Application of renewable fuels in ternary blends for the reduction of emissions in diesel engines

The increasing use of biofuels to replace fossil fuels as well as more stringent emission regulations for internal combustion engines cause a challenge for the engine manufacturers to design engines that can cope with a wide range of fuels, but still offer low exhaust emissions.In this work a compression ignition engine test bed has been used to measure emissions when using ternary fuel blends between diesel, biodiesel and ethanol as well as implementing Low Temperature Combustion (LTC) techniques. A high fidelity simulation of the engine was also created to enable studies incorporating transient drive cycles to predict engine emissions.The aim of this project was to determine a fuel blend that achieves a 10% renewable content as well as reduce legislated engine emissions. LTC was also used to further reduce the engine emissions running on the ternary fuel blend.A mixture design of experiment (DoE) was used to optimise toward a fuel blend containing 2% biodiesel and 9% ethanol which results in a reduction of 34% in CO emissions, 10% in \NOx emissions and 21% in CO2 emissions compared to running the engine on pump diesel fuel. The optimisation of a Central Composite DoE showed that NOx emissions can decrease a further 25% when the maximum exhaust gas recirculation is set to 45%, the main injection is retarded by 2 CADs, the pilot injection dwell time is set to 21 CADs and 20% of the fuel is delivered through the pilot injection. CO emissions increase as a result of the increase in EGR percentage

Monitoring sustainable urban development using builtup area indicators: a case study of Stellenbosch, South Africa

Abstract: Rapid urbanisation in many developing countries causes land transformation from agricultural, rural, and natural landscapes into urban areas. Data to monitor this transformation is often out of date, unreliable, not in standard format, cumbersome and expensive to collect or simply unavailable. This inhibits local authorities and other stakeholders’ capacity to monitor and leverage resources toward sustainable urban development. This paper investigates the use of earth observation (EO) data for supporting sustainable urban development planning. The study demonstrates that EO adds value to sustainable urban development by providing area-wide and up-to-date thematic and geometric characterisation of the urban built-up area, which would be difficult to obtain from other data sources. This helps local planning authorities to monitor urban growth and sustainability, facilitate evidence-based decision making and an array of other practical uses

Developing an urban sustainability toolbox using earth observation data and GIS for monitoring rapid urbanisation in developing countries

Abstract: An overview of the toolbox is summarised in Table 2. For the exploration of the socio-economic impacts relating to social and spatial integration, health and safety, the Global Land Use Mix Index (GLUM) and Local Land Use Mix Index (LLUM) indexes and Land Use Frequency (LUF) can be used. Similarly, land use change, impervious surface concentration and the urban extent highlights environmental impacts and are useful for determining the rate of land transformation, human-nature interaction and growth of the urban footprint. LUC informs decisions pertaining to the preparation of local and zoning plans and spatial development frameworks (SDFs). SDFs and local plans illustrate projected land patterns and developments

Admission criteria for post graduate MBL students

There is a great need for qualified MBL and MBA graduates in South Africa to support and maintain the current growth rate that the economy is experiencing. Diligent effort is required to ensure that the locally acquired MBA/MBL qualifications remain on par with international qualifications. As an initial step to ensure high standards, the Council for Higher Education (CHE) did accreditation evaluations and only 18 MBA courses are now accredited. Admission criteria for the MBA/MBL is one of the minimum standards being assessed as part of the accreditation process conducted by the CHE. To be effective some of the aims of the admissions process at the UNISA SBL should be to: • Determine as accurately as possible, which students are capable to complete the MBL qualification successfully; (this has two implications, not denying any students who could have completed the course, and not admitting students who will not be able to complete the course). • Ensure that a culturally diverse and representative student body is admitted. • Do the above mentioned by using a practical process that is as financially and time efficient as possible. This research study focuses on the admissions criteria for MBL students at UNISA. The objectives of the study are: • Understanding the admissions criteria in use at universities globally and locally in South Africa. • Understanding the success rate of the GMAT as admissions predictor for MBA completion (globally). • Determining the success rate of the current admissions criteria as admissions predictor for the UNISA MBL completion. • Determine what data or combinations of data on the MBL application registration form can be used as a more successful predictor. iv The data collected for this study was obtained from the UNISA SBL administration department and consisted of a list of 724 students that enrolled for their MBL in 2003. The corresponding list of students that completed their studies in 2005 was also collected, which were 151 of the 724 students, or 20.9%. The data was re-coded and tested to determine in which of the data fields on the admissions form were there a statistically significantly correlation with regards to completing the MBL in 3 years. The following data fields indicated a statistically significant correlation: Race, Nationality, Age Group and Language. In order to test the final hypothesis, a classification tree making use of CHAID algorithms was used. The classification tree selected the data fields that showed statistically significant correlations. The data fields used was nationality, race and age groups. The classification tree re-grouped the data to achieve a 38.7% and 35.8% pass rate. Indicating that the newly developed admission tool is more successful in predicting students who will complete their MBL qualification in 3 years, than the current process, with which only 20.9% of the students passed. The pass rate of 38.7% might not sound significant, but it is an improvement of 85% on the current system. The research question was whether the data fields on the MBL application registration could be used to develop admissions criteria in order to serve as a predictor of the post graduate MBL student’s ability to complete the qualification in the prescribed period of time. This question was answered in two ways, firstly by the literature review, where Cate et al (2004) created a discriminant model that predicted MBA no-shows with 94.2% accuracy. Secondly by way of hypothesis 8 where the classification tree making use of CHAID algorithms grouped the students to achieve a pass rate of 38.7% and 35.8%, by only making use of the information available on the current UNISA admissions form. All the objectives of the study were met, and the following recommendations were made: Modify the admissions form to include some fields that may prove to be better predictors. Do not show away students, who according to the model will not pass, rather give them additional tutoring or require the students to complete a preparatory programme such as the Programme in Business Leadership (PBL), prior to starting with their MBL. Refine the admissions prediction model up to a point where the model is able to predict 80% to 90% of the cases correctly, prior to it being implemented, by using more than one MBL group that will give a more representative sample, and do not limit the study to only students that finished in the minimum period, but to all students that finished within 5 years. This study therefore concludes that the data fields on the MBL application registration form can be used to develop admissions criteria in order to serve as a predictor of the post graduate MBL student’s ability to complete the qualification in the prescribed period of time.Graduate School for Business LeadershipM.B.L

Data set for influence of blends of diesel and renewable fuels on compression ignition engine emissions

The present data article is based on the research work which investigates the influence of blends of diesel and renewable fuels on compression ignition engine emissions. In this experimental work, a 2.4 L, turbocharged, direct injection compression ignition engine and water brake dynamometer were used. Different ternary blends were created by mixing diesel, biodiesel and ethanol together in accordance with a mixture design of experiments. The homogeneity of each ternary blend was qualitatively checked by observing the samples for 24 hours for visible separation. The engine was run over the WLTP drive cycle for each individual ternary blend and the exhaust emissions were recorded. NOVA 7466K and TESTO 350 gas analysers were used to record the exhaust emissions. A factory standard MAF sensor was used to record the inlet air mass flow and an aftermarket ECU was used to determine the fuel flow. The ternary blends were blended using standard laboratory measuring equipment

A revision of the 2004 growth potential of towns in the Western Cape study

CITATION: Van Niekerk, A., Donaldson, R., Du Plessis, M. & Spocter, M. 2010. A revision of the 2004 growth potential of towns in the Western Cape study. Stellenbosch University.One of the objectives of the Department of Environmental Affairs and Development Planning (DEA&DP) is to undertake spatial planning that promotes and guides the sustainable future development of the Western Cape province and redresses spatial inequalities. This goal led to the development of the Provincial Spatial Development Framework (PSDF), which identifies the areas of growth in the province and the areas where, in terms of the sustainable development paradigm, growth should be emphasised in the future. It also addresses the form that this growth or development should take and further emphasises the restructuring of urban settlements to facilitate their sustainability. To provide guidance and support for implementing the PSDF, a thorough understanding and knowledge of the characteristics and performances of all the settlements in the province is needed

Compiling a land audit in large rural areas: Results from the methodology applied in the non-urban areas of the Matzikama municipal area

To compile a comprehensive land audit in large, mainly rural-based municipalities such as the Matzikama Municipality in the Western Cape warrants an alternative methodology than that conventionally done through exhaustive property visits. This study attempts to showcase such an alternative methodology to compile the land audit for the municipality. The end result of the audit was a geographical information system (GIS) database that contains a wide variety of information required for spatial planning and land use management purposes. Each of these elements required a unique data-collection methodology that included spatial data collection; aerial photography and satellite image pre-processing; mapping of property boundaries; defining area of interest; determining land ownership through property valuation rolls; establishing the status of access roads and routes; mapping current land uses, and overlaying land use control measures in order to infer land uses and deriving potential land use zoning. The methodology applied succeeded in successfully linking land parcels as follows: valuation data: 3 731 out of 4 176 (89.3%) were linked; state land audit: 378 out of 4 176 (9.1%) were linked, and deeds data: 1 680 out of 4 176 (40.2%) were linked. The study found that creating and updating land audits require advanced skills in GIS and it is recommended that municipalities employ suitably qualified officials in this regard. Working with outdated planning scheme legislation/policy can become a time-consuming and costly exercise for municipalities

Assessing the influence of DEM source on derived streamline and catchment boundary accuracy

Accurate DEM-derived streamlines and catchment boundaries are essential for hydrological modelling. Due to the popularity of hydrological parameters derived mainly from free DEMs, it is essential to investigate the accuracy of these parameters. This study compared the spatial accuracy of streamlines and catchment boundaries derived from available digital elevation models in South Africa. Two versions of Stellenbosch University DEMs (SUDEM5 and DEMSA2), the second version of the 30 m advanced spaceborne thermal emission and reflection radiometer global digital elevation model (ASTER GDEM2), the 30 and 90 m shuttle radar topography mission (SRTM30 and SRTM90 DEM), and the 90 m Water Research Commission DEM (WRC DEM) were considered. As a reference, a 1 m GEOEYE DEM was generated from GeoEye stereo images. Catchment boundaries and streamlines were extracted from the DEMs using the Arc Hydro module. A reference catchment boundary was generated from the GEOEYE DEM and verified during field visits. Reference streamlines were digitised at a scale of 1:10 000 from the 1 m orthorectified GeoEye images. Visual inspection, as well as quantitative measures such as correctness index, mean absolute error, root mean squares error and figure of merit index were used to validate the results. The study affirmed that high resolution (<30 m) DEMs produce more accurate parameters and that DEM source and resampling techniques also play a role. However, if high resolution DEMs are not available, the 30 m SRTM DEM is recommended as its vertical accuracy was relatively high and the quality of the streamlines and catchment boundary was good. In addition, it was found that the novel Euclidean distancebased MAE and RMSE proposed in this study to compare reference and DEM-extracted raster datasets of different resolutions is a more reliable indicator of geometrical accuracy than the correctness and figure of merit indices.Keywords: hydrology, catchment delineation, digital elevation model, correctness index, figure of merit index, Euclidean distance inde

In-vitro screening of Kalahari browse species for rumen methane mitigation

The nutritional value of browse foliage from the Thorny Kalahari Dune Bush veld of South Africa is not characterized. Most of this browse species is rich in tannin, but still palatable, and is consumed by ruminants during the dry season, as well as having a role to play in mitigating enteric methane emission from ruminants. In this study, the rumen methane mitigation potential of 19 browse species foliage collected from the Thorny Kalahari Dune Bush veld, was analyzed in terms of chemical composition, in vitro fermentation, digestibility and methane production. In vitro gas and methane production and organic matter digestibility (IVOMD) were determined by using rumen fluid collected, strained and anaerobically prepared. A semi-automated system was used to measure gas production (GP) from each browse species by incubating 400 mg samples in a shaking incubator at 39 °C with or without inclusion of 400 mg of polyethylene glycol (PEG). Data for all the parameters collected were statistically analyzed using the SAS (9.0) general linear model (GLM) procedure, and differences between foliage species were determined using Duncan’s multiple-range test. Acacia luederitziiand Monechma incanumshowed the best potential for decreasing methane production by up to 90 % after 48 h of incubation. The secondary components (mainly tannins) of the browse species appeared to have a significant effect on volatile fatty acids (VFA), methane and gas production as judged by the comparison of samples incubated with or without PEG inclusion. The substantial amount of crude protein (CP) content coupled with their anti-methanogenic effect during fermentation would make these browses a potential mitigation option for small scale farmers and pastoralists in sub-Sahara Africa. However, it is also very important that systematic and strategic supplementation in a mixed diet should be looked at as the way forward in terms of best utilization