Engineering Commons^™

Information For Operation Of Water Supply Systems, L. Douglas James, Glen E. Stringham, J. Clair Batty

Reports

Introduction: Water requirements increase as more people use more water for domestic purposes. The increase is augmented as technological advances add to the water needs of agriculture and industry. Additional urban landscaping adds further to the demand. Simultaneously, the same forces increase demands for flood control, hydrelectric power, and navigation; and a more urbanized population want more flows preserved for productive natural environments, recreational use, and aesthetic enjoyment. The response over the years to these growing demands on water resources has been to supply increasing amounts of water and greater levels of development for other purposes by building more projects, …

Hydrologic Efficiency In Water Conservation, L. Douglas James

Reports

Introduction: The hydrologic cycle can be subdivided into three phases: 1)Humidity is transported within the atmosphere and becomes precipitation, and 2) Water moves downhill until eventually reaching the sea while all the time 3) Evapotranspiration returns exposed moisture to the atmosphere. During its movement, flowing water transports suspended sediments and dissolved minerals to reshape landforms and redistribute the mineral composition of the earth's surface throughout geologic time. It is during the second phase that flowing water can be diverted for uses that generally add to evaportranspiration (through consumptive use) and transport (through waste disposal). The water resources development that serves …

Optical Fibre Technology, Gerald Farrell

Articles

No abstract provided.

Applications Of Extenics To 2d-Space And 3d-Space, Florentin Smarandache, Victor Vladareanu

Branch Mathematics and Statistics Faculty and Staff Publications

In this article one proposes several numerical examples for applying the extension set to 2D- and 3D-spaces. While rectangular and prism geometrical figures can easily be decomposed from 2D and 3D into 1D linear problems, similarly for the circle and the sphere, it is not possible in general to do the same for other geometrical figures.

Electrochemical Behavior Of Galvanized Steel Embedded In Soil, Jesus F. Hinojos

Open Access Theses & Dissertations

The investigation focused on the corrosion of galvanized steel embedded in soil. The primary objective of the study was to develop a technique for monitoring the corrosion behavior of samples in the field by measuring the potential and current with respect to time (or electrochemical noise). Electrochemical electrodes were designed to simulate the galvanized steel in contact with a thin-film of electrolytes which are usually generated in soils as they collect and drain rain water depending on soil porosity. The exposure of the galvanized steel to thin-film electrolytes consisted of cycling between two days of wetted soil followed by the …

Thin Film Growths Of Znte And Cdte On Various Substrates Using A Novel Close Space Sublimation Reactor Css4, Damian Marrufo

Open Access Theses & Dissertations

Thin films of CdTe have been grown on CdS in a variety of methods for use in thin film photovoltaic systems. Limits to the efficiency of CdTe/CdS solar cells have been attributed to defects in the lattice that occur between the interface of CdS and CdTe due to a lattice mismatch. A close space sublimation (CSS) reactor known as the CSS4 was designed and fabricated in UTEP to deposit complex layers of CdTe and ZnTe on top of a CdS film that is grown via chemical bath deposition in order to obtain a CdTe photovoltaic. Unfortunately, the original design and …

Surface And Guided Waves On Structured Surfaces, Javier Polanco

Open Access Theses & Dissertations

Surface and guided waves on structured surfaces and inhomogeneous media studies the propagation of waves in systems with spatially varying parameters. In the rainbow case (chapter 1), the dielectric constant changes with coordinates. In the cylinder case: boundary and the metal (chapter 2), it is a curved surface. Finally, in the last case (chapter 3), the dielectric constant changes in z-direction.

A Novel Method For The Curing Of Metal Particle Loaded Conductive Inks And Pastes, David Adrian Roberson

Open Access Theses & Dissertations

The emerging technology of printed microelectronics involving the use of conductive inks in conjunction with standard printing techniques offers a fast and low waste method for creating microelectronics compared with standard manufacturing processes. A clear path to the creation of flexible electronics is present due to the ease of printing on flexible substrates. Moreover, creation of novel 3D structural electronics is possible via the integration of printing technologies and additive manufacturing (AM) techniques.

A key obstacle to the manufacturing of flexible and structural electronics comes from the temperature restrictions imposed by the substrates, which are typically polymeric. This hindrance has …

Structure Morphology And Optical Properties Of Nanocrystalline Ga2o3 Thin Films, Sampath Kumar Samala

Open Access Theses & Dissertations

Gallium Oxide thin films were produced by sputter deposition by varying the substrate temperature (T_s) in a wide range (T_s=25-800 oC) and under variable deposition time. The structural characteristics and optical properties of Ga₂O₃ films were evaluated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), Rutherford backscattering spectrometry (RBS) and spectrophotometric measurements. The effect of growth temperature is significant on the chemistry, crystal structure and morphology of Ga₂O₃ films. XRD and SEM analyses indicate that the Ga₂O₃ films grown at lower temperatures were …

An Evaluation Of The Performance Of Network Rtk Gnss Services In Ireland, Audrey Martin, Eugene Mcgovern

Conference Papers

The national Geodetic infrastructure for the island of Ireland has developed rapidly to a fully GNSS compatible coordinate reference system - Irish Transverse Mercator (ITM) which is realised through a Continuously Operating Reference System (CORS) network of active GNSS stations. The National Mapping Authority’s CORS network provides data for post processing and streamed raw data for real-time network (NRTK) solutions. This NRTK raw data is currently being used by both Leica and Topcon to provide independent NRTK solutions. A second CORS network, known as VRS Now Ireland, with both RINEX and NRTK capabilities, was established in 2008 by Trimble and …

The Significance Of Equi-Biaxial Bubble Inflation In Determining Elastomeric Fatigue Properties, Stephen Jerrams, Niall Murphy, John Hanley

Books/Book Chapters

It is well documented that for the effective modelling of the static and dynamic behaviour of elastomeric components using the finite element (FE) method it is essential to obtain material parameters that are derived from a range of physical tests. For a conventional linear solid, uniaxial testing suffices to fully characterise the material, but for rubber it is necessary to test in at least two deformation modes. Also, the determination of fatigue lives of rubber components is still in its infancy and a reliable, repeatable fatigue test for rubber will have important consequences for component design, functionality, maintenance and cost. …

The Use Of A Fiber Comb Filter Fabricated By A Co2 Laser Irradiation To Improve The Resolution Of A Ratiometric Wavelength Measurement System, Pengfei Wang, Gilberto Brambilla, Ming Ding, Yuliya Semenova, Qiang Wu, Gerald Farrell

Articles

An edge filter-based ratiometric wavelength measurement system is modeled and analyzed in this paper. The results confirm that the noise of input signal and photodetectors limits the resolution of the wavelength measurement system. The achievable resolution is calculated for a given noise level of the input signal and photodetectors' resolution. An improved ratiometric wavelength measurement system consisting of two fiber comb filters is presented both theoretically and experimentally, which performs coarse and fine wavelength measurements simultaneously. The resolution of the system is significantly improved to better than 5 pm while maintaining the potential for high measurement speed and wide measurable …

Germanium Microsphere High-Q Resonator, Pengfei Wang, Timothy Lee, Ming Ding, Anirban Dhar, Thomas Hawkins, Paul Foy, Yuliya Semenova, Qiang Wu, Jayanta Sahu, Gerald Farrell, John Ballato, Gilberto Brambilla

Articles

In this Letter, the fabrication and characterization of a microsphere resonator from the semiconductor germanium is demonstrated. Whispering gallery modes are excited in a 46 μm diameter germanium microsphere resonator using evanescent coupling from a tapered silica optical fiber with a waist diameter of 2 μm. Resonances with Q factors as high as 3.8×104 at wavelengths near 2 μm are observed. Because of their ultrahigh optical nonlinearities and extremely broad transparency window, germanium microsphere resonators offer the potential for optical processing devices, in particular at long wavelengths, such as around 2 μm.

A Silica Single-Mode Fibre-Chalcogenide Multimode Fibre-Silica Single-Mode Fibre Structure, Pengfei Wang, Ming Ding, Lin Bo, Yuliya Semenova, Qiang Wu, Gerald Farrell

Articles

In this letter we theoretically and experimentally investigate a single-mode-multimode-single-mode (SMS) structure based on chalcogenide (As2S3) multimode fibre and silica single-mode fibres. The experimental results show a general agreement with the numerical simulation results based on a wide angle-beam propagation method (WA-BPM). Multimode interference variation was observed as a result of photo-induced refractive index changes arising from either localized laser irradiation at a wavelength of 405 nm or the use of a UV lamp. Our result provides a platform for the development

Influence Of Fluctuations Of The Geometrical Parameters On The Photonic Band Gaps In One-Dimensional Photonic Crystals, Vladimir A. Tolmachev, Anna .. Baldycheva, Kevin Berwick, Tatiana Perova

Articles

The influence of random fluctuations in the layer thicknesses in high contrast, one-dimensional Photonic Crystals (PCs) on the transmission spectra and Photonic Band Gaps (PBGs) is investigated. The change in the PBGs depends on the magnitude of the fluctuations and increases with an increase in the order of the PBG. Introducing thickness non-uniformity into the PC of up to 0.004 times the value of lattice constant for different types of fluctuation distributions has a negligible effect on either the position or the shape of the 1st and nearest PBGs. The approach suggested here allows the determination of the tolerances required …

What Do Final Year Engineering Students Know About Sustainable Development, Iacovos Nicolaou, Eddie Conlon

Articles

This paper presents data from a project which aims to determine the level of knowledge and understanding of engineering students about Sustainable Development (SD). The data derives from a survey completed by final year engineering students in three Irish Higher Education Institutions. This paper is part of a larger study which examines the relationship between students’ and teachers’ understanding of SD. The results from the survey show that final year engineering students have a discipline-led conception of SD. The majority of the participants fail to acknowledge the complexity of the concept and focus only on environmental protection. Their knowledge of …

A Front Tracking Model Of The Maxus-8 Microgravity Solidification Experiment On A Ti-45.5at.% Al-8at.%Nb Alloy, Robin Mooney, Shaun Mcfadden, Marek Rebow, David J. Browne

Articles

On 26th March 2010 the MAXUS-8 sounding rocket was launched from the Esrange Space Center in Sweden. As part of the Intermetallic Materials Processing in Relation to Earth and Space Solidification (IMPRESS) project, a solidification experiment was conducted on a Ti-45.5at.%Al-8at.%Nb intermetallic alloy in a module on this rocket. The experiment was designed to investigate columnar and equiaxed microstructures in the alloy. A furnace model of the MAXUS 8 experiment with a Front Tracking Model of solidification has been developed to determine the macrostructure and thermal history of the samples in the experiment. This paper gives details of results of …

An Improved Flood Forecasting Model Of The Blue Nile River In Sudan, Gamal Abdo, Ahmed Nasr

Articles

Reliable flood predictions with a reasonable lead time in the Blue Nile River in Sudan are vitally important to avoid catastrophic damages due to flooding of this river and the main River Nile. A HEC-RAS model was initially applied to the Blue Nile by representing the river as a single reach. The resulting original model was subsequently improved by including the two tributaries of the river, Rahad and Dindir, and also the two existing reservoirs, Rosaries and Sinnar, to the model. The original and the improved models were calibrated using 1988 flood data for the period from June to September …

Mobispatial: Open Source For Mobile Spatial Interaction, Junjun Yin, James Carswell

Conference papers

This paper describes our Mobile Spatial Interaction (MSI) prototype MobiSpatial, which benefits from location and orientation aware smartphones and existing open source spatial data initiatives to facilitate user interaction with the geospatial query process. We utilize today’s ubiquitous mobile device as the central computing platform to calculate a mobile user’s visibility shape at his/her current location. MobiSpatial uses this shape as a query “window” in a spatial database to perform line-of-sight, field-of-view and 360º Isovist visibility searches. These visibility based spatial queries reduce the risk of “information overload” by exploiting “hidden query removal” functionality to retrieve only those objects that …

A Teaching Practice Review Of The Use Of Multiple-Choice Questions For Formative And Summative Assessment Of Student Work On Advanced Undergraduate And Postgraduate Modules In Engineering, Aidan O'Dwyer

Articles

This paper reflects on, reports on and evaluates the use of multiple-choice questions, in both formative and summative assessment modes, on control engineering modules taken by advanced undergraduate and postgraduate engineering students, over four academic years. The material covered by the modules is analytical in nature. The rationale for examining the assessment strategy was the poor performance by students in a closed book traditional terminal examination on one of the advanced undergraduate modules over some years. The change in assessment strategy has improved student learning, as measured by assessment data; student feedback on the assessment methods is broadly positive. The …

Cable Heating Effects Due To Harmonic Distortion In Electrical Installations, Jonathan Blackledge, Kevin O'Connell, Martin Barrett, Anthony Sung

Conference papers

The increasing use of non-linear loads in electrical installations has exacerbated the problems of harmonic distortion in industrial and commercial electrical systems. In the UK the current practice to determine the cable size for an electric circuit is to use BS7671. However, previously the 16th edition IEE Wiring Regulations only dealt with situations where cables attain the conductor temperature generated by sinusoidal currents at the fundamental power frequency. This paper outlines the methods available to determine the minimum size of line conductors for protection against overload currents, taking into account the harmonic content of the load current, and explains the …

A Video Encoder Design Combining Edge-Adaptive Lifting And Scalable Block-Matching With Motion Compensation, Sedat Telçeken, Ömer Nezi̇h Gerek

Turkish Journal of Electrical Engineering and Computer Sciences

This study aimed to achieve video compression by using a novel lifting-based hybrid encoder that also uses motion compensation. The proposed encoder separates video frames into temporal groups, within which certain frames are selected for producing temporal and spatial predictions over the rest of the frames. The predictions utilize spatiotemporal lifting together with motion compensation. The combination of spatial information with temporal changes is inspired from the idea of edge-adaptive lifting, which alters prediction directions in images. A further incorporation of well-known block-matching methods with different levels was observed to improve the performance. To provide the first compression results, unpredicted …

Tunable Srr-Based Substrate For A Microstrip Patch Antenna, Adnan Sondaş, Mustafa Hi̇kmet Bi̇lgehan Uçar, Yunus Emre Erdemli̇

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a microstrip patch antenna over an artificial substrate composed of split-ring resonator (SRR) elements is introduced. As the SRR-based substrate provides miniaturization for the patch, metallic loadings placed between the rings of the SRR elements offer frequency-tuning capability. Practical switch models are employed in lieu of those loadings to demonstrate dynamic control of the operational frequency. The full-wave analysis and design of the proposed tunable patch were carried out using CST Microwave Studio, and the cross-comparisons were provided via Ansoft HFSS. Preliminary measurements are also presented, demonstrating the prospective performance of the proposed design.

Research On Cutoff Wavelength Of Dominant Mode And Field Patterns In Trapezoidal Microshield Lines, Hai Sun, Yujiang Wu

Turkish Journal of Electrical Engineering and Computer Sciences

The influence of the position of the metallic signal strip on the cutoff characteristic of the dominant mode and the field patterns in 3 types of trapezoidal microshield lines are calculated by the edge-based finite element method. These trapezoidal microshield lines include trapezoidal microshield lines with a single signal line, dual signal lines, and 3 signal lines. The cutoff wavelength of the dominant mode can be adjusted by changing the dimensions of metallic signal strips as well as by adjusting their positions. Field patterns of the dominant mode and the first-higher-order mode for different dimensions and the dielectric constant of …

A New Multipath Channel Transformation Technique, Tuğrul Çavdar

Turkish Journal of Electrical Engineering and Computer Sciences

A new channel transformation technique is introduced in this paper The technique is employed on the receiver side and has 2 filters. The first filter is the inverse complex conjugate of the estimated channel. The profile of this filter's output is triangular. The taps of the second filter are calculated according to the output of the first filter to produce an exponentially decreasing profile. This technique transforms most channel profiles to exponentially decreasing channel profiles. Thus equalizers adopting the proposed technique may have better bit error rates and lower computational complexity on frequency-selective channels. This paper evaluates the efficiency of …

Effects Of Diacritics On Turkish Information Retrieval, Adi̇l Alpkoçak, Meltem Ceylan

Turkish Journal of Electrical Engineering and Computer Sciences

We investigate the effects of improper use of diacritics in the Turkish alphabet on information retrieval. A diacritic is simply a supplementary sign added to a letter to change the sound value of the letter, and the Turkish alphabet has 5 special letters derived from Latin by adding different diacritics. The statistical analysis performed in this study shows that retrieval performance significantly decreases when documents and queries contain letters with different forms, such that documents consist of letters with diacritics while queries consist of standard Latin letters and vice versa. In order to tackle this challenge, we propose 3 approaches: …

Context Gathering And Management For Centralized Context-Aware Handover In Heterogeneous Mobile Networks, Behrouz Shahgholi Ghahfarokhi, Naser Movahhedinia

Turkish Journal of Electrical Engineering and Computer Sciences

Context-aware handover decision has recently been considered as a candidate for next-generation heterogeneous wireless networks. The context-aware handover methods proposed in the literature differ in some aspects, including the location of the handover decision (distributed or centralized). Depending on the location of the decision point, the appropriate part of the context knowledge should be transferred in those methods. This paper proposes a context gathering mechanism for a policy-based context-aware handover method, which implements mobile-initiated and network assisted handover. The proposed network context gathering mechanism is based on a media-independent handover (MIH) framework and the paper justifies the usability of the …

Observer Path Design By Imitation Of Competing Constraints For Bearing Only Tracking, Ridvan Gürcan, Mesut Kartal

Turkish Journal of Electrical Engineering and Computer Sciences

In the bearing only tracking (BOT) problem the observer tries to estimate the position of the target. The observer maneuver is a requirement to guarantee the uniqueness of the estimation. Determining an observer maneuver for BOT is a difficult problem due to its nonlinear nature. This paper proposes a new method that combines the reference BOT scenarios as a priori knowledge with the incoming bearing measurements to obtain an observer maneuver in a generic optimization framework. The use of a priori knowledge makes the observer maneuver design more realistic. The maneuver recommendation process uses the imitation of competing constraints. In …

Vertical Response Of A Footbridge Subjected To Stocastic Crowd Loading, Joe Keogh

Conference papers

No abstract provided.

The Response Of A Footbridge To Pedestrians Carrying Additional Mass, Darragh O'Sullivan, Colin Caprani, Joe Keogh

Conference papers

Footbridges with low natural frequency are susceptible to excessive vibration serviceability problems if the pedestrian pacing frequency matches the bridge natural frequency. Much research has been done into describing the response of a footbridge to single pedestrian loading. However, many pedestrians carry additional mass such as shopping bags and backpacks, and this has generally not been accounted for in previous research. This work examines this problem using an experimental bridge excited with many single pedestrian events, both with and without additional mass. The vertical acceleration response is measured and compared to moving force, moving mass, and moving spring-mass-damper models. The …