Development of manganese phthalocyanine decorated with silver nanoparticles nanocomposite for improved electrocatalytic oxidation of hydrazine:
- Mpeta, Lekhetho S, Sen, Pinar, Nyokong, Tebello
- Authors: Mpeta, Lekhetho S , Sen, Pinar , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148472 , vital:38742 , https://doi.org/10.1016/j.jelechem.2020.114173
- Description: In this study we report on the synthesis of tetrakis [4-(4-(5-chloro-1H-benzo [d]imidazol-2-yl) phenoxy phthalocyaninato] manganese (III) chloride (MnPc). The MnPc was first used to modify a glassy carbon electrode, followed by the growth of silver nanoparticles (AgNPs) onto the MnPc modified electrode to form MnPc-AgNPs modified electrode. The modified electrode was characterized using cydic voltammetry, chronoamperometry, scanning electrochemical microscopy and electrochemical impedance spectroscopy. The modified MnPc-AgNPs electrode was employed for the detection of hydrazine. The MnPc-AgNPs gave better current responses for electrooxidation of hydrazine relative to MnPc and AgNPs, individually. The catalytic rate constant was 1.90 x 10(5 )M(-1) S-1, with the detection limit (LoD) of 2.42 pM (using 3 sigma notation), and sensitivity of 61.56 mu A mM(-1), for MnPc-AgNPs. (C) 2020 Elsevier B.V. All rights reserved.
- Full Text:
- Date Issued: 2020
- Authors: Mpeta, Lekhetho S , Sen, Pinar , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148472 , vital:38742 , https://doi.org/10.1016/j.jelechem.2020.114173
- Description: In this study we report on the synthesis of tetrakis [4-(4-(5-chloro-1H-benzo [d]imidazol-2-yl) phenoxy phthalocyaninato] manganese (III) chloride (MnPc). The MnPc was first used to modify a glassy carbon electrode, followed by the growth of silver nanoparticles (AgNPs) onto the MnPc modified electrode to form MnPc-AgNPs modified electrode. The modified electrode was characterized using cydic voltammetry, chronoamperometry, scanning electrochemical microscopy and electrochemical impedance spectroscopy. The modified MnPc-AgNPs electrode was employed for the detection of hydrazine. The MnPc-AgNPs gave better current responses for electrooxidation of hydrazine relative to MnPc and AgNPs, individually. The catalytic rate constant was 1.90 x 10(5 )M(-1) S-1, with the detection limit (LoD) of 2.42 pM (using 3 sigma notation), and sensitivity of 61.56 mu A mM(-1), for MnPc-AgNPs. (C) 2020 Elsevier B.V. All rights reserved.
- Full Text:
- Date Issued: 2020
Development of phthalocyanine functionalised TiO 2 and ZnO nanofibers for photodegradation of methyl orange
- Mapukata, Sivuyisiwe, Nyokong, Tebello
- Authors: Mapukata, Sivuyisiwe , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186323 , vital:44485 , xlink:href="https://doi.org/10.1039/D0NJ03326J"
- Description: The photocatalytic activity of TiO2 and ZnO based catalysts, which is based on their ability to generate electron–hole pairs upon photoillumination is limited due to their wide band gaps and lack of efficient retrievability post-application. This work reports on the fabrication, characterisation and comparison of electrospun TiO2 and ZnO nanofibers when bare vs when functionalised with a phthalocyanine. The generated photocatalysts are attractive because they absorb visible light and are easily retrievable and hence reusable. With the Pc anchored onto their surfaces, the anatase TiO2 nanofibers and the wurzite ZnO nanofibers possessed singlet oxygen quantum yields of 0.22 and 0.16 in water, respectively. Evaluation of the photocatalytic efficiencies of the nanofibers was conducted by studying the photodegradation of methyl orange. The Pc decorated nanofibers were found to be more effective photocatalysts than the bare ones with the phthalocyanine TiO2 nanofibers being the best. The degradation kinetics were found to follow pseudo first order kinetics and obeyed the Langmuir Hinshelwood model. The nanocatalysts reported herein are therefore feasible candidates for real-life water purification applications.
- Full Text:
- Date Issued: 2020
- Authors: Mapukata, Sivuyisiwe , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186323 , vital:44485 , xlink:href="https://doi.org/10.1039/D0NJ03326J"
- Description: The photocatalytic activity of TiO2 and ZnO based catalysts, which is based on their ability to generate electron–hole pairs upon photoillumination is limited due to their wide band gaps and lack of efficient retrievability post-application. This work reports on the fabrication, characterisation and comparison of electrospun TiO2 and ZnO nanofibers when bare vs when functionalised with a phthalocyanine. The generated photocatalysts are attractive because they absorb visible light and are easily retrievable and hence reusable. With the Pc anchored onto their surfaces, the anatase TiO2 nanofibers and the wurzite ZnO nanofibers possessed singlet oxygen quantum yields of 0.22 and 0.16 in water, respectively. Evaluation of the photocatalytic efficiencies of the nanofibers was conducted by studying the photodegradation of methyl orange. The Pc decorated nanofibers were found to be more effective photocatalysts than the bare ones with the phthalocyanine TiO2 nanofibers being the best. The degradation kinetics were found to follow pseudo first order kinetics and obeyed the Langmuir Hinshelwood model. The nanocatalysts reported herein are therefore feasible candidates for real-life water purification applications.
- Full Text:
- Date Issued: 2020
Dietary fatty acids of spiders reveal spatial and temporal variations in aquatic-terrestrial linkages
- Chari, Lenin D, Richoux, Nicole B, Moyo, Sydney, Villet, Martin H
- Authors: Chari, Lenin D , Richoux, Nicole B , Moyo, Sydney , Villet, Martin H
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441919 , vital:73935 , https://doi.org/10.1016/j.fooweb.2020.e00152
- Description: Stream and riparian food webs can be strongly linked by inputs of aquatic emergent insect prey to terrestrial predators. However, quantifying these linkages and understanding how they vary in time and space is challenging. We investigated the dynamic width of a riverine trophic subsidy zone by determining the relationship between perpendicular distance from a river and dietary contributions of aquatic insect prey to web-building spiders' diets. To assess this relationship, riparian web-building spiders at two river sites were sampled during four seasons and analysed for the fatty acids 16:0, 16:1ω7 and 20:5ω3, their total ω3-fatty acid content and their ω3:ω6 ratio to evaluate trophic subsidies reaching them from an adjacent river. River-derived fatty acids generally declined with increased distance from the river, indicating a diffusion of aquatically derived subsidies into the riparian zone. While the river was only 16 m wide at its broadest, river-derived trophic subsidies were detected up to four times that distance from the river edge. Spiders at a downstream section of the river, characterised by generally higher emergence rates of aquatic insects, contained higher proportions of aquatic indicator fatty acids compared with spiders located upstream, where emergence rates were lower. Similarly, proportions of aquatic indicator fatty acids in spiders were lowest during winter when aquatic insect emergence rates were lowest. The fatty acid 20:5ω3 (eicosapentaenoic acid; EPA) held the best promise as a biomarker of aquatic-derived tropic subsidies and could be developed as a useful tool for riparian research and management.
- Full Text:
- Date Issued: 2020
- Authors: Chari, Lenin D , Richoux, Nicole B , Moyo, Sydney , Villet, Martin H
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441919 , vital:73935 , https://doi.org/10.1016/j.fooweb.2020.e00152
- Description: Stream and riparian food webs can be strongly linked by inputs of aquatic emergent insect prey to terrestrial predators. However, quantifying these linkages and understanding how they vary in time and space is challenging. We investigated the dynamic width of a riverine trophic subsidy zone by determining the relationship between perpendicular distance from a river and dietary contributions of aquatic insect prey to web-building spiders' diets. To assess this relationship, riparian web-building spiders at two river sites were sampled during four seasons and analysed for the fatty acids 16:0, 16:1ω7 and 20:5ω3, their total ω3-fatty acid content and their ω3:ω6 ratio to evaluate trophic subsidies reaching them from an adjacent river. River-derived fatty acids generally declined with increased distance from the river, indicating a diffusion of aquatically derived subsidies into the riparian zone. While the river was only 16 m wide at its broadest, river-derived trophic subsidies were detected up to four times that distance from the river edge. Spiders at a downstream section of the river, characterised by generally higher emergence rates of aquatic insects, contained higher proportions of aquatic indicator fatty acids compared with spiders located upstream, where emergence rates were lower. Similarly, proportions of aquatic indicator fatty acids in spiders were lowest during winter when aquatic insect emergence rates were lowest. The fatty acid 20:5ω3 (eicosapentaenoic acid; EPA) held the best promise as a biomarker of aquatic-derived tropic subsidies and could be developed as a useful tool for riparian research and management.
- Full Text:
- Date Issued: 2020
Dietary fatty acids of spiders reveal spatial and temporal variations in aquatic-terrestrial linkages
- Chari, Lenin D, Richoux, Nicole B, Moyo, Sydney, Villet, Martin H
- Authors: Chari, Lenin D , Richoux, Nicole B , Moyo, Sydney , Villet, Martin H
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454320 , vital:75335 , xlink:href="https://doi.org/10.1016/j.fooweb.2020.e00152"
- Description: Stream and riparian food webs can be strongly linked by inputs of aquatic emergent insect prey to terrestrial predators. However, quantifying these linkages and understanding how they vary in time and space is challenging. We investigated the dynamic width of a riverine trophic subsidy zone by determining the relationship between perpendicular distance from a river and dietary contributions of aquatic insect prey to web-building spiders' diets. To assess this relationship, riparian web-building spiders at two river sites were sampled during four seasons and analysed for the fatty acids 16:0, 16:1ω7 and 20:5ω3, their total ω3-fatty acid content and their ω3:ω6 ratio to evaluate trophic subsidies reaching them from an adjacent river. River-derived fatty acids generally declined with increased distance from the river, indicating a diffusion of aquatically derived subsidies into the riparian zone. While the river was only 16 m wide at its broadest, river-derived trophic subsidies were detected up to four times that distance from the river edge. Spiders at a downstream section of the river, characterised by generally higher emergence rates of aquatic insects, contained higher proportions of aquatic indicator fatty acids compared with spiders located upstream, where emergence rates were lower. Similarly, proportions of aquatic indicator fatty acids in spiders were lowest during winter when aquatic insect emergence rates were lowest. The fatty acid 20:5ω3 (eicosapentaenoic acid; EPA) held the best promise as a biomarker of aquatic-derived tropic subsidies and could be developed as a useful tool for riparian research and management.
- Full Text:
- Date Issued: 2020
- Authors: Chari, Lenin D , Richoux, Nicole B , Moyo, Sydney , Villet, Martin H
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454320 , vital:75335 , xlink:href="https://doi.org/10.1016/j.fooweb.2020.e00152"
- Description: Stream and riparian food webs can be strongly linked by inputs of aquatic emergent insect prey to terrestrial predators. However, quantifying these linkages and understanding how they vary in time and space is challenging. We investigated the dynamic width of a riverine trophic subsidy zone by determining the relationship between perpendicular distance from a river and dietary contributions of aquatic insect prey to web-building spiders' diets. To assess this relationship, riparian web-building spiders at two river sites were sampled during four seasons and analysed for the fatty acids 16:0, 16:1ω7 and 20:5ω3, their total ω3-fatty acid content and their ω3:ω6 ratio to evaluate trophic subsidies reaching them from an adjacent river. River-derived fatty acids generally declined with increased distance from the river, indicating a diffusion of aquatically derived subsidies into the riparian zone. While the river was only 16 m wide at its broadest, river-derived trophic subsidies were detected up to four times that distance from the river edge. Spiders at a downstream section of the river, characterised by generally higher emergence rates of aquatic insects, contained higher proportions of aquatic indicator fatty acids compared with spiders located upstream, where emergence rates were lower. Similarly, proportions of aquatic indicator fatty acids in spiders were lowest during winter when aquatic insect emergence rates were lowest. The fatty acid 20:5ω3 (eicosapentaenoic acid; EPA) held the best promise as a biomarker of aquatic-derived tropic subsidies and could be developed as a useful tool for riparian research and management.
- Full Text:
- Date Issued: 2020
Dimensions and indicators of non-profit financial condition: evidence from South African public universities
- Authors: Bunting, Mark B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150296 , vital:38965 , DOI: https://doi.org/10.4102/sajems.v23i1.2974
- Description: More than three decades of research have failed to achieve convergence on a method for the measurement of non-profit financial condition, with the literature reporting a bewildering array of financial dimensions, and more than 100 ratios and indicators. This article offers a contribution to a broader discourse in non-profit financial analysis by recognising, and taking action in response to, the potential threat to research validity arising from the generally unchallenged presumption that accounting numbers provide a complete, unbiased and error-free representation of an entity’s underlying economic reality.
- Full Text:
- Date Issued: 2020
- Authors: Bunting, Mark B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150296 , vital:38965 , DOI: https://doi.org/10.4102/sajems.v23i1.2974
- Description: More than three decades of research have failed to achieve convergence on a method for the measurement of non-profit financial condition, with the literature reporting a bewildering array of financial dimensions, and more than 100 ratios and indicators. This article offers a contribution to a broader discourse in non-profit financial analysis by recognising, and taking action in response to, the potential threat to research validity arising from the generally unchallenged presumption that accounting numbers provide a complete, unbiased and error-free representation of an entity’s underlying economic reality.
- Full Text:
- Date Issued: 2020
Direct nonlinear optical absorption measurements of asymmetrical zinc (II) phthalocyanine when covalently linked to semiconductor quantum dots
- Mgidlana, Sithi, Sen, Pinar, Nyokong, Tebello
- Authors: Mgidlana, Sithi , Sen, Pinar , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186056 , vital:44459 , xlink:href="https://doi.org/10.1016/j.molstruc.2020.128729"
- Description: We report on nonlinear optical properties of tris[(4-tert-butyl)-2-thio (phenyl)acetic acid (1) and tris(dimethyl-5-(3,4-phenoxy) isophthalate (2) phthalocyaninato zinc (II) complexes. The synthesized complexes were covalently conjugated to glutathione-capped CdTe/ZnSe/ZnO quantum dots. We observed an increase in triplet quantum yield with corresponding decrease in fluorescence quantum yield of conjugates compared to Pc complexes alone. Z-scan technique was employed to experimentally test the nonlinear optical response of complexes and nanoconjugates in solution at laser excitation wavelength of 532 nm with 7 ns pulse. Nonlinear absorption coefficient, third-order optical susceptibility and optical limiting threshold of the materials were obtained from the Z-scan data. The nonlinear absorption parameters improved in the presence of CdTe/ZnSe/ZnO, with 1 and 1-CdTe/ZnSe/ZnO, giving the best results due to the presence of electron donating substituents.
- Full Text:
- Date Issued: 2020
- Authors: Mgidlana, Sithi , Sen, Pinar , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186056 , vital:44459 , xlink:href="https://doi.org/10.1016/j.molstruc.2020.128729"
- Description: We report on nonlinear optical properties of tris[(4-tert-butyl)-2-thio (phenyl)acetic acid (1) and tris(dimethyl-5-(3,4-phenoxy) isophthalate (2) phthalocyaninato zinc (II) complexes. The synthesized complexes were covalently conjugated to glutathione-capped CdTe/ZnSe/ZnO quantum dots. We observed an increase in triplet quantum yield with corresponding decrease in fluorescence quantum yield of conjugates compared to Pc complexes alone. Z-scan technique was employed to experimentally test the nonlinear optical response of complexes and nanoconjugates in solution at laser excitation wavelength of 532 nm with 7 ns pulse. Nonlinear absorption coefficient, third-order optical susceptibility and optical limiting threshold of the materials were obtained from the Z-scan data. The nonlinear absorption parameters improved in the presence of CdTe/ZnSe/ZnO, with 1 and 1-CdTe/ZnSe/ZnO, giving the best results due to the presence of electron donating substituents.
- Full Text:
- Date Issued: 2020
Do spotted hyaenas outcompete the big cats in a small, enclosed system in South Africa?:
- Comley, J, Joubert, C J, Mgqatsa, Nokubonga, Parker, Daniel M
- Authors: Comley, J , Joubert, C J , Mgqatsa, Nokubonga , Parker, Daniel M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150099 , vital:38940 , doi:10.1111/jzo.12772
- Description: Carnivores are adapted to kill, meaning sympatric carnivores can have particularly aggressive and harmful competitive interactions. The co‐existence of multiple carnivores in an ecosystem could be restricted by their similarity in ecological niches (e.g. dietary overlap); however, high prey abundances could facilitate their co‐existence. Although the development of small, enclosed reserves (over 400 km2) in South Africa has reduced human–carnivore conflict, these systems may increase the likelihood of carnivore intra‐guild competition due to the clumping of competing carnivores into these restricted spaces. Using carnivore scat and kill site analyses, we determined the dietary preferences and overlap of sympatric large carnivores in a small, enclosed reserve, Selati Game Reserve (Selati).
- Full Text:
- Date Issued: 2020
- Authors: Comley, J , Joubert, C J , Mgqatsa, Nokubonga , Parker, Daniel M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150099 , vital:38940 , doi:10.1111/jzo.12772
- Description: Carnivores are adapted to kill, meaning sympatric carnivores can have particularly aggressive and harmful competitive interactions. The co‐existence of multiple carnivores in an ecosystem could be restricted by their similarity in ecological niches (e.g. dietary overlap); however, high prey abundances could facilitate their co‐existence. Although the development of small, enclosed reserves (over 400 km2) in South Africa has reduced human–carnivore conflict, these systems may increase the likelihood of carnivore intra‐guild competition due to the clumping of competing carnivores into these restricted spaces. Using carnivore scat and kill site analyses, we determined the dietary preferences and overlap of sympatric large carnivores in a small, enclosed reserve, Selati Game Reserve (Selati).
- Full Text:
- Date Issued: 2020
Double-and quintuple-decker phthalocyaninato chelates as optical limiters in solution and thin film
- Sekhosana, Kutloano E, Nyokong, Tebello
- Authors: Sekhosana, Kutloano E , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186733 , vital:44529 , xlink:href="https://doi.org/10.1016/j.dyepig.2019.107836"
- Description: The rare-earth quintuple-decker phthalocyaninato chelates (3a and 3b) were synthesized from their parent rare-earth double-decker phthalocyaninato precursors (2b and 2a). After extensive structural elucidation, these complexes were subjected to various spectroscopic techniques to investigate their electronic behavior. It was found that complexes 3a and 3b existed as the oxidized forms. When investigating the optical limiting properties, all these complexes were found to exhibit reverse saturable absorption, with complex 2a showing a more enhanced open-aperture Z-Scan signature than complex 2b. Interestingly, complexes 3a and 3b (in solution) exhibited better open-aperture Z-Scan signatures than their parent rare-earth double-decker phthalocyaninato precursors (2b and 2a). However, thin films fabricated from these complexes did not show an improvement in the optical limiting properties when compared to 2a, 3a, 3b except for that which was prepared from 2b. This study shows the importance of extensive π-electron system in phthalocyaninato complexes for optical limiting applications.
- Full Text:
- Date Issued: 2020
- Authors: Sekhosana, Kutloano E , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186733 , vital:44529 , xlink:href="https://doi.org/10.1016/j.dyepig.2019.107836"
- Description: The rare-earth quintuple-decker phthalocyaninato chelates (3a and 3b) were synthesized from their parent rare-earth double-decker phthalocyaninato precursors (2b and 2a). After extensive structural elucidation, these complexes were subjected to various spectroscopic techniques to investigate their electronic behavior. It was found that complexes 3a and 3b existed as the oxidized forms. When investigating the optical limiting properties, all these complexes were found to exhibit reverse saturable absorption, with complex 2a showing a more enhanced open-aperture Z-Scan signature than complex 2b. Interestingly, complexes 3a and 3b (in solution) exhibited better open-aperture Z-Scan signatures than their parent rare-earth double-decker phthalocyaninato precursors (2b and 2a). However, thin films fabricated from these complexes did not show an improvement in the optical limiting properties when compared to 2a, 3a, 3b except for that which was prepared from 2b. This study shows the importance of extensive π-electron system in phthalocyaninato complexes for optical limiting applications.
- Full Text:
- Date Issued: 2020
Dragonfly (Odonata) community structure in the Eastern Highlands Biodiversity Hotspot of Zimbabwe: potential threats of land use changes on freshwater invertebrates
- Mafuwe, Kudzai, Moyo, Sydney
- Authors: Mafuwe, Kudzai , Moyo, Sydney
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158265 , vital:40167 , https://doi.org/10.1080/13887890.2020.1768156
- Description: We examined the diversity and potential drivers of dragonfly distribution in a biodiversity hotspot of Southern Africa (Eastern Highlands, Zimbabwe) by surveying 30 sites (13 lentic and 17 lotic habitats) located within this region. Additionally, we identified the anthropogenic factors that may threaten Odonata diversity and abundance.
- Full Text:
- Date Issued: 2020
- Authors: Mafuwe, Kudzai , Moyo, Sydney
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158265 , vital:40167 , https://doi.org/10.1080/13887890.2020.1768156
- Description: We examined the diversity and potential drivers of dragonfly distribution in a biodiversity hotspot of Southern Africa (Eastern Highlands, Zimbabwe) by surveying 30 sites (13 lentic and 17 lotic habitats) located within this region. Additionally, we identified the anthropogenic factors that may threaten Odonata diversity and abundance.
- Full Text:
- Date Issued: 2020
Ecosystem disservices matter when valuing ecosystem benefits from small-scale arable agriculture:
- Herd-Hoare, Shannon C, Shackleton, Charlie M
- Authors: Herd-Hoare, Shannon C , Shackleton, Charlie M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175744 , vital:42620 , https://doi.org/10.1016/j.ecoser.2020.101201
- Description: The contribution of ecosystem services to smallholder agriculture is widely recognised. However, they are seldom analysed in tandem with the ecosystem disservices, such as crop weeds and pests, which the same systems produce. We do so by quantifying the provisioning ecosystem services and disservices in smallholder arable agricultural systems in three rural villages in southeastern South Africa. Using a mixed methods approach we consider the relative benefits from ecosystem services after the effects of disservices, and the management and strategies that households adopt to minimise disservices. The role of ecosystem services and disservices was expressed in economic terms to provide a common framework to assess the relative magnitude of their contribution or loss.
- Full Text:
- Date Issued: 2020
- Authors: Herd-Hoare, Shannon C , Shackleton, Charlie M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175744 , vital:42620 , https://doi.org/10.1016/j.ecoser.2020.101201
- Description: The contribution of ecosystem services to smallholder agriculture is widely recognised. However, they are seldom analysed in tandem with the ecosystem disservices, such as crop weeds and pests, which the same systems produce. We do so by quantifying the provisioning ecosystem services and disservices in smallholder arable agricultural systems in three rural villages in southeastern South Africa. Using a mixed methods approach we consider the relative benefits from ecosystem services after the effects of disservices, and the management and strategies that households adopt to minimise disservices. The role of ecosystem services and disservices was expressed in economic terms to provide a common framework to assess the relative magnitude of their contribution or loss.
- Full Text:
- Date Issued: 2020
Editorial for Special Issue: Education for Sustainability in a Time of Crises
- Authors: Rosenberg, Eureta
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/370533 , vital:66352 , xlink:href="10.4314/sajee.v36i1.1"
- Description: There is an old and still popular saying that a crisis is an opportunity for change. The Chinese symbol for crisis is translated in Wikipedia as “danger at a point of juncture”. In the year 2020, first China and then the rest of humanity have been presented with a monumental crisis: a new and lethal virus that spread fast and far, causing actions and reactions, with dramatic consequences for social and economic life around the globe. Rebecca Solnit wrote of another crisis in her book Hope in the Dark: The Untold Story of People Power. In Grounds for Hope, a foreword to the 2015 edition (p.2), she stated: “This is an extraordinary time full of vital, transformative movements, that could not be foreseen. It’s also a nightmarish time. Full engagement requires the ability to perceive both.”.
- Full Text:
- Date Issued: 2020
- Authors: Rosenberg, Eureta
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/370533 , vital:66352 , xlink:href="10.4314/sajee.v36i1.1"
- Description: There is an old and still popular saying that a crisis is an opportunity for change. The Chinese symbol for crisis is translated in Wikipedia as “danger at a point of juncture”. In the year 2020, first China and then the rest of humanity have been presented with a monumental crisis: a new and lethal virus that spread fast and far, causing actions and reactions, with dramatic consequences for social and economic life around the globe. Rebecca Solnit wrote of another crisis in her book Hope in the Dark: The Untold Story of People Power. In Grounds for Hope, a foreword to the 2015 edition (p.2), she stated: “This is an extraordinary time full of vital, transformative movements, that could not be foreseen. It’s also a nightmarish time. Full engagement requires the ability to perceive both.”.
- Full Text:
- Date Issued: 2020
Education in times of COVID-19: Looking for silver linings in the Southern Africa’s educational responses
- Mukute, Mutizwa, Francis, Buhle, Burt, Jane C, De Souza, Ben
- Authors: Mukute, Mutizwa , Francis, Buhle , Burt, Jane C , De Souza, Ben
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/389799 , vital:68484 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/198219"
- Description: Coronavirus Disease 2019 (COVID-19) has disrupted socio-economic activities, including formal and non-formal education, across the world at lightning speed. By mid-April 2020, it had interrupted the formal education of nearly 1.6 billion students in 192 countries. COVID-19’s disruption of education in Africa, and especially in southern Africa, has been severe for several reasons. However, educational responses to COVID-19 suggest that it has stimulated the appetite for developing educational innovations – silver linings to the COVID-19 cloud. This paper is based on interviews conducted with 56 parents, students and educators involved in formal and non-formal education in Botswana, Malawi, Namibia, South Africa, Zambia and Zimbabwe. We identified the main educational challenges in these countries as being concerned with adapting to: (i) online education and learning, (ii) continuity of education from home, and (iii) community-based learning in small groups. The silver linings that we identified are: (i) putting greater emphasis on finding context-specific solutions to education and health problems (improvisation), which is important for educational relevance and reveals the value of local actors, (ii) making linkages between social and ecological systems clearer, which is making the value of education for sustainable development (ESD) in this century more explicit, and (iii) revealing structural inequality and justice issues in education, which draws attention to the need for urgently addressing them as part of transformative change in education and sustainable development.
- Full Text:
- Date Issued: 2020
- Authors: Mukute, Mutizwa , Francis, Buhle , Burt, Jane C , De Souza, Ben
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/389799 , vital:68484 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/198219"
- Description: Coronavirus Disease 2019 (COVID-19) has disrupted socio-economic activities, including formal and non-formal education, across the world at lightning speed. By mid-April 2020, it had interrupted the formal education of nearly 1.6 billion students in 192 countries. COVID-19’s disruption of education in Africa, and especially in southern Africa, has been severe for several reasons. However, educational responses to COVID-19 suggest that it has stimulated the appetite for developing educational innovations – silver linings to the COVID-19 cloud. This paper is based on interviews conducted with 56 parents, students and educators involved in formal and non-formal education in Botswana, Malawi, Namibia, South Africa, Zambia and Zimbabwe. We identified the main educational challenges in these countries as being concerned with adapting to: (i) online education and learning, (ii) continuity of education from home, and (iii) community-based learning in small groups. The silver linings that we identified are: (i) putting greater emphasis on finding context-specific solutions to education and health problems (improvisation), which is important for educational relevance and reveals the value of local actors, (ii) making linkages between social and ecological systems clearer, which is making the value of education for sustainable development (ESD) in this century more explicit, and (iii) revealing structural inequality and justice issues in education, which draws attention to the need for urgently addressing them as part of transformative change in education and sustainable development.
- Full Text:
- Date Issued: 2020
Education versus screening
- Kong, Camillia, Efrem, Mehret, Campbell, Megan M
- Authors: Kong, Camillia , Efrem, Mehret , Campbell, Megan M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302461 , vital:58198 , xlink:href="http:// 10.1136/medethics-2019-105396"
- Description: Informed consent procedures for participation in psychiatric genomics research among individuals with mental disorder and intellectual disability can often be unclear, particularly because the underlying ethos guiding consent tools reflects a core ethical tension between safeguarding and inclusion. This tension reflects important debates around the function of consent tools, as well as the contested legitimacy of decision-making capacity thresholds to screen potentially vulnerable participants. Drawing on human rights, person-centred psychiatry and supported decisionmaking, this paper problematises the use of consent procedures as screening tools in psychiatric genomics studies, particularly as increasing normative emphasis has shifted towards the empowerment and participation of those with mental disorder and intellectual disabilities. We expound on core aspects of supported decisionmaking, such as relational autonomy and hermeneutic competence, to orient consent procedures towards a more educative, participatory framework that is better aligned with developments in disability studies. The paper concludes with an acknowledgement of the pragmatic and substantive challenges in adopting this framework in psychiatric genomics studies if this participatory ethos towards persons with mental disorder and intellectual disability is to be fully realised.
- Full Text:
- Date Issued: 2020
- Authors: Kong, Camillia , Efrem, Mehret , Campbell, Megan M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302461 , vital:58198 , xlink:href="http:// 10.1136/medethics-2019-105396"
- Description: Informed consent procedures for participation in psychiatric genomics research among individuals with mental disorder and intellectual disability can often be unclear, particularly because the underlying ethos guiding consent tools reflects a core ethical tension between safeguarding and inclusion. This tension reflects important debates around the function of consent tools, as well as the contested legitimacy of decision-making capacity thresholds to screen potentially vulnerable participants. Drawing on human rights, person-centred psychiatry and supported decisionmaking, this paper problematises the use of consent procedures as screening tools in psychiatric genomics studies, particularly as increasing normative emphasis has shifted towards the empowerment and participation of those with mental disorder and intellectual disabilities. We expound on core aspects of supported decisionmaking, such as relational autonomy and hermeneutic competence, to orient consent procedures towards a more educative, participatory framework that is better aligned with developments in disability studies. The paper concludes with an acknowledgement of the pragmatic and substantive challenges in adopting this framework in psychiatric genomics studies if this participatory ethos towards persons with mental disorder and intellectual disability is to be fully realised.
- Full Text:
- Date Issued: 2020
Effect of a low density dust shell on the propagation of gravitational waves:
- Bishop, Nigel T, van der Walt, Petrus J, Naidoo, Monos
- Authors: Bishop, Nigel T , van der Walt, Petrus J , Naidoo, Monos
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159935 , vital:40357 , https://0-doi.org.wam.seals.ac.za/10.1007/s10714-020-02740-9
- Description: Using the Bondi-Sachs formalism, the problem of a gravitational wave source surrounded by a spherical dust shell is considered. Using linearized perturbation theory, the geometry is found in the regions: in the shell, exterior to the shell, and interior to the shell. It is found that the dust shell causes the gravitational wave to be modified both in magnitude and phase, but without any energy being transferred to or from the dust.
- Full Text:
- Date Issued: 2020
- Authors: Bishop, Nigel T , van der Walt, Petrus J , Naidoo, Monos
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159935 , vital:40357 , https://0-doi.org.wam.seals.ac.za/10.1007/s10714-020-02740-9
- Description: Using the Bondi-Sachs formalism, the problem of a gravitational wave source surrounded by a spherical dust shell is considered. Using linearized perturbation theory, the geometry is found in the regions: in the shell, exterior to the shell, and interior to the shell. It is found that the dust shell causes the gravitational wave to be modified both in magnitude and phase, but without any energy being transferred to or from the dust.
- Full Text:
- Date Issued: 2020
Effect of drought on communal livestock farmers in KwaZulu-Natal, South Africa:
- Vetter, S, Goodall, V L, Alcock, R
- Authors: Vetter, S , Goodall, V L , Alcock, R
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179006 , vital:40105 , https://doi.org/10.2989/10220119.2020.1738552
- Description: Despite the size of the informal small-scale farming sector and its livestock holdings in South Africa, there has been little detailed work to assess how livestock populations are affected by drought. South Africa experienced a major drought in 2015–2016. We analysed goat and cattle census data from the Msinga area in KwaZulu-Natal, which represent the livestock of some 3 000 households. Cattle farmers in the study area lost 43% of the herd, compared with 29% for goats, in 2015–2016. Three years after the drought, cattle numbers remained depressed, whereas goat numbers had recovered. Larger herds suffered lower mortality rates, suggesting that owners of larger herds had better means to support their herds. Support to reduce drought losses and aid recovery should take into consideration the different capabilities and requirements of small and large herd owners. Effects of high stocking rates and resource condition on mortality and herd growth were apparent during the drought year of 2016, but not the other years. Most die-offs appear to have been concentrated in a short period once forage and water resources became too scarce and far to reach. Recognising when this threshold is imminent would be useful for targeting strategic interventions.
- Full Text:
- Date Issued: 2020
- Authors: Vetter, S , Goodall, V L , Alcock, R
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179006 , vital:40105 , https://doi.org/10.2989/10220119.2020.1738552
- Description: Despite the size of the informal small-scale farming sector and its livestock holdings in South Africa, there has been little detailed work to assess how livestock populations are affected by drought. South Africa experienced a major drought in 2015–2016. We analysed goat and cattle census data from the Msinga area in KwaZulu-Natal, which represent the livestock of some 3 000 households. Cattle farmers in the study area lost 43% of the herd, compared with 29% for goats, in 2015–2016. Three years after the drought, cattle numbers remained depressed, whereas goat numbers had recovered. Larger herds suffered lower mortality rates, suggesting that owners of larger herds had better means to support their herds. Support to reduce drought losses and aid recovery should take into consideration the different capabilities and requirements of small and large herd owners. Effects of high stocking rates and resource condition on mortality and herd growth were apparent during the drought year of 2016, but not the other years. Most die-offs appear to have been concentrated in a short period once forage and water resources became too scarce and far to reach. Recognising when this threshold is imminent would be useful for targeting strategic interventions.
- Full Text:
- Date Issued: 2020
Effectiveness of private land conservation areas in maintaining natural land cover and biodiversity intactness
- Shumba, Tafadzwa, de Vos, Alta, Biggs, Reinette, Esler, Karen J, Ament, Judith M, Clements, Hayley S
- Authors: Shumba, Tafadzwa , de Vos, Alta , Biggs, Reinette , Esler, Karen J , Ament, Judith M , Clements, Hayley S
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/415852 , vital:71294 , xlink:href="https://doi.org/10.1016/j.gecco.2020.e00935"
- Description: Private land conservation areas (PLCAs) are increasingly looked to for meeting the deficit left by state-owned protected areas in reaching global conservation targets. However, despite the increasing extent and recognition of PLCAs as a complementary conservation strategy, little research has been done to quantify their effectiveness; a critical consideration if they are to be counted towards international biodiversity conservation targets. The long history of PLCAs in South Africa provides an interesting case study to address this knowledge gap. Here, we quantified the effectiveness of South African PLCAs by comparing losses in natural land cover and biodiversity intactness within PLCAs with different levels of protection to that of unprotected control points. Points within PLCAs were matched with unprotected control points to test the prediction that if PLCAs offer effective protection, losses in natural land cover and biodiversity intactness would be significantly lower within their boundaries in comparison to unprotected controls exposed to similar conditions. Consequences of natural land cover loss on biodiversity intactness were thus assessed, thus advancing standard approaches for quantifying effectiveness.
- Full Text:
- Date Issued: 2020
- Authors: Shumba, Tafadzwa , de Vos, Alta , Biggs, Reinette , Esler, Karen J , Ament, Judith M , Clements, Hayley S
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/415852 , vital:71294 , xlink:href="https://doi.org/10.1016/j.gecco.2020.e00935"
- Description: Private land conservation areas (PLCAs) are increasingly looked to for meeting the deficit left by state-owned protected areas in reaching global conservation targets. However, despite the increasing extent and recognition of PLCAs as a complementary conservation strategy, little research has been done to quantify their effectiveness; a critical consideration if they are to be counted towards international biodiversity conservation targets. The long history of PLCAs in South Africa provides an interesting case study to address this knowledge gap. Here, we quantified the effectiveness of South African PLCAs by comparing losses in natural land cover and biodiversity intactness within PLCAs with different levels of protection to that of unprotected control points. Points within PLCAs were matched with unprotected control points to test the prediction that if PLCAs offer effective protection, losses in natural land cover and biodiversity intactness would be significantly lower within their boundaries in comparison to unprotected controls exposed to similar conditions. Consequences of natural land cover loss on biodiversity intactness were thus assessed, thus advancing standard approaches for quantifying effectiveness.
- Full Text:
- Date Issued: 2020
Effects of an eight-week lumbar stabilization exercise programme on selected variables of patients with chronic low back pain:
- Abass, Ademola O, Alli, Abiola R, Olagbegi, Oladapo M, Christie, Candice J, Bolarinde, Olufemi S
- Authors: Abass, Ademola O , Alli, Abiola R , Olagbegi, Oladapo M , Christie, Candice J , Bolarinde, Olufemi S
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150307 , vital:38966 , DOI: https://doi.org/10.3329/bjms.v19i3.45864
- Description: Lumbar stabilisation exercise has been shown to reduce pain and disability in patients with low back pain but information on its potential benefits in term of back muscle endurance is scarce. This study was aimed at investigating the effects of augmenting conventional physiotherapy with lumbar stabilization exercises on selected variables of patients with non-specific chronic low back pain (NSCLBP).
- Full Text:
- Date Issued: 2020
- Authors: Abass, Ademola O , Alli, Abiola R , Olagbegi, Oladapo M , Christie, Candice J , Bolarinde, Olufemi S
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150307 , vital:38966 , DOI: https://doi.org/10.3329/bjms.v19i3.45864
- Description: Lumbar stabilisation exercise has been shown to reduce pain and disability in patients with low back pain but information on its potential benefits in term of back muscle endurance is scarce. This study was aimed at investigating the effects of augmenting conventional physiotherapy with lumbar stabilization exercises on selected variables of patients with non-specific chronic low back pain (NSCLBP).
- Full Text:
- Date Issued: 2020
Electricity use behaviour in a high-income neighbourhood in Johannesburg, South Africa:
- Williams, Stephanie P, Thondhlana, Gladman, Kua, Harn W
- Authors: Williams, Stephanie P , Thondhlana, Gladman , Kua, Harn W
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149725 , vital:38878 , https://doi.org/10.3390/su12114571
- Description: Worldwide, households’ consumption of electricity contributes to a substantial proportion of total national energy demand. Thus, the residential sector is a major entity in efforts to define and achieve global sustainability goals. Understanding electricity use behaviour and factors underlying behaviour is critical for designing behaviour change interventions, particularly in contexts characterised by fast-growing economies, burgeoning number of high-income households, and consumption growth. However, relative to developed economies, very little is known on this subject in South Africa. Using structured questionnaires, this study examines electricity use behaviour among high-income households in Johannesburg, South Africa.
- Full Text:
- Date Issued: 2020
- Authors: Williams, Stephanie P , Thondhlana, Gladman , Kua, Harn W
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149725 , vital:38878 , https://doi.org/10.3390/su12114571
- Description: Worldwide, households’ consumption of electricity contributes to a substantial proportion of total national energy demand. Thus, the residential sector is a major entity in efforts to define and achieve global sustainability goals. Understanding electricity use behaviour and factors underlying behaviour is critical for designing behaviour change interventions, particularly in contexts characterised by fast-growing economies, burgeoning number of high-income households, and consumption growth. However, relative to developed economies, very little is known on this subject in South Africa. Using structured questionnaires, this study examines electricity use behaviour among high-income households in Johannesburg, South Africa.
- Full Text:
- Date Issued: 2020
Electrodeposited Benzothiazole Phthalocyanines for Corrosion Inhibition of Aluminium in Acidic Medium
- Nnaji, Nnaemeka, Nwaji, Njemuwa, Nyokong, Tebello
- Authors: Nnaji, Nnaemeka , Nwaji, Njemuwa , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186112 , vital:44464 , xlink:href="https://doi.org/10.1155/2020/8892559"
- Description: Tetrakis[(benzo[d]thiazol-2-yl-thio) phthalocyaninato] gallium(III)chloride (1) and tetrakis[(benzo[d]thiazol-2ylphenoxy) phthalocyaninato] gallium(III)chloride (2) were successfully electrodeposited onto aluminium for corrosion retardation in 1.0 M hydrochloric acid solution. The aim of this study was to compare the corrosion resistance of electrodeposited metallated phthalocyanines. Scanning electron microscopy, X-ray diffraction, electrochemical impedance spectroscopy (EIS), and polarization confirmed the aluminium corrosion inhibition potentials of complexes 1 and 2. EIS and polarization techniques showed that complex 2 performed better than complex 1, with values from EIS measurements of 82% for 1 and 86% for 2 in 1.0 M hydrochloric acid solution. The importance of electrodeposition in industries and a dearth of research on the use of electrodeposited metallated phthalocyanines necessitated this study, and results show that coatings formed by electrodeposition of 1 and 2 onto aluminium reduced its susceptibility to corrosion attack.
- Full Text:
- Date Issued: 2020
- Authors: Nnaji, Nnaemeka , Nwaji, Njemuwa , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186112 , vital:44464 , xlink:href="https://doi.org/10.1155/2020/8892559"
- Description: Tetrakis[(benzo[d]thiazol-2-yl-thio) phthalocyaninato] gallium(III)chloride (1) and tetrakis[(benzo[d]thiazol-2ylphenoxy) phthalocyaninato] gallium(III)chloride (2) were successfully electrodeposited onto aluminium for corrosion retardation in 1.0 M hydrochloric acid solution. The aim of this study was to compare the corrosion resistance of electrodeposited metallated phthalocyanines. Scanning electron microscopy, X-ray diffraction, electrochemical impedance spectroscopy (EIS), and polarization confirmed the aluminium corrosion inhibition potentials of complexes 1 and 2. EIS and polarization techniques showed that complex 2 performed better than complex 1, with values from EIS measurements of 82% for 1 and 86% for 2 in 1.0 M hydrochloric acid solution. The importance of electrodeposition in industries and a dearth of research on the use of electrodeposited metallated phthalocyanines necessitated this study, and results show that coatings formed by electrodeposition of 1 and 2 onto aluminium reduced its susceptibility to corrosion attack.
- Full Text:
- Date Issued: 2020
Electronic and nonlinear optical properties of 2-(((5-aminonaphthalen-1-yl) imino) methyl) phenol
- Ojo, Nathanael D, Krause, Rui W M, Obi-Egbedi, Nelson O
- Authors: Ojo, Nathanael D , Krause, Rui W M , Obi-Egbedi, Nelson O
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193397 , vital:45328 , xlink:href="https://doi.org/10.1016/j.molliq.2020.114157"
- Description: In this study, solvent dependence of electronic and nonlinear optical properties of a new Schiff base, 2-(((5-aminonaphthalen-1-yl)imino)methyl) phenol (DANOHB), has been investigated. Electronic and optical properties of the Schiff base studied using Uv-visible absorption and fluorescence spectroscopic techniques in solution show that the Schiff base exhibits fluorescence with a quantum yield of 0.21 and a Stokes shift of 39 nm. Quantum chemical calculations were performed on the Schiff base at time-dependent density functional level of theory using Becke-3-Lee-Yang-Parr method with 6-311++G(d,p) basis set. Solvent dependence of the excited state energies (EE), energy gap (ΔE), first-order (β) and second-order (γ) hyperpolarizabilities were studied in gas, cyclohexane and ethanol. The medium perturbed the energy levels which implies that the reactivity, activity and stability of the system are solvent sensitive. The γ is more than thirty times higher than urea (standard NLO material) and this property is further enhanced in less polar medium. Small ΔE and large hyperpolarizabilities obtained for this system suggest its good potential in photonics and nonlinear optical devices.
- Full Text:
- Date Issued: 2020
- Authors: Ojo, Nathanael D , Krause, Rui W M , Obi-Egbedi, Nelson O
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193397 , vital:45328 , xlink:href="https://doi.org/10.1016/j.molliq.2020.114157"
- Description: In this study, solvent dependence of electronic and nonlinear optical properties of a new Schiff base, 2-(((5-aminonaphthalen-1-yl)imino)methyl) phenol (DANOHB), has been investigated. Electronic and optical properties of the Schiff base studied using Uv-visible absorption and fluorescence spectroscopic techniques in solution show that the Schiff base exhibits fluorescence with a quantum yield of 0.21 and a Stokes shift of 39 nm. Quantum chemical calculations were performed on the Schiff base at time-dependent density functional level of theory using Becke-3-Lee-Yang-Parr method with 6-311++G(d,p) basis set. Solvent dependence of the excited state energies (EE), energy gap (ΔE), first-order (β) and second-order (γ) hyperpolarizabilities were studied in gas, cyclohexane and ethanol. The medium perturbed the energy levels which implies that the reactivity, activity and stability of the system are solvent sensitive. The γ is more than thirty times higher than urea (standard NLO material) and this property is further enhanced in less polar medium. Small ΔE and large hyperpolarizabilities obtained for this system suggest its good potential in photonics and nonlinear optical devices.
- Full Text:
- Date Issued: 2020