Charge transport and density of trap states in balanced high mobility ambipolar organic thin-film transistors

We report on charge transport and density of trap states (trap DOS) in ambipolar diketopyrrolopyrrole-benzothiadiazole copolymer thin-film transistors. This semiconductor possesses high electron and hole field-effect mobilities of up to 0.6 cm 2/V-s. Temperature and gate-bias dependent field-effect mobility measurements are employed to extract the activation energies and trap DOS to understand its unique high mobility balanced ambipolar charge transport properties. The symmetry between the electron and hole transport characteristics, parameters and activation energies is remarkable. We believe that our work is the first charge transport study of an ambipolar organic/polymer based field-effect transistor with room temperature mobility higher than 0.1 cm 2/V-s in both electrons and holes.

A Bit-Stream based space vector modulator

Bit-Stream based control, which uses one bit wide signals to control power electronics applications, is a new approach for controller design in power electronic systems. Bit-Stream signals are inherently high frequency in nature, and as such some form of down sampling or modulating is essential to avoid excessive switching losses. This paper presents a novel three-phase space vector modulator, which is based on the Bit-Stream technique and suitable for standard three-phase inverter systems. The proposed modulator simultaneously converts a two phase reference to the three-phase domain and reduces switching frequencies to reasonable levels. The modulator consumes relatively few logic elements and does not require sector detectors, carrier oscillators or trigonometric functions. The performance of the modulator was evaluated using ModelSim. Results indicate that, subject to limits on the modulation index, the proposed modulator delivers a spread-spectrum output with total harmonic distortion comparable to standard space vector pulse width modulation techniques.

Improving the shear capacities of lipped channel beams with web openings using plate stiffeners

Cold-formed steel lipped channel beams (LCB) are used extensively in residential, industrial and commercial buildings as load bearing structural elements. Their shear capacities are considerably reduced when web openings are included for the purpose of locating building services. Past research has shown that the shear capacities of LCBs were reduced by up to 70% due to the inclusion of these web openings. Hence there is a need to improve the shear capacities of LCBs with web openings. A cost effective way of eliminating the detrimental effects of large web openings is to attach suitable stiffeners around the web openings and restore the original shear strength and stiffness of LCBs. Hence detailed experimental studies were undertaken to investigate the behaviour and strength of LCBs with stiffened web openings subject to shear, and combined bending and shear actions. Both plate and stud stiffeners with varying sizes and thicknesses were attached to the web elements of LCBs using different screw-fastening arrangements. Simply supported test specimens of LCBs with aspect ratios of 1.0 and 1.5 were loaded at mid-span until failure. Numerical studies were also undertaken to investigate the strength of LCBs with stiffened web openings. Finite element models of LCBs with stiffened web openings under shear, combined bending and shear actions were developed to simulate the behaviour of tested LCBs. The developed models were then validated by comparing their results with experimental results and used in further studies. Both experimental and finite element analysis results showed that the stiffening arrangements recommended by past research and available design guidelines are not adequate to restore the original shear strengths of LCBs. Therefore new stiffener arrangements were proposed based on screw fastened plate stiffeners. This paper presents the details of this research study and the results.

Interaction of metal salts with cytoskeletal motor protein systems

Interactions of chemicals with the microtubular network of cells may lead to genotoxicity. Micronuclei (MN) might be caused by interaction of metals with tubulin and/or kinesin. The genotoxic effects of inorganic lead and mercury salts were studied using the MN assay and the CREST analysis in V79 Chinese hamster fibroblasts. Effects on the functional activity of motor protein systems were examined by measurement of tubulin assembly and kinesin-driven motility. Lead and mercury salts induced MN dose-dependently. The no-effect-concentration for MN induction was 1.1 μM PbCl2, 0.05 μM Pb(OAc)2 and 0.01 μM HgCl2. The in vitro results obtained for PbCl2 correspond to reported MN induction in workers occupationally exposed to lead, starting at 1.2 μM Hg(II) (Vaglenov et al., 2001, Environ. Health Perspect. 109, 295-298). The CREST Analysis indicate aneugenic effects of Pb(II) and aneugenic and additionally clastogenic effects of Hg(II). Lead (chloride, acetate, and nitrate) and mercury (chloride and nitrate) interfered dose-dependently with tubulin assembly in vitro. The no-effect-concentration for lead salts in this assay was 10 μM. Inhibition of tubulin assembly by mercury started at 2 μM. The gliding velocity of microtubules along immobilised kinesin molecules was affected by 25 μM Pb(NO3)2 and 0.1 μM HgCl2 in a dose-dependent manner. Our data support the hypothesis that lead and mercury genotoxicity may result, at least in part, via disturbance of chromosome segregation via interaction with cytoskeletal proteins.

Effects of dietary folate intake on migraine disability and frequency

Objective Migraine is a highly disabling disease affecting a significant proportion of the Australian population. The Methylenetetrahydrofolate Reductase (MTHFR) C677T variant has been associated with increased levels of homocysteine and risk of migraine with aura (MA). Folic acid, Vitamin B6 and B12 supplementation has been previously shown to reduce increased levels of homocysteine and decrease migraine symptoms. However the influence of dietary folate intake on migraine has been unclear. The aim of the current study was to analyse the association of dietary folate intake in the form of dietary folate equivalent (DFE), folic acid (FA) and total food folate (TFF) on migraine frequency, severity and disability. Methods A cohort of 141 adult females of Caucasian descent with MA was genotyped for the MTHFRC677T variant using restriction enzyme digestion. Dietary folate information was collected from all participants and analysed using the “FoodWorks” 2009 package. Folate consumption was compared to migraine frequency, severity and disability using linear regression. Results A significant inverse relation was observed between DFE [R2= 0.201, P= 0.045, CI (-0.004, -0.001)] and FA [R2= 0.255, P= 0.036, 95% CI (-0.009, -0.002)] consumption and migraine frequency. It was also observed that in individuals with the CC genotype for the MTHFR C677T variant, migraine frequency was significantly linked to FA consumption [R2= 0.077, P= 0.029, CI (-0.009, -0.005)]. Conclusions The results from this study indicate that folate intake in the form of folic acid may influence migraine frequency in female MA sufferers.

Developing affordable and sustainable housing through energy, transport, and building utility integration

Housing affordability and sustainable development are not polarised ideologies as both are necessary with increasing urbanisation. We must bridge the gap between current median house pricing and target affordable house pricing whilst pursuing sustainability. This paper examines the potential of initial construction cost and ongoing utilities and transport cost reduction through the integration of sustainable housing design and transit oriented development principles in a Commuter Energy and Building Utilities System (CEBUS). It also introduces current research on the development of a Dynamic Simulation Model for CEBUS applications in the Australian property development and construction industry.

Spontaneous volunteering : trends and challenges in the Australian context

This chapter reviews spontaneous volunteering in Australia and its challenges for volunteers and volunteer organisations. Drawing on their own empirical research mzd the wider literature, the authors suggest that better understanding of the nature and functions of spontaneous volunteering is needed to support community resilience and individual wellbeing.

Activity patterns of preschool-aged children at risk for obesity

BACKGROUND Although the prevalence of obesity in young children highlights the importance of early interventions to promote physical activity (PA), there are limited data on activity patterns in this age group. The purpose of this study is to describe activity patterns in preschool-aged children and explore differences by weight status. METHODS Analyses use baseline data from Healthy Homes/Healthy Kids- Preschool, a pilot obesity prevention trial of preschool-aged children overweight or at risk for overweight. A modified parent-reported version of the previous-day PA recall was used to summarize types of activity. Accelerometry was used to summarize daily and hourly activity patterns. RESULTS "Playing with toys" accounted for the largest proportion of a child's previous day, followed by "meals and snacks", and "chores". Accelerometry-measured daily time spent in sedentary behavior, light PA, and moderate-to-vigorous PA (MVPA) was 412, 247, and 69 minutes, respectively. Percent of hourly time spent in MVPA ranged from 3% to 13%, peaking in the late morning and evening hours. There were no statistically significant MVPA differences by weight status. CONCLUSIONS This study extends our understanding of activity types, amounts, and patterns in preschool-age children and warrants further exploration of differences in physical activity patterns by weight status.

Introduction : Picture Books ... Then, Now and Beyond

Picture books are known and familiar objects to many children and adults. They have been variously described as art objects, cultural documents, hybrid texts and verbal-visual art forms. They have also been variously categorised according to their readership – ranging from very young children to older readers, the latter can extend through the primary years to high school and even into adulthood. Scholars and students study picture books as part of an evolving literary and cultural landscape which has given rise to new genres and trends, such as ‘multicultural picture books’, ‘environmental picture books’ and ‘postmodern picture books’, and what Cherie Allan terms, ‘postmodernesque picture books’, that is, ‘picturebooks about postmodernity’ (Allan, 2012, p. 141). Picture books are also the staple literature in many early years and primary school classrooms for literacy and literary development, thus supporting the designated strands for literacy, literature, and language in the Australian Curriculum: English.

A sunburnt country – storms, surges and sea levels : of insurance and flooding rains

Increasing population pressures and life-style choices are resulting in more people living in areas that are at risk of inundation from rising sea levels and flooding. However, following natural disaster events, such as the 2011 Queensland floods, many Australians discovered they were uninsured. Either their insurance policies did not cover flood; or multiple (and confusing) water-related definitions led them to believe they had cover when they did not. Several theories are analysed to try to explain what is a world-wide underinsurance problem but these do not provide an answer to the problem. This research focuses on uncovering the reasons consumers fail to adequately insure for flood and other water-related events. Recent Australian legislative attempts to overcome insureds’ confusion of water related definitions are examined for this purpose. The authors conclude that Australian and other) legislators should set a maximum premium for a minimum amount of flood and sea related cover; and restrict the building and style of homes in flood prone areas.

Automated melanoma diagnosis system

An automated melanoma diagnosis system, the so-called Skin Polar-probe, was developed to improve the chances of early detection of skin cancers and help save the lives of melanoma victims. The system will offer unique benefits to aid early detection of melanoma - the key to reducing deaths caused by this cancer.