Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

Technological University Dublin

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 2311 - 2340 of 2381

Full-Text Articles in Physical Sciences and Mathematics

The Design And Construction Of An Out-Of-Plane Sensitive Electronic Speckle Pattern Interferometer For Non-Destructive Testing Applications, Alexander Burden Aug 1999

The Design And Construction Of An Out-Of-Plane Sensitive Electronic Speckle Pattern Interferometer For Non-Destructive Testing Applications, Alexander Burden

Masters

There are many non-destructive testing (NDT) techniques use din industry, which employ acoustic emission, ultrasound, X-rays and thermography. Optical interferometric methodology is being increasingly used in industry. Electronic Speckle Pattern Interferometry (ESPI) is one of the principal optical interferometric techniques used in NDT to measure deformations. Optical surface metrology offers many advantages over conventional methods. These include greater sensitivity, improved lateral and vertical resolution, non-contact and full field measurement. Conventional methods of NDT however continue to be chosen over ESPI. The objective of this thesis is focused on making ESPI more feasible as a NDT technique for use in industry. …

Go to article

Sketch-Based Image Queries In Topographic Databases, James Carswell Jun 1999

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 …

Go to article

An Investigation Into The Use Of The Virtual Reality Modelling Language (Vrml) As A Means Of Distribution Virtual Reality Tourist Information Across The World Wide Web, Hugh Mcatamney, Ciaran Mcdonnell May 1999

An Investigation Into The Use Of The Virtual Reality Modelling Language (Vrml) As A Means Of Distribution Virtual Reality Tourist Information Across The World Wide Web, Hugh Mcatamney, Ciaran Mcdonnell

Conference papers

The purpose of the work described was to investigate the use of the Virtual Reality Modelling Language (VRML) as a tool to distribute tourist information across the web. This was done by the creation of a web site containing two Virtual Reality models of tourist interest. These were then valuated using a number of techniques both online and offline. This paper describes the methods used to create and evaluate these models as well as giving a overview of some of the results obtained.

Go to article

Temperature Dependence Of Stark Width Of The 463.054 Nm Nii Spectral Line, Vladimir Milosavljevic, Ruzica Konjevic, Stevan Djenize Mar 1999

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.

Go to article

A Feature Library Approach To On-Line Image Querying And Retrieval For Topographic Applications, James Carswell Jan 1999

A Feature Library Approach To On-Line Image Querying And Retrieval For Topographic Applications, James Carswell

Conference papers

In this paper we address the problem of content-based image retrieval using queries on shape and topology. We focus on the particularities of image databases encountered in typical topographic applications, and present the development of a spatial data management system that enables such queries. The query uses as input user-provided sketches of the shape and spatial configuration of the object (or objects) which should appear in the images to be retrieved. The objective of the search is to retrieve images that contain a configuration of objects sufficiently similar to the one specified in the query. Our novel approach introduces the …

Go to article

Note On The Voltammetry Of Ferrocene Carboxylate In Aqueous Solution, John Cassidy, John O'Gorman, M. Ronane, Enda Howard Jan 1999

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-.

Go to article

The Development And Validation Of A Methodology For The Analysis Of Polyaromatic Hydrocarbons In Air Particulates (Indoor And Outdoor), Kathryn O'Malley Jan 1999

The Development And Validation Of A Methodology For The Analysis Of Polyaromatic Hydrocarbons In Air Particulates (Indoor And Outdoor), Kathryn O'Malley

Masters

PAH form a large class of ubiquitous pollutants mainly of anthropogenic origin. Several PAH found in air particulates have been identified as carcinogens and mutagens. Sixteen of these PAH have been listed by the USEPA as priority pollutants. This research is concerned with the development and optimisation of a method for the analysis of these sixteen PAH in air particulates. Soxhlet and ultrasonic extraction procedures were investigated to optimise the recoveries from spiked glass fibre filters with a standard 1ppm mixture of the 16PAH. Standard mixtures of the 16 PAH were analysed by HPLC with fluorescence detection with approx. linearity …

Go to article

Studies On The Amylolytic Breakdown Of Damaged Starch In Cereal And Non-Cereal Flours, Karen Bailey Jan 1999

Studies On The Amylolytic Breakdown Of Damaged Starch In Cereal And Non-Cereal Flours, Karen Bailey

Masters

The term starch damage refers to a number of changes to the starch granule structure, which are detectable by different analytical techniques. Damaged starch is the substrate for amylases, which in turn provides carbohydrates that are used in the production of certain foods and food ingredients; as a result, therefore, determination of levels in flours is a procedure carried out routinely by many manufacturers of starch based products. Enzymatic assay methods emulate the susceptibility of damaged starch granules to enzymatic attack. The first aim of this study was to evaluate enzymatic methods(1,2) to determine damaged starch in wheat flours and …

Go to article

Use Of Excel To Obtain Voltammetric Information On Microelectrodes, Enda Howard, John Cassidy Jan 1999

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) …

Go to article

Experimental Observation Of Individual Single Wall Nanotube Species By Raman Microscopy, G. S. Duesberg, W. Blau, Hugh Byrne, J. Muster, M. Burghard, S. Roth Jan 1999

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.

Go to article

Reactions Of Chlorine Atoms With Aromatic Compounds, Barbara O'Leary Oct 1998

Reactions Of Chlorine Atoms With Aromatic Compounds, Barbara O'Leary

Masters

This thesis presents the results of kinetic studies on the reactions of chlorine atoms with a series of aromatic compounds. (please see full text for complete abstract)

Go to article

The Development And Characterisation Of A Red-Sensitised Photopolymer Holographic Recording Material, Clodagh Feely Oct 1998

The Development And Characterisation Of A Red-Sensitised Photopolymer Holographic Recording Material, Clodagh Feely

Doctoral

The development and characterisation of a photopolymerisable photopolymer holographic recording material, for red sensitisation is described. The material comprises dye (methylene blue), an electron donor (triethanolamine) and monomer (acrylamide and methylene-bis-acrylamide). A binder is also included (poly(vinylalcohol) to allow recording in dry layer format. One of the main advantages of the material is its ability to self-develop, which makes it highly suitable for a range of applications which includes the fabrication of Holographic Optical Elements (HOEs). The optimisation of the material formula for red-sensitisation using holographic techniques is described. Diffraction efficiencies of over 70% were obtained in 25 seconds with …

Go to article

Measured Stark Widths And Shifts Of Several Niii Sectral Lines: Temperature Dependence, Stevan Djenize, Vladimir Milosavljevic Aug 1998

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.

Go to article

Digital Image Retrieval Using Shape-Based Queries, James Carswell Jul 1998

Digital Image Retrieval Using Shape-Based Queries, James Carswell

Conference papers

In this paper we present the development of a spatial data management system utilizing sketch-based queries for the content-based retrieval of digital images from topographic databases. We discuss our overall strategy and associated algorithmic and implementational aspects, and present the 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 strategy is scale-independent. It is inspired by least-squares matching (lsm), and represents an extension of lsm to function with a variety of raster representations. The results …

Go to article

Endomorphism Rings And Automorphism Groups Of Separable Torsion-Free Modules Over Valuation Domains, Brendan Goldsmith, P. Zanardo Jan 1998

Endomorphism Rings And Automorphism Groups Of Separable Torsion-Free Modules Over Valuation Domains, Brendan Goldsmith, P. Zanardo

Book chapter/book

No abstract provided.

Go to article

Isomorphic Automorphism Groups Of Torsion-Free P-Adic Modules, Brendan Goldsmith, A. L. S. Corner Jan 1998

Isomorphic Automorphism Groups Of Torsion-Free P-Adic Modules, Brendan Goldsmith, A. L. S. Corner

Book chapter/book

No abstract provided.

Go to article

Transitive And Fully Transitive Groups, Steve Files, Brendan Goldsmith Jan 1998

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.

Go to article

On Unit Sum Number Of Rings And Modules, Brendan Goldsmith, S. Pabst, A. Scott Jan 1998

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

Articles

No abstract available

Go to article

Characterisations Of Slender Groups, Thomas Kelly Jan 1998

Characterisations Of Slender Groups, Thomas Kelly

Masters

Chapter 1 summarises some necessary results concerning free, divisible, algebraically compact and cotorsion groups. A detailed proof of the well-known result that the Specker group P is ℵ1 free but not free is included and the structure of the quotient group P/S is determined. The basic properties of slender groups are examined and cotorsion groups of cardinality less than or equal to that of the continuum are shown to be epimorphic images of P. Chapter II presents Nunke’s characterisation of slender groups. This approach establishes that homomorphic images of the Specker group P are the direct sum of a cotorsion …

Go to article

Electroanalysis Using Differential Pulse Methods At A Microelectrode, Enda Howard, John Cassidy, John O'Gorman Jan 1998

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

Go to article

On The Stark Broadening Parameters Of The Two Nii Spectral Lines Of The 3d-4f Transition, Vladimir Milosavljevic, Stevan Djenize Jun 1997

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

Go to article

Describing Ideals Of Endomorphism Rings, Brendan Goldsmith, Simone Pabst Jan 1997

Describing Ideals Of Endomorphism Rings, Brendan Goldsmith, Simone Pabst

Articles

No abstract available.

Go to article

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 Jan 1997

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 …

Go to article

Solvent Impregnated Resins For The Recovery Of Gold From Gold(I)Thiourea Solutions, Fiona Fitzpatrick Jan 1997

Solvent Impregnated Resins For The Recovery Of Gold From Gold(I)Thiourea Solutions, Fiona Fitzpatrick

Masters

Solvent Impregnated Resins (SIRs) are high surface area, macroporous, polymeric resins which have been physically impregnated with an organic solvent. In this research, three resins have been impregnated with Di-2-ethylhexyl phosphoric acid, a solvent which has shown selectivity to gold. The ability of the resins to recover gold (1) thiourea perchlorate from solution has been investigated. The resins have been studied both bare and when impregnated with the solvent and their efficiency was seen to increase upon impregnation. The overall efficiency of the resins was found to be pH dependent. It is also related to the level of impregnation of …

Go to article

Synthesis And Characterisation Of New Dimolybdenum (Ii,Ii) Dicarboxylates And Their Use As Polymerization Catalysts, Elizabeth Whelan Aug 1996

Synthesis And Characterisation Of New Dimolybdenum (Ii,Ii) Dicarboxylates And Their Use As Polymerization Catalysts, Elizabeth Whelan

Masters

The purpose of this work was to prepare a series of new dimolybdenum(II,II) dicarboxylate complexes, to characterize the complexes and to investigate their use as potential catalysts for the ring-opening metathesis polymerization (ROMP) of the bicyclic monomer norbornene.

Go to article

Hypertext Theory And Narrative, Eoin Kilfeather Jan 1996

Hypertext Theory And Narrative, Eoin Kilfeather

Articles

No abstract provided.

Go to article

A New Archaeoastronomical Investigation Of The Irish Axial-Stone Circles, Frank T. Prendergast, Clive L. Ruggles Jan 1996

A New Archaeoastronomical Investigation Of The Irish Axial-Stone Circles, Frank T. Prendergast, Clive L. Ruggles

Conference Papers

This paper presents the preliminary results of a project undertaken in 1994 to investigate the astronomical potential of the axial-stone circles (ASCs) of seven or more stones in Counties Cork and Kerry, south-west Ireland. This group of sites is of particular interest in that the monuments in the group bear a striking resemblance to the recumbent stone circles (RSCs) of Aberdeenshire, eastern Scotland, which appear to exhibit a strong pattern of alignment in relation to prominent hilltop summits and the rising and setting position of the moon. The first indications from the Irish data are that similar patterns of alignment …

Go to article

A Formal Preparation For Object-Oriented Query Optimisation, Catherine Higgins Jan 1996

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.

Go to article

On Transitive And Fully Transitive Abelian P-Groups, D. Carroll, Brendan Goldsmith Jan 1996

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.

Go to article

Rotating Disk Ion Selective Electrodes, John Cassidy, David Mullen, Karen Casey, Patrick Cullen Jan 1996

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 …

Go to article

First Prev Next Last