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Technological University Dublin

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2003

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Articles 1 - 16 of 16

Full-Text Articles in Engineering

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 …


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 …


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 …


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 …


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.


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 …


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.


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


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 …