Phase behavior and nanomechanical mapping of block ionomer complexes

Block ionomer complexes SSEBS-c-PCL were prepared, as a consequence of proton transfer from the sulfonic acid of sulfonated polystyrene-block- poly(ethylene-ran-butylene)-block-polystyrene (SSEBS) to the tertiary amine of a tertiary amine terminated poly(?-caprolactone) (APCL). The phase behavior of SSEBS-c-PCL was thoroughly investigated and the results showed that APCL in SSEBS-c-PCL displays unique crystallization behavior owing to the influence of interactions between the amine and sulfonic acid groups as well as the effects of confinement. Further, small-angle X-ray scattering study revealed that SSEBS-c-PCL displays a less ordered micro-phase structure compared to SSEBS. A quantitative mapping of mechanical properties at the nanoscale was achieved using peak force mode atomic force microscopy. It is found that the block ionomer complex possesses a higher average elastic modulus after complexation with crystallizable APCL. Additionally, the moduli for both hard and soft phases increase and the phase with higher modulus assignable to the hard SPS component shows much more pronounced changes after complexation, confirming that APCL interacts mainly with the SPS blocks. This provides an understanding of the composition and nanomechanical properties of these new block ionomer complexes and an alternative insight into the micro-phase structures of multi-phase materials.

Microstructure and hardness evolution during simulated coiling of a direct strip cast low carbon low niobium steel

This paper examines the impact of coiling temperature and duration on the phase transformation and precipitation behavior of a low carbon and low niobium direct strip cast steel. Coiling was performed at three carefully chosen temperatures: (1) in the ferrite (600°C), (2) during the austenite decomposition (700°C) and (3) in the austenite (850°C). The coiling conditions were found to strongly affect the final microstructure and hardness response, thus highlighting the necessity to judiciously design the coiling treatment. Optical microscopy, and scanning and transmission electron microscopy were used to characterize the microstructural constituents (polygonal ferrite, bainite and pearlite) and the NbC precipitates. Vickers macrohardness measurements are utilized to quantify the mechanical properties. The differences in hardening kinetics for the three different temperatures are shown to come from a complex combination of strengthening contributions.

Architecture of supramolecular soft functional materials: from understanding to micro-/nanoscale engineering

This article gives an overview of the current progress of a class of supramolecular soft materials consisting of fiber networks and the trapped liquid. After discussing the up-to-date knowledge on the types of fiber networks and the correlation to the rheological properties, the gelation mechanism turns out to be one of the key subjects for this review. In this concern, the following two aspects will be focused upon: the single fiber network formation and the multi-domain fiber network formation of this type of material. Concerning the fiber network formation, taking place via nucleation, and the nucleation-mediated growth and branching mechanism, the theoretical basis of crystallographic mismatch nucleation that governs fiber branching and formation of three-dimensional fiber networks is presented. In connection to the multi-domain fiber network formation, which is governed by the primary nucleation and the subsequent formation of single fiber networks from nucleation centers, the control of the primary nucleation rate will be considered. Based on the understanding on the the gelation mechanism, the engineering strategies of soft functional materials of this type will be systematically discussed. These include the control of the nucleation and branching-controlled fiber network formation in terms of tuning the thermodynamic driving force of the gelling system and introducing suitable additives, as well as introducing ultrasound. Finally, a summary and the outlook of future research on the basis of the nucleation-growth-controlled fiber network formation are given.

Comparative evaluation of PBL and traditional lecturebased teaching in undergraduate engineering courses : evidence from controlled learning environment

Project and problem-based learning (PBL) has been widely recognised as an active, collaborative, cumulative and integrative learning approach that engages learners, motivates team creativity and centres on practical education. On the other hand, traditional lecture-tutorial teaching is often criticised for being a passive, surface learning and exam-focused approach. In spite of these evidence-based observations and claims over the years, the traditional lecture-tutorial teaching approach still dominates as the preferred teaching approach at Australian universities. This study sets up a control environment to compare these two teaching and learning approaches by analysing data from students' actual performance, course evaluation and expectation in two large undergraduate engineering courses in 2009 and 2010. The evidence reported in this study is broadly interesting in that both courses were taught by the same teaching staff using two entirely different learning and teaching approaches to the same cohort of students in the same semester within the same degree program. The analysis shows that there are significant differences between the students' actual performance, course evaluation and their expectation. Such conflicting differences may be some of the reasons that may negatively impact teaching staff deterring them from switching to PBL from traditional lecture-tutorial teaching.

Providing a practical education for off-campus engineering students

This paper considers the provision of laboratory-practicals for distance-education students in engineering degree programmes. The authors discuss the role of laboratory-practical work in the curriculum and reflect on five methods that can be used to ensure off-campus students have an equivalent practical experience as the traditional on-campus cohort. On-campus sessions, videotapes (or ‘on-line’ movie-clips), computer simulations, home experiment kits and laboratories controlled over the internet are covered. Some examples are given to show how these can be incorporated into the curriculum. A case study then discusses the problem of (and an exemplar solution to) delivering the laboratory-practical components of two microcontroller units offered at Deakin University – a leading provider of distance-education in Australia. In doing so, it leads the reader through the solution process and cites some constraints that drive the choice of model - for example, cost considerations and the need for relevant didactic materials.

Ontological engineering for conceptual modeling

In acknowledging the importance of ontologies in conceptual modeling, database integration and business process modeling, this paper introduces a set of principles for building ontologies. Starting from Guarino's meta-properties of ontological terms, the paper describes the denotational semantics of the meta-properties and derives from them some engineering rules and checks for constructing domain specific conceptual models, based on the overarching requirement to assign meanings to concepts using tags and labels. Parallel research by the authors into the use of contextual references and roles to restrict such meanings will be published elsewhere.

Requirements engineering during global software development : some impediments to the requirements engineering process : a case study

Requirements engineering is not straightforward for any software development team. Developing software when team members are located in widely distributed geographic locations poses many challenges for developers, particularly during the requirements engineering phase. This paper reports on a case study concerning a large software development project that was completed in just seven months between users located in the UK and software developers from an international software house based in New Zealand. The case indicates that while “true” global requirements engineering may be desirable in achieving economy of resources, a “hybrid” structure of requirements engineering processes is more realistic so that lasting relationships with clients may be formed, and requirements engineering activities achieved. The main impediment to the process of requirements engineering during global software development, as recounted by the team members in this case, is communication. Communication issues may be further described in terms of four categories: distribution of the clients and the development team, distribution of the development team, cultural differences between the clients and the development team and cultural differences among the development team.

Targeted clinical education for staff attitudes towards deliberate self-harm in borderline personality disorder : randomized controlled trial

Objective: The aim of the present study was to assess the impact of attending targeted clinical education on borderline personality disorder on the attitudes of health clinicians towards working with deliberate self-harm behaviours commonly exhibited by patients diagnosed with this complex disorder. Comparisons of clinicians across service settings, occupational fields, and other demographic areas were also made.

Method: A purpose-designed demographic questionnaire and the Attitudes Towards Deliberate Self-Harm Questionnaire were used to collect the demographic information and assess the attitudes of 99 mental health and emergency medicine practitioners across two Australian health services and a New Zealand health service, both before and after education attendance.

Results: Statistically significant improvements in attitude ratings were found for both emergency medicine clinicians and mental health clinicians in working with deliberate self-harm behaviours in borderline personality disorder, following attendance at the education program with a medium affect size (t(32)=−3.45, p=0.002, d=0.43 and t(65)=−5.12, p=0.000, d=0.42, respectively). Clinicians across occupational areas of nursing, allied health, and medical fields demonstrated equivocal levels of improvement in their attitude ratings.

Conclusions: Results are discussed in terms of the necessity of providing regular access to targeted clinical education for health professionals working with patients diagnosed with borderline personality disorder.

The learning outcomes of an online reflective journal in engineering

Reflective thinking based on experiential learning is a key skill required for the lifelong learner and the socially mature professional. Following several semesters employing a written reflective journal as an assessable task, a fourth-year engineering management unit adopted an online reflective journal. During the initial semester of use, an evaluation was undertaken to investigate student perceptions of the online journal. A summary of this previous work is presented here. Following three semesters of use of the online journal, an analysis of the student use of the journal was undertaken to investigate its contribution to unit learning outcomes. Based on the evaluation of student perceptions of the online reflective journal, it was found that a majority of students understood the purpose of the journal, and valued the journal in their learning; a majority of students read the journal entries of other students, and indicated that this assisted their learning; and the two most frequently reported ‘most useful’ aspects of the journal were the ‘enforced’ continuous revision of course material, and the ability to compare their understanding of the course material with that of other students. Based on a regression analysis of the factors related to student usage of the online reflective journal, it was found that the significant contributors to final unit mark where: prior academic performance; number of journal postings; and mode of study. This research confirmed that the online reflective journal was fertile territory in the landscape of educational technology, both in terms of student perceptions and contribution to unit learning outcomes.

Adolescents' use of purpose built shade in secondary schools : cluster randomised controlled trial

Objective To examine whether students use or avoid newly shaded areas created by shade sails installed at schools.

Design Cluster randomised controlled trial with secondary schools as the unit of randomisation.

Setting 51 secondary schools with limited available shade, in Australia, assessed over two spring and summer terms.

Participants Students outside at lunch times.

Intervention Purpose built shade sails were installed in winter 2005 at full sun study sites to increase available shade for students in the school grounds.

Main outcome measure Mean number of students using the primary study sites during weekly observations at lunch time.

Results Over the study period the mean change in students using the primary study site from pre-test to post-test was 2.63 (95% confidence interval 0.87 to 4.39) students in intervention schools and –0.03 (–1.16 to 1.09) students in control schools. The difference in mean change between groups was 2.67 (0.65 to 4.68) students (P=0.011).

Conclusions Students used rather than avoided newly shaded areas provided by purpose built shade sails at secondary schools in this trial, suggesting a practical means of reducing adolescents’ exposure to ultraviolet radiation.

Trial registration Exempt.

Inter-bonded fibrous matrices for 3D tissue engineering scaffolds

The thesis established a stable three-dimensional fibrous tissue scaffold that has controlled pore structure and inter-bonded fibrous structure, and also examined the effects of the 3D fibrous matrices and functional surfaces including nano-scale topography, bioactive CaP coating and antibacterial treatment on the cell growth behavior for tissue engineering application.

Inter-bonded fibrous matrics for 3D tissue engineering scaffolds

This thesis established a stable three-dimensional fibrous tissue scaffold that has controlled pore structure and inter-bonded fibrous structure, and also examined the effects of the 3D fibrous matrices and functional surfaces including nano-scale topography, bioactive CaP coating and antibacterial treatment on the cell growth begaviour for tissue engineering application.

Efficacy of a referral and physical activity program for survivors of prostate cancer [ENGAGE] : rationale and design for a cluster randomised controlled trial

Background: Despite evidence that physical activity improves the health and well-being of prostate cancer survivors, many men do not engage in sufficient levels of activity. The primary aim of this study (ENGAGE) is to determine the efficacy of a referral and physical activity program among survivors of prostate cancer, in terms of increasing participation in physical activity. Secondary aims are to determine the effects of the physical activity program on psychological well-being, quality of life and objective physical functioning. The influence of individual and environmental mediators on participation in physical activity will also be determined.
Methods/Design: This study is a cluster randomised controlled trial. Clinicians of prostate cancer survivors will be randomised into either the intervention or control condition. Clinicians in the intervention condition will refer eligible patients (n = 110) to participate in an exercise program, comprising 12 weeks of supervised exercise sessions and unsupervised physical activity. Clinicians allocated to the control condition will provide usual care to eligible patients (n = 110), which does not involve the recommendation of the physical activity program. Participants will be assessed at baseline, 12 weeks, 6 months, and 12 months on physical activity, quality of life, anxiety, depression, self-efficacy, outcome expectations, goals, and socio-structural factors.
Discussion: The findings of this study have implications for clinicians and patients with different cancer types or other chronic health conditions. It will contribute to our understanding on the potential impact of clinicians promoting physical activity to patients and the long term health benefits of participating in physical activity programs.

Modern enhancements in teaching design theories to mechanical engineering students

This paper describes the application of computer aided design (CAD) in teaching advanced design methodologies to fourth-year undergraduate students majoring in mechanical engineering. This involves modern enhancements in teaching strategies for subjects such as design-for-X (DFx) and failure mode effect analysis (FMEA) concepts, which are traditionally categorised as advanced design methodologies. The main subsets of DFx including design-for-assembly (DFA), design-for-disassembly (DFD), design-for-manufacturing (DFM), design-for-environment (DFE) and design-for-recyclability (DFR) were covered by studying various engineering and consumer products. The unit was designed as a combination of practical hands-on workshop-based classes along with a software-based evaluation of different products. In addition to CAD, finite element modelling techniques were utilised to enhance the students’ understanding of design faults and failures. The inquiry into teaching practice and design of this fourth-year unit was carried out during past two years and it revealed some interesting outcomes from our teaching practice in terms of students’ learning experiences. Finally, the paper discusses some critical factors in the context of teaching advanced design methodologies to the undergraduates in mechanical engineering and even manufacturing engineering.

Engineering a multimodal nerve conduit for repair of injured peripheral nerve

Injury to nerve tissue in the peripheral nervous system (PNS) results in long-term impairment of limb function, dysaesthesia and pain, often with associated psychological effects. Whilst minor injuries can be left to regenerate without intervention and short gaps up to 2 cm can be sutured, larger or more severe injuries commonly require autogenous nerve grafts harvested from elsewhere in the body (usually sensory nerves). Functional recovery is often suboptimal and associated with loss of sensation from the tissue innervated by the harvested nerve. The challenges that persist with nerve repair have resulted in development of nerve guides or conduits from non-neural biological tissues and various polymers to improve the prognosis for the repair of damaged nerves in the PNS. This study describes the design and fabrication of a multimodal controlled pore size nerve regeneration conduit using polylactic acid (PLA) and (PLA):poly(lactic-co-glycolic) acid (PLGA) fibers within a neurotrophin-enriched alginate hydrogel. The nerve repair conduit design consists of two types of PLGA fibers selected specifically for promotion of axonal outgrowth and Schwann cell growth (75:25 for axons; 85:15 for Schwann cells). These aligned fibers are contained within the lumen of a knitted PLA sheath coated with electrospun PLA nanofibers to control pore size. The PLGA guidance fibers within the nerve repair conduit lumen are supported within an alginate hydrogel impregnated with neurotrophic factors (NT-3 or BDNF with LIF, SMDF and MGF-1) to provide neuroprotection, stimulation of axonal growth and Schwann cell migration. The conduit was used to promote repair of transected sciatic nerve in rats over a period of 4 weeks. Over this period, it was observed that over-grooming and self-mutilation (autotomy) of the limb implanted with the conduit was significantly reduced in rats implanted with the full-configuration conduit compared to rats implanted with conduits containing only an alginate hydrogel. This indicates return of some feeling to the limb via the fully-configured conduit. Immunohistochemical analysis of the implanted conduits removed from the rats after the four-week implantation period confirmed the presence of myelinated axons within the conduit and distal to the site of implantation, further supporting that the conduit promoted nerve repair over this period of time. This study describes the design considerations and fabrication of a novel multicomponent, multimodal bio-engineered synthetic conduit for peripheral nerve repair.