Physical Sciences and Mathematics Commons^™

Required Features Of A Virtual Classroom Tool For Use In Higher Education, Arnold Hensman

Articles

The integration of virtual-classroom systems into the arsenal of e-learning tools represents a major evolution in the landscape of modern distance education. For many courses, standard virtual learning environments (VLEs) provide only a foundation upon which to base a distance learning programme. However, synchronous live online-teaching software such as Microsoft Office Communicator and Adobe Connect allow educators to simulate a real-time classroom environment over the internet like never before. Since these tools are being used more and more within higher education, questions must be asked about how effective they ultimately can be in meeting student learning requirements. More importantly, what …

Dark Solitons Of The Qiao's Hierarchy, Rossen Ivanov, Tony Lyons

Articles

We obtain a class of soliton solutions of the integrable hierarchy which has been put forward in a series of works by Z. Qiao. The soliton solutions are in the class of real functions approaching constant value fast enough at infinity, the so-called 'dark solitons'.

G-Strands, Darryl Holm, Rossen Ivanov, James Percival

Articles

A G-strand is a map g(t,s): RxR --> G for a Lie group G that follows from Hamilton's principle for a certain class of G-invariant Lagrangians. The SO(3)-strand is the G-strand version of the rigid body equation and it may be regarded physically as a continuous spin chain. Here, SO(3)_K-strand dynamics for ellipsoidal rotations is derived as an Euler-Poincar'e system for a certain class of variations and recast as a Lie-Poisson system for coadjoint flow with the same Hamiltonian structure as for a perfect complex fluid. For a special Hamiltonian, the SO(3) …

Spectral Cross Correlation As A Supervised Approach For The Analysis Of Complex Raman Datasets: The Case Of Nanoparticles In Biological Cells, Mark Keating, Franck Bonnier, Hugh Byrne

Articles

Spectral Cross-correlation is introduced as a methodology to identify the presence and subcellular distribution of nanoparticles in cells. Raman microscopy is employed to spectroscopically image biological cells previously exposed to polystyrene nanoparticles, as a model for the study of nano-bio interactions. The limitations of previously deployed strategies of K-means clustering analysis and principal component analysis are discussed and a novel methodology of Spectral Cross Correlation Analysis is introduced and compared with the performance of Classical Least Squares Analysis, in both unsupervised and supervised modes. The previous study demonstrated the feasibility of using Raman spectroscopy to map cells and identify polystyrene …

Nitrogen And Copper Doped Solar Light Active Tio2 Photocatalysts For Water Decontamination, Mike Fisher, Donal Keane, Pilar Fernandez-Ibanez, John Colreavy, Stephen Hinder, Kevin Mcguigan, Suresh Pillai

Articles

A novel class of photocatalytic coating capable of degrading bacterial and chemical contaminants in the presence of visible sunlight wavelengths was produced by depositing a stable photocatalytic TiO

2 film on the internal lumen of glass bottles via a sol–gel method. This coating was prepared in either undoped form or doped with nitrogen and/or copper to produce visible light-active TiO2 films which were annealed at 600 ◦C and were characterized by Raman and X-ray photoelectron spectroscopy. The presence of doped and undoped TiO2 films was found to accelerate the degradation of methylene blue in the presence of natural sunlight, while …

Cyclic Universe With An Inflationary Phase From A Cosmological Model With Real Gas Quintessence, Rossen Ivanov, Emil Prodanov

Articles

Phase-plane stability analysis of a dynamical system describing the Universe as a two-fraction uid containing baryonic dust and real virial gas quintessence is presented. Existence of a stable periodic solution experiencing in ationary periods is shown. A van der Waals quintessence model is revisited and cyclic Universe solution again found.

The Effect Of Genetic Background And Dose On Non-Targeted Effects Of Radiation, Sarah Irons, Virginia Sierra, Deborah Bowler, Kim Chapman, Stefania Militi, Fiona Lyng, Munira Kadhim

Articles

Purpose: This work investigates the hypothesis that genetic background plays a significant role in the signalling mechanisms underlying induction and perpetuation of genomic instability following radiation exposure.

Materials and methods: Bone marrow from two strains of mice (CBA and C57) were exposed to a range of X-ray doses (0, 0.01, 0.1, 1 and 3 Gy). Different cellular signalling endpoints: Apoptosis, cytokine levels and calcium flux, were evaluated at 2 h, 24 h and 7 d post-irradiation to assess immediate and delayed effects.

Results: In CBA (radiosensitive) elevated apoptosis levels were observed at 24 h post X-irradiation, and …

The Influence Of Auxiliary Ligands On The Photophysical Characteristics Of A Series Of Ruthenium (Ii) Polypyridyl Complexes, Luke O'Neill, Laura Perdisatt, Christine O'Connor

Articles

A series of ruthenium polypyridyl complexes were studied using UV/Vis absorption and luminescence spectroscopy as well as luminescence lifetime determination by time correlated single photon counting (TCSPC). The complexes were characterised with regard to the variation in the electronic band-gap as a result of the sequential variation of the auxiliary ligand 2,2’-bipyridine (bpy), 1,10-phenanthroline (phen) and 2,2’-biquinoline (biq) ligands while the main ligand remained constant for three different main ligand types. Luminescence yields were calculated and correlated with structural and electronic variation. It was found that both the absorption and emission characteristics could be tailored through the systematic variation of …

A Theoretical Framework For Serious Game Design: Exploring Pedagogy, Play And Fidelity And Their Implications For The Design Process, Pauline Rooney

Articles

It is widely acknowledged that digital games can provide an engaging, motivating and “fun” experience for students. However an entertaining game does not necessarily constitute a meaningful, valuable learning experience. For this reason, experts espouse the importance of underpinning serious games with a sound theoretical framework which integrates and balances theories from two fields of practice: pedagogy and game design (Kiili, 2005; Seeney & Routledge, 2009). Additionally, with the advent of sophisticated, immersive technologies, and increasing interest in the opportunities for constructivist learning offered by these technologies, concepts of fidelity and its impact on student learning and engagement, have emerged …

Evaluation Of Cirs String Doppler Phantom As A Test Tool For Use In A Doppler Ultrasound Quality Assurance Program, Jacinta Browne, S. Cournane, Andrew Fagan

Articles

Ultrasound Doppler systems are routinely used to perform blood flow velocity measurements which assist in the clinical assessment and diagnosis of vascular. Doppler measurements of peak velocities for vascular applications provide an indication of the degree of the stenosis which will ultimately assist in deciding how a patient is managed. It is imperative that Doppler systems are capable of accurately measuring blood flow velocities to ensure correct diagnosis and appropriate patient treatment; therefore such systems should be evaluated regularly as part of a Quality Assurance program. Although a range of Doppler test phantoms have been developed for quality control (QC) …

Modifications Of Existing Doppler Ultrasound Test Devices For The Evaluations Of Colour Doppler Spatial Resolution, Nisma Arshad, Jacinta Browne

Articles

No abstract provided.

Characterisation Of The Colour Doppler "Twinkle" Artefact, Deirdre Cassidy, Andrew Fagan, Jacinta Browne

Articles

This investigation involved the development of a range of Colour Doppler Twinkle Artefact phantoms to characterise and quantify the “Twinkle” artefact which is often present when an irregular structure is encountered in the imaged field of view. The artefact occurs in both colour and power Doppler ultrasound imaging and manifests as a false depiction of colour velocity information in stationary soft tissue and therefore can cause significant misdiagnosis of areas of flow within the patient. It has been hypothesised that it is generated due to a strongly reflecting medium composed of individual reflectors and therefore becomes a clinical concern when …

Search For A T-Odd, P-Even Triple Correlation In Neutron Decay, T. E. Chupp, R. L. Cooper, K. P. Coulter, S. J. Freedman, B. K. Fujikawa, A. Garcia, Gordon L. Jones, H. P. Mumm, J. S. Nico, A. K. Thompson, C. A. Trull, F. E. Wietfeldt, J. F. Wilkerson

Articles

Background: Time-reversal-invariance violation, or equivalently CP violation, may explain the observed cosmological baryon asymmetry as well as indicate physics beyond the Standard Model. In the decay of polarized neutrons, the triple correlation D⟨⃗Jn⟩/Jn⋅(⃗βe׈pν) is a parity-even, time-reversal-odd observable that is uniquely sensitive to the relative phase of the axial-vector amplitude with respect to the vector amplitude. The triple correlation is also sensitive to possible contributions from scalar and tensor amplitudes. Final-state effects contribute to D at the level of 10−5 and can be calculated with a precision of 1% or better.

Purpose: We have improved the sensitivity to T-odd, P-even …

Software Process Improvement To Assist Medical Device Software Development Organisations To Comply With The Amendments To The Medical Device Directive, Martin Mchugh, Fergal Mccaffery, Valentine Casey

Articles

A recent revision to the European Medical Device Directive (MDD) 2007/47/EC made fourteen amendments to the original directive (93/42/EEC). A number of these changes directly affect the development of software for use in healthcare. The most significant change in relation to medical device software development is that standalone software is now seen as an active medical device and should be developed following state of the art medical device software development processes. State of the art medical device software processes is understood within the industry as developing software in accordance with IEC 62304 and standards that are aligned with it. This …

A Review On The Visible Light Active Titanium Dioxide Photocatalysts For Environmental Applications, Miguel Pelaez, Nicholas Nolan, Suresh Pillai, Michael Seery, Polycarpos Falaras, Athanassios G. Kontos, Patrick S.M. Dunlop, Jeremy W.J. Hamiltone, J. Anthony Byrne, Kevin O’Shea, Mohammad H. Entezari, Dionysios D. Dionysiou

Articles

Development of visible light active (VLA) titania photocatalysts

Fujishima and Honda (1972) demonstrated the potential of titanium dioxide (TiO 2) semiconductor mate-rials to split water into hydrogen and oxygen in a photo-electrochemical cell. Their work triggered the development of semiconductor photocatalysis for a wide range of environmental and energy applica-tions. One of the most significant scientific and commercial advances to date has been the development of visible light active (VLA) TiO2 photocatalytic materials. In this review, a background on TiO2 struc-ture, properties and electronic properties in photocatalysis is presented. The development of different strategies to modify TiO2 for the utilization …

Comparative Review Of Imaging Methods Used For Diagnosing Renal Artery Stenosis (Ras), Deirdre King, Carmel Moran, Jacinta Browne

Articles

This comparative review examines the efficacy of different imaging methods to detect and quantify renal artery stenosis (RAS). Detection of RAS is important because it can lead to renovascular hypertension which is the most common form of secondary hypertension. Furthermore, it is important that a RAS is detected as early as possible as it is a potentially correctable cause of hypertension.¹ If detected at an early stage RAS can potentially be treated using a minimally invasive drug treatment regimen rather than the more invasive percutaneous transluminal renal angioplasty without or with stent placement or surgery. Currently there are a …

The 2-Component Dispersionless Burger's Equation Arising In The Modelling Of Bloodflow, Tony Lyons

Articles

This article investigates the properties of the solutions of the dispersionless two-component Burgers (B2) equation, derived as a model for blood- ow in arteries with elastic walls. The phenomenon of wave breaking is investigated as well as applications of the model to clinical conditions.

Changes To The International Regulatory Environment, Martin Mchugh, Fergal Mccaffery, Valentine Casey

Articles

Since 2010, two significant international regulations regarding medical device development have come into force, the amendment to the European Union (EU) Medical Device Directive (MDD) 2007/47/EC and the United States (US) Food and Drug Administration (FDA) Final rule on Medical Device Data Systems (MDDS). Adherence to these regulations is mandatory to be able to market a medical device in the respective region. The ability to understand these regulations and apply them to a development project can be difficult. The MDDS final rule changes the safety classification of a number of devices from Class III-high risk to Class I-low risk. The …

Designing And Implementing A Platform For Collecting Multi-Modal Data Of Human-Robot Interaction, Brian Vaughan, Jing Guang Han, Emer Kilmartin, Nick Campbell

Articles

This paper details a method of collecting video and audio recordings of people inter- acting with a simple robot interlocutor. The interaction is recorded via a number of cameras and microphones mounted on and around the robot. The system utilised a number of technologies to engage with interlocutors including OpenCV, Python, and Max MSP. Interactions over a three month period were collected at The Science Gallery in Trinity College Dublin. Visitors to the gallery freely engaged with the robot, with interactions on their behalf being spontaneous and non-scripted. The robot dialogue was a set pattern of utterances to engage interlocutors …

Hadamard Renormalization Of The Stress Energy Tensor In A Spherically Symmetric Black Hole Space-Time With An Application To Lukewarm Black Holes, Cormac Breen, Adrian Ottewill

Articles

We consider a quantum field which is in a Hartle-Hawking state propagating in a spherically symmetric black hole space-time. We calculate the components of the stress tensor, renormalized using the Hadamard form of the Green's function, in the exterior region of this space-time. We then specialize these results to the case of the `lukewarm' Riessner-Nordstrom-de Sitter black hole.

Stiefel And Grassmann Manifolds In Quantum Chemistry, Eduardo Chiumiento, Michael Melgaard

Articles

We establish geometric properties of Stiefel and Grassmann manifolds which arise in relation to Slatertype variational spaces in many-particle Hartree-Fock theory and beyond. In particular, we prove thatthey are analytic homogeneous spaces and submanifolds of the space of bounded operators on the single-particle Hilbert space. As a by-product we obtain that they are complete Finsler manifolds. These geometric properties underpin state-of-the-art results on existence of solutions to Hartree-Fock type equations.

Kinetic Studies Of The Photo-Degradation Of Poly Arylene Vinylenes, Luke O'Neill, Patrick Lynch, Niamh Mcgoldrick, Hugh Byrne, Mary Mcnamara

Articles

The kinetics of the degradation of a homologous series of Poly phenylene vinylenes in which the phenylene units of the PPV structure are systematically substituted by naphthyl and anthyrl units is presented. Degradation is monitored according to the decay of the long wavelength absorption maximum upon illumination with UV radiation. Compared to Toluene solution, the photo-degradation is seen to be accelerated in Chloroform solution. All decays are fitted with first order kinetics. It is found that all substitutions improve the stability of the vinylene polymers against decay. In particular the highly electro-negative naphthyl group serves to drastically increase the stability …

Impaired Clearance And Enhanced Pulmonary Inflammatory/Fibrotic Response To Carbon Nanotubes In Myeloperoxidase-Deficient Mice, Aidan Meade, Anna Shvedova, Alexandr Kapralov, Wei Hong Feng, Elena Kisin, Ashley Murray, Robert Mercer, Claudette St. Croix, Megan Lang, Simon Watkins, Nagarjun Konduru, Brett Allen, Jennifer Conroy, Gregg Kotchey, Bashir Mohamed, Yuri Volkov, Alexander Star, Bengt Fadeel, Valerian Kagan

Articles

Advancement of biomedical applications of carbonaceous nanomaterials is hampered by their biopersistence and proinflammatory action in vivo. Here, we used myeloperoxidase knockout B6.129X1-MPO (MPO k/o) mice and showed that oxidation and clearance of single walled carbon nanotubes (SWCNT) from the lungs of these animals after pharyngeal aspiration was markedly less effective whereas the inflammatory response was more robust than in wild-type C57Bl/6 mice. Our results provide direct evidence for the participation of MPO – one of the key-orchestrators of inflammatory response – in the in vivo pulmonary oxidative biodegradation of SWCNT and suggest new ways to control the biopersistence of …

Multiple Solutions Of The Quasi Relativistic Choquard Equation, Michael Melgaard, Frederic D. Y. Zongo

Articles

We prove existence of multiple solutions to the quasi relativistic Choquard equations with a scalar potential.

Hadamard Renormalisation Of The Stress Energy Tensor On The Horizons Of A Spherically Symmetric Black Hole Space-Time, Cormac Breen, Adrian Ottewill

Articles

We consider a quantum field which is in a Hartle-Hawking state propagating in a general spherically symmetric black hole space-time. We make use of uniform approximations to the radial equation to calculate the components of the stress tensor, renormalized using the Hadamard form of the Green's function, on the horizons of this space-time. We then specialize these results to the case of the `lukewarm' Reissner-Nordstrom-de Sitter black hole and derive some conditions on the stress tensor for the regularity of the Hartle-Hawking state

On Soliton Interactions For A Hierarchy Of Generalized Heisenberg Ferromagnetic Models On Su(3)/S(U(1) $\Times$ U(2)) Symmetric Space, Vladimir Gerdjikov, Georgi Grahovski, Alexander Mikhailov, Tihomir Valchev

Articles

We consider an integrable hierarchy of nonlinear evolution equations (NLEE) related to linear bundle Lax operator L. The Lax representation is Z2 \times Z2 reduced and is naturally associated with the symmetric space SU(3)/S(U(1) \times U(2)). The simplest nontrivial equation in the hierarchy is a generalization of Heisenberg ferromagnetic model. We construct the N-soliton solutions for an arbitrary member of the hierarchy by using the Zakharov-Shabat dressing method with an appropriately chosen dressing factor. Two types of soliton solutions: quadruplet and doublet solitons are found. The one-soliton solutions of NLEEs with even and odd dispersion laws have different properties. In …

Physicochemical And Microbiological Quality Of Harvested Rainwater From An Agricultural Installation In Ireland, Sean O'Hogain, Liam Mccarton, Niamh Mcintyre, Jenny Pender, Anna Reid

Articles

Members of DTC Research Group. Dublin Institute of Technology was commissioned in 2005 by the Department of Environment, Heritage and Local Government in Ireland to assess the feasibility of utilising rainwater to replace treated mains water for nonpotable uses. The project involved the design, installation, commissioning and monitoring of rainwater harvesting on a farm. Two monitoring programmes, Regime 1 and Regime 2, examined the physicochemical and microbiological quality of the harvested rainwater. Samples were taken monthly and tested. Regime 1 analysis showed that the microbiological quality of the rainwater from the site did not comply with the requirements of the …

Optical Properties Of High Refractive Index Thin Films Processed At Low-Temperature, Mohamed Oubaha, Salem Elmaghrum, Robert Copperwhite, Brian Corcoran, Colette Mcdonagh, Arnaud Gorin

Articles

This study reports on the first development of high refractive index thin film materials processed at temperatures not greater than 100 degrees celsius. Three materials were synthesised by the sol–gel technique, each employing different transition metal precursors (niobium, tantalum and vanadium alkoxides). The optical properties of these materials were characterised by ellipsometry and the propagation losses at 638 nm were measured by the prism coupling method. It is shown that refractive indices as high as 1.870, 2.039 and 2.308 are obtained from niobium-, tantalum- and vanadium-based materials respectively, attributed to the influence of the transition metal atomic size on the …

Preparation And Rapid Analysis Of Antibacterial Silver, Copper And Zinc Doped Sol–Gel Surfaces, Brendan Duffy, Swarna Jaiswal, Patrick Mchale

Articles

The colonisation of clinical and industrial surfaces with microorganisms, including antibiotic-resistant strains, has promoted increased research into the development of effective antibacterial and antifouling coatings. This study describes the preparation of metal nitrate (Ag, Cu, Zn) doped methyltriethoxysilane (MTEOS) coatings and the rapid assessment of their antibacterial activity using polyproylene microtitre plates. Microtitre plate wells were coated with different volumes of liquid sol–gel and cured under various conditions. Curing parameters were analysed by thermogravimetric analysis (TGA) and visual examination. The optimum curing conditions were determined to be 50–70C using a volume of 200ul. The coated wells were challenged with Gram-positive …

Assessment Of An Osteoblast-Like Cell Line As A Model For Human Primary Osteoblasts Using Raman Spectroscopy, Lindsay Mcmanus, Franck Bonnier, George Burke, Brian Meenan, Adrian Boyd, Hugh Byrne

Articles

Raman spectroscopy is employed to determine the suitability of the U20S osteoblast-like cell line for use as a model for human primary osteoblasts, with emphasis on the ability of these cell types to replicate their tissue of origin. It was found that both cell types demonstrated early stage mineral deposition that followed significantly different growth patterns. Analysis of the growth pattern and spectral data from primary cells revealed increasing bone quality ratios and a high crystallinity, consistent with previous reports. Conversely the investigation of the U20S osteoblast-like cell line provided evidence of dense multilayered mineralised regions that corresponded more closely …