Click chemistry electrode modification using 4-ethynylbenzyl substituted cobalt phthalocyanine for applications in electrocatalysis
- Mpeta, Lekhetho S, Fomo, Gertrude, Nyokong, Tebello
- Authors: Mpeta, Lekhetho S , Fomo, Gertrude , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187626 , vital:44681 , xlink:href="• https://doi.org/10.1080/00958972.2018.1466118"
- Description: In this work, we report on the synthesis and applications of a new cobalt tetrakis 4-((4-ethynylbenzyl) oxy) phthalocyanine (3) for the detection of hydrazine. The glassy carbon electrode (GCE) was first grafted through diazotization, providing the GCE surface layer with azide groups. Thereafter, the 1,3-dipolar cycloaddition reaction, catalyzed by a copper(I) catalyst was used to “click” complex 3 to the grafted surface of GCE. The new platform was then characterized using cyclic voltammetry (CV), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). This work shows that 3 is an effective sensor with sensitivity of 91.5 μA mM−1 and limit of detection of 3.28 μM which is a great improvement compared to other reported sensors for this analyte.
- Full Text:
- Date Issued: 2018
- Authors: Mpeta, Lekhetho S , Fomo, Gertrude , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187626 , vital:44681 , xlink:href="• https://doi.org/10.1080/00958972.2018.1466118"
- Description: In this work, we report on the synthesis and applications of a new cobalt tetrakis 4-((4-ethynylbenzyl) oxy) phthalocyanine (3) for the detection of hydrazine. The glassy carbon electrode (GCE) was first grafted through diazotization, providing the GCE surface layer with azide groups. Thereafter, the 1,3-dipolar cycloaddition reaction, catalyzed by a copper(I) catalyst was used to “click” complex 3 to the grafted surface of GCE. The new platform was then characterized using cyclic voltammetry (CV), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). This work shows that 3 is an effective sensor with sensitivity of 91.5 μA mM−1 and limit of detection of 3.28 μM which is a great improvement compared to other reported sensors for this analyte.
- Full Text:
- Date Issued: 2018
Social-ecological systems as complex adaptive systems
- Preiser, Rika, Biggs, Reinette, de Vos, Alta, Folke, Carl
- Authors: Preiser, Rika , Biggs, Reinette , de Vos, Alta , Folke, Carl
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416410 , vital:71346 , xlink:href="https://doi.org/10.5751/ES-10558-230446"
- Description: The study of social-ecological systems (SES) has been significantly shaped by insights from research on complex adaptive systems (CAS). We offer a brief overview of the conceptual integration of CAS research and its implications for the advancement of SES studies and methods. We propose a conceptual typology of six organizing principles of CAS based on a comparison of leading scholars’ classifications of CAS features and properties. This typology clusters together similar underlying organizing principles of the features and attributes of CAS, and serves as a heuristic framework for identifying methods and approaches that account for the key features of SES. These principles can help identify appropriate methods and approaches for studying SES. We discuss three main implications of studying and engaging with SES as CAS. First, there needs to be a shift in focus when studying the dynamics and interactions in SES, to better capture the nature of the organizing principles that characterize SES behavior. Second, realizing that the nature of the intertwined social-ecological relations is complex has real consequences for how we choose methods and practical approaches for observing and studying SES interactions. Third, engagement with SES as CAS poses normative challenges for problemoriented researchers and practitioners taking on real-world challenges.
- Full Text:
- Date Issued: 2018
- Authors: Preiser, Rika , Biggs, Reinette , de Vos, Alta , Folke, Carl
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416410 , vital:71346 , xlink:href="https://doi.org/10.5751/ES-10558-230446"
- Description: The study of social-ecological systems (SES) has been significantly shaped by insights from research on complex adaptive systems (CAS). We offer a brief overview of the conceptual integration of CAS research and its implications for the advancement of SES studies and methods. We propose a conceptual typology of six organizing principles of CAS based on a comparison of leading scholars’ classifications of CAS features and properties. This typology clusters together similar underlying organizing principles of the features and attributes of CAS, and serves as a heuristic framework for identifying methods and approaches that account for the key features of SES. These principles can help identify appropriate methods and approaches for studying SES. We discuss three main implications of studying and engaging with SES as CAS. First, there needs to be a shift in focus when studying the dynamics and interactions in SES, to better capture the nature of the organizing principles that characterize SES behavior. Second, realizing that the nature of the intertwined social-ecological relations is complex has real consequences for how we choose methods and practical approaches for observing and studying SES interactions. Third, engagement with SES as CAS poses normative challenges for problemoriented researchers and practitioners taking on real-world challenges.
- Full Text:
- Date Issued: 2018
The socialisation and leader identity development of school leaders in Southern African countries
- Moorosi, Pontso, Grant, Carolyn
- Authors: Moorosi, Pontso , Grant, Carolyn
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281142 , vital:55696 , xlink:href="https://doi.org/10.1108/JEA-01-2018-0011"
- Description: Purpose: The purpose of this paper is to explore the socialisation and leader identity development of school leaders in Southern African countries. Design/methodology/approach: The study utilised a survey of qualitative data where data collection primarily involved in-depth interviews with school principals and deputy principals of both primary and secondary schools. Findings: Findings revealed that early socialisation to leadership transpired during childhood and early schooling at which points in time the characteristics and values of leadership integral to the participants’ leadership practice were acquired. Initial teacher training was found to be significant in introducing principalship role conception. Leader identity was also found to develop outside the context of school through pre-socialising agents long before the teaching and leading roles are assumed. Originality/value: The study presents an overview of the findings from four countries in Southern Africa, providing a complex process with overlapping stages of career socialisation. Existing research puts emphasis on formal leadership preparation as a significant part of socialisation – this study suggests alternatives for poorly resourced countries. Significantly, the paper improves our understanding that school leader identity is both internal and external to the school environment.
- Full Text:
- Date Issued: 2018
- Authors: Moorosi, Pontso , Grant, Carolyn
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281142 , vital:55696 , xlink:href="https://doi.org/10.1108/JEA-01-2018-0011"
- Description: Purpose: The purpose of this paper is to explore the socialisation and leader identity development of school leaders in Southern African countries. Design/methodology/approach: The study utilised a survey of qualitative data where data collection primarily involved in-depth interviews with school principals and deputy principals of both primary and secondary schools. Findings: Findings revealed that early socialisation to leadership transpired during childhood and early schooling at which points in time the characteristics and values of leadership integral to the participants’ leadership practice were acquired. Initial teacher training was found to be significant in introducing principalship role conception. Leader identity was also found to develop outside the context of school through pre-socialising agents long before the teaching and leading roles are assumed. Originality/value: The study presents an overview of the findings from four countries in Southern Africa, providing a complex process with overlapping stages of career socialisation. Existing research puts emphasis on formal leadership preparation as a significant part of socialisation – this study suggests alternatives for poorly resourced countries. Significantly, the paper improves our understanding that school leader identity is both internal and external to the school environment.
- Full Text:
- Date Issued: 2018
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