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Articles 2581 - 2610 of 4606

Full-Text Articles in Engineering

Design Of A Transpired Air Heating Solar Collector With An Inverted Perforated Absorber And Asymmetric Compound Parabolic Concentrator., Nasif Shams Mar 2013

Design Of A Transpired Air Heating Solar Collector With An Inverted Perforated Absorber And Asymmetric Compound Parabolic Concentrator., Nasif Shams

Doctoral

absorber and an asymmetric compound parabolic concentrator was applied to increase the intensity of solar radiation incident on the perforated absorber. A 2D ray tracing model quantified optical efficiency at different incident angles within 27o to 89o incident angles. The beam efficiency was found to vary between 72% and 79% and diffuse efficiency was found to vary between 48.2% and 65%. The average thermal efficiency was found to be approximately 55%-65% with average radiation above 400 W/m2 for flow rates in the range of 0.03 kg/s/m2 to 0.09 kg/s/m2. Experimental results at air flow rates of 0.03 kg/s/m2 and 0.09 …


Advances In The Synthesis Of Zno Nanomaterials For Varistor Devices, Suresh Pillai, John M. Kelly, Raghavendra Ramesh, Declan Mccormack Feb 2013

Advances In The Synthesis Of Zno Nanomaterials For Varistor Devices, Suresh Pillai, John M. Kelly, Raghavendra Ramesh, Declan Mccormack

Articles

ZnO based varistors are widely used for overvoltage protection in many electrical and electronic circuits, at voltages ranging from a few to over a million volts. By careful control of the microstructure, through nanostructuring by chemical routes, it should be possible to produce varistors with high breakdown voltage (Vc), as this is proportional to the number of active grain boundaries in the sintered body. This property is particularly important for the production of the small-sized varistors needed for modern electronic instruments such as tablet computers and mobile phones. The current review will outline the recent advances in the chemical processing …


Sustainable Purchasing Practices: An Investigation Into Current Industry Awareness And Practice, Frank Palisi, Kathryne Newton, Edward Sweeney Feb 2013

Sustainable Purchasing Practices: An Investigation Into Current Industry Awareness And Practice, Frank Palisi, Kathryne Newton, Edward Sweeney

Conference papers

This research study illustrates the importance of sustainable purchasing practices for organizations in the U.S. distribution industry and answers several important questions: what is the current awareness of U.S. organizations regarding sustainable purchasing practices; to what extent are U.S. organizations evaluating, selecting, and retaining suppliers based upon sustainable purchasing practices; and to what extent are sustainable purchasing practices being implemented by the U.S. organizations under study? With an ever increasing global economy, is it critically important for organizations to put in place sustainability practices; the biggest impact organizations can make is often in an organization’s purchasing department. The researcher begins …


Anti-Bacterial Activity Of Indoor Light Activated Photocatalysts, Suresh Pillai, Michael Seery, Damian Synnott, Stephen Hinder, Georg Michlits Feb 2013

Anti-Bacterial Activity Of Indoor Light Activated Photocatalysts, Suresh Pillai, Michael Seery, Damian Synnott, Stephen Hinder, Georg Michlits

Articles

Nanocrystalline photocatalysts, prepared under ambient conditions using a microwave assisted syn-thesis, show indoor light photocatalytic activity for the degradation of Staphylococcus aureus and Escherichia coli. The zinc sulphide (ZnS) nanomaterials, prepared by a microwave assisted synthesis, are shown to be cubic blende structure with an average crystallite size of 4–6 nm. The anti-bacterial activ-ity of these nanomaterials is investigated under irradiation from a 60 W light bulb and photocatalytic activity is revealed to be due to the defects present in the crystal structure. The ZnS shows anti-bacterial action as both a bacteriostatic and bacteriocidal (88% reduction in the amount of …


Evaluation Of Time Series Techniques To Characterise Domestic Electricity Demand, Fintan Mcloughlin, Aidan Duffy, Michael Conlon Feb 2013

Evaluation Of Time Series Techniques To Characterise Domestic Electricity Demand, Fintan Mcloughlin, Aidan Duffy, Michael Conlon

Articles

This paper discusses time series approaches, often used by Transmission System Operators (TSOs) to forecast system demand, and applies them at an individual dwelling level. In particular, two techniques, Fourier transforms and Gaussian processes were evaluated and used to characterise individual household electricity demand. The performance of the characterisation approaches were evaluated based on Pearson correlation coefficient, descriptive statistics and paired sample t-tests for electrical parameters: Total Electricity Consumption, Maximum Demand, Load Factor and Time of Use of maximum electricity demand. Finally, a number of time series tests were carried out to ensure certain properties remained between the original and …


Characterising Domestic Electricity Demand For Customer Load Profile Segmentation, Fintan Mcloughlin Feb 2013

Characterising Domestic Electricity Demand For Customer Load Profile Segmentation, Fintan Mcloughlin

Doctoral

The aim of this research was to characterise domestic electricity patterns of use on a diurnal, intra-daily and seasonal basis as a function of customer characteristics. This was done in order to produce a library of representative electricity demand load profiles that are characteristic of how households consume electricity. In so doing, a household’s electricity demand can be completely characterised based solely on their individual customer characteristics.

A number of different approaches were investigated as to their ability to characterise domestic electricity use. A statistical regression approach was evaluated which had the advantage of identifying key dwelling, occupant and appliance …


State Of The Irish Housing Stock - Modelling The Heat Losses Of Ireland’S Existing Detached Rural Housing Stock & Estimating The Benefit Of Thermal Retrofit Measures On This Stock, Ciara Ahern, Philip Griffiths, Micheal O'Flaherty Jan 2013

State Of The Irish Housing Stock - Modelling The Heat Losses Of Ireland’S Existing Detached Rural Housing Stock & Estimating The Benefit Of Thermal Retrofit Measures On This Stock, Ciara Ahern, Philip Griffiths, Micheal O'Flaherty

Articles

Ireland’s housing stock has been identified as being amongst the least energy efficient in Northern Europe. Consequently, atmospheric emissions are greater than necessary. Government funded schemes have been introduced to incentivise the uptake of thermal retrofit measures in the domestic Irish market. A study of Ireland’s housing highlights the dominance of detached houses (43%), 72% of which are rurally located and are predominantly heated with fuel oil. This paper investigates the economic and carbon case for thermal retrofit measures to the existing detached, oil centrally heated, rural housing stock. The study found the case for energy efficiency measures to be …


Where Next For Supply Chain Management?, Des Lee Jan 2013

Where Next For Supply Chain Management?, Des Lee

Books/Book chapters

Supply chain management (SCM) has been so successful that it is largely taken for granted. Its success has been built on improving three key flows – of product, of money and of information – and on one core principle – core competence. What next for SCM? This article outlines the vulnerabilities that are embedded in modern supply chains and the unintended consequences of outsourcing activities that are not core competences. These consequences are global and have the potential to undermine past achievements. Finally, broad suggestions are made as to how these issues can be addressed and the areas on which …


Technology Adoption In Small And Medium-Sized Logistics Providers, Pietro Evangelista, Alan Mckinnon, Edward Sweeney Jan 2013

Technology Adoption In Small And Medium-Sized Logistics Providers, Pietro Evangelista, Alan Mckinnon, Edward Sweeney

Articles

Purpose - The main aim of the research is to shed light on the role of information and communication technology (ICT) in the logistics innovation process of small and medium- sized third party logistics providers (3PLs).

Design/methodology/approach – A triangulated research strategy was designed using a combination of quantitative and qualitative methods. The former involved the use of a questionnaire survey of small and medium-sized Italian 3PLs with 153 usable responses received. The latter comprised a series of focus groups and the use of seven case studies.

Findings – There is a relatively low level of ICT expenditure with few …


Transient And Quasi-Steady Thermal Behaviour Of A Building Envelope Due To Retrofitted Cavity Wall And Ceiling Insulation, Aimee Byrne, Gerard Byrne, Anna Davies, Anthony Robinson Jan 2013

Transient And Quasi-Steady Thermal Behaviour Of A Building Envelope Due To Retrofitted Cavity Wall And Ceiling Insulation, Aimee Byrne, Gerard Byrne, Anna Davies, Anthony Robinson

Articles

Accurate understanding of the thermal behaviour of building components is essential for predicting heat-ing or cooling needs and facilitates the implementation of more successful energy saving strategies and retrofits. This paper focuses on a specific measure commonly introduced through the residential energy efficiency retrofit programmes in Ireland–insulation. Traditionally, assessments of the performance of building envelopes have been based on assumed thermal resistances of the materials involved, labora-tory tests and computer modelling. The aim of the present work is to investigate the in situ thermal behaviour of a case study building and its components under transient and quasi-steady environmental conditions, comparing …


Resilient Digital Image Watermarking Using A Dct- Component Perturbation Model, Jonathan Blackledge, Oleksandr Iakovenko Jan 2013

Resilient Digital Image Watermarking Using A Dct- Component Perturbation Model, Jonathan Blackledge, Oleksandr Iakovenko

Books/Book chapters

The applications of the Discrete Cosine Transform (DCT) for Computer Generated Imagery, image processingand, in particular, image compression are well known and the DCT also forms the central kernel for a number ofdigital image watermarking methods. In this paper we consider the application of the DCT for producing a highlyrobust method of watermarking images using a block partitioning approach subject to a self-alignment strategyand bit error correction. The applications for the algorithms presented include the copyright protection of imagesand Digital Right Management for image libraries, for example. However, the principal focus of the researchreported in this paper is on the …


Exploring Spatial Business Data: A Roa Based Ecampus Application, Thanh Thoa Pham Thi, Linh Truong- Hong, Junjun Yin, James Carswell Jan 2013

Exploring Spatial Business Data: A Roa Based Ecampus Application, Thanh Thoa Pham Thi, Linh Truong- Hong, Junjun Yin, James Carswell

Conference papers

In "Smart" environments development, providing users with search utilities for interacting efficiently with web and wireless devices is a key goal. At smaller scales, Google Maps and Google Earth with satellite and street views have helped users for querying general information at specific locations. However, at larger local scales, where detailed 3D geometries linked to business data are needed, there is a recognized lack of related information and functionality for in depth exploration of an area. Linking spatial data and business data helps to enrich the user experience by fulfilling more task specific user needs. This paper presents an eCampus …


An Cuardach Ar Infreastruchtur Pobail - Bhainistithe Athleimneach In Eirinn, Liam Mccarton, Sean Ó Hógáin Jan 2013

An Cuardach Ar Infreastruchtur Pobail - Bhainistithe Athleimneach In Eirinn, Liam Mccarton, Sean Ó Hógáin

Other Resources

This presentation explores the search for resilient community infrastructure provision.

Chun Straitéis Chomhtháite a fhorbairt d’Éireann, teastaíonn: Smaoineamh Nuálach, Teicneolaíochtaí Inbhuanaithe agus Athléimneach, Leasú ar churaclam oideachais, Gníomhaíocht Rialtais agus Phobail Comhordaithe, •Tuiscint do bháisteach agus fuíolluisce mar acmhainní luachmhara.


Using Model Building In Structural Engineering To Enhance Understanding Of Construction Principles And Methods, Niall Holmes, Henry Mullen Jan 2013

Using Model Building In Structural Engineering To Enhance Understanding Of Construction Principles And Methods, Niall Holmes, Henry Mullen

Articles

This paper presents a new model building exercise in a second year module in the Department of Civil & Structural Engineering in the Dublin Institute of Technology (DIT). The activity aimed to improve students’ understanding of structural engineering, construction principles and methods. It allowed students to practically apply lecture material and construct a scaled model giving them an opportunity to study and visualise a real structure and generate their own ideas on how it should be assembled within a constructivist active learning environment. As a result, lectures were found to be more interactive and students more engaged in the discussions …


Development And Implementation Of A Simplified Residential Energy Asset Rating Model, Daire Reilly, Aidan Duffy, David Willis, Michael Conlon Jan 2013

Development And Implementation Of A Simplified Residential Energy Asset Rating Model, Daire Reilly, Aidan Duffy, David Willis, Michael Conlon

Other resources

In accordance with national and European policies, the provision of financial assistance to residential energy consumers has led to a greater awareness of and interest in energy retrofit technologies. However, at present Irish energy consumers have no appropriate advice on the future performance of retrofit options available to them. This is a significant limitation to decision making and technology uptake, since this group need to know whether their investment is likely to be worthwhile.

The asset rating methodology developed for the certification of energy performance of buildings is the current industry standard of prediction of energy demand and post retrofit …


Designing A Framework For Exchanging Partial Sets Of Bim Information On A Cloud-Based Service, Alan Redmond Jan 2013

Designing A Framework For Exchanging Partial Sets Of Bim Information On A Cloud-Based Service, Alan Redmond

Doctoral

The rationale behind this research study was based on the recognised difficulty of exchanging data at element or object level due to the inefficiencies of compatible hardware and software. Interoperability depicts the need to pass data between applications, allowing multiple types of experts and applications to contribute to the work at hand. The only way that software file exchanges between two applications can produce consistent data and change management results for large projects is through a building model repository. The overall aim of this thesis was to design and develop an integrated process that would advance key decisions at an …


Has Supply Chain Management Lost Its Relevance?, Natalie Descheres Jan 2013

Has Supply Chain Management Lost Its Relevance?, Natalie Descheres

Books/Book chapters

The context of business has changed dramatically over the last 15 years. The definition of need satisfaction, the shift from “dot to web” competition and the embedding of the organisation into a wider political and societal environment has transformed SCM contributions and the meaning of work for employees. Interdependence must evolve from the do-it-alone approach and yet the ashes are not proving fertile ground. In many ways, traditional models of management have not kept up with the changes and are taken aback by the complexity that surrounds us. Complexity is however not a feature of our world, but one of …


High Sensitivity Fiber Refractometer Based On An Optical Microfiber Coupler, Lin Bo, Pengfei Wang, Yuliya Semenova, Gerald Farrell Jan 2013

High Sensitivity Fiber Refractometer Based On An Optical Microfiber Coupler, Lin Bo, Pengfei Wang, Yuliya Semenova, Gerald Farrell

Articles

An optical microfiber coupler-based refractive index sensor is proposed and experimentally demonstrated in this letter. A microfiber coupler with a minimum diameter of 2.5 µm and a uniform waist with a length of 2 mm is fabricated and used for sensing surrounding refractive index. Both theoretical and experimental results have shown that the spectral response of the proposed microfiber coupler is highly sensitive to the surrounding refractive index over the range from 1.3340 to 1.3800. An average sensitivity of 2723 nm/RIU over this entire refractive index range has been achieved experimentally. Furthermore, for the refractive index range from 1.3340 to …


Wave Function Solutions By Transformation From The Helmholtz To Laplacian Operator, Jonathan Blackledge, Bazar Babajanov Jan 2013

Wave Function Solutions By Transformation From The Helmholtz To Laplacian Operator, Jonathan Blackledge, Bazar Babajanov

Articles

The Helmholtz, Schr¨odinger and Klein-Gordon equations all have a similar form (for constant wavelength) and have applications in optics, quantum mechanics and relativistic quantum mechanics, respectively. Central to these applications is the theory of barrier and potential scattering,which, through application of the Green’s function method yields transcendental equations for the scattered wave function thereby requiring approximation methods to be employed. This paper reports on a new approach to solving this problem which is based on transforming the Helmholtz operator to the Laplacian operator and applying a Green’s function solution to the Poisson equation. This approach yields an exact forward and …


Packaged Chalcogenide Microsphere Resonator With High Q-Factor, Pengfei Wang, Ming Ding, Timothy Lee, Ganapathy Senthil Murugan, Lin Bo, Yuliya Semenova, Qiang Wu, Dan Hewak, Gilberto Brambilla, Gerald Farrell Jan 2013

Packaged Chalcogenide Microsphere Resonator With High Q-Factor, Pengfei Wang, Ming Ding, Timothy Lee, Ganapathy Senthil Murugan, Lin Bo, Yuliya Semenova, Qiang Wu, Dan Hewak, Gilberto Brambilla, Gerald Farrell

Articles

The fabrication and characterization of a packaged As2S3 microsphere resonator coupled to a tapered fiber using a low refractive index UV-curable polymer are reported. Embedding provides an efficient means to remove the highest order whispering gallery modes in the microsphere resonator, thus cleaning the resonator spectrum. The device photosensitivity, useful for tuning, is still present and useable after the packaging process


The Influence Of Light Beam Convergence On The Stop-Bands Of A One-Dimensional Photonic Crystal, Vladimir A. Tolmachev, Kevin Berwick, Tatiana S. Perova Jan 2013

The Influence Of Light Beam Convergence On The Stop-Bands Of A One-Dimensional Photonic Crystal, Vladimir A. Tolmachev, Kevin Berwick, Tatiana S. Perova

Articles

The influence of beam convergence on the photonic band-gaps, or stop-bands (SBs), of onedimensional photonic crystals (1D PCs) is investigated. The investigation is based on an analysis of the gap map obtained from reflection spectra, calculated by the transfer matrix method for various angles of light incidence, φ, The calculated data is compared with reflection spectra taken using Fourier Transform Infrared microspectroscopy. It was found that the introduction of the parameter, Δφ to account for the focused light beam, for angles up to 20°, has little effect on the first, or lowest SB and the SBs adjacent to it. However, …


Financial Forecasting Using The Kolmogorov-Feller Equation, Jonathan Blackledge, Marc Lamphiere, Kieran Murphy, Shaun Overton Jan 2013

Financial Forecasting Using The Kolmogorov-Feller Equation, Jonathan Blackledge, Marc Lamphiere, Kieran Murphy, Shaun Overton

Articles

An approach to analysing a financial time series using the Kolmogorov-Feller Equation is considered, in particular, the Generalised Kolmogorov-Feller Equation (GKFE) subject to variations in the Stochastic Volatility. Using the Mittag-Leffler memory function, we derive an expression for the Impulse Response Function associated with a short time window of data which is then used to derive an algorithm for computing a new index using a standard moving window process. It is shown that application of this index to financial time series, subject to a low volatility condition, correlates with the start, direction and end of a trend depending on the …


Cryptography Using Evolutionary Computing, Jonathan Blackledge, S. Bezobrazov, Paul Tobin, F. Zamora Jan 2013

Cryptography Using Evolutionary Computing, Jonathan Blackledge, S. Bezobrazov, Paul Tobin, F. Zamora

Conference papers

No abstract provided.


The Integration Of Sustainable Development Competencies In Irish Engineering Education: Findings Of A Curriculum Content Investigation Of Four Engineering Programmes, Iacovos Nicolaou, Eddie Conlon Jan 2013

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 …


Control Of The Shunt Active Power Filter Under Non-Ideal Grid Voltage And Unbalanced Load Conditions, Samet Biricik, Soydan Redif, Ozgur Ozerdem, Malabika Basu Jan 2013

Control Of The Shunt Active Power Filter Under Non-Ideal Grid Voltage And Unbalanced Load Conditions, Samet Biricik, Soydan Redif, Ozgur Ozerdem, Malabika Basu

Conference papers

In this study a new method is proposed in order to improve the harmonic suppression efficiency of Active Power Filter for the problems caused by the distorted and unbalanced voltages with unbalanced load currents in control strategy. The proposed control method gives an adequate compensating current reference even for non ideal voltage and unbalanced current conditions. The results of simulation study are presented to verify the effectiveness of the proposed control technique in this study.


Sustainability Of Grid-Tie Micro-Generation System, Lubna Mariam, Malabika Basu, Michael Conlon Jan 2013

Sustainability Of Grid-Tie Micro-Generation System, Lubna Mariam, Malabika Basu, Michael Conlon

Conference papers

Both the outcomes of technical and economical feasibility analysis of a renewable based power system should be positive to achieve sustainability. Energy production or Renewable Energy Feed-in-Tariff (REFIT) cost should be lower or higher respectively than the existing grid electricity cost. As the renewable energy sources are variable and where REFIT is also applicable for the system connected to the grid, the detailed hourly time series analysis is very important. Based on this issue, in this paper, a techno-economic feasibility analysis has been performed for a PV based micro-generation system to find out the possible ways to make the micro-generation …


Estimation Of Wave Energy From Wind Velocity, Jonathan Blackledge, Eugene Coyle, Derek Kearney, Ronan Mcguirk, Brian Norton Jan 2013

Estimation Of Wave Energy From Wind Velocity, Jonathan Blackledge, Eugene Coyle, Derek Kearney, Ronan Mcguirk, Brian Norton

Articles

The aim of this paper is to report on a possible correlation between the Levy index for wind velocity and the mean Energy Density of sea surface waves in the same location. The result is based on data obtained from 6 buoys located around the coast of Ireland and maintained by the Marine Institute of Ireland and a further 144 buoys located at various locations off the coast of the United States of America and maintained by the National Data Buoy Centre. These buoys provide historical data on the wind velocity, wave height and wave period as well as other …


Economic Challenges And Optimisation Of Ocean Energy Electrical Systems, Fergus Sharkey Jan 2013

Economic Challenges And Optimisation Of Ocean Energy Electrical Systems, Fergus Sharkey

Books/Book chapters

No abstract provided.


Chapter Green Nanotechnology: Development Of Nanomaterials For Environmental And Energy Applications, Rachel Fagan, Changseok Han, Joel Andersen, Suresh Pillai, Polycarpos Falaras, Anthony Byrne, Patrick S.M. Dunlop, Hyeok Choi, Wenjun Jiang, Kevin O’Shea, Dionysios D. Dionysiou Jan 2013

Chapter Green Nanotechnology: Development Of Nanomaterials For Environmental And Energy Applications, Rachel Fagan, Changseok Han, Joel Andersen, Suresh Pillai, Polycarpos Falaras, Anthony Byrne, Patrick S.M. Dunlop, Hyeok Choi, Wenjun Jiang, Kevin O’Shea, Dionysios D. Dionysiou

Books/Book Chapters

This book chapter discusses the syntheses of various nanomaterials, for green nanotechnology applications in detail. Special attention is given to the development of emerging areas, such as environmental as well as energy materials. Various approaches for preparing nanostructured photocatalysts, such as titanium dioxide, zinc oxide, iron oxide, and metal sulfides, different conventional methods and novel methods, including sol-gel methods, hydrothermal methods, microwave-assisted methods and sonochemical methods are introduced. The use of nanomaterials as photocatalysts, supporting materials for solar cells, and disinfectants is reported for environmental remediation and energy applications. Advanced applications of nanomaterials for water detoxification, air purification, and the …


Regional Integration Of Renewable Energy Systems In Ireland: The Role Of Hybrid Energy Systems For Small Communities, Craig Goodbody, Eileen Walsh, Kevin Mcdonnell, Philip Owende Jan 2013

Regional Integration Of Renewable Energy Systems In Ireland: The Role Of Hybrid Energy Systems For Small Communities, Craig Goodbody, Eileen Walsh, Kevin Mcdonnell, Philip Owende

Articles

Due to a lack of indigenous fossil energy resources, Ireland’s energy supply constantly teeters on the brink of political, geopolitical, and geographical unease. The potential risk to the security of the energy supply combined with the contribution of anthropogenic greenhouse gas emissions to climate change gives a clear indication of Ireland's need to reduce dependency on imported fossil fuels as primary energy source. A feasibility analysis to investigate the available renewable energy options was conducted using HOMER software. The Net Present Cost, the Cost of Energy, and the CO2 emissions of each potential energy combination were considered in determining the …