Squeeze-film levitation characteristics of plates excited by piezoelectric actuators

A small mass is levitated by a vibrating plate with an arrangement of four piezoelectric actuators that generate a squeeze-film in the gap between the plate and the mass. Different arrangements of actuators and plate design are explored using simulation in order to produce better performance

Stationary and non-stationary fluid flow of a Bose-Einstein condensate through a penetrable barrier

We experimentally study the fluid flow induced by a broad, penetrable barrier moving through an elongated dilute gaseous Bose-Einstein condensate. The barrier is created by a laser beam swept through the condensate, and the resulting dipole potential can be either attractive or repulsive. We examine both cases and find regimes of stable and unstable fluid flow: At slow speeds of the barrier, the fluid flow is stationary due to the superfluidity of the condensate. At intermediate speeds, we observe a non-stationary regime in which the condensate gets filled with dark solitons. At faster speeds, soliton formation completely ceases and a remarkable absence of excitation in the condensate is seen again.Comment: 4 pages, 4 figure

Fiduciary Principles: Corporate Responsibilities to Stakeholders

The recent corporate scandals and financial crisis has increased demand for accountability in business decisions. Corporate governance reform initiatives designed to increase financial disclosure and responsibility are insufficient to rebuild public trust in business. Corporate boards and officers must comply with the legal norms to which they are already subject; as fiduciaries they have duties of care, loyalty and good faith. This article examines modern fiduciary duties that currently govern corporate conduct and thus severely limit corporate responsibility. Revisiting the historical and religious origins of fiduciaries that shaped the ethical and moral duties gives insight into the true role of a fiduciary. We propose a new, well-defined definition of fiduciary duties that could offer corporate managers guidance in developing new stakeholder relationships

Effect of surface roughness on friction behaviour of steel under boundary lubrication

The friction behaviour of grinded and polished surfaces was evaluated by using a reciprocal sliding tester under lubrication with PAO, PAO + ZnDTP and PAO + ZnDTP + MoDTC. Friction coefficients on the smooth surfaces showed higher values compared to those on the rough surfaces. For lubrication incorporating PAO and PAO + ZnDTP + MoDTC, friction coefficients on both the smoothest and the roughest surfaces decreased with sliding time. On the other hand, friction coefficients between these extremes decreased with sliding time. In this paper, the effects of surface roughness on friction behaviour are discussed

Plate actuator vibration modes for levitation

The design of an aluminium or steel plate of various thicknesses for achieving levitation of a small aluminum disk is investigated by simulation using ANSYS. Each plate design is excited by an arrangement of four hard piezoelectric actuators driven with an AC voltage, which produces a centre displacement for generating a squeeze-film in the gap between the vibrating plate and the disk. Physical experiments show levitation conditions for one of the designs

Non-Newtonian and flow pulsatility effects in simulation models of a stented intracranial aneurysm

Permission to redistribute provided by publishers.Three models of different stent designs implanted in a cerebral aneurysm, originating from the Virtual Intracranial Stenting Challenge'07, are meshed and the flow characteristics simulated using commercial computational fluid dynamics (CFD) software in order to investigate the effects of non-Newtonian viscosity and pulsatile flow. Conventional mass inflow and wall shear stress (WSS) output are used as a means of comparing the cfd simulations. In addition, a WSS distribution is presented, which clearly discriminates in favour of the stent design identified by other groups. It is concluded that non-Newtonian and pulsatile effects are important to include in order to avoid underestimating wss, to understand dynamic flow effects, and to discriminate more effectively between stent designs. © Authors 2011

Capital Region Climate Change Forum: Citizens' Report

The Capital Region Climate Change Forum was organised, facilitated and evaluated by the Institute for Sustainable Futures (ISF) at the University of Technology, Sydney (UTS). The NSW Greenhouse Office and the ACT Department of Territory and Municipal Services provided funding for the Forum. The Forum was held from Friday 1 December to Sunday 3 December 2006. The primary objectives of the Forum were to: * Test the use of a citizens jury as a way of helping the community to engage with the issue of climate change and develop informed recommendations on how to respond * Provide the NSW and ACT Governments with a greater understanding of how the community in the Capital Region would like to respond to climate change * Improve understanding of community perspectives on climate change more broadly. The Forum grew out of an earlier proposal for a National Conversation on Climate Change (NCCC), developed by ISF. The NCCC proposal is provided in Appendix A. The aim of the NCCC is to stimulate public debate on Australia's response to climate change by undertaking a series of high profile citizen forums in all Australian states and developing an associated website and other media outputs. It seeks to promote public deliberation on climate change response. Deliberation is an approach to decision making in which citizens consider relevant facts from multiple points of view, converse with one another to think critically about options before them and enlarge their perspectives, opinions and understandings. In a deliberative process, participants are provided with information, training, time and other resources to allow them to learn about and debate an issue and come to a considered view. A deliberative process acts as a capacity building exercise in which non expert members of the community are empowered to discuss and form valid opinions about the subject