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127204 full-text articles. Page 3087 of 3480.

Physiological And Histopathological Responses Following Closed Rotational Head Injury Depend On Direction Of Head Motion, Stephanie A. Eucker 2011 University of Pennsylvania

Physiological And Histopathological Responses Following Closed Rotational Head Injury Depend On Direction Of Head Motion, Stephanie A. Eucker

Departmental Papers (BE)

Rotational inertial forces are thought to be the underlying mechanism for most severe brain injuries. However, little is known about the effect of head rotation direction on injury outcomes, particularly in the pediatric population. Neonatal piglets were subjected to a single non-impact head rotation in the horizontal, coronal, or sagittal direction, and physiological and histopathological responses were observed. Sagittal rotation produced the longest duration of unconsciousness, highest incidence of apnea, and largest intracranial pressure increase, while coronal rotation produced little change, and horizontal rotation produced intermediate and variable derangements. Significant cerebral blood flow reductions were observed following sagittal but not ...


Proposal For A Simple Integrated Optical Ion Exchange Waveguide Polarizer With A Liquid Crystal Overlay, Pengfei Wang, Yuliya Semenova, Jie Zheng, Qiang Wu, Agus Hatta, Gerald Farrell 2011 Dublin Institute of Technology

Proposal For A Simple Integrated Optical Ion Exchange Waveguide Polarizer With A Liquid Crystal Overlay, Pengfei Wang, Yuliya Semenova, Jie Zheng, Qiang Wu, Agus Hatta, Gerald Farrell

Articles

A simple, compact electrooptic polarizer based on an ion-exchanged glass channel waveguide covered with a nematic liquid crystal (LC) is proposed. A full vectorial beam propagation method is employed to simulate this device for the first time. For the cases of zero and strong LC surface anchoring, the performance of the proposed polarizer under different applied voltages is analyzed numerically. Analysis indicates that surface anchoring of the liquid crystal is a key issue influencing the performance for the proposed optical polarizer device.


Lead Silicate Glass Microsphere Resonators With Absorption-Limited Q, Pengfei Wang, Genapathy Murugan, Timothy Lee, Xian Feng, Yuliya Semenova, Qiang Wu, Wei Loh, Gilberto Brambilla, James Wilkinson, Gerald Farrell 2011 Dublin Institute of Technology

Lead Silicate Glass Microsphere Resonators With Absorption-Limited Q, Pengfei Wang, Genapathy Murugan, Timothy Lee, Xian Feng, Yuliya Semenova, Qiang Wu, Wei Loh, Gilberto Brambilla, James Wilkinson, Gerald Farrell

Articles

We report the fabrication and characterization of a lead-silicate glass microsphere resonator. We show that at the wavelengths near 1555 nm high Q modes can be efficiently excited from a 109 μm diameter lead-silicate glass microsphere via evanescent coupling using a tapered silica fiber with a waist diameter of 2 μm. Resonances with Q-factors as high as 0.9×107 were observed. This is very close to the theoretical material-limited Q-factor and is the highest Q-factor reported so far from a nonlinear glass microsphere.


A High Sensitivity, Evanescent Feld Refractometric Sensor Based On Tapered Multimode Fiber Interference, Pengfei Wang, Gilberto Brambilla, Ming Ding, Qiang Wu, Gerald Farrell 2011 Dublin Institute of Technology

A High Sensitivity, Evanescent Feld Refractometric Sensor Based On Tapered Multimode Fiber Interference, Pengfei Wang, Gilberto Brambilla, Ming Ding, Qiang Wu, Gerald Farrell

Articles

We propose and experimentally demonstrate an enhanced evanescent field fiber refractometer based on a tapered multimode fiber sandwiched between two single-mode fibers. Experiments show that this fiber sensor offers ultrahigh sensitivity [better than 1900 nm/RIU at a refractive index (RI) of 1.44] for RI measurements within the range of 1.33–1.44 , in agreement with the theoretical predictions. This is the highest value reported to date (to our knowledge) in the literature.


Investigation And Experimental Measurement Of Scissor Blade Cutting Forces Using Fiber Bragg Grating Sensors., Dean Callaghan, Ginu Rajan, M. Mc Grath, Eugene Coyle, Yuliya Semenova, Gerald Farrell 2011 Dublin Institute of Technology

Investigation And Experimental Measurement Of Scissor Blade Cutting Forces Using Fiber Bragg Grating Sensors., Dean Callaghan, Ginu Rajan, M. Mc Grath, Eugene Coyle, Yuliya Semenova, Gerald Farrell

Articles

This paper investigated the application of FBG sensors in the measurement of scissor blade–tissue interaction forces. Sensor placement at the blade–tissue interaction site provides the basis for increased force measurement accuracy, without compromising the functionality of the instrument. This increased accuracy provided the foundation for in-depth analysis of the force components generated during typical scissor cutting cycles. Theoretical analysis and experimental investigation explored the decoupling of the major forces present during cutting. The isolation of tissue-fracture forces from inter-blade friction forces was carried out. This is useful as knowledge of the fracture properties of biological tissues can be ...


Formation Of Infrared Windows Of Transparency In One-Dimensional Silicon Photonic Crystals, Anna Baldycheva, Vladmir A; Tolmachev, Tatiana S. Perova, Kevin Berwick 2011 Trinity College Dublin

Formation Of Infrared Windows Of Transparency In One-Dimensional Silicon Photonic Crystals, Anna Baldycheva, Vladmir A; Tolmachev, Tatiana S. Perova, Kevin Berwick

Articles

The optical properties of three-component one-dimensional photonic crystal (1-D PC) structures were investigated by modeling them as two-component PCs with an additional regular t-layer, using the gap map approach and the transfer matrix method. Numerical results demonstrate that the introduction of the t-layer affects the properties of the high-order photonic band gaps, replacing them with transmission bands and creating regions of transparency over certain wavelength ranges. For the first time, a map of the transmission bands for a three-component 1-D PC was generated. This map constitutes a unique design tool for infrared optical filters for silicon-based photonic integrated ...


Experimental Demonstration Of An All-Fiber Variable Optical Attenuator Based On Liquid Crystal Infiltrated Photonic Crystal Fiber, Sunish Mathews, Gerald Farrell, Yuliya Semenova 2011 Dublin Institute of Technology

Experimental Demonstration Of An All-Fiber Variable Optical Attenuator Based On Liquid Crystal Infiltrated Photonic Crystal Fiber, Sunish Mathews, Gerald Farrell, Yuliya Semenova

Articles

The application of a nematic liquid crystal infiltrated solid core Photonic Crystal Fiber as a novel all-fiber in-line electronically controlled broadband fiber optic attenuator in the wavelength range from 1500 nm – 1600 nm is demonstrated. The device based on photonic bandgap transmission, is electronically controlled and due to its compact configuration, can be easily incorporated into an optical network. A low insertion loss at zero attenuation state and a high extinction ratio of ~ 40 dB is obtained between the high and low transmission states of the attenuator. The device works on the application of a varying voltage applied perpendicular to ...


Investigation Of Singlemode-Multimode-Singlemode And Singlemode-Tapered Multitmode-Singlemode Fibre Structures And Their Application For Refractive Index Sensing, Pengfei Wang, Gilberto Brambilla, Ming Ding, Yuliya Semenova, Qiang Wu, Gerald Farrell 2011 Dublin Institute of Technology

Investigation Of Singlemode-Multimode-Singlemode And Singlemode-Tapered Multitmode-Singlemode Fibre Structures And Their Application For Refractive Index Sensing, Pengfei Wang, Gilberto Brambilla, Ming Ding, Yuliya Semenova, Qiang Wu, Gerald Farrell

Articles

All-fiber in-line single-mode–multimode–single-mode (SMS) and single-mode–tapered-multimode–single-mode (STMS) fiber structures are investigated. A wide-angle beam propagation method in cylindrical coordinates is developed and employed for numerical simulations of the light propagation performance of such fiber devices. The effect of strong mode interference on the performance of the devices is studied and verified numerically; results indicate that the proposed STMS structure can be exploited for measuring a broad refractive index range with reasonable high resolution, compared with the conventional SMS structure.


A Fiber-Optic Voltage Sensor Based On Macrobending Structure, Pengfei Wang, Yuliya Semenova, Qiang Wu, Gerald Farrell 2011 Dublin Institute of Technology

The Influence Of Thermal Expansion Of A Composite Material On Embedded Polarimetric Sensors, Manjusha Ramakrishnan, Ginu Rajan, Yuliya Semenova, Piotr Lesiak, Andrzej Domanski, Tomasz Wolinksi, Anna Boczkowska, Gerald Farrell 2011 Dublin Institute of Technology

The Influence Of Thermal Expansion Of A Composite Material On Embedded Polarimetric Sensors, Manjusha Ramakrishnan, Ginu Rajan, Yuliya Semenova, Piotr Lesiak, Andrzej Domanski, Tomasz Wolinksi, Anna Boczkowska, Gerald Farrell

Articles

Abstract. Some of the most critical issues of the influence of the thermal expansion of composite materials on embedded polarimetric sensors for measurements of strain and temperature are studied in this paper. A composite material sample with polarimetric fiber sensors embedded in two distinct layers of a multi-layer composite structure is fabricated and characterized. The polarimetric fiber sensors used in this study are based on panda type fiber and polarization maintaining photonic crystal fiber (PM-PCF). The temperature sensitivities of polarimetric fiber sensors with acrylate buffer coated and buffer stripped polarization maintaining optical fibers are measured in free space and compared ...


Non-Gaussian Analysis Of Wind Velocity Data For The Determination Of Power Quality Control, Jonathan Blackledge, Eugene Coyle, Derek Kearney 2011 Dublin Institute of Technology

Non-Gaussian Analysis Of Wind Velocity Data For The Determination Of Power Quality Control, Jonathan Blackledge, Eugene Coyle, Derek Kearney

Articles

The quality of power (i.e. the sustainable power output as a function time) of any wind dependent energy converter (including wind turbines and wave energy converters) is determined by many design and environmental factors but timedependent variations in the wind speed are arguably the most important. In this paper we consider a non-Gaussian model for analysing and then simulating wind velocity data. In particular, we consider a Lévy distribution for the statistical characteristics of wind velocity and show how this distribution can be used to derive a stochastic fractional diffusion equation for the wind velocity as a function of ...


Virtual Ed: Utilisation Of A Discrete Event Simulation-Based Framework In Identifying "Real-Time’ Strategies To Improve Patient Experience Times In An Emergency Department, Waleed Abo-Hamad, John McInerney, Amr Arisha 2011 Dublin Institute of Technology

Virtual Ed: Utilisation Of A Discrete Event Simulation-Based Framework In Identifying "Real-Time’ Strategies To Improve Patient Experience Times In An Emergency Department, Waleed Abo-Hamad, John Mcinerney, Amr Arisha

Articles

Objectives and Backgrounds Emergency Department (ED) overcrowding and associated excessive Patient Experience Times (PETs) have proven deleterious impacts on patient mortality, morbidity and overall length of hospital stay. Health systems constantly seek cost-effective organisational strategies to reduce ED crowding and improve patient outcomes, but complex change implementation is constrained by the necessity of maintaining concurrent safe patient-care. Computer modelling in a “virtual reality” has been successfully utilised in industries outside medicine, in providing innovative “real-time” solutions to outdated practices. Therefore a bespoke “Virtual ED” computer model, based on a Discrete Event Simulation (DES) -Based Framework was constructed to determine the ...


On The Applications Of Deterministic Chaos For Encrypting Data On The Cloud, Jonathan Blackledge, Nikolai Ptitsyn 2011 Dublin Institute of Technology

On The Applications Of Deterministic Chaos For Encrypting Data On The Cloud, Jonathan Blackledge, Nikolai Ptitsyn

Conference papers

Cloud computing is expected to grow considerably in the future because it has so many advantages with regard to sale and cost, change management, next generation architectures, choice and agility. However, one of the principal concerns for users of the Cloud is lack of control and above all, data security. This paper considers an approach to encrypting information before it is ‘placed’ on the Cloud where each user has access to their own encryption algorithm, an algorithm that is based on a set of iterated function systems that outputs a chaotic number stream, designed to produce a cryptographically secure cipher ...


Finite Element Modeling Of High Current Density Effects & Power Handling Capability Of Rf Mems Capacitive Switches, Bora Baloglu 2011 Lehigh University

Finite Element Modeling Of High Current Density Effects & Power Handling Capability Of Rf Mems Capacitive Switches, Bora Baloglu

Theses and Dissertations

No abstract provided.


Evaluation Of Unbonded Strand Reinforcement For Precast Concrete Floor Diaphragms, Timothy Allen Cullen 2011 Lehigh University

Evaluation Of Unbonded Strand Reinforcement For Precast Concrete Floor Diaphragms, Timothy Allen Cullen

Theses and Dissertations

No abstract provided.


Acceleration And Stabilization Techniques For Column Generation Applied To Capacitated Resource Management Problems, Alper Uygur 2011 Lehigh University

Acceleration And Stabilization Techniques For Column Generation Applied To Capacitated Resource Management Problems, Alper Uygur

Theses and Dissertations

No abstract provided.


Band-Pass Filter Feedback System For Use In Am Radio Receivers, Kevin Robert Ford 2011 Lehigh University

Band-Pass Filter Feedback System For Use In Am Radio Receivers, Kevin Robert Ford

Theses and Dissertations

No abstract provided.


Signal Processing Algorithms And Their Applications, Xuebin Wu 2011 Lehigh University

Signal Processing Algorithms And Their Applications, Xuebin Wu

Theses and Dissertations

No abstract provided.


A Quality Control System Using Texture Analysis In Metallurgy, Jonathan Blackledge, Dymitiy Dubovitskiy 2011 Dublin Institute of Technology

A Quality Control System Using Texture Analysis In Metallurgy, Jonathan Blackledge, Dymitiy Dubovitskiy

Conference papers

Object detection, recognition and texture classification is an important aspect of many industrial quality control systems. In this paper, we report on a system designed for the inspection of surfaces which has a range of applications in the area of metallurgy. The approach considered is based on the application of Fractal Geometry and Fuzzy Logic for texture classification and, in this paper, focuses on the manufacture of rolled steel. The manufacture of high quality metals requires automatic surface inspection for the assessment of quality control. Quality control systems are required for several tasks such as screening defected products, monitoring the ...


Diffusion Model And Experimental Verification Of Interfacial Multiple Phase Growth In A Thermal Energy Storage Binary System, Bandar Abdulrahman Alzahrani 2011 Lehigh University

Diffusion Model And Experimental Verification Of Interfacial Multiple Phase Growth In A Thermal Energy Storage Binary System, Bandar Abdulrahman Alzahrani

Theses and Dissertations

No abstract provided.


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