http://ulir.ul.ie:80 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. 2017-11-04T23:32:32Z http://hdl.handle.net/10344/6230 Application of the discrete-time structured singular value for DC-DC converters Halton, Mark; Scharrer, Martin; Scanlan, Tony This paper considers the application of the discrete-time structured singular value to assess the robustness of systems subject to real parametric uncertainties. Since the associated uncertainty set is strictly real, the resulting mu bounds may be discontinuous irrespective of the fineness of the frequency sweep. It is therefore necessary to seek other more reliable methods of test. One such method detailed is a discrete robust stability state-space test that is not dependent on a frequency sweep. It is shown that this is a discrete skewed structured singular value problem. For illustration purposes, a robustness analysis using both a frequency sweep and state-space transformation is performed on a forward converter with a real parameter uncertainty. The results are detailed and critically assessed. peer-reviewed 2008-01-01T00:00:00Z http://hdl.handle.net/10344/6229 Solution synthesis of lead seeded germanium nanowires and branched nanowire networks and their application as Li-ion battery anodes Flynn, Grace; Palaniappan, Kumaranand; Sheehan, Martin; Kennedy, Tadhg; Ryan, Kevin M Herein, we report the high density growth of lead seeded germanium nanowires (NWs) and their development into branched nanowire networks suitable for application as lithium ion battery anodes. The synthesis of the NWs from lead seeds occurs simultaneously in both the liquid zone (solution-liquid-solid (SLS) growth) and solvent rich vapor zone (vapor-liquid-solid (VLS) growth) of a high boiling point solvent growth system. The reaction is sufficiently versatile to allow for the growth of NWs directly from either an evaporated catalyst layer or from pre-defined nanoparticle seeds and can be extended to allowing extensive branched nanowire formation in a secondary reaction where these seeds are coated onto existing wires. The NWs are characterized using TEM, SEM, XRD and DF-STEM. Electrochemical analysis was carried out on both the single crystal Pb-Ge NWs and the branched Pb-Ge NWs to assess their suitability for use as anodes in a Li-ion battery. Differential capacity plots show both the germanium wires and the lead seeds cycle lithium and contribute to the specific capacity that is approximately 900 mAh/ g for the single crystal wires, rising to approximately 1100 mAh/ g for the branched nanowire networks. peer-reviewed; The full text of this article will not be available in ULIR until the embargo expires on the 1/6/2018 2017-01-01T00:00:00Z http://hdl.handle.net/10344/6228 Low cost portable 3-D printed optical fiber sensor for real-time monitoring of lower back bending Kam, Wern; O'Sullivan, Kieran; O'Keeffe, Mary; O'Keeffe, Sinead; Waleed, Mohammed S; Lewis, Elfed A mechanically robust and compact novel optical fiber sensor system is described to monitor the bending of the lower back bone in both sagittal and frontal planes. Both bending modes are monitored through the change of the coupled optical intensity ratio between three output fibers aligned to one input fiber. This provides real-time feedback to the clinical therapist when different postures are sustained. The output ratio is calibrated against bending angle using an optical setup utilizing a precise rotational stage. The measured data is also correlated to the curvature of the lower back through the implementation of an ad-hoc imaging scheme. Sequences of images are also captured while the optical fiber sensor is attached on the skin surface to the lower back. The imaging system tracks three spots placed on the sensor and skin to trace the angle changes. The optical fiber sensor system has an operational range between −12° to +12°. It is demonstrated that the sensor is suitable for clinical use with the additional benefits of being non-invasive, robust, straightforward to use and low cost. It also allows record of spinal curvature in the home and other real-world settings and potentially reduces the requirement for the use of X-rays and MRI in the clinic. peer-reviewed; The full text of this article will not be available in ULIR until the embargo expires on the 4/09/2019 2017-01-01T00:00:00Z http://hdl.handle.net/10344/6227 A life course examination of the physical environmental determinants of physical activity behaviour: A "Determinants of Diet and Physical Activity" (DEDIPAC) umbrella systematic literature review Carlin, Angela; Perchoux, Camille; Puggina, Anna; Aleksovska, Katina; Buck, Christoph; Burns, Con; Cardon, Greet; Chantal, Simon; Ciarapica, Donatella; Condello, Giancarlo; Coppinger, Tara; Cortis, Cristina; D'Haese, Sara; De Craemer, Marieke; Di Blasio, Andrea; Hansen, Sylvia; Iacoviello, Licia; Issartel, Johann; Izzicupo, Pascal; Jaeschke, Lina; Kanning, Martina; Kennedy, Aileen; Lakerveld, Jeroen; Chun Man Ling, Fiona; Luzak, Agnes; Napolitano, Giorgio; Nazare, Julie-Anne; Pischon, Tobias; Polito, Angela; Sannella, Alessandra; Schulz, Holger; Sohun, Rhoda; Steinbrecher, Astrid; Schlicht, Wolfgang; Ricciardi, Walter; MacDonncha, Ciaran; Capranica, Laura; Boccia, Stefania Background Participation in regular physical activity is associated with a multitude of health benefits across the life course. However, many people fail to meet PA recommendations. Despite a plethora of studies, the evidence regarding the environmental (physical) determinants of physical activity remains inconclusive. Objective To identify the physical environmental determinants that influence PA across the life course. Methods An online systematic literature search was conducted using MEDLINE, ISI Web of Science, Scopus and SPORTDiscus. The search was limited to studies published in English (January 2004 to April 2016). Only systematic literature reviews (SLRs) and meta-analyses (MAs) of observational studies, that investigated the association between physical determinants and physical activity outcomes, were eligible for inclusion. The extracted data were assessed on the importance of determinants, strength of evidence and methodological quality. Results The literature search identified 28 SLRs and 3 MAs on 67 physical environmental characteristics potentially related to physical activity that were eligible for inclusion. Among preschool children, a positive association was reported between availability of backyard space and outdoor toys/equipment in the home and overall physical activity. The availability of physical activity programs and equipment within schools, and neighbourhood features such as pedestrian and cyclist safety structure were positively associated with physical activity in children and adolescents. Negative street characteristics, for example, lack of sidewalks and streetlights, were negatively associated with physical activity in adults. Inconsistent associations were reported for the majority of reviewed determinants in adults. Conclusion This umbrella SLR provided a comprehensive overview of the physical environment determinants of physical activity across the life course and has highlighted, particularly amongst youth, a number of key determinants that may be associated with overall physical activity. Given the limited evidence drawn mostly from cross-sectional studies, longitudinal studies are needed to further explore these associations. peer-reviewed 2017-01-01T00:00:00Z