David Philip

Authors: Kruger, David Philip
Date: 1996
Subjects: Xiphophorus helleri -- Nutrition , Fish culture
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:5219 , http://hdl.handle.net/10962/d1005062 , Xiphophorus helleri -- Nutrition , Fish culture
Description: The aim of this work was to investigate the nutrition of a popular ornamental fish, the swordtail (Xiphophorus helleri), under intensive aquaculture conditions. The study focused on the formulation and manufacture of artificial dry diets, as well as the influence of livefeed supplementation on growth and nutritional indices of both juvenile and broodstock fish. A combination of 65% fishmeal and 35% soya oil cake meal was found to closely approximate the essential amino acid profile of X helleri (r² = 94,3%) and lysine was identified as the first limiting amino acid. The influence of dietary protein and energy on the growth of X helleri was investigated by means of a growth trial comparing a range of nine test diets combining 3 crude protein (45,38 and 30%) and 3 digestible energy (16,5, 14,5 and 12,5 kJ/gram) levels. A high crude protein content (45% dry matter) and a protein to energy ratio of ≥ 27 mg protein per kJ digestible energy was shown to promote optimal growth rate and feed conversion ratio in juvenile X helleri. The final body protein and lipid content of the fish were significantly correlated with the dietary protein to energy ratio. The nutritional value of identical dietary formulations prepared by drum-drying or cold extrusion techniques and presented either as flake or crumble particles was evaluated in a growth trial and through analysis of vitamin C levels in the diets. Up to 27% of vitamin C activity was destroyed during the drum-drying of flake diets, while 80% of the remaining vitamin C was lost through leaching within 10 minutes of immersion in water. A crumble-type diet was shown to be acceptable to X helleri, and yielded significantly better growth rate and feed conversion than the equivalent flake feed. Almost 19% of fish fed the flake diets developed vitamin C deficiency symptoms including scoliosis and lordosis, while this was completely prevented by feeding crumbles, indicating a significant restriction of leaching losses from this type of particle. The use of livefeed (Daphnia spp.) as a daily supplement to dry feeds was shown to result in a significant improvement in growth rate and survival of juvenile swordtail fish. Furthermore, the synergistic action of nutrients contained in the livefeed resulted in an improvement in the feed conversion efficiency of the artificial formulation. While mortalities of 13,4% and 15% were recorded in fish fed exclusively on flake feed or Daphnia, no mortality occurred in the group fed the supplemented diet. Furthermore, the incidence of vitamin C deficiency symptoms was prevented by daily supplementation with Daphnia. Fish fed exclusively on Daphnia exhibited significantly more intense pigmentation due to carotenoids contained in the livefeed. In broodstock fish maintained primarily on flake diets, growth rate, feed conversion ratio as well as reproductive performance, as measured by fecundity, were significantly improved by daily livefeed supplementation. Weekly supplementation showed no measurable advantage over flake feed only. A direct correlation was demonstrated between fecundity and size of female fish with a mean fecundity of 190 embryos per female in those fed a daily Daphnia supplement. This was significantly higher than the yield from the non-supplemented or weekly supplemented treatments (133 and 140 embryos per female respectively). Despite these differences, the number of young harvested during the experiment did not differ between treatments and this discrepancy was ascribed to parental cannibalism of newborn juveniles. This phenomenon constitutes a major potential bottleneck in production with estimates of up to seventy percent of young lost in some exp experimental tanks. In conclusion, the present study demonstrated that established aquaculture nutrition principles and techniques are applicable to the tropical ornamental fish species, X helleri. It was demonstrated that by using balanced crumble feed formulations, and regular livefeed supplementation, production yields under intensive conditions may be significantly improved. Suggestions for future work on poeciliid production in South Africa include investigation of the economic implications of the recommendations stemming from this project, and further research into effective restriction of parental cannibalism of newborn fish.
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Date Issued: 1996

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Aspects of the physiology of the South African abalone, Haliotis Midae L., and implications for intensive abalone culture

- Lyon, Robert Gary

Authors: Lyon, Robert Gary
Date: 1996
Subjects: Abalones -- Physiology , Abalone culture
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:5226 , http://hdl.handle.net/10962/d1005069 , Abalones -- Physiology , Abalone culture
Description: A physiological study was carried out to determine the effects of temperature, quantity of food fed, feeding activity and size class on the oxygen consumption and ammonia production of the South African abalone Haliotis midae L.. A set of intermittent flow respirometer chambers were used in a recirculating system to measure the oxygen consumption rates of fed (postprandial) and unfed (postabsorptive) abalone for three different size classes (15, 30, and 50mm) at three different temperatures (16°, 20° and 23°C) over a 24 hour period. Ammonia production rates and food consumption rates were simultaneously determined. Oxygen consumption and Ammonia production rates per gram abalone were linear functions of abalone size, temperature, and mass of food consumed. Oxygen consumption and ammonia production rates were found to increase proportionally to temperature and in inverse proportion to abalone size. These rates were significantly higher for fed as opposed to unfed abalone. Equations were derived to predict oxygen consumption and ammonia production for fed and unfed animals for a range of temperatures and size classes of abalone. A 96h LC50 lethal toxicity test for exposure to ammonia established 1.08mg.1⁻¹ of unionised ammonia as the lethal limit. A test on the long term effects on growth of acute exposure (12h) to various sublethal concentrations of ammonia showed no significant effects on growth for concentrations below 0.88 mg.1⁻¹. A safe chronic exposure level of 0.02 mg.1¹ NH₃-N was used to predict optimal flow rates required per kilogram of abalone in a rearing tank over a range of size classes and temperatures. The physiological and biological requirements of H. midae and the implications of this knowledge for rearing tank management and optimal design are discussed.
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Date Issued: 1996

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Basin analysis and sequence stratigraphy a review, with a short account of its applicability and utility for the exploration of auriferous placers in the Witwatersrand Basin

- Van Eeden, Johan

Authors: Van Eeden, Johan
Date: 1996
Subjects: Geology, Stratigraphic , Sedimentary basins -- South Africa , Placer deposits -- South Africa
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:4934 , http://hdl.handle.net/10962/d1005546 , Geology, Stratigraphic , Sedimentary basins -- South Africa , Placer deposits -- South Africa
Description: The Witwatersrand basin is unique in terms of its mineral wealth. The gold in the Witwatersrand basin is mainly concentrated in the placers and two types of unconformities are associated with the placer formation. This paper attempts to quantitatively describe the origin and depositional process of placers within the context of basin analysis, geohistory and sequences stratigraphic framework. Several tectonic models have been proposed for the evolution of the Witwater~rand basin and it seems as if a cratonic foreland basin accounts for many of the observed features observed the Central Rand Group basin. The tectonic subsidence curve generated for the Witwatersrand Basin clearly implies foreland basin response which was superimposed an older, deep seated extensional basin. These compressive tectonics can be superimposed on extensional basins, where the shift from extensional to compressional tectonics lead to inversion processes. The critical issues about the Witwatersrand basin which were addresed in this review, is the validity of basin wide correlation of placer unconformuties and whether sequence stratigraphy is applicable to fluvial systems of the Witwatersrand sequence. It is believed that the Central Rand Group was deposited as alluvial - fan deltas by fluvially dominated, braidplain systems with minor marine interaction which had a considerable impact on the preservation of economically viable placers. Most important to the exploration geologist is the recognition of stacking patterns of the fluvial strata to determine change in the rate at which accommodation was created. Identifying sequence boundaries and other relevant surfaces important for identifying these stacking patterns of the sequences, depends entirely on the recognition of a hierarchy of stratal units including beds, bedsets, parasequences, parasequence sets and the surfaces bounding sequences. Placers are closely associated with the development of disconformities and therefore become important to recognise in fluvial strata. If these placers are to become economic, the duration of subaerial exposure of the unconformities that allowed the placers to become reworked and concentrated must be determined. In order to preserve the placer, a sudden marine transgression is necessary to allow for minimal shoreline reworking and to cap the placer to prevent it from being dispersed. The placers in the Witwatersrand basin occur in four major gold-bearing placer zones in the Central Rand Group. Accordingly they can be assigned to four supercycles, which are cyclical and therefore predictive. It is the predictive nature of these rocks and the ability of sequence stratigraphy to enhance this aspect, which is a pre-requisite for an effective exploration tool in the search for new ore bodies or their extension in the Witwatersrand basin.
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Date Issued: 1996

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Batsh' abantwana

- Ngqoko music ensemble participants, Composer not specified, Dargie, Dave

Authors: Ngqoko music ensemble participants , Composer not specified , Dargie, Dave
Date: 1996
Subjects: Folk music , Sacred music , Field recordings , Africa, Sub-Saharan , Africa South Africa Alice sa
Language: IsiXhosa
Type: sound recordings , field recordings , sound recording-musical
Identifier: http://hdl.handle.net/10962/342241 , vital:62869 , International Library of African Music, Rhodes University, Makhanda, South Africa , Dave Dargie Field Tapes, Rhodes University, Makhanda, South Africa , DDC338b-14
Description: Ngqoko music ensemble accompanied by rattle and igubu
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Date Issued: 1996

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Belethe

- Hogsback festival participants, Thukani, M. J., Dargie, Dave

Authors: Hogsback festival participants , Thukani, M. J. , Dargie, Dave
Date: 1996
Subjects: Folk music , Sacred music , Field recordings , Africa, Sub-Saharan , Africa South Africa Hogsback sa
Language: IsiXhosa
Type: sound recordings , field recordings , sound recording-musical
Identifier: http://hdl.handle.net/10962/344698 , vital:63165 , International Library of African Music, Rhodes University, Makhanda, South Africa , Dave Dargie Field Tapes, Rhodes University, Makhanda, South Africa , DDC348a-03
Description: Xhosa music at Hogsback festival
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Date Issued: 1996

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Bleak future for multi-party elections in Kenya

- Fox, Roddy C

Authors: Fox, Roddy C
Date: 1996
Language: English
Type: Article
Identifier: vital:6683 , http://hdl.handle.net/10962/d1006681
Description: With attention turning towards Kenya's second multi-party elections, due to be held before the end of 1997, it is imperative to look back to the flaws in the system which helped deliver President Daniel arap Moi and the Kenya African National Union (KANU) their victories in 1992. At present there is no sign of these defects being eradicated and the creation of new districts since then has demonstrated the Government's intention of enhancing an already biased structure. The underlying distribution of tribes and ethnic groups has had a fundamental impact on the electoral geography of Kenya, since they have controlled the delimitation of both the parliamentary constituencies and the administrative machinery of the whole country.
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Date Issued: 1996

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Boyzie Cekwana the South African dancing body in transition

- Pienaar, Samantha

Authors: Pienaar, Samantha
Date: 1996
Subjects: Cekwana, Ntsikelelo , Dance -- South Africa
Language: English
Type: Thesis , Masters , MA
Identifier: vital:2144 , http://hdl.handle.net/10962/d1002376 , Cekwana, Ntsikelelo , Dance -- South Africa
Description: Boyzie Cekwana is one of many black male dancers and choreographers that is currently receiving widespread support and recognition for his contribution to the field of contemporary dance in South Africa. Why certain images of the dancing body - as presented by this individual dance practitioner - are currently being promoted as artistically more viable than others by dance critics and the media is the central concern of this thesis. An analysis of the dancing body in contemporary South Africa must take into account the current post-apartheid condition, a condition of transformation and reconstruction that allows people greater freedom to select the country's leaders, popularize its heroes and heroines, market and capitalize on images and icons of a New South Africa. By opting to look specifically at a black male dancer, social appreciations of the body in terms of ethnicity and gender can be challenged. This latter area of research - the role of gender in the production, presentation and appreciation of the dancing body - is largely unchallenged in South Africa. Yet, if South African's want to truly rid themselves of the shackles of hegemonic rule, gender-construction is an area of social experience that needs intensive confrontation. Chapter one will suggest some of the obstacles that might limit the South African dance researcher seeking an indepth analysis of the black dancing body, taking into consideration the country's history of elitist and autonomous rule. Attention will be drawn to multidisciplinary sites of information that might assist the researcher in such an excavation. The context of the research, however, is less interested in historical descriptions of the dancing body than with current motivating factors behind the preferential promotion of certain images over others in contemporary dance. Personal interviews and observations will therefore also provide crucial resource material. In chapter two, a case study of Boyzie Cekwana will be made looking at his personal background and the way in which it may have informed his contemporary experiences as a black male dancer and choreographer. The underlying belief of such a case-study approach is that "it carries implications about the extents to which the resulting analysis is applicable to other similar cases" ¹. This individual analysis includes information gathered from persona1 interviews with Cekwana; the author's own observations and experiences of Cekwana' s work at the Vita FNB Dance Umbrella, the Grahamstown National Arts Festival, and the Durban Playhouse Theatre; and analyses of articles on Cekwana by journalists, and performance reviews by dance and theatre critics such as Adrienne Sichel (The Star Tonight!), Tommy Ballantyne (The Natal Sunday Tribune) and David Coleman (The Mercury). Further examinations in chapter three and four will assess to what degree Cekwana re-presents culture-specific images of gender-modelling in his own performing body and the bodies of his multi-racial and multi-gendered dancers in selected dances. To prevent placing sole responsibility at Cekwana' s feet for the representation of the dancing body to a society in transformation, the role of dance critics and mass mediators in this process of artistic communication will also be dealt with. It is hoped that the ensuing discussion will suggest the possible effects that present frameworks of aesthetic appreciation may hold for choreographers and dancers in the country's future cultural development; this involves confronting a still controversial issue in South Africa the relationship between dance and politics, choreographer and social responsibility. The thesis will round-off very briefly with suggestions to dance practitioners and educators in South Africa of alternative ways of perceiving and appreciating the dancing body based on gender, and· not just racial, constructions; this is especially invaluable in the light of current efforts to include dance as a core-curriculum subject in all schools.
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Date Issued: 1996

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Cell-free biosynthesis of abscisic acid (ABA) in extracts of flavedo from Citrus sinensis (L.) osbeck

- Richardson, Gaynor Rose-Marie

Authors: Richardson, Gaynor Rose-Marie
Date: 1996
Subjects: Biosynthesis Abscisic acid Citrus fruits
Language: English
Type: Thesis , Doctoral , PhD
Identifier: vital:4221 , http://hdl.handle.net/10962/d1003790
Description: The biosynthetic origin of the plant growth regulator abscisic acid remains equivocal and almost nothing is known about the enzymes involved in this process. The present research programme describes the development of a cell-free system, capable of synthesizing abscisic acid and attempts to provide further information about the biochemistry and enzymology of this important biosynthetic pathway. Cell-free extracts were prepared either directly from the flavedo (crude) or from an acetone powder derived from flavedo, of mature coloured fruits of Citrus sinensis L. cv. Midknight and incubated with mevalonic acid, isopentenyl pyrophosphate, famesylpyrophosphate, geranylgeranyl pyrophosphate, ß-carotene and 1',4'-trans-abscisic acid diol. The neutral and acidic products formed were purified by thin-layer chromatography and high performance liquid chromatography, and quantified by high performance liquid chromatography, gas chromatography-electron capture and unequivocally identified by combined gas chromatography-mass spectrometry. Abscisic acid, 1',4'-trans-abscisic acid diol and phaseic acid were unequivocally identified as the major acidic products formed in this cell-free system. The acid fraction also contained xanthoxin acid. Labelled and unlabelled ß-carotene was converted into the neutral compounds xanthoxin and xanthoxin alcohol. In addition. high performance liquid chromatography-photodiode array analYSis of the oxy-carotenoid fraction revealed the complete spectrum of ß, ß-carotenoids induding zeaxanthin, antheraxanthin and violaxanthin with accumulation of an oxygenated carotenoid tentatively identified as 9- cis-violaxanthin. Identification of putative C₁₅ intermediates was achieved by either UV spectrophotometry and combined capillary gas chromatography-mass spectrometry or microchemical analYSis and co-chromatography. Refeeding studies using (±)-[2-¹⁴C]_ abscisic acid diol as substrate revealed that abscisic acid was not metabolized to abscisic acid diol, suggesting that it was/is produced as an intermediate rather than as a catabolite of ABA in this system. Stigmasterol, and to a lesser extent cholesterol reduced conversion of ß-carotene to abscisic acid but did not influence transformation of 1',4'-trans-abscisic acid diol to abscisic acid. AM01618 stimulated fonnation of abscisic acid and appeared to exert its effect at the level of conversion of 1' ,4'-trans-abscisic acid diol. Zeatin and the cytokinin analogue, ancymidol inhibited the biosynthesis of abscisic acid whereas dithiothreitol increased incorporation of label from ß-carotene into abscisic acid suggesting involvement of a cytochrome P450-type mixed function oxidase in this reaction sequence. Sodium dodecylsulphate polyacrylamide gel electrophoresis of the enzyme extract derived from Citrus flavedo revealed the presence of a 53 kD protein with peroxidase activity characteristic of a cytochrome P-450. Abscisic acid biosynthesizing activity was always greater in extracts from acetone powder and abscisic acid biosynthesis was enhanced in the presence of AMO 1618, NAD+, NADH, NADPH, MgCI₂ and Molybdate but was inhibited by FAD. Activity was further enhanced by the addition of (R,S)-abscisic acid as a cold-pool trap and by induding 0.1% w/v of either Tween 20 or Triton X 100 in the extraction buffer. When cis-ß-carotene was used as substrate, no abscisic acid was produced. Conversely when either all-trans-ß-carotene or a mixture of the two isomers was used, incorporation into abscisic acid occurred. Upoxygenase activity in cell-free extracts of Citrus flavedo increased with increasing protein concentration. As the ability of lipoxygenase to make xanthoxin from violaxanthin, had been reported, increased activity in the cell-free system implied that carotenoid deavage was being brought about by a non-haem oxygenase with lipoxygenase-like properties. Reports had implicated phoshorylation in the activation of many catalytic enzymes (Hanks et aI., 1985). Phosphorylation of the enzymes in this cell-free system proved unsuccessful. Further, it had been reported that in vitro phosphorylation of several membrane polypeptides and soluble polypeptides from com, had been promoted by the addition of Ca²₊ In this cell-free system Ca + did not have a stimulatory effect on protein phosphorylation. Dioxygenases generally occur as soluble enzymes, where they catalyse many oxygenation reactions in metabolic pathways. The addition of 2-oxo-glutarate, a requirement of most soluble oxidases, did not affect the activity of the cell-free system.
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Date Issued: 1996

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Centralised bargaining now!

- CWIU

Authors: CWIU
Date: 1996
Subjects: CWIU
Language: English
Type: text
Identifier: http://hdl.handle.net/10962/119104 , vital:34701
Description: Keynote addresses were delivered by the Acting General Secretary, Cde Muzi Buthelezi, Cde Jay Naidoo COSATU General Secretary and CWIU President, Cde Don Gumede. Cde Gumede outlined the purposes of the conference “to assess progress and problems, to plan our path in order to provide a clear programme towards centralised bargaining as a result of proper analysis”, He urged delegates “to push employers into joint employers forums to negotiate on proper wages, job creation and an end to retrenchments”. Cde Jay Naidoo addressed the conference on the burning issues of the day. He spoke about VAT, the National Economic Negotiating Forum, trade union unity and CODESA. Cde Naidoo stressed that future economic and political policies must be formulated on the basis of daily and immediate issues facing the working people. Acting General Secretary, Cde Muzi Buthelezi outlined the progress made in the struggle for centralised bargaining. “We have to note” he said, “that the chemical bosses are very tough on this question. They do not want to negotiate, meet or do anything as an industry. They want to keep all activities at a plant or company level”. The remainder of the conference was given the task of redefining the sectors within the chemical industry, developing core demands and outlining a programme of action. Delegates broke into their different sectors to discuss these issues before returning to plenary to thrash out the major steps to be taken by the union in the coming months.
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Date Issued: 1996

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Cognition and multiple sclerosis: a neuropsychological and MRI study

- Thornton, Helena Barbara

Authors: Thornton, Helena Barbara
Date: 1996
Subjects: Multiple sclerosis -- Magnetic resonance imaging , Cognitive neuroscience
Language: English
Type: Thesis , Masters , MA
Identifier: vital:3144 , http://hdl.handle.net/10962/d1007290 , Multiple sclerosis -- Magnetic resonance imaging , Cognitive neuroscience
Description: Ten people with multiple sclerosis (MS) who felt they had cognitive difficulties because of their MS were investigated. This study had multiple aims. Firstly, to explore the subjective experience of cognitive deficits. Secondly, to assess whether or not there was objective evidence of cognitive difficulties on neuropsychological testing, and whether this was commensurate with a pattern of subcortical dementia. Thirdly, to determine whether their magnetic resonance imaging (MRI) scans replicated the patterns of atrophy frequently reported in MS patients with cognitive difficulties. And finally, to investigate the psychological well-being of the subjects. In depth neuropsychiatric interviews, psychiatric and psychological inventories, a comprehensive neuropsychological battery, and MRI investigations were done. The mean Full Scale Intelligence Quotient (FSIQ) fell within the superior range, at the 89th percentile. On tests of general intelligence, mental state examinations, there was little or no indication of cognitive deterioration. However, on sophisticated neuropsychological testing, there was convincing evidence of cognitive problems. Magnetic resonance imaging lesions were atypical of the reported research on cognitively compromised MS patients.
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Date Issued: 1996

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Computer modelling of pyrotechnic combustion

- Taylor, Steven John

Authors: Taylor, Steven John
Date: 1996
Subjects: Combustion -- Computer simulation
Language: English
Type: Thesis , Doctoral , PhD
Identifier: vital:4426 , http://hdl.handle.net/10962/d1006913
Description: One of the most important industrial uses of pyrotechnic compositions is as delay fuses in electric detonators. Many factors influence the rate of burning of such fuses. These include (a) the primary choice of chemical components, followed by (b) the physical properties of these components, particularly the particle-size and distribution of the fuel, (c) the composition of the system chosen and (d) the presence of additives and/or impurities. A full experimental study of the influences of even a few of these factors, while attempting to hold other potential variables constant, would be extremely time consuming and hence attention has been focused on the possibilities of modelling pyrotechnic combustion. Various approaches to the modelling of pyrotechnic combustion are discussed. These include:- (i) one-dimensional finite-difference models; (ii) two-dimensional finite-element models; (iii) particle-packing considerations; (iv) Monte Carlo models. Predicted behaviour is compared with extensive experimental information for the widely-used antimony/potassium permanganate pyrotechnic system, and the tungsten /potassium dichromate pyrotechnic system. The one-dimensional finite-difference model was investigated to give a simple means of investigating the effects of some parameters on the combustion of a pyrotechnic. The two-dimensional finite-difference model used similar inputs, but at the expense of considerably more computer power, gave more extensive information such as the shape of the burning front and the temperature gradients throughout the column and within the casing material. Both these models gave improved results when allowance was made for autocatalytic kinetics in place of the usual assumption of an "order-of-reaction", n ≤ 1. The particle-packing model investigated the qualitative relationship between the maximum burning rate of a pyrotechnic system and the maximum number of contact points (per 1.00 g composition) calculated for that system. Qualitative agreement was found for those systems which are presumed to burn mainly via solid-solid reactions. The Monte Carlo model investigated the effect of the random packing of fuel and oxidant particles on the variability of the burning rate of a pyrotechnic composition.
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Date Issued: 1996

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Computer modelling of the thermal decomposition of solids

- De la Croix, Annemarie

Authors: De la Croix, Annemarie
Date: 1996
Subjects: Solids -- Thermal properties -- Computer simulation
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:4302 , http://hdl.handle.net/10962/d1004960 , Solids -- Thermal properties -- Computer simulation
Description: Decompositions of solids are typically of the form: A(s) ----> B(s) + gases. Symmetry-controlled routes (based on known and hypothetical crystal structures) for transforming the solid reactant into the solid product were devised as possible decomposition pathways. Lattice energies of the reactants, of the postulated transient intermediate structures and of the final solid products were then estimated by crystal modelling procedures. Profiles of lattice energy changes during the proposed decomposition routes were constructed and any energy barriers were compared with experimental activation energies reported for the thermal decompositions. The crystal modelling was performed with the computer program WMIN. Calculation of the lattice energies involved the development of a model potential for the perfect lattice and the evaluation of the interatomic parameters. The potential was based on the Born model of ionic solids using the Buckingham potential (Ø(r)= Ae⁻r/p - C/r⁶) to describe the short-range energy contribution. Empirical fitting was used to establish reliable interatomic energy parameters. The reliability of the interatomic potentials was assessed by calculating crystal structures and lattice energies (which were not included in the fitting). The particular reactions selected for modelling were the decompositions of the alkaline-earth metal (Ca, Sr, Ba) peroxides and carbonates: M0₂(s) ---> MO(s) + ¹/₂0₂(g) MC0₃(s) ---> MO(s) + CO₂(g)The lattice energies calculated for the known structures were in good agreement with reported values, (except for Ba0₂ and BaC0₃) which provided support for the adequacy of the potential model used. Activation energies calculated for the decomposition of the carbonates were in the correct order but hlgher than experimental values, i. e., 422, 422, 465 and 499 kJ mol̄̄⁻¹ compared to the experimental values of 205, 87(?), 222 and 283 kJ mol̄̄⁻¹ for CaC0₃ (calcite), CaC0₃(aragonite), SrC0₃ and BaC0₃. The values calculated for the peroxides (91 and 100 kJ mol⁻¹ compared to the experimental values of 119 and 185 kJ mol⁻¹ for Sr0₂ and Ba0₂ respectively) were less satisfactory but could be a reflection of the poor structural data used for the peroxides. The significance of this approach to the modelling of solid decompositions is discussed.
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Date Issued: 1996

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Conrad's impressionism : the treatment of space and atmosphere in selected works

- De Lange, Adriaan Michiel

Authors: De Lange, Adriaan Michiel
Date: 1996
Subjects: Conrad, Joseph, 1857-1924 -- Criticism and interpretation Conrad, Joseph, 1857-1924 -- Heart of darkness Conrad, Joseph, 1857-1924 -- Nigger of the Narcissus Conrad, Joseph, 1857-1924 -- Nostromo Conrad, Joseph, 1857-1924 -- Lord Jim
Language: English
Type: Thesis , Doctoral , PhD
Identifier: vital:2229 , http://hdl.handle.net/10962/d1002272
Description: This thesis focuses on Conrad's representation of space and atmosphere in the "impressionistic" works published between 1897 and 1904, notably The Nigger of the "Narcissus" (1897), "Heart of Darkness" (1899), Lord Jim (1900), and Nostromo (1904). The many conflicting statements regarding the nature of Conrad's impressionism lead one to ask two fundamental questions: What constitutes this strange and elusive phenomenon, and how does it bear upon interpretation? This thesis works towards defining the elusive quality of Conrad's writing by investigating and assessing the contribution of impressionist techniques in the creation of a pervasive space and atmosphere; secondly, it considers how the various constituent elements interact with, and complement one another to form a dominant mode of fictional space in each work; and, thirdly, it indicates the possible impact that these particular Conradian configurations of space and atmosphere might have upon the interpretation of his impressionist works. The thesis argues that the existential condition of isolatio~experienced by Conrad's heroes and narrators is a consequence of epistemological frustration and fragmentation, which, in turn, is a function of impressionist ontology. There is a definite and complementary relationship between each of these notions in Conrad's fiction. The mysterious atmosphere in his works results from the interplay between various configurations of theme, narration and description, and these novelistic elements correspond roughly with the notions of existential isolation (the dominant theme), epistemology (narrating, telling and (re)telling as a method of knowing and understanding the space in which the characters find themselves) and, lastly, the ontological dimensions of the various modes of fictional space (as realized in description). The evocation and invocation of cosmic space in The Nigger of the "Narcissus," the mapping of a dorriinant symbolic space in "Heart of Darkness," the (re)constructions of Jim's psychological space in Lord Jim, and, finally, the "transcription" and "inscription" of a mythical space in Nostromo, indicate a definite development from epistemological to ontological issues. Phrased in more theoretical terms, this development is a movement from asking predominantly epistemological questions like "How can I interpret this world of which I am a part?" "What is there to be known?" "Who knows it ... and with what degree of certainty?", to asking predominantly ontological questions, such as "Which world is this?" "What kinds of worlds are there ... and how are they constituted?". Such questions, categorized by McHale as the dominant characteristics of Modernist and Postmodernist fiction respectively, are already present in Conrad's texts, thus undermining any clear-cut division between these broad categories. Indeed, this thesis suggests that these categories are at best tenuous, and that they should perhaps be used heuristically, rather than definitively
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Date Issued: 1996

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