Engineering Commons^™

Optimized Monopole And Dipole Antennas For Uwb Asset Tag Location Systems, Antoine Dumoulin, Matthias John, Max Ammann, Patrick Mcevoy

Articles

Miniaturized monopole and dipole antenna designs are reported with performances optimized for ultrawideband pulsed radio applications. The geometries are created using Bézier spline shapes, which have been refined with a genetic algorithm to simultaneously take account of both frequency- and time-domain criteria. Time-domain measurements of ultra wideband antennas with uniformly distributed energy across the full 3.1-10.6 GHz mask are reported for the first time and validate a new approach to minimization of pulse dispersion effects in the antenna designs.

Omnidirectional Circularly Polarised Microstrip Patch Antenna, Max Ammann, Adam Narbudowicz, Xiulong Bao

Articles

An omnidirectional circularly-polarised patch antenna is proposed. The antenna radiates right-handed circular-polarisation with an average axial ratio of 2.3 dB over a full 360° . A shallow diagonal CPW inset-feed was used to achieve good matching to the back-to-back coupled patches, providing a measured S11 < -15 dB at the centre frequency. The measured cross-polar performance is better than 13 dB and the realised gain variation is ~3 dB in the plane normal to the substrate.

Antipodal Vivaldi Antenna For Water Pipe Sensor And Telemetry, Giuseppe Ruvio, Domenico Gaetano, Max Ammann, Patrick Mcevoy

Articles

An antipodal Vivaldi antenna operates simultaneously for telemetry and sensing when placed conformally onto PVC pipes. Good radiation efficiency is realised and the antenna impedance matching remains stable when the pipe is empty or contains water. The Fidelity Factor performance based on an input Ultra Wideband Gaussian pulse is a suitable figure of merit to detect water presence. Different water levels and pipe conditions correspond to Fidelity Factors between 90% and 96%, which are a suitable dynamic range for sensing and the appropriate quality for pulse communications for remote monitoring.

Enhancement Factors For The Vertical Response Of Footbridges Subjected To Stochastic Crowd Loading, Colin Caprani, Joe Keogh, Paul Archbold, Paul Fanning

Articles

The vertical acceleration response of a hypothetical footbridge is predicted for a sample of single pedestrians and a crowd of pedestrians using a probabilistic approach. This approach uses statistical distributions to account for the fact that pedestrian parameters are not identical for all pedestrians. Enhancement factors are proposed for predicting the response due to a crowd based on the predicted accelerations of a single pedestrian. The significant contribution of this work is the generation of response curves identifying enhancement factors for a range of crowd densities and synchronization levels.

The Implementation Of A Visco-Hyperelastic Numerical Material Model For Simulating The Behaviour Of Polymer Foam Materials, Conor Briody, Barry Duignan, Stephen Jerrams, John Tiernan

Articles

Polyurethane foam has been in use for some time in wheelchair seating systems as it offers good pressure relieving capabilities in most cases. However, little characterisation work has gone into seating foam materials by comparison with conventional elastomeric materials. Accurate material models could allow better prediction of foam in-service behaviour, which could potentially improve seating design practises. The objective of this work was to develop an approach for the validation of hyperelastic and viscoelastic material model parameters used to simulate polyurethane foam behaviour. Material parameters were identified from relevant test procedures and implemented in a Finite Element simulation of an …

A Microfiber Coupler Tip Thermometer, Ming Ding, Pengfei Wang, Gilberto Bramilla

Articles

A compact thermometer based on a broadband microfiber coupler tip is demonstrated. This sensor can measure a broad temperature interval ranging from room temperature to 1283 degrees C with sub-200 mu m spatial resolution. An average sensitivity of 11.96 pm/degrees C was achieved for a coupler tip with similar to 2.5 mu m diameter. This is the highest temperature measured with a silica optical fiber device. (C)2012 Optical Society of America

A Survey Based Analysis Of It Adoption And 3pls’ Performance, Pietro Evangelista, Riccardo Mogre, Alessandro Perego, Antonino Raspagliesi, Edward Sweeney

Articles

Purpose – In today’s competitive scenario, effective supply chain management is increasingly dependant on third party logistics (3PL) companies’ capabilities and performance. The dissemination of information technology (IT) has contributed to change the supply chain role of 3PL companies and IT is considered an important element influencing performance of modern logistics companies. Therefore, the purpose of this paper is to explore the relationship between IT and 3PLs’ performance, assuming that logistics capabilities play a mediating role in this relationship.

Design/methodology/approach – Empirical evidence based on a questionnaire survey conducted on a sample of logistics service companies operating in the Italian …

Characterising Domestic Electricity Consumption Patterns By Dwelling And Occupant Socio-Economic Variables: An Irish Case Study, Fintan Mcloughlin, Aidan Duffy, Michael Conlon

Articles

This paper examines the influence of dwelling and occupant characteristics on domestic electricity consumption patterns by analysing data obtained from a smart metering survey of a representative cross section of approximately 4,200 domestic Irish dwellings. A multiple linear regression model was applied to four parameters: total electricity consumption, maximum demand, load factor and time of use (ToU) of maximum electricity demand for a number of different dwelling and occupant socio-economic variables. In particular, dwelling type, number of bedrooms, head of household (HoH) age, household composition, social class, water heating and cooking type all had a significant influence over total domestic …

A Review Of Situation Identification Techniques In Pervasive Computing, Juan Ye, Simon Dobson, Susan Mckeever

Articles

Pervasive systems must offer an open, extensible, and evolving portfolio of services which integrate sensor data from a diverse range of sources. The core challenge is to provide appropriate and consistent adaptive behaviours for these services in the face of huge volumes of sensor data exhibiting varying degrees of precision, accuracy and dynamism. Situation identification is an enabling technology that resolves noisy sensor data and abstracts it into higher-level concepts that are interesting to applications. We provide a comprehensive analysis of the nature and characteristics of situations, discuss the complexities of situation identification, and review the techniques that are most …

Evanescent Field Coupling Between Two Parallel Close Contact Sms Fiber Structures, Qiang Wu, Youqiao Ma, Jinhui Yuan, Yuliya Semenova, Pengfei Wang, Chongxiu Yu, Gerald Farrell

Articles

We proposed a novel optical coupling technique based on two parallel singlemode-multimode- singlemode (SMS) fiber structures. This technique utilizes one SMS structure to excite multiple cladding modes within an output singlemode fiber. The excited multiple cladding modes will be coupled to the input SMF in the second SMS structure by placing the two SMS fiber structures in parallel and in close contact each other. The coupled cladding modes will be re-coupled to a guided core mode by the second SMS fiber structure. Theoretical analysis for such technique was provided and experimentally we have achieved a pass band spectral response with …

A Fast-Response, High- Temperature Microfiber Coupler Thermometer, Ming Ding, Pengfei Wang, Gilberto Brambilla

Articles

A compact temperature sensor based on a broadband microfiber coupler tip is demonstrated. The thermometer dynamic range spans from room temperature to 1511 with a response time of tens of milliseconds. This is the highest temperature measured with a silica optical fiber device. A resolution of 0.66 was achieved for a coupler tip diameter of . Better resolution can be achieved with smaller sized microfiber coupler tips.

Hemp Lime Bio-Composite As A Building Material In Irish Construction, Patrick Daly, Paolo Ronchetti, Tom Woolley Dr

Articles

This report presents the findings of scoping study into the potential application of hemp lime biocomposite as a construction material in Irish context. The research was carried out under STRIVE funding administered under the Irish Environmental Protection Agency (EPA) examining the state of play of hemp lime in construction toward assessing its potential application in Ireland.

The research involved a range of methods, mainly qualitative, including significant literature review and extensive collation of data on hemp lime performance and testing data, semi structured interviews and field work / review of key case studies in Ireland, UK and Europe.

The study …

Increased Susceptibility Of Arterial Tissue To Wire Perforation With The Application Of High Frequency Mechanical Vibrations, Mark Wylie, Garrett Mcguinness, Graham Gavin

Articles

High frequency mechanical vibrations (20–50 kHz), delivered via small diameter flexible wire waveguides represent a minimally invasive technology for the treatment of chronic total occlusions (CTOs) and in other tissue ablation applications. Tissue disruption is reported to be caused by repetitive mechanical contact and cavitation. This work focuses on the effects of vibrating wire waveguides in contact with arterial tissue. An apparatus with clinically relevant parameters was used, characterized as operating at 22.5 kHz and delivering amplitudes of vibration of 17.8 - 34.3 µm (acoustic intensity, I_SATA: 1.03 - 3.83 W/cm²) via 1.0 mm diameter waveguides. …

Electrically Tunable Fabry-Perot Resonator Based On Microstructured Si Contaning Liquid Crystal, V. A. Tolmachev, V. A. Melnikov, A. V. Baldycheva, Kevin Berwick, T. S. Perova

Articles

We have built Fabry-Pérot resonators based on microstructured silicon and a liquid crystal. The devices exhibit tuning of the resonance peaks over a wide range, with relative spectral shifts of up to Δλ/λ = 10%. In order to achieve this substantial spectral shift, cavity peaks of high order were used. Under applied voltages of up to 15 V, a variation in the refractive index of the nematic liquid crystal E7 from Δn_LC = 0.12 to Δn_LC = 0.17 was observed. These results may have practical applications in the near-, mid and far-infrared range.

High-Q Bismuth-Silicate Nonlinear Glass Microsphere Resonators, Pengfei Wang, Ganapathy Murugan, Timothy Lee, Ming Ding, Gilberto Brambilla, Yuliya Semenova, Qiang Wu, Fumihito Koizumi, Gerald Farrell

Articles

The fabrication and characterization of a bismuth-silicate glass microsphere resonator has been demonstrated. At wavelengths near 1550 nm, high-modes can be efficiently excited in a 179-μm diameter bismuth-silicate glass microsphere via evanescent coupling using a tapered silica fiber with a waist diameter of circa 2 μm. Resonances with Q-factors as high as were observed. The dependence of the spectral response on variations in the input power level was studied in detail to gain an insight into power-dependent thermal resonance shifts. Because of their high nonlinearity and high- factors, bismuth-silicate glass microspheres offer the potential for robustly assembled fully integrated all-optical …

Development And Evaluation Of A Desktop Vr System For Electrical Services Engineers, Martin Barrett, Jonathan Blackledge

Articles

This paper presents a prototype desktop virtual reality model, developed to enhance electrical safety and design in the built environment. The model presented has the potential to be used as an educational tool for third level students, an industry design tool or as a virtual electrical safety manual for the general public. A description of the development of the virtual reality model is presented along with the applications that were developed within the model. Subsequently, a case study is carried out to evaluate the users’ attitudes toward VR learning environments and also the usability of the prototype model developed. Based …

Tendering Procedures In Ppp: A Literature Review, Nunzia Carbonara, Louis Gunnigan, Roberta Pellegrino, Fabio Sciancalepore

Articles

Purpose – This paper aims at providing an overview about literature on tendering process in PPP, with particular regard to transportation PPP case.

Design/methodology/approach – The approach is based on the analysis of the pertinent publications on the theme.

Findings – Three main interest areas can be found in the literature: tendering procedures, evaluation methods and evaluation criteria. Social implications – Contract authorities have several tools in order to pre-qualify and select bidders and negotiate with them: they can choose the instruments which best fit to their market

Originality/value – The paper provides a complete overview on PPP tendering procedures …

2:1 The Paper Tube Project, Noel Brady

Articles

Review of applied technological solution to rapid building techniques using paper tube and analogous materials to create space enclosing geodesic systems.

Co-Operatives As Social Innovation – How Older Models Of Social Enterprise Are More Relevant Than Ever, Gerard Doyle

Articles

Ireland faces a number of socio-economic issues, including, an over-reliance on fossil fuels, inequality, unsustainable approaches to urban regeneration and unbalanced regional development. This chapter will demonstrate how social enterprise can lead to the implementation of socially innovative responses to addressing these issues.

Examining The Role Of The University In Creating Jobs, Mike Murphy, Michael Dyrenfurth

Articles

This paper begins by setting out the rationale for why today’s university must be involved with job creation in terms of institutional mission and global competitiveness. We present a review of recent literature, from both sides of the Atlantic, regarding universities, technology and science parks and job creation. Measuring the impact of university actions is reviewed in terms of general criteria, impact of incubators, and where jobs are being created. A case study of Silicon Valley is reviewed as well as a discussion of roles that government might play. The paper concludes with the presentation of findings from the literature …

High Temperature Performance Of An Optical Microfibre Coupler And Its Potential Use As A Sensor, Pengfei Wang, Ming Ding, Gilberto Bramilla, Yuliya Semenova, Qiang Wu, Gerald Farrell

Articles

The dependence of the transmission spectrum of an optical microfibre coupler at high temperatures is investigated experimentally. Results show a temperature sensitivity up to 36.59 pm/oC at a taper waist outer diameter of 2.5 μm; such a temperature-dependent performance can be utilized for temperature sensing up to 1000oC.

Monte Carlo Simulation Of Extreme Traffic Loading On Short And Medium Span Bridges, Bernard Enright, Eugene J. Obrien

Articles

The accurate estimation of site-specific lifetime extreme traffic load effects is an important element in the cost-effective assessment of bridges. A common approach is to use statistical distributions derived from weigh-in-motion measurements as the basis for Monte Carlo simulation of traffic loading. However, results are highly sensitive to the assumptions made, not just with regard to vehicle weights but also to axle configurations and gaps between vehicles. This paper presents a comprehensive model for Monte Carlo simulation of bridge loading for free-flowing traffic, and shows how the model matches results from measurements on five European highways. The model has been …

Optical Fibre Technology, Gerald Farrell

Articles

No abstract provided.

The Use Of A Fiber Comb Filter Fabricated By A Co2 Laser Irradiation To Improve The Resolution Of A Ratiometric Wavelength Measurement System, Pengfei Wang, Gilberto Brambilla, Ming Ding, Yuliya Semenova, Qiang Wu, Gerald Farrell

Articles

An edge filter-based ratiometric wavelength measurement system is modeled and analyzed in this paper. The results confirm that the noise of input signal and photodetectors limits the resolution of the wavelength measurement system. The achievable resolution is calculated for a given noise level of the input signal and photodetectors' resolution. An improved ratiometric wavelength measurement system consisting of two fiber comb filters is presented both theoretically and experimentally, which performs coarse and fine wavelength measurements simultaneously. The resolution of the system is significantly improved to better than 5 pm while maintaining the potential for high measurement speed and wide measurable …

Germanium Microsphere High-Q Resonator, Pengfei Wang, Timothy Lee, Ming Ding, Anirban Dhar, Thomas Hawkins, Paul Foy, Yuliya Semenova, Qiang Wu, Jayanta Sahu, Gerald Farrell, John Ballato, Gilberto Brambilla

Articles

In this Letter, the fabrication and characterization of a microsphere resonator from the semiconductor germanium is demonstrated. Whispering gallery modes are excited in a 46 μm diameter germanium microsphere resonator using evanescent coupling from a tapered silica optical fiber with a waist diameter of 2 μm. Resonances with Q factors as high as 3.8×104 at wavelengths near 2 μm are observed. Because of their ultrahigh optical nonlinearities and extremely broad transparency window, germanium microsphere resonators offer the potential for optical processing devices, in particular at long wavelengths, such as around 2 μm.

Enhanced Refractometer Based On Periodically Tapered Small Core Singlemode Fiber, Pengfei Wang, Gilberto Brambilla, Ming Ding, Timothy Lee, Lin Bo, Yuliya Semenova, Qiang Wu, Gerald Farrell

Articles

Abstract—An all-fiber 1 refractive index (RI) sensor with a 2 simple configuration of periodical tapers is proposed and inves3 tigated experimentally. The proposed fiber RI sensor consists of 4 a small core fiber sandwiched between two standard singlemode 5 fibers, with tapers periodically fabricated along the small core 6 fiber using a focused CO2 laser beam. Such a structure can be 7 used for RI sensing by measuring the dip wavelength shift of 8 the multimode interference within the small core fiber cladding. 9 An average sensitivity of 226.6 nm/RIU (RI Unit) has been 10 experimentally achieved in the RI …

A Silica Single-Mode Fibre-Chalcogenide Multimode Fibre-Silica Single-Mode Fibre Structure, Pengfei Wang, Ming Ding, Lin Bo, Yuliya Semenova, Qiang Wu, Gerald Farrell

Articles

In this letter we theoretically and experimentally investigate a single-mode-multimode-single-mode (SMS) structure based on chalcogenide (As2S3) multimode fibre and silica single-mode fibres. The experimental results show a general agreement with the numerical simulation results based on a wide angle-beam propagation method (WA-BPM). Multimode interference variation was observed as a result of photo-induced refractive index changes arising from either localized laser irradiation at a wavelength of 405 nm or the use of a UV lamp. Our result provides a platform for the development

Influence Of Fluctuations Of The Geometrical Parameters On The Photonic Band Gaps In One-Dimensional Photonic Crystals, Vladimir A. Tolmachev, Anna .. Baldycheva, Kevin Berwick, Tatiana Perova

Articles

The influence of random fluctuations in the layer thicknesses in high contrast, one-dimensional Photonic Crystals (PCs) on the transmission spectra and Photonic Band Gaps (PBGs) is investigated. The change in the PBGs depends on the magnitude of the fluctuations and increases with an increase in the order of the PBG. Introducing thickness non-uniformity into the PC of up to 0.004 times the value of lattice constant for different types of fluctuation distributions has a negligible effect on either the position or the shape of the 1st and nearest PBGs. The approach suggested here allows the determination of the tolerances required …

What Do Final Year Engineering Students Know About Sustainable Development, Iacovos Nicolaou, Eddie Conlon

Articles

This paper presents data from a project which aims to determine the level of knowledge and understanding of engineering students about Sustainable Development (SD). The data derives from a survey completed by final year engineering students in three Irish Higher Education Institutions. This paper is part of a larger study which examines the relationship between students’ and teachers’ understanding of SD. The results from the survey show that final year engineering students have a discipline-led conception of SD. The majority of the participants fail to acknowledge the complexity of the concept and focus only on environmental protection. Their knowledge of …

A Front Tracking Model Of The Maxus-8 Microgravity Solidification Experiment On A Ti-45.5at.% Al-8at.%Nb Alloy, Robin Mooney, Shaun Mcfadden, Marek Rebow, David J. Browne

Articles

On 26th March 2010 the MAXUS-8 sounding rocket was launched from the Esrange Space Center in Sweden. As part of the Intermetallic Materials Processing in Relation to Earth and Space Solidification (IMPRESS) project, a solidification experiment was conducted on a Ti-45.5at.%Al-8at.%Nb intermetallic alloy in a module on this rocket. The experiment was designed to investigate columnar and equiaxed microstructures in the alloy. A furnace model of the MAXUS 8 experiment with a Front Tracking Model of solidification has been developed to determine the macrostructure and thermal history of the samples in the experiment. This paper gives details of results of …