Mechanical properties and blow forming of rolled AZ31 Mg alloy sheet

Rolling was conducted at 373-673 K for AZ31 Mg alloy; mechanical properties of the rolled Mg alloy were investigated by tensile and blow forming tests. The grain sizes of all the rolled specimens were smaller than that of the specimen prior to rolling. At tensile temperatures under 373 K, the rolled specimens showed much higher 0.2% proof stresses than the non-rolled specimens due to their fine-grained microstructure. However, the strength of the rolled specimens decreased significantly at 473 K. Superplastic behavior was obtained at 573-723 K for the specimens rolled at 498 K. Blow forming tests demonstrated that specimens rolled at 498 K exhibited a high degree of formability at 723 K.

Developing english skills through reflective portfolios in Hong Kong universities

This research concerns the use of portfolios by teachers of English (L2) to assist non-native speakers in Hong Kong universities to complete their studies in English. Portfolios as an English learning tool have yet to win converts from the ranks of language teachers in Hong Kong chiefly because of concerns about reliability and fairness. Two recent initiatives in Hong Kong have, however, prompted a reappraisal of the place of portfolios in English language learning. They include the use of learning portfolios in secondary school and ePortfolios by university students for learning and employment purposes.

As an English (L2) teacher of many years, I initiated my research to investigate the experiences of seven university students in Hong Kong in using reflective portfolios for English learning. Three research questions framed my research: 1) in what ways can reflective portfolios impact on L2 learning strategies? 2) what are the effects of reflective portfolios on progress in L2 acquisition as perceived by students? 3) what are the perceptions of university students towards reflective portfolios as a method of L2 learning?

To gain a holistic understanding of the complex phenomena under scrutiny, a case study methodology and grounded theory were utilised, the former to organise and generate qualitative data, and the latter to analyse data from three sources provided by the seven participating students: semi-structured interviews, portfolio artefacts, and weekly learning diaries.

There were two levels of data analysis. For the first level, analysis focused on coded data from portfolio artefacts, diary entries and interview transcripts as reported by students. The second level involved analysis from the Confucian and sociocultural perspectives. I pursued interpretation and continuous refinement of the data by using techniques drawn from grounded theory. The findings revealed that students generally employed a wide spread of L2 learning strategies in the cognitive, meta-cognitive, and socio-affective domain, reported increased awareness of effective language strategies, and considered portfolios a means of supporting time management and record-keeping, and a site for extended writing practice through reflection.

The findings suggest that students display a cyclical, context-specific shift in learning conception from quantitative to qualitative. Connected to this is students’ apparent ability to formulate strategic responses to externally imposed demands. It is found that such responses are culturally triggered, underpinned by Confucian beliefs. Although the Confucian tradition emphasises respect for established authority, the findings point to students’ creative re-configuration of mental schemata to engender change in role enactment and power relations, with the portfolio as a mediating tool of their experiences.

Based on the findings, I argue that my research has addressed the three research questions and contributed to two crucial aspects of L2 learning. The first pertains to the need for a balanced view of individual effort and social context in second language acquisition, corroborating the significant link between context and learner engagement. Another contribution centres on an enhanced understanding of the relationship between portfolios, reflection and L2, where students’ diaries in English and portfolio artefacts enable them to engage in critical reflection and to identify strategies for L2 improvement.

Evaluation of three remote camera systems for detecting mammals and birds

Automated camera systems have widespread application in wildlife studies and their use is increasing (Kucera & Barrett 1993; Cutler & Swann 1999; Swann et al. 2004; Parker et al. 2008). Among other applications, they have been used to produce species inventories, estimate population sizes, study behaviour and examine the impact and activity of predators (Cutler & Swann 1999; Swann et al. 2004). Modern camera systems can operate for extended durations, are relatively non-invasive, easy to operate, portable, durable and can take good-quality images by day and night (Kucera & Barrett 1993; Peterson & Thomas 1998; Allison & Destefano 2006; Parker et al. 2008). Beyond their scientific applications, the generation of high-quality images can be useful for educational and conservation purposes (Cutler & Swann 1999). The two most common types of systems currently used in ecological research are passive and active infrared (IR) systems (Cutler & Swann 1999; Parker et al. 2008). An older form of remote photography is video which captures a continuous record of activity at a focal site (Stewart et al.1997; King et al. 2001). Camera systems have certain limitations and biases (Swann et al. 2004), yet these have not been well studied. Refinement of the use of camera systems is required to fully realize their value (Towerton et al. 2008). Here, we describe a comparison of detection rates of mammals and birds by passive and active IR camera systems, using a video system to benchmark detection rates.

Advice on assessing large classes

After a decade of rapid expansion in Australian higher education, student numbers have grown considerably in many courses and subjects, especially at the undergraduate level.
Larger class sizes pose significant teaching challenges, not least in the assessment of student learning. Perhaps most troubling, large classes may limit the amount of feedback provided to students.
In response to the pressures and challenges of assessing larger groups of students, academic staff are responding through:
• greater attention to the communication of clear assessment criteria to students;
• the development and use of marking guides to be used by teaching and assessing teams;
• the increasing use of various forms of exemplars to guide student efforts — as well as to guide marking and grading — including the modelling of discipline-based thinking, writing and performance; and
• the continuous refinement and dissemination of assessment policy and practice in relation to large student groups.
The issue of workload is central in any decisions about assessment of large classes for it is a serious one for students and staff alike. Staff teaching large student groups invariably undertake an informal, qualitative weighing-up of the efficiency of assessment tasks vis-à-vis their educational effectiveness.
There is little doubt that establishing an effective assessment program — developing criteria, guides, exemplars and models; discussing and refining them and communicating them to students and other staff — will have an initial negative impact on workload for staff with coordinating responsibilities.
However, this preparatory work is likely to lead to three gains. The first is a reduction in the time required for marking due to a higher quality of student submission. The second is a resolution of some of the potential issues likely when many staff are involved in marking and grading, through a streamlining of marking and grading practices. Finally, the availability of clear, transparent criteria and examples of work will contribute positively to the overall quality of teaching and learning.

Abstracting by constructing and revising a ‘partially correct construct’ : a case study

This study draws on data from a broader video-stimulated interview study of the role of optimism in collaborative problem solving. It examines the activity of a Grade 5 student, Tom, whose initial constructing activity resulted in a ‘Partially Correct Construct’. Insistent questioning from another group member pressuring for clarification led to Tom developing a ‘more correct construct’ with further potential for revision. This paper raises questions about influences that can stimulate or inhibit construct refinement.

Teacher change in exploring representational approaches to learning science

The researcher worked closely with two biology-trained teachers to plan three teaching sequences in the topics of forces, substances and astronomy that were subsequently taught to Year 7 students. The sequences sought to develop a model of classroom practice that foregrounds students’ negotiation of conceptual representations.

The difficulties encountered by individuals in learning science point to the need for a very strong emphasis of the role of representations in learning. There is a need for learners to use their own representational, cultural and cognitive resources to engage with the subject-specific representational practices of science. Researchers who have undertaken classroom studies whereby students have constructed and used their own representations have pointed to several principles in the planning, execution and assessment of student learning (diSessa, 2004; Greeno & Hall, 1997). A key principle is that teachers need to identify big ideas, key concepts, of the topic at the planning stage in order to guide refinement of representational work. These researchers also point out the need for students to engage with multiple representations in different modes that are both teacher and student generated. A representation can only partially explain a particular phenomenon or process and has both positive and negative attributes to the target that it represents. The issue of the partial nature of representations needs to be a component of classroom practice (Greeno & Hall, 1997) in terms of students critiquing representations for their limitations and affordances and explicitly linking multiple representations to construct a fuller understanding of the phenomenon or process under study. The classroom practice should also provide opportunities for students to manipulate representations as reasoning tools (Cox, 1999) in constructing the scientifically acceptable ideas and communicating them.

Research question: What impact was there on the participating teacher’s practice through the adoption of a representational focus to teaching science?

Data collection included video sequences of classroom practice and student responses, student work, field notes, tape records of meetings and discussions, and student and teacher interviews based in some cases on video stimulated recall. Video analysis software was used to capture the variety of representations used, and sequences of representational negotiation.

The teachers in this study reported substantial shifts in their classroom practices, and in the quality of classroom discussions, arising from adopting a representational focus. The shifts were reported by them as a three-fold challenge. First, there was an epistemological challenge as they came to terms with the culturally produced nature of representations in the topics of force, substance and astronomy and their flexibility and power as tools for analysis and communication, as opposed to their previous assumption that this was given knowledge to be learnt as an end point. The second challenge was pedagogical, in that this approach was acknowledged to place much greater agency in the hands of students, and this brought a need to learn to run longer and more structured discussions around conceptual problems. The third challenge related to content coverage. The teachers sacrificed coverage for the greater depth offered by this approach, and were unanimous in their judgment that this had been a change that had paid dividends in terms of student learning.

n-3 Polyunsaturated fatty acid-rich vegetable oils and blends

α-Linseed, camelina. perilla, and echium oils are n-3 C₁₈ polyunsaturated fatty acid (PUFA)-rich vegetable oil sources viewed as favorable replacements to fish oil in aquaculture feed (aquafeed) production in consideration of their high (α-linolenic acid (ALA, 18:3n-3) and/or stearidonic acid (SDA, 18:4n-3) contents and potential for subsequent bioconversion to n-3 long-chain polyunsaturated fatty acids (LC-PUFA) in farmed aquatic species. While the total production of these oils is currently low in comparison with that of other terrestrial oil sources, their distinct fatty acid composition and high n-3 to n-6 ratio deliver a unique substitute to fish oil in aquafeeds, presently unparalleled in other alternative terrestrial oil sources. The dietary inclusion of these oil sources has therefore attracted significant research attention, resulting in a multitude of investigations across a broad range of aquatic species (finfish and crustaceans). Generally, providing that the essential fatty acid (EFA) requirements of the species under investigation were met and an adequate level of fish meal was present in the diet, it was found possible to replace 100% and 60-70% of the dietary fish oil component for freshwater and marine species, respectively, with minimal impact on growth performance indices. However, the substitution of fish oil with n-3-rich vegetable oils and/or vegetable oil blends resulted in substantially reduced concentrations of health-promoting eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) in the edible portion of the farmed species. This chapter provides an overview of the use of n-3 PUFA-rich vegetable oils and/or vegetable oil blends for use in aquafeeds. In particular, key aspects of oil production, processing, and refinement will be presented, and individual differences pertaining to the physical, chemical, and nutritional characteristics of the oil types will be highlighted. Following on from this, a summary of the key findings relevant to n-3 PUFA-rich vegetable oil inclusion in aquafeeds will be discussed, with particular emphasis placed on growth performance and nutritional modification.

Journeying on the frinj of outdoor education

In this chapter we offer a conceptualisation of the construction of the pedagogical relationship between people and place. This conceptualisation considers pedagogical experiences that might prompt students to think differently about relations between people and places of learnng often utilised within outdoor education. We see ourselves as journeying on the fiinj of outdoor education in so far as we are arguing for a reconceptualisation of what constitutes good 'pedagogical' practice within this field of inquiry. This observation is based on what we believe is a troubling perception that distinguishes between outdoor activities as a site for the refinement of practical knowledge, and the classroom as a space for the 'theoretical study of environmental history, ecology and the social studies of human-nature relationships' (Victorian Curriculum and Assessment Authority, 2005, p.1). Our objective is to argue for the value of a pedagogical approach that situates study of these rheoretical issues while journeying in the outdoors.

Microstructure and properties of a C-Mn steel subjected to heavy plastic deformation

In the present paper an effect of severe plastic deformation (SPD) on the microstructural evolution and properties of a plain C-Mn steel was investigated. The SPD was accomplished by the MaxStrain system which deforms material along two perpendicular axes while the deformation along the third axis is fully constrained. The applied amounts of true strains were 5 and 20 in total. Deformation was conducted at room and 500°C temperatures. Some samples deformed at room temperature were subsequently annealed at 500°C. A microstructural analysis by SEM/EBSD was used for recognition the low- and high-angle grain boundaries. It was found that the collective effect of severe plastic deformation (true strain of 20) and further annealing promotes the formation of high-angle grain boundaries and uniform fine grained microstructure. The refinement of ferrite microstructure results in a significant increase in strength and hardness.

Exploiting low levels of rare earth addition in Mg extrusion alloys

The present work examines the extrusion and mechanical properties of MExlOO alloys, which contain levels of rare earth alloying additions up to 0.4 wt%. It is shown that these alloys can display the high extrudability of alloy Ml with strengths nearing those of AZ31. Most importantly, the grades display high room temperature ductility; values of total tensile elongation as high as 30% have been observed. These benefits derive from a combination of grain refinement and texture weakening.

A conceptual framework of corporate and business ethics across organizations

Purpose – The objective of this paper is to introduce and describe a conceptual framework of corporate and business ethics across organizations in terms of ethical structures, ethical processes and ethical performance.

Design/methodology/approach – A framework is outlined and positioned incorporating an ethical frame of reference in the field of organizational chain management.

Findings – A number of areas and sub-areas of corporate and business ethics are framed in the context across organizations.

Research limitations/implications – The introduced framework should be seen as a seed for further development and refinement. It provides opportunities for further research of ethical concerns across organizations.

Practical implications – Organizations may benefit from the findings and insights presented and they may be used to enhance their ability to manage, monitor and evaluate ethical business practices across organizations.

Social implications – Changing societal and market patterns may enforce organizations to address ethical concerns across organizations. A myopic approach restricted to the judicial system may become insufficient and unsatisfactory from the perspective of other stakeholders of the organization.

Originality/value – The framework makes a contribution bringing in ethical concerns across organizations, providing a basis for their ethical values and culture, as well as asymmetric relationships in terms of power and dependence. The authors believe that a true learning organization needs to realise the importance of an extended view of its endeavors of corporate and business ethics in terms of ethical structures, ethical processes and ethical performance across organizations.

Lithium doped N,N-dimethyl pyrrolidinium tetrafluoroborate organic ionic plastic crystal electrolytes for solid state lithium batteries

The organic ionic plastic crystal material N,N-dimethyl pyrrolidinium tetrafluoroborate ([C1mpyr][BF4]) has been mixed with LiBF4 from 0 to 8 wt% and shown to exhibit enhanced ionic conductivity, especially in the higher temperature plastic crystal phases (phases II and I). The materials retain their solid state well above 100 °C with the melt not being observed up to 300 °C. Interestingly the conductivity enhancement is highest with the lowest level of LiBF4 addition in phase II, but then the order of enhancement is reversed in phase I. In all cases, a conductivity drop is observed at the II → I phase transition (105 °C) which is associated with increased order in the pure matrix, as previously reported, although the conductivity drop is least for the highest LiBF4 amount (8 wt%). The 8 wt% sample displays different conductivity behaviours compared to the lower LiBF4 concentrations, with a sharp increase above 50 °C, which is apparently not related to the formation of an amorphous phase, based on XRD data up to 120 °C. Symmetric cells, Li/OIPC/Li, were prepared and cycled at 50 °C and showed evidence of significant preconditioning with continued cycling, leading to a lower over-potential and a concomitant decrease in the cell resistivity as measured by EIS. An SEM investigation of the Li/OIPC interfaces before and after cycling suggested significant grain refinement was responsible for the decrease in cell resistance upon cycling, possibly as a result of an increased grain boundary phase.

Development and validation of the Diet Quality Tool for use in cardiovascular disease prevention settings

The aim of this study was to develop and evaluate a dietary screening tool for use in a secondary cardiovascular disease (CVD) prevention setting to identify an individual’s overall dietary quality. The Diet Quality Tool (DQT) was validated against a 4-day food diary for 37 individuals with established CVD attending cardiac rehabilitation. Construct validity was demonstrated for % energy from saturated fat (P = 0.002, r = –0.500), dietary fibre (P < 0.001, r = 0.559) and omega-3 fatty acids (P = 0.048, r = 0.327). Criterion validity was established with a significant difference found between mean (95% CI) dietary intakes of fibre (28.2 g, 4.4 to 17.3) and % total energy from saturated fat (10.6%, –4.8 to –0.8) for those with better DQT scores (>60%) versus those with poorer scores (≤60%) when compared with 4-day food diary nutrient values. The usefulness of the DQT was confirmed by both patients (n = 25) and cardiac rehabilitation health professionals (n = 8). The DQT was found to be a valid and useful dietary assessment tool with potential for use in a secondary CVD prevention setting. The tool has the capacity to be used in a wider variety of settings and further refinement of the tool would enable a greater amount of nutrients to be reliably screened.

Design of a valid simulation for researching physical, physiological and cognitive performance in volunteer firefighters during bushfire deployment.

Every year, Australian firefighters protect our nation from the devastation of bushfire. Understanding the impact of consecutive long shifts in hot, smoky conditions is essential for making decisions during campaign fires. At present, the evidence-base for such decisions is limited to laboratory studies with little relevance to bushfire suppression or field research where the impact of environmental and workload stressors cannot be measured. To counter these limitations, we have developed a three-day simulation that mimics the work and environment of campaign bushfire suppression. Construction of the simulation involved three stages; 1) data collection and analysis; 2) design and development; and 3) trial and refinement. The frequency, intensity, duration and type of physical work performed on the fireground is well documented and a modified applied cognitive task analysis, using experienced firefighters was used as a framework to describe in detail the non-physical aspects of the work. The design and development of the simulation incorporated the physical and non-physical aspects of the work into simulated tasks. Finally, experienced firefighters participated in trials of the simulation and reviewed digital recordings to ensure that the simulation accurately represented campaign bushfire suppression work. The outcome of this project is a valid, realistic, and reliable simulation of the physiological, physical and cognitive aspects of a volunteer firefighter on a three-day bushfire deployment.