Digital Commons Network^™

Inverse Scattering Solutions With Applications To Electromagnetic Signal Processing, Jonathan Blackledge, Timo Hamalainen, Jyrki Joutsensalo

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When a signal is recorded that has been physically generated by some scattering process (the interaction of electromagnetic, acoustic or elastic waves with inhomogeneous materials, for example), the ‘standard model’ for the signal (i.e. information content convolved with a characteristic Impulse Response Function) is usually based on a single scattering approximation. An additive noise term is introduced into the model to take into account a range of non-deterministic factors including multiple scattering that, along with electronic noise and other background noise sources, is assumed to be relatively weak. Thus, the standard model is based on a ‘weak field condition’ and …

Three-Dimensional Spatial Information Systems: State Of The Art Review, Bianca Schoen-Phelan, D. Laefer, S. W. Morrish, M. Bertolotto

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A spatial information system (SIS) is critical to the hosting, querying, and analyzing of spatial data sets. The increasing availability of three-dimensional (3D) data (e.g. from aerial and terrestrial laser scanning) and the desire to use such data in large geo-spatial platforms have been dual drivers in the evolution of integrated SISs. Within this context, recent patents demonstrate efforts to handle large data sets, especially complex point clouds. While the development of feature-rich geo-systems has been well documented, the implementation of support for 3D capabilities is only now being addressed. This paper documents the underlying technologies implemented for the support …

Simple Versatile Shearing Interferometer Suitable For Measurements On A Microscopic Scale, Emilia Mihaylova, Vincent Toal

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Microelectromechanical systems (MEMS) behave differently from massive samples. Conventional testing and inspection techniques usually fail at the microscale. Recently there has been an increasing interest in the application of optical techniques for microstructure testing, because they are high-resolution, non-contact, full-field, fast and relatively inexpensive. New interferometric systems, which are suitable for microscopic optical metrology, are of interest for engineering and industrial applications. A modified electronic speckle pattern shearing interferometer (ESPSI) with a very simple shearing device has been designed for metrology applications on the microscale. The shearing device consists of two partially reflective glass plates. The reflection coefficients of the …

Electro-Optical Switching Of The Holographic Polymer-Dispersed Liquid Crystal Diffraction Gratings, Pavani Kotakonda, Izabela Naydenova, Raghavendra Jallapuram, Suzanne Martin, Vincent Toal

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Polymer-dispersed liquid crystal (PDLC) is a material promising for application in optical communications, diffractive optics and optical data storage. Diffraction gratings were optically recorded in a novel PDLC material developed at the Centre for Industrial and Engineering Optics. Details of the fabrication and preliminary results of electro-optical switching of the holographic PDLC (HPDLC) diffraction gratings are presented. The redistribution of LCs was observed by using phase contrast microscopy and confocal Raman spectroscopy.

Entrepreneurship And Law: Accessing The Power Of The Creative Impulse Foreword, Steven H. Hobbs

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No abstract provided.

The Perils And The Promise Of Comparative Constitutional Law: The New Globalism And The Role Of The United States Shaping Human Rights, Ronald J. Krotoszynski Jr.

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No abstract provided.

Hmgb1 Mediates Endogenous Tlr2 Activation And Brain Tumor Regression, James Curtin, Naiyou Liu, Marianela Candolfi, Weidong Xiong, Hikmat Assi, Kader Yagiz, Matthew Edwards, Kathrin Michelsen, Kurt Kroeger, Chunyan Liu, Akm Ghulam Muhammad, Mary Clark, Moshe Arditi, Begonya Comin-Anduix, Antoni Ribas, Pedro Lowenstein, Maria Castro

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BACKGROUND: Glioblastoma multiforme (GBM) is the most aggressive primary brain tumor that carries a 5-y survival rate of 5%. Attempts at eliciting a clinically relevant anti-GBM immune response in brain tumor patients have met with limited success, which is due to brain immune privilege, tumor immune evasion, and a paucity of dendritic cells (DCs) within the central nervous system. Herein we uncovered a novel pathway for the activation of an effective anti-GBM immune response mediated by high-mobility-group box 1 (HMGB1), an alarmin protein released from dying tumor cells, which acts as an endogenous ligand for Toll-like receptor 2 (TLR2) signaling …

The Bundle Dispersion Of Swnt On Interaction With P-Terphenyl, Theresa Hedderman, Anika Mostaert, Anne Shanahan, Hugh Byrne

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This paper investigates the interaction and bundle dispersion of single walled carbon nanotubes (SWNT) produced by arc discharge and by the high pressure decomposition of carbon monoxide, often referred to as the HiPco method, in the presence of the molecule p-terphenyl. The study will show that the extent of SWNT bundle dispersion and the degree of interaction with p-terphenyl is related to the level of purity of the SWNT sample. This study compares the bundle dispersion and interaction of SWNT with p-terphenyl in their as produced state and after purification. A number of spectroscopic and microscopic techniques are used to …

Titanium Dioxide Nanoparticles Induce Oxidative Stress And Dna-Adduct Formation But Not Dna-Breakage In Human Lung Cells, Kunal Bhattacharya, Maria Davoren, Jens Boertz, Roel P.F. Schins, Eik Hoffmann, Elke Dopp

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Titanium dioxide (TiO2), also known as titanium (IV) oxide or anatase, is the naturally occurring oxide of titanium. It is also one of the most commercially used form. To date, no parameter has been set for the average ambient air concentration of TiO2 nanoparticles (NP) by any regulatory agency. Previously conducted studies had established these nanoparticles to be mainly non-cyto- and -genotoxic, although they had been found to generate free radicals both acellularly (specially through photocatalytic activity) and intracellularly. The present study determines the role of TiO2-NP (anatase, ∅ < 100 nm) using several parameters such as cyto- and genotoxicity, DNA-adduct formation and generation of free radicals following its uptake by human lung cells in vitro. For comparison, iron containing nanoparticles (hematite, Fe2O3, ∅ < 100 nm) were used. The results of this study showed that both types of NP were located in the cytosol near the nucleus. No particles were found inside the nucleus, in mitochondria or ribosomes. Human lung fibroblasts (IMR-90) were more sensitive regarding cyto- and genotoxic effects caused by the NP than human bronchial epithelial cells (BEAS-2B). In contrast to hematite NP, TiO2-NP did not induce DNA-breakage measured by the Comet-assay in both cell types. Generation of reactive oxygen species (ROS) was measured acellularly (without any photocatalytic activity) as well as intracellularly for both types of particles, however, the iron-containing NP needed special reducing conditions before pronounced radical generation. A high level of DNA adduct formation (8-OHdG) was observed in IMR-90 cells exposed to TiO2-NP, but not in cells exposed to hematite NP. Our study demonstrates different modes of action for TiO2- and Fe2O3-NP. Whereas TiO2-NP were able to generate elevated amounts of free radicals, which induced indirect genotoxicity mainly by DNA-adduct formation, Fe2O3-NP were clastogenic (induction of DNA-breakage) and required reducing conditions for radical formation.

Land Use Planning In Ireland: A Life Cycle Energy Analysis Of Recent Residential Development In The Greater Dublin Area, Aidan Duffy

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Background, aim, and scope: One third of the total housing stock in the Republic of Ireland has been built in 10 years up to and including 2006 and of this approximately 34% was built in the Greater Dublin Area (GDA). Much of the housing was low-density with poor public transport links leading to doubts over its sustainability—particularly in terms of energy use. Although the country is committed to reducing greenhouse gases to 13% above 1990 levels by the period 2008–2012, by 2005, emissions were already 25.4% higher than the aseline and current projections are that this figure will rise to …

Engineering Of A Single Alkaline Fuel Cell Part Ii: Long Term Operation In Air, Jonathan Blackledge, Eugene Coyle, David Kennedy, Heinz Schmidt-Walter, Hans Kohnke, Steffen Schudt, Gerhard Sauer, James Hamilton

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Research into renewable energy sources has previously lacked sufficient investment. However, emphasis has now shifted and funding is being made available in a proactive manner by various governments eager to encourage renewable energy technology and reduce carbon taxes. Fuel Cells offer a realistic, sustainable and clean alternative energy option for stationary and mobile applications. Hydrogen and fuel cell technologies are recognised by many as possible long term energy solutions, but to-date, have failed to make an impact on the energy market. This is due to a number of key reasons, some of which include efficiency, scale, accessories and power output. …

Engineering Of A Single Alkaline Fuel Cell Part I: Construction Of A Test Bed, Jonathan Blackledge, James Brunton, Eugene Coyle, David Kennedy, Heinz Schmidt-Walter, Hans Kohnke, Gerhard Sauer, Steffen Schudt, James Hamilton

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Fuel Cells offer a realistic, sustainable and clean alternative energy option for stationary and mobile applications. Hydrogen and fuel cell technologies are recognised by many as possible long term energy solutions, but to-date have failed to make an impact on the energy market. This is due to a number of key reasons, some of which include, efficiency, scale, accessories and power output. Applying fuel cells to small telecommunication components requires the applications of Micro and Nanotechnology, which have yet to be perfected to make them long lasting and cost effective. This paper outlines the reasons for commercialisation of fuel cells …

From Environment To Energy: China's Reconceptualization Of Climate Change, Dongsheng Zang

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Domestically and internationally, by the first half of 2009 it was already questionable whether the Copenhagen Conference could achieve anything. Anthony Giddens warned-in an otherwise inspiring book on climate change-that "doomsday is no longer a religious concept, a day of spiritual reckoning, but a possibility imminent in our society and economy." In such a context, it becomes imperative to revisit some of the fundamental issues in the Kyoto Protocol framework. Are timetables and targets really the best way to regulate climate change? Does the current framework create bad politics? Where are the powerful driving forces towards a low-carbon society?

This …

Hiding Behind "Tradition"? Should U.S. Vessel Traffic Centers Exercise Greater Direction And Control Over Vessels In Their Areas?, Craig H. Allen

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In the alermath of the 2007 COSCO BUSAN allision and oil spill, some asked whether United States Coast Guard Vessel Traffic Service (VTS) operators monitoring the developing incident should have intervened explicitly to wam the vessel or even order it to take avoiding action.

The controversy called to mind a speech by a former IMO secretary-general in which he suggested that those resisting greater shore-based control were "hiding behind tradition." In its investigation of the COSCO BUSAN incident, the National Transportation Safety Board (NTSB) urged the Coast Guard to better define its expectations regarding the exercise of VTS control authority …

Success Or Failure?: Japan's National Strategy On Intellectual Property And Evaluation Of Its Impact From The Comparative Law Perspective, Toshiko Takenaka

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This short Article will discuss Japan's national IP strategy and changes brought to the IP system, focusing on features that follow the U.S. IP system. Additionally, it will review these changes from the comparative law perspective and evaluate whether the new system has accomplished its national strategy mission.

An Investigation Into The Semantics Of English Topological Prepositions, John D. Kelleher, Colm Sloan, Brian Mac Namee

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This paper describes a psycholinguistic experiment that investigates whether the applicability of the topological spatial prepositions "at", "on" or "in" to describe the spatial configuration between two objects is related to the topological relationships between objects being described

Dispersion Medium Modulates Oxidative Stress Response Of Human Lung Epithelial Cells Upon Exposure To Carbon Nanomaterial Samples, Eva Herzog, Hugh Byrne, Maria Davoren, Alan Casey, Albert Duschl, Gertie Janneke Oostingh

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Due to their large specific surface area, the potential of nanoparticles to be highly reactive and to induce oxidative stress is particularly high. In addition, some types of nanoparticles contain transition metals as trace impurities which are known to generate reactive oxygen species (ROS) in biological systems. This study investigates the potential of two types of single-walled carbon nanotube samples, nanoparticulate carbon black and crocidolite asbestos to induce ROS in lung epithelial cells in vitro. Carbon nanotube and carbon black samples were used as produced, without further purification or processing, in order to best mimic occupational exposure by inhalation of …

Raman Spectroscopy: A Potential Platform For The Rapid Measurement Of Carbon Nanotube-Induced Cytotoxicity, Peter Knief, Colin Clarke, Eva Herzog, Maria Davoren, Fiona Lyng, Aidan Meade, Hugh Byrne

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In this study the suitability of Raman spectroscopy for the determination of carbon nanotube mediated toxicity on human alveolar carcinoma epithelial cells (A549) is explored. The exposure of this cell line represents the primary pathway of exposure in humans, that of inhalation. Peak ratio analysis demonstrates a dose dependent response which correlates to previous toxicological studies. Principal component analysis is employed to further classify cellular response as a function of dose and to examine differences between spectra as a function of exposed concentration. To further illustrate the potential of Raman spectroscopy in this field, Partial Least Squares (PLS) regression and …

Providing Academic Leadership Through The Role Of Senior Lecturer 1 (Teaching) Using The Theme Of 'Sustainable Energy' As An Example, Jim Mcgovern

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An academic leader should lead in their particular area and should love what they are doing. An example of leadership in the area of 'sustainable energy use' is presented that involves leading through identifying and participating in the development of emerging technologies. Excellent academic leadership can be provided by a Senior Lecturer through active research, incorporating the latest developments in student-centred learning in their work and providing example and encouragement for colleagues and learners.

Rating Requirements Of The Upqc To Integrate The Fsig Type Wind Generation To The Grid, N. Jayanti, Malabika Basu, Michael Conlon, Kevin Gaughan

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The ability of wind generation to remain connected to the grid in the event of system faults and dynamic reactive power compensation are two aspects of grid integration, which have received particular attention. The wind driven, fixed-speed induction generator (FSIG) on its own fails to fulfil these requirements of grid integration. The application of a unified power quality conditioner (UPQC) to overcome the grid integration problems of the FSIG is investigated. The role of the UPQC in enhancing the fault ride-through capability of the generator is also investigated under both full and partial terminal voltage restoration. A realistic estimation of …

Relating Fractal Dimension To Branching Behaviour In Filamentous Microorganisms, David Barry, Onwuarolu Ifeyinwa, Shauna Mcgee, Raymond Ryan, Gwilym Williams, Jonathan Blackledge

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The productivity of an industrial fermentation process involving a filamentous microbe is heavily dependent on the morphological form adopted by the organism. The development of systems capable of rapidly and accurately characterising morphology within a given process represents a significant challenge to biotechnologists, as the complex phenotypes that are manifested are often not easily quantified. Conventional parameters employed in these analyses are of limited value, as they reveal little about the specific branching behaviour of the organism, which is an important consideration given the demonstrated link between branching frequency and metabolite production. More recently, fractal geometry has been employed in …

A Covert Encryption Method For Applications In Electronic Data Interchange, Jonathan Blackledge, Dmitry Dubovitskiy

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A principal weakness of all encryption systems is that the output data can be ‘seen’ to be encrypted. In other words, encrypted data provides a ‘flag’ on the potential value of the information that has been encrypted. In this paper, we provide a new approach to ‘hiding’ encrypted data in a digital image.

In conventional (symmetric) encryption, the plaintext is usually represented as a binary stream and encrypted using an XOR type operation with a binary cipher. The algorithm used is ideally designed to: (i) generate a maximum entropy cipher so that there is no bias with regard to any …

Scattering From A Tenuous Random Medium With Applications In Optics, Jonathan Blackledge

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Mathematical models for the scattering of light (and other radiation) tend to fall into two categories based on a weak field condition (single scattering processes) or a strong field condition (multiple scattering processes). In the latter case, the complexity of deterministic models coupled with available solutions often fail to provide results that are of value to engineering systems (e.g. imaging systems). For this reason, multiple scattering problems are often approached using stochastic modelling methods whose foundations lie in random walk theory where the amplitude and phase of the scattered field are taken to conform to an appropriate statistical process and …

The Effect Of Air Preheating In A Biomass Cfb Gasifier Using Aspen Plus Simulation, Wayne Doherty, Anthony Reynolds, David Kennedy

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In the context of climate change, increasing efficiency and energy security, biomass gasification is likely to play an important role in energy production. Atmospheric circulating fluidised bed (CFB) technology was selected for the current study. The primary objective of this research is to develop a computer simulation model of a CFB biomass gasifier that can accurately predict gasifier performance under various operating conditions. An original model was developed using ASPEN Plus (Advanced System for Process ENgineering Plus). The model is based on Gibbs free energy minimisation. The restricted equilibrium method was used to calibrate the model against experimental data. This …

Renewable Energy Resources And Technologies Applicable To Ireland, Fergal O'Rourke, Fergal Boyle, Anthony Reynolds

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The energy consumed in Ireland is primarily achieved by the combustion of fossil fuels. Ireland’s only indigenous fossil fuel is peat; all other fossil fuels are imported. As well as fossil fuels continually becoming more expensive, their use as an energy source also has a negative impact on the environment. Ireland’s energy consumption can be separated into 3 divisions; transportation, electricity generation and heat energy. Ireland however has a vast range of high quality renewable energy resources. Ireland has set a target of 33% of its electricity will be generated from renewable sources by 2020[1]. The use of biomass, wind …

Simulation Of A Tubular Solid Oxide Fuel Cell Stack Operating On Biomass Syn-Gas Using Aspen Plus, Wayne Doherty, Anthony Reynolds, David Kennedy

Articles

A tubular solid oxide fuel cell (SOFC) stack is modelled and its operation on biomass syn-gas is investigated. The objective of this work is to develop a computer simulation model of a biomass gasification-SOFC (BG-SOFC) system capable of predicting performance under various operating conditions and using diverse fuels. The stack is modelled using Aspen Plus and considers ohmic, activation and concentration losses. It is validated against published data for operation on natural gas. Operating parameters such as fuel and air utilisation factor (U_f and U_a), current density (j) and steam to carbon ratio ( …

Double-Glazing Interferometry, Vincent Toal, Emilia Mihaylova

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This note describes how white light interference fringes can be seen by observing the Moon through a double-glazed window. White light interferometric fringes are normally observed only in a well-aligned interferometer whose optical path difference is less than the coherence length of the light source, which is approximately one micrometer for white light. Obtaining such fringes in a Michelson interferometer is not a trivial task.1 The interferometer is typically illuminated with a monochromatic source and the path length difference adjusted with a wedge angle between the interferometer mirrors so that five or six vertical fringes are visible, indicating nearly equal …

First Approaches To Standard Protocols And Reference Materials For The Assessment Of Potential Hazards Associated With Nanomaterialss, Gordon Chambers, Hugh Byrne, Iseult Lynch, Micheal Riediker, Hans Bouwmeester, Hans Marvin, Alan Casey, Markus Berges, Martin Clift, Teresa Fernandez, Lise Fjellsbo, Lucienne Juillerat, Gert Roebben, Christoph, Klein, Qinglan Wu, Vince Hackley, Jean-Pierre Kaiser, Wolfganag Kreyling, Michael Garner, Peter Hatto,, Kenneth Dawson

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All new technologies have an inherent risk, which is typically assessed alongside the development of applications of the technology. This is also the case for nanotechnology: a key concern in the case of engineered nanomaterials (ENMs) is that due to their very small size, NMs can reach areas such as the cell that are inaccessible to other materials, such as implants and drugs. As a result of their large surface area, NMs may be more reactive than other larger materials. The large physical and chemical variability of NMs, and the fact that small changes can have large consequences, mean that …

Optical Properties Of Silica-Mfi Doped Acrylamide-Based Photopolymer, Tzvetanka Babeva, Rosen Todorov, Svetlana Mintova, Temenujka Yovcheva, Izabela Naydenova, Vincent Toal

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The optical properties of acrylamide-based photopolymer doped with pure silica MFI-type zeolites are studied by refractometric and spectrophotometric means. Dynamic Light Scattering and Transmission Electron Microscopy are used for zeolite characterization and laser refractometry and White Light Interferometric profilometry are used for surface characterization of the composites. Refractive indices and absorption coefficients of composites are determined from their transmittance and reflectance spectra. The calculated dispersion curves are further used for deriving the zeolites refractive index and porosity and the latter compared to the values of total pore volume obtained from N2-sorption measurements. The impact of the doping level on the …

Optical And Holographic Characteristics Of Photopolymer Layers, Temenujka Yovcheva, Izabela Naydenova, Ivanka Vlaeva, Suzanne Martin, Vincent Toal, Simeon Sainov

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In the present work the optical and holographic characteristics of acrylamide-based photopolymer layers are studied. For the first time the refractive index change of a liquid acrylamide photopolymer due to exposure at 532 nm is obtained using a critical angle laser micro-refractometer. The 30 mm thick solid photopolymer films are prepared by casting on glass substrates. Bragg holographic gratings with spatial frequencies of 710 mm-1, 1050 mm-1 and 1600 mm-1 are recorded using a diode laser operating at 532 nm wavelength. The diffraction efficiency dependence on the exposure energy is investigated. The obtained results are compared with the Stetson holographic …