Digital Commons Network^™

Field Investigation Of Spalling In Bridge Decks With Partial-Depth Precast Concrete Panel Systems Using Non-Destructive Testing, Kandi Rebecca Wieberg

Masters Theses

"This study involved the investigation of the causes of spalling observed in several partial-depth precast prestressed bridge decks in the state of Missouri. Recently it has been observed that several bridges in Missouri with this type of construction have experienced spalling of concrete at the edges of the panels revealing an extreme condition of corrosion in the prestressing tendons, some to the point of rupture. Ground penetrating radar (GPR), which has been shown to be successful in bridge deck evaluation, was used to determine the relative condition of the prestressing tendons as well as the relative condition of the concrete …

Foundry Parameters For Casting High-Aluminum Lightweight Steel In Complex Shapes, Angella Marie Schulte

Masters Theses

"This work investigated the liquid metal treatment and molding practices for Fe- 30wt.%Mn-9wt.%Al-1wt.%Si-0.9wt.%C-0.5wt.%Mo steel. The goal of this research was to determine the process conditions that would produce a tough Fe-Mn-Al-C alloy and the appropriate mold design to produce a defect-free P900 plate.

Notch toughness of age-hardenable Fe-Mn-Al-C alloys decreases as phosphorus increases. Thermodynamic calculations and experimental work show that additions of Ca followed by Ce can be used to mitigate the deleterious effects of phosphorus, and the addition of Ar-stirring can be used to decrease the number of harmful aluminum nitride inclusions. In the solution-treated and aged condition (Brinell …

Stability Of Streambanks Subjected To Highly Variable Streamflows: The Osage River Downstream Of Bagnell Dam, Kathryn Nicole Heinley

Masters Theses

"Streambank erosion of the Osage River downstream of Bagnell Dam is naturally-occurring; however, it may be significantly worsened due to releases made from the dam to generate hydropower. In this study, six typical outflow release patterns from Bagnell Dam were evaluated to determine their effects, if any, on the stability and the rate and amount of erosion of the banks of the Osage River.

The Bank Stability and Toe Erosion Model (BSTEM), version 5.2, was used to carry out the erosion and stability calculations. The model was validated by using data from another study and comparing the results from BSTEM …

Evaluation Of Liquefaction-Induced Lateral Spreading In The Midwest, Kermit Nathanial Applegate

Masters Theses

"The Central United States is home to several seismically active regions: the Wabash Valley Seismic Zone, the South Central Illinois Seismic Zone, and the New Madrid Seismic Zone. All three of these regions are capable of inducing large ground motion throughout the Mississippi Valley and along the eastern border of Missouri. This has been supported by many paleoseismic studies conducted throughout the region, which have identified numerous instances of liquefaction phenomena. The fluvial deposition process associated with the Mississippi river valley makes it a prime location for possible liquefaction and lateral spreading effects. However, there are few studies pertaining to …

Quantification Of Channel Performance And Development And Characterization Of Small Magnetic Field Probes, Surbhi Mittal

Masters Theses

"This thesis presents a new approach to quantifying channel performance using a transmitter waveform and dispersion penalty (TWDP) with frequency domain S-parameter data. Initially TWDP was defined to characterize the performance of a transmitter in optical links. More recently its use has been extended to include the quantification of channel performance, especially in high-speed copper links. This project focused mainly on channel characterization. Instead of using the time-domain oscilloscope measurements involved in the original approach, it proposes a new method that relies on frequency-domain S-parameter data obtained either from measurements or simulations. It included a parametric study of TWDP with …

Contribution-Based Priority Assessment In A Web-Based Intelligent Argumentation Network For Collaborative Software Development, Maithili Satyavolu

Masters Theses

"Decision making is an important aspect of the collaborative software development process which usually involves complex process of conflict resolution. Stakeholders approach decision making process from multiple perspectives and their priorities play a vital role in it. The priority assessment methods used in the argumentation process so far are usually static. Priorities remain constant throughout the decision making process. In order to make the collaborative system more closely replicate real-world scenarios, this work incorporates dynamic priority assessment into a web-based collaborative system which is based on intelligent computational argumentation. It evaluates priorities dynamically for each cycle of decision process based …

Corrosion Resistance Of Enamel-Coated Steel Reinforcement For Concrete, Charles Robert Werner

Masters Theses

"Originally developed to enhance the bond between concrete and steel, reactive enamel coatings have shown great promise in protecting steel from corrosive environments. However, the corrosion resistance of the material has not yet been tested beyond 40 days. Moreover, when the material was tested, it was applied to smooth steel pins, not deformed steel bars which are commonly used in reinforced concrete structures. Therefore, this study focused on the corrosion resistance of three different enamel coatings, along with a standard epoxy coating, each of which were applied to both smooth and deformed steel bars and included both short-term and long-term …

Synthesis And Characterization Of Microspheres For Controlled Release, Gurpartap Singh Sandhu

Masters Theses

"Synthetic hydroxyapatite (HAp, (Ca₁₀(PO₄)₆(OH)₂) has always been of interest in medical applications because of its similarities to inorganic bone matrix. It has been used in biomedical applications for bone repair and substitution due to its biocompatibility. However, there are some differences in the stoichiometry, composition, and mechanical properties of human bone as compared to pure HAP. HAp particles have been successfully used as drug delivery carriers which deliver the drug to the affected part of the body and the remaining apatite gets degraded by the physiological processes in the body. In the present work, emphasis was on developing mechanically stronger …

Application Of Quality Function Deployment In New Product And Service Development, Anusha Uppalanchi

Masters Theses

"Quality Function Deployment (QFD) is a systematic process to integrate customer requirements into every aspect of the design and delivery of products and services. Understanding the customers wants or needs from a product or service is crucial to the successful design and development of new products and services. QFD is a system that utilizes customer demands to meet client missions by outlining what the customer wants in a service or product. QFD was used in this research to determine customer needs and thus to ensure that customer demands are met. This methodology is demonstrated using two case studies: Hydrogen Fuel …

Enhanced Photorefractivity In A Polymeric Composite Photosensitized With Modified Carbon Nanotubes, Naveen Kumar Lingam

Masters Theses

"This work involves the photosensitization of photorefractive polymeric composites through the inclusion of multiwalled and singlewalled carbon nanotubes grafted to poly(N-vinyl carbazole). The photorefractive nature of the holograms gratings was established using two-beam-coupling, yielding two-beam-coupling gain coefficients approaching 80 cm⁻¹. Degenerate-four-wave-mixing experiments exhibited diffraction efficiencies as high as 60% as well as over-modulation voltages as low as ~ 40 V/µm. These notable figures of merit indicate that the grafting of the various carbon nanotubes to the poly(N-vinyl carbazole) polymer resulted in enhanced photorefractive performance. The mechanism responsible for this enhancement in photorefractive performance is investigated using a variety of experimental …

Evaluation Of Metal Detection Audio Alert Signals Of An/Pss-14 By Means Of Real Time Visualization, Sandesh Srikantaiah Chandrashekar

Masters Theses

"The sweep arm of the AN/PSS-14 Landmine Detector attached to an independent visualization device will transform the AN/PSS-14 into a hand-held data acquisition system for conversion of real time MD and GPR audio alert signals into captured visual trace displays on an on-board PDA computer screen so that momentary sounds of millisecond durations can be captured and displayed for visual scrutiny and interpretation by analytical on-board data processing procedures. This is a part of a two-man team that is developing a visual data adapter for the AN/PSS-14 Landmine Detector where the current thesis is concentrating only on MD audio alerts. …

Detection And Estimation Of Image Blur, Harish Narayanan Ramakrishnan

Masters Theses

"The airborne imagery consisting of infrared (IR) and multispectral (MSI) images collected in 2009 under airborne mine and minefield detection program by Night Vision and Electronic Sensors Directorate (NVESD) was found to be severely blurred due to relative motion between the camera and the object and some of them with defocus blurs due to various reasons. Automated detection of blur due to motion and defocus blurs and the estimation of blur like point spread function for severely degraded images is an important task for processing and detection in such airborne imagery. Although several full reference and reduced reference methods are …

A Real-Time Visualization Of An/Pss-14 Audio Alert Signals For Land Mine Detection Validation, Nitin Kolekar

Masters Theses

"The central idea of the current research is visualization of audio alerts from AN/PSS-14. A visualization device connected to the arm of PSS-14 will show real-time display of MD and GPR Audio Alert signals from PSS-14. This visualization device displays both amplitude-time and spectral frequency-time formats of the signals. The latter format achieves visual separation of combined, simultaneous, MD and GPR alerts. The joint occurrence of MD and GPR signals in a specific time window confirms the presence of landmine. This window is defined by the time of occurrence of MD peak and time of occurrence GPR diffraction from onset …

Standoff Raman Spectroscopy Detection Of Trace Explosives, Abhijeet Singh

Masters Theses

"During the 2003-present Iraq war, Improvised Explosive Devices (IEDs) are being used extensively by the terrorists against the coalition forces and these IEDs were responsible for 40% of coalition force casualties, by the end of 2007. As these IEDs are not based on standard production formulae, their tracking and detection becomes extremely complicated. Laser Induced Breakdown Spectroscopy (LIBS) and Raman Spectroscopy are among the many techniques that have shown promise in detection of explosive compounds. However, the performance of these systems is dependent on the concentration of explosives and ambient noise.

The research presented in this thesis applies signal processing …

Thermodynamic Based Modeling For Nonlinear Control Of Combustion Phasing In Hcci Engines, Joshua Bradley Bettis

Masters Theses

"Low temperature combustion modes, such as Homogeneous Charge Compression Ignition (HCCI), represent a promising means to increase the efficiency and significantly reduce the emissions of internal combustion engines. Implementation and control are difficult, however, due to the lack of an external combustion trigger. This thesis outlines a nonlinear control-oriented model of a single cylinder HCCI engine, which is physically based on a five state thermodynamic cycle. This model is aimed at capturing the behavior of an engine which utilizes fully vaporized gasoline-type fuels, exhaust gas recirculation and intake air heating in order to achieve HCCI operation. The onset of combustion, …

Cloud Security Requirements Analysis And Security Policy Development Using A High-Order Object-Oriented Modeling Technique, Kenneth Kofi Fletcher

Masters Theses

"Security continues to be a major challenge for cloud computing, and it is one that must be addressed if cloud computing is to be fully accepted. Most technological means of securing non-cloud computing systems can be either applied directly or modified to secure a cloud; however, no integrated model-based methodology is yet available to analyze cloud security requirements and develop policy to deal with both internal and external security challenges. This work proposes just such a methodology and demonstrates its application with specific cases. Cloud assets are represented by high order object models, and misuse cases together with malactivity swimlane …

Dynamic Networking For Programmable Logic Controller Communication, Richard Andrew Hardison

Masters Theses

"This thesis confronts the issue of set path communication in Programmable Logic Controllers (PLCs). In order to increase reliability in a networked automated process, it is necessary to develop a dynamic method of communication between PLCs. Three methods for dynamic messaging in PLCs are explored in this work. These methods are based on the real-time reconfiguration of message paths when communication fails on the originally configured path. The simplest method involves replacing the original message block with an Add-On Instruction (AOI) which can accept multiple communication paths and has the ability to switch between these paths to maintain communication. A …

The Study Of A Model For Via Transition And The Multi-Layer Via Transition Tool Gui Design, Ketan Shringarpure

Masters Theses

"One of the many challenges faced by engineers working with the present design scenario is to estimate the extent to which a signal, with significant high frequency content, is affected when it is routed on a printed circuit board. The printed circuit board routing will include the transition through the geometries like micro-strip or strip-line transmission lines, via transitions, and irregularities or asymmetries in the aforementioned geometries. One of these discontinuities, the via transition, results in the interaction of the signal on the via and the cavity (plane-pair) through which it passes. The via transition modeling will help characterize a …

Modeling The Practical Performance Of Switched-Capacitor Converters And A Method For Automating State-Space Model Generation, Jordan M. Henry

Masters Theses

"A new modeling technique and a method for automating the modeling process are introduced for analyzing complex switched-capacitor (SC) converters. The model uses conventional circuit analysis methods to derive state-space models of each switching state. Steady-state performance is derived and expressed as an equivalent resistance. Whereas previous techniques have provided either the detailed performance of a simple SC converter or the limiting performance of a complex SC converter, this new model is flexible enough to provide detailed performance for any practical converter. Nonuniform component choices, asymmetric duty cycles, and other deviations from an ideal converter can be readily included. Dynamics …

Doubly Fed Induction Generator With Integrated Energy Storage System For Smoothening Of Output Power, Nishant Swaraj Chouhan

Masters Theses

"Wind energy is one of the fastest growing renewable energies in the world today. However, integration of wind power into the power system network is still confronting many challenges. One of the main challenges is the suppression of wind power fluctuations. This thesis focuses on integration of wind power with energy storage to overcome the integration challenges. The first part of this thesis investigates the suitability of energy storage systems for transmission, distribution and wind farm applications. A review on the available energy storage systems is performed considering several criteria. Efforts are made to investigate solutions that meet all the …

Power Distribution Network Inductance Calculation, Transient Current Measurement And Conductor Surface Roughness Extraction, Fan Zhou

Masters Theses

"The first part in the thesis discussed the modeling of the mid-frequency inductance for Zpp type plane pairs in power distribution networks (PDN). It is a key step for the placement of the decoupling capacitors. This paper gives an efficient approach for the calculation of the inductance for different capacitor placements. The PEEC based formulations takes advantage of the opposite currents in the planes. This leads to compute time reductions and memory savings for both the element calculation and the matrix solve step. A formulation is used where placement of capacitors leads to only small changes in the circuit matrix. …

Measuring Blast Induced Rock Damage From Pre-Splitting Sandstone By Applying The Multichannel Analysis Of Surface Waves Geophysical Method, Charles Bradford Zdazinsky

Masters Theses

"Many blasting applications in the mining industry demand that the hard rock being blasted remains structurally competent. For example, pre-splitting is a common technique to reduce fracturing, and operators of dimension stone quarries use this blasting method to eliminate overbreak. When pre-split design parameters are not applied correctly, there will be a redistribution of stresses within the rock, resulting in Blast Induced Rock Damage (BID). Advances in geophysical technology are enabling blast technicians to monitor BID and then use the results to correctly design their blasts. The Multichannel Analysis of Surface Waves (MASW) geophysical method is new technology that is …

A Value Model For Product Development Process Using Lean Principles, Salik Yadav

Masters Theses

"This research presents a value quantification model for multi-stage product development Process (PDP) using lean value principles. The PDP stages considered in this research include conceptual development, systems design, detailed design and prototyping stages. The value at any of the PDP stages is formulated as a function of six factors: (a) importance of customer requirements, (b) cost of customer's ownership, (c) parts/service availability, (d) weighted average cost of capital, (e) information evolution, and (f) risk reduction. Factors (a)-(d) are adequately addressed in the literature. This study focuses on information evolution and risk reduction factors. These two factors are defined by …

A Comparison Of Case-Based Reasoning And Regression Analysis Approaches For Cost Uncertainty Modeling, Karan Banga

Masters Theses

"This thesis presents case-based reasoning approach for estimating the cost and modeling cost uncertainty of a new product in the concept selection stage. Case-based reasoning (CBR) is an approach which uses old cases/experiences to understand and solve new problems. The CBR approach consists of creating a knowledge-base (or database) containing past cases (products), defining a new case (concept), retrieving cases similar to the new case, and adjusting the solution of the retrieved cases to the new case. The first paper compares case-based reasoning, in studying the effects of varying design attribute specifications on cost estimation accuracy and cost distribution reliability. …

Strategic Process Integration Of Energy And Environmental Systems In Wastewater Treatment Plants, Bharath Kumar Gangichetty

Masters Theses

"Green environmental practices are increasingly important in combating serious global energy and environmental issues. Most wastewater treatment facilities were built when energy costs were not a concern; however, an increasing demand for energy, changing climatic conditions, and constrained energy supplies have resulted in the need to apply more energy-conscious choices in the maintenance or upgrade of existing wastewater treatment facilities. A detailed analysis of the majority of water and wastewater treatment services shows that most facilities operate far below the efficiency levels needed for effective energy use. Failure to comply with regulated environmental standards is also a problem. Although standards …

Population Control In Evolutionary Algorithms, Jason Edward Cook

Masters Theses

"Traditional evolutionary algorithms (EAs) are powerful robust problem solvers that have several fixed parameters which require prior specification. Having to determine good values for any of these parameters can be problematic, as the performance of EAs is generally very sensitive to these parameters, requiring expert knowledge to set optimally without extensive use of trial and error. Parameter control is a promising approach to achieving this automation and has the added potential of increasing EA performance based on both theoretical and empirical evidence that the optimal values of EA strategy parameters change during the course of executing an evolutionary run. While …

Strategic Criteria For Evaluating Inland Freight Hub Locations, Robert Tyler Lipscomb

Masters Theses

"The aim of this thesis is to develop criteria that can be used to evaluate the current capabilities and sustainability of inland freight hubs. A review of the literature highlights the need for a more efficient freight distribution system to combat supply chain deficiencies and the important role that inland freight hubs play in creating this system. Also in the literature is a call for a more comprehensive approach to hub development decisions and the use of multi-criteria decision analysis. The decision to devote resources to logistics developments in a specific region must consider many factors that are both quantitative …

The Effects Of Personal Protective Equipment Level A Suits On Human Task Performance, Yvette L. Simon

Masters Theses

"First response teams dealing with hazardous substances often require the highest level of protection provided by Level A suits. These suits are fully encapsulating, bulky, and heat retentive. The effect of these suits on the wearer's ability to perform various tasks is of interest when it comes to human performance analysis. This research effort examined the effect of the Level A suit on fine motor and gross motor dexterity. Seven members of the National Guard's Civil Support Team (CST) performed a battery of six tasks designed to test these abilities. Tasks comprised the Minnesota Dexterity test and the Mirror Tracer …

The Mitigation Effects Of A Barrier Wall On Blast Wave Pressures, Nathan Thomas Rouse

Masters Theses

"The study examined the mitigating effects of a blast barrier wall. This area of blast mitigation is of interest due to the many different applications involved in protecting a specific target from an explosive attack. The research follows a 1:50 scale layout using 73 gram, hemisphere-shaped, Composition-4 charges detonated at combinations of three standoff distances from a blast barrier wall set at three different heights. This project used 45 data points for each combination of standoff distance and wall height. This project expanded prior research conducted by the United States Army Corps of Engineers (USACE) by increasing the database of …

The Placement Of Remediation Amendments Into Contaminated Sediments Via Waterjet Technologies, Gavin Hunter Ray Risley

Masters Theses

"The use of amendments to perform in situ remediation of contaminated sediments is a technique that is relatively mature. The need exists to develop a method of amendment delivery that will efficiently place the amendments into the contaminated zone at depth with minimal impacts to the benthic communities and contaminant resuspension. Waterjets have been used for hundreds of years as an excavation, cutting, and cleaning tool, but they can also be used to inject remediation amendments into contaminated sediments if setup properly. In order to test this concept, a waterjet amendment injection system and nozzle have been developed and tested. …