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Punishment in schools: perspectives of parents, teachers and pupils

- Sedumedi, Susan Dimakatso

  • Authors: Sedumedi, Susan Dimakatso
  • Date: 1997
  • Subjects: Punishment -- South Africa , Discipline of children -- Psychological aspects , Discipline of children -- South Africa , High school teachers -- South Africa -- Attitudes , High school students -- South Africa -- Attitudes , Parents -- South Africa -- Attitudes , Corporal punishment , Corporal punishment -- South Africa
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:3051 , http://hdl.handle.net/10962/d1002560 , Punishment -- South Africa , Discipline of children -- Psychological aspects , Discipline of children -- South Africa , High school teachers -- South Africa -- Attitudes , High school students -- South Africa -- Attitudes , Parents -- South Africa -- Attitudes , Corporal punishment , Corporal punishment -- South Africa
  • Description: While some research has been done on the use of corporal punishment in South African schools, there is a dearth of research on other forms of punishment and little has been done to research the meaning of punishment. This study explores the meaning of punishment in a high school context and focuses on the different attitudes of parents, teachers and pupils, with a view to identifying, in particular, how they justify the use of punishment. A sample of 50 pupils, 30 teachers and 30 parents were selected for the study. Focus groups and a questionnaire with closed and open-ended questions were used to collect the data. The questionnaire was constructed to explore themes which emerged in the focus group discussions . Results were grouped into themes and arranged by tables , and the Chi-square test of statistical significance was used to analyze some of the data. The results show that the meaning and the approach to punishment is differently construed by participants. Parents construe punishment as an educative instrument and a disciplinary measure used for the good of pupils and the society. Teachers see it as a discip1inary measure, a strategy used for effective learning, and a negative stimulus used to inflict pain towards the goal of an orderly school environment. To pupils the punishment scene provides an opportunity for what they perceive as sadistic enjoyment and as something negative which is used by teachers to vent their own frustrations. Participants agree that clear, consensually agreed upon rules should be set to regulate school behaviour and that there should be clear and consensually agreed upon ways of ensuring that these rules are adhered to; and constructive ways of dealing with violation of these rules. The central concern seems to be to move away from a retributive, punitive mode of thinking about punishment, towards a purposeful one. The implications of the research findings are discussed in the context of existing literature in the area and in relation to policy development.
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  • Date Issued: 1997

Qonqonqo

- Group performance, Group composition, Dargie, Dave

Radio observation of the Gum Nebula Region

- Woermann, Beate

  • Authors: Woermann, Beate
  • Date: 1997
  • Subjects: Radio sources (Astronomy) Nebulae -- Observations Radio astronomy
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:5485 , http://hdl.handle.net/10962/d1005271
  • Description: This thesis describes the results of an investigation of the physical properties of the Gum Nebula. For this investigation a radio continuum map of the region was made at 2326 MHz and resolution ⅓° with the HartRAO antenna. This map was used to generate spectral index images and an infrared to radio flux density ratio (IRR) image. The latter image shows that the IRR of the nebula is in the range 20 to 250, identifying it as an old SNR. Several spectral index images of this region were generated using two different methods, one based on the isolation of the nebula from its background radiation, the other based on TT-plots (Turtle et al., 1962). The two methods yield similar results, which show that the nebula has a thermal shell with a non-thermal region in its interior. Below the galactic plane the thermal region dominates and above the plane the nonthermal region. These results suggest a model of an old SNR with an H II region shell. Spectral line observations of hydrogen recombination lines and hydroxyl (OH) were made with the HartRAO and the Mopra telescopes. The detection of hydrogen recombination lines at four positions in the thermal regions of the nebula give electron temperatures and emission measures in the ranges 4000 to 6000 K and 220 to 460 pc.cm⁻⁶ respectively. The turbulent velocities are of the order of 20 km/s. A search for shocked OH lines at 1667 MHz and 1720 MHz in the Gum Nebula gave results that were negative, but numerous unshocked 1667 MHz OH lines were detected. The latter were used in a test for an expansion of the nebula. The most plausible fit to the data gives an expansion centre at l = 260.5°, b = -2.5° and at a distance of 0.7 kpc from us. The front face angular radius and expansion velocity are 10.5° and 16 km/s respectively. The back face angular radius and expansion velocity are 8.50 and 7 km/s respectively.
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  • Date Issued: 1997

Regional and local economic development strategies in the Eastern Cape and guidelines for future development

- Nel, E L

  • Authors: Nel, E L
  • Date: 1997
  • Subjects: Community development -- South Africa -- Eastern Cape Case studies Community development Community development -- South Africa -- Eastern Cape Eastern Cape (South Africa) -- Economic conditions
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4848 , http://hdl.handle.net/10962/d1005524
  • Description: Local Economic Development (LED) is an applied economic development strategy which seeks to address site-specific needs through locally appropriate solutions. In this thesis, the faith being accorded to the potential of LED in South Africa is critically examined. The study is based on a detailed examination of the experience of regional development and several emerging cases of LED in the Eastern Cape Province of South Africa. High levels of poverty and unemployment necessitate and justify innovative approaches to address such problems. The thesis examines the potential of LED strategies and identifies applied policy guidelines which can help address the Province's development needs. The theoretical framework of this research is based on a critical examination of international and South African literature dealing with development issues, LED and localities theory. A detailed documentary examination of early LED endeavours and the experience of regional development in the present century was undertaken. Results suggest that LED is not a new concept and that regional development, through its political bias, achieved only limited success. Contemporary examples of LED were identified and examined through detailed site-specific investigations. This was carried out through the use of semistructured interviews supplemented by participatory rural appraisal and questionnaire surveys which served as a means to triangulate the results. The research findings indicate that regional development, as applied in the study area, did not lead to the establishment of a permanent industrial base. In terms of the concept of LED, it is apparent that it has allowed for socio-political empowerment but has only improved economic conditions in the more well-endowed case-studies. In these areas, positive antecedent conditions and the key role played by community supportive nongovernmental organizations is apparent. Despite the limited degree of success which many initiatives attain, the thesis regards LED as a development alternative for areas which are unlikely to draw in external investment. Some of the key contributions of the thesis include the advancement of a refined typology of LED, the development of a research schedule to investigate and assess LED initiatives and the postulation of appropriate development guidelines and theoretical constructs.
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  • Date Issued: 1997

Regulation of tryptophan-2,3-dioxygenase and pineal indoleamines by selected tryptophan derivatives and antidepressants

- Walsh, Harold Archibold

  • Authors: Walsh, Harold Archibold
  • Date: 1997
  • Subjects: Antidepressants Tryptophan -- Physiological effect Tryptophan -- Therapeutic use Depression, Mental -- Treatment
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4017 , http://hdl.handle.net/10962/d1004077
  • Description: The regulation of tryptophan-2,3-dioxygenase (TDO) (EC 1.13.1.12) and, to a lesser extent, pineal indoleamines, both in vitro and in vivo, is examined in this study. Rat liver TDO is a cytosolic enzyme which plays a crucial role in the regulation of circulating tryptophan (TRP) levels. Stimulation of this enzyme by heme enhances the catabolism of TRP, making less TRP available for uptake into the brain and other tissues, and for protein synthesis. At pH 7, the enzyme has an approximate Km of 100μM, is subject to substrate inhibition immediately beyond Sopt([S] at Vmax), and response of the enzyme is cooperative in both uninhibited and inhibited regions. Hill analysis of the uninhibited region reveals a biphasic plot and two classes of binding sites. Negative cooperativity is brought about through deprotonation of the enzyme. Substrate iphibition also occurs at both acidic and basic pH values with concomitant shifts in Sopt. The results obtained indicate that substrate inhibition could be an additional mechanism whereby the flux through the TRP-kynurenine pathway is regulated. TDO is subject to a diurnal rhythm, with peak activity during the pre-dark period and the loweSt activity towards the end of the dark period. It is possible that the enzyme controls the synthesis of the neurotransmitter serotonin (5-HT), and that the circadian rhythm in TDO activity is due to the endogenous rhythm of melatonin (aMT) production by the pineal gland. In the present study, aMT displaces TRP from bovine serum albumin (BSA) in vitro, and it is therefore possible for the indoleamine to regulate the availability of TRP for uptake into the brain for conversion to its derivatives. Chronic intraperitoneal administration of aMT affects physiological hepatic parameters in rats, such as TDO activity and stromal fatty acid composition, whilst no observable effect is demonstrable with respect to protein synthesis, nucleic acid metabolism, membrane fatty acid composition and pineal indole biosynthesis. On the other hand, chronic treatment of rats with antidepressants, the tricyclic desmethylimipramine (DMI) and the selective serotonin reuptake inhibitor (SSRI), fluoxetine, reveals significant negative alterations in TDO concentrations and pineal indole amine synthesis. Combining aMT with any of these two drugs normalises the activity of the hepatic enzyme. DMI is found to be an effective inhibitor of TDO in the micromolar range in vitro, and also affects total enzyme concentrations in vivo. Fluoxetine has no effect on TDO in vitro, but in vivo also reduces total enzyme levels in the liver. However, the SSRI does not affect conjugation between apo- and holoenzyme. Instead, it decreases extant holoenzyme levels. Indoleamine synthesis by the pineal gland, in organ culture, is altered by both antidepressants, although in different ways. DMI increases N-acetylserotonin levels and reduces the output of methoxyindole acetic acid and meth6xytryptophol. Fluoxetine treatment markedly reduces aMT concentrations and also brings about high levels of the 5-HT catabolites, 5-hydroxytryptophol and 5-hydroxyindole acetic acid. Insulin also lowers aMT synthesis significantly in pineal organ cultures, via a mechamsm that involves inhibition of the enzyme, N-acetyl transferase, that regulates aMT synthesis. The effects of insulin on pineal indole metabolism are due to the observation that a carbohydrate rich diet which induces insulin release elevates plasma TRP and brain 5-HT, but has no effect on pineal TRP and indole amine synthesis. It could thus be possible for insulin to have an effect on the pineal, since the latter is outside the blood brain barrier. The finilings of this study support the biogenic amine deficiency hypothesis, implicating some of the major biogenic amines such as noradrenaline (NA), 5-HT and aMT in depression. There is believed to be a deficiency of NA and 5-HT at their respective synapses in the depressed state. The drug DMI could act, firstly, by inhibiting TDO and thus increasing plasma TRP levels, and could, secondly, stimulate NA release and inhibit NA reuptake at the pineal membrane. The combined effect would be to enhance aMT synthesis, with eventual remission. Fluoxetine, on the other hand, appears to utilize a slightly different mode of action to DMI, which seems to focus on the preservation of 5-HT. The fact that aMT counteracts the effects of both antidepressants, and restores the activity of TDO to that of the controls, is also consistent with the observation that the therapeutic action of drugs such as these coincides willi the restoration of normal plasma levels of the neurohormone in depressives. In view of the biogenic amine deficiency hypothesis of depression and the contentious claim that TDO is the major peripheral determinant of brain TRP, brain 5-HT and ultimately aMT, the regulation of TDO is investigated and discussed. The study concludes that TDO activity is regulated by a number of endogenous compounds which are mainly derivatives of TRP, such as aMT and oxidized nicotinamide adenine dinucleotide and exogenous substances, of which DMI and fluoxetine are but two. In addition, modulation of IDO activity in depression appears to be an important aspect of antidepressant action. aMT, the product of the pineal gland, also has the potential to increase plasma TRP and hence forebrain TRP levels, and ultimately 5-HT concentrations, firstly by displacing TRP from serum albumin and secondly by inhibiting TDO.
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  • Date Issued: 1997

Reproductive and feeding biology of the Natal mountain catfish, Amphilius natalensis (Siluriformes: Amphiliidae)

- Marriott, Michael S, Booth, Anthony J, Skelton, Paul H (Paul Harvey)

  • Authors: Marriott, Michael S , Booth, Anthony J , Skelton, Paul H (Paul Harvey)
  • Date: 1997
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/125837 , vital:35823 , https://doi.10.1023/A:1007361511052
  • Description: The family Amphiliidae comprises nine genera and about 60 species. Only five species are found in southern Africa, three of which belong to the genus Amphilius (Skelton 1993). These soft-bodied catlets inhabit clear, fast flowing mountain streams where they live amongst cobbles, feeding predominantly on benthic invertebrates (Crass 1964, Skelton 1993). The Natal mountain catfish, A. natalensis Boulenger, 1917, is a small, nocturnal species with a restricted distribution along the eastern seaboard of southern Africa. It occurs in mountain streams from the Umkomaas River north to the Limpopo system in South Africa. It is also present in the Marozi River, a tributary of the Zambezi River in Zimbabwe and in the Ruo River, Malawi (Skelton 1984, 1993). Skelton (1993) suggested that predation by introduced trout species has led to scarcity of A. natalensis in many streams. In spite of this, no studies on the biology of this catfish species have been published. This study presents the first quantitative information on the biology of an amphiliid catfish, A. natalensis including gametogenesis, spawning seasonality, size-at-maturity, adult sex ratio and diet.
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  • Date Issued: 1997

Research as intervention within community mental health

- Macleod, Catriona I

  • Authors: Macleod, Catriona I
  • Date: 1997
  • Language: English
  • Type: Article
  • Identifier: vital:6286 , http://hdl.handle.net/10962/d1014525 , http://www.curationis.org.za/index.php/curationis/article/view/1307
  • Description: This paper raises some issues for discussion and debate concerning the nature of research within a mental health setting. Research, no matter what form it takes, is always an intervention. Sensitivity to various concerns surrounding research is required of the mental health worker. Participatory research, which is seen as empowering participants, has become popular in mental health programmes. Attention needs to be paid however, to the meaning of participation and the process of decision-making. Researchers are often uncomfortable with shedding their “objective informer” stance and adopting a position that requires social action. Some of this has to do with the epistemological view taken by the researcher. This paper suggests that the knowledge produced in research is a social construction created in interaction between the researcher and participants and has a multiplicity of potential meanings. The instrumental, conceptual and persuasive uses of research are discussed, and two intervention-type research procedures (needs assessment and evaluation) are critically reviewed It is concluded that research, as with all other interventions, should be carefully planned, implemented, monitored and evaluated. , This paper was written by Catriona Macleod as M.Ed (Psych), Department of Educational Psychology, University of Zululand
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  • Date Issued: 1997

Research report

- NALEDI

  • Authors: NALEDI
  • Date: 1997
  • Subjects: NALEDI
  • Language: English
  • Type: text
  • Identifier: http://hdl.handle.net/10962/151396 , vital:39063
  • Description: The intention of this paper is to highlight debates and issues regarding the use of guota systems in strengthening women’s leadership in the labour movement. The paper is aimed at broadening the debate from mere acceptance or rejection of the guota. Debates on the use of guotas tend to be heated and controversial and can lose sight of the central objective, which is the development of strategies for women’s empowerment. A large proportion of trade unions internationally have adopted forms of the quota system as a strong measure to deal with the ongoing under-representation of women in leadership. The quota system has also been introduced effectively in a number of parliaments all over the world, including South Africa. The countries with the highest representation of women in parliament have all had to use quotas to achieve this. The paper draws from a review of some of the international literature, as well as interviews undertaken with trade unionists and parliamentarians (see Appendix A for a list of interviewees). This paper will also highlight some examples where quota systems have been adopted, including three COSATU affiliates, namely CWIU, NEHAWU and SAMWU.
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  • Date Issued: 1997

Resisting racism: a teachers' guide to equality in education

- Eyber, Carola, Dyer, Dorothy, Versfeld, Ruth

  • Authors: Eyber, Carola , Dyer, Dorothy , Versfeld, Ruth
  • Date: 1997
  • Subjects: Discrimination in education -- South Africa -- Prevention , Educational equalization -- South Africa , Multicultural education -- South Africa , Racism -- South Africa , School integration -- South Africa
  • Language: English
  • Type: text , book
  • Identifier: http://hdl.handle.net/10962/73690 , vital:30217 , 1874864462
  • Description: While South Africa's new democracy has meant that schools are now open to all, there is still racism in our schools. The changes in schools have in some cases exacerbated racial tensions and mistrust. Teachers everywhere are struggling with the changing dynamics of their classrooms and schools. There is much talk about how to work against racism. Various programmes and schools have developed different ways of dealing with it. All have particular ideas about how best to counter it. Resisting Racism aims to discuss and understand the beliefs and assumptions underlying many of these approaches. We look at the theories behind the different practices, present a range of ideas to illustrate them and consider their limits and possibilities. The book is a starting point for teachers and schools to reflect on their practices and help them to work out new strategies in the classroom and school. The approaches described will probably work best if they are used together, specially adapted to the specific context in which they are to be used. In the first part of the book we look at psychological and sociological explanations of why people are racist. Four different ways of looking at the issues are described. Each suggests practical ways of dealing with racism in the classroom and in the school. Chapter Three, on multi-cultural and anti-racist education, covers similar ground but from a slightly different angle, looking at curriculum debates about race, culture and equality. The final section looks at the concerns that many teachers have every day, such as "How can I deal with the language problem?" and "How can I involve parents in these issues?" In discussing these questions we have tried to use current theory to inform the practical ideas suggested. You will discover that this book is not neutral. It does have a point of view. It seeks to explain the limitations of assimilating students into a status quo and asks that schools take a critical look at their policies and practices. There are no easy answers or quick solutions. However thinking about and understanding the issues of racism and the ways in which it may be resisted can only bring us closer to positive change.
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  • Date Issued: 1997

Responding to literature: empowering girls to speak with their own voices in a multicultural context

- Foster, Lesley

  • Authors: Foster, Lesley
  • Date: 1997
  • Subjects: Reader-response criticism--South Africa Multicultural education
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1742 , http://hdl.handle.net/10962/d1003626
  • Description: The purpose of this study was to investigate whether the space provided by a readerresponse transaction between girls and the text, Roll of Thunder, Hear My Cry (Taylor 1977) .. empowered pupils to tell their own stories. It also sought to identify ways in which the problems and possibilities perceived by these pupils might guide curriculum decisions in a transforming education system. In addition to engaging in reader-response activities around the text, drama and videos providing social context were integral to the programme. Related work in the subject areas of history and lifeskills was also undertaken. Data was drawn from pupils' reading journals, responses to specific passages, transcripts of small group discussions, and interviews. The study is ethnographic in nature and all the data qualitative. Theoretical insights were drawn from the felds of cultural studies, postmodern criticism, and postructural modes of cultural and social analysis inasfar as they illuminate and inform the relationship between language, knowledge and power. The research was conducted in an historically white, girls' school which adopted a nonracial admissions policy in January 1991. Despite the fact that existing traditions and values of the the school to a very large extent influence what is taught, the data suggests that pupils were becoming agents in their own learning and were taking up multiple identities both within and without the world of the school.
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  • Date Issued: 1997

Rhodes University Annual Report 1997

- Rhodes University

Rhodes University Graduation Ceremony 1997

- Rhodes University

  • Authors: Rhodes University
  • Date: 1997
  • Language: English
  • Type: text
  • Identifier: vital:8131 , http://hdl.handle.net/10962/d1006776
  • Description: Rhodes University 1997 Graduation Ceremony [at] 1820 Settlers National Monument Friday, 18 April at 10:30 a.m., 08:15 p.m. [and] Saturday, 19 April at 10:30 a.m. , Rhodes University 1997 Graduation Ceremony City Hall, East London Friday, 9 May at 6:00 p.m.
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  • Date Issued: 1997

SA in the global economy

- TURP

  • Authors: TURP
  • Date: 1997
  • Subjects: TURP
  • Language: English
  • Type: text
  • Identifier: http://hdl.handle.net/10962/160942 , vital:40569
  • Description: There are growing ties in the world between countries which coincides with current major social, political and economic restructuring. This is what many refer to as “globalisation”. Globalisation is a process which involves greater influence by global forces on individual countries such as South Africa. It means that global rules are being set which impact on: the policies of our government, the way companies in South Africa make their plans, the way that trade unions, community organisations and development organisations take up issues, and the way individuals make a living in the country. Globalisation has raised new and difficult issues for the labour movement and have thrown up new forms of struggle. Some of these issues have stumped and even demobilised some unionists in South Africa and internationally. Some feel that globalisation cannot be challenged and that there is no alternative. Others feel that we have not become powerless and that there are ways to fight its negative effects. Turp has published a book on these issues entitled, South Africa in the Global Economy: understanding the challenges, working towards alternatives. One of the main purposes of the book is to clarify what the new complex and challenging issues are. By doing this, we hope to clarify what we are up against.
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  • Date Issued: 1997

Share-net: a case study of environmental education resource material development in a risk society

- Taylor, Robert James

  • Authors: Taylor, Robert James
  • Date: 1997
  • Subjects: Environmental education Environmental education -- South Africa Environmental education -- Activity programs -- South Africa Environmental education -- South Africa -- Information resources
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:1765 , http://hdl.handle.net/10962/d1003650
  • Description: This narrative study reviews the development of Share-Net, an informal resource materials network, located within the developing environmental education activities of the Wildlife and Environment Society of South Africa. Historical shaping factors within the Society are discussed and changing views on conservation, environmental education and research are described. Rather than the research process being a utilitarian and outside endeavour for clarifying and monitoring, the research orientation of this study is one of grounded activity within and integrally part of processes of change. Within a developing story of resource materials and workshops, themes are traced and emergent tensions are critically reviewed. Teacher workshops from 1981 until 1995 are analysed and developing orientations are described. Within this review changes are evident from an orientation of 'us' informing 'them' to joint, collaborative endeavours within the development and use of resource materials. The study reviews and illuminates the Share-Net project around questions of project orientation and management and this is done through the narration of case studies. Principles and patterns emerging within these are examined to guide future resource development projects. Popularist notions of networking and structural functionalist notions of social change are also examined. Grand, modernist strategies designed to cause change in others are questioned and the role of small-scale nodes of resource material activity cooperating within an open network are clarified as useful alternatives. Local resourcing centres such as these have proved useful in supporting teachers in the development, use and adaptation of resource materials. The study also examines income and expenditure of the Share-Net project since 1988 to review economic sustainability. A case is made for sustaining the project conceptually and financially through the sales of products and services rather than through external donor sources. Finally the study raises questions and challenges within the project and proposes guiding frameworks for future review, in action, as the story continues.
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  • Date Issued: 1997

Solid state thermal decomposition of amide complexes of nickel(II) chloride

- Nelwamondo, Aubrey Ndifelani

  • Authors: Nelwamondo, Aubrey Ndifelani
  • Date: 1997
  • Subjects: Decomposition (Chemistry) Materials -- Thermal properties Amides
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4345 , http://hdl.handle.net/10962/d1005008
  • Description: The thermal decompositions of a series of amide complexes of nickel(II) chloride have been studied. Thermochemical, kinetic, structure and solid-state stability correlations have been investigated. Complexes containing homologous amide ligands (L) of the form NiLCℓ₂, Ni₃L₂Cℓ₆, Ni₃LCℓ₆, NiL₂Cℓ₂(2H₂0) and ML₂Cℓ₂ (where M = Ni(II), Co(II) or Cu(II)) have been prepared. Chemical analysis, spectral and thermogravimetric measurements were used to characterize the complexes and their decomposition stoichiometries. Three sets of reactions were identified as yielding stable products in a single step: (i) NiLCℓ₂ (s) → NiCℓ₂ (s) + L (g) (ii) Ni₃LCℓ₆ (s) → 3NiCℓ₂ (s) + 2L (g) (iii) Ni₃LCℓ₆ (s) → 3NiCℓ₂ (s) + L (g) Characterization of the processes in the ML₂Cℓ₂ and NiL₂Cℓ₂(2H₂0) complexes was not straightforward. Reaction enthalpies (ΔH) were determined using DSC. The orders of the reaction onset temperatures (Tc), peak temperatures (Tmax) and ΔHL values for the NiCℓ₂ system were: N-methylacetamide < acetamide < N-methylformamide, suggesting the importance of steric hindrance of the methyl-substituent groups in the amide skeleton. In the Ni₃LCℓ₆, NiL₂Cℓ₂(2H₂0) and ML₂Cℓ₂ systems no simple orders could be deduced. The Te and Tmax sequences obtained from analogous metal(II) chloride complexes indicated that the copper(II) complexes were the least stable. The kinetics of the loss of L from NiLCℓ₂ complexes were investigated using isothermal TG, non-isothermal TG and DSC measurements. The contracting geometry models described the course of the decompositions in the most satisfactory manner. Apparent activation energies ( Ea) were estimated from Arrhenius plots of rate coefficients from: (i) an approximate zero-order relationship, (ii) the contracting-area (R2) and contracting-volume (R3) equations, (iii) a new empirical (B2) expression, (iv) the half-life ( 1/t₀.₅) and (v) the characteristic feature of the rate-time curve ( 1/tmax/2 ). The non-dependence of Ea on the rate equation used supports the reliability of the kinetic parameters. Non-isothermal experiments were analyzed by the Coats-Redfern, the modified BorchardtDaniels and the Kissinger methods. Arrhenius parameters were in keeping with results from the isothermal kinetic measurements. The values of Ea obtained for the NiLCℓ₂ system increased with an increase in basicity of the amide ligands. No straightforward correlation was found between Ea and Te, Tmax, ΔHL or spectral properties.
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  • Date Issued: 1997

Somagwaza

- Performer not specified, Composer not specified, Dargie, Dave

Somagwaza

- Performer not specified, Composer not specified, Dargie, Dave

Somagwaza

- Performer not specified, Composer not specified, Dargie, Dave

Somagwaza

- Hogsback festival participants, Composer not specified, Dargie, Dave

Somagwaza

- Performer not specified, Composer not specified, Dargie, Dave

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