Engineering Commons^™

Effect Of Atmospheric Transmittance On Performance Of Adaptive Spd-Vacuum Switchable Glazing, Aritra Ghosh, Brian Norton, Aidan Duffy

Articles

Combined suspended particle device (SPD)-vacuum glazing is a potential adaptive glazing for low energy building application. Glazing transmission is an essential parameter to determine indoor comfort level of building due to glazing. In this work, above 0.5 clearness index, a strong correlation between glazing transmission and clearness index (Atmospheric transmission) has been evaluated for south facing vertical plane glazing. Below 0.5 clearness index, isotropic diffuse transmittance was dominant and one single value of glazing transmission was found which is suitable for building energy calculation throughout the year. Below 0.5 clearness index, for south facing vertical plane SPD-vacuum glazing transmission was …

Solar Dryers For Tropical Food Preservation: Thermophysics Of Crops, Systems And Components, Vivek Tomar, G. N. Tiwari, Brian Norton

Articles

Drying reduces the moisture content of harvested crops thus slowing decay processes to enable longerterm storage. Solar dryers contain the crop being dried, to enhance solar energy collection incurring lower crop losses than are associated with open-sun drying and recurrent costs than are inherent to uses of fossil-fuels for drying. The influences of key environmental, operational and design parameters for solar dryers are discussed including: (i) psychrometry of drying processes and ambient conditions, (ii) how initial crop properties are converted to final desired product attributes, (iii) feasibility of using powered components such as fans and (iv) air-heating solar collector selection.

A Comparison Of Supervised Machine Learning Classification Techniques And Theory-Driven Approaches For The Prediction Of Subjective Mental Workload, Dmitrii Gmyzin

Dissertations

In the modern world of technological progress, systems and interfaces are becoming more and more complex. As a consequence, it is a crucial to design the human-computer interaction in the most optimal way to improve the user experience. The construct of Mental Workload is a valid metric that can be used for such a goal. Among the different ways of measuring Mental Workload, self-reporting procedures are the most adopted for their ease of use and application. This research is focused on the application of Machine Learning as an alternative to theory-driven approaches for Mental Workload measurement. In particular, the study …

Thermal Inactivation Analysis Of Water-Related Pathogens In Domestic Hot Water Systems, Liam Mccarton, Sean O'Hogain

Articles

This study aims to investigate whether hot water systems supplied with harvested rainwater present an increased risk to health over hot water systems supplied with potable mains water. It reviews previous studies investigating the health effects of utilising rainwater within domestic systems. The main risk to public health of mains-supplied hot water systems is the operation, maintenance, age, location and temperature of the system. Rainwater-harvesting systems contain an inherent water treatment train consisting of flocculation, settlement, sorption and bioreaction, and stored rainwater quality improves as metal and chemical contaminants settle to form sludge. Laboratory experiments were conducted using a variety …

Magnetic Field Sensor Based On A Combination Of A Microfiber Coupler Covered With Magnetic Fluid And A Sagnac Loop, Fangfang Wei, Arun Mallik, Dejun Liu, Qiang Wu, Gang-Ding Peng, Gerald Farrell, Yuliya Semenova

Articles

This paper proposes a novel magnetic field sensor based on a microfiber coupler (MFC) combined with a magnetic fluid (MF) in a Sagnac loop formed from a polarization maintaining fiber (PMF). Thanks to the small (~2.6 μm) waist diameter of the MFC, the resulting interference is strongly influenced by the presence of the MF and this leads to the desirable high sensitivity of the structure to the applied magnetic field. The maximum magnetic field sensitivities of −100 pm/mT and −488 pm/mT have been experimentally demonstrated with the PMF lengths of 75 cm and 20 cm respectively in the range of …

A Chalcogenide Multimode Interferometric Temperature Sensor Operating At A Wavelength Of 2 Μm, Lin She, Pengfei Wang, Weimin Sun, Xianfan Wang, Wenlei Yang, Gilberto Brambilla, Gerald Farrell

Articles

This paper investigated the fabrication of a singlemode-multimode-singlemode fiber structure based on a chalcogenide (As2S3 and AsxS1−x) multimode fiber sandwiched between two standard silica singlemode fibers using a commercial fiber fusion splicer. The temperature dependence of this hybrid fiber structure was investigated and a first proof of concept showed that the hybrid SMS fiber structure has an average experimental temperature sensitivity of circa 84.38 pm/°C over a temperature range of 20 °C∼100°C at the wavelength range around 2 μm. The measured results show a general agreement with numerical simulations based on a guided-mode propagation analysis method. Our result provides a …

A Curvature Sensor Based On Twisted Single-Mode-Multimode-Single-Mode Hybrid Optical Fiber Structure, Ke Tian, Yifan Xin, Wenlei Yang, Tao Geng, Jing Ren, Ya-Xian Fan, Gerald Farrell, Elfed Lewis, Pengfei Wang

Articles

An optical fiber curvature sensor based on a twisted multimode fiber (MMF) sandwiched between two single-mode fibers (SMF) is proposed and investigated theoretically and experimentally. The measured transmission spectrum exhibits good agreement with theoretical predictions. Compared with a traditional single-mode-multimode-single-mode fiber structure sensor, the proposed configuration offers a higher average curvature sensitivity of -2.42 nm/m -1 over a curvature measurement range of 0-1.7390 m -1 and -7.09 dB/m -1 at an operating wavelength of 1537 nm. The temperature sensitivity of this sensor has been determined as 0.01 nm/°C over a wavelength range of 1535-1550 nm and circa 0.007 dB/°C at …

Investigation Of The Self-Imaging Position Of A Singlemode-Multimode-Singlemode Optical Fiber Structure, Xianfan Wang, Elfed Lewis, Pengfei Wang

Articles

In this paper, a theoretical and experimental investigation of the multimode interference induced self-imaging phenomenon in a singlemode-multimode-singlemode (SMS) fiber structure is described. The simulated transmission spectra based on guided modal propagation analysis and beam propagation method are presented and compared with experimental obtained results. The temperature dependence of the self-imaging position of the SMS fiber structure is also investigated. These investigations provide excellent opportunities for multiple future applications including telecommunications and sensing.

High Sensitivity Refractometer Based On Reflective Smf-Small Diameter No Core Fiber Structure, Guorui Zhou, Qiang Qu, Rahul Kumar, Wai Pang Ng, Hao Liu, Longfei Niu, Nageswara Lalam, Xiaodong Yuan, Yuliya Semenova

Conference Papers

A high sensitivity refractive index sensor based on a single mode-small diameter no core fiber structure is proposed. In this structure, a small diameter no core fiber (SDNCF) used as a sensor probe, was fusion spliced to the end face of a traditional single mode fiber (SMF) and the end face of the SDNCF was coated with a thin film of gold to provide reflective light. The influence of SDNCF diameter and length on the refractive index sensitivity of the sensor has been investigated by both simulations and experiments, where results show that the diameter of SDNCF has significant influence. …

Factors That Contribute To Communities Establishing Sustainable Development Initiatives In Ireland, Gerard Doyle

Conference Papers

Community gardens contribute to addressing a range of environmental, economic and social issues facing urban communities across the globe (Keeney, 2000; Calvin, 2011; McIvaine-Newsad and Porter, 2013). In response to the benefits that they generate, there has been a significant increase in community gardens internationally over the last thirty years (Firth et al., 2011). Community gardens can be considered a form of sustainable development initiative (SDI). This paper is concerned with the factors that contribute to the establishment of sustainable development initiatives in Ireland by focusing on community gardens in Dublin City. The core question being addressed is: What capacities …

New Epoch For Community Co-Operatives In Ireland: Factors Required For Their Implementation, Gerard Doyle

Conference Papers

Over the past century co-operatives have made a significant contribution to alleviating many economic and social crises Irish society has encountered. For example, producer co-operatives have enabled farmers to gain a superior price for their produce rather than dealing with middlemen (Tucker, 1983). In the 1950s the credit union movement enabled thousands of families’ access to affordable credit (Quinn, 1999). Since the 1970s, Ireland has experienced many crises including mass unemployment, emigration and housing shortages. It was also affected by fuel rationing, emanating from our over-reliance on imported fossil fuels combined with the oil crisis of 1973 and 1977. In …

Formative Assessment In Mathematics For Engineering Students, Eabhnat Ni Fhloinn, Michael Carr

Articles

this paper, we present a range of formative assessment types for engineering mathematics, including in-class exercises, homework, mock examination questions, table quizzes, presentations, critical analyses of statistical papers, peer-to-peer teaching, online assessments and electronic voting systems. We provide practical tips for the implementation of such assessments, with a particular focus on time or resource constraints and large class sizes, as well as effective methods of feedback. In addition, we consider the benefits of such formative assessments for students and staff.

Characteristics Of Different Systems For The Solar Drying Of Crops, Brian Norton

Articles

Solar dryers are used to enable the preservation of agricultural crops, food processing industries for

dehydration of fruits and vegetables, fish and meat drying, dairy industries for production of milk powder,

seasoning of wood and timber, textile industries for drying of textile materials. The fundamental concepts and

contexts of their use to dry crops is discussed in the chapter. It is shown that solar drying is the outcome of

complex interactions particular between the intensity and duration of solar energy, the prevailing ambient

relative humidity and temperature, the characteristics of the particular crop and its pre-preparation and the

design and …

Interior Colour Rendering Of Daylight Transmitted Through A Suspended Particle Device Switchable Glazing, Aritra Ghosh, Brian Norton

Articles

The colour rendering index (CRI) and correlated colour temperature (CCT) of daylight change upon transmission through a variable transmittance suspended particle device (SPD) switchable glazing.

The luminous transmittance of SPD glazing was found to vary from 0.02 to 0.55 in opaque and transparent state respectively. Below 0.14 transmittance, the CRI for a particular SPD glazing was less than 80.

No strong correlation was found between CCT and CRI. The CRI of SPD glazing in a transparent state was similar to double panes glazing for SPD glazing transmittance greater than 0.24.

Hybrid Solar Thermophotovoltaic-Biomass/Gas Power Generation System With A Spectrally Matched Emitter For Lower Operating Temperatures, C. M. Iftekhar Hussain Cmih, Brian Norton, Aidan Duffy, Mohamed Oubaha

Conference Papers

Three conceptual designs have been developed for hybrid solar-biomass/gas thermophotovoltaic (TPV) system for a non-intermittent power generation which can operate at relatively low TPV operating temperatures. TPV cells with lower band gap has been chosen for this conceptual hybrid device. The low band TPV cell generates electricity at longer photonic wavelength which corresponds a lower operating temperature. The development methodology is presented for a spectrally matched emitter which emits maximum photonic energy in the 600°C -1000°C temperature range with correspondingly lower photonic energy emission in the 0°C -600°C range. This approach for spectral control in TPV systems requires fewer system …

A Packaged Whispering Gallery Mode Strain Sensor Based On A Polymer Wire Cylindrical Micro Resonator, Vishnu Kavungal, Gerald Farrell, Qiang Wu, Arun Mallik, Yuliya Semenova

Articles

We propose a whispering gallery mode (WGM) strain sensor formed by a polymer-wire cylindrical micro resonator for strain measurement applications. WGMs are generated by evanescently coupling light into the polymer-wire resonator from a silica fiber taper fabricated by the micro heater brushing technique. Accurate and repeatable measurements of a strains up to one free spectral range (FSR) shift of the WGMs (corresponding to 0.33 % of the polymer-wire elongation, 3250 μɛ) are demonstrated experimentally with the proposed sensor. Practical packaging method for the proposed strain sensor on a glass microscope slide has also been realized making the sensor portable and …

Strain Distribution In The Porcine Lumbar Laminae Under Asymmetric Loading, Colin Bright, Stephen Tiernan, Fiona Mcevoy, Patrick Kiely

Conference Papers

If the articular facets of the vertebra grow in an asymmetric manner, the developed geometry causes an asymmetry of loading. When the loading environment is altered by way of increased activity, the likelihood of acquiring a stress fracture may be increased. The combination of geometric asymmetry and increased activity is hypothesised to be the precursor to the stress fracture under investigation in this study, spondylolysis. This vertebral defect is an acquired fracture with 7% prevalence in the paediatric population. This value increases to 21% among athletes who participate in hyperextension sports. Tests were carried out on porcine lumbar vertebrae, on …

Development Of Magnetorheological Elastomers (Mres) For Strength And Fatigue Resistance, J. Mcintyre, Stephen Jerrams

Books/Book Chapters

Natural rubber (NR)-based magnetorheological elastomers (MREs) exhibiting a reasonable switching effect were fabricated and tested. They were strong enough for use in automotive applications but still needed protection against ageing. Ethylene–propylene–diene rubber (EPDM) is a cost-effective material that is frequently used in the automotive industry because of its advantageous range of properties. With these applications in mind, it was a logical progression to the development of EPDM-based MREs. Unlike strain-crystallising NR, EPDM requires reinforcement to render its tensile and fatigue strength suitable for use in most applications. While small amounts of carbon black were sufficient for the NR-based MREs, a …

Thermal Mass Performance Of Concrete Panels Incorporated With Phase Change Materials, Dervilla Niall, Roger West, Oliver Kinnane, Sarah Mccormack

Conference papers

Using the mass of a building as a thermal storage system can reduce the demand on the auxiliary heating and cooling systems of the building. Concrete combines a high specific heat capacity with a thermal conductivity that is appropriate for the diurnal heating and cooling cycle of buildings. The heat storage capacity of concrete can be enhanced by adding phase change materials (PCMs) which provide a high latent heat storage capacity. However the addition of PCM to concrete reduces the conductivity of the concrete which may affect the ability of a PCM-concrete panel to absorb and release heat within the …

Study Of The Influence Of The Agarose Hydrogel Layer Thickness On Sensitivity Of The Coated Silica Microsphere, Arun Mallik, Gerald Farrell, Qiang Wu, Yuliya Semenova

Articles

In this paper, we investigate both theoretically and experimentally the influence of the agarose hydrogel layer thickness on the sensitivity of a proposed relative humidity (RH) sensor based on a silica microsphere resonator coated with agarose hydrogel. The operating principle of the sensor relies on excitation of whispering gallery modes (WGMs) in the coated silica microsphere using the evanescent field of a tapered fiber. A change in the ambient relative humidity is detected by measuring the wavelength shift of the WGMs in the transmission spectrum of the tapered fiber. Using perturbation theory, we analyze the influence of the agarose coating …

Characterization Of The Sub-Micrometer Hierarchy Levels In The Twist-Bend Nematic Phase With Nanometric Helices Via Photopolymerization: Explanation For The Sign Reversal In The Polar Response, Vitaly Panov, Sithara Sreenilayam, Yuri Panarin, Jagdish Vij, Chris Welch, Georg Mehl

Articles

Photopolymerization of a reactive mesogen mixed with a mesogenic dimer, shown to exhibit the twist-bend nematic phase (NTB), reveals the complex structure of the self-deformation patterns observed in planar cells. The polymerized reactive mesogen retains the structure formed by liquid crystalline molecules in the twist bend phase, thus enabling its observation by scanning electron microscopy (SEM). Hierarchical ordering scales ranging from tens of nanometers to micrometers are imaged in detail. Submicron features, anticipated from earlier X-ray experiments, are visualized directly. In the self-deformation stripes formed in the NTB phase, the average director field is found tilted in …

Grid Voltage Sensorless Single-Phase Half-Bridge Active Filter And Dc Bus Voltage Regulation, Samet Biricik

Articles

In this paper, a method is presented for the control of grid voltage sensorless single-phase half-bridge shunt active power filter to reduce the grid current harmonics of low-power single-phase non-linear loads. The proposed system forces the grid current to be sinusoidal without sensing and processing the grid voltage on the line. For this reason, instead of grid voltage the load current is processed by using self-tuning filter to generate reference grid current to eliminate current harmonic distortions. In order to design a low-cost system, a half-bridge voltage source converter is used to reduce driver circuits. In addition, the switching losses …

Simulation And Analysis Of Switched Reluctance Generator For Renewable Energy Applications, Simone Sartori, Malabika Basu, Michael Farrell, Andrea Tortella

Conference papers

The purpose of the paper is to investigate the application of a Switched Reluctance Generator (SRG) for future wave energy converters. This machine presents some favourable features as compared to others. The machine optimal operation can be obtained after a detailed assessment of the control strategy. For this purpose, a SRG model is implemented in Matlab® Simulink® environment to find out the values of the switching angles which maximize the converted power and to set up an appropriate control of the power exchange with the grid to which the machine is connected. The simulation results provide evidence that a proper …

Nonlinear Control Methods For Single-Ended Primary-Inductor Power Converters, Samet Biricik, Tuan Ngo, Hasan Komurcugil, Malabika Basu

Conference papers

This paper investigates nonlinear control methods for single-ended primary-inductor converters (SEPIC). The fastswitching and average models show the converter nonlinearity in terms of inductor currents, capacitor voltages, and the switching duty cycle. The control law intuitively should be nonlinear to drive and guarantee the system stability. Two different control laws based on the passivity and back-stepping technique are examined and designed to have asymptotically global stability in the system. Unlike the passivity method which regulates the duty cycle directly, the back-stepping method adjusts the switching duty by a driver integrator/low pass filter system. The simulation results have shown the benefits …

Nano-Magnetic Resonance Imaging (Nano-Mri) Gives Personalized Medicine A New Perspective, Lorenzo Rosa, Jonathan Blackledge, Albert Boretti

Articles

This paper reviews some of the major and most recent advances in nanoscale-magnetic resonance imaging (nano-MRI) for personalized medicine (PM). Nano-MRI may drastically expand the capabilities of the traditional magnetic resonance images (MRI), down to the nanometer scale and possibly, in the near future, at the atomic scale. Nano-MRI is potentially able to observe structures which cannot be seen using today’s molecular imaging, with sensitivities of many billions of times better than MRI as currently used in hospitals, for example. The paper briefly reports on the foremost research themes in nano-MRI.

Armagh Observatory: Historic Building Information Modelling For Virtual Learning In Building Conservation, Maurice Murphy, Alain Chenaux, Garrett Keenaghan, V. Gibson, John Butler, C. Pybusr

Conference papers

In this paper the recording and design for a Virtual Reality Immersive Model of Armagh Observatory is presented, which will replicate the historic buildings and landscape with distant meridian markers and position of its principal historic instruments within a model of the night sky showing the position of bright stars. The virtual reality model can be used for educational purposes allowing the instruments within the historic building model to be manipulated within 3D space to demonstrate how the position measurements of stars were made in the 18th century. A description is given of current student and researchers activities concerning on-site …

Current State Of The Art Historic Building Information Modelling, Conor Dore, Maurice Murphy

Conference papers

In an extensive review of existing literature a number of observations were made in relation to the current approaches for recording and modelling existing buildings and environments: Data collection and pre-processing techniques are becoming increasingly automated to allow for near real-time data capture and fast processing of this data for later modelling applications. Current BIM software is almost completely focused on new buildings and has very limited tools and pre-defined libraries for modelling existing and historic buildings. The development of reusable parametric library objects for existing and historic buildings supports modelling with high levels of detail while decreasing the modelling …

Strengthening The Development Of The Short-Rotation Plantations Bioenergy Sector: Policy Insights From Six European Countries, Carlos Parra-Lopez, Martin Holley, Kevin Lindegaard, Samir Sayadi, Gonzalo Esteban-Lopez, Victor Duran-Zuazo, Christoph Knauer, Hans-Georg Von Engelbrechten, Ralf Winterber, Annika Henriksson, Annette Lamley, Anders Nylander, Susanne Paulrud, Pauline Leonard, Patrick Daly, Lukasz Drzewaszewski, Wojciech Rzewuski

Articles

This paper, based on a participatory methodological framework involving expert stakeholders and researchers from six European countries (Germany, Ireland, Poland, Spain, Sweden and UK), analyses the priority issues for the development of short-rotation plantations (SRP), and proposes a series of policy strategies to strengthen this development. The results indicate that there is a lack of awareness of the multifaceted benefits of SRP at the level of farmers, policy makers and public authorities. More research is required to put a value on the multifunctionality of SRP and justify its public support. Small-scale projects using established technologies are also required with energy …

Investigation Into The Local Nature Of Rate Of Change Of Frequency In Electrical Power Systems, Damien Doheny, Michael Conlon

Conference papers

In recent years power systems world-wide have seen large increases in wind power penetration and this trend is expected to continue. This is having the undesirable consequence of reducing the inertia of electrical power systems, especially at times of high wind generation. Reduced inertia makes a power system more susceptible to a larger rate of change of frequency (RoCoF) following a grid disturbance, such as the sudden disconnection of a load or generator. High RoCoF events could trigger generator protective devices or anti-islanding RoCoF relays, disconnecting generation from the grid, compounding the initial grid disturbance and in extreme cases result …

Compact Facility For Testing Steady And Transient Thermal Performance Of Building Walls, Aimee Byrne, Gerard Byrne, Anthony Robinson

Articles

Energy efficiency retrofit of buildings represents a key effort in reducing EU energy demand by 20% by 2020. However, predictions tend to overestimate savings by large percentages. The shortfall in savings can be attributed to incorrect predictive techniques, comfort takeback along with other behavioural and workmanship variables. Common predictive techniques related to heat loss tend to be based on the U-value of the building envelope. This paper presents the design of a more straightforward and compact version of the traditional Hot-Box apparatus (measures U-value) which instead determines the thermal resistance of samples of building envelope. U-value includes the need to …