Digital Commons Network^™

Reformulating The Binary Masking Approach Of Adress As Soft Masking, Ruairí De Fréin

Articles

Binary masking forms the basis for a number of source separation approaches that havebeen successfully applied to the problem of de-mixing music sources from a stereo recording.A well-known problem with binary masking is that, when music sources overlap in the time-frequencydomain, only one of the overlapping sources can be assigned the energy in a particulartime-frequency bin. To overcome this problem, we reformulate the classical pan-pot source separationproblem for music sources as a non-negative quadratic program. This reformulation gives rise toan algorithm, called Redress, which extends the popular Adress algorithm. It works by definingan azimuth trajectory for each source based on …

Optimal Sizing Of Energy Storage With Embedded Wind Power Generation, Nicholas Roche, Jane Courtney

Articles

Energy storage technologies are key to increased penetration of renewable energies on the distribution system. Not only do they increase availability of energy, but they contribute to the overall reliability of the system. However, the cost of large-scale storage systems can often be prohibitive, and storage needs to be sized appropriately, both to fill the energy gaps inevitable in renewable energies such as wind and to minimize costs. In this work, a Monte Carlo Simulation is performed to optimally size an energy storage system while minimizing overall system cost. 30 years of historical wind speed data are used to model …

Impact Assessment Of High-Power Domestic Ev Charging Proliferation Of A Distribution Network, Arsalan Zaidi, Keith Sunderland, Michael Conlon

Articles

Transport electrification is becoming the mainstream as a means to improve efficiency, performance, andsustainability of transportation systems. Electrical vehicles (EVs) can help to de-carbonise the environment, but a downside isthe technical issues presented to the low-voltage distribution network. To quantify the stochastic nature of transport-affectedelectrification, probabilistic load flow is employed. Monte Carlo-based simulation is applied to accommodate the probabilisticuncertainties associated with variable EV charging patterns. This study considers high-power charging (up to 11 kW) at thedomestic level while monitoring power quality variations (voltage drop, voltage unbalance factor, voltage sag) standards. Thiswork focuses on the Irish and UK, distribution system operator's–transmission …

A Conceptual Model To Explain Dark Matter And Dark Energy, Jonathan Blackledge

Articles

t This paper considers a conceptual model that attempts to explain ‘Dark Matter’ and ‘Dark Energy’. The model is based on considering a gravitational field to be the result of a mass (a Higgs field) scattering pre-existing cosmic background space-time waves or ‘Uber-waves’. The term ‘Uber’ is used to denote an outstanding or supreme example of a particular kind of gravitational wave with cosmic-scale wavelengths that are far in excess of those associated with the gravitational waves generated by accelerating masses. Such waves are taken to be the very lowest frequency components associated with the spectrum of space-time waves generated …

A Wide Frequency Scanning Printed Bruce Array Antenna With Bowtie And Semi-Circular Elements, Zeeshan Ahmed, Patrick Mcevoy, Max Ammann

Articles

A printed edge-fed counterpart of the wire Bruce array antenna, for frequency scanning applications, is presented in this paper. The unit-cell of the proposed antenna consists of bowtie and semi-circular elements to achieve wide bandwidth from below 22 GHz to above 38 GHz with open-stopband suppression. The open-stopband suppression enables a wide seamless scanning range from backward, through broadside, to forward endfire. A sidelobe threshold level of −10 dB is maintained to evaluate efficient scanning performance of the antenna. The antenna peak realized gain is 15.30 dBi, and, due to its compact size, has the ability to scan from −64° …

Anti-Resonance, Inhibited Coupling And Mode Transitionin Depressed Core Fibers, Xiaokang Lian, Gerald Farrell, Qiang Wu, Wei Han, Changyu Shen, Youqiao Ma, Yuliya Semenova

Articles

The depressed core fiber (DCF), consisting of a low-index solid core, a high-index cladding and air surrounding, is in effect a bridge between the conventional step-index fiber and the tube-type hollow-core fiber from the point of view of the index profile. In this paper the dispersion diagram of a DCF is obtained by solving the full-vector eigenvalue equations and analyzed using the theory of anti-resonant and the inhibited coupling mechanisms. While light propagation in tube-type hollow-core fibers is commonly described by the symmetric planar waveguide model, here we propose an asymmetric planar waveguide for the DCFs in an anti-resonant reflecting …

Investigation On The Polarization Dependence Of An Angled Polished Multimode Fibre Structure, Ruoning Wang, Ke Tian, Meng Zhang, Yuxuan Jiang, Libo Yuan, Guoyong Jin, Gerald Farrell, Elfed Lewis, Pengfei Wang

Articles

An angled polished multimode (APM) fibre structure is described for the first time, to the best our knowledge, and its polarization dependence is investigated theoretically and experimentally. Two angled planes are established in the multimode fibre (MMF) section of a single-mode-multimode-single-mode (SMS) fibre structure using the fibre side-polishing technique, forming the APM fibre structure. This designed circular asymmetric geometry induces different propagation characteristics for the TE and TM modes within the MMF. Simulated and experimental results both show that this difference is enhanced as the polishing angle increases, and a maximum extinction ratio (ER) of the spectrum of 13 dB …

Spectral Dependence Of Transmission Losses In High-Index Polymer Coated No-Core Fibers, Xiaokang Lian, Gerald Farrell, Qiang Wu, Wei Han, Changyu Shen, Youqiao Ma, Yuliya Semenova

Articles

A high-index polymer coated no-core fiber (PC-NCF) is effectively a depressed core fiber, where the light is guided by the anti-resonant, inhibited coupling and total internal reflection effects and the dispersion diagram shows periodic resonant and anti-resonant bands. In this paper, the transmission spectra of the straight and bent PC-NCFs (length > 5 cm) are measured and analyzed from a modal dispersion perspective. For the purpose of the study, the PC-NCFs are contained within a fiber hetero-structure using two single-mode fiber (SMF) pigtails forming a SMF-PC-NCF-SMF structure. The anti-resonance spectral characteristics are suppressed by the multimode interference in the PC-NCF with …

Application Of Demand Response To Improve Voltage Regulation With High Dg Penetration, Chittesh Veni Chandran, Malabika Basu, Keith Sunderland, Shivananda Pukhrem, João Catalão

Articles

The ability of a consumer friendly demand response based voltage control (DR-VC) program to improve the voltage regulation in a low voltage distribution network (LVDN) with high penetration of DG is investigated. The use of active and reactive power management to regulate the nodal voltage in a distribution network with simple incremental reduction algorithm, in conjunction with DR, is proposed as a solution for over voltage and undervoltage issues in the LVDN. The algorithm micromanages the load and generation in the network enabling the operator to utilize grid resources economically and efficiently while maintaining fairness between consumers with minimum inconvenience. …

Indirect Sliding Mode Control For Dc-Dc Sepic Converters, Hasan Komurcugil, Samet Biricik, Naki Guler

Articles

This article presents an indirect sliding mode control (SMC) for single-ended primary-inductor converters (SEPIC). Unlike the conventional SMC methods, the proposed SMC method employs a sliding surface function based on the input current error only. The use of such sliding surface function not only simplifies the implementation but also reduces the cost of implementation. It is shown that the output voltage control can be achieved indirectly. The input current reference is generated by a proportional-integral (PI) regulator. The existence condition and the region of the closed-loop system are determined for all possibilities of the PI gains. The performance of the …

Carbon-Based Interlayers In Perovskite Solar Cells, Aleksandr P. Litvin, Xiaoyu Zhang, Kevin Berwick, Anatoly V. Fedorov, Weitao Zheng, Alexander V. Baranov

Articles

Perovskites are solution-processed, high-performance semiconductors of interest in low-cost photovoltaics. The interfaces between the perovskite photoactive layers and the top and bottom contacts are crucial for efficient charge transport and minimizing trapping. Control of the collection of charge carriers at these interfaces is decisive to device performance. Here, we review recent progress in the realization of efficient perovskite solar cells using cheap, easily processed, stable, carbon-based interlayers. Interface materials including graphene, carbon nanotubes, fullerenes, graphene quantum dots and carbon dots are introduced and their influence on device performance is discussed.

Impact Of Cold Plasma Processing On Major Peanut Allergens, Harshitha Venkataratnam, Orla Cahill, Chaitanya Sarangapani, Patrick J. Cullen, Catherine Barry-Ryan

Articles

Cold plasma is emerging as a novel food processing technology, with demonstrated efficacies for microbial inactivation and residual chemical dissipation of food products. Given the technology’s multimodal action it has the potential to reduce allergens in foods, however data on the efficacy and mechanisms of action are sparse. This study investigates the efficacy of cold plasma on major peanut allergens (Ara h 1 and Ara h 2). For this purpose, dry, whole peanut (WP) and defatted peanut flour (DPF) were subjected to an atmospheric air discharge using a pin to plate cold plasma reactor for different treatment durations. With increases …

Pre-Clinical Models Of Small Cell Lung Cancer And The Validation Of Therapeutic Targets, Jane S.Y. Sui, Petra Martin, Steven Gray

Articles

Introduction: Small-cell lung cancer (SCLC) is an aggressive form of lung cancer that has a dismal prognosis. One of the factors hindering therapeutic developments for SCLC is that most SCLC is not surgically resected resulting in a paucity of material for analysis. To address this, significant efforts have been made by investigators to develop pre-clinical models of SCLC allowing for downstream target identification in this difficult to treat cancer.

Areas covered: In this review, we describe the current pre-clinical models that have been developed to interrogate SCLC, and outline the benefits and limitations associated with each. Using examples …

Microfluidics In Haemostasis: A Review, Heta Jigar Panchal, Nigel Kent, Andrew Knox, Leanne Harris

Articles

Haemostatic disorders are both complex and costly in relation to both their treatment and subsequent management. As leading causes of mortality worldwide, there is an ever-increasing drive to improve the diagnosis and prevention of haemostatic disorders. The field of microfluidic and Lab on a Chip (LOC) technologies is rapidly advancing and the important role of miniaturised diagnostics is becoming more evident in the healthcare system, with particular importance in near patient testing (NPT) and point of care (POC) settings. Microfluidic technologies present innovative solutions to diagnostic and clinical challenges which have the knock-on effect of improving health care and quality …

Silicon Microcantilever Sensors To Detect The Reversible Conformational Change Of A Molecular Switch, Spiropyan, Catherine M. Grogan, George Amarandei, Shauna Lawless, Francis Pedreschi, Fiona Lyng, Fernando Benito-Lopez, Roberto Raiteri, Laisa Florea

Articles

The high sensitivity of silicon microcantilever sensors has expanded their use in areas ranging from gas sensing to bio-medical applications. Photochromic molecules also represent promising candidates for a large variety of sensing applications. In this work, the operating principles of these two sensing methods are combined in order to detect the reversible conformational change of a molecular switch, spiropyran. Thus, arrays of silicon microcantilever sensors were functionalized with spiropyran on the gold covered side and used as test microcantilevers. The microcantilever deflection response was observed, in five sequential cycles, as the transition from the spiropyran (SP) (CLOSED) to the merocyanine …

Towards A Rapid Screening Of Liver Grafts At The Operating Room Using Mid-Infrared Spectroscopy, David Perezguaita, Marta Moreno Torres, Ramiro Jover, Eugenia Pareja, Bernard Lendl, Julia Kuligowsky, Guillermo Quintas

Articles

The estimation of steatosis in a liver graft is mandatory prior to liver transplantation, as the risk of graft failure increases with the level of infiltrated fat. However, the assessment of liver steatosis before transplantation is typically based on a qualitative or semiquantitative characterization by visual inspection and palpation and histological analysis. Thus, there is an unmet need for transplantation surgeons to have access to a diagnostic tool enabling an in situ fast classification of grafts prior to extraction. In this study, we have assessed an attenuated total reflection−Fourier transform infrared (ATR−FTIR) spectroscopic method compatible with the requirements of an …

In-Situ Ellipsometric Study Of The Optical Properties Of Ltl-Doped Thin Film Sensors For Copper(Ii) Ion Detection, Dervil Cody, Tsvetanka Babeva, Violeta Madjarova, Anastasia Kharchenko, Sabad-E- Gul, Svetlana Mintova, Christopher J. Barrett, Izabela Naydenova

Articles

Optical sensors fabricated in zeolite nanoparticle composite films rely on changes in their optical properties (refractive index, n, and thickness, d) to produce a measurable response in the presence of a target analyte. Here, ellipsometry is used to characterize the changes in optical properties of Linde Type L (LTL) zeolite thin films in the presence of Cu2+ ions in solution, with a
/="/">view to improving the design of optical sensors that involve the change of n and/or d due to the adsorption of Cu2+ ions. The suitability of two different ellipsometry techniques (single wavelength and spectroscopic) for the evaluation …

Classification And Biological Identity Of Complex Nano Shapes, Luca Boselli, Hender Lopez, Wei Zhang, Qi Cai, Valeria A. Giannone, Jingji Li, Alirio Moura, João M. De Araujo, Jennifer Cookman, Valentina Castagnola, Yan Yan, Kenneth A. Dawson

Articles

Everywhere in our surroundings we increasingly come in contact with nanostructures that have distinctive complex shape features on a scale comparable to the particle itself. Such shape ensembles can be made by modern nano-synthetic methods and many industrial processes. With the ever growing universe of nanoscale shapes, names such as “nanoflowers” and “nanostars” no longer precisely describe or characterise the distinct nature of the particles. Here we capture and digitise particle shape information on the relevant size scale and create a condensed representation in which the essential shape features can be captured, recognized and correlated. We find the natural emergence …

Dual Contrast In Computed Tomography Allows Earlier Characterization Of Articular Cartilage Over Single Contrast, Abhisek Bhattarai, Behdad Pouran, Janne T.A. Mäkelä, Rubina Shaikh, Miitu K.M. Honkanen, Mithilesh Prakash, Heikki Kröger, Mark W. Grinstaff, Harrie Weinans, Jukka S. Jurvelin, Juha Töyräs

Articles

Cationic computed tomography contrast agents are more sensitive for detecting cartilage degeneration than anionic or non-ionic agents. However, osteoarthritis-related loss of proteoglycans and increase in water content contrarily affect the diffusion of cationic contrast agents, limiting their sensitivity. The quantitative dual-energy computed tomography technique allows the simultaneous determination of the partitions of iodine-based cationic (CA4+) and gadolinium-based non-ionic (gadoteridol) agents in cartilage at diffusion equilibrium. Normalizing the cationic agent partition at diffusion equilibrium with that of the non-ionic agent improves diagnostic sensitivity. We hypothesize that this sensitivity improvement is also prominent during early diffusion time points and that the technique …

Synchrotron Microct Reveals The Potential Of The Dual Contrast Technique For Quantitative Assessment Of Human Articular Cartilage Composition, Miitu K.M. Honkanen, Annina E.A. Saukko, Mikael J. Turunen, Rubina Shaikh, Mithilesh Prakash, Goran Lovric, Antti Joukainen, Heikki Kröger, Mark W. Grinstaff, Juha Töyräs

Articles

Dual contrast micro computed tomography (CT) shows potential for detecting articular cartilage degeneration. However, the performance of conventional CT systems is limited by beam hardening, low image resolution (full-body CT), and long acquisition times (conventional microCT). Therefore, to reveal the full potential of the dual contrast technique for imaging cartilage composition we employ the technique using synchrotron microCT. We hypothesize that the above-mentioned limitations are overcome with synchrotron microCT utilizing monochromatic X-ray beam and fast image acquisition. Human osteochondral samples (n = 41, four cadavers) were immersed in a contrast agent solution containing two agents (cationic CA4+ and non-ionic gadoteridol) …

The Missing Parameter In Renewable Energy Power Quality Analysis, I.E. The Coefficient Of Variation: Case Study Of A 3-Mw On-Site Wind Turbine Project In Ireland, Tony Kealy

Articles

Businesses are employing distributed generation techniques, such as wind turbines, to decarbonise their electrical energy supply by reducing their dependence on fossil-fuel-generated energy. This study investigates the effectiveness of a company making a €3,500,000 investment in a 3-MW on-site wind turbine to supply some or all of their factory electrical loads. The results should benefit the investing company and other potential investors by evaluating the economic, environmental, and social outcomes of the investment. A case study methodology was used. The study found that the payback period was six and a half years, and the turbine installation benefited the environment by …

The Viability Of Organic Dyes In Luminescent Down-Shifting Layers For The Enhancement Of Si Solar Cell Efficiency, Aaron Glenn, Conor Mcloughlin, Hind Ahmed, Hoda Akbari, Subhash Chandra, Sarah Mccormack

Articles

The main energy losses in solar cells are related to spectral losses where high energy photons are not used efficiently, and energy is lost via thermalization which reduces the solar cell’s overall efficiency. A way to tackle this is to introduce a luminescent down-shifting layer (LDS) to convert these high energy photons into a lower energy bracket helping the solar cell to absorb them and thus generating a greater power output. In this paper, lumogen dye Violet 570 has been used as LDS coated films of 10μm and 60μm placed on top of Si solar cells. The dye was incorporated …

Investigation Of The Chemical Composition Of Plasma-Treated Water By Midiplexc And Its Antimicrobial Effect On L. Monocytogenes And Pseudomonas Fluorescens Monospecies Suspension Cultures, Oliver Handorf, Harald Below, Uta Schnabel, Katharina Riedel

Articles

Plasma -generated compounds conceived by microwave -induced plasma (MidiPLexc) were physicochemically investigated in their molecular compositions. Therefore, plasma -treated water (PTW) was generated by treatment with the MidiPLexc within a 1 l glass bottle for a pre -treatment time of 100 s, 300 s and 900 s. The PTW was further investigated in its composition of reactive oxygen/nitrogen species. For this purpose, the hydrogen peroxide (H2O2) concentration of the PTW was determined electrochemically using chronoamperometry, and the anionic components were determined using ion chromatography. As a result, H2O2 concentrations of up to 720 mg l−1 , nitrite concentrations of 1600 …

Risk Communication Approaches For Preventing Private Groundwater Contamination In The Republic Of Ireland: A Mixed-Methods Study Of Multidisciplinary Expert Opinion, S. Mooney, J. O'Dwyer, Paul Hynds

Articles

The mechanisms of private-well groundwater contamination are uniquely complex, necessitating a multisector communicative approach to risk management, premised on behaviour promotion. In countries such as the Republic of Ireland (ROI), characterised by oftentimes high groundwater contamination risk and concurrently limited user awareness, incorporation of multidisciplinary, ‘expert-based’ knowledge may facilitate design of evidence-based, practical interventions. Expert interviews represent an efficient form of expert consultation, enabling ease of access to niche information and comparison of procedure, but remain under-utilised within the groundwater management literature. In response, the current study elicited opinion from 50 experts across four broad categories (communications, engineering/science, policy, and …

Fabrication Of Dielectric Elastomers With Improved Electromechanical Properties Using Silicone Rubber And Walnut Polyphenols Modified Dielectric Particles, Liang Jiang, Yuhao Wang, Shipeng Wen, Yanfen Zhou, Qingdao University, Stephen Jerrams

Articles

In this work, polyphenolic extract from walnut green husks (denoted as walnut polyphenols), which is an abun-dant agroindustrial residue/waste, was used to modify barium titanate (BT) particles in the preparation of sili-cone rubber (SR) based dielectric elastomer (DE) composites with enhanced electromechanical performance.By employing walnut polyphenols modification, the dispersibility of BT particles in the SR matrix and the com-patibility between BT and SR were greatly improved, which resulted in enhanced mechanical performance ofthe DE composites. Dielectric property measurement showed that DE composites containing walnut polyphenolsmodified BT particles (WNBT) had higher dielectric constants and lower dielectric losses than that of DEs …

Enhanced Fatigue And Durability Of Carbon Black/Natural Rubber Composites Reinforced With Graphene Oxide And Carbon Nanotubes, Hao Guo, Stephen Jerrams, Zongchao Xu, Yanfen Shou, Liang Jiang, Liqun Zhang, Li Liu, Shipeng Wen

Articles

Graphene oxide (GO) sheets and carbon nanotubes (CNTs) are of nanometer size and offer large shape factors which are beneficial in reducing crack propagation rates of composites when used in carbon black (CB) reinforced natural rubber (NR), thereby prolonging the service lives of rubber composites. In this research, CNT-CB/NR and GO-CB/NR composites were prepared by partially replacing CB with one-dimensional CNTs and two-dimensional flaky graphene oxide GO, respectively. The results showed that the complex filler dispersion in NR matrices was improved due to the isolation effect between the different fillers. The strain-induced crystallization (SIC) ability of CB/NR was effectively enhanced …

The Fabrication And Properties Of Magnetorheological Elastomers Employing Bio-Inspired Dopamine Modified Carbonyl Iron Particles, Yanfen Zhou, Lele Li, Wenyue Li, Shipeng Wen, Liang Jiang, Stephen Jerrams, Jianwei Ma, Shaojuan Chen

Articles

To obtain magnetorheological elastomers (MREs) with improved mechanical properties and exhibiting an enhanced magnetorheological (MR) effect, bio-inspired dopamine modification has been used to improve the functionality at the surface of carbonyl iron (CI) particles. Various techniques including x-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to confirm that a polydopamine (PDA) layer of about 27.5 nm had been successfully deposited on the surface of the carbonyl iron particles prior to their inclusion in the MRE composites. The magnetic properties of PDA modified CI particles were shown to be almost the same as those …

Enhanced Covalent Interface, Crosslinked Network And Gas Barrier Property Of Functionalized Graphene Oxide/Styrene-Butadiene Rubber Composites Triggered By Thiol-Ene Click Reaction, Long Zheng, Stephen Jerrams, Tian Su, Zongchao Xu, Liqun Zhang, Li Liu, Shipeng Wen

Articles

The high gas barrier property of a rubber composite is of great significance for reducing the exhaust gas emissions due to tire rolling resistance and hence the contribution this factor makes to environmental protection. Enhanced covalent interfaces and crosslinked networks are crucial to the gas barrier property of rubber composites. In this research, γ-mercaptopropyltriethoxysilane (MPS) modified GO (MGO)/styrene-butadiene rubber (SBR) composites were prepared by a synergetic strategy of latex compounding method and thiol-ene click reaction. It was found that the mercapto groups in MGO reacted with the vinyl groups in SBR molecules through thiol-ene click reaction during the crosslinking process …

Stacked Volume Holographic Gratings For Extending The Operational Wavelength Range In Led And Solar Applications, Sanjay Keshri, Julia Marín-Sáez, Izabela Naydenova, Kevin Murphy, Jesús Atencia, Daniel Chemisana, Sean Garner, María-Victoria Collados, Suzanne Martin

Articles

A novel stacking procedure is presented for volume phase holographic gratings (VPHGs) recorded in photopolymer material using Corning Willow Glass as a flexible substrate in order to achieve broader angular and spectral selectivity in a diffractive device with high efficiency for solar and LED applications. For the first time to our knowledge, we have shown a device designed for use with a white LED that has the same input and output angles and high efficiency when illuminated by different wavelengths. In this paper, two VPHGs were designed, experimentally recorded, and tested when illuminated at normal incidence. The experimental approach is …

Stakeholder Engagement And The Future Of Irish Public–Private Partnerships, Gail Sheppard, Matthias Beck

Articles

Building on recent works that stress the importance of stakeholder engagement in partnerships, we propose a novel benchmarking framework for the evaluation of public–private partnerships. This framework describes mutuality and the preservation of organisational identity as the ideal characteristics of partnerships because they, in turn, encourage stakeholder support for public–private partnerships. Applying this framework to infrastructure public–private partnerships in Ireland, we note that mutual accountability has been weakened following the financial crisis. Meanwhile, con-sultation with clients such as key public–private partnership stakeholders, which would help articulate organisational identities, remains patchy across the education, justice
and health public–private partnership that we …