J.A. VISSER and H. ROLFES
By modelling the unsteady heat transfer in liquid gas tanks, the temperature distribution in the tank as well as the heat flux reaching the liquid gas can be predicted. Knowledge…
Abstract
By modelling the unsteady heat transfer in liquid gas tanks, the temperature distribution in the tank as well as the heat flux reaching the liquid gas can be predicted. Knowledge of the temperature distribution and heat flux can be used to predict evaporation losses from the tank. By minimizing the evaporation losses, the thermal design of a gas tank can be optimized. This paper presents a finite difference simulation of the unsteady three‐dimensional heat transfer in gas tanks and an optimized configuration. The numerical procedure accounts for radiation from the sun as well as radiative and convective heat transfer with the environment. A non‐uniform grid is used because the tank consists of several different materials of varying dimensions and properties. Geometrical effects such as variations in the thickness of the insulation material and the diameter and height of the tanks are also studied in an attempt to optimize the design configuration.
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C.J. de Villiers and P. Barnard
The content of the annual reports of listed South African mining companies from 1994 to 1999 was analysed to determine how many disclose certain environmental information. This…
Abstract
The content of the annual reports of listed South African mining companies from 1994 to 1999 was analysed to determine how many disclose certain environmental information. This number, expressed as a percentage, was compared with the corresponding percentage disclosure among the Financial Mail Top 100 industrial companies for the same years. A greater number of mining companies, when compared to other large companies, disclose environmental information. This finding is consistent with legitimacy, which is the notion that an organisation will not continue to prosper if its aims and methods are in conflict with that of society. Mining companies have a greater need to legitimise their operations by means of environmental disclosure, because their environmental impact is extensive and obvious.
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Evaluations of environmental performances are of increasing importance for environmental management systems. In the automotive sector of South Africa, suppliers of components lack…
Abstract
Purpose
Evaluations of environmental performances are of increasing importance for environmental management systems. In the automotive sector of South Africa, suppliers of components lack the ability to provide customers in the value chain with the necessary information to assess and compare environmental performances. Original equipment manufacturers (OEMs) in South Africa have systematically commenced to obtain limited process information from first‐tier suppliers. However, the information is not an accurate reflection of the true environmental burdens associated with the supplied components. Based on the available process information, this paper introduces a performance evaluation methodology that is applicable for South Africa.
Design/methodology/approach
The LCA methodology, as stipulated by ISO 14040, has been applied to obtain quantified environmental performance resource impact indicators (EPRIIs) associated with limited process parameters in the South African context. Three first‐tier suppliers of an OEM are used as a case study to demonstrate the application of the indicator methodology.
Findings
The EPRII procedure considers the spatially differentiated ambient environmental state of the South African natural environment for normalisation factors of typical LCIA categories. The procedure further incorporates costs in order to compare supplied components (and companies) equally.
Originality/value
The EPRII procedure provides the means for OEMs to obtain a first approximate of environmental concerns in the supply chain, based on three basic process parameters. Thereby, tiers can be prioritised to determine where assistance is required to improve environmental performances.
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C.J. Visser, A.G. Malan and J.P. Meyer
The purpose of this paper is to focus on modeling buoyancy driven viscous flow and heat transfer through saturated packed pebble‐beds via a set of homogeneous volume‐averaged…
Abstract
Purpose
The purpose of this paper is to focus on modeling buoyancy driven viscous flow and heat transfer through saturated packed pebble‐beds via a set of homogeneous volume‐averaged conservation equations in which local thermal disequilibrium is accounted for.
Design/methodology/approach
The local thermal disequilibrium accounted for refers to the solid and liquid phases differing in temperature in a volume‐averaged sense, which is modeled by describing each phase with its own governing equation. The partial differential equations are discretized and solved via a vertex‐centered edge‐based dual‐mesh finite volume algorithm. A compact stencil is used for viscous terms, as this offers improved accuracy compared to the standard finite volume formulation. A locally preconditioned artificial compressibility solution strategy is employed to deal with pressure incompressibility, whilst stabilisation is achieved via a scalar‐valued artificial dissipation scheme.
Findings
The developed technology is demonstrated via the solution of natural convective flow inside a heated porous axisymmetric cavity. Predicted results were in general within 10 per cent of experimental measurements.
Originality/value
This is the first instance in which both artificial compressibility and artificial dissipation is employed to model flow through saturated porous materials.
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C.J. de Villiers and D.S. Lubbe
Previous research has revealed industry differences in respect of environmental reporting in South Africa. However, these studies concentrated on particular types of environmental…
Abstract
Previous research has revealed industry differences in respect of environmental reporting in South Africa. However, these studies concentrated on particular types of environmental reporting and therefore precluded many other types of environmental reporting in the annual reports surveyed. Past surveys also awarded equal credit to any reference to a particular type of environmental information, whether it comprised a single sentence or several pages. The annual reports of the top 100 companies, in terms of market capitalisation, were analysed and a sentence count of environmental disclosure was done with the use of the Hackston & Milne (1996) methodology. The group of energy companies was defined as comprising companies in energy‐intensive industries or companies that are producers of energy carriers. The survey revealed that these companies disclosed significantly more environmental information than other companies, in total and in each category These findings are consistent with the notion of legitimacy, which holds that companies cannot prosper if their aims and methods are not perceived to be in line with that of society. For this reason, companies that have the most obvious environmental impact tend to disclose more environmental information than other companies in an effort to legitimise their aims and methods in the eyes of society.
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This paper examines the effect of intergroup competition on intragroup cooperation. Three experiments are reviewed. The first experiment establishes that intergroup competition…
Abstract
This paper examines the effect of intergroup competition on intragroup cooperation. Three experiments are reviewed. The first experiment establishes that intergroup competition can effectively increase intragroup cooperation in a laboratory setting where symmetric players make binary decisions in one‐shot dilemma games. The second experiment shows that this constructive effect of intergroup competition is generalizable to a real‐life setting in which asymmetric players make continuous decisions in an ongoing interaction. The third experiment demonstrates that the increase in intragroup cooperation can be accounted for at least in part by motivational, rather than structural, effects of the intergroup competition. Theoretical and practical issues concerning the applications of these findings are discussed.
This chapter explores issues around children's voice, physical education and social, emotional and behavioural difficulties (SEBD) in England. Research has previously highlighted…
Abstract
This chapter explores issues around children's voice, physical education and social, emotional and behavioural difficulties (SEBD) in England. Research has previously highlighted the physical, social, effective and cognitive benefits of participation in physical education (PE) (Bailey, 2006). Furthermore, practical, physical and expressive creative experiences in education have been cited as being an important constituent when educating children with SEBD (Cole & Visser, 1998). However, research has yet to address the experiences of the child with SEBD alongside the ideological benefits of their participation in PE. After a period of sensitisation to the field, in a number of pilot schools, a total of 24 weeks were spent immersed in the cultures of two mainstream schools in the West of England. After six weeks of local familiarisation, during which field notes and research diaries were kept, weekly interviews with each of six case study participants commenced. This process resulted in an intensely interactive and personal process of engagement (Sparkes, 1994) which was at times magnified when working in a PE environment. In this research, a PE environment afforded opportunities to spend time and build trust through co-participation in the negotiation of socially constructed roles in the subject. The six case study participants whose experiences have been studied make reference to, amongst others, their affinity towards the physical nature of PE, the perception of it being a subject allowing for freedoms not found elsewhere in the curriculum and one which cemented both the positive and negative social systems in relation to their relationships with peers. Inductive processes of analysis utilising constant comparison methods between data sources have generated data which shows signs of both the idiosyncratic nature of multiple truths and some common ground in their experiences.
Bryan Pieterse, Kofi Agyekum, Patrick Manu, Saeed Reza Mohandes, Clara Cheung and Akilu Yunusa-Kaltungo
Major maintenance projects are often regarded as maintenance activities regardless of the projects' complexity and scale. Consequently, very scarce research attention has hitherto…
Abstract
Purpose
Major maintenance projects are often regarded as maintenance activities regardless of the projects' complexity and scale. Consequently, very scarce research attention has hitherto been paid to the critical skills required when undertaking these projects. More specifically, the body of relevant knowledge is deprived of a study focusing on maintenance projects within the energy sector. In view of this shortcoming, this research aims to examine the critical project management (PM) skills required to deliver major maintenance projects within the energy sector.
Design/methodology/approach
Based on a quantitative research strategy, this study addressed the knowledge gap through a cross-sectional survey of professionals involved in the delivery of major maintenance projects in the United Kingdom's (UK) energy sector. Data obtained were analyzed via descriptive (e.g. frequencies, mean and standard deviation [SD]) and inferential statistical analyses (One sample t-test and exploratory factor analysis (EFA)).
Findings
Out of the 45 PM skills identified in the literature and examined by the respondents, the results obtained from the One sample t-test (based on p (1-tailed) = 0.05) showed that 37 were considered to be at least “important,” accounting for 80.4% of all the skills identified. EFA revealed a clustering of the PM skills items into seven components: “skills related to work scheduling and coordination”; “communication, risk, safety and stakeholder management skills”; “quality assurance skills”; “people management skills”; “skills related to forecasting scope and duration of outage”; “implementation of processes and time management skills” and “technical/engineering skills and experience pertaining to the outage and local site knowledge.”
Originality/value
This study has identified and contributed to the limited state-of-the-art skills project managers must possess to manage major maintenance projects in the energy sector successfully. The findings would be useful to organizations within the energy sector in ensuring that the organizations have suitable personnel in place to deliver major maintenance projects on the organizations' assets.
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Alan C. Brent and Carin Labuschagne
The purpose of this paper is to introduce methods that have been developed to consider social sustainability aspects in the initial phases of projects in industry, i.e. in the…
Abstract
Purpose
The purpose of this paper is to introduce methods that have been developed to consider social sustainability aspects in the initial phases of projects in industry, i.e. in the design stage of technological systems, whereby a proactive approach in industry can be ensured. The inclusion of social aspects in both the sustainability debate and practice has been marginal compared with the focus on the other two dimensions of sustainable development, i.e. economic and environmental performances, especially from a business perspective. The tools that have focused on social business sustainability aspects have mainly addressed business sustainable development reporting, operational conditions, and product social life cycle assessments.
Design/methodology/approach
The first method builds on a framework of social sustainability criteria that has been introduced for the South African process industry. A Social Impact Indicator (SII) calculation procedure has been developed based on a previously introduced Life Cycle Impact Assessment (LCIA) calculation procedure for environmental Resource Impact Indicators (RIIs). The second method applies questionnaires and checklists following more traditional risk approaches.
Findings
Information availability and standardisation of social criteria are problematic for quantitative approaches at present. It is therefore proposed that social sustainability should be incorporated into project and technology management methodologies in phases, commencing with the questionnaires and checklists. In future, the proposed indicator method can be implemented when information is more readily available.
Originality/value
The questionnaires and checklists provide practical means for project and technology developers to assess and communicate potential social risk associated with technological systems to decision‐makers.