Publications by authors named "Patrick Keogh"
The annuus fibrosus (AF) and nucleus pulposus (NP) of the intervertebral disc (IVD) work in conjunction to dissipate spinal loads. In this study we have isolated the contribution of the NP to the overall response of the disc and investigated the effect of extreme structural changes to the disc on the mechanical behaviour. Linear stiffness, overall load range, hysteresis area and total energy were used to evaluate the impact of these changes on the spine and surrounding structures.
View Article and Find Full Text PDFIndoor localization is a key enabling technology for mobile robot navigation in industrial manufacturing. As a distributed metrology system based on multi-station intersection measurement, the workshop measurement positioning system (wMPS) is gaining increasing attention in mobile robot localization. In this paper, a new, to the best of our knowledge, wMPS-based resection localization method is proposed using a single onmidirectional transmitter mounted on a mobile robot with scanning photoelectric receivers distributed in the work space.
View Article and Find Full Text PDFSelf-Healing Dielectric Elastomers for Damage-Tolerant Actuation and Energy Harvesting.
ACS Appl Mater Interfaces
February 2020
Article Synopsis
- The study showcases a new self-healing dielectric elastomer made from poly(styrene-butadiene-styrene) (SBS), designed for optimal actuation and energy-harvesting capabilities.
- The elastomer features high permittivity (ε = 7.5) and low dielectric loss (tan δ = 0.03), allowing it to withstand large mechanical strains (up to 1000%) and respond effectively under electric fields.
- Post-mechanical damage, the elastomer can regain 44% of its strength, highlighting its potential for robust applications in smart transducers and energy harvesting systems.
The hip joint is subjected to cyclic loading and motion during activities of daily living and this can induce micromotions at the bone-implant interface of cementless total hip replacements. Initial stability has been identified as a crucial factor to achieve osseointegration and long-term survival. Whilst fixation of femoral stems achieves good clinical results, the fixation of acetabular components remains a challenge.
View Article and Find Full Text PDFA novel method to assess primary stability of press-fit acetabular cups.
Proc Inst Mech Eng H
November 2014
Article Synopsis
- Initial stability is crucial for successful osseointegration of press-fit acetabular cups in hip replacements, which is often not accurately assessed in current in vitro methods.
- The study explored how bone density and acetabular shape impact cup stability using a new technique to measure micromotion under realistic loading conditions.
- Results showed that lower bone density, such as in osteoporotic cases, leads to increased micromotion and a higher risk of cup loosening, highlighting the limitations of simplified models in evaluating cup stability.
Non-smooth Hopf-type bifurcations arising from impact-friction contact events in rotating machinery.
Proc Math Phys Eng Sci
November 2014
We analyse the novel dynamics arising in a nonlinear rotor dynamic system by investigating the discontinuity-induced bifurcations corresponding to collisions with the rotor housing (touchdown bearing surface interactions). The simplified Föppl/Jeffcott rotor with clearance and mass unbalance is modelled by a two degree of freedom impact-friction oscillator, as appropriate for a rigid rotor levitated by magnetic bearings. Two types of motion observed in experiments are of interest in this paper: no contact and repeated instantaneous contact.
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