Modification of thermoplastic coatings for improved cathodic disbondment performance on a steel substrate : a study on failure mechanisms

The effect of blending two different materials with a medium density polyethylene for use as pipe coatings is presented. The influence of such blending on properties such as cathodic disbondment (CD) and wet adhesion on steel is investigated. The components blended include a functionalised polyethylene (PE) containing the polar functionality, maleic anhydride (MAH) and an amorphous elastomer, ethylene-propylene-diene terpolymer (EPDM). It was found that modification of PE with small amount (2.5–3 wt%) of either blended MAH-g-PE or EPDM resulted in a significant improvement in CD performance and wet adhesion strength. The mode of failure and disbondment mechanism was investigated using energy dispersive X-ray spectroscopy (EDXS) and X-ray photoelectron spectroscopy (XPS). The greater resistance of migration of sodium ions increases with the incorporation of the modifiers, and it is proposed that this results in an increase in CD performance.

Examination of the stability and consistency of investigative interviewer performance across similar mock interview contexts

Purpose. Three studies examined the degree to which investigative interviewers’ adherence to best-practice guidelines is consistent across similar mock interviews.
Method. In each study, two interviews were administered within a period of several hours. Further, group and individual stability of interviewer performance was analysed, and performance was measured by calculating the proportion of open-ended and leading questions as well as the presence of predetermined problem behaviours. The studies varied depending on the type of interview paradigm employed. Interviewer performance in Study 1was measured in a group context where participants rotated between the role of interviewer, child respondent, and observer. In Study 2, an adult played the role of a child recalling abuse but this occurred in isolation (participants did not observe others or play the child). Study 3 was similar to Study 2 except that in each interview an unfamiliar child aged 5–7 years recalled an innocuous event.
Results. Interviewer performance was relatively stable across tasks, although the strength of the relationship between measures varied across analyses. Improvement in open-ended question usage occurred in Study 1 but not Studies 2 and 3. Irrespective of the assessment context, the dichotomous rating scale yielded greater consistency than when questions were tallied. Further, group stability overestimated individual stability. The practical implications of these findings for trainers and researchers are discussed.

A model for improving board performance : the case of a national sport organisation

The transition of many sport organisations from being predominantly volunteer-administered and anchored in an amateur ethos to professionally managed entities has created unique challenges for the governance of sport. This paper provides a contribution to the governance literature through the presentation of a situational case where a four-stage model, drawn from an action research approach, has been used for developing a board’s strategic capability and subsequent improvement in organisational performance.

Action research is founded on the premise that change and research are not mutually exclusive and that dual foci on improving practice and developing theory are possible (Coghlan & Brannick, 2001). Utilising a national sport organisation (NSO) in New Zealand the study developed and tested a structured model for improving board functioning and, specifically, strategic contribution.

While the case to which the model has been applied is an NSO, the model and the subsequent reflections have value for non-profit as well as commercial entities particularly with regard to a greater understanding of the mechanisms associated with balancing the performance and conformance roles of the board.

A learning laboratory approach for business improvement : the case of discontinuous innovation

This paper considers the current situation within Australian manufacturing SMEs and their approaches to innovation and international competitive advantage. Using the viewpoint and language of complexity theory, we consider the variety of possibilities available to SMEs in this area. We then consider a particular international project on Discontinuous Innovation, how this has been deployed in Europe and Australia and the knowledge gained from our interactions with Australian SMEs to date around this project. Finally we consider the general development of a “Learning Laboratory” approach to working with SMEs and the differences required to make such approach successful in Europe and in different settings in Australia.

Collaborative improvement : interplay but not a game

Collaboration literally means working together. Collaborative improvement is an extension of continuous improvement and can be defined as a purposeful inter-company interactive process that focuses on continuous incremental innovation aimed at enhancing the collaboration’s overall performance. Developing collaborative improvement is a protracted and difficult process. Previous research has identified a number of factors affecting that process and suggested that it is not so much the individual factors, but rather their interplay that determines the successful development of collaborative improvement. This article reports research aimed at developing a deeper understanding of that interplay. Ten relationships between ten factors are presented and discussed. It appears that vision, approach, trust and commercial reality are the strongest factors. These factors are, however, influenced by, or affect the other factors, notably national culture, partner characteristics and competences, the use of power, individual behaviour and commitment. The way this interplay develops varies from case to case and has great influence on the development of collaborative improvement.

Strategy and continuous improvement in small-to-medium Australian manufacturers

While Australian firms have generally recognised the value of continuous improvement (CI) in improving performance, many have yet to develop systems to ensure that the efforts of the CI program are focussed on issues of strategic importance to the company. In fact, as recognised in operations management generally, CI activities can have a significant impact on the development of strategy as well as its implementation. The research reported here uses a CI mapping methodology to chart the relationship between CI and strategy in small- to medium-sized manufacturers. Analysis of the link between the firms’ strategies and CI programs indicates that most firms involved in the study made little attempt to link the two and some appear to be unaware of any need to do so. However, such findings seem to be dependent on company size, the maturity of the CI program and the competitive position of the firm. The paper also includes an examination of the role of operations and shopfloor CI in company strategy, particularly as related to SMEs.

Optimising the life cycle energy performance of residential buildings

A holistic approach to low-energy building design is essential to ensure that any efficiency improvement strategies provide a net energy benefit over the life of the building. Previous work by the authors has established a model for informing low-energy building design based on a comparison of the life cycle energy demand associated with a broad range of building assemblies. This model ranks assemblies based on their combined initial and recurrent embodied energy and operational energy demand. The current study applies this model to an actual residential building in order to demonstrate the application of the model for optimising a building’s life cycle energy performance. The aim of this study was to demonstrate how the availability of comparable energy performance information at the building design stage can be used to better optimise a building’s energy performance. The life cycle energy demand of the case study building, located in the temperate climate of Melbourne, Australia, was quantified using a comprehensive embodied energy assessment technique and TRNSYS thermal energy simulation software. The building was then modelled with variations to its external assemblies in an attempt to optimise its life cycle energy performance. The alternative assemblies chosen were those shown through the author’s previous modelling to result in the lowest life cycle energy demand for each building element. The best performing assemblies for each of the main external building elements were then combined into a best-case scenario to quantify the potential life cycle energy savings possible compared to the original building. The study showed that significant life cycle energy savings are possible through the modelling of individual building elements for the case study building. While these findings relate to a very specific case, this study demonstrates the application of a model for optimising building life cycle energy performance that may be applied more broadly during early-stage building design to optimise life cycle energy performance.

Performance optimization problem in speculative prefetching

Speculative prefetching has been proposed to improve the response time of network access. Previous studies in speculative prefetching focus on building and evaluating access models for the purpose of access prediction. This paper investigates a complementary area which has been largely ignored, that of performance modeling. We analyze the performance of a prefetcher that has uncertain knowledge about future accesses. Our performance metric is the improvement in access time, for which we derive a formula in terms of resource parameters (time available and time required for prefetehing) and speculative parameters (probabilities for next access). We develop a prefetch algorithm to maximize the improvement in access time. The algorithm is based on finding the best solution to a stretch knapsack problem, using theoretically proven apparatus to reduce the search space. An integration between speculative prefetching and caching is also investigated.

Influence of atmospheric helium plasma on the surface energy of jute fibres and the performance of resulting composites

In this work, an atmospheric pressure glow discharge helium plasma treatment was employed to modify the surface properties of jute fibres. The resulting bio-composites showed an increase in flexural properties and interlaminar shear strength (ILSS) compared to composites produced using untreated jute fibres. To understand the reason behind the ILSS improvement, the acid–base properties of jute fibres were determined by contact angle analysis using the capillary rise method. The results were fitted further to van Oss–Chaudhury–Good (vOCG) and Chang–Qin–Chen (CQC) models to determine the Lifshitz–van der Waals (LW) and acid–base components of surface energy. Surface energy determined by the vOCG model revealed that plasma treatment of jute fibre resulted in a 22% increase in total surface energy, a 19% increase in the LW component and a 24% increase in the acid–base component of surface energy. The increase in the acid–base component is due to the significant increase (69%) in the electron-accepting (γ+S) parameter. On the other hand, the CQC model clearly indicates an amphoteric nature of the fibre surface based on opposite signs of the acid and base principal values (PSa and PSb). Overall, the results indicated that increases in both LW and acid–base components were responsible for improvement in the properties of the composites.

Performance modelling of speculative prefetching for compound requests in low bandwidth networks

To improve the accuracy of access prediction, a prefetcher for web browsing should recognize the fact that a web page is a compound. By this term we mean that a user request for a single web page may require the retrieval of several multimedia items. Our prediction algorithm builds an access graph that captures the dynamics of web navigation rather than merely attaching probabilities to hypertext structure. When it comes to making prefetch decisions, most previous studies in speculative prefetching resort to simple heuristics, such as prefetching an item with access probabilities larger than a manually tuned threshold. The paper takes a different approach. Specifically, it models the performance of the prefetcher and develops a prefetch policy based on a theoretical analysis of the model. In the analysis, we derive a formula for the expected improvement in access time when prefetch is performed in anticipation for a compound request. We then develop an algorithm that integrates prefetch and cache replacement decisions so as to maximize this improvement. We present experimental results to demonstrate the effectiveness of compound-based prefetching in low bandwidth networks.

A performance model of speculative prefetching in distributed information systems

Previous studies in speculative prefetching focus on building and evaluating access models for the purpose of access prediction. This paper investigates a complementary area which has been largely ignored, that of performance modelling. We use improvement in access time as the performance metric, for which we derive a formula in terms of resource parameters (time available and time required for prefetching) and speculative parameters (probabilities for next access). The performance maximization problem is expressed as a stretch knapsack problem. We develop an algorithm to maximize the improvement in access time by solving the stretch knapsack problem, using theoretically proven apparatus to reduce the search space. Integration between speculative prefetching and caching is also investigated, albeit under the assumption of equal item sizes.

The performance of a student evaluation of teaching system

Student evaluation of teaching (SET) is now commonplace in many universities internationally. While much effort has been devoted to examining the statistical validity of SET instruments, there has been limited examination of the methodological and consequential validity (together referred to as ‘utility’) of the ways in which SET data are used. This paper examines the SET system at Deakin University from the perspective of utility. It draws on publicly available SET results for an entire annual cycle of unit offerings. Consideration is given to the representativeness of the data produced, and to the utility of the data reported, by the system. While this investigation focuses on the SET system currently employed at Deakin University, it offers both an analysis methodology and conclusions that can be applied more generally.

Strategies for improving the thermal performance and comfort levels of a kindergarten in the mountains of Nepal

Located on the Annapurna trekking trail in Nepal, Siurung is a remote mountain village where outside influences are almost non-existent. The thermal comfort levels of a recently-constructed kindergarten are well below international standards because of the climate and poor building envelope. A TRNSYS model of the kindergarten has been used to predict the current occupant comfort levels and subsequently determine the most effective way to alter the traditional construction methods to improve comfort levels. Improvements investigated were: reduced air infiltration, roof and wall insulation (separately and together), installation of a smokeless stove and a combination of all strategies.The model predicted that in the current building the PMV ranges from -1.94 in October to - 0.99 in July. It also predicted that the current PPD (%) ranges from 100 in January to 26 in July. With the combination of strategies, the predicted PMV values were all improved to between -1.08 and +0.34, and the PPD values of all months except January were reduced to below 10%. When improving the comfort levels of an existing school, reducing air infiltration, adding roof insulation and installing a smokeless stove are the most effective strategies. When constructing a new school, however, reducing air infiltration and adding insulation to the walls and roof are the most effective and feasible strategies. If a smokeless stove can be afforded and transported to the site, it is recommended that one be installed as it provides a more significant improvement than any other single strategy.

Counterfactual thinking and anticipated emotions enhance performance in computer skills training

The present study examined the relationship between novice learners’ counterfactual thinking (i.e. generating ‘what if’ and ‘if only’ thoughts) about their initial training experience with a computer application and subsequent improvement in task performance. The role of anticipated emotions towards goal attainment in task performance was also assessed. Undergraduate students (N ¼ 42) with minimal experience in using computer spreadsheets underwent basic training in using Microsoft Excel. All participants were assessed on their anticipated positive and negative emotions regarding goal attainment at the outset. After completing their first task, participants allocated to a counterfactual condition received instructions to generate counterfactual thoughts regarding their initial task performance, whereas participants in a control condition did not. The counterfactual group showed only marginally greater improvement in task performance (measured by task completion time and accuracy) than the control group.  However, we also found that positive anticipated emotions were associated with improvement in task performance but for the counterfactual group only. Our data have implications for incorporating counterfactual thinking into information technology skills training to enhance learning outcomes for novice learners.

Improving peak shapes with counter gradients in two-dimensional high performance liquid chromatography

To achieve the greatest peak capacity in two-dimensional high performance liquid chromatography (2D-HPLC) a gradient should be operated in both separation dimensions. However, it is known that when an injection solvent that is stronger than the initial mobile phase composition is deleterious to peak performance, thus causing problems when cutting a portion from one gradient into another. This was overcome when coupling hydrophilic interaction with reversed phase chromatography by introducing a counter gradient that changed the solvent strength of the second dimension injection. It was found that an injection solvent composition of 20% acetonitrile in water gave acceptable results in one-dimensional simulations with an initial composition of 5% acetonitrile. When this was transferred to a 2D-HPLC separation of standards it was found that a marked improvement in peak shape was gained for the moderately retained analytes (phenol and dimethyl phthalate), some improvement for the weakly retained caffeine and very little change for the strongly retained n-propylbenzene and anthracene which already displayed good chromatographic profiles. This effect was transferred when applied to a 2D-HPLC separation of a coffee extract where the indecipherable retention profile was transformed to a successful application multidimensional chromatography with peaks occupying 71% of the separation space according to the geometric approach to factor analysis.