Engineering Commons^™

Improving Tribological Properties Of Cast Al-Si Alloys Through Application Of Wear-Resistant Thermal Spray Coatings, David Culliton, Tony Betts, Sandra Carvalho, David Kennedy

Articles

Flame Spray Thermal Spray coatings are low-cost, high-wear surface-treatment technologies. However, little has been reported on their potential effects on cast automotive aluminum alloys. The aim of this research was to investigate the tribological properties of as-sprayed NiCrBSi and WC/12Co Flame Spray coatings applied to two cast aluminum alloys: high-copper LM24 (AlSi8Cu3Fe), and low-copper LM25 (AlSi7Mg). Potential interactions between the mechanical properties of the substrate and the deposited coatings were deemed to be significant. Microstructural, microhardness, friction, and wear (pin-on-disk, microabrasion, Taber abrasion, etc.) results are reported, and the performance differences between coatings on the different substrates were noted. The …

Simulation Of Textured Audio Harmonics Using Random Fractal Phaselets, Jonathan Blackledge, Derry Fitzgerald, Ruairi Hickson

Conference papers

We present a method of simulating audio signals using the prin- ciples of random fractal geometry which, in the context of this paper, is concerned with the analysis of statistically self-affine ‘phaselets’. The approach is used to generate audio signals that are characterised by texture and timbre through the Fractal Dimension such as those associated with bowed stringed instruments. The paper provides a short overview on potential simulation methods us- ing Artificial Neural Networks and Evolutionary Computing and on the problems associated with using a deterministic approach based on solutions to the acoustic wave equation. This serves to quantify the …

On The Application Of Two-Dimensional Chirplets For Resilient Digital Image Watermarking, Jonathan Blackledge, Oleksandr Iakovenko

Conference papers

Chirplets (swept-frequency harmonic signals) find applications in several areas, including real and synthetic aperture radar, (Fresnel) optics and image processing. The robustness of chirplets to extreme (additive) noise make them an ideal choice in the role of embedding patterns for resilient digital signal and image watermarking. In this paper we present a new watermarking technique which is based on embedding two-dimensional chirplet coded binary sequences in digital images. This approach provides a pattern embedded recovery algorithm which is robust to a variety of distortions. However, chirplets have certain parameters that need to be specified, and given a set of target …

A Study On The Power Quality Of Dg Integrated Building Energy System In Virtual Environment, Shafiuzzaman K. Khadem, Ruth Kerrigan, Malabika Basu, Biswajit Basu

Conference papers

In this paper, the electrical energy demand of a typical residential building has been extracted from a Virtual Environment (VE) simulation. The extracted energy demand is generated by input load demand and hourly operating information. Based on the electrical energy demand for a typical day, a building integrated photovoltaic (PV) system is then simulated in MATLAB to extract the current/voltage disturbance information into the network. Outcome of this simulation shows the voltage/current waveform along with the disturbances at different locations in the building. The city of Dublin, Ireland has been chosen as a geographical location and VE-Pro software has been …

Fault Identification Of Lcc Hvdc Using Signal Processing Techniques, Benish Paily, Malabika Basu, Michael Conlon

Conference papers

Line commutated HVDC (LCC HVDC) technology has been in operation with a high level reliability and little maintenance requirements for more than 30 years. This technology plays an important role in particular in the wind energy industry. The current-source based or classical LCC-HVDC systems are being considered for buried cable transmission as well as overhead transmission. The fault analysis and protection of LCC-HVDC system is a very important aspect in terms of power system stability. This paper presents a comparative study of abc to dq⁰ transformation, and wavelet transform-based analysis for the identification of faults in an LCC HVDC …

Using Weigh-In-Motion Data To Determine Aggressiveness Of Traffic For Bridge Loading, Eugene J. Obrien, Bernard Enright

Articles

This paper presents results based on the analysis of an extensive database of weigh-in-motion (WIM) data collected at five European highway sites in recent years. The data are used as the basis for a Monte Carlo simulation of bridge loading by two lane traffic, both bidirectional and same-direction. Long runs of the simulation model are used to calculate characteristic bridge load effects (bending moments and shear forces), and these characteristic values are compared with design values for bridges of different length as specified by the Eurocode for bridge traffic loading. Various indicators are tested as possible bases for a “Bridge …

Argumentation Theory In Health Care, Luca Longo, Bridget Kane, Lucy Hederman

Books/Book Chapters

Argumentation theory (AT) has been gaining momentum in the health care arena thanks to its intuitive and modular way of aggregating clinical evidence and taking rational decisions. The basic principles of argumentation theory are described and demonstrated in the breast cancer recurrence problem. It is shown how to represent available clinical evidence in arguments, how to define defeat relations among them and how to create a formal argumentation framework. Argumentation semantics are then applied over the built framework to compute arguments justification status. It is demonstrated how this process can enhance the clinician decision-making process. A encouraging predictive capacity is …

Phases: Opto-Mechanical Solutions To Perform Absolute Spectrophotometry From Space, Carlos Del Burgo, Dinesh Vather, Niall Murphy

Conference papers

This work provides an update of the current status of PHASES, which is a project aimed at developing a space-borne telescope to perform absolute flux calibrated spectroscopy of bright stars. PHASES will make it possible to measure micromagnitude photometric variations due to, e.g., exo-planet/moon transits. It is designed to obtain 1% RMS flux calibrated low resolution spectra in the wavelength range 370–960 nm with signal-to-noise ratios >100 for stars with V∼1 minute. The strategy to calibrate the system using A-type stars is outlined. PHASES will make possible a complete characterization of stars, some of them hosting planets. From the comparison …

Image Authentication Using Stochastic Diffusion, Abdulrahman I. Al-Rawi, Jonathan Blackledge

Conference papers

This paper considers an approach to encrypted information hiding based on Stochastic Diffusion for encrypting digital images coupled with the application of a Least Significant Bit (LSB) method for information embedding. After providing a brief summary of various information hiding methods based on spatial and transform domain techniques, two new methods are introduced. The first of these considers a binary image watermarking algorithm for hiding an image in a single host image which is based on binarization of the encrypted data. The second method extends this approach to solving the problem of 24-bit image hiding in three host images which …

Community Microgrid Based On Micro-Wind Generation System, Lubna Mariam, Malabika Basu, Michael Conlon

Conference papers

Penetration of renewable energy sources (such as solar/wind) are being explored mostly as micro power generation (μGen) or mega power plant system. In recent years, emphasis has been given on Microgrid (μGrid) systems because of their few advantages over μGen systems in terms of power quality, stability, reliability, economics etc. But the commercial installation of the μGrid system is not yet progressing significantly. This paper presents the techno-economic aspects of μGen and μGrid systems towards the development of grid connected community based μGrid (C-μGrid) system. Emphasis has been given to identify the benefits of the μGrid over the μGen system. …

A New Placement And Integration Method Of Upqc To Improve The Power Quality In Dg Network, Shafiuzzaman K. Khadem, Malabika Basu, Michael Conlon

Conference papers

A new proposal for the placement and integration of UPQC in DG connected microgrid/micro generation (μG) system has been presented here. DG converters (with storage), the load and shunt part of the UPQC will be placed at or after the PCC. The series part of the UPQC will be placed before the PCC and in series with the grid. DC link can be connected to the storage system also. Hence, it is termed UPQCμ_G. The advantages of the proposed UPQCμ_G over the normal UPQC are to compensate voltage interruptions in addition to voltage sags / swells, harmonic …

Reduction Of Circulating Current Flow In Parallel Operation Of Apf Based On Hysteresis Current Control, Shafiuzzaman K. Khadem, Malabika Basu, Michael Conlon

Conference papers

Capacity enhancement and operation flexibility are two of the important limitations of the centralized Shunt Active Power Filter (APF_sh) unit. This can be overcome by multiple and parallel APF_sh units (in distributed mode) with a common DC link. In that case, a circulating current (CC) can flow. In the case of a hysteresis current controller based multiple APF_sh units in load sharing mode, this CC control is not yet achieved. One of the difficulties of this CC flow control or reduction is the variable switching frequency of the APF_sh units. In this paper, the model …

Microsimulation Evaluation Of Eurocode Load Model For American Long-Span Bridges, Bernard Enright, Colm Carey, Colin Caprani

Articles

The ability to accurately predict traffic loading is essential for cost-effective bridge maintenance and repair programs. The traffic load model currently used in the United States for the design of long-span bridges was developed over three decades ago. In the meantime vehicle characteristics and traffic patterns have changed. The Eurocode for traffic loading is more recent, but was calibrated only for bridges up to 200 m long. In this work, Weigh-In-Motion traffic records from 11 different sites across Alabama are used to establish congested traffic loading. Traffic microsimulation is used to generate the congestion, based on the real traffic data. …

Mathematical Self-Efficacy: Addressing The Declining Interest In Engineering Careers, Eileen Goold

Conference Papers

This paper presents the findings of a study investigating whether there is a relationship between students’ experiences with school mathematics and their choice of engineering as a career. The study was inspired by the observation that there is a lacuna in the scholarly literature concerning the nature of mathematics’ role, if any, as a significant cause of the declining number of students entering professional engineering courses. The population of interest in this study comprises professional engineers practising in Ireland. Engineers’ experiences of school mathematics, factors that contributed to their engagement with school mathematics and the impact of their feelings about …

An Investigation Of The Biochemical Properties Of Tetrazines As Potential Coating Additives, Swarna Jaiswal, Brendan Duffy, Luke O'Neill, Patrick Mchale

Articles

1,2,4,5-Tetrazine and its 3,6-disubstituted derivatives are currently used for a range of industrial and medical applications as they exhibit particular coordination chemistries, characterized by electron and charge transfer phenomena. The aim of the present work is to describe the synthesis of two tetrazine derivatives, namely 3,6-dihydrazino-1,2,4,5-tetrazine (DHDTZ) and 1,2,4,5-tetrazine dicarboxylic acid (DCTZ), and determine their antibacterial, antioxidant and anticorrosion characteristics as additives in a sol-gel coating on SS316L steel. The structure of the tetrazines was confirmed by NMR and FTIR while the surface morphology of bacterial cells in their presence was observed by AFM. Their ability to inhibit corrosion on …

The Effect Of Microstructure On The Dynamic Equi-Biaxial Fatigue Behaviour Of Magnetorheological Elastomers, Yanfen Zhou, Stephen Jerrams, Tony Betts, Lin Chen

Conference Papers

Dynamic equi-biaxial fatigue behaviour of isotropic and anisotropic magnetorheological elas-tomers (MREs) based on a silicone rubber matrix was investigated using the bubble inflation method. Con-stant engineering stress amplitude was used as the control mode and samples were fatigued over different stress ranges between 0.75MPa and 1.4MPa. S-N (Wöhler) curves showing plots of stress amplitude (σa) ver-sus cycles to failure (N) are presented. Stress-strain behaviour throughout the fatigue process is described. Elastic modulus (E*) was studied for the specific cycles measured. It was found that anisotropic MREs exhi-bited greater fatigue resistance than isotropic MREs for a given magnetic particle content. Stress …

Mid-Infrared Raman Sources Using Spontaneous Raman Scattering In Germanium Core Optical Fibers, Pengfei Wang, Christy Charlton O'Mahony, Timothy Lee, Rand Ismaeel, Thomas Hawkins, Yuliya Semenova, Lin Bo, Qiang Wu, Colette Mcdonagh, Gerald Farrell, John Ballato, Gilberto Brambilla

Articles

Mid-infrared Raman sources based on spontaneous Raman scattering have been demonstrated in a 15-lm diameter glass-clad crystalline germanium optical fiber and in a germanium-wire. A quantum cascade laser was used as pump at a wavelength of 5.62 lm. Because of their ultra-high optical nonlinearities and extremely broad transparency window, germanium core fibers offer the possibility of fabricating compact and efficient mid-infrared sources.

Learning From Learning Groups, Mike Murphy, S. M. Chance, Gavin Duffy, Brian Bowe

Articles

Collaborative learning is a key, and complementary, component of student-centred enquiry-based pedagogy. Today, many educators understand that students learn effectively when working together with their peers to construct new knowledge. Many teachers are working to help their students develop such ability. Teachers do this to help students better understand the relevance of new content, connect new ideas into existing frameworks of understanding, and construct new neurological pathways and connect synapses in their brains. In addition, group learning has been shown to increase students’ critical thinking skills, creativity, collaborative behaviours, understanding of ethics, and the like. In the literature, attention has …

A Highly Efficient Tio2-Xcx Nano-Heterojunction Photocatalyst For Visible-Light Induced Antibacterial Applications, Vinodkumar Etacheri, Michael Seery, Stephen Hinder, Georg Michlits, Suresh Pillai

Articles

Visible-light-induced antibacterial activity of carbon-doped anatase-brookite titania nano-heterojunction photocatalysts are reported for the first time. These heterostructures were prepared using a novel low temperature (100 °C) non-hydrothermal low power microwave (300 W) assisted method. Formation of interband C 2p states was found to be responsible for the band gap narrowing of the carbon doped heterojunctions. The most active photocatalyst obtained after 60 minutes of microwave irradiation exhibits a 2-fold higher visible-light induced photocatalytic activity in contrast to the standard commercial photocatalyst Evonik-Degussa P-25. Staphylococcus aureus inactivation rate constant for carbon-doped nano-heterojunctions and the standard photocatalyst was 0.0023 and -0.0081 min …

Finite Element Analysis Of Balloon-Expandable Coronary Stent Deployment: Influence Of Angioplasty Balloon Configuration, David Martin, Fergal Boyle

Articles

Today, the majority of coronary stents are balloon-expandable and are deployed using a balloon-tipped catheter. To improve deliverability, the membrane of the angioplasty balloon is typically folded about the catheter in a pleated configuration. As such, the deployment of the angioplasty balloon is governed by the material properties of the balloon membrane, its folded configuration and its attachment to the catheter. Despite this observation, however, an optimum strategy for modelling the configuration of the angioplasty balloon in finite element studies of coronary stent deployment has not been identified, and idealised models of the angioplasty balloon are commonly employed in the …

Impact Of Intermetallic Precipitates On The Tribological And/Or Corrosion Performance Of Cast Aluminium Alloys: A Short Review, David Culliton, Tony Betts, David Kennedy

Articles

The role of various intermetallic precipitates (IMP), or secondary phase particles, in governing the wear and corrosion performance characteristics of cast aluminium alloys is outlined in this brief review. Such alloys are especially important in transport applications where their low weight, low cost and recyclability make them very attractive. However alloy wear and/or corrosion behaviour often limit their industrial application and more work needs to done to extend their use into other areas. Careful control of IMP nucleation and growth rates may be beneficial, especially in alloys exposed to corrosive environments. Silicon, copper and magnesium are all important elements for …

Derivation Of A Fuzzy National Phosphorus Export Model Using 84 Irish Catchments, Ahmed Nasr, Michael Bruen

Articles

Implementation of appropriate management strategies to mitigate diffuse phosphorus (P) pollution at the catchment scale is vitally important for the sustainable development of water resources in Ireland. An important element in the process of implementing such strategies is the prediction of their impacts on P concentrations in a catchment using a reliable mathematical model. In this study, a state-of-the-art adaptive neuro-fuzzy inference system (ANFIS) has been used to develop a new national P model capable of estimating average annual ortho-P concentrations at un-gauged catchments. Data from 84 catchments dominated by diffuse P pollution were used in developing and testing the …

Manufacturing Strategy & Operations: Reflections On Key Current Issues: Challenges And Associated Human Resource Implications, Lorraine Mcgrath

Books/Book chapters

This chapter evaluates the current issues and challenges in defining a company’s manufacturing strategy and its production operations in consideration of the contemporary shift to low cost manufacturing locations. Competitive priorities of cost, quality, delivery and flexibility are reviewed. The structural and infrastructure elements of a manufacturing strategy are outlined. Mitigating risks in a global arena are reviewed. Collaborative efforts, including the cultural and personality issues of being human are included in the discussion of managing diversity in such a highly competitive and challenging enterprise resource planning environment.

The Integration Of Sustainable Development Competencies In Irish Engineering Education: Findings Of A Curriculum Content Investigation Of Four Engineering Programmes, Iacovos Nicolaou, Eddie Conlon

Conference papers

This paper presents the initial findings of an investigation of the Sustainable Development (SD) content in five professional engineering degree programmes in a large Irish Institute of Technology.

A comprehensive investigation of the modules content was conducted to see to what extent the learning outcomes for SD as set out in the Barcelona Declaration and SD competencies were covered by the modules. It was found that 40% of the 137 modules included SD learning outcomes and/or addressed SD competencies. The modules have a focus on environmental issues and tend to address only one of the three dimensions, environmental, social and …

Near Field Radiation Patterns For An Ultra-Wide-Band Antenna, Jonathan Blackledge, Bazar Babajanov

Conference papers

We present a three-dimensional time dependent model for simulating the electromagnetic radiation field patterns generated by Ultra-Wide- Band (UWB) antennas. UWB antennas are pulsed mode radiators used to communicate information at high bit rates over short distance. This affects the spatial characteristics of the field patterns assumed to be generated when a Continuous Wave (CW) model is used and this paper investigates the difference between the near field intensity patterns generated when a pulse and CW mode is used. The purpose of this is to develop a numerical simulation that provides information on the three-dimensional electromagnetic field subject to a …

Identifying High And Low Walkable Neighbourhoods Using Multi-Disciplinary Walkability Criteria, Lorraine Fitzsimons D'Arcy, Kevin M. Leyden, Catherine Woods

Conference papers

Neighbourhood features contributing to the walkability (pedestrian friendliness) of a neighbourhood are diverse and depend on both its physical and social attributes. Earlier work in the Cleaner, Greener, Leaner (CGL) Study identified differences in opinion between professional stakeholder groups (planners, designers, engineers, public representatives, and public health and advocacy professionals) on what constitutes a walkable environment [1]. This diversity has implications for neighbourhood design and planning policy. The findings of a multi-disciplinary focus group study were used to generate a list of walkability criteria to select areas for a population study. In this study twenty areas were shortlisted and grouped …

Achieving A Holistic View Of The Life Cycle Performance Of Existing Dwellings, Albert Famuyibo, Aidan Duffy, P. Strachan

Articles

Models which fully evaluate the life cycle energy and greenhouse gas (GHG) emissions of national housing stocks are not reported in literature. Capturing a holistic view of energy and emissions of the residential sector is an important process that can lead to a more effective policy making. This paper presents a methodology which evaluates the life cycle energy and GHG emissions of retrofitting housing stocks considering all life cycle stages and incorporating, to the greatest extent possible, all upstream inputs.

To achieve this, we developed a hybrid model of the existing Irish housing stock, comprising a process-based approach supplemented by …

Correspondence: Comparing Led Luminaires, James Duff

Articles

A recent editorial within Lighting Research and Technology 1 suggests the need for ‘a simple set of questions to ask the LED supplier’. This article will present such a set of questions, but also, and perhaps more importantly, a set of responses that might be considered appropriate. The information used to form these questions and answers has been drawn from a number of useful resources 2-7, interaction with various lighting professionals and through the authors own experience. The purpose of these questions is to generate discussion. The author understands the questions posed can be improved upon and it is hoped …

Lumped Time-Delay Compensation Scheme For Coding Synchronization In The Nonlinear Spectral Quantization-Based All-Optical Analog-To-Digital Conversion, Zhe Khang, Jinhui Yuan, Qiang Wu, Tao Wang, Sha Li, Chongxiu Y, Gerald Farrell

Articles

this paper, we propose a novel lumped time-delay compensation scheme for the all-optical analog-to-digital conversion based on soliton self-frequency shift and optical interconnection techniques. By inserting a segment of negative dispersion fiber between the quantization and the coding module, the time delay of different quantized pulses can be accurately compensated with a simple structure compared to the multiple time-delay lines. The simulation results show that the coding pulses can be well synchronized using a span of fiber, with the flattened negative dispersion within the wavelength range of 1558-1620 nm. In addition, the problems of pulse broadening and time error are …

Biaxial Order Parameter In The Homologous Series Of Orthogonal Bent-Core Smectic Liquid Crystals, S. Sreenilayam, Yuri Panarin, J. K. Vij, M. Osipov, A. Lehmann, C. Tschierske

Articles

The fundamental parameter of the uniaxial liquid crystalline state that governs nearly all of its physical properties is the primary orientational order parameter (S) for the long axes of molecules with respect to the director. The biaxial liquid crystals (LCs) possess biaxial order parameters depending on the phase symmetry of the system. In this paper we show that in the first approximation a biaxial orthogonal smectic phase can be described by two primary order parameters: S for the long axes and C for the ordering of the short axes of molecules. The temperature dependencies of S and C are obtained …