Selection and optimization of piezoelectric polyvinylidene fluoride polymers for adaptive optics in space environments

Various piezoelectric polymers based on polyvinylidene fluoride (PVDF) are of interest for large aperture space-based telescopes. Dimensional adjustments of adaptive polymer films depend on charge deposition and require a detailed understanding of the piezoelectric material responses which are expected to deteriorate owing to strong vacuum UV, � -, X-ray, energetic particles and atomic oxygen exposure. We have investigated the degradation of PVDF and its copolymers under various stress environments detrimental to reliable operation in space. Initial radiation aging studies have shown complex material changes with lowered Curie temperatures, complex material changes with lowered melting points, morphological transformations and significant crosslinking, but little influence on piezoelectric d33 constants. Complex aging processes have also been observed in accelerated temperature environments inducing annealing phenomena and cyclic stresses. The results suggest that poling and chain orientation are negatively affected by radiation and temperature exposure. A framework for dealing with these complex material qualification issues and overall system survivability predictions in low earth orbit conditions has been established. It allows for improved material selection, feedback for manufacturing and processing, material optimization/stabilization strategies and provides guidance on any alternative materials.

Effect of simulated space environments on piezoelectric vinylidene flouride-based polymers

Piezoelectric polymers based on polyvinylidene flouride (PVDF) are of interest as adaptive materials for large aperture space-based telescopes. In this study, two piezoelectric polymers, PVDF and P(VDF-TrFE), were exposed to conditions simulating the thermal, radiative and atomic oxygen conditions of low Earth orbit. The degradation pathways were governed by a combination of chemical and physical degradation processes with the molecular changes primarily induced via radiative damage, and physical damage from temperature and atomic oxygen exposure, as evident from depoling, loss of orientation and surface erosion. The piezoelectric responsiveness of each polymer was strongly dependent on exposure temperature. Radiation and atomic oxygen exposure caused physical and chemical degradation, which would ultimately cause terminal damage of thin films, but did not adversely affect the piezoelectric properties.

Struggles Over Difference: Curriculum, texts and pedagogy in the Asia-Pacific

Struggles over Difference addresses education, schools, textbooks, and pedagogies in various countries of the Asia-Pacific, offering critical curriculum studies and policy analyses of national and regional educational systems. These systems face challenges linked to new economic formations, cultural globalization, and emergent regional and international geopolitical instabilities and conflicts. Contributors offer insights on how official knowledge, text, discourse and discipline should be shaped; who should shape it; through which institutional agencies it should be administered: and social and cultural practices through which this should occur.

Best practices in prediction for decision-making : lessons from the atmospheric and earth sciences

Predictions that result from scientific research hold great appeal for decision-makers who are grappling with complex and controversial environmental issues, by promising to enhance their ability to determine a need for and outcomes of alternative decisions. A problem exists in that decision-makers and scientists in the public and private sectors solicit, produce, and use such predictions with little understanding of their accuracy or utility, and often without systematic evaluation or mechanisms of accountability. In order to contribute to a more effective role for ecological science in support of decision-making, this paper discusses three ``best practices'' for quantitative ecosystem modeling and prediction gleaned from research on modeling, prediction, and decision-making in the atmospheric and earth sciences. The lessons are distilled from a series of case studies and placed into the specific context of examples from ecological science.

A framework for strategic infrastructure asset management

The concept of asset management is not a new but an evolving idea that has been attracting attention of many organisations operating and/or owning some kind of infrastructure assets. The term asset management have been used widely with fundamental differences in interpretation and usage. Regardless of the context of the usage of the term, asset management implies the process of optimising return by scrutinising performance and making key strategic decisions throughout all phases of an assets lifecycle (Sarfi and Tao, 2004). Hence, asset management is a philosophy and discipline through which organisations are enabled to more effectively deploy their resources to provide higher levels of customer service and reliability while balancing financial objectives. In Australia, asset management made its way into the public works in 1993 when the Australian Accounting Standard Board issued the Australian Accounting Standard 27 – AAS27. Standard AAS27 required government agencies to capitalise and depreciate assets rather than expense them against earnings. This development has indirectly forced organisations managing infrastructure assets to consider the useful life and cost effectiveness of asset investments. The Australian State Treasuries and the Australian National Audit Office was the first organisation to formalise the concepts and principles of asset management in Australia in which they defined asset management as “ a systematic, structured process covering the whole life of an asset”(Australian National Audit Office, 1996). This initiative led other Government bodies and industry sectors to develop, refine and apply the concept of asset management in the management of their respective infrastructure assets. Hence, it can be argued that the concept of asset management has emerged as a separate and recognised field of management during the late 1990s. In comparison to other disciplines such as construction, facilities, maintenance, project management, economics, finance, to name a few, asset management is a relatively new discipline and is clearly a contemporary topic. The primary contributors to the literature in asset management are largely government organisations and industry practitioners. These contributions take the form of guidelines and reports on the best practice of asset management. More recently, some of these best practices have been made to become a standard such as the PAS 55 (IAM, 2004, IAM, 2008b) in UK. As such, current literature in this field tends to lack well-grounded theories. To-date, while receiving relatively more interest and attention from empirical researchers, the advancement of this field, particularly in terms of the volume of academic and theoretical development is at best moderate. A plausible reason for the lack of advancement is that many researchers and practitioners are still unaware of, or unimpressed by, the contribution that asset management can make to the performance of infrastructure asset. This paper seeks to explore the practices of organisations that manage infrastructure assets to develop a framework of strategic infrastructure asset management processes. It will begin by examining the development of asset management. This is followed by the discussion on the method to be adopted for this paper. Next, is the discussion of the result form case studies. It first describes the goals of infrastructure asset management and how they can support the broader business goals. Following this, a set of core processes that can support the achievement of business goals are provided. These core processes are synthesised based on the practices of asset managers in the case study organisations.

Kaolinite platelet orientation for XRD and AFM applications

The structure-building phenomena within clay aggregates are governed by forces acting between clay particles. The nature of such forces is important to understand in order to manipulate the aggregate structure for applications such as settling and dewatering. A parallel particle orientation is required when conducting force measurements acting between the basal planes of clay mineral platelets using atomic force microscopy (AFM). In order to prepare a film of clay particles with the optimal orientation for conducting AFM measurements, the influences of particle concentration in suspension, suspension pH and particle size on the clay platelet orientation were investigated using scanning electron microscopy (SEM) and X-ray diffraction (XRD) methods. From these investigations, we conclude that high clay (dry mass) concentrations and larger particle diameters (up to 5 µm) in suspension result in random orientation of platelets on the substrate. The best possible laminar orientation in the clay dried film as represented in the XRD by the 001/020 intensity ratio of more than 150 and by SE micrograph assessments, was obtained by drying thin layers from 0.2 wt% of -5 µm clay suspensions at pH 10.5. These dried films are stable and suitable for close-approach AFM studies in solution.

Impacts and adaptation response of infrastructure and communities to heatwaves : the southern Australian experience of 2009

From 27 January to 8 February during the summer of 2009, southern Australia experienced one of the nation‘s most severe heatwaves. Governments, councils, utilities, hospitals and emergency response organisations and the community were largely underprepared for an extreme event of this magnitude. This case study targets the experience and challenges faced by decision makers and policy makers and focuses on the major metropolitan areas affected by the heatwave — Melbourne and Adelaide. The study examines the 2009 heatwave‘s characteristics; its impacts (on human health, infrastructure and human services); the degree of adaptive capacity (vulnerability and resilience) of various sectors, communities and individuals; and the reactive responses of government and emergency and associated services and their effectiveness. Barriers and challenges to adaptation and increasing resilience are also identified and further areas for research are suggested. This study does not include details of the heatwave‘s effects beyond Victoria and South Australia, or its economic impacts, or of Victoria‘s 'Black Saturday‘ bushfires.

Bushfire sustainability : Strategies for reconciling bushfire and biodiversity with daily life

This exhibition and catalogue provides a visual record of student work exhibited at the Australian Institute of Architects offices in Brisbane from November 15 to 29, 2010. The exhibition features the final design outcomes of the inaugural Bushfire Sustainability unit conducted at QUT in semester two, 2010. The core objective of this unit was to develop our students’ skills in collaborative practice in design, research and presentation. The theme of ‘bushfire sustainability’ was chosen because living sustainably in bushfire prone landscapes presents a number of problems, the nature of which might only be resolved via multidisciplinary collaboration among the design disciplines. The students involved represent the disciplines of Interior Design, Landscape Architecture, Industrial Design, Architecture and Sustainability – all from within the School of Design at QUT. 55 students, mostly in their third year of study, worked in teams of five (one from each discipline) to design one of a number of homes in highly bushfire prone sites in either Western Australia or SE Queensland. This year level and the interdisciplinary mix are perhaps the best placed to resolve these problems: being unrestrained from the burdens of professional practice and technical overload they retain the potential for innovative, lateral thinking across the range of spatial scales and philosophical perspectives associated with inhabitation of bushfire prone landscapes. It is envisaged that, through the ‘vehicle’ of this design research, that the students’ work will contribute to understandings of how creative design disciplines might respond to this significant national problem, which hitherto has been attended to primarily by engineering and the sciences.

Designing the future

While there have been improvements in Australian engineering education since the 1990s, there are still strong concerns that more progress needs to be made, particularly in the areas of developing graduate competencies and in outcomes-based curricula. This paper comments on the findings from a two-day Australian Learning and Teaching Council funded forum that sought to establish a shared understanding with the thee stakeholders (students, academics and industry) about how to achieve a design-based engineering curriculum. This paper reports on the findings from the first day’s activities, and reveals that there is a shared desire for design and project-based curricula that would encourage the development of the “three-dimensional” graduate: one who has technical, personal, and professional and systems-thinking/design-based competence. In addition, the data also reveal industry willingness to engage in the engineering curriculum to enhance authentic learning experiences.