63 resultados para Minimal surfaces.

em Deakin Research Online - Australia


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When human observers move forward and rotate their eyes, a complex pattern of light flows across the retina. This pattern is referred to as retinal flow. A model has been proposed to explain how humans perceive their direction of self-movement (or heading) from (1) static depth, (2) direction of image motion, and (3) whether image velocity undergoes acceleration or deceleration (Wang & Cutting, 1999). However, findings from past research in which sparse or minimalist stimuli were used have suggested that not all of the information to which participants are sensitive is captured within the scope of this model. In particular it has been suggested that the magnitude or size of image velocity change may be of significance beyond simply whether image velocity could be categorized as speeding up (i.e., accelerating) or slowing down (i.e., decelerating). In two experiments, the influence of this factor on heading judgments under minimal conditions was investigated. Evidence was found in support of the idea that the rate of image velocity change can influence judgments of the direction of self-movement in minimalist conditions.

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The use of tris(2,2'-bipyridyl) ruthenium (III) as a chemiluminescent spray reagent spot-test for heroin is discussed. Two forms of the reagent are investigated an aqueous and an anhydrous where both were found to give vastly different results. The aqueous reagent giving slow, low intensity chemiluminescence whilst the anhydrous reagent gave a fast, bright response in the presence of 3,6-diacetylmorphine. The anhydrous reagent is less sensitive the slow, intensity response is characteristic of only two opiates tested 3,6-diacetylmorphine and 3-monoacetylmorphine.

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A reduced dynamics stabiliser for multi-machine power systems is presented in this paper. The design of the stabiliser is based on the theory of linear functional observers and the solution of a simple parameter optimisation problem. The order of the stabiliser could be as low as the number of machines in the system. The design is applied to an open-loop unstable multi-machine power system.

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Globally, almost every nation is facing some form of water crisis (World Commission on Water 2000). In Australia, the sport and recreation industry is one of the highest consumers of water. Other high water consuming industries (such as agriculture and farming) have been forced to adhere to strict managerial and governance reform due to the water crisis, yet in the sport and recreation industry, such changes are yet to be implemented and fully realised across the sector.

This research examines the impacts of drought and sustainable water management for sport and recreation. Specifically, it provides a case study of sport and recreation provision in a municipality that has already undergone considerable reform due to long-term drought. Sport and recreation use water for purposes such as irrigation of playing fields/pitches, filling swimming pools, stadium amenities and facilities, kitchens, maintenance and cleaning, and clubhouse amenities.

For sports that are heavy users of water for the maintenance of playing fields (such as soccer, Australian Rules football, rugby league, rugby union, grass and clay tennis courts to name a few) the impacts of drought and water restrictions have been severe. Some sports have reported an increase in the risk of injury to participants because of the condition of un-watered playing fields (Sport and Recreation Victoria 2007). Others have been forced to delay or shorten their seasons (Sleeman 2007), or worse still, cancel training and organised competition completely (Connolly and Bell 2007). While the impact of water restrictions has been profound on most sports, there are some sports that are not heavy water users and the impact of drought and water restrictions has been minimal. This problem creates issues and apparent inequities raising the need to further examine water consumption in sport and recreation. The potential outcome that arises is that the future of those sports that cannot conduct their competitions may be disadvantaged, while other sports that do not have such problems may be able to flourish.

Water, and those who control the supply of it, then defines which sports are able to flourish and sustain sport development pathways, compared to those whose survival may be in jeopardy. This research explores the stakeholder management and governance issues that have resulted for sport and recreation in the City of Greater Geelong (CoGG) located in Victoria, Australia--a region in long-term water crisis. The supply of sport and recreation facilities in the CoGG (like most municipalities in Australia) is largely the responsibility of the municipal council. The corporation responsible for the supply of water to the municipality is Barwon Water.

Although other sport and recreation facilities exist in the CoGG, the municipal council of CoGG owns and maintains over 120 sporting ovals (including the stadium used by its professional Australian Football League (AFL) team, the Cats), six swimming pools, and three golf courses. The CoGG host their professional AFL team, a range of local, national and international sport events, and provide a wide range of sport and recreation facilities for the community residents.

Eight interviews were conducted in total. Interviews were conducted with representatives from CoGG municipal council (who are responsible for the delivery of sport and recreation services and facilities in Geelong), and representatives from Barwon Water (who are responsible for the ongoing provision and maintenance of sport and recreation services and facilities) through the provision of water. Results show that the ten highest users of water in the municipality are sport and recreation facilitieswhich between them use almost one-third of the city's total water consumption (City of Greater Geelong 2006).

The municipal council is under considerable pressure to find ways to continue to provide sport and recreation opportunities for community members, as well as professional athletes and teams who use these facilities despite water restrictions. After all, these facilities provide benefit to spectators and participants, as well as businesses that rely on visitors to Geelong for sport and recreation events.

Due to such pressures, from 2007, the CoGG and Barwon Water agreed to provide the sport and recreation sector with water allocations rather than to be denied of all water under the water restriction regimes in place in the municipality. During 2007 summer sport season, this allowed the CoGG to keep 16 of its 120 sporting ovals open for participation through allocating all available water to these fields in order to keep them safe and playable. However, CoGG and Barwon Water were required to devise a rating scale to determine which sports (and sport facilities) were to share the allocated water, and which were not. These decisions also had knock on effects through sports. In order to ensure the safety of the playing surfaces, the CoGG and Barwon Water also restricted use of fields to competition only, therefore sport participants were forced to train on local beaches and other parkland areas-transferring issues of safety and public liability to other locations and facilities in the community. Further, it was reported that scheduling of competition seasons and individual matches; as well as the allocation of "home ground" gate receipts and concessions profits were required to be governed by the CoGG and Barwon Water as the competing sports were unable to agree. Perhaps more importantly, the rating scale developed for water allocation also resulted in some sports being rated as ineligible for water and as a result were unable to stage their entire competitions.

Clearly, the water allocation rating scale, and approach taken in this municipality to the continued delivery of sport and recreation has provided a workable solution. However, this study also signals that new stakeholders have entered the arena for the governance of sport. Governance structures in sport and recreation are being impacted as a result of the water crisis.

Those making decisions about which sport and recreation activities and/or facilities will be assisted with water resources are being made by local councils and water corporations. Sport managers are being required to understand existing areas of knowledge (such as turf management) in different ways, to gain knowledge in new areas (such as sustainable water management), and to lobby new stakeholder groups (such as water corporations) in order to secure their futures. The continued existence of some sports is no longer in the hands of governing bodies, but in the hands of local councils, and water corporations.

Clearly, any of the solutions implemented as discussed above, require multiple stakeholders to interact, and to reach agreement in order to assist in sustainable management of water in sport and recreation. In this sense, the management of water in sport (and all other industries) is more than a rational decision about policy, legislation, restrictions and resource allocations. It is a social and political process requiring scholarly attention for practical solutions.

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Aim: The study's purpose was to describe patients' experiences of minimal conscious sedation during diagnostic and interventional cardiology procedures.

Methods:
Over a 6-week period, 119 consecutive patients (10% of annual throughput) from a major metropolitan hospital in Melbourne, Australia, were interviewed using a modified version of the American Pain Society Patient Outcome Questionnaire. Patients identified pain severity using a 10-point visual analogue scale and rated their overall comfort on a 6-point Likert scale ranging from very comfortable to very uncomfortable.

Results: Patients were aged 67.6 years (standard deviation 11.1), 70.8% were male, and the mean body mass index was 27.7 (standard deviation 4.8). Patients underwent diagnostic coronary angiography (67.5%), percutaneous coronary interventions (13.3%), or combined procedures (19.2%). Most patients (65%) were comfortable in the context of low-dose conscious sedation. Slight discomfort was reported by 26% of patients; 9% reported feeling uncomfortable primarily as a result of a combination of musculoskeletal pain, angina, and vasovagal symptoms experienced during the procedure. There was significant correlation (rho = .25, P = .01) between procedure length and patients' report of overall comfort, suggesting longer procedures were less comfortable for patients.

Conclusions:
The minimal sedation protocol was effective for the majority of patients; however, 9% of patients experienced significant discomfort related to preexisting conditions, highlighting the need for individual patient assessment before, during, and after the procedure.

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Lawsone (2-hydroxy-1,4-naphthoquinone) reacts with latent fingermark deposits on paper surfaces to yield purple-brown impressions of ridge details which are also photoluminescent; this compound represents the first in a completely new class of fingermark detection reagents.

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Parametric modelling is gaining in popularity as both a fabrication and design tool, but its application in the architectural design industry has not been widely explored. This form of modelling has the ability to generate complex forms with intuitively reactive components, allowing designers to express and
fabricate structures previously too laborious and geometrically complex to realise. The key aim of the paper is to address the increasing need for seamless and bi-directional connectivity between the design, modelling and
fabrication ambit.

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Use of high reflectance surfaces reduces the amount of solar radiation absorbed through building envelopes and urban structures and thus keeping their surfaces cooler. The cooling energy savings by using high reflectance surfaces have been well documented. Higher surface temperatures add to increasing the ambient temperature as convection intensity is higher. Such temperature increase has significant impacts on the air conditioning energy utilization in hot climates. This study makes use of numerical simulations to analyze the effect of commonly used building materials on the air temperature. A part of the existing CBD (Central Business District) area of Singapore was selected for the study. A series of Computational Fluid Dynamics (CFD) simulations have been carried out using the software CFX-5.6. It was found that at low wind speeds, the effect of materials on the air temperature was significant and the temperature at the middle of a narrow canyon increased up to 2.5[degrees]C with the facade material having lower reflectance.

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The mass (e.g. carbon) transfer coefficient at a workpiece surface is an important kinetic factor to control the heat treatment process of the workpiece and to evaluate heat treatment equipment. The coefficient can be calculated from the carbon concentration at the surface of a sample carburized in a carburizing furnace for a given time. Two common measurement methods which use a thin plate and employ a component as samples respectively are evaluated and compared for sensitivity and uncertainty. The comparison shows that the use of a component produces higher measurement precision and also has the advantage in measuring the carbon transfer coefficients at different treated positions. This method is then extended and discussed methodologically. Also two equations are proposed to calculate the carbon transfer coefficient and its uncertainty, respectively. This method is also applied to measure the carbon transfer coefficient in a fluidized bed heat treatment furnace.

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In the current work, two different coatings, nitrocarburised (CN) and titanium carbonitride (TiCN) on M2 grade high speed tool steel, were prepared by commercial diffusion and physical vapour deposition (PVD) techniques, respectively. Properties of the coating were characterised using a variety of techniques such as Glow-Discharge Optical Emission Spectrometry (GD-OES) and Scanning Electron Microscopy (SEM). Three non-commercial, oil-based lubricants with simplified formulations were used for this study. A tribological test was developed in which two nominally geometrically-identical crossed cylinders slide over each other under selected test conditions. This test was used to evaluate the effectiveness of a pre-applied lubricant film and a surface coating for various conditions of sliding wear. Engineered surface coatings can significantly improve wear resistance of the tool surface but their sliding wear performances strongly depend on the type of coating and lubricant combination used. These coating-lubricant interactions can also have a very strong effect on the useful life of the lubricant in a tribological system. Better performance of lubricants during the sliding wear testing was achieved hen used with the nitrocarburised (CN) coating. To understand the nature of the interactions and their possible effects on the coating-lubricant system, several surface analysis techniques were used. The molecular level investigation of Fourier Transform Infrared Spectroscopy (FTIR) revealed that oxidative degradation occurred in all used oil-based lubricants during the sliding wear test but the degradation behaviour of oil-based lubricants varied with the coating-lubricant system and the wear conditions. The main differences in the carbonyl oxidation region of the FTIR spectra (1900-1600 cm-1) between different coating-lubricant systems may relate to the effective lifetime of the lubricant during the sliding wear test. Secondary Ion Mass Spectrometry (SIMS) depth profiling shows that the CN coating has the highest lubricant absorbability among the tested tool surfaces. Diffusion of chlorine (C1), hydrogen (H) and oxygen (O) into the surface of subsurface of the tool suggested that strong interactions occurred between lubricant and tool surface during the sliding wear test. The possible effects of the interactions on the performance of whole tribological system are also discussed. The study of Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) indicated that the envelope of hydrocarbons (CmHn) of oil lubricant in the positive TOF-SIMS spectra shifted to lower mass fragment after the sliding wear testing due to the breakage of long-chain hydrocarbons to short-chain ones during the degradation of lubricant. The shift of the mass fragment range of the hydrocarbon (CmHn) envelope caries with the type of both tool surface and lubricant, again confirming that variation in the performance of the tool-lubricant system relates to the changes in surface chemistry due to tribochemical interactions at the tool-lubricant interface under sliding wear conditions. The sliding wear conditions resulted in changes not only in topography of the tool surface due to mechanical interactions, as outlined in Chapter 5, but also in surface chemistry due to tribochemical interactions, as discussed in Chapters 6 and 7.

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In the present study, titanium (Ti) samples were surface-modified by titania (TiO2), silica (SiO2) and hydroxyapatite (HA) coatings using a sol-gel process. The bioactivity of the film-coated Ti samples was investigated by cell attachment and morphology study using human osteoblast-like SaOS-2 cells. Results of the cell attachment indicated that the densities of cell attachment on the surfaces of Ti samples were significantly increased by film coatings; the density of cell attachment on HA film-coated surface was higher than those on TiO2 and SiO2 film-coated surfaces. Cell morphology study showed that the cells attached, spread and grew well on the three kinds of film-coated surfaces. It can be concluded that the three kinds of film coatings can bioactivate the surfaces of Ti samples effectively. Overall, Ti sample with HA film-coated surface exhibited the best bioactivity.

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The introduction of ninhydrin treatment as a chemical technique for the visualisation of latent fingermarks on porous surfaces revolutionised approaches to forensic fingermark examination. Since then, a range of amino acid sensitive reagents has been developed and such compounds are in widespread use by law enforcement agencies worldwide. This paper reviews the development and use of these reagents for the detection of latent fingermarks on porous surfaces. A brief overview is provided, including an historical background, forensic significance, and a general approach to the development of latent fingermarks on porous surfaces. This is followed by a discussion of specific amino acid sensitive treatments.

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A novel approach to producing improved bio-interfaces by combining continuous wave (CW) and pulsed plasma polymerization (PP) modes is reported. This approach has enabled the generation of stable interfaces with a higher density of primary amine functionality on metal, ceramic and semiconductor surfaces. Heptylamine (HA) was used as the amine-precursor. In this new design, a thin CW PPHA layer is introduced to provide strong cross-linking and attachment to the metal or semiconductor surfaces and to provide a good foundation for better bonding a pulsed PPHA layer with high retention of functional groups. The combined mode provides the pulsed mode advantage of a 3-fold higher density of primary amines, while retaining much of the markedly higher stability in aqueous solutions of the continuous mode.

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Parametric modelling is gaining in popularity as both a fabrication and design tool, but its application in the architectural design industry has not been widely explored. Parametric modelling has the ability to generate complex forms with intuitively reactive components, allowing designers to express and fabricate structures previously too laborious and geometrically complex to realise. This alIows designers to address a project at both the macro and micro levels of resolution in the governing control surface and the individual repetitive component. This two level modelling control, of component and overall surface, can allow designers to explore new types of form generation subject to parametric constraints. Shading screens have been selected as the focus for this paper and are used as a medium to explore form generation within a given set of functional parameters. Screens can have many applications in a building but for the purpose of the following case studies, lighting quality and passive sun control are the main functional requirement. A set of screen components have been designed within certain shading parameters to create a generic component that can automatically adapt to any given climatic conditions. These will then be applied to surfaces of varying degrees of geometric complexity to be analysed in their ability to correctly tessellate and create a unified screening array true to the lighting requirements placed on the generic component.

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The syntheses and structures of the novel Ce–Fe bimetallic complexes [{Fe(sal)2(bpy)}2Ce(NO3)(H2O)3]·EtOH and [{Fe(sal)2(bpy)}4Ce2(H2O)11][salH]2·EtOH·3H2O (salH2 = salicylic acid) suggest Fe3+–sal2− units and Ce–OC(R)O–Fe bridging contribute to the formation of corrosion inhibitive layers on steel surfaces exposed to [Ce(salH)3(H2O)].