Engineering Commons^™

Decentralized Perimeter Surveillance Using A Team Of Uavs, Randal Beard, David Casbeer, Derek Kingston

Faculty Publications

Sponsorship: NASA, AFOSR. This paper develops a distributed algorithm to maintain a current estimate of the state of the perimeter using a team of UAVs. Using notions of consensus, an algorithm is developed and shown to distribute a UAV team uniformly around the perimeter.

Structural Properties And Crystallization Of Sodium Tellurite Glasses, Kresimir Furic, Masa Rajic-Linaric, C. S. Ray, A. Šantić, Andrea Moguš-Milanković, D. E. Day

Materials Science and Engineering Faculty Research & Creative Works

The structural properties and crystallization behaviour of xNa2O-(100-x)TeO2 (0 <= x <= 33.3, x-% mole fraction) glasses have been investigated by Raman spectroscopy, X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The Raman spectra of glasses show systematic changes in structural units, from TeO4 trigonal bypiramids (tbps) to TeO3 trigonal pyramids (tps) with increasing Na2O content in glass. These structural changes are result of Te-eqOax-Te disruption and the formation of non-bridging oxygens (NBOs) in glass network. when heated at 623 K for 10 h glasses crystallized to different phases: alpha-TeO2, Na2Te4O9 and a new crystalline phase which is believed to be a polymorph of Na2Te2O5.

Measurement Of Liquid Water Accumulation In A Proton Exchange Membrane Fuel Cell With Dead-Ended Anode, Jason B. Siegel, Denise A. Mckay, Anna G. Stefanopoulou

Engineering: Faculty Publications

The operation and accumulation of liquid water within the cell structure of a polymer electrolyte membrane fuel cell (PEMFC) with a dead-ended anode is observed using neutron imaging. The measurements are performed on a single cell with 53 square centimeter active area, Nafion 111-IP membrane and carbon cloth Gas Diffusion Layer (GDL). Even though dry hydrogen is supplied to the anode via pressure regulation, accumulation of liquid water in the anode gas distribution channels was observed for all current densities up to 566 mA cm-2 and 100% cathode humidification. The accumulation of liquid water in the anode channels is followed …

From Elastic Deformation To Terminal Flow Of A Monodisperse Entangled Melt In Uniaxial Extension, Yangyang Wang, Shi-Qing Wang

College of Polymer Science and Polymer Engineering

Using a well-entangled monodisperse styrene-butadiene random-copolymer (SBR) melt as a model system, we illustrate generic features of uniaxial extension behavior that may be shared by all well-entangled thermoplastic and elastomeric materials. Depending on the imposed extensional rate, the same sample may behave like a viscous liquid or an elastic "solid." Analogous to the recently revealed shear inhomogeneity, the SBR melt inevitably undergoes cohesive failure in the form of sample breakage whenever the Weissenberg number is much greater than unity, making it challenging to reach steady state. In the elastic deformation regime where the external deformation rate is faster than Rouse …

Piles Under Earthquake Loads, Shamsher Prakash, Vijay K. Puri

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Piles are preferred type of foundation for supporting structures in seismic areas. their performance is affected by soil, pile and earthquake related parameters. in non-liquefying soils, the shear modulus may degrade, and material damping may increase with increasing strain/displacement. in liquefying soils, the lateral ground displacement may lead to increased lateral loads and moments on the pile leading to pile failure in bending. the loss of lateral support can also lead to buckling type failure. These issues for pile design in seismic areas are examined. © 2008 ASCE.

A Comparison Of Three Phase Induction Motor Performance Subjected To Frequency, Voltage, And Load Changes By Pwm And Square Wave Inverters, Aliosman Demirbas

Masters Theses and Doctoral Dissertations

This paper presents a comparison of three-phase induction motor performance subjected to frequency, voltage and load changes by Square wave inverter and Pulse Width Modulated (PWM) inverter. A computer program which is backed by a laboratory study is used to characterize the motor performance during the comparison. A 1 hp induction motor is tested by a Square wave and a PWM inverter and the motor performance data including various harmonic losses at 30 Hz, 40 Hz and at 60 Hz are measured. An advanced electrical model that accounts for the skin effect in the rotor bar to predict motor impedance …

Generation And Analysis Of Fcg Data Using A Single Specimen And Kmax - ∆K Testing Matrix, Sree Phani Chandar Reddy

Masters Theses

A custom method to generate fatigue crack growth (FCG) data requires testing of multiple specimens at different load ratios. In addition, it includes the application of a load shedding procedure from pre-cracking level to threshold.

In this thesis, a novel method of testing has been investigated that utilizes a single specimen and a testing matrix in terms of K_maxand ∆K values corresponding to predetermined R-ratios for which FCG data, da/dN, are recorded. Automatic K-controlled tests on 2324-T39 Al alloy were conducted using the ∆K increasing and ∆K decreasing procedures while K_maxwas kept constant. Results show that …

Global Skin Friction Diagnostics In Complex Separated Flows, Sudesh A. Woodiga

Masters Theses

This work describes the application of a global luminescent oil film skin friction meter to quantitative global skin friction diagnostics in complex separated flows. The development of this technique is based on the relationship between the oil film thickness and luminescent intensity of an oil film mixed with a luminescent dye. The projected thin oil film equation is given to relate the normalized luminescent intensity with skin friction. The basis for this technique is the variational solution for the thin oil film equation on the image plane. The variational formulation with a smoothness constraint on skin friction is proposed to …

The North American Transportation Security Center, Steven Douglas Kreis, Michael M. Barclay

Kentucky Transportation Center Research Report

No abstract provided.

Predicting Young’S Modulus Of Nanowires From First-Principles Calculations On Their Surface And Bulk Materials, Guofeng Wang, Xiaodong Li

Faculty Publications

Using the concept of surface stress, we developed a model that is able to predict Young’s modulus of nanowires as a function of nanowire diameters from the calculated properties of their surface and bulk materials. We took both equilibrium strain effect and surface stress effect into consideration to account for the geometric size influence on the elastic properties of nanowires. In this work, we combined first-principles density functional theory calculations of material properties with linear elasticity theory of clamped-end three-point bending. Furthermore, we applied this computational approach to Ag, Au, and ZnOnanowires. For both Ag and Aunanowires, our theoretical predictions …

Fatigue Risks In The Connections Of Sign Support Structures: Phase 1, Christopher Foley, Baolin Wan, Mathew Weglarz, Matthew Hellenthal, Jordan Komp, Andrew Smith, Joseph Schmidt

Transportation Reports with the Wisconsin Department of Transportation

Wisconsin sought to assess the risk of fatigue-induced fracture in its existing sign support structures designed before the latest AASHTO specifications that included fatigue design. A framework for assessing fatigue-induced fracture risk is developed and detailed synthesis of fatigue testing of connections is conducted. Statistical analysis of tests conducted since 1970 is made and models for characterizing uncertainty in the fatigue life of these connections are proposed. Recommendations regarding further fatigue testing (specimen configuration, number and stress range) are given. Statistical models for wind speed and direction are developed using historical records obtained through the National Climatic Data Center for …

Green Roofs For A Green Town: Possibilities Of Green Roof Implementation In The Town Of Normal, Lindsey Sihau, '09

Outstanding Senior Seminar Papers

Green roofs have been growing in popularity throughout the world. Scientists have been studying them since the 1980’s. This research project reviews the literature regarding both the benefits and barriers to green roof construction and management. Policies around the nation are then examined and analyzed. Suggestions are made regarding possible additions to the local Stormwater Management Policy that would emphasize the importance of sustainable building techniques such as green roofs, and hopefully offer incentive to their implementation.

Development Of A New System Vulnerability Index - The Overload Risk Index, John Rossmaier, Badrul Chowdhury

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a new index to better determine the vulnerability of a power system. the procedure for calculating this index combines stochastic and probabilistic methods to determine the likelihood of a line overloading in a power system. the methods used include a basic load flow analysis using network security factors and Monte Carlo simulation that incorporates the likelihood of component failure within the system. a case study has been performed to analyze the ability of such an index in accurately measuring one aspect of power system vulnerability. Three different variations of this indexing method are explored in an attempt …

A Bist Technique For Crosstalk Noise Detection In Fpgas, Waleed K. Al-Assadi, Sindhu Kakarla

Electrical and Computer Engineering Faculty Research & Creative Works

As Integrated Circuits are migrated to more advanced technologies, it has become clear that crosstalk noise is an important phenomenon that must be taken into account. Also, crosstalk noise has emerged as a serious problem in recent years, because more and more devices and wires have been packed on electronic chips. Despite being more immune to crosstalk noise than their ASIC (Application Specific Integrated Circuit) counterparts, the dense interconnected structures of FPGAs (Field Programmable Gate Arrays) invite more vulnerabilities to crosstalk noise. Due to the lack of electrical detail concerning FPGA devices it is quite difficult to test the faults …

Damping Inter-Area Oscillations In Power Systems By Statcoms, Mahyar Zarghami, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

Shunt FACTS devices such as STATCOMs are best known for their impact on reactive power flow in power networks. This is usually done by local reactive compensation which also regulates voltage magnitude of the bus to which the shunt FACTS device is connected. on the other hand, these devices are less known for their effect on active power flow. This paper discusses a novel approach for damping inter-area oscillations in a large power network using multiple STATCOMs. in the paper, it will be shown that these oscillations can be controlled by changing STATCOMs' bus voltage angles, hence regulating active power …

On The Mutual Information And Power Allocation For Vector Gaussian Channels With Finite Discrete Inputs, Chengshan Xiao, Yahong Rosa Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the mutual information and power allocation are discussed for vector Gaussian channels with finite discrete inputs. It is shown that the classic water filling and mercury-water filling policies, which are allocating power to a bank of independent parallel channels, may lead to significant loss compared to the original system without power allocation for finite discrete inputs. a generalized linear precoder, which is a non-diagonal and non-unitary matrix, is proposed for cross- channel power allocation to maximize the mutual information for vector channels. Numerical examples show that the new precoding-Based power allocation provides significant gain for a broad …

A Model Based Fault Detection And Prognostic Scheme For Uncertain Nonlinear Discrete-Time Systems, Balaje T. Thumati, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

A new fault detection and prognostics (FDP) framework is introduced for uncertain nonlinear discrete time system by using a discrete-time nonlinear estimator which consists of an online approximator. A fault is detected by monitoring the deviation of the system output with that of the estimator output. Prior to the occurrence of the fault, this online approximator learns the system uncertainty. In the event of a fault, the online approximator learns both the system uncertainty and the fault dynamics. A stable parameter update law in discrete-time is developed to tune the parameters of the online approximator. This update law is also …

Pmu Placement For Power System Observability Using Binary Particle Swarm Optimization, S. Chakrabarti, Ganesh K. Venayagamoorthy, E. Kyriakides

Electrical and Computer Engineering Faculty Research & Creative Works

A binary particle swarm optimization (BPSO) based methodology for the optimal placement of phasor measurement units (PMUs) for complete observability of a power system is presented in this paper. The objectives of the optimization problem are to minimize the total number of PMUs required, and to maximize the measurement redundancy at the power system buses. Simulation results on the IEEE 14-bus and 30-bus test systems are presented in this paper.

Proper Orthogonal Decomposition In The Generation Of Reduced Order Models For Interconnects, Wu Zhong Lin, Yao Jiang Zhang, Er Ping Li

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, reduced order models are generated using the technique of proper orthogonal decomposition (POD), also known as Karhunen-Loève decomposition (KLD) for the simulations of interconnect problems. Model order reduction is achieved by projecting the state-space of the original problems onto a subspace spanned by a few numbers of proper orthogonal modes (POMs) extracted by the POD procedure from an ensemble of system responses at a series of selected frequencies. the proper orthogonal values (POVs) corresponding to the POMs indicate the level of the importance of each POM and provide a guidance for the number of POMs to be …

Trade-Off Analysis Methodology For Asset Management, Qiang Bai, Samuel Labi, Zongzhi Li

JTRP Technical Reports

In an era that is characterized by funding limitations, increased stakeholder participation, and the need for increased accountability and transparency, transportation agencies seek to ensure that comprehensive evaluation processes are identified and used for decision-making. Consistent with such processes is the incorporation of multiple performance criteria from different program areas, optimization of decisions under constrained budgets, and investigation of trade-offs between program areas, performance measures, budgetary levels, risk levels, and performance thresholds. To help INDOT carry out these processes, this study developed theoretical constructs for scaling and amalgamation of the different performance measures, and for analyzing the different kinds of …

High-Performance Concrete Bridge Decks: A Fast-Track Implementation Study, Volume 1: Structural Behavior, Robert J. Frosch, Timothy S. Aldridge

JTRP Technical Reports

Transverse cracking of concrete bridge decks is problematic in numerous states. Cracking has been identified in the negative and positive moment regions of bridges and can appear shortly after opening the structure to live loads. To improve the service life of the bridge deck as well as decrease maintenance costs, changes to current construction practices in Indiana are being considered. A typical bridge deck was instrumented which incorporated the following: increased reinforcement amounts, decreasing reinforcement spacing, and high-performance, low-shrinkage concrete. The low shrinkage concrete was achieved using a ternary concrete mix. The objective of this research was to determine the …

Alternative Land Use Patterns To Minimize Congestion (Volume 2: Evaluating The Feasibility Of New Urbanism In An Existing Neighborhood), Huei Koh, Jon D. Fricker

JTRP Technical Reports

Urban sprawl creates serious traffic congestion. Alternative land use patterns may be the best solution. New Urbanists claim that, by placing frequently-visited sites within walking distance of homes and creating a pleasant walking environment, people are more willing to choose non-motorized transportation mode to do such activities.

Part I of this study investigated the ability of travel demand models to estimate the impacts of alternative land use patterns. Part II conducted an economic viability analysis for a mixed land use neighborhood and collected land use preferences at meetings of neighborhood associations. The objective in Part III was to evaluate the …

Methods Of Safety Improvements At Coordinated Signals, Wei Li, Andrew P. Tarko

JTRP Technical Reports

In this research, the safety impact of arterial signal coordination is investigated. Based on the findings, procedures are proposed to incorporate safety considerations into signal coordination design. In addition, a software tool is developed to facilitate the use of the research findings. Signal coordination has been extensively employed as a tool to optimize an arterial system’s mobility performance, commonly measured by the total number of vehicle stops and the time of delays. Although vehicle crashes at signalized intersections have long been recognized as a major safety threat, studies to date have been limited locally to non-coordinated signals or the noncoordinated …

Human Microvasculature Fabrication Using Thermal Inkjet Printing Technology, Xiaofeng Cui

All Dissertations

The current tissue engineering paradigm is that successfully engineered thick tissues must include vasculature. As biological approaches alone such as VGEF have fallen short of their promises, one may look for an engineering approach to build microvasculature. With the advent of cell printing, one may be able to build precise human microvasculature with suitable bio-ink. Human Microvascular Endothelial Cells (HMVEC) and fibrin were studied as bio-ink for microvasculature construction. Endothelial cells are the only cells to compose the human capillaries and also the major cells of blood vessel intima layer. Fibrin has been already widely recognized as tissue engineering scaffold …

Approach Slope For Midwest Guardrail System, Erin A. Johnson, Karla A. Lechtenberg, Dean L. Sicking, Robert W. Bielenberg M.S.C.E., E.I.T., Ronald K. Faller, John R. Rohde, John D. Reid

Nebraska Department of Transportation: Research Reports

No abstract provided.

Influence Of Reinforced Plastomers On Injection Moulds Wear, A Guzanová, J Brezinová

Journal of Metals, Materials and Minerals

The contribution deals with wear of injection moulds based on aluminium alloy Alumec 89 in friction couples with plastomers reinforced with different glass fibres content. Friction relations in injection moulding were simulated by adhesion dry wear test with help of Amsler equipment with area contact of friction couple. Wear intensity was evaluated by friction coefficient and relative wear by weight loss. Simultaneously, changes of aluminium alloy surface morphology after wear in particular friction couples were analysed.

Production Of Sponge Rubber For Monolayer Rubber Stamp Using Salt Leaching Method, W Trakanpruk, Y Rodthong

Journal of Metals, Materials and Minerals

Sponge rubber used for monolayer rubber stamp was produced from nitrile butadiene rubber (NBR). Open cells in sponge rubber were created using salt leaching method. Effect of size and amount of sodium chloride which was used as a water soluble salt on the creation of open cells in the rubber was investigated. Carbon black was used as a filler. A different type of surfactant was added to increase the leaching out of salt from the rubber. Cure characteristics of the compound rubbers: maximum torque, minimum torque, scorch time and cure time as well as hardness of the prepared sponge rubber …

Properties Evaluation Of Sodium Nitrite Treated Chitosan-Cotton Fabric, S Srisuk, K Srikulkit

Journal of Metals, Materials and Minerals

In this study, chitosan coated-cotton fabric was prepared and then treated with sodium nitrite under mild condition, aiming at the partial removal of surface-chitosan in order to solve the problems of surface dyeing and fabric stiffness. The results showed that sodium nitrite treated chitosan-fabric exhibited an improvement of dyeability (higher dye exhaustion and color strength) when compared to untreated fabric. The improvement in dyeability was due to the availability of chitosan amino groups which had an affinity to anionic dyes including reactive dyes. Other fabric properties were evaluated. The results showed that color fastness properties (crocking fastness and light fastness) …

Preparation Of Ultrafine Silver Powder Using Glycerol As Reducing Agent, E Nisaratanaporn, K Wongsuwan

Journal of Metals, Materials and Minerals

The production of silver nanoparticles and sub-micron particles can be achieved by silver alkoxide from silver sulfate and subsequently reducing with glycerol. To reduce the particle size of silver sulfate precursors, ball milling was employed to reduce particle sizes down to 0.81 microns. However, silver sulfate without grinding provided smaller particle sizes of silver particles as opposed to ground specimens. Stirring silver alkoxide simultaneously was efficient to provide for uniform distribution of silver powder. The silver powder thus produced had brain-like shape consisted of very fine aggregate silver particles. The yield of silver powder was in the range of 95-99 …

Demonstration Of The Ntc Ceramic Application For Temperature Measurement And Control Using The Labview-Based Measurement System, T Panmatarith, K Poatong

Journal of Metals, Materials and Minerals

In the present paper, ZnO+0.01SnO2 ceramics were prepared using a standard ceramic method. We present the NTC ceramic application for temperature measurement and control using the LabVIEW-based measurement system. The measured resistance of the sample at room temperature was about 6.5 kΩ. The electrical resistance versus temperature of the sample was measured. The negative temperature coefficient of resistance of the sample was -1.018 %/°C. This sample showed NTC effect and exhibited NTC resistor, indicating their potential application as temperature sensor with low cost. It can be used as temperature sensor by using the NTC effect . The measured temperature (T) …