Engineering Commons^™

Investigation Of Macrobending Losses Of Standard Single Mode Fiber With Small Bend Radii, Pengfei Wang, Qiang Wu, Gerald Farrell, Ginu Rajan, Thomas Freir, John Cassidy

Articles

An investigation of macrobending loss characteristics of a standard singlemode fiber (SMF28) for small bend radii is presented theoretically and experimentally, which includes the bend loss of the SMF28 with coating layers and the bare SMF28 after stripping the coating layers and chemical etching of partial cladding. The significant influence of reflection occurring at the interface between the cladding and coating layer or the cladding layer and air on the bend loss is investigated theoretically and experimentally.

Investigation Of Macrobending Losses Of Standard Single Mode Fiber With Small Bend Radii, Pengfei Wang, Qian Wang, Gerald Farrell, Ginu Rajan, Thomas Freir, John Cassidy

Articles

An investigation of macrobending loss characteristics of a standard singlemode fiber (SMF28) for small bend radii is presented theoretically and experimentally, which includes the bend loss of the SMF28 with coating layers and the bare SMF28 after stripping the coating layers and chemical etching of partial cladding. The significant influence of reflection occurring at the interface between the cladding and coating layer or the cladding layer and air on the bend loss is investigated theoretically and experimentally.

Wideband Reconfigurable Rolled Planar Monopole Antenna, Giuseppe Ruvio, Max Ammann, Zhi Ning Chen

Articles

A novel technique to reconfigure the frequency range of a planar monopole antenna is presented. By adjusting the degree of spiral tightness, a shift of the well-matched operating frequency range is achieved. The proposed antenna is capable of covering the frequencies in the range from 2.9 to 15 GHz, depending on the degree of spiral tightness. The antenna yields a high-efficiency across the full operating bandwidth. Radiation patterns show good omni-directional features in all primary cuts and remain relatively stable with the change of antenna configuration, so that it is a remarkable candidate for indoor or mobile applications where a …

Macrobending Fiber Loss Filter, Ratiometric Wavelength Measurement And Application, Qian Wang, Ginu Rajan, Gerald Farrell, Pengfei Wang, Yuliya Semenova, Thomas Freir

Articles

A macrobending standard single-mode fibre (SMF28) is optimized as an edge filter, with the optimal bending radius and length determined according to the bend loss and polarization sensitivity of the bending fibre. An all-fibre ratiometric wavelength system is built and calibrated. The system's accuracy and resolution is discussed with the influence of noise of input signal and photodetectors. Finally, the ratiometric system is employed for the demodulation of FBG strain sensing.

A Method To Measure Reference Strain In Fbg Strain Sensor Interrogation System Involving Actuators, Ginu Rajan, Yuliya Semenova, Qian Wang, Gerald Farrell, Pengfei Wang

Articles

A method for reference strain measurement for FBG strain sensor in the testing stage while applying strain using actuators like piezo translators or micro screw is introduced. Unlike conventional methods of surface mounting, in our method the strain gauge is affixed directly to the optical fibre, which allows it to use with systems where the strain is applied directly using actuators while testing the FBG sensing system. Different bonding techniques were tested and a comparison with the results from calculated values are presented. Since the contact area between the fibre and strain gauge is very small a corrected gauge factor …

Thermal Effectiveness Characteristics Of Low Approach Indirect Evaporative Cooling Systems In Buildings, Ben Costelloe, Donal Finn

Articles

Meteorological enthalpy analysis of temperate and maritime climates above latitude 45°N suggests that the water-side evaporative cooling technique has considerable unrealised potential with contemporary “high temperature” building cooling systems—such as chilled ceilings and displacement ventilation. As low approach conditions are the key to exploiting the cooling potential of the ambient air, thermal performance at such conditions needs to be investigated. To address the research issues, an industrial scale test rig, based on a low approach open cooling tower and plate heat exchanger and designed to maximise evaporative cooling potential, has been constructed. The thermal effectiveness of such systems (as a …

Preparing A Property Statement For A Property Company: The Key Stages., Myles Keaveney

Articles

No abstract provided.

Slow Flow Between Concentric Cones, O. Hall, C. P. Hills, A. D. Gilbert

Articles

This paper considers the low-Reynolds-number flow of an incompressible fluid contained in the gap between two coaxial cones with coincident apices and bounded by a spherical lid. The two cones and the lid are allowed to rotate independently about their common axis, generating a swirling motion. The swirl induces a secondary, meridional circulation through inertial effects. For specific configurations complex eigenmodes representing an infinite sequence of eddies, analogous to those found in two-dimensional corner flows and some three-dimensional geometries, form a component of this secondary circulation. When the cones rotate these eigenmodes, arising from the geometry, compete with the forced …

Krylov Subspaces From Bilinear Representations Of Nonlinear Systems, Marissa Condon, Rossen Ivanov

Articles

For efficient simulation of state-of-the-art dynamical systems as arise in all aspects of engineering, the development of reduced-order models is of paramount importance. While linear reduction techniques have received considerable study, increasingly nonlinear model reduction is becoming a significant field of interest. From a circuits and systems viewpoint, systems involving micromachined devices or systems involving mixed technologies necessitate the development of reduced-order nonlinear models. From a control systems viewpoint, the design of controllers for nonlinear systems is greatly facilitated by nonlinear model reduction strategies. To this end, the paper proposes two novel model-reduction strategies for nonlinear systems. The first involves …

A Simple Sol-Gel Processing For The Development Of High-Temperature Stable Photoactive Anatase Titania, Suresh Pillai, Declan Mccormack, John Colreavy

Articles

No abstract provided.

Experimental Study For The Conditions Of Analog Switching In Ferroelectric Liquid Crystal Cells, V. Manjuladevi, Yuri Panarin, J.K. Vij

Articles

The authors study the effect of the spontaneous polarization (PS) of a ferroelectric liquid crystal mixture with compensated helix and of the thickness of the alignment layer (da) on the analog switching in a cell. The quality of analog switching is established in terms of its contrast ratio, texture in the dark state, and the electrostatic energy. The latter approximates to PS 2da for da

Influence Of Electric Field And Light On An Easy Axis Of Nlc Confined By Rectangular Channel At Weak Surface Anchoring, S.V. Pasechnik, A.V. Dubtsov, Yuri Panarin, D.V. Shmeliova, V.A. Tsvetkov, V.G. Chigrinov

Articles

We present new experimental results on combined action of light and electric field on a nematic liquid crystal in a rectangular channel at a weak surface anchoring. The first experimental study of slow surface dynamics at combined action of electric field and polarized light in new experimental geometry was performed. Influence of polarized light on spatial twist-like deformation of a director field induced by electric field was established.

Discontinuous Change In The Smectic Layer Thickness In Ferrielectric Liquid Crystals, V. P. Panov, J. K. Vij, Yuri Panarin, C. Blanc, V. Lorman, J. W. Goodby

Articles

The temperature dependence of the thickness of thick free-standing films is studied using a high-resolution film thickness measurement technique. A small discontinuity in the temperature dependence of the smectic layer thickness at every phase transition between ferro-, ferri-, and antiferroelectric phases is observed. We show that the major contribution to it arises from a change in the smectic tilt angle.

Pure Non-Blocking Lc Based Matrix Optical Switch For All-Optical Fibre Networks, Yuri Panarin, V. Alex

Articles

New pure non-blocking matrix optical switch scheme for fiber networks is presented. The optical switch is based on conventional LCD technology, where the each pixel controls the polarization state of the light beam. The suggested switch offers several advantages over the conventional cross-point architecture such as: cost; complexity; size; adjustment; and optical performance

Optical Performance Of Non-Blocking 4x4 Optical Switch: Simulation And Experiment, V. Alex, A. Dubtsov, Yuri Panarin, T. Wilkinson

Articles

A prototype of pure non-blocking 4x4 optical LC switch was designed and built. This switch is based on conventional LCD technology, where the each pixel controlled the polarization state of the light beam. An addressing algorithm was described. The optical performance of the switch, such as cross-talk and insertion loss, was simulated and experimentally studied. The suggested approach offers several advantages over the conventional cross-point architecture such as: cost; complexity; size; adjustment; and optical performance.

Textual Case-Based Reasoning For Spam Filtering: A Comparison Of Feature-Based And Feature-Free Approaches, Sarah Jane Delany, Derek Bridge

Articles

Spam filtering is a text classification task to which Case-Based Reasoning (CBR) has been successfully applied. We describe the ECUE system, which classifies emails using a feature-based form of textual CBR. Then, we describe an alternative way to compute the distances between cases in a feature-free fashion, using a distance measure based on text compression. This distance measure has the advantages of having no set-up costs and being resilient to concept drift. We report an empirical comparison, which shows the feature-free approach to be more accurate than the feature-based system. These results are fairly robust over different compression algorithms in …

Modeling Liquid-Crystal Devices With The Three-Dimensional Full-Vector Beam Propagation Method, Qian Wang, Gerald Farrell, Yuliya Semenova

Articles

Simulation of light propagation within nematic liquid-crystal (LC) devices is considered, of which the director is aligned normal to the z axis. A three-dimensional full-vector finite-difference beam propagation method for an anisotropic medium is presented and an alternating direction implicit scheme is adopted. Simulations of light propagation in a bulk polarization converter, a waveguide with a LC covering layer, and an integrated polarization splitter and optical switch are presented. Comparison with an existing simulation method is carried out for beam behavior within the bulk polarization converter. The effect of strong surface anchoring of a LC cell on the beam behaviors …

The Effect Of Physiological Cyclic Stretch On The Cell Morphology, Cell Orientation And Protein Expression Of Endothelial Cells, V. Barron, Claire Brougham, K. Coghlan, C. Stenson-Cox, D. O'Mahoney, P.E. Mchugh

Articles

In vivo, endothelial cells are constantly exposed to pulsatile shear and tensile stresses. The main aim of this study was to design and build a physiological simulator, which reproduced homogenous strain profiles of the tensile strain experienced in vivo, and to investigate the effect of this cyclic tensile strain on the cell morphology, cell orientation and protein expression of endothelial cells. The biological response of human umbilical vein endothelial cells to a uniaxial cyclic stretch, in this newly developed simulator, was examined experimentally using immunohistostaining and confocal imaging and it was

found that the cells elongated and oriented at 58.9± …

Low-Cost Wavelength Measurement Based On A Macrobending Single-Mode Fiber, Qian Wang, Gerald Farrell, Thomas Freir, Ginu Rajan, Pengfei Wang

Articles

A low-cost all-fiber wavelength measurement technique is proposed and demonstrated. A macrobending standard single-mode fiber is developed as an edge filter with an optimal design and simple surface processing. A ratiometric wavelength measurement system employing the developed macrobending fiber filter demonstrates a resolution of ∼10 pm in a wavelength range from 1500 to 1560 nm with ease of assembly and calibration.

Preliminary Results For A Monocular Marker-Free Gait Measurement System, Jane Courtney, Annraoi Depaor

Articles

This paper presents results from a novel monocular marker-free gait measurement system. The system was designed for physical and occupational therapists to monitor the progress of patients through therapy. It is based on a novel human motion capture method derived from model-based tracking. Testing is performed on two monocular, sagittal-view, sample gait videos – one with both the environment and the subject’s appearance and movement restricted and one in a natural environment with unrestricted clothing and motion. Results of the modelling, tracking and analysis stages are presented along with standard gait graphs and parameters.

A New Eccentric Geomagnetic Dipole To Give The Correct Dip Pole Locations, Annraoi De Paor, Ted Burke

Articles

In this paper, we describe a new eccentric dipole model of the Earth’s magnetic field. The constraints under which the conventional eccentric dipole model is defined result in predicted dip pole locations that differ significantly from the measured locations. Here, we give a preliminary exposition of a new dipole model which, because it is constrained by the observed dip pole locations, overcomes this problem.

Integrated Antenna For Multiband Multi-National Wireless Combined With Gsm1800/Pcs1900/Imt2000 + Extension, Matthias John, Max Ammann

Articles

A printed triple-band monopole antenna appropriate for use as a terminal antenna in modern wireless multiband systems is proposed. The impedance bandwidth of each band has been optimised using a quasi-Newton technique and the bandwidth includes virtually all wireless bands. Various parameter sweeps are presented which improve our understanding of the antenna, in particular, the effect of groundplane-size and branch-off point on impedance bandwidth and radiation pattern.

Low-Cost Wavelength Measurement Based On A Macrobending Single-Mode Fiber, Qian Wang, Gerald Farrell, Thomas Freir, Ginu Rajan, Pengfei Wang

Articles

A low-cost all-fiber wavelength measurement technique is proposed and demonstrated. A macrobending standard single-mode fiber is developed as an edge filter with an optimal design and simple surface processing. A ratiometric wavelength measurement system employing the developed macrobending fiber filter demonstrates a resolution of∼10 pmin a wavelength range from1500to1560 nmwith ease of assembly and calibration.

Design Of Integrated Polarization Beam Splitter With Liquid Crystal, Qian Wang, Gerald Farrell, Yuliya Semenova

Articles

An integrated polarization beam splitter based on a directional coupler (DC) with an etched slot and filled-in liquid crystal covering layer, which utilizes the birefringence of liquid crystal materials, is proposed. A supermode solution for the DC involving birefringence materials and the corresponding full-vector anisotropic beam propagation method are employed as modeling tools. A numerical design of the proposed structure is presented. Beam propagation behavior along the whole structure involving curved input and output regions and central coupling region is simulated. Simulation result shows an extinction ratio of 25.3 and 41.9 dB for the TE and TM mode, respectively.

Planar Antennas, Zhi Ning Cheng, Max Ammann, Xianming Qing, Xuan Hui Wu, T. S.P. See, A. Cai

Articles

This article reviews the state of the art in broadband antennas for emerging UWB applications and addresses the important issues of the broadband antenna design for UWB applications. First, a variety of planar monopoles with finite ground planes are reviewed. Next, the roll antennas with enhanced radiation performance are outlined. After that, the planar antennas printed on PCBs are described. A directional antipodal Vivaldi antenna is also presented for UWB applications. Last, a UWB antenna for wearable applications is exemplified

A Novel Gps Patch Antenna On A Fractal Hi-Impedance Surface Substrate, Xiulong Bao, Giuseppe Ruvio, Max Ammann, Matthias John

Articles

A compact high-performance circularly-polarized microstrip antenna for the global positioning system application is proposed. It comprises a fractal hi-impedance surface electromagnetic bandgap (EBG) structure printed on a high permittivity substrate. Measurements and simulation of return loss and axial ratio are in good agreement. It is shown that the proposed Global Positioning System antenna has good axial ratio performance in the upper half-plane, an improvement in gain and a significantly wider axial ratio bandwidth when compared to the same antenna without EBG

Process Modeling For Simulation, John Ryan, Cathal Heavey

Articles

This paper discusses shortfalls in relation to the requirements gathering phases of simulation. While many developments have taken place around supporting the model coding task of simulation, there are few tools available to assist in the requirements gathering phase. This is surprising as it has been reported by several researchers that the requirements phase can absorb twice as much resources as the coding phase. There are numerous process modeling tools available (over 100) that can and have been used to support the requirements phase of simulation. This paper provides a selective review of some of the most important in relation …

Geographic Variation Of Solar Water Heater Performance In Europe, Y. Yohanis, O. Popel, S. Frid, Brian Norton

Articles

Solar water heater (SWH) performance has been analysed using the ‘number of days’ method for 147 different sites in all European countries. The total number of days that the temperature of delivered solar heated water reaches or exceeds specified demand temperatures is correlated with solar radiation on a horizontal surface for summer, warm half-year, and whole year periods. Maps are presented and discussed showing the contours for the number of days that an illustrative SWH met different hot water demand temperatures. Correlations between number of days water is provided at a specified temperature and solar fractions for the same periods …

Voice Activated Command And Control With Speech Recognition Over Wifi, Brian Nolan, Tony Ayres

Articles

This paper presents work conducted to date on the development of a voice activated command and control framework specifically for the control of remote devices in a ubiquitous computing environment. The prototype device is a Java controlled Lego Mindstorm robot. The research considers three different scenario configurations. A recognition grammar for command and control of the robot has been created and implemented in Java, in part in the recognition engine and in part on the robot. The physical topology involves Java at each node endpoint, that is, at the handheld PC (iPaq), the PC workstation, the Linux server and onboard …

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

Articles

No abstract provided.