Accuracy of the activation energy calculated from a thermoluminescence glow‐peak using a method that uses three points on the peak
- Ogundare, F O, Chithambo, Makaiko L
- Authors: Ogundare, F O , Chithambo, Makaiko L
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123016 , vital:35397 , https://doi:10.1002/pssc.200521077
- Description: The utility of thermoluminescence (TL) in detecting changes in defect concentration in insulators is well established [1–3]. The underlying premise leading to the emission of TL is that exposure of a material to ionizing radiation causes a redistribution of charge in defect centres within the material. When the material is heated at a controlled linear rate, the thermoluminescence is emitted as a temperature-dependent set of peaks collectively known as a glow-curve. The shape and intensity of each of the glow-peaks may be characterized by a set of parameters consisting of the activation energy E, the frequency factors, the number of electrons n0 trapped in defect centres at the start of the heating, and the order of kinetics b. The order of kinetics b is an indication of the retrapping probability i.e. the probability that a free electron from the conduction band will be retrapped rather than recombine with a hole at a recombination centre to produce thermoluminescence. Retrapping of electrons reduces the TL intensity at any particular temperature during the heating process. The physical mechanisms of TL associated with a given glow curve are unique and may be characterized by analysis of the glow-curve for the said kinetic parameters.
- Full Text:
- Date Issued: 2006
- Authors: Ogundare, F O , Chithambo, Makaiko L
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123016 , vital:35397 , https://doi:10.1002/pssc.200521077
- Description: The utility of thermoluminescence (TL) in detecting changes in defect concentration in insulators is well established [1–3]. The underlying premise leading to the emission of TL is that exposure of a material to ionizing radiation causes a redistribution of charge in defect centres within the material. When the material is heated at a controlled linear rate, the thermoluminescence is emitted as a temperature-dependent set of peaks collectively known as a glow-curve. The shape and intensity of each of the glow-peaks may be characterized by a set of parameters consisting of the activation energy E, the frequency factors, the number of electrons n0 trapped in defect centres at the start of the heating, and the order of kinetics b. The order of kinetics b is an indication of the retrapping probability i.e. the probability that a free electron from the conduction band will be retrapped rather than recombine with a hole at a recombination centre to produce thermoluminescence. Retrapping of electrons reduces the TL intensity at any particular temperature during the heating process. The physical mechanisms of TL associated with a given glow curve are unique and may be characterized by analysis of the glow-curve for the said kinetic parameters.
- Full Text:
- Date Issued: 2006
Trade and the environmental Kuznets curve: is Southern Africa a pollution haven?
- Nahman, Anton, Antrobus, Geoffrey G
- Authors: Nahman, Anton , Antrobus, Geoffrey G
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143202 , vital:38210 , DOI: 10.1111/j.1813-6982.2005.00055.x
- Description: Evidence that the environmental Kuznets curve (EKC) may be explained by trade patterns casts doubt on the oft‐stated conclusion that economic growth automatically leads to environmental improvement. Trends in net exports as a proportion of consumption for both USA and UK trade with SACU were examined for various dirty industries. Some evidence of pollution haven effects is found, although a similar trend for clean industries suggests that this effect is weak. However, even a general shift in manufacturing industries from North to South (as opposed to a shift in specifically dirty industries) may explain the EKC to some extent.
- Full Text:
- Date Issued: 2006
- Authors: Nahman, Anton , Antrobus, Geoffrey G
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143202 , vital:38210 , DOI: 10.1111/j.1813-6982.2005.00055.x
- Description: Evidence that the environmental Kuznets curve (EKC) may be explained by trade patterns casts doubt on the oft‐stated conclusion that economic growth automatically leads to environmental improvement. Trends in net exports as a proportion of consumption for both USA and UK trade with SACU were examined for various dirty industries. Some evidence of pollution haven effects is found, although a similar trend for clean industries suggests that this effect is weak. However, even a general shift in manufacturing industries from North to South (as opposed to a shift in specifically dirty industries) may explain the EKC to some extent.
- Full Text:
- Date Issued: 2006
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