RESUMO
Developing accurate computational models of wildfire dynamics is increasingly important due to the substantial and expanding negative impacts of wildfire events on human health, infrastructure, and the environment. Wildfire spread and emissions depend on a number of factors, including fuel type, environmental conditions (moisture, wind speed, etc.), and terrain/location. However, there currently exist only a few experimental facilities that enable testing of the interplay of these factors at length scales <1 m with carefully controlled and characterized boundary conditions and advanced diagnostics. Experiments performed at such facilities are required for informing and validating computational models. Here, we present the design and characterization of a tilting wind tunnel (the "WindCline") for studying wildfire dynamics. The WindCline is unique in that the entire tunnel platform is constructed to pivot around a central axis, which enables the sloping of the entire system without compromising the quality of the flow properties. In addition, this facility has a configurable design for the test section and diffuser to accommodate a suite of advanced diagnostics to aid in the characterization of (1) the parameters needed to establish boundary conditions and (2) flame properties and dynamics. The WindCline thus allows for the measurement and control of several critical wildfire variables and boundary conditions, especially at the small length scales important to the development of high-fidelity computational simulations (10-100 cm). Computational modeling frameworks developed and validated under these controlled conditions can expand understanding of fundamental combustion processes, promoting greater confidence when leveraging these processes in complex combustion environments.
RESUMO
BACKGROUND: The cost of performing cardiac surgery in the public health system in Australia is unclear. This paper analyses the cost of cardiac surgery performed at Flinders Medical Centre (FMC), South Australia, comparing cost by procedure, rheumatic valvular heart disease status, Aboriginality and location. METHODS: This study is a retrospective, population-based analysis of cardiac surgery data held in the Cardiac Surgery Registry cross-referenced to cost data provided by the FMC Department of Finance and Patient Travel, Accommodation and Transport Services at the Royal Darwin Hospital. Seven hundred ninety-five (795) patients who underwent cardiac surgery at FMC from 1 July 2014 to 30 June 2016 were included. RESULTS: Across all procedures, Northern Territory (NT) Aboriginal patients had a mean total cost of $78,506 which was $24,113 more than NT non-Aboriginal, $28,443 more than South Australian (SA) Aboriginal and $22,955 more than SA non-Aboriginal patients. The total cost of a patient undergoing a repeat sternotomy (reoperative procedure) was found to be significantly higher than a primary procedure ($85,797 versus $59,097). In patients undergoing valve surgery procedures, those identified with rheumatic heart disease had a higher mean total cost than those without (a difference of $25,094). Significantly, the rheumatic patient group showed a higher proportion of reoperative procedures (19% versus 5%). CONCLUSIONS: The cost of treating NT Aboriginal cardiac surgical patients remotely has a significant financial impact upon the health care delivery system, as does the impact of rheumatic heart disease. This study found that the cost for the NT Aboriginal patient group was substantially higher than the NT non-Aboriginal, SA Aboriginal and SA non-Aboriginal patient groups. The additional cost to family and dislocation of social structures is not able to be calculated, but would also clearly weigh heavily on both patient groups. These findings suggest that future health funding models should recognise Aboriginality, remoteness and rheumatic heart disease.