INTRODUCTION
The Faculty of Science constantly produces exceptional research results that are also to the benefit of society. Amongst others, the Faculty is internationally renowned for its breakthrough in solar energy research, which opens new possibilities for affordable electricity from the sun.
Another example of the Faculty’s social responsiveness, is The Enerkey Sustainable Mega-Cities project which is a collaborative initiative between, amongst others, UJ and the University of Stuttgart. In collaboration with our German partners, the Faculty addresses energy related technical, economic, ecological and social challenges with the aim of uplifting the urban region of greater Johannesburg.
Our Botany and Plant Biotechnology department played a key role in the ground-breaking discovery of a ‘barcode’ gene, This gene provides scientists with innovative ways to easily identify different plants by analysing the DNA of the species. Further, this department is developing an extensive global database of DNA information from the majority of tree species on earth and is also delivering excellent research results in plant classification and the use of medicinal plants.
Water, its chemistry, its purification, and its relationship with its fauna and flora. These are all explored in the Faculty of Science. A case in point is the novel research being conducted in the Department of Chemical Technology on the development of nanomaterials that are capable of removing pollutants from water. Research undertaken by our department of Zoology includes pollution monitoring in aquatic environments and the sustainable utilisation and conservation of freshwater fish species.
We are proud that our staff in the Physics Departments are playing a part in the ground-breaking research on The Large Hadron Collider. Moreover, the Department of Physics currently operates the only laboratory in Africa where the physical properties of matter can be studied in experimental temperatures below 2 degrees Kelvin and down to within 0.34 Kelvin from the absolute zero of temperature; and in magnetic fields up to close a million times the magnetic field of the earth.
The Faculty is proud to have a unique regional analytical facility (Spectrau), which houses the analytical apparatus of the Faculty under one roof. No other university in South Africa can boast about such a centre in which the expensive equipment and expert analytical personnel of each Department is so centralized, thus making it of use to all the Departments in the Faculty in respect of student training.
ACADEMY OF COMPUTER SCIENCE AND SOFTWARE ENGINEERING
Contact: Prof E Ehlers
One of the Academy’s areas of research is that of Information Security. Research projects in this area cover the whole spectrum of Information Security – from the more technical side to the management and governance side. Examples are:
- Using advanced IT technologies (smart cards, biometrics etc) to secure logical access to IT systems.
- Information Security in the mobile (wireless, cell phones etc) environments.
- Information Security Governance (driven by international best practices).
- Information security in the wider e-Commerce environment.
Another area of research is that of Agents Architectures and Agent Applications. Research projects in this area focus on the component-based embedding of Agent-enhancing characteristics in Agents and Multi-Agent Systems (MAS). Examples are:
- Embedding Intelligence in a Specialized Architecture for Auctioneer Agents.
- A Specialized Architecture for embedding Intelligence into Multi-Agent Systems.
- A Specialized Architecture for embedding Information Security characteristics into Agents.
- Embedding mobility characteristics into Agents.
A third area of research is that of Computer Graphics. Research projects in this area focus on modelling and visualization, but also include aspects of computational geometry and other topics. Examples are:
- Parameterization of triangle meshes.
- Subdivision surfaces.
- Genetic algorithms for the development of 3D models.
- Visualization of fluids and terrain.
- Level of detail algorithms.
APPLIED MATHEMATICS
Contact: Prof C Villet
Research in the Department comprises projects in Quantum calculations; Non-linear dynamics; Deterministic chaos; Fractals; Wavelets; Cellular automata; Neural networks; Genetic algorithms; Numeric analysis; Symmetry solutions of differential equations; Computer Algebra and Software and hardware development. .
BIOCHEMISTRY
Contact: Prof IA Dubery
Research activities in the Biochemistry division focus on host : pathogen interactions and special emphasis is placed on defence mechanisms in the host and factors that determine susceptibility. This research is conducted in host : pathogen models of both plant and animal systems, and provides students with a unique opportunity to obtain biochemical training in an environment in which both plant and biomedical biochemistry is practised. This lateral approach to host : pathogen interactions is carried out biochemically, molecular biologically, genetically or cytobiologically.
With plants as hosts, the focus is on innate immunity and inducible defense responses that protect the plant against pathogen attack. The pathogens that are studied include organisms that are pathogenic for various economically important plants. The purpose of this research is the acquisition of knowledge for the promotion of the disease resistant state in plants and to obtain a better understanding of the genetic and biochemical aspects of pathogenesis and host defense. Here we investigate the promoter elements of inducible defense genes that determine where and when the genes are expressed. This basic research has biotechnological applications in the area of crop protection and food security.
Another focus is the interaction of stress responses and defense responses, with emphasis on programmed cell death in two different model systems. When an organism is subjected to a physiological or environmental stress, a set of highly conserved proteins, known as heat shock proteins, are expressed, and function to assist with protection against the stress condition. However, if the cell cannot recover and is damaged beyond repair, it is then programmed to undergo cell death, a process known as apoptosis. The research explores the mechanisms how heat shock proteins function in the adaptive responses to stress, including programmed cell death, in normal and mutated plant cells or malignant/cancerous cells.
The genetics of host susceptibility
to human pathogens are also studied and here the investigations focus on connection between the promoter structure of the vitamin D receptor gene, epigenetics and susceptibility towards tuberculosis. Another focus is the interaction of histone proteins with DNA and how post-tranlational modifications can affect gene transcription.
The Department of Biochemistry and the Analytical Sciences Group of the CSIR were recently successful with an application to the National Equipment Programme of the National Research Foundation for the acquisition of a high-performance liquid chromatograph coupled to a high definition ion mobility mass spectrometer. This technology allows a very unique and novel approach to the science of mass spectrometry and allowed scientists to work on the cutting edge of their research. The combination of high (ultra) performance liquid chromatography and ion mobility mass spectrometry provide a unique platform for scientists giving them the tools to extract novel data. The system also has many additional and unique features which would allow new experimentation techniques. The incorporation of ion mobility allows molecules to be analysed according to their size and shape, over and above looking at accurate mass, fragmentation patterns, elemental composition and isotopic ratio determinations. This represents a massive step up from conventional technologies which could only give accurate mass on compounds and their fragments.
BOTANY AND PLANTBIOTECHNOLOGY
Plant Growth and Development
Contact: Prof CW Whitehead
The main thrust of research in this field is in the areas of plant biotechnology and postharvest
physiology and technology of fresh fruit, vegetables and cut flowers.
Taxonomy, Medicinal Plants and Ethno Botany
Contact: Prof B-E van Wyk
The Department is widely known as a centre of excellence in the field of African medicinal plants, ethno botany and the classification of African plants. One of the main aims of their taxonomic endeavour is to investigate the taxonomic, genetic, chemical and geographical variations in various commercially important indigenous plants, especially those that are potentially useful to the pharmaceutical industry.
Regional patterns of biodiversity and conservation in South Africa: the flora of the Kruger National Park
Contact: Prof M van der Bank
A thorough understanding of biodiversity patterns and processes is also required for efficient conservation. Indeed, one of the biggest challenges for conservation biology is to provide conservation planners with ways to prioritise effort. Much attention has been focused on species richness and endemism; however, the conservation of evolutionary process is now acknowledged as a priority in the face of rapid global change. With this research, we are taking a synthetic approach towards explaining the evolution of biodiversity within one of the world’s most renowned protected areas, the Kruger National Park. The scientific goal is to understand how evolutionary history and ecology have shaped biodiversity in the region, and to use this new knowledge to help design science-based conservation actions. Research activities are designed around three complementary disciplines:
- Molecular Systematics
A ‘barcode’ gene that can be used to distinguish between the majority of plant species on Earth has been identified by scientists from UJ and research partners. This gene, which can be used to identify plants using a small sample, could lead to new ways of easily cataloguing different types of plants in species-rich areas like rainforests. It could also lead to accurate methods for identifying plant ingredients in powdered substances, such as in traditional Chinese medicines, and could help to monitor and prevent the illegal transportation of endangered plant species. The team behind the discovery found that DNA sequences of the gene ‘matK’ differ among plant species, but are nearly identical in plants of the same species. This means that the matK gene can provide scientists with an easy way of distinguishing between different plants, even closely related species that may look the same to the human eye. The researchers made this discovery by analysing the DNA from different plant species. They found that when one plant species was closely related to another, differences were usually detected in the matK DNA. Researchers carried out two large-scale field studies: one on the exceptionally diverse species of orchids found in the tropical forests of Costa Rica, and the other on the trees and shrubs of the Kruger National Park in South Africa. This was a collaborative project between teams from South Africa (Dr Michelle van der Bank, Department of Botany and Plant Biotechnology, University of Johannesburg), United Kingdom (Dr Vincent Savolainen, dual appointee at Imperial College London’s Department of Life Sciences and the Royal Botanic Gardens, Kew) and Costa Rica (Diego Bogarin, Lankester Botanical Garden, University of Costa Rica). Using specimens collected from Costa Rica, were able to use the matK gene to identify 1,600 species of orchid. In the course of this work, they discovered that what was previously assumed to be one species of orchid was actually two distinct species that live on different slopes of the mountains and have differently shaped flowers adapted for different pollinating insects. The team was also able to use the matK gene to identify the trees and shrubs of the Kruger National Park, also well known for its big game animals. In the long run the aim is to build on the genetic information the team gathered from Costa Rica and South Africa to create a genetic database of the matK DNA of as many plant species as possible, so that samples can be compared to this database and different species accurately identified.
- Evolutionary Ecology
Research focuses on the following questions: What is the regional pattern of biodiversity; how is biodiversity structured within the various ecoregions (ecozones) of the Kruger National Park, and beyond? How can phylogenetic relationships inform community assembly? Are communities some random assemblages of the regional species pool? Or instead, are communities made of well-adapted taxa in which similar traits have converged independently in separate lineages?
- Conservation Biology
Research focuses on the following questions: What is the geographic distribution of biodiversity as measured by various indices, such as endemism, species richness, or phylogenetic diversity? How are these indices correlated, could one be used as a surrogate for the others? How is extinction risk distributed geographically and with regard to the phylogeny? Are there ecoregions or specific lineages more prone to extinction? Are there traits that increase extinction risks? Are there regions that deserve particular conservation attention due to their exceptional phylogenetic diversity and evolutionary history?
CHEMISTRY
Contact: Dr L den Drijver
The University of Johannesburg and St Andrews University have signed an agreement allowing the joint offering of PhD degrees. The degree is jointly awarded by the two institutions after the student has spent research time at both universities. The UJ group has strong synthesis expertise and has been working for some years on ligand synthesis and has been improving known catalysed reactions such as the Suzuki, Stille and hydroformylation reactions. The UStA group has stronger process chemistry and reaction kinetics elements as core capabilities. The collaboration intends to produce new ligands for the rhodium catalysed hydroformylation reaction at UJ and to undertake reaction testing and kinetics studies at UStA.
Research in the chemical sciences focuses on three areas, namely synthetic methodologies, speciation analysis and water treatment, and the determination of molecular structure.
Research collaboration with different universities and research institutes in the USA and Europe such as the School of Water Sciences, Cranfield Universiteit in England; University of Leipzig in Germany, Ben-Gurion University in Israel; Hauptman-Woodward Institute in the USA, creates opportunities for students to work in leading laboratories abroad as part of their PhD studies.
Synthetic Organic Chemistry
The research programme in synthetic organic chemistry focuses on synthetic methodologies of industrial and pharmaceutical interest. A very successful research programme in the field of carbonyl reactions, by means of palladium-catalysed reactions among others, is currently being undertaken in conjunction with SASOL. Another exciting project, which is very important in combating malaria, focuses on the isolation, identification and synthesis of new compounds with possible anti-malaria functioning. Furthermore, research is also underway that aims to synthesise a variety of antiviral compounds (eg against HIV and Herpes simplex viruses).
The Catalysis Research Centre
Contact: Prof DBG Williams
Catalysis is a means of facilitating chemical reactions that are otherwise difficult or uneconomical to perform. The catalyst may be in the same phase/medium as the substrate (homogeneous catalysis) or in a different phase (heterogeneous catalysis). There is a global need for improved catalyst systems in terms of catalyst performance, longevity and recyclability in all areas of endeavour relating to the manufacture of chemicals. Accordingly, it is a focus of this research centre to investigate catalysts with improved performance characteristics as measured against selected benchmark systems. The current focus is in the area of homogeneous catalysis strongly underpinned by organic and organometallic synthesis, especially of new classes of ligands and catalyst precursors. Reactions of interest are cross-coupling reactions, carbonylation reactions and alkene transformations, which are of special interest to the South African commodity chemicals industry and internationally also to the fine chemicals and pharmaceutical.
Water chemistry, element and species analysis
Water is a crucial commodity to an arid country such as South Africa. As such, an understanding of the various aspects of water chemistry is essential to ensure adequate supplies of water of sufficient quality. This research programme focuses on water chemistry and the analytical chemistry of chemical species of the same element in different physico-chemical forms, eg elements in different oxidation states, state of complexation, and adsorbed species. Current projects include:
- The development of oxidation state speciation methods, which are important for the mining and chemical industry and environmental monitoring.
- The chemistry of physical water treatment processes. Recent success in this research field involves a patented treatment of water with certain free metal ions for the reduction of the formation of scale in industrial and domestic installations.
- The chemistry of fluoride adsorption and the development of cost-effective defluoridation methods for contaminated surface waters for application in rural areas.
- The development and implementation of sequential extraction techniques in environmental monitoring.
Crystal and Structural Chemistry
This program is concerned with the phase chemistry of industrially important materials, with the focus on the mineral and wax industries. The relationships between structure and properties of the crystalline forms of these materials are studied by the determination and analysis of their three-dimensional structures. The use of supramolecular techniques for the preparation of unique compounds is stressed. Current projects include:
- The synthesis and structure determination of modified wax components and layered organic/inorganic hybrids.
- The determination of crystal structures and phase behaviour of titanium-containing slags, produced by the heavy mineral industry.
Research on medicinal plants of South Africa is also done in the Department.
CHEMICAL TECHNOLOGY
Contact: Prof B Mamba
The research in the department is mainly focused on four research areas: Nanomaterials research which is part of the Center of Excellence for Strong Materials established by the Department of Science and Technology, Water treatment research which is part of the UJ Water and Health research, an NRF recognized research niche area, Natural products and Phosphorus Chemistry. The water research group in the department has been recognized by the Department of Science and Technology as a Nanotechnology Innovation Centre (Water research platform).
Nanotechnology
UJ’s involvement in nanotechnology research dates back six years, spanning four key thrusts – the development of novel carbon-based nanomaterials, their modification to act as supports for other chemicals (such as catalysts), the development of “nanosponges” for the purification of water, and developing an understanding of nano-scale magnetic material properties. Through these research efforts the UJ has gained national recognition for a sound research programme in this domain, and is a formal partner in the NRF/DST Centre of Excellence for Strong Materials (centred at Wits University) and the DST/Mintek Nanotechnology Innovation Centre. The programme has also recently been formally approved as a Developing Research Niche Area by the NRF. .
Nanomaterials
This research group focuses on the synthesis, functionalisation, characterization and applications of carbon-based nanomaterials. Nanomaterials under investigation include carbon nanotubes which exhibit novel physical and chemical properties due to their size and unusual strength. They are used in components for the electronic industry, nanotransistors and nanowires, in sporting goods and even cosmetics. Examples of ongoing research in this group include projects on the synthesis of nanomaterials for catalysis, the synthesis and characterization of aligned multi-walled nanotubes by nebulised spray pyrolysis and the use of structurally modified nanomaterials in water purification. The team has just been granted an NRF Research Niche Area on Carbon Nanomaterials Science and Engineering at a developing level of activity.
Water treatment research
There are two main thrusts in the water research field. One focuses on nanoporous polymers (alias nanosponges) for use in water purification. This involves the synthesis of water insoluble cyclodextrin- and calixarene-based polymers and their derivatives to remove organic pollutants. Nanosponges bind organic molecules strongly in aqueous media, but release the same contaminants in organic media. As part of the Nanomaterials Innovation Centre (NIC), the group is linked to other national and international groups in water treatment and health.
Other research focuses on water quality and the effects on industrial and domestic usage. The emphasis is on the effects of the natural organic matter (NOM) in certain water industrial applications. Current projects on the nature and effects of NOM on electricity production, particularly cooling water treatment, involve Eskom and the Technical University of Delft in the Netherlands. .
Natural products
This research group focuses on identifying and sourcing indigenous Southern African medicinal plants. It involves the investigation of their efficacies, distribution, and active ingredients that provide a basis for medicinal use. The active ingredients from the plants are extracted and characterized, and the biological activity is established together with collaborators. Current projects focus on African tonics with emphasis on Sutherlandia (cancer bush). Regional collaboration with other African universities forms an important part of the group’s activities
Phosphorus chemistry
This area focuses on the synthesis of phosphorus derivatives and their application as organic synthesis tools, bio-medical agents, and material precursors. Current projects involve the synthesis of new bisphosphonate derivatives and their biological evaluation as anti-tumour and anti-viral agents. Other projects focus on the synthesis of phosphorylated carbon nanotubes and their application as fire retardants, metals scavengers, and polymer composite precursors.
FOOD TECHNOLOGY
Contact: Dr S de Kock
Currently the Department of Food Technology is conducting collaborative research with Professor Dutton within the discipline of Mycotoxins. Projects are being conducted on mycotoxins in milk and maize. Milk is not only a food in its own right but is also used to make a range of dairy products like cheese, ice cream and yogurt. All these commodities may become contaminated with mycotoxins if the animal producing the original milk consumed feed containing mycotoxins. The main contaminant is aflatoxin M1 (AFM1) which arises by the animal’s metabolism of aflatoxin B1 (AFB1). Other toxins, however, can appear in milk, e.g., ochratoxin. These toxins can pass over to the dairy products during processing. During processing cheese can become contaminated with other toxins due to the use of fungi as maturation organisms. Although the primary source of dairy product contamination is the producing animal it is important in food safety that the contamination is traced through the production chain. Therefore, particular attention will be focused on the primary source of mycotoxin, which is the all the feed material the lactating animal (in this case the cow) may be consuming. Sampling will take place further down the chain to find out the effect of the processing and distribution has on any contaminant identified in the feed.
The maize project sets out to develop a sampling protocol that would minimise the numbers of samples to be analysed for a specified mycotoxin, fumonisin B1 but would give reliable confidence limits of mycotoxin levels in the target commodity, maize, which would allow a practical assessment of the usability of a large batch consignment. It also seeks to identify a rapid screen based on immuno-assay, e.g., Elisa that gives comparable results to those derived from a more definitive method, e.g., high performance liquid chromatography that would be acceptable to quality control assessments.
In addition, our Department is also conducting collaborative research with Professor Bob Stafford, Faculty of Engineering and the Built Environment and external research partners within the field of brewing and beverage production. Projects are being done on the intensification of the brewing process through the application of ultrasound and the development of a mathematical model to predict the risk of microbial spoilage of ready-to-drink non-alcoholic beverages. The brewing process is a prodigious consumer of raw materials, energy, water and time whilst simultaneously producing considerable quantities of effluent. Our research, in partnership with CSIR, addresses the intensification of the process through the exploitation of sono-chemistry. In this regard, we are considering intensification to result in one or more of the following: a shortening of process time; an increase of yield; a reduction in consumption of energy, water, raw materials and processing aids; a reduction of effluent; a reduction of CAPEX and OPEX etc.
The risk of microbial spoilage of ready-to-drink non-alcoholic beverages which are non-aseptically cold-filled and distributed via an ambient temperature distribution chain is a multi-factorial problem involving several microbiological, chemical and engineering parameters. With our research partners, Tigerbrands, we are investigating the development of a mathematical model to predict, for a given set of product recipe and processing conditions, the quantified risk of spoilage in trade for use in establishing process control limits and as a decision-making tool.
GEOGRAPHY, ENVIRONMENTAL MANAGEMENT & ENERGY STUDIES
Contact: Prof H Annegarn
Sustainable Energy and Geo-Informatics (consisting of Geographic Information Systems (GIS) and Remote Sensing) are the main research areas in the department. A flagship project in the department is ENERKEY. .
ENERKEY
‘Enerkey Sustainable Mega-Cities Project’ is a collaborative initiative between UJ, Tshwane, Ekurhuleni and Johannesburg, the University of Stuttgart and the Metropolitan Council of Stuttgart, Germany.
The project objectives are to establish a research network of South African and German institutions in sustainability research; to develop and implement energy projects as exemplary case studies to improve sustainability in large urban agglomerations; to demonstrate an integrated approach including technical, economic, ecological and socio-economic aspects; to show the feasibility and practical use of model tools and planning instruments; and to elaborate together new approaches, methods and projects for a longer fruitful collaboration.
Through this collaboration with the University of Stuttgart, the UJ has become the South African lead partner in this massive programme aimed at analyzing energy needs and uses of the greater Johannesburg megacity as well as certain peri-urban and rural areas, and implementing several pilot projects intended to demonstrate the use of more sustainable energy technologies. Programme partners involve local and regional governments, Eskom, the South African National Energy Research Agency, NGOs, and several private companies. Current projects address vehicle operating performance and emissions monitoring; thermal efficiency of school buildings; rural biofuels modelling; social and environmental sustainability factors in alternate rural biofuel strategies; solar water heating strategies; energy modelling; thermal properties of building materials; energy efficient low cost housing; energy use and domestic safety (safer paraffin stoves).
Support for this niche builds on the UJ’s emerging research reputation for energy-related research activities, including its pathbreaking work on the development of revolutionary technologies for cost-efficient photovoltaic cells, and promotes the emergence of a UJ research focus on energy.
Within the pilot phase, selected critical energy areas were studied within the broader framework.
- The Residential Thermal Energy Project developed, tested and piloted improved thermal energy devices for residential buildings and settlements, including pilot supply of safe(r) paraffin stoves, lamps and fire-proof bedding and curtains;
- The Schools Energy Efficiency Project retrofitted insulation into existing classrooms and measured the energy performance of school building types. This was combined with awareness raising and educational efforts;
- The Mobility & Traffic Project modelled motor vehicle fuel use, air pollutant emissions and congestion in greater Johannesburg, and developed an improved emissions inventory model for use in air quality management and transportation infrastructure planning.
- The Solar Water Heating Project developed economic, business and administrative plans for the large-scale rollout of domestic solar water heaters in the domestic sector. These plans were developed jointly with the cities, Eskom, DBSA and NGO partners and will be implemented starting in 2008.
- Student exchanges – During 2006 and 2007 two German students and two South Africa students have visited the partner countries for periods of up to four months within the framework of the Enerkey programme.
GEOLOGY
Contact: Prof B Cairncross
Projects are undertaken in cooperation with various institutions and universities worldwide. The national and international projects currently being undertaken include:
- Interaction between styles of mineralization and environmental change in the Precambrian:
- Geochronology, sedimentary provenance, sequence stratigraphy and palaeomagnetism of Mesoarchean to Palaeoproterozoic sedimentary successions on the Kaapvaal and Pilbara cratons.
- Multidisciplinary study of the Precambrian biosphere and surficial oxygenation, Kaapvaal Craton, South Africa.
- Ferrous mineral research.
- Base metal deposits of the Bushmanland region, South Africa.
- Tectonic setting and Cu-mineralization in the Areachap Group, Northern Cape Province.
- Base metal mineralization in the Zambian Copperbelt.
- Provenance studies applied to understanding basin evolution and palaeogeographic reconstructions through time:
- Neoproterozoic relations between Southern Africa and South America.
- Provenance studies applied to the understanding of basin evolution through time.
- Geology, sedimentology, evaluation and utilization of southern African coal resources.
- Documenting and publicising South Africa's national geological, mineral and gemstone heritage.
- Geodynamics of high-grade metamorphic terrains.
- Geology of Venetia kimberlite pipes.
- Geology of certain nature reserves in the Limpopo Province.
- Greenstone belt geology and associated granites.
- Geology of the Bushveld Complex and associated platinum group element mineralization.
- Mineralogical control on natural surface water quality in South Africa.
Centre in Economic Geometallurgy (integrated with the Paleoproterozoic Mineralization (PPM) Research Group)
The Palaeo-Proterozoic Mineralization (PPM) Research Group in economic geology and geometallurgy already enjoys national recognition and international exposure, with the UJ’s first NRF Research Chair awarded to the group’s leader.
The Paleoproterozoic Mineralization Research Group (PPM) has become the largest research group in the geosciences in South Africa. It is internationally recognized as a leading force in the study of Precambrian paleoenvironmental evolution and associated ore forming processes. The research efforts of the PPM Group are focused on – but by no means restricted to – the Paleoproterozoic Era of Earth History (1.8 and 2.5 billion years before present). This Era represents a time of unique changes of System Earth, including a rapid rise in atmospheric oxygen concentrations, and the formation of the first Supercontinents, with associated continental rifts and collisional mountain belts. The Paleoproterozoic Era is also one of the most richly mineralized Eras in geological history, hosting by far the largest concentrations of iron, manganese, platinum and chromium in the world. Many of these mineral deposits are time-bounded and related to the profound environmental changesexperienced by System Earth during this time interval.
A considerable proportion of the research carried out by members and students of the PPM Group is aimed to further our understanding of the relationship between environmental change and styles of mineralization in the Paleoproterozoic. This research focus of the PPM Group has particular regional relevance, as much of the formidable mineral wealth of the Paleoproterozoic occurs in Africa - and in particular Southern Africa. Geometallurgical characterization of ores and beneficiation products is a second important research focus of the PPM Group. The latter is aimed to provide detailed quantitative mineralogical and textural information for non-renewable mineral resources that are heterogeneous in composition, in order to assure their sustainable use.
In 2006, the PPM group was integrated into a newly establised research centre. The research centre enjoys close links to industry, currently being engaged in a 5-year research project into the iron ore resource potential of the Northern Cape Province, funded in equal parts by African Rainbow Minerals and Associated Ore and Metals. The centre’s excellent and unrivalled research equipment infrastructure plays a key role not only in its research contracts with mining companies, but has also placed the UJ at the forefront of palaeomagnetic research not only in Africa, but also in the world by enabling international research collaborations with, e.g., Caltech, MIT, Yale, the University of Texas at Austin, Occidental College, and the US Geological Survey. In addition, the group has taken the lead role in the Agouron Geobiology research project, a privately-funded research drilling project involved participants from Caltech, MIT, Harvard, Yale, the Universities of Bern, Muenster, Bremen, amongst others.
MATHEMATICS
Contact: Prof E Jonck
Graph Theory
The exiting and rapidly growing area of Graph Theory is rich in theoretical results as well as applications to real world problems.
One primary activity is modeling, a process involving formulating a problem in such a way that it can be attacked by techniques in Graph Theory. Applicable fields include amongst others Chemistry, Computer Science, Social Sciences, Broadcasting and Music.
In Graph Theory at UJ, we concentrate on theoretical Random Graph Theory, Domination in graphs and Additive and Hereditary Graph Theory.
Functional Analysis
In Functional Analysis research focuses on Spectral Theory in Banach algebras and Ordered Banach algebras. One can say that the theory of Banach algebras stands with its feet in analysis and its head in algebra.
Spectral theory is the study of the properties of the spectrum function and the spectral radius function. With the advent and development of the new Quantum Mechanics in the 1920’s it became increasingly obvious that the mathematical concept of “spectrum” corresponds closely to a notion already familiar in Physics. As such, contemporary research in Spectral Theory draws ideas from both these fields. Research in the Department specializes in the more abstract setting, where we employ the latest techniques to obtain results connecting the algebraic and spectral structure of elements in the particular Space.
In a somewhat different vein, research is also being conducted on connections between abstract Spectral Theory and the Theory of Generalized Inversion, the latter of which has important applications in the field of Mathematical Statistics.
Since the presence of a partial ordering in Ordered Banach algebras is not yet fully understood, research is being conducted to determine the effect of positivity on spectral and algebraic properties of elements. Ordering plays an important role in the approximation of continuous functions by positive functions, time dependent partial differential equations, computational molecular dynamics and wireless communications. Another recent research topic where positivity plays a role is the so-called Google matrix, the worlds largest one. This is a matrix with positive entries and it is used to compute the PageRank, used by the Google Web search engine.
Logic
The third area of research within the department focuses on Mathematical Logic. This is a dynamic and rapidly developing field with its origins in philosophy and the foundations of mathematics, but which these days also finds major applications within theoretical computer science, artificial intelligence, and linguistics. At UJ, research in this area focuses mainly on modal and algebraic logic. Modal logic is used to formalize and study reasoning involving the ways (or modes) in which a statement can be said to be true. Algebraic logic uses the methods of universal algebra to study logical questions. In particular, some recent outputs have investigated topics including modal correspondence and completeness theory, description logics, interpolation, logics of rational structures, (interval based) temporal logics, finite model properties, and properties of MTL chains.
PHYSICS
Contact: Prof AM Strydom
Four main directions of Physics research are pursued
CONDENSED MATTER PHYSICS
Magnetism and ultra-low-temperature Physics
This group focuses on magnetic effects in the elasticity, thermal expansion and electrical transport properties of chromium and chromium alloys. Studies are done as functions of temperature, high pressure and alloy concentration. The purpose is to enhance our understanding of the physical behaviour of chromium and chromium alloys, of which South Africa is a major producer. Presently the studies are extended to thin film Cr and Cr alloys, which have application in data storage. Strong Correlations in f-electrons involves experimental studies of a wide variety of physical properties in condensed matter. The experimental parameters include high magnetic fields, and very low temperatures. The Department has built up country-wide unique experimental facilities with which to study ground-state phenomena of solids under these extreme conditions. Two research topics of special interest are quantum criticality in rare-earth based systems, and thermoelectric properties in cage-structured, strongly correlated materials.
The Research Laboratory for Strong Electron Correlations in Condensed Matter under leadership of Professor André M. Strydom in the Physics Department, Faculty of Science of UJ is reaping reaping the benefits of two large investments in research facilities.
Ultra-low temperature measurements of magnetic properties, the first of its kind on the content of Africa, is a very specialized research field opened up by the opportunity to conduct measurements on a SQUID magnetometer (Superconducting Quantum Interference Device) on sample material cooled down to less than half a degree away from the absolute zero of temperature.
This is an extremely sensitive instrument for probing the magnetic states of matter, and its extraordinary application lies in the instrument's unsurpassed ability to detect the tiniest of changes, –as little as one part in a trillion (1012), in the magnetic state of a material, at extremely low sample temperatures.
The acquisition of this equipment is made possible by a grant award to Strydom under the National Equipment Programme of the South African National Research Foundation, in conjunction with support from the Research Committee of the University of Johannesburg.
The second new research facility follows from a grant award to Prof Strydom from the German Research Foundation (DFG) to further the collaboration between Strydom and colleagues at the Max Planck Institute for Chemical Physics of Solids (CPfS) in Dresden, Germany. This facility involves the installation of a new ultra-low temperature cryogenic plant in the Physics-UJ laboratory of Strydom to enable physical properties (heat capacity and electronic transport) to be investigated at temperatures down to 0.3 Kelvin (–272.85 degrees centigrade), and in magnetic fields up to 9 Tesla. This award crowns more than 5 years' collaboration and visits of Strydom to Dresden as an invited scientist.
In our research into quantum criticality, –one of the most exciting new research fields in Condensed Matter Physics, the very lowest energy states of matter are looked at through the windows of micro-changes in magnetic and thermodynamic phenomena occurring near phase instabilities. Phase changes that are located very near the absolute zero of temperature (–273.15 degrees centigrade) reward us with a glance into the fascinating world of quantum excitations and the way in which systems organize themselves into cooperative behaviour on all size scales: from the solidification of water into ice to form snow flakes, ice cubes, frozen lakes, or polar ice caps, to stellar dust that forms planetary objects of galactic proportions over millions of years. Measurements of the temperature– and magnetic field dependences of physical properties at very low temperatures enable us to probe the energy scales that drive these self-organizing processes in nature. Cooperative processes are not confined to low temperatures only – they are evident at all temperatures of matter and are very much a part of our daily lives. However, at elevated and ambient conditions there are such a multitude of different types of energies at work in a solid substance that the cause–and–effect labeling of energies becomes a daunting task, and hence the need to perform these investigations at low temperatures.
Chromium based Research
The Chromium Research Group was established by Prof Herman Alberts, and now includes also Prof Aletta Prinsloo, Dr Charles Sheppard, Dr Krish Reddy, Ms Susan Jacobs and Mr Blessed Muchono. The group has over the past few years made important contributions to the knowledge in this field. Chromium alloy systems exhibit a great variety of interesting antiferromagnetic properties that are associated with nesting of the Fermi surface sheets. The beauty of the properties of these materials originates in their spin-density-wave (SDW) state, which contributes a large component, of magnetic origin, to nearly all their physical properties. What makes these materials more attractive is the fact that, due to the large contribution of SDW origin to their physical properties, once the fundamental role of the SDW in these properties is understood, one can tailor the alloys to give desired physical properties that can be useful in practical applications. Significant innovation will be the role of dimensionality effects in the properties of Cr and its alloys through the studies on magnetic thin films. There is renewed interest in literature in the physical properties of dilute Cr alloys, particularly in their magnetic phase diagrams and more recently in the quantum critical point effects in dilute Cr alloys. In studies on single crystalline alloys, in their anharmonic effects and in their role as spacer layers in magnetic multilayer thin film structures with giant magnetoresistance properties. Studies at UJ are aimed at gaining insight and understanding into the unique effects of the spin- density-wave on the physical properties of chromium and its alloys, both in bulk and thin film forms.
Diamond Physics
Diamond exhibits more than 20 properties, which represent an extreme when compared to any other material. Diamond near the theoretical limits of perfection would make an excellent host the fabrication of electronic devices, particle detectors, X-ray optical elements or, more speculatively, as a crystal undulator laser source of gamma rays, amongst other applications. This group studies the physics and the engineering of diamond to realize these devices.
Materials physics at extreme pressure-temperature conditions
In the last two years this research group has established capabilities for attaining extreme pressure conditions using diamond-anvil cells (DACs). Pressure is a key thermodynamic parameter for clean and controlled tuning of the physical properties of a material (eg, structural changes to new phases with advanced properties). Pressures up to 30 GPa (300 000 atmospheres) can be reached on a routine basis, concurrently with temperatures of 2 – 2000 K. Low temperatures are obtained with cryogenic facilities and high temperatures are reached with the aid of laser heating. In the DAC, a tiny amount of sample material is sandwiched between the flat tips of two opposed diamonds with truncated tips. A force is applied to the back of the diamonds driving the anvils together so as to create the high-pressure conditions at the sample area. The use of diamond anvils is important not only because of their high hardness but also because of the transparency. It permits optical access (eg, sample color and shape changes may be discerned) and other forms of probing radiation (eg, X-rays) may be transmitted to the pressurised sample.
There are have various versatile miniature DACs for the in situ characterisation of materials under extreme pressure-temperature (P-T) conditions. These DACs readily fit into cryostats, under microcopes, in furnaces and so on. The availability of existing characterisation facilities like Raman or Brillouin spectrometers for investigating mechanical-elastic properties may be exploited, 57Fe Mössbauer spectroscopy to probe magnetic-electronic properties, XRD for structural evolution and lead wires can be introduced into the sample cavity for electrical-transport studies, as a function of pressure in various materials comprising mainly metal oxides. These include (i) strongly correlated systems like Mott (magnetic) insulators with spectacular pressure tuned magnetic- electronic properties, these also have considerable overlap with the physics involved in deep Earth materials of the geo-sciences, (ii) pressure response of nanomaterials as well as (iii) a search for potentially new ultra-hard ultra-stable materials (superceramics).
The above-mentioned techniques are used on a routine basis to pressures of ~30 GPa in the DAC. Where necessary this can be extended to much higher pressures into the megabar (~100 GPa) regime. These pressures correspond to depths ranging from a few hundred to about two thousand kilometers in the earth. The DAC is therefore a window into the interior (lower mantle) of the planet and is regarded as a very important tool in the geo-sciences.
Electronic structure and surface science
The electronic structure and surface science group based in the Physics Department at UJ is made up of Dr Bryan Doyle (Senior Lecturer), Dr Emanuela Carleschi (Lecturer), and the three MSc students Prosper Ngabonziza, Mubarak Yagoub and Arlette Sohanfo Ngankeu (who just very recently joined the group). The current research topics investigatedby this group are mainly based on the study of the interplay between magnetism, superconductivity and other exotic behaviours in correlated transition metal oxides, as well as the study of the effect of the dopants on the electronic structure of p-conjugated molecules adsorbed on metal surfaces.
The experiments are carried out in collaboration with European groups based in Dresden, Salerno, Trieste and Modena, and are mostly performed at synchrotron radiation source facilities located in Europe, such as Elettra (Trieste, Italy), BESSY II (Berlin, Germany) and Soleil (Paris, France). Trips to Europe are funded either by the National Research Foundation or the Faculty of Science of the University of Johannesburg. Synchrotron radiation is an indispensable tool for our research, because it provides high-brilliance and high-resolution monochromatic radiation with polarization and energy tunability.
ASTROPHYSICS AND SOLAR ENERGY
Multi-wavelength astrophysical research
Dr Lerothodi Leeuw conducts multi-wavelength astrophysical research on the evolution of elliptical galaxies and their progenitors, in both gravitationally lensed and un-lensed systems. For this he exploits observations at infrared to radio and complementary wavebands obtained using ground and space telescopes, both large and small. Recently publication highlights from this research includes The Detection of a Population of Submillimeter Bright, Strongly Lensed Galaxies by M Negrello, et al, Science, 330, 800-804 (2010) and Observation of H2O in a strongly lensed Herschel-ATLAS source at z = 2.3 by A Omont, et al, Astronomy & Astrophysics, 530, L30 (2011). This research has attracted interest for graduate projects from students as far as Cape Town, with Sidiki Zongo of the African Institute of Mathematical Sciences having recently completed his Postgraduate Diploma Essay and Itumeleng Monageng of the University of Cape Town starting his Honours Project in this area.
Further, Bernard Asabere just joined the group to begin his PhD on The submillimetre-to-radio view of high- redshift star-forming galaxies and galaxy clusters co-supervised by Prof Cathy Horellou of Onsala Space Observatory and Chalmers University of Technology in Sweden. Bernard, who is under the South African Square Kilometer Array Project Postgraduate Scholarship Programme, hails from Ghana where he was a research scientist at the Ghana Space Science and Technology Centre and the project manager of the African Very Large Baseline Interferometer Network-Ghana.
The Kepler Space Telescope
The Asteroseismology Research Group joined the Kepler Asteroseismic Science Consortium (KASC), an international body of astrophysicists, in 2010. Kepler is a 600- million- dollar NASA mission, launched in 2009, which has changed the face of asteroseismology in its first two years of operation. Dr Engelbrecht has co- authored one paper on Kepler data in 2011, while CT Middleton has just completed his MSc dissertation at UJ on an intriguing Kepler discovery.
The current postdoctoral fellow in the group, Dr Ceren Ulusoy, has organised and executed a very successful trans- continental follow-up campaign on yet another Kepler target, involving researchers in Mexico, the USA, Italy, Turkey, Japan and South Africa. Tim Gülmez, a PhD student in the group, has assisted admirably in the execution of the campaign.
Participation in MeerKAT/SKA
Dr Engelbrecht is a member of the international TRAPUM consortium, one of the survey projects that was successful in obtaining MeerKAT observing time for the first 5 years of operation (anticipated to be 2014 – 2018). TRAPUM has been allocated 3000 hours of observing time to detect and observe new pulsars, one of the five key science programmes in the international SKA project.
Active Galactic Nuclei and Solar Energy
Under the guidance of Prof Hartmut Winkler a team in the Department is quantifying the ground-level characteristics of solar radiation with the aim of determining its solar energy generation potential in the Gauteng urban environment, considering specific location altitude, land aspect, aerosol concentrations and weather patterns. This project aims to create an internet-based provincial solar atlas that will be available as a resource to the solar power industry and the public for solar panel installation. The work is part of the regional Enerkey initiative, which is exploring Gauteng’s energy consumption, management and future requirements.
Prof Winkler is also studying the variations and optical spectral characteristics of active galactic nuclei (AGN). He is developing a web-based atlas of the visual spectra of comparatively nearby Seyfert galaxies, as well as a catalogue of AGN based on a revised, more sophisticated, spectral characterization scheme.
HIGH ENERGY PHYSICS, NUCLEAR PHYSICS AND THEORETICAL PHYSICS
SA-Atlas Project
The UJ High Energy Physics group is a member institution of SA-ATLAS working on the giant multi-purpose ATLAS detector, one of the experiments at the Large Hadron Collider (LHC) at CERN in Switzerland. ATLAS is investigating a wide range of physics, including the search for the Higgs boson, extra dimensions, particles that could make up dark matter and the quark-gluon plasma. The UJ group is participating in the search for the Higgs and also physics beyond the Standard Model. This group plays an important role in the development of the UJ high performance computing cluster for local data analysis and Grid computing.
The hunt for the Higgs particle at CERN is reaching a critical point – and its proceeding faster than expected. The current status is an exclusion of the existence of the Higgs to the 95% confidence level overmost of the mass range from 145 – 466 GeV. Whether the Higgs is found or not, particle Physics is on the brink of new discoveries. UJ was the first South African University working in the ATLAS collaboration, participating in this search. UJ is a founder member of the SA-CERN programme as well as the SA-Grid, a high performance computing system that allows the data from CERN to be transferred here and analyzed locally. The UJ team participates in other searches for Physics beyond the Standard Model.
Nuclear structure and reactions
Prof Steven Karataglidis joined the Department of Physics in April 2010. His expertise lies in both Nuclear Structure and Reaction Theory, and the overlap between them, and works with colleagues around the world, both in theory and experiment, to gain a better understanding of that still most elusive of creatures: the atomic nucleus. He heads the Nuclear Structure and Reactions Group.
The nucleus is an elusive beast: a many-nucleon (proton and neutron) system which can only be studied through reactions. But this is a catch-22: the purpose of the reactions is to gain knowledge of its structure but, to understand the reactions, one needs to know a priori its structure. This double-edged sword is where the problem lies, and can only be done through modelling. Prof Karataglidis uses both structure and reaction theory to work towards that end. The microscopic theories of scattering he has developed with his colleagues overseas, in particular, has shed new light on the structures of exotic nuclei (those that decay a short time after being formed in the laboratory). For halo nuclei, where one or two nucleons lie well outside the nuclear core, forming an odd bound system, the work has shown that the nucleon density forming the halo is depleted in the core. This is contrary to the view of cluster models, which hold that the core remains unchanged from those of stable nuclei. A proper many-body understanding is needed, and the large- scale shell model work on the structure side of Prof Karataglidis’ research has proved essential. 2011 marks the centenary of the discovery of the nucleus by Ernest Rutherford. After 100 years we are much closer in understanding what makes the nucleus tick, but there is still much work ahead in trying to unlock its secrets.
Theoretical High Energy Nuclear, Particle and Astro-Physics
Prof Azwinndini Muronga’s main field of research is in theoretical high-energy nuclear, particle and astro- physics. Astrophysical objects and processes, both connected with very early and very late phenomena in the cosmological evolution of strongly interacting matter, present an enormous challenge to modern nuclear and particle physics: can scientists recreate – in experiments carried out in the terrestrial laboratory – the conditions prevailing during the first microseconds of the cosmological expansion, or during the late stages of a violent supernova stellar implosion? These investigations culminate for the time being in the Large Hadron Collider (LHC) at the European Center for Nuclear Research (CERN), Geneva, and in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL), USA. Under extremely high temperatures and densities, protons and neutrons overlap to such a degree that a quark–gluon plasma is formed. The universe, 1 microsecond after the Big Bang, is believed to have been a plasma of weakly interacting quarks, gluons and leptons. This plasma might even still exist in the deep interiors of neutron stars. Observing the plasma is one of the world’s most prominent scientific goals. Detection of the quark–gluon plasma would not only serve as direct evidence of quarks and gluons, but would also open a new era in physics. Measurements and studies of its properties would hopefully allow scientists to answer some of the fundamental questions about the origin of the universe.
Prof Muronga’s main focus is in the understanding of matter under extreme conditions of temperature and density. This is accomplished by studying ultra-relativistic nucleus- nucleus collisions such as those at RHIC and LHC. The study of ultra- relativistic heavy-ion collisions brings together aspects of nuclear, particle and astro-physics. His approach involves using relativistic dissipative fluid dynamics and relativistic microscopic transport models to study space- time evolution of hot and dense nuclear matter - from the initial stages of compression via the expansion to the final stage of observables.
STATISTICS
Contact: Mr F van der Walt
The main fields in which research is undertaken in the Department are Financial Statistics and Industrial Statistics. The applications are primarily in finance and in industrial quality control. The research in finance involves the study risk and finacial instruments. Industrial research is done in collaboration with ESKOM.
ZOOLOGY
Contact: Prof J Janse van Vuren
Aquatic ecotoxicology
Over the last 20 years a group of scientists in the UJ Zoology Department have developed a branch of aquatic research into the field of freshwater and estuarine eco-toxicology. Eco-toxicology is the science that studies the influence of human activities on the environment, from a global (e.g., global warming) to a more local perspective (e.g., mining effluent in the Blesbokspruit). Research in the department has been active in all facets of the eco-toxicological concept ranging from toxicant identification and environmental distribution (i.e., quantifying and qualifying levels) to biological / environmental effects (i.e., at different levels of biological organization from sub-cellular to ecosystem responses), to management implications (e.g. ecological risk assessment). While research in eco-toxicology is not confined only to the UJ, the UJ is distinct in its integrated focus on the aquatic environment. Research in this area is strongly informed by requirements of various national Acts.
A specific strength of this research programme is its external applied and consulting research activities that ensure constant feedback on national research priorities into the programme. These links have also enabled the research group to leverage funding and partnerships across a wide range of organizations. Most importantly, the activities in this research niche complement the UJ’s other water-based research activities, thereby enhancing the emergence of a UJ research focus on Water Studies.
Other research areas:
- Physiological effects (Biomarkers)
- Fish Health index (Including Parasitology)
- Effects on Reproductive Physiology
- Histopathological effects
- Biological control of water plants
- Aquatic Integrity
· Population Genetics:
· Biosystematics