http://espace.library.uq.edu.au/ The University of Queensland en Fez http://blogs.law.harvard.edu/tech/rss http://espace.library.uq.edu.au/view/UQ:185163 2009-10-22T00:00:00Z Chang, Man Wai. http://espace.library.uq.edu.au/view/UQ:291914 2013-02-22T07:48:32Z Ariotti, Nicholas Richard http://espace.library.uq.edu.au/view/UQ:106638 2007-08-24T00:00:00Z Edeling, Melissa Anne http://espace.library.uq.edu.au/view/UQ:261468 Macrophages are cells differentiated from circulating blood monocytes that represent the first line of defence against pathogen invasion. Macrophages are widely distributed throughout the body, which comprising 15% - 20% of cell populations in many organs and are particularly abundant at the route of pathogen entry. They play a critical role in immune defence by initiating, promoting, preventing, suppressing or terminating immune responses. Macrophages act as a key player in both the pro-inflammatory and anti-inflammatory responses. Characterisation of important macrophage proteins could helps to understand the molecular mechanisms of macrophages in these responses. We established a high-throughput pipeline at the University of Queensland to investigate the structures and functions of novel macrophage proteins. This PhD project began with the selection of 12 novel, biologically interesting and crystallization-feasible targets that were then designed into 96 different constructs. Processing of the 96 constructs was performed in parallel using simple automated applications of ligation-independent cloning, small-scale bacterial expression, small-scale purification and solubility assessment. After processing these 12 targets, I found that 16 constructs of three targets yielded soluble protein. From the three soluble targets, I focused on two proteins BinCARD and Fam96a, because in the meantime the third target was solved by another group. Bcl10 interacting CARD protein (BinCARD) is a CARD-domain containing protein that was reported to interact with Bcl10 through CARD-CARD interactions to down-regulate NF-κB transcription factor activation. The crystal structure of BinCARD solved at 1.5 Å resolution revealed six anti-parallel α-helices, showing that this protein is similar to other CARDs of known structures. Before progress toward the interaction study between BinCARD and Bcl10, I also addressed the bottleneck of expressing Bcl10 as soluble protein. Several rescue strategies were used including expression using different constructs and bacterial strains, insect cell system, and matrix-assisted refolding strategy. Carma1 was introduced as a positive control for the BinCARD and Bcl10 interaction study. GST-pull down assay suggests that dimerisation of Bcl10 is required for its interaction with Carma1. However, I have not yet been able confirm an interaction between BinCARD and Bcl10 interaction. Family with sequence similarity 96, member a (Fam96a) is a novel DUF59 domain containing protein that belongs to a group of diverse proteins with no function characterised yet. The crystal structures of Fam96a at 1.8 Å resolution revealed two different types of novel domain swapped-dimer conformation, a major dimer and a minor dimer. I also confirmed by chemical crosslinking and size-exclusion chromatography that Fam96a forms a complex with cytosolic iron-sulfur protein assembly 1 (Ciao1). Crystals of the Fam96a and Ciao1 complex were obtained and diffracted to 7.0 Å resolution. 2011-11-15T00:00:00Z Kai-en Chen http://espace.library.uq.edu.au/view/UQ:158084 This thesis investigated the structural adequacy of using a renewable lightweight material, bamboo, to construct a commonly used lattice structure, double layer grid, in a dimension of 2.6m x 2.6m x 0.9m. The structural potential of two Australian grown bamboo species, Phyllostachy Pubesecens and Phyllostachy Bambusoides, were conducted through compression, bending and buckling tests. A structurally stronger bamboo specie was then chosen to build the grid and subjected to a total load of 10kN testing. Material elastic geometry non-linear analysis using high order beam-column elements were performed to predict the deformation characteristics of the grid for comparison with test data. An important feature of this project was the development of a lightweight PVC (polyvinyl chloride) joint system, consisted of hub and connector, to connect bamboo members. The designed joint system was simple, efficient in fabrication and assembly, and was economical. Finite element method (FEM) was adopted to establish the detailed configuration of the joint and to perform both material and geometry linear structural analysis. A total of 8 joint prototypes were tested under load cases of tension, compression and bending, and the results were validated with FEM. This thesis proved that Mao Jue was mechanically strong for structural application, and the proposed new joint system worked well with bamboo in the grid. 2008-11-21T00:00:00Z Goh, Gim Yau http://espace.library.uq.edu.au/view/UQ:216759 2010-09-21T00:00:00Z Silcock, Annette Lester. http://espace.library.uq.edu.au/view/UQ:107203 2007-08-24T00:00:00Z Burrows, J. http://espace.library.uq.edu.au/view/UQ:216729 2010-09-20T00:00:00Z Bell, Thomas Kevin http://espace.library.uq.edu.au/view/UQ:158128 The bioactive properties of food and their relationship to the maintenance of health and protection from degenerative diseases are receiving much attention from nutritionists and consumers. Eating fruits and vegetables is strongly recommended for good health and a desirable intake of antioxidants. Thus the trend in the food industry is toward producing functional foods with increased levels of bioactive compounds. One of the reasons that Australian native plants have become commercial ingredients is that they personify truly Australian cuisine. There is growing interest in value adding native food plants for local and export markets. There is also an increasing interest in the bioactive components of native plants and as a result identifying a role for native plant foods in the functional food market. However there are a number of commercial issues facing native food producers and food processors in delivering consistent quality products to commercial end users based on a food technology and nutrition platform. Some specific bioactive compounds were measured. Lycopene, β-carotene and ascorbic acid were determined by HPLC. The method for determining lycopene and β-carotene required optimisation. It was found that the accuracy of measurement of lycopene and β-carotene was improved if the sample was finely blended to release the lycopene from the food matrix to maximise extraction. Considerable losses were found during the measurement of ascorbic acid by HPLC. An oxygen quenching agent, sodium metabisulphite, was used to delay the rate of ascorbic acid degradation. The rate of addition at 500 μg/mL was found to be very effective. Moreover, since the degradation kinetics can be expressed as a first order reaction, the rate constant k was calculated for each sample. Since loss of ascorbic acid was still observed during long HPLC sequence runs, the k values were used to extrapolate back to the initial ascorbic acid concentration in the samples. Only Australian native plants currently used as commercial ingredients were selected and used through out the work. These were bush tomato, Kakadu plum, wild lime, finger lime, Davidson’s plum, wattle seed and lemon myrtle. The post harvest and handling procedures of all of those above plants were documented. The information was gathered from the farmers, distributors, representatives of Aboriginal community and from the literature. The samples were also collected and tested for bioactive compounds. It was found that post harvest methods of the native plants had an effect on the survival of bioactive compounds. There are two documented post harvest and handling methods for bush tomato, sun and oven drying. Sun drying seemed to give a better appearance however there was lower survival of bioactive compounds. Most of the native plant fruits are frozen for sale commercially. It was found that for the frozen fruit, the levels of bioactive compounds fluctuated probably due to differences in size and species. Bush tomatoes are one of the most commonly used native fruits and these and other native fruits are frequently made into sauces, chutneys and jams. The stability of bioactive compounds is therefore of importance in these kinds of products. A shelf life study was carried out on bush tomato sauce and chutney. Lycopene was measured in the products together with sensory and colour measurements throughout a period of 9 months. The effect of light and temperature was studied. Lycopene was affected by all of the factors and the study also showed changes in colour and flavour in the products. The behaviour of bioactive compounds during processing was studied. Samples were collected during the production of commercial sauces. Bush tomato ketchup, chutney and Kakadu plum chilli sauce were sampled from the start, middle and the end of the processing run. The samples were tested for specific bioactive compounds; lycopene for bush tomato sauces and ascorbic acid for Kakadu plum sauce. The studies showed that lycopene content was constant through out the run for both bush tomato sauces. Similarly, for the Kakadu plum sauce, ascorbic acid content was constant. However the losses appeared to have taken place prior to the making of the final sauce. The effect of heat processing on bioactive compounds was studied on a laboratory scale product. Formulated bush tomato and Kakadu plum sauces were made in the laboratory and also were tested for specific bioactive compounds. Lycopene content increased by 48 % which can be explained by the release of the lycopene from the food matrix. In contrast, there was a large loss of ascorbic acid in Kakadu plum sauce during the heating process. There are two aspects to the food safety issues in dealing with the use of Australian native plants. First, finding ways to eliminate toxic compounds is essential. For example, it is recommended that bush tomato be collected at the ripe and dried stage when any toxins are at a minimum. Second, during the processing of the products, the critical control points need to be carefully tested in order to protect the products from any contamination. The antioxidant capacity of native plants using DPPH, TEAC and total phenol assays was determined. A positive correlation was found between the DPPH and TEAC assays but not between either of these with total phenol content. Kakadu plum was found to be the most effective antioxidant containing plant. However, the results showed relatively low antioxidant activity in Davidson’s plum even though it contains a high amount of total anthocyanins (polyphenols). This could be due to the colour of the fruit extract interfering with the measurement of antioxidant activity because ABTS radical used in the TEAC assay is purple. LC-MS was used for the analysis of flavonoids and anthocyanins in a number of native plants. Davidson’s plum was analysed differently due to the large amount of anthocyanin detected. A lower cone voltage was found out to give a better anthocyanin M+ molecular ion plus fragment ions for the sequential loss of sugar molecule and finally the anthocyanidin M+ ion. The results shown that 6 anthocyanins were found which are in order of decreasing concentration: delphinidin-hexosepentose, cyanidin-hexose-pentose, petunidin-hexose-pentose, pelargonidin-hexose, peonidin-hexose and malvidin-hexose. 2008-11-21T00:00:00Z Sommano, Sarana http://espace.library.uq.edu.au/view/UQ:204235 Abstract In open pit mining operations, blast induced rock mass displacement can have a significant impact on ore recovery and downstream productivity. A comprehensive review of the literature has shown that quantifying displacement on a regular basis has generally been limited by the complexity involved in measuring the process. As a result, various empirical and numerical modelling approaches have been developed to estimate the magnitude of displacement for given blast design inputs. Advanced three-dimensional numerical approaches are limited by their computational requirements and are yet to be routinely applied to full scale conditions. The use of simpler numerical approaches have shown potential but previous attempts have been limited by the oversimplification of boundary conditions, disregard for key processes such as inter-particle collisions and are generally two dimensional in nature. The implementation of these models within the production environment has been onerous as a result of the numerous calibration parameters required to generate reliable results. The recent development of the Blast Movement Monitoring (BMM) system and advances in software and hardware dedicated to computational rigid body dynamics, have facilitated new avenues in which blast induced rock mass displacement can be studied and modelled. The main objective of this thesis is to improve our knowledge of the key factors that influence rock mass displacement through: • the analysis of direct physical measurements of full scale production blasts; • and the development of a practical three dimensional blast movement modelling framework aimed at the production stages of operating mines. To gain a better understanding of the main factors which control rock mass displacement in open pit production blasting environments, a comprehensive analysis of physically measured displacement data has been conducted using a combination of advanced data mining and classical statistical techniques. Three main data sets were used for this analysis, including existing data published as part of two Masters thesis from the Mackay School of Mines; data collected during the development of the BMM system at the University of Queensland’s Julius Kruttschnitt Mineral Research Centre (JKMRC), and new data collected as part of this thesis to supplement the sparse areas within the Mackay and JKMRC data sets. This new data set was gathered at the Mogalakwena Platinum Mine in the Republic of South Africa. Results from the analysis of the three data sets has shown that the main parameters controlling rock mass displacement in open pit production blasting include the three dimensional explosive energy distribution, the orientation of timing contours and confinement effects such as the distance from the free face and stemming influence. These parameters provide the basis from which displacement outcomes such as the magnitude and direction of movement can be estimated and allowed the development of a novel framework to model blast induced rock mass displacement in three dimensions. The proposed modelling framework takes a mechanistic approach by combining rigid body dynamics with established empirical relations and material properties to simulate the displacement of the rock mass under specified blasting conditions. To improve on the current limitations of existing models, the framework addresses six major requirements. These are: 1. the ability to model displacement in three dimensional space while taking into account particle interaction, 2. the ability to incorporate input parameters available to engineers onsite, 3. the ability to model the transition from unconfined to confined blasting conditions, 4. the ability to run within a reasonable time frame, 5. the ability to be calibrated to production blasting conditions using existing technology, and 6. the ability to build models that can be linked directly to block modelling techniques found in geological and mine planning software. The modelling framework consists of a discretised block model of the blast volume that can be described by the positions and orientations of the blocks at each time step during the simulation. All blocks are assigned two initial conditions based on spatial energy distribution and timing contour analysis. These initial conditions define the blocks initial displacement vector prior to the rigid body dynamics program’s particle collision algorithms taking over. To account for the loss of shock and ineffective energy during the breakage process, an energy loss weighting factor is applied to the calculated energy values. Results from three case studies of full scale production blasts have shown that the model generally responds well to the horizontal component of the three-dimensional displacement vector but is less accurate in the vertical displacement direction. This is the first time that a three dimensional displacement model has been evaluated against actual sub-surface displacement data. The model evaluation has indicated that the introduced energy loss factor can be successfully used as a calibration parameter. For all three case studies, the model ran within a reasonable time frame, the longest averaging 45 minutes to simulate a blast volume in the order of 125,000 m3. Detailed analysis has also helped identify the main limitations of the current framework and directions for future work. 2010-04-23T00:00:00Z Alan Tordoir http://espace.library.uq.edu.au/view/UQ:218825 2010-10-20T00:00:00Z Bennett, Rebekah. http://espace.library.uq.edu.au/view/UQ:107255 2007-08-24T00:00:00Z Mark Quinnell http://espace.library.uq.edu.au/view/UQ:283839 2012-10-24T14:27:28Z Davis, Jonathan James http://espace.library.uq.edu.au/view/UQ:273503 Employee cynicism is now widely acknowledged to be a complex phenomenon that pervades many contemporary workplaces. Yet, while considerable research attention has been directed towards understanding the effects of cynicism on workplace outcomes, there remains little consensus regarding the precise nature of cynicism and the role it performs in shaping individuals’ relationship with their organisation. While some conceptual research acknowledges that cynicism is capable of existing as a ‘malignant’ or a ‘benign’ force in organisations, capable of affecting some individuals and the organisations in which they work more or less negatively than others, few empirical explanations have been provided to account for this duality. Cynicism research as a whole has been criticised for its lack of theoretical development, despite attempts by researchers from diverse backgrounds to fit the construct into various theoretical frameworks. However, in competition with the majority of mainstream research applications of cynicism, one conceptualisation of cynicism has emerged which characterises it as a rational defence strategy fostering the disengagement of the individual from the organisation. This element of organisational disengagement (OD), proposed to lie at the heart of employee cynicism, has been suggested to be a driving force behind how individuals interact with their organisations. Organisational disengagement is a conceptual space that has not been adequately addressed by existing research. I argue that extending cynicism research by understanding and investigating the disengagement it is capable of engendering between employees and their organisations provides an intuitive way to understand the link between cynicism and workplace outcomes. Further, better understanding the nature and extent of the organisational disengagement created by employee cynicism provides a means through which to explain how cynicism affects different individuals and organisations differently. The aim of this research is to explore and operationalise the concept of organisational disengagement in a contemporary organisational context. In this thesis, I focus on exploring organisational disengagement in the context of employee cynicism, which has been proposed by a small group of researchers to a major force behind the psychological separation of the individual from their organisation. I propose that organisational disengagement performs an important role in determining how workplace defences such as employee cynicism manifest as organisational outcomes. Moreover, I propose that organisational disengagement itself may act as a more powerful predictor of attitudes and behaviours at work than employee cynicism and other organisational phenomena. To these ends, I conducted three studies. Study 1 was conducted in order to investigate whether organisational disengagement is experienced by employees facing undesirable or negative events at work, and, further, to document the nature and extent of this disengagement from the organisation. Phenomenological interviews were conducted on a sample of 15 working individuals within a large Australian university. Findings from the study suggested that organisational disengagement is, indeed, experienced by individuals — cynical or otherwise. Participants reported that their disengagement was commonly experienced in four distinct ways: as cognitive withdrawal (OD-CW), behavioural withdrawal (OD-BW), emotional divestment (OD-ED), and as a separation of the self-concept from the organisation (OD-SS). These dimensions of organisational disengagement were not mutually exclusive; rather, participants reported experiencing multiple dimensions simultaneously, suggesting that the four dimensions uncovered in this study might be used to create a profile of an individual’s organisational disengagement, which may account for individual differences in the outcomes of change. In Study 2, I developed and validated scales to measure each of the four OD dimensions using established scale development procedures and multiple samples. Study 3 was designed to assess the performance of the four OD measures, and of an overall, latent OD variable in explaining attitudinal and behavioural workplace outcomes, alone and in conjunction with employee cynicism. Self-report questionnaires were used to collect data from a sample of working individuals from a diverse range of organisations and industries. Structural equation modelling techniques were used to test the hypothesised relationships between cynicism, OD, and sets of attitudinal and behavioural outcomes. Results suggested that OD was associated with organisational commitment and job satisfaction, partially mediating the effects of cynicism. OD was also found to be negatively related with three organisational citizenship behaviours, again mediating the effects of cynicism on these outcomes. Overall, the findings from this body of research provide support for the organisational disengagement construct being worthy of empirical investigation. Further, they provide evidence of the ability of OD to profile the disengagement produced by defence strategies including cynicism, emplaced by individuals in order to control their interaction with the organisation at which they work. By operationalising organisational disengagement, this thesis makes a contribution to the theoretical understanding of employee cynicism and organisational disengagement, and, in applied settings, allows for organisations to understand and monitor the extent to which individuals are psychologically connected to their organisation. 2012-05-01T00:00:00Z Gareth John Snowden Simpson http://espace.library.uq.edu.au/view/UQ:158636 This study is to evaluate the influence of dominant discourse on news-making decisions affecting the coverage of the Bali Bombing 2002 by the Indonesian newspapers KOMPAS, Republika, and Bali Post. Norman Fairclough’s Critical Discourse Analysis method has been chosen for this study, since it provides two levels of analysis, textual level and discursive level. In the case of the textual level analysis, the texts of the news stories from the three newspapers were analysed and at the discursive level of analysis, results from observations of newsroom procedure and interviews with journalists were analysed. The discourses revealed were examined to ascertain which discourses were dominant at what time and in which news organisation in order to uncover the reason for the influence and the dominance. In most cases, the dominant discourses reflected in the stories of each news organisations coincided with the opinions of the majority of the staff and owners of that news organisations. 2008-11-21T00:00:00Z Aziz, Syamsuddin http://espace.library.uq.edu.au/view/UQ:215480 2010-09-02T00:00:00Z Kathage, B. A. http://espace.library.uq.edu.au/view/UQ:217185 The deregulation of the electricity industry had fall short of recognising the uniqueness of electricity. As electricity produced has to be instantaneously consumed, while ensuring that the power system is secure at all time. However, short term issues such as demand variations resulting in uncertain pool prices, market inefficiencies, participants’ displaying strategic behaviours will all contributed to short term market problems. Such short term issues can aggregate into long term investment problems, effectively setting up market barriers against new generation investments or research into new technologies. This thesis sets out to address the above short and long term problems in the context of the Australia National Electricity Market (NEM) . The market operator of the Australia NEM utilises a Linear Programming (LP) optimisation engine to dispatch generators into production. Despite LP speed in convergence to an optimum solution, the boundary search technique may not offer sufficient optimum dispatch outcomes. A chapter in this thesis presents the application of Genetic algorithms in the solving of market dispatch problem similar to that performed by the market operator. This study has indicated that transmission capacities can be better utilised when dispatch problem is optimised by genetic algorithm, potentially offering interconnected regions greater ability to share reserves. A hybrid model was proposed in one of this thesis chapter to forecast pool prices based on historical price demand characteristics. The area of pool price forecasts was a well study area, with a number of well established time series and data mining models. However, this model proposed seeks to reduce computation resources while producing accurate forecasting results by creating dependency of the forecast pool prices with the variations in system demand. This model enables more efficient forecast of pool prices based on prices respond characteristic to variations in system demand. This allows users to perform greater range of sensitivity studies. In some occasions, the NEM pool prices are not driven by increases in demand or network constraints; but participants exhibiting strategic behaviour through rebidding their capacity offers at higher price bands. An agent based model was detailed in one chapter of this thesis to model such behaviour. The model consisted of several modules emulating the processes a typical market participant will perform when trading in the market. The study noticed that that when the marginal generator game the market at times of tight demand-supply condition, the pool prices would not reflect optimum market outcomes. New generation capacity is a crucial part in ensuring supply demand balance in the NEM, therefore second half of this thesis is devoted to present works performed in long term generation investment issues. In the Australia NEM the market operator can only inform market participants of new capacity opportunities within a set range of study scenarios and conditions. To expand the number of scenarios that can be study, an integrated model is proposed in this thesis. The proposed model look at new generation entry using market simulation results from a market simulator. The model begins with the market simulator stepping through the simulation horizon annually, where the simulated results are then feed into the proposed new entry evaluation module. This proposed new entry evaluation model will then select a new entry with the highest economic return to enter the market. The selected new entry must fulfil a list of criteria which includes cost recovery, resource availability, construction time and the overall system adequacy. In the case study performed, it was noticed that when the pool prices were sufficiently high to support the investment of most new entrants in the new entry list, units with the shortest construction time and lowest capital cost such as an Open Cycle Gas Turbine will be the first to enter the market. Enhancements were added later in the form of risk evaluation of prospective projects within a single scenario. This enhancement potentially enables investors to perform several studies of prospective projects. In this enhanced model, the risk represented expected revenue distributions due to outages of the new entrant. This will also allows investors with greater insight on the risk a potential new entry is likely to face when it enters the market. In summary, this thesis identify knowledge gap in the Australia NEM and hence set out to address some of these vital short and long term issues that are important to the structural health of the NEM. 2010-09-26T00:00:00Z Kin Onn Wong http://espace.library.uq.edu.au/view/UQ:158346 The decision to research motivation through repertoire in intermediate cellists arose from two different perceived areas of need. Firstly, it was found that there was a scarcity of availability and accessibility of Australian compositions for intermediate cellists. Secondly, the literature suggested that there was a need for the further research of intrinsic motivation in the field of instrumental pedagogy. A review of the literature found that research into intrinsic motivation in instrumental pedagogy was mostly related to the 'process' of developing and maintaining motivation. Of the research which examined the aspect of 'content' in the maintenance of intrinsic motivation, this was mostly related to 'student choice'. This study emerged as a way of providing information to composers and teachers about what aspects of repertoire may be motivational. It investigates intrinsic motivation by questioning students and their teachers about which aspects of music repertoire are most likely to inspire students to practice more and strive for excellence. A discussion of the philosophies of Bruner and Csikszentmihalyi is included to give meaning and context to 'intrinsic motivation' in instrumental pedagogy. Research was conducted through purpose-designed questionnaires distributed to cello teachers and their students in Queensland. Questionnaires for teachers and students were very similar although the student questionnaire was a little shorter. The questionnaires gathered information on the most frequently used general teaching repertoire, as well as teachers’ experiences in teaching contemporary and Australian repertoire. Musical aspects investigated included style, emotional content, harmony, articulation, tempo (speed), tonality, and rhythm as well as cellistic techniques. This information was balanced with questions regarding the technical developmental requirements perceived necessary for intermediate students. In comparison with other motivators such as verbal encouragement, ensemble participation and preparation for performances and exams, repertoire was found to be a significant motivator for 'students' best work'. Students' preference for challenging music, or by contrast, beautiful music was a persistent theme throughout the results. The three characteristics which were nominated as most motivating by both teachers and students were fast and lively, from the Romantic period and for cello and piano. The strongest difference between results for teachers and students was on the characteristic of folk feel which produced opposite results for the two groups of respondents. Some differences were also found within the respondent groups on the basis of gender and age. It is noted that students acknowledged the benefits of learning more advanced aspects of technique, such as thumb position, in expanding the pool of repertoire which they would be able to play. It was confirmed that Australian repertoire was not often taught to students at this level and that this was, at least in part, because of a lack of availability. Suggestions have been made for both composers and teachers in choosing techniques and repertoire for intermediate students. However, the importance of asking students about their preferences is borne out by the volume and detail of students' individual responses. Also, by questioning their students, teachers are likely to be stimulating the valued development of 'metacognitive strategies' in adolescent students. 2008-11-21T00:00:00Z Berry, Anne Irma http://espace.library.uq.edu.au/view/UQ:247410 2011-09-07T00:00:00Z Nolan, Glenda R. http://espace.library.uq.edu.au/view/UQ:194384 In this thesis we study the physics of quantum many-body systems confined to one-dimensional geometries. The work was motivated by the recent success of experimentalists in developing atom traps, capable of restricting the motion of the individual atoms to a single spatial dimension. Specifically, we look at aspects of the one-dimensional Bose gas including; excitation spectrum, correlation functions, and dynamical behaviour. In Chapter \ref{ch:excitation1D} we consider the Lieb-Liniger model of interacting bosons in one-dimension. We numerically solve the equations arising from the Bethe ansatz solution for the exact many-body wave function in a finite-size system of up to twenty particles for attractive interactions. We discuss novel features of the solutions, including deviations from the well-known string solutions due to finite size effects. We present excited state string solutions in the limit of strong interactions and discuss their physical interpretation, as well as the characteristics of the quantum phase transition that occurs as a function of interaction strength in the mean-field limit. Our results are compared to those obtained via exact diagonalization of the Hamiltonian in a truncated basis. In Chapter \ref{ch:g2} we analytically calculate the spatial nonlocal pair correlation function for an interacting uniform one dimensional Bose gas at finite temperature and propose an experimental method to measure nonlocal correlations. Our results span six different physical realms, including the weakly and strongly interacting regimes. We show explicitly that the characteristic correlation lengths are given by one of four length scales: the thermal de Broglie wavelength, the mean interparticle separation, the healing length, or the phase coherence length. In all regimes, we identify the profound role of interactions and find that under certain conditions the pair correlation may develop a global maximum at a finite interparticle separation due to the competition between repulsive interactions and thermal effects. In Chapter \ref{ch:casimirdrag} we study the drag force below the critical velocity for obstacles moving in a superfluid. The absence of drag is well established in the context of the mean-field Gross-Pitaevskii theory. We calculate the next order correction due to quantum and thermal fluctuations and find a non-zero force acting on a delta-function impurity moving through a quasi-one-dimensional Bose-Einstein condensate at all subcritical velocities and at all temperatures. The force occurs due to an imbalance in the Doppler shifts of reflected quantum fluctuations from either side of the impurity. Our calculation is based on a consistent extension of Bogoliubov theory to second order in the interaction strength, and finds new analytic solutions to the Bogoliubov-de Gennes equations for a gray soliton. In Chapter \ref{ch:solitons} we study the effect of quantum noise on the stability of a soliton. We find the soliton solutions exactly define the reflectionless potentials of the Bogoliubov-de Gennes equations. This results in complete stability of the solitons in a purely one dimensional system. We look at the modifications to the density profile of a black soliton due to quantum fluctuations. 2010-02-01T00:00:00Z Andrew Sykes http://espace.library.uq.edu.au/view/UQ:199834 Abstract In the existing JKMRC breakage testing method for AG/SAG mill modelling, ore is characterised using mainly high energy single impact tests. However, recent DEM studies have suggested that breakage in AG/SAG mills is mainly due to low energy repetitive (or multiple) collisions rather than single high energy impacts. Furthermore, several of the published AG/SAG ore hardness tests developed outside the JKMRC use laboratory tumbling mills to quantify the specific power required to grind the ore to a set product size. Comprehensive experiments were carefully designed using two mill diameters of 1.1 and 0.6 m to mimic the reported low energy repetitive impact breakage under low load conditions. The ore breakage characterisation parameters derived from high energy single impact tests were used to predict the low energy repetitive impact breakage behaviour. Significant bias has been shown to be associated with the traditional high energy single impact characterisation approach, suggesting an alternative method was required. An extensive experimental program with more than 1400 tests was conducted using a newly developed JKRBT (JKMRC Rotary Breakage Tester) device, gravity drop test and laboratory tumbling mills. Comprehensive data were collected and analysed to provide an understanding of low energy repetitive impact breakage of particles and high energy single impact breakage. Details of the experimental study and findings are presented in Chapter 5. A breakage characterisation model has been developed, which takes into account the various impact energy classes and their associated body breakage and surface breakage responses. The breakage conditions were analysed and used to derive two sets of impact breakage parameters (body breakage and surface breakage). These parameters were then combined using a procedure believed to account for the two key breakage modes in tumbling, and successfully applied to predict the breakage in the two laboratory tumbling mills. Chapter 6 presents the breakage modelling approach and results. Based on the understanding of different breakage modes, a novel particle breakage characterisation method for AG/SAG mill modelling has been proposed and validated. Different from the prior-art JKMRC approach in which the breakage tests are conducted at high energy single impact, the proposed method incorporates high energy single impact, low energy multiple impacts and a simplified tumbling test. Both breakage probability and degree of breakage are used to characterise the breakage behaviour of ores. The details of the new characterisation method can be found in Chapter 7. The studies conclude that • The JKRBT can be used to investigate rock breakage characteristics under single and repetitive impacts; • The breakage of rocks in tumbling mills (under very low load conditions) can be likened to the low energy JKRBT repetitive impact breakage. • The behaviour of particle breakage as observed in AG/SAG milling can be modelled using a combination of JKRBT and tumbling ore breakage characterization; • A methodology for ore breakage characterization for AG/SAG mill modelling has been proposed and validated using independent sets of ores samples. 2010-03-18T00:00:00Z Stephen Larbi-Bram http://espace.library.uq.edu.au/view/UQ:158413 2008-11-21T00:00:00Z Papinczak, Tracey Ann http://espace.library.uq.edu.au/view/UQ:283518 2012-10-17T00:00:00Z Dowsett, Kerry Francis http://espace.library.uq.edu.au/view/UQ:107082 2007-08-24T00:00:00Z Leong, Koay Teng. http://espace.library.uq.edu.au/view/UQ:157949 Abstract The aim of this study was to understand the relationships among the personality traits, risk attitudes, risk management practices, and decision making processes of dairy farmers in SE Queensland. Risk management and decision making processes are two of many components of managerial ability. The hypothesis was proposed that dairy farmers’ personalities influence their risk attitudes, decision making processes, and risk management abilities. Case studies of 46 dairy farmers in SE Queensland involving the completion of personality inventories (NEO-PI-R) based on the Five-Factor Model of personality; questionnaires and informal interviews were used to test the hypotheses. The thesis contains three parts. The first part, Chapter 1, is the introduction to the thesis. The second part of the thesis, Chapter 2 through Chapter 6, consists of an extensive review of the literature on the major topics pertinent to the project. In Chapter 2, a definition of “competence” in the context of this study is given, and an explanation of the evidence for a connection between personality and competence and thus job performance is detailed. In Chapter 3, the literature on personality is reviewed with particular emphasis on trait theory and the development of the Five-Factor Model of personality (FFM). In Chapter 4, the literature review on personality assessment using testing instruments designed for use in the context of the FFM is presented, and the rationale for the personality test instrument is expounded. It is the task of the manager to manage risk, so that considering risk attitude when making decisions is also an integral part of the study of the role of managers. Chapter 5 reviews the contemporary literature on risk and risk management with an emphasis on the application of risk management principles to dairy farms. In Chapter 6, the literature on decision theory is reviewed. Decision-making and risk management are intertwined. The behaviour resulting from the process of making a decision reflects the personality and risk attitude of the decision-maker. In this chapter, the distinction is made between formal and informal models of decision making, and examples are given. The third part of the project comprises Chapters 7 through Chapter 11. Chapter 7 outlines the research approach used – case studies - and paves the way for the following two chapters, which present a qualitative and a quantitative analysis of the data from the case studies. Chapter 8 presents part 1 of the investigation - the qualitative analysis of the case studies. This chapter introduces and explains the terminology used in the questionnaire and examines the trends and feeling in the farmers’ answers. Chapter 9 presents part 2 of the analysis – quantitative results of the personality assessments and interviews from the case studies with SE Queensland dairy farmers which were conducted to assess their risk management and decision making abilities. Chapter 10 provides a summary of the research findings, and then discusses the results with respect to the diverse responses of farmers to common external pressures. The chapter discusses the relevance of personality to the formation of management strategy and concludes with a short introduction to systems thinking as a way of thinking about the complex systems inherent in dairy farming. Chapter 11 reviews the subjects covered in the thesis and draws conclusions from the research. It outlines implications for policy makers and managers and proposes directions for further research in this area of investigation. Key Words: Five-Factor Model of Personality, risk, decision making processes, dairy farmers, management 2008-11-21T00:00:00Z Marchant, David Durack http://espace.library.uq.edu.au/view/UQ:284229 2012-11-01T00:00:00Z Degefu, Teshale http://espace.library.uq.edu.au/view/UQ:209318 Campylobacter is currently the most common cause of acute bacterial diarrhoea in Australia among all the notified enteric pathogens with more than 15,000 cases each year. The incidence of notified campylobacteriosis has steadily increased during the past 15 years from 67.0/100,000 population in 1991 to 121.4/100,000 in 2005, though the factors contributing to this increase had not been studied. Adjusting for under-reporting there are, at this point in time, an estimated 225,000 infections occurring each year in Australia, most of which are sporadic in nature. Much of our knowledge in Australia about risk factors for sporadic disease has been based on overseas literature. Prior to the studies undertaken in this thesis, the epidemiology of Campylobacter infection had not been thoroughly studied in Australia, nor had there been any national studies examining risk factors for locally-acquired infection. The broad aim of this thesis was to examine in depth the descriptive epidemiology of Campylobacter infection in Australia, explore the reasons for the sustained increase in incidence of infection and to identify the major risk factors for locally acquired infection using a multi-centre case-control study design. The descriptive study of the epidemiology of campylobacteriosis in Australia was based on Australian notifiable disease surveillance data collected over a 15-year period between 1991 and 2005. This study described the key epidemiological characteristics of this disease in Australia and identified some significant differences in incidence trends across states and territories and among different age groups which had not been previously reported. The study identified gaps in our knowledge of this disease in Australia and made recommendations for future research including the investigation of factors associated with the decline in incidence of infection among children aged  4 years and further studies to identify age and sex-specific risk factors for infection. The issue of seasonality, transmission routes and infection was addressed and areas for further research were specified including longitudinal studies at a regional level that incorporate a comparison of human, animal and environmental genotypes. This study also provided strong compelling evidence to support the hypothesis that the increase in notification rates in Australia during this period represented a real increase in the incidence of infection and that the main driving force behind this rise has been the ongoing increase in chicken consumption among the Australian public. The multi-centre case-control study, involving 1,714 participants  5 years of age, identified the major foodborne and non-foodborne risk factors for Campylobacter infection among the general population in Australia. This study confirmed that chicken meat is a major source of sporadic infection in this country and is responsible for almost one-third of all cases that occur in the Australian community each year. Other independent risk factors for sporadic infection in Australia included consumption of offal and ownership of domestic dogs or chickens aged  6 months. The Nagelkerke R² value of 16% for the final multivariable model indicated a considerable proportion of our case-patients had unexplained risk factors. The combined population attributable risk (PAR) estimate for the independent foodborne risk factors in this study was 31%, which is considerably less than the 75% to 80% of cases in the general population which are thought to be caused through foodborne transmission. Possible explanations for these results include the likelihood that a proportion of foodborne transmission in Australia occurs through food vehicles other than chicken due to cross-contamination from raw products, and the likelihood that much of the population attributable risk that is unaccountered for, may in fact be due to inherent limitations of study design resulting in systematic errors (information bias) and possibly reduced estimates of effect. The burden of illness among the general population in Australia attributable to different independent risk factors was estimated using a novel method developed specifically for this study. Briefly, community incidence data was coupled with PAR data from the case-control study and simulation techniques were used to: (i) estimate the number of infections attributable to specific risk factors, and (ii) derive credible intervals for these estimates by modeling the uncertainty in each variable component. This model of using case-control data in conjunction with pre-existing surveillance data provides researchers with a simple but robust tool for conducting source attribution studies on enteric pathogens. In conclusion, the studies undertaken in this thesis have made important contributions to our understanding of the epidemiology of sporadic Campylobacter infection in Australia. 2010-07-21T00:00:00Z Russell Stafford http://espace.library.uq.edu.au/view/UQ:106331 2007-08-24T00:00:00Z Phillips, Nancy Jane. http://espace.library.uq.edu.au/view/UQ:287503 2012-12-18T00:00:00Z Limpus, Colin James http://espace.library.uq.edu.au/view/UQ:158197 With an increasing focus on safety in the Australian underground coal mining industry and government legislation requiring employers to provide a safe workplace, there is a clear need for today’s strata control engineers to have design capabilities in relation to coal mine rib support that provide effective, reliable and consistent solutions. There has been a relatively limited amount of research undertaken with respect to the study of the mechanics of coal mine rib deformation and rib support and prior to this study no systematic rib support design technique had been developed for any country’s underground coal mining industry. This is in direct contrast to other geotechnical issues, such as coal mine roof support and pillar design, which have been extensively researched resulting in numerous technical papers, conferences/workshops dedicated to these specific issues and several proposed design techniques and/or guidelines. It is assessed that the primary reasons for this disparity have been a lack of understanding concerning the failure mechanisms associated with ribline behaviour and not being able to delineate the significant factors that affect ribline behaviour. This thesis has investigated the mechanical behaviour of coal mine ribs under various loading environments and with a wide variety of rib support hardware as a basis upon which an engineered design methodology could be formulated. A program of full scale field trials were conducted at ten collieries (representing four of the five major Australian coalfields), in conjunction with a comprehensive industry wide review of ribline performance from which a database was formulated and statistically analysed. The results of the field based experimental program and statistical analyses strongly suggest that the mechanical nature of rib movement is consistent with the buckling of thin coal plates or slabs. While a precursor to buckling may be tensile failure in the form of vertical splitting along cleat, mining induced fractures (as a result of roadway development) or the formation of new cracks due to longwall abutment loading; it is clear from the extensometry that the nature and magnitude of the lateral displacement is a result of buckling. There was a significant reduction with respect to the extent of softening within the riblines that utilised areal support in the form of steel or plastic mesh. The major structural or mechanistic benefit of mesh to overall ribline performance is that it maintains the buckled coal plate to the ribline allowing it to behave (to a degree) like a spring, which in this instance not only provides resistance to the vertical stress but also provides an active lateral force to the inner coal plates. Essentially the best rib support in terms of overall roadway maintenance is potentially the rib itself. Based on the results of this study and an improved understanding of the mechanistic behaviour of coal mine ribs, a design methodology (the first of its type), known as Analysis and Design of Rib Support (ADRS), has been developed for the Australian underground coal mining industry. Since its release to the Australian collieries in February/March 2005 via ACARP technology transfer workshops, ADRS has now been registered and successfully used by most Australian collieries, the NSW Mining Inspectorate and several consultants. ADRS is an empirical technique, which recognises that several geotechnical and design factors affect ribline performance and in addition that operational and safety issues essentially dictate the level of performance required. Therefore the design recommendations associated with ADRS are specific to the Australian coal industry; however the procedure(s) for data collection and analysis could be applied to other countries’ underground coal industries. 2008-11-21T00:00:00Z Colwell, Mark Gerard http://espace.library.uq.edu.au/view/UQ:215475 2010-09-02T00:00:00Z Just, G. D. http://espace.library.uq.edu.au/view/UQ:105906 2007-08-24T00:00:00Z Dam, Thien Quang. http://espace.library.uq.edu.au/view/UQ:158252 Ras proteins are monomeric GTPases which operate in cellular signal transduction pathways to regulate cell growth, differentiation and apoptosis. Mutations at amino acid residue 12, 13 or 61 render the protein constitutively active and oncogenic. These mutations are found in 30% of human cancers. There are three isoforms of the Ras protein: H-ras, N-ras and K-ras. All three isoforms localize to the inner leaflet of the plasma membrane, and this localization is important for their biological function. H-ras and N-ras traffic to the plasma membrane via the classical exocytic pathway, while the K-ras trafficking pathway is non-vesicular and is currently poorly characterized. In order to identify the proteins that may be involved in the K-ras trafficking pathway, an affinity chromatography approach was developed. The method utilized the C-terminal membrane-targeting regions of K-ras (CTK) and H-ras (CTH) as baits to purify cellular proteins from mouse brain cytosol. Proteins which selectively interacted with CTK but not CTH were identified by mass spectrometry. Four of these proteins, B23, Ncl, LANCL1 and laminin receptor-1, were further characterized and evaluated as putative K-ras transport factors. B23 localizes to P100 and nuclear fractions, and selectively interacts with K-ras in vivo. However, overexpression or siRNA-mediated knockdown of B23 does not affect plasma membrane localization of K-ras. Ncl localizes to the P100, S100 and nuclear fractions. Nuclear Ncl, but not extranuclear Ncl, selectively interacts with K-ras in vivo. Overexpression of Ncl does not affect the intracellular localization of either H-ras or K-ras. LANCL1 is associated with the P100, S100 and nuclear fractions, and preliminary results show that LANCL1 may selectively interact with K-ras in vivo. Selective interaction between laminin receptor-1 and K-ras could not be confirmed, either in vitro or in vivo. Also, overexpression of laminin receptor-1 has no effect on the P100/S100 distribution of K-ras, or its downstream MEK/ERK signalling. In conclusion, this thesis represents the first known proteomic approach dedicated to the discovery of K-ras transport factors. Three novel selective interacting partners of the membrane targeting domain of K-ras are identified, although their precise function in K-ras trafficking remains to be elucidated. 2008-11-21T00:00:00Z Lau, Chiyan http://espace.library.uq.edu.au/view/UQ:209256 2010-07-20T00:00:00Z Beiers, John Leonard http://espace.library.uq.edu.au/view/UQ:105916 2007-08-24T17:53:17Z Mohajerani, Shahroo. http://espace.library.uq.edu.au/view/UQ:209535 2010-07-24T00:00:00Z Fox, William Edward. http://espace.library.uq.edu.au/view/UQ:106523 2007-08-24T00:00:00Z Ofori, Philip Kwadwo. http://espace.library.uq.edu.au/view/UQ:157965 This thesis deals with diffusion and flow of sub-critical hydrocarbons in activated carbon by using a differential permeation method. The hydrocarbons are selected according to the effect on environmental concerns and their unique characteristics such as polarity and affinity towards activated carbon. Although it has been known that transport processes in activated carbon consist of Knudsen diffusion, gaseous viscous flow, adsorbed phase diffusion (so called, surface diffusion) and condensate flow, there have been no rigorous models to describe the transport processes in activated carbon with a full range of pressures. In particular among the four processes, the mechanism of adsorbed phase diffusion in activated carbon is still far from complete understanding. Also due to the dispersion interactions between adsorbing molecules and the solid surface, one would expect that Knudsen diffusion is influenced by the dispersive forces. From intensive experimental observations with a great care over a full range of pressures, conventional methods (for example, direct estimation from inert gas experiments) to determine adsorbed phase diffusion are found to be inadequate for strongly adsorbing vapors in activated carbon. By incorporating the effect of adsorbate-adsorbent interactions into Knudsen diffusivity, the general behavior of adsorbed phase diffusion in terms of pressure (or surface loading) can be obtained, showing a significant role in transport at low pressures. For non-polar hydrocarbons such as benzene, carbon tetrachloride and n-hexane, a mathematical model, which accounts for the effects of adsorbate-adsorbent interactions and pore size distribution, is formulated and validated, resulting in a good agreement with experimental data. Moreover, the adsorption and dynamic behaviors of alcohol molecules (which are polar compounds) are investigated with an aim to compare their behaviors against those of non-polar compounds. 2008-11-21T00:00:00Z BAE, Jun-Seok http://espace.library.uq.edu.au/view/UQ:107174 2007-08-24T18:40:23Z Sabarinah Sh. Ahmad http://espace.library.uq.edu.au/view/UQ:106323 2007-08-24T00:00:00Z Lai, Kim (Hsin-Jung) http://espace.library.uq.edu.au/view/UQ:253914 2011-10-03T00:00:00Z Wang, Jianxiong. http://espace.library.uq.edu.au/view/UQ:180083 Asymmetric dependence (AD) is defined as dependence that differs across opposing regions of the joint return distribution. Recent evidence of AD between equity returns suggests that dependence can be decomposed into a linear component, captured by the correlation matrix, and a higher order component. When these higher order terms are characterised by increased correlation in bear or bull markets, the effectiveness of diversification strategies is reduced. To the extent that an investor is unable to completely diversify these higher order terms of dependence, it follows that they should be reflected in asset prices and managed explicitly during the portfolio construction process. The aim of this thesis is to determine the extent of AD amongst asset returns, to investigate whether AD is priced and to develop a means of managing AD in the portfolio. I justify the existence of AD and the separation of AD from linear dependence via the bivariate Edgeworth expansion, finding that the joint return distribution may be described by an infinite number of higher order co-moments. Correlation (and hence β) describes one dimension of an infinite number of higher dimensions describing dependence. To determine the importance of AD in finance, I first develop measures that can detect AD independent of the level of linear dependence and idiosyncratic risk. These measures are used to determine the extent of AD amongst US stock returns and the market, to obtain an understanding of how AD changes through time and to re-examine the evidence of AD between equity portfolios. By measuring AD separate from linear dependence, I demonstrate several findings. First, I find evidence of non-stationary AD that can exists irrespective of the magnitude of linear dependence, measured by β. This time-varying AD consists of both significant upper tail dependence (UTD) and significant lower tail dependence (LTD), although LTD is found to occur more frequently than UTD, especially for small stocks and stocks displaying high idiosyncratic risk. Significant time-varying AD is also detected between domestic equity indices and international equity markets, implying that if a portfolio is weighted towards certain industries or countries, portfolio construction methods may need to be adjusted in order too meet risk and return targets, particularly if future AD cannot be adequately forecasted. Next, I investigate whether AD is priced in US equities using the Fama and MacBeth (1973) regression methodology in conjunction with my β invariant AD metrics. I find that AD is as important as linear dependence in explaining the variation in returns. In particular, a positive relationship between LTD and return is found. I document an AD risk premium of 2.7% pa, compared to a β risk premium of 6.18% pa. The AD risk premium increases to 6.9% pa for stocks with significant LTD. This result holds after controlling for size, book-to-market ratio, downside β and coskewness. I also find past AD is a significant variable in predicting the future returns of small firms, whilst neither AD nor linear dependence predict the future returns of large firms. I subsequently demonstrate a means of incorporating AD structures during the portfolio construction process using copula functions. I then investigate how asymmetric return dependencies affect the efficient frontier and subsequent portfolio performance under a dynamic rebalancing framework. By considering the problem of tactically allocating a small set of domestic equity indices, I demonstrate several findings. First, I show that a Mean-Variance efficient frontier differs from the efficient frontier constructed under AD. Constructing paper portfolios based upon these differences, I find that real economic value lies in correctly accounting for AD structures. The primary source of this economic value stems from the ability to better protect portfolio value and reduce the size of any erosion in return relative to the normal portfolio. Finally, I document the benefits of actively managing AD during the portfolio construction process and determine a number of portfolio management principles required to successfully manage AD. I illustrate that managing asymmetry risk in a portfolio of international equity indices results in increased return, decreased risk and decreased transaction costs. I show that in order to yield these benefits, investors must actively and dynamically manage their portfolio. Furthermore, I illustrate that the ability to short-sell assets provides most of the benefits described. 2009-08-28T00:00:00Z Anthony Hatherley http://espace.library.uq.edu.au/view/UQ:107362 2007-08-24T18:48:32Z Henderson, Tracy May http://espace.library.uq.edu.au/view/UQ:284328 2012-11-05T00:00:00Z Macharia, John Mwaura http://espace.library.uq.edu.au/view/UQ:246402 2011-08-25T00:00:00Z Wiranatha, Anak Agung Putu Agung Suryawan. http://espace.library.uq.edu.au/view/UQ:205337 2010-05-18T00:00:00Z Joel Cullin http://espace.library.uq.edu.au/view/UQ:106045 2007-08-24T17:58:15Z Carden, Michael, 1952- http://espace.library.uq.edu.au/view/UQ:106453 2007-08-24T18:13:39Z Keane, Shelley L. http://espace.library.uq.edu.au/view/UQ:105988 2007-08-24T00:00:00Z Copley, Jodie Ann. http://espace.library.uq.edu.au/view/UQ:158771 This thesis investigates the issue of how stone ‘drill points’ were manufactured at the Late Neolithic workshop of Bai Ben, Northeastern Vietnam, from a technological perspective, and with the aim of understanding the organisation of technology at the site. Within this organisational approach, the issue is investigated in a comprehensive manner from raw material procurement to drill manufacture, use, maintenance, and discard. Attribute based statistical methods are developed to observe the time-ordering of dimensional and morphological changes of classes of cores and drills with the ultimate aim of reconstructing the reduction sequences so that the position of drill points within these sequences is better identified. The analyses show that raw material used to produce drill points is variable in size as well as locally available and readily accessible in the region. The availability and the variation of raw material size are in turn shown to be key factors that strongly affect the whole process of core reduction at Bai Ben. It can be seen in both freehand and bipolar core populations that there is not a simple single reduction trajectory but a complex reduction process that involves reduction sequences of varying lengths. Raw material of different sizes could be transformed either by first employing freehand percussion followed by bipolar percussion, or by directly employing a bipolar technique. Cores could be discarded at many points along the reduction continuum, creating a complex pattern of core size and reduction intensity. In contrast to core reduction, drill reduction was not substantially influenced by raw material selection, but by the initial size and shape of drill blanks. This determined how much reduction was necessary to create a standardized product. The time-ordering of dimensional and morphological changes in various artefact classes thus permits us to understand the causes of assemblage variability at the site. This research represents the first application of a technological approach to the archaeological record of Vietnam. This study illustrates the benefits of conducting future technological investigations at the numerous other workshop sites known from Vietnam. It is argued that such investigations are required to build an understanding of the nature and importance of specialized lithic activities, trade, and exchange in this period of significant cultural change. 2008-11-21T00:00:00Z Nguyen, Dong