The distribution and spread of citrus canker in Emerald, Australia

Citrus canker is a disease of citrus and closely related species, caused by the bacterium Xanthomonas citri subsp. citri. This disease, previously exotic to Australia, was detected on a single farm [infested premise-1, (IP1). IP is the terminology used in official biosecurity protocols to describe a locality at which an exotic plant pest has been confirmed or is presumed to exist. IP are numbered sequentially as they are detected] in Emerald, Queensland in July 2004. During the following 10 months the disease was subsequently detected on two other farms (IP2 and IP3) within the same area and studies indicated the disease first occurred on IP1 and spread to IP2 and IP3. The oldest, naturally infected plant tissue observed on any of these farms indicated the disease was present on IP1 for several months before detection and established on IP2 and IP3 during the second quarter (i.e. autumn) 2004. Transect studies on some IP1 blocks showed disease incidences ranged between 52 and 100% (trees infected). This contrasted to very low disease incidence, less than 4% of trees within a block, on IP2 and IP3. The mechanisms proposed for disease spread within blocks include weather-assisted dispersal of the bacterium (e.g. wind-driven rain) and movement of contaminated farm equipment, in particular by pivot irrigator towers via mechanical damage in combination with abundant water. Spread between blocks on IP2 was attributed to movement of contaminated farm equipment and/or people. Epidemiology results suggest: (i) successive surveillance rounds increase the likelihood of disease detection; (ii) surveillance sensitivity is affected by tree size; and (iii) individual destruction zones (for the purpose of eradication) could be determined using disease incidence and severity data rather than a predefined set area.

AITPM Email Newsletter Volume 0904, April 2009: Presidents Message

President’s Report Hello fellow AITPM members, A few weeks ago we saw another example of all levels of Government pulling together in real time to try to deal with a major transport incident, this time it was container loads of ammonium nitrate falling off the Pacific Adventurer during Cyclone Hamish and the associated major oil spill due to piercing of its hull off Moreton Bay in southern Queensland. The oil spill was extensive, affecting beaches and estuaries from Moreton Island north to the Sunshine Coast; a coastal stretch of at least 60km. We saw the Queensland Government, Brisbane, Moreton Bay and Sunshine Coast Regional Council crews deployed quickly once the gravity of the situation was realised to clean up toxic oil on beaches and prevent extensive upstream contamination. Environmental agencies public and private were quick to respond to help affected wildlife. The Navy’s HMAS Yarra and another minesweeper were deployed to search for the containers in the coastal area in an effort to have them salvaged before all ammonium nitrate could leach into and harm marine habitat, which would have a substantial impact not only on that environment but also the fishing industry. all of this during the final fortnight before a State election.) While this could be branded as a maritime problem, the road transport and logistics system was crucial to the cleanup. The private vehicular ferries were enlisted to transport plant and equipment from Brisbane to Moreton Island. The plant themselves, such as graders, were drawn from road building and maintenance inventory. Hundreds of Councils’ staff were released from other activities to undertake the cleanup. While it will take some time for us to know the long term impacts of this incident, it seems difficult to fault “grassroots” government crews and their private counterparts, such as Island tourism staff, in the initial cleanup effort. From a traffic planning and management perspective, we should also remember that this sort of incident has happened on road and rail corridors in the past, albeit on lesser scales. It underlines that we do need to continue to protect communities, commercial interests, and the environment through rigorous heavy vehicle management, planning and management of dangerous goods routesincluding rail corridors through urban areas), and carefully considered incident and disaster recovery plans and protocols. I’d like to close in reminding everyone again that AITPM’s flagship event, the 2009 AITPM National Conference, Traffic Beyond Tomorrow, is being held in Adelaide from 5 to 7 August. SA Branch President Paul Morris informs me that we have had over 50 paper submissions to date, from which a very balanced and informative programme of sessions has been prepared. www.aitpm.com has all of the details about how to register, sponsor a booth, session, etc. Best regards all, Jon Bunker

External pressure in the hardening of phosphate in tribofilm on iron surfaces

Purpose: In the present work we consider our (in progress) spectroscopy study of zinc and iron phosphates under the influence external high pressure to determine zinc ion change coordination from tetrahedral to octahedral (or hexahedral) structure.----- Design/methodology/approach: The standard equipment is the optical high pressure cell with diamond (DAC). The DAC is assembled and then vibrational or electronic spectra are collected by mounting the cell in an infrared, Raman, EXAFS or UV-visible spectrometer.----- Findings: Mechanism by which zinc and iron methaphosphate material is transformed to glassy meta-phosphate is enhancing mechanical properties of tribofilm. The two decades of intensive study demonstrates that Zn (II) and Fe (III) ions participate to cross-link network under friction, hardening the phosphate.----- Research limitations/implications: Transition metal atoms with d orbital have flexible coordination numbers, for example zinc acts as a cross-linking agent increasing hardness, by changing coordination from tetrahedral to octahedral. Perhaps the external pressure effect on the [Zn–(O-P-)4 ] complex causes a transformation to an [Zn –(O-P-)6] grouping.----- Originality/value: This paper analyses high-pressure spectroscopy which has been applied for the investigation of 3D transition metal ions in solids. When studying pressure effects on coordination compounds structure, we can expect changes in ground electronic state (spin-crossovers), electronic spectra due to structural distortions (piezochromism), and changes in the ligand field causing shifts in the electronic transitions.

Transfer of learning across the globe : pre-service teachers taking the initiative

A continuing challenge for pre-service teacher education is the learning transfer between the university based components and the practical school based components of their training. It is not clear how easily pre-service teachers can transfer university learnings into ‘in school’ practice. Similarly, it is not clear how easily knowledge learned in the school context can be disembedded from this particular context and understood more generally by the pre-service teacher. This paper examines the effect of a community of practice formed specifically to explore learning transfer via collaboration and professional enquiry, in ‘real time’, across the globe. “Activity Theory” (Engestrom, 1999) provided the theoretical framework through which the cognitive, physical and social processes involved could be understood. For the study, three activity systems formed community of practice network. The first activity system involved pre-service teachers at a large university in Queensland, Australia. The second activity system was introduced by the pre-service teachers and involved Year 12 students and teachers at a private secondary school also in Queensland, Australia. The third activity system involved university staff engineers at a large university in Pennsylvania, USA. The common object among the three activity systems was to explore the principles and applications of nanotechnology. The participants in the two Queensland activity systems, controlled laboratory equipment (a high powered Atomic Force Microscope – CPII) in Pennsylvania, USA, with the aim of investigating surface topography and the properties of nano particles. The pre-service teachers were to develop their remote ‘real time’ experience into school classroom tasks, implement these tasks, and later report their findings to other pre-service teachers in the university activity system. As an extension to the project, the pre-service teachers were invited to co-author papers relating to the project. Data were collected from (a) reflective journals; (b) participant field notes – a pre-service teacher initiative; (c) surveys – a pre-service teacher initiative; (d) lesson reflections and digital recordings – a pre-service teacher initiative; and (e) interviews with participants. The findings are reported in terms of the major themes: boundary crossing, the philosophy of teaching, and professional relationships The findings have implications for teacher education. The researchers feel that deliberate planning for networking between activity systems may well be a solution to the apparent theory/practice gap. Proximity of activity systems need not be a hindering issue.

Treadmill adaptation and verification of self-selected walking speed : a protocol for children

The term self-selected (i.e., individual or comfortable walking pace or speed) is commonly used in the literature (Frost, Dowling, Bar-Or, & Dyson, 1997; Jeng, Liao, Lai, & Hou, 1997; Wergel-Kolmert & Wohlfart, 1999; Maltais, Bar-Or, Pienynowski, & Galea, 2003; Browning & Kram, 2005; Browning, Baker, Herron, & Kram, 2006; Hills, Byrne, Wearing, & Armstrong, 2006) and is identified as the most efficient walking speed, with increased efficiency defined by lower oxygen uptake (VO^sub 2^) per unit mechanical work (Hoyt & Taylor, 1981; Taylor, Heglund, & Maloiy, 1982; Hreljac, 1993). [...] assessing individual and group differences in metabolic energy expenditure using oxygen uptake requires individuals to be comfortable with, and able to accommodate to, the equipment.

A study into the permeability and compressibility of Australian bagasse pulp

This is an experimental study into the permeability and compressibility properties of bagasse pulp pads. Three experimental rigs were custom-built for this project. The experimental work is complemented by modelling work. Both the steady-state and dynamic behaviour of pulp pads are evaluated in the experimental and modelling components of this project. Bagasse, the fibrous residue that remains after sugar is extracted from sugarcane, is normally burnt in Australia to generate steam and electricity for the sugar factory. A study into bagasse pulp was motivated by the possibility of making highly value-added pulp products from bagasse for the financial benefit of sugarcane millers and growers. The bagasse pulp and paper industry is a multibillion dollar industry (1). Bagasse pulp could replace eucalypt pulp which is more widely used in the local production of paper products. An opportunity exists for replacing the large quantity of mainly generic paper products imported to Australia. This includes 949,000 tonnes of generic photocopier papers (2). The use of bagasse pulp for paper manufacture is the main application area of interest for this study. Bagasse contains a large quantity of short parenchyma cells called ‘pith’. Around 30% of the shortest fibres are removed from bagasse prior to pulping. Despite the ‘depithing’ operations in conventional bagasse pulp mills, a large amount of pith remains in the pulp. Amongst Australian paper producers there is a perception that the high quantity of short fibres in bagasse pulp leads to poor filtration behaviour at the wet-end of a paper machine. Bagasse pulp’s poor filtration behaviour reduces paper production rates and consequently revenue when compared to paper production using locally made eucalypt pulp. Pulp filtration can be characterised by two interacting factors; permeability and compressibility. Surprisingly, there has previously been very little rigorous investigation into neither bagasse pulp permeability nor compressibility. Only freeness testing of bagasse pulp has been published in the open literature. As a result, this study has focussed on a detailed investigation of the filtration properties of bagasse pulp pads. As part of this investigation, this study investigated three options for improving the permeability and compressibility properties of Australian bagasse pulp pads. Two options for further pre-treating depithed bagasse prior to pulping were considered. Firstly, bagasse was fractionated based on size. Two bagasse fractions were produced, ‘coarse’ and ‘medium’ bagasse fractions. Secondly, bagasse was collected after being processed on two types of juice extraction technology, i.e. from a sugar mill and from a sugar diffuser. Finally one method of post-treating the bagasse pulp was investigated. The effects of chemical additives, which are known to improve freeness, were also assessed for their effect on pulp pad permeability and compressibility. Pre-treated Australian bagasse pulp samples were compared with several benchmark pulp samples. A sample of commonly used kraft Eucalyptus globulus pulp was obtained. A sample of depithed Argentinean bagasse, which is used for commercial paper production, was also obtained. A sample of Australian bagasse which was depithed as per typical factory operations was also produced for benchmarking purposes. The steady-state pulp pad permeability and compressibility parameters were determined experimentally using two purpose-built experimental rigs. In reality, steady-state conditions do not exist on a paper machine. The permeability changes as the sheet compresses over time. Hence, a dynamic model was developed which uses the experimentally determined steady-state permeability and compressibility parameters as inputs. The filtration model was developed with a view to designing pulp processing equipment that is suitable specifically for bagasse pulp. The predicted results of the dynamic model were compared to experimental data. The effectiveness of a polymeric and microparticle chemical additives for improving the retention of short fibres and increasing the drainage rate of a bagasse pulp slurry was determined in a third purpose-built rig; a modified Dynamic Drainage Jar (DDJ). These chemical additives were then used in the making of a pulp pad, and their effect on the steady-state and dynamic permeability and compressibility of bagasse pulp pads was determined. The most important finding from this investigation was that Australian bagasse pulp was produced with higher permeability than eucalypt pulp, despite a higher overall content of short fibres. It is thought this research outcome could enable Australian paper producers to switch from eucalypt pulp to bagasse pulp without sacrificing paper machine productivity. It is thought that two factors contributed to the high permeability of the bagasse pulp pad. Firstly, thicker cell walls of the bagasse pulp fibres resulted in high fibre stiffness. Secondly, the bagasse pulp had a large proportion of fibres longer than 1.3 mm. These attributes helped to reinforce the pulp pad matrix. The steady-state permeability and compressibility parameters for the eucalypt pulp were consistent with those found by previous workers. It was also found that Australian pulp derived from the ‘coarse’ bagasse fraction had higher steady-state permeability than the ‘medium’ fraction. However, there was no difference between bagasse pulp originating from a diffuser or a mill. The bagasse pre-treatment options investigated in this study were not found to affect the steady-state compressibility parameters of a pulp pad. The dynamic filtration model was found to give predictions that were in good agreement with experimental data for pads made from samples of pretreated bagasse pulp, provided at least some pith was removed prior to pulping. Applying vacuum to a pulp slurry in the modified DDJ dramatically reduced the drainage time. At any level of vacuum, bagasse pulp benefitted from chemical additives as quantified by reduced drainage time and increased retention of short fibres. Using the modified DDJ, it was observed that under specific conditions, a benchmark depithed bagasse pulp drained more rapidly than the ‘coarse’ bagasse pulp. In steady-state permeability and compressibility experiments, the addition of chemical additives improved the pad permeability and compressibility of a benchmark bagasse pulp with a high quantity of short fibres. Importantly, this effect was not observed for the ‘coarse’ bagasse pulp. However, dynamic filtration experiments showed that there was also a small observable improvement in filtration for the ‘medium’ bagasse pulp. The mechanism of bagasse pulp pad consolidation appears to be by fibre realignment. Chemical additives assist to lubricate the consolidation process. This study was complemented by pulp physical and chemical property testing and a microscopy study. In addition to its high pulp pad permeability, ‘coarse’ bagasse pulp often (but not always) had superior physical properties than a benchmark depithed bagasse pulp.

A novel system for the measurement of body shape and construction of seating supports for patients

Patients with severe back deformities can greatly benefit from customized medical seating. Customized medical seating is made by taking measurements of each individual patient and making the seat as per these measurements. The current measuring systems employed by the industry are limited to use in clinics which are generally located only in major population centres. Patients living in remote areas are severely affected by this as the clinics could be far away and inaccessible for these patients. To provide service of customized medical seating requires a new measurement system which is portable so that the system could be transported to the patients in remote areas. The requirements for a new measurement system are analysed to suite the needs of Equipment Technology Services of the Cerebral Palsy League of Queensland. Design for a new measurement system was conceptualised by reviewing systems and technologies in various scientific disciplines. Design for a new system was finalised by optimizing each individual component. The final approach was validated by measuring difficult models and repeating the process to check for process variances. This system has now been adopted for clinical evaluation by ETS Suggestions have been made for further improvements in this new measurement approach.

Apparatus for monitoring load bearing rehabilitation exercises of a transfemoral amputee fitted with an osseointegrated fixation : a proof-of-concept study

The purpose of this proof-of-concept study was to determine the relevance of direct measurements to monitor the load applied on the osseointegrated fixation of transfemoral amputees during static load bearing exercises. The objectives were (A) to introduce an apparatus using a three-dimensional load transducer, (B) to present a range of derived information relevant to clinicians, (C) to report on the outcomes of a pilot study and (D) to compare the measurements from the transducer with those from the current method using a weighing scale. One transfemoral amputee fitted with an osseointegrated implant was asked to apply 10 kg, 20 kg, 40 kg and 80 kg on the fixation, using self-monitoring with the weighing scale. The loading was directly measured with a portable kinetic system including a six-channel transducer, external interface circuitry and a laptop. As the load prescribed increased from 10 kg to 80 kg, the forces and moments applied on and around the antero-posterior axis increased by 4 fold anteriorly and 14 fold medially, respectively. The forces and moments applied on and around the medio-lateral axis increased by 9 fold laterally and 16 fold from anterior to posterior, respectively. The long axis of the fixation was overloaded and underloaded in 17 % and 83 % of the trials, respectively, by up to ±10 %. This proof-of-concept study presents an apparatus that can be used by clinicians facing the challenge of improving basic knowledge on osseointegration, for the design of equipment for load bearing exercises and for rehabilitation programs.

Load on osseointegrated fixation of a transfemoral amputee during a fall : loading, descent, impact and recovery analysis

Falling represents a health risk for lower limb amputees fitted with an osseointegrated fixation mainly because of the potential damage to the fixation. The purpose of this study was to characterise a real forward fall that occurred inadvertently to a transfemoral amputee fitted with an osseointegrated fixation while attending a gait measurement session to assess the load applied on the residuum. The objective was to analyse the load applied on the fixation with an emphasis on the sequence of events, the pattern and the magnitude of the forces and moments. The load was measured directly at 200 Hz using a six-channel transducer. Complementary video footage was also studied. The fall was divided into four phases: loading (240 ms), descent (620 ms), impact (365 ms) and recovery (2495 ms). The main impact forces and moments occurred 870 ms and 915 ms after the heel contact, and corresponded to 133 %BW and 17 %BWm, or 1.2 and 11.2 times the maximum forces and moments applied during the previous steps of the participant, respectively. This study provided key information to engineers and clinicians facing the challenge to design equipment, and rehabilitation and exercise programs to restore safely the locomotion of lower limb amputees.

Computational fluid dynamics for improved bioreactor design and 3D culture

The complex relationship between the hydrodynamic environment and surrounding tissues directly impacts on the design and production of clinically useful grafts and implants. Tissue engineers have generally seen bioreactors as 'black boxes' within which tissue engineering constructs (TECs) are cultured. It is accepted that a more detailed description of fluid mechanics and nutrient transport within process equipment can be achieved by using computational fluid dynamics (CFD) technology. This review discusses applications of CFD for tissue engineering-related bioreactors -- fluid flow processes have direct implications on cellular responses such as attachment, migration and proliferation. We conclude that CFD should be seen as an invaluable tool for analyzing and visualizing the impact of fluidic forces and stresses on cells and TECs.

High fashion

High Fashion is a practice-led research enquiry that examines the processes involved in producing a no-budget film of high aesthetic standards that can confidently compete in the global film festival market, and to reflect on the production techniques tested during the making of the film. The practical outcome of the research is a twenty-five minute short drama. It incorporates a large cast and crew, original designer clothing, extravagant sets, and a popular soundtrack. The thesis considers how over one hundred professionals volunteered their time, expertise, and equipment to help produce the film. The thesis also examines the many obstacles encountered while producing the film and how these were overcome. It is written for the student filmmaker as a guide to "learn by doing."

A miniaturised wideband frequency synthesiser

Wideband frequency synthesisers have application in many areas, including test instrumentation and defence electronics. Miniaturisation of these devices provides many advantages to system designers, particularly in applications where extra space and weight are expensive. The purpose of this project was to miniaturise a wideband frequency synthesiser and package it for operation in several different environmental conditions while satisfying demanding technical specifications. The four primary and secondary goals to be achieved were: 1. an operating frequency range from low MHz to greater than 40 GHz, with resolution better than 1 MHz, 2. typical RF output power of +10 dBm, with maximum DC supply of 15 W, 3. synthesiser package of only 150  100  30 mm, and 4. operating temperatures from 20C to +71C, and vibration levels over 7 grms. This task was approached from multiple angles. Electrically, the system is designed to have as few functional blocks as possible. Off the shelf components are used for active functions instead of customised circuits. Mechanically, the synthesiser package is designed for efficient use of the available space. Two identical prototype synthesisers were manufactured to evaluate the design methodology and to show the repeatability of the design. Although further engineering development will improve the synthesiser’s performance, this project has successfully demonstrated a level of miniaturisation which sets a new benchmark for wideband synthesiser design. These synthesisers will meet the demands for smaller, lighter wideband sources. Potential applications include portable test equipment, radar and electronic surveillance systems on unmanned aerial vehicles. They are also useful for reducing the overall weight and power consumption of other systems, even if small dimensions are not essential.

H-house

The author's approach to the problems associated with building in bushfire prone landscapes comes from 12 years of study of the biophysical and cultural landscapes in the Great Southern Region of Western Australia - research which resulted in the design and construction of the H-house at Bremer Bay. The house was developed using a 'ground up' approach whereby Dr Weir conducted topographical surveys and worked with a local botanist and a bushfire risk consultant to ascertain the level of threat that fire presented to this particular site. The intention from the outset however, was not to design a bushfire resistant house per se, but to develop a design which would place the owners in close proximity to the highly biodiverse heath vegetation of their site. The research aim was to find ways - through architectural design-to link the patterns of usage of the house with other site specific conditions related to the prevailing winds, solar orientation and seasonal change. The H-house has a number of features which increase the level of bushfire safety. These include: Fire rated roller shutters (tested by the CSIRO for ember attack and radiant heat), Fire resistant double glazing (on windows not protected by the shutters), Fibre-cement sheet cladding of the underside of the elevated timber floor structure, Manually operated high pressure sprinkler system on exposed timber decks, A fire refuge (an enlarged laundry, shower area) within the house with a dedicated cabinet for fire fighting equipment) and A low pressure solar powered domestic water supply system.

Camera Botanica 1

Camera Botanica 1 - testing a design process (unrealised buildings). ---------- Sited in a highly biodiverse and bushfire prone heathlands on the South-east coast of Western Australia, Camera Botanica 1 is a test of a new design methodology for achieving ecologically sustainable architecture in biodiverse, bushfire prone landscapes. ---------- The design methods were intensively site-based with the author-designer conducting his own site surveys using high-end professional grade surveying equipment such as: Real Time Kinematic GPS (landform survey); Terrestrial laser scanning (vegetation survey); laser levelling and Total Station surveys (erection of scaffolds and contour lines). ---------- This was the first time, internationally, that terrestrial laser scanning was used to measure vegetation. These precise surveys enabled the construction of highly detailed models and drawings - a facility that has not been available prior to this technology. ---------- Designed for a real client and a real site - Camera Botanica 1 is a hypothetical design outcome which demonstrates the efficacy of a new design methodology and thus expands on knowledge of the applicability of new surveying technologies to the design of ecologically sustainable architecture in biodiverse landscapes.

Camera Botanica 2

Camera Botanica 2 - testing a design process (unrealised building). Sited in a highly biodiverse and bushfire prone heathlands on the South-east coast of Western Australia, Camera Botanica 2 is a test of a new design methodology for achieving ecologically sustainable architecture in biodiverse, bushfire prone landscapes. ---------- The design method was intensively site-based with the author-designer conducting his own site surveys using high-end professional grade surveying equipment such as: Real Time Kinematic GPS (landform survey); Terrestrial laser scanning (vegetation survey); laser levelling and Total Station surveys (erection of scaffolds and contour lines). ---------- This was the first time, internationally, that terrestrial laser scanning was used to measure vegetation. These precise surveys enabled the construction of highly detailed models and drawings - a facility that has not been available prior to this technology. ---------- Designed for a real client and a real site - Camera Botanica 2 is a hypothetical design outcome which demonstrates the efficacy of a new design methodology and thus expands on knowledge of the applicability of new surveying technologies to the design of ecologically sustainable architecture in biodiverse landscapes.