'Committed, motivated and joyful?'Job satisfaction and organisational commitment of managers at a South African public utility
- Mayer, Claude-Hélène, Louw, Lynette, Baxter, Jeremy
- Authors: Mayer, Claude-Hélène , Louw, Lynette , Baxter, Jeremy
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123320 , vital:35427 , https://doi.org/10.4102/acom.v15i1.291
- Description: During the past decade, publications and conferences on management in African organisations (Kamoche 2011a; 2011b) and in global contexts (Mangaliso 2001; Jackson 2004)1 have increased steadily. In various African contexts and organisations, job satisfaction (JS) (Walumbwa et al. 2005) and organisational commitment (OC) (Gbadamosi 2003; Wasti 2003; Nyengane 2007; Pillay 2008) have been researched. Most of the previous research is quantitative in nature. Although quantititative research provides insights into the relationships between variables, it does not necessarily provide in-depth meaningful conclusions on micro-psychological levels (e.g. Sempane, Rieger & Roodt 2002; Buitendach & De Witte 2005).
- Full Text:
- Date Issued: 2015
- Authors: Mayer, Claude-Hélène , Louw, Lynette , Baxter, Jeremy
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123320 , vital:35427 , https://doi.org/10.4102/acom.v15i1.291
- Description: During the past decade, publications and conferences on management in African organisations (Kamoche 2011a; 2011b) and in global contexts (Mangaliso 2001; Jackson 2004)1 have increased steadily. In various African contexts and organisations, job satisfaction (JS) (Walumbwa et al. 2005) and organisational commitment (OC) (Gbadamosi 2003; Wasti 2003; Nyengane 2007; Pillay 2008) have been researched. Most of the previous research is quantitative in nature. Although quantititative research provides insights into the relationships between variables, it does not necessarily provide in-depth meaningful conclusions on micro-psychological levels (e.g. Sempane, Rieger & Roodt 2002; Buitendach & De Witte 2005).
- Full Text:
- Date Issued: 2015
Human, vector and parasite Hsp90 proteins: a comparative bioinformatics analysis
- Faya, Ngonidzashe, Penkler, David L, Tastan Bishop, Özlem
- Authors: Faya, Ngonidzashe , Penkler, David L , Tastan Bishop, Özlem
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148038 , vital:38704 , DOI: 10.1016/j.fob.2015.11.003
- Description: The treatment of protozoan parasitic diseases is challenging, and thus identification and analysis of new drug targets is important. Parasites survive within host organisms, and some need intermediate hosts to complete their life cycle. Changing host environment puts stress on parasites, and often adaptation is accompanied by the expression of large amounts of heat shock proteins (Hsps). Among Hsps, Hsp90 proteins play an important role in stress environments. Yet, there has been little computational research on Hsp90 proteins to analyze them comparatively as potential parasitic drug targets. Here, an attempt was made to gain detailed insights into the differences between host, vector and parasitic Hsp90 proteins by large-scale bioinformatics analysis.
- Full Text:
- Date Issued: 2015
- Authors: Faya, Ngonidzashe , Penkler, David L , Tastan Bishop, Özlem
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148038 , vital:38704 , DOI: 10.1016/j.fob.2015.11.003
- Description: The treatment of protozoan parasitic diseases is challenging, and thus identification and analysis of new drug targets is important. Parasites survive within host organisms, and some need intermediate hosts to complete their life cycle. Changing host environment puts stress on parasites, and often adaptation is accompanied by the expression of large amounts of heat shock proteins (Hsps). Among Hsps, Hsp90 proteins play an important role in stress environments. Yet, there has been little computational research on Hsp90 proteins to analyze them comparatively as potential parasitic drug targets. Here, an attempt was made to gain detailed insights into the differences between host, vector and parasitic Hsp90 proteins by large-scale bioinformatics analysis.
- Full Text:
- Date Issued: 2015
Maximum firepower: Vale van der Merwe, an emergent ceramic artist at Starways Arts, Hogsback, Eastern Cape, South Africa
- Authors: Steele, John
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/979 , vital:30078
- Description: Vale van der Merwe has been working as a ceramic artist for the past five years, and in that time has developed a remarkably diverse repertoire of both thrown and handbuilt works. These include rapidly thrown utilityware as well as carefully conceived sculptural works that engage with ideas rather than primarily with function. She also makes full use of opportunities offered by high-temperature woodburn firings, and despite works collapsing while being made, breaking while being carried to the kiln and slumping during firing, she has used such occasions as opportunities for learning rather than despondency. Van der Merwe is also an actively hands-on ceramic artist who engages with all levels of tasks associated with studio ceramics in a village setting, so has found herself, for example, both creating a new chimney for the kiln, and simultaneously leading discussion around concepts for new collaborative exhibitions. There is a seriousness of intent combined with infectious confidence evident in both her daily presence and ceramics, and it is hoped that she will develop her repertoire and thinkings even further in forthcoming years.
- Full Text:
- Date Issued: 2015
- Authors: Steele, John
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/979 , vital:30078
- Description: Vale van der Merwe has been working as a ceramic artist for the past five years, and in that time has developed a remarkably diverse repertoire of both thrown and handbuilt works. These include rapidly thrown utilityware as well as carefully conceived sculptural works that engage with ideas rather than primarily with function. She also makes full use of opportunities offered by high-temperature woodburn firings, and despite works collapsing while being made, breaking while being carried to the kiln and slumping during firing, she has used such occasions as opportunities for learning rather than despondency. Van der Merwe is also an actively hands-on ceramic artist who engages with all levels of tasks associated with studio ceramics in a village setting, so has found herself, for example, both creating a new chimney for the kiln, and simultaneously leading discussion around concepts for new collaborative exhibitions. There is a seriousness of intent combined with infectious confidence evident in both her daily presence and ceramics, and it is hoped that she will develop her repertoire and thinkings even further in forthcoming years.
- Full Text:
- Date Issued: 2015
Optimisation of the emulsion liquid membrane composition and demulsification for rhodium extraction
- Moyo, Francis, Tandlich, Roman
- Authors: Moyo, Francis , Tandlich, Roman
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76743 , vital:30626 , https://doi.org/10.1515/lwr-2015-0002
- Description: This study was aimed at designing an optimised emulsion liquid membrane (ELM) for the extraction of rhodium from precious metal refinery wastewaters. The demulsification process and the structure of the optimised ELM are reported on. Two optimised ELMs were prepared. The first one contained a 30 % solution of toluene in kerosene as diluent with the following concentrations of the ELM components: 30.000 g/L (w/v) polyisobutylene, 10.870 g/L (m/v) of trioctyl amine and 51.001 g/L (m/v) of SPAN 80. The second ELM contained the same diluent, but the concentrations of the other ELM components in it were as follows: 20.000 g/l of polyisobutylene, 10.268 g/l trioctyl amine and 50.024 g/l of SPAN 80. The stripping phase was the same in both optimised ELMs, namely a 2 M solution of HNO3. The stripping phase and the diluent solution were mixed together in ratios of 1:1 and 2:1, respectively. Two methods were used to characterise the microdroplet diameters, i.e. optical microscopy and the Zeta-sizer. For the t-test, the p-value of 0.3018 at 5 % level of significance showed that there was statistically no significant difference in the mean micro-droplet size for 1:2 ELMs containing 20 g/l and 30 g/l of polyisobutylene after 40 minutes of emulsification. The best demulsification results were obtained using the chemical demulsification with polyethylene glycol with molecular weight of 400 g/mol (PEG 400) at 50 ± 1 °C for 24 hours. However, significant carryover of toluene, trioctyl amine and polyethylene glycol into the aqueous phase was observed.
- Full Text:
- Date Issued: 2015
- Authors: Moyo, Francis , Tandlich, Roman
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76743 , vital:30626 , https://doi.org/10.1515/lwr-2015-0002
- Description: This study was aimed at designing an optimised emulsion liquid membrane (ELM) for the extraction of rhodium from precious metal refinery wastewaters. The demulsification process and the structure of the optimised ELM are reported on. Two optimised ELMs were prepared. The first one contained a 30 % solution of toluene in kerosene as diluent with the following concentrations of the ELM components: 30.000 g/L (w/v) polyisobutylene, 10.870 g/L (m/v) of trioctyl amine and 51.001 g/L (m/v) of SPAN 80. The second ELM contained the same diluent, but the concentrations of the other ELM components in it were as follows: 20.000 g/l of polyisobutylene, 10.268 g/l trioctyl amine and 50.024 g/l of SPAN 80. The stripping phase was the same in both optimised ELMs, namely a 2 M solution of HNO3. The stripping phase and the diluent solution were mixed together in ratios of 1:1 and 2:1, respectively. Two methods were used to characterise the microdroplet diameters, i.e. optical microscopy and the Zeta-sizer. For the t-test, the p-value of 0.3018 at 5 % level of significance showed that there was statistically no significant difference in the mean micro-droplet size for 1:2 ELMs containing 20 g/l and 30 g/l of polyisobutylene after 40 minutes of emulsification. The best demulsification results were obtained using the chemical demulsification with polyethylene glycol with molecular weight of 400 g/mol (PEG 400) at 50 ± 1 °C for 24 hours. However, significant carryover of toluene, trioctyl amine and polyethylene glycol into the aqueous phase was observed.
- Full Text:
- Date Issued: 2015
Polyurethane composite adsorbent using solid phase extraction method for preconcentration of metal ion from aqueous solution
- Olorundare, O F, Msagati, T A M, Okonkwo, J O, Krause, Rui W M, Mamba, Bhekie B
- Authors: Olorundare, O F , Msagati, T A M , Okonkwo, J O , Krause, Rui W M , Mamba, Bhekie B
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125386 , vital:35778 , https://doi.org/10.1007/s13762-014-0645-5
- Description: Polyurethane composite adsorbent polymeric material was prepared and investigated for selected solid-phase extraction for metal ions, prior to its determination by inductively coupled plasma optical emission spectrometry. The surface characterisation was done using Fourier transform infrared spectroscopy. The separation and preconcentration conditions of the analytes investigated includes influence of pH, sample loading flow rate, elution flow rate, type and concentration of eluents. The optimum pH for the highest efficient recoveries for all metal ions, which ranged from 70 to 85 %, is pH 7. The metal ions were quantitatively eluted with 5 mL of 2 mol/L HNO3. Common coexisting ions did not interfere with the separation. The percentage recovery of the metal ions ranged between 70 and 89 %, while the results for the limit of detection and limit of quantification ranged from 0.249 to 0.256 and 0.831 to 0.855, respectively. The experimental tests showed good preconcentration results of trace levels of metal ions using synthesised polyurethane polymer adsorbent composite.
- Full Text:
- Date Issued: 2015
- Authors: Olorundare, O F , Msagati, T A M , Okonkwo, J O , Krause, Rui W M , Mamba, Bhekie B
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125386 , vital:35778 , https://doi.org/10.1007/s13762-014-0645-5
- Description: Polyurethane composite adsorbent polymeric material was prepared and investigated for selected solid-phase extraction for metal ions, prior to its determination by inductively coupled plasma optical emission spectrometry. The surface characterisation was done using Fourier transform infrared spectroscopy. The separation and preconcentration conditions of the analytes investigated includes influence of pH, sample loading flow rate, elution flow rate, type and concentration of eluents. The optimum pH for the highest efficient recoveries for all metal ions, which ranged from 70 to 85 %, is pH 7. The metal ions were quantitatively eluted with 5 mL of 2 mol/L HNO3. Common coexisting ions did not interfere with the separation. The percentage recovery of the metal ions ranged between 70 and 89 %, while the results for the limit of detection and limit of quantification ranged from 0.249 to 0.256 and 0.831 to 0.855, respectively. The experimental tests showed good preconcentration results of trace levels of metal ions using synthesised polyurethane polymer adsorbent composite.
- Full Text:
- Date Issued: 2015
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