Digital Commons Network^™

Circular Loop Antenna Operating At 434 Mhz For Medical Applications: Loop-Tissue Interaction, Sergio Curto, Max Ammann

Conference papers

The interaction between the circular loop antenna and human tissue is investigated. Return loss, radiation efficiency and specific absorption rate (SAR) when in proximity to human tissue is evaluated for various loop orientations with respect to the tissue. The simulated internal SAR distribution is shown for various orientations with respect to the tissue

High Performance Circularly Polarized Antenna Based On Fractal Ebg Structure, Xiulong Bao, Max Ammann, Giuseppe Ruvio, Matthias John

Conference papers

Circularly polarized patch antennas have been widely applied in wireless communication system, global positioning system, etc., because of their low-profile, lightweight, ease of fabrication and low lost [1,2]. To achieve high performance for circularly polarized patch antennas, some new structures were reported in the literature, such as antennas array, stack layer antennas, using periodic structures [3-7], etc. In this paper, a high performance circularly polarized low frequency patch antenna based on the compact fractal high-impedance surface EBG structure has been fabricated and experimented. The measured results show that the proposed circularly polarized patch antenna has good performance in impedance bandwidth, …

Study Of The Behaviour Of Video Streaming Over Ieee 802.11b Wlan Networks, Nicola Cranley, Mark Davis

Conference papers

The performance of video streaming over WLAN networks is not only influenced by the state of the network but also by the encoding configuration parameters of the video stream, such as the video content being streamed, how the vide is encoded and how it is transmitted. In this paper, we analyse the unique delay characteristic of video streaming applications in a WLAN environment. We show that the “burstiness” of video is due to the frame-based nature of encoded video. We show how each video frame is transmitted as a burst of packets that is queued at the Access Point causing …

Bridge Dynamics And Loading, Colin C. Caprani, Eugene O'Brien, Arturo Gonzalez, Yingyan Li, Paraic Rattigan, Niall Harris

Conference papers

Recent UCD research on dynamic bridge-truck interaction and bridge traffic loading in general is reported. The accuracy of bridge traffic load assessment has been significantly improved by identifying the differences in the sources of traffic loading on short- to medium-span bridges and treating them separately. It is shown that results can be significantly improved by treating 1-,2-,3- and 4-truck loading events separately. Gaps between trucks are also identified as a critical issue that strongly influences the frequency of key3-and 4-truck events. Trends in the dynamics of traffic loading are identified using simple force models on simply supported beams. It is …

Estimating Risk Of Failure Of Engineering Structures Using Predictive Likelihood, Colin C. Caprani, A. Bordallo-Ruiz, E. J. O'Brien

Conference papers

It has been common engineering practice to define characteristic values for loading and capacity of structures in order to assess the structural capacity of existing structures. This approach, yet practical and intuitive, lead to the comparison of deterministic values (characteristic values) that had to represent all the variability of the problem and is considered to be conservative, as usually loading is overestimated and capacity underestimated, yielding to calculations with high safety margins for the extreme events. Probabilistics methods have tried to overcom e this limitation by computing the overall probability of failure (Pf) for the lifetime of the structure, taking …

Determination Of Characteristic Bridge Daf Using Dynamic Finite Element Analysis Of Critical Static Loading Scenarios, Colin C. Caprani, Paraic Rattigan, Arturo Gonzalez, E. J. O'Brien

Conference papers

The development of accurate codes for the design of bridges and the evaluation of existing structures requires adequate assessment of site-specific heavy traffic loading and also the dynamic interaction that may occur as this traffic traverses the structure. Shortcomings in current design codes occur due to the relatively independent manner in which critical static loading values and the corresponding allowance for dynamic amplification factor (DAF) are obtained. It is important that an approach is adopted that allows for the reduced probability of both high static loading and high dynamic amplification occurring simultaneously. Consideration of only relevant critical loading events will …

Online Learning Delivered Via Blended Problem-Based Learning, Roisin Donnelly

Books/Book Chapters

Course and Institution: Online Learning Module on the Postgraduate Diploma in Third Level Learning and Teaching; located in the Technological University Dublin. Teaching Strategy: Blended Problem Based Learning approach for 10 weeks. Students/Participants: 10 lecturers/academic staff members from a variety of higher education institutions from around the Republic of Ireland. Average Age: mature participants; some are new to teaching in higher education, and some have been teaching for anywhere between 5-25 years.

Techonology Usage In The Supply Chain: The Case Of Small 3pls, Pietro Evangelista, Edward Sweeney

Articles

Purpose - In today’s supply chain management (SCM) practices, a successful strategy depends
increasingly on the performance of Third Party Logistics (3PL) providers as they play a key
integrative role linking the different supply chain elements more effectively. Information and
Communications Technology (ICT) has become an important element of 3PL competitive
capability as it enables higher levels of supply chain integration. Recent industry developments
have widened the technological gap between large and small 3PLs. This is critical particularly for
those markets populated by a large number of small 3PLs such as the Italian logistics industry. The
purpose of this paper …

Novel Gene Therapeutic Approaches To Brain Cancer, Maria Castro, James Curtin, Gwendalyn King, Marianela Candolfi, Peter Czer, Sandra Sciascia, Kurt Kroeger, Tamer Fakhouri, Sarah Honig, William Kuoy, Terry Kang, Stephen Johnson, Pedro Lowenstein

Books/Book chapters

In the United States, approximately 17,000 people per year are diagnosed with brain tumors, the leading cause of death from cancers in children ages 1-15 year (1,2). Gliomas are the most prevalent type of brain tumors in adults, affecting 3.2/100,000 persons/yr in the United States (www.CBTRUS.org). In spite of advances in surgery, chemotherapy, and radiotherapy, the mean survival time of patients post-diagnosis remains approximately 9-12 months.

Why Renewables Need Nuclear?: A Brief Narrative, John Ratcliffe, Ruth Saurin

Articles

No abstract provided.

Replay At Optical Communications Wavelengths Of Holographic Gratings Recorded In The Visible, Vincent Toal, Maurice Whelan, Alberto Volcan, Izabela Naydenova, Suzanne Martin

Conference Papers

In this paper we report on holographic diffraction gratings recorded at visible light wavelength, which can be probed at telecommunication wavelengths. The recording material is an easily prepared, self-processing photopolymer, all of whose components are water soluble. Transmission gratings of various types, namely unslanted, slanted, totally internally reflecting and Bragg gratings were all fabricated. Diffraction efficiencies at telecommunications wavelengths compare favourably with those obtained in visible light.

Comparison Of Three Electronic Speckle Pattern Shearing Interferometers Using Photopolymer Holographic Optical Elements., Emilia Mihaylova, Izabela Naydenova, Vincent Toal, Suzanne Martin

Conference Papers

Three electronic speckle pattern shearing interferometers (ESPSI) using photopolymer holographic gratings to produce the sheared image are presented. In the first ESPSI system two holographic gratings are used. The gratings are placed between the object and an imaging lens in front of the CCD camera. In the second ESPSI system one grating is used in combination with a sheet of ground glass. The sheared images on the ground glass are further imaged onto a CCD camera. In the third ESPSI system only one grating is used - it is placed in front of the object. The image and the sheared …

Characterization Of An Acrylamide Based Photopolymer For Fabrication Of Liquid Crystal Devices, Pavani Kotakonda, Izabela Naydenova, Suzanne Martin, Vincent Toal

Conference Papers

Photopolymers are increasingly interesting as new materials for the fabrication of electro optical liquid crystal devices. Photoinduced surface relief gratings in dry, self developing acrylamide based photopolymers can be used to align liquid crystals (LCs) as an alternative to the rubbing technique. These optically recorded surface relief patterns can be used to fabricate electro-optical switchable LC Bragg gratings. An investigation of the dependence of photoinduced surface relief gratings on recording intensity and thickness of the photopolymer layer is reported. The surface relief gratings were filled with E7 LCs and a switchable LC diffraction grating was fabricated.

Design And Development In The Field Of Alkaline Fuel Cell Technology, Steffen Schudt

Masters

This thesis is about the research on alkaline fuel cell (AFC) technology to investigate the long term operation with air. The aim was to solve the two main problems arising from long term operation and especially from operation with air: • Dilution of the liquid electrolyte by the water from the reaction • Cell damage due to the formation of carbonate In recent years the development of fuel cells has gained a growing interest again. However the interest in alkaline fuel cells was low as the polymer electrolyte membrane fuel cell (PEMFC) seemed to be the superior system. One reason …

Controlled Braking Scheme For A Wheeled Walking Aid, Eugene Coyle, Aidan O'Dwyer, Eileen Young, Kevin Sullivan, A. Toner

Conference papers

A wheeled walking aid with an embedded controlled braking system is described. The frame of the prototype is based on combining features of standard available wheeled walking aids. A braking scheme has been designed using hydraulic disc brakes to facilitate accurate and sensitive controlled stopping of the walker by the user, and if called upon, by automatic action. Braking force is modulated via a linear actuating stepping motor. A microcontroller is used for control of both stepper movement and for supervisory control. An encoder is used to supervise walker movement in terms of time, distance and speed.

Global Macroeconomic Trends, Thomas Power

Articles

The business of real estate is but a subset of the wider investment markets and macroeconomic trends will significantly shape the way real estate investment decisions are made. The McKinsey Institute is a global economic consultancy firm providing cutting-edge research on a wide range of macroeconomic and business trends. This article reviews macroeconomic trends that they believe will transform the global economy. McKinsey research show that “over two-thirds of organic growth of western companies can be attributed to being in the right markets and geographies” and “companies that ride the tide succeed and those that swim against it usually struggle” …

Synthesis Of High-Temperature Stable Anatase Tio2 Photocatalyst, Suresh Pillai, Declan Mccormack, Michael Seery, Pradeepan Periyat, Steven Hinder, John Colreavy, Reenamol George, Hugh Hayden

Articles

In the absence of a dopant or precursor odification, anatase to rutile transformation in synthetic TiO2 sually ccurs at a temperature of 600 700 °C. Conventionally, metal oxide dopants (e.g., Al2O3 nd SiO2 are used o tune the anatase to rutile transformation. A simple methodology is reported here to extend the anatase utile transformation by employing various concentrations of urea. XRD and Raman spectroscopy were used uring thermal treatment. A significantly higher anatase phase (97%) as been obtained at 800 C with use of a 1:1 Ti(OPr)4 urea composition and 11% anatase composition is etained even after calcining …

Study Of Same-Lane And Inter-Lane Gvw Correlation, Bernard Enright, Eugene J. O'Brien, Colin C. Caprani

Conference papers

The methodology used is to generate a number of years of simulated traffic and to use extreme value statistics to predict more accurately the characteristic loading for a given bridge. The parameters and probability distributions used in the Monte Carlo simulation must be based on observed sample traffic data. Some previous studies have made unsubstantiated assumptions regarding correlation between the Gross Vehicle Weights (GVW) of trucks in the same lane, or between trucks in adjacent, same-direction lanes. For this paper, an extensive database of Dutch Weigh-in-Motion data is analysed. Data are collected from two same-direction lanes and are time-stamped to …

What Light Do Professional Doctorates Throw On The Question On The Question Of What Counts As Knowledge In The Academy At The Start Of The 21st. Century, Sandra Fisher

Level 3

In their article, ‘Professional Doctorates in England’, Bourner et al. (2001: 81) pose the question ‘What light do professional doctorates throw on the question of what counts as knowledge in the academy at the start of the twenty-first century?’ This article attempts to address this question.

The article provides some background to the development of professional doctorates. It looks at forces, such as the rise of the knowledge society, economic drivers, and the demands of lifelong learning, that are shaping knowledge in the academy in the twenty-first century. I attempt to interpret these forces in the context of …

The Emergence Of Quality Assurance In Irish Higher Education: A Review Of European And National Policy And Description Of The Dublin Institute Of Technology Practice, Aidan Kenny

Level 3

This is the second in a series of three papers which explore and describe ‘quality’ as a tool in the Irish Higher Education sector. This paper reviews macro, mesco and micro issues relating to quality assurance within the context of European Union Education Ministers’ communiqués and in Irish national policy. A micro perspective is then undertaken pertaining to the Dublin Institute of Technology describing how quality assurance systems and procedures emerged in the Institute. It also includes the Institute’s response to provisions made in the 1999 Qualifications (Education and Training) Act with reference to the necessity of carrying out quality …

Experiences Of Learning And Teaching On A Taught Masters Course In Engineering: From A Didactic Approach To A More Student Centered Learning Approach, Aidan O'Dwyer

Conference papers

This paper reports on, reflects on, and evaluates the author’s experiences of teaching the Advanced Control module on the Masters degree in Advanced Engineering at Dublin Institute of Technology (DIT) over the past four academic years. The teaching approach has evolved from a traditional didactic lecture and laboratory course, with associated assessments, in the first academic year, to the implementation of a more learner-centred approach over the past two academic years. This new approach has been made possible by the appropriate use of real case studies, information technology tools, and web-based virtual laboratories. Assessment methodology has also evolved. In the …

Alkaline Fuel Cell Engineering And Testing, James Brunton, David Kennedy, Eugene Coyle

Conference Papers

A fuel cell is a device that directly converts the chemical energy of reactants (a fuel and an oxidant) into low d. c. electricity [1]. Used in conjunction with other sustainable energy options, hydrogen and fuel cell technology can provide a realistic alternative to fossil fuels. Although research is continuing in many areas we are no closer now to commercialisation than ten to twenty years ago. This is due to a number of key reasons, some of which include efficiency, scale, accessories and power output. This paper outlines the benefits that could be derived from switching to a hydrogen based …

Can Blending Face-To-Face Teaching With E-Learning Support The Development Of Phase 4 Apprentices In Mathematics: A Formative Evaluation Research Study, Peter Hinch

Theses

This thesis is a formative evaluation research study_ Its purpose is to establish if

blending face--to-face and e-leaming delivery methods can support the development of

Phase 4 apprentice plumbers in mathematics in the Department of Construction Skills in

the Technologicl University Dublin. The study also included the design, development

and evaluation of a mathematics web site called Plumatics 4 U which is grounded in

established theoretical criteria for effective blended delivery within third level

education. This web site is currently in use by Phase 4 apprentice plumbers and is

delivered through WebCT. The CD accompanying this thesis contains a short …

Harmonically Combined Contour Icons For Concurrent Auditory Display, Charlie Cullen, Eugene Coyle

Conference papers

This paper considers the harmonic combination of basic melodic shapes known as contour icons in concurrent auditory displays. Existing work in the field (such as that concerning earcons) has considered the combination of patterns designed using low level cognitive features, and so effective streaming is difficult. This work investigates means by which musical patterns with high level cognitive features (such as contour) representing data values can be rendered concurrently, so that multiple data sets can be effectively conveyed using an auditory display. The detection and comprehension of harmonically combined contour icons was tested in comparison to those combined uniquely (non …

Experimental Comparison Of Wired Versus Wireless Video Streaming Over Ieee 802.11b Wlans, Tanmoy Debnath, Nicola Cranley, Mark Davis

Conference papers

In this paper the performance of streaming MPEG-4 video with a video server located on the wired network streaming to wireless clients is compared with the performance of a video server located in the wireless network streaming to wireless video clients. We experimentally investigate the performance for a number of concurrent video streams with varying video frame sizes, frame rates and packetisation schemes. The performance is measured in terms of the key parameters of bit rate, loss rate and mean delay. We show how that there is a trade-off for these parameters for a wired and wireless located server. We …

A Comparative Test Of Brillouin Amplification And Erbium-Doped Fiber Amplification For The Generation Of Millimeter Waves With Low Phase Noise Properties, Markus Junker, Max Ammann, Andreas Schwarzbacher, Jens Klinger, Kai-Utwe Lauterback, Thomas Schneider

Articles

Measurements of phase noise of a 40-GHz carrier signal are presented. The carrier is generated by the amplification of harmonics due to stimulated Brillouin scattering. An analogy to a generation of millimeter waves by an erbium-doped fiber instead of the Brillouin amplifier is investigated and discussed. In our setup, both show a comparable behavior in respect to their noise characteristics.

Quarter-Wave Metal Plate Solar Antenna, S. Shynu, Max Ammann, Brian Norton

Articles

A novel design of a quarter-wave shorted trapezoidal metal plate solar antenna using high efficiency polycrystalline silicon solar cells is presented. Using the DC conductive parts of the cell as RF antenna elements as well as choosing the radiating element to be a small base trapezoid, better coupling between the the feed and shorting plates is ensured and 40.3% size reduction compared to a conventional shorted quarter-wave patch is obtained. The trapezoidal radiating element covers merely 2.7% of the total available illumination area of the solar cell, leaving its efficiency essentially unaffected. The proposed design strategy has been verified by …

Compact Concentric Annular-Ring Patch Antenna For Triple Frequency Operation, Xiulong Bao, Max Ammann

Articles

A novel single-layer, single-feed concentric annular-ring microstrip patch antenna providing triple-frequency operation is proposed and experimentally studied. This is achieved by embedding a small circular patch into a dual stub-loaded concentric annular-ring structure and by employing a cross-slot in the ground plane. The proposed technique can provide triple-band operation and reduce the antenna size by over 50% compared to the conventional annular-ring patch antenna for a given frequency. Experimental results show the proposed antenna to have impedance bandwidths of 6.38, 6.30 and 35% for the three bands, at 1.17, 1.428 and 1.9 GHz, respectively. The proposed structure is capable of …

From L-Shaped Planar Monopoles To A Novel Folded Antenna With Wide Bandwidth, Giuseppe Ruvio, Max Ammann

Articles

A novel folded monopole antenna is investigated numerically and experimentally. The proposed antenna comprises a short folded monopole suitably shaped at the base with two vertical grounding probes. This small antenna is shown to have a fractional impedance bandwidth up to 125% (1.6 GHz to 7.5 GHz) for a 10 dB return loss. An interesting compromise between impedance bandwidth and pattern control is found by tuning a double side bevel at the base of the monopole, the position of the feeding point and its distance from the ground plane. Measurements and simulations are in good agreement and show a dramatic …

All-Fiber Multimode-Interference-Based-Refractometer Sensor:Proposal And Design, Qian Wang, Gerald Farrell

Articles

A novel all-fiber refractometer sensor is proposed, which is based on multimode interference in the multimode fiber core section sandwiched between two single-mode fibers. A wide-angle beam propagation method in the cylindrical coordinate is employed as the modeling tool for simulation and design of the proposed refractometer sensor. The design for a refractometer is presented that shows that the refractometer would have an estimated resolution of 5.4×10−5 for refractive indices from 1.33 to 1.45 and of 3.3×10−5 for refractive indices from 1.38 to 1.45 through the choice of an appropriate length of the multimode fiber core section.