Experimental study of load-bearing cold-formed steel walls exposed to realistic design fires

This paper presents the details of full scale fire tests of LSF wall panels conducted using realistic fire time-temperature curves. Tests included eight LSF wall specimens of various configurations exposed to both parametric design and natural fire curves. Details of the fire test set-up, test procedure and the results including the measured time-temperature and deformation curves of LSF wall panels are presented along with wall stud failure modes and times. This paper also compares the structural and thermal behavioural characteristics of LSF wall studs with those based on the standard time-temperature curve. Finally, the stud failure times and temperatures are summarized for both standard and realistic design fire curves. This study provides the necessary test data to validate the numerical models of LSF wall panels and to undertake a detailed study into the structural and thermal performance of LSF wall panels exposed to realistic design fire curves.

Fouling of waste heat recovery : numerical and experimental results

Numerical results are presented to investigate the performance of a partly-filled porous heat exchanger for waste heat recovery units. A parametric study was conducted to investigate the effects of inlet velocity and porous block height on the pressure drop of the heat exchanger. The focus of this work is on modelling the interface of a porous and non-porous region. As such, numerical simulation of the problem is conducted along with hot-wire measurements to better understand the physics of the problem. Results from the two sources are then compared to existing theoretical predictions available in the literature which are unable to predict the existence of two separation regions before and after the porous block. More interestingly, a non-uniform interface velocity was observed along the streamwise direction based on both numerical and experimental data.

Contributions to Bayesian experimental design

This thesis progresses Bayesian experimental design by developing novel methodologies and extensions to existing algorithms. Through these advancements, this thesis provides solutions to several important and complex experimental design problems, many of which have applications in biology and medicine. This thesis consists of a series of published and submitted papers. In the first paper, we provide a comprehensive literature review on Bayesian design. In the second paper, we discuss methods which may be used to solve design problems in which one is interested in finding a large number of (near) optimal design points. The third paper presents methods for finding fully Bayesian experimental designs for nonlinear mixed effects models, and the fourth paper investigates methods to rapidly approximate the posterior distribution for use in Bayesian utility functions.

Fruit-feeding behaviour and use of olfactory cues by the fruit bat Rousettus leschenaulti: an experimental study

This paper describes the feeding behaviour ofRousettus leschenaulti Desmarest, 1820 on lychees, the preferred cultivated food of this bat in captive conditions. We found that feeding comprised 25–30% of the total activity of these animals in a flight cage and that feeding durations were not significantly different between two sexes. To evaluate the role of odor and vision in foraging behaviour, we provided animals with artificial lychees, real lychees and artificial lychees soaked in the juice of real lychees and we recorded the number of feeding approaches to the different “fruit” types. The results indicated that bats approached real fruit significantly more than artificial fruit, and that the number of approaches to the soaked artificial fruit was also significantly higher than to the unsoaked artificial fruit. There were no significant differences between sexes in approach rates to any “fruit” type. We discuss the role of different sensory cues in the foraging behaviour of these bats and emphasize that the olfactory cue is important in detecting food resources and discriminating between different kinds of food items.

Development of fourth-grade students’ understanding of experimental and theoretical probability

Students explored variation and expectation in a probability activity at the end of the first year of a 3-year longitudinal study across grades 4-6. The activity involved experiments in tossing coins both manually and with simulation using the graphing software, TinkerPlots. Initial responses indicated that the students were aware of uncertainty, although an understanding of chance concepts appeared limited. Predicting outcomes of 10 tosses reflected an intuitive notion of equiprobability, with little awareness of variation. Understanding the relationship between experimental and theoretical probability did not emerge until multiple outcomes and representations were generated with the software.

A lucky break : contingency in the storied worlds of prickly pear

In July 1926, the science behind biological control transitioned from an experimental method to a trusted policy tool in invasive species management. In local storytelling, historical writing and scientific analysis, the ‘lucky’ discovery of the South American Cactoblastis cactorum moth was a watershed moment for scientists concerned with prickly pear, Opuntia and Nopalea spp. Within 10 years, Queensland declared itself pest free. Overnight success is the climax in this tale's narrative arc. Articulating this introduction as a ‘lucky break’ worked to stabilize the narrative of human control in the agricultural environments of post-colonial Queensland, and, in doing so, consolidated biological control as critical management technique. I argue that ‘luck’ elides the assemblage of elements and actors necessary to enable this change, allowing settlers to distance themselves from the responsibility for disruptions associated with nineteenth-century plant transfers. To challenge the rhetorical function of luck, three episodes of contingency are discussed: (1) transnational mobility of things and knowledge, (2) the unpredictable adaptation of insect diet, and; (3) human vectors in industrialized insect–plant complexes. There are important distinguishing differences between luck and contingency, which I frame as a critical analytical tool for understanding the political role of non-humans, in the storied worlds of science in prickly pear land.

Experimental Study of crack propagation in carbon steel using acoustic emission

Acoustic emission technique has become a significant and powerful structural health monitoring tool for structures. Researches to date have been done on crack location, fatigue crack propagation in materials and severity assessment of failure using acoustic emission technique. Determining severity of failure in steel structures using acoustic emission technique is still a challenge to accurately determine the relationship between the severity of crack propagation and acoustic emission activities. In this study three point bending test on low carbon steel samples along with acoustic emission technique have been used to determine crack propagation and severity. A notch is introduced at the tension face of the loading point to the samples to initiate the crack. The results show that the percentage of load drop of the steel specimen has a reciprocal relationship with the crack opening i.e. crack opening zones are influenced by the loading rate. In post yielding region, common acoustic emission signal parameters such as, signal strength, energy and amplitudes are found to be higher than those at pre-yielding and at yielding.

Do we need a law to help people try experimental drugs?

People with life-threatening or incurable diseases may be willing to try experimental drugs and unproven treatments, but they face the risk of exploitation. Is the law the best avenue to ensure that they are protected while medical innovation is encouraged? Protection of vulnerable people is a thread running through many laws, in Australia and elsewhere. In medical law, for instance, children and people with impaired decision-making capacity warrant special attention. But what of the ordinary person diagnosed with a life-threatening disease? Such people are vulnerable to harm and potential exploitation when they seek access to innovative, experimental or unproven treatments that depart from the existing range of accepted medicine.

Copycat firesetting : bridging two research areas

Deliberate firesetting costs our community in destruction to property and lives. Public concern heightens when similar fires occur in a series, raising the specter of copycat firesetting. Difficulties associated with researching copycat crimes in general mean that not a lot is known about copycat firesetting. As an initial step toward filling this research gap, we explore connections between research on copycat crime and research into deliberate firesetting. The intention is to extract salient features from what is known about the phenomena of deliberate firesetting and copycat crime, map them together, and point out shared and unique characteristics. It is argued that a “copycat firesetter” is likely to exist as a distinct subgroup and potentially requiring targeted interventions.

Assessing the welfare effects of microfinance in Vietnam : empirical results from a quasi-experimental survey

This article analyses the effects of NGO microfinance programmes on household welfare in Vietnam. Data on 470 households across 25 villages were collected using a quasi-experimental survey approach to overcome any self-selection bias. The sample was designed so that member households of microfinance programmes were compared with non-member households with similar characteristics. The analysis shows no significant effects of participation in NGO microfinance on household welfare, proxied by income and consumption per adult equivalent.

Planning and governance approaches for protecting World Heritage Areas: A comparison of the Great Barrier Reef and the Florida Everglades

The focus of this paper is on two World Heritage Areas: the Great Barrier Reef in Queensland, Australia and the Everglades in Florida. While both are World Heritage listed by the UNESCO, the Everglades is on the "World Heritage in Danger" list and the Great Barrier Reef could be on this list within the next year if present pressures continue. This paper examines the planning approaches and governance structures used in these two areas (Queensland and Florida) to manage the growth and development pressures. To make the analysis manageable, given the scale of these World Heritage areas, case studies at the local government level will be used: the Cairns Regional Council in Queensland and Monroe County in Florida. The case study analysis will involve three steps: (1) examination of the various plans at the federal, state, local levels that impact upon environmental quality in the Great Barrier Reef and Everglades; (2) assessing the degree to which these plans have been implemented; and (3) determine if (and how) the plans have improved environmental quality. In addition to the planning analysis we will also examine the governance structures (Lebel et al. 2006) within which planning operates. In any comparative analysis context is important (Hantrais 2009). Contextual differences between Queensland and Florida have previously been examined by Sipe, et al. (2007) and will be used as the starting point for this analysis. Our operating hypothesis and preliminary analysis suggests that the planning approaches and governance structures used in Florida and Queensland are considerably different, but the environmental outcomes may be similar. This is based, in part, on Vella (2004) who did a comparative analysis of environmental practices in the sugar industry in Florida and Queensland. This research re-examines this hypothesis and broadens the focus beyond the sugar industry to growth and development more broadly.

Experimental and numerical investigation of strain-rate dependent mechanical properties of single living cells

The objective of this project is to investigate the strain-rate dependent mechanical behaviour of single living cells using both experimental and numerical techniques. The results revealed that living cells behave as porohyperlastic materials and that both solid and fluid phases within the cells play important roles in their mechanical responses. The research reported in this thesis provides a better understanding of the mechanisms underlying the cellular responses to external mechanical loadings and of the process of mechanical signal transduction in living cells. It would help us to enhance knowledge of and insight into the role of mechanical forces in supporting tissue regeneration or degeneration.

Experimental studies of cold-formed steel hollow section columns at elevated temperatures

This paper reports the details of an experimental study of cold-formed steel hollow section columns at ambient and elevated temperatures. In this study the global buckling behaviour of cold-formed Square Hollow Section (SHS) slender columns under axial compression was investigated at various uniform elevated temperatures up to 700℃. The results of these column tests are reported in this paper, which include the buckling/failure modes at elevated temperatures, and ultimate load versus temperature curves. Finite element models of tested columns were also developed and their behaviour and ultimate capacities at ambient and elevated temperatures were studied. Fire design rules given in European and American standards including the Direct Strength Method (DSM) based design rules were used to predict the ultimate capacities of tested columns at elevated temperatures. Elevated temperature mechanical properties and stress-strain models given in European steel design standards and past researches were used with design rules and finite element models to investigate their effects on SHS column capacities. Comparisons of column capacities from tests and finite element analyses with those predicted by current design rules were used to determine the accuracy of currently available column design rules in predicting the capacities of SHS columns at elevated temperatures and the need to use appropriate elevated temperature material stress-strain models. This paper presents the important findings derived from the comparisons of these column capacities.

Dynamics of nitrogen and suspended solids removal in experimental stormwater biofilters under intermittent wetting and drying

This research study comprehensively analyses the dynamics of nitrogen and suspended solids removal in stormwater biofilters. The study focuses on pollutant removal during an event with time, rather than the conventional event-mean analysis. Antecedent dry days (number of days in between rainfall) during which biofilters remain dry and the inflow concentration of pollutants were two other important variables analysed in this study. The research outcome highlights the significance of dry-phase processes and the process of stabilization on filter performance and sets a paradigm shift from the current approach towards an innovative way of performance analysis of biofilters.

Experimental and statistical investigation of Australian native plants for second-generation biodiesel production

This work explores the potential of Australian native plants as a source of second-generation biodiesel for internal combustion engines application. Biodiesels were evaluated from a number of non-edible oil seeds which are grow naturally in Queensland, Australia. The quality of the produced biodiesels has been investigated by several experimental and numerical methods. The research methodology and numerical model developed in this study can be used for a broad range of biodiesel feedstocks and for the future development of renewable native biodiesel in Australia.