Latest News Archive

Please select Category, Year, and then Month to display items
Previous Archive
18 April 2022 | Story Leonie Bolleurs | Photo Stephen Collett
Prof Ted Kroon
Prof Ted Kroon from the Department of Physics recently delivered his inaugural lecture on the topic What’s the use of a rainbow on the UFS Bloemfontein Campus.

“A rainbow is a natural phenomenon, the result of the refraction and reflection of the sun’s rays in drops of rain. As far as mankind is concerned, it’s a perfectly useless object and won’t make anyone money. Yet the poet who said, My heart leaps up when I behold a rainbow in the sky, only put into word the feeling of wonder and excitement we all have when we see a rainbow.”

“Every day I see a rainbow in my work; I do not need to wait to see one in the sky,” says Prof Ted Kroon, Professor in the Department of Physics at the University of the Free State (UFS), who used this phenomenon to introduce the topic of his inaugural lecture: What’s the use of a rainbow. 

“Far from being only a colourful spectacle with no practical value, rainbows are useful – and lead to useful things,” he believes. 

According to Prof Kroon, one can find examples of real rainbows and rainbow analogies used not only in everyday life, but also in physics. “Besides it being familiar devices in literature, culture, and even marketing, studies of rainbows can yield practical engineering information and may even help us to find new habitable planets,” he says.

Inspired by the many uses of a rainbow

In his lecture, he discussed the basic features of natural rainbows and how they come about. He also explored how the rainbow gives meaning to colour, and how this relates to the temperature of objects. He looked at an array of instances where the rainbow is used; from depicting the life of a star to indicating that we are sick (a thermometer) or when we need to refill a gas cylinder.
Moreover, Prof Kroon pointed out that rainbows are used in computer chips, stress identification, and to transmit internet data through underwater cables of glass fibre. He also referred to how the rainbow was harnessed as an engineering tool to measure refractive index and characterise fine droplet sprays used in industry. 

He continues, “Remarkably, the science developed to understand the natural rainbow can be redirected and applied to the optical properties of metallic nanoparticles, allowing the development of nanotechnology. Knowing how the natural rainbow works and its limitations, better systems have been developed to produce rainbows. Such rainbows have been used to discover new elements and to determine the age of the universe.”

As a member of an international community of phosphor researchers who are privileged to work with rainbows every day, he has used them to study the light-emitting properties of materials doped with bismuth. With this project – an initiative with the African Laser Centre taking place between 2016 and 2021 – he collaborated with the University of Khartoum in Sudan and trained a number of its postgraduate students. “My role included the guidance of students and the measurement and interpretation of the light-emitting properties of the materials. Our research during this time, considering more than a dozen materials, was summarised in 34 scientific publications that contributed to a greater understanding of bismuth ions as light-emitting materials,” he explains. 

Developing new materials, efficient in emitting blue light

He has been developing luminescent materials since 2006, primarily for general lighting (fluorescent tubes and LEDs) and displays (television, computer, and cellphone screens), as well as niche applications in medical and forensic science. 

As part of his current research, he is examining the effect of plasmonic metal nanoparticles on phosphor light emission. He is also exploring materials that absorb infrared light but emit visible light. “For this, I would like to consider the long-term stability of such materials and develop new materials that are more efficient in emitting particularly blue light,” he says. 

Prof Kroon holds a C2 rating from the National Research Foundation and has published more than 150 articles and book chapters, obtaining a Scopus h-index of 26.

News Archive

Code-switching, tokenism and consumerism in print advertising
2014-10-27

Code-switching, linguistic tokenism and modern consumerism in contemporary South African print advertising. This is the current research focus of two lecturers from the Faculty of the Humanities at the UFS, Prof Angelique van Niekerk and Dr Thinus Conradie.

The act of switching between two or more languages is replete with socio-cultural meaning, and can be deployed to advance numerous communicative strategies, including attempts at signalling cultural familiarity and group affiliation (Chung 2006).

For advertising purposes, Fairclough’s (1989) seminal work on the ideological functions of language remark on the usefulness of code-switching as a means of fostering an advertiser-audience relationship that is conducive to persuasion. In advertising, code-switching is a valuable means with which a brand may be invested with a range of positive associations. In English-dominated media, these associations derive from pre-existing connotations that target audiences already hold for a particular (non-English) language. Where exclusivity and taste, for example, are associated with a particular European language (such as French), advertising may use this languages to invest the advertised brand with a sense of exclusivity and taste.

In addition, empirical experiments with sample audiences (in the field of consumer research) suggest that switching from English to the first language of the target audience, is liable to yield positive results in terms of purchase intentions (Bishop and Peterson 2011). This effect is enhanced under the influence of modern consumerism, in which consumption is linked to the performance of identity and ‘[b]rands are more than just products; they are statements of affiliation and belonging’ (Ngwenya 2011, 2; cf. Nuttall 2004; Jones 2013).

In South African print magazines, where the hegemony of English remains largely uncontested, incorporating components of indigenous languages and Afrikaans may similarly be exploited for commercial ends. Our analysis suggests that the most prevalent form of code-switching from English to indigenous South African languages represents what we have coded as linguistic tokenism. That is, in comparison with the more expansive use of both Afrikaans and foreign languages (such as French), code-switching is used in a more limited manner, and mainly to presuppose community and solidarity with first-language speakers of indigenous languages. In cases of English-to-Afrikaans code-switching, our findings echo the trends observed for languages such as French and German. That is, the language is exploited for pre-existing associations. However, in contrast with French (often associated with prestige) and German (often associated with technical precision), Afrikaans is used to invoke cultural stereotypes, notably a self-satirical celebration of Afrikaner backwardness and/or lack of refinement that is often interpolated with hyper-masculinity.

References


We use cookies to make interactions with our websites and services easy and meaningful. To better understand how they are used, read more about the UFS cookie policy. By continuing to use this site you are giving us your consent to do this.

Accept