Faculty of Engineering and the Built Environment (Research Outputs)
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Browsing Faculty of Engineering and the Built Environment (Research Outputs) by Type "Article"
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Item Contractor's plant: whether to buy or to lease?(University of the Free State, 1997) Muller, Marius M.This article comments on the concepts of buying versus leasing in terms of decision-making theory regarding the procurement of contractor's plant. It was found that leasing offered the better option in the worked example presented herein, but that every plant buying or lease decision would have to be made individually on proven calculation and on merit. In hierdie ortikel word die bestoonde opsies behondel woorvoor die boukontrokteur te stoon kom wonneer hy toerusting oonskof. Die vroog is: moet hy huur of koop. Uit die voorbeeld wot hier oongehool word blyk dit dot huur 'n beter opsie bied. Dit is egter ook boie duidelik dot elke gevol meriete het en dus individueel bekyk moet word. Kostes moet teen mekoor opgeweeg word. verol met die kontrokteur se doelwit voor oe.Item Expert systems : the fifth generation -more than a genealogical pursuit(University of the Free State, 1995-12) Muller, Marius M.This paper describes the nature of Expert Systems and outlines their possible use in the field of building economics. Their usefulness in terms of quantification of uncertainty is also examined. It was found that the benefits of developing Expert Systems are tremendous, but that the success of Expert Systems would be determined by their acceptance by the general public.Item How Rapid Urbanisation, Neighbourhood Management Affects Living Conditions. A Survey of Agege Local Government Area, Lagos, Nigeria(Canadian Center of Science and Education, 2014-11-23) Ijasan, K.C.; Ogunro, V. O.This paper explores the issues around urbanisation, neighbourhood degeneration and its effects on the living condition on the residents of Agege area of Lagos, Nigeria. This paper traces the historical background of the area, examines the meaning of neighbourhood degeneration and explores factors responsible for neighbourhood degeneration. The paper adopts quantitative data collection strategies of investigation, and compares these with past literature on the issue. From the survey of 120 households in the area, the study realized street hooliganism; destitution, bad roads and considerable inequality in the distribution of wealth as the greatest problems in the area. It concluded on the need for holistic approach by government to fast-track housing conditions improvement in the entire areas. Moreover, the redevelopment of the area needs to be community-led participatory planning where all stakeholders harness ideas that can be used to improve the present situation of the area.Item In vitro Evaluation of Porous borosilicate, borophosphate and phosphate Bioactive Glasses Scaffolds fabricated using Foaming Agent for Bone Regeneration(Nature Research, 2018) Erasmus, E. P.; Sule, R.; Johnson, O. T.; Massera, J.; Sigalas, I.In this work, glasses within the borosilicate borophosphate and phosphate family were sintered into 3D porous scaffolds using 60 and 70 vol. % NH4(HCO3) as a foaming agent. All scaffolds produced remained amorphous; apart from one third of the glasses which crystallized. All produced scaffolds had porosity >50% and interconnected pores in the range of 250–570 μm; as evidenced by μCT. The in-vitro dissolution of the scaffolds in SBF and changes in compression were assessed as a function of immersion time. The pH of the solution containing the borosilicate scaffolds increased due to the typical noncongruent dissolution of this glass family. Borophosphate and phosphate scaffolds induced a decrease in pH upon dissolution attributed to the congruent dissolution of those materials and the large release of phosphate within the media. As prepared, scaffolds showed compressive strength of 1.29 ± 0.21, 1.56 ± 0.63, 3.63 ± 0.69 MPa for the borosilicate, borophosphate and phosphate samples sintered with 60 vol. % NH4 (HCO3), respectively. Evidence of hydroxyapatite precipitation on the borosilicate glass scaffolds was shown by SEM/EDS, XRD and ICP-OES analysis. The borophosphate scaffolds remained stable upon dissolution. The phosphate scaffolds were fully crystallized, leading to very large release of phosphate in the media.Item Investing in the Future: A Comparative Analysis of Green Technology Investments and Youth Unemployment in the US and South Africa(Common Ground, 2024-05-14) Weaich, Malcolm; Weaich, Sherwyn; Simbanegavi, Prisca; Ndlovu, PrideThis study explores the nuanced relationship between sustainable investments, particularly from entities such as the United States (US), and their impact on unemployment trends in South Africa, contributing to discussions on sustainable development goals (SDGs). Utilizing a quantitative approach with data from sources such as the World Bank and Statistics SA, this study employs statistical and econometric methods to assess the socioeconomic consequences of international sustainability funding. The findings indicate a significant link between US sustainable investments and youth unemployment in South Africa, challenging and reinforcing existing research. It depicts that while foreign investments in green initiatives are crucial, they may inadvertently affect local employment negatively. This study recommends policy adjustments in both US and South African legislation to align foreign investments with SDGs, aiming to mitigate youth unemployment. This study underscores the importance of understanding the implications of international funding conditions on local economies, offering insights for policymakers and scholars to develop strategies that leverage sustainable investments for economic growth and employment opportunities. This study provides a fresh perspective on the dynamics between international investments and local unemployment, offering valuable insights for economic planning and policy formulation in South Africa and across other African nations.Item Phase proportions, carbon equivalent, mechanical properties and their effect on material cost of railway axle steels(Springer, 2018-04) Klenam, D.E.P.; Chown, L.H.; Papo, M.J.; Cornish, L.A.Commuter trains with solid axle configuration are produced from medium carbon steel due to cost restrictions. High-speed trains have hollow axle configuration for reduced weight and are made from high strength low-alloy (HSLA) steels. The HSLA steels have higher amounts of C, Cr, Ni, Mo, V and Nb, and are more expensive than medium carbon steels. The effects of phase proportions, carbon equivalent (CE), yield strength and ultimate tensile strength (UTS) on material costs of existing railway axle steels were studied using Thermo-Calc. Medium carbon rail axle steels had higher Fe3C phase proportions than the HSLA steel rail axle grades. Higher affinity of Cr, Mo and V for C than Fe resulted in decreased cementite proportions. The HSLA steels had yield strengths above 370 MPa, and UTS above 750 MPa, with increased material cost above $3300 per ton. A scattered distribution was observed for the pearlite weight fraction and material costs, with most between $3200 and $3400. The yield and tensile strengths increased with increasing carbon equivalent and pearlite weight fraction. The data aided the selection and design of alloys with better mechanical and corrosion properties at reduced material cost.Item The 'Massive, Little' Houses: 'Prefabs', A Solution for Informal Settlement Housing Crisis in South Africa! A Scoping Review(Construction Business and Project Management Group, University of Cape Town, 2024-08-27) Simbanegavi, Prisca; Weaich, Malcolm; Adewunmi, Yewande; Ndlovu, Pride; Gethe, FarananiUnlike most continents, Africa still grapples with urban informality, where housing shortages affect most people living in substandard conditions. Prefabricated housing (PH) presents an alternative option that provides a quicker and cheaper housing supply, although it currently lags behind demand. This paper examines whether 1) informal settlements can be upgraded using prefabricated/modular houses, 2) these housing types are desirable to occupants, and 3) alternative houses should receive as much emphasis and policy support as possible, particularly considering the challenges experienced during the COVID-19 pandemic. Based on a comprehensive literature survey utilising a scoping review methodology, the paper indicates that stakeholders such as developers, financiers, and occupants of prefabricated housing increasingly embrace PH despite its challenges. The literature unanimously agrees that substantial efforts are required to catalyse more investment in PH regarding further research, education, supply chain improvements, and enhanced communication and collaboration among industry stakeholders. Additionally, numerous research gaps need addressing, including in-depth examinations of PH's contextual feasibility and performance across different geographical areas. The paper recommends that South African governments adopt PH as an alternative housing solution, as it is faster and cheaper, thereby aiding in achieving the 2030 Sustainable Development Goal 11.Item The persistence and rise of master planning in urban Africa: transnational circuits and local ambitions(Informa UK Limited, trading as Taylor & Francis Group, 2022-03-27) Harrison, Philip; Croese, SylviaMaster plans have long been criticized by critical planners who have argued in favour of more strategic, collaborative and relational forms of spatial planning that can more adequately respond to local needs and realities, especially in the context of the global South. Rather than critiquing master planning, this paper seeks to interrogate its recent rise in urban Africa. Building on a review of international planning trajectories, the paper seeks to challenge dominant narratives in the Western literature around the rise and decline of master planning. Planning experiences from across the African continent illustrate how master planning was a limited practice under colonialism and emerged more strongly in early post-colonial years, while persisting through a quiet period of planning and proliferating in recent times. By exploring the diversity in the influences and approaches to master planning for new and existing cities in Africa over time, the paper positions master planning as the product of a complex array of transnational circuits and multiple local actors and ambitions which intersect across different scales. The study of master planning should therefore be considered as an important entry point into understanding and rethinking the contemporary politics of urban planning, implementation, and development in Africa.Item The role of education as an agent of change: a two fold effect(1997) Muller, Marius M.; Hindle, R.D.Several aspects of change to the procedures in the construction delivery process have been described in recent times, particularly those affecting building procurement systems. This paper describes the results of an investigation into one of the underlying causes of such change, particularly that which is affecting the traditional roles of the various parties that participate in the construction procurement process. It is proposed that one of the 'agents' of change is the product of tertiary education programmes that have been producing 'professional builders'. It describes how a new generation of builders, equipped with business skills and an inherent dissatisfaction with the traditional structure and procedures of the industry, are allowing leading construction companies to develop innovative construction marketing strategies and systems. These systems are based upon sound business practice, offer improved customer satisfaction and allow them to get closer to customers. In so doing they are taking over the roles of various built environment consultants who were principal agents and leaders in the traditional building procurement system.Item The transcalar politics of urban master planning: the Japan International Cooperation Agency (JICA) in Africa(Informa UK Limited, trading as Taylor & Francis Group, 2022-09-22) Croese, Sylvia; Miyauchi, YoheiThis article sheds light on the growing, but understudied role of the Japan International Cooperation Agency (JICA) in supporting the local production of master plans across the African continent as a tool for guiding long-term investments in urban development. To explore the multiple logics, actors and interests driving the conception, preparation and implementation of these plans, we approach urban master planning as a transcalar process, through which diverse investment, planning and governance arrangements are produced and mobilized in ways that transcend the city scale. We illuminate these dynamics by building on an analysis of the history of Japanese development cooperation and drawing on case studies of JICA master planning in Malawi, Ghana and Tanzania.