Physical Sciences and Mathematics Commons^™

Metallopharmaceuticals As Photoactivatable Anticancer Drugs, Samar Moqadasi, Christine O'Connor, Denis O'Shea, Michael Devereux

Conference Papers

Target-based research (treating infected site only), directed towards the design and mechanism of action of metal-based anticancer complexes is expanding rapidly due to the selectivity and activity of such novel therapeutics. The photo activation of Ruthenium (II) complexes as therapeutic drugs has recently escalated as the complexes are suitable for photoactivation due to their well published photochemical and photophysical properties which in turn is the basis of photodynamic approaches to therapy.1-5 The aim of this study is to synthesise a series of metallo-complexes of which will be tested on tumour and non-tumour cell lines in the Radiation & Environmental Science …

Metallo-Cyclodextrin Complexes For The Separation Of Chiral Materials, Synthesis And Characterisation, Ciaran Francis Potter

Doctoral

The processes of separation and detection of chiral compounds are extremely important in the pharmaceutical industry. This study aims to investigate a safe and variable methods for the separation of the two enantiomers of the drug DOPA (Dihydroxyphenylalanine). L-DOPA is the most effective drug at present used to combat Parkinson’s disease while D-DOPA is inactive, thus for drug efficacy only the single biologically active enantiomer should be present in the formulation. In this work, cyclodextrins (CDS) were utilised fro their ability to act as a host for guest species, acting in the role as both a first and second sphere …

An Investigation Of Introductory Physics Students’ Approaches To Problem Solving, Laura Walsh, Robert Howard, Brian Bowe

Articles

This paper outlines ongoing research investigating students’ approaches to quantitative and qualitative problem solving in physics. This is an empirical study, which was conducted using a phenomenographic approach to analyse and interpret data from individual semi-structured interviews with students from introductory physics courses. The result of the study thus far is a preliminary set of hierarchical categories that describe the students’ problem-solving approaches when faced with various physics problems. The findings from the research presented here indicate that many introductory students in higher education do not approach problem solving in a strategic manner and many do not try to link …

An Open Source Approach To Wireless Positioning Techniques, Seamus Rooney, Keith Gardiner, James Carswell

Conference papers

There are several problems encountered when trying to determine the location of a mobile phone, including weather you are in an urban or rural environment. Also, it is well known that different positioning technologies can work better than others depending on the environment they are in. For example, GPS works well in rural areas but not as well in urban areas, GSM positioning accuracy can be acceptable in urban areas with the right triangulation technology, but is less accurate in rural areas. Positioning with other technologies such as WiFi, Bluetooth, and Semacode all have their own advantages and disadvantages also, …

Continuous Improvement In E-Learning: Investigating The Effect And Impact Of Our Webct Chemistry Support Initiative (Csi) And Implications For Further Enhancement Of The Virtual Learning Environments (Vles) Developed, Christine O'Connor, Claire M. Mcdonnell, Michael K. Seery

Conference Papers

A Virtual Learning Environment (VLE) was developed using WebCT software and was piloted in 2004 in the School of Chemical and Pharmaceutical Sciences in DIT by the authors. This was one of a number of measures introduced with the aim of supporting and retaining first year undergraduates on the Science ordinary degree programme and was designed as a Chemistry Support Initiative (CSI) for first year Chemistry learning and teaching (O’Connor, 2005). This work was supported through funding from the DIT Learning and Teaching Centre which allowed a summer research assistant to be taken on. Since the launch of the first …

Urban Location Based Services Using Mobile Clients: The Icing Approach, Eoin Kilfeather, James Carswell, Keith Gardiner, Seamus Rooney

Conference papers

The ICING project is conducting research into eGovernment and Location Based Services and also into two-way interaction with the physical environment. The research focuses on the areas of embedded intelligence, tighter integration of operator platforms and city infrastructure to enable novel services, empowerment of citizens to evolve systems of interaction with the city via social software, input from citizens and sensors for management systems and decision modelling, and a combination of city systems and multi-modal, multi-device communications to provide enhanced services. The technology platforms are gathering indicators from the City, processing the information, proposing actions to be taken with human …

A Three‐Dimensional Numerical Method For Modelling Weakly Ionized Plasmas, Stephen O'Sullivan, Turlough Downes

Articles

Astrophysical fluids under the influence of magnetic fields are often subjected to single- or two-fluid approximations. In the case of weakly ionized plasmas, however, this can be inappropriate due to distinct responses from the multiple constituent species to both collisional and non-collisional forces. As a result, in dense molecular clouds and protostellar accretion discs, for instance, the conductivity of the plasma may be highly anisotropic leading to phenomena such as Hall and ambipolar diffusion strongly influencing the dynamics.

An Open Approach To Contextualising Heterogeneous Cultural Heritage Datasets, John Mcauley, James Carswell

Conference papers

This paper describes a semantic museum application, which aims to present a holistic impression of the Etruscan civilisation. Through the use of a distributed computing paradigm and the CIDOC CRM ontology, the system presents a unified view of a fragmented heritage, while supporting browse and search at a semantic level. Within the cultural heritage world, however, much value is placed on ‘context’, both in describing and presenting heritage artefacts. From this perspective, a platform built upon the distributed search paradigm, although useful in many respects, does not convey how an artefact sits within a broader setting. Narrative concepts are proposed …

Reissner–Nordstrom¨ Expansion, Emil Prodanov, Rossen Ivanov, V.G. Gueorguiev

Conference papers

We propose a classical mechanism for the cosmic expansion during the radiation-dominated era, assuming the Universe as a two-component gas. The first component is the ultra-relativistic “standard” fraction described by an equation of state of an ideal quantum gas of massless particles. The second component consist of superheavy charged particles and their interaction with the “standard” fraction drives the expansion. This interaction is described by the Reissner–Nordstr¨om metric purely geometrically — the superheavy charged particles are modeled as zero-dimensional naked singularities which exhibit gravitational repulsion. The radius of a repulsive sphere, surrounding a naked singularity of charge Q, is inversely …

Shellability Of Noncrossing Partition Lattices, Colum Watt, Thomas Brady, Christos Athanasiadis

Articles

We give a case-free proof that the lattice of noncrossing partitions associated to any finite real reflection group is EL-shellable. Shellability of these lattices was open for the groups of type $D_n$ and those of exceptional type and rank at least three.

Synthesis And Characterisation Of Tetra-Tetrazole Macrocycles, Andrew Bond, Adrienne Fleming, Fintan Kelleher, John Mcginley, Vipa Prajapati, Signe Skovsgaard

Articles

The syntheses of tetra-tetrazole macrocycles, containing two bis-tetrazole units linked by a variety of alkyl chain lengths from four to eight carbons, are described. The crystal structures of three of these derivatives are reported, and the molecular conformation in the solid state is compared to that of one previously reported tetra-tetrazole macrocycle and to other bis- and tris(tetrazole)benzene structures. The macrocycle conformation is influenced by the length of the alkyl chain linker, the relative orientation of the tetrazole rings on the benzene ring, and by intermolecular interactions. In the macrocycles based on 1,2-bis(tetrazole)benzene, the adjacent tetrazole rings on the benzene …

Growth Substrate Induced Functional Changes Elucidated By Ftir And Raman Spectroscopy In In-Vitro Cultured Human Keratinocytes., Aidan Meade, Fiona Lyng, Peter Knief, Hugh Byrne

Articles

Non-invasive measurements of cellular function in in-vitro cultured cell lines using vibrational spectroscopy require the use of spectroscopic substrates such as quartz, ZnSe and MirrIR etc. These substrates are generally dissimilar to the original in-vivo extracellular environment of a given cell line and are often tolerated poorly by cultured cell lines resulting in morphological and functional changes in the cell. The present study demonstrates various correlations between vibrational spectroscopic analyses and biochemical analyses in the evaluation of the interaction of a normal human epithelial keratinocyte cell line (HaCaT) with MirrIR and quartz substrates coated with fibronectin, laminin and gelatin. The …

Silver Doped Titanium Dioxide Nanomaterials For Enhanced Visible Light Photocatalysis, Michael Seery, Reena George, Suresh Pillai, Patrick Floris

Articles

This paper presents a systematic study on two different preparation methods for titanium dioxide with silver. The silver can be incorporated by irradiating the reaction mixture during preparation to reduce silver ion to silver metal or by direct calcination of the sol–gel material to decompose silver nitrate to silver. Of the two methods, we found the latter produces a more effective photocatalytic material (6–50% improvement in catalytic efficiency), which is attributed to the fact that the silver is homogeneously dispersed throughout the material. The efficiency of the materials were examined using a Q-Sun solar simulator (visible light) and in Dublin …

Destination Website Effectiveness – A Delphi-Based Emetric Approach – A Dms Perspective, Patrick Horan, Andrew Frew

Conference papers

This paper outlines the development and evaluation of a comprehensive set of eMetrics for measuring the effectiveness of a Destination Management Systems’ (DMS) websites from the perspective of small and medium-sized hotel enterprises. Ultimately, from a hotel’s viewpoint, website effectiveness depends on how well a site performs with respect to the related business goals. The priority of the research is thus to establish which criteria are important for destination websites and to determine a mechanism for their measurement. These criteria are divided into both macro- and micro- level metrics which each combine to provide information that is actionable from a …

Improved Nitrate Sensing Using Ion Selective Electrodes Based On Urea–Calixarene Ionophores, Benjamin Schazmann, Dermot Diamond

Articles

Urea–calix[4]arenes 1 and 2 were synthesised and incorporated into ISE membranes for assessment as sensors for inorganic anions in water. 1 revealed a strong response to all anions following the Hofmeister selectivity order. For ISEs of 2, the response to a portion of the anion series was suppressed, increasing the margin of selectivity of nitrate over chloride, a common interferant of nitrate in fresh and marine water samples. The performance of ISEs containing 2 was compared to commercially available alkylammonium nitrate ion-exchange salts used for nitrate sensing. Our ISEs performed favourably in terms of sensitivity, linear range and LOD performing …

A Novel Tio2 / Pvc Layer For Use In A Photoelectrochemical Cell, Faiza Touati, John Cassidy, Kevin Mcguigan

Articles

A novel method of coating titanium dioxide on a glassy carbon electrode as a polyvinylchloride composite , is described. On illumination , there is an enhanced voltammetric current at this TiO2/PVC composite in aqueous formic acid solution. This electrode is used as the basis of a formic acid fuel cell where oxygen is reduced at a platinum cathode. The system yields 100 cm-2 for 0.01 mol dm-3 HCOOH in 0.1 mol dm-3 NaOH under illumination from a 150 W xenon lamp. The current without illumination is 0.5 cm-2.

Reissner–Nordstrom Expansion, Emil Prodanov, Rossen Ivanov, Vesselin Gueorguiev

Articles

We propose a classical mechanism for the cosmic expansion during the radiation-dominated era, assuming the Universe as a two-component gas. The first component is the ultra-relativistic “standard” fraction described by an equation of state of an ideal quantum gas of massless particles. The second component consist of superheavy charged particles and their interaction with the “standard” fraction drives the expansion. This interaction is described by the Reissner–Nordstr¨om metric purely geometrically — the superheavy charged particles are modeled as zero-dimensional naked singularities which exhibit gravitational repulsion. The radius of a repulsive sphere, surrounding a naked singularity of charge Q, is inversely …

On Cosmall Abelian Groups, Brendan Goldsmith, O. Kolman

Articles

It is a well-known homological fact that every Abelian groupGhas the property that Hom(G,−)com-mutes with direct products. Here we investigate the ‘dual’ property: an Abelian groupGis said to be cosmallif Hom(−,G)commutes with direct products. We show that cosmall groups are cotorsion-free and that nogroup of cardinality less than a strongly compact cardinal can be cosmall. In particular, if there is a properclass of strongly compact cardinals, then there are no cosmall group

Landscape And Geotourism: Market Typologies And Visitor Needs, Catherine Elizabeth Gorman

Conference papers

Purpose: The purpose of this paper is to explore Geotourism (landscape tourism) in the context of the Irish tourism experience, to develop visitor typologies and propose an approach that will ensure greater sustainability by addressing market value and requirements through the use of marketing techniques and tools.

Methodology/Approach: An evaluation of existing geotourism resources and information was undertaken. A gap was identified in terms of marketing the Geotourism product. This gap is identified as a break the delivery of the experience to the most suitable customer and is addressed by identifying specific typologies, their requirements and making suggestions …

Time-Temperature And Relative Humidity Profiles Of Chilled And Frozen Foods In Retail Outlets Nationwide, And Evaluation Of Related Practices, Caroline Garvan

Masters

Temperature abuse combined with poor operational practices are the dominant factors in the mishandling of food products which can result in outbreaks of food borne disease. The objective of this work was to determine efficacy of temperature and relative humidity control using recorded data and to assess the food safety management systems in operation in retail outlets in the Republic of Ireland. This study also aims to examine food safety risk to consumers as a result of inadequate temperature control and poor food hygiene practices using microbial analysis and predictive modelling. External air temperature, core temperature and relative humidity of …

On Cosmall Abelian Groups, Brendan Goldsmith, O. Kolman

Articles

It is a well-known homological fact that every Abelian group G has the property that Hom(G,−) commutes with direct products. Here we investigate the ‘dual’ property: an Abelian group G is said to be cosmall if Hom(−,G) commutes with direct products. We show that cosmall groups are cotorsion-free and that no group of cardinality less than a strongly compact cardinal can be cosmall. In particular, if there is a proper class of strongly compact cardinals, then there are no cosmall groups.

Hamiltonian Formulation, Nonintegrability And Local Bifurcations For The Ostrovsky Equation, S. Roy Choudhury, Rossen Ivanov, Yue Liu

Articles

The Ostrovsky equation is a model for gravity waves propagating down a channel under the influence of Coriolis force. This equation is a modification of the famous Korteweg-de Vries equation and is also Hamiltonian. However the Ostrovsky equation is not integrable and in this contribution we prove its nonintegrability. We also study local bifurcations of its solitary waves.

Water Waves And Integrability, Rossen Ivanov

Articles

The Euler’s equations describe the motion of inviscid fluid. In the case of shallow water, when a perturbative asymtotic expansion of the Euler’s equations is taken (to a certain order of smallness of the scale parameters), relations to certain integrable equations emerge. Some recent results concerning the use of integrable equation in modeling the motion of shallow water waves are reviewed in this contribution.

Slow Flow Between Concentric Cones, O. Hall, C. P. Hills, A. D. Gilbert

Articles

This paper considers the low-Reynolds-number flow of an incompressible fluid contained in the gap between two coaxial cones with coincident apices and bounded by a spherical lid. The two cones and the lid are allowed to rotate independently about their common axis, generating a swirling motion. The swirl induces a secondary, meridional circulation through inertial effects. For specific configurations complex eigenmodes representing an infinite sequence of eddies, analogous to those found in two-dimensional corner flows and some three-dimensional geometries, form a component of this secondary circulation. When the cones rotate these eigenmodes, arising from the geometry, compete with the forced …

Krylov Subspaces From Bilinear Representations Of Nonlinear Systems, Marissa Condon, Rossen Ivanov

Articles

For efficient simulation of state-of-the-art dynamical systems as arise in all aspects of engineering, the development of reduced-order models is of paramount importance. While linear reduction techniques have received considerable study, increasingly nonlinear model reduction is becoming a significant field of interest. From a circuits and systems viewpoint, systems involving micromachined devices or systems involving mixed technologies necessitate the development of reduced-order nonlinear models. From a control systems viewpoint, the design of controllers for nonlinear systems is greatly facilitated by nonlinear model reduction strategies. To this end, the paper proposes two novel model-reduction strategies for nonlinear systems. The first involves …

Generalised Fourier Transform For The Camassa-Holm Hierarchy, Adrian Constantin, Vladimir Gerdjikov, Rossen Ivanov

Articles

The squared eigenfunctions of the spectral problem associated to the Camassa-Holm equation represent a complete basis of functions, which helps to describe the Inverse Scattering Transform for the Camassa-Holm hierarchy as a Generalised Fourier transform. The main result of this work is the derivation of the completeness relation for the squared solutions of the Camassa-Holm spectral problem. We show that all the fundamental properties of the Camassa-Holm equation such as the integrals of motion, the description of the equations of the whole hierarchy and their Hamiltonian structures can be naturally expressed making use of the completeness relation and the recursion …

Spectroscopic Characterisation Of Novel Polycyclic Aromatic Polymers, Luke O'Neill, Patrick Lynch, Mary Mcnamara, Hugh Byrne

Articles

A series of novel polyphenylenevinylene (PPV) derivative polymers were studied by absorption and photoluminescence spectroscopies. The effect of the sequential introduction of polycyclic aromatic ring substituents into the delocalized backbone was examined with relation to hypsochromatic and bathochromatic shifting. While the replacement of the phenyl units by naphthyl units results in a substantial hypsochromic shift of both the absorption and emission spectra, their subsequent substitution by anthryl units results in a bathochromic shift. The system is modeled according to, and is found to be consistent with, a previous study of donor-acceptor polyenes of varying length. The electronic structure of the …

Vibrational Characterisation And Fluorescence Optimisation Of Polycyclic Polymers, Luke O'Neill, Patrick Lynch, Mary Mcnamara, Hugh Byrne

Articles

A systematic series of polycyclic novel polymers was studied by Raman spectroscopy. The effect of the sequential introduction of polycyclic aromatic ring substituents into the delocalized backbone was examined in relation to the variation of the relative ring breathing and stretching as well as the vinyl stretch frequencies. Replacement of the phenyl units by higher order acene moieties such as naphthyl and anthryl results in a shift of the characteristic stretching frequencies, and analysis of the vinyl stretch leads to the confirmation that higher order acene substitution into the delocalized backbone substantially weakens the vinyl bond. Semiquantitative integrated Raman analysis …

A Systematic Study Of The Effects Of Naphthalene And Anthracene Substitution On The Properties Of Ppv Derivative Conjugated Systems, Patrick Lynch, Luke O'Neill, David Bradley, Hugh Byrne, Mary Mcnamara

Articles

The systematic synthesis of poly(phenylvinylene) (PPV) derivatives by the Wittig-Horner reaction is reported. The phenyl units of the PPV structure are methodically substituted by naphthyl and anthryl units to form a homologous series of structures. The 2,6 attachment of the vinylene linkage on the anthryl ring provides novel structures that have not been reported before due to their synthetic inaccessibility. The introduction of naphthyl units results in a hypsochromatic shift in the absorption and emission spectra, while the introduction of anthryl units leads to a bathochromatic shift relative to the naphthalene structures. The observed structural variation of the spectroscopic properties …

Some Transitivity Results For Torsion Abelian Groups, Brendan Goldsmith, Lutz Strungmann

Articles

We introduce a new class of fully transitive and transitive Abelian p-groups and study the new concept of weak transitivity which is the missing link between full transitivity and transitivity.