Comprehensive kinetic analysis of thermoluminescence peaks of α-Al2O3: C, Mg
- Kalita, Jitumani M, Chithambo, Makaiko L
- Authors: Kalita, Jitumani M , Chithambo, Makaiko L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/116142 , vital:34323 , https://doi.org/10.1016/j.jlumin.2017.01.003
- Description: A comprehensive kinetic analysis of the glow peaks in α-Al2O3:C,Mg is reported. A thermoluminescence glow curve measured at 1 °C/s after beta irradiation to 1 Gy shows a high intensity peak hereafter referred to as the main peak at 161 °C and six lower intensity secondary peaks at 42, 72, 193, 279, 330, 370 °C respectively. For ease of reference, the secondary peaks are labelled as I, II, IV, V, VI and VII respectively and the main peak denoted peak III. Kinetic analysis of the glow peaks has been carried out using the initial rise, whole glow peak, peak shape, variable heating rate and glow curve deconvolution methods as well as by way of phosphorescence. Using Tm-Tstop, Tm-dose and phosphorescence analyses, the order of kinetics of the peaks has been evaluated as first order. Analysis by the peak shape, whole glow peak and deconvolution methods produce the same conclusion. The activation energy of peaks I through VII are calculated as ~0.83, 0.96, 1.37, 1.20, 1.15, 1.61 and 1.94 eV respectively. The frequency factors for all the peaks are of the order of 109 to 1014 s−1. The question of thermal quenching affecting the peaks was considered. The peaks III, IV and V, the only ones that could be conveniently studied in this regard, were found to be affected by thermal quenching. The activation energy for thermal quenching was calculated for peak III as 0.96±0.03 eV, for peak VI as 0.95±0.07 eV and for peak V as 1.26±0.08 eV. The thermal quenching phenomenon has been discussed with reference to F+ and F centres. An energy band model has been developed to discuss the luminescence mechanisms in α-Al2O3:C,Mg in light of finding in this work.
- Full Text: false
- Date Issued: 2017
- Authors: Kalita, Jitumani M , Chithambo, Makaiko L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/116142 , vital:34323 , https://doi.org/10.1016/j.jlumin.2017.01.003
- Description: A comprehensive kinetic analysis of the glow peaks in α-Al2O3:C,Mg is reported. A thermoluminescence glow curve measured at 1 °C/s after beta irradiation to 1 Gy shows a high intensity peak hereafter referred to as the main peak at 161 °C and six lower intensity secondary peaks at 42, 72, 193, 279, 330, 370 °C respectively. For ease of reference, the secondary peaks are labelled as I, II, IV, V, VI and VII respectively and the main peak denoted peak III. Kinetic analysis of the glow peaks has been carried out using the initial rise, whole glow peak, peak shape, variable heating rate and glow curve deconvolution methods as well as by way of phosphorescence. Using Tm-Tstop, Tm-dose and phosphorescence analyses, the order of kinetics of the peaks has been evaluated as first order. Analysis by the peak shape, whole glow peak and deconvolution methods produce the same conclusion. The activation energy of peaks I through VII are calculated as ~0.83, 0.96, 1.37, 1.20, 1.15, 1.61 and 1.94 eV respectively. The frequency factors for all the peaks are of the order of 109 to 1014 s−1. The question of thermal quenching affecting the peaks was considered. The peaks III, IV and V, the only ones that could be conveniently studied in this regard, were found to be affected by thermal quenching. The activation energy for thermal quenching was calculated for peak III as 0.96±0.03 eV, for peak VI as 0.95±0.07 eV and for peak V as 1.26±0.08 eV. The thermal quenching phenomenon has been discussed with reference to F+ and F centres. An energy band model has been developed to discuss the luminescence mechanisms in α-Al2O3:C,Mg in light of finding in this work.
- Full Text: false
- Date Issued: 2017
Do microplastic loads reflect the population demographics along the southern African coastline?
- Nel, Holly A, Hean, Jeffrey W, Noundou, Xavier S, Froneman, P William
- Authors: Nel, Holly A , Hean, Jeffrey W , Noundou, Xavier S , Froneman, P William
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67961 , vital:29174 , https://doi.org/10.1016/j.marpolbul.2016.11.056
- Description: Publisher version , Plastic pollution is a major anthropogenic contaminant effecting the marine environment and is often associated with high human population densities and industrial activities. The microplastic (63 to 5000 μm) burden of beach sediment and surf-zone water was investigated at selected sites along the entire length of the South African coastline. It was predicted that samples collected in areas of high population density, would contain a higher microplastic burden than those along coasts that demonstrate very low population densities. With the exception of water column microplastics within Richard's Bay Harbour (413.3 ± 77.53 particles·m− 3) and Durban Harbour (1200 ± 133.2 particles·m− 3), there were no significant spatial differences in microplastic loads. This supports the theory that harbours act as a source of microplastics for the surrounding marine environment. Additionally, the absence of any spatial variation highlights the possible long range distribution of microplastic pollutants by large scale ocean currents.
- Full Text: false
- Date Issued: 2017
- Authors: Nel, Holly A , Hean, Jeffrey W , Noundou, Xavier S , Froneman, P William
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67961 , vital:29174 , https://doi.org/10.1016/j.marpolbul.2016.11.056
- Description: Publisher version , Plastic pollution is a major anthropogenic contaminant effecting the marine environment and is often associated with high human population densities and industrial activities. The microplastic (63 to 5000 μm) burden of beach sediment and surf-zone water was investigated at selected sites along the entire length of the South African coastline. It was predicted that samples collected in areas of high population density, would contain a higher microplastic burden than those along coasts that demonstrate very low population densities. With the exception of water column microplastics within Richard's Bay Harbour (413.3 ± 77.53 particles·m− 3) and Durban Harbour (1200 ± 133.2 particles·m− 3), there were no significant spatial differences in microplastic loads. This supports the theory that harbours act as a source of microplastics for the surrounding marine environment. Additionally, the absence of any spatial variation highlights the possible long range distribution of microplastic pollutants by large scale ocean currents.
- Full Text: false
- Date Issued: 2017
Education and the common good
- Authors: Lotz-Sisitka, Heila
- Date: 2017
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/126060 , vital:35846 , ISBN 9783319513225 , https://link.springer.com/chapter/10.1007/978-3-319-51322-5_5?utm_source=twitter&utm_medium=social&utm_content=ads&utm_campaign=SRHS_2_VB_Edu-Series-FTA-Nine#citeas , https://doi.org/10.1007/978-3-319-51322-5_5
- Description: The chapter responds to a recent invitation by the UNESCO to respond to the contents of their book on the purpose of education, entitled Rethinking Education: Towards a Global Common Good? I explore the concept of the common good (as it relates to concepts of commons and commoning activity) and what it might mean to engage with commoning as an educational activity, if the commons, as argued by Amin and Howell, is to be “released” from historical descriptions of commons and commoning activity, to embrace a futures orientation. Drawing on critical realism and decolonization theory, as well as experience of working with expansive social learning, I propose that an educational theory grounded in a concept of emergence is needed in such a context.
- Full Text: false
- Date Issued: 2017
- Authors: Lotz-Sisitka, Heila
- Date: 2017
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/126060 , vital:35846 , ISBN 9783319513225 , https://link.springer.com/chapter/10.1007/978-3-319-51322-5_5?utm_source=twitter&utm_medium=social&utm_content=ads&utm_campaign=SRHS_2_VB_Edu-Series-FTA-Nine#citeas , https://doi.org/10.1007/978-3-319-51322-5_5
- Description: The chapter responds to a recent invitation by the UNESCO to respond to the contents of their book on the purpose of education, entitled Rethinking Education: Towards a Global Common Good? I explore the concept of the common good (as it relates to concepts of commons and commoning activity) and what it might mean to engage with commoning as an educational activity, if the commons, as argued by Amin and Howell, is to be “released” from historical descriptions of commons and commoning activity, to embrace a futures orientation. Drawing on critical realism and decolonization theory, as well as experience of working with expansive social learning, I propose that an educational theory grounded in a concept of emergence is needed in such a context.
- Full Text: false
- Date Issued: 2017
Environmental and social recovery asymmetries to large-scale disturbances in small island communities
- Aswani, Shankar, Van Putten, Ingrid, Miñarro, Sara
- Authors: Aswani, Shankar , Van Putten, Ingrid , Miñarro, Sara
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67325 , vital:29073 , https://doi.org/10.1007/s11069-016-2685-2
- Description: publisher version , People’s livelihoods in tropical small-island developing states are greatly dependent on marine ecosystem services. Yet services such as fisheries and coastal buffering are being degraded at an alarming rate, thus making people increasing vulnerable to protracted and sudden environmental changes. In the context of the occurrences of extreme events such as earthquakes and tsunamis, it is vital to uncover the processes that make people in these island states resilient, or not, to environmental disruptions. This paper compares people’s perceptions of social and environmental impacts after an extreme event in the Western Solomon Islands (11 different villages on 8 different islands) to better understand how knowledge systems influence the coupling of human and natural systems. We examine the factors that contributed to perceptions of respective recovery in the environmental versus the social domains across communities with different traditional governance and modernization characteristics in a tsunami impact gradient. First, we separately assessed, at the community and individual level, the potential determinants of perceived recovery in the environmental and social domains. At the community level, the average values of the perceived environmental and social recovery were calculated for each community (1 year after the tsunami), and at the individual level, normally distributed environmental and social recovery variables (based on the difference in perceptions immediately and 1 year after the tsunami) were used as dependent variables in two General Linear Models. Results suggest that environmental and social resilience are not always coupled correspondingly and, less unexpectedly, that asymmetries during recovery can occur as a result of the underlying social and ecological context and existing adaptive capacity. More generally, the study shows how by evaluating post-disturbance perceptional data in tsunami-affected communities, we can better understand how subjective perceptions of change can affect the (de)-coupling of human and natural systems.
- Full Text: false
- Date Issued: 2017
- Authors: Aswani, Shankar , Van Putten, Ingrid , Miñarro, Sara
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67325 , vital:29073 , https://doi.org/10.1007/s11069-016-2685-2
- Description: publisher version , People’s livelihoods in tropical small-island developing states are greatly dependent on marine ecosystem services. Yet services such as fisheries and coastal buffering are being degraded at an alarming rate, thus making people increasing vulnerable to protracted and sudden environmental changes. In the context of the occurrences of extreme events such as earthquakes and tsunamis, it is vital to uncover the processes that make people in these island states resilient, or not, to environmental disruptions. This paper compares people’s perceptions of social and environmental impacts after an extreme event in the Western Solomon Islands (11 different villages on 8 different islands) to better understand how knowledge systems influence the coupling of human and natural systems. We examine the factors that contributed to perceptions of respective recovery in the environmental versus the social domains across communities with different traditional governance and modernization characteristics in a tsunami impact gradient. First, we separately assessed, at the community and individual level, the potential determinants of perceived recovery in the environmental and social domains. At the community level, the average values of the perceived environmental and social recovery were calculated for each community (1 year after the tsunami), and at the individual level, normally distributed environmental and social recovery variables (based on the difference in perceptions immediately and 1 year after the tsunami) were used as dependent variables in two General Linear Models. Results suggest that environmental and social resilience are not always coupled correspondingly and, less unexpectedly, that asymmetries during recovery can occur as a result of the underlying social and ecological context and existing adaptive capacity. More generally, the study shows how by evaluating post-disturbance perceptional data in tsunami-affected communities, we can better understand how subjective perceptions of change can affect the (de)-coupling of human and natural systems.
- Full Text: false
- Date Issued: 2017
Factors influencing the shape of CW-OSL signal obtained by stimulation of very deep traps in carbon-doped aluminium oxide: an experimental study
- Nyirenda, Angel N, Chithambo, Makaiko L
- Authors: Nyirenda, Angel N , Chithambo, Makaiko L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/115493 , vital:34149 , https://doi.org/10.1016/j.jlumin.2017.07.016
- Description: The optically stimulated luminescence from carbon-doped aluminium oxide (α-Al2O3:C) displays a peak with time under certain measurement conditions. In this paper, we present factors that influence the peak-like shape of continuous-wave optically stimulated luminescence (CW-OSL) signal. The report is based on the experimental study of OSL signals obtained by stimulation of very deep traps in α-Al2O3:C. Methods exploiting post-irradiation annealing, variable dose and temperature dependent OSL measurements were used in the investigation. It is found that the rising part of the CW-OSL peak is obtained when the rate of retrapping at the most optically active trap (main trap) exceeds the rate of direct radiative recombination following optical release of charges from all optically active traps. This is possible if, during optical stimulation, the primary trap responsible for OSL i.e. the main trap, is substantially unoccupied and the very deep, donor traps are substantially filled up. The rate of charge retrapping itself is deduced to depend on the occupancy of the acceptor traps i.e. shallow, main and secondary traps; concentration of charge carriers in the very deep, donor traps; the post-irradiation annealing temperature and the temperature at which the OSL is measured.
- Full Text: false
- Date Issued: 2017
- Authors: Nyirenda, Angel N , Chithambo, Makaiko L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/115493 , vital:34149 , https://doi.org/10.1016/j.jlumin.2017.07.016
- Description: The optically stimulated luminescence from carbon-doped aluminium oxide (α-Al2O3:C) displays a peak with time under certain measurement conditions. In this paper, we present factors that influence the peak-like shape of continuous-wave optically stimulated luminescence (CW-OSL) signal. The report is based on the experimental study of OSL signals obtained by stimulation of very deep traps in α-Al2O3:C. Methods exploiting post-irradiation annealing, variable dose and temperature dependent OSL measurements were used in the investigation. It is found that the rising part of the CW-OSL peak is obtained when the rate of retrapping at the most optically active trap (main trap) exceeds the rate of direct radiative recombination following optical release of charges from all optically active traps. This is possible if, during optical stimulation, the primary trap responsible for OSL i.e. the main trap, is substantially unoccupied and the very deep, donor traps are substantially filled up. The rate of charge retrapping itself is deduced to depend on the occupancy of the acceptor traps i.e. shallow, main and secondary traps; concentration of charge carriers in the very deep, donor traps; the post-irradiation annealing temperature and the temperature at which the OSL is measured.
- Full Text: false
- Date Issued: 2017
Features of an annealing-induced thermoluminescence peak in α-Al2O3: C, Mg
- Kalita, Jitumani M, Chithambo, Makaiko L
- Authors: Kalita, Jitumani M , Chithambo, Makaiko L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/116013 , vital:34289 , DOI: 10.1016/j.optmat.2017.05.034
- Description: We report the thermoluminescence glow curves of beta irradiated single crystal α-Al2O3:C,Mg after annealing at 700 and 900 °C. A glow curve measured at 1 °C/s from samples irradiated to 1 Gy following annealing at 700 and 900 °C shows a high intensity peak at 163 °C and seven secondary peaks of weaker intensity at 43, 73, 100, 195, 280, 329 and 370 °C. Comparing the position of the peaks in the annealed samples with those in an un-annealed one, it is observed that the peak at 100 °C appears only after annealing at and above 700 °C. Kinetic analysis of this annealing-induced peak was carried out using the initial rise, whole glow peak, peak shape, curve fitting and variable heating rate methods. The order of kinetics of the peak was determined as first order using various methods including the Tm-Tstop technique and the dependence of Tm on irradiation dose. The activation energy of the peak is about 1.01 eV and the frequency factor of the order of 1012 s−1. The peak was found to be affected by thermal quenching in analysis based on change of peak intensity with heating rate. The activation energy of thermal quenching was evaluated as 1.06 ± 0.08 eV. We speculate that the annealing-induced peak is due to formation of a new electron trap after destruction of the F22+(2 Mg) centre when the sample is annealed at 700 °C. The annealing-induced peak fades with storage between irradiation and measurement. It was also concluded that electrons from traps corresponding to secondary peaks get re-trapped at the main electron trap.
- Full Text: false
- Date Issued: 2017
- Authors: Kalita, Jitumani M , Chithambo, Makaiko L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/116013 , vital:34289 , DOI: 10.1016/j.optmat.2017.05.034
- Description: We report the thermoluminescence glow curves of beta irradiated single crystal α-Al2O3:C,Mg after annealing at 700 and 900 °C. A glow curve measured at 1 °C/s from samples irradiated to 1 Gy following annealing at 700 and 900 °C shows a high intensity peak at 163 °C and seven secondary peaks of weaker intensity at 43, 73, 100, 195, 280, 329 and 370 °C. Comparing the position of the peaks in the annealed samples with those in an un-annealed one, it is observed that the peak at 100 °C appears only after annealing at and above 700 °C. Kinetic analysis of this annealing-induced peak was carried out using the initial rise, whole glow peak, peak shape, curve fitting and variable heating rate methods. The order of kinetics of the peak was determined as first order using various methods including the Tm-Tstop technique and the dependence of Tm on irradiation dose. The activation energy of the peak is about 1.01 eV and the frequency factor of the order of 1012 s−1. The peak was found to be affected by thermal quenching in analysis based on change of peak intensity with heating rate. The activation energy of thermal quenching was evaluated as 1.06 ± 0.08 eV. We speculate that the annealing-induced peak is due to formation of a new electron trap after destruction of the F22+(2 Mg) centre when the sample is annealed at 700 °C. The annealing-induced peak fades with storage between irradiation and measurement. It was also concluded that electrons from traps corresponding to secondary peaks get re-trapped at the main electron trap.
- Full Text: false
- Date Issued: 2017
Ferrocenyl and organic novobiocin derivatives: synthesis and their in vitro biological activity
- Mbaba, Mziyanda, Mabhula, Amanda N, Boel, Natasha, Edkins, Adrienne L, Isaacs, Michelle, Hoppe, Heinrich C, Khanye, Setshaba D
- Authors: Mbaba, Mziyanda , Mabhula, Amanda N , Boel, Natasha , Edkins, Adrienne L , Isaacs, Michelle , Hoppe, Heinrich C , Khanye, Setshaba D
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66189 , vital:28914 , https://doi.org/10.1016/j.jinorgbio.2017.04.014
- Description: publisher version , A focused series of novobiocin derivatives containing a ferrocene unit together with their corresponding organic novobiocin analogues have been synthesized in modest to good yields. These compounds were screened for biological activity against a chloroquine-sensitive strain of Plasmodium falciparum (3D7) and human breast cancer cell line (HCC38). With the exception of compounds 5c and 5d, the general trend observed is that incorporation of the ferrocene moiety into novobiocin scaffold resulted in compounds 6a–d/6f showing enhanced activity compared to organic analogues 5a–b and 5e–f.
- Full Text: false
- Date Issued: 2017
- Authors: Mbaba, Mziyanda , Mabhula, Amanda N , Boel, Natasha , Edkins, Adrienne L , Isaacs, Michelle , Hoppe, Heinrich C , Khanye, Setshaba D
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66189 , vital:28914 , https://doi.org/10.1016/j.jinorgbio.2017.04.014
- Description: publisher version , A focused series of novobiocin derivatives containing a ferrocene unit together with their corresponding organic novobiocin analogues have been synthesized in modest to good yields. These compounds were screened for biological activity against a chloroquine-sensitive strain of Plasmodium falciparum (3D7) and human breast cancer cell line (HCC38). With the exception of compounds 5c and 5d, the general trend observed is that incorporation of the ferrocene moiety into novobiocin scaffold resulted in compounds 6a–d/6f showing enhanced activity compared to organic analogues 5a–b and 5e–f.
- Full Text: false
- Date Issued: 2017
Framing of transitional pedagogic practices in the sciences: enabling access
- Authors: Ellery, Karen
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66381 , vital:28942 , https://doi.org/10.1080/13562517.2017.1319812
- Description: publisher version , Educational literature shows that students from working-class backgrounds are significantly less likely to persist to completion in higher education than middle-class students. This paper draws theoretically and analytically on Bernstein’s ([1990. Class, Codes and Control, Volume IV: The Structuring of Pedagogic Discourse. London: Routledge; 2000. Pedagogy, Symbolic Control, and Identity: Theory, Research, Critique. Lanham: Rowman and Littlefield]) thesis that, through differential framing of pedagogic practices, the curriculum has capacity to accommodate all groups of students. Pedagogic practices in both a science foundation course and four first-year mainstream science courses in a higher education institution in the South African context are examined. Whilst the foundation course exhibits modalities that generally favour access, the mainstream courses have some modalities that appear to be constraining. It is argued from a social justice perspective that holistic curriculum transformations that better enable epistemic transitions are an urgent imperative, and that consideration of differential framing of pedagogic modalities offer a close-up empirical means of conceptualising such reforms.
- Full Text: false
- Date Issued: 2017
- Authors: Ellery, Karen
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66381 , vital:28942 , https://doi.org/10.1080/13562517.2017.1319812
- Description: publisher version , Educational literature shows that students from working-class backgrounds are significantly less likely to persist to completion in higher education than middle-class students. This paper draws theoretically and analytically on Bernstein’s ([1990. Class, Codes and Control, Volume IV: The Structuring of Pedagogic Discourse. London: Routledge; 2000. Pedagogy, Symbolic Control, and Identity: Theory, Research, Critique. Lanham: Rowman and Littlefield]) thesis that, through differential framing of pedagogic practices, the curriculum has capacity to accommodate all groups of students. Pedagogic practices in both a science foundation course and four first-year mainstream science courses in a higher education institution in the South African context are examined. Whilst the foundation course exhibits modalities that generally favour access, the mainstream courses have some modalities that appear to be constraining. It is argued from a social justice perspective that holistic curriculum transformations that better enable epistemic transitions are an urgent imperative, and that consideration of differential framing of pedagogic modalities offer a close-up empirical means of conceptualising such reforms.
- Full Text: false
- Date Issued: 2017
From contradictions to complementarities: a social realist analysis of the evolution of academic development within a department
- Case, Jennifer M, Heydenrych, Hilton, Kotta, Linda, Marshall, Delia, McKenna, Sioux, Willliams, Kevin
- Authors: Case, Jennifer M , Heydenrych, Hilton , Kotta, Linda , Marshall, Delia , McKenna, Sioux , Willliams, Kevin
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66752 , vital:28990 , ISSN 1470-1294 , https://doi.org/10.1080/03075079.2015.1045479
- Description: Publisher version , Academic development is a recent project in the university, intended to enable the university to respond to the needs of a more diverse student body. In South Africa, such work arose during late apartheid, and has now moved to a more central institutional position advocating responsiveness in the light of the educational disparities that are the legacy of apartheid. The present study uses a social realist perspective to analyse the 25-year evolution of an academic development project within an engineering department at a South African university. The findings show that while academic development initially posed a contradictory logic to the department, the response was to reform the nature of this project into one that suited the other commitments of the department: a logic of complementarity. The department's relationships with industry were shown to have played a key role in fostering this form of change.
- Full Text: false
- Date Issued: 2017
- Authors: Case, Jennifer M , Heydenrych, Hilton , Kotta, Linda , Marshall, Delia , McKenna, Sioux , Willliams, Kevin
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66752 , vital:28990 , ISSN 1470-1294 , https://doi.org/10.1080/03075079.2015.1045479
- Description: Publisher version , Academic development is a recent project in the university, intended to enable the university to respond to the needs of a more diverse student body. In South Africa, such work arose during late apartheid, and has now moved to a more central institutional position advocating responsiveness in the light of the educational disparities that are the legacy of apartheid. The present study uses a social realist perspective to analyse the 25-year evolution of an academic development project within an engineering department at a South African university. The findings show that while academic development initially posed a contradictory logic to the department, the response was to reform the nature of this project into one that suited the other commitments of the department: a logic of complementarity. The department's relationships with industry were shown to have played a key role in fostering this form of change.
- Full Text: false
- Date Issued: 2017
Fuelwood preferences, use and availability in the #Khomani San resettlement farms, southern Kalahari, South Africa
- Nott, Michelle, Thondhlana, Gladman
- Authors: Nott, Michelle , Thondhlana, Gladman
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67667 , vital:29127 , https://doi.org/10.1080/14728028.2017.1294507
- Description: Publisher version , Local level assessments of fuelwood preferences, demand and supply are important for ensuring a balance between ecological functions and livelihood needs. This study reports on an examination of fuelwood preferences, use and abundance in the #Khomani San resettlement farms in southern Kalahari, South Africa. The results show that Acacia erioloba was the most preferred fuelwood species, while Acacia mellifera was abundant but avoided. Across the study area, there were approximately 64 trees ha−1 but riverine sites had significantly more trees (approximately 80 trees ha−1) than non-riverine sites (48 trees ha−1). Live trees showed evidence of damage (cutting or breaking) and this was more pronounced in the riverine sites (close to human settlement) than in the non-riverine sites. However, overall current woody stocks and productivity rates of harvestable fuelwood are well above current fuelwood demand, suggesting fuelwood use may be within sustainable limits, though there is evidence of localised fuelwood depletion. The implications of these results for fuelwood management interventions, including the importance of context, are discussed.
- Full Text: false
- Date Issued: 2017
- Authors: Nott, Michelle , Thondhlana, Gladman
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67667 , vital:29127 , https://doi.org/10.1080/14728028.2017.1294507
- Description: Publisher version , Local level assessments of fuelwood preferences, demand and supply are important for ensuring a balance between ecological functions and livelihood needs. This study reports on an examination of fuelwood preferences, use and abundance in the #Khomani San resettlement farms in southern Kalahari, South Africa. The results show that Acacia erioloba was the most preferred fuelwood species, while Acacia mellifera was abundant but avoided. Across the study area, there were approximately 64 trees ha−1 but riverine sites had significantly more trees (approximately 80 trees ha−1) than non-riverine sites (48 trees ha−1). Live trees showed evidence of damage (cutting or breaking) and this was more pronounced in the riverine sites (close to human settlement) than in the non-riverine sites. However, overall current woody stocks and productivity rates of harvestable fuelwood are well above current fuelwood demand, suggesting fuelwood use may be within sustainable limits, though there is evidence of localised fuelwood depletion. The implications of these results for fuelwood management interventions, including the importance of context, are discussed.
- Full Text: false
- Date Issued: 2017
Generic gold standard or contextualised public good? Teaching excellence awards in post-colonial South Africa
- Behari-Leak, Kasturi, McKenna, Sioux
- Authors: Behari-Leak, Kasturi , McKenna, Sioux
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66774 , vital:28992 , ISSN 1470-1294 , https://doi.org/10.1080/13562517.2017.1301910
- Description: Publisher version , Teaching Excellence Awards have raised the profile of teaching as a scholarly project. There are however a number of questions about what constitutes teaching excellence and how ‘excellence’ is understood in current higher education. In a post-colonial South Africa, where significant injustices permeate our society, we question whether excellence can be understood in a generic manner. Furthermore, we argue that as universities are a public good, teaching excellence needs to explicitly attend to the ways in which universities contribute to broad goals of transformation and inclusivity. We analysed data from the national Teaching Excellence Awards and 13 South African universities’ awards to interrogate the discourses that underpin ‘excellence’ in this context of social inequality. We found that while the awards have gone some way to enhancing the position of teaching in institutions, ‘excellence’ was largely articulated in fairly generic ways which failed to take into account the enablements and constraints of the discipline and the institution. Furthermore, the guidelines and criteria privilege a decontextualised notion of excellence that seeks a ‘gold standard’ and validates performativity, rather than a contextualised response to the needs of the students.
- Full Text: false
- Date Issued: 2017
- Authors: Behari-Leak, Kasturi , McKenna, Sioux
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66774 , vital:28992 , ISSN 1470-1294 , https://doi.org/10.1080/13562517.2017.1301910
- Description: Publisher version , Teaching Excellence Awards have raised the profile of teaching as a scholarly project. There are however a number of questions about what constitutes teaching excellence and how ‘excellence’ is understood in current higher education. In a post-colonial South Africa, where significant injustices permeate our society, we question whether excellence can be understood in a generic manner. Furthermore, we argue that as universities are a public good, teaching excellence needs to explicitly attend to the ways in which universities contribute to broad goals of transformation and inclusivity. We analysed data from the national Teaching Excellence Awards and 13 South African universities’ awards to interrogate the discourses that underpin ‘excellence’ in this context of social inequality. We found that while the awards have gone some way to enhancing the position of teaching in institutions, ‘excellence’ was largely articulated in fairly generic ways which failed to take into account the enablements and constraints of the discipline and the institution. Furthermore, the guidelines and criteria privilege a decontextualised notion of excellence that seeks a ‘gold standard’ and validates performativity, rather than a contextualised response to the needs of the students.
- Full Text: false
- Date Issued: 2017
Kinetic analysis and general features of thermoluminescence of B2O3-Li2O-ZnF2 glass
- Thomas, Sunil, Chithambo, Makaiko L
- Authors: Thomas, Sunil , Chithambo, Makaiko L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/116154 , vital:34324 , https://doi.org/10.1016/j.radmeas.2017.03.038
- Description: The intention of this study is to explore the thermoluminescence of beta irradiated B2O3-Li2O-ZnF2 glass. The glow-curve corresponding to 200 Gy shows three peaks; two weak-intensity peaks at 60 and 243 °C and a more prominent one at 118 °C, when measured at 1 °C/s. The dose response of the main peak at 118 °C was found to be sublinear in the range 200–1000 Gy. Regarding the kinetic analysis of the main peak, the activation energy of the corresponding electron trap was evaluated as 0.96 eV and the frequency factor as ∼1011 s−1. It is proposed that the thermoluminescence in B2O3-Li2O-ZnF2 glass is due to recombination of electrons, thermally released from Zn+ ionic defect sites, with the holes at boron-oxygen hole centres.
- Full Text: false
- Date Issued: 2017
- Authors: Thomas, Sunil , Chithambo, Makaiko L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/116154 , vital:34324 , https://doi.org/10.1016/j.radmeas.2017.03.038
- Description: The intention of this study is to explore the thermoluminescence of beta irradiated B2O3-Li2O-ZnF2 glass. The glow-curve corresponding to 200 Gy shows three peaks; two weak-intensity peaks at 60 and 243 °C and a more prominent one at 118 °C, when measured at 1 °C/s. The dose response of the main peak at 118 °C was found to be sublinear in the range 200–1000 Gy. Regarding the kinetic analysis of the main peak, the activation energy of the corresponding electron trap was evaluated as 0.96 eV and the frequency factor as ∼1011 s−1. It is proposed that the thermoluminescence in B2O3-Li2O-ZnF2 glass is due to recombination of electrons, thermally released from Zn+ ionic defect sites, with the holes at boron-oxygen hole centres.
- Full Text: false
- Date Issued: 2017
Multilingualism and intercultural communication: a South African perspective
- Kaschula, Russell H, Maseko, Pamela, Wolff, H Ekkehard
- Authors: Kaschula, Russell H , Maseko, Pamela , Wolff, H Ekkehard
- Date: 2017
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/67015 , vital:29019 , ISBN 9781776140275 , https://muse.jhu.edu/book/52741
- Description: publisher version , To date, there has been no published textbook which takes into account changing sociolinguistic dynamics that have influenced South African society. Multilingualism and Intercultural Communication breaks new ground in this arena. Its scope ranges from macro-sociolinguistic questions pertaining to language policies and their implementation (or non-implementation), to micro-sociolinguistic observations of actual language-use in verbal interaction, mainly in multilingual contexts of Higher Education (HE). There is a gradual move for the study of language and culture to be taught in the context of (professional) disciplines in which they would be used, such as Journalism and African languages, Education and African languages, etc. The book caters for this growing market. Because of its multilingual nature, it caters to English and Afrikaans language speakers, as well as the Sotho and Nguni language groups. It brings together various inter-linked disciplines such as Sociolinguistics and Applied Language Studies, Media Studies and Journalism, History and Education, Social and Natural Sciences, Law, Human Language Technology, Music, Intercultural Communication and Literary Studies. The unique cross-cutting disciplinary features of the book will make it a must-have for twenty-first century South African students and scholars and those interested in applied language issues.
- Full Text: false
- Date Issued: 2017
- Authors: Kaschula, Russell H , Maseko, Pamela , Wolff, H Ekkehard
- Date: 2017
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/67015 , vital:29019 , ISBN 9781776140275 , https://muse.jhu.edu/book/52741
- Description: publisher version , To date, there has been no published textbook which takes into account changing sociolinguistic dynamics that have influenced South African society. Multilingualism and Intercultural Communication breaks new ground in this arena. Its scope ranges from macro-sociolinguistic questions pertaining to language policies and their implementation (or non-implementation), to micro-sociolinguistic observations of actual language-use in verbal interaction, mainly in multilingual contexts of Higher Education (HE). There is a gradual move for the study of language and culture to be taught in the context of (professional) disciplines in which they would be used, such as Journalism and African languages, Education and African languages, etc. The book caters for this growing market. Because of its multilingual nature, it caters to English and Afrikaans language speakers, as well as the Sotho and Nguni language groups. It brings together various inter-linked disciplines such as Sociolinguistics and Applied Language Studies, Media Studies and Journalism, History and Education, Social and Natural Sciences, Law, Human Language Technology, Music, Intercultural Communication and Literary Studies. The unique cross-cutting disciplinary features of the book will make it a must-have for twenty-first century South African students and scholars and those interested in applied language issues.
- Full Text: false
- Date Issued: 2017
New Beginnings in an Ancient Region: well-being in Sub-Saharan Africa
- Moller, Valerie, Roberts, Benjamin J
- Authors: Moller, Valerie , Roberts, Benjamin J
- Date: 2017
- Language: English
- Type: book chapter , text
- Identifier: http://hdl.handle.net/10962/61701 , vital:28050 , https://link.springer.com/chapter/10.1007/978-3-319-39101-4_7
- Description: In this chapter, we trace the well-being of people living in the sub-Saharan region of Africa over time, focusing on what are universally considered to be main ingredients of the good life in modern times: health, education, and the income and resources needed to meet basic needs and to prosper. The people of sub-Saharan Africa do not have a common identity, but we have isolated some of the experiences and commonalities that bind the people of the region. The glory of earlier civilizations and of traditional religious beliefs and rituals that cemented the social order and the disruption of African society by foreign incursions during the period of discovery and the Atlantic slave trade and colonialism all had their impact on the African imagination. Well-being in Africa south of the Sahara suffered when people living in Africa were oppressed and exploited between the fifteenth and early twentieth centuries. The winds of change in the 1960s brought freedom and a new sense of dignity. Since independence, there are signs of improvements in key domains of life, but the modern states of sub-Saharan Africa are still addressing the many political and development challenges they face. Optimism and resilience are characteristic of the people living south of the Sahara who have faith that their dreams of a better life will come true.
- Full Text: false
- Date Issued: 2017
- Authors: Moller, Valerie , Roberts, Benjamin J
- Date: 2017
- Language: English
- Type: book chapter , text
- Identifier: http://hdl.handle.net/10962/61701 , vital:28050 , https://link.springer.com/chapter/10.1007/978-3-319-39101-4_7
- Description: In this chapter, we trace the well-being of people living in the sub-Saharan region of Africa over time, focusing on what are universally considered to be main ingredients of the good life in modern times: health, education, and the income and resources needed to meet basic needs and to prosper. The people of sub-Saharan Africa do not have a common identity, but we have isolated some of the experiences and commonalities that bind the people of the region. The glory of earlier civilizations and of traditional religious beliefs and rituals that cemented the social order and the disruption of African society by foreign incursions during the period of discovery and the Atlantic slave trade and colonialism all had their impact on the African imagination. Well-being in Africa south of the Sahara suffered when people living in Africa were oppressed and exploited between the fifteenth and early twentieth centuries. The winds of change in the 1960s brought freedom and a new sense of dignity. Since independence, there are signs of improvements in key domains of life, but the modern states of sub-Saharan Africa are still addressing the many political and development challenges they face. Optimism and resilience are characteristic of the people living south of the Sahara who have faith that their dreams of a better life will come true.
- Full Text: false
- Date Issued: 2017
On the sensitivity of thermally and optically stimulated luminescence of α-Al2O3: C and α-Al2O3: C, Mg
- Kalita, Jitumani M, Chithambo, Makaiko L
- Authors: Kalita, Jitumani M , Chithambo, Makaiko L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/119803 , vital:34784 , https://doi.org/10.1016/j.radmeas.2017.03.006
- Description: The luminescence sensitivity of α-Al2O3:C and α-Al2O3:C, Mg is of interest because of the contemporary use of these materials in dosimetry related applications. We report investigations concerning the change in sensitivity of thermoluminescence (TL) and optically stimulated luminescence (OSL) from α-Al2O3:C and α-Al2O3:C, Mg with re-use. The study was carried out on a set of un-annealed samples and others annealed at 700 and 900 °C. The TL and OSL sensitivity in α-Al2O3:C and α-Al2O3:C, Mg was found to increase with sample re-use whether the intensity was monitored as peak area or peak height for the main TL peak or, in the case of OSL, as the maximum intensity or the area under a decay curve. The fractional increase in area under either the main TL peak or the OSL decay curve exceeds that of the TL peak height or maximum OSL intensity when samples are re-used. However, when un-annealed samples are used, any increase in TL peak height or peak area per measurement is less than observed in annealed samples. It is also interesting to note that the change in maximum OSL intensity or OSL area is minimal for samples annealed at 900 °C. In general, the TL sensitivity in α-Al2O3:C increases more than that in α-Al2O3:C, Mg with re-use. On the other hand, the OSL sensitivity in α-Al2O3:C, Mg increases more than that in α-Al2O3:C with re-use. These findings suggest that it is advisable to take into account the fractional increase in sensitivity per measurement when one uses α-Al2O3:C as a TL dosimeter and α-Al2O3:C, Mg as an OSL dosimeter.
- Full Text: false
- Date Issued: 2017
- Authors: Kalita, Jitumani M , Chithambo, Makaiko L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/119803 , vital:34784 , https://doi.org/10.1016/j.radmeas.2017.03.006
- Description: The luminescence sensitivity of α-Al2O3:C and α-Al2O3:C, Mg is of interest because of the contemporary use of these materials in dosimetry related applications. We report investigations concerning the change in sensitivity of thermoluminescence (TL) and optically stimulated luminescence (OSL) from α-Al2O3:C and α-Al2O3:C, Mg with re-use. The study was carried out on a set of un-annealed samples and others annealed at 700 and 900 °C. The TL and OSL sensitivity in α-Al2O3:C and α-Al2O3:C, Mg was found to increase with sample re-use whether the intensity was monitored as peak area or peak height for the main TL peak or, in the case of OSL, as the maximum intensity or the area under a decay curve. The fractional increase in area under either the main TL peak or the OSL decay curve exceeds that of the TL peak height or maximum OSL intensity when samples are re-used. However, when un-annealed samples are used, any increase in TL peak height or peak area per measurement is less than observed in annealed samples. It is also interesting to note that the change in maximum OSL intensity or OSL area is minimal for samples annealed at 900 °C. In general, the TL sensitivity in α-Al2O3:C increases more than that in α-Al2O3:C, Mg with re-use. On the other hand, the OSL sensitivity in α-Al2O3:C, Mg increases more than that in α-Al2O3:C with re-use. These findings suggest that it is advisable to take into account the fractional increase in sensitivity per measurement when one uses α-Al2O3:C as a TL dosimeter and α-Al2O3:C, Mg as an OSL dosimeter.
- Full Text: false
- Date Issued: 2017
Phototransferred thermoluminescence in α-Al2O3: C, Mg under 470 nm blue light stimulation
- Kalita, Jitumani M, Chithambo, Makaiko L
- Authors: Kalita, Jitumani M , Chithambo, Makaiko L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/116026 , vital:34290 , https://doi.org/10.1016/j.jlumin.2017.04.059
- Description: Phototransferred thermoluminescence (PTTL) in α-Al2O3:C,Mg under 470 nm blue light has been investigated. Conventional thermoluminescence (TL) measured at 1 °C/s following irradiation to 10 Gy shows the main peak (labelled as III) at 163 °C and six secondary peaks I, II, IV, V, VI and VII at 45, 74, 200, 279, 328, 370 °C respectively. When a sample irradiated to 10 Gy is preheated to 220 °C at 1 °C/s to remove peaks I, II, III and IV and then exposed to 470 nm blue light for 100 s, it is found that three peaks I, II and III are reproduced under phototransfer. Kinetic analysis of the PTTL peaks shows that their kinetic parameters are similar to those of peaks I, II and III from conventional TL. Pulse annealing experiments, intended to study the dependence of PTTL peak intensity on preheating temperature, show that the electron traps corresponding to peaks V, VI and VII act as donor traps whereas the traps corresponding to peaks I, II and III act as acceptor traps. Further, it was found that no PTTL can be generated when all the traps corresponding to peaks I, II…VII are erased by preheating after irradiation. The primary conclusion here is that α-Al2O3:C,Mg does not have any deep traps beyond 400 °C sensitive to 470 nm stimulation or if there are any, their concentration is negligible. The PTTL for any of the PTTL peaks mentioned earlier increases with illumination time to a maximum within 400 s for measurements corresponding to doses between 6 and 15 Gy. The dose response of PTTL peaks II and III is linear within 1–15 Gy. Regarding fading, PTTL peak II fades to background level within 18000 s whereas in the same time, PTTL peak III fades down to 40% of its initial intensity.
- Full Text: false
- Date Issued: 2017
- Authors: Kalita, Jitumani M , Chithambo, Makaiko L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/116026 , vital:34290 , https://doi.org/10.1016/j.jlumin.2017.04.059
- Description: Phototransferred thermoluminescence (PTTL) in α-Al2O3:C,Mg under 470 nm blue light has been investigated. Conventional thermoluminescence (TL) measured at 1 °C/s following irradiation to 10 Gy shows the main peak (labelled as III) at 163 °C and six secondary peaks I, II, IV, V, VI and VII at 45, 74, 200, 279, 328, 370 °C respectively. When a sample irradiated to 10 Gy is preheated to 220 °C at 1 °C/s to remove peaks I, II, III and IV and then exposed to 470 nm blue light for 100 s, it is found that three peaks I, II and III are reproduced under phototransfer. Kinetic analysis of the PTTL peaks shows that their kinetic parameters are similar to those of peaks I, II and III from conventional TL. Pulse annealing experiments, intended to study the dependence of PTTL peak intensity on preheating temperature, show that the electron traps corresponding to peaks V, VI and VII act as donor traps whereas the traps corresponding to peaks I, II and III act as acceptor traps. Further, it was found that no PTTL can be generated when all the traps corresponding to peaks I, II…VII are erased by preheating after irradiation. The primary conclusion here is that α-Al2O3:C,Mg does not have any deep traps beyond 400 °C sensitive to 470 nm stimulation or if there are any, their concentration is negligible. The PTTL for any of the PTTL peaks mentioned earlier increases with illumination time to a maximum within 400 s for measurements corresponding to doses between 6 and 15 Gy. The dose response of PTTL peaks II and III is linear within 1–15 Gy. Regarding fading, PTTL peak II fades to background level within 18000 s whereas in the same time, PTTL peak III fades down to 40% of its initial intensity.
- Full Text: false
- Date Issued: 2017
Phototransferred thermoluminescence of α-Al2O3: C: experimental results and empirical models
- Chithambo, Makaiko L, Seneza, Cleophace, Kalita, Jitumani M
- Authors: Chithambo, Makaiko L , Seneza, Cleophace , Kalita, Jitumani M
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/115681 , vital:34215 , https://doi.org/10.1016/j.radmeas.2017.08.009
- Description: The thermoluminescence glow curve of α-Al2O3:C consists of a prominent apparently-single peak and a number of weaker intensity secondary peaks. Phototransferred thermoluminescence (PTTL) from secondary glow peaks in α-Al2O3:C is reported. For completeness and to aid discussion, complementary results for the main peak are included. The problem studied is one of phototransferred thermoluminescence for a system of multiple acceptors and multiple donors. A TL glow curve recorded at 5 °C/s following irradiation to 0.5 Gy shows the main peak (labelled II) at 240 °C and two secondary peaks at 86 °C (peak I) and 360 °C (peak III). Peak I is reproduced under phototransfer after any preheating between 100 and 500 °C. Peak II is also reproduced as a PTTL peak after preheating to any temperature up to 800 °C. For the latter, the duration of preheating matters because if the sample is preheated at 800 °C for say, 6 min, PTTL is obtained but not when this is extended to say, 15 min. No PTTL was observed from peak III at all. A study of the time dependence of the PTTL intensity from peak III, following preheating that removes peaks I and II, shows that its electron trap acts as an acceptor when the duration of illumination to stimulate electrons from deep traps is brief but that when the illumination time is extended, the electron trap for peak III loses some of its trapped electrons to the shallower traps thus acting as a donor trap.
- Full Text: false
- Date Issued: 2017
- Authors: Chithambo, Makaiko L , Seneza, Cleophace , Kalita, Jitumani M
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/115681 , vital:34215 , https://doi.org/10.1016/j.radmeas.2017.08.009
- Description: The thermoluminescence glow curve of α-Al2O3:C consists of a prominent apparently-single peak and a number of weaker intensity secondary peaks. Phototransferred thermoluminescence (PTTL) from secondary glow peaks in α-Al2O3:C is reported. For completeness and to aid discussion, complementary results for the main peak are included. The problem studied is one of phototransferred thermoluminescence for a system of multiple acceptors and multiple donors. A TL glow curve recorded at 5 °C/s following irradiation to 0.5 Gy shows the main peak (labelled II) at 240 °C and two secondary peaks at 86 °C (peak I) and 360 °C (peak III). Peak I is reproduced under phototransfer after any preheating between 100 and 500 °C. Peak II is also reproduced as a PTTL peak after preheating to any temperature up to 800 °C. For the latter, the duration of preheating matters because if the sample is preheated at 800 °C for say, 6 min, PTTL is obtained but not when this is extended to say, 15 min. No PTTL was observed from peak III at all. A study of the time dependence of the PTTL intensity from peak III, following preheating that removes peaks I and II, shows that its electron trap acts as an acceptor when the duration of illumination to stimulate electrons from deep traps is brief but that when the illumination time is extended, the electron trap for peak III loses some of its trapped electrons to the shallower traps thus acting as a donor trap.
- Full Text: false
- Date Issued: 2017
Radioluminescence of annealed synthetic quartz
- Chithambo, Makaiko L, Niyonzima, P
- Authors: Chithambo, Makaiko L , Niyonzima, P
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/115504 , vital:34150 , https://doi.org/10.1016/j.radmeas.2017.02.005
- Description: The radioluminescence of synthetic quartz annealed at various temperatures up to 1000 °C is reported. The amplitude of the emission bands increases with annealing temperature. In addition, when samples are annealed at temperatures exceeding 700 °C, the intensity of the radioluminescence increases with duration of annealing. The corresponding emission spectra show seven emission bands at 2.04, 2.54, 2.77, 3.04, 3.40, 3.75 and 3.91 eV. The change in dominant emission band with annealing is consistent with annealing-induced variations in lifetimes determined previously from time-resolved optically stimulated luminescence spectra in the same samples.
- Full Text: false
- Date Issued: 2017
- Authors: Chithambo, Makaiko L , Niyonzima, P
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/115504 , vital:34150 , https://doi.org/10.1016/j.radmeas.2017.02.005
- Description: The radioluminescence of synthetic quartz annealed at various temperatures up to 1000 °C is reported. The amplitude of the emission bands increases with annealing temperature. In addition, when samples are annealed at temperatures exceeding 700 °C, the intensity of the radioluminescence increases with duration of annealing. The corresponding emission spectra show seven emission bands at 2.04, 2.54, 2.77, 3.04, 3.40, 3.75 and 3.91 eV. The change in dominant emission band with annealing is consistent with annealing-induced variations in lifetimes determined previously from time-resolved optically stimulated luminescence spectra in the same samples.
- Full Text: false
- Date Issued: 2017
Re-framing academic staff development
- Vorster, Jo-Anne, Quinn, Lynn
- Authors: Vorster, Jo-Anne , Quinn, Lynn
- Date: 2017
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/66535 , vital:28960 , https://doi.org/10.1007/978-94-6300-983-6_8
- Description: publisher version , Globally higher education is situated in a supercomplex world (Barnett, 2000) that is constantly in a state of flux and subject to multiple pressures. This situation has been exacerbated in South African higher education that has been characterised by student protests in the last two years (2015–2016). One of the major causes for the recents protests, particularly in our institutional context, has been students’ anger that despite the official demise of apartheid and the end of colonial rule, some universities in South Africa are still attempting to be copies of Oxford and Harvard.
- Full Text: false
- Date Issued: 2017
- Authors: Vorster, Jo-Anne , Quinn, Lynn
- Date: 2017
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/66535 , vital:28960 , https://doi.org/10.1007/978-94-6300-983-6_8
- Description: publisher version , Globally higher education is situated in a supercomplex world (Barnett, 2000) that is constantly in a state of flux and subject to multiple pressures. This situation has been exacerbated in South African higher education that has been characterised by student protests in the last two years (2015–2016). One of the major causes for the recents protests, particularly in our institutional context, has been students’ anger that despite the official demise of apartheid and the end of colonial rule, some universities in South Africa are still attempting to be copies of Oxford and Harvard.
- Full Text: false
- Date Issued: 2017
Sherlock Holmes in context
- Authors: Naidu, Samantha
- Date: 2017
- Language: English
- Type: Book
- Identifier: vital:26345 , http://hdl.handle.net/10962/53888 , http://www.palgrave.com/us/book/9781137555946 , https://orcid.org/0000-0001-9456-8657
- Description: This book of interdisciplinary essays serves to situate the original Sherlock Holmes, and his various adaptations, in a contemporary cultural context. This collection is prompted by three main and related questions: firstly, why is Sherlock Holmes such an enduring and ubiquitous cultural icon; secondly, why is it that Sherlock Holmes, nearly 130 years after his birth, is enjoying such a spectacular renaissance; and, thirdly, what sort of communities, imagined or otherwise, have arisen around this figure since the most recent resurrections of Sherlock Holmes by popular media? Covering various media and genres (TV, film, literature, theatre) and scholarly approaches, this comprehensive collection offers cogent answers to these questions
- Full Text: false
- Date Issued: 2017
- Authors: Naidu, Samantha
- Date: 2017
- Language: English
- Type: Book
- Identifier: vital:26345 , http://hdl.handle.net/10962/53888 , http://www.palgrave.com/us/book/9781137555946 , https://orcid.org/0000-0001-9456-8657
- Description: This book of interdisciplinary essays serves to situate the original Sherlock Holmes, and his various adaptations, in a contemporary cultural context. This collection is prompted by three main and related questions: firstly, why is Sherlock Holmes such an enduring and ubiquitous cultural icon; secondly, why is it that Sherlock Holmes, nearly 130 years after his birth, is enjoying such a spectacular renaissance; and, thirdly, what sort of communities, imagined or otherwise, have arisen around this figure since the most recent resurrections of Sherlock Holmes by popular media? Covering various media and genres (TV, film, literature, theatre) and scholarly approaches, this comprehensive collection offers cogent answers to these questions
- Full Text: false
- Date Issued: 2017