Physical Sciences and Mathematics Commons^™

Development Of A Novel Method For Assessing Balance: The Quantitative Posturography System, Jacinta Browne, Neil O'Hare

Articles

Balance is the ability to maintain equilibrium while sitting or standing. There are a number of different methods, which are used to assess balance: technical methods such as Sway Magnetometry, Ataxia Meter and Force Platforms and clinical methods such as Functional Reach Test, Berg Balance Test and Fall Risk Index. The most frequently used technical method is the force platform. There are two types of Force Platform a static and a dynamic Force Platform of which the dynamic Force Platform has been found to be more sensitive at detecting impaired balance. The Quantitative Posturography System (QPS) described in this paper …

Development Of A Quality Control Procedure For Force Platforms, Jacinta Browne, Neil O'Hare

Articles

A force platform is a technical method of quantitatively assessing balance indirectly. The use of force platforms in physiotherapy departments has become more prominent over the last few years. However, the main drawback in the use of force platforms is the lack of comprehensive calibration procedures, which casts doubt on the results obtained with these systems. Existing calibration tests are limited to testing the spatial accuracy of the force platform. This paper describes a comprehensive quality control test procedure which was developed. It is proposed that the developed quality control test procedure could be used to test all types of …

Rotary Honing: A Variant Of The Taylor Paint-Scraper Problem, Christopher Hills, H. Moffatt

Articles

The three-dimensional Row in a corner of fixed angle α induced by the rotation in its plane of one of the boundaries is considered. A local similarity solution valid in a neighbourhood of the centre of rotation is obtained and the streamlines are shown to be closed curves. The effects of inertia are considered and are shown to be significant in a small neighbourhood of the plane of symmetry of the flow. A simple experiment confirms that the streamlines are indeed nearly closed; their projections on planes normal to the line of intersection of the boundaries are precisely the 'Taylor' …

Bounds For The Points Of Spectral Concentration Of Sturm-Liouville Problems, Daphne Gilbert, B.J. Harris

Articles

§1. Introduction. We consider the spectral function ρα(λ) associated with the Sturm–Liouville equation

with the boundary condition

Rational Generalised Moonshine From Orbifolds, Rossen Ivanov, Michael Tuite

Articles

Frenkel, Lepowsky and Meurman constructed the Moonshine Module (MM) as a Z₂ orbifold of the Leech Lattice Meromorphic Conformal field theory. The group of automorphisms of this theory is the 'Monster Group' M - the largest finite sporadic simple group (with order ~ 8. 10⁵³ ). 'Monstrous Moonshine' is the famous observation that the Thompson series, corresponding to each class of M, is a hauptmodule for some genus zero fixing group. Norton considered Generalised Moonshine Functions (GMF), depending on two commuting Monster elements, and suggested that they are also hauptmodules. Using meromorphid Abelian orbifoldings of MM we identify …

Enantioselective Complexation Of Amino Acids By 6a-Deoxy-6a-Hydroxyethylamino- Β -Cyclodextrin And Its Metallo-Derivatives In Aqueous Solution, Nicole Van Hoof, Noel Russell, Mary Mcnamara, Raphael Darcy

Articles

Enantioselectivity towards several amino acids by metallo-6A-deoxy-6A-hydroxyethylamino-β-cyclodextrins (metallo- β CDea’s) was investigated by potentiometric titration of the various amino acid/metallo- β CDea systems with NaOH solution. It was shown that the cyclodextrin derivative is capable of distinguishing between enantiomers of amino acid species in the presence of certain metal ions (Co, Ni, Cu and Zn). Ni- β CDea complexes show the most enantioselectivity,whereas for Cu and Co2C-_CDea complexes less selectivity is observed. As expected, Zn- β CDea complexes exhibit no enantioselectivity. Stability and selectivity, however, do not go hand in hand, since the most stable complexes are formed …

Thickness Variation Of Self-Processing Acrylamide-Based Photopolymer And Reflection Holography, F. O'Neill, Justin Lawrence, J. Sheridan

Articles

There are many types of holographic recording material. The acrylamide-based recording material examined here has one significant advantage: it is self-processing. This simplifies the recording process and enables holographic interferometry to be carried out without the need for complex realignment procedures. However, the effect that the polymerization process has on the grating thickness must be examined. This question is fundamental to the material's use in holographic optical elements, as thickness variations affect the replay conditions of the produced elements. This paper presents a study of this thickness variation and reports for the first time the production of reflection holographic gratings …

Production Of A Signal By Irradiated Cells Which Leads To A Response In Unirradiated Cells Characteristic Of Initiation Of Apoptosis, Fiona Lyng, C. Seymour, C. Mothersill

Articles

This study investigated the ability of medium from irradiated cells to induce early events in the apoptotic cascade, such as mobilization of intracellular calcium, loss of mitochondrial membrane potential and increase in reactive oxygen species, in cells which were never exposed to radiation. Medium from irradiated human keratinocytes was harvested and transferred to unirradiated keratinocytes. Endpoints characteristic of the initiation of apoptosis were monitored for a period of 24 h following medium transfer. Clonogenic survival was also measured. Rapid calcium fluxes (within 30 s), loss of mitochondrial membrane potential, increases in reactive oxygen species (from 6 h after medium transfer), …

Sketch-Based Image Queries In Topographic Databases, James Carswell

Articles

In this paper we present the development of a system prototype for sketch-based queries for the content-based retrieval of digital images from topographic databases. We discuss our overall strategy and associated algorithmic and implementation aspects, and present associated database design issues. The query tools devised in this research are employing user-provided sketches of the shape and spatial configuration of the object(s) which should appear in the images to be retrieved. Our matching tool is inspired by least-squares matching (lsm), and represents an extension of lsm to function with a variety of raster representations. Our strategy makes use of a hierarchical …

Temperature Dependence Of Stark Width Of The 463.054 Nm Nii Spectral Line, Vladimir Milosavljevic, Ruzica Konjevic, Stevan Djenize

Articles

Stark width of the 463.054 nm singly ionized nitrogen spectral line, that belong to transition, have been measured in a linear pulsed, low pressure, arc discharge. The working gas was helium-nitrogen-oxygen mixture. Electron densities of 0.7510²³ to 1.4510²³ were determined in the electron temperature range between 30000 K - 38000 K. The measured values have been compared with our calculated data, using the modified semiempirical approximation. On the basis of the agreement among experimental and theoretical Stark width data, the isolated 463.054 nm NII spectral line can be recommended as convenient spectral line for plasma diagnostics.

Note On The Voltammetry Of Ferrocene Carboxylate In Aqueous Solution, John Cassidy, John O'Gorman, M. Ronane, Enda Howard

Articles

Cyclic voltammetry of ferrocene dicarboxylate in aqueous solutions at high pH, in the presence of oxygen, showed evidence of an EC' mechanism where the oxidised form of ferrocene dicarboxylate reacts with H02- , which had been produced at a lower potential. However, an analogous experiment with ferrocene carboxylate yielded a cyclic voltammogram with a post peak: following the anodic peak: for ferrocene carboxylate. The reason for the post peak: is not clear but may be due to a delay in the reaction between the oxidised form of ferrocene carboxylate and H02-.

Use Of Excel To Obtain Voltammetric Information On Microelectrodes, Enda Howard, John Cassidy

Articles

The use of curve fitting for the analysis and interpretation of voltammetric data obtained while working with micro electrodes is discussed as a useful exercise for introducing students to the principle of problem solving using least-squares curve-fitting techniques. The advantages associated with this approach to data processing over the approach where the limiting current (i L) alone is used are discussed and its limitations are highlighted. This technique was applied to the determination of unknown concentrations of ferrocyanide and the most satisfactory recovery of concentrations was found when both the va1ues of the formal potential (EO') and concentration ( C) …

Experimental Observation Of Individual Single Wall Nanotube Species By Raman Microscopy, G. S. Duesberg, W. Blau, Hugh Byrne, J. Muster, M. Burghard, S. Roth

Articles

Individual single-wall carbon nanotubes (SWNT) or small ropes of SWNTs with the same diameter have been characterised by Raman spectroscopy. Highly pure, length-selected SWNTs adsorbed onto substrates designed for surface-enhanced Raman spectroscopy were investigated with a Raman microscope. Various spectra, each with a distinct sharp peak in the radial breathing mode area and four C–C stretching modes could be observed. The modes also showed a strong variation in the relative intensities. In correlation with theoretical predictions this should establish Raman microscopy as a non-destructive nano-technological tool, capable of determining the diameter, symmetry and position of individual SWNTs.

Measured Stark Widths And Shifts Of Several Niii Sectral Lines: Temperature Dependence, Stevan Djenize, Vladimir Milosavljevic

Articles

Stark parameters (width and shift) of four doubly ionized nitrogen spectral lines, that belong to 3s-3p and 3p-3d transitions (lower multiplets), have been measured in a linear pulsed, low pressure, arc discharge in the nitrogen-oxygen and helium-nitrogen-oxygen plasmas in a (30 000 - 54 000) K electron temperature and a (0.75 10²³ - 2.8 10²³) electron density ranges. The measured values have been compared to the existing experimental and calculated data.

Transitive And Fully Transitive Groups, Steve Files, Brendan Goldsmith

Articles

The notions of transitivity and full transitivity for abelian p-groups were introduced by Kaplansky in the 1950s. Important classes of transitive and fully transitive p-groups were discovered by Hill, among others. Since a 1976 paper by Corner, it has been known that the two properties are independent of one another. We examine how the formation of direct sums of p-groups affects transitivity and full transitivity. In so doing, we uncover a far-reaching class of p-groups for which transitivity and full transitivity are equivalent. This result sheds light on the relationship between the two properties for all p-groups.

On Unit Sum Number Of Rings And Modules, Brendan Goldsmith, S. Pabst, A. Scott

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No abstract available

Electroanalysis Using Differential Pulse Methods At A Microelectrode, Enda Howard, John Cassidy, John O'Gorman

Articles

This communication characterises the differential pulse voltammetric response of ultramicroelectrodes in connection with two different models

On The Stark Broadening Parameters Of The Two Nii Spectral Lines Of The 3d-4f Transition, Vladimir Milosavljevic, Stevan Djenize

Articles

Stark parameters (width and shift) of two singly ionized nitrogen spectral lines, that belong to 3d-4f transition have been measured in a linear pulsed, low pressure, arc discharge in the nitrogen-oxygen plasma at a 54000 K electron temperature and at a 2.8×10 23 m−3 electron density. The measured values have been compared to the existing experimental and calculated data

Describing Ideals Of Endomorphism Rings, Brendan Goldsmith, Simone Pabst

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No abstract available.

Diffraction From Polarization Holographic Gratings With Surface Relief In Side-Chain Azobenzene Polyesters, Izabela Naydenova, Ludmila Nikolova, Todor Todorov, N.C.R. Holme, P.S. Ramanujam, S. Hvilsted

Articles

We investigate the polarization properties of holographic gratings in side-chain azobenzene polyesters in which an anisotropic grating that is due to photoinduced linear and circular birefringence is recorded in the volume of the material and a relief grating appears on the surface. A theoretical model is proposed to explain the experimental results, making it possible to understand the influence of the different photoinduced effects. It is shown that at low intensity the polarization properties of the diffraction at these gratings are determined by the interaction of the linear and circular photobirefringences, and at larger intensity the influence of the surface …

Hypertext Theory And Narrative, Eoin Kilfeather

Articles

No abstract provided.

A Formal Preparation For Object-Oriented Query Optimisation, Catherine Higgins

Articles

This paper describes work that is in progress on a formalised preparation to object-oriented query optimisation. Such preparation is conducive to the development of optimisation strategies. As an example of a formal preparation, this paper presents a formalised object algebra, a suggested optimisation method and an implementation of an algebraic converter suitable for DAPLEX.

On Transitive And Fully Transitive Abelian P-Groups, D. Carroll, Brendan Goldsmith

Articles

It is a long standing problem of A.L.S. Corner as to whether there exists a non-transitive fully transitive Abelian p-group with finite Ulm subgroups. The principal result of this paper shows that no such group exists for a special class of p-groups if the Ulm subjgroup is the direct sum of two cyclic groups. Some results on summands of trnsitive and fully transitive groups are obtained.

Rotating Disk Ion Selective Electrodes, John Cassidy, David Mullen, Karen Casey, Patrick Cullen

Articles

A simulation was undertaken to predict the transient potential response following a concentration step at a rotating disk electrode comprised of an ion selective layer. A basis for this simulation was that the potential response would be independent of rotation rate since the diffusion layer is larger than the double layer at the electrode. In practice it was found that the potential response does vary with rotation rate. The response was such that the apparent concentration of the analyte in solution decreased with increased rotation rate. The reason for this behavior is due to the disruption of the double layer …

Measured Stark Widths Of A 425,94 Nm Ari Spectral Line, Ljiljana Skuljan, Vladimir Milosavljevic, Aleksandar Sreckovic, Stevan Djenize

Articles

No abstract provided.

Chp And Energy Conservation, Jim Mcgovern

Articles

The principles of the use of 'combined heat and power' (CHP) for the achievement of fuel energy conservation, minimisation of environmental impact and economic advantage are explained. A distinction is made between the two types of outputs: heat and work. It is argued that an efficiency value that is defined as the sum of the heat and work outputs divided by the energy of the fuel used is not very meaningful. An alternative, rational, efficiency is explained. It is concluded that CHP is an option to be considered where both heating and power are required, but is not a general …

The Trace Of An Abelian Group:An Application To Digraphs, J. M. Burns, Brendan Goldsmith

Articles

The trace of a finite Abelian group is used to give a short proof of a result of Arlinghaus and Harary on the digraph number of such a group

Experimental Stark Shift Of Several Nii And Oii Spectral Lines, Mara Scepanovic, Vladimir Milosavljevic, Stevan Djenize, Mihajlo Platisa, Jaroslav Labat

Articles

Stark shift of four NII and seven OII spectral lines have been measured for the first time in the linear low pressure pulsed arc plasma and compared with existing theoretical values.

Dielectric Response Of Ferroelectric Liquid Crystal Cells, Yuri Panarin, Huan Xu, Seamus Mac Lughadha, Jagdish Vij

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No abstract provided.

On Endomorphisms And Automorphisms Of Some Pure Subgroups Of The Baer-Specker Group, A. L.S. Corner, Brendan Goldsmith

Articles

The endomoprhism algebras of certain pure subgroups of the Baer-Specker group are investigated to answer a question of Irwin. Automorphism groups of these Abelian groups are investigated and a realization theme is established.