List of Titles

Energy generation from full strength domestic wastewater using a sandwich dual chamber microbial fuel cell with an uncatalyzed mesh current collector cathode

- Adeniran, J.A., De Koker, J.J., Arotiba, O.A., Van Zyl, E., Du Plessis, S.

Authors: Adeniran, J.A. , De Koker, J.J. , Arotiba, O.A. , Van Zyl, E. , Du Plessis, S.
Date: 2015
Subjects: Microbial fuel cells , Power generation , Mesh current collector cathodes , Wastewater
Language: english
Type: article
Identifier: http://hdl.handle.net/10210/15528 , uj:15671 , Adeniran, J.A. et al. 2015. Energy generation from full strength domestic wastewater using a sandwich dual chamber microbial fuel cell with an uncatalyzed mesh current collector cathode. International journal of green energy
Description: A sandwich domestic wastewater fed dual-chamber microbial fuel cell (MFC) was designed for energy generation and wastewater treatment. Power density for the MFC increased with increasing domestic wastewater concentration, reaching a maximum of 251 mW/m2 for full strength wastewater (3400 mg/L chemical oxygen demand (COD)) at a current density of 0.054 mA/cm2 at an external resistance of 200Ω. These values dropped to 60 mW/m2 (76% lower) and 0.003 mA/cm2 using wastewater 91% diluted to 300 mg/L COD. Maximum removals were: of COD, 89%; nitrite, 60%; nitrate, 77%; total nitrogen, 36%; and phosphate, 26%.
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An appraisal of housing satisfaction in South Africa low income housing scheme

- Wellington, D. T, Aigbavboa, C. O.

Authors: Wellington, D. T , Aigbavboa, C. O.
Date: 2012
Subjects: Housing - South Africa
Language: English
Type: article
Identifier: http://hdl.handle.net/10210/15562 , uj:15674 , Citation: Aigbavboa, C.O. & Thwala W.D. 2012. An appraisal of housing satisfaction in South Africa low income housing scheme. The International Journal of Construction Management, 12(1):1-21.
Description: Abstract: Post-occupancy evaluation techniques have been developed to provide a means for evaluating occupant responses to changes in an environment and linking this response to physical measures of that environment. POE has been used to evaluate the performance of buildings after they have been built and occupied for some time. This paper presents findings on the social and physical factors which influence residential satisfaction in four different government Housing Subsidy locations in the Gauteng Province of South Africa. Data obtained from the occupant survey were analyzed through the use of descriptive statistics. Findings arising from the survey revealed that the respondents were satisfied with their overall housing situation, but had complaints about certain aspects of the housing unit. However, the respondents informed that most of their housing needs were not being met. Also, a comparison is also made of the perceived factors of dissatisfaction amongst the housing subsidy occupants. It is recommended that a wider systematic coverage of the subject through investigation and diagnostic POE and occupants’ need assessment should be carried out in housing subsidy schemes in South Africa.
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Assessment of surface finish and dimensional accuracy of tools manufactured by metal casting in rapid prototyping sand moulds

- Nyembwe, K., De Beer, D.J., Van der Walt, J.G., Bhero, S.

Authors: Nyembwe, K. , De Beer, D.J. , Van der Walt, J.G. , Bhero, S.
Date: 2012
Subjects: Metal castings , Metal-work , Sand casting
Language: English
Type: article
Identifier: http://hdl.handle.net/10210/15459 , uj:15665 , Nyembwe, K. et al. 2012. Assessment of surface finish and dimensional accuracy of tools manufactured by metal casting in rapid prototyping sand moulds. South African Journal of Industrial Engineering, 23(2):130-143.
Description: Abstract In this paper, an initial assessment of the quality parameters of the surface finish and dimensional accuracy of tools made by metal casting in rapid prototyping (RP) sand moulds is undertaken. A case study from a local tool room, dealing with the manufacturing of an aluminium die for the lost wax process, is employed. Modern techniques, including surface roughness analysis and three dimensional scanning, are used to determine and understand how each manufacturing step influences the final quality of the cast tool. The best surface finish obtained for the cast die had arithmetic average roughness (Ra) and mean average roughness (Rz) respectively equal to 3.23μm and 11.38μm. In terms of dimensional accuracy, 82% of cast-die points coincided with the Computer Aided Design (CAD) data, which is within the typical tolerances of sand cast products.
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Comparison of metastable phases induced by heat treatment of unmilled and milled cobalt powders

- Bolokang, A. S., Phasha, M. J., Bhero, S.

Authors: Bolokang, A. S. , Phasha, M. J. , Bhero, S.
Date: 2012
Subjects: Cobalt powders , Water quenching , Heat - Treatment
Language: English
Type: article
Identifier: http://hdl.handle.net/10210/15398 , uj:15657 , Bolokang, A.S., Phasha, M.J. & Bhero, S. 2012. Comparison of metastable phases induced by heat treatment of unmilled and milled cobalt powders. International Journal of Refractory Metals and Hard Materials, 36:111–115.
Description: Abstract The sintered and water quenched compact samples were prepared from unmilled and milled Co powders. Characterisation was performed by differential scanning calorimetry, scanning electron microscopy and X-ray diffraction techniques. Several metastable phases were obtained upon sintering and quenching. However, more metastable phases were induced on quenching the milled–sintered samples due to introduction of large number of defects in addition to those induced by milling. Micro hardness values for unmilled sintered samples were the lowest while those of 30 h milled-sintered samples were the highest. The current study reveals that the two FCC metastable phases obtained by quenching unmilled powder were similar to those found in milled–sintered samples.
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Structural characterization of mechanically milled and annealed tungsten powder

- Bolokang, A.S., Phasha, M.J., Maweja, K., Bhero, S.

Authors: Bolokang, A.S. , Phasha, M.J. , Maweja, K. , Bhero, S.
Date: 2012
Subjects: Nanocrystalline , Tungsten , Mechanical milling
Type: article
Identifier: http://hdl.handle.net/10210/15304 , uj:15644 , A.S. Bolokang, M.J. Phasha, Kasonde Maweja, S. Bhero, Structural characterization of mechanically milled and annealed tungsten powder, Powder Technology 225 (2012) 27–31, Elsevier Ltd
Description: Abstract Nanocrystalline W powders with an average crystallite size of about 50 nm were produced by mechanical milling. BCT phase was mechanically induced as a result of BCC lattice deformation (compression) along [110], upon 10 h, 20 h and 30 h milling corresponding to a magnetic saturation of 1.3, 6.9, and 9.8 μTm3/kg. This BCT phase suggests the tetragonal deformation path to be responsible for the observed anomalous magnetism in W. Following DSC–TG thermal analysis, a magnetic saturation of 68 μTm3/kg was obtained upon annealing the 30 h milled W powder at 1200 °C. In addition, two BCT phases with c/a=1.313 (a=0.29066, c=0.38170 nm) and 0.907 (a=0.32602, c=0.29575 nm) were detected.
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Performance Evaluation of a Simplified Multi-Function Current Transformer for High Frequency Power Converters

- Pentz, D.C., Van der Merwe, F.H.

Authors: Pentz, D.C. , Van der Merwe, F.H.
Date: 2011
Subjects: Current transformer , Current sensor , Power electronic converter
Language: english
Type: article
Identifier: http://hdl.handle.net/10210/15904 , uj:15715
Description: Abstract A multi-function current transformer introduced some years ago is revisited in an effort to improve its manufacturability. The original current sensor has the ability to accurately represent load and phase-arm currents in single phase full-bridge dc-dc-converter topologies under normal operating conditions. In the event of a phase-arm fault the shoot-through current can also be detected and the information used in the protection scheme. This sensor is however very complex to manufacture and this work presents a simplified version of the sensor, which still gives the most important information with a far less complex structure. This paper briefly discusses the original current sensor, proposes a simplified sensor and evaluates the new sensor in terms of performance.
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Lessons learned from in situ upgrading and eradication of informal settlement in Gauteng Province in South Africa

- Aigbavboa, Clinton Ohis, Thwala, Wellington Didibhuku

Authors: Aigbavboa, Clinton Ohis , Thwala, Wellington Didibhuku
Date: 2010
Subjects: Housing - Government policy - South Africa , Squatter settlements - South Africa - Gauteng
Language: English
Type: article
Identifier: http://hdl.handle.net/10210/15603 , uj:15679 , Citation: Aigbavboa, C.O. & Thwala, W.D. 2010. Lessons learned from in situ upgrading and eradication of informal settlement in Gauteng Province in South Africa. International Journal of Housing Markets and Analysis, 3(3):233-244. DOI: 10.1108/17538271011063898 , ISSN: 1753-8270
Description: Abstract: The purpose of this paper is to give an insight into lessons learned so far on the in situ upgrading and eradication of informal settlements in South Africa. This is with a view to accessing progress made to date, the line of focus and to ascertain whether in situ upgrading or eradication of informal settlement is the best option in solving the problem of informal settlement integration into the large society. Design/methodology/approach – The research is conducted with reference to existing theoretical literature, published and unpublished South Africa research. The study is mainly a literature survey/ review and looks at challenges that have been overcome to bring about the success made to date, thus striving to achieve the goals and objectives of a city without slums. The research ties up the identified challenges with recommendations to the problems to enhance the reality of having a city without slums. Findings – One of the primary findings that emanated from the study revealed that all development where people have to be displaced or inconvenienced has come with problems. Other findings attribute the little success achieved to date to the in situ upgrading of the existing settlement and the eradication of the settlement. Though policy activated has not been well implemented for the betterment of all, progress has been made nonetheless. Originality/value – The upgrading and eradication of informal settlement have long been a subject of global discussion, which has taken firmer root since it was declared to be one of the Millennium Development Goals agenda. The paper contributes to this body of knowledge.
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Labour underutilisation, unemployment and underemployment

- Graham, W., Mccutcheon, R.T, Quainoo, H.A

Authors: Graham, W. , Mccutcheon, R.T , Quainoo, H.A
Date: 2009
Subjects: Labour , Unemployment
Language: English
Type: article
Identifier: http://ujcontent.uj.ac.za8080/10210/391498 , http://hdl.handle.net/10210/15287 , uj:15641 , School of Civil & Environmental Engineering University of the Witwatersrand Private Bag 3 Wits 2050 South Africa
Description: Abstract The Kenyan RARP, institutionalised within the Ministry of Works, was the first and remains the largest labour intensive road construction and maintenance programme in Africa. The objectives of the programme were (a) to provide all weather access between high potential farming areas and market centres (farmers said they could grow more food but they could not reach the secondary road network and, therefore, the market centres where the surplus could be sold); (b) to provide meaningful employment opportunities; (c) to encourage the production of cash crops; (d) to improve the quality of rural life and access to services at "growth centres". The programme was financed by eight donor agencies and the Kenyan government. Since 1974 it has been responsible for the construction of 8 000 kms of earth road of which nearly 6 000 kms have been gravelled. During the peak of its construction phase 14 5000 casual labourers were employed and 1 400 supervisory staff: in sum over 70 000 years of casual employment have been created and 6 000 years of supervisory employment. The KRARP was immensely successful and it should be the basic model for any country wishing to introduce such a programme. Reasons for success could be used as a primary check list against which to assess any proposed programme in a new country or any established programme embarking upon new directions.
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