Engineering Commons^™

Application Of Advanced Computational Modelling In The Numerical Prediction Of The Haemodynamic Impact Of Coronary Stent Implantation, Jonathan Murphy, Fergal Boyle

Conference Papers

Coronary stent implantation can improve blood flow in an artery narrowed by the build up of arterial plaque. However, the haemodynamic effect of stent placement is unclear and may influence arterial restenosis (re-blockage). In this investigation the stent induced, non-Newtonian blood flow disturbances have been captured in a three dimensional computational domain. The results clearly show areas of low wall shear stress proximal and distal to the stent wires, a characteristic which is known to encourage restenosis. Furthermore, this computational method of observing the complex haemodynamics of the stent environment can be used in conjunction with medical trial data to …

Exchange Faculty Perspectives On International Collaborations, Donal Mchale

Conference Papers

The main purpose of the paper is to document key issues in developing successful transatlantic faculty exchanges and to document perspectives and key learnings’ emanating from the development and implementation of an international exchange process.

Thermal Performance Of Low Approach Evaporative Cooling Systems In Buildings, Ben Costelloe, Donal Finn

Conference Papers

Meteorological enthalpy analysis of temperate and maritime climates above 45˚N suggests that the water-side evaporative cooling technique has considerable unrealised potential with contemporary "high temperature" building cooling systems - such as chilled ceilings. As low approach conditions are the key to exploiting the cooling potential of the ambient air, thermal performance at such conditions needs to be investigated. To address the research issues a test rig, based on an open cooling tower and plate heat exchanger and designed to maximise evaporative cooling potential, has been constructed at DIT. A combination of experimental measurement and analysis is used in the investigations. …

Cutting Rate Effect On Temperature During Cortical Bone Sawing, Hamid Khalili Parsa, Ger Reilly, Brendan Mccormack

Conference Papers

When bone is cut the occurrence of thermal damage to the bone is of major concern to the surgeon. If the temperature exceeds 44°C for longer than 1 min, bone repair is impaired (Eriksson et al, 1984) and necrosis may occur. Repeated use of cutting blades may reduce the cutting efficiency (Wevers et al, 1987; Toksvig-Larsen et al, 1992). Wevers et al also found that there is a greater force required to cut cortical bone using a blunt saw compared to new one.

Indentation Fracture Of Bovine Cortical Bone: Acoustic Emission Technique, Ashkan Safari, Ger Reilly, Brendan Mccormack

Conference Papers

Indentation cutting may result in microcracking and main crack growth which was previously reported. In this study, we recorded the AE signals produced by cracking processes during cutting on cortical bone, measuring the cutting force and correlating between load-displacement curves and AE activities.

Hand Posture Recognition In Sign Language Using Shape Distributions, Eamonn Young, Gary Clynch

Conference Papers

A shape distribution is a histogram used to uniquely identify different shapes. The histogram is produced by taking random distances on the surface of a shape or object. Theoretically, each shape or object should produce a unique histogram, as the distribution of distances for each shape should be different. Shape distributions have recently been implemented in a number of object recognition areas. They are an attractive method as they are inherently simple, fast and generic. This paper presents the results of research undertaken on the application of shape distributions for the purpose of sign language recognition. There are four main …

A Numerical Acoustic Fluid-Structure Simulation Of Therapeutic Ultrasound Angioplasty, Graham Gavin, Finbar Dolan, M.S J. Hashmi, Garrett Mcguinness

Conference Papers

INTRODUCTION Therapeutic ultrasound angioplasty is the delivery of high amplitude ultrasonic displacements to the distal-tip of small diameter wire waveguides with the goal of disrupting atherosclerotic plaques. This is a minimally invasive procedure that may have potential' in the treatment of complicated chronic total occlusions. The disruption of plaque is due to direct contact ablation and also cavitation, pressure waves and acoustic streaming in the fluid surrounding the vibrating waveguide distal-tip [1]. Cavitation appears to play a major role and some authors have suggested that plaque ablation is only evident above the cavitation threshold [2]. Makin and Everbach [3] performed …

A Numerical Acoustic Fluid-Structure Model Of A Therapeutic Ultrasound Angioplasty Device, Graham Gavin, M.S. J. Hashmi, Finbar Dolan, Garrett Mcguinness

Conference Papers

Ultrasonic angioplasty involves the use of ultrasonic vibrations delivered to the distal-tip of small diameter wire waveguides and is an emerging technology the may have potential use in the treatment of complicated atherosclerotic plaques during cardiovascular surgery. Complicated plaques, including chronic total occlusions and calcified lesions, seriously reduce success rates during standard intervention involving guidewire access, followed by balloon dilation or stent delivery. The large amplitude (0-150 μm) wire waveguide distal-tip displacements in the low-frequency ultrasonic (18-45 kHz) range have been shown to disrupt plaque material by direct contact ablation and cavitation, acoustic streaming and pressure wave components in adjacent …

Alkaline Fuel Cell Engineering And Testing, James Brunton, David Kennedy, Eugene Coyle

Conference Papers

A fuel cell is a device that directly converts the chemical energy of reactants (a fuel and an oxidant) into low d. c. electricity [1]. Used in conjunction with other sustainable energy options, hydrogen and fuel cell technology can provide a realistic alternative to fossil fuels. Although research is continuing in many areas we are no closer now to commercialisation than ten to twenty years ago. This is due to a number of key reasons, some of which include efficiency, scale, accessories and power output. This paper outlines the benefits that could be derived from switching to a hydrogen based …

Refinements In Using Historical Process Data To Optimize Tolerance Allocation, Kevin Delaney, Pat Phelan

Conference Papers

Tolerance allocation for new products calls for experience and judgment. Whenever products are manufactured using production processes that are similar to existing products it is likely that the trend in production tolerances for both the new and existing products will be similar. It must be assumed that there have been no improvements to the tooling, modifications to the machines being used, or a change in process stability. The data employed to understand and exploit these trends is commonly referred to as process capability data and it is stored in a Process Capability DataBase (PCDB). There are several challenges to be …

The Tromped, An In-Flight Exercise Device To Prevent Flight Related Deep Vein Thrombosis, Carolyn Collins, David Kennedy, Thomas Corrigan, Stephen Jerrams

Conference Papers

Medical and Engineering research studies have shown the potential risks of long haul flight travel and methods of preventing it occurring. The risk of serious health problems or even death is known to arise from lack of venous movement and increased coagulation (clotting) of the blood. These factors contribute to the development of deep vein thrombosis (DVT) and this is more likely to occur in situations where people are seated for long periods during travel on land or in air. Currently long haul airlines have yet to be seen to introduce physical preventative measures against this syndrome.

A prototype design …

The Role And Future Of Nanotechnology In Research, Industry And Education, David Kennedy

Conference Papers

Major developments in Nanotechnology have taken place across the world
over the last few years. From a humble beginning, Ireland inc. became a leader in the Microelectronics industry and now has to face the challenge of developing a strategic plan to maintain its lead position in the nano field which in most cases will supersede the micro phase. Most countries are taking a similar path of development all be it alone or in collaboration with other countries. This process is expensive and requires market drivers and experts to lead and deliver demands from the industries of the future. The approach …