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Full-Text Articles in Engineering

A System For Monitoring Pressures And Spinal Curvature In Spinally Injured People Immobilised On A Spinal Raft, Ruairí De Fréin, Eoin Flinn, Ted Burke May 2004

A System For Monitoring Pressures And Spinal Curvature In Spinally Injured People Immobilised On A Spinal Raft, Ruairí De Fréin, Eoin Flinn, Ted Burke

Articles

We present a system designed to study the pressure at various ‘hot spots’ on the back of the body and the deformation of the spine experienced by a patient when strapped to a spinal board, and the potential alleviation of both by the addition of an inflatable “spinal raft” (or other similar device). In measuring pressure we devised a system of air-filled sacks interfaced with a PC. Each sack, placed under a particular key point on the body, is inflated until its faces just begin to separate and a switch thereby opens. The pressure reading is then captured and displayed …


A Vocalisation-Based Drawing Interface For Disabled Children, Ted Burke May 2004

A Vocalisation-Based Drawing Interface For Disabled Children, Ted Burke

Articles

In our work with disabled children at Ireland’s National Rehabilitation Hospital, a problem we have experienced in the facilitation of art activities is that traditional art materials and standard computer drawing programs sometimes prove inaccessible. In this paper, an original system, called “PaintMyVoice” is presented which facilitates the creation of two or three-dimensional images using a variety of novel input modalities. In particular, vocalisations can be used to create original images of a variety of objects, including trees, flowers and landscape elements. Additional input to the system can optionally be provided via mouse, keyboard, switch interface or digital camera depending …


Liquid Crystal Based Optical Switches, Yuliya Semenova, S. Dovgalets, Yuri Panarin, Gerald Farrell Jan 2004

Liquid Crystal Based Optical Switches, Yuliya Semenova, S. Dovgalets, Yuri Panarin, Gerald Farrell

Articles

Optical switches using two electro-optical effects in liquid crystals are proposed and investigated for incorporation in a switch matrix for optical networks. These two devices employ selective reflection in cholesteric layers and total reflection at the border between glass and nematic liquid crystal. Prototypes of these switches have been designed and their parameters have been investigated. Initial results suggest the switching contrast ratio of 38.5 and 42 dB, respectively, with insertion loss about 2.3…2.9 dB for polarized light.


Microstructural Analysis Of Varistors Prepared From Nanosize Zno, Suresh Pillai, Declan Mccormack, John Kelly, Ramesh Raghavendra Jan 2004

Microstructural Analysis Of Varistors Prepared From Nanosize Zno, Suresh Pillai, Declan Mccormack, John Kelly, Ramesh Raghavendra

Articles

No abstract provided.


Microwave Induced Preparation Of A-Axis Oriented Double-Ended Needle-Shaped Zno Microparticles, Suresh Pillai, John Kelly, Graeme Watson, Deirdre Ledwith Jan 2004

Microwave Induced Preparation Of A-Axis Oriented Double-Ended Needle-Shaped Zno Microparticles, Suresh Pillai, John Kelly, Graeme Watson, Deirdre Ledwith

Articles

Microwave irradiation of solutions of Zn(NO3)2 and urea provides a straightforward route to a-axis oriented crystals of needle-like morphology.




Low-Temperature Crystallization Of Sol–Gel Processed Pb0.5ba0.5tio3: Powders And Oriented Thin Films, Suresh Pillai, Stacey Boland, Sossina Haile Jan 2004

Low-Temperature Crystallization Of Sol–Gel Processed Pb0.5ba0.5tio3: Powders And Oriented Thin Films, Suresh Pillai, Stacey Boland, Sossina Haile

Articles

A novel sol– gel process suitable for depositing thin-film lead
barium titanate has been developed. X-ray diffraction analysis
showed perovskite phase crystallization to occur at a temperature
as low as 400°C with single-phase Pb0.5Ba0.5TiO3 (PBT)
resulting at a temperature as low as 500°C. Small concentrations
of barium carbonate were evident by X-ray diffraction at
400°C, and indications of minor, carbonate-containing phases
were evident by FTIR at 600°C. Deposition of the sol by spin
coating on single-crystal and thin-film MgO on silicon resulted
in highly oriented PBT films after calcination at 600°C. Mixed
(100)/(001) films were obtained on single-crystal MgO,
whereas …


Tradition Versus Technology: Careers Fairs In The 21st Century, Christiane Brennan, Margaret Daly, Eileen Fitzpatrick, Edward Sweeney Jan 2004

Tradition Versus Technology: Careers Fairs In The 21st Century, Christiane Brennan, Margaret Daly, Eileen Fitzpatrick, Edward Sweeney

Articles

The traditional methods of graduate recruitment do not adequately meet the needs of the changing profile of students and graduates. As industry becomes internationalized, the needs of employers are also changing. Graduate recruitment is in response to short term needs and varying levels of experience are required. A case study method was used in Technological University Dublin to evaluate effectiveness of a virtual careers fair in providing greater access to job opportunities for students and graduates. Access by employers to potential employees was also measured. Findings showed that while access improved, other issues requiring attention emerged.


A Simple Phase-Shifting Lateral Shearing Interferometer, Emilia Mihaylova, Maurice Whelan, Vincent Toal Jan 2004

A Simple Phase-Shifting Lateral Shearing Interferometer, Emilia Mihaylova, Maurice Whelan, Vincent Toal

Articles

A phase-shifting electronic speckle pattern shearing interferometer with a very simple shearing device is proposed. Two partially reflective glass plates are used to introduce the shear in this new interferometer. The reflection coefficients of the coatings on the two plates are 0.3 and 0.7. The distance between the two glass plates controls the size of the shear. The proposed new interferometric system is simple, flexible, and low cost.


Power Coupling Between Two Step-Index Multimode Fibers Of Different Numerical Apertures With An Angular Misalignment, Cheng Gao, Gerald Farrell Jan 2004

Power Coupling Between Two Step-Index Multimode Fibers Of Different Numerical Apertures With An Angular Misalignment, Cheng Gao, Gerald Farrell

Articles

Coupling efficiency between two step- index multimode fibers of different numerical aper- tures with an angular misalignment is calculated. The theory is presented using radiometry and geometrical optics. The limit case of the calculation is consistent with a previously published result. The results may be useful for applications such as power launching between two types of fibers with different numerical apertures for example silica fiber and plastic optical fiber(POF) and with an angular misalignment.


Purchasing Consortia And Electronic Markets: A Procurement Direction In Integrated Supply Chain Management, Bernd Huber, Edward Sweeney, Austin Smyth Jan 2004

Purchasing Consortia And Electronic Markets: A Procurement Direction In Integrated Supply Chain Management, Bernd Huber, Edward Sweeney, Austin Smyth

Articles

In supply chain management literature, there has been little empirical research investigation on purchasing consortium issues focusing on a detailed analysis of information and communication (ICT) based procurement strategies. Based on the exploration of academic literature and two surveys among purchasing organisations as well as e-Marketplaces / procurement service providers (PSPs) in the automotive and electronics industry sectors, the research methodology follows a positivistic approach in order to assess the overall statement: ‘Effective participation in electronic purchasing consortia (EPC) can have the potential to enhance competitive advantage. Implementation therefore requires a clear and detailed understanding of the major process structures …


Preparation Of (Pb,Ba)Tio3 Powders And Highly Oriented Thin Films By A Sol-Gel Process, Stacey Boland, Suresh Pillai, Wein-Duo Yang, Sossina Haile Jan 2004

Preparation Of (Pb,Ba)Tio3 Powders And Highly Oriented Thin Films By A Sol-Gel Process, Stacey Boland, Suresh Pillai, Wein-Duo Yang, Sossina Haile

Articles

Solid solution Pb1-xBaxTiO3, with particular emphasis on Pb0.5Ba0.5TiO3, was prepared
using a sol-gel process incorporating lead acetate trihydrate, barium acetate, and
titanium isopropoxide as precursors, acetylacetone (2,4 pentanedione) as a chelating
agent, and ethylene glycol as a solvent. The synthesis procedure was optimized by
systematically varying acetylacetone: Ti and H2O:Ti molar ratios and calcination
temperature. The resulting effects on sol and powder properties were studied using
thermogravimetric analysis/differential scanning calorimetry, Fourier transform infrared
spectroscopy, Brunauer-Emmett-Teller analysis, and x-ray diffraction (XRD).
Crystallization of the perovskite structure occurred at a temperature as low as 450 °C.
Thin films were prepared by spin …


On The Empirical Balanced Truncation For Nonlinear Systems, Marissa Condon, Rossen Ivanov Jan 2004

On The Empirical Balanced Truncation For Nonlinear Systems, Marissa Condon, Rossen Ivanov

Articles

Novel constructions of empirical controllability and observability gramians for nonlinear systems for subsequent use in a balanced truncation style of model reduction are proposed. The new gramians are based on a generalisation of the fundamental solution for a Linear Time-Varying system. Relationships between the given gramians for nonlinear systems and the standard gramians for both Linear Time-Invariant and Linear Time-Varying systems are established as well as relationships to prior constructions proposed for empirical gramians. Application of the new gramians is illustrated through a sample test-system.


Application Of Espi-Method For Strain Analysis In Thin Wall Cylinders, David Kennedy, Zdravko Schauperl, Seamus Greene, Emilia Mihaylova Jan 2004

Application Of Espi-Method For Strain Analysis In Thin Wall Cylinders, David Kennedy, Zdravko Schauperl, Seamus Greene, Emilia Mihaylova

Articles

The Centre for Industrial and Engineering Optics, DIT, Ireland, have recently developed and applied new optical techniques for the measurement of mechanical strain, one of which was based on electronic speckle pattern interferometry (ESPI). The accuracy of this optical technique when used on flat surfaces is well established. In this research the technique is tested on curved surfaces, and results are compared with the theoretical hoop strain as predicted by the bi-axial strain equation modified for the thin cylinder, and by those obtained by electrical resistance strain gauge (ERSG) undoubtedly the principal method of measuring mechanical strain. For testing procedures, …


Mechancial Characterization Of Unplasticised Polyvinylchloride Thick Pipes Using Electronic Speckle Pattern Interferometry, Emilia Mihaylova, Benjamin Potelon, Guntaka Tulasi Sridhar Reddy, Vincent Toal, Ciaran Smith Jan 2004

Mechancial Characterization Of Unplasticised Polyvinylchloride Thick Pipes Using Electronic Speckle Pattern Interferometry, Emilia Mihaylova, Benjamin Potelon, Guntaka Tulasi Sridhar Reddy, Vincent Toal, Ciaran Smith

Articles

In this work a number of techniques (electronic speckle pattern interferometry, holographic interferometry, strain gauge and finite element method) are brought to bear in order to establish consistency in the results of strain measurement. This is necessary if optical nondestructive testing methods, such as those used here, are to gain acceptance for routine industrial use. The FE model provides a useful check. Furthermore, ESPI fringe data facilitates the extension of FE models, an approach that is of growing importance in component testing. The use of in-plane and out-of-plane sensitive electronic speckle pattern interferometry (ESPI) for non-destructive material characterization of thick …


Turning An Articulated Truck On A Spreadsheet, Jim Mcgovern Nov 2003

Turning An Articulated Truck On A Spreadsheet, Jim Mcgovern

Articles

This paper describes how a standard office spreadsheet application was used to set up an engineering model for the simulation and analysis of the turning of articulated trucks


Engineering Is Fun - Let's Celebrate, Jim Mcgovern Sep 2003

Engineering Is Fun - Let's Celebrate, Jim Mcgovern

Articles

In this news article the author outlines why the Faculty of Engineering at DIT and all its professional engineering graduates have cause to celebrate 50 years of engineering at DIT from September 2003.


Rainwater Harvesting And Grey Water Recycling Systems, Liam Mccarton, Sean O'Hogain Jun 2003

Rainwater Harvesting And Grey Water Recycling Systems, Liam Mccarton, Sean O'Hogain

Articles

The benefits of water efficiency measures, rainwater harvesting and greywater reuse are principally water savings and reduced volume of consumption. Cost savings can accrue to the water supplier and water user. These benefits can be felt at a local level. Only with widespread use of such technology will reduced pressure on water resources and the supply infrastructure be realised. These technologies should be considered in the context of an overall water conservation strategy and each situation evaluated separately. A water audit should be undertaken to establish existing water usage and possible demands that can be met by using these technologies. …


Water Conservation Technologies, Liam Mccarton May 2003

Water Conservation Technologies, Liam Mccarton

Articles

Given the increasing incidence of serious flooding in Europe in recent years it might seem odd to be addressing the problem of water conservation. However, recent economic prosperity has led to an increased per capita use of water for domestic and industrial use. The traditional approach to meeting increased demand is to augment supply. However, mobilising new resources involves ever higher costs. Allied to this is the concept of sustainability, which can be defined as ‘development that meets the needs of the present without compromising the ability of future generations to meet their own needs’. An important consideration of …


Study Of Structure And Quality Of Different Silicon Oxides Using Ftir And Raman Microscopy, C. Moore, T. S. Perova, B. Kennedy, Kevin Berwick, I. I. Shaganov, R. A. Moore Jan 2003

Study Of Structure And Quality Of Different Silicon Oxides Using Ftir And Raman Microscopy, C. Moore, T. S. Perova, B. Kennedy, Kevin Berwick, I. I. Shaganov, R. A. Moore

Articles

In this work, SiO2 and fluorine and phosphorous doped SiO2 thin films are investigated using FTIR and Raman techniques. FTIR spectroscopy was performed at normal and oblique incidence of the probe beam in transmission and reflection modes. The effect of polarisation and angle of incidence of the probe beam is examined for the case of reflection mode. Infrared spectra taken from doped oxides show that the structure changes with the passage of time. Alternate methods to calculate the thickness of the doped film are therefore discussed. Infrared spectra of electron beam evaporated oxides give valuable information on their …


Circular Annular Planar Monopoles With Em Coupling, Z. N. Chen, Max Ammann, M.Y. W. Chia, T.S. P. See Jan 2003

Circular Annular Planar Monopoles With Em Coupling, Z. N. Chen, Max Ammann, M.Y. W. Chia, T.S. P. See

Articles

A circular annular planar monopole with electromagnetic coupling shows broadband properties. The planar radiator is electromagnetically coupled with a probe-fed strip, and separated from it by a thin dielectric sheet. The parametric effects on the bandwidth are examined experimentally. The measurements demonstrate that the proposed monopoles have the merit of broad impedance bandwidths in the order of 100% for VSWR=2:1 and of 4:1 for VSWR=3:1 and acceptable radiation patterns across the bandwidths.


Experimental Energy Performance Of Open Cooling Towers Used Under Low And Variable Approach Conditions For Indirect Evaporative Cooling Of Buildings, Ben Costelloe, Donal Finn Jan 2003

Experimental Energy Performance Of Open Cooling Towers Used Under Low And Variable Approach Conditions For Indirect Evaporative Cooling Of Buildings, Ben Costelloe, Donal Finn

Articles

The success of chilled ceilings and displacement ventilation systems as a means of sensible cooling in buildings has prompted a review of evaporative cooling technology as an effective means of generating the required cooling water. When such cooling water is generated at low approach conditions (2–5 K), at the higher temperatures required in these systems (14–18°C), very high levels of availability result. In many north western European locations the levels of availability are such that the prospect of supplanting rather than simply supplementing the refrigeration system, for sensible cooling purposes, arises. The viability of the technique, however, largely depends on …


A Wide-Band Shorted Planar Monopole With Bevel, Max Ammann, Zhi Ning Chen Jan 2003

A Wide-Band Shorted Planar Monopole With Bevel, Max Ammann, Zhi Ning Chen

Articles

A new wide-band shorted planar monopole with a bevel is presented. The numerical simulations and measurements demonstrate that the impedance bandwidth of a wide-band planar square monopole is shown to increase dramatically by combining bevelling and a shorting technique. The radiation pattern stability is also discussed.


The Effect Of Processing Conditions On Varistors Prepared From Nanocrystalline Zno, Suresh Pillai, Declan Mccormack, John Kelly, Ramesh Raghavendra Jan 2003

The Effect Of Processing Conditions On Varistors Prepared From Nanocrystalline Zno, Suresh Pillai, Declan Mccormack, John Kelly, Ramesh Raghavendra

Articles

Nanoparticles of ZnO were prepared by the reaction of ethanolic solutions of zinc acetate and oxalic acid
followed by drying (80 uC) and calcination (500 uC). Subsequently varistor materials were fabricated from this
nanoparticular ZnO via two separate routes:- a) from a ‘‘core shell’’ material using metal salts as additives; b)
by using a conventional solid state mixing of metal oxides. Sintering (1050 uC) and subsequent electrical studies
were carried out for each of these samples and they were compared with commercial varistor samples prepared
under similar conditions. ‘‘Core shell’’ type varistor material showed considerably higher breakdown voltage
(Vc ~ …


Enhanced Magnetoresistance In Nanocrystalline Magnetite, M Venkatesan, S. Nawka, Suresh Pillai, Jm D. Coey Jan 2003

Enhanced Magnetoresistance In Nanocrystalline Magnetite, M Venkatesan, S. Nawka, Suresh Pillai, Jm D. Coey

Articles

The magnetic and magnetotransport properties of nanoparticulate magnetite with different grain
sizes are investigated using x-ray diffraction, microscopy, magnetometry, and magnetoresistance
measurements. The magnetization varies significantly with grain size and is sensitive to preparation conditions. The reduction in saturation magnetization in coprecipitated particles is probably due to the surface spin disorder. Magnetoresistance of pressed powder compacts is significantly enhanced
in material composed of small grain size magnetite particles prepared by coprecipitation. Useful
magnetoresistance persists well above room temperature in sintered ceramic material.


Optimization And Comparison Of Broadband Monopoles, Z. N. Chen, M.Y. W. Chia, Max Ammann Jan 2003

Optimization And Comparison Of Broadband Monopoles, Z. N. Chen, M.Y. W. Chia, Max Ammann

Articles

The impedance and radiation properties of four broadband monopoles are compared and the parameters of a new roll monopole are optimised experimentally and numerically. The performances of the roll monopole with various numbers of roll turns are discussed and optimised numerically. The measurements and simulations show that, compared with conventional broadband monopoles, the roll monopole


Optical Switches Using Electro-Optical Effects In Liquid Crystals, Yuliya Semenova, S. Dovgalets, Yuri Panarin, Gerald Farrell Jan 2003

Optical Switches Using Electro-Optical Effects In Liquid Crystals, Yuliya Semenova, S. Dovgalets, Yuri Panarin, Gerald Farrell

Articles

A simple displacement sensor based on a bent singlemode-multimode-singlemode (SMS) fiber structure is proposed and experimentally investigated. The sensor offers a wider displacement range, not limited by the risk of fiber breakage, as well as a three-fold increase in displacement sensitivity by comparison with a straight SMS structure sensor. This sensor can be interrogated by either an optical spectral analyzer (OSA) or a ratiometric interrogation system: (1) if interrogated by an OSA assuming a resolution of 1 pm, it has a sensitivity of 28.2 nm for a displacement measurement range from 0 to 280 μm; (2) if interrogated by a …


Design Criteria And Optical Characteristics Of One-Dimensional Photonic Crystals Based On Periodically Grooved Silicon, Vladimir Tolmachev, Tatiana Perova, Kevin Berwick Jan 2003

Design Criteria And Optical Characteristics Of One-Dimensional Photonic Crystals Based On Periodically Grooved Silicon, Vladimir Tolmachev, Tatiana Perova, Kevin Berwick

Articles

Photonic bandgap (PBG) regions have been calculated for periodically grooved Si structures, acting as a one-dimensional photonic crystal. The wavelength range of the PBG as a function of the ratio (DSi/A) is presented, where DSi is the width of the Si walls and A is the grooved silicon lattice constant. The influence of the parameter DSi, the refractive index of the space between the Si walls and the number of structure periods, m, on the forming of PBG regions is discussed. A good correlation between the calculated and the experimentally observed …


Air Intake Cooling Motor Vehicle Performance Enhancement, James Brunton, David Kennedy, John D. Kelleher Jan 2003

Air Intake Cooling Motor Vehicle Performance Enhancement, James Brunton, David Kennedy, John D. Kelleher

Articles

This research examined the practical effects of cooling the intake air, on the combustion characteristics of a modern motor vehicle operating under simulated road conditions as well as its subsequent impact on the environment. The cooling effect was achieved by taking a typical air conditioning rig as fitted to a modern motor vehicle and incorporating it into the induction system of the car. The test vehicle used was a 1993 Renault Safrane 2.0Vi standard passenger car that was modified as part of the research to facilitate the extraction of the required test information. A series of tests were conducted using …


Indirect Evaporative Cooling Potential In Air-Water Systems In Temperate Climates, Ben Costelloe, Donal Finn Jan 2003

Indirect Evaporative Cooling Potential In Air-Water Systems In Temperate Climates, Ben Costelloe, Donal Finn

Articles

Recent developments have prompted a review of evaporative cooling technology as an effective means of cooling modern deep plan buildings. Prominent among these developments is the success of high temperature sensible cooling systems, particularly, chilled ceilings, which require a supply of cooling water at 14–18 °C. Crucial to the success of evaporative cooling technology, as a significant means of cooling in modern applications, is the ability to generate cooling water, in an indirect circuit, at a temperature which closely approaches the ambient adiabatic saturation temperature (AST) or wet bulb temperature (WBT). Recent experimental research has demonstrated that it is technically …


A Simulation Model To Characterize Photolithography Process Of A Semiconductor Wafer Fabrication, Amr Arisha, Paul Young, Mohie El Baradie Jan 2003

A Simulation Model To Characterize Photolithography Process Of A Semiconductor Wafer Fabrication, Amr Arisha, Paul Young, Mohie El Baradie

Articles

The pressures on semiconductor manufacturers due to cost considerations, rapid growth of process technology, quality constraints, feature size reduction, and increasingly complex products are requiring ever higher efficiency from manufacturing facilities. The complexity of manufacturing high capacity semiconductor devices means that it is impossible to analyze the process control parameters and the production configurations using traditional analytical models. There is, therefore, an increasing need for effective models of each manufacturing process, characterizing and analyzing the process in detail, allowing the effect of changes in the production environment on the process to be predicted. The photolithography process is one of the …