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Sebene

- Martin Lompela, Performer not specified, Composer not specified, Tracey, Hugh

Sendifun'ukubema

- Snowy Radebe and Company, Performer not specified, Composer not specified, Tracey, Hugh

Sendifun'ukubema

- Snowy Radebe and Company, Performer not specified, Composer not specified, Tracey, Hugh

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

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.
  • Full Text:
  • Date Issued: 1953

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.
  • Full Text:
  • Date Issued: 1953

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

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.
  • Full Text:
  • Date Issued: 1953

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.
  • Full Text:
  • Date Issued: 1953

Title not specified

- Performer not specified, Composer not specified, Tracey, Hugh

Title not specified

- Performer not specified, Composer not specified, Tracey, Hugh

Title not specified

- Performer not specified, Composer not specified, Tracey, Hugh

Ubani ozosithinta

- Home Division N .Q, Zwane .S, Recordist not specified

Unamashende

- Home Division N .Q, Zwane .S, Recordist not specified

Wemfo ka Zwane

- Home Division N .Q, Zwane .S, Recordist not specified

Zimbambe Ndoda

- Home Division N .Q, Zwane .S, Recordist not specified

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