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Die evolusie van nedersetting in die Sondagsriviervallei

- Potgieter, J M

Authors: Potgieter, J M
Date: 1953
Subjects: Land settlement -- South Africa -- Sundays River Valley , Agriculture -- South Africa -- Sundays River Valley , Irrigation -- South Africa -- Eastern Cape -- Sundays River Valley
Language: Afrikaans
Type: Thesis , Doctoral , PhD
Identifier: vital:4875 , http://hdl.handle.net/10962/d1013041
Description: Soos die titel aandui is hierdie verhandeling 'n volledige en noukeurige oorsig van die evolusie (ontwikkeling) van blanke nedersetting in die Sondagsriviervallei. Dis die eerste poging wat aangewend is om die ontwikkeling op alle gebiede van die grondlegging af tot op die huidige datum teen 'n geskiedkundige agtergrond te skilder. Maar dwarsdaur is daar getrag om 'n duidelike begrip van die interaksie van natuur en mens te handhaaf.
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Date Issued: 1953

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Studies in chromium complexes

- Friend, Maurice Temple

Authors: Friend, Maurice Temple
Date: 1953
Subjects: Complex ions , Chromium
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:4474 , http://hdl.handle.net/10962/d1011892 , Complex ions , Chromium
Description: In this work physical and analytical methods have been used to investigate the potassium salts of certain dioxalato chromium (III) complexes. The solid potassium salts of the trioxalatochromiate and the cis and trans dioxalatodiaquochromiates together with a salt corresponding to potassium dioxalatosulphatoaquochromiate were prepared. The mono- and dihydroxo derivatives of the cis and trans dioxalatochromiates were also obtained in aqueous solution. The methods of preparation and analysis used are described. Spectrophotometric absorption curves obtained on solutions of these salts using a Beckman Spectrophotometer are in agreement with results of previous workers, and the new absorption curve obtained from a solution of the solid cis dioxalatodiaquochromia salt shows that it is pure and gives additional proof of the completeness of the trans - cis isomerisation. Summary, p. i.
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Date Issued: 1953

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Studies in chromium complexes

- Cooper, Desmond Rudolph

Authors: Cooper, Desmond Rudolph
Date: 1953
Subjects: Chromium , Complex ions
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:4523 , http://hdl.handle.net/10962/d1014707
Description: The chemistry of co-ordination compounds in general has played an important role in the development of the modern theory of valency, but the properties of complex salts between chromium and organic compounds containing carboxyl and amino- groups are of additional interest because of their bearing on the theory of certain technological processes such as chromium plating and, in particular, chrome-tanning. Owing to the rapid development of valence theory over the last two decades the technological chemist finds himself at a disadvantage vis-a-vis his academic counterpart in attempting to interpret the results of researches relating to these compounds as he must rely on the less powerful "classical" approach to his problems. Hence the need was felt for a brief survey of modern concepts of valency in terms of wave mechanics. For a more extended study the reader may consult the appropriate references and text books.
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Date Issued: 1953

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Studies on Paragus (Diptera, Syrphidae)

- Stuckenberg, B R

Authors: Stuckenberg, B R
Date: 1953
Subjects: Syrphidae , Diptera
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:5887 , http://hdl.handle.net/10962/d1013321
Description: As several new species are described in this thesis its full value can only be realised by its publication, and it has therefore been prepared with that end in view. The subject matter is divided into two parts, each of which has been treated quite independently of the other. Both parts are presented here in the form in which they have been offered for publication. The first paper consists of a systematic study of a complex of species within the genus Paragus. It includes descriptions of four new species, a new subspecies, an allotype, and redescriptions of two incompletely defined species. This paper has been offered for publication in the Transactions of the Royal Entomological Society of London. The second part consists of a study of all the Ethiopian species of Paragus except those covered by the first paper. It includes the definition of a new subgenus, and descriptions of two new species and three allotypes. It has been sent for publication in the "Revue Zoologie et Botanique de Africaine" at the invitation of Dr. P. Basilewsky of the Musee du Congo Belge, Tervuren.
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Date Issued: 1953

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The chemistry of the wattle tannins

- Roux, David Gerhardus

Authors: Roux, David Gerhardus
Date: 1953
Subjects: Tannin plants , Tannins , Wattles (Plants)
Language: English
Type: text , Thesis , Doctoral , PhD
Identifier: vital:4492 , http://hdl.handle.net/10962/d1013098
Description: Four species of acacia of Auatralian origin are associated with the wattle industry in South Africa. Black wattle, Acacia mollissima willd., is the most important of these and is today almost exclusively cultivated. The tree grows successfully only in a limited area of rich soil and high rainfall and is easily affected by adverse conditions caused by insect pests, frost damage and drought. Expansion of the area under cultivation is therefore, not feasible, although the world demand for vegetable extracts far exceeds the available supply. The remaining species such as green (Acacia decurrrens willd.) and silver wattles (Acacia dealbata Link.) possess many desirable characteristics which resist such adverse factors. Their barks, however, give reddish extracts, which are considered unsuitable for tannery usage because of the red colour they impart to the leather. Hybridisation studies, involving the crossing of green and silver wattle with the black, and aimed at produc1ng progenies containing many of the desirable characterlstics of the parent plants, are thus a natural result and have been in progress for a considerable period. Summary, p. i.
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Date Issued: 1953

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The petrology of the Khale dolerite sheet

- Eales, Hugh V

Authors: Eales, Hugh V
Date: 1953
Subjects: Petrology -- Botswana , Diabase -- Botswana
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:5076 , http://hdl.handle.net/10962/d1014853
Description: In the hills and in the plain of the Khale area are exposed two sheets of quartz-dolerite, the upper sheet being locally mushroom-shaped. The rock corresponds loosely with the Downes mountain type of dolorite, and contains numerous horizons of coarse-grained dolorite-pegmatite. The plagioclase felspars are described with special reference to the variation of grain-size, the features of zoned crystals, and the possible causes of a peculiar brown clouding in the basic zones of the crystals. Phenocrysts of augite and pigeonite, as well as plagioclase are recorded in the chilled contact rock. The micrometric data indicate that the mineral composition of the specimens is largely governed by the oxidation state of the iron, and that the Soret effect has caused the marginal rock to be enriched in basic elements. Hydrothermal veinlets composed largely of chlorite occur in both the dolorite and the country rock, and evidence suggests that veins of both residual material and mobilised granite occur in the upper finer-grained dolorite.
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Date Issued: 1953

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The response of pure organic crystals to ionising radiations

- King, J W

Authors: King, J W
Date: 1953
Subjects: Inorganic scintillators , Crystals
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:5529 , http://hdl.handle.net/10962/d1012641 , Inorganic scintillators , Crystals
Description: The introduction contains introductory remarks on scintillation counters together with a brief description of the exciton theory believed to be the means of primary energy migration within organic crystals. Part I contains a review of the data published on the reletive responses of different organic crystals and the attempted correlations of these results with the molecular structures of the different phosphors. From data which may be accepted as being both reliable and suitable for comparison it is concluded that theories involving correlations between phosphor efficiencies and molecular structures may be tested only if the efficiency data has (i) been extrapolated to give results for crystals of very small thickness and {ii) been obtained at very low temperatures. Part II contains accurate calculations based on the exciton theory proposed by Birks (1951 ) to account for the response of crystals to different types of ionising radiations. Satisfactory agreement is obta1ned with all the avalable experimental data in the literature. In part III an account is given of the response of organic crystals observed by the author for low-energy ⋉particles, and of the similar behaviour found by Taylor et al, (1951 ) for low-energy electrons. A possible extension of the theory described in part II, allowing for the escape of excitons through the crystal surface is given accounting for this behaviour. An exciton mean free path in anthracene, terphenyl and stilbene of about 3 - 7/u is obtained. Results were obtained with strong ⋉-particle sources which could not be explained. in terms ot normal response of the phosphor used. This effect was inventigatea as described in part IV, and it is shown that photons are produced in air, glass and quartz when these materials are irradiated by ⋉particles. This luminescence was probably responsible for the "scintillations" which Richards and Cole (1951) have ascribed to thin films of various materials. Problems requiring further investigation are indicated.
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Date Issued: 1953

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A preliminary investigation of the toxic principle of Moraea polystachya Ker

- Dry, L J

Authors: Dry, L J
Date: 1954
Subjects: Iridaceae Moraea polystachya ker
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:4461 , http://hdl.handle.net/10962/d1011494
Description: A member of the Iridaceae family, the plant (also known as the Blue Tulp) ... is a monocotyledon. The blue tulp grows profusely in rainy parts of the Union, for example along much of the Cape coastal belt as far east as Grahamstown, in both the Karroos, and in parts of the Transvaal. It is a perennial plant but only appears above the ground once a year for about two months. This is at the start of the rainy season and in Grahamstown the plant appears in April and May, after which it disappears again. Chapter 1, p.1.
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Date Issued: 1954

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An exposition and evaluation of John Calvin's teaching on the sacraments, with particular reference to the sacrament of the Lord's supper in its liturgical context

- Orr, Robert

Authors: Orr, Robert
Date: 1954
Subjects: Lord's Supper (Liturgy) -- History , Sacraments -- Reformed Church , Calvin, Jean, 1509-1564
Language: English
Type: Thesis , Bachelor , BDiv
Identifier: vital:1294 , http://hdl.handle.net/10962/d1015226
Description: Misinterpretations of John Calvin's theology are legion. It is hoped that this thesis does not add to their number. The basis for this lies in the fact that the task of writing on the subject has of course compelled the writer to do his utmost to comprehend what Calvin had to say concerning the Sacraments both in the Institutions and in the Scriptural Commentaries ... .The attempt has been made to refract Calvin's thought on the Sacrament, using certain key-concepts as prisms, and from the results thus obtained, to draw certain conclusions from which, it is hoped, will not be unprofitable to the life of the Holy Catholic Church. It is thus to be reagrded as an essay in historical theology rather than a whole-hearted attempt to reconstruct Calvin's exposition of the sacrament in the light of what has been revealed to us in the intervening years.
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Date Issued: 1954

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An investigation of the equivalent circuit of a conductivity cell

- Allison, Francis Sutton

Authors: Allison, Francis Sutton
Date: 1954
Subjects: Electrolytic cells
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:4508 , http://hdl.handle.net/10962/d1013376
Description: ( i) A linear circuit is shown not to explain the behaviour of a conductivity cell towards a long rectangular pulse of amplitude less than the decomposition potential of the solution in the cell. (ii) It is shown that the flow of current through the cell is governed by diffusion to the electrode. The diffusion current expression is the familiar one used in the case of diffusion up to a plane micro-electrode, except that in this case the concentration in the layer next to the electrode is not zero, but only somewhat less than the bulk concentration. (iii) Except during a short initial period (less than 10 seconds), the resistance of the electrolytic cell varies directly with the square root of the time for which an e.m.f. (less than the decomposition potential) is applied to the cell, and inversely with the concentration difference between the electrode surface and the bulk of the solution.
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Date Issued: 1954

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Aspects of the resorcinol-formaldehyde condensation

- Waldron, Ronald Augustus Frank

Authors: Waldron, Ronald Augustus Frank
Date: 1954
Subjects: Resorcinol , Formaldehyde
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:4514 , http://hdl.handle.net/10962/d1013460
Description: An attempt was made to producea -β or Ϫ - resorcinyl alcohol from disubstituted resorcinyls. To accomplish this 3,5-dibromo-β-resorcylic acid was reacted with lithium aluminium hybride, a mild reducing agent, in an attempt to reduce the acid group to the alcohol group. This disubstituted resorcinol was recovered unchanged. 3,5-dibromo-β-resorcyl-aldehyde was reduced by lithium aluminium hydride, but, instead of the alcohol forming, resinification took place. 2-methyl- 4-ethylresorcinol and 4,6-diethyrecorinol were reacted with formaldehyde under alkaline and acidic conditions. In each case a resin formed. The above experlments indicated that condensation took place in the meta position of the resorcinol molecule. Trimethylresorcinol was therefore reacted with formaldehyde under alkaline conditions, resulting in a small quantity ot the alcohol derivative. A better yield of the alcohol derivative was obtained by the hydrolysis or the chloromathyl derivative. In pursuing this line, a seres of new compounds and their derivatives were prepared. The condensation of the alcohol derivative with trimethylresorcinol and also with resorcinol was investigated.
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Date Issued: 1954

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Boerdery in die Suid-Afrikaanse Republiek 1858-1899

- Naudé, Petrus

Authors: Naudé, Petrus
Date: 1954
Subjects: Agriculture -- South Africa -- History -- 19th century , Agricultural laborers -- South Africa -- History , Agriculture -- Economic aspects -- South Africa -- History , Farmers -- South Africa -- History -- 19th century
Language: Afrikaans
Type: Thesis , Doctoral , PhD
Identifier: vital:1092 , http://hdl.handle.net/10962/d1012946
Description: In Suid-Afrika het die opkoms van die sosialistiese gedagte teen die einde van die negentiende eeu ook merkbare invloed op die staatshuishouding gehad. In die negentiende eeu was die ekonomiese wetgewing, hoofsaaklik onder invloed van die indiwidualisme volgens die leer van "Laissez- faire", daarop gerig om die maksimum welvaart te verkry deur vrye mededinging aan te moedig en te beskerm, en om privaat inisiatief sy gang te laat gaan. Daar het egter geleidelik 'n verandering in hierdie houding en beleid ingetree. Deur 'n verandering in die beskouing omtrent die einddoel van die menslike arbeid en sy ekonomiese bedrywigheid moes die staat uit sosiaal-ekonomiese oorwegings sekere seksies van die samelewing deur spesiale en beskermende wetgewing te hulp kom. Die ontwikkeling van die aandeel wat die staat geneem het in die beheer en bevordering van die welvaart van die boere in die Suid-Afrikaanse Republiek is ' n voorbeeld van die voorgenoemde omwenteling in die ekonomiese en bedryfslewe teen die einde van die vorige eeu. Die staat het aanvanklik weinig gedoen vir die bevordering en beheer van die onderhoudsboerdery. Later, met die veranderde boerderyekonomie, het staatshulp, staatsvoorligting en -beheer egter noodsaaklik geword. Gedurende die laaste jare van die Suid- Afrikaanse Republiek het die owerheid meer en meer verpligtings teenoor die boeregemeenskap aanvaar. Namate die staat groter hulp en diens verskaf het, na dié mate moes hy ook groter beheer uitoefen.
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Date Issued: 1954

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Defoe and Scottish politics after union

- Gathorne, R

Authors: Gathorne, R
Date: 1954
Subjects: Defoe, Daniel, 1661?-1731 -- Political and social views , Scotland -- History -- 1689-1745
Language: English
Type: Thesis , Masters , MA
Identifier: vital:2605 , http://hdl.handle.net/10962/d1011941
Description: It would indeed have been a difficult matter for anybody possessing a taste for self-expression, a facility with words and an insatiable imagination to avoid becoming involved in political controversy in England during the early part of the Eighteenth Century. For one who, in addition, was confident in his ability to solve problems of state of whatever complexity it was clearly an impossibility. Daniel Defoe's close connection with politics during the first years of the Eighteenth Century involved him in numerous hardships. In later years it brought him much less fame than his excursions into fiction; but it was the means of providing him, albeit sparsely at times, with sufficient money to keep his creditors at bay. On more than one occasion the protection he gained helped to rescue him from imprisonment. Intro., p. 1.
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Date Issued: 1954

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Die aktualiteit in die poësie van A Roland Holst

- Bezuidenhout, Gertruida Catharina

Authors: Bezuidenhout, Gertruida Catharina
Date: 1954
Subjects: Roland Holst, Adrianus, 1888-1976 -- Criticism and interpretation , Dutch poetry -- 20th century -- History and criticism
Language: Afrikaans
Type: Thesis , Masters , MA
Identifier: vital:3639 , http://hdl.handle.net/10962/d1013499
Description: From Verantwoording: By die ondersoek na die rol wat die aktualiteit in die poësie van A. Roland Holst speel, wou ons veral nagaan of die gedigte waarin elemente van die aktualiteit aanwesig is, in wese van sy orige werk verskil. Hoofstuk II, “Teen die Wereld” gaan veral sover dit die inhoud betref, op hierdie vraag in. In die derde en vierde hoofstukke is na aanleiding van ‘n aantal verteenwoordigende gedigte getrag om meer in besonderhede, en ook wat die vorm aangaan, die saak van nader te beskou, en die resultate van die ondersoek is in die Slotbeskouing saamgevat.
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Date Issued: 1954

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