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- Austempered ductile iron (1)
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Articles 1 - 9 of 9
Full-Text Articles in Engineering
Analysis Of Indentation Loading Of Cortical Bone Using Acoustic Emission Techniques, Ashkan Safari, Ger Reilly, Brendan Mccormack
Analysis Of Indentation Loading Of Cortical Bone Using Acoustic Emission Techniques, Ashkan Safari, Ger Reilly, Brendan Mccormack
Conference Papers
In this study, we recorded the number of Acoustic emission (AE) hits and related AE energy during indentation fracture of cortical bone using a PAC PCI-2 card and pico sensor. A threshold value of 43dB was used to filter premature trigger due to background noise. Registered AE hits had more than one count (threshold crossing). Amplifier gain was set at 40dB with a (0.1-1) MHz band pass filter. 8mm cubes of cortical bones were indented in the longitudinal direction at constant crosshead speed of 1 mm min-1 using a large 2D, 50˚ wedge indenter. We hypothesised that signals occurring as …
Manufacture Of Near Net Shaped 3-Dimensional Components For Industrial Applications, David Kennedy, Donal Brosnan
Manufacture Of Near Net Shaped 3-Dimensional Components For Industrial Applications, David Kennedy, Donal Brosnan
Conference Papers
The development of near net shape 3-Dimensional products for industrial applications has been one main goal for Manufacturing Industries over the last few decades. Processes such as polymer blow moulding and its various stages of development, glass forming, extrusion, forging, centrifugal and sand casting, bulge forming and vacuum forming are typical processes that have contributed to this development. Current practices centre on Surface coatings, Rapid Prototyping, laser forming and nanotechnology manufacture of complex 3-D shapes and assemblies. The work described in this paper is a new and highly efficient and cost effective technique for producing 3-Dimensional thin walled shapes by …
Experimental And Numerical Investigation Of Therapeutic Ultrasound Angioplasty, Graham Gavin, M.S. J. Hashmi, Garrett B. Mcguinness
Experimental And Numerical Investigation Of Therapeutic Ultrasound Angioplasty, Graham Gavin, M.S. J. Hashmi, Garrett B. Mcguinness
Other resources
Therapeutic ultrasound angioplasty is an emerging minimally invasive cardiovascular surgical procedure that involves the delivery of ultrasonic displacements to the distal-tip of small diameter wire waveguides. The ultrasonic distal-tip displacements affect atherosclerotic plaque and thrombus by direct contact ablation, pressure wave components and cavitation, in addition to an acoustic streaming event around the distal-tip. This study uses experimental and numerical methods to investigate ultrasonic displacements in wire waveguides and the effect the distal-tip displacements have on the surrounding fluid. An experimental therapeutic ultrasound wire waveguide apparatus is described that delivers displacements to the distal-tip of 1.0 mm and tapered 0.35 …
An Acoustic Fluid-Structure Simulation Of A Therapeutic Ultrasound Wire Waveguide Apparatus, Graham Gavin, M. Hashmi, Finbar Dolan, Garret Mcguinness
An Acoustic Fluid-Structure Simulation Of A Therapeutic Ultrasound Wire Waveguide Apparatus, Graham Gavin, M. Hashmi, Finbar Dolan, Garret Mcguinness
Conference Papers
The use of high-power low-frequency ultrasound transmitted down small diameter wire waveguides is an emerging technology that may have potential in the treatment of complicated atherosclerotic plaques in cardiovascular surgery. This form of energy delivery results in vibrating the distal-tip of the wire waveguide disrupting material by means of direct contact ablation and also cavitation, pressure waves and acoustic streaming in the surrounding fluid. This work describes a numerical acoustic fluid-structure model of the ultrasound wire waveguide and blood surrounding the distal tip. The structural analysis of the model predicts the natural frequencies of the waveguide and shows the extent …
Development And Performance Characteristics Of An Ultrasound Angioplasty Device, Graham Gavin, Garrett Mcguinness, Finbar Dolan, M.S. J. Hashmi
Development And Performance Characteristics Of An Ultrasound Angioplasty Device, Graham Gavin, Garrett Mcguinness, Finbar Dolan, M.S. J. Hashmi
Conference Papers
INTRODUCTION The effect of atherosclerosis is well documented and many procedures such as balloon angioplasty and stentimplantation have been developed to reopen occluded arteries. However, there are considerable differences in the material properties of various atherosclerotic lesions as they develop. Many authors have suggested that rigid calcified plaques may require specific procedures that target this rigid material through de-bulking or complete removal (Salunke et al, 1997). Ultrasound angioplasty is the delivery of high power low frequency ultrasound via a wire waveguide to the lesion location. This results in distal tip wire displacements of up to 100um peak-to-peak (p-p) at frequencies …
An Investigation On The Suitability Of Surface Engineered Austempered Ductile Iron As A Gear Material, M. Grech, David Kennedy, Zdravko Schauperl
An Investigation On The Suitability Of Surface Engineered Austempered Ductile Iron As A Gear Material, M. Grech, David Kennedy, Zdravko Schauperl
Conference Papers
This preliminary study demonstrates that surface engineered austempered ductile iron is a valid alternative gear material to carburised steel. The impact energy of ductile cast iron samples in various conditions, including as – cast, austempered at 240oC and austempered and shot peened using both 0.7mm and 1.4mm steel balls, was measured. As expected the as-cast material exhibited nominal impact energy. This has been attributed mainly to the pearlitic matrix structure.Austempering generally increases the impact energy. The extent of the improvement is however dependent on the austempering temperature and the resulting microstructure. It was shown that the structure following …
Micro Shot Blasting Of Machine Tools For Improving Surface Finish And Reducing Cutting Forces In Manufacturing, James Vahey, David Kennedy
Micro Shot Blasting Of Machine Tools For Improving Surface Finish And Reducing Cutting Forces In Manufacturing, James Vahey, David Kennedy
Articles
Micro blasting of cutting tips and tools is a very effective and reliable method of advancing the life of tools under the action of turning, milling, drilling, punching and cutting. This paper outlines the ways in which micro blasted tools, both coated and un coated have benefited from shot blasting and resulted in greater productivity, lower cutting forces, improved surface finish of the work pieces and less machine downtime. The process of micro blasting is discussed in the paper. Its effectiveness depends on many parameters including the shot media ad size, the mechanics of impact and the application of the …
Current And Future Applications Of Surface Engineering, David Kennedy, Yueqiang Xue, Emilia Mihaylova
Current And Future Applications Of Surface Engineering, David Kennedy, Yueqiang Xue, Emilia Mihaylova
Articles
No abstract provided.
Audio Time-Scale Modification, David Dorran
Audio Time-Scale Modification, David Dorran
Doctoral
Audio time-scale modification is an audio effect that alters the duration of an audio signal without affecting its perceived local pitch and timbral characteristics. There are two broad categories of time-scale modifications algorithms, time-domain and frequency-domain. The computationally efficient time-domain techniques produce high quality results for single pitched signals such as speech, but do not cope well with more complex signals such as polyphonic music. The less efficient frequency-domain techniques have proven to be more robust and produce high quality results for a variety of signals; however they introduce a reverberant artefact into the output. This dissertation focuses on incorporating …