Eng-PostgradGraag wil ons vir Sebastian Bode, en die res van sy entoesiastiese Meganiese en Megatroniese span, baie hartlik gelukwens met hul welverdiende oorwinning in die “Dual Stick” kompetisie tydens ons nagraadse sosiale geleentheid in Oktober vanjaar! Deel van die M&M wenspan se taai spanlede is (agter v.l.n.r.) Gregg Walker, André Louw, Jacques du Preez, Rick Nel, Gerro Prinsloo, en Holger Kretzschmar; en voor (v.l.n.r.) is Ivan Deetlefs, Sebastian Bode, en Hugo Smit.Elkeen van die spanlede het na afloop van die wedstryd ‘n oulike “Trust Me, I’m an Engineer” vlekvrye staal koffiefles ontvang, waarna Prof Perold die gesogte Ingenieurswese Beker aan die spankaptein, Sebastian Bode, oorhandig het. Ons is baie dankbaar dat AM de Jager weereens tyd kon inruim in sy besige skedule om ons fotograaf te wees tydens hierdie nagraadse sosiale geleentheid. Loer gerus na AM se indrukwekkende fotografie portefeulje op sy webblad: www.amdejager.com

Desember 2012

Fakulteit Ingenieurswese Nagraadse Nuusbrief

Faculty of Engineering, Stellenbosch UniversityPublished by the Vice Dean (Research): Prof Willem PeroldEditor: Tanya Ficker www.eng.sun.ac.za

Bo links: Jacques du Preez klou verbete vas, terwyl sy spanmaats in spanning toekyk hoe hy die Ingenieurswese Beker verdedig.Heel bo en bo regs: Die Meganiese en Megatroniese Ingenieurswese span spog vir die soveelste keer met die Ingenieurswese Beker!

‘n Studentespan bestaande uit Meesters studente in die Elektroniese Stelsels Laboratorium (ESL), nl. Pieter Botma, Mike-Alec Kearney, Willem Jordaan, Jako Gerber, Alex Erlank, Christo Groenewald, Emile Thesnaar en Francois Nolte, het verlede week by die US/Japan Nanosatelliet Sim-posium in Nagoya, Japan, die studenteprys in ‘n “Mission Idea Contest” vir nanosatelliete gewen. Benewens ‘n sertifi-kaat en 50 000 Yen prysgeld, is baie blootstelling gegee aan die Universiteit van Stellenbosch se vermoëns. ‘n Hele aan-tal dosente by die Departement Elektriese en Elektroniese Ingenieurswese, o.a. Arno Barnard, Dr Dirk de Villiers, Prof Johann de Swart, en Prof Keith Palmer, het gehelp om ‘n goeie tegniese voorstel voor te berei. Daar het altesaam 74 spanne wêreldwyd deelgeneem, en ‘n span bestaande uit PhD studente, postdoks en ruimte-eksperts by Massachu-setts Institute of Technology (MIT) het die kompetisie gewen.

Van links na regs: Willem Jordaan en Mike-Alec Kearney ontvang die prys, namens die ESL span, by Dr Rainer Sandau van die Inter-national Academy of Astronautics (IAA).

A huge congratulations to Prof Neels Fourie at the Depart-ment of Industrial Engineering, for receiving a Category III Recognition Award on 18 September this year. A Category III Recognition Award is awarded to a non-member of the Operations Research Society of South Africa (ORSSA) for outstanding contributions over a long period of time. After 17 years in the industry, Prof Fourie decided on a ca-reer change and in 1987 joined the Department of Industrial Engineering at Stellenbosch University as a senior lecturer, and director of the Centre for Robotics within the department. During his lecturing career, Prof Fourie focused on teach-ing undergraduate subjects in the fields of manufacturing and operational management, and on postgraduate level he taught courses in project management and robotics. He was promoted to full professor of industrial engineering in 2004 and as Chairperson of the Department of Industrial Engi-neering, a position he held until May 2009.Prof Fourie has been contracted by the Department of Indus-trial Engineering to teach undergraduate and postgraduate courses, to carry out relevant research, and to supervise and examine postgraduate students. During the period 2009 to 2010, he negotiated the establishment of a Chair for Main-tenance and Engineering Management with the Passenger Rail Agency of South Africa (PRASA), and was subsequently appointed chair incumbent in this position within the Depart-ment of Industrial Engineering in 2011, a position that he still holds. Prof Fourie is the author of 11 peer-reviewed journal papers, 3 keynote conference addresses and 33 papers at international conferences. He has supervised 20 postgradu-ate students to completion. He has been registered with the Engineering Council of South Africa as professional engineer since 1975 and also serves on the Professional Advisory Committee for Industrial Engineering on this council. Prof Fourie was nominated for this award because he has always firmly supported the sustained inclusion of operations research as a fundamental component of the industrial en-

gineering curriculum at the Faculty of Engineering. He ap-preciates the value that expertise in operations research can add to the constitution of an industrial engineer, and has for more than 25 years been an advocate and proponent of the field. Thanks in part to Prof Fourie’s insight and conviction, operations research is still a fundamental part of the under-graduate and postgraduate curriculum at the Department of Industrial Engineering today. There are hundreds of indus-trial engineering graduates who have left the university with an understanding of, and respect and appreciation for, the value of operations research as a result of Prof Fourie’s sup-port of the field, and its resulting inclusion in the industrial engineering syllabi. For this contribution to the profession of operations research in South Africa, Cornelius Jacobus Fou-rie was, on 18 September 2012, duly awarded a Category III ORSSA Recognition Award.

From left to right: Prof Neels Fourie, Pieter Conradie (senior re-search engineer, PRASA Chair), and Karl Rommelspacher (junior research engineer, PRASA Chair).

In September this year students from the Faculty of Engi-neering, after six months of hard work in the multinational Global Engineering Teams (GET), presented their final re-ports on several low cost ways to improve South Africa’s health system through innovative engineering:Team “InnovUS” developed an application for Stellenbosch Universities’ Innovus and Biomedical Engineering Research Group (BERG), that turns regular smart phones into medical diagnostic systems. These allow nurses in mobile clinics and local nurses to perform treatment evaluation examinations for chronic diseases such as diabetes and high blood pres-sure (hypertension), as well as capture images that can be sent to a centrally located physician for inspection.Team “OxiCam”, which is part of the broader PhoneOximeter project (phoneoximeter.org), also developed a smartphone application, which, by illuminating a finger with the camera flash can accurately detect the pulse of the patient (and soon the respiratory rate and blood oxygen saturation level). A Pneumonia Clinical Guide application, which replaces tradi-tional paper guidebooks with current World Health Organisa-

tion (WHO) protocols, was also developed. The latter appli-cation improves transfer and storage opportunities at greatly reduced costs.Team “MRC”, funded by the South African Medical Research Council, developed a new and much improved design for mo-bile health clinics. By in-depth analysis, the team identified a better vehicle platform and developed a modular workspace design, which will greatly increase efficiency and comfort for patients and nurses alike.“Innovative engineering is a great and cost effective way to improve aspects of Africa’s health systems. We are very proud to be making a contribution towards making the most basic health support better”, says Prof Cornie Scheffer, pro-gramme manager of the teams.Global Engineering Teams (www.global-engineering-teams.org) is a six-month intercultural and interdisciplinary engi-neering and design program, where students from South Af-rica, Germany, Botswana, Brazil, Chile and the USA together develop actual and sustainable problem solutions for interna-tional industrial companies and organisations.

GET members from the Faculty of Engineering: James van der Walt (1), Dr Walter Karlen (2), Hendrik Bosman (3), Barend de Villiers (4), Cebo Silinga (5), Wayne Swart (6), Dr Mike Blanckenberg (7), and Christo van der Westhuizen (8)

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Title: From turbo-machines to solar chimneysDepartment: Department of Mechanical and Mechatronic EngineeringPromoter: Prof TM Harms

Summary:Prof von Backström made substantial experimental and analytical contributions to mechanical engineering knowledge. This is evident from a selection of his most cited, peer-reviewed papers on axial compressors and fans, centrifugal compressors, torque converters, computational fluid mechanics and the fluid mechanics and thermodynamics of solar chimney turbines and power plants. Original analytical and computational solutions were found for the turbo machinery through-flow problem, for the effect of off-axis inflow into fans, for the prediction of centrifugal compressor slip factor and for the determination of the optimal operating point of solar chimney power plants. Areas of application are turbo machinery design and renewable energy power plants.

Congratulations to Theo von Backström for obtaining his DEng qualification during the December ‘12 graduation ceremony!

Prof Theo von Backström

A Year of Science seminar regarding the impact of climate change on extreme loading on infrastructure and buildings, based on concepts of risk management, will be presented at the Stias Wallenberg Conference Centre in Stellenbosch on Wednesday, 13 February 2013. Attendance is free of charge and all interested postgraduate students, researchers and engineering practitioners are most welcome to attend. In or-der to secure your seat, kindly confirm your attendance via email (albe@sun.ac.za) as soon as possible, but by no later than 8 February 2013.The Year of Science seminar forms part of a cooperative activity between Stellenbosch University and the Regens-burg University of Applied Sciences, Germany. The review intends to assess the application of structural risk assess-ment methodologies in order to consider climate change in a rational and optimal manner; with a complementary objective to establish ways and means for incorporating provisions for climate change in future design and risk assessment proce-dures for infrastructure and buildings. Specific objectives are to identify cooperative and coordinated future research by the two partners; ultimately leading to input for international activities, of which the two partners are joint members. This includes the Joint Committee on Structural Safety (JCSS) and the International Standards Organisation (ISO) Techni-cal Committees. One of the immediate follow-up activities is considering ways and pre-normative procedures for imple-mentation in the design, operation and maintenance of facili-ties. The significance of this topic is that, although there is gen-eral consensus on the importance of climate change, there is little information on how to go about assessing relevant risks to existing facilities, or providing for effects in the design of new installations. More directly related to the activities of the two Universities, it is envisaged to identify topics for research activities to be done cooperatively with the objectives of ad-vancing the fundamental methodologies for risk based treat-ment of climate change and providing for the specific condi-tions of the various countries, providing for the exchange of graduate students and researchers.The seminars are also intended to create awareness of the potential implications of climate change, and the way in

which engineering practice in each country could and should treat the topic systematically and rationally. The target group therefore ranges from international specialists, local engi-neering specialists, who should develop appropriate stan-dards and requirements, and general design practitioners who are confronted with decisions on maintenance of exist-ing facilities or design of new works.The project is funded by the NRF (National Research Foun-dation), the DST (Department of Science and Technology), and the German Federal Ministry of Education and Re-search, as part of the German-South African Year of Science Celebrations: “Enhancing Science Partnerships for Innova-tion and Development”. Some of the presenters at the seminar include Prof Diaman-tidis (structural reliability expert, Regensburg University of Applied Sciences), Dr Andries Kruger (expert in strong wind characteristics, South African Weather Service), Dr Francois Engelbrecht (climate modelling expert) and Dr Adam Goliger (wind engineering expert) at the CSIR, as well as a number of senior researchers at the Department of Civil Engineering.

Collaborators from the Department of Civil Engineering pre-sented a project-related seminar in Regensberg, Germany, last year. From left to right: Dr Celeste Barnardo-Viljoen (se-nior researcher), Sonel Reynolds (Masters student), and Prof Johan Retief (senior researcher).

During the past year, the Department of Electrical and Elec-tronic Engineering has established a very promising rela-tionship with The French National Institute for Research in Computer Science and Control (INRIA) in Lille, France. As part of their national research and development brief, INRIA has created a very powerful network simulation platform, re-motely accessible by Internet, which is used to model the be-haviour of a variety of types of data communication networks, in both ad hoc and fixed configurations. Their facilities are located in four main regions in France, i.e. Rennes, Stras-bourg, Grenoble and Lille. To date there are more than 80 industry partners, and over 36 nationalities, involved.INRIA and Stellenbosch University are embarking on joint research and development projects, particularly in terms of network simulation, protocol evaluation and development, routing strategies and communication link quality manage-ment. One of the main motivations for the project is to pro-vide environmental and animal behavioural monitoring solu-tions based on sensor networks. To date relatively little is known about the ecology of smaller predators responsible for the bulk of human-wildlife conflict in Southern Africa. One of the greatest problems has been finding innovative ways to study these elusive animals in rugged and remote regions.

Several of the students at the Department of Electrical and Electronic Engineering have already undergone training by the INRIA team on their Senslab simulation platform during a workshop that was held at Stellenbosch University in August this year. Two of the department’s postgraduate students, Johan Piet-erse and Jaco du Toit, are currently attending a four month in-ternship at INRIA’s facility in Lille, France, which commenced in September this year. Johan is working on the mobility characteristic in a range of IPv6 networks with particular ap-plication to sensor networks, and Jaco is currently develop-ing a theoretical platform for the evaluation and performance comparisons between different ad hoc routing algorithms.This type of research is important from both an academic and commercial/industrial point of view, and as such several exchange programs are being prepared for 2013.Dr Riaan Wolhuter, senior researcher at the department, also visited INRIA in November this year, and ascertained that Jaco and Johan are progressing well and are very com-fortable in the French environment. Some very useful discus-sions took place regarding joint projects, and the planning of a workshop in Lille in 2013 is already in progress.

Johan Pieterse (left) and Jaco du Toit, hard at work in France!JKF Airport like you’ve never seen it before.

Points to PonderPolice in Oakland, California, spent two hours attempting to subdue a gunman who had barricaded himself inside his home. After firing ten tear gas canisters, officers discovered that the man was standing beside them, shouting pleas to come out and give himself up.An Illinois man, pretending to have a gun, kidnapped a mo-torist and forced him to drive to two different automated teller machines. The kidnapper then proceeded to withdraw mon-ey from his own bank accounts.In Modesto, CA, Steven Richard King was arrested for trying to hold up a Bank of America branch without a weapon. King used a thumb and a finger to simulate a gun, but unfortu-nately, he failed to keep his hand in his pocket.A man walked in to Kansas Kwik Shop, and asked for all the

money in the cash drawer. Apparently, the take was too small, so he tied up the store clerk and worked the counter himself for three hours until police showed up and grabbed him.Police in Los Angeles had good luck with a robbery suspect who just couldn’t control himself during a lineup. When detec-tives asked each man in the lineup to repeat the words “Give me all your money or I’ll shoot,” the man shouted: “That’s not what I said!”A man spoke frantically into the phone: “My wife is pregnant and her contractions are only two minutes apart!” “Is this her first child?” the doctor asked. “No, you idiot!” the man shout-ed. “This is her husband!”

CUM LAUDE GRADUANDI

Charlotte Human Bedryfsingenieurswese MScIng Chris Franklin Bedryfsingenieurswese MScIng Jan-Hendrik Baum Bedryfsingenieurswese MScIng Johan Stadler Bedryfsingenieurswese MScIng Mariette van Niekerk Bedryfsingenieurswese MScIng Zureka Loubser Bedryfsingenieurswese MScIng

Alex Ibbotson Elektriese en Elektroniese Ingenieurswese MScIng Ernst Krige Elektriese en Elektroniese Ingenieurswese MScIng Gerton Mouton Elektriese en Elektroniese Ingenieurswese MScIng Hendrik Odendaal Elektriese en Elektroniese Ingenieurswese MScIng JP Jansen van Rensburg Elektriese en Elektroniese Ingenieurswese MScIng Johannes du Preez Elektriese en Elektroniese Ingenieurswese MScIng Karien du Preez Elektriese en Elektroniese Ingenieurswese MScIng Teaan van Staden Elektriese en Elektroniese Ingenieurswese MScIng Waldo Minnaar Elektriese en Elektroniese Ingenieurswese MScIng Wikus Brink Elektriese en Elektroniese Ingenieurswese MScIng

Frikkie Botha Meganiese en Megatroniese Ingenieurswese MScIng Tiaan Franken Meganiese en Megatroniese Ingenieurswese MScIng CJ Liebenberg Prosesingenieurswese MScIng Ebon Schoeman Prosesingenieurswese MScIng Katiana Gomes Prosesingenieurswese MScIng André Greyling Siviele Ingenieurswese MScIng Christian Seifart Siviele Ingenieurswese MScIng Hester Scheepers Siviele Ingenieurswese MScIng Juané Brits Siviele Ingenieurswese MScIng Karel Verlinde Siviele Ingenieurswese MScIng Stefano Redivo Siviele Ingenieurswese MIng

Dit is vir die Fakulteit Ingenieurswese ‘n voorreg om die volgende studente hartlik geluk te wens met hul uitsonderlike prestasie in die voltooiing van hul meestersgrade. Hierdie vooruitstrewende MIng/MScIng studente het in Desember vanjaar met cum laude gegradueer, en met so ‘n uitmuntende studierekord wens ons hulle alle voorspoed toe met hul rooskleurige toekomsplanne.Interessant genoeg het James Bekker, Bedryfsingenieurswese, se vier meestersgraadstudente al vier hul graad met cum laude geslaag - dit is werklik iets om baie trots op te wees, veral aan-gesien James ook so pas sy PhD kwalifikasie ontvang het!

Title: Characterisation and dynamic modelling of the behaviour of platinum group metals in high pressure sulphuric acid/oxygen leaching systemsDepartment: Department of Process EngineeringPromoter: Prof SM Bradshaw & Prof G Akdogan

Summary:Pressure leaching is employed in base metal refineries to dissolve base metals selectively from the nickel-copper matte, which bears the platinum group metals. Optimum operation is challenging because of the complex chemistry, varying mineralogy of the feed, and interaction between the process variables. In this project, the effect of key process variables on the leaching behaviour of base and precious metals was determined experimentally. Chemical reactions were proposed to describe the leaching behaviour, and the associated reaction kinetics was quantified. Models were developed to simulate the process, providing improved understanding and allowing the identification of optimum operating conditions.

Congratulations to Christie Dorfling for obtaining his PhD qualification during the December ‘12 graduation ceremony!

Dr Christie Dorfling

Die ‘Joint Institution of Nuclear Research (JINR) Student Practice’, wat in Dubna in Rusland geleë is, is ‘n inisiatief wat sedert 2007 bestaan en bedryf word deur die JINR en NRF. Die program laat toe dat nagraadse studente wat afkomstig is van lande wat lede is van die JINR, jaarliks navorsing in Rusland kan gaan doen. Die hoof doel van die program is om studente die geleentheid te bied om meer inligting te bekom aangaande die navorsing waarmee die JINR tans besig is, asook die fasiliteite wat beskikbaar is. Dit bied ook vir hierdie studente die geleentheid om terug te gaan na Rusland en hul nagraadse studies daar voort te sit of te voltooi.Vanjaar is Hercules du Plessis, MscIng student by die De-partement Elektriese en Elektroniese Ingenieurswese, tesa-me met 29 ander studente van regoor Suid-Afrika, gekies om deel te wees van hierdie interessante uitruilprogram.Die uitruilprogram, wat vier weke duur, bestaan uit lesings soggens oor partikelfisika, kernfisika, gekondenseerde ma-terie fisika, en dan ‘n projek wat voltooi moet word onder lei-ding van ‘n studieleier by die JINR. Hercules se projek het gehandel oor rekenaarsimulasies van die tonnel eienskappe van supergeleidende nanostrukture. Hierdie projek is onder

leiding van Dr Yu M Shukrinov, een van die senior navorsers by die teoretiese fisika afdeling van die JINR.Die program bied natuurlik ook vir die studente die geleent-heid om Rusland ‘n bietjie te verken, en dus was uitstappies na Moskou en St Petersburg afgelê om die russiese kulteer te absorbeer.

Hercules du Plessis verken St Petersburg tydens die uitruilprogram.

Congratulations to Oswald Jumira, PhD student at the Depart-ment of Electrical and Electronic Engineering, for being one of only 25 winners of the Green Talents Competition. On October 23, as part of this year’s FONA-Forum for Sustainability in Berlin, the 25 winners of the Green Talents competition were pre-

sented with their awards. Hosted by the Federal Ministry of Education and Research (BMBF) for the fourth time, the “Green Talents International Forum for High Potentials in Sustainable Development” attracted over 400 applications from 69 countries this year. In the end, the distinguished jury of experts selected 25 winners from 20 different countries, from Brazil to Zimbabwe, for their outstanding achievements in the area of sustainability. The awards ceremony was the final highlight of the winners’ two-week tour of Germany. Building on the new insights and contacts gained from the Germany tour, each of this year’s winners will have the opportunity to return to Germany in 2013 for a research stay funded by the BMBF. Oswald’s research focus is the design and development of energy efficiency and energy harvesting techniques for

embedded wireless communication systems. Communicating around the clock and around the globe requires more energy than we might think. According to the SMART 2020 study, carbon emissions from Information Communications Technologies (ICT’s) alone are increasing at a rate of 6% per year and could represent 12% of worldwide emissions by 2020.Oswald is developing new ways to achieve ecologically sustainable and cost effective communications infrastructure. Jumira focuses on energy harvesting techniques, which allow wireless communication devices to draw the energy they need from the immediate environment. These devices can tap into vibrational energy, thermal energy, outdoor solar energy or indoor lighting for their power needs, and reduce or even eliminate their dependence on batteries.“In Africa the number of people with cell phones currently exceeds those with access to grid-based electricity and this exponential growth of ICT’s is being fed by electricity from highly inefficient legacy power stations,” says Jumira. “We as researchers in the ICT and engineering field have recognized the vital need for new approaches and techniques to begin reducing Africa’s carbon footprint.”The jury felt that Jumira’s work developing more sustainable and energy efficient ICT systems could bring great ecological and economic benefits, especially to Africa. They were particularly impressed with his breakthroughs in energy efficiency and energy harvesting techniques for embedded wireless communication systems.

Oswald Jumira

Title: Simulating the medium temperature chalcopyrite oxidation system in batch and continuous autoclavesDepartment: Department of Process EngineeringPromoter: Prof SM Bradshaw & Prof G Akdogan

Summary:The economically ideal operating window to leach concentrates of chalcopyrite, the most abundant copper-containing mineral, is highly dependent on the mineralogy, particle size and temperature. This dissertation presents an internally consistent simulation of chalcopyrite oxidation under medium temperature autoclave conditions, and in so doing, quantifies the effects of the key control parameters on the reactor and primary circuit performance. It consists of various modules, each addressing particular thermodynamic and kinetic aspects of the primary processes occurring in a pressure oxidation reactor. The end product is applicable not only to chalcopyrite process development but also to sulfide mineral oxidation in general.

Congratulations to Johann Steyl for obtaining his PhD qualifica-tion during the December ‘12 graduation ceremony!

Dr Johann Steyl

Eben Uys has spent the last few years studying the hydrodynamic behaviour of tray type distillation columns. His MScEng (cum laude) involved the construction and commissioning of a pilot plant setup on a scale not seen before in the Process Engineering department. The state-of-the-art setup was then used during his doctoral studies to investigate the effect of the physical properties of the liquid and the gas on the hydrodynamic behaviour of tray distillation columns. A new correlation was proposed that is able to predict the hydrodynamic behaviour of distillation columns more accurately than the previously proposed, widely accepted correlations. In the words of one of his doctoral thesis examiners: “This is an excellent piece or work that, once published, will be quoted by practitioners for years to come”. Eben has been an integral part of the Process Engineering department for the last ten years. In addition to the excellent setup he has constructed, he has also constructed a mini-brewery as part of his dissertation and in subsequent years was a member of the award-winning Stellenbosch University brewing team. Christie Dorfling has completed his doctoral studies on the characterisation and dynamic modelling of the behaviour of platinum group metals in high pressure leaching systems. In nature, platinum group metals typically occur together with base metals such as copper and nickel. One of the process steps in the production of platinum involves the separation of the base metals from the platinum group metals by dissolving the base metals, while the platinum group metals remain in the solid phase. In this work, the chemistry and rates of the dissolution reactions were determined for a pressure leaching reactor. This novel information was incorporated in a dynamic model that can be used to assist with the optimisation of this process unit in industry. Christie’s work also elicited high praise from his external examiner: “The candidate addresses a challenging problem to industry with a depth of insight, understanding of a broad range of diverse aspects (such as the thermodynamics, kinetics, process control, dynamic materials balancing, and experimental methods), and attention to detail seldom found in other academic theses.”Christie has been lecturing full-time at the Process Engineering department since 2009, while enrolled as a part-time PhD student. He is no stranger to high praise, being the recipient of the prestigious Eskom Chairman’s

award for the best university engineering student in South Africa in 2005, and the FirstRand Laurie Dippenaar Scholarship for International Postgraduate Study in 2007.Johan Steyl’s PhD dissertation considered the economic leaching of chalcopyrite. The economically ideal operating window to leach concentrates of chalcopyrite, the most abundant copper-containing mineral, is highly dependent on the mineralogy, particle size and temperature. His work presents an internally consistent simulation of chalcopyrite oxidation under medium temperature autoclave conditions, and in so doing, quantifies the effects of the key control parameters on the reactor and primary circuit performance. It consists of various modules, each addressing particular thermodynamic and kinetic aspects of the primary processes occurring in a pressure oxidation reactor. The end product is applicable not only to chalcopyrite process development but also to sulfide mineral oxidation in general. The range and depth of topics covered in Johann’s dissertation drew significant praise from the examiners: “This is, without a doubt, the single most detailed, comprehensive, scientifically mature, well documented, and carefully argued thesis that I have ever had the pleasure to read. Not only has every relevant aspect of medium-temperature chalcopyrite autoclaving been considered, but the consideration of each of these aspects represents in itself an exemplary study, any one of which might have constituted a valid PhD thesis.”

From left to right: Prof Steven Bradshaw (Johann and Christie’s promoter), Dr Christie Dorfling, Dr Eben Uys, Prof Hansie Knoetze (Eben’s promoter), Prof Andre Burger (chairman at the department), Dr Johann Steyl (insert).

Dr Stephen Matope

Title: An application of Van-der-Waals forces in micro-material handlingDepartment: Department of Industrial EngineeringPromoter: Dr AF van der Merwe

Summary:Micro-material handling is complicated due to the natural presence of adhesive forces. These forces include Van-der-Waals forces. However, Van-der-Waals forces are advantageous in that they do not leave residual stresses, strain, and charges when applied in micro-material handling operations. Furthermore, they do not only work under atmospheric conditions, but also in aqueous and under vacuum conditions. The study revealed how the Van-der-Waals forces could profitably be manipulated to produce a reliable micro-material handling system by logically varying surface roughness, material type and geometrical configuration of the interacting surfaces involved in the system.

Congratulations to Stephen Matope for obtaining his PhD qualifica-tion during the December ‘12 graduation ceremony!

Stephen Matope obtains PhD qualification

Title: Formulation of a weakly compressible two-fluid flow solver and the development of a compressive surface capturing scheme using the volume-of-fluid approachDepartment: Department of Mechanical and Mechatronic EngineeringPromoter: Prof TM Harmse & Dr AG Malan

Summary:This study presents the development and extension of numerical modelling techniques for the purpose of simulating two-fluid systems accurately and efficiently. Building on existing numerical methods, the volume-of-fluid approach is extended in two ways: Firstly, to account for variations in the gas density a weakly compressible formulation is presented. Secondly, a compressive free-surface interface capturing formulation that preserves the integrity of the interface shape is detailed. It is demonstrated that the proposed extensions offer a measurable improvement in accurately capturing the physics and it is furthermore found to provide a reduction in computational cost.

Congratulations to Johan Heyns Swart for obtaining his PhD qualification during the December ‘12 graduation ceremony!

Johan Heyns obtains PhD qualification

Dr Johan Heyns

The Department of Process Engineering, in association with Aston University and Cranfield University in England, organi-sed a workshop entitled ‘From Biomass to Bio-energies via Thermochemical Processes’, which aimed at gathering per-spectives on the future of thermochemical technologies in South Africa. This workshop, which took place on 22 and 23 October at the STIAS Wallenberg Conference Centre in Stellenbosch, attracted 65 delegates from various countries and various fields, including academics as well as representatives from municipalities and industries.Prof Tony Bridgwater, who plays a key role in several major European funded projects on bioenergy, biofuels and biore-fineries, as well as Prof Sai Gu, promoted the organisation of this workshop by sponsoring it through the Engineering and Physical Sciences Research Council.The overall objective of the workshop was to promote the thermochemical processing technologies related to the con-version of plant biomass resources into bioenergy and added value products such as chemicals and biochar. Nineteen oral presentations were delivered and mentioned progresses made on pyrolysis and gasification development, application of pyrolytic and gasification products, and technico-econo-mic assessment in South Africa.The discussion concluded that the conversion of biomass to energy and added value products is a viable opportunity in South Africa. Markets should be made aware of the alter-

native energy products derived from biomass, which could encourage the use of renewable products and stimulate further investment and competitiveness in the industry. A joint lobby from industry and academia should be established to promote the audit and approval of technologies and assist investors in obtaining finance.The workshop has been accredited with two points for con-tinuing professional development by the Engineering Coun-cil of South Africa (http://www.ecsa.co.za). The following web link contains further information regarding Bioprocess Engineering: http://processengineering.sun.ac.za/research-themes/biotechnology-2

Workshop participants found the presentations highly informative.

Amanda de Wet, na-graadse administra-tiewe beampte by die Departement Siviele Ingenieurswese, het op ‘n innoverende manier die departement se data aangaande hul 2012 ge-registreerde nagraadse studente verwerk. Teen Maart vanjaar was daar 239 nagraadse studente geregistreer, waarvan 180 Suid-Afrikaners en 59 buitelanders was. Onder hierdie 59 buite-landse studente word nie minder nie as 18 verskillende lande verteenwoordig! Die top drie lande wat verteenwoordig word is Zambia met 13 na-graadse studente, Zimbabwe met 10 nagraadse studente, en Namibia met sewe nagraadse studente.

Die diversiteitsprofiel van die departement se nagraadse studente is as volg: 157 wit studente, 63 swart studente, 13 bruin studente, en 6 Indiër studente.

Bo links: Diversiteitsprofiel van nagraadse studente by die Departement Siviel Ingenieurswese.Bo regs: Buitelandse nagraadse studente by die Departement Siviele Ingenieurswese.

Department of Civil Engineering Foreign Post Graduate Students 2012

BangladeshBurkino VasoChinaDRC (Republic of Congo)GermanyIranItalyLesothoLibyaMalawiMozambiqueNamibiaNigeriaRwandaUgandaUnited KingdomZambiaZimbabwe

Department of Civil Engineering Post Graduate Student Diversity Profile

Asian

Black

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Research into Alternative Heat Transfer FluidsAs developers strive to increase the upper working tempera-tures of CSP plants, several research projects are currently investigating the potential use of alternative heat transfer fluids (HTF’s), including molten-salt and liquid metal-based materials.As project leader Perry Li at the University of Arizona ex-plains: “The currently available heat transfer fluid, [based on] a nitrate salts eutectic mixture, cannot work at a temperature above 550 Celsius. Therefore, we need to develop the next generation heat transfer fluid. The new salts we develop will have similar properties and cost below one dollar per kilo-gram.”An interesting project at the Faculty of Engineering also aims to investigate the potential of using metallic phase change materials as a storage concept to enable high temperature storage, at lower cost and with better heat transfer proper-ties. As Johan Kotzé, PhD student at the Department of Me-chanical and Mechatronic Engineering explains, the material used is a eutectic Sodium and Potassium alloy (NaK), which has a melting point as low as -12.8 Celsius.“This solves another very tricky issue of solar power, in that most of the high temperature heat transfer fluids either so-lidify at fairly high temperatures, or need to be pressurised at very high pressure. Here is a heat transfer solution that is always liquid, and with fairly low pressures can obtain tem-peratures exceeding 1200 Celsius,” says Kotzé.“This is obviously easier said than done. NaK is very reactive with water, but so are many other chemicals. To be honest, most of us are used to driving a car filled with highly combus-tible petrol. This argument cannot be used as proof that NaK is safe, but rather the argument can be made that we can learn how to use this material in a safe manner,” he adds.Experiments are still in progress and, at this stage, a key

question remains the suitability of NaK as a metallic phase change storage material. As an alternative, the team are cur-rently looking into the viability of eutectic aluminium-silicon alloy, since it is well known, and it melts at a fairly moderate temperature.However, in terms of its use as a HTF, Kotzé points out that the results look good thus far and he believes that there is no doubt that NaK will work as a HTF, since it has been proven in the nuclear industry many times. Ultimately, the main aim of the project is the reduction of the LCOE through an in-crease in thermal efficiency, and, although the team would very much like to commercialise the concept, Kotzé thinks it would require some serious investment.“I simulated an entire plant in Flownex [simulation software], and the results show that the system is very much feasible. I think that there is still much work to be done on this in order to obtain its full potential, but I believe that we are at a place that it is very much possible to build a system that can at least demonstrate the concept,” he says.

Johan Kotzé presents his research findings.

Dr Innocent Okoloko

Title: Multi-path planning and multi-body constrained attitude controlDepartment: Department of Mechanical and Mechatronic EngineeringPromoter: Prof AH Basson & Dr Y Kim

Summary:A study of some of the current approaches to navigation control of multiple mobile systems is presented, exposing some with associated complexity issues. Dr Okoloko’s research introduces a new approach, based Linear Matrix Inequalities, to collision avoidance, a consensus theory of quaternions, a new multi-path planning algorithm, a new proof of the consensus protocol, a new algorithm for constrained attitude synchronization of multiple bodies, and a new algorithm for collective motion in a spherical coordinate system. The new algorithms have reduced computational complexity and can cope with interaction constraints, while maintaining stability and efficiency.

Congratulations to Innocent Okoloko for obtaining his PhD qualification during the December ‘12 graduation ceremony!

Ons studente presteer by SKA Afrika KonferensieBy die onlangse prysuitdeling van die konferensie vir na-graadse beurshouers van Square Kilometre Array (SKA) Af-rika, het studente van die Universiteit Stellenbosch met die helfte van die pryse weggestap, onder meer dié vir die alge-heel beste aanbieding deur onderskeidelik ’n MSc student en ‘n PhD student. Marisa Geyer, ’n MSc student in fisika, het die prys vir algeheel beste aanbieding deur ’n magister-student ontvang, terwyl André Young, ’n PhD student in ing-enieurswese, as algehele wenner in die kategorie vir dokto-rale studente aangewys is.Twee van André se medestudente wat, soos hy, aan die SKA-navorsingsleerstoel by die Departement Elektriese en Elektroniese Ingenieurswese verbonde is, het ook pryse ont-vang. Hulle is Mark Volkmann en Joely Andriambeloson. Meer as 90 nagraadse studente en nadoktorale navorsers van Suid-Afrika, en vennote op die vasteland wie se stud-ies deur die SKA Afrika-program vir die ontwikkeling van menslike kapitaal gefinansier word, het hul werk gedurende die week lange konferensie aangebied. Dié geleentheid, wat aan die einde van November by die STIAS Wallenberg Kon-ferensiesentrum in Stellenbosch plaasgevind het, het ook studieleiers en SKA-ondersteunde navorsingsleerstoele van verskeie Suid-Afrikaanse universiteite, ’n handvol belowende voorgraadse SKA-beurshouers, sowel as tien internasionale gaste byeengebring.Young het sy navorsing oor die moontlike verbetering van straalpatroonskatting vir toekomstige radioteleskope aange-bied. Hy studeer onder prof David Davidson, die bekleër van die navorsingsleerstoel in Ingenieurselektromagnetika by die Departement Elektriese en Elektroniese Ingenieurswese. Dié departement het ’n sterk teenwoordigheid op die kon-ferensieprogram gehandhaaf. Die departement se nadok-torale navorsers en MSc- en PhD-studente het aanbiedings gedoen oor hul werk in die ontwikkeling van die antennastel-sels, radiofrekwensiestelsels en digitale verwerking wat vir die MeerKAT- en SKA-radioteleskope vereis word.Mark Volkmann se praatjie oor die moontlike gebruik van su-pergeleiers in die SKA het nie net die gehoor stof tot nadenke gegee nie, maar hom ook die prys vir die beste MSc student in die ingenieurswese-afdeling besorg. Sy studieleiers by die departement is proff Coenrad Fourie, Willie Perold en David Davidson.

Die prys vir die beste aanbieding deur ’n PhD student in in-genieurswese is toegeken aan Brendon Potgieter, wat in sy werk die gebruik van probabilistiese-modelbywerking vir die bekragtiging van antennamodelle ondersoek. Sy navorsing staan onder leiding van prof Gerhard Venter by die Departe-ment Meganiese en Megatroniese Ingenieurswese.Die beste plakkaat deur ’n PhD student in die ingenieurs-wese-afdeling was dié van Andriambeloson. Prof Howard Reader dien as studieleier vir dié projek oor tyddomeinstu-dies in reverberasiekamers. Die pryse is oorhandig deur dr Jaap Baars, ’n afgetrede astronoom van die Max Planck Instituut vir Radioastronomie, Nederland, en ’n baanbreker in radioastronomie-tegnieke, wat groot lof gehad het vir die professionele manier waarop die studente hul werk aange-bied het. “Ek was nog nooit by ’n konferensie waar almal so stiptelik by hul toegewese tyd gehou het nie,” het hy opge-merk. Volgens dr Baars beny die internasionale wetenskap-like gemeenskap die blote omvang van die groep studente wat vir die konferensie byeengekom het en deur die projek gefinansier word. “Deur op dié manier in mense te belê, lê julle ’n grondslag in die wetenskap en tegnologie wat die be-hoorlike ontwerp, konstruksie en gebruik van die MeerKAT en SKA sal verseker,” reken hy.

Voor van links na regs: Joely Andriambeloson, André Young, Mark Volkmann, en (agter) Marisa Geyer. Brendon Potgieter was onge-lukkig nie teenwoordig met die neem van die foto nie.

Title: The influence of gas and liquid physical properties on entrainment inside a sieve tray columnDepartment: Department of Process EngineeringPromoter: Prof JH Knoetze & Prof AJ Burger

Summary:Distillation is used extensively by industry to separate chemicals on large scale. In distillation columns the entrainment of liquid droplets with the up-flowing gas phase reduces the efficiency with which chemical components are separated. Historically, accurate prediction of such entrainment was problematic, since correlations mostly relied on data generated with air-water systems. Dr Uys developed a significantly more accurate entrainment model through a systematic evaluation of the hydraulic behaviour of different liquids and gasses in a pilot-scale sieve tray column. This useful model now also makes provision for the noticeable effects of liquid surface tension and dynamic viscosity on entrainment.

Congratulations to Eben Uys for obtaining his PhD qualifica-tion during the December ‘12 graduation ceremony!

Dr Eben Uys

Title: Applying the cross-entropy method in multi- objective optimization of dynamic stochastic processesDepartment: Department of Industrial EngineeringPromoter: Prof JH van Vuuren & Dr AF van der Merwe

Summary:Computer simulation of dynamic and stochastic engineering optimisation problems is time-consuming due to the computational burden implied by statistical inference principles. In multi-objective optimisation of engineering problems, large decision spaces and large objective spaces prevail, and the computational burden associated with solving such problems is very large, hence an efficient algorithm that searches the vast decision space is required. In this research, a multi-objective optimisation algorithm, based on the cross-entropy method for single-objective optimisation, was developed and assessed. The algorithm reduces the number of objective function evaluations, and supports optimisation of dynamic, stochastic processes.

Congratulations to James Bekker for obtaining his PhD quali-fication during the December ‘12 graduation ceremony!

Dr James Bekker

Peter van Wyk, MEng student at the Department of Civil Engineering, along with fellow students, have been working on different engineering projects involving the building of the Matjiesfontein Space Geodesy and Earth Observation Observatory (MGO) in the Western Cape. These include the Lunar Laser Ranger (LLR) station, a gravimeter vault, an access road

to the site, and an analysis of the surroundings such as paleo-landslide activity. This work is done by graduate and postgraduate students at the Faculty, under the supervision of Leon Croukamp, PhD student working on Lunar Geotechnical Properties at the Department of Civil Engineering.Lunar Laser Ranging involves the use of a large laser that shoots a beam in the direction of the moon, which is reflected

from retro-reflectors that were placed on the moon during the Apollo program. This can be used to determine the distance to the moon, and forms part of the international network of similar geodetic stations in the northern hemisphere to analyse discrepancies in Earth-Moon relationship models. It can also be used to determine the validity of Einstein’s Theory of Relativity. Uncertainties were discovered in that tidal earth movement affected the data. Like the occurrence of tides at sea, the earth’s crust experiences tidal movement of approximately thirty centimetres a day. This can be determined through the use of a highly sensitive gravimeter which, along with an accelerometer and seismograph, detect movements in the earth’s crust. The project is driven by Dr Stoffel Fourie, project leader at the Department of Environmental Water and Earth Science, Tswane University of Technology (TUT), and Prof Ludwig Combrinck, associate director at Hartebeesthoek Radio Astronomy Observatory (HartRAO). In order to promote future cooperation, several memoranda of understanding were signed bringing all the role players and interested parties

together in this project. The involvement of these institutions, through strong partnerships between government, international support and the academic world, seeks to increase the exposure of science and technology in this field in particular, and to train and develop South African students in the process. The observatory is to include sophisticated collocated devices such as a Global Positioning System (GPS) and a Dopler Orbitography and Radiopositioning Integrated by Satellite (DORIS) system. Students at the Department of Civil Engineering were involved in particular with the geotechnical investigations of certain aspects of the site at Matjiesfontein. Amongst other analyses, local rock samples have been analysed to determine whether or not local materials could be used for the construction of the buildings on the observatory site. The use of local materials could reduce procurement costs, transport costs, as well as impacts on the environment. Local wildlife such as the Klipspringer and the endangered Riverine Rabbit are inhabitants of the area and due precautions need to be taken to preserve this pristine environment. Envisaged buildings include the gravimeter vault, LLR station and other outbuildings. The gravimeter vault is to house a Lacoste & Rohmberg microgravimeter, seismograph and accelerometer, and the LLR station a seven-ton telescope used for lunar ranging which is currently being developed at Hartebeestpoort (HartRAO base). As part of the yearly Combined Science and Technology Train and Space Geodesy Observatory workshop, which was held at Matjiesfontein in April this year, a new computer facility at the Matjiesfontein Primary School, as well as a Science Centre and refurbished library, were amongst the initiatives launched by Minister Derek Hanekom, Deputy Minister of Science and Technology. This workshop was attended by more than 30 delegates from the various stakeholders.Both the Director of International Cooperation at the National Research Foundation (NRF), Mr. Robert Kriger and Chief Director: Human Capital and Science Platforms at the Department of Science & Technology, Dr. Phethiwe Matutu pledged their full support to the project indicating that this legacy project has the potential to become one of South Africa’s educational gem’s.

1m Diameter Lunar Laser Ranger

From left to right: Minister Derek Hanekom, Dr Stoffel Fourie (TUT) and Prof Pieter Marais (Dean, Faculty of Science, TUT) during the unveiling of the computer centre at Matjiesfontein in April.

Peter van Wyk

Die RILEM Internasionale Simposium oor Vesel Versterkte Beton (BEFIB 2012) wat in September plaasgevind het, dien as gespreksgeleentheid oor die moontlikhede en uitdagings aangaande die gebruik van vesel versterkte beton. Die simposium is bygewoon deur nagenoeg 200 afgevaardigdes van 36 lande en 123 instansies. Die klein Middeleeuse dorpie van Guimarães, in die Noordwes van Portugal, het die agtste weergawe van die simposium gehuisves. Volgens Riaan Combrinck, PhD student by die Departement Siviele Ingenieurswese, lyk die dorpie self baie soortgelyk aan ons geliefde Stellenbosch, met die Universiteitskampus wat sonder moeite insmelt tussen die historiese geboue van die outentieke dorp, terwyl verskeie wingerde en woudagtige heuwels die dorp omring. Die streek is ook wyd bekend vir die produksie van wyn en, meer spesifiek, Port wat dan ook daar amptelik Port genoem mag word. Vier afgevaardigdes van die Departement Siviele Ingenieurswese het die simposium bygewoon, nl. Prof Gideon van Zijl, Prof Billy Boshoff, sowel as Riaan Combrinck en Suvash Chandra Paul, albei PhD studente by die departement. Beide Prof Billy Boshoff en Riaan Combrinck het artikels aangebied op dag een van die simposium. Hierdie artikels was goed ontvang en het, deur die loop van die simposium, baie opvolggesprekke met eweknieë in verskeie vakgebiede uitgelok. Na afloop van die simposium het al vier afgevaardigdes ook ʼn amptelike RILEM Taakgroep vergadering bygewoon, waarvan Prof van Zijl die voorsitter is. Die taakgroep se doel

is om ʼn ontwerp raamwerk te skep vir die Duursaamheid van Vesel Versterkte Vervorming Verharding Sement gebaseerder Samestellings. Laasgenoemde is ʼn hoë verrigting tipe beton met hoë duktiliteit, en word veral gebruik vir struktuur elemente waar groot deformasies vereis word weens, byvoorbeeld, aardbewings. Tydens die vergadering het Suvash Chandra Paul ook die geleentheid gekry om sy PhD planne met die komitee te deel. Suvash se aanbieding was baie positief ontvang, en almal teenwoordig het saamgestem dat daar meer geleenthede vir sulke tipe aanbiedings geskep behoort te word, veral aangesien die hoogs ervare komiteelede waardevolle raad en insette kan lewer ten opsigte van so ‘n nuwe studie. Afgesien van die simposium en vergadering, noem Riaan Combrinck dat Guimarães self ʼn paar onvergeetlike geleenthede opgelewer het. Tydens een van die dorp se vele laatnag feeste het al die inwoners van Guimarães, vanaf kleuters tot en met oupas en oumas, die middedorp ingevaar om te stap en te kuier. Daar was duisende mense op die strate, ten spyte van die feit dat daar geen harde musiek, amptelike opvoerings, oormatige drinkery of self geraas was nie. By nadere ondersoek is daar ontdek dat die hele dorp blykbaar net besluit het om ‘n bietjie tyd saam te spandeer as vriende, gesinne en kollegas, sodat hulle die dorp kan geniet en weer van voor af kan beleef. Volgens Riaan was dit ʼn ongelooflike atmosfeer van samesyn, aanvaarding en lewe op die strate van Guimarães, en dat hierdie tipe samesyn iets is wat hy graag meer van sou wou beleef in Suid-Afrika!

RILEM Internasionale Simposium

Van links na regs: Suvash Chandra Paul, Riaan Combrinck, Prof Romildo Toledo Filho (Rio de Janeiro), Prof Billy Boshoff, Prof Gregor Fischer (Denemarke), Prof Gideon van Zijl, Prof Petr Kabele (Praag), Prof Volker Slowik (Leipzig, Duitsland), Christian Wagner (Leipzig, Duitsland), en Esmaeel Esmaeeli (Guimaraes, Portugal)

Dept of Industrial EngineeringAcademic: Prof PJ Vlok 021 808 8680 (pjvlok@sun.ac.za)Coordinator: Mrs Amelia Henning 021 808 4240 (ah2@sun.ac.za)

Dept of Electrical & Electronic EngineeringAcademic: Prof Johan du Preez021 808 4342 (dupreez@sun.ac.za)Coordinator: Mrs Anita van der Spuy 021 808 2483 (ajvdspuy@sun.ac.za)

Dept of Mechanical & Mechatronic Engineering Academic: Prof Albert Groenwold021 808 4243 (albertg@sun.ac.za)Coordinator: Mrs Welma Liebenberg 021 808 4095 (welmal@sun.ac.za)

Dept of Process Engineering Academic (left): Prof Kim Clarke021 808 4421 (kclarke@sun.ac.za)Coordinator: Mrs Lynette Bresler 021 808 4712 (lbresler@sun.ac.za)

Dept of Civil Engineering Academic: Prof Breda Strasheim021 808 4435 (javbs@sun.ac.za)Coordinator: Mrs Amanda de Wet 021 808 4404 (amandadw@sun.ac.za)

Dean’s Office Vice Dean (Research): Prof Willem Perold021 808 4368 (wjperold@sun.ac.za)Coordinator: Ms Tanya Ficker 021 808 9403 (tanya@sun.ac.za)