Digital Commons Network^™

A Review Of Doppler Ultrasound Quality Assurance Protocols And Test Devices, Jacinta Browne

Articles

In this paper, an overview of Doppler ultrasound quality assurance (QA) testing will be presented in three sections. The first section will review the different Doppler ultrasound parameters recommended by professional bodies for use in QA protocols. The second section will include an evaluation and critique of the main test devices used to assess Doppler performance, while the final section of this paper will discuss which of the wide range of test devices have been found to be most suitable for inclusion in Doppler QA programmes. Pulsed Wave Spectral Doppler, Colour Doppler Imaging QA test protocols have been recommended over …

Mechanism Of Multiple Grating Formation In High-Energy Recording Of Holographic Sensors, Ali K. Yetisen, Yunuen Montelongo, Nicholas M. Farandos, Izabela Naydenova, Christopher R. Lowe, Seok Hyun Yun

Articles

We report numerical analyses of Bragg diffraction by Denisyuk reflection holograms recorded by a high-energy pulsed laser. An intensity threshold must be passed to pattern a multilayer reflection and transmission hologram, which exhibits a nonlinear fringe structure. Numerical evaluations are provided for the laser light intensity, readout diffraction offset angle, transmission of the layer, and thickness of the polymer matrix during hologram recording. A non-sinusoidal surface pattern is formed at the top of the multilayer structure, and its effect on the diffraction properties of the structure becomes significant when the recording tilt angle is increased. Experimental results show that the …

Suppression Of Raman Soliton Self-Frequency Shift In Photonic Cystal Fibers With Tellurite Subwavelength Core, Shua Wei, Jinhui Yuan, Chongxiu Yu, Sha Li, Boyuan Jin, Xiaoming Hu, Gerald Farrell, Qiang Wu

Articles

A new nonlinear evolution equation including the vector nature of the electromagnetic field and the frequency variation of the mode profile is derived. A kind of new nonlinearity is demonstrated. Its magnitude is strongly dependent on the waveguide geometrical parameters, which will lead to a suppression of the Raman soliton self-frequency shift in a photonic crystal fiber with a tellurite subwavelength core. Our results can be supported by the detailed numerical simulations

Photonic Crystal Fiber Half-Taper Probe Based Refractometer, Pengfei Wang, Ming Ding, Lin Bo, Chunying Guan, Yuliya Semenova, Weimin Sun, Libo Yuan, Gilberto Brambilla, Gerald Farrell

Articles

A compact singlemode - photonic crystal fibre - singlemode fibre tip (SPST) refractive index sensor is demonstrated in this paper. A CO₂ laser cleaving technique is utilsed to provide a clean-cut fibre tip which is then coated by a layer of gold to increase reflection. An average sensitivity of 39.1 nm/RIU and a resolvable index change of 2.56×10^-4 are obtained experimentally with a ~3.2 µm diameter SPST. The temperature dependence of this fiber optic sensor probe is presented. The proposed SPST refractometer is also significantly less sensitive to temperature and an experimental demonstration of this reduced sensitivity is …

Resilient Digital Image Watermarking For Document Authentication, Jonathan Blackledge, Oleksandr Iakovenko

Articles

Abstract—We consider the applications of the Discrete Cosine Transform (DCT) and then a Chirp coding method for producing a highly robust system for watermarking images using a block partitioning approach subject to a self-alignment strategy and bit error correction. The applications for the algorithms presented and the system developed include the copyright protection of images and Digital Right Management for image libraries, for example. However, the principal focus of the research reported in this paper is on the use of printscan and e-display-scan image authentication for use in e-tickets where QR code, for example, are embedded in a full colour …

Ireland's Tidal Energy Resource: An Assessment Of A Site In The Bulls Mouth And The Shannon Estuary Using Measured Data, Fergal O'Rourke, Fergal Boyle, Anthony Reynolds

Articles

The issues associated with Ireland’s over reliance on fossil fuels to meet energy demands have sparked an interest in renewable energy. Renewable energy resources typically are intermittent and vary significantly in energy intensity. Tidal energy however has the advantage of predictability over large time scales and high power densities. A study of Ireland's tidal-current-energy resource has identified several viable sites. As part of this resource assessment, Acoustic Doppler Current Profilers were installed at two locations along Ireland's west coast, at a site in the Bulls Mouth and the Shannon Estuary. The Acoustic Doppler Current Profilers measured tidal current speed and …

A Review Of Psychometric Data Analysis And Applications In Modelling Of Academic Achievement In Tertiary Education, Geraldine Gray, Colm Mcguinness, Philip Owende, Aiden Carthy

Articles

Increasing college participation rates, and diversity in student population, is posing a challenge to colleges in their attempts to facilitate learners achieve their full academic potential. Learning analytics is an evolving discipline with capability for educational data analysis that could enable better understanding of learning process, and therefore mitigate these challenges. The outcome from such data analysis will be dependent on the range, type, and quality of available data and the type of analysis performed. This study reviewed factors that could be used to predict academic performance, but which are currently not systematically measured in tertiary education. It focused on …

Getting Started With Research " Beginning: Defining A Research Question And Preparing A Research Plan, Jacinta Browne

Articles

Research is the lifeblood of medicine with innovations being made in the different technologies used to diagnose and / or screen for the presence of disease or to deliver treatments with higher efficacy. Scientific publication is the network of vessels which delivers the lifeblood. The outputs of research provides us with tomorrows medicine. In this series of articles we will be discussing the different aspects of carrying out research from the conception of the research idea to publication in a peer reviewed journal with the cycle repeating again with new research ideas emerging from the research conducted.

Getting Started With Research " Writing-Up The Results Of Your Research", Jacinta Browne

Articles

This paper gives an overview of the considerations and practical aspects of writing-up the results of your research which may be of interest to those beginning their research career or simply carrying out a research project for the first time as part of an academic qualification. It outlines practical steps for both writing-up the results of your research as an academic report and thereafter disseminating your results more widely as a peer-reviewed scientific publication.

Getting Started With Research "Carrying Out Your Research Project", Jacinta Browne

Articles

This paper gives an overview of the considerations and practical aspects of carrying out a research project which may be of use to those beginning their research career or simply carrying out a research project for the first time as part of an academic qualification. It outlines practical steps for consideration in the day to day management of a research project and highlights areas which require particular consideration for a project to be completed successfully.

Investigation Of The Sensitivity To Humidity Of An Acrylamide-Based Photopolymer Containing N-Phenylglycine As A Photoinitiator, Tatsiana Mikulchyk, Suzanne Martin, Izabela Naydenova

Articles

Sensitivity of holographic recording materials to the relative humidity (RH) of the environment often restricts their use in fabrication of holographic optical elements and other applications. It is important to develop materials with little or no sensitivity to humidity. In this paper the humidity response of transmission gratings recorded in an acrylamide-based photopolymer containing N-phenylglycine (NPG) as a photoinitiator is studied at RH = 20 – 90 %. The hologram is found to be completely insensitive to humidity at RH below 70 % and its diffraction efficiency remains constant. A decrease in diffraction efficiency is observed at RH = 80 …

Holographic Sensors: Three-Dimensional Analyte-Sensitive Nanostructures And Their Applications, Ali K. Yetisen, Izabela Naydenova, Fernando Da Cruz Vasconcellos, Jeffrey Blyth, Christopher R. R. Lowe

Articles

Holographic sensors are analytical devices that systematically diffract narrow-band light in the ultraviolet to near-infrared range for application in the detection and quantification of analytes and/or physical parameters. They can be functionalized with analyte-responsive materials to construct highly sensitive optical sensors for use in testing, where a visual readout, fast turnaround time, and reversibility are needed. Holography allows fabrication of disposable sensors that are lightweight for miniaturization and multiplexing purposes.3 Holographic sensors offer three capabilities on a single analytical device: (i) label-free analyte-responsive polymer, (ii) real-time, reversible quantification of the external stimuli, and (iii) three-dimensional visual image display.

An Audit Of A Hospital-Based Doppler Ultrasound Quality Control Protocol Using A Commercial String Doppler Phantom, S. Cournane, Andrew Fagan, Jacinta Browne

Articles

Results from a four-year audit of a Doppler quality assurance (QA) program using a commercially available Doppler string phantom are presented. The suitability of the phantom was firstly determined and modifications were made to improve the reliability and quality of the measurements. QA of Doppler ultrasound equipment is very important as data obtained from these systems is used in patient management. It was found that if the braided-silk filament of the Doppler phantom was exchanged with an O-ring rubber filament and the velocity range below 50cm/s was avoided for Doppler quality control (QC) measurements, then the Maximum Velocity Accuracy (MVA) …

The Utility Of Deformable Image Registration For Small Artery Visualisation In Contrast-Enhanced Whole Body Mr Angiography, Daniel Foley, Jacinta Browne, Xiahai Zhuang, Barry Sheane, Dearbhail O'Driscoll, Daniel Cannon, Niall Sheehy, James Meaney, Andrew Fagan

Articles

Purpose;

An investigation was carried out into the effect of three image registration techniques on the diagnostic image quality of contrast-enhanced magnetic resonance angiography (CE-MRA) images.

Methods Whole-body CE-MRA data from the lower legs of 27 patients recruited onto a study of asymptomatic atherosclerosis were processed using three deformable image registration algorithms. The resultant diagnostic image quality was evaluated qualitatively in a clinical evaluation by four expert observers, and quantitatively by measuring contrast-to-noise ratios and volumes of blood vessels, and assessing the techniques’ ability to correct for varying degrees of motion.

Results The first registration algorithm (‘AIR’) introduced significant stenosis-mimicking …

Economic Valuation Of The Mortality Benefits Of A Regulation On So2 In 20 European Cities, Olivier Chanel, Susann Henschel, Patrick J. Goodman, Antonis Analitis, Richard W. Atkinson, Alain Le Tertre, Ariana Zeka, Sylivia Medina

Articles

Background: Since the 1970s, legislation has led to progress in tackling several air pollutants. We quantify the annual monetary benefits resulting from reductions in mortality from the year 2000 onwards following the implementation of three European Commission regulations to reduce the sulphur content in liquid fuels for vehicles. Methods: We first compute premature deaths attributable to these implementations for 20 European cities in the Aphekom project by using a two-stage health impact assessment method. We then justify our choice to only consider mortality effects as short-term effects. We rely on European studies when selecting the central value of …

New Insights Into The Mechanism Of Visible Light Photocatalysis, Suresh Pillai, Swagata Banerjee, Polycarpos Falaras, Kevin O'Shea, John A. Byrne, Dionysios D. Dionysiou

Articles

ABSTRACT: In recent years, the area of developing visible-lightactive photocatalysts based on titanium dioxide has been enormously investigated due to its wide range of applications in energy and environment related fields. Various strategies have been designed to efficiently utilize the solar radiation and to enhance the efficiency of photocatalytic processes. Building on the fundamental strategies to improve the visible light activity of TiO2-based photocatalysts, this Perspective aims to give an insight into many contemporary developments in the field of visible-light-active photocatalysis. Various examples of advanced TiO2 composites have been discussed in relation to their visible light induced photoconversion efficiency, dynamics …

Photocatalytic Activity Indicator Inks For Probing A Wide Range Of Surfaces, Suresh Pillai, Andrew Mills, James Hepburn, David Hazafy, Christopher O'Rourke, Nathan Wells, Josef Krysa, Michal Baudys, Martin Zlamal, Hana Bartkova, Claire E. Hill, Kim R. Winn, Morten E. Simonsen, Erik G. Sogaard, Swagata Banerjee, Rachel Fagan

Articles

Three photocatalyst inks based on the redox dyes, Resazurin (Rz), Basic Blue 66 (BB66) and Acid Violet 7 (AV7, are used to assess the photocatalytic activities of a variety of different materials, such as commercial paint, tiles and glass and laboratory made samples of sol-gel coated glass and paint, which collectively exhibit a wide range of activities that cannot currently be probed by any one of the existing ISO tests. Unlike the ISO tests, the ink tests are fast (typically < 10 min), simple to employ and inexpensive. Previous work indicates that the Rz ink test at least correlates linearly with other photocatalytic tests such as the photomineralisation of stearic acid. The average time to bleach 90% of the key RGB colour component of the ink (red for Rz and BB66 inks) and green for AV7 ink) is determined, ttb(90), for eight samples of each of the different materials tested. Five laboratories conducted the tests and the results revealed an average repeatability and reproducibility of: ca. 11% and ca 21%, respectively, which compare well with those reported for the current ISO tests. Additional work on commercial self-cleaning glass using an Rz ink showed that the change in the red component of the RGB image of the ink correlated linearly with that of the change of absorbance (at 608 nm) (as measured using UV/Vis spectroscopy) and the change in the a* component of the Lab colour analysis of the ink, as measured using diffuse reflectance spectroscopy. As a consequence, all three methods generate the same ttb(90). The advantages of the RGB digital image analysis method are discussed briefly.

Breast Cancer Detection Using Interferometric Music: Experimental And Numerical Assessment, Giuseppe Ruvio, Raffaele Solimene, Antonio Cuccaro, Domenico Gaetano, Jacinta Browne, Max Ammann

Articles

Purpose: In microwave breast cancer detection it is often beneficial to arrange sensors in close proximity to the breast. The resulting coupling generally changes the antenna response. As an a priori characterization of the radio-frequency system becomes difficult, this can lead to severe degradation of the detection efficacy. The purpose of this paper is to demonstrate advantages of adopting an Interferometric Multiple Signal Classification (I-MUSIC) approach due to its limited dependence 25 from a priori information on the antenna. The performance of I-MUSIC detection was measured in terms of Signal-to-Clutter Ratio (SCR), Signal-to-Mean Ratio (SMR) and Spatial Displacement (SD) and …

Diagnostics Of An O2–He Rf Atmospheric Plasma Discharge By Spectral Emission, Vladimir Milosavljevic, Mick Donegan, Patrick J. Cullen, Denis Dowling

Articles

In this paper optical emission spectroscopy (OES) is used as a Diagnostic technique for the measurement of atomic and molecular spectral emissions generated using a helium rf industrial atmospheric plasma jet system. The OES of neutral atomic spectral lines and molecular bands are investigated over a range of plasma process parameters.
/="/">Wavelength resolve optical emission profiles suggest that the emission of helium’s spectral lines shows that the high energy electrons have a larger influence than helium metastables on the overall spectral emission. Furthermore, the experimental data indicates that the use of high helium flow rates, in any confined open …

Play Hard, Work Harder. Alternative Reality Game And Scenario Based Assessments For Learning., Barry Ryan

Articles

In this paper, an evaluative case study is detailed as an example of alternative reality game and scenario based assessments for learning. This pedagogic approach is evaluated and recommendations for practice offered. Integrating technology into the assessment process, and final student product, influenced the chosen pedagogy. The use of technology permitted this assessment approach to be adopted for a medium sized (n=40) student cohort. The use of wikis, eportfolios and digital reflective diaries were central to creating a learning environment that centralised the student and allowed them to construct and create their knowledge through scaffolded alternative reality games and scenarios. …

Fully Inert Subgroups Of Abelian P-Groups, Brendan Goldsmith, Luigi Salce, Paolo Zanardo

Articles

A subgroup H of an Abelian group G is said to be fully inert in G, if for every endomorphism ϕ of G, the factor group (H+ϕ(H))/H" role="presentation"> is finite. This notion arises in the study of the dynamical properties of endomorphisms (entropy). The principal result of this work is that fully inert subgroups of direct sums of cyclic p-groups are commensurable with fully invariant subgroups of the direct sum.

Concern-Driven Integrated Toxicity Testing Strategies For Nanomaterials - Report Of The Nanosafety Cluster Working Group 10, Hugh Byrne, Agnes G. Oomen, Peter M.J. Bos, Teresa F. Fernandes, Kerstin Hund-Rinke, Diana Boraschi, Karin Aschberger, Stefania Gottardo, Frank Von Der Kammer, Dana Kühnel, Danail Hristozov, Antonio Marcomini, Lucia Migliore

Articles

Bringing together topic-related European Union-(EU)-funded projects, the so-called “NanoSafety Cluster” aims at identifying key areas for further research on risk assessment procedures for nanomaterials (NM). The outcome of NanoSafety Cluster Working Group 10, this commentary presents a vision for concern-driven integrated approaches for the (eco-)toxicological testing and assessment (IATA) of NM. Such approaches should start out by determining concerns, i.e. specific information needs for a given NM based on realistic exposure scenarios. Recognized concerns can be addressed in a set of tiers using standardized protocols for NM preparation and testing. Tier 1 includes determining physico-chemical properties, non-testing (e.g. structure …

Effect Of Substrate Choice And Tissue Type On Tissue Preparation For Spectral Histopathology By Raman Microspectroscopy, Hugh Byrne, Leanne M. Fullwood, Dave Griffiths, Katherine Ashton, Timothy Dawson, Robert W. Lea, Charles Davis, Franck Bonnier, Matthew J. Baker

Articles

Raman spectroscopy is a non-destructive, non-invasive, rapid and economical technique which has the potential to be an excellent method for the diagnosis of cancer and understanding disease progression through retrospective studies of archived tissue samples. Historically, biobanks are generally comprised of formalin fixed paraffin preserved tissue and as a result these specimens are often used in spectroscopic research. Tissue in this state has to be dewaxed prior to Raman analysis to reduce paraffin contributions in the spectra. However, although the procedures are derived from histopathological clinical practice, the efficacy of the dewaxing procedures that are currently employed is questionable. Ineffective …

Omnidirectional Microstrip Patch Antenna With Reconfigurable Pattern And Polarisation, Max Ammann, Xiulong Bao, Adam Narbudowicz

Articles

An omnidirectional microstrip patch antenna, capable of reconfiguring both polarisation and radiation pattern is proposed. It operates with two orthogonal ±45° slanted linear polarisations and can produce two dipole-like radiation patterns, providing 360° coverage in either the horizontal or elevation plane. With appropriate steering, this enables a single antenna to provide full spherical coverage for any polarisation. The reconfiguration is realised by phase shifting, thus does not require switching elements, such as MEMS or pin diodes embedded into antenna. The basic principles of operation are discussed and validated by numerical and measured data.

Two Models Of Unpatentable Subject Matter, Alan L. Durham

Articles

Patentable subject matter has become one of the most controversial areas of patent law Efforts to articulate a lucid and productive theory of patentable subject matter must acknowledge that there are two competing models of unpatentable subject matter One posits that natural laws natural phenomena and abstract ideas are themselves ineligible for patenting and that each example of a natural law natural phenomenon or abstract idea further defines a class of inventions that cannot be patented because they lack an additional element of ingenuity "” or "inventive concept" "” that sufficiently distinguishes those inventions from their natural counterparts This "penumbral" …

Shifting The Fat-Tailed Distribution Of Blockbuster Punitive Damages Awards, W. Kip Viscusi, Benjamin J. Mcmichael

Articles

The distribution of blockbuster punitive damages awards has fat tails similar to the distributions of losses from natural disasters Extremely large awards occur more often and are more difficult to predict than if blockbuster awards were distributed normally The size and predictability of awards are important factors in the US Supreme Court's decisions on punitive damages This article examines the effect of the Court's decision in iState Farm v Campbelli on blockbuster punitive damages awards iState Farmi shifts the fat tail of the distribution of blockbuster awards down or "thins" the tail which is consistent with a restraining effect on …

Multi-Criteria Approach Using Simulation-Based Balanced Scorecard For Supporting Decisions In Health-Care Facilities: An Emergency Department Case Study, Waleed Abo-Hamad, Amr Arisha

Articles

Health research is a priority in every economy, and this research – set in the context of building a more sustainable and efficient health-care system – examines how operations management practices can be translated to clinical applications. Health-care systems in general (and emergency departments (EDs) in particular) around the world are facing enormous challenges in meeting the increasingly conflicting objectives of providing wide accessibility and delivering high-quality services efficiently and promptly. The framework proposed in this study integrates simulation modelling, the Balanced Scorecard, and multicriteria decision analysis with the aim of providing a decision support system for health-care managers. Using …

White Like Me: The Negative Impact Of The Diversity Rationale On White Identity Formation, Osamudia R. James

Articles

In several cases addressing the constitutionality of affirmative action admissions policies, the Supreme Court has recognized a compelling state interest in schools with diverse student populations. According to the Court and affirmative action proponents, the pursuit of diversity does not only benefit minority students who gain expanded access to elite institutions through affirmative action. Rather, diversity also benefits white students who grow through encounters with minority students, it contributes to social and intellectual life on campus, and it serves society at large by aiding the development of citizens equipped for employment and citizenship in an increasingly diverse country.

Recent scholarship …

Concentrated Enforcement, Leigh Osofsky

Articles

When enforcement resources are limited, how should the scarce enforcement resources be allocated to increase compliance with the law? The answer to this question can determine to what extent the law on the books translates to the law in practice. A dominant school of thought in the tax literature suggests that they should be allocated based on a "worst-first" method, whereby the individuals likely to be most noncompliant are targeted. However, while "worst-first" methods can encourage all individuals to increase compliance so as not to be deemed the "worst, " they can also provide cover to engage in noncompliance that …

The True Legacy Of Atkins And Roper: The Unreliability Principle, Mentally Ill Defendants, And The Death Penalty's Unraveling, Scott E. Sundby

Articles

No abstract provided.