Engineering Commons^™

The Application Of Multi Frequency Resonant Controllers In In A Dfig To Improve Performance By Reducing Unwanted Power And Torque Pulsations And Reducing Current Harmonics., Joseph Kearney, Michael Conlon, Eugene Coyle

Conference papers

The paper describes a method to control the rotor-side and grid side converters in a DFIG when subjected to the effects of network voltage unbalance conditions. Multi Frequency Resonant Controllers are incorporated into the grid side and rotor side converters to assist in the control functions. The Resonant Controllers are tuned to twice the network frequency to assist in the control of power and torque pulsations and to three times the network frequency to assist in the control of the generated third harmonic currents. A DFIG model is implemented in Matlab/Simulink and simulations show the reduction in power and torque …

Evidence Based Evaluation Research In Engineering, Kevin Kelly

Conference papers

An argument for evidence based evaluation of sustainable engineering projects in buildings

Peat Improvement Under Vacuum Preloading:A Novel Approach For Bog Roads In Ireland, Juan Pablo Osorio, Eric R. Farrell, Brendan C. O'Kelly

Conference papers

This paper presents the preliminary findings of a TCD/NRA vacuum preloading field trial that is part of a research project into the construction options for improving rampart roads. Vacuum preloading is a construction method used to accelerate settlement and the increase shear strength by applying a vacuum pressure to the ground by means of prefabricated vertical drains, an impervious tight sheet and a vacuum pump. Consolidating the ground by applying a vacuum load has several advantages over other techniques, for example; no fill material is required; construction periods are generally shorter; and there is no need for chemical admixtures. This …

Development Of A New Marine Exposure Site On The Atlantic North-West Coast Of Ireland, Niall Holmes, L. Basheer, S. Nanukuttan, S. Srinivasan, Pam Basheer, J. Mccarter, M. Chrisp

Conference papers

This paper presents a new marine exposure site being developed on the North-west Atlantic coastline of Ireland in Co. Donegal by the Centre for Built Environment Research at Queen’s University Belfast. The site will initially contain a number of large precast concrete stems, each 1.5m high, 1.5m wide and 1m thick placed on concrete plinths poured in-situ. The concrete stems will be placed at three levels to achieve different exposure conditions outlined in EN 206, namely atmospheric (XS1), a splash or spray zone (XS3) and a tidal zone (XS3) where the stems will be submerged by the incoming tide twice …

Reducing Whole Body Vibration Levels In Off-Road, Heavy-Duty Vehicles: A Case Study With Computer Modelling, Shaun Mcfadden, Matthieu Morhan, Brian Hurley

Conference Papers

This paper describes a case study involving the dynamic ride performance of a 30-ton, articulated dumper vehicle. The vehicle in question was originally fitted with a front-end, solid axle with leading arm mechanism. After an engineering design program, the vehicle was custom-fitted with a Timoney Independent suspension system. Extensive testing and modelling activities using LMS Virtual.lab Motion® were undertaken to determine the productivity levels of each vehicle. It was demonstrated that the vehicle fitted with a Timoney suspension could achieve a productivity increase of up to 50%. A health analysis is also presented which shows the Timoney Independent suspension system …

Green Supply Chains Initiatives In Transport And Logistics Service Industry: An Exploratory Case Study Analysis, Pietro Evangelista, Edward Sweeney, Gabriella Ferruzzi, Juan Carlos Carrasco

Conference papers

No abstract provided.

Methodology For Designing Structures To Withstand Extreme Environments: Performance Based Specifications, S. Nanukuttan, Niall Holmes, S. Srinivasan, L. Basheer, P.A.M. Basheer, L. Tang, J. Mccarter

Conference papers

Existing guidelines in BS 8500 allow the selection of concrete mix based on variables such as compressive strength, maximum water to binder ratio, minimum cement content and minimum cover thickness. This approach does not guarantee the durability and expected performance of the concrete structure in a given environment. One alternative is to develop performance- based specifications that supplement the existing guidelines in BS 8500, by specifying the required performance of concrete in terms of measurable properties such as resistance to environmental penetrations. This paper demonstrates one of such methodology for developing performance-based specifications for concretes exposed to marine environments. Chloride …

Cloud Computing:Strategies For Cloud Computing Adoption, Faith Shimba

Dissertations

The advent of cloud computing in recent years has sparked an interest from different organisations, institutions and users to take advantage of web applications. This is a result of the new economic model for the Information Technology (IT) department that cloud computing promises. The model promises a shift from an organisation required to invest heavily for limited IT resources that are internally managed, to a model where the organisation can buy or rent resources that are managed by a cloud provider, and pay per use. Cloud computing also promises scalability of resources and on-demand availability of resources.

Although, the adoption …

A Cross-Layer Modification To The Dsr Routing Protocol In Wireless Mesh Networks, Mustafa Ramadhan

Doctoral

A cross-layer modification to the DSR routing protocol that finds high throughput paths in WMNs has been introduced in this work. The Access Efficiency Factor (AEF) has been introduced in this modification as a local congestion avoidance metric for the DSR routing mechanism as an alternative to the hop count (Hc) metric. In this modification, the selected path is identified by finding a path with the highest minimum AEF (max_min_AEF) value. The basis of this study is to compare the performance of the Hc and max_min_AEF as routing metrics for the DSR protocol in WMNs using the OPNET modeler. Performance …

Wavelet Based Islanding Detection Of Dc-Ac Inverter Interfaced Dg Systems, Mohamed Moin Hanif, Malabika Basu, Kevin Gaughan

Conference papers

The increased penetration of distributed generation (DG) often connected to grid through dc-ac interface has made islanding detection an important and challenging issue to power engineers. Several methods based on passive and active detection scheme have been proposed in the literature. While passive schemes have a large non detection zone (NDZ), concern has been raised on active method due to its degrading power quality effect. This paper proposes a wavelet based passive islanding detection scheme with almost zero NDZ for dc-ac inverter interfaced grid connected DGs. The key idea is to utilize the spectral changes in the higher frequency components …

Evaluation Of A Part-Time Engineering Degree Programme That Aimed To Unify And Diversify, Kevin Kelly, Vincent Kenny

Conference papers

The School of Electrical Engineering within DIT attempted to address the challenge of increasing diversity in Engineering Education by developing a part-time Electrical Services Engineering degree programme that began as a certificate in 2001 and as a degree in 2003. This four year evening programme had a number of innovations: • Recognition of Prior Learning (RPL) • Application of a Student Centred paradigm • Innovative Curriculum Development using Constructivist principles and Project Based Learning (in part) This paper will be an evaluation of the four year part time degree programme. There are issues deserving investigation with regard to the programme. …

Bs News September/October

Building Services Engineering

No abstract provided.

Integration Of Antennas And Solar Cells For Autonomous Communication Systems, Maria Jose Roo Ons

Doctoral

Solar energy is becoming an attractive alternative for powering autonomous communication systems. These devices often involve the use of separate photovoltaics and antennas, which demand a compromise in the utilization of the limited space available. This thesis deals with the design, analysis, fabrication and validation of different techniques for the integration of antennas and solar cells in a single multifunctional device. Four different photovoltaic technologies are considered within this work, namely, polycrystalline silicon (poly-Si), monocrystalline (mono-Si) emitter-wrap-through (EWT) rear contact solar cells, amorphous silicon (a-Si) thin film on glass substrate, and bifacial solar cells. The use of a poly-Si solar …

Customer Management Analysis Of Irish Plumbing & Heating Distribution System: A Simulation Study, Amr Arisha, Amr Mahfouz, John Crowe, Finbarr Bennett

Conference papers

The sudden burst of the property bubble, coupled with current global economic conditions has resulted in a huge decrease in demand for plumbing and heating fixtures in the Irish construction industry. Moreover, inefficient supply chain management policies have imposed further pressures on companies resulting in more system bottlenecks and unnecessary costs. Inventory management is seen as a functional area that can ease such bottlenecks and in turn increase supply chain efficiency, decrease costs and increase customer satisfaction. The challenge is to predict the balance of on-hand inventory and order quantity to optimise customer satisfaction and minimise inventory cost. It is …

A Monocular Marker-Free Gait Measurement System, Jane Courtney, Annraoi M. De Paor

Articles

This paper presents a new, user-friendly, portable motion capture and gait analysis system for capturing and analyzing human gait, designed as a telemedicine tool to monitor remotely the progress of patients through treatment. The system requires minimal user input and simple single-camera filming (which can be acquired from a basic webcam) making it very accessible to nontechnical, nonclinical personnel. This system can allow gait studies to acquire a much larger data set and allow trained gait analysts to focus their skills on the interpretation phase of gait analysis. The design uses a novel motion capture method derived from spatiotemporal segmentation …

Investigation Of The Slow- And Fast-Light Effect On The Basis Of Stimulated Brillouin Scattering For Application In Optical Communication And Information Systems., Ronny Henker

Doctoral

In today's information age demand for ultra-fast information transfer with ultra-high bandwidths has reached extraordinary levels. Hence, the transmission in the future internet-backbone will be increasingly constrained in the network nodes. At the same time, the power consumption of the network systems will increase to unsustainable levels.

Nowadays, optical signal processing and switching can be implemented relatively easily. However, the realization of optical bu ers and short-term memories is still an unsolved challenge. The slow- and fast-light e ect has been investigated as one solution for the optical bu ering over the last few years. It means the slowing down …

A Suggested Building Block Geometry Without Continuous Radial Joints Of Possible Relevance For Particle Detectors, Jim Mcgovern

Articles

A geometry for concentrc shells or tubes, built-up from a single rhombohedral block type, is described. Continuous radial joints are avoided.

Cloud Computing For Schools, Shane O'Doherty

Dissertations

This project evaluates previous Information and Communication Technology policy and practice relating to primary schools in Ireland with a view to suggesting a better way forward in light of advances in ICT, such as the availability of fast broadband services, including fibre broadband, browser-based applications and the advent of cloud computing. Cloud computing refers to the Internet as a source of both software programs and also data retention, in effect the Internet provides the software and data services via browsers to users who may remain entirely unaware of the technology at work, uncluttered by hardware or software licensing issues or …

The Future Is Urban, Where ‘Up Mayo’ Politics Just Won’T Do, Lorcan Sirr, Conor Skehan

Media

No abstract provided.

Experiences Of Teaching, Learning And Assessment Of Student Research Skills On A Level 9 Taught Programme In Engineering, Aidan O'Dwyer

Conference papers

This contribution reports on the teaching, learning and assessment of a Research Methods module on a Level 9 taught programme in engineering at DIT. The module was run in the 2008-9 and 2009-10 academic years. The module is a generic one, whose aim is to facilitate students in developing a comprehensive proposal for their engineering research project. A team approach was taken to module instruction. Students were assessed (at different stages during the module) by evaluation of a written research proposal planner document, a reflective PowerPoint presentation and a final written research project proposal. The contribution reflects on the module …

A Life Cycle Cost Analysis Of Large-Scale Thermal Energy Storage Technologies For Buildings Using Combined Heat And Power, Kenneth Gaine, Aidan Duffy

Conference Papers

Buildings account for approximately 40% of energy consumption and greenhouse gas (GHG) emissions in developed economies, of which approximately 55% of building energy is used for heating and cooling. The reduction of building-related GHG emissions is a high international policy priority. For this reason and because there are many technical solutions for this, these polices should involve significant improvements in the uptake of small-scale energy efficient (EE) systems. However the widespread deployment of many technologies, must overcome a number of barriers, one of which is a temporal (diurnal or seasonal) mismatch between supply and demand. Costeffective thermal storage solutions have …

The Generation Of Domestic Electricity Load Profiles Through Markov Chain Modelling, Aidan Duffy, Fintan Mcloughlin, Michael Conlon

Conference Papers

Micro-generation technologies such as photovoltaics and micro-wind power are becoming increasing popular among homeowners, mainly a result of policy support mechanisms helping to improve cost competiveness as compared to traditional fossil fuel generation. National government strategies to reduce electricity demand generated from fossil fuels and to meet European Union 20/20 targets is driving this change. However, the real performance of these technologies in a domestic setting is not often known as high time resolution models for domestic electricity load profiles are not readily available. As a result, projections in terms of reducing electricity demand and financial paybacks for these micro-generation …

Validated Real-Time Energy Models For Small-Scale Grid-Connected Pv-Systems, Lacour Ayompe, Aidan Duffy, Sarah Mccormack, Michael Conlon

Articles

This paper presents validated real-time energy models for small-scale grid-connected PV-systems suitable for domestic application. The models were used to predict real-time AC power output from a PV system in Dublin, Ireland using 30-min intervals of measured performance data between April 2009 and March 2010. Statistical analysis of the predicted results and measured data highlight possible sources of errors and the limitations and/or adequacy of existing models, to describe the temperature and efficiency of PV-cells and consequently, the accuracy of power prediction models. PV-system AC output power predictions using empirical models for PV-cell temperature and efficiency prediction showed lower percentage …

Bs News July/August

Building Services Engineering

No abstract provided.

Analysis Of Engineering Students Learning Styles On Level 7, Level 8 And Level 9 Programmes, Aidan O'Dwyer

Conference papers

This contribution reports on research, carried out over three academic years, into the learning styles of engineering students, on a number of Level 7, Level 8 and Level 9 programmes at DIT, using the index of learning styles survey developed by Felder and Soloman (1991). The contribution explores the results obtained in detail, placing them particularly in the national context. The correlation between student performance and individual learning styles is examined. Knowledge of the strongly visual learning style of these cohorts of students may be used to improve the learning environment.

Energy-Related Carbon Emissions In Ireland: Scenarios To 2020, Tadhg O'Mahony

Doctoral

The consumption of energy and related carbon emissions are a development challenge requiring analysis and policy insights. Current analysis of future change in Ireland relies on quantitative point forecasts within which accuracy is difficult to achieve. A scenario analysis approach has often been applied with the longer term but is also useful on shorter time-scales. This research applied a combination of decomposition analysis and scenario analysis to identify and analyse the driving forces of change in Ireland historically from 1990-2007 and in the future to 2020. The historical decomposition used the LMDI I technique and was further quantified to 2020 …

Intelligibility Of Electrolarynx Speech Using A Novel Actuator, Brian Madden, Mark Nolan, Ted Burke, James Condron, Eugene Coyle

Conference Papers

During voiced speech, the larynx provides quasi-periodic acoustic excitation of the vocal tract. Following a laryngectomy, some people speak using an electrolarynx which replaces the excitatory function of the absent larynx. Drawbacks of conventional electrolarynx designs include the buzzing monotonic sound emitted, the need for a free hand to operate the device, and difficulty experienced by many laryngectomees in adapting to its use. Despite these shortcomings, it remains the preferred method of speech rehabilitation for a substantial minority of laryngectomees. In most electrolarynxes, mechanical vibrations are produced by a linear electromechanical actuator, the armature of which percusses against a metal …

Computer Simulation Of A Biomass Gasification-Solid Oxide Fuel Cell Power System Using Aspen Plus, Wayne Doherty, Anthony Reynolds, David Kennedy

Articles

The operation and performance of a solid oxide fuel cell (SOFC) stack on biomass syn-gas from a biomass gasification combined heat and power (CHP) plant is investigated. The objective of this work is to develop a model of a biomass-SOFC system capable of predicting performance under diverse operating conditions. The tubular SOFC technology is selected. The SOFC stack model, equilibrium type based on Gibbs free energy minimisation, is developed using Aspen Plus. The model performs heat and mass balances and considers ohmic, activation and concentration losses for the voltage calculation. The model is validated against data available in the literature …

A Full-Range, Multi-Variable, Cfd-Based Methodology To Identify Abnormal Near-Wall Hemodynamics In A Stented Coronary Artery, Jonathan Murphy, Fergal Boyle

Articles

The benefit of coronary stent implantation is reduced by excessive intimal hyperplasia which re-narrows the artery and the prevention of which is still a primary concern for clinicians. Abnormal hemodynamics create non-physiological viscous stress on the artery wall, one of the root causes of intimal hyperplasia following stent implantation. A methodology to comprehensively evaluate the viscous stress on the artery wall following stent implantation would be useful to evaluate a stent’s hemodynamic performance. The proposed methodology employs 3D computational fluid dynamics, the variables wall shear stress (WSS), WSS gradient (WSSG), WSS angle gradient (WSSAG) and a statistical analysis to evaluate …

The Relevance Of Teaching Traditional Measurement Techniques To Undergraduate Quantity Surveying Students., Fiacra P. Mcdonnell

Articles

Measurement of quantities is a core skill which must be inherent in all graduates from Quantity Surveying courses. Many students find this subject difficult to grasp, and the learning experience can be problematic especially in the first semester of first year. This is not unique to measurement as in many cases first year students are in the process of adapting to a new stage in their life, along with attempting to master many new subjects (Cottrell, 2008). This is reinforced by Johnston (2010) who highlights the many challenges being experienced by first year students and observes that “ entering first …