Engineering Commons^™

Evaluation Of Fire-Fighting Helmet Surface Technology For High Radiant Heat Applications, David L. Barnett

University of Kentucky Master's Theses

Protective helmets used by fire-fighters must be designed to minimize the amount of heat transferred to the users head while providing durability, comfort, and affordable costs. This thesis highlights the evaluation of new helmet technology specifically tailored to high radiant heat environments to advance the state-of-the-art in head protection for this application. The research focused on the assessment of the outer shells of helmets and the properties of the surfaces. The development included the evaluation of radiation heat transfer, in a laboratory environment, to various helmet shell surface constructions. Industry standards were considered, and critiqued. Experiments were designed to isolate …

Experimental Investigation Of Separation In A Low Pressure Turbine Blade Cascade Model, Brian Hollon

University of Kentucky Master's Theses

The flow field around a low pressure turbine blade is examined using smoke-wire flow visualization, static surface pressure measurements, and particle image velocimetry (PIV). The purpose of the experimental study is to investigate the transition and separation characteristics on low pressure turbine blades under low Reynolds number (Re) and varying freestream turbulence intensity (FSTI). A cascade model consisting of 6 Pratt andamp; Whitney PAK-B low pressure turbine blades was examined in a wind tunnel using PIV and flow visualization. Smoke-wire visualization was performed for test section exit angles of 93°, 95°, and 97°, in the range Re = …

Measurements In A Rotating Serpentine Duct With Multiple Rib Arrangements, Rahul Bharadwajh

University of Kentucky Master's Theses

The effect of rotation on flow in a gas turbine blade cooling duct model is investigated experimentally. The present work consists of velocity measurements at different locations in a test section with a 180° bend with ribs on one wall. Three geometric rib parameters are considered; rib-rib spacing, rib orientation angle and rib blockage ratio. PIV is used for flow visualization and analysis. Along with the clean duct measurements, ribs with blockage ratios, b/h, of 0.25 and 0.125 were considered. The b/h = 0.25 cases have been comprehensively analyzed while the b/h = 0.125 cases have been studied at …

Study Of The "Poor Man's Navier-Stokes" Equation Turbulence Model, Stewart Andrew Bible

University of Kentucky Master's Theses

The work presented here is part of an ongoing effort to develop a highly accurate and numerically efficient turbulence simulation technique. The paper consists of four main parts, viz., the general discussion of the procedure known as Additive Turbulent Decomposition, the derivation of the "synthetic velocity" subgrid-scale model of the high wavenumber turbulent fluctuations necessary for its implementation, the numerical investigation of this model and a priori tests of said models physical validity. Through these investigations we have demonstrated that this procedure, coupled with the use of the "Poor Mans Navier-Stokes" equation subgrid-scale model, has the potential to be …

Proper Orthogonal Decomposition Of Hartmann Wavefront Sensor Data For A Plane Mixing Layer, Peter J. Szyjka

Mechanical Engineering ETDs

The ''snapshot" proper orthogonal decomposition (POD) was used to analyze the turbulent characteristics of a plane mixing layer. A two-dimensional (2-D) Hartmann wavefront sensor measured optical tilt propagation through a flow field downstream of a splitter plate. The velocity difference across the splitter plate produced roller vortices via the Kelvin-Helmholtz instability. Refractive-index fluctuations were produced by slightly heating the flow on the low-speed side of the splitter plate. The Hartmann sensor detects gradients in refractive index (and thus temperature) in directions perpendicular to its direction of propagation. The measured field of two-dimensional tilt (or optical deflection) is proportional to the …

The Development Of An Interactive Multimedia Based Professional Development, James New

Theses : Honours

The role of the teacher has changed over time such that teachers are asked to augment their own specialist knowledge with skills from other domains, for example information technology. This study has examined the perceptions and experiences of teachers and speech pathologists involved in the production of an instructive Interactive Multimedia (IMM) product to deliver Professional Development (PD). The individuals involved in this project were teachers from the High Valley Language School (HVLS) -a specialised primary school. The study used a social action research methodology, which allowed the researcher to build theories from emergent data. The data collection process consisted …

Wireless Local Area Network Security : An Investigation Into Security Tool Usage In Wireless Networks, Susan Webb

Theses : Honours

Many organisations and individuals installing wireless local area networks (WLANs), which are based on the IEEE 802.11 b standard, have little understanding of the security issues that surround this technology.

This study was initiated to determine how WLAN security issues affect organisations in Perth, Western Australia. The scope of the study was restricted to 802.llb WLANs operating in infrastructure mode, where all traffic is transmitted by wireless access points (APs). This study was conducted in two phases. The general aims of the first phase were to determine the number of detectable WLANs in the Perth Central Business District (CBD) and …

Device Structure Effects On Electrical Crosstalk In Backwall Illuminated Cmos Compatible Photodiode Arrays, Paul Vernon Jansz

Theses : Honours

This research has made a comparative investigated of crosstalk in backside illuminated and frontside illuminated single junction photodiode and vertical double junction photodiode CMOS compatible pixels, using a commercial 2D device simulation package, SEMICAD DEVICE (1994). Comparison of pixel total, electron and hole quantum efficiency response and Absorption Volume data is undertaken. This is so that the underlying carrier drift-diffusion dynamics responsible for optimal pixel response resolution may be qualitatively understood, allowing prediction of even more optimal photodiode pixel configurations. The effect of varying the double junction and single junction photodiode pixel's geometry on response resolution is considered. Only for …

Nebraska Summary: S438 New Holland Tm190, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Test 1821: Challenger Mt735 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Test 1819: John Deere 8120 16-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA

The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data.

EXPLANATION OF THE TEST PROCEDURES

Purpose

The purpose of …

Tests 2077 & 2095: Case Ih Jx 80u Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Adaptive Baseband Predistortion For Rf Power Amplifier Linearization., Laura Faus-Ferrer

Theses

In order to make use of spectrally efficient linear modulation methods for mobile communications, it is necessary to linearise the underlying RF power amplifier (PA). A number of techniques for linearizing a PA have been studied, focusing on the Adaptive Baseband Predistortion. The work is centred on the research concentrates on the analysis of different algorithms, their simulation using MatLab, and implementation of a predistorter as a subsystem of a prototype Cartesian based transmitter.

The thesis describes the typical architecture of a transceiver with an emphasis on the nonlinear analysis. Cavers’ algorithm has been examined in terms of its computational …

Multiple Model Control With Intelligent Switching To Ensure Robustness To Process Variations., Peter Cunningham

Theses

One of the most popular approaches for dealing with process that undergo large variations with time, of late, is the multiple model approach. This method has considerable intuitive appeal and has received widespread dissemination in academia. Numerous successful simulations have been reported although few real-time results have been published. The principal contribution of this thesis is the application of the multiple model control scheme in real-time.

A number of practical concepts that enable the use of multiple model control in real-time are discussed. Many of these issues arose when the multiple model control scheme was applied to a laboratory scale …

Hot Carrier Reliability Of Lateral Dmos Transistors In Power Process Applications, Vicky O'Donovan

Theses

The purpose of this study is to investigate and validate the mechanism of hot carrier degradation of the LDMOS device. The LDMOS device is a new technology to Analog Devices, and a relatively new topic to the semiconductor industry, evident from the limited published research in the field. A prerequisite for device release on a product in the market place, is comprehensive hot carrier reliability testing, as hot carrier degradation has evolved as one of the foremost concerns in submicron devices. Both the high voltage and the structural difference of the LDMOS device, from standard MOSFET device, pose a hot …

Investigation Of Soluble Salts On Kentucky Bridges, Sudhir Palle, Rick Younce, Theodore Hopwood Ii

Kentucky Transportation Center Research Report

Invisible soluble salts present on steel highway structures can act to promote corrosion even after maintenance painting. Soluble salts include chloride, nitrate and sulfate ions. Soluble salts found on bridge decks and roadways are the result of usage of deicing salts (chlorides), and the deposition of atmospheric pollution (nitrates and sulfates) on exterior surfaces. Typical pollution-related sources of soluble salts are coal-fired power plants, refineries, farming operations, vehicle emissions, and chemical plants. Sites for soluble salt damage on bridges include:

• Beam ends under open or leaking expansion joints,
• Flanges and lower portions of webs of overpass structures,
• Lower chords and …

Anisotropy And Its Relation To Liquefaction Resistance Of Granular Material, Isao Ishibashi, Omer F. Capar

Civil & Environmental Engineering Faculty Publications

This research establishes quantitative relationships between soil's anisotropy and liquefaction resistance for granular materials. Uniform medium density (D_r = 50%) sand specimens were prepared using three different sample preparation techniques (air pluviated (AP), moist tamped (NIT), and moist vibrated (MV)) to create different initial soil fabrics. Undrained cyclic triaxial tests were then performed to determine the liquefaction resistance of each soil specimen. On the same specimens in the triaxial cell, vertical and horizontal compression wave velocities and vertical shear wave velocity (V_s) were measured using piezoelectric bender elements. Anisotropic (transversely isotropic) elastic constants of the soil specimens were …

Jsb Composability And Web Services Interoperability Via Extensible Modeling & Simulation Framework (Xmsf), Model Driven Architecture (Mda), Component Repositories, And Web-Based Visualization, Don Brutzman, Andreas Tolk

Computational Modeling & Simulation Engineering Faculty Publications

"Study Report prepared for the U. S. Air Force, Joint Synthetic Battlespace Analysis of Technical Approaches (ATA) Studies & Prototyping"

Overview: This paper summarizes research work conducted by organizations concerned with interoperable distributed information technology (IT) applications, in particular the Naval Postgraduate School (NPS) and Old Dominion University (ODU). Although the application focus is distributed modeling & simulation (M&S) the results and findings are in general easily applicable to other distributed concepts as well, in particular the support of operations by M&S applications, such as distributed mission operations. The core idea of this work is to show the necessity of …

Hydrodynamic And Sediment Transport Modeling Of Deltaic Sediment Processes, Hassan Shahid Mashriqui

LSU Doctoral Dissertations

This dissertation tests the hypothesis that the early phases of deltaic bar and distributary channel formation and sediment transport on an adverse slope could be simulated with a 2D finite element sediment transport model. The models used were RMA2 and SED2D modules of the TABS-MD model suite. A finite element mesh of the lower Atchafalaya River and the delta was developed, using the Surface Water Modeling System (SMS) software package. Calibration and validation of the model were performed, using data collected during field surveys and from available Atchafalaya River archived flow, suspended sediment, and dredging records. In a test simulation …

Granulometry, Chemistry And Physical Interactions Of Non-Colloidal Particulate Matter Transported By Urban Storm Water, Hong Lin

LSU Doctoral Dissertations

Urban rainfall-runoff is a major source of anthropogenic pollutions to the natural water bodies. Particulate matter generated from anthropogenic environments and activities is a constituent of environmental concern as well as a carrier substrate for reactive contaminants such as metals. Partitioning, transport and transformation of particulate-bound contaminants are determined by the granulometry, physical and geochemical properties of the particulate carriers. Previous research emphasized in the transport of colloidal and suspended particles in rainfall-runoff. The settleable and sediment material were ignored though they are a major granulometric fraction which may contain most of the sorbed or transported constituents such as metals, …

Rainfall-Runoff Control: Variably Saturated Transport For An Infiltration System Controlling Water Quality And Quantity, Zheng Teng

LSU Doctoral Dissertations

Rainfall-runoff impacted by anthropogenic activities transports significant quantities of particulate, aqueous and complexed constituents. These diffuse, unsteady and stochastic event-based loadings are unique challenges for water quality and quantity control. The design, water quality and quantity functions of a partial exfiltration reactor (PER) utilizing Fe-coated-sand and porous pavement (CPP) is examined specifically across three representative rainfall-runoff events. Total concentrations and mass for metals (Zn, Pb, Cu and Cd), suspended solids, and Chemical oxygen demand were reduced significantly. Rainfall-runoff volume and peak flow were reduced and time to peak was extended. Influent dm/dp ratios based on particle analyses suggest that the …

Investigation Of Bond Slip Between Concrete And Steel Reinforcement Under Dynamic Loading Conditions, John Henry Weathersby

LSU Doctoral Dissertations

Structural failures during recent earthquakes and terrorist attacks have demonstrated shortcomings in the design procedures for reinforced concrete structures. Earlier research has demonstrated that a major limitation of the Finite Element (FE) modeling of the response of reinforced concrete is the accurate modeling of the interaction of the concrete with the steel reinforcement. Presently, there are insufficient data on the dynamic nonlinear interaction between the concrete material and the steel reinforcement to develop a numerical model of this interaction. The primary objective of this study was to experimentally investigate the dynamic interaction (bond slip) of reinforcement with concrete and gain …

A Simulation Model To Characterize Photolithography Process Of A Semiconductor Wafer Fabrication, Amr Arisha, Paul Young, Mohie El Baradie

Articles

The pressures on semiconductor manufacturers due to cost considerations, rapid growth of process technology, quality constraints, feature size reduction, and increasingly complex products are requiring ever higher efficiency from manufacturing facilities. The complexity of manufacturing high capacity semiconductor devices means that it is impossible to analyze the process control parameters and the production configurations using traditional analytical models. There is, therefore, an increasing need for effective models of each manufacturing process, characterizing and analyzing the process in detail, allowing the effect of changes in the production environment on the process to be predicted. The photolithography process is one of the …

On Stability Of Affine Blending Systems, Ruiyao Gao, Aidan O'Dwyer, Seamus Mcloone, Eugene Dermot Coyle Professor

Conference papers

This paper presents a novel approach to stability analysis of affine blending systems. The analysis is based on Quadratic Lyapunov functions. The approach considers the nonlinear offset term in affine blending systems as non-vanishing perturbations added to the corresponding nominal linear blending systems. The affine blending systems will be bounded if the corresponding linear blending system is exponentially stable. The bound is determined by an ultimate limit, which is proportional to the maximum of the offset terms of each affine system.

New Modified Smith Predictor Designs, Pauline Sourdille, Aidan O'Dwyer

Conference papers

By combining several existing modified Smith predictor structures, presented in a literature review, a generalised form of the Smith predictor is proposed. From this structure, excellent servo and regulator responses can be obtained by specifying three controller dynamic elements. Two new modified Smith predictor structures are presented with their associated tuning rules. The results of the simulations indicate that the two new designs give better overall responses than the original Smith predictor.

Comparison Of Process Identification Techniques In The Time And Frequency Domains, Tony Kealy, Aidan O'Dwyer

Conference papers

This paper describes ten methods to identify a mathematical model for a real process with a time delay. The process is the Process Trainer, PT326 from Feedback Instruments Limited. Six of the methods use step response data and one of the methods uses impulse response data for identification. Two of the methods use frequency response data and the final method uses information from relay-based experiments. The best results are obtained using a combined analytical and gradient method [6] in the frequency-domain and, in the time-domain, using the two-point algorithm [1] and a method proposed by Suganda et al. [5].

Analytical Ise Calculation And Optimum Control System Design, Tony Kealy, Aidan O'Dwyer

Conference papers

In control system theory, a performance index is a quantitative measure of the performance of a system and is chosen so that emphasis is given to the important system parameters. In this paper, the authors demonstrate two methods to determine analytically the ISE performance index value for a FOPDT process model under PI control. The ability of proportional/integral (PI) and proportional/integral/derivative (PID) controllers to compensate most practical industrial processes has led to their wide acceptance in industrial applications. The most direct way to set up PI/PID controller parameters is the use of tuning rules. The second part of this paper …

System Identification Using Higher Order Spectra, Aidan O'Dwyer

Conference papers

This communication will explore the use of particular types of frequency domain concepts, labelled higher order spectra, to help determine the frequency response of a process. This will allow the identification of the parameters of a single input, single output (SISO) model for a process (which includes a time delay), in both open loop and closed loop environments.

Speech-Adaptive Time-Scale Modification For Computer Assisted Language Learning, Olivia Donnellan, Elmar Jung, Eugene Coyle

Conference papers

In traditional foreign language learning programmes students are offered a tutor model characterised by slow, deliberate speech. This is insufficient to prepare them to cope with native, colloquial speech. By applying a timescale modification (TSM) algorithm to natural-speed, native speech, students have access to a more desirable, natural speech corpus which permits them to practise essential listening skills in a more focussed manner. This paper presents a method which allows slowing down speech without compromising the quality, pitch or naturalness of the slowed speech by applying different scaling factors to different types of speech segments. The new method is compared …

Dynamic Average-Value Modeling Of A Four-Level Drive System, Keith Corzine, Xiaomin Kou, J. R. Baker

Electrical and Computer Engineering Faculty Research & Creative Works

Multilevel power converters have gained much attention in recent years due to their high power quality, low switching losses, and high-voltage capability. These advantages make the multilevel converter a candidate for the next generation of naval ship prolusion systems. Evaluation of these systems is typically assisted with a dynamic average-value models in order to rapidly predict system performance under several operating scenarios. In this paper, an average-value model is developed for the four-level diode-clamped converter which takes into account the active capacitor voltage balancing control. This model performance prediction is compared to a detailed model and laboratory measurements on an …