Engineering Commons^™

Watershed Delineation In The Field: A New Approach For Mobile Applications Using Lidar Elevation Data, Samuel Adam Noel

Open Access Theses

With the advancement of mobile devices, opportunities to take watershed management tasks out of the office and into the field can be realized. In turn, field workers can utilize these technologies to expedite the decision-making process so that they may focus on meeting with clients and addressing agricultural watershed management issues. High-resolution (∼1.5 m postspacing) elevation data gathered by light detection and ranging (LiDAR) provides the topographic detail necessary to model hydrology at the field-scale (∼1 km2).

Non-artifactual surface depressions lead to erroneous surface flow patterns when using existing algorithms. So a sequential depression-filling algorithm (SDFA) has been developed to …

Evaluation Of Lane Use Management Strategies, Chaitanya Paleti Siva Sai Krishna

Open Access Theses

The limited funding available for roadway capacity expansion and the growing funding gap, in conjunction with the increasing congestion, creates a critical need for innovative lane use management options. Various cost-effective lane use management strategies have been implemented in the United States and worldwide to address these challenges. However, these strategies have their own costs, operational characteristics, and additional requirements for field deployment. Hence, there is a need for systematic methodologies to evaluate lane use management strategies.

In this thesis, a systematic simulation-based methodology is proposed to evaluate lane use management strategies. It involves identifying traffic corridors that are suitable …

Algorithm Development And Analysis For Advanced Enginetechnologies Including Piezoelectric Fuel Injection And Variablevalve Actuation, Bradley W. Pietrzak

Open Access Theses

As vehicle emissions standards and fuel economy constraints become increasingly strict, the automotive industry must employ the use of advanced engine technologies to overcome these challenges. Fuel injection rate shaping and cylinder deactivation (CDA) are two such technologies, and both of them require the design and implementation of algorithms using various hardware and software tools.

Fuel injection rate shaping is one path towards cleaner and more efficient diesel engines. Piezoelectrically-actuated fuel injectors are well-suited for rate shaping operation, but are difficult to control. Control-related challenges arise primarily due to the lack of measurements available in a fuel injection system on-engine, …

Identifying Conditions To Optimize Lactic Acid Production From Food Waste, Raymond M. Redcorn

Open Access Theses

There is an increased demand for lactic acid for the production of biopolymers and to aid nutrient removal in wastewater treatment. Food waste offers a source of soluble sugars to produce lactic acid, which does not increase land demand, but digestion conditions have yet to be optimized when co-digested with primary sludge. Food waste was collected from cafeteria waste bins, homogenized and seeded with primary sludge. A Box Behnken Response surface design was used to optimize lactic acid production based on pH, temperature, loading rate, and retention time. Subsequent experiments verified and refined those conditions to optimize for both yield …

Analysis Of The Impact Of Early Exhaust Valve Opening And Cylinder Deactivation On Aftertreatment Thermal Management And Efficiency For Compression Ignition Engines, Leighton Edward Roberts

Open Access Theses

In order to meet strict emissions regulations, engine manufacturers have implemented aftertreatment technologies which reduce the tailpipe emissions from diesel engines. The effectiveness of most of these systems is limited when exhaust temperatures are low (usually below 200°C to 250°C). This is a problem for extended low load operation, such as idling and during cold start. Use of variable valve actuation, including early exhaust valve opening (EEVO) and cylinder deactivation (CDA), has been proposed as a means to elevate exhaust temperatures. This thesis discusses a research effort focused on EEVO and CDA as potential enablers of exhaust gas temperature increase …

Development Of Sound Quality Metrics For Gear Rattle In Diesel Engines, Brandon Sobecki

Open Access Theses

Sound quality is an important factor in the design of competitive diesel engines. The noise produced by specific components and mechanisms in the engine can play a significant role in determining the perceived quality of the overall noise and in turn the perceived quality of the engine. The goal of the present research is to characterize the sounds produced by the phenomenon known as gear rattle and to develop a model that can be used to assess gear rattle levels in a way that connects directly with human perception of rattle. Most previous work in this area has been focused …

Measurement Of The Responses Of Polyurethane And Confortm Foams And The Development Of A System Identification Technique To Estimate Polyurethane Foam Parameters From Experimental Impulse Responses, Vaidyanadan Sundaram

Open Access Theses

Flexible polyurethane foam is the main cushioning element used in car seats. Optimization of an occupied seat's static and dynamic behavior requires models of foam that are accurate over a wide range of excitation and pre-compression conditions. Experiments were conducted to measure the response of foam over a wide range of excitation which include slowly varying uniaxial compression tests on a 3 inch cube foam sample, base excitation and impulse excitation test on a foam-mass system. The foam used was the same in all of the experiments, thus obtaining all the responses on the same foam sample which helps eliminate …

Evaluating Intensity As A Controller Function For Nextgen Scenarios With Increased Capacity, Caitlin Anne Surakitbanharn

Open Access Theses

Automated separation assurance is the most mature concept to handle increasing airspace traffic and capacity needs, yet the system lacks a way to pre-emptively identify aircraft separation problems. The intensity control measure looks to find situations where if an aircraft pair makes an unplanned change in heading or altitude at the wrong moment, an unrecoverable situation arises. This research analyzes static, open loop air traffic data in an en-route sector to determine how many high intensity aircraft pairs (HIP) exist per minute, and if the intensity measure is a safely manageable function for air traffic controllers. It is found that …

Waste Heat Recovery Options In A Large Gas-Turbine Combined Power Plant, Ularee Upathumchard

Open Access Theses

This study focuses on power plant heat loss and how to utilize the waste heat in energy recovery systems in order to increase the overall power plant efficiency. The case study of this research is a 700-MW natural gas combined cycle power plant, located in a suburban area of Thailand. An analysis of the heat loss of the combustion process, power generation process, lubrication system, and cooling system has been conducted to evaluate waste heat recovery options. The design of the waste heat recovery options depends to the amount of heat loss from each system and its temperature. Feasible waste …

Computational Fluid Dynamics Analysis Of Freeze Drying Process And Equipment, Nikhil P. Varma

Open Access Theses

Freeze drying is an important, but expensive, inefficient and time consuming process in the pharmaceutical, chemical and food processing industries. Computational techniques could be a very effective tool in predictive design and analysis of both freeze drying process and equipment. This work is an attempt at using Computational Fluid Dynamics(CFD) and numerical simulations as a tool for freeze drying process and equipment design.

Pressure control is critical in freeze dryers, keeping in view the product stability. In industrial freeze dryers, loss of pressure control can lead to loss of an entire batch. Pressure variation within the chamber could also lead …

Transport In Ultra-Thin Heat Pipes For Low Power Applications, Yashwanth Yadavalli

Open Access Theses

Heat pipes and vapor chamber heat spreaders offer a potential solution to the increasing thermal management challenges in thin-form-factor mobile computing platforms, where efficient spreading is required to simultaneously prevent overheating of internal components and formation of hot regions on the device exterior surfaces. The operating conditions for such applications are also characterized by low input heat fluxes, which in combination with the geometric constraints, give rise to unique performance limitations that require examination. This thesis aims to characterize the steady-state and transient heat pipe performance limitations unique to such ultra-thin form factors, and characterizes the key heat transfer mechanisms …

Impact Of Nanostructure On Polymer-Based Nonvolatile Memory Devices, Seung Hyun Sung

Open Access Theses

Memory functionality is essential for many high-end electronic applications (e.g. , smart phones, personal computers). Particularly, organic nonvolatile memory devices based on polymer ferroelectric materials are a promising approach toward the development of low-cost memory due to the ease of processing and flexibility associated with the device. Here, we will focus on a memory device with a two-component active layer and a diode structure. This ferroelectric diode (FeD) has a nanostructured active layer, composed of ferroelectric and semiconducting polymers, and it can provide easy access to high-performance polymer-based memory devices. In order to create these nanostructured active layers, we …

Dissolution Rate And Mechanism Of Metals In Molten Aluminum Alloy A380, Hengyu Zhu

Open Access Theses

Shot sleeve is a very easily worn out part in a high-pressure die-casting machine due to serious dissolution of the area underneath the pouring hole. It is because during a normal pouring process, the high temperature molten aluminum will impact and dissolve that area of the shot sleeve by complex chemical and physical process. Rotation experiment was carried out to H13 and four kinds of refractory metal samples. SEM and EDS pictures were taken in order to investigate the microstructure and the dissolution mechanism of these materials. This suggests a high strength niobium is an ideal material for that area …

Fire Behavior Of Bolted Connections, Qiaqia Zhu

Open Access Theses

Bolted connection failures have been observed in building fires and large-scale structural fire tests. Limited information is available on plate bearing behavior at elevated temperatures. The failure mode of a shear-tab connection could change from plate bearing failure to bolt shear failure between 400 (degree Celsius) °C to 600°C. Component-based models have been used to predict the behavior of bolted connections. Earlier researchers have developed simple mathematical models to represent the force-displacement relationships of bolt shear and plate bearing components of bolted connections. However, these models need to be verified experimentally for US building construction and materials. Therefore, eleven single-bolted …

Engineering Community Engagement Partnerships: Investigating Motivation, Nature, And Structure, Julia D. Thompson

Open Access Dissertations

Engineering community engagement programs have increased in popularity over the last decade or so, with related research and scholarship in this area focused primarily on student motivation and learning outcomes. Since 2000, however, the wider service-learning field has started investigating partnerships and community voice. Building from the existing service-learning literature, this study aims to better understand community-university partnerships in engineering community engagement programs from the perspectives of both the academic program and the served community. This study addresses three research questions: (1) Why are individuals and local community organizations involved in engineering service-learning partnerships?, (2) How does engineering community engagement …

Microwave Chemical Sensing Using Overmoded T-Line Designs And Impact Of Real-Time Digitizer In The System, Yu-Ting Huang

Open Access Dissertations

Microwave spectrometers have unique advantages in the ability to determine high resolution features that are specific to a given chemical. Very sharp lines which correspond to quantum states of the chemical allow for unique identification of the chemical. Recent advances have shown the possibility of room temperature microwave spectroscopy analysis in which the data is collected in a short amount of time using broadband chirp pulse Fourier transform microwave (CP-FTMW) spectroscopy. In this report, we explore the design of reduced size spectrometers focusing on the reduction as well as expansion of operation frequency of the microwave analysis cell, where the …

Probabilistic Uncertainty Quantification And Experiment Design For Nonlinear Models: Applications In Systems Biology, Vu Cao Duy Thien Dinh

Open Access Dissertations

Despite the ever-increasing interest in understanding biology at the system level, there are several factors that hinder studies and analyses of biological systems. First, unlike systems from other applied fields whose parameters can be effectively identified, biological systems are usually unidentifiable, even in the ideal case when all possible system outputs are known with high accuracy. Second, the presence of multivariate bifurcations often leads the system to behaviors that are completely different in nature. In such cases, system outputs (as function of parameters/inputs) are usually discontinuous or have sharp transitions across domains with different behaviors. Finally, models from systems biology …

A Stochastic Multi-Criteria Assessment Of Security Of Transportation Assets, Michelle Sophie Dojutrek

Open Access Dissertations

Transportation project evaluation and prioritization use traditional performance measures including travel time, safety, user costs, economic efficiency, and environmental quality. The project impacts in terms of enhancing the infrastructure resilience or mitigating the consequences of infrastructure damage in the event of disaster occurrence are rarely considered in project evaluation. This dissertation presents a methodology to address this issue so that in evaluating and prioritizing investments, infrastructure with low security can receive the attention they deserve. Secondly, the methodology can be used for evaluating and prioritizing candidate investments dedicated specifically to security enhancement. In defining security as a function of threat …

Application Of Integer Quadratic Programming In Detection Of High-Dimensional Wireless Systems, Ali Ahmed Elghariani

Open Access Dissertations

High-dimensional wireless systems have recently generated a great deal of interest due to their ability to accommodate increasing demands for high transmission data rates with high communication reliability. Examples of such large-scale systems include single-input, single-output symbol spread OFDM system, large-scale single-user multi-input multi-output (MIMO) OFDM systems, and large-scale multiuser MIMO systems. In these systems, the number of symbols required to be jointly detected at the receiver is relatively large. The challenge with the practical realization of these systems is to design a detection scheme that provides high communication reliability with reasonable computational complexity, even as the number of simultaneously …

Hierarchical Cell Fluid Extracellular Matrix Interaction In Cell Microenvironment, Soham Ghosh

Open Access Dissertations

Hierarchical structural interactions between components of cell microenvironment, the extracellular matrix (ECM), cytoplasm, nucleus and fluid, are important phenomena that decide cell level physiological process and tissue engineering applications. One of those tissue engineering modalities is freezing of biomaterials, important in a wide variety of biomedical applications including cryopreservation and cryosurgeries. In order to design these applications, freezing-induced changes of the cells and tissues and corresponding biophysical mechanisms need to be well understood. Although the effects of freezing on cells in suspension have been extensively studied, the intracellular mechanics of cells embedded in the extracellular matrix (ECM) during freezing are …

Solid Oxide Fuel Cell Electrolytes Produced Via Very Low Pressure Suspension Plasma Spray And Electrophoretic Deposition, James D Fleetwood

Open Access Dissertations

Solid oxide fuel cells (SOFCs) are a promising element of comprehensive energy policies due to their direct mechanism for converting the oxidization of fuel, such as hydrogen, into electrical energy. Both very low pressure plasma spray and electrophoretic deposition allow working with high melting temperature SOFC suspension based feedstock on complex surfaces, such as in non-planar SOFC designs. Dense, thin electrolytes of ideal composition for SOFCs can be fabricated with each of these processes, while compositional control is achieved with dissolved dopant compounds that are incorporated into the coating during deposition. In the work reported, sub-micron 8 mole % Y …

Coupled Fluid-Thermal Analysis Of Low-Pressure Sublimation And Condensation With Application To Freeze-Drying, Arnab Ganguly

Open Access Dissertations

Freeze-drying is a low-pressure, low-temperature condensation pumping process widely used in the manufacture of bio-pharmaceuticals for removal of solvents by sublimation. The goal of the process is to provide a stable dosage form by removing the solvent in such a way that the sensitive molecular structure of the active substance is least disturbed. The vacuum environment presents unique challenges for understanding and controlling heat and mass transfer in the process. As a result, the design of equipment and associated processes has been largely empirical, slow and inefficient.^ A comprehensive simulation framework to predict both, process and equipment performance is critical …

Dynamic Control Of Plasmonic Resonances With Graphene Based Nanostructures, Naresh Kumar Emani

Open Access Dissertations

Light incident on a metallic structure excites collective oscillations of electrons termed as plasmons. These plasmons are useful in control and manipulation of information in nanoscale dimensions and at high operating frequencies. Hence, the field of plasmonics opens up the possibility of developing nanoscale optoelectronic circuitry for computing and sensing applications. One of the challenges in this effort is the lack of tunable plasmonic resonance. Currently, the resonant wavelength of plasmonic structure is fixed by the material and structural parameters. Post-fabrication dynamic control of a plasmonic resonance is rather limited.^ In this thesis we explore the combination of optoelectrical properties …

Analysis Of The Interaction Of Two Parallel Surface Cracks, Jeeyeon Hahn

Open Access Dissertations

The objective of this research is to analyze and predict the interaction of surface cracks that occur in parallel planes. Multiple cracks may form in aging aircraft that forms at stress concentrations such as fastener holes and notched components by stress corrosion and fatigue cracking. The lifetime of the structures are significantly affected by the interaction between these cracks. Depending on relative positions and orientations of neighboring cracks, local stress fields and crack driving forces can be affected by the presence of adjacent cracks. Even small subcritical cracks may rapidly grow to a size that will cause failure in service …

Intranuclear Strain Measured By Iterative Warping In Cells Under Mechanical And Osmotic Stress, Jonathan T Henderson

Open Access Dissertations

The nucleus is a membrane bound organelle and regulation center for gene expression in the cell. Mechanical forces transfer to the nucleus directly and indirectly through specific cellular cytoskeletal structures and pathways. There is increasing evidence that the transferred forces to the nucleus orchestrate gene expression activity. Methods to characterize nuclear mechanics typically study isolated cells or cells embedded in 3D gel matrices. Often report only aspect ratio and volume changes, measures that oversimplify the inherent complexity of internal strain patterns. This presents technical challenges to simultaneously observe small scale nuclear mechanics and gene expression levels inside the nuclei of …

Development Of Planar Patch Clamp With Potentiometric Calcium Ion-Selective Electrode, Kul Inn

Open Access Dissertations

Ion channels are proteins in cell lipid bilayer membranes and act as pores which can adopt closed and open states, thus gating the flow of ions in and out of the cell. Patch clamp technology has been the proven standard for fundamental studies of ion channel activities. However, the technique has some basic limitations: low throughput, time consuming nature of its process, need of highly skilled personnel and inability to identify ionic composition of electrophysiological events. Many different materials and fabrication methods have been introduced to replace traditional patch clamp setup to overcome limitations.^ In this dissertation, a planar patch …

Modeling The Dynamics And Stresses Of Elongated Particles In Vertical Axis Mixers, Xia Hua

Open Access Dissertations

Vertical axis mixers, such as high shear granulators and agitated filter dryers (AFDs), are commonly used in the processing of particulate materials. For example, AFDs are regularly used in the pharmaceutical industry to dry the wet active pharmaceutical ingredient (API) particles. During the drying process, an impeller blade agitates the bed to increase the drying rate and enhance drying uniformity. Unfortunately, the needle-shaped API particles tend to flow poorly, are frequently damaged, and can sometimes form undesirable agglomerates, causing manufacturing inefficiencies, flow stoppages, and unpredictable product quality. Therefore, it is important to gain an improved understanding of the system's particle …

Quantifying Aesthetics Of Visual Design Applied To Automatic Design, Ali Jahanian

Open Access Dissertations

In today's "Instagram" world, with advances in ubiquitous computing and access to social networks, digital media is adopted by art and culture. In this dissertation, we study what makes a good design by investigating mechanisms to bring aesthetics of design from realm of subjection to objection. These mechanisms are a combination of three main approaches: learning theories and principles of design by collaborating with professional designers, mathematically and statistically modeling good designs from large scale datasets, and crowdscourcing to model perceived aesthetics of designs from general public responses. We then apply the knowledge gained in automatic design creation tools to …

Tools For Efficient Design Of Multicomponent Separation Processes, Joshua Lee Huff

Open Access Dissertations

Separations account for as much as 85% of plant operating costs in chemical production; it is therefore important that they be designed with energy efficiency in mind. This can only be achieved if two things are achieved: the complete space of design options is known, and an accurate way is developed to compare all possible design options. For both membrane separation cascades and multicomponent distillation configurations, this dissertation explores methods for designing energy efficient separations.^ The operating cost of membranes used in production of nitrogen gas from air is largely driven by the compressors required to maintain a pressure differential. …

Strategic Flexibility, Kihyung Kim

Open Access Dissertations

A flexible system is defined as one that can change the entity's stance, capability or status reacting to a change of the entity's environment. Flexibility has gathered the attention of academic researchers and industry practitioners as an efficient approach to cope with today's volatile environment. As the environments become more unpredictable and volatile, it is imperative for a flexible system to respond quickly to a change in its circumstance. How much flexibility is embedded into the system also has a critical impact on the long-term effectiveness of the flexible system. Moreover, this research focuses on the strategic environment where a …