Engineering Commons^™

Monte-Carlo Ray-Trace Modelling Of Quantum Dot Solar Concentrators, Manus Kennedy

Doctoral

Due to the finite resources of fossil fuel and nuclear reserves, renewable energy technologies much provide an increasing proportion of future energy needs, if the world’s population are to expect a secure and sustainable developed society. Quantum dot solar concentrators (QDSCs) can potentially reduce the cost of photovoltaic (PV) electrical power generation and thereby further the growth in installed PV capacity. QDSCs can concentrate both the direct and diffuse components of solar radiation which makes them particularly suitable for climates where the diffuse component is predominant. A QDSC model has been developed based on Monte-Carlo ray-trace techniques. The model allows …

One-Pot Synthesis Of Anionic (Nitrogen) And Cationic (Sulfur) Codoped High-Temperature Stable, Visible Light Active, Anatase Photocatalysts, Suresh Pillai, Declan Mccormack, Steven Hinder, Pradeepan Periyat

Articles

No abstract provided.

Improving Knowledge Sharing In An Open Informal Network: Knowledge Management In Open Coffee, Adrian Mihai

Dissertations

The 21st century opened a new era in communications bringing in faster, more efficient and more advanced information and communication technologies than ever. New ideas and innovations, as well as interactions and collaborations determine the landscape of knowledge and consequently add new requirements to the know-how. The creators of knowledge and design add new communication architecture bodies through the use of technology.

Meanwhile knowledge management inspires 21st century enterprises to adopt new learning patterns throughout organisations and adopt new ideas. However, internal sharing mechanisms leverage a trusted environment where people can engage freely and securely in sharing knowledge and feel …

Cross-Disciplinary Approaches For Developing Serious Games In Higher Education: Frameworks For Food Safety And Environmental Health Education, Pauline Rooney, K.C. O'Rourke, Greg Burke, Brian Mac Namee, Claudia Igbrude

Conference papers

While some educators have adopted commercial off the-shelf games for use in the classroom, such games may not always meet the individual requirements of lecturers whose courses are tied to specific learning utcomes. An alternative is to capitalise on in-house expertise in Higher Education and create serious games through cross-disciplinary team projects. This paper outlines such a project within one Higher Education institution. It describes synergies created across disciplines as a result of the collaboration on game design and implementation. It looks at tensions generated between the pedagogical requirements (of lecturers), entertainment objectives (of games designers) and technical excellence (sought …

Compensating For Expressiveness In Queries To A Content Based Music Information Retrieval System, Bryan Duggan, Brendan O'Shea, Mikel Gainza, Padraig Cunningham

Conference papers

MATT2 is a content based music information retrieval system adapted to the characteristics of traditional Irish dance music. MATT2 compensates for expressive artefacts commonly employed by traditional musicians. Specifically these are ornamentation, "the long note", reversing and phrasing. In this paper we describe the main components of MATT2 and present an experiment where we demonstrate that using this higher level knowledge of melodic similarity in traditional Irish dance music results in a significant improvement in annotation accuracy over standard approaches from the MIR literature.

Error Metrics For Impaired Auditory Nerve Responses Of Different Phoneme Groups, Andrew Hines, Naomi Harte

Conference papers

An auditory nerve model allows faster investigation of new signal processing algorithms for hearing aids. This paper presents a study of the degradation of auditory nerve (AN) responses at a phonetic level for a range of sensorineural hearing losses and flat audiograms. The AN model of Zilany & Bruce was used to compute responses to a diverse set of phoneme rich sentences from the TIMIT database. The characteristics of both the average discharge rate and spike timing of the responses are discussed. The experiments demonstrate that a mean absolute error metric provides a useful measure of average discharge rates but …

Synthesis Of Maleic Anhydride Grafted Polypropylene-Butadiene Copolymer And Its Application In Pp/Ommt/Sbs Composite As Compatibilizer, Qiaohuan Cheng, Zhanxia Lu, Hugh Byrne

Articles

Maleic Anhydride (MA) grafted propylene-butadiene copolymer (PPB) was prepared. FTIR and 1H-NMR results indicated that the MA molecules reacted with the double bond in the butadiene unit of the PPB and the grafting percentage increased with the butadiene content in the initial copolymer. GPC results showed the introduction of butadiene in the copolymer prevented the degradation of the PPB. The MA-g-PPB (MPPB) was applied in PP/SBS/OMMT composite as compatibilizer. In the presence of 10phr MPPB, the impact strength of the composite was improved by ~20%. XRD patterns indicated the formation of β-phase crystallization of polypropylene in the presence of MPPB …

Analysis Of Learning Styles Of First Year Engineering Students On Two Level 7 Programmes, Aidan O'Dwyer

Conference papers

This paper investigates the learning styles of first year, Level 7, mechanical and electrical engineering students at DIT, over two academic years, using the index of learning styles survey as developed by Felder and Soloman (1991). Student learning styles on these programmes are compared with the results from other such surveys. The correlation between student performance and their 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.

Prior Understanding Of Basic Electrical Circuit Concepts By First Year Engineering Students, Aidan O'Dwyer

Conference papers

There is a broad diversity of educational background of students entering Level 7 programmes in engineering. As a result, students’ reasoning regarding basic electrical concepts often differs from accepted explanations. This contribution reports, analyses and reflects on the results of a multiple-choice diagnostic test to assess student understanding of such concepts (developed by Engelhardt and Beichner (2004) for high school and college students), taken by three cohorts of first year, Level 7, engineering students at Dublin Institute of Technology during the 2008-9 academic year.

Response Of Academics To Demands For Change In Engineering Education, Kevin Kelly

Conference papers

This paper attempts to show what academics and other stakeholders think about academic change in an Institute of Technology in Ireland as this HEI attempts to respond to a rapidly changing external s becoming a university and moving to a new campus on a green field site. It is a summary of aspects of a doctoral thesis undertaken by an experienced academic that set out to explore how the unprecedented challenges now facing higher education internationally might best be met in the Dublin Institute of Technology. It is insider research and this paper identifies and examines barriers and enablers to …

Imaging Reconstruction For Light Scattering From A Tenuous Random Medium, Jonathan Blackledge

Conference papers

We consider the basis for describing strong scattering in terms of diffusive processes based on the diffusion equation. Intermediate strength scattering is then considered in terms of a fractional diffusion equation which is studied using results from fractional calculus. This approach is justified in terms of the generalization of a random walk model with no statistical bias in the phase to a random walk that has a phase bias and is thus, only `partially' or `fractionally' diffusive. A Green's function solution to the fractional diffusion equation is studied and a result derived that provides a model for an incoherent image …

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Building Services Engineering

No abstract provided.

Modelling Behavioural Antecedents Of Inter-Firm Linkages In The Irish Road Freight Industry: An Application Of The Theory Of Planned Behaviour, Eoin Plant

Doctoral

The Irish road haulage industry exhibits a structure dominated by singlevehicle owner-managed operators. This has implications for the Irish economy through reduced efficiency. It is crucial that Ireland’s transport policies sustain its trade-dependent economy and this study can help inform those policies. The European Union has made a commitment to promoting sustainable mobility through advanced transport logistics. One of the principal areas not previously addressed is that of barriers to ollaboration. This thesis initially examines economies of scale within the road freight industry and argues that collaborative networks can aid sustainable transport and increase efficiencies in logistics. It addresses the …

The Bundle Dispersion Of Swnt On Interaction With P-Terphenyl, Theresa Hedderman, Anika Mostaert, Anne Shanahan, Hugh Byrne

Articles

This paper investigates the interaction and bundle dispersion of single walled carbon nanotubes (SWNT) produced by arc discharge and by the high pressure decomposition of carbon monoxide, often referred to as the HiPco method, in the presence of the molecule p-terphenyl. The study will show that the extent of SWNT bundle dispersion and the degree of interaction with p-terphenyl is related to the level of purity of the SWNT sample. This study compares the bundle dispersion and interaction of SWNT with p-terphenyl in their as produced state and after purification. A number of spectroscopic and microscopic techniques are used to …

Titanium Dioxide Nanoparticles Induce Oxidative Stress And Dna-Adduct Formation But Not Dna-Breakage In Human Lung Cells, Kunal Bhattacharya, Maria Davoren, Jens Boertz, Roel P.F. Schins, Eik Hoffmann, Elke Dopp

Articles

Titanium dioxide (TiO2), also known as titanium (IV) oxide or anatase, is the naturally occurring oxide of titanium. It is also one of the most commercially used form. To date, no parameter has been set for the average ambient air concentration of TiO2 nanoparticles (NP) by any regulatory agency. Previously conducted studies had established these nanoparticles to be mainly non-cyto- and -genotoxic, although they had been found to generate free radicals both acellularly (specially through photocatalytic activity) and intracellularly. The present study determines the role of TiO2-NP (anatase, ∅ < 100 nm) using several parameters such as cyto- and genotoxicity, DNA-adduct formation and generation of free radicals following its uptake by human lung cells in vitro. For comparison, iron containing nanoparticles (hematite, Fe2O3, ∅ < 100 nm) were used. The results of this study showed that both types of NP were located in the cytosol near the nucleus. No particles were found inside the nucleus, in mitochondria or ribosomes. Human lung fibroblasts (IMR-90) were more sensitive regarding cyto- and genotoxic effects caused by the NP than human bronchial epithelial cells (BEAS-2B). In contrast to hematite NP, TiO2-NP did not induce DNA-breakage measured by the Comet-assay in both cell types. Generation of reactive oxygen species (ROS) was measured acellularly (without any photocatalytic activity) as well as intracellularly for both types of particles, however, the iron-containing NP needed special reducing conditions before pronounced radical generation. A high level of DNA adduct formation (8-OHdG) was observed in IMR-90 cells exposed to TiO2-NP, but not in cells exposed to hematite NP. Our study demonstrates different modes of action for TiO2- and Fe2O3-NP. Whereas TiO2-NP were able to generate elevated amounts of free radicals, which induced indirect genotoxicity mainly by DNA-adduct formation, Fe2O3-NP were clastogenic (induction of DNA-breakage) and required reducing conditions for radical formation.

Providing Academic Leadership Through The Role Of Senior Lecturer 1 (Teaching) Using The Theme Of 'Sustainable Energy' As An Example, Jim Mcgovern

Articles

An academic leader should lead in their particular area and should love what they are doing. An example of leadership in the area of 'sustainable energy use' is presented that involves leading through identifying and participating in the development of emerging technologies. Excellent academic leadership can be provided by a Senior Lecturer through active research, incorporating the latest developments in student-centred learning in their work and providing example and encouragement for colleagues and learners.

The Effect Of Air Preheating In A Biomass Cfb Gasifier Using Aspen Plus Simulation, Wayne Doherty, Anthony Reynolds, David Kennedy

Articles

In the context of climate change, increasing efficiency and energy security, biomass gasification is likely to play an important role in energy production. Atmospheric circulating fluidised bed (CFB) technology was selected for the current study. The primary objective of this research is to develop a computer simulation model of a CFB biomass gasifier that can accurately predict gasifier performance under various operating conditions. An original model was developed using ASPEN Plus (Advanced System for Process ENgineering Plus). The model is based on Gibbs free energy minimisation. The restricted equilibrium method was used to calibrate the model against experimental data. This …

Modelling And Simulation Of A Biomass Gasification-Solid Oxide Fuel Cell Combined Heat And Power Plant Using Aspen Plus, Wayne Doherty, Anthony Reynolds, David Kennedy

Conference Papers

In this paper the operation and performance of a high temperature solid oxide fuel cell (SOFC) stack on biomass syn-gas from a demonstration biomass gasification combined heat and power (CHP) plant is investigated. The objective of this work is to develop a computer simulation model of a biomass-SOFC CHP system, flexible enough for use in industry, capable of predicting system performance under various operating conditions and using diverse fuels. The biomass gasifier is of the dual fluidised bed (DFB) type with steam as the gasifying agent and is operated at atmospheric pressure. The tubular SOFC configuration, developed by Siemens Power …

Alternative Sources Of Energy, David Kennedy

Conference Papers

Ireland relies on imports of fossil fuels for up to 83% of its energy needs and this statistic is relatively common in other European countries. Apart from the high import costs and pollutions associated with fossil fuels and the need to meet new targets in terms of CO2 emissions, energy security is essential. This paper provides an overview and outline of the different alternative energy sources available for use either at domestic or on large scale production, some of which are established and others less likely to succeed in our climate.
Some of the alternative energy sources such as wind …

Engineering Of A Single Alkaline Fuel Cell Part Ii: Long Term Operation In Air, Jonathan Blackledge, Eugene Coyle, David Kennedy, Heinz Schmidt-Walter, Hans Kohnke, Steffen Schudt, Gerhard Sauer, James Hamilton

Articles

Research into renewable energy sources has previously lacked sufficient investment. However, emphasis has now shifted and funding is being made available in a proactive manner by various governments eager to encourage renewable energy technology and reduce carbon taxes. Fuel Cells offer a realistic, sustainable and clean alternative energy option for stationary and mobile applications. Hydrogen and fuel cell technologies are recognised by many as possible long term energy solutions, but to-date, have failed to make an impact on the energy market. This is due to a number of key reasons, some of which include efficiency, scale, accessories and power output. …

Engineering Of A Single Alkaline Fuel Cell Part I: Construction Of A Test Bed, Jonathan Blackledge, James Brunton, Eugene Coyle, David Kennedy, Heinz Schmidt-Walter, Hans Kohnke, Gerhard Sauer, Steffen Schudt, James Hamilton

Articles

Fuel Cells offer a realistic, sustainable and clean alternative energy option for stationary and mobile applications. Hydrogen and fuel cell technologies are recognised by many as possible long term energy solutions, but to-date have failed to make an impact on the energy market. This is due to a number of key reasons, some of which include, efficiency, scale, accessories and power output. Applying fuel cells to small telecommunication components requires the applications of Micro and Nanotechnology, which have yet to be perfected to make them long lasting and cost effective. This paper outlines the reasons for commercialisation of fuel cells …

A Covert Encryption Method For Applications In Electronic Data Interchange, Jonathan Blackledge, Dmitry Dubovitskiy

Articles

A principal weakness of all encryption systems is that the output data can be ‘seen’ to be encrypted. In other words, encrypted data provides a ‘flag’ on the potential value of the information that has been encrypted. In this paper, we provide a new approach to ‘hiding’ encrypted data in a digital image.

In conventional (symmetric) encryption, the plaintext is usually represented as a binary stream and encrypted using an XOR type operation with a binary cipher. The algorithm used is ideally designed to: (i) generate a maximum entropy cipher so that there is no bias with regard to any …

Inverse Scattering Solutions With Applications To Electromagnetic Signal Processing, Jonathan Blackledge, Timo Hamalainen, Jyrki Joutsensalo

Articles

When a signal is recorded that has been physically generated by some scattering process (the interaction of electromagnetic, acoustic or elastic waves with inhomogeneous materials, for example), the ‘standard model’ for the signal (i.e. information content convolved with a characteristic Impulse Response Function) is usually based on a single scattering approximation. An additive noise term is introduced into the model to take into account a range of non-deterministic factors including multiple scattering that, along with electronic noise and other background noise sources, is assumed to be relatively weak. Thus, the standard model is based on a ‘weak field condition’ and …

An Investigation Into The Semantics Of English Topological Prepositions, John D. Kelleher, Colm Sloan, Brian Mac Namee

Articles

This paper describes a psycholinguistic experiment that investigates whether the applicability of the topological spatial prepositions "at", "on" or "in" to describe the spatial configuration between two objects is related to the topological relationships between objects being described

An Enhanced Data Mining Life Cycle, Markus Hofmann, Brendan Tierney

Conference papers

Data mining projects are complex and can have a high failure rate. In order to improve project management and success rates of such projects a life cycle is vital to the overall success of the project. This paper reports on a research project that was concerned with the life cycle development for data mining projects, its team members and their role. The paper provides a detailed view of the design and development of the data mining life cycle called DMLC. The life cycle aims to support all members of data mining project teams as well as IT managers and academic …

Generating Natural Language Descriptions Of Ontology Concepts, Niels Schütte

Conference papers

This paper gives an overview of ongoing work on a system for the generation of NL descriptions of classes defined in OWL ontologies. We present a general structuring approach for such descriptions. Since OWL ontologies do not by default contain the information necessary for lexicalization, lexical information has to be added to the data via annotations. A rulebased mechanism for automatically deriving these annotations is presented.

Measurement Of Phonemic Degradation In Sensorineural Hearing Loss Using A Computational Model Of The Auditory Periphery, Andrew Hines, Naomi Harte

Conference papers

A computational model of the auditory periphery enables faster investigation of new signal processing algorithms for hearing aids. This paper presents a study of the degradation of auditory nerve (AN) responses at a phonetic level for a range of sensorineural hearing losses. The AN model of Zilany & Bruce was used to compute responses to a diverse set of phoneme rich sentences from the TIMIT database. The characteristics of both the average discharge rate and spike timing of the responses are discussed. The experiments demonstrate that the model responses are consistent with respect to impairment and inaudible thresholds.

Systematic Analysis Of Unknown Integrated Circuits, Michael Brutscheck

Doctoral

In recent years the efficient and structured analysis of unknown CMOS integrated circuits (ICs) has attracted a lot of interest. Over the last decade different and non-invasive strategies have been developed to analyse unknown ICS. However, invasive procedures must always lead to the destruction of the system under investigation. Non-invasive approaches published so far have the disadvantage that ICs are analysed using very complex and very time consuming algorithms. The focus of this thesis is to develop a non-invasive and efficient procedure to determine fully unclassified digital CMOS ICs solely by their input-output behaviour. In this research, automata theory was …

Converging Flow Between Coaxial Cones, O. Hall, A. D. Gilbert, C. P. Hills

Articles

Fluid flow governed by the Navier-Stokes equation is considered in a domain bounded by two cones with the same axis. In the first, 'non-parallel' case, the two cones have the same apex and different angles θ = α and β in spherical polar coordinates (r, θ, φ). In the second, 'parallel' case, the two cones have the same opening angle α, parallel walls separated by a gap h and apices separated by a distance h/sinα. Flows are driven by a source Q at the origin, the apex of the lower cone in the parallel case. The Stokes solution for the …

Nonaxisymmetric Stokes Flow Between Concentric Cones, O. Hall, C. P. Hills, A. D. Gilbert

Articles

We study the fully three-dimensional Stokes flow within a geometry consisting of two infinite cones with coincident apices. The Stokes approximation is valid near the apex and we consider the dominant flow features as it is approached. The cones are assumed to be stationary and the flow to be driven by an arbitrary far-field disturbance. We express the flow quantities in terms of eigenfunction expansions and allow for the first time for nonaxisymmetric flow regimes through an azimuthal wave number. The eigenvalue problem is solved numerically for successive wave numbers. Both real and complex sequences of eigenvalues are found, their …