3,773 research outputs found
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 -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 -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
Modular minds and input in second language acquisition
The aim of this paper is twofold: i. firstly, to show why second language learners (from perhaps as early as age six, but certainly after age twelve or thereabouts) are claimed to. require instruction in addition to communicative exposure to the language; and ii. secondly, to dispel the idea that, as long as theories of how second languages are acquired keep changing, no insight into the acquisition process can be gained from them. The focus will be on theories of L2 acquisition that have a strong linguistic base to the exclusion of, for example, psychological process-based theories. By narrowing the focus of the paper, I hope to keep the main thrust of the argument clear. The choice of focus should not be taken to imply that other approaches have not provided useful perspectives on aspects of L2 acquisition
On control: An analysis of control phenomena in Afrikaans and an argument for dispensing with the minimal distance principle
No abstract
Exploring Educators’ Expectations and Experiences of In-Service Education and Training [INSET] as Continuing Professional Development Opportunities
In-Service Education and Training (INSET) is widely used to support educators to cope with ongoing changes in education. This paper examines the results of two surveys of INSET recipients’ expectations and their experiences of INSET before and after having attended a series of INSET workshops that were held with the intention of strengthening participants’ capacity to teach environmental education. The educators who participated in the survey were from three rural districts in the Limpopo Province, a far northern province in South Africa which borders on Zimbabwe. The survey outcomes were appraised against the backdrop of what is identified in the literature as constituting meaningful INSET. The analysis was undertaken to determine the capacity of INSET programmes to realise the presumed goals of INSET. The outcomes of this survey point to a measure of continuity between theory and practice, but also to trends in participants’ experiences of INSET that are not predominant in the literature
Linguistic theory and second language acquisition: How not to lose sight of the wood for the trees
No Abstrac
An exploratory Q study of corporate brand identity elements governing corporate brand image formation
Because of the growing demands on businesses to distinguish themselves from competitors, corporate brand identity and image are considered to be fundamental in enhancing the visibility and credibility of a business. This study identified the perceptions of South African businesses across various industries of corporate brand identity elements that govern corporate brand image formation. In doing so, a theoretical perspective was adopted that borrows from both marketing communication and corporate communication theories. Firstly, the corporate brand identity elements deemed signifi cant in corporate brand image formation were identifi ed from earlier literature and research. Secondly, Q methodology was used to categorise the variety and span of subjective opinion on those corporate identity elements deemed signifi cant for corporate brand image formation. Finally, the dominant perceptions of the factors that govern corporate brand image formation were isolated through Q factor analysis. Seven richly diverse factors were derived, refl ecting the most salient perceptions on the topic, namely trustworthiness of the brand, creative marketing, effective management and administration, stability through business innovation, customer satisfaction, effective integrated communication and strategic positioning of the brand.Key words: corporate brand, corporate brand identity, corporate brand image, corporatebrand image formation, Q methodology, Q study, Q factor analysi
Personal protective equipment (PPE) in a pandemic: Approaches to PPE preservation for South African healthcare facilities
Personal protective equipment (PPE) is key to protecting healthcare workers from COVID-19 infection, but the pandemic has disrupted supply chains globally and necessitated rapid review of the scientific evidence for PPE re-use. In South Africa, where the COVID-19 epidemic is still developing, healthcare facilities have a short window of opportunity to improve PPE supply chains, train staff on prudent PPE use, and devise plans to track and manage the inevitable increases in PPE demand. This article discusses the available PPE preservation strategies and addresses the issue of decontamination and re-use of N95 respirators as a last-resort strategy for critical shortages during the pandemic
Steps Towards Averting Desertification in the Sefiane Rural Community, Algeria: The Role of Environmental Education
Desertification reflects and contributes towards societal problems such as poverty, underdevelopment and lack of food security. For mere survival purposes, many people feel they have no option but to engage in environmentally unsustainable activities that further contribute to desertification and perpetuate the cycle. Constraints in successfully dealing with desertification have been identified as being a lack of adequate and validated information on the different aspects of the phenomenon in individual areas, a lack of sustainable development plans for desertified areas, a lack of active awareness-raising campaigns, a lack of appropriate training on assessment and mitigation of desertification and the neglect of local stakeholder involvement in addressing land degradation and desertification. This paper provides a contextual profile of desertification and land degradation processes in the Sefiane rural community in Algeria, focusing on how the community’s survival is affected by their current farming activities. A qualitative study using a snowball sampling technique to identify respondents was conducted. Data collection tools included observation, interviews and questionnaires. The research findings, which highlighted activities that farmers engage in that compromise their ability to sustain their environment and their livelihood, were considered and used as a guideline to develop a framework for a contextually relevant environmental education programme that could empower the local community to address the land degradation and sustainable agricultural concerns in their community
Supporting Tutoring Within a Namibian Environmental Education Course: Challenges and Opportunities
This paper is based on a case study of tutoring in the Namibian Environmental Education Certificate (NEEC) Course. In order to support tutoring, the National NEEC Coordinator investigated the way NEEC tutors are supported and the kinds of challenges faced in the tutoring process. The case study was framed within a naturalistic paradigm and the grounded theory approach was used to analyse data. Hence theory is built on data generated throughout the research process. Data were collected from 11 NEEC tutors/support tutors using interviews and questionnaires. Document analysis provided further data and a means of triangulation. Significant challenges to the tutoring process emerged from the data analysis. The most significant challenge was the tutors’ lack of experience in, knowledge of, and enthusiasm for environmental education and distance teaching. Moreover, restrictions on time and communication (i.e. access to work sponsored telephones) caused by the working environment and a lack of adequate financial incentive emerged. Recommendations regarding the improvement of the infrastructure and management, particularly in the areas of recruitment, induction and ongoing professional development support, are made as a way of overcoming the challenges
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