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An understanting of mirrors and mirroring in a schizophrenic patient obsessed with his appearance

  • Authors: Zworestine, Barry John
  • Date: 1993-04
  • Subjects: Uncatalogued
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10962/191702 , vital:45149
  • Description: This work addresses the role of mirroring and mirrors encountered while working with a patient obsessed with his appearance. At the same time, however, it also attempts to provide an understanding of the process of mirroring from the developing unborn child to the adult. It examines the womb as a reflective space, the mirroring role of the mother, psychological work as mirror work, the psychopathologies of disruptive mirroring and the nature of reflection as a story, confusion and a ghostly other, and finally, the relationship between mirror reflection and psychological life. What is examined and described in this process applies not only to the specific case in study but is relevant at a universal level to all of mankind regardless of race or religion. The case-study method was used to examine the process of therapy that took place over three months. The patient’s identifying data, reasons for referral, presenting problem, family background, basic personality, interpersonal relationships, mental state, diagnosis, dynamic formulation and rationale for psychotherapy were covered in detail. The process of psychotherapy over 27 sessions was recounted and discussed in detail. Theoretical understandings drawn on to facilitate an understanding of the case were from Davis and Walbridge on Winnicolt, Winnicot, Liedloff, Kay, Romanyshyn, Bettelheim, Schwartz and others. , Thesis (MA) -- Faculty of Humanities, Psychology, 1993
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  • Date Issued: 1993-04

Aetiological factors that lead to suicide attempts among the youth of Lusikisiki area

  • Authors: Zweni, Mzamile Benute
  • Date: 2022-10
  • Subjects: Grahamstown (South Africa) , Eastern Cape (South Africa) , South Africa
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10353/27544 , vital:69314
  • Description: The general aim of this study was to investigate the aetiological factors that lead to suicidal attempts among the youth of Lusikisiki area in the Eastern Cape Province. A sample of hundred and fifty participants with an average age of 24 years old was selected using convenient sampling. Data was collected using self-administered questionnaires. After the data were collected, it was then analysed through descriptive and inferential statistics. Findings show that various factors lead to suicide ideation and suicide attempts among youth of Lusikisiki. Economic hardship, depression and substance abuse to name few, were found to be among factors that lead to suicide attempt. Based on the research findings, the researcher recommends that various stakeholders such as the Department of Social development should work in corroboration. Departments such as Department of Education and Sports, Recreation and Culture should make awareness campaigns that will psycho-educate youth in rural areas, possibly alleviating drug and substance abuse. Those awarenesses may also tap into strengthening psychosocial well-being of youth. Furthermore, Department of Social Development should come up with community outreach programs aimed at alleviating poverty as the contributory factor towards suicide attempt. , Thesis (MSoc) -- Faculty of Social Sciences and Humanities, 2022
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  • Date Issued: 2022-10

Communal property associations and protected areas management: some participation controversies in Dwesa-Cwebe Nature Reserve, Eastern Cape

  • Authors: Zwelakhe, Loyiso
  • Date: 2021-12
  • Subjects: National parks and reserves -- South Africa -- Eastern Cape -- Management
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/54355 , vital:46478
  • Description: The management and protection of protected areas such as nature reserves remains a primary concern for the different stakeholders involved; especially the marginalised rural communities that are deprived of genuine ownership of the natural resources. The representation of the marginalised rural communities adjacent to the protected areas has become significant in the control and utilisation of natural resources in protected areas. Communal Property Associations (CPAs) were established to help represent their communities in such matters of natural resources ownership and control. Despite; the formation of the CPAs, the participation of these associations in the management of the nature reserve in Dwesa-Cwebe has been questioned and under scrutiny. Therefore, this study seeks to understand the dynamics around the participation of the Dwesa-Cwebe Community Property Association in the management of Dwesa-Cwebe Nature Reserve. The study sought to find out experiences of the members of Dwesa-Cwebe CPA regarding their participation in the management of Dwesa-Cwebe Nature Reserve. Some questions needed to be answered, such as: To what extent is the membership in Dwesa-Cwebe CPAs a true representation of the needs of the local communities in the management of Dwesa-Cwebe Nature Reserve? What are the challenges faced by the members of the Dwesa-Cwebe CPA in representing the local communities in the management of the Dwesa-Cwebe Nature Reserve? What recommendations can be provided to solve the challenges faced by the Dwesa-Cwebe CPA in the management of Dwesa-Cwebe Nature Reserve? The study utilised a qualitative research methodology to obtain the answers to the main research questions. The study utilised convenience sampling to select ten suitable participants who were prepared to participate in the study and who are members of the CPA from Dwesa-Cwebe area. The research used interviews and non-participant observation to gather data. The collected data was analysed using thematic analysis. The analysis of the data revealed that there is limited participation by the CPA members in the management of Dwesa-Cwebe Nature Reserve. The study’s findings also indicated the CPA members are not involved in the management of the utilisation of generated revenue. The findings of this study also revealed that there are benefits that are entrenched in the participation of CPA members in the activities of the Dwesa-Cwebe Nature Reserve. However, the participation mechanisms are not producing the desired outcomes. Based on these findings the study recommends that the management of the Dwesa-Cwebe Nature Reserve review their management approach so as to ensure effective participation by CPA members. Further, there is a need to produce reports that update the Dwesa-Cwebe community on how the management of the nature reserve is utilising the generated revenue and its development plans. , Thesis (MBA) -- Faculty of Business and Economic Sciences, 2021
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  • Date Issued: 2021-12

Leveraging LTSP to deploy a sustainable e-infrastructure for poor communities in South Africa

  • Authors: Zvidzayi, Tichaona Manyara
  • Date: 2022-10-14
  • Subjects: Uncatalogued
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/365577 , vital:65761
  • Description: Poverty alleviation is one of the main challenges the South African government is facing. Information and knowledge are key strategic resources for both social and economic development, and nowadays they most often rely on Information and Communication Technologies (ICTs). Poor communities have limited or no access to functioning e-infrastructure, which underpins ICT. The Siyakhula Living Lab (SLL) is a joint project between the universities of Rhodes and Fort Hare that has been running for over 15 years now. The SLL solution is currently implemented in schools in the Eastern Cape’s Dwesa-Mbhashe municipality as well as schools in Makhanda (formerly Grahamstown). Over the years, a number of blueprints for the meaningful connection of poor communities was developed. The research reported in this thesis sought to review and improve the Siyakhula Living Lab (SLL) blueprint regarding fixed computing infrastructure (as opposed to networking and applications). The review confirmed the viability of the GNU/Linux Terminal Server Project (LTSP) based computing infrastructure deployed in schools to serve the surrounding community. In 2019 LTSP was redesigned and rewritten to improve on the previous version. Amongst other improvements, LTSP19+ has a smaller memory footprint and supports a graphical way to prepare and maintain the client’s image using virtual machines. These improvements increase the potential life of ICT projects implementing the SLL solution, increasing the participation of members of the community (especially teachers) to the maintenance of the computing installations. The review recommends the switching from thin clients deployments to full ("thick") clients deployments, still booting from the network and mounting their file systems on a central server. The switch is motivated by reasons that go from cost-effectiveness to the ability to survive the sudden unavailability of the central server. From experience in the previous deployment, electrical power surge protection should be mandatory. Also, UPS to protect the file system of the central server should be configured to start the shutdown immediately on electrical power loss in order to protect the life of the UPS battery (and make it possible to use cheaper UPS that report only on network power loss). The research study contributed to one real-life computing infrastructure deployment in the Ntsika school in Makhanda and one re-deployment in the Ngwane school in the Dwesa-Mbhashe area. For about two years, the research also supported continuous maintenance for the Ntsika, Ngwane and Mpume schools. , Thesis (MSc) -- Faculty of Science, Computer Science, 2022
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  • Date Issued: 2022-10-14

Investigation of the potency of topical corticosteroids using the vasoconstrictor assay

  • Authors: Zvidzayi, Kudzayi Michael
  • Date: 2017
  • Language: English
  • Type: text , Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/65279 , vital:28717
  • Description: Expected release date-May 2019
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  • Date Issued: 2017

Aspects of the ecology of the estuarine round-herring Gilchristella aestuaria (Pisces: Clupeidae) and its small-scale fishery potential

  • Authors: Zvavahera, Munetsi https://orcid.org/0000-0002-5337-1943
  • Date: 2021-05
  • Subjects: Small-scale fisheries , Silversides
  • Language: English
  • Type: Doctoral theses , text
  • Identifier: http://hdl.handle.net/10353/22765 , vital:52752
  • Description: In the past two decades, there has been increasing pressure for small-scale inland fisheries to play a central role in food and nutrient security for poor communities in South Africa. For decades, South African inland fisheries have focussed on the exploitation of large fish species and generally ignored the exploitation of inland small fish species (SFS). This research aimed to assess the ecology and small-scale fishery potential of the estuarine round-herring, Gilchristella aestuaria. To understand the ecology of G. aestuaria better, morphometric trait analysis and fish condition of populations in relation to environmental variables (salinity, pH, temperature, turbidity and chlorophyll-a) were done. Fish were supplemented with samples acquired from the SAIAB collection facility for 14 sites to cover all the three South African biogeographic regions, stretching from Lake Sibaya (KZN) to the Orange River estuary in the western parts of the country. The morphometric trait analysis showed that G. aestuaria populations can be distinguished based on the trait variation, however there were many overlaps for populations that are interconnected, with distant/ geographically separated populations showing clear differences. Morphometric traits of the G. aestuaria population were significantly different, however there was no strong directional relationship with environmental variables and variation in morphometric traits. However, fish condition as measured by Fulton’s condition (K) and relative weight (Wr) showed variation between populations found in different environments. These differences suggest that these populations must be managed differently if G. aestuaria is to be exploited in managed fisheries. To determine the potential nutrient value of G. aestuaria to the human diet, samples from two freshwater sites and five estuarine sites were analysed for essential macro and micronutrients. The nutrient content of G. aestuaria revealed there is potential for exploitation, as the species has a high macro (protein and fat) and micronutrient composition (calcium, iron and zinc). Mean ± SD of selected nutrients were protein (61.7±5.0 g/100g), fat (20.4±3.7g/ 100g), calcium (3507.5±314.0mg), iron (40.37±14.0mg/ 100g), zinc (22.47±5.6mg/ 100) and vitamin A (37.3±44.4 RAE/ 100g). The nutrient composition of fish collected from freshwater sites was comparable to those collected from estuarine environments. Using the recommended dietary allowances (RDA) from literature, the mass of fish and the number of fish that would provide a minimum amount for each nutrient were calculated. A child would require only 13.4g of dry G. aestuaria or approximately 74 dried fish to meet the daily requirements of zinc. Other minerals such as iron and calcium also showed a similar low weight or number of fish required to meet daily requirements for the different categories. A small number of G. aestuaria are needed to meet RDA for groups (children, adult men, adult women, pregnant women and lactating mothers). A comparison was done for the nutrient composition of G. aestuaria with reference species that are already harvested for human consumption in some African and Asian countries. The protein content of G. aestuaria was comparable to Chisense (Microthrissa moeruensis) and Kapenta Limnothrissa miodon), while the fat composition was more than twice Chisense and Kapenta. Comparing the mineral composition, G. aestuaria had more than three times higher calcium than Mola (Amblypharyngodon mola) and Puti (Puntius sophore). Zinc composition was four times higher than M. moeruensis and L. miodon. Further exploration of the ecology of G. aestuaria was studied using the Sundays River irrigations ponds as a case study that would represent small impoundments across South Africa. Species rank abundance curve and catch per unit effort (CPUE) on the Sundays Irrigation ponds revealed that G. aestuaria dominated numerically and biomass in the Sundays River irrigation ponds. To assess the potential of harvesting G. aestuaria harvesting experiments were conducted using depletion (removal) sampling. Catchweight (kg) ranged from 2.16 (1.03; 3.28) to 61.25 (44.40; 78.09) kg and the estimated biomass from the depletion model ranged from 1.05 to 40.19 kg/ha for September 2019. The depletion model revealed that small impoundments have high biomass per hectare of G. aestuaria ranging from which indicates that the species may not support a commercial fishery but small-scale fisheries. In conclusion, G. aestuaria could become a meaningful contribution to the food and nutrient security of poor communities where available as a food source through small-scale fishery exploitation. The extent of this contribution may depend on its production potential in various regions and environments. More research is however needed to determine the long-term sustainability of harvesting of G aestuaria by looking at how populations respond to harvesting. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
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  • Date Issued: 2021-05

Mulch tower treatment system Part I: Overall performance in greywater treatment

  • Authors: Zuma, Bongumusa M , Tandlich, Roman , Whittington-Jones, Kevin J , Burgess, Jo E
  • Date: 2009
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/71537 , vital:29862 , https://doi.org/10.1016/j.desal.2008.03.030
  • Description: A mulch tower (MT) system for greywater treatment is introduced in this paper. Materials used to assemble the MT system included mulch, coarse sand, fine and coarse gravel. Limited removal efficiency of the MT system was demonstrated for alkalinity, total hardness, pH, Cl–, PO43–, NH4+, and SO42–, with the estimated cumulative removals ranging from 7 to 12%. Intermediate removal efficiency was observed for chemical oxygen demand (COD), NO3–, and S2– with the estimated cumulative removals ranging from 24 to 28%. The highest removal efficiency was observed for the total suspended solids (TSS) with the estimated cumulative removal equal to 52%. Given the minute residence time in the MT system, the results obtained were promising and justify scale-up studies for potential on-site applications. The MT effluent did not meet hygienic norms with respect to the faecal coliform concentration (FC) and the total coliform concentration (TC), and further effluent treatment is required before any discharge or reuse of the treated greywater. Further research should focus on characterisation of the microbial community of the MT, and the fate of Cl–, PO43–, NH4+, and SO42–.
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  • Date Issued: 2009

Challenges facing teachers in implementing alternative measures of discipline in schools: a case study of five secondary schools in the Umzimkhulu circuit of the Sisonke District in Kwazulu-Natal

  • Authors: Zulu, Xolani Wycliff
  • Date: 2014
  • Subjects: School discipline , Secondary schools , Sisonke District -- Kwazulu-Natal, South Africa
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/11260/2393 , vital:41455
  • Description: This dissertation is a report on a study that was conducted in rural schools of the Sisonke District in KwaZulu-Natal, a province of South Africa. The study covered the challenges experienced by teachers in implementing the alternative measures of discipline. The study was conducted because the researcher was the head of the disciplinary committee in the school where he was employed and he often dealt with disciplinary problems which usually occurred between the teachers, learners and SMTs. It was important to know from other schools, what problems they faced in implementing the alternative measures of discipline. The study used a qualitative research design in the form of a case study. Purposive sampling was used. The sample comprised 15 SMT members, and 20 post level 1 teachers, and the total number of participants was 35. Data was collected through observations which were followed by interviews. Qualitative methods were used to analyse data. This involved reduction and interpretation of data collected. The findings of the study highlighted the role that could be played by SMTs, teachers, parents, and the Department of Education in the smooth running of the school in dealing with the misunderstandings of alternative measures of discipline and so advance an effective work ethos. The study also illuminated the issue of negligence on the part of SMTs in enforcing the implementation of the alternative measures of discipline. There was a great need for school teachers to be well versed in the general legislation of the Department of Education so as to align themselves with the correct rules and regulations when they deal with disciplinary problems. , Thesis (MEd) -- Faculty of Humanities, Educational Management and Policy, 2014
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  • Date Issued: 2014

Synthesis, characterization and antibacterial studies of metal complexes of substituted thiourea

  • Authors: Zulu, Happy Nonkululeko
  • Date: 2012-03
  • Subjects: Complex compounds , Halides , Ligands
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10353/24327 , vital:62636
  • Description: Eighteen complexes Co(II), Cu(II), Zn(II), and Fe(III) with phenylthiourea, diethylthiourea, disopropylthiourea and dimethylthiourea were synthesized and characterized by elemental analysis, UV-Vis, FTIR, conductivity measurements. The complexes were formulated as either four coordinate for the metal(II) or six coordinate for Fe(III). The proposed formulations are consistent with the spectroscopic data for the complexes. The single crystal X-ray structure of the Zn(II) complex of phenylthiourea, Co(II) complex of diethylthiourea and Zn(II) complex of diisopropylthiourea are also reported. The X-ray crystal structures for these complexes revealed distorted tetrahedral geometry around the metal ions showed that the metal ions are coordinated to two molecules of the substituted thiourea through the sulphur atom and two either acetates or chlorides ions complete the four-coordinate geometry. The in vitro antibacterial activity of the complexes was studied against six bacterial strains using disc diffusion and broth micro-dilution methods. The complexes showed selective antibacterial activity. , Thesis (MSc) -- Faculty of Science and Agriculture, 2012
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  • Date Issued: 2012-03

Synthesis, characterization and antiparasitic evaluation of chalcone hybrids

  • Authors: Zulu, Ayanda Ignatia
  • Date: 2021-10-29
  • Subjects: Uncatalogued
  • Language: English
  • Type: Doctoral theses , text
  • Identifier: http://hdl.handle.net/10962/192853 , vital:45271
  • Description: Thesis (PhD) -- Faculty of Science, Chemistry, 2021
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  • Date Issued: 2021-10-29

Synthesis and evaluation of arylpyrrole-chalcone hybrids as antiplasmodial and antitrypanosomal agents

  • Authors: Zulu, Ayanda Ignatia
  • Date: 2017
  • Language: English
  • Type: text , Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/65268 , vital:28716
  • Description: Expected release date-May 2019
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  • Date Issued: 2017

Synthesis, structure and in vitro anti-trypanosomal activity of non-toxic Arylpyrrole-Based Chalcone derivatives:

  • Authors: Zulu, Ayanda I , Oderinlo, Ogunyemi O , Kruger, Cuan , Isaacs, Michelle , Hoppe, Heinrich C , Smith, Vincent J , Veale, Clinton G L , Khanye, Setshaba D
  • Date: 2020
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/179017 , vital:40096 , https://doi.org/10.3390/molecules25071668
  • Description: With an intention of identifying chalcone derivatives exhibiting anti-protozoal activity, a cohort of relatively unexplored arylpyrrole-based chalcone derivatives were synthesized in moderate to good yields. The resultant compounds were evaluated in vitro for their potential activity against a cultured Trypanosoma brucei brucei 427 strain. Several compounds displayed mostly modest in vitro anti-trypanosomal activity with compounds 10e and 10h emerging as active candidates with IC50 values of 4.09 and 5.11 µM, respectively. More importantly, a concomitant assessment of their activity against a human cervix adenocarcinoma (HeLa) cell line revealed that these compounds are non-toxic.
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  • Date Issued: 2020

Perceptions of Kwazulu-Natal radiographers regarding the role of professional development in clinical practice

  • Authors: Zulu Anelisa
  • Date: 2022-12
  • Subjects: Radiography -- KwaZulu Natal , radiographers regarding
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/60290 , vital:64292
  • Description: Professional development in the form of continuing education is associated with professional competence and good service delivery to the patient, and this understanding of professional development applies to the radiography profession. A manager may prompt participation in professional development, or the needs of a radiography department may influence it, or it may be driven by the personal and professional ambitions of the radiographer. Participation could also be due to regulatory body requirements, which require tracking and documentation as in the case of the Health Professions Council of South Africa (HPCSA) which may audit the professional’s continuing professional development (CPD) compliance. Professional development is a concept inclusive of all learning such as CPD; postgraduate qualifications; staff development; and reflective practice, pursued for the betterment of the radiographers’ professional expertise. Few if any qualitative studies have sought to explore South African radiographers’ perceptions of professional development as a concept inclusive of all learning. The purpose of the study was to explore and describe the perceptions of KwaZulu-Natal radiographers regarding the role of professional development in clinical practice to make recommendations to radiography managers on how to optimise the participation of radiographers in professional development. Bandura’s social learning theory was used as the theoretical framework for a study of the perceptions of practising KZN radiographers regarding the role of professional development in clinical practice and exploring how people learn from one another, including concepts such as observational learning, imitation, and modelling. The target population for the study consisted of practising radiographers working in the public and private, rural and urban hospitals in KZN. Data were gathered using semi-structured one-on-one interviews and were coded using Tesch’s eight steps. The trustworthiness of this study was enhanced using Lincoln and Guba’s (1985) model of trustworthiness, namely: credibility, transferability, dependability and confirmability. , Thesis (MA) -- Faculty of Health Sciences, 2022
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  • Date Issued: 2022-12

Comparative phototransformation of environmental pollutants using metallophthalocyanines supported on electrospun polymer fibers

  • Authors: Zugle, Ruphino , Nyokong, Tebello
  • Date: 2013
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/190509 , vital:45001 , xlink:href="https://doi.org/10.1002/app.38381"
  • Description: The fluorescence and photoactivity of a series of Zn and Lu phthalocyanine complexes incorporated in various polymer fibers were investigated for the phototransformation of 4-chlorophenol, 4-nitrophenol, and methyl orange. The phthalocyanine complexes functionalized on polystyrene and polysulfone polymer fibers could be applied in the degradation of 4-chlorophenol, 4-nitrophenol, and methyl orange with 4-chlorophenol being much more susceptible to degradation while methyl orange was the least. Also polymer fibers of polystyrene were found to be reusable.
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  • Date Issued: 2013

Zinc (II) 2, 9, 16, 23-tetrakis [4-(N-methylpyridyloxy)]-phthalocyanine anchored on an electrospun polysulfone polymer fiber: Application for photosensitized conversion of methyl orange

  • Authors: Zugle, Ruphino , Nyokong, Tebello
  • Date: 2013
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/232741 , vital:50020 , xlink:href="https://doi.org/10.1016/j.molcata.2012.10.001"
  • Description: In this work, a comparative study of photodegradation of methyl orange, an azo dye, in homogeneous aqueous solution of a quarternized cationic zinc phthalocyanine and a heterogeneous catalytic system based on the same phthalocyanine anchored on polysulfone polymer fiber is presented. In both cases, conversion involved the azo bond of the dye with no detectable opening up of the aromatic benzene rings. The reaction kinetics in both cases were consistent with first order with the conversion occurring in the homogeneous system being faster than when the functionalized polymer fiber was used. The reaction products consisted of a coupling product as well as a series of oligopolymeric products.
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  • Date Issued: 2013

Electrospun polyacrylic acid polymer fibers functionalized with metallophthalocyanines for photosensitizing and gas sensing applications

  • Authors: Zugle, Ruphino , Nyokong, Tebello
  • Date: 2012
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/243543 , vital:51162 , xlink:href="https://doi.org/10.1080/10601325.2012.662006"
  • Description: The photophysical and photochemical properties of tetraaminophthalocyanine complexes of lutetium and zinc covalently linked to polyacrylic acid were studied alongside those of unsubstituted zinc phthalocyanine within the same polymeric fiber matrix. All three phthalocyanines within the solid fiber matrices showed photoactivity by the generation of singlet oxygen as was observed in solution. The fluorescence behaviors of the composite fibers equally parallel those in solution. For the unsubstituted zinc phthalocyanine composite, the fiber showed fluorescence quenching on interaction with gaseous nitrogen dioxide similar to that in DMF and, thus could be a promising nanofabric material in developing optoelectronic devices that are responsive to the gas.
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  • Date Issued: 2012

Photophysical characterization of dysprosium, erbium and lutetium phthalocyanines tetrasubstituted with phenoxy groups at non-peripheral positions

  • Authors: Zugle, Ruphino , Litwinski, Christian , Nyokong, Tebello
  • Date: 2011
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/247561 , vital:51595 , xlink:href="https://doi.org/10.1016/j.poly.2011.03.030"
  • Description: Dysprosium bis-phthalocyanine and monomeric phthalocyanines of erbium and lutetium with non-peripheral phenoxy substituents have been synthesized using two different preparative routes. Photophysical studies on these phthalocyanines revealed that the triplet states of dysprosium and erbium are not populated while the monomeric phthalocyanine complex of lutetium is populated with a quantum yield of 0.83 and a lifetime of 25 μs in DMSO. It was further found that the phthalocyanine complex of lutetium was capable of photochemical generation of singlet state molecular oxygen with yield of 0.71 in THF, thus a promising photosensitizer. However, the three phthalocyanine molecules have very low fluorescence quantum yields of less than 0.01.
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  • Date Issued: 2011

Physico-chemical properties of lutetium phthalocyanine complexes in solution and in solid polystyrene polymer fibers and their application in photoconversion of 4-nitrophenol

  • Authors: Zugle, Ruphino , Nyokong, Tebello
  • Date: 2012
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/243520 , vital:51160 , xlink:href="https://doi.org/10.1016/j.molcata.2012.02.010"
  • Description: The photophysical and photochemical behavior of two phthalocyanine complexes of lutetium peripherally substituted with tetraphenoxy and tetra-2-pyridiloxy groups were studied in solution and when dispersed in polystyrene polymer fiber. The phthalocyanines were found not to fluoresce significantly in solution and not at all within the fiber matrix as compared with standard unsubstituted zinc phthalocyanine. They showed very promising photoactivity in solution with high singlet oxygen quantum yields. Their photoactivity within the polymer fiber matrix was also demonstrated with the photoconversion of 4-nitrophenol, a water pollutant. The photodegradation process with both phthalocyanines follows first order kinetics similar to that observed for the zinc phthalocyanine and the photo-products were found to be hydroquinone, benzoquinone and 4-nitrocatechol.
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  • Date Issued: 2012

Photooxidation of 4-chlorophenol sensitized by lutetium tetraphenoxy phthalocyanine anchored on electrospun polystyrene polymer fiber

  • Authors: Zugle, Ruphino , Antunes, Edith M , Khene, Samson M , Nyokong, Tebello
  • Date: 2012
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/245787 , vital:51405 , xlink:href="https://doi.org/10.1016/j.poly.2011.11.005"
  • Description: An electrospun polystyrene (PS) fiber incorporating tetraphenoxy phthalocyanine complex of lutetium (LuTPPc/PS) as a photosensitizer was applied for the degradation of 4-chlorophenol in aqueous solution in the presence of visible light. The photocatalytic activity of the LuTPPc in the fiber was compared to that of zinc phthalocyanine (ZnPc) incorporated into the PS fiber, and the former showed higher activity. UV–Vis spectral changes of sample solutions indicated transformation of the analyte with first order kinetics and half-lives that are within one and half hours for LuTPPc/PS. Products identified from the spectral changes and gas chromatography were benzoquinone, hydroquinone and 4,4′-dihydroxydiphenol suggesting that the photodegradation of 4-chlorophenol was through both Types I and II mechanisms.
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  • Date Issued: 2012

Photophysical and photochemical behavior of electrospun fibers of a polyurethane polymer chemically linked to lutetium carboxyphenoxy phthalocyanine

  • Authors: Zugle, Ruhpino , Litwinski, Christian , Torto, Nelson , Nyokong, Tebello
  • Date: 2011
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/248428 , vital:51685 , xlink:href="https://doi.org/10.1039/C1NJ20126C"
  • Description: A phthalocyanine complex of lutetium substituted with four peripherally substituted 4-carboxyphenoxy groups was synthesized using cyclotetramerisation reaction. Its structure was elucidated using conventional spectroscopic methods and elemental analysis. The spectral behavior of the complex was studied in DMF solution and in a solid polyurethane fiber matrix. The UV-Visible spectrum showed a red shift in its Q-band maximum absorption within the fiber as compared to that in solution. The triplet quantum yield in DMF was determined to be 0.51 with a lifetime of 2.7 μs and a singlet oxygen quantum yield of 0.33 with a lifetime of 19.85 μs in the same solvent. The functionalized phthalocyanine fiber could be a promising fabric material for applications such as self-disinfecting in wound dressing. A method based on the conversion of ADMA was used to estimate the singlet oxygen quantum yield of the Pc in the hybrid fiber. An estimated singlet oxygen quantum yield value of 0.11 in aqueous medium was obtained. The fluorescence quantum yield of the Pc was found to be 0.01 with a lifetime of 3.20 ns in DMF.
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  • Date Issued: 2011
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