Engineering Commons^™

Study Of And Design Procedure For Dual Circularly Polarized Waveguide Slot Arrays, Lee M. Paulsen

Dissertations, Master's Theses and Master's Reports - Open

For the past sixty years, waveguide slot radiator arrays have played a critical role in microwave radar and communication systems. They feature a well-characterized antenna element capable of direct integration into a low-loss feed structure with highly developed and inexpensive manufacturing processes. Waveguide slot radiators comprise some of the highest performance—in terms of side-lobe-level, efficiency, etc. — antenna arrays ever constructed.

A wealth of information is available in the open literature regarding design procedures for linearly polarized waveguide slots. By contrast, despite their presence in some of the earliest published reports, little has been presented to date on array designs …

Emission Cross Sections For Neutral Xenon Impacted By Xe+ And Xe2+, Jason D. Sommerville

Dissertations, Master's Theses and Master's Reports - Open

Ion impact emission cross sections for eleven transitions from the 5p⁵6p configuration to the 5p⁵6s configuration of neutral xenon occurring in the spectral region between 700 nm and 1000 nm have been measured experimentally. Collisions between both singly- and doublyionized xenon and neutral xenon have been studied. These cross sections are of primary use in the development of a spectrographic diagnostic for Hall effect thruster plasma. A detailed discussion of the experimental methods and the subsequent data reduction is included. The results are presented and the importance of these data for spectrographic emission models of Hall …

Postharvest Treatment To Control Codling Moth In Fresh Apples Using Water Assisted Radio Frequency Heating, Shaojin Wang, Sohan Birla, J. D. Hansen

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Apples destined for export to Japan and South Korea are currently disinfested for codling moth, Cydia pomonella L. (Lepidoptera: Tortricidae), using methyl bromide fumigation. Restrictions and limitations imposed on the uses of methyl bromide have increased interest in developing alternative non-chemical quarantine treatments. It is imperative that the treatment is effective against codling moth yet maintains the quality of treated apples. The present study explored the application of radio frequency (RF) energy in conjunction with conventional hot water treatment to develop feasible heat treatments. Treatment parameters were selected based on minimum time–temperature conditions required for 100% mortality of fifth-instar codling …

Feasibility Study For Bicycle Safety: Data Assessment And Network Evaluation, Michael Seth Klobucar, Jon D. Fricker

JTRP Technical Reports

Bicycles offer a promising transportation alternative to private motor vehicles, especially in areas with congestion, poor air quality, and high fuel prices. This study sought rational methods for evaluating the benefits of incorporating bicycle-friendly features into highway project designs. Data on recent bicyclist fatalities and other collisions involving bicyclists in Indiana were analyzed to determine factors that could help to explain the incidents and offer insights into countermeasures or remedies. Human error – on the part of the bicyclist or the motorist – was found to be the most common factor. Poor lighting and noncompliance with sidewalk ordinances also were …

Indot Customer Service, Ananth V. Iyer, Michael Hoeck, Amanda Thompson, Kailas Dandgaval, Jairo Bohorquez, Justina Mikals

JTRP Technical Reports

This study focuses on the flow of customer complaints to the INDOT central office and districts, their handling within the INDOT system and the customer experienced lead time. The processes were examined based on customer segments, complaint type, and district of origin. Detailed data analyses for specific transactions within the INDOT system were used to document the process. In addition, as per the study advisory committee suggestions, a tracking of transactions flow using a paper system was used to reconcile archived data. Although lead time metrics were developed at both the central office and district level, the lack of data …

Investigation Of The Performance Of Neat And Modified Asphalt Binders, Yalan Tang, John E. Haddock

JTRP Technical Reports

The Superpave binder specifications are performance-based criteria for binder selection for use in hot-mix asphalt mixtures. However, these specifications may not be applicable to modified binders. This research investigates the a new method for determining hot-mix asphalt mixing and compaction temperatures as well as the performance of neat (unmodified) and modified binders of the same performance grade. The first phase of the research focuses on determining mixing and compaction temperatures for hot-mix asphalt mixtures. Modified binders are shear rate and temperature dependent and the conventional methods of determining mixing and compaction temperatures can yield extreme results. The Zero Shear Viscosity …

Simplification Of Resilient Modulus Testing For Subgrades, Daehyeon Kim, Nayyar Zia Siddiki

JTRP Technical Reports

Resilient modulus has been used for characterizing the stress-strain behavior of subgrade soils subjected to traffic loadings in the design of pavements. With the recent release of the M-E Design Guide, highway agencies are further encouraged to implement the resilient modulus test to improve subgrade design. In the present study, physical property tests, unconfined compressive tests, resilient modulus (Mr) tests and Several Dynamic Cone Penetrometer (DCP) tests were conducted to assess the resilient and permanent strain behavior of 14 cohesive subgrade soils and five cohesionless soils encountered in Indiana. The applicability for simplification of the existing resilient modulus test, AASHTO …

Technical Issues Related To The Use Of Fly Ash And Slag During Late-Fall (Low Temperature) Construction Season, Anand Krishnan, Jinesh K. Mehta, J. Olek, W. Jason Weiss

JTRP Technical Reports

The potential for scaling of concrete pavement containing fly ash is one of the durability concerns which imposes restrictions on the use of fly ash in paving applications in Indiana during the period of low temperatures (e.g., the late fall construction season). These restrictions increase the cost of paving projects, and occasionally, results in seasonal cement shortages. The objective of this study was to develop a better understanding of the scaling mechanism through a series of laboratory tests that focused on the role of material properties and length and temperature of curing in controlling scaling. Additionally, an attempt was made …

Evaluation Of Rapid Setting Cement-Based Materials For Patching And Repair, Amit D. Barde, Swathi Parameswaran, Todd Chariton, W. Jason Weiss, Menashi D. Cohen, Scott Andrew Newbolds

JTRP Technical Reports

The efficient repair and replacement of concrete pavements and bridge decks often requires a rapid setting material that can be placed, cured, and opened to traffic in a relatively short period of time. Frequently, temporary repairs are made using materials that are later found to be incompatible with the existing pavement, structures, and environment. This practice causes these materials to fail prematurely, frequently requiring re-repair. Research is needed to determine which rapid setting repair materials demonstrate the best behavior with rapid strength gain, low potential for cracking, and excellent durability. The objective of this research is to evaluate the performance …

Jointless And Smoother Bridges: Behavior And Design Of Piles, Robert J. Frosch, Voraniti Chovichien, Katrinna Durbin, David Fedroff

JTRP Technical Reports

Integral abutment bridges have been used in the United States for decades. By eliminating expensive expansion joints, the piles supporting the end bent accommodate the total thermal movement of the bridge. Currently, integral bridges are designed based upon experience, and a rational design specification has not been developed. Furthermore, the interaction of the abutment, pile, and soil remains uncertain. A better understanding regarding the behavior of this system is needed. The objective of this research is to evaluate the behavior of the integral abutment-pile system and evaluate any limitations of its use. To achieve this objective, two phases of research …

Expert System To Support Site Investigation For Safety Improvement, Andrzej Marcin. Kwasniak, Bogdan Chivoiu, Andrzej P. Tarko

JTRP Technical Reports

One of the goals of traffic safety specialists is to improve road geometry and traffic control at high-crash locations to reduce the risk of crash. The most difficult part of site investigation is determining the causes of crashes. This task may be overwhelming, particularly for inexperienced investigators. Experienced investigators often may have difficulties in connecting various pieces of information and knowledge due to the high level of uncertainty, the high complexity of safety impacts, and the gaps in what is known about driver performance during the crash occurrence. An AI method is proposed to help investigators identify the crash causes. …

The Effectiveness And Criteria For Placement Of Raised Pavement Markers (Synthesis Study), Yi Jiang

JTRP Technical Reports

Raised pavement markers (RPM) are used in highway centerlines and edge lines as a traffic safety measure to provide more positive guidance for motorists in inclement weather and low light conditions. They have been widely applied by highway agencies as delineation treatments to improve driver preview distances. The Indiana Department of Transportation (INDOT) has installed RPMs on selected roadway sections primarily as position guidance devices in order to better guide drivers in night conditions. In Indiana, RPMs are installed on all interstate highways and multilane divided highways. However, RPMs are used on only a few of the Indiana’s two-lane highways. …

Heat Transfer And Chemical Processes In Chemical Vapor Deposition Reactor For Synthesis Of Carbon Nanotubes, Wahed Rezk Wasel

University of Kentucky Doctoral Dissertations

A small-scale model of a CVD reactor was built. Axial and radial of major species concentrations and temperature profiles were obtained with a micro gas chromatograph and a fine thermocouple. Those temperature and species concentrations revealed detailed thermal and chemical structures of the CVD reactor.

The concentrations of argon plus hydrogen, methane, and C₂H_x (C₂H₂ + C₂H₄ + C₂H₆) resulting from xylene decomposition were measured along the CVD at different temperatures. Ferrocene was added to xylene to investigate the effect of a catalyst on composition profiles. The …

Variational Approach To The Volume Viscosity Of Fluids, Allan J. Zuckerwar, Robert L. Ash

Mechanical & Aerospace Engineering Faculty Publications

The variational principle of Hamilton is applied to develop an analytical formulation to describe the volume viscosity in fluids. The procedure described here differs from those used in the past in that a dissipative process is represented by the chemical affinity and progress variable (sometimes called "order parameter") of a reacting species. These state variables appear in the variational integral in two places: first, in the expression for the internal energy, and second, in a subsidiary condition accounting for the conservation of the reacting species. As a result of the variational procedure, two dissipative terms appear in the Navier-Stokes equation. …

A Fast Parallelized Computational Approach Based On Sparse Lu Factorization For Predictions Of Spatial And Time-Dependent Currents And Voltages In Full-Body Biomodels, Ashutosh Mishra, Ravindra P. Joshi, Karl H. Schoenbach, C. D. Clark Iii

Electrical & Computer Engineering Faculty Publications

Realistic and accurate numerical simulations of electrostimulation of tissues and full-body biomodels have been developed and implemented. Typically, whole-body systems are very complex and consist of a multitude of tissues, organs, and subcomponents with diverse properties. From an electrical standpoint, these can be characterized in terms of separate conductivities and permittivities. Accuracy demands good spatial resolution; thus, the overall tissue/animal models need to be discretized into a fine-grained mesh. This can lead to a large number of grid points (especially for a three-dimensional entity) and can place prohibitive requirements of memory storage and execution times on computing machines. Here, the …

Radio Frequency Enabled Soil Redox Potential Sensor Networks, Chris Holme

Theses : Honours

There is a need for' cost effective tools and data collection methods for field measurements; to increase both productivity and volumes of collected data in the quest for enhanced understanding and management of environmental systems. To such end, various technologies that may be combined into a cost effective soil redox sensor network were explored. Suitability of each technology, as a component of said network was evaluated. A prototype soil redox sensor network was constructed and basic laboratory and field testing was completed. Results indicate that the prototype sensor network functions correctly within bounds. Both laboratory and field testing show that …

Test 1877: Challenger Mt 655b Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Fundamental And Applied Experimental Investigations Of Corrosion Of Steel By Lbe Under Controlled Conditions: Kinetics, Chemistry Morphology, And Surface Preparation, John Farley, Allen L. Johnson, Dale L. Perry

Transmutation Sciences Materials (TRP)

Advanced nuclear processes such as the transmutation of nuclear waste, fast reactors, liquid-metal-cooled reactors, and spallation neutron sources require advanced materials systems to contain them. The required structural materials must be stable in the presence of nonmoderating coolants. A prime candidate for such a coolant is Lead Bismuth Eutectic (LBE). Materials in these systems must be able to tolerate high neutron fluxes, high temperatures, and chemical corrosion. Unfortunately, LBE corrodes stainless steel.

The corrosive behaviors of structural materials in LBE are not well understood. The Russians have over 80 reactor-years experience with LBE coolant in their Alpha-class submarine reactors. The …

Theoretical Modeling Of Protective Oxide Layer Growth In Non-Isothermal Lead Alloy Coolant Systems, Yitung Chen, Jinsuo Zhang, Huajun Chen, Jichun Li

Transmutation Sciences Materials (TRP)

The goal of this research project is to provide a basic understanding of the protective oxide layer behaviors and to develop oxide layer growth models of steels in non-isothermal lead alloys (lead or lead-bismuth eutectic) coolant systems. Precise studies and simulations of all hydrodynamics with thermal conditions encountered in practical coolant loop systems by use of different flowing conditions in the laboratory are difficult and expensive, if not impossible. Therefore it is important and necessary to develop theoretical models to predict the protective oxide layer behaviors at the design stage of a practical lead-alloy coolant system, to properly interpret and …

Air Exchange Rate In A Horse Trailer During Road Transport, Joseph L. Purswell, Richard S. Gates, Laurie M. Lawrence, Jamey D. Jacob, Timothy S. Stombaugh, Robert J. Coleman

Biosystems and Agricultural Engineering Faculty Publications

Horses traveling by road commonly experience heat stress conditions and poor air quality, which may be caused by insufficient ventilation; however, there are few estimates of air exchange in a horse trailer during transport. Air exchange rate was measured at ten locations within a four-horse trailer (internal volume 18.5 m³) using tracer gas decay measurement to assess the adequacy of ventilation. Three vehicle speeds (13, 48, and 97 km h^-1) and three window configurations (all windows and roof vents closed, all windows open, all windows open and roof vents open forward) were tested with and without …

Development Of A Micro-Shot Peening Process And Testing Of Micro-Shot Peened Engineering Materials, James Vahey

Masters

A precision, air blast, shot peening machine was designed and developed and used to carry out peening operations on engineering materials and components. The machine was designed to allow all the variables of the peening process to be controlled and adjusted. The micro-shot peening process was applied to a series of standard High Speed Steel twist drills, carbide inserts for milling cutters, turning tools and EPDM material. The drills were used under controlled CNC conditions to machine mild steel plates. The useful cutting life of the drills was monitored. The surface finish and the dimensional accuracy of the holes were …

Wideband Dual Polarized Directional Base Station Antenna, Francisco L. Lerma

Masters

The thesis presents a study of different microwave radiators for wireless applications in the frequency range of 2.2 – 2.5GHz. The performance of microstrip patch antennas and dual polarized dipole antennas were evaluated numerically and experimentally verified. A single microstrip patch and a four- element microstrip array were simulated, fabricated and tested. Simulation was carried out by the finite integration time domain (FITD) method. Polarization diversity is realised using crossed dipoles printed elements. For the crossed dipole elements, two different feed arrangements were studied. Parameters such as return loss, isolation, radiation pattern, gain and bandwidth were measured and found to …

An Investigation Into The Behaviour Of Sheet Metal Workpieces When Subjected To Simultaneous Double Bending, Arthur Henry

Masters

Simultaneous double bending, where two 90° bends are formed in a single workpiece, in close proximity to each other and in alternate directions, are common in the metal forming industry, especially so in small production batches where press brakes and their associated tooling is extensively used. This bending process, resulting in what is commonly called a ‘joggle’ bend, is executed using specially shaped forming dies. The geometry of these dies determines the geometry of the bend and also the amount of sliding and /or stretching that takes place in the workpiece during the forming process. This in turn determines the …

System Identification Of A Pasteurisation Process: A Comparison Of Direct And Indirect Methods, Niel Canty

Theses

The primary focus of this research is to identify a linear model for a direct steam injection (DSI) pasteurisation process which is a component of a large-scale pilot evaporation process widely used in the dairy industry. The pasteurisation process has been identified as a key component of the evaporation process. The author believes that no previously published work has focused on identifying models for a DSI pasteurisation process which makes this work an original contribution to the area. The pasteurisation process can be modelled as a single-input, single-output (SISO) process with a measurable disturbance. Thus two transfer functions were required …

Next Generation Heterogenous Telemetry Modules, Pierce Brady

Theses

Remote monitoring is used in many applications within the scientific, industrial and commercial communities. These applications can range from the simple monitoring of wind farm generators to the complex behavioural monitoring of a local fox habitat to the simple but extremely urgent monitoring of water depth for a flood prone river. Each application of remote monitoring requires different aspects of the remote monitoring device, but typically, not all these applications can be implemented, as the technologies required for their construction are extremely large, expensive, energy inefficient, slow and do not meet the constraints for the given application.

However with the …

Efficient Strategies For Robust Constrained Model Predictive Control, Marcin Tomasz Cychowski

Theses

Practical difficulties associated with the implementation of stabilizing robust model predictive control (MPC) laws are well known. The algorithms typically rely on the solution of the so-called min-max optimization problem. All such algorithms display a large online computational burden and often suffer excessive conservativeness. In this thesis, two original algorithms will be developed that address the conservativeness and complexity issues in min-max MPC.

The first algorithm is a min-max MPC based on the concept of closed-loop prediction. The synthesis procedure is realized using linear matrix inequalities and thus the implementation of the closed-loop min-max MPC control law can be performed …

Investigating The Male-Driven Evolution Hypothesis Using Human AluRepeat Elements, Sridhar Ramachandran

Browse all Theses and Dissertations

Thousands of copies of short interspersed repeats (SINEs) are scattered essentially ran-domly through the human genome. Although copies of each repeat subfamily are identical at the time of their insertion, they become subject to individual substitutions after insertion. As the relative time of insertion is known for many of these repeats, such "junk DNA" can be used to provide a sizeable number of time-series data points for studying substitution effects in a variety of genomic contexts. This dissertation specifically discusses the usefulness of the Alufamily of SINE repeats towards addressing open problems in genomics, population genetics, and biology in …

Rf Low Pass Filter Design And Fabrication Using Integrated Passive Device Technology, Heli Li

Electronic Theses and Dissertations

In this thesis, the whole process of design a low pass filter (LPF) for the wireless communication application has been presented. Integrated passive device technology based on GaAs substrate has been utilized to make the LPF. Schematic simulation and electromagnetic simulations are extensively used in the design process. EM simulation is used in the selection of layout design and processing parameters for design optimization of both the inductors and IPD harmonic filters. The effective use of EM simulation enables us to realize the successful development of high performance harmonic filters. To make the optimization be more flexible and also for …

Rapid Prototyping Of Microfluidic Packages, Michael Pepper

Electronic Theses and Dissertations

In the area of MEMS there exists a tremendous need for communication between the micro-device and the macro world. A standard protocol or at least multiple standards would be of great use. Electrical connections have been standardized for many uses and configurations by the integrated circuit industry. Standardization in the IC industry has created a marketplace for digital devices unprecedented. In addition to the number of "off the shelf" products available, there exists the possibility for consumers to mix and match many devices from many different manufacturers. This research proposes some similar solutions as those for integrated circuits for fluid …

Experimental Techniques For Nonlinear Material Characterization: A Nonlinear Spectrometer Using A White-Light Continuum Z-Scan, Mihaela Balu

Electronic Theses and Dissertations

The main goal of this dissertation is to introduce and demonstrate a new method for the rapid determination of the nonlinear absorption spectra and the dispersion of the nonlinear refraction of optical materials in the visible and near IR spectral regions. However, conventional methods like, white-light continuum pump-probe and Z-scan techniques were used to measure the peak 2PA cross-sections for a number of commercially available photoinitiators. In the new method mentioned above, a high energy, broadband femtosecond white-light continuum is used to replace the single wavelength source conventionally used in a Z-scan experiment. In a Z-scan experiment, the transmittance of …