Digital Commons Network^™

Geospatial Drivers Of The Groundwater Δ18o Isoscape In A Temperate Maritime Climate (Republic Of Ireland), S. Regan, R. Goodhue, O. Naughton, Paul Hynds

Articles

In recent years, the concept of “isoscapes” has been used to describe spatiotemporal stable isotope distributions within natural environments including groundwater systems at multiple scales. This study presents an updated groundwater δ18O isoscape for the Republic of Ireland and describes the climatic and geological drivers influencing 18O composition. In all, 142 geographically and geologically representative groundwater installations were sampled and analysed, in addition to 35 samples from six nested boreholes. Geospatially, Irish groundwater exhibits high δ18O values in southern and western coastal regions, becoming progressively depleted inland before reaching lowest measured values along the eastern coast, equating to a national …

Stochastic Modelling For Levy Distributed Systems, Jonathan Blackledge, T Raja Rani

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The purpose of this paper is to examine a range of results that can be derived from Einstein’s evolution equation focusing on (but not in an exclusive sense) the effect of introducing a L´evy distribution. In this context, we examine the derivation (as derived from the Einstein’s evolution equation) of the classical and fractional diffusion equations, the classical and generalised Kolmogorov-Feller equations, the evolution of self-affine stochastic fields through the fractional diffusion equation and the fractional Schr¨odinger equation, the fractional Poisson equation (for the time independent case), and, a derivation of the Lyapunov exponent. In this way, we provide a …

Humidity And Temperature Induced Changes In The Diffraction Efficiency And The Bragg Angle Of Slanted Photopolymer-Based Holographic Gratings, Tatsiana Mikulchyk, James Walshe, Dervil Cody, Suzanne Martin, Izabela Naydenova

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This work explores the humidity and temperature response of volume phase slanted gratings recorded in photopolymers with varied chemical composition. Acrylamide and diacetone acrylamide were used as monomers and triethanolamine and N-phenylglycine were used as photoinitiators. The study demonstrates that the response of photopolymer-based holographic gratings to relative humidity (RH) and temperature (T) can be tuned by alteration of the photopolymer composition.Humidity and temperature response of the holograms has been characterized by recording Bragg selectivity curves of transmission gratings and by monitoring the position of the maximum intensity in the spectral response of reflection gratings. Investigation of the humidity response …

Plasmonic Luminescent Down Shifting Layers For The Enhancement Of Cdte Mini-Modules Performance, Hind Ahmed, S.J. Mccormack, John Doran

Articles

In this investigation, plasmonic coupling between luminescent species (lumogen yellow, and silver nanoparticles (Ag NPs) has been exploited to produce significant enhancement in absorption and fluorescence emission of lumogen yellow dye luminescent downshifting (LDS) layers. The optimum dye concentration in a poly(methyl,methacrylate) polymer LDS layer of ∼100μm thickness was established. Subsequently, plasmonic coupling with Ag NPs was introduced and optimum concentration has been determined for the composite plasmonic Luminescent Down-Shifting (pLDS) layers. The optimum plasmonic coupling has been observed to produce fluorescence emission enhancement of up to 81% for the dye-pLDS layers. The pLDS layers were deposited on top of …

Barriers To Glaucoma Case Finding As Perceived By Optometrists In Ireland, Catriona Barrett, Colm O'Brien, John Butler, James Loughman

Articles

Background: This research was designed to provide an in-depth exploration of the perceptions of optometrists relating to the challenges of glaucoma case finding in the Irish health-care system.

Methods: A survey was developed, piloted and distributed for anonymous completion by optometrists registered to practice in Ireland. The survey included 10 five-level Likert items exploring potential barriers to glaucoma detection and a free-text box for participants to comment more broadly.

Results: One hundred and ninety-nine optometrists (27 per cent of registrants) responded to the survey. Among the barriers identified, there was notable agreement (71 per cent) with the need for extra …

Perceived Barriers Of Optometrists To Glaucoma Case Findings In Ireland, James Loughman, Catriona Barrett, Colm O’Brien, John S. Butler

Articles

Background:

This research was designed to provide an in-depth exploration of the perceptions of optometrists relating to the challenges of glaucoma case finding in the Irish health-care system.

Methods: A survey was developed, piloted and distributed for anonymous completion by optometrists registered to practise in Ireland. The survey included 10 five-level Likert items exploring potential barriers to glaucoma detection and a free-text box for participants to comment more broadly.

Results: One hundred and ninety-nine optometrists (27 per cent of registrants) responded to the survey. Among the barriers identified, there was notable agreement (71 per cent) with the need for extra …

Optimization Of Atmospheric Air Plasma For Degradation Of Organic Dyes In Wastewater, Chaitanya Sarangapani, Yash Dixit, Vladimir Milosavljevic, Carl Sullivan, Paula Bourke, Patrick J. Cullen

Articles

This study optimises the degradation of a cocktail of the dyes methyl orange and bromothymol blue by atmospheric air plasma. Response surface methodology (RSM) was employed to investigate the efficacy of the plasma process parameters on degradation efficiency. A Box–Behnken design (BBD) was employed to optimise the degradation of dyes by air plasma discharge. A second order polynomial equation was proposed to predict process efficiency. It was observed that the predicted values are significant (p < 0.001) with coefficients of determination 0.98, 0.96, 0.98 for dye degradation, pH value and ozone concentration, respectively. The analysis of variance results showed …

Laser Induced Breakdown Spectroscopy For Quantification Of Sodium And Potassium In Minced Beef: A Potential Technique For Detecting Beef Kidney Adulteration, Y. Dixit, Maria Piedad Casado-Gavalda, R. Cama-Moncunill, Xavier Cama-Moncunill, Maria Markiewicz-Keszycka, Patrick J. Cullen, Carl Sullivan

Articles

Beef is a rich source of important minerals, with potassium (K) being the most abundant mineral quantitatively except in cured meats where sodium (Na) from the added salt predominates. This study evaluates the capability of LIBS for quantification of the Na and K contents of minced beef as a potential method of detecting beef kidney adulteration. Additionally, the study aims to demonstrate the ability of LIBS to provide spatial mineral information of minced beef. A LIBS system was employed to collect spectral information of adulterated minced beef samples. Atomic absorption spectroscopy (AAS) was used to obtain reference values for Na …

Challenges In Model Development For Meat Composition Using Multipoint Nir Spectroscopy From At‐Line To In‐Line Monitoring, Yash Dixit, Maria Piedad Casado-Gavalda, R. Cama-Moncunill, Patrick J. Cullen, Carl Sullivan

Articles

This study evaluates the efficiency of multipoint near‐infrared spectroscopy (NIRS) to predict the fat and moisture content of minced beef samples both in at‐line and on‐line modes. Additionally, it aims at identifying the obstacles that can be encountered in the path of performing in‐line monitoring. Near‐infrared (NIR) reflectance spectra of minced beef samples were collected using an NIR spectrophotometer, employing a Fabry‐Perot interferometer. Partial least squares regression (PLSR) models based on reference values from proximate analysis yielded calibration coefficients of determination of 0.96 for both fat and moisture. For an independent batch of samples, fat was estimated with a prediction …

A Rational Design Of A Selective Inhibitor For Kv1.1 Channels Prevalent In Demyelinated Nerves That Improves Their Impaired Axonal Conduction, Ahmed Al-Sabi, Declan Daly, Patrick Hoefer, Gemma K. Kinsella, Charles Metais, Mark Pickering, Caroline Herron, Seshu Kumar Kaza, Kieran Nolan, J. Oliver Dolly

Articles

K+ channels containing Kv1.1 α subunits, which become prevalent at internodes in demyelinated axons, may underlie their dysfunctional conduction akin to muscle weakness in multiple sclerosis. Small inhibitors were sought with selectivity for the culpable hyper-polarizing K+ currents. Modeling of interactions with the extracellular pore in a Kv1.1-deduced structure identified diaryldi(2-pyrrolyl)methane as a suitable scaffold with optimized alkyl ammonium side chains. The resultant synthesized candidate [2,2′-((5,5′(di-p-topyldiaryldi(2-pyrrolyl)methane)bis(2,2′carbonyl)bis(azanediyl)) diethaneamine·2HCl] (8) selectively blocked Kv1.1 channels (IC50 ≈ 15 μM) recombinantly expressed in mammalian cells, induced a positive shift in the voltage dependency of K+ current activation, and slowed its kinetics. It …

Quantification Of Trace Metals In Infant Formula Premixes Using Laser-Induced Breakdown Spectroscopy, Raquel Cama-Moncunill, Maria Piedad Casado-Gavalda, Xavier Cama-Moncunill, Maria Markiewicz-Keszycka, Yash Dixit, Patrick J. Cullen, Carl Sullivan

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Infant formula is a human milk substitute generally based upon fortified cow milk components. In order to mimic the composition of breast milk, trace elements such as copper, iron and zinc are usually added in a single operation using a premix. The correct addition of premixes must be verified to ensure that the target levels in infant formulae are achieved. In this study, a laser-induced breakdown spectroscopy (LIBS) system was assessed as a fast validation tool for trace element premixes. LIBS is a promising emission spectroscopic technique for elemental analysis, which offers real-time analyses, little to no sample preparation and …

Feasibility Of Laser-Induced Breakdown Spectroscopy (Libs) As An At-Line Validation Tool For Calcium Determination In Infant Formula, Xavier Cama-Moncunill, Maria Markiewicz-Keszycka, Yash Dixit, Raquel Cama-Moncunill, Maria Piedad Casado-Gavalda, Patrick J. Cullen, Carl Sullivan

Articles

In this study, a 150 mJ laser-induced breakdown spectroscopy (LIBS) system was assessed to determine calcium content in infant formula (IF) samples. LIBS is a promising emission spectroscopic technique for elemental analysis, which offers advantages over conventional methods such as real-time analyses, little to no sample preparation and ease of use. The aim of this work was to evaluate the feasibility of LIBS as an at-line tool for IF manufacturing. To this end, IF mixtures with varying content of calcium were prepared over a range (approx. 1.5–7 mg/g of calcium) selected to be in conformity with the guidelines provided by …

Evaluation Of Chemical Immersion Treatments To Reduce Microbial Populations In Fresh Beef, Ahmed Kassem, Joseph Meade, James Gibbons, Kevina Mcgill, Ciara Walsh, James Lyng, Paul Whyte

Articles

The aim of the current study was to assess the ability of a number of chemicals (acetic Acid (AA), citric acid (CA) lactic acid (LA), sodium decanoate (SD) and trisodium phosphate (TSP)) to reduce microbial populations (total viable count, Campylobacter jejuni, Escherichia coli, Salmonella typhimurium and Listeria monocytogenes) on raw beef using an immersion system. The following concentrations of each chemical were used: 3 & 5% for AA, CA, LA, SD and 10 & 12% for TSP. Possible synergistic effects of using combinations of two chemicals sequentially (LA +CA and LA +AA) were also investigated. L*, a* and b* values …

Impact Of Atmospheric Pressure Nonequilibrium Plasma Discharge On Polymer Surface Metrology, Laurence Scally, James Lalor, Patrick J. Cullen, Vladimir Milosavljevic

Articles

Due to the attraction of plasma technologies as a clean and efficient means of surface modification, significant research has gone into the physical and chemical aspects of polymer functionalization. In this study, it was shown that the use of an atmospheric plasma jet can efficiently modify the surface of polyethylene terephthalate samples and change their hydrophobic properties to more hydrophilic characteristics. The dependence on the changes with respect to time, distance, and atomic oxygen (O I) intensity were considered as factors. It was found that with closer proximity to the plasma source (without causing thermal degradation) and with increasing levels …

Hamiltonian Dynamics Of Cosmological Quintessence Models, Rossen Ivanov, Emil Prodanov

Articles

The time-evolution dynamics of two nonlinear cosmological real gas models has been reexamined in detail with methods from the theory of Hamiltonian dynamical systems. These examples are FRWL cosmologies, one based on a gas, satisfying the van der Waals equation and another one based on the virial expansion gas equation. The cosmological variables used are the expansion rate, given by the Hubble parameter, and the energy density. The analysis is aided by the existence of global first integral as well as several special (second) integrals in each case. In addition, the global first integral can serve as a Hamiltonian for …

Hamiltonian Models For The Propagation Of Irrotational Surface Gravity Waves Over A Variable Bottom, Alan Compelli, Rossen Ivanov, Michail D. Todorov

Articles

A single incompressible, inviscid, irrotational fluid medium bounded by a free surface and varying bottom is considered. The Hamiltonian of the system is expressed in terms of the so-called Dirichlet-Neumann operators. The equations for the surface waves are presented in Hamiltonian form. Specific scaling of the variables is selected which leads to approximations of Boussinesq and KdV types taking into account the effect of the slowly varying bottom. The arising KdV equation with variable coefficients is studied numerically when the initial condition is in the form of the one soliton solution for the initial depth.

On Integrable Wave Interactions And Lax Pairs On Symmetric Spaces, Vladimir S. Gerdjikov, Georgi G. Grahovski, Rossen Ivanov

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No abstract provided.

G-Strands On Symmetric Spaces, Alexis Arnaudin, Darryl Holm, Rossen Ivanov

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We study the G-strand equations that are extensions of the classical chiral model of particle physics in the particular setting of broken symmetries described by symmetric spaces. These equations are simple field theory models whose configuration space is a Lie group, or in this case a symmetric space. In this class of systems, we derive several models that are completely integrable on finite dimensional Lie group G, and we treat in more detail examples with symmetric space SU(2)/S1 and SO(4)/SO(3). The latter model simplifies to an apparently new integrable nine-dimensional system. We …

Generalised Hopficity And Products Of The Integers, Brendan Goldsmith

Articles

Hopfian groups have been a topic of interest in alge-braic settings for many years. In this work a natural generalizationof the notion, so-called R-Hopficity is introduced. Basic propertiesof R-Hopfian groups are developed and the question of whether ornot infinite direct products of copies of the integers are R-Hopfian isconsidered. An unexpected result is that the answer to this purelyalgebraic question depends on the set theory assumed.

Epidemiological, Clinical And Genetic Aspects Of Adult Onset Isolated Focal Dystonia In Ireland, L. Williams, E. Mcgovern, O. Kimmich, A. Molloy, I. Beiser, John Butler, F. Molloy, P. Logan, D.G. Healy, T. Lynch, R. Walsh, Lorraine Cassidy, P. Moriarty, H. Moore, T. Mcswiney, C. Walsh, S. O'Riordan, M. Hutchinson

Articles

Background: Adult onset idiopathic isolated focal dystonia presents with a number of phenotypes. Reported prevalence rates vary considerably; well-characterized cohorts are important to our understanding of this disorder.

Aim: To perform a nationwide epidemiological study of adult onset idiopathic isolated focal dystonia in the Republic of Ireland.

Methods: Patients with adult onset idiopathic isolated focal dystonia were recruited from multiple sources. Diagnosis was based on assessment by a neurologist with an expertise in movement disorders. When consent was obtained, a number of clinical features including family history were assessed.

Results: On the prevalence date there were 592 individuals in Ireland …

Prediction Of Viral Loads For Diagnosis Of Hepatitis C Infection In Human Plasma Samples Using Raman Spectroscopy Coupled With Partial Least Squares Regression Analysis, Hugh Byrne, Franck Bonnier, H. Nawaz, N. Rashid, M. Saleem

Articles

Raman spectroscopy has been used to identify the biochemical changes associated with the presence of the Hepatitis C virus (HCV) in infected human blood plasma samples as compared with healthy samples, as control. The aim of the study was to establish the Raman spectral markers of hepatitis infection, which could be used for diagnostic purposes. Moreover, multivariate data analysis techniques, including Principal Component Analysis (PCA), coupled with Linear Discriminant Analysis (LDA), and Partial Least Square Regression (PLSR) are employed to further demonstrate the diagnostic capability of the technique. The PLSR model is developed to predict the viral loads of the …

Linking Atr-Ftir And Raman Features To Phenolic Extractability And Other Attributes In Grape Skin, Hugh Byrne, Abigail Rooney, Julio Nogales-Bueno, Jose Miguel Hernandez-Hierro, Francisco Jose Heredia

Articles

The importance of wine phenolics on the sensory characteristic of red wines is well-known. Therefore, it is necessary to control the extractability of phenolic compounds from grape skins, which depends significantly on grape ripeness and hence, on cell wall degradation.

In the present study, attenuated total reflectance Fourier transform infrared (ATR-FTIR) and Raman spectra of grape skin have been recorded. Then, these spectral matrices have been studied and the main spectral features have been linked to extractabilities of phenolic compounds (anthocyanins, flavanols and total phenols). Moreover, spectral differences between external and internal grape skin surfaces also have been studied.

It …

Determination Of Spectral Markers Of Cytotoxicity And Genotoxicity Using In Vitro Raman Microspectroscopy: Cellular Responses To Polyamidoamine Dendrimer Exposure, Esen Efeoglu, Alan Casey, Hugh Byrne

Articles

Although consumer exposure to nanomaterials is ever increasing, with potential increased applications in areas such as drug and/or gene delivery, contrast agents and diagnosis, determination of cyto- and geno- toxic effect of nanomaterials on human health and the environment still remains challenging. Although many techniques have been established and adapted to determine the cytotoxicity and genotoxicity of nano-sized materials, these techniques remain limited by the number of assays required, total cost, use of labels and they struggle to explain the underlying interaction mechanisms. In this study, Raman microspectroscopy is employed as an in vitro label free high content screening technique …

A Natural, Calcium-Rich Marine Multi-Material Complex Preserves Bone Structure, Composition And Strength In An Ovariectomized Rat Model Of Osteoporosis, Orlaith Brennan, Joseph Sweeney, Brian O'Meara, Amro Widaa, Franck Bonnier, Hugh Byrne, Denis O'Gorman, Fergal O'Brien

Articles

Calcium supplements are used as an aid in the prevention of osteopenia and osteoporosis and also for the treatment of patients when used along with medication. Many of these supplements are calcium carbonate based. This study compared a calcium-rich, marine multi-mineral complex (Aquamin) to calcium carbonate in an ovariectomised rat model of osteoporosis in order to assess Aquamin’s efficacy in preventing the onset of bone loss. Animals were randomly assigned to either non-ovariectomy control (Control), ovariectomy (OVX) plus calcium carbonate, ovariectomy plus Aquamin or ovariectomy plus Aquamin delay where Aquamin treatment started 8 weeks post OVX. At the end of …

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 …

A Survey Of The Prior Programming Experience Of Undergraduate Computing And Engineering Students In Ireland, Glenn Strong, Catherine Higgins, Nina Bresnihan, Richard Millwood

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It has become apparent that increasing numbers of students arriving into undergraduate computing and engineering degree programmes in Irish 3^rd-level institutions have prior experience of computer programming. As the extent of this prior exposure as well as its nature, origins, and usefulness is not known beyond anecdotal evidence, an annual survey of prior programming experience of freshman undergraduates who study programming as part of their degree has been designed and administered. This paper reports on the first two years of this survey in 2015 and 2016. It found that around one third had some prior experience of programming …

Isolation And Spectroscopic Characterization Of Zn(Ii), Cu(Ii), And Pd(Ii) Complexes Of 1,3,4-Thiadiazole-Derived Ligand, Dariusz Karcz, Arkadiusz Matwijczuk, Bozena Boron, Bernadette Creaven, Leszek Fiedor, Andrzej Niewiadomy, Mariusz Gagos

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A series of complexes incorporating Zn(II), Cu(II), and Pd(II) ions, and 4-(5-heptyl-1,3,4-thiadiazol-2-yl)benzene-1,3-diol (L1) as model ligand, was synthesized in order to examine the nature of potential interactions between biologically active ligands, 1,3,4-thiadiazoles and metal ions with proven biological relevance. The structures of the compounds isolated were characterized using a number of spectroscopic methods including IR, Uv–vis, AAS, steady state and time-resolved fluorescence (TRF). The results obtained suggest that the L1-Zn(II) and L1-Pd(II) complexes consist of one molecule of L1 and one acetate ion acting as ligands, while the L1-Cu(II) complex adapts a 2:1 (L1: metal) stoichiometry. The coordination of L1 …

Longer-Term Impact Of Highand Low Temperature On Mortality: An International Study To Clarify Length Of Mortality Displacement, Ben Armstrong, Michelle Bell, Micheline De Sousa Zanotti Stagliorio Coelho, Yue Liang Leon Guo, Yuming Guo, Patrick J. Goodman, Masahiro Hashizume, Yasushi Honda, Ho Kim, Eric Lavigne, Paola Michelozzi, Paulo Hilario Nascimento Saldiva, Joel Schwartz, Matteo Scortichini, Francesco Sera, Aurelio Tobias, Shilu Tong, Chang Fu Wu, Antonella Zanobetti, Ariana Zeka, Antonio Gasparrini

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In many places, daily mortality has been shown to increase after days with particularly high or low temperatures, but such daily time-series studies cannot identify whether such increases reflect substantial life shortening or short-term displacement of deaths (harvesting).

Subjective Usability, Mental Workload Assessments And Their Impact On Objective Human Performance, Luca Longo

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Self-reporting procedures and inspection methods have been largely employed in the fields of interaction and web-design for assessing the usability of interfaces. However, there seems to be a propensity to ignore features related to end-users or the context of application during the usability assessment procedure. This research proposes the adoption of the construct of mental workload as an additional aid to inform interaction and web-design. A user-study has been performed in the context of human-web interaction. The main objective was to explore the relationship between the perception of usability of the interfaces of three popular web-sites and the mental workload …

A Conceptual Framework For A Software Development Process Based On Computational Thinking, Catherine Higgins, Ciaran O'Leary, Orla Hanratty, Fredrick Mtenzi

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A software development process is a mechanism for problem solving to help software developers plan, design and structure the development of software to solve a problem. Without a process to guide the structured evolution of a solution, it is extremely likely that at least some aspect of the resulting software will be omitted or incorrectly implemented. Even though the importance of utilising a software process for solving problems is accepted in the business and academic communities, it is a topic that is addressed very lightly (if at all) in most freshman undergraduate computing courses with most courses focussing on programming …