Conformational Control of Exciton-Polariton Physics in Metal - Poly(9,9-dioctylfluorene) - Metal Cavities

Control is exerted over the exciton-polariton physics in metal - Poly(9,9-dioctyl fluorene) - metal microcavities via conformational changes to the polymer backbone. Using thin-film samples containing increasing fractions of $\beta$-phase chain segments, a systematic study is reported for the mode characteristics and resulting light emission properties of cavities containing two distinct exciton sub-populations within the same semiconductor. Ultrastrong coupling for disordered glassy-phase excitons is observed from angle-resolved reflectivity measurements, with Rabi splitting energies in excess of 1.05 eV (more than 30% of the exciton transition energy) for both TE- and TM-polarized light. A splitting of the lower polariton branch is then induced via introduction of $\beta$-phase excitons and increases with their growing fraction. In all cases, the photoluminescence emanates from the lowermost polariton branch, allowing conformational control to be exerted over the emission energy and its angular variation. Dispersion-free cavities with highly saturated blue-violet emission are thus enabled. Experimental results are discussed in terms of the full Hopfield Hamiltonian generalized to the case of two exciton oscillators. The importance of taking account of the molecular characteristics of the semiconductor for an accurate description of its strong coupling behaviour is directly considered, in specific relation to the role of the vibronic structure

The junior South African individual scale as predictor of scholastic achievement at Sub A, Sub B & Std One levels

This study examines the relationship between the eight subtest form of the Junior South African Individual Scale (JSAIS - 8) and scholastic performance at Sub A, Sub B and Std One levels, as measured by teacher evaluations. An unreferred sample of 104 pupils who had been tested on the JSAIS- 8 in their Sub A year were followed up at the end of Std One. The pupils' three sets of year-end symbols, as recorded in the official school records, were obtained. Pearson correlations were calculated between the Global, Verbal Performance and Numerical Scales and each of the subtests on the one hand, and selected school subjects and a computed average of the subjects on the other. The JSAIS scales and subtests were regressed on the computed averages for each standard. A test was performed to evaluate the longitudinal stability of the correlation matrix of Pearson correlations. The results were compared with those of similar studies employing non-South African intelligence scales, and with a study employing the full, twelve subtest version of the JSAIS (JSAIS - 12). The values of the correlations yielded were found to be of the same general magnitude as those reported in studies employing non-South African scales. The test for the longitudinal stability of the Pearson correlation matrix indicated that the test probably predicted equally over the three standard levels. The Global, Verbal and Numerical Scales and their associated subtests correlated moderately to highly with measures of scholastic achievement. The Performance Scale and its subtests yielded lower and sometimes non-significant correlations. Some discrepancies were noted between the results of the present study and that which employed the JSAIS - 12. It was observed that three of the five subtests which yielded the highest correlations with scholastic achievement in the study employing the JSAIS - 12 are excluded from the JSAIS - 8. The possibility of substituting these subtests for three subtests currently incorporated in the JSAIS - 8 was explored. Limitations of the present study were discussed and the tentative nature of the findings emphasised. Suggestions were made for further research

Reflecting on the knowledge management practices of a University of Technology

Published ArticleKnowledge is universally considered to be a public good and something that should be developed and supported. The information explosion and enabling technologies (such as the Internet and cellular technologies) of the past decade has firmly established the Age of Knowledge. Knowledge has normative value that extends far beyond a single discipline and the Age of Knowledge has resulted in a paradigm shift with regard to the way in which knowledge is generated, applied and stored. As the custodians of knowledge, universities should pay particular attention to the management of knowledge as they take the lead not only in generating new knowledge, but also in converting new and existing knowledge into innovative ideas, products and practices that benefit society at large. Knowledge should, for this reason, be strategically managed to be of value to universities. It is thus imperative that universities should ascertain the nature and extent of their knowledge resources and pay special attention to their Knowledge Management practices that include the way in which knowledge is acquired, disseminated and rewarded. Universities of Technology (UoTs), with their distinct emphasis on applied research, innovation and knowledge transfer, need to manage knowledge in such a way that it enhances the creation of solution-based technologies. This paper provides a theoretical basis for understanding Knowledge Management in a UoT context and reflects on the Knowledge Management practices of a UoT in the South African context

Using life history to understand the interplay between identity, critical agency and social justice education

Published ArticleIn this article we use the concepts identity, agency and social justice education as a lens to explore the role of life history research in the study of the interconnection between emerging teacher identities, critical agency and social justice education. By exploring the life history of a white woman pre-service teacher, this study foregrounds the use of life history research to help teacher educators to understand the contexts through which student teachers' identities are constructed, and how these identities feed into agency and a stance to bring about social change

The challenge of quality and relevance in South African education: a philosophical perspective

Within a changing South African socio-political context, quality education and schooling mean radically different things to different people. The call for contextualising education within an African life-world, and the fear of declining quality and standards in education, necessitate a closer look at the role and meaning of quality and relevance in education. This article consequently attempts a philosophical perspective on quality education and the role of educational standards and relevance. (South African Journal of Education: 2001 21(4): 208-212

Teaching for social justice education: the intersection between identity, critical agency, and social justice education

In line with national policy requirements, educators are increasingly addressing forms of social justice education by focusing on classroom pedagogies and educational practices to combat different forms of oppression such as racism and sexism. As all educators have a role to play in dismantling oppression and generating a vision for a more socially just future, teacher education has the responsibility to capacitate pre-service teachers to work in areas of social justice education. It is, however, difficult to conceptualise programmes for social justice education without considering the interconnection between various social identities and how such identities can feed into critical agency and education for social justice. Working with the assumption that white women teachers must be part of the solution to bring about social change in South African education, we used in-depth interviewing to explore pre-service teachers’ emerging identities as teachers, and how these identities are connected to notions of critical agency and a stance towards social justice.Keywords: agency; anti-oppressive education; identity; social justice education; teacher education; white women pre-service teacher

The Wide-field High-resolution Infrared TElescope (WHITE)

The Wide-field High-resolution Infrared TElescope (WHITE) will be dedicated in the first years of its life to carrying out a few (well focused in terms of science objectives and time) legacy surveys. WHITE would have an angular resolution of ~0.3'' homogeneous over ~0.7 sq. deg. in the wavelength range 1 - 5 um, which means that we will very efficiently use all the available observational time during night time and day time. Moreover, the deepest observations will be performed by summing up shorter individual frames. We will have a temporal information that can be used to study variable objects. The three key science objectives of WHITE are : 1) A complete survey of the Magellanic Clouds to make a complete census of young stellar objects in the clouds and in the bridge and to study their star formation history and the link with the Milky Way. The interaction of the two clouds with our Galaxy might the closest example of a minor merging event that could be the main driver of galaxy evolution in the last 5 Gyrs. 2) The building of the first sample of dusty supernovae at z<1.2 in the near infrared range (1-5 um) to constrain the equation of state from these obscured objects, study the formation of dust in galaxies and build the first high resolution sample of high redshift galaxies observed in their optical frame 3) A very wide weak lensing survey over that would allow to estimate the equation of state in a way that would favourably compete with space projects.Comment: Invited talk to the 2nd ARENA Conference : "The Astrophysical Science Cases at Dome C" Potsdam 17-21 September, 200

Challenges in stakeholders self-organising to enhance disaster communication

Purpose - This paper combines disaster risk reduction (DRR) and communication management literature to investigate the challenges and opportunities encountered when stakeholders spontaneously self-organise communication efforts during a disaster. The 2017 Knysna Fire Disaster in South Africa is used as context. Research methodology - The qualitative, exploratory research was supported by data obtained through thematic analysis of qualitative in-depth interviews and the Facebook page created by the community. Information from the disaster debrief was also included. Findings - The findings suggest that disaster information needs to be sent every 30 seconds to a minute to coordinate rescue and relief efforts. The challenges for disaster management teams to manage this mammoth task and the role that the self-organising community played in assisting the communication process was found not to be recognised in disaster management policies or systems. This adversely affected the work of the disaster management team and stakeholder relationship. Research limitations - This study focussed on one disaster. Future studies could possibly compare various disaster examples to provide even greater insight into the self-organising communicative behaviour of those affected by disasters. Originality/value - The research gives one of the first clear indications of the scope of disaster communication needed during a disaster. It also highlights the community’s ability to contribute to communication management during a disaster, and which is not catered for in the practice, guidelines, or management systems used for disaster management