Engineering Commons^™

High Gradient Multilayer Insulator Technology, Harlan U. Anderson, Stephen E. Sampayan, G. J. Caporaso, W. C. Nunnally, D. M. Sanders, J. A. Watson, Mike L. Krogh

Materials Science and Engineering Faculty Research & Creative Works

We are investigating a novel insulator concept that involves the use of alternating layers of conductors and insulators with periods less than 1 mm. These structures perform 1.5 to 4 times better than conventional insulators in long pulse, short pulse, and alternating polarity applications. We have surveyed our ongoing studies by investigating the performance under long pulse electron beam, short pulse, and full reversing conditions.

Computation Of Shock Induced Noise In Imperfectly Expanded Supersonic Jets, Bulent Imamoglu

Mechanical & Aerospace Engineering Theses & Dissertations

Screech noise exists only in imperfectly expanded jets. The exit pressure of imperfectly expanded jets does not match ambient pressure, so expansion or compression waves appear out of the nozzle and generate shock cell patterns. Screech is generated by the interaction of shock cells and instability waves. Many experiments and computations have been done to model screech noise, but it is not yet a very well known subject.

A numerical study is performed to understand screech generation mechanisms and to compare with latest experiments. A supersonic underexpanded jet of 25.4 mm diameter is modeled for cases of Mach numbers of …

Acknowledgement Response And Interference Timing During The Processing Of Voice And Datalink Atc Commands, Matthew R. Risser

Psychology Theses & Dissertations

In aviation, effective communication between air traffic control (ATC) and pilots is critical to pilot performance and safety. Problems and limitations of current radio communications initiated the development of datalink technology. Datalink is a text system used to send messages between ATC and pilots. Although datalink was intended to reduce errors associated with radio communication, there are new concerns related to changes in information processing demands associated with executing speech and text ATC commands. In addition, the nature of responses differs between voice and datalink systems. In a voice environment, responses are immediate. However, time delays exist with datalink. These …

Position Sensorless Control, Babak Fahimi, Ali Emadi, Raymond B. Sepe

Electrical and Computer Engineering Faculty Research & Creative Works

The switched reluctance machines (SRM) drives applications are studied. the introduction of SRM drives in mission critical applications calls for high levels of survivability and fault tolerance. the various methods are proposed for the sensor less control of SRM drives. the best version of the sensor less technique is selected by continuous monitoring of the back-EMF. the results show that four-quadrant sensor less control of the SRM drive is a feasible technique and can be considered as a technology ready for application.

Innovative Cooling Configurations For Low Emission Gas Turbine Combustors, Ryan Thomas Hebert

LSU Master's Theses

Presently, effective cooling of modern low NOx combustor liners is achieved through combinations of innovative impingement configurations and other heat transfer enhancement methods. An inherent characteristic of conventional impingement configurations is the occurrence of downstream heat transfer degradation due to increased crossflow effects. In the present study, two different impingement configurations are studied. Both impingement configurations examined in this study aim to increase heat transfer effectiveness by reducing the detrimental effects of spent air crossflow. In Part I, a combination technique wherein impingement is combined with ribs placed in between impingement rows is studied. Three configurations with increased rib placements …

Administration And Management Of Local Roads And Streets 2004, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Publications

This handbook begins by examining government officials’ authority to carry out their road and street work. Next is the ever important challenge of intergovernmental relations, becoming more routine, albeit challenging. Funding road and street efforts, inherent in the intergovernmental environment, and transportation planning follow. The chapter on right-of-way issues is varied and extensive because current topics are now often confrontational. The management chapter addresses such topics as managerial functions, training, and a number of related issues. The discussion then moves to the serious matter of risk management and transportation security, along with traditional tort liability topics, the imperative of transportation …

Life And Cost Comparison Of Three Rehabilitation Techniques On I-65 Between Sr-2 And Sr-114, Sedat Gulen, John Weaver, Samy Noureldin

JTRP Technical Reports

Construction of hot mix asphalt (HMA) overlays on top of old concrete pavements is the most common concrete pavement rehabilitation strategy. These overlays, however, are usually subject to reflection cracking related to the movement of the old concrete slab. In addition, these overlays may also be vulnerable to rutting when subjected to large traffic volumes of heavy trucks. Concrete overlays have the advantage of being rut resistant compared to HMA overlays. However, the current national experience of the performance of these overlays is still, relatively, limited compared to HMA overlays. In addition, doubts are often raised about the cost effectiveness …

Meta-Analysis Of Two-Treatment Clinical Trials Including Both Continuous And Dichotomous Results, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

To expedite the timely creation of medical practice guidelines, a meta-analytic method was developed to combine of both dichotomous survival data and continuous physiologic data from multiple studies comparing the same innovative clinical intervention to standard care. The method is adapted for synthesis of small, early studies of novel treatments. An aggregate ratio, R*, of the observed treatment effect to a clinically optimal treatment effect for studies in a series is computed, and compared to the 95% confidence limit for R* under the null hypothesis. Weights assigned to each study may reflect its precision, quality, or clinical relevance. Input data …

High-Field Quasi-Ballistic Transport In Short Carbon Nanotubes, Ali Javey, Jing Guo, Magnus Paulsson, Qian Wang, Mark S. Lundstrom, Hongjie Dai, David Mann

Department of Electrical and Computer Engineering Faculty Publications

Single walled carbon nanotubes with Pd Ohmic contacts and lengths ranging from several microns down to 10 nm are investigated by electron transport experiments and theory. The mean-free path (MFP) for acoustic phonon scattering is estimated to be lap ~300  nm, and that for optical phonon scattering is lop ~15  nm. Transport through very short (~10  nm) nanotubes is free of significant acoustic and optical phonon scattering and thus ballistic and quasiballistic at the low- and high-bias voltage limits, respectively. High currents of up to 70   μA can flow through a short nanotube. Possible mechanisms for the eventual electrical breakdown …

A Three-Dimensional Quantum Simulation Of Silicon Nanowire Transistors With The Effective Mass Approximation, Jing Wang, Eric Polizzi, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

The silicon nanowire transistor (SNWT) is a promising device structure for future integrated circuits, and simulations will be important for understanding its device physics and assessing its ultimate performance limits. In this work, we present a three-dimensional (3D) quantum mechanical simulation approach to treat various SNWTs within the effective-mass approximation. We begin by assuming ballistic transport, which gives the upper performance limit of the devices. The use of a mode space approach (either coupled or uncoupled) produces high computational efficiency that makes our 3D quantum simulator practical for extensive device simulation and design. Scattering in SNWTs is then treated by …

Optimizing Chest Compression To Rescue Ventilation Ratios During One-Rescuer Cpr By Professionals And Lay Persons: Children Are Not Just Little Adults, Charles F. Babbs, Vinay Nadkarni

Weldon School of Biomedical Engineering Faculty Publications

Objective: To estimate the optimum ratio of chest compressions to ventilations for onerescuer CPR that maximizes systemic oxygen delivery in children. Method: Equations describing oxygen delivery and blood flow during CPR as functions of the number of compressions and the number of ventilations delivered over time were adapted from the former work of Babbs and Kern. These equations were solved explicitly as a function of body weight, using scaling algorithms based upon principles of developmental anatomy and physiology. Results: The optimal compression to ventilation (C/V) ratios for infants and younger children increase sharply as a function of body weight. Optimal …

Optimization Of Thermal Interface Materials For Electronics Cooling Applications, Vishal Singhal, Thomas Siegmund, Suresh V. Garimella

School of Mechanical Engineering Faculty Publications

Thermal interface materials (TIMs) are used in electronics cooling applications to decrease the thermal contact resistance between surfaces in contact. A methodology to determine the optimal volume fraction of filler particles in TIMs for minimizing the thermal contact resistance is presented. The method uses finite element analysis to solve the coupled thermo-mechanical problem. It is shown that there exists an optimal filler volume fraction which depends not only on the distribution of the filler particles in a TIM but also on the thickness of the TIM layer, the contact pressure and the shape and the size of the filler particles. …

Fast Algorithms For Fragment Based Completion In Images Of Natural Scenes, Siddharth Rajkumar Borikar

Electronic Theses and Dissertations

Textures are used widely in computer graphics to represent fine visual details and produce realistic looking images. Often it is necessary to remove some foreground object from the scene. Removal of the portion creates one or more holes in the texture image. These holes need to be filled to complete the image. Various methods like clone brush strokes and compositing processes are used to carry out this completion. User skill is required in such methods. Texture synthesis can also be used to complete regions where the texture is stationary or structured. Reconstructing methods can be used to fill in large-scale …

Using The Six Sigma Policy Deployment Cycle To Mitigate Project Failur, Archana Magadi

Electronic Theses and Dissertations

Many organizations are struggling to improve customer-focused quality in today's highly competitive domestic and global markets. At the same time, these organizations have failed to implement the Six Sigma methodology into their daily control and strategic planning processes. Six Sigma deployment failures have been categorized as coming from many sources, both management related and person related. Some of the key management related Six Sigma project failures have been identified and discussed in this research work. For continuous improvement to truly take root, organizations must realize that just successfully applying quality tools on any process will not necessarily provide dramatic results, …

Monolithic Integration Of Dual Optical Elements On High Power Semicond, Laurent Vaissie

Electronic Theses and Dissertations

This dissertation investigates the monolithic integration of dual optical elements on high power semiconductor lasers for emission around 980nm wavelength. In the proposed configuration, light is coupled out of the AlGaAs/GaAs waveguide by a low reflectivity grating coupler towards the substrate where a second monolithic optical element is integrated to improve the device performance or functionality. A fabrication process based on electron beam lithography and plasma etching was developed to control the grating coupler duty cycle and shape. The near-field intensity profile outcoupled by the grating is modeled using a combination of finite-difference time domain (FDTD) analysis of the nonuniform …

Data Transmission Scheduling For Distributed Simulation Using Packet A, Juan Vargas-Morales

Electronic Theses and Dissertations

Communication bandwidth and latency reduction techniques are developed for Distributed Interactive Simulation (DIS) protocols. Using logs from vignettes simulated by the OneSAF Testbed Baseline (OTB), a discrete event simulator based on the OMNeT++ modeling environment is developed to analyze the Protocol Data Unit (PDU) traffic over a wireless flying Local Area Network (LAN). Alternative PDU bundling and compression techniques are studied under various metrics including slack time, travel time, queue length, and collision rate. Based on these results, Packet Alloying, a technique for the optimized bundling of packets, is proposed and evaluated. Packet Alloying becomes more active when it is …

General Interference Suppression Technique For Diversity Wireless Rece, Tianyu Yang

Electronic Theses and Dissertations

The area of wireless transceiver design is becoming increasingly important due to the rapid growth of wireless communications market as well as diversified design specifications. Research efforts in this area concentrates on schemes that are capable of increasing the system capacity, providing reconfigurability/reprogrammability and reducing the hardware complexity. Emerging topics related to these goals include Software Defined Radio, Multiple-Input-Multiple-Output (MIMO) Systems, Code Division Multiple Access, Ultra-Wideband Systems, etc. This research adopts space diversity and statistical signal processing for digital interference suppression in wireless receivers. The technique simplifies the analog front-end by eliminating the anti-aliasing filters and relaxing the requirements for …

Determination Of Indot Highway Construction Production Rates And Estimation Of Contract Times, Yi Jiang, Hongbo Wu

JTRP Technical Reports

The duration of a highway construction project depends primarily on the quantity or magnitude of the construction work and the productivity of the construction crew. In addition, many other factors may also affect the construction duration, such as the type of construction, traffic features, location (urban or rural site), and weather conditions. When a state highway construction project contract is bid, a reasonable time must set and specified in the contract documents for completion of the contracted project. The time for contract completion (often called “contract time”) is estimated based on the average completion times of individual construction items within …

Performance Metrics For Freeway Sensors, Christos D. Achillides, Darcy M. Bullock

JTRP Technical Reports

Performance measures play a critical role in the operation of Intelligent Transportation Systems (ITS), because they provide feedback to the operators regarding system operations and efficiency. Traffic management systems use archived data, provided by various sensors, as a basis for describing normal conditions and predicting traffic conditions that may be expected at a particular time and place in the highway system. However, data quality is one of the principal concerns of archived ITS data users for the following reasons: 1) Manual inspection techniques are unable to detect significant errors because of the large volume of ITS data; 2) Only minimal …

Quality Control Procedures For Weigh-In-Motion Data, Andrew P. Nichols, Darcy M. Bullock

JTRP Technical Reports

For the past two decades, weigh-in-motion (WIM) sensors have been used in the United States to collect vehicle weight data for designing pavements and monitoring their performance. The use of these sensors is now being expanded for enforcement purposes to provide virtual weigh stations for screening vehicles in traffic streams for overweight violations. A study found that static weigh stations in Indiana were effective for identifying safety violations, but ineffective for identifying overweight vehicles. It was also determined that the alternative approach to identifying overweight vehicles using virtual weigh stations requires a high level of WIM data accuracy and reliability …

Safety Of Intersections On High-Speed Road Segments With Superelevation, Peter T. Savolainen, Andrzej P. Tarko

JTRP Technical Reports

In recent years, the State of Indiana has built a number of intersections where one or both of the roads are located on curves. The AASHTO Policy on Geometric Design of Highways and Streets recommends that in such cases “the alignment should be as straight and the gradient as flat as practical.” This wording, consistent with Part V of the Indiana Design Manual, allows for the design of intersections on curves if other solutions prove to be too expensive. Several of these intersections have raised safety concerns and led to expensive corrective measures. Due to these safety and economic issues, …

Rocket Plume Particulate Characterization By Multiple Wavelength Opacity And Mie Scattering, Andrew P. Chouinard

Theses and Dissertations

In the presented work, experiments were conducted to assess the utility of plume opacity monitoring for hybrid rocket diagnostics. The first phase of the work involved measuring plume opacity at a single wavelength and then at two wavelengths simultaneously. Results showed excellent correlation between plume opacity and rocket motor firing cycle and correlation between plume opacity and oxidizer flow rate, thereby validating the utility of the technique. Additionally, a spectral dependence of plume opacity was demonstrated that indicated the possible presence of transparent particulates in the plume. Further phase 1 experiments investigated the performance requirements of a laser-based instrument to …

Lean Product Development Flow, Bohdan W. Oppenheim

Systems Engineering Faculty Works

A general holistic framework, also called a process—named “Lean Product Development Flow (LPDF)”—for organizing the engineering work of Product Development (PD), has been proposed as a contribution to the emerging field of Lean Systems Engineering. The framework is based on Lean Principles, with emphasis on PD value-pulling workflow pulsed by takt periods. The value is defined as (1) mission assurance/product quality, (the traditional goals of Systems Engineering) and (2) reduced program cost and schedule achieved by a radical reduction of waste. LPDF is recommended for smaller design programs based on a high degree of legacy knowledge, with technologies mature enough …

Evaluation And Repair Of Wrought Iron And Steel Structures In Indiana, Mark D. Bowman, Amy M. Piskorowski

JTRP Technical Reports

Throughout the state of Indiana, there a number of older, historical bridges which have been in service since the late 19th century. Many, although not all, of these bridges are truss structures comprised either partially or completely of wrought iron members. Moreover, most of them need some degree pf maintenance or rehabilitation. However, engineers who must recommend repair or rehab operations typically do not know the material properties and behavior of wrought iron members. Consequently, an investigation was initiated to review and classify typical material properties of wrought iron members. This investigation involved three phases that included a literature review …

Characterization Of Aligned Carbon Nanotube/Polymer Composites, Sumanth Banda

Theses and Dissertations

The main objective of this thesis is to efficiently disperse and align SWNTs in two different polymer matrices to obtain an orthotropic composite whose strength, stiffness and electrical properties depend on the orientation of the SWNTs. The SWNTs are successfully dispersed and aligned in a polyimide matrix and a polymer blend of UDMA/HDDMA. In-situ polymerization under sonication is used to disperse the SWNTs in polyimide matrix and sonication is used to disperse SWNTs in the UDMA/HDDMA matrix. In both cases, an electric field is used to align the SWNTs in the polymer matrices. In the polyimide, the SWNTs are aligned …

Reconciling Speed Limits With Design Speeds, Alberto Miguel Figueroa-Medina, Andrzej P. Tarko

JTRP Technical Reports

In recent years, context-sensitive highway design has been promoted to ensure that designers consider the environmental, scenic, aesthetic, historic, community, and preservation aspects of the road. Context-sensitive design may lead to situations where the current design standards cannot be met because of restricting local conditions. Indiana has road sections designed and built some time ago. In a considerable number of roads with the statutory limit of 55 mph (90 km/h), the road geometry does not meet the current standards. At individual intersections and on curves, advisory speeds are posted together with warning signs. Although this solution increases the safety of …

Remediation Of Soils And Ground Water Contaminated By Aromatic And Chlorinated Hydrocarbons And Metals, Inez Hua, P. Suresh Rao, Linda S. Lee, Barry K. Partridge, Ben Lawrence

JTRP Technical Reports

Many of the Indiana Department of Transportation (INDOT) sites are contaminated with aromatic hydrocarbons and chlorinated solvents; these contaminants often occur in the form of light non-aqueous phase liquids (LNAPLs) or dense non-aqueous phase liquids (DNAPLs). Considerable effort has recently been focused on developing in-situ technologies for removing or destroying NAPL source zones, and several potentially viable methods have emerged, including in-situ chemical oxidation (ISCO). ISCO has become an attractive remediation option to managers at many contaminated sites. The three oxidants that are most often applied in-situ are hydrogen peroxide (H2O2) with iron catalysts, potassium permanganate (KMnO4), and ozone (O3). …

Using Imaging Technology To Evaluate Highway Safety, Praprut Songchitruksa, Andrzej P. Tarko

JTRP Technical Reports

Crash-based safety analysis is set back by several shortcomings such as randomness and rarity of crash occurrences, lack of timeliness, and inconsistency in crash reporting. Non-crash-based safety analysis has been around for more than three decades but its potential was limited due to a difficulty in the data collection and the evaluation. Recent advancement in digital videos and image detection technology renewed our interest in facilitating the data collection and improving the evaluation method. Two image detection systems for the measurement of traffic characteristics were evaluated: (a) a commercial video detection system and (b) proprietary image processing software. The measurement …

Parameterization And Validation Of A Lumped Parameter Diffusion Model For Fuel Cell Stack Membrane Humidity Estimation#, Denise Mckay, Anna Stefanopoulou

Engineering: Faculty Publications

We present here a model for estimating the electrode humidity of a proton exchange membrane fuel cell (PEMFC) stack. We use this model to develop a nonlinear open loop estimator of the membrane humidity based on monitoring the pressure and temperature entering and exiting the electrodes, as well as the upstream humidity of each electrode. This lumped parameter model, calibrated and experimentally validated, quantifies the average vapor mass transport across a 24 cell, PEMFC stack of 1.4 kW continuous power output. The experimental method devised here for the parameterization of the model is simple and reproducible. The estimator can be …

Design And Analysis Of An R-Shaped Dual-Band Planar Inverted-F Antenna For Vehicular Applications, Mohammod Ali, Guangli Yang, Huan-Sheng Hwang, Tuangsit Sittironnarit

Faculty Publications

A dual-band R-shaped planar inverted-F antenna is proposed for vehicular application. Utilization of this unique geometry dual-frequency operation is achieved with a single feed. The proposed antenna operates in the 225- and 450-MHz bands. Input impedance and return loss data as function of various antenna parameters are presented, which show that parameters can be adjusted in order to obtain optimum tuning. Radiation pattern data for the antenna mounted on the roof of two types of vehicles are given. The pattern in the low-frequency band is essentially omnidirectional while that in the high-frequency band is directional and normal to the antenna …