Properties of lignin and poly(hydroxybutyrate) blends

The Queensland University of Technology (QUT) allows the presentation of a thesis for the Degree of Doctor of Philosophy in the format of published or submitted papers, where such papers have been published, accepted or submitted during the period of candidature. This thesis is composed of Seven published/submitted papers and one poster presentation, of which five have been published and the other two are under review. This project is financially supported by the QUTPRA Grant. The twenty-first century started with the resurrection of lignocellulosic biomass as a potential substitute for petrochemicals. Petrochemicals, which enjoyed the sustainable economic growth during the past century, have begun to reach or have reached their peak. The world energy situation is complicated by political uncertainty and by the environmental impact associated with petrochemical import and usage. In particular, greenhouse gasses and toxic emissions produced by petrochemicals have been implicated as a significant cause of climate changes. Lignocellulosic biomass (e.g. sugarcane biomass and bagasse), which potentially enjoys a more abundant, widely distributed, and cost-effective resource base, can play an indispensible role in the paradigm transition from fossil-based to carbohydrate-based economy. Poly(3-hydroxybutyrate), PHB has attracted much commercial interest as a plastic and biodegradable material because some its physical properties are similar to those of polypropylene (PP), even though the two polymers have quite different chemical structures. PHB exhibits a high degree of crystallinity, has a high melting point of approximately 180°C, and most importantly, unlike PP, PHB is rapidly biodegradable. Two major factors which currently inhibit the widespread use of PHB are its high cost and poor mechanical properties. The production costs of PHB are significantly higher than for plastics produced from petrochemical resources (e.g. PP costs $US1 kg-1, whereas PHB costs $US8 kg-1), and its stiff and brittle nature makes processing difficult and impedes its ability to handle high impact. Lignin, together with cellulose and hemicellulose, are the three main components of every lignocellulosic biomass. It is a natural polymer occurring in the plant cell wall. Lignin, after cellulose, is the most abundant polymer in nature. It is extracted mainly as a by-product in the pulp and paper industry. Although, traditionally lignin is burnt in industry for energy, it has a lot of value-add properties. Lignin, which to date has not been exploited, is an amorphous polymer with hydrophobic behaviour. These make it a good candidate for blending with PHB and technically, blending can be a viable solution for price and reduction and enhance production properties. Theoretically, lignin and PHB affect the physiochemical properties of each other when they become miscible in a composite. A comprehensive study on structural, thermal, rheological and environmental properties of lignin/PHB blends together with neat lignin and PHB is the targeted scope of this thesis. An introduction to this research, including a description of the research problem, a literature review and an account of the research progress linking the research papers is presented in Chapter 1. In this research, lignin was obtained from bagasse through extraction with sodium hydroxide. A novel two-step pH precipitation procedure was used to recover soda lignin with the purity of 96.3 wt% from the black liquor (i.e. the spent sodium hydroxide solution). The precipitation process is presented in Chapter 2. A sequential solvent extraction process was used to fractionate the soda lignin into three fractions. These fractions, together with the soda lignin, were characterised to determine elemental composition, purity, carbohydrate content, molecular weight, and functional group content. The thermal properties of the lignins were also determined. The results are presented and discussed in Chapter 2. On the basis of the type and quantity of functional groups, attempts were made to identify potential applications for each of the individual lignins. As an addendum to the general section on the development of composite materials of lignin, which includes Chapters 1 and 2, studies on the kinetics of bagasse thermal degradation are presented in Appendix 1. The work showed that distinct stages of mass losses depend on residual sucrose. As the development of value-added products from lignin will improve the economics of cellulosic ethanol, a review on lignin applications, which included lignin/PHB composites, is presented in Appendix 2. Chapters 3, 4 and 5 are dedicated to investigations of the properties of soda lignin/PHB composites. Chapter 3 reports on the thermal stability and miscibility of the blends. Although the addition of soda lignin shifts the onset of PHB decomposition to lower temperatures, the lignin/PHB blends are thermally more stable over a wider temperature range. The results from the thermal study also indicated that blends containing up to 40 wt% soda lignin were miscible. The Tg data for these blends fitted nicely to the Gordon-Taylor and Kwei models. Fourier transform infrared spectroscopy (FT-IR) evaluation showed that the miscibility of the blends was because of specific hydrogen bonding (and similar interactions) between reactive phenolic hydroxyl groups of lignin and the carbonyl group of PHB. The thermophysical and rheological properties of soda lignin/PHB blends are presented in Chapter 4. In this chapter, the kinetics of thermal degradation of the blends is studied using thermogravimetric analysis (TGA). This preliminary investigation is limited to the processing temperature of blend manufacturing. Of significance in the study, is the drop in the apparent energy of activation, Ea from 112 kJmol-1 for pure PHB to half that value for blends. This means that the addition of lignin to PHB reduces the thermal stability of PHB, and that the comparative reduced weight loss observed in the TGA data is associated with the slower rate of lignin degradation in the composite. The Tg of PHB, as well as its melting temperature, melting enthalpy, crystallinity and melting point decrease with increase in lignin content. Results from the rheological investigation showed that at low lignin content (.30 wt%), lignin acts as a plasticiser for PHB, while at high lignin content it acts as a filler. Chapter 5 is dedicated to the environmental study of soda lignin/PHB blends. The biodegradability of lignin/PHB blends is compared to that of PHB using the standard soil burial test. To obtain acceptable biodegradation data, samples were buried for 12 months under controlled conditions. Gravimetric analysis, TGA, optical microscopy, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), FT-IR, and X-ray photoelectron spectroscopy (XPS) were used in the study. The results clearly demonstrated that lignin retards the biodegradation of PHB, and that the miscible blends were more resistant to degradation compared to the immiscible blends. To obtain an understanding between the structure of lignin and the properties of the blends, a methanol-soluble lignin, which contains 3× less phenolic hydroxyl group that its parent soda lignin used in preparing blends for the work reported in Chapters 3 and 4, was blended with PHB and the properties of the blends investigated. The results are reported in Chapter 6. At up to 40 wt% methanolsoluble lignin, the experimental data fitted the Gordon-Taylor and Kwei models, similar to the results obtained soda lignin-based blends. However, the values obtained for the interactive parameters for the methanol-soluble lignin blends were slightly lower than the blends obtained with soda lignin indicating weaker association between methanol-soluble lignin and PHB. FT-IR data confirmed that hydrogen bonding is the main interactive force between the reactive functional groups of lignin and the carbonyl group of PHB. In summary, the structural differences existing between the two lignins did not manifest itself in the properties of their blends.

The influence of conformity and group identity on drink walking intentions : comparing intentions to drink walk across risky pedestrian crossing scenarios

Despite the dangers associated with drink walking, limited research is currently available regarding the factors which influence individuals to engage in this risky behaviour. This study examined the influence of psychosocial factors upon individuals’ intentions to drink walk across four experimental scenarios (and a control condition). Specifically, a 2 × 2 repeated measures design was utilised in which all of the scenarios incorporated a risky pedestrian crossing situation (i.e., a pedestrian crossing against a red man signal) but differed according to the level of group identity (i.e., low/strangers and high/friends) and conformity (low and high). Individuals were assessed for their intentions to drink walk within each of these different scenarios. Undergraduate students (N = 151), aged 17–30 years, completed a questionnaire. Overall, most of the study's hypotheses were supported with individuals reporting the highest intentions to drink walk when in the presence of friends (i.e., high group identity) and their friends were said to be also crossing against the red man signal (i.e., high conformity). The findings may have significant implications for the design of countermeasures to reduce drink walking. For instance, the current findings would suggest that potentially effective strategies may be to promote resilience to peer influence as well as highlight the negative consequences associated with following the behaviour of other intoxicated pedestrians who are crossing against a red signal.

Exploring intercultural competence : a service-learning approach

This study explored the developing intercultural competence of fourth-year Australian education pre-service teachers through a core unit of study on inclusive education, following a service-learning pathway. The Australian pre-service teachers volunteered to be 'of service' to a cohort of second-year Malaysian pre-service teachers studying in Australia in a transnational twinning program. Students participated in a Patches program which included writing 'patches' (reflections) and engaging in social exchanges. Data were gathered from focus group interviews, written reflection logs and Patches writing books and were analysed through Butin's (2005) four-lenses of service-learning: technical, cultural, political and post-modern lenses. Data revealed that initially the Australian pre-service teachers felt their presumptions but by the end of the semester embraced the basic tenants of inclusion and were able to project how they could take their new understandings into the classroom as inclusive teachers.

Indigenous studies in all schools

Cherbourg State School is approximately 300 km northwest of Brisbane. It is situated in an Aboriginal community at Cherbourg with approximately 250 students. At the Cherbourg State School, the aim was to generate good academic outcomes for all students from kindergarten to Year 7 and to nurture a strong and positive sense of what it means to be Aboriginal in today's society. In this paper, I will discuss modernism and postmodernism in indigenous studies and how this has impacted on the design and development of the Indigenous Studies Programme at the Cherbourg State School. The programme was designed to provide students with the opportunity to learn about the history of Indigenous people from Indigenous voices and provide an understanding of the impact of invasion and the consequences on the lives of Indigenous people, in the past and present. The stories from the elders and members of their own community provided knowledge that allowed students to challenge Aboriginal identity by taking on existing perceptions so that they could be better processed and understood.

The effectiveness of a short-term group music therapy intervention for young parents and their children

The quality of early life experiences are known to influence a child’s capacities for emotional, social, cognitive and physical competence throughout their life (Peterson, 1996; Zubrick et al., 2008). These early life experiences are directly affected by parenting and family environments. A lack of positive parenting has significant implications both for children, and the broader communities in which they live (Davies & Cummings, 1994; Dryfoos, 1990; Sanders, 1995). Young parents are known to be at risk of experiencing adverse circumstances that affect their ability to provide positive parenting to their children (Milan et al., 2004; Trad, 1995). There is a need to provide parenting support programs to young parents that offer opportunities for them to come together, support each other and learn ways to provide for their children’s developmental needs in a friendly, engaging and non-judgemental environment. This research project examines the effectiveness of a 10 week group music therapy program Sing & Grow as an early parenting intervention for 535 young parents. Sing & Grow is a national early parenting intervention program funded by the Australian Government and delivered by Playgroup Queensland. It is designed and delivered by Registered Music Therapists for families at risk of marginalisation with children aged from birth to three years. The aim of the program is to improve parenting skills and parent-child interactions, and increase social support networks through participation in a group that is strengths-based and structured in a way that lends itself to modelling, peer learning and facilitated learning. During the 10 weeks parents have opportunities to learn practical, hands-on ways to interact and play with their children that are conducive to positive parent-child relationships and ongoing child development. A range of interactive, nurturing, stimulating and developmental music activities provide the framework for parents to interact and play with their children. This research uses data collected through the Sing & Grow National Evaluation Study to examine outcomes for all participants aged 25 years and younger, who attended programs during the Sing & Grow pilot study and main study from mid-2005 to the end of 2007. The research examines the change from pre to post in self-reported parent behaviours, parent mental health and parent social support, and therapist observed parent-child interactions. A range of statistical analyses are used to address each Research Objective for the young parent population, and for subgroups within this population. Research Objective 1 explored the patterns of attendance in the Sing & Grow program for young parents, and for subgroups within this population. Results showed that levels of attendance were lower than expected and influenced by Indigenous status and source of family income. Patterns of attendance showed a decline over time and incomplete data rates were high which may indicate high dropout rates. Research Objective 2 explored perceived satisfaction, benefits and social support links made. Satisfaction levels with the program and staff were very high. Indigenous status was associated with lower levels of reported satisfaction with both the program and staff. Perceived benefits from participation in the program were very high. Employment status was associated with perceived benefits: parents who were not employed were more likely than employed parents to report that their understanding of child development had increased as a result of participation in the program. Social support connections were reported for participants with other professionals, services and parents. In particular, families were more likely to link up with playgroup staff and services. Those parents who attended six or more sessions were significantly more likely to attend a playgroup than those who attended five sessions or less. Social support connections were related to source of family income, level of education, Indigenous status and language background. Research Objective 3 investigated pre to post change on self-report parenting skills and parent mental health. Results indicated that participation in the Sing & Grow program was associated with improvements in parent mental health. No improvements were found for self-reported parenting skills. Research Objective 4 investigated pre to post change in therapist observation measures of parent-child interactions. Results indicated that participation in the Sing & Grow program was associated with large and significant improvements in parent sensitivity to, engagement with and acceptance of the child. There were significant interactions across time (pre to post) for the parent characteristics of Indigenous status, family income and level of education. Research Objective 5 explored the relationship between the number of sessions attended and extent of change on self-report outcomes and therapist observed outcomes, respectively. For each, an overall change score was devised to ascertain those parents who had made any positive changes over time. Results showed that there was no significant relationship between high attendance and positive change in either the self-report or therapist observed behavioural measures. A risk index was also constructed to test for a relationship between the risk status of the parent. Parents with the highest risk status were significantly more likely to attend six or more sessions than other parents, but risk status was not associated with any differences in parent reported outcomes or therapist observations. The results of this research study indicate that Sing & Grow is effective in improving outcomes for young parents’ mental health, parent-child interactions and social support connections. High attendance by families in the highest category for risk factors may indicate that the program is effective at engaging and retaining parents who are most at-risk and therefore traditionally hard to reach. Very high levels of satisfaction and perceived benefits support this. Further research is required to help confirm the promising evidence from the current study that a short term group music therapy program can support young parents and improve their parenting outcomes. In particular, this needs to address the more disappointing outcomes of the current research study to improve attendance and engagement of all young parents in the program and especially the needs of young Indigenous parents.

Everything is political

Everything is Political Ben Eltham, Kieran Lord, Jeff Brand, Truna. Chair: Daniel Golding Videogames don’t exist in isolation. They are part of artistic, cultural, and political spheres – even if some would much rather they weren’t. This panel takes a look at the way videogames are used as political tools and how we as developers and critics can better engage with that, and perhaps wrestle some of the conversation back into our hands.

Employee perceived workplace stress : examining core self-evaluations, political skill, coping strategies and support

-

Charity law, advocacy and the aid/watch decision : compatibility of charitable purposes and political objects — the view from Australia

Introduction In 1952 the Nathan report stated that: Some of the most valuable activities of voluntary societies consist, however, in the fact that they may be able to stand aside from and criticize State action or inaction, in the interests of the inarticulate man in the street. Some 60 years later it remained the case that if a voluntary society wanted to gain or retain charitable status then, contrary to the Nathan report, the one thing it could not do was set itself up with the purpose of criticizing State action or inaction. This legal position was adopted by the authorities in Australia with the Australian Taxation Office (ATO) noting in Taxation Ruling TR2005/21: 102. An institution or fund is not charitable if its purpose is advocating a political party or cause, attempting to change the law or government policy, or propagating or promoting a particular point of view. So, why, if it is such a valuable activity, have governments steadfastly refused to allow charities to have as their purpose the freedom to advocate in this way and how has this situation been affected by the recent High Court of Australia decision in Aid/Watch v Commissioner of Taxation? This article proposes to address such questions. Beginning with some background history, it explains that, initially, the current constraints did not apply. Then it looks at the nature of these constraints: how does the law define what constitutes the type of political activity that a charity must not undertake? What is the rationale for prohibition? How has the judiciary contributed to the development of the law in this area in recent years? This will lead into a consideration of the Aid/Watch case and the implications arising from the recent final decision. The article concludes by reflecting on what has changed and why the view on this contentious matter now looks different from Australia.

Mapping intermedia news flows : topical discussions in the Australian and French political blogospheres

The growth of technologies and tools branded as =new media‘ or =Web 2.0‘ has sparked much discussion about the internet and its place in all facets of social life. Such debate includes the potential for blogs and citizen journalism projects to replace or alter journalism and mainstream media practices. However, while the journalism-blog dynamic has attracted the most attention, the actual work of political bloggers, the roles they play in the mediasphere and the resources they use, has been comparatively ignored. This project will look at political blogging in Australia and France - sites commenting on or promoting political events and ideas, and run by citizens, politicians, and journalists alike. In doing so, the structure of networks formed by bloggers and the nature of communication within political blogospheres will be examined. Previous studies of political blogging around the world have focussed on individual nations, finding that in some cases the networks are divided between different political ideologies. By comparing two countries with different political representation (two-party dominated system vs. a wider political spectrum), this study will determine the structure of these political blogospheres, and correlate these structures with the political environment in which they are situated. The thesis adapts concepts from communication and media theories, including framing, agenda setting, and opinion leaders, to examine the work of political bloggers and their place within the mediasphere. As well as developing a hybrid theoretical base for research into blogs and other online communication, the project outlines new methodologies for carrying out studies of online activity through the analysis of several topical networks within the wider activity collected for this project. The project draws on hyperlink and textual data collected from a sample of Australian and French blogs between January and August 2009. From this data, the thesis provides an overview of =everyday‘ political blogging, showing posting patterns over several months of activity, away from national elections and their associated campaigns. However, while other work in this field has looked solely at cumulative networks, treating collected data as a static network, this project will also look at specific cases to see how the blogospheres change with time and topics of discussion. Three case studies are used within the thesis to examine how blogs cover politics, featuring an international political event (the Obama inauguration), and local political topics (the opposition to the =Création et Internet‘, or HADOPI, law in France, the =Utegate‘ scandal in Australia). By using a mixture of qualitative and quantitative methods, the study analyses data collected from a population of sites from both countries, looking at their linking patterns, relationship with mainstream media, and topics of interest. This project will subsequently help to further develop methodologies in this field and provide new and detailed information on both online networks and internet-based political communication in Australia and France.

Modeling key compromise impersonation attacks on group key exchange protocols

Two-party key exchange (2PKE) protocols have been rigorously analyzed under various models considering different adversarial actions. However, the analysis of group key exchange (GKE) protocols has not been as extensive as that of 2PKE protocols. Particularly, an important security attribute called key compromise impersonation (KCI) resilience has been completely ignored for the case of GKE protocols. Informally, a protocol is said to provide KCI resilience if the compromise of the long-term secret key of a protocol participant A does not allow the adversary to impersonate an honest participant B to A. In this paper, we argue that KCI resilience for GKE protocols is at least as important as it is for 2PKE protocols. Our first contribution is revised definitions of security for GKE protocols considering KCI attacks by both outsider and insider adversaries. We also give a new proof of security for an existing two-round GKE protocol under the revised security definitions assuming random oracles. We then show how to achieve insider KCIR in a generic way using a known compiler in the literature. As one may expect, this additional security assurance comes at the cost of an extra round of communication. Finally, we show that a few existing protocols are not secure against outsider KCI attacks. The attacks on these protocols illustrate the necessity of considering KCI resilience for GKE protocols.

An Introduction to Political Communication, 5th Edition

An Introduction to Political Communication introduces students to the complex relationship between politics, the media and democracy in the United Kingdom, United States and other contemporary societies. Brian McNair examines how politicians, trade unions, pressure groups, NGOs and terrorist organisations make use of the media. Individual chapters look at political media and their effects, the work of political advertising, marketing and public relations, and the communicative practices of organizations at all levels, from grass-root campaigning through to governments and international bodies. This fifth edition has been revised and updated to include: • the 2008 US presidential election, and the early years of Barack Obama’s term • the MPs’ expenses scandal in Britain, and the 2010 UK election campaign • the growing role of bloggers and online pundits such as Guido Fawkes in the political agenda setting process • the emergence of social media platforms such as Twitter, YouTube and Facebook, and their destabiising impact on the management of political crises all over the world, including the Iranian pro-reform protests of July 2009 and the Israeli atack on the anti-blockade flotilla of May 2010 • the growing power of Wikileaks and other online information sources to challenge state control of classified information

Verbal instruction abolishes fear conditioned to racial out-group faces

Previous research has shown resistance to extinction of fear conditioned to racial out-group faces, suggesting that these stimuli may be subject to prepared fear learning. The current study replicated and extended previous research by using a different racial out-group, and testing the prediction that prepared fear learning is unaffected by verbal instructions. Four groups of Caucasian participants were trained with male in-group (Caucasian) or out-group (Chinese) faces as conditional stimuli; one paired with an electro-tactile shock (CS+) and one presented alone (CS). Before extinction, half the participants were instructed that no more shocks would be presented. Fear conditioning, indexed by larger electrodermal responses to, and blink startle modulation during the CS+, occurred during acquisition in all groups. Resistance to extinction of fear learning was found only in the racial out-group, no instruction condition. Fear conditioned to a racial out-group face was reduced following verbal instructions, contrary to predictions for the nature of prepared fear learning.

A fast tabu search algorithm for the group shop scheduling problem

Three types of shop scheduling problems, the flow shop, the job shop and the open shop scheduling problems, have been widely studied in the literature. However, very few articles address the group shop scheduling problem introduced in 1997, which is a general formulation that covers the three above mentioned shop scheduling problems and the mixed shop scheduling problem. In this paper, we apply tabu search to the group shop scheduling problem and evaluate the performance of the algorithm on a set of benchmark problems. The computational results show that our tabu search algorithm is typically more efficient and faster than the other methods proposed in the literature. Furthermore, the proposed tabu search method has found some new best solutions of the benchmark instances.

Has increasing the age for child passengers to wear child restraints improved the extent to which they are used? Results from an Australian focus group and survey study.

Acknowledgement that many children in Australia travel in restraints that do not offer them the best protection has led to recent changes in legislation such that the type of restraint for children under 7 years is now specified. This paper reports the results of two studies (observational; focus group/ survey) carried out in the state of Queensland to evaluate the effectiveness of these changes to the legislation. Observations suggested that almost all of the children estimated as aged 0-12 years were restrained (95%). Analysis of the type of restraint used for target-aged children (0-6 year olds) suggests that the proportion using an age-appropriate restraint has increased by an estimated 7% since enactment of the legislation. However, around 1 in 4 children estimated as aged under 7 years were using restraints too large for good fit. Results from the survey and focus group suggested parents were supportive of the changes in legislation. Non-Indigenous parents agreed that the changes had been necessary, were effective at getting children into the right restraints, were easy to understand as well as making it clear what restraint to use with children. Moreover, they did not see the legislation as too complicated or too hard to comply with. Indigenous parents who participated in a focus group also regarded the legislation as improving children’s safety. However, they identified the cost of restraints as an important barrier to compliance. In summary, the legislation appears to have had a positive effect on compliance levels and on raising parental awareness of the need to restrain children child-specific restraints for longer. However, it would seem that an important minority of parents transition their children into larger restraints too early for optimal protection. Intervention efforts should aim to better inform these parents about appropriate ages for transition, especially from forward facing childseats. This could potentially be through use of other important transitions that occur at the same age, such as starting school. The small proportion of parents who do not restrain their children at all are also an important community sector to target. Finally, obtaining restraints presents a significant barrier to compliance for parents on limited incomes and interventions are needed to address this.