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Articles 2131 - 2160 of 4606

Full-Text Articles in Engineering

Equi-Biaxial Fatigue Testing Of Epm Utilising Bubble Inflation, Mark Johnson, Niall Murphy, Ray Ekins, John Hanley, Stephen Jerrams Jan 2016

Equi-Biaxial Fatigue Testing Of Epm Utilising Bubble Inflation, Mark Johnson, Niall Murphy, Ray Ekins, John Hanley, Stephen Jerrams

Articles

This paper describes an equi-biaxial tension fatigue test system which utilises the bubble inflation method to subject elastomers to equi-biaxial fatigue loading between user-defined limits of pressure, volume, stretch ratio or stress. The test system integrates a hydraulic inflation system, a high speed vision system and a control system. The high-speed vision system allows the stretch ratio and stress acting on the test specimen to be evaluated in real-time during testing. This in turn allows either stretch ratio or stress to be used as a direct control limit. In this research, constant maximum engineering stress control tests have been carried …


Oxygen Mass Transport In Stented Coronary Arteries, Eoin Murphy, Adrian S. Dunne, David Martin, Fergal Boyle Jan 2016

Oxygen Mass Transport In Stented Coronary Arteries, Eoin Murphy, Adrian S. Dunne, David Martin, Fergal Boyle

Articles

Oxygen deficiency, known as hypoxia, in arterial walls has been linked to increased intimal hyperplasia, which is the main adverse biological process causing in-stent restenosis. Stent implantation has significant effects on the oxygen transport into the arterial wall. Elucidating these effects is critical to optimizing future stent designs. In this study the most advanced oxygen transport model developed to date was assessed in two test cases and used to compare three coronary stent designs. Additionally, the predicted results from four simplified blood oxygen transport models are compared in the two test cases. The advanced model showed good agreement with experimental …


Computational Tracking Of Shear-Mediated Platelet Interactions With Von Willebrand Factor, Adam Ralph, Martin Somers, Jonathan Cowman, Bruno Voisin, Emma Hogan, Hannah Dunne, Eimear Dunne, Barry Byrne, Nigel Kent, Antonio J. Ricco, Dermot Kenny, Simon Wong Jan 2016

Computational Tracking Of Shear-Mediated Platelet Interactions With Von Willebrand Factor, Adam Ralph, Martin Somers, Jonathan Cowman, Bruno Voisin, Emma Hogan, Hannah Dunne, Eimear Dunne, Barry Byrne, Nigel Kent, Antonio J. Ricco, Dermot Kenny, Simon Wong

Articles

The imaging of shear-mediated dynamic platelet behavior interacting with surface-immobilized von Willebrand factor (vWF) has tremendous potential in characterizing changes in platelet function for clinical diagnostics purposes. However, the imaging output, a series of images representing platelets adhering and rolling on the surface, poses unique, non-trivial challenges for software algorithms that reconstruct the positional trajectories of platelets. We report on an algorithm that tracks platelets using the output of such flow run experiments, taking into account common artifacts encountered by previously-published methods, and we derive seven key metrics of platelet dynamics that can be used to characterize platelet function. Extensive …


A Different Type Of Lighting Research: A Qualitative Methodology, Kevin Kelly Jan 2016

A Different Type Of Lighting Research: A Qualitative Methodology, Kevin Kelly

Articles

As lighting researchers we can learn from our colleagues in the humanities who have progressed Qualitative Research methods to a high level of rigour. We should consider using Qualitative Research Methods more. Such methods allow exploration of complex issues involving human behaviour and facilitate researchers to address difficult to answer questions that otherwise go unanswered. Good quality Qualitative Research can provide rich explanations of what went on in a given situation. Validity and Reliability are considered differently with this type of research methodology. This paper attempts to identify when qualitative research is appropriate, what questions it can answer in lighting …


Time Series Analysis For A 1/Tb Memory Function And Comparison With The Lyapunov Exponent Using Volatility Scaling, Paddy Walsh, Jonathan Blackledge Jan 2016

Time Series Analysis For A 1/Tb Memory Function And Comparison With The Lyapunov Exponent Using Volatility Scaling, Paddy Walsh, Jonathan Blackledge

Articles

Being able to provide accurate forecasts on the trending behaviour of time series is important in a range of applications involving the real time evolution of signals, most notable in financial time series analysis but control engineering in general. A critical solution for providing high accuracy forecasts is the filtering operation used to identify the position in time at which a trend occurs subject to a time delay factor that is inherent in the filtering strategy used. The paper explores this strategy and presents some example results that provide a quantitative measure of the accuracy used.


A Techno-Economical Appraisal Of A Pv Domestic Plant On A Irish Dwelling, Roberto Sandano Jan 2016

A Techno-Economical Appraisal Of A Pv Domestic Plant On A Irish Dwelling, Roberto Sandano

Articles

A comprehensive study of a domestic PV installation is addressed in this paper. A series of economic results are presented for a domestic installation in Ireland.


Three-Level Hysteresis Current Control Strategy For Three-Phase Four-Switch Shunt Active Filters, Samet Biricik, Hasan Komurcugil Jan 2016

Three-Level Hysteresis Current Control Strategy For Three-Phase Four-Switch Shunt Active Filters, Samet Biricik, Hasan Komurcugil

Articles

In this study, a three-level hysteresis current-control (HCC) strategy is proposed for three-phase four-switch shunt active power filters. The four-switch topology which utilises four switching devices together with two series connected capacitors is able to reduce the cost, switching losses and improve the reliability of system. In this topology, when the current control of phases A and B is achieved successfully, the current control of phase C which is connected to the midpoint of the series connected capacitors is achieved automatically. The current control is achieved by using a three-level HCC strategy. An important consequence of using this control strategy …


Impacts On One-Off Housing Arising From Amended Building Control Regulations In Ireland, Myles Keaveney, Kieran Compton Jan 2016

Impacts On One-Off Housing Arising From Amended Building Control Regulations In Ireland, Myles Keaveney, Kieran Compton

Conference papers

Single rural housing is very common in the Irish countryside. The Irish Central Statistics Office reported that one-off housing represented over a quarter of the total number of households in 2011. One-off houses are defined as occupied detached houses with individual septic tank wastewater treatment systems in rural areas (which include towns with a population of 1,500 or less).

The purpose of this study is to determine the increased cost to the consumer resulting from the introduction of the new Building Control (Amendment) Regulations 2014. In order to achieve the objective, a detailed description of past and current building control …


Urban Resilience: The Regeneration Of The Dublin Docklands, Aoife Doyle Jan 2016

Urban Resilience: The Regeneration Of The Dublin Docklands, Aoife Doyle

Conference papers

Resilience, and more specifically ‘urban resilience’, is a ‘fuzzy’ concept, which has gained increasing public, political and academic interest over the past two decades; particularly in the context of the global financial crisis of the late 2000s. This paper adopts an understanding of resilience as the ability of cities to change, adapt and, crucially, transform in response to stresses and strains. Yet how have cities – and urban planning – responded to the recent economic crisis; and how can one examine this in practice? This paper investigates the case of Dublin, Ireland. In particular, it utilises the resilience concept to …


Optimized Sliding Mode Control To Maximize Existence Region For Single-Phase Dynamic Voltage Restorers, Samet Biricik, Hasan Komurcugil Jan 2016

Optimized Sliding Mode Control To Maximize Existence Region For Single-Phase Dynamic Voltage Restorers, Samet Biricik, Hasan Komurcugil

Articles

This paper presents an optimized sliding mode control (SMC) strategy to maximize existence region for single-phase dynamic voltage restorers. It is shown analytically that there exists an optimum sliding coefficient which enlarges the existence region of the sliding mode to its maximum. Also, it is pointed out that the optimum sliding coefficient improves the dynamic response. In addition, a double-band hysteresis control which ensures the switching of a transistor in the voltage source inverter during a half-cycle while it remains either on or off in the other half cycle is used to mitigate the switching frequency. The theoretical considerations and …


New Hybrid Active Power Filter For Harmonic Current Suppression And Reactive Power Compensation, Samet Biricik, Ozgur Cemal Ozerdem, Soydan Redif, Mustafa Sezai Dincer Jan 2016

New Hybrid Active Power Filter For Harmonic Current Suppression And Reactive Power Compensation, Samet Biricik, Ozgur Cemal Ozerdem, Soydan Redif, Mustafa Sezai Dincer

Articles

In the case of undistorted and balanced grid voltages, low ratio shunt Active Power Filters (APFs) can give unity power factors and achieve current harmonic cancellation. However, this is not possible when source voltages are distorted and unbalanced. In this study, the cost-effective hybrid active power filter (HAPF) topology for satisfying the requirements of harmonic-current suppression and non-active power compensation for industry is presented. An effective strategy is developed to observe the effect of the placement of power capacitors and LC filters with the shunt active power filter. A new method for alleviating the negative effects of a non-ideal grid …


Investigation Of Humidity And Temperature Response Of A Silica Gel Coated Microfiber Coupler, Yuliya Semenova, Gerald Farrell, Dejun Liu Jan 2016

Investigation Of Humidity And Temperature Response Of A Silica Gel Coated Microfiber Coupler, Yuliya Semenova, Gerald Farrell, Dejun Liu

Conference Papers

The humidity and temperature responses of a microfiber coupler (MFC) coated with silica gel are investigated. Two MFC structures with different waist diameters of 2.5 and 3.5 μm were fabricated by fusing and tapering two single-mode fibers using a microheater brushing technique. The influences of the coating thickness and tapered waist diameter on the sensing performance are analyzed. For the proposed sensor with a waist diameter of 2.5 μm and 8-layers thick coating, the change in the relative humidity (RH) results in an exponential blueshift with a maximum sensitivity of 1.6 nm/% RH in the range from 70 to 86% …


Fatigue Properties Of Magnetorheological Elastomers And The Design Of Interfacial Layers To Improve Fatigue Life., Yanfen Zhou Jan 2016

Fatigue Properties Of Magnetorheological Elastomers And The Design Of Interfacial Layers To Improve Fatigue Life., Yanfen Zhou

Doctoral

The primary aim of this PhD programme was to understand the fatigue behaviour of magnetorheological elastomers (MREs) and provide a reliable fatigue life predictor for this class of materials. To realise this aim required the study of the dynamic behaviour of MREs using the equi-biaxial bubble inflation test method. Isotropic and anisotropic MREs were fabricated from silicone rubber (SR) filled with soft carbonyl iron (CI) particles. The equi-biaxial fatigue behaviour of these samples was determined using a bubble inflation method. Wohler (S-N) curves for both isotropic and anisotropic MREs were produced by subjecting the compounds to cycling over a range …


Monitoring Voip Speech Quality For Chopped And Clipped Speech, Andrew Hines, Jan Skoglund, Anil C. Kokaram, Naomi Harte Jan 2016

Monitoring Voip Speech Quality For Chopped And Clipped Speech, Andrew Hines, Jan Skoglund, Anil C. Kokaram, Naomi Harte

Articles

No abstract provided.


A New Educational Mobile Devices Platform For Social Inclusion In Tanzania, Fredrick Mtenzi Jan 2016

A New Educational Mobile Devices Platform For Social Inclusion In Tanzania, Fredrick Mtenzi

Articles

Abstract— It is evident that advances in technology has led to improvement in societal wellbeing. In this paper we demonstrate how mobile phones are used in providing reliable and quality education to students in disadvantaged areas of Tanzania. The main contribution is on leveraging on the success that Tanzania has had on using mobile banking to the un-banked population. These lessons are adapted to the education sector, where clever/smart integration of existing disruptive technologies such as mobile phones and social networks are be used to provide access to high quality educational contents. Further, the paper shows how educational content can …


Modeling Mental Workload Via Rule-Based Expert System: A Comparison With Nasa-Tlx & Workload Profile, Lucas Rizzo, Sarah Jane Delany, Pierpaolo Dondio, Luca Longo Jan 2016

Modeling Mental Workload Via Rule-Based Expert System: A Comparison With Nasa-Tlx & Workload Profile, Lucas Rizzo, Sarah Jane Delany, Pierpaolo Dondio, Luca Longo

Conference papers

In the last few decades several fields have made use of the construct of human mental workload (MWL) for system and task design as well as for assessing human performance. Despite this interest, MWL remains a nebulous concept with multiple definitions and measurement techniques. State-of-the-art models of MWL are usually ad-hoc, considering different pools of pieces of evidence aggregated with different inference strategies. In this paper the aim is to deploy a rule-based expert system as a more structured approach to model and infer MWL. This expert system is built upon a knowledge-base of an expert and transates into computable …


Kicm: A Knowledge-Intensive Context Model, Fredrick Mtenzi, Denis Lupiana Jan 2016

Kicm: A Knowledge-Intensive Context Model, Fredrick Mtenzi, Denis Lupiana

Conference papers

A context model plays a significant role in developing context-aware architectures and consequently on realizing context-awareness, which is important in today's dynamic computing environments. These architectures monitor and analyse their environments to enable context-aware applications to effortlessly and appropriately respond to users' computing needs. These applications make the use of computing devices intuitive and less intrusive. A context model is an abstract and simplified representation of the real world, where the users and their computing devices interact. It is through a context model that knowledge about the real world can be represented in and reasoned by a context-aware architecture. This …


Switchless Reconfigurable Antenna With 360° Steering, Adam Narbudowicz, Max Ammann, Dirk Heberling Jan 2016

Switchless Reconfigurable Antenna With 360° Steering, Adam Narbudowicz, Max Ammann, Dirk Heberling

Conference Papers

—A novel reconfigurable antenna capable of rotating a bidirectional pattern by 360◦ in azimuth is proposed. The antenna has two ports, no aperture switching components, and offers a more compact solution than an array. It provides a reconfigurable pattern in the band 2.525–2.595 GHz and a fixed omnidirectional pattern from 2.235 to 2.725 GHz. The measured gains for four investigated configurations are between 2.1 and 3.1 dBi with total efficiencies between 80% and 89%. The antenna is intended to operate with software defined radio [digital beamforming or multiple-input–multiple-output (MIMO)], where the potential of pattern generation using the dual-port antenna can …


A Two-Level Identity Model To Support Interoperability Of Identity Information In Electronic Health Record Systems., Xu Chen Jan 2016

A Two-Level Identity Model To Support Interoperability Of Identity Information In Electronic Health Record Systems., Xu Chen

Doctoral

The sharing and retrieval of health information for an electronic health record (EHR) across distributed systems involves a range of identified entities that are possible subjects of documentation (e.g., specimen, clinical analyser). Contemporary EHR specifications limit the types of entities that can be the subject of a record to health professionals and patients, thus limiting the use of two level models in healthcare information systems that contribute information to the EHR. The literature describes several information modelling approaches for EHRs, including so called “two level models”. These models differ in the amount of structure imposed on the information to be …


Fatigue Properties Of Magnetorheological Elastomers And The Design Of Interfacial Layers To Improve Fatigue Life., Yanfen Zhou Jan 2016

Fatigue Properties Of Magnetorheological Elastomers And The Design Of Interfacial Layers To Improve Fatigue Life., Yanfen Zhou

Doctoral

The primary aim of this PhD programme was to understand the fatigue behaviour of magnetorheological elastomers (MREs) and provide a reliable fatigue life predictor for this class of materials. To realise this aim required the study of the dynamic behaviour of MREs using the equi-biaxial bubble inflation test method. Isotropic and anisotropic MREs were fabricated from silicone rubber (SR) filled with soft carbonyl iron (CI) particles. The equi-biaxial fatigue behaviour of these samples was determined using a bubble inflation method. Wöhler (S-N) curves for both isotropic and anisotropic MREs were produced by subjecting the compounds to cycling over a range …


A Coplanar Vivaldi Antenna With Integrated Filter For Ka-Band, Kansheng Yang, Abraham Loutridis, Xiulong Bao, Patrick Mcevoy, Max Ammann Jan 2016

A Coplanar Vivaldi Antenna With Integrated Filter For Ka-Band, Kansheng Yang, Abraham Loutridis, Xiulong Bao, Patrick Mcevoy, Max Ammann

Conference Papers

A new design approach of a dual-stub coplanar Vivaldi antenna with integrated filter is presented. The dual-stub excites coupling between a parasitic elliptical element and tapered slots. The dimensions of the parasitic element are studied and optimized for wide beamwidth. The band pass filter is used for sub harmonic suppression and pattern shaping.


Lightweight And Cost Efficient Spaceborn Patch Antenna, Korbinian Schraml, Ralf Wilke, Dirk Heberling, Adam Narbudowicz Jan 2016

Lightweight And Cost Efficient Spaceborn Patch Antenna, Korbinian Schraml, Ralf Wilke, Dirk Heberling, Adam Narbudowicz

Conference Papers

In order to achieve lightweight yet low cost antennas for use in a geostationary space environment, the GeReLEO-SMART project develops a substrate-based, multilayer antenna structure which can replace traditional horn antennas as feeds for reflector antennas. To verify a design, an example mission is developed, consisting of a 2×2 patch antenna array with an integrated stripline bandpass filter. The operation frequency is 25.935 GHz. This multilayer antenna will be tested on board of the German technology demonstration mission “Heinrich-Hertz” (H2SAT). The design passed all tests for space qualification without decrease in performance.


Reconfigurable Axial Ratio In Compact Gnss Antennas, Adam Narbudowicz Jan 2016

Reconfigurable Axial Ratio In Compact Gnss Antennas, Adam Narbudowicz

Articles

A new adaptive technique for steering the direction of minimum axial ratio (AR) (


Unique Characterization Of Materials With Memory, John Murrough Golden Jan 2016

Unique Characterization Of Materials With Memory, John Murrough Golden

Articles

In general, materials with linear memory constitutive relations are characterized by a relaxation function. This leads to a situation where the free energy for most materials with memory is not unique. There is a convex set of free energy functionals with a minimum and a maximum element. An alternative procedure is proposed which characterizes a material by the kernel of the rate of dissipation functional. Using some recent results, we find that a unique free energy and relaxation function may then be deduced. An example is given for discrete spectrum materials. Also, the new results are used to show that …


The Influence Of Phthalocyanine Aggregation In Complexes With Cdse/Zns Quantum Dots On The Photophysical Properties Of The Complexes, Irina V. Martynenko, Anna O. Orlova, Vladimir G. Maslov, Anatoly V. Federov, Kevin Berwick, Alexander V. Baranov Jan 2016

The Influence Of Phthalocyanine Aggregation In Complexes With Cdse/Zns Quantum Dots On The Photophysical Properties Of The Complexes, Irina V. Martynenko, Anna O. Orlova, Vladimir G. Maslov, Anatoly V. Federov, Kevin Berwick, Alexander V. Baranov

Articles

The formation of nonluminescent aggregates of aluminium sulfonated phthalocyanine in complexes with CdSe/ZnS quantum dots causes a decrease of the intracomplex energy transfer efficiency with increasing phthalocyanine concentration. This was confirmed by steady-state absorption and photoluminescent spectroscopy. A corresponding physical model was developed that describes well the experimental data. The results can be used at designing of QD/molecule systems with the desired spatial arrangement for photodynamic therapy.


Sol-Gel Silica Coated Optical Fiber Sensor For Ammonia Gas Detection, Dejun Liu, Arun Mallik, Wei Han, Qiang Wu Jan 2016

Sol-Gel Silica Coated Optical Fiber Sensor For Ammonia Gas Detection, Dejun Liu, Arun Mallik, Wei Han, Qiang Wu

Conference papers

A high sensitivity ammonia gas sensor based on a tapered small core single-mode fiber (SCSMF) structure for measurement of ammonia gas concentration is reported. The proposed tapered SCSMF fiber structure has a waist diameter of 13.5 μm and it is fabricated using a customized microheater brushing technique. The silica based material prepared by sol-gel method is used as a coating applied to the surface of tapered fiber structures. Experimental results show that sensor is very sensitive to ammonia. The best measurement resolution of the ammonia concentration is estimated to be 16 ppb for gas concentrations of 0.5 ppm to 2.5 …


Exploitation Of Food Industry Waste For High Value Products, Rajeev Ravindran, Amit Jaiswal Jan 2016

Exploitation Of Food Industry Waste For High Value Products, Rajeev Ravindran, Amit Jaiswal

Articles

A growing global population calls for an increasing demand for food production and processing industry associated with it, and consequently generation of large amounts of food waste. This problem is further intensified due to slow progress in the development of effective waste management strategies, and less measure for the proper treatment and disposal of waste. Food waste is a reservoir of complex carbohydrates, proteins, lipids and nutraceuticals and can form the raw materials for commercially important metabolites. The current legislation on food waste treatment prioritises the prevention of waste generation and least emphasises disposal. Recent valorisation studies for food supply …


New Approach Of Modifying The Anatase To Rutile Transition Temperature In Tio2 Photocatalysts, Ciara Byrne, Rachel Fagan, Steven Hinder, Declan Mccormack, Suresh Pillai Jan 2016

New Approach Of Modifying The Anatase To Rutile Transition Temperature In Tio2 Photocatalysts, Ciara Byrne, Rachel Fagan, Steven Hinder, Declan Mccormack, Suresh Pillai

Articles

In pure synthetic titanium dioxide, the anatase to rutile phase transition usually occurs between the temperatures of 600 °C and 700 °C. The phase transition temperature can be altered by various methods, including modifying the precursor or by adding dopant or modifier to the TiO2 sample. In an attempt to investigate the phase transition using aromatic carboxylic acids, the current study examines the impact of increasing concentrations of benzoic acid (1 : 0, 1 : 1, 1 : 4 and 1 : 8 molar ratio TiO2 : benzoic acid) on anatase to rutile transition. The samples were characterised using Raman …


Synthesis And Doping Feasibility Of Composite-Hydroxide-Mediated Approach For The Cu1-Xznxo Nanomaterials, Tauseef Shahid, Muhammad Arfan, Waqas Ahmad, Tayyaba Bibi, Taj Muhammad Khan Jan 2016

Synthesis And Doping Feasibility Of Composite-Hydroxide-Mediated Approach For The Cu1-Xznxo Nanomaterials, Tauseef Shahid, Muhammad Arfan, Waqas Ahmad, Tayyaba Bibi, Taj Muhammad Khan

Articles

In this article, we report feasibility of composite hydroxide-mediated (CHM) approach for the synthesis and doping of Cu1-xZnxO (x=0%, 3%, 6% and 9%) nanomaterial. The proposed method offers a low cost, low temperature and environmentally friendly approach to preparing doped nanomaterials in a feasible and cost- effective route. Further, we investigate the effect of incorporated Zn +2 on the properties of produced Cu (II) O nanostructures. The X-ray diffraction analysis confirms formation of the single-phase monoclinic Cu (II) O and incorporation of Zn at the Cu-lattice sites. The crystalline structure is improved and the average grain size has increased from …


Digital Energy Networks: A Post Occupancy Evaluation And Appraisal Of An Intelligent Low Energy Lighting System, Anthony Colohan, Joseph Teehan, Keith Sunderland, Martin Barrett, James Preston Dec 2015

Digital Energy Networks: A Post Occupancy Evaluation And Appraisal Of An Intelligent Low Energy Lighting System, Anthony Colohan, Joseph Teehan, Keith Sunderland, Martin Barrett, James Preston

Conference Papers

The reduction in the electrical power requirements of LED lighting and the coinciding advancements in digital technology have now enabled luminaires to be powered and controlled exclusively over safety extra low voltage (SELV) wiring systems. The implementation of LED luminaires powered via a centralised 48 Volt DC low-latency communication network, with the capability to gather real-time data, has provided the potential to yield considerable electrical energy savings within a building. This paper will present an appraisal of this technology and will examine the technologies potential to make electrical energy savings, improve the quality of lighting and achieve cost savings on …