Timing and frequency data for passenger walk through metal detection at Melbourne domestic airport

The data covers the timing and frequency for passengers walking through the metal detectors as part of the screening process at Melbourne Airport, Victoria.

Timing and frequency data for passenger walk through metal detection at Sydney domestic airport

The data covers the timing and frequency for passengers walking through the metal detectors as part of the screening process at Sydney Airport, New South Wales.

Timing and frequency data for passenger walk through metal detection at Adelaide domestic airport

The data covers the timing and frequency for passengers walking through the metal detectors as part of the screening process at Adelaide Airport, South Australia.

The drainage of thin liquid films between solid surfaces

We present measurements of the thickness as a function of time of liquid films as they are squeezed between molecularly smooth mica surfaces. Three Newtonian, nonpolar liquids have been studied: octamethylcyclotetrasiloxane, n-tetradecane, and n-hexadecane. The film thicknesses are determined with an accuracy of 0.2 nm as they drain from ∼1 μm to a few molecular layers. Results are in excellent agreement with the Reynolds theory of lubrication for film thicknesses above 50 nm. For thinner films the drainage is slower than the theoretical prediction, which can be accounted for by assuming that the liquid within about two molecular layers of each solid surface does not undergo shear. In very thin films the continuum Reynolds theory breaks down, as drainage occurs in a series of abrupt steps whose size matches the thickness of molecular layers in the liquid. The presence of trace amounts of water has a dramatic effect on the drainage of a nonpolar liquid between hydrophilic surfaces, causing film rupture which is not observed in the dry liquids.

The 'wimple' : rippled deformation of a fluid drop caused by hydrodynamic and surface forces during thin film drainage

It is well-known that hydrodynamic pressures in a thin draining liquid film can cause inversion of the curvature of a drop or bubble surface as it approaches another surface, creating a so-called “dimple”. Here it is shown that a more complicated rippled shape, dubbed a “wimple”, can be formed if a fluid drop that is already close to a solid wall is abruptly pushed further toward it. The wimple includes a central region in which the film remains thin, surrounded by a ring of greater film thickness that is bounded at the outer edge by a barrier rim where the film is thin. This shape later evolves into a conventional dimple bounded by the barrier rim, which then drains in the normal way. During the evolution from wimple to dimple, some of the fluid in the thicker part of the film ring flows toward the central region before eventually draining in the opposite direction. Although the drop is pressed toward the wall, the central part of the drop moves away from the wall before approaching it again. This is observed even when the inward push is too small to create a wimple.

The influence of surface forces on thin film drainage between a fluid drop and a flat solid

An experiment is described in which a mica surface is driven towards a mercury drop immersed in aqueous electrolyte. Under appropriate conditions, hydrodynamic pressure in the aqueous film creates a classical dimple in the mercury drop. The use of optical interferometry and video recording to monitor the shape of the drop and the thickness of the aqueous film with sub-nanometre resolution yields a high density of precise data showing the formation and evolution of the dimple as the film drains. Variation of electrical potential applied to the mercury phase allows control of the surface forces acting between the drop and the mica surface, so that the effect of surface forces on the film drainage process is highlighted. It is found that the film thickness at the centre of the dimple and the lateral extent of the dimple are not significantly affected by surface forces. On the other hand, the minimum film thickness at the edge of the dimple is sensitive even to weak surface forces. Since this minimum film thickness is a major determinant of the film drainage rate, it is shown that surface forces have an important effect on the overall drainage process.

Thin film drainage : hydrodynamic and disjoining pressures determined from experimental measurements of the shape of a fluid drop approaching a solid wall

Accurate measurements of the shape of a mercury drop separated from a smooth flat solid surface by a thin aqueous film reported recently by Connor and Horn (Faraday Discuss. 2003, 123, 193-206) have been analyzed to calculate the excess pressure in the film. The analysis is based on calculating the local curvature of the mercury/aqueous interface, and relating it via the Young-Laplace equation to the pressure drop across the interface, which is the difference between the aqueous film pressure and the known internal pressure of the mercury drop. For drop shapes measured under quiescent conditions, the only contribution to film pressure is the disjoining pressure arising from double-layer forces acting between the mercury and mica surfaces. Under dynamic conditions, hydrodynamic pressure is also present, and this is calculated by subtracting the disjoining pressure from the total film pressure. The data, which were measured to investigate the thin film drainage during approach of a fluid drop to a solid wall, show a classical dimpling of the mercury drop when it approaches the mica surface. Four data sets are available, corresponding to different magnitudes and signs of disjoining pressure, obtained by controlling the surface potential of the mercury. The analysis shows that total film pressure does not vary greatly during the evolution of the dimple formed during the thin film drainage process, nor between the different data sets. The hydrodynamic pressure appears to adjust to the different disjoining pressures in such a way that the total film pressure is maintained approximately constant within the dimpled region.

Nurses’ advice regarding sterile or clean urinary drainage bags for individuals with a long-term Indwelling urinary catheter

PURPOSE: The purpose of this study was to identify, compare, and explore advice nurses give to community-dwelling long-term indwelling catheter users on the use of sterile or clean urinary drainage bags, and to obtain information that would inform the design of a larger-scale international survey.


SUBJECTS AND SETTINGS: A survey was targeted to nurse members of the International Continence Society (n = 130). Respondents (n = 28; 21.5%) included nurses from Australia, Canada, Belgium, Switzerland, the United Kingdom, and the United States, who specialized in managing incontinence.


METHODS: The project was conducted as a descriptive, exploratory pilot study. Respondents completed an online anonymous survey that was distributed by the International Continence Society. The survey instrument was designed by the investigators and comprised 14 questions with both fixed and open-ended response options.


RESULTS: Most respondents in this survey advised indwelling catheter users to reuse their catheter bags (n = 15; 68%). Factors that influenced advice included concerns about the cost of catheter bags, an evaluation of the individual's infection risk, local and national policies, evidence-based guidelines, users' living arrangements, and their ability to clean the bags. Advice on decontamination methods varied; however, the most commonly recommended cleaning agent was water and vinegar, followed by a sterilizing or bleach solution or dishwashing detergent.


CONCLUSION: Nurses play a key role in educating and supporting indwelling catheter users. Results of this study highlight variability in the advice nurses give to community-dwelling long-term indwelling catheter users about sterile or clean urinary drainage bags. This variability requires further investigation and affirms the need for a larger-scale study that draws on a broader sample of nurses.

Simulation-based knowledge management in airport operations

Capturing and retaining knowledge in any organization is a major challenge. This talk describes how these challenges have been addressed through simulation and modeling techniques for complex engineered systems. A series of case studies that focus on airport processes are used to demonstrate the concepts. Furthermore, the additional benefits that a simulation model can bring, through online control and decision-making support, are discussed.

Airport and air cargo operation systems

Analysis of airport and air cargo operations is commonly performed in isolation, sharing only simple information such as flight schedules. Systems theory and Systems methodology can enhance such analysis by considering all aspects of air operations. It provides the decision-maker with an improved understanding of the implication of policy decisions, resource allocations and infrastructure investment strategies, through the capture of emergent behaviours and interdependencies. For example, the term airport operations, initially reminds us of the thought of passengers being transported by aircraft. Deeper thinking would identify activities that affect passenger operations, such as baggage handling systems, aircraft maintenance, and passenger security. In reality, airport operations consist of numerous aspects, including; concourses, runways, airlines, fuel depots, cargo terminal operators, retail, parking, cleaning, catering and many interacting people including travellers, service providers and visitors. For the airport to function effectively, these numerous systems must work together. This talk will focus on new tools and methodologies that are required for model development and analysis. It will then focus on modelling, simulation and analysis of the airport operations, providing greater understanding of airport operation with an emphasis towards security.