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Dr Lucas Erasmus
Dr Lucas Erasmus, Junior Researcher in the Department of Physics, has just returned from Belgium where he had his public defence of a joint PhD with Ghent University, titled: Luminescent solar concentrators – where Sm2+ doped phosphors shine.

“I like taking what I have learned from literature and going to the laboratory to test it. Sometimes the results surprise me, leading to additional experiments or refining. This process could continue for several months and even years, with me slowly building the puzzle. And finally, one day, all the pieces come together, and everything becomes very clear to me as a physicist. And if I am lucky, I will have the privilege of knowing a secret about nature that nobody else has known up to this point. However, as an innovator, I am tasked with using this new knowledge to develop ways to manipulate nature to deliver a helpful device.”

These are the thoughts of Dr Lucas Erasmus, Junior Researcher in the Department of Physics at the University of the Free State (UFS), who has just returned from Ghent, Belgium, where he had his public defence of a joint PhD with Ghent University, titled: Luminescent solar concentrators – where Sm2+ doped phosphors shine.

The research project is part of a bilateral collaboration between the Department of Physics at the UFS and the Department of Solid State Sciences at Ghent University. In this study, the strengths, experience, and resources of both research groups – experienced in developing luminescent materials for various applications – are used to ensure a stronger final product. To meet the requirements stipulated in the cooperation agreement between the two institutions for the joint supervision and certification of Dr Erasmus’ doctoral studies, research was conducted both at the UFS and at Ghent University.

Dr Erasmus’ research is significant in the light of rising energy prices, energy scarcity, and the pursuit of a carbon-free society, where there are strong incentives to develop new and renewable energy sources.

Combining windows and solar cells increase their relevancy in many applications

He says that although solar panels play an essential role in renewable energy – since they provide a route to directly convert solar radiation into electricity – there are limitations to installing conventional panels, which are bulky, rigid, and opaque. He believes that combining windows and solar cells could increase their relevance in the built environment, agricultural sector, and modern consumer electronics.

Explaining about the luminescent solar concentrator (LSC) in his study, he states that it is a device used as a large-area solar radiation collector that converts and emits radiation. The emitted radiation is directed to photovoltaic cells located in the small side area of the device. According to him, a basic LSC consists of a transparent waveguide with an embedded luminescent material and a strategically placed photovoltaic cell on the edge.

Dr Erasmus continues, “The large area of the waveguide collects a portion of the solar radiation, while the luminescent material absorbs the energy and downshifts it to longer wavelengths. Internal reflection directs the emitted photons towards smaller areas on the sides where the photovoltaic cells are used to convert the concentrated light into electricity.”

In his view, creating a large and efficient LSC is a challenging endeavour that requires an in-depth study of multiple domains. “This includes developing and optimising the luminescent material, studying its behaviour and the characteristics of the waveguide, and finally adding these two components and developing, characterising, and simulating the hybrid device,” he remarks.

“While the current prototype we have developed delivers good results, it is still far from perfect and not commercially viable,” he says, stating that this study could, however, serve as a guide for future researchers interested in developing LCSs. Dr Erasmus believes the underlying science behind the results contributes to a general understanding of the materials, making this study valuable to other fields and contributing to the larger body of science. At the end of the study, he also makes some recommendations for future research in this field. 

Study a reflection of theoretical knowledge and a practical system

The public defence consisted of both an internal and an external defence. The internal defence took place in January at the UFS between Dr Erasmus and the examination committee. The external defence occurred at Ghent University and was also open to the broader public. Also present at this event in Belgium were colleagues from the UFS – Prof David Motaung, an examiner; Prof Koos Terblans, co-supervisor; and Prof Hendrik Swart, supervisor for the PhD thesis.

Dr Erasmus’ experience of the oral examination was that the examiners were primarily positive in their critique but also thorough in their questioning. According to him, some of their remarks pointed out that they were impressed with the meticulous planning, execution, and interpretation of the experimental results and that the researchers involved ensured that any parameter that might have influenced the device was maximised. “Moreover, they liked the fact that I went all the way from theoretical knowledge to a practical system. The examiners also noted that the study compares well with the current state-of-the-art research in the field,” adds Dr Erasmus.

He says that having the public defence in Belgium was a once-in-a-lifetime experience, allowing him to interact and deliberate directly with the examiners and communicate their findings and conclusions to the broader public. Dr Erasmus hopes that this will lead to stronger collaboration and better public sentiment toward spending funding for scientific projects.

For future steps, he states, the research group involved in the project plans to continue this research by further increasing the device's efficiency. “To this end, we have already developed another luminescent material that can address some of the challenges we encountered while developing the first prototype device. This forms part of the work that Johané Odendaal is doing in her master’s degree, of which I am a co-supervisor. We also plan to enlarge the scope of our research to consider the challenges that are currently hampering the next generation of photovoltaic cells and to find ways in which we could address these issues,” comments Dr Erasmus.

News Archive

The state of HIV/AIDS at the UFS
2010-05-11

“The University of the Free State (UFS) remains concerned about the threat of HIV/AIDS and will not become complacent in its efforts to combat HIV/AIDS by preventing new infections”, states Ms Estelle Heideman, Manager of the Kovsies HIV/AIDS Centre at the UFS.

She was responding to the results of a study that was done at Higher Education Institutions (HEIs) in 2008. The survey was initiated by Higher Education AIDS (HEAIDS) to establish the knowledge, attitudes, behaviours and practices (KABP) related to HIV and AIDS and to measure the HIV prevalence levels among staff and students. The primary aim of this research was to develop estimates for the sector.

The study populations consisted of students and employees from 21 HEIs in South Africa where contact teaching occurs. For the purpose of the cross-sectional study an ‘anonymous HIV survey with informed consent’ was used. The study comprised an HIV prevalence study, KABP survey, a qualitative study, and a risk assessment.

Each HEI was stratified by campus and faculty, whereupon clusters of students and staff were randomly selected. Self-administered questionnaires were used to obtain demographic, socio-economic and behavioural data. The HIV status of participants was determined by laboratory testing of dry blood spots obtained by finger pricks. The qualitative study consisted of focus group discussions and key informant interviews at each HEI.

Ethical approval was provided by the UFS Ethics Committee. Participation in all research was voluntary and written informed consent was obtained from all participants. Fieldwork for the study was conducted between September 2008 and February 2009.

A total of 1 004 people participated at the UFS, including the Main and the Qwaqwa campuses, comprising 659 students, 85 academic staff and 256 administration/service staff. The overall response rate was 75,6%.

The main findings of the study were:

HIV prevalence among students was 3,5%, 0% among academics, 1,3% among administrative staff, and 12,4% among service staff. “This might not be a true reflection of the actual prevalence of HIV at the UFS, as the sample was relatively small,” said Heideman. However, she went on to say that if we really want to show our commitment towards fighting this disease at our institution a number of problem areas should be addressed:

  • Around half of all students under the age of 20 have had sex before and this increased to almost three-quarters of students older than 20.

     
  • The majority of staff and a third of students had ever been tested for HIV.

     
  • More than 50% of students drink more than once per week and 44% of students reported being drunk in the past month. Qualitative data suggests that binge drinking over weekends and at campus ‘bashes’ is an area of concern.

Recommendations of the study:

  • Emphasis should be on increased knowledge of sexual risk behaviours, in particular those involving a high turnover of sexual partners and multiple sexual partnerships. Among students, emphasis should further be placed on staying HIV negative throughout university study.

     
  • The distribution of condoms on all campuses should be expanded, systematised and monitored. If resistance is encountered, attempts should be made to engage and educate dissenting institutional members about the importance of condom use in HIV prevention.

     
  • The relationship between alcohol misuse and pregnancy, sexually transmitted infections (STIs), HIV and AIDS needs to be made known, and there should be a drive to curb high levels of student drinking, promote non-alcohol oriented forms of recreation, and improve regulation of alcohol consumption at university-sponsored “bashes”.

     
  • There is need to reach out to students and staff who have undergone HIV testing and who know their HIV status, but do not access or benefit from support services. Because many HIV-positive students and staff are not receiving any kind of support, resources should be directed towards the development of HIV care services, including support groups.

Says Heideman, “If we really want to prove that we are serious about an HIV/AIDS-free campus, these results are a good starting point. It definitely provides us with a strong basis from which to work.” Since the study was done in 2008 the UFS has committed itself to a more comprehensive response to HIV/AIDS. The current proposed ‘HIV/AIDS Institutional response and strategic plan’, builds and expands on work that has been done before, the lessons learned from previous interventions, and a thorough study of good practices at other universities.

Media Release
Issued by: Mangaliso Radebe
Assistant Director: Media Liaison
Tel: 051 401 2828
Cell: 078 460 3320
E-mail: radebemt@ufs.ac.za  
10 May 2010

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