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Full-Text Articles in Engineering

Fatigue And Damage Of Porcine Pars Interarticularis During Asymmetric Loading, Colin Bright, Stephen Tiernan, Fiona Mcevoy, Pat Kiely Jan 2018

Fatigue And Damage Of Porcine Pars Interarticularis During Asymmetric Loading, Colin Bright, Stephen Tiernan, Fiona Mcevoy, Pat Kiely

Articles

If the articular facets of the vertebra grow in an asymmetric manner, the developed bone 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, …


Surface Water Flooding, Groundwater Contamination, And Enteric Disease In Developed Countries: A Scoping Review Of Connections And Consequences, L. Andrade, J. O'Dwyer, E. O'Neill, Paul Hynds Jan 2018

Surface Water Flooding, Groundwater Contamination, And Enteric Disease In Developed Countries: A Scoping Review Of Connections And Consequences, L. Andrade, J. O'Dwyer, E. O'Neill, Paul Hynds

Articles

Significant volumes of research over the past four decades has sought to elucidate the social, infrastructural, economic, and human health effects of climate change induced surface flooding. To date, epidemiological and public health studies of flooding events have focused on mental health effects, vector-borne diseases, and infectious enteric disease due to floodwater contact (i.e. typically low consumption rates). The inherent nature of groundwater (i.e. out of sight, out of mind) and the widely held belief that aquifers represent a pristine source of drinking water due to natural attenuation may represent the “perfect storm” causing direct consumption of relatively large volumes …


Problem-Based Learning: Student Perceptions Of Its Value In Developing Professional Skills For Engineering Practice, Una Beagon, Dervilla Niall, Eabhnat Ni Fhloinn Jan 2018

Problem-Based Learning: Student Perceptions Of Its Value In Developing Professional Skills For Engineering Practice, Una Beagon, Dervilla Niall, Eabhnat Ni Fhloinn

Articles

This study explores students’ perceptions of the effectiveness of a Problem-Based Learning (PBL) design project, taken as part of a first-year engineering module, in developing professional skills needed for engineering practice. Students completed surveys before and after the PBL group project, and produced personal reflections on the process. The closed survey questions were analysed quantitatively and the main themes from the reflections outlined using General Inductive Analysis. Students rated themselves as having improved across a range of professional skills as a result of the project, with particular emphasis on teamwork, communication skills, understanding of the design process and self-directed learning. …


High Sensitivity Optical Fiber Sensors For Simultaneous Measurement Of Methanol And Ethanol, Dejun Liu, Rahul Kumarb, Fangfang Wei, Wei Han, Arun Kumar Mallik, Jinhui Yuanc, Shengpeng Wan, Xingdao He, Zhe Kange, Feng Li, Chongxiu Yu, Gerald Farrell, Yuliya Semenova, Qiang Wu Jan 2018

High Sensitivity Optical Fiber Sensors For Simultaneous Measurement Of Methanol And Ethanol, Dejun Liu, Rahul Kumarb, Fangfang Wei, Wei Han, Arun Kumar Mallik, Jinhui Yuanc, Shengpeng Wan, Xingdao He, Zhe Kange, Feng Li, Chongxiu Yu, Gerald Farrell, Yuliya Semenova, Qiang Wu

Articles

High sensitivity volatile organic compounds (VOCs) sensors based on a tapered small core single mode fiber (TSCSMF) and a microfiber coupler (MFC) are reported. The TSCSMF had a waist diameter of ~5.1 μm and the MFC had a waist diameter of ~1.9 μm each and both were fabricated using a customized microheater brushing technique. Silica based materials containing immobilized Nile red prepared by sol-gel method with two different recipes (recipe I and recipe II) are investigated. Initially recipe I based coating materials were applied to the surfaces of the TSCSMF and MFC. The experimental results show that the sensor based …


Investigation Of Temperature Dependence Of Microfibre Coil Resonators, Yu Yin, Jibo Yu, Yuxuan Jiang, Shi Li, Jing Ren, Gerald Farrell, Elfed Lewis, Pengfei Wang Jan 2018

Investigation Of Temperature Dependence Of Microfibre Coil Resonators, Yu Yin, Jibo Yu, Yuxuan Jiang, Shi Li, Jing Ren, Gerald Farrell, Elfed Lewis, Pengfei Wang

Articles

The temperature-sensitive performance of a microfiber coil resonator (MCR) is thoroughly investigated. The MCR is fabricated by wrapping a microfiber on a PMMA rod coated with a UV-curable low refractive index epoxy. The temperature sensitivity is measured by investigating the correlation between the shift of the resonant wavelength and the surrounding temperature. It is determined that a range of parameters of the MCRs, including the gap between two adjacent rings, the diameter of the supporting rod, the number of rings, and the diameter of the microfiber, have a great influence on the temperature sensitivity of the MCRs. By optimizing the …


Investigation Of A Novel Sms Fiber Based Planar Multimode Waveguide And Its Sensing Performance, Xianfan Wang, Jiquan Zhang, Ke Tian, Shunbin Wang, Libo Yuan, Elfed Lewis, Gerald Farrell, Pengfei Wang Jan 2018

Investigation Of A Novel Sms Fiber Based Planar Multimode Waveguide And Its Sensing Performance, Xianfan Wang, Jiquan Zhang, Ke Tian, Shunbin Wang, Libo Yuan, Elfed Lewis, Gerald Farrell, Pengfei Wang

Articles

A novel, MMI-based all-fiber structure, which consists of two single-mode fibers and a multimode fiber polished on both sides, is described. The light propagation characteristics of this fiber structure, as well as its superior sensing performance, are analyzed theoretically by using the beam propagation method (BPM). This fiber structure demonstrates a significant spectral response to changes of the surrounding refractive index (RI), and the measured results exhibit good agreement with the predicted data. The measured average RI sensitivity is as high as 151.29 nm/RIU over an RI range from 1.3450 to 1.4050, when the polished depth is 30 µm on …


A Simple All-Fiber Comb Filter Based On The Combined Effect Of Multimode Interference And Mach- Zehnder Interferometer, Guorui Zhou, Rahul Kumar, Qiang Wu, W. P. Ng, Richard Binns, Lalam Nageswara, Xinxiang Miao, Longfei Niu, Xiaodong Yuan, Yuliya Semenova, Gerald Farrell, Jinhui Yuan, Chongxiu Yu, Xinzhu Sang, Xiangjun Xin, Bo Liu, Haibing Lv, Yong Qing Fu Jan 2018

A Simple All-Fiber Comb Filter Based On The Combined Effect Of Multimode Interference And Mach- Zehnder Interferometer, Guorui Zhou, Rahul Kumar, Qiang Wu, W. P. Ng, Richard Binns, Lalam Nageswara, Xinxiang Miao, Longfei Niu, Xiaodong Yuan, Yuliya Semenova, Gerald Farrell, Jinhui Yuan, Chongxiu Yu, Xinzhu Sang, Xiangjun Xin, Bo Liu, Haibing Lv, Yong Qing Fu

Articles

A polarization-dependent all-fiber comb filter based on a combination effect of multimode interference and Mach-Zehnder interferometer was proposed and demonstrated. The comb filter was composed with a short section of multimode fiber (MMF) fusion spliced with a conventional single mode fiber on the one side and a short section of a different type of optical fiber on the other side. The second type of optical fiber is spliced to the MMF with a properly designed misalignment. Different types and lengths of fibers were used to investigate the influence of fiber types and lengths on the performance of the comb filter. …


High-Sensitivity Salinity Sensor Based On Optical Microfiber Coil Resonator, Y. Yin, S. Li, J. Ren, Gerald Farrell, E. Lewis, Pengfei Wang Jan 2018

High-Sensitivity Salinity Sensor Based On Optical Microfiber Coil Resonator, Y. Yin, S. Li, J. Ren, Gerald Farrell, E. Lewis, Pengfei Wang

Articles

In recent years, salinity sensing has attracted much attention in potential areas ranging from marine monitoring, marine circulation, marine climate and environment protection in oceanography [1–4]. Generally, traditional methods of salinity measurement have been based on electronic methods (electrochemical) to detect the existence of chlorine ions of the seawater [5,6]. However, this method is affected greatly from the harsh environment, such as high corrosivity, extreme temperature and strong electromagnetic interference and is not used widely in micro scale due to its large size and complex structure. Electrochemical sensors are also prone to cross-sensitivity from and can even be damaged by …


Silica Gel Coated Spherical Micro Resonator For Ultra-High Sensitivity Detection Of Ammonia Gas Concentration In Air, Arun Mallik, Gerald Farrell, Dejun Liu, Vishnu Kavungal, Qiang Wu, Yuliya Semenova Jan 2018

Silica Gel Coated Spherical Micro Resonator For Ultra-High Sensitivity Detection Of Ammonia Gas Concentration In Air, Arun Mallik, Gerald Farrell, Dejun Liu, Vishnu Kavungal, Qiang Wu, Yuliya Semenova

Articles

A silica gel coated microsphere resonator is proposed and experimentally demonstrated for measurements of ammonia (NH3) concentration in air with ultra-high sensitivity. The optical properties of the porous silica gel layer change when it is exposed to low (parts per million (ppm)) and even ultra-low (parts per billion (ppb)) concentrations of ammonia vapor, leading to a spectral shift of the WGM resonances in the transmission spectrum of the fiber taper. The experimentally demonstrated sensitivity of the proposed sensor to ammonia is estimated as 34.46 pm/ppm in the low ammonia concentrations range from 4 ppm to 30 ppm using an optical …


Evaluating The Effect Of Turbulence On Aircraft During Landing And Take-Off Phases, Anthony O'Connor, Derek Kearney Jan 2018

Evaluating The Effect Of Turbulence On Aircraft During Landing And Take-Off Phases, Anthony O'Connor, Derek Kearney

Articles

— Low level wind shear and turbulence present a serious safety risk to aircraft during the approach, landing and take-off phases. Low level wind shear has been identified as one of the primary factors for aircraft go-arounds and aborted landings. During any given year, wind shear occurs thousands of times at airports around the world, affecting the arrival and departure of aircraft. This paper has quantified the direct cost of flight Go-arounds. This paper will show the potential savings to the aviation industry. This paper will argue that a solution to the problem of forecasting low level wind shear and …


Optical Fiber Fresnel Reflection Sensor For Direct Detection Of The Solid-Liquid Phase Change In N-Octadecane, Wei Han, Marek Rebow, Dejun Liu, Yuliya Semenova, Qiang Wu Prof. Jan 2018

Optical Fiber Fresnel Reflection Sensor For Direct Detection Of The Solid-Liquid Phase Change In N-Octadecane, Wei Han, Marek Rebow, Dejun Liu, Yuliya Semenova, Qiang Wu Prof.

Articles

An all optical fiber Fresnel reflection sensor for detecting the solid–liquid phase change in n-octadecane is proposed and experimentally demonstrated. The sensor probe consists of a single-mode fiber with a cleaved end which is immersed in the material sample under test. As the n-octadecane changes from solid to liquid or from liquid to solid, its refractive index (RI) changes resulting in changes of the light power ratio reflected by the probe. Since the RI of n-octadecane during its phase transition changes discontinuously, inflection in the reflected light power ratio dependence indicates the phase change of the sample in the vicinity …


Effect Of High- And Low-Molecular-Weight Hyaluronic-Acid-Functionalized-Az31 Mg And Ti Alloys On Proliferation And Differentiation Of Osteoblast Cells, Sankalp Agarwal, Brendan Duffy, James Curtin, Swarna Jaiswal Jan 2018

Effect Of High- And Low-Molecular-Weight Hyaluronic-Acid-Functionalized-Az31 Mg And Ti Alloys On Proliferation And Differentiation Of Osteoblast Cells, Sankalp Agarwal, Brendan Duffy, James Curtin, Swarna Jaiswal

Articles

The quality of patient care has increased dramatically in recent years because of the development of lightweight orthopedic metal implants. The success of these orthopedic implants may be compromised by impaired cytocompatibility and osteointegration. Biomimetic surface engineering of metal implants using biomacromolecules including hyaluronic acid (HA) has been used an effective approach to provide conditions favorable for the growth of bone forming cells. To date, there have been limited studies on osteoblasts functions in response to metal substrates modified with the hyaluronic acid of different molecular weight for orthopedic applications. In this study, we evaluated the osteoblasts functions such as …


Impact Of Plasma Jet Geometry On Residence Times Of Radical Species, James Lalor, Laurence Scally, Patrick J. Cullen, Vladimir Milosavljevic Jan 2018

Impact Of Plasma Jet Geometry On Residence Times Of Radical Species, James Lalor, Laurence Scally, Patrick J. Cullen, Vladimir Milosavljevic

Articles

Numerous electrode geometries and power supplies, both commercial and in-house, have been employed for the generation of low-temperature atmospheric plasma jets. In this work, the development and operation of a 12 jet nonthermal atmospheric plasma system is presented. The study is based on optical spectroscopy as a diagnostic method due to its nonintrusive nature. A key focus of this study was the material selection (conductive and nonconductive), with several polymers screened for the jet design leading to polyacetal as the choice material. Their results are compared with other atmospheric plasma jet systems. The results show a significant increase in residence …


The Different Stages Of Prpd Pattern For Positive Point To Plane Corona Driven By A Dc Voltage Containing A Ripple, Tobias Dezenzo, Thomas Betz, Andreas Schwarzbacher Jan 2018

The Different Stages Of Prpd Pattern For Positive Point To Plane Corona Driven By A Dc Voltage Containing A Ripple, Tobias Dezenzo, Thomas Betz, Andreas Schwarzbacher

Articles

The different phase resolved partial discharge patterns, which can be recognized when a positive dc voltage containing a ripple due to a half-wave rectification is used are presented in this paper. Results are given from corona onset to the appearance of breakdown streamers. The outcomes are five different patterns, which represent the four stages of positive corona and their transition zones. Three of them are clearly identifiable with respect to patterns from other discharge sources that have already been reported for dc voltages containing a ripple. For an assessment of pattern formation discharge pulses as recorded at the test object …


Special Issue On The Use Of Accurate Tissue And Body Models In Rf And Mw Medical Applications, Giuseppe Ruvio, Marta Cavagnaro Jan 2018

Special Issue On The Use Of Accurate Tissue And Body Models In Rf And Mw Medical Applications, Giuseppe Ruvio, Marta Cavagnaro

Articles

No abstract provided.


Quantitative Fine-Grained Human Evaluation Of Machine Translation Systems: A Case Study On English To Croatian, Filip Klubicka, Antonio Toral, Victor Manuel Sanchez-Cartagena Jan 2018

Quantitative Fine-Grained Human Evaluation Of Machine Translation Systems: A Case Study On English To Croatian, Filip Klubicka, Antonio Toral, Victor Manuel Sanchez-Cartagena

Articles

This paper presents a quantitative fine-grained manual evaluation approach to comparing the performance of different machine translation (MT) systems. We build upon the well-established Multidimensional Quality Metrics (MQM) error taxonomy and implement a novel method that assesses whether the differences in performance for MQM error types between different MT systems are statistically significant. We conduct a case study for English-to- Croatian, a language direction that involves translating into a morphologically rich language, for which we compare three MT systems belonging to different paradigms: pure phrase-based, factored phrase-based and neural. First, we design an MQM-compliant error taxonomy tailored to the relevant …


Energy Efficient Hybrid Routing Protocol Based On The Artificial Fish Swarm Algorithm And Ant Colony Optimisation For Wsns, Xinlu Li, Brian Keegan, Fredrick Mtenzi Jan 2018

Energy Efficient Hybrid Routing Protocol Based On The Artificial Fish Swarm Algorithm And Ant Colony Optimisation For Wsns, Xinlu Li, Brian Keegan, Fredrick Mtenzi

Articles

Wireless Sensor Networks (WSNs) are a particular type of distributed self-managed network with limited energy supply and communication ability. The most significant challenge of a routing protocol is the energy consumption and the extension of the network lifetime. Many energy-efficient routing algorithms were inspired by the development of Ant Colony Optimisation (ACO). However, due to the inborn defects, ACO-based routing algorithms have a slow convergence behaviour and are prone to premature, stagnation phenomenon, which hinders further route discovery, especially in a large-scale network. This paper proposes a hybrid routing algorithm by combining the Artificial Fish Swarm Algorithm (AFSA) and ACO …


Design Of Event-Triggered Fault-Tolerant Control For Stochastic Systems With Time-Delays, Yi Gao, Yunji Li, Li Peng, Junyu Liu Jan 2018

Design Of Event-Triggered Fault-Tolerant Control For Stochastic Systems With Time-Delays, Yi Gao, Yunji Li, Li Peng, Junyu Liu

Articles

This paper proposes two novel, event-triggered fault-tolerant control strategies for a class of stochastic systems with state delays. The plant is disturbed by a Gaussian process, actuator faults, and unknown disturbances. First, a special case about fault signals that are coupled to the unknown disturbances is discussed, and then a fault-tolerant strategy is designed based on an event condition on system states. Subsequently, a send-on-delta transmission framework is established to deal with the problem of fault-tolerant control strategy against fault signals separated from the external disturbances. Two criteria are provided to design feedback controllers in order to guarantee that the …


Using Moocs To Promote Digital Accessibility And Universal Design, The Moocap Experience, John Gilligan, W. Chen, J. Darzentas Jan 2018

Using Moocs To Promote Digital Accessibility And Universal Design, The Moocap Experience, John Gilligan, W. Chen, J. Darzentas

Articles

The recently completed Massive Open Online Course for Accessibility Partnership project (MOOCAP), had the twin aims of establishing a strategic partnership around the promotion of Universal Design and Accessibility for ICT professionals and of developing a suite of Open Educational resources (OERs) in this domain. MOOCAP's eight university partners from Germany, Norway, Greece, Ireland, the UK and Austria have a significant history in developing and providing courses in the domains of Universal Design and Accessibility, as well as leading research and advocacy roles within Europe. The MOOCAP project consisted of two phases: the development of an introductory MOOC on Digital …


Experienced Mental Workload, Perception Of Usability, Their Interaction And Impact On Task Performance, Luca Longo Jan 2018

Experienced Mental Workload, Perception Of Usability, Their Interaction And Impact On Task Performance, Luca Longo

Articles

No abstract provided.


Examining The Effects Of A Virtual Character On Learning And Engagement In Serious Games, Vihanga Gamage, Cathy Ennis Jan 2018

Examining The Effects Of A Virtual Character On Learning And Engagement In Serious Games, Vihanga Gamage, Cathy Ennis

Articles

Virtual characters have been employed for many purposes including interacting with players of serious games, with a purpose to increase engagement. These characters are often embodied conversational agents playing diverse roles, such as demonstrators, guides, teachers or interviewers. Recently, much research has been conducted into properties that affect the realism and plausibility of virtual characters, but it is less clear whether the inclusion of interactive agents in serious applications can enhance a user’s engagement with the application, or indeed increase efficacy. In a first step towards answering these questions, we conducted a study where a Virtual Learning Environment was used …


The Efficacy Of Financial Futures As A Hedging Tool In Electricity Markets, Jim Hanly, Lucia Morales, Damien Cassells Jan 2018

The Efficacy Of Financial Futures As A Hedging Tool In Electricity Markets, Jim Hanly, Lucia Morales, Damien Cassells

Articles

Abstract This paper estimates and applies a risk management strategy for electricity spot exposures using futures hedging. We apply our approach to three of the most actively traded European electricity markets, Nordpool, APXUK and Phelix. We compare both optimal hedging strategies and the hedging effectiveness of these markets for two hedging horizons, weekly and monthly using both Variance and Value at Risk (VaR). Our key finding is that electricity futures can effectively manage risk only for specific time periods when using hedging strategies that have been very successful in financial and other commodity markets. More generally they are ineffective as …


Dual-Stub Ka-Band Vivaldi Antenna With Integrated Bandpass Filter, Kansheng Yang, Manh-Ha Hoang, Xiulong Bao, Patrick Mcevoy, Max Ammann Jan 2018

Dual-Stub Ka-Band Vivaldi Antenna With Integrated Bandpass Filter, Kansheng Yang, Manh-Ha Hoang, Xiulong Bao, Patrick Mcevoy, Max Ammann

Articles

A dual-stub coplanar Vivaldi antenna with a parasitic element is presented. The dual-stub is coupled between the parasitic element and two tapered slots. The parasitic element shape and size is optimised. The use of slits on the outer edge of the ground plane is shown to provide control of beamwidth and maximum gain. A bandpass filter is used for performance control and sub-harmonic suppression.


Measurements Of Milli-Newton Surface Tension Forces With Tilted Fiber Bragg Gratings, Changyu Shen, Chuan Zhong, Dejun Liu, Xiokang Lian, Jianyao Zheng, Jingjing Wang, Yuliya Semenova, Gerald Farrell, Jacques Albert, John F. Donegan Jan 2018

Measurements Of Milli-Newton Surface Tension Forces With Tilted Fiber Bragg Gratings, Changyu Shen, Chuan Zhong, Dejun Liu, Xiokang Lian, Jianyao Zheng, Jingjing Wang, Yuliya Semenova, Gerald Farrell, Jacques Albert, John F. Donegan

Articles

Small lateral forces (lower than 0.1 N) cannot normally be measured with conventional single-mode fiber-based sensors because of the high value of their Young modulus (>70 GPa). Here we demonstrate the measurement of lateral forces in the range from 0.2 to 1.4 × 10−3 N with a tilted fiber Bragg grating (TFBG) in conventional single-mode fiber pushed against the surface tension (ST) of a bead of water. The measured transmission changes of individual cladding mode resonances of the TFBG corresponding to these force values are of the order of 29 dB. Separate measurements of the contact angle between the …


Optical Fibre Sensors For Monitoring Phase Transitions In Phase Changing Materials, Rahul Kumar, Wei Han, Dejun Liu, W. P. Ng, Binns, Richard Binns, Richard, Krishna K. Busawon, Yong Qing Fu, Zabih Ghassemlooy, Chris P. Underwood, Khamid Kh Mahkamov, Jinhui Yuan, Chongxiu Yu, Huazhong Shu, Xing Ao Li, Tuan Guo, Gerald Farrell, Yuliya Semenova, Qiang Wu Jan 2018

Optical Fibre Sensors For Monitoring Phase Transitions In Phase Changing Materials, Rahul Kumar, Wei Han, Dejun Liu, W. P. Ng, Binns, Richard Binns, Richard, Krishna K. Busawon, Yong Qing Fu, Zabih Ghassemlooy, Chris P. Underwood, Khamid Kh Mahkamov, Jinhui Yuan, Chongxiu Yu, Huazhong Shu, Xing Ao Li, Tuan Guo, Gerald Farrell, Yuliya Semenova, Qiang Wu

Articles

A platinum coated singlemode-multimode (SM) structure is investigated in this paper as an optical fibre sensor (OFS) to monitor the phase transition of a phase change material (PCM). Paraffin wax has been used as an example to demonstrate the sensor's performance and operation. Most materials have the same temperature but different thermal energy levels during the phase change process, therefore, sole dependency on temperature measurement may lead to an incorrect estimation of the stored energy in PCM. The output spectrum of the reflected light from the OFS is very sensitive to the bend introduced by the PCM where both liquid …


Formation And Development Of Nanometer-Sized Cybotactic Clusters In Bent-Core Nematic Liquid Crystalline Compounds, Yuri Panarin, Sithara P. Sreenilayam, Jagdish K. Vij, Anne Lehmann, Carsten Tschierske Jan 2018

Formation And Development Of Nanometer-Sized Cybotactic Clusters In Bent-Core Nematic Liquid Crystalline Compounds, Yuri Panarin, Sithara P. Sreenilayam, Jagdish K. Vij, Anne Lehmann, Carsten Tschierske

Articles

Two homologue achiral bent-core liquid crystals (LCs), BCN66 and BCN84, in their nematic phases are studied by dielectric spectroscopy in the frequency range 10 Hz–10 MHz. In each of these compounds, two relaxation processes are identified and assigned to (i) collective dynamics of molecules in nanometer-sized cybotactic clusters and (ii) individual molecular relaxations, in the ascending order of frequency of the probe field. The temperature and the bias electric field dependence of the dielectric strength and relaxation frequency for these processes are shown to give rise to sharpness in cluster boundaries, increased size and volume fraction in the LC nematic …


The Role Of The Dendritic Growth Models Dimensionality In Predicting The Columnar To Equiaxed Transition (Cet), M. Seredyński, Marek Rebow, J. Banaszek Jan 2018

The Role Of The Dendritic Growth Models Dimensionality In Predicting The Columnar To Equiaxed Transition (Cet), M. Seredyński, Marek Rebow, J. Banaszek

Articles

The dendrite tip kinetics model accuracy relies on the reliability of the stability constant used, which is usually experimentally determined for 3D situations and applied to 2D models. The paper reports authors` attempts to cure the situation by deriving 2D dendritic tip scaling parameter for aluminium-based alloy: Al-4wt%Cu. The obtained parameter is then incorporated into the KGT dendritic growth model in order to compare it with the original 3D KGT counterpart and to derive two-dimensional and three-dimensional versions of the modified Hunt’s analytical model for the columnar-to-equiaxed transition (CET). The conclusions drawn from the above analysis are further confirmed through …


An Lcl-Filter Design With Optimum Total Inductance And Capacitance, Sampath Jayalath, Mohamed Moin Hanif Jan 2018

An Lcl-Filter Design With Optimum Total Inductance And Capacitance, Sampath Jayalath, Mohamed Moin Hanif

Articles

LCL-filter is among the best performing filters for grid-connected voltage source inverters. Designing of the filter parameters (grid-side and inverter-side inductors and capacitor), takes an iterative approach due to the coherence between the parameters and design requirements such as IEEE-519 Std for harmonic current limitations, reactive power compensation limit, and maximum allowable voltage drop across the filter to limit the switching losses. Most of the proposed LCL-filter optimization strategies emphasize on reducing the total inductance and losses of the filter while meeting the design requirements. There is less emphasis given on the capacitor selection and optimizing its value. Therefore, this …


Absorption Coefficient Dependent Non-Linear Properties Of Thin Film Luminescent Solar Concentrators, S. Chandra, M. Rafiee, John Doran, S. J. Mccormack Jan 2018

Absorption Coefficient Dependent Non-Linear Properties Of Thin Film Luminescent Solar Concentrators, S. Chandra, M. Rafiee, John Doran, S. J. Mccormack

Articles

This research article studied absorption coefficient dependent losses and efficiency of thin film luminescent solar concentrator (LSC). The optimum absorption coefficient was determined by fabricating red dye doped thin film LSCs with varying absorption coefficients of 24–202 cm-1. The optical, electrical, and ray-trace model predicted results were compared to establish the optimum absorption coefficient for fabricated thin film LSCs. The optical and electrical efficiencies of thin film LSCs are a function of absorption coefficient; follow linearly at lower values, gradually becoming non- linear at higher values of absorption coefficient which restricts the overall efficiency. The multi layered ray–trace model predicted …


Nanostructured Apatite-Mullite Glass-Ceramics For Enhanced Primary Human Osteoblast Cell Response, Gordon Cooke, Conor Dunne, Sarah Keane, Daithi De Faoite, Seamas Donnelly, Kenneth Stanton Dec 2017

Nanostructured Apatite-Mullite Glass-Ceramics For Enhanced Primary Human Osteoblast Cell Response, Gordon Cooke, Conor Dunne, Sarah Keane, Daithi De Faoite, Seamas Donnelly, Kenneth Stanton

Articles

This work investigates the difference in viability of primary human foetal osteoblast cells on a glass-ceramic surface with nanoscale topography relative to viability on a smooth glass-ceramic surface containing a bioactive phase. Apatite-mullite glass-ceramics containing bioactive fluorapatite (Ca10(PO4)6F2) and bioinert mullite (Si2Al6O13) were synthesised and subsequent heat-treatment was optimised to form nano-sized fluorapatite crystals. Etching was used to selectively remove the bioactive phase, producing a surface with disordered nanoscale topography. Cells were seeded onto a smooth polished glass-ceramic substrate with the bioactive phase intact, an etched …