Engineering Commons^™

Impact Of Intermetallic Precipitates On The Tribological And/Or Corrosion Performance Of Cast Aluminium Alloys: A Short Review, David Culliton, Tony Betts, David Kennedy

Articles

The role of various intermetallic precipitates (IMP), or secondary phase particles, in governing the wear and corrosion performance characteristics of cast aluminium alloys is outlined in this brief review. Such alloys are especially important in transport applications where their low weight, low cost and recyclability make them very attractive. However alloy wear and/or corrosion behaviour often limit their industrial application and more work needs to done to extend their use into other areas. Careful control of IMP nucleation and growth rates may be beneficial, especially in alloys exposed to corrosive environments. Silicon, copper and magnesium are all important elements for …

Derivation Of A Fuzzy National Phosphorus Export Model Using 84 Irish Catchments, Ahmed Nasr, Michael Bruen

Articles

Implementation of appropriate management strategies to mitigate diffuse phosphorus (P) pollution at the catchment scale is vitally important for the sustainable development of water resources in Ireland. An important element in the process of implementing such strategies is the prediction of their impacts on P concentrations in a catchment using a reliable mathematical model. In this study, a state-of-the-art adaptive neuro-fuzzy inference system (ANFIS) has been used to develop a new national P model capable of estimating average annual ortho-P concentrations at un-gauged catchments. Data from 84 catchments dominated by diffuse P pollution were used in developing and testing the …

Achieving A Holistic View Of The Life Cycle Performance Of Existing Dwellings, Albert Famuyibo, Aidan Duffy, P. Strachan

Articles

Models which fully evaluate the life cycle energy and greenhouse gas (GHG) emissions of national housing stocks are not reported in literature. Capturing a holistic view of energy and emissions of the residential sector is an important process that can lead to a more effective policy making. This paper presents a methodology which evaluates the life cycle energy and GHG emissions of retrofitting housing stocks considering all life cycle stages and incorporating, to the greatest extent possible, all upstream inputs.

To achieve this, we developed a hybrid model of the existing Irish housing stock, comprising a process-based approach supplemented by …

Correspondence: Comparing Led Luminaires, James Duff

Articles

A recent editorial within Lighting Research and Technology 1 suggests the need for ‘a simple set of questions to ask the LED supplier’. This article will present such a set of questions, but also, and perhaps more importantly, a set of responses that might be considered appropriate. The information used to form these questions and answers has been drawn from a number of useful resources 2-7, interaction with various lighting professionals and through the authors own experience. The purpose of these questions is to generate discussion. The author understands the questions posed can be improved upon and it is hoped …

Lumped Time-Delay Compensation Scheme For Coding Synchronization In The Nonlinear Spectral Quantization-Based All-Optical Analog-To-Digital Conversion, Zhe Khang, Jinhui Yuan, Qiang Wu, Tao Wang, Sha Li, Chongxiu Y, Gerald Farrell

Articles

this paper, we propose a novel lumped time-delay compensation scheme for the all-optical analog-to-digital conversion based on soliton self-frequency shift and optical interconnection techniques. By inserting a segment of negative dispersion fiber between the quantization and the coding module, the time delay of different quantized pulses can be accurately compensated with a simple structure compared to the multiple time-delay lines. The simulation results show that the coding pulses can be well synchronized using a span of fiber, with the flattened negative dispersion within the wavelength range of 1558-1620 nm. In addition, the problems of pulse broadening and time error are …

Biaxial Order Parameter In The Homologous Series Of Orthogonal Bent-Core Smectic Liquid Crystals, S. Sreenilayam, Yuri Panarin, J. K. Vij, M. Osipov, A. Lehmann, C. Tschierske

Articles

The fundamental parameter of the uniaxial liquid crystalline state that governs nearly all of its physical properties is the primary orientational order parameter (S) for the long axes of molecules with respect to the director. The biaxial liquid crystals (LCs) possess biaxial order parameters depending on the phase symmetry of the system. In this paper we show that in the first approximation a biaxial orthogonal smectic phase can be described by two primary order parameters: S for the long axes and C for the ordering of the short axes of molecules. The temperature dependencies of S and C are obtained …

Using Modelling And Simulation To Improve Elderly Care In Ireland: A Case Study, Mohamed Ragab, Wael Rashwan, Waleed Abo-Hamad, Amr Arisha

Articles

Health care services both globally and domestically - are encountering critical issues due to the increasing demand for services at the time of economic recession. Hospital performance is subject to many constraints, and planning is made more difficult by the complexity and uncertainty of demand. Population ageing is creating immense pressures on healthcare facilities across the world, leaving them struggling to cope with the growing demand for elderly healthcare services. Current demand-supply gaps result in prolonged waiting times for patients and substantial cost burdens for healthcare systems due to delayed discharges. This paper reports on a project that uses modelling …

Ultrasound For Improved Crystallisation In Food Processing, N. Misra, Navneet Deora, Brijesh Tiwari, Patrick J. Cullen

Articles

Within the food industry, controlling crystallisation is a key factor governing food structure, texture and consumer appeal, with some foods requiring the promotion of crystallisation in a controlled manner (e.g. chocolate) and others a check (e.g. in honey). Sonocrystallisation is the application of ultrasound energy to control the nucleation of a crystallisation process. The use of power ultrasound provides a non-invasive approach to producing crystals with desired properties. Sonocrystallisation facilitates process control, primarily by modulating crystal size distribution and morphology. This paper details the governing mechanisms of sonocrystallisation. Proven and potential applications of the process in foods, including chocolates, honey, …

Human And Organisational Factors As A Risk Management Strategy In An Aviation Maintenance Company, Samuel Cromie, Paul Liston, Derek Ross, Siobhan Corrigan, Lindita Vani, Dara Lynch, Solonas Demosthenous, Maria Chiara Leva, Alison Kay, Vangelis Demosthenous

Articles

Aviation has for many years been one of the leading industries in addressing human and organisational factors (HOF) within its different sectors – flight operations, air traffic control, ground operations, maintenance, etc. In particular aviation has led the way in mandating a range of measures that address HOF issues – reporting systems, shift-handover procedures, etc (e.g. UK CAA, 2003). A key element of the regulation has been the mandating of initial and continuation training in HOF for virtually all personnel working in aviation maintenance. By contrast the development of practice and regulation of risk and safety management in aviation has …

A Window Of Opportunity: Assessing Behavioural Scoring, Kenneth Kennedy, Brian Mac Namee, Sarah Jane Delany, Michael O'Sullivan, Neil Watson

Articles

After credit has been granted, lenders use behavioural scoring to assess the likelihood of default occurring during some specific outcome period. This assessment is based on customers’ repayment performance over a given fixed period. Often the outcome period and fixed performance period are arbitrarily selected, causing instability in making predictions. Behavioural scoring has failed to receive the same attention from researchers as application scoring. The bias for application scoring research can be attributed, in part, to the large volume of data required for behavioural scoring studies. Furthermore, the commercial sensitivities associated with such a large pool of customer data often …

Dual-Band Omnidirectional Circularly Polarized Antenna, Adam Narbudowicz, Xiulong Bao, Max Ammann

Articles

A dual-band omnidirectional circularly polarized antenna is proposed. The antenna comprises back-to-back microstrip patches fed by a coplanar waveguide. A very low frequency ratio of 1.182 has been achieved, which can be easily tuned by adjusting four lumped capacitors incorporated into the antenna. An analysis of the omnidirectional circular polarization mechanism as well the dual band operation is provided and confirmed by numerical and experimental data. Key parameters to tune the resonant frequencies and the axial ratio have been identified. The prototype antenna provides omnidirectional circular polarization in one plane with cross polar isolation better than 12 dB for both …

Novel Microwave Assisted Synthesis Of Zns Nanomaterials, Suresh Pillai, Michael Seery, Damian Synnott, John Colreavy, Stephen Hinder

Articles

A novel ambient pressure microwave-assisted technique is developed in which silver and indium modified ZnS is synthesised. The as prepared ZnS is characterised by X-ray diffraction, UV-Vis spectroscopy, X-ray photoelectron spectroscopy and luminescence spectroscopy. This procedure produced crystalline materials with particle sizes below 10 nm. The synthesis technique leads to defects in the crystal which induce mid energy levels in the band gap and lead to indoor light photocatalytic activity. Increasing the amount of silver causes a phase transition from cubic blende to hexagonal phase ZnS. In a comparative study, when the ZnS cubic blende is heated in a conventional …

Ecotoxicological Assessment Of Silica And Polystyrene Nanoparticles Assessed By A Multitrophic Test Battery, Maria Casado-Gavalda, Ailbhe Macken, Hugh Byrne

Articles

The acute ecotoxicity of different diameters of silica and polyethyleneimine polystyrene (PS-PEI)nanoparticles (NPs)was assessed on a test battery of aquatic organisms representing different trophic levels. Daphnia magna, Thamnocephalus platyurus, Pseudokirchneriella subcapitata and Vibrio fischeri, were employed in a series of standard acute ecotoxicity tests and work was complemented with two cytotoxicological end points on a rainbow trout gonadal cell line (RTG-2). Physico-chemical characterization of the NPs was performed in the different test media employed, using dynamic light scattering (DLS) and zeta potentiometry. In contrast to silica NPs exposure, for which no effect was observed for concentrations up …

Proximity Heating Effects In Power Cables, Jonathan Blackledge, Eugene Coyle, Kevin O'Connell

Articles

Researchers at Technological University Dublin (DIT) have developed a new modelling system for evaluating the two and three dimensional heating effects in power cables due to harmonic distortion and proximity field effects.

Three Dimensional Simulation Of The Radiation Field Patterns Generated By An Integrated Antenna, Jonathan Blackledge, Bazar Babajanov

Articles

Simulating the electromagnetic field patterns generated by integrated antennas uses in mobile phones, for example, is fundamental to understanding their transmission characteristics and thereby engineering designs that optimize the directional properties of electromagnetic propagation. Modern integrated antennas have complex three-dimensional geometry designed to optimize their performance in terms of their multi-band and multi -modal attributes. This geometry, coupled with their close proximity to other component of the device (such as the battery and Printed Circuit Board, for example) produce complex field patterns due to the scattering of the electric (and magnetic) field within a spatial domain that is the same …

Evaluation Of Proximity Heating Effects In Power Cables, Jonathan Blackledge, Eugene Coyle, Kevin O'Connell

Articles

No abstract provided.

Inverter Performance For Small Wind Turbines When Connected In Paralled With The Low-Voltage Distribution System, Jonathan Blackledge, Eugene Coyle, Derek Kearney, Eamonn Murphy

Articles

Small wind turbines have been installed in urban and turbulent locations with surprisingly poor performance and this has been backed up by data from a trial at the Technological University Dublin. In order to develop the small wind turbine industry a careful examination of assessment methods for the wind resource is required. Small wind turbines connected in parallel with the grid use inverters. As the wind turbine is not always at max output, a Weighted Average Efficiency for wind inverters is proposed. Pitfalls associated with developing an accurate weighted average efficiency for an inverter are identified and this will enable …

The Fractional Schrodinger-Klein-Gordon Equation And Intermediate Relativism, Jonathan Blackledge, Bazar Babajanov

Articles

By considering a random walk model compounded in Einstein's evolution equation, we show that both the classical Schrodinger and Klein-Gordon equations can be viewed a s consequence of introducing a memory function.

The purpose of this is to derive a wave equaiton that, on a phenomenological basis at least, describes the transitional characteristics of wave functions for spin-less particles that may exist in the intermediate of "semi relativistic regime.

A Review Of Existing Microgrid Architectures, Lubna Mariam, Malabika Basu, Michael Conlon

Articles

The future electricity network must be flexible, accessible, reliable, and economic according to the worldwide smartgrid initiative. This is also echoed by the Sustainable Energy Authority of Ireland (SEAI) and European Electricity Grid Initiative (EEGI). In order to facilitate these objectives and to reduce green house gas (GHG) emission, research on various configurations of microgrid system is gaining importance, particularly with high penetration of renewable energy sources. Depending on the resource availability, geographical locations, load demand, and existing electrical transmission and distribution system, uG can be either connected to 6the grid or can work in an autonomous mode. Storage can …

On The Dirac Scattering Problem, Jonathan Blackledge, Bazar Babajanov

Articles

We consider a method of solving the Dirac scattering problem based on an approach previously used by the authors to solve the Schrodinger scattering problem to develop a conditional exact scattering solution and an unconditional series solution. We transform the Dirac scattering problem into a form that facilitates a soltuion based on the relativistic Lippmann-Schwinger equation using the relativistic Green's function that is transcendental in terms of the scattered field. Using the Dirac operator, this solution is transformed further to yield a modified relativistic Lippman-Schwinger equation that is also transcendental in terms of the scattered field. This modified solution faclitates …

Selection Of Design Parameters To Reduce The Zero-Sequence Circulating Current Flow In Parallel Operation Of Dc Linked Multiple Shunt Apf Units, Shafiuzzaman Khadem, Malabika Basu, Michael Conlon

Articles

Capacity enhancement and operational flexibility are two of the important limitations of the centralized shunt APF unit. These limitations can be conquered by the operation of multiple APF units in parallel and connected back to back by a common DC link capacitor. In that case, a circulating current (CC) flows within the APF units. This CC flow becomes out of control when the APF units operate in hysteresis based current controlled mode. One of the difficulties of this CC flow control or reduction is the variable switching frequency of the APF units. In this paper the model for CC flow …

Predicting Stock Market Using Online Communities Raw Web Traffic Streams, Pierpaolo Dondio

Articles

This paper investigates the predictive power of online communities traffic in regard to stock prices. Using the largest dataset to date, spanning 8 years and almost the complete set of SP500 stocks, we analyze the predictive power of raw unstructured traffic by filtering stock daily returns with traffic features. Our results partially challenge the assumption that raw traffic simply trails stock prices, as expected from a noisy signal without the sentiment direction. Raw traffic is shown to predict prices with statistical significance but with small economic impact. Anyway, this impact rises to moderate under the following conditions: 3 to 7 …

Reducing In-Stent Restenosis Through Novel Stent Flow Field Augmentation, Eoin Murphy, Fergal Boyle

Articles

In-stent restenosis (ISR), manifested as a re-narrowing of the arterial lumen post-implantation of a stent, is a detrimental limitation of stent technology. Understanding and consequently devising ways of reducing the frequency of ISR has been a continuing goal of research into improved stent designs. The biological processes that can lead to ISR have been found to be partially flow dependent with the local hemodynamics at the arterial wall of crucial importance. This paper investigates these biological processes and their instigating factors. Furthermore, the history and theory behind three stent technologies which endeavour to reduce ISR rates through stent flow field …

Prediction Of Compressive Creep Bhaviour In Flexible Polyurethane Foam Over Long Time Scales And At Elevated Temperatures, Conor Briody, Barry Duignan, Stephen Jerrams, Stephen Ronan

Articles

Compressive creep gradually affects the structural performance of flexible polymeric foam material over extended time periods. When designing components, it is often difficult to account for long-term creep, as accurate creep data over long time periods or at high temperatures is often unavailable. This is mainly due to the lengthy testing times and/or inadequate high temperature testing facilities. This issue can be resolved by conducting a range of short-term creep tests and applying accurate prediction methods to the results. Short-term creep testing was conducted on viscoelastic polyurethane foam, a material commonly used in seating and bedding systems. Tests were conducted …

Purchasing Green Transport And Logistics Services: Implications For Small Business, Pietro Evangelista, Maria Huge-Brodin, Karin Isaksson, Edward Sweeney

Articles

Considering its strong environmental impact, logistics plays a critical role in green supply chain management. It provides strategic links in the supply chain and is an essential function in the delivery of green products to the consumer. There is a general consensus on the fact that more environmentally sustainable companies may be achieved only if transport and logistics activities also become greener. To achieve this objective, buyer companies need to incorporate green considerations in the purchasing of transport and logistics services. This appears particularly challenging for small and medium sized enterprises (SMEs) because of their traditional lack of managerial, organisational …

Primitivec-Adl: Primitive Component Architecture Description Language, Basel Magableh

Articles

In this paper, we introduce an architecture descrip- tion language (ADL) for PCOMs (a context oriented component model). The language is described at three levels: (1) Building blocks (PCOMs context oriented components types) (2) Connec- tors, which connect components externally and internally, and (3) Architectural Configuration, which includes a full description of composition and decomposition mechanisms.

The contribution is designing ADL. That supports context- orinted component by providing new architecture elements, which fulfil the requirements of designing context oriented component based applications. Context oriented component is a behavioural unit composed of static parts and dynamic parts. A PCOMs component model …

Proximity Study Of A Uwb Directional Conformal Antenna On Water Pipe, Domenico Gaetano, Max Ammann, Patrick Mcevoy, Matthias John, Louise Keating, Frances Horgan

Articles

A preliminary study on the conformal properties of an antipodal exponentially tapered antenna placed on the surface of a flow meter system in the UWB range is presented. It was observed that the water effect can be mitigated by shifting the antenna away from the pipe surface.

Chalcogenide Microsphere Fabricated From Fiber Tapers Using Contact With A High-Temperature Ceramic Surface, Pengfei Wang, Ganapathy Murugan, Gilberto Bramilla, Ming Ding, Yuliya Semenova, Qiang Wu, Gerald Farrell

Articles

The fabrication 1 and characterization of a 2 chalcogenide glass microsphere resonator has been demonstrated. 3 At wavelengths near 1550 nm, whispering gallery mode 4 resonances can be efficiently excited in a 74-μm-diameter 5 chalcogenide glass microsphere via evanescent coupling using a 6 tapered silica glass fiber with a waist diameter of circa 2 μm. 7 Resonances with Q-factors greater than 105 were observed. 8 Due to the high nonlinearity properties of the chalcogenide 9 material and the ease of fabrication process, chalcogenide 10 microspheres offer the potential for robustly assembled fully 11 integrated photonic devices. 12 Index Terms—Chalcogenide

Developing Archetypes For Domestic Dwellings:An Irish Case Study, Albert Famuyibo, Aidan Duffy, Paul Strachan

Articles

Stock modelling, based on representative archetypes, is a promising tool for exploring areas for resource and emission reductions in the residential sector. The use of archetypes developed using detailed statistical analysis (multi-linear regression analysis, clustering and descriptive statistics) rather than traditional qualitative techniques allows a more accurate representation of the overall building stock variability in terms of geometric form, constructional materials and operation. This paper presents a methodology for the development of archetypes based on information from literature and a sample of detailed energy-related housing data. The methodology involves a literature review of studies to identify the most important variables …

Nanostructured Ti1‑Xsxo2‑Yny Heterojunctions For Efficient Visible- Light-Induced Photocatalysis, Vinodkumar Etacheri, Michael Seery, Stephen Hinder, Suresh Pillai

Articles

Highly visible light active S, N co-doped anatase-rutile heterojunctions is reported for the first time. The formation of heterojunctions at a relatively low temperature and visible light activity are achieved through thiourea modification of the peroxo-titania complex. FT-IR spectroscopic studies indicated the formation of a Ti⁴⁺-thiourea complex upon reaction between peroxo-titania complex and thiourea. Decomposition of the Ti⁴⁺-thiourea complex and formation of visible light active S, N co-doped TiO₂ heterojunctions are confirmed using X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM) and UV/Vis spectroscopic studies. Existence of sulfur as sulfate ions (S⁶⁺) …