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2008

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Articles 3211 - 3240 of 4190

Full-Text Articles in Engineering

Glass Transition Behavior Of Poly(Methyl Acrylate) End-Grafted By Atrp To Amorphous Silica, Manikantan B. Nair, Frank D. Blum Jan 2008

Glass Transition Behavior Of Poly(Methyl Acrylate) End-Grafted By Atrp To Amorphous Silica, Manikantan B. Nair, Frank D. Blum

Chemistry Faculty Research & Creative Works

Ultra-thin polymer films attached to solid substrates (supported films) have attracted significant interest in recent years. Supported films are used in the design of advanced materials like photoresists, lubricants and other electronic devices. Glass transition temperatures (Tgs) of supported polymer films have also been of significant interest. The Tg has been shown to depend on the thickness of the polymer film on the surface and the inherent nature of the surface. The effect of end-grafting of a polymer chain to a surface, on the Tg of the polymer has been studied previously.1 Reports on the study of glass transition behaviors …

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Modeling The Fate Of Pharmaceuticals And Personal Care Products In Sewage Treatment Plants, Craig D. Adams Jan 2008

Modeling The Fate Of Pharmaceuticals And Personal Care Products In Sewage Treatment Plants, Craig D. Adams

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Chemical fate models can be used to estimate the transformation reactions and the partitioning behavior of pharmaceuticals and personal care products (PPCPs) in sewage treatment plants (STPs). Modeling the fate of PPCPs in a STP requires parameters such as rate constants or partition coefficients that are often unique to a specific STP, and that may exhibit significant temporal variability. Chemical fate models provide both a valuable test of our understanding of the fundamental underlying mechanisms regarding the fate of PPCPs in STPs, as well as a means of providing both qualitative and quantitative estimates for PPCP removal. This paper is …

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Functorial Coalgebraic Logic: The Case Of Many-Sorted Varieties, Alexander Kurz, Daniela Petrişan Jan 2008

Functorial Coalgebraic Logic: The Case Of Many-Sorted Varieties, Alexander Kurz, Daniela Petrişan

Engineering Faculty Articles and Research

Following earlier work, a modal logic for T-coalgebras is a functor L on a suitable variety. Syntax and proof system of the logic are given by presentations of the functor. This paper makes two contributions. First, a previous result characterizing those functors that have presentations is generalized from endofunctors on one-sorted varieties to functors between many-sorted varieties. This yields an equational logic for the presheaf semantics of higher-order abstract syntax. As another application, we show how the move to functors between many-sorted varieties allows to modularly combine syntax and proof systems of different logics. Second, we show how to associate …

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Responses Of Engineering Students To Lectures Using Powerpoint, Aidan O'Dwyer Jan 2008

Responses Of Engineering Students To Lectures Using Powerpoint, Aidan O'Dwyer

Conference papers

This contribution reports on, reflects on and evaluates engineering students responses to the use of PowerPoint in a lecture environment, compared to a more traditional lecturing approach. The contribution concludes that, on average, students value PowerPoint based lectures both as a means of better understanding the material and for the mediums structural and organisational advantages. Students also strongly favour the PowerPoint lectures being available on-line and that a paper copy of the PowerPoint presentation be distributed at the lecture.

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Using Student Presentations For Learning And Assessment: Some Experiences, Aidan O'Dwyer Jan 2008

Using Student Presentations For Learning And Assessment: Some Experiences, Aidan O'Dwyer

Conference papers

This contribution reports on, reflects on and evaluates the author’s experiences, over a number of academic years, of using formal student presentations as a means of learning and assessment in a taught postgraduate programme in engineering at Dublin Institute of Technology. Students were asked to prepare PowerPoint presentations on individual engineering topics; relevant references in books and technical papers were provided as assistance. Peer assessment of the presentations was employed, following a structured guideline agreed with the students. The contribution discusses the peer assessment experience in detail, including formal student feedback on the process. Some analysis work suggests that there …

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Electric-Powered Wheelchairs As An Assistive Technology, Aidan O'Dwyer, Malabika Basu, Eugene Coyle Jan 2008

Electric-Powered Wheelchairs As An Assistive Technology, Aidan O'Dwyer, Malabika Basu, Eugene Coyle

Conference papers

This paper briefly outlines recent work done, particularly in control systems, for electric powered wheelchairs. These mobility aids, first developed in the 1950’s [1], were improved with the incorporation of microprocessors. The requirement for mobility aids in general is rising; for example, it is reckoned that 1.5% of the U.K. population require such aids. As an assistive technology, electric powered wheelchairs have many benefits. Nevertheless, a reliable and robust such wheelchair has still to evolve.

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Enhancing Learning On A First Year Engineering Programme With A Student Design Project, Aidan O'Dwyer Jan 2008

Enhancing Learning On A First Year Engineering Programme With A Student Design Project, Aidan O'Dwyer

Conference papers

This contribution reports on, and evaluates, the use of a design project for enhancing student learning on a first year module in electrical engineering at Dublin Institute of Technology. The project objective, as outlined to the students, was to design and build a, possibly innovative, everyday device that can generate electricity from sources of “free energy”, so as to encourage first year engineering students to use their natural design creativity in a freeform, brainstorming manner. The project allows students to further develop their academic interests, assists student retention and facilitates student interaction, among other advantages. The work encourages students to …

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A New Configuration And Control Of Doubly Fed Induction Generator (Upqc-Wg), N. G. Jayanti, Malabika Basu, Kevin Gaughan, Michael Conlon Jan 2008

A New Configuration And Control Of Doubly Fed Induction Generator (Upqc-Wg), N. G. Jayanti, Malabika Basu, Kevin Gaughan, Michael Conlon

Conference papers

The paper presents detailed simulation based analysis and investigation on grid code compliance of a new configuration of a 2 MW doubly fed induction generator. The converters of DFIG are connected and controlled to function like a unified power quality conditioner (UPQC). One of the converters is connected in series with the stator terminals and acts to maintain the stator voltage at a predetermined value. It can also transfer power to or from the rotor side converter through the common DC link. The other converter is connected to the rotor like a conventional DFIG and is controlled to maintain appropriate …

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Portfolio Diversification Using Subspace Factorizations, Ruairí De Fréin, Konstantinos Drakakis, Scott Rickard Jan 2008

Portfolio Diversification Using Subspace Factorizations, Ruairí De Fréin, Konstantinos Drakakis, Scott Rickard

Conference papers

Successful investment management relies on allocating assets so as to beat the stock market. Asset classes are affected by different market dynamics or latent trends. These interactions are crucial to the successful allocation of monies. The seminal work on portfolio management by Markowitz prompts the adroit investment manager to consider the correlation between the assets in his portfolio and to vary his selection so as to optimize his riskreturn profile. The factor model, a popular model for the return generating process has been used for portfolio construction and assumes that there is a low rank representation of the stocks. In …

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A Stabilized Rbf Collocation Scheme For Neumann Type Boundary Value Problems, Nicolas Ali Libre, Arezoo Emdadi, Edward J. Kansa, Mohammad Rahimian, Mohammad Shekarchi Jan 2008

A Stabilized Rbf Collocation Scheme For Neumann Type Boundary Value Problems, Nicolas Ali Libre, Arezoo Emdadi, Edward J. Kansa, Mohammad Rahimian, Mohammad Shekarchi

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The numerical solution of partial differential equations (PDEs) with Neumann boundary conditions (BCs) resulted from strong form collocation scheme are typically much poorer in accuracy compared to those with pure Dirichlet BCs. In this paper, we show numerically that the reason of the reduced accuracy is that Neumann BC requires the approximation of the spatial derivatives at Neumann boundaries which are significantly less accurate than approximation of main function. Therefore, we utilize boundary treatment schemes that based upon increasing the accuracy of spatial derivatives at boundaries. Increased accuracy of the spatial derivative approximation can be achieved by h-refmement reducing the …

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Carbon Permits, Jun-Ki Choi, Bhavik R. Bakshi Jan 2008

Carbon Permits, Jun-Ki Choi, Bhavik R. Bakshi

Mechanical and Aerospace Engineering Faculty Publications

The Encyclopedia of Global Warming and Climate Change helps readers learn about the astonishingly intricate processes that make ours the only planet known to be habitable. These three volumes include more than 750 articles that explore major topics related to global warming and climate change—ranging geographically from the North Pole to the South Pole, and thematically from social effects to scientific causes.

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A Review Of Negation In Clinical Texts, John D. Kelleher, Brian Mac Namee Jan 2008

A Review Of Negation In Clinical Texts, John D. Kelleher, Brian Mac Namee

Reports

Negation is commonly seen in clinical documents [Chapman et al., 2001a] ”In clinical reports the presence of a term does not necessarily indicate the presence of the clinical condition represented by that term. In fact, many of the most frequently described findings and diseases in discharge summaries, radiology reports, history and physical exams, and other transcribed reports are denied in the patient” [Chapman et al., 2001b, page. 301].

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An Investigation Of Block Searching Algorithms For Video Frame Codecs, Jerome Casey Jan 2008

An Investigation Of Block Searching Algorithms For Video Frame Codecs, Jerome Casey

Other Resources

Block matching is the most computationally demanding aspect of the video encoding process. In many applications real-time video encoding is desired and therefore it is important that the encoding is fast. Also where handheld devices such as a PDA or mobile phone are concerned a less computationally intensive algorithm means a simpler processor can be used which saves on hardware costs and also extends battery life. An optimised algorithm also allows these devices to be used in low bandwidth wireless networks. The challenge is to decrease the computational load on the system without compromising the quality of the video stream …

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Patient-Centred Laboratory Validation Using Software Agents, John Mcgrory, Jane Grimson, Frank Clarke, Peter Gaffney Jan 2008

Patient-Centred Laboratory Validation Using Software Agents, John Mcgrory, Jane Grimson, Frank Clarke, Peter Gaffney

Conference Papers

Guidelines are self-contained documents which healthcare professionals reference to obtain knowledge about a specific condition or process. They interface with these documents and apply known facts about specific patients to gain useful supportive information to aid in developing a diagnosis or manage a condition. To automate this process a series of Standard Operating Procedures (SOP) and workflow processes are constructed using the contents of these documents in order to manage the validation flow of a patient sample. These processes decompose the guidelines into workflow plans, which are then called using condition triggers controlled by a centralised management engine. The software …

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Phase Change Cooling Applications - Engine Cooling, Kiran Kumar Katta Jan 2008

Phase Change Cooling Applications - Engine Cooling, Kiran Kumar Katta

Open Access Theses & Dissertations

Waste heat recovery system composed of two phase cooling system, exhaust heat exchanger, and mini-turbine has been proposed by Henry Works, Inc to generate auxiliary power via harvesting engine cooling and exhaust heat loss from heavy duty vehicles. The objective of this research is to evaluate the two phase cooling system through the engine dynamometer test and obtain initial test data for the development of the waste heat recovery system. Engine dynamometer experiment for evaluating two phase cooling has been conducted using Perkins diesel engine. During two phase cooling phase, the coolant temperature showed less than 1 °C variation in …

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Thermodynamic Modelling And Ray-Trace Modelling Of Luminescent Solar Concentrators: A Comparison Of The Two Approaches, Manus Kennedy, Amanda Chatten, Daniel Farrell, Rahul Bose, Andreas Büchtemann, Sarah Mccormack, John Doran, Brian Norton, Keith Barnham Jan 2008

Thermodynamic Modelling And Ray-Trace Modelling Of Luminescent Solar Concentrators: A Comparison Of The Two Approaches, Manus Kennedy, Amanda Chatten, Daniel Farrell, Rahul Bose, Andreas Büchtemann, Sarah Mccormack, John Doran, Brian Norton, Keith Barnham

Conference Papers

The electrical and spectral output from luminescent solar concentrator (LSC) devices is predicted using thermodynamic modelling and ray-trace modelling techniques. Predicted output from four LSCs of varying dimensions, containing different luminescent dyes, are found to be in good agreement with measured output taken from fabricated LSCs. Despite the many different processes involved in the two modelling approach, predicted short circuit current densities from both approaches are found to be in excellent agreement.

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Ray Trace Modelling Of Multiple Dyes In A Luminescent Solar Concentrator, Manus Kennedy, Mike Dunne, Sarah Mccormack, John Doran, Brian Norton Jan 2008

Ray Trace Modelling Of Multiple Dyes In A Luminescent Solar Concentrator, Manus Kennedy, Mike Dunne, Sarah Mccormack, John Doran, Brian Norton

Conference Papers

A previously developed Monte-Carlo ray-trace model has been modified to incorporate multiple luminescent species. Liquid luminescent solar concentrators (LSCs) have been fabricated to verify the ray-trace predictions for LSCs containing multiple luminescent dyes. Single dye and multiple dye solutions of varying concentrations can be easily prepared and inserted into the experimental liquid LSC setup. In this way, experimental uncertainties, such as reduction in the luminescent quantum yield, can be reduced. Hence, the spectral effects of various single and multiple dyes can be analysed and compared more accurately with ray-trace predictions. Initial results from the liquid LSC characterisation and comparison with …

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Comparison Of Vacuum Glazing Thermal Performance Predicted Using Two- And Three-Dimensional Models And Their Experimental Validation, Brian Norton, Philip Eames, Yueping Fang, Trevor Hyde, Neil Hewitt Jan 2008

Comparison Of Vacuum Glazing Thermal Performance Predicted Using Two- And Three-Dimensional Models And Their Experimental Validation, Brian Norton, Philip Eames, Yueping Fang, Trevor Hyde, Neil Hewitt

Conference Papers

The thermal performance of vacuum glazing was predicted using two dimensional (2-D) finite element and three dimensional (3-D) finite volume models. In the 2-D model, the vacuum space, including the pillar arrays, was represented by a material whose effective thermal conductivity was determined from the specified vacuum space width, the heat conduction through the pillar array and the calculated radiation heat transfer between the two interior glass surfaces within the vacuum gap. In the 3-D model, the support pillar array was incorporated and modeled within the glazing unit directly. The difference in predicted overall heat transfer coefficients between the two …

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Linguatag: An Emotional Speech Analysis Application, Charlie Cullen, Brian Vaughan, Spyros Kousidis Jan 2008

Linguatag: An Emotional Speech Analysis Application, Charlie Cullen, Brian Vaughan, Spyros Kousidis

Conference papers

The analysis of speech, particularly for emotional content, is an open area of current research. Ongoing work has developed an emotional speech corpus for analysis, and defined a vowel stress method by which this analysis may be performed. This paper documents the development of LinguaTag, an open source speech analysis software application which implements this vowel stress emotional speech analysis method developed as part of research into the acoustic and linguistic correlates of emotional speech. The analysis output is contained within a file format combining SMIL and SSML markup tags, to facilitate search and retrieval methods within an emotional speech …

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Emotional Speech Corpora For Analysis And Media Production, Charlie Cullen, Brian Vaughan, Spyros Kousidis Jan 2008

Emotional Speech Corpora For Analysis And Media Production, Charlie Cullen, Brian Vaughan, Spyros Kousidis

Conference papers

Research into the acoustic correlates of emotional speech as part of the SALERO project has led to the construction of high quality emotional speech corpora, which contain both IMDI metadata and acoustic analysis data for each asset. Research into semi-automated, re-usable character animation has considered the development of online workflows based on speech corpus assets that would provide a single point of origin for character animation in media production. In this paper, a brief description of the corpus design and construction is given. Further, a prototype workflow for semi-automated emotional character animation is also provided, alongside a description of current …

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Damping Of Magnetorheological Elastomers, Lin Chen Jan 2008

Damping Of Magnetorheological Elastomers, Lin Chen

Articles

The damping property of magnetorheological (MR) elastomers is characterized by a modified dynamic mechanical-magnetic coupled analyzer. The influences of the external magnetic flux density, damping of the matrix, content of iron particles, dynamic strain and driving frequency on the damping properties of MR elastomers were investigated experimentally. The experimental results indicate that the damping properties of MR elastomers greatly depend on the interfacial slipping between the inner particles and the matrix. Different from general composite materials, the interfacial slipping in MR elastomers is affected by the external applied magnetic field.

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A Low Polarization Sensitivity All-Fiber Wavelength Measurement System, Ginu Rajan, Yuliya Semenova, Gerald Farrell, Qian Wang, Pengfei Wang Jan 2008

A Low Polarization Sensitivity All-Fiber Wavelength Measurement System, Ginu Rajan, Yuliya Semenova, Gerald Farrell, Qian Wang, Pengfei Wang

Articles

A low polarization-sensitive all-fiber wavelength measurement system using a twisted macro-bend fiber edge filter together with polarization-insensitive (PI) 3-dB coupler is presented. Eliminating the polarization-dependent loss (PDL) is essential when macro-bending single-mode fiber is utilized as an edge filter. A new bending configuration to eliminate the PDL of a fiber edge filter is proposed in this letter by twisting the fiber by 90deg between two bending sections with equal length. The PDL of this configuration retains a low value even while the bending length is increased to achieve a steeper response for the edge filter. This configuration together with a …

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An All-Fiber Temperature Sensor Based On A Macro-Bend Singlemode Fiber Loop, Ginu Rajan, Yuliya Semenova, Gerald Farrell Jan 2008

An All-Fiber Temperature Sensor Based On A Macro-Bend Singlemode Fiber Loop, Ginu Rajan, Yuliya Semenova, Gerald Farrell

Articles

An all-fibre temperature sensor is proposed based on a macro-bend singlemode fibre loop using a ratiometric power measurement scheme. The sensor has a linear characteristic with temperature at a fixed wavelength and bend radius. A direct linear relationship between the bend loss of the singlemode fibre and temperature is reported for the first time. By measuring the change in bend loss of the system a change in temperature can be measured assuming the system is calibrated. The proposed sensor has a higher temperature resolution than other conventional fibre-optic sensors and also benefits from simplicity.

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Investigation On Singlemode-Multimode-Singlemode Fiber Structure, Qian Wang, Gerald Farrell, W. Yan Jan 2008

Investigation On Singlemode-Multimode-Singlemode Fiber Structure, Qian Wang, Gerald Farrell, W. Yan

Articles

This paper presents an investigation on a single-mode-multimode-single-mode fiber structure. A one-way guided-mode propagation analysis for the circular symmetry waveguide is employed to model the light propagation and the approximated formulations are derived and evaluated concerning the accuracy. Phase conjunction of the multimode interference within the fiber structure is revealed. A simple way to predict and analyze the spectral response of the structure is presented through the space to wavelength mapping with the derived approximated formulations. The prediction of spectral response is verified numerically and experimentally.

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Dual Frequency Dual Circularly-Polarised Patch Antenna With Wide Beamwidth, Xiulong Bao, Max Ammann Jan 2008

Dual Frequency Dual Circularly-Polarised Patch Antenna With Wide Beamwidth, Xiulong Bao, Max Ammann

Articles

A dual-frequency dual-circularly polarised patch antenna with wide beamwidth is proposed. The two-layer structure comprises circular patches with offset circular slots connected to rectangular slots. They provide orthogonal perturbations realising RHCP and LHCP for the lower and upper bands, respectively. The wide beamwidth is realised by extending the substrate beyond the groundplane. Measurements show a maximum beamwidth of 180deg and gains of 3.9 and 0.5 dBic for zenith and 10deg elevation, respectively, for the upper band. The measured beamwidth for the low band is 130deg with a maximum gain of 3.9 and -0.7 dBic for zenith and 10deg elevation, respectively. …

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Ratiometric Wavelength Monitor Based On Singlemode-Multimode-Singlemode Fiber Structure, Agus Hatta, Gerald Farrell, Qian Wang, Ginu Rajan, Pengfei Wang, Yuliya Semenova Jan 2008

Ratiometric Wavelength Monitor Based On Singlemode-Multimode-Singlemode Fiber Structure, Agus Hatta, Gerald Farrell, Qian Wang, Ginu Rajan, Pengfei Wang, Yuliya Semenova

Articles

An all-fiber ratiometric wavelength monitor for optical wavelength measurement is proposed and is investigated theoretically and experimentally. Two edge filters with opposite slope spectral responses based on singlemode-multimode-singlemode (SMS) fiber structures are developed. A ratiometric wavelength measurement system employing the developed SMS edge filters demonstrates a high discrimination range of 20.41 dB and a potential wavelength measurement resolution of 10 pm over a wavelength range from 1530 to 1560 nm.

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Fast And Simple High Resolution Optical Spectrum Analyser, Kai-Uwe Lauterback, Thomas Schneider, Ronny Henker, Max Ammann, Andreas Schwarzbacher Jan 2008

Fast And Simple High Resolution Optical Spectrum Analyser, Kai-Uwe Lauterback, Thomas Schneider, Ronny Henker, Max Ammann, Andreas Schwarzbacher

Conference papers

A simple method for fast optical spectroscopy with high resolution is shown. The method is based on the narrowband Brillouin gain process in optical fibers.

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Effects Of Klopfenstein Tapered Feedlines On The Frequency-And-Time Domain Performance Of Planar Monopole Uwb Antennas, Giuseppe Ruvio, Max Ammann Jan 2008

Effects Of Klopfenstein Tapered Feedlines On The Frequency-And-Time Domain Performance Of Planar Monopole Uwb Antennas, Giuseppe Ruvio, Max Ammann

Conference papers

The effects of a Klopfenstein tapered transmission line used to feed a typical planar monopole UWB antenna have been investigated in terms of impedance bandwidth, phase linearity and radiation properties. The analysis shows that the taper allows manipulation of the resonances occurring within the operating bandwidth. A Klopfenstein tapered feedline that matches the 50 Omega input impedance to 30 Omega along 50 mm is able to reduce the maximum group delay variation by 85% with an acceptable variation of the impedance bandwidth and minor changes in the radiation pattern.

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Augmented Control Of Hands Free Voice Prostheses, Brian Madden, James Condron, Ted Burke, Eugene Coyle Jan 2008

Augmented Control Of Hands Free Voice Prostheses, Brian Madden, James Condron, Ted Burke, Eugene Coyle

Conference Papers

Laryngectomy patients often use an electrolarynx to facilitate speech following a tracheotomy. Devices of this type provide the most intelligible means of communication for tracheotomy patients. However, the electro-larynx has inherent drawbacks such as the buzzing monotonic sound emitted, the need for a free hand to operate the device, and the difficulty experienced by many tracheotomy patients in adapting to use it. The most effective means of addressing the shortcomings of existing electro-larynges is to provide the user with a hands-free facility. This allows the user to perform other manual tasks whilst speaking, or simply to communicate more effectively through …

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The New Engineer: Between Employability And Social Responsibility, Eddie Conlon Jan 2008

The New Engineer: Between Employability And Social Responsibility, Eddie Conlon

Articles

The reasons behind the demand for what is sometimes called the New Engineer are critically examined and it is argued that a focus on employability alone is not sufficient to prepare socially responsible engineers. By examining issues around work organisation and sustainability it is proposed that engineers need to understand the wider social context in which they work. It is argued that the focus of ethics education should be broadened to focus on the social structure and the way it both enables and constrains socially responsible conduct. There is a call to refocus engineers’ attitudes towards the systems of regulation …

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