A study of the E region of the ionosphere
- Authors: Barnard, A J
- Date: 1950
- Subjects: Ionosphere -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5549 , http://hdl.handle.net/10962/d1013464
- Description: After a brief historical introduction, the apparatus used in the investigation of the ionosphere in Grahamstown, is described with special reference to the recording equipment, which consists essentially of a camera focussed on the screen of a C.R.O. with z-axis deflection. The equations of the magneto-ionic theory are quoted. The basic formulae of the theories of layer formation in an isothermal (Chapman's),and linear temperature gradient (Gledhill and Szendrei) atmosphere are also quoted.
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- Date Issued: 1950
An investigation of certain complex ions of trivalent chromium by spectrophotometric and other physical methods
- Authors: Burley, Ralph Walter
- Date: 1950
- Subjects: Chromium
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4521 , http://hdl.handle.net/10962/d1014675
- Description: Although chromium coordination compounds are of considerable technological importance, they have been subjected to few thorough investigations since Werner's original experlments, in spite of the fact that we now possess a number of accurate physical methods, not available in Werner's time for the study of coordination complexes, The object of the work described in this thesis was to obtain further information on the chemistry of complex chromium(III) ions with special reference to the dioxalato-diaquochromiate system, [Cr(C₂0₄)₂(H₂0)₂]. For this purpose; spectrophotometric and potentlometrlc measurements were combined to yield information on a number of topics, The spectrophotometric investigations consisted in measuring the absorption spectra of the potassium salts of the complexes under consideration and in observing the changes in light absorption which occur during their formatlon and decomposition. The instrument used was a Beckmann Quartz Spectrophotometer model du. More than than twelve new absorption spectra were measured in this work and in conjunction with the spectra of other chromium and cobalt complexes reported by earlier workers, these are used to review the position of spectrophotometry as a method of investigating chromium complexes. The reasons for the shapes of the absorption spectra are discussed and it is concluded that spectrophotometry is useful for observing the progress of reactions involving complex ions and for analysing solutions, but that more fundamental data cannot be expected from the absorption curves.
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- Date Issued: 1950
Studies in the plant ecology of Fern Kloof near Grahamstown
- Authors: Seagrief, S C
- Date: 1950
- Subjects: Plant communities -- South Africa -- Eastern Cape , Plant ecology -- South Africa -- Eastern Cape , Plants -- South Africa -- Eastern Cape , Forest ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4267 , http://hdl.handle.net/10962/d1014299
- Description: The area studied at Fern Kloof, near Grahamstown, consists of a strip of vegetation approximately 260 yds. long and 50 yds. wide, in which there are two communities: 1) indigenous forest 2) exotic Pine forest (which has only one tree species Pinus pinaster). Throughout the thesis this species is referred to as the pine. The object of the investigation has been to determine whether these communities are natural or not. This has involved a study of the floristic composition, the life forms and the structure of the plant communities. In addition, various soil and environmental factors have been studied.
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- Date Issued: 1950