Studies in Carangid fishes No.6: key to the western Indian Ocean species of the Genus Carangoides Bleeker, 1851, with a description of Carangoides Nitidus Smith
- Authors: Smith, Margaret M
- Date: 1972
- Language: English
- Type: text , Article
- Identifier: vital:7124 , http://hdl.handle.net/10962/d1004450
- Description: From introduction: Fishes in the family Carangidae commonly known as Jacks or Kingfishes are generally characterised by a silvery ovate body with s mall insignificant cycloid scales,a lateral line with curved anterior portion and a posterior straight portion bearing scules, a moderate mouth usually with feeble teeth, no dorsal and anal finlets, and a deeply forked caudal with a slender peduncle. A horizontally forwardly directed spine from the dorsal pterygiophore visible in front of the dorsal fin in shrunken or dried specimens, and the first two anal spines separate from the third and the rest of the fin are more pronounced in juvenile specimens.
- Full Text:
- Authors: Smith, Margaret M
- Date: 1972
- Language: English
- Type: text , Article
- Identifier: vital:7124 , http://hdl.handle.net/10962/d1004450
- Description: From introduction: Fishes in the family Carangidae commonly known as Jacks or Kingfishes are generally characterised by a silvery ovate body with s mall insignificant cycloid scales,a lateral line with curved anterior portion and a posterior straight portion bearing scules, a moderate mouth usually with feeble teeth, no dorsal and anal finlets, and a deeply forked caudal with a slender peduncle. A horizontally forwardly directed spine from the dorsal pterygiophore visible in front of the dorsal fin in shrunken or dried specimens, and the first two anal spines separate from the third and the rest of the fin are more pronounced in juvenile specimens.
- Full Text:
Teacher training : objectives and objections : inaugural lecture delivered at Rhodes University
- Authors: Noble, Arthur
- Date: 1972
- Subjects: Teachers -- Training of
- Language: English
- Type: Text
- Identifier: vital:655 , http://hdl.handle.net/10962/d1020724
- Description: Inaugural lecture delivered at Rhodes University , Rhodes University Libraries (Digitisation)
- Full Text:
- Authors: Noble, Arthur
- Date: 1972
- Subjects: Teachers -- Training of
- Language: English
- Type: Text
- Identifier: vital:655 , http://hdl.handle.net/10962/d1020724
- Description: Inaugural lecture delivered at Rhodes University , Rhodes University Libraries (Digitisation)
- Full Text:
The geography of the Bedford, Adelaide, Fort Beaufort, Stockenström and Victoria East magisterial districts
- Authors: Childs, Nicol Treloar
- Date: 1972
- Subjects: Eastern Cape (South Africa) -- Geography , Land use, Rural -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:4861 , http://hdl.handle.net/10962/d1006845 , Eastern Cape (South Africa) -- Geography , Land use, Rural -- South Africa -- Eastern Cape
- Description: From introduction: This is a study of the physical landscape, climate, natural vegetation, historical geography and rural land use of the Bedford, Adelaide, Fort Beaufort, Stockenström and Victoria East magisterial districts. These five districts may be regarded as a natural region bounded by the crest of the Amatole-Winterberg range in the north and by the Great Fish River in the west. The southern boundary is a zone of semi-arid scrub bordering the Great Fish River valley. The Ciskei may be regarded as the eastern boundary of the region.
- Full Text:
- Authors: Childs, Nicol Treloar
- Date: 1972
- Subjects: Eastern Cape (South Africa) -- Geography , Land use, Rural -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:4861 , http://hdl.handle.net/10962/d1006845 , Eastern Cape (South Africa) -- Geography , Land use, Rural -- South Africa -- Eastern Cape
- Description: From introduction: This is a study of the physical landscape, climate, natural vegetation, historical geography and rural land use of the Bedford, Adelaide, Fort Beaufort, Stockenström and Victoria East magisterial districts. These five districts may be regarded as a natural region bounded by the crest of the Amatole-Winterberg range in the north and by the Great Fish River in the west. The southern boundary is a zone of semi-arid scrub bordering the Great Fish River valley. The Ciskei may be regarded as the eastern boundary of the region.
- Full Text:
The geology of a portion of the country between Witvlei and Omitara, South West Africa
- Fey, P
- Authors: Fey, P
- Date: 1972
- Subjects: Petrology -- Namibia , Stratigraphy -- Namibia , Mineralogy -- Namibia , Geology -- Namibia
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5052 , http://hdl.handle.net/10962/d1011821
- Description: A brief account of the location and physical aspects of the region is followed by descriptions of mapping and laboratory techniques employed. Recent ideas on regional stratigraphical correlation in South West Africa are critically reviewed. Strata lying southeast of the farm Losberg 105 have, on the basis of lithology and copper mineralisation, been correlated with the Tsumis Formation. The Hasib Formation, of predominantly marine character, has on structural grounds been excluded from the Damara System. The latter here has a greater thickness than elsewhere in South West Africa, unless isoclinal folding is much more prevalent than has been assumed. The occurrence on Eintracht 118 of a pebble conglomerate, tentatively equated with the Chuos Tillite, makes possible a subdivision of the Damara strata into the various series established in the literature. It has been found possible to differentiate between Kamtsas and Damara quartzites on petrological grounds. Further, it is concluded that the bulk of Hakos carbonate rocks originated as dolomites and have subsequently been dedolomitized to a greater or lesser extent. The area contains both ortho- and para-amphibolites, as well as one occurrence of intrusive granite. Evidence is given for at least three periods of deformation. It is oonsidered that, if the Hosib Formation was involved in a pre-Damara orogenic episode, later folding must have been co-axial with this. Sedimentation and metamorphism are treated in broad outline. There appears to have been a deepening of the basin of deposition from Hasib to Damara times. Cyclicity in sedimentation is evidenced by lithological associations in the Damara strata. The entire area falls into the greenschist facies of regional metamorphism. Superficial deposits include river gravel and, silt, quartzite- and vein quartz-rubble, calcrete and Kalahari sand. The economic geology is described with special reference to the widespread copper mineralisation.
- Full Text:
- Authors: Fey, P
- Date: 1972
- Subjects: Petrology -- Namibia , Stratigraphy -- Namibia , Mineralogy -- Namibia , Geology -- Namibia
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5052 , http://hdl.handle.net/10962/d1011821
- Description: A brief account of the location and physical aspects of the region is followed by descriptions of mapping and laboratory techniques employed. Recent ideas on regional stratigraphical correlation in South West Africa are critically reviewed. Strata lying southeast of the farm Losberg 105 have, on the basis of lithology and copper mineralisation, been correlated with the Tsumis Formation. The Hasib Formation, of predominantly marine character, has on structural grounds been excluded from the Damara System. The latter here has a greater thickness than elsewhere in South West Africa, unless isoclinal folding is much more prevalent than has been assumed. The occurrence on Eintracht 118 of a pebble conglomerate, tentatively equated with the Chuos Tillite, makes possible a subdivision of the Damara strata into the various series established in the literature. It has been found possible to differentiate between Kamtsas and Damara quartzites on petrological grounds. Further, it is concluded that the bulk of Hakos carbonate rocks originated as dolomites and have subsequently been dedolomitized to a greater or lesser extent. The area contains both ortho- and para-amphibolites, as well as one occurrence of intrusive granite. Evidence is given for at least three periods of deformation. It is oonsidered that, if the Hosib Formation was involved in a pre-Damara orogenic episode, later folding must have been co-axial with this. Sedimentation and metamorphism are treated in broad outline. There appears to have been a deepening of the basin of deposition from Hasib to Damara times. Cyclicity in sedimentation is evidenced by lithological associations in the Damara strata. The entire area falls into the greenschist facies of regional metamorphism. Superficial deposits include river gravel and, silt, quartzite- and vein quartz-rubble, calcrete and Kalahari sand. The economic geology is described with special reference to the widespread copper mineralisation.
- Full Text:
The geology of the Shamrocke Mine and surrounding area, Rhodesia
- Authors: Kyle, Derek Lyndon
- Date: 1972
- Subjects: Shamrocke Mine -- Zimbabwe , Copper mines and mining -- Zimbabwe , Copper ores -- Zimbabwe , Formations (Geology) -- Zimbabwe , Petrology -- Zimbabwe , Geology -- Zimbabwe , Mineralogy -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5070 , http://hdl.handle.net/10962/d1013473
- Description: The geology of the Shamrocke area is described relative to its regional setting and position within the stratigraphic succession of the Lomagundi System. The stratigraphy in the immediate vicinity of the Shamrocke Mine is detailed and discussed relative to the work of others south of the project area and in other regions. The petrography of the rocks of the Shamrocke Mine area is described and the results of a great deal of mineralogical work recorded. Maps of the project area are presented at various scales from field and photogeological evidence. The thesis area is situated on the South Zambezi Escarpment of Rhodesia, and the geology described included the basaI succession of the Lomagundi System and the pre-Lomagundi Escarpment Series. The Shamrocke Mine is located on a copper orebody associated with a granulite or granofels zone within the Dolomite Series of the Lomagundi System. This ore zone granulite appears to be a metasomatised calcareous grit some 1000 feet above the upper contact of the Deweras Series (basal Lomagundi) and, within the graphitic schist and phyllite, below a dolomitic horizon in the Dolomite Series. The Lomagundi succession in the Mine area unconformably overlies the pre-Lomagundi gneiss and meta-arkose of the older, metamorphosed and deformed Escarpment Series. The basal meta-arkose, meta-quartzite and coarse schist of the Deweras Series ascends southwards through the Dolomite Series (graphitic phyllite and schist, granulite, calcareous grit, dolomite, limestone), and the Argillaceous Series (schist, phyllite, quartzite), the beds dipping steeply to the south at an angle of between 50º and 70º. Post-Lomagundi plagioclase amphibolite (altered, intrusive meta-diabase) forms Iarge semi-concordant and transgressive sills throughout the area, particularly along the contact between the Deweras and Dolomite Series. The Shamrocke Mine is on the northern limb of a large synclinal structure, the Rusere Syncline, which forms a large embayment of Lomagundi rocks into the pre-Lomagundi gneisses and granodiorites northeast from the Mine. The fold is overturned to the east and southeast. The copper mineralisation within the area and in the areas to the south is considered to be invariably associated with the basal rocks of the Lomagundi System. It occurs within both the Deweras and Dolomite Series rocks and more often than not Iies close to the contact between these two Series. The sulphide mineralisation of the Shamrocke orebody is considered, from the results of the present study, to be metasomatically emplaced during carbonate metasomatism, either from an extraneous source or from within the ore zone rock itself. The present writer favours the origin of the copper sulphide to be original syngenetic sulphide of the basal rocks of the Lomagundi depository, which has been mobilised and metasomatically relocated, possibly by the effects of regional metamorphism related to intense deformation. It is perhaps not fortuitous that the majority of the copper occurrences in the area occur where the basaI beds of the succession have been cross-folded. The copper ore comprises a simple suite of minerals, the main constituents being chalcopyrite, cubanite and pyrrhotite. The deposit is compared relative to the other copper deposits of the Lomagundi System.
- Full Text:
- Authors: Kyle, Derek Lyndon
- Date: 1972
- Subjects: Shamrocke Mine -- Zimbabwe , Copper mines and mining -- Zimbabwe , Copper ores -- Zimbabwe , Formations (Geology) -- Zimbabwe , Petrology -- Zimbabwe , Geology -- Zimbabwe , Mineralogy -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5070 , http://hdl.handle.net/10962/d1013473
- Description: The geology of the Shamrocke area is described relative to its regional setting and position within the stratigraphic succession of the Lomagundi System. The stratigraphy in the immediate vicinity of the Shamrocke Mine is detailed and discussed relative to the work of others south of the project area and in other regions. The petrography of the rocks of the Shamrocke Mine area is described and the results of a great deal of mineralogical work recorded. Maps of the project area are presented at various scales from field and photogeological evidence. The thesis area is situated on the South Zambezi Escarpment of Rhodesia, and the geology described included the basaI succession of the Lomagundi System and the pre-Lomagundi Escarpment Series. The Shamrocke Mine is located on a copper orebody associated with a granulite or granofels zone within the Dolomite Series of the Lomagundi System. This ore zone granulite appears to be a metasomatised calcareous grit some 1000 feet above the upper contact of the Deweras Series (basal Lomagundi) and, within the graphitic schist and phyllite, below a dolomitic horizon in the Dolomite Series. The Lomagundi succession in the Mine area unconformably overlies the pre-Lomagundi gneiss and meta-arkose of the older, metamorphosed and deformed Escarpment Series. The basal meta-arkose, meta-quartzite and coarse schist of the Deweras Series ascends southwards through the Dolomite Series (graphitic phyllite and schist, granulite, calcareous grit, dolomite, limestone), and the Argillaceous Series (schist, phyllite, quartzite), the beds dipping steeply to the south at an angle of between 50º and 70º. Post-Lomagundi plagioclase amphibolite (altered, intrusive meta-diabase) forms Iarge semi-concordant and transgressive sills throughout the area, particularly along the contact between the Deweras and Dolomite Series. The Shamrocke Mine is on the northern limb of a large synclinal structure, the Rusere Syncline, which forms a large embayment of Lomagundi rocks into the pre-Lomagundi gneisses and granodiorites northeast from the Mine. The fold is overturned to the east and southeast. The copper mineralisation within the area and in the areas to the south is considered to be invariably associated with the basal rocks of the Lomagundi System. It occurs within both the Deweras and Dolomite Series rocks and more often than not Iies close to the contact between these two Series. The sulphide mineralisation of the Shamrocke orebody is considered, from the results of the present study, to be metasomatically emplaced during carbonate metasomatism, either from an extraneous source or from within the ore zone rock itself. The present writer favours the origin of the copper sulphide to be original syngenetic sulphide of the basal rocks of the Lomagundi depository, which has been mobilised and metasomatically relocated, possibly by the effects of regional metamorphism related to intense deformation. It is perhaps not fortuitous that the majority of the copper occurrences in the area occur where the basaI beds of the succession have been cross-folded. The copper ore comprises a simple suite of minerals, the main constituents being chalcopyrite, cubanite and pyrrhotite. The deposit is compared relative to the other copper deposits of the Lomagundi System.
- Full Text:
The great bonds : nature, law and grace in "King Lear", "Antony and Cleopatra" and "Macbeth"
- Authors: Simpson, Mary-Helen Dawn
- Date: 1972
- Subjects: Shakespeare, William, 1564-1616. Macbeth , Shakespeare, William, 1564-1616. Antony and Cleopatra , Shakespeare, William, 1564-1616. King Lear
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2315 , http://hdl.handle.net/10962/d1013229
- Description: By looking at the world inhabited by those characters who partake of the dramatic action in King Lear, Antony and Cleopatra and Macbeth, and the relationship of these characters to their world, or universe, it is hoped to establish how certain factors affect the genesis, development and resolution of the tragedies in which they play their roles. This will be done by an examination of what Shakespeare sometimes called the "Bonds," which, as we shall see, derive from the mediaeval concepts of Nature, Law and Grace that were current in his time. This thesis does not claim to offer a complete or exclusive solution to the problem of the critical interpretation of these three tragedies: one of the dangers of Literary criticism has always appeared to the writer to be that of maintaining that the approach adopted is the only one and of attempting to demonstrate that the theory coincides at every point with the work - admitting of no inconsistencies or alternatives, and thereby making nonsense of a theory that does have considerable validiity. Similarly, it is with considerable hesitation that names have been given to the various Bonds discussed. Once one names them and applies a certain range of definitions to these names, it is difficult to stress that the names and definitions are not static or rigid. The Bond of Nature, for example, although it has a central core of meaning common to all three tragedies, is not treated from the same viewpoint in King Lear as it is in Antony and Cleopatra or Macbeth. Three considerations have prompted the writer to select this subject for the theme of a thesis. Firstly , the hypothesis that some failure, violation, misunderstanding or inadequacy of the Bonds lies at the heart of the tragic movement does appear to augment existing concepts of the nature of tragedy and help us better to understand the Why? How? and When? of the tragic process. Secondly, the concept of the principles of Nature, Law and Grace as determinants of the Bonds, which occurs so frequently in Elizabethan thinking, does seem to offer us a unified approach to their treatment of man and the world he inhabits at any particular point in history. By quoting from a wide range of sources dealing with this subject, the writer hopes to demonstrate that such a concept did exist, and that it was relatively consistent and generally accepted by Shakespeare and many of his contemporaries. It is, moreover, a system of thought that can embrace within its ambit such diverse materials as the great chain of being; the microcosm and the macrocosm; the nature of the soul; the structure of the family, the clan or the nation; the concepts of sin, damnation and life everlasting; the four elements; and the humours - and assign to these and many others a proper nature, place and function in the overall scheme. Thirdly, the writer was prompted to select this subject for a thesis because no critical writing to date appears to have dealt fully with the subject of the Bonds and their relationship to these principles of Nature, Law and Grace in Shakespearean tragedy . There have, it is true, been critics who have dealt with facets of these principles, and there have been critics who have commented on the violation, misunderstanding or inadequacy of various Bonds, but none of them seems to have dealt with the subject as a whole. Preface, p. iv-vi.
- Full Text:
- Authors: Simpson, Mary-Helen Dawn
- Date: 1972
- Subjects: Shakespeare, William, 1564-1616. Macbeth , Shakespeare, William, 1564-1616. Antony and Cleopatra , Shakespeare, William, 1564-1616. King Lear
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2315 , http://hdl.handle.net/10962/d1013229
- Description: By looking at the world inhabited by those characters who partake of the dramatic action in King Lear, Antony and Cleopatra and Macbeth, and the relationship of these characters to their world, or universe, it is hoped to establish how certain factors affect the genesis, development and resolution of the tragedies in which they play their roles. This will be done by an examination of what Shakespeare sometimes called the "Bonds," which, as we shall see, derive from the mediaeval concepts of Nature, Law and Grace that were current in his time. This thesis does not claim to offer a complete or exclusive solution to the problem of the critical interpretation of these three tragedies: one of the dangers of Literary criticism has always appeared to the writer to be that of maintaining that the approach adopted is the only one and of attempting to demonstrate that the theory coincides at every point with the work - admitting of no inconsistencies or alternatives, and thereby making nonsense of a theory that does have considerable validiity. Similarly, it is with considerable hesitation that names have been given to the various Bonds discussed. Once one names them and applies a certain range of definitions to these names, it is difficult to stress that the names and definitions are not static or rigid. The Bond of Nature, for example, although it has a central core of meaning common to all three tragedies, is not treated from the same viewpoint in King Lear as it is in Antony and Cleopatra or Macbeth. Three considerations have prompted the writer to select this subject for the theme of a thesis. Firstly , the hypothesis that some failure, violation, misunderstanding or inadequacy of the Bonds lies at the heart of the tragic movement does appear to augment existing concepts of the nature of tragedy and help us better to understand the Why? How? and When? of the tragic process. Secondly, the concept of the principles of Nature, Law and Grace as determinants of the Bonds, which occurs so frequently in Elizabethan thinking, does seem to offer us a unified approach to their treatment of man and the world he inhabits at any particular point in history. By quoting from a wide range of sources dealing with this subject, the writer hopes to demonstrate that such a concept did exist, and that it was relatively consistent and generally accepted by Shakespeare and many of his contemporaries. It is, moreover, a system of thought that can embrace within its ambit such diverse materials as the great chain of being; the microcosm and the macrocosm; the nature of the soul; the structure of the family, the clan or the nation; the concepts of sin, damnation and life everlasting; the four elements; and the humours - and assign to these and many others a proper nature, place and function in the overall scheme. Thirdly, the writer was prompted to select this subject for a thesis because no critical writing to date appears to have dealt fully with the subject of the Bonds and their relationship to these principles of Nature, Law and Grace in Shakespearean tragedy . There have, it is true, been critics who have dealt with facets of these principles, and there have been critics who have commented on the violation, misunderstanding or inadequacy of various Bonds, but none of them seems to have dealt with the subject as a whole. Preface, p. iv-vi.
- Full Text:
The novelistic documentary : a study of the non-fiction novel
- Authors: Visser, N W
- Date: 1972
- Subjects: Nonfiction novel , Reportage literature -- History and criticism
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2316 , http://hdl.handle.net/10962/d1013280
- Full Text:
- Authors: Visser, N W
- Date: 1972
- Subjects: Nonfiction novel , Reportage literature -- History and criticism
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2316 , http://hdl.handle.net/10962/d1013280
- Full Text:
Theoretical aspects of the generation of radio noise by the planet Jupiter
- Authors: Deift, Percy A
- Date: 1972
- Subjects: Jupiter (Planet) , Radio astronomy , Radio noise
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5516 , http://hdl.handle.net/10962/d1011051 , Jupiter (Planet) , Radio astronomy , Radio noise
- Description: Decameter radiation was first observed from Jupiter by Burke and Franklin (JGR 60, 213, 1955). In 1964 Bigg (Nature, 203, 1008, (1964)) found that 1o exerted a profound effect on the radiation. The majority of the early theories to explain the origin of the decameter emissions, attributed the radiation to an emission process occurring at or near the electron gyrofrequency or the plasma frequency. Intro., p. 1. The majority of the early theories to explain the origin of the decameter emissions, attributed the radiation to an emission process occurring at or near the electron gyrofrequency or the plasma frequency (for a review see eg. Warwick, Space Sci. Rev. &" 841 (1967)). More recent work centred around the question of how 10 modulates the emission (see the article of Carr and Gulkis (Annual Review of Astronomy and Astrophysics Vol 8 (1970)) for a detailed review).
- Full Text:
- Authors: Deift, Percy A
- Date: 1972
- Subjects: Jupiter (Planet) , Radio astronomy , Radio noise
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5516 , http://hdl.handle.net/10962/d1011051 , Jupiter (Planet) , Radio astronomy , Radio noise
- Description: Decameter radiation was first observed from Jupiter by Burke and Franklin (JGR 60, 213, 1955). In 1964 Bigg (Nature, 203, 1008, (1964)) found that 1o exerted a profound effect on the radiation. The majority of the early theories to explain the origin of the decameter emissions, attributed the radiation to an emission process occurring at or near the electron gyrofrequency or the plasma frequency. Intro., p. 1. The majority of the early theories to explain the origin of the decameter emissions, attributed the radiation to an emission process occurring at or near the electron gyrofrequency or the plasma frequency (for a review see eg. Warwick, Space Sci. Rev. &" 841 (1967)). More recent work centred around the question of how 10 modulates the emission (see the article of Carr and Gulkis (Annual Review of Astronomy and Astrophysics Vol 8 (1970)) for a detailed review).
- Full Text:
Thermal decomposition of ammonium metavanadate
- Authors: Stewart, Brian Victor
- Date: 1972
- Subjects: Decomposition (Chemistry) , Solids -- Thermal properties , Ammonia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4503 , http://hdl.handle.net/10962/d1013274
- Description: The isothermal, endothermic, stepwise decomposition of ammonium metavanadate (AMV) in inert (argon or nitrogen), oxidising (air or oxygen) and reducing (ammonia) atmospheres as well as under high vacuum (pressure < IOn bar) conditions has been investigated. The reverse reaction, the isothermal recombination of V₂ 0₅ with ammonia and water vapour has also been investigated. The decomposition and recombination reactions were followed by continuously recording the mass loss of the sample with time using a Cahn R.G. Automatic Electrobalance. This enabled small samples ( ~ lOmg) to be used and consequently any self cooling of the sample during the decomposition was minimized. The intermediates and final products formed have been characterized by chemical analysis, X-ray powder diffraction studies, infrared spectroscopy and the mass loss involved in their formation. The changes in the physical properties of the samples during decomposition and recombination have been investigated by surface area measurements (using the BET method and krypton adsorption) and eIectron microscopy. Values for the enthalpy changes involved in the decomposition have been obtained by differential scanning calorimetry. The stoichiometry of the isothermal decomposition of ammonium metavanadate, under the various conditions of surrounding atmosphere has been discussed. Except for the later stages of the decomposition in ammonia, the results correspond well to the gradual reduction of the ratio of "(NH₄)₂ 0" to "V₂0₅" units from the original 1:1 ratio in ammonium metavanadate to pure "V₂0₅" with ammonia and water being evolved throughout the decomposition in the mole ratio of 2:1. The final product of the decomposition in vacuum, argon and air is "V₂0₅" and in ammonia, below 360°, V0₂. The kinetic parameters for each of the stages of the decomposition of AMV in each of the atmospheres studied have been determined. The mechanism of the first stage of the decomposition under the different conditions of surrounding atmosphere has been discussed from both the kinetic and the thermodynamic points of view. The absolute reaction rate theory has been applied to the decomposition in inert atmospheres enabling the formulae of the activated complexes formed during each stage to be calculated. It has also been shown that the detailed atomic movements occurring during the first stage of the decomposition in ammonia can be predicted from a knowledge of the stoichiometry of the reaction and of the detailed crystal structures of the starting and product materials. The kinetics and mechanism of the recombination of "V₂0₅" with ammonia and water vapour to form AMV have also been discussed in detail.
- Full Text:
- Authors: Stewart, Brian Victor
- Date: 1972
- Subjects: Decomposition (Chemistry) , Solids -- Thermal properties , Ammonia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4503 , http://hdl.handle.net/10962/d1013274
- Description: The isothermal, endothermic, stepwise decomposition of ammonium metavanadate (AMV) in inert (argon or nitrogen), oxidising (air or oxygen) and reducing (ammonia) atmospheres as well as under high vacuum (pressure < IOn bar) conditions has been investigated. The reverse reaction, the isothermal recombination of V₂ 0₅ with ammonia and water vapour has also been investigated. The decomposition and recombination reactions were followed by continuously recording the mass loss of the sample with time using a Cahn R.G. Automatic Electrobalance. This enabled small samples ( ~ lOmg) to be used and consequently any self cooling of the sample during the decomposition was minimized. The intermediates and final products formed have been characterized by chemical analysis, X-ray powder diffraction studies, infrared spectroscopy and the mass loss involved in their formation. The changes in the physical properties of the samples during decomposition and recombination have been investigated by surface area measurements (using the BET method and krypton adsorption) and eIectron microscopy. Values for the enthalpy changes involved in the decomposition have been obtained by differential scanning calorimetry. The stoichiometry of the isothermal decomposition of ammonium metavanadate, under the various conditions of surrounding atmosphere has been discussed. Except for the later stages of the decomposition in ammonia, the results correspond well to the gradual reduction of the ratio of "(NH₄)₂ 0" to "V₂0₅" units from the original 1:1 ratio in ammonium metavanadate to pure "V₂0₅" with ammonia and water being evolved throughout the decomposition in the mole ratio of 2:1. The final product of the decomposition in vacuum, argon and air is "V₂0₅" and in ammonia, below 360°, V0₂. The kinetic parameters for each of the stages of the decomposition of AMV in each of the atmospheres studied have been determined. The mechanism of the first stage of the decomposition under the different conditions of surrounding atmosphere has been discussed from both the kinetic and the thermodynamic points of view. The absolute reaction rate theory has been applied to the decomposition in inert atmospheres enabling the formulae of the activated complexes formed during each stage to be calculated. It has also been shown that the detailed atomic movements occurring during the first stage of the decomposition in ammonia can be predicted from a knowledge of the stoichiometry of the reaction and of the detailed crystal structures of the starting and product materials. The kinetics and mechanism of the recombination of "V₂0₅" with ammonia and water vapour to form AMV have also been discussed in detail.
- Full Text:
Tom Brown in South Africa
- Authors: Honey, J R de S
- Date: 1972
- Subjects: Education -- South Africa -- History
- Language: English
- Type: Text
- Identifier: vital:638 , http://hdl.handle.net/10962/d1020707
- Description: Inaugural lecture delivered at Rhodes University , Rhodes University Libraries (Digitisation)
- Full Text:
- Authors: Honey, J R de S
- Date: 1972
- Subjects: Education -- South Africa -- History
- Language: English
- Type: Text
- Identifier: vital:638 , http://hdl.handle.net/10962/d1020707
- Description: Inaugural lecture delivered at Rhodes University , Rhodes University Libraries (Digitisation)
- Full Text: