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Oil penetration into vetkoek analysed at Fluorescence Microscopy penetration into vetkoek analysed at Fluorescence MicroscopyE Els<p style="text-align:justify;">The first study using confocal micrographs on the quantitative analysis of <em>vetkoek</em> or <em>magwinya</em> crumb and crust properties was done by scientists from the University of Venda at the CAF Fluorescence Microscopy facility. The confocal laser scanning microscopy was chosen to visualise the changes in fried foods due to its ability to produce images with clear contrast, differentiating food components (fat, protein or carbohydrates) from each other and from the empty pores. The use of recognizable fluorescent dyes in sample preparation proved adequate for characterisation of oil penetration and structural changes in the samples using an image analysis technique. Important knowledge about the relationship between oil uptake and the microstructure of <em>vetkoek</em> were revealed.</p><p style="text-align:justify;">Cross-section micrographs of the fried dough showed notable differences in terms of oil distribution, depth of oil penetration, structure and pore properties of the fried products. This emphasises the impact of ingredient formulation (water and bran variation) on oil penetration. The inclusion of oat and wheat bran in the <em>vetkoek</em> formulation reduced porosity and oil penetration.</p><p style="text-align:justify;">The protocol used in this study can be applied to other thick deep-fried foods for qualitative observation and quantitative measurement of a specific physical or chemical property.<br></p><p style="text-align:justify;"><img src="/english/faculty/science/CAF/PublishingImages/vetkoek%20image%201.jpg" alt="" style="margin:5px;width:500px;height:279px;" /><br></p><p><em>Cross-section micrographs of fried dough enriched with oat bran.</em></p><ul style="list-style-type:disc;"><li>The article  'Confocal Laser Scanning Microscopy and Image Analysis for Elucidating Crumb and Crust Microstructure of Bran-Enriched South African Fried Dough and Batter ' was published in <em>Foods (</em>2020, 9, 605) and is available online at  <a href=""></a></li></ul><p style="text-align:justify;"><strong>Media requests:</strong></p><p style="text-align:justify;">Lize Engelbrecht<br></p><p style="text-align:justify;">E-mail: <a href=""></a><br></p><p>Afam I. O. Jideani</p><p>E-mail: <a href=""></a><br></p><p style="text-align:justify;"><br></p><p>​<br></p>
X-ray micro-tomography used to study respiratory anatomy in live larvae micro-tomography used to study respiratory anatomy in live larvae E Els<p></p><p style="text-align:justify;">How respiratory structures vary with, or are constrained by, an animal's environment is of great importance to see the differences in evolutionary development and for comparative physiology hypotheses. </p><p style="text-align:justify;">It is challenging to investigate the respiratory structures of insects because they are so small, therefore only a handful of species have been examined. The analytical process in several methods that have been used is lethal and destructive and takes a lot of time and work.</p><p style="text-align:justify;">In this study researchers explored and tested a different approach to measuring tracheal volume using X-ray micro-tomography scanning on living, sedated larvae. This were done at the CAF CT Scanner Facility on Stellenbosch campus. Novel data on the resistance of the larvae to the radiation dose absorbed during X-ray micro-tomography scanning are provided. By comparing how tracheal dimension (reflecting metabolic supply) and basal metabolic rate (reflecting metabolic demand) increase with mass, the study showed that tracheal oxygen supply capacity increases during development at a comparable, or even higher rate than metabolic demand. </p><p style="text-align:justify;">The study provides methodological insights and novel biological data on key issues in rapidly quantifying insect respiratory anatomy on live insects.<br></p><p style="text-align:justify;"><img src="/english/faculty/science/CAF/PublishingImages/CT_larvae_web.jpg" alt="" style="margin:5px;width:400px;height:221px;" /><br></p><p style="text-align:justify;">Image: X-ray micro-tomography images of larvae of the beetle <em>Cacosceles Newmannii.</em></p><p> </p><ul style="list-style-type:disc;"><li>The article  'Using µCT in live larvae of a large wood-boring beetle to study tracheal oxygen supply during development ' was published in <em>Journal of Insect Physiology (</em>2021; 130: 104199) and is available online at  <a href=""></a></li></ul><p> </p><p style="text-align:justify;"><strong>Media requests:</strong></p><p style="text-align:justify;">Prof Anton du Plessis</p><p style="text-align:justify;">E-mail: <a href=""></a></p><p>Prof John Terblanche<br></p><p>E-mail: <a href=""></a><br></p><p style="text-align:justify;"><br></p><p>​<br></p>
Meet the Teaching Excellence Award winner: Dr Mags Blackie the Teaching Excellence Award winner: Dr Mags BlackieCorporate Communication and Marketing/Korporatiewe Kommunikasie en Bemarking [Rozanne Engel]<p></p><p>​</p><p>Dr Mags Blackie is no stranger to winning awards.<br></p><p>The senior lecturer in the Department of Chemistry and Polymer Science at Stellenbosch University's (SU) Faculty of Science at Stellenbosch University (SU) has won numerous awards over the years.</p><p>Blackie won the 2020 South African Chemical Society Education Medal, the 2015 HB and MJ Thom Award for overseas research, the SU Teaching Fellowship 2020–2022 and most recently the 2020 Distinguished Teacher Award for her ongoing commitment and hard work as an excellent teacher.</p><p>According to Blackie, winning the Distinguished Teacher Award feels like “a moment of celebration" in the midst of a long journey and validation for the complex path that she has chosen to walk.</p><p>“My first teaching job was in a high school between my Bachelor in Science (BSc) and BSc Honours degrees. I thoroughly enjoyed it and very nearly stayed teaching, but I am glad I chose to study more. At the time, I decided to take what I called 'the path of least regret' and has been teaching at university level since 2007," says Blackie.</p><p>She chose the field of chemistry after being inspired by her aunt and godmother who was a well-respected chemistry teacher. After her aunt died, Blackie decided to honour her memory by working hard at school in chemistry, which turned out to be something that she was good at. </p><p>Blackie holds her BSc degree from Rhodes University, a BSc Hons degree and a PhD in Chemistry from the University of Cape Town and is currently completing a PhD in Education from SU. </p><p>“As I began as a PhD student I realised that chemistry (at least what I do – making new molecules) is creative and I discovered my own creativity in my chemistry research. In the last decade, education research has become more and more significant to me, and combines the various passions I have – chemistry, teaching and human development."</p><p>Apart from her passion for science, Blackie says she also has a significant interest in Christian spirituality and have helped others in their faith journey too. She has a blog and has written numerous papers and a couple of books on the topic of spirituality.</p><p>Despite the ongoing global coronavirus pandemic, Blackie feels positive about the year ahead. </p><p>“This year is going to be a significant year for me. I am an editor on two education research books that will be published this year and I am part of a multinational longitudinal project following chemistry and chemical engineering students through their degrees. It has been a great learning curve for me working with some of the leaders in higher education and engineering education in the world. I am hoping that some of the work that will come out this year will have an impact on tertiary science education in South Africa."</p><p><strong>More on the SU Teaching Excellence Awards</strong></p><p>Launched in 2017, the SU Teaching Excellence Awards acknowledge lecturers in two categories, 'Distinguished Teacher' and 'Developing Teacher', based on their experience and leadership in the scholarship of teaching and learning.</p><p>Applicants have to submit a portfolio that demonstrate their reflection on and evidence of four main components: context, students, knowledge and professional growth. They also have to indicate the lessons they had learnt on their journey to becoming excellent teachers.</p><p>For more information about the Teaching Excellence Awards, contact Dr Karin Cattell-Holden at <a href=""><span class="ms-rteThemeForeColor-2-0" style=""><strong></strong></span></a>. ​<br></p><p>​<br></p>
Polhilia – revision of lesser known Cape plant genus ensures conservation – revision of lesser known Cape plant genus ensures conservationWiida Fourie-Basson<p>​One of the Cape Floral Kingdom's most threatened plant genera, <em>Polhilia</em>, has now been comprehensively revised and populations of these endangered species documented, thereby aiding efforts to ensure its conservation.</p><p>This is thanks to the field work and research completed by Brian du Preez, a keen botanist and PhD student, for his MSc studies in the <a href="/english/faculty/science/botany-zoology/Pages/default.aspx">Department of Botany and Zoology</a> at Stellenbosch University (SU). The result of his work was recently published as a monograph of the genus <em>Polhilia</em> in the <a href=""><em>South African Journal of Botany</em></a>. In this study, four new species are described, bringing the total number of species in this genus to 11, all of which are threatened with extinction, and classified as critically endangered.</p><p>“<em>Polhilia</em> species grow in Renosterveld, a vegetation type endemic to the Cape. But more than 90% of Renosterveld has been severely transformed for crop agriculture, resulting in <em>Polhilia</em> species, along with countless other threatened plants, being confined to small patches of remaining Renosterveld," he explains.</p><p>Brian set out to revise the taxonomy of this lesser-known plant genus after he accidentally rediscovered 13 bushes of the long-lost species <em>Polhilia ignota</em> growing on the farm Goede Hoop near Eendekuil in 2016. Until this discovery, this species was known from only two collections made in 1924 and 1928 in the Porterville and Saldanha areas respectively, and thus listed as extinct on <a href="">SANBI's Red List of South African Plants</a>. In 2017 he discovered a single plant of <em>Polhilia ignota</em> growing along a fence next to the N7 highway only five kilometers north of Piketberg. Subsequently, members of the <a href="">Custodians of Rare and Endangered Wildflowers</a> (CREW) found another two populations nearby Voëlvlei Nature Reserve and southwest of Porterville, bringing the total number of known plants to roughly 230.</p><p>Brian says he covered nearly 8 000 kilometers by road, and nearly a hundred by foot, searching for more populations of <em>Polhilia</em> growing in the small patches of remaining Renosterveld in the Overberg and Swartland, including two field trips to the Roggeveld escarpment near Sutherland. One of the high lights of his many field trips was the discovery of a new species, <em>Polhilia fortunata</em>, near Vanwyksdorp in the Little Karoo. </p><p>While passionate about his fieldwork, Brian says he felt overwhelmed when confronted with the degradation and destruction of the original Renosterveld: “One can only try to imagine what the area used to look like before the first ploughs moved in. Back then there were no environmental laws regarding protected species or their habitats."</p><p>Prof Léanne Dreyer, a botanist at SU and one of Brian's study leaders, says the taxonomic revision of these endangered species are extremely important: “If we don't know about these species and their populations, then we cannot conserve them. Based on Brian's work, herbariums the world over will now revise and update their collections based on the latest information. He also established the conservation status of each of the 11 species, which is critically important for their future."</p><p>Brian is currently working with the curator of the Stellenbosch University Botanical Gardens, Dr Donovan Kirkwood, to establish al 11 species of <em>Polhilia</em> in its collection. This means that plant material can be shared with other botanical gardens in the world, another insurance policy to ensure the future survival of these species. In the case of one of the newly discovered species, <em>Polhilia groenewaldii</em>, for example, there are only four plants left in the wild. </p><p><b>On the photo above: </b>The newly discovered <em>Polhilia groenewaldii</em> honours Mr Jannie Groenewald, former plant specialist at Haarwegskloof Nature Reserve, who first discovered it near Bonnievale. There are currently only four of these plants known to have survived in the wild. <em>Photo: Brian du Preez</em></p><p><strong>Media enquiries</strong></p><p>Brian du Preez</p><p>E-mail: <a href=""></a></p><p>Mobile: 072 553 1442<br></p><p>​<br></p>
New initiative will boost use of water-smart technologies in agriculture initiative will boost use of water-smart technologies in agricultureMedia & Communication, Faculty of Science<p></p><p>A multi-stakeholder platform which aims to boost the use of water-smart technologies by farmers in Limpopo, Free State and Mpumalanga will be launched on 23 February 2021.</p><p>The Triple Helix (3H) initiative will provide a platform for farmers to work with local government, agri-business and research institutions towards finding joint solutions for their specific, local challenges. These solutions range from the introduction of new technologies, to the sharing of knowledge, opening networks to finance and providing skills training. </p><p>The 3H platform is the result of a collaboration between Stellenbosch University (SU) and the Maastricht School of Management (MSM), and facilitated by Agricolleges International (ACI).</p><p>“The 3H platform will act as a multi-stakeholder initiative in the domain of water-smart agriculture and horticulture. It will unite local government, local academia and researchers with farmers and agri-businesses. The aim is to further boost adaptation of water-smart technology in these regions," says project managers Hans Nijhoff from MSM and Manuel Jackson from SU.</p><p>The establishment of this platform is based on a labour market needs assessment, conducted by researchers from SU and MSM in 2019, to gain better insights into the skills needs of the horticultural and agricultural industry sector when hiring graduates from Technical and Vocational Education and Training (TVET) Colleges in South Africa. The project, “Strengthening Skills of TVET Staff and Students for Optimizing Water Usage and Climate Smart Agriculture in South Africa" was funded by the Netherlands Universities Foundation for International Cooperation (NUFFIC), through the Dutch Ministry of Foreign Affairs. </p><p>During the launch of the Triple Helix platform initiative, researchers will provide feedback on their findings from the labour market needs assessment survey. The speakers are Prof Danie Brink and Manuel Jackson from SU, Hans Nijhoff and André Dellevoet from MSM, Huba Boshoff from Nuffic/NESO, Jolanda Andrag from AgriSA, Prof Peliwe Lolwana from the South African Qualifications Authority, Wynand Espach from ACI, Johan Klinck from Motheo TVET College and representatives from the Nkangala, Vhembe and Motheo TVET Colleges.</p><p><strong>Date: </strong>23 February 2021</p><p><strong>Time:</strong> 10:00-14:00</p><p><strong>Platform:</strong> Zoom Meeting</p><p>Join Zoom Meeting</p><p><a href=""></a> </p><p>Meeting ID: 968 0699 9555</p><p>Passcode: 566480</p><p><strong>RSVP:</strong> <a href=""></a></p><p>Image by <a href="">Ngobeni Communications</a> on <a href="">Unsplash</a><br></p><p>​<br></p>
‘Science meets art’ exhibit addresses stigma of illness‘Science meets art’ exhibit addresses stigma of illnessWiida Fourie-Basson<p></p><p>The public has until the end of February to visit a unique exhibition at the interface of science, art and the stigma around illness at the Rupert Museum in Stellenbosch.</p><p>The exhibit, '<a href="">Science meets Art: Art addressing stigma in illness</a>', is an initiative of the postgraduate students in Physiological Sciences at Stellenbosch University (SU), in collaboration with Prof Elmarie Constandius from the SU Department of Visual Arts, and the Rupert Museum. It involves curated micrograph images of cells and cell processes associated with neurodegenerative illnesses such as Alzheimer's disease and depression, as well as cancer. They were produced by Prof Ben Loos and the postgraduate students in his research group. </p><p>Prof Loos says his students realised there is a need in African communities to understand mental illness and neurodegeneration better. Often, the scientific nomenclature for these diseases does not exist in African languages, or their African names are unknown, making communication a particular challenge.</p><p>The curator of the collection, Elizabeth Miller-Vermeulen, then worked with six artists from Kayamandi and Gordon's Bay to engage with the micrographs and articulate their interpretation of it through various mediums, including beadwork, recycled material and paper. </p><p>The collection is beautifully captured in a full-colour brochure, with explanations of the micrographs and accompanying artworks in English and isiXhosa. There is an effort underway to have the text translated into more languages in an effort to reach out to more communities.</p><p>During an interactive workshop on 30 January this year, Miller-Vermeulen explained how a beautifully crafted beaded basket by artist Nomsa Mukwira, based on a micrograph of a brain cancer sphere (human glioma) imaged by PhD student Jurgen Kriel, can become the visual link to help a community talk about and deal with an illness that is mostly hidden to us.</p><p>The artworks therefore become the entry point to discuss symptoms such as depression and forgetfulness, associated with mental illnesses such as dementia, Alzheimer's disease and adolescent depression.</p><p>According to Miller-Vermeulen, completing the exhibit during strict lockdown conditions last year was a huge challenge, but at the same time it provided a lifeline to the artists involved, as so many other exhibitions were cancelled.</p><p>“I want to thank the Rupert Museum for hosting this exhibit. Working towards completing it on time became a symbol of hope and survival for all involved."</p><p>The postgraduate students, postdoctoral fellows and colleagues involved are: Dr André du Toit, Kim Fredericks, Jurgen Kriel, Prof Craig Kinnear, Naomi Okugbeni, Dr Tando Maduna, Kyra Waso, Tamryn Barron, Sinnead Cogill, Demi Pylman, and Nsuku Nkuna.</p><p>Participating artists are Gerald Choga, Portia Mphangwa, Nomsa Mukwira, Zacharia Mukwira, Simon Shumi and Zingisa Vula.<br></p><p><img src="/english/PublishingImages/Lists/dualnews/My%20Items%20View/science%20meets%20art%20group%20pic.png" alt="science meets art group pic.png" style="margin:5px;" /><br></p><p>At the launch of the 'Science meets Art' exhibition at the Rupert Museum in October 2020, from left to right, Nicola Heathcote, Kim Fredericks, Jurgen Kriel, Dr Tando Maduna, Prof Ben Loos, Elizabeth Miller-Vermeulen, artists Zacharia and Nomsa Mukwira, Tamryn Barron, Demi Pylman, Sinnead Cogill, Naomi Okugbeni, Dr Caroline Beltran, Prof Elmarie Costandius, Nsuku Nkuna and Robyn-Leigh Cedras-Tobin (director of the Rupert Museum). <em>Photo: Tatum Cogan</em></p><p>​<br></p>
World Cancer Day: Personalised medicine, biotechnology offer new hope for cancer patients Cancer Day: Personalised medicine, biotechnology offer new hope for cancer patientsAnna-Mart Engelbrecht <p></p><p>Thursday (4 February) is World Cancer Day. In an opinion piece for <em>Health24</em>, Prof Anna-Mart Engelbrecht (Department of Physiological Sciences) writes about how advances in personalised medicine and biotechnology offer new hope for cancer patients.</p><ul><li>Re​ad the article below or click <a href=""><strong class="ms-rteThemeForeColor-5-0" style="">here</strong></a><strong class="ms-rteThemeForeColor-5-0" style=""> </strong>for the piece as published.</li></ul><p><strong>Anna-Mart Engelbrecht*</strong><br></p><p style="text-align:justify;">Each year on February 4<sup>th</sup>, World Cancer Day raises awareness about cancer as a critical health issue that we cannot dare to neglect. The global cancer burden is increasing rapidly in developing countries as population numbers continue to grow and life expectancies rise. In low-income countries, poor patients receive only affordable or available treatments, rather than optimal ones. Other concerns regarding conventional cancer treatment are the many adverse side effects, the high rates of treatment resistance, and the rising cost of medical care to both patients and healthcare systems. The economic burden of cancer is substantial due to both healthcare expenditure, as well as lost productivity due to morbidity and premature death.</p><p style="text-align:justify;">​In 2003, scientists mapped out the human genome, or DNA, for the first time. This project meant that better understanding of genetics was possible and led to the discovery of many different genetic diseases. While this project initially cost R41 billion and took 10 years to complete, the cost to sequence a human genome has dropped to under R10 000 less than two decades later. It is predicted to reduce even further to approximately R1500 in the next five years. Because of its affordability, this technique has become so much more accessible to the medical world and may help advance personalised medicine. This helps doctors and clinicians to choose therapies and treatments that are more likely to work – treatments that are more personalised to individual patients and their specific disease.<br></p><p style="text-align:justify;">Cancer occurs when mutations, or accidental changes, take place in the DNA of specific cells or tissue within the body. These cells then continue to grow excessively, forming a tumour, which then pushes into the surrounding body tissues, and may spread to other parts of the body. The same type of tumour, e.g. a lung tumour from different patients can have different mutations, and the primary tumour can also have different mutations compared to tumours which have spread to other organs in the same patient. However, understanding exactly where the DNA is mutated could help oncologists to choose more effective therapies for each specific type of cancer. This is known as precision oncology, and would aim to improve treatment efficacy, while reducing adverse effects.<br></p><p style="text-align:justify;">Considering the need to understand the genetic mutations within cancer, there has been much research done in this field over the past few years. Some of the biggest breakthroughs include the discovery of both CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) and circulating tumour DNA.<br></p><p style="text-align:justify;">While it may sound unusual, bacteria can also get infected by viruses which are over a hundred times smaller than bacteria. To protect themselves against viruses and other invaders, some bacteria have “anti-virus DNA" called CRISPR which they use to edit the genes within the virus and render it powerless. After scientists discovered this, they realized that this could be used to edit DNA in other settings too. Considering the powerful role played by mutated or “broken" DNA in the development of cancer, it was hoped that CRISPR, along with an intracellular pair of “scissors" called Cas9, could be used to edit these damaged genes within cancer cells.<br></p><p style="text-align:justify;">Several methods of gene-editing have been developed over the years, but CRISPR could alter the DNA of human cells in a precise, simple and affordable manner. CRISPR has taken the research world by storm and has shifted the border between the possible and impossible. It has become the major gene-editing technology in many research labs all over the world where it is now moving out of petri dishes and into clinical trials with cancer patients. CRISPR is an extremely useful tool in the bioengineering space which accelerated innovation in basic research, drug discovery, diagnostics and therapeutics.  In a small study, CRISPR was able to successfully edit immune cells which were then injected into cancer patients. Immune cells can fight and kill cancer cells, and these CRISPR-edited immune cells became more successful at hunting down and attacking cancer cells within the body. However, CRISPR technology is still in its infancy, and many scientists are still cautious about its use in people.<br></p><p style="text-align:justify;">Another advancement in the field of oncology was the discovery that tumours deposit fragments of mutated DNA into the blood stream, known as circulating tumour DNA. This can be identified in blood samples by cancer biomarker tests, leading to the earlier detection of cancer. This would also enable doctors to better guide therapy and monitor patients' progress after therapy. With the recent advances in research and biotechnology, early-stage cancer detection tests will soon become commercially available and will most likely decrease cancer mortality rates drastically. <br></p><p style="text-align:justify;">Cancer therapy has evolved from radical surgery, radiotherapy and chemotherapy to personalised medicine and targeted biological therapies, which harness the body's biological processes, such as the immune system. Personalised medicine can lead to more effective healthcare as a precise diagnosis is provided. This will cost the patient less in the long term as it avoids unnecessary and ineffective treatments. It will also prevent adverse events, improve quality of life and more effective targeted therapeutics will lead to reduced morbidity and mortality. Additionally, the information gained through these advances, along with machine learning, will help healthcare providers by offering sophisticated tools for decision-making. <br></p><p style="text-align:justify;">It is now time for medical schools to start providing their students with an educational background and hands-on experience in genomic tests and the interpretation thereof.  Personalised medicine will have a profound impact on human health, and although genomics is the driving force behind it, the combination of next-generation sequencing, artificial intelligence and gene-editing could cure cancer.</p><p style="text-align:justify;"><strong>*Prof Anna-Mart Engelbrecht leads the Cancer Research Group in the Department of Physiological Sciences at Stellenbosch University (SU). She is also co-director of the SU Spin-Out Company, BIOCODE Technologies, which develops biomarker and biosignal screening solutions for inflammatory disease and cancer risk identification. The other team members are Prof Resia Pretorius (Physiologist), Prof Willie Perold (Electronic Engineer), Este Burger (Research and Design Engineer), Dr Andre du Toit (Biochemist) and Annemie Pretorius (Engineer). </strong></p><p style="text-align:justify;"> </p><p style="text-align:justify;"> </p><p>​<br></p>
Welcome to the 2021 new first-year students in the Faculty of Science to the 2021 new first-year students in the Faculty of ScienceMedia & Communication, Faculty of Science<p></p><p>The Faculty of Science at Stellenbosch University would like to extend a warm welcome to our first-year students of 2021.</p><p>Despite the many challenges posed by the COVID-19 pandemic and lockdown regulations, we are ready to provide you with a world-class education in the natural sciences, both in person and via our online platforms.</p><p>Before welcoming you to the campus on 4 March, we encourage you to make use of the on-boarding programme on SUNLearn and to familiarise yourself with the workings of the Faculty and its academic programmes. Please use your student e-mail address and password to access the Stellenbosch University's general First-year onboarding programme, as well as the Faculty of Science's specific onboarding programme at these links:</p><ul><li>SU's first-year onboarding programme: <a href=""></a></li><li>Faculty of Science's onboarding programme: <a href=""></a></li></ul><p>Prof Stan du Plessis, chair of the Institutional Committee for Business Continuity of Stellenbosch University, reassured staff and students of the University's commitment to successfully present and complete the 2021 academic year: “We are better prepared this year, and I am confident that we will face the challenges that this year will undoubtedly bring with equal aplomb". <a href="/english/Lists/news/DispForm.aspx?ID=7948">Click here</a> to read his message and watch the University's <a href="/english/welcome/Pages/Online-Onboarding.aspx">web page</a> for new announcements and details regarding the welcoming programme.</p><p>And a word from Prof Louise Warnich, Dean of the Faculty of Science: “I hope you feel at home soon, in spite of the unusual circumstances of this academic year. All the best with your new life as a Matie!"​</p>
Large-scale production of high-performance additively manufactured cellular structures now a reality production of high-performance additively manufactured cellular structures now a realityMedia & Communication, Faculty of Science<p><br><br></p><p style="text-align:justify;">Additive manufacturing or 3D printing of industrially-relevant high-performance parts and products is today a reality, especially for metal additive manufacturing technologies, and is used globally for the production of end-use, mission-critical parts. </p><p style="text-align:justify;">But while the design complexity now made possible by additive manufacturing makes it particularly useful to improve product performance in various applications, the structural integrity and long-term (cyclic-loading) performance of such complex structures is sometimes still in question.</p><p style="text-align:justify;">In a comprehensive review article published in the high-impact journal <a href=""><em>Materials Science and Engineering R</em></a> recently, a group of international researchers argue that our knowledge-base has increased to such an extent to overcome some of the major challenges hindering the large-scale commercial production of industrially-relevant and high performance parts and products incorporating such structures.</p><p style="text-align:justify;">Prof Anton du Plessis, leader of the <a href="">3D innovation research group</a> at Stellenbosch University and one of the authors of the review article, says one of the major challenges is fatigue performance: “Fully understanding fatigue performance makes it possible to mitigate potential problems, which opens up the possibilities for using this technology in many more applications".</p><p style="text-align:justify;">Du Plessis, an associate professor in the Department of Physics at SU, collaborated with researchers from Norway, Italy and the United States for this review on the mechanical properties and fatigue performance of metallic cellular structures manufactured by additive manufacturing. These structures have many advantages but their mechanical performance needs to be fine-tuned and optimised. The review highlights specific insights in this regard for the manufacturing of fatigue-tolerant cellular structures.</p><p style="text-align:justify;">Du Plessis explains: “Fatigue is the most important failure mechanism in most structures. This is caused by continued loading and unloading, creating cracks over time, so it is important to prevent it particularly for high-performance parts like those used in aeroplanes, cars and medical implants. Fatigue failure is often driven by defects, microstructural imperfections, residual stresses, surface roughness, and, as this review has also highlighted, strut junctions in lattice structures."</p><p style="text-align:justify;"><strong>Overcoming the challenge of fatigue failure</strong></p><p style="text-align:justify;">The review shows that the effective use of these light, high-performing structures depends on an understanding of the design parameters, materials and manufacturing parameters, in order to achieve good mechanical properties, Du Plessis explains.</p><p style="text-align:justify;">“Technological challenges have affected the quality of their production so far, leading to some doubts over their widespread use in the past. This includes defects in parts, lack of fusion, poor surface finish, residual stress and distortion. But it has been proven that excellent properties can be achieved by considering all the above factors, and that some cellular architectures are better suited to achieve high-fatigue performance.</p><p style="text-align:justify;">“We believe the growing knowledge base in this area will allow a better understanding of these meta-materials and specifically on how to achieve best performance from them, for various new applications. It is clear that many new applications of these structures are waiting to be revealed in different industries and application areas," Du Plessis concludes.</p><p style="text-align:justify;"><strong>What is additive manufacturing?</strong></p><p style="text-align:justify;">Additive manufacturing (AM), also known as 3D printing, is the general term used for processes that join materials to make objects directly from 3D model data, sometimes by using thermal energy or lasers to add layer upon layer of materials. Metal AM is extensively used in many industries, such as the automotive, aerospace, sports and biomedical industries, where reliable, fatigue tolerant, strong, yet lightweight, materials are an important requirement.</p><p style="text-align:justify;">Porous cellular or lattice structures are a complex design style made possible by AM. These can be tailored or architected for unique mechanical or other performance requirements and have many advantages including large surface area, low mass, a regular repeated structure and open, interconnected spaces. Using AM makes it possible to more precisely control the micro-architecture of these structures to optimise their shape, weight, stiffness and strength. </p><p style="text-align:justify;">These structures are particularly useful for long-lasting medical implants (ranging from 'standard' knee and hip implants, to customised patient-specific bone implants) and for lightweight automotive and aerospace components. These are the main industry drivers currently. </p><p style="text-align:justify;">Cellular structures are particularly well suited to creating complex individualised designs for medical implants because they are lightweight, long-lasting and allow bone in-growth into the porous metallic structure, allowing a stronger attachment and higher success rate. Many new applications are waiting to be discovered for these architectured cellular structures, with some interesting developments and potential in fluid flow and thermal management applications in high-performance engineering devices.  – <em>Prof Anton du Plessis</em></p><p style="text-align:justify;"><em>On the image above: Cellular structures, also called lattice structures or meta-materials, are a complex design style made possible by additive manufacturing. Pictured above is a series of lattice cubes printed in titanium at the Central University of Technology (CUT) in Bloemfontein. <em>Image: CUT</em></em></p><p style="text-align:justify;"><em><em></em></em></p><ul><li>The article  'Architected cellular materials: A review on their mechanical properties towards fatigue-tolerant design and fabrication' was published in <em>Materials Science and Engineering: R: Reports (</em>2021; 144: 100606) and is available online at  <a href=""></a></li><li>Please contact Prof Du Plessis for access to an electronic pdf of the article.</li></ul><p style="text-align:justify;"><strong>Media interviews</strong></p><p style="text-align:justify;">Prof Anton du Plessis</p><p style="text-align:justify;">3D Innovation research group, Department of Physics, Stellenbosch University</p><p style="text-align:justify;">E-mail: <a href=""></a></p><p style="text-align:justify;">Tel: +27 21 808 9389<br></p><p style="text-align:justify;"><em></em></p><p>​<br></p>
‘Sacred Forests’ store carbon, help combat climate change‘Sacred Forests’ store carbon, help combat climate changeCorporate Communication and Marketing / Korporatiewe Kommunikasie en Bemarking<p>​An international team of scientists from universities in Europe and South Africa found that “Sacred Forests"* in Togo, West Africa play a vital role in the storage of carbon and could help to mitigate the effects of climate change. It is important to preserve the soil in these forests, which cover several hundred square kilometres, not just for carbon storage, but also for biodiversity and ecosystem functioning.</p><p>The findings of their study were published in the open-access journal <a href="">Catena</a> recently.</p><p>The researchers wanted to gain a better understanding of the variations in soil properties and the process of carbon formation in the soil under these highly biodiverse “Sacred Forests" which are used for religious purposes and believed to be inhabited and protected by gods, totem animals or ancestors.  They analysed the structure, components and features of the soil as well as the minerals that it contains.</p><p>“Our study showed that soils in these forests preserve at least 8.64 tonnes of inorganic carbon per hectare. This carbon is derived directly from the CO<sub>2</sub> in the air of the soil. In real terms, we are talking about an area the size of a rugby field that permanently removed as much CO<sub>2</sub> as is released by a power station burning 15.8 tonnes of coal," says one of the researchers Dr Michele Francis from the Department of Soil Science at Stellenbosch University. She conducted the study with Dr Hafeez Rehman (Norwegian University of Life Sciences, Norway), and Profs Rosa Poch (University of Lleida, Catalonia, Spain), and Fabio Scarciglia (University of Calabria, Italy).</p><p>Francis says “soil inorganic carbon is an important carbon sink because the carbon is permanently locked away in mineral form, unlike carbon derived from soil organic matter such as leaf litter and humus. The organic matter decomposes and releases the carbon back to the atmosphere as CO<sub>2</sub> again, unless there is a intermediary step which is able to capture and store the carbon permanently  ̶  as in the sacred forest soils. </p><p>She adds that due to the dry nature of the area, the mineral form of this inorganic carbon remains in the soil and does not dissolve. This will be an even more important form of carbon storage in the future, since the long-term trend is to an increasing severity of the aridity in Togo.</p><p>According to Francis, there is a high potential for development of the soils of the area in terms of agriculture and agroforestry and for potential carbon sequestration relevant to global change policies.</p><p>“Understanding these natural processes is fundamental for the implementation of soil management practices leading to carbon sequestration and improvement of soil quality status in the region, and possibly in other countries with similar climates, vegetation, and land use/land cover histories.</p><p>This is particularly important in areas where these forests are becoming rarer and more fragmented because of population growth, expansion of buildings, construction of roads, and erosion of traditional religious beliefs."</p><p>Francis adds that their findings would be of interest to people in agriculture, ecology, biology, forestry and earth sciences. </p><p>*<em>The sacred forest is located in the </em><a href=""><em>Centre de Formation Rurale de Tami (CFRT</em></a><em>), which trains local farmers. Much of the farming techniques rely on adding organic matter back to the depleted soils, for example by adding leaf litter, which mirrors the processes in the sacred forests. It is run by the La Salle brothers.</em> </p><p> </p><ul><li><strong>SOURCE</strong>: Rehman, HU; Poch, RM; Scarciglia, F & Francis, ML 2020.  A carbon-sink in a sacred forest: Biologically-driven calcite formation in highly weathered soils in Northern Togo (West Africa). <em>Catena</em>: <a href=""></a>​<br></li></ul><p><br></p>