Natural and Agricultural Sciences

NWU symposium addresses water and climate challenges

EVASHNI JANSEN — Fri, 13 Dec 2024 16:56:56 +0000

NWU symposium addresses water and climate challenges

EVASHNI JANSEN Fri, 12/13/2024 - 18:56

Nature-based solutions such as rainwater harvesting and infrastructure designed to withstand floods and other climate impacts were among the practical ideas raised at a recent two-day symposium on water management and climate change in the Ngaka Modiri Molema District of the North West Province.

Held at the North-West University’s (NWU’s) Mahikeng Campus on 4 and 5 December, the event brought together community leaders, researchers, policymakers and industry experts to discuss local challenges and identify innovative strategies.

It was organised by NWU’s Nano Environment Incubation Programme and the office of the deputy dean for teaching and learning in the Faculty of Natural and Agricultural Sciences, in partnership with the Water Research Commission (WRC) and WaterNet.

Dr Naledi Seheri from the chemistry subject group, who helped organise the event, emphasised its collaborative nature. “This symposium was about bringing people together to find practical, community-driven solutions.”

Leave no one behind

On 3 December, the WRC led a stakeholder engagement session to set the stage for discussions. On 4 December Deputy Minister of Water and Sanitation David Mahlobo delivered the keynote address which emphasised the urgent need for innovative approaches to address South Africa’s water challenges.

“No community should be left behind in water, sanitation and development,” he said, highlighting the importance of inclusive governance and collaboration, as well as the potential to integrate technology, governance and climate-sensitive infrastructure into water management.

Deputy minister Mahlobo shared a success story of a school that received clean water through a system using solar energy, rainwater harvesting tanks and efficient sanitation solutions. “This project not only provided water for students but also supported the surrounding community.”

He urged stakeholders to explore nature-based solutions and to design infrastructure that could withstand floods and other climate impacts. The deputy minister also stressed the need for circular water systems and the separation of stormwater from wastewater to enhance sustainability.

Technology was another key focus of his address. He pointed to the potential of artificial intelligence and real-time data systems to improve water monitoring and disaster management. “With more cell phones than people in the country, these devices can be used as tools for empowering communities.”

Collaboration in action

The symposium featured interactive panels that tackled water resource management, climate adaptation, water conservation technologies and the role of governance in strengthening water resilience. Discussions included input from representatives of the NWU, WaterNet, the WRC, the Magalies Water Board, the Department of Water and Sanitation and the North West Department of Economic Development, Environment, Conservation and Tourism.

It concluded with recommendations for improving water security in the region by fostering partnerships, leveraging science and technology and keeping in mind the interconnectedness of water, energy, food and climate resilience.

The symposium also resulted in the signing of a memorandum of agreement (MoA) between the NWU and the WRC to address regional water challenges.

Dignitaries at the NWU’s Water and Climate Changes symposium.

Water symposium leads to collaboration agreement between NWU and WRC

BELINDA BANTHAM — Tue, 10 Dec 2024 07:18:50 +0000

Water symposium leads to collaboration agreement between NWU and WRC

by Phenyo Mokgothu

BELINDA BANTHAM Tue, 12/10/2024 - 09:18

The North-West University (NWU), in partnership with the Water Research Commission (WRC) and Ngaka Modiri Molema District Municipality, hosted a Water Symposium at the NWU’s Mahikeng Campus on 4 to 5 December 2024.

The symposium resulted in the signing of a memorandum of agreement (MoA) between the NWU and the WRC to address regional water challenges. The agreement is for five years.

The agreement establishes a formal collaboration between the NWU and the WRC that is aimed at advancing water research, innovation and capacity building in the North West Province. The partnership will focus on addressing water-related challenges through research and stakeholder engagement.

Dr Mamohloding Tlhagale, head of partnerships and business development at the WRC, explained the significance of the agreement. “The MoA is a foundation for knowledge sharing, innovation and coordinated efforts to address the water issues affecting our communities. It ensures that our actions are aligned with provincial needs.”

The symposium identified several focus areas, including improving water governance, reducing pollution and addressing climate-related water challenges. Key initiatives under the MoA include implementing water research, development and innovation projects and providing training programmes to strengthen capacity in municipalities and communities.

The agreement also positions the NWU as a key partner in generating science-based solutions for water and sanitation issues in the region. Plans include joint research initiatives, the development of water-related education programmes and hosting public seminars and conferences.

Speaking about the university’s role, Dr Tlhagale said, “This partnership leverages the NWU’s expertise to develop practical solutions for municipalities and water boards. Collaboration like this is essential for addressing water management challenges effectively.”

Prof David Modise, executive dean of the Faculty of Natural and Agricultural Sciences, expressed satisfaction with the formalisation of the partnership. “The MoA highlights our commitment to working with the WRC to address water challenges. Through clear frameworks, this collaboration has the potential to create meaningful benefits for communities.”

From left are Dr Mamohloding Tlhagale, Prof David Modise, Prof Sylvester Mpadeli and Prof Thebe Medupe during the signing of the MoA.

Alumnus makes his mark in full-time farming

BELINDA BANTHAM — Tue, 10 Dec 2024 06:49:19 +0000

Alumnus makes his mark in full-time farming

by Oscar Mosiane

BELINDA BANTHAM Tue, 12/10/2024 - 08:49

Farming is often regarded as a noble profession that demands a unique set of qualities, including a profound appreciation for the land and animals and a steadfast commitment to hard work. Thamsanqa Ramosotho, an alumnus of the North-West University (NWU), embodies these attributes and has the qualifications to match.

He holds a diploma in agriculture and animal sciences and a BScHons in animal sciences from the NWU’s Mahikeng Campus, as well as a qualification in new venture creation from the NWU Business School.

In 2010, following the passing of his father, Thamsanqa started farming on communal land with an initial herd of 20 breeding cows. Presently, he oversees a total of 87 cows and heifers, which include two stud bulls of the Simbra and Bonsmara breeds, as well as one young Brahman bull. He also farms with sheep, goats, turkeys, chickens and ducks.

Before his full-time engagement in farming, he dedicated 24 months to working with unemployed agricultural graduates and completed three months as an agricultural practitioner. Subsequently, he chose to pursue farming as a full-time career.

"I am currently operating on communal land; however, I have participated in several interviews for the government's land lease programme since 2021. I remain optimistic that I will secure a farm in the future," says Thamsanqa.

North West MEC for Agriculture and Rural Development, Madoda Sambatha, recently handed over 30 pregnant heifers and a bull to Thamsanqa as a beneficiary of the Department’s Unemployed Agricultural Graduates Programme. The handover was graced by the Deputy Minister of Agriculture, Nokuzola Capa, and took place on 22 November 2024 at Lekung Village just outside Mahikeng.

Thamsanqa Ramosotho.

Some of the pregnant Bonsmara heifers that Thamsanqa received from the Department of Agriculture and Rural Development.

Prof Raubenheimer is advancing quantitative risk analysis

BELINDA BANTHAM — Fri, 06 Dec 2024 08:06:11 +0000

Prof Raubenheimer is advancing quantitative risk analysis

by Steve Maphakathe

BELINDA BANTHAM Fri, 12/06/2024 - 10:06

Prof Helgard Raubenheimer, director of the Centre for Business Mathematics and Informatics (CBMI) in the Faculty of Natural and Agricultural Sciences at the North-West University (NWU), delivered a presentation demonstrating his expertise to the National Institute for Theoretical and Computational Science (NITheCS) community.

The title of his presentation was “Extremes in risk management – a non-parametric approach to the estimation of the quantiles of compound distributions”. In his opening remarks, Prof Helgard gave an overview of operational risk, which is defined as the risk of loss resulting from inadequate internal processes or external events. He highlighted how operational risk differs from other types of financial risks, emphasising that it has no upside potential and is primarily concerned with losses.

In the same vein, Prof Helgard examined the limitations of traditional parametric methods such as the single-loss and perturbative approximations, which depend on predicting more extreme quantiles of an underlying severity distribution. He argued that inaccurate evaluations of these quantiles may result from faulty parametric distributional assumptions.

To get around this issue, Prof Helgard presented a new non-parametric multiplier technique that is based on the single-loss and perturbative approximations as well as the extreme value theory. This novel approach estimates a less extreme lower quantile of the severity distribution and seeks to increase accuracy without making significant parametric assumptions.

The Monte Carlo simulation, by which the novel approach was assessed, validates Prof Helgard’s innovative non-parametric technique as a reliable alternative for extreme quantile estimation – especially in cases where there is little data available.

Further, Prof Raubenheimer emphasised the need for accurate extreme quantile estimation, stating that incorrect assumptions about parametric distributions can lead to inaccuracies in quantile estimation, ultimately impacting financial stability.

His presentation featured a discussion of the practical implications of using the proposed methods in operational risk management in financial institutions.

Prof Helgard concluded by highlighting the importance of not just historical data, but also expert judgement and scenario analysis in improving risk assessments.

About Prof Helgard Raubenheimer

Prof Helgard holds a PhD in Risk Analysis, which he obtained at the NWU in 2010, and his primary research interest is quantitative risk management. From 2016 to 2021 Prof Raubenheimer served as the head of the Scientific Analytical Services (SAS) laboratory. His responsibilities included organising industry training initiatives and promoting interactions with the SAS Global Academic Programme, both domestically and abroad.

Prof Raubenheimer co-authored a number of peer-reviewed publications that Risk.net, the Actuarial Society of South Africa (ASSA), and the South African Statical Association (SASA) have praised both domestically and internationally.

Prof Helgard Raubenheimer

Academic honoured with prestigious award

BELINDA BANTHAM — Fri, 06 Dec 2024 07:57:42 +0000

Academic honoured with prestigious award

by Mafumane Tlhapi

BELINDA BANTHAM Fri, 12/06/2024 - 09:57

Prof Roelof Coetzer, an academic from the North-West University’s (NWU’s) research focus area for Pure and Applied Analytics, has been awarded the prestigious Thought Leader Award by the South African Statistical Association (SASA).

This accolade recognises individuals who have profoundly impacted the South African statistical community through academic excellence, leadership, and industry contributions.

Prof Coetzer brings a wealth of experience, having spent more than 30 years in the industry before joining the NWU in 2021. He has led multidisciplinary teams in developing artificial intelligence and process modelling solutions, and has contributed to applied and theoretical statistical research globally. Among his accomplishments are 53 co-authored scientific publications, a patent in coal processing technologies, and numerous successful postgraduate supervision projects.

He has also held influential positions, including that of SASA president in 2013 and being a council member of the South African Council for Natural Scientific Professions since 2015. Notably, he led efforts to address South Africa's academic statistics crisis, resulting in significant government support for developing local talent.

Prof Coetzer focuses on teaching, research, and securing impactful industry collaborations. His work showcases the importance of integrating theoretical and applied statistics to solve real-world problems in areas such as energy efficiency, environmental compliance and sustainability.

He emphasises that statistics is vital across disciplines. “The greatest ideas come from industry problems with no existing solutions. Framing these as academic challenges generates innovative solutions for value creation.”

Receiving the Thought Leader Award, Prof Coetzer expressed his pride and hopes to use this recognition to inspire younger generations to explore the boundless opportunities in mathematical and statistical sciences.

"Statistics are making a difference in many areas, including business, industry, medicine, government and society. The next generation of statisticians has the chance to shape a better world," he says.

Prof Roelof Coetzer, recipient of the SASA Thought Leader Award, celebrates decades of contributions to the field of statistics.

Academic completes international training in nuclear forensic methodologies

BELINDA BANTHAM — Thu, 05 Dec 2024 07:13:34 +0000

Academic completes international training in nuclear forensic methodologies

by Phenyo Mokgothu

BELINDA BANTHAM Thu, 12/05/2024 - 09:13

Amid plans to establish a nuclear forensic and crime scene management laboratory at the North-West University (NWU), a senior member of the Centre for Applied Radiation Science and Technology (CARST) in Mahikeng has undergone specialist training in Karlsruhe, Germany.

Dr Tebogo Gilbert Kupi, who leads the university’s nuclear forensics initiatives, took part in the International Training Course on Nuclear Forensic Methodologies from 14 to 25 October 2024.

The course was hosted by the International Atomic Energy Agency (IAEA) in collaboration with the National Nuclear Security Administration (NNSA) and the Joint Research Centre of the European Commission. It aimed to enhance knowledge in nuclear forensic science through presentations and hands-on exercises.

Nuclear forensics entails examining nuclear and other radioactive materials to determine their origins and history. Investigators can then respond to the unauthorised use of such materials and assist states to make informed decisions about their nuclear security practices.

Dealing with radiological crime scenes

Participants on the international programme received training on managing radiological crime scenes, handling nuclear and conventional forensic evidence, and preventing contamination during forensic processes. The programme also covered the development of analytical plans, techniques for radionuclide identification, gamma spectrometry and legal considerations in nuclear forensics.

Dr Kupi says the training aligns with the university’s plans to establish a nuclear forensic and crime scene management laboratory at CARST. The knowledge gained would strengthen the NWU’s capacity in nuclear security and radiological crime scene management.

“This training forms part of the partnership between the NWU and the IAEA to train students in nuclear forensic science, with the goal of linking radiological crime scenes to the nuclear forensics laboratory,” says Dr Kupi.

The proposed facility will support research, training and investigations in nuclear forensics.

This initiative reflects the NWU’s commitment to advancing research and fostering collaborations to address critical global issues.

Dr Tebogo Gilbert Kupi took part in the International Training Course on Nuclear Forensic Methodologies from 14 to 25 October 2024

North-West University at the forefront of agricultural innovation

BELINDA BANTHAM — Tue, 03 Dec 2024 07:44:54 +0000

North-West University at the forefront of agricultural innovation

by Bertie Jacobs

BELINDA BANTHAM Tue, 12/03/2024 - 09:44

Crop production in South Africa is overshadowed by storm clouds, and not the type that farmers crave. A multitude of uncertainties combine to darken prospects for the country’s crop farmers, which include climate change, water shortages, soil degradation, disease, economic instability and infrastructure and energy restrictions.

That is why researchers at the Faculty of Natural and Agricultural Sciences of the North-West University (NWU) pursue active solutions for the country’s most critical agricultural issues.

To be able to do this, the NWU must remain at the forefront of innovation, and two new agriculture-oriented projects testify to the commitment of the university in this regard: the NWU AgriHub and the HVAC Growth Facility.

Prof Jacques Berner, subprogramme leader, is an expert in the field of crop physiology, with a focus on photosynthesis and the adjustment of ancient grain crops to environmental stress. His expertise lies in the investigation of physiological reactions of crops to drought and extreme temperatures. He explains more about the Heating, Ventilation and Air Conditioning Growth Facility (HVAC Growth Facility): “This advanced facility will offer controlled environments that mimic various climatic conditions, including variations in temperature, light, humidity, drought and flooding. It will create the ideal environment for research on the impact of climate change on plant growth and development. By simulating different environmental variables the facility will enable researchers to study how plants react to varying light conditions, temperature stressors and water shortages. This will provide valuable insights into their resilience, adaptability and overall health in changing environmental conditions. This research can potentially make a considerable contribution to agricultural practices and strategies to mitigate climate change,” says Berner.

The university is also looking beyond the immediate future at other possibilities of supporting the agricultural sector.

Prof Gerhard du Preez of the Agricultural Sciences group adds: “We want to establish the NWU AgriHub of Excellence, which is located just 4 km from the Potchefstroom Campus of the NWU, as a centre for agricultural innovation, research and training. This season we are starting a grain-based long-term trial and will focus on diverse agricultural systems to promote sustainable food production. Our vision is to develop solutions that will ensure food security and environmental sustainability while we bridge knowledge gaps between the academic world, the industry, the government and farmers. This centre will serve as a platform for influential research, industry

cooperation and the development of agricultural systems that are designed for the challenges of the future,” Berner says.

According to Prof Bismark Tyobeka, principal and vice-chancellor of the NWU, the university is investigating the possibility of establishing a veterinary school, which will work with, among other institutions, the NWU’s subject group Animal Health, and the agricultural programme will work to make food security a priority.

“In the country and in North West agriculture plays an important role in adding economic value, providing job opportunities, promoting rural development and creating food security. If we look at food security, there is currently a great need in our province and in our country, but the university has the capacity and expertise to make an appreciable difference in this sector, and we increase our involvement in the agricultural sector by further developing our partnerships with the government and the private sector,” says Prof Tyobeka.

In addition to these efforts, the NWU is also looking at cooperation with the struggling agricultural colleges in the province, and considerable progress has already been made in this regard.

Agriculture is one of the pillars supporting the South African economy, and the NWU is committed to ensuring that this sector is not only healthy, but also grows.

Society of Atmospheric Sciences awards highest honour in the field to NWU researcher

BELINDA BANTHAM — Mon, 02 Dec 2024 06:59:35 +0000

Society of Atmospheric Sciences awards highest honour in the field to NWU researcher

by Willie du Plessis

BELINDA BANTHAM Mon, 12/02/2024 - 08:59

In a world of extreme climate change where air pollution is rife and people’s health is at stake, it has become paramount to predict the impact of chemical processes within the Earth’s atmosphere to plan measures for the future. A researcher at the North-West University (NWU) has made it his life’s labour to study atmospheric sciences.

Prof Stuart Piketh, director of the School for Geo- and Spatial Sciences on the NWU’s Potchefstroom Campus, recently received recognition from the South African Society of Atmospheric Sciences (SASSAS) for his significant contributions to the field. His work has advanced the understanding of atmospheric processes and their implications for local and regional pollution, transport, environmental policy and community health initiatives.

He received the Mathieu Rouault Medal – the highest honour in South African atmospheric sciences – during the annual SASSAS congress on 29 and 30 October, which the NWU hosted in venues across the Potchefstroom Campus. The medal is named after the late Prof Mathieu Rouault, an internationally respected expert in ocean environment and weather systems.

“You try to work consistently in building your research and your academic career over years and the best people to give you recognition for the work you have done are your peers and your colleagues,” Prof Piketh says. “That makes this recognition very meaningful and special. It acknowledges the efforts one put in not only in terms of research but also the graduation of more than 40 postgraduate students over the years.”

The commendation accompanying the medal stated that it was in recognition of the work that Prof Piketh has put in in atmospheric sciences in Southern Africa over the course of his career. It specifically referred to his extensive research, publications and dedication to training the next generation of scientists.

He still hopes to make many more significant contributions in the field. “In the end it is all about creating a better, safer and healthier world,” he concludes.

More about Prof Piketh’s career

Prof Stuart Piketh obtained a PhD in geography and environmental studies at the University of the Witwatersrand in Johannesburg in 2000. Since being appointed as a full professor at the NWU in 2012, he has served as co-chair of the Eskom Power Plant Institute (EPPEI) in the School of Geo- and Spatial Science and became its director in 2015.

Currently a B-rated scientist of the National Research Foundation (NRF), he is also a member of the Academy of Science of South Africa (ASSaf).

“Over the past decade, my researched has focused especially on the understanding of air pollution emissions, transport and impacts.”

He considers the fact that many of his students now hold prominent positions in both government and the private sector as one of his greatest achievements.

Prof Stuart Piketh

Botany professor and leading scholar on forbs publishes in respected journal series

BELINDA BANTHAM — Fri, 29 Nov 2024 07:06:47 +0000

Botany professor and leading scholar on forbs publishes in respected journal series

by Phenyo Mokgothu

BELINDA BANTHAM Fri, 11/29/2024 - 09:06

Prof Frances Siebert from the subject group Botany at the North-West University (NWU) was recently invited to publish in the Annual Reviews journal series.

This paper is the first from the NWU’s Unit for Environmental Sciences and Management (UESM) in this highly regarded publication series on ecology, evolution and systematics.

Annual Reviews journals are widely recognised for synthesising expert knowledge across scientific fields, facilitating key insights for scholars and society. Editorial committees in each discipline select emerging topics and invite researchers to contribute reviews that shape the direction of study within their fields.

Prof Siebert, identified by the committee as a leading scholar on forbs (i.e. non-grass flowering plants in the herbaceous layer), collaborated with a team of international experts to examine the ecological significance of forbs in tropical and sub-tropical grasslands.

Despite their significant contribution to ecosystem services, this plant growth form was neglected among scientists as being an important plant group in grassland ecosystems. In the review paper, the authors provided several examples of the direct and indirect benefits of forbs. For instance, how livestock and indigenous African herbivores select certain forb species to self-medicate when they are infected by parasites, the traditional use of forbs as food- and medicinal plants, and how forbs provide important regulating services such as carbon sequestration and pollination services.

“This publication is a milestone for the UESM and reflects the NWU’s presence in key academic discussions,” says Prof Siebert. “I am grateful for the opportunity to bring the role of forbs in grasslands and savannas to the fore.”

This paper is the NWU’s third contribution to Annual Reviews, following earlier work by Prof Don Kurtz in astronomy and astrophysics and Dr Paul Janssen in mathematics and statistics.

Invited as a distinguished speaker at the 74CNBot conference in the city of Brasilia in Brazil on 19 November 2024, Prof Siebert’s publication attracted attention from vegetation scientists abroad. The international journal, Annals of Botany, sponsored her research. Her plenary lecture at the 74CNBot conference was selected as one of eight invitational manuscript submissions to Annals of Botany in 2025.

Prof Siebert also presented her findings as an invited seminar speaker at Sao Paulo State University in Rio Claro on 22 November.

Her efforts are proof of the NWU’s commitment to promoting research that benefits not only South Africa, but the world.

Prof Francis Siebert surrounded by forbs.

Academy of Science of South Africa honours professor of Radio Chemistry as a top scholar

BELINDA BANTHAM — Tue, 26 Nov 2024 09:09:15 +0000

Academy of Science of South Africa honours professor of Radio Chemistry as a top scholar

by Willie du Plessis

BELINDA BANTHAM Tue, 11/26/2024 - 11:09

Nuclear technology is a powerful instrument, and research has shown that it can have a significant impact on disease prevention and treatment. An extraordinary professor at the North-West University (NWU) and specialist in nuclear technology – in radiochemistry in particular – is one of 44 leading scholars and scientists to be inaugurated as new members of the Academy of Science of South Africa (ASSAf).

Prof Jan Rijn Zeevaart, general research manager in Applied Radiation at the South African Nuclear Energy Corporation (Necsa) and lecturer at both the Mahikeng Campus and Potchefstroom Campus of the NWU, considers it a great honour to be counted among the best researchers in the country.

“I have been driven throughout my career to use excellent research as the basis for driving innovation that will ultimately benefit society. The application of science is very close to my heart, although some of my best science outputs have been fundamental work.”

Prof Zeevaart says he has been blessed with opportunities to expand his horizons and connected him to universities for the development of new drugs (radiopharmaceuticals) from bench to bedside.

Becoming less dependent on imports

“Through the new Nuclear Medicine Research Infrastructure (NuMeRI) facility in which the government’s Department of Science and Innovation (DSI) has invested heavily, we are poised to make a big contribution to drug development in our country. This will enable us to become less dependent on pharmaceutical imports and capitalise on the current phenomenal growth in the radiopharmaceutical and nuclear medicine market worldwide.”

He is a firm believer in the saying by poet WH Auden that “Those that will not reason, perish in the act. Those who will not act, perish for that reason.” Prof Zeevaart says this has guided his professional career and defines his leadership style.

A career dedicated to radio chemistry

Prof Zeevaart is a bio-inorganic chemist who specialises in radiochemistry and radiopharmacy. One of the products he developed in the late 1990s was iodine-131. This is a radioactive isotope (meaning one of two forms of the same element) of iodine that is used in nuclear medicine procedures to diagnose and treat thyroid conditions. Iodine-131 still earns more than R150 million in foreign currency annually.

“There was no university in South Africa that offered PhD studies in radiochemistry. I wanted to change this. Necsa decided to start the Centre for Applied Radiation Science and Technology (CARST) together with the NWU in Mahikeng, and I joined the team in 2010 as an extraordinary professor to promote radiochemistry in the country.”

He also became involved with the Preclinical Drug Development Platform (PCDDP) on the NWU’s Potchefstroom Campus in 2014, where he expanded his work in radiochemistry to include new molecules (radiopharmaceuticals) for preclinical tests.

Prof Zeevaart is currently still working primarily in applied radiation at Necsa. He is also the chief scientific officer of NuMeRi and lectures at both the NWU and the University of Pretoria.

More about the ASSAf

With the dawn of democracy in South Africa, ASSAf started to address the need for an Academy of Science entity in 1996.

The Parliament of South Africa passed the Academy of Science of South Africa Act (Act 67 of 2001), which came into force in 2002. This made ASSAf the only academy of science in South Africa officially recognised by the government and representing the country in the international community of science academies and elsewhere.

Members of ASSAf are nominated and selected annually through a final vote by the full existing membership, all of whom are leading scientists and researchers. Being chosen is considered exclusive recognition of scholarly achievement and excellence. The addition of the latest cohort of members brings the total membership of ASSAf to 730.

For more information on ASSAf visit: https://www.assaf.org.za/

Prof Jan Rijn Zeevaart