Engineering Commons^™

Cleavage Of Acetyl Groups For Acetic Acid Production In Kraft Pulp Mills, Ravikant Amogisidha Patil

Electronic Theses and Dissertations

The objective of this thesis was to determine appropriate conditions for cleavage of acetyl groups from northeast hardwood. Currently, acetyl groups end up in a waste product stream in most wood based pulp mills and thus are underutilized. Recently, a techno‐economic analysis was published that evaluated the suitability of the ‘Near‐Neutral Extraction’ process for recovery of acetic acid and ethanol in Kraft pulp mills. The results showed that the proposed process suffered from high capital investment and a low rate of return on investment. Additionally, the revenues generated by the sale of acetic acid were two times greater than the …

Phenomenological Modeling Of Image Irradiance For Non-Lambertian Surfaces Under Natural Illumination., Shireen Y. Elhabian

Electronic Theses and Dissertations

Various vision tasks are usually confronted by appearance variations due to changes of illumination. For instance, in a recognition system, it has been shown that the variability in human face appearance is owed to changes to lighting conditions rather than person's identity. Theoretically, due to the arbitrariness of the lighting function, the space of all possible images of a fixed-pose object under all possible illumination conditions is infinite dimensional. Nonetheless, it has been proven that the set of images of a convex Lambertian surface under distant illumination lies near a low dimensional linear subspace. This result was also extended to …

Assessment Of Audio Interfaces For Use In Smartphone Based Spatial Learning Systems For The Blind, Shreyans Jain

Electronic Theses and Dissertations

Recent advancements in the field of indoor positioning and mobile computing promise development of smart phone based indoor navigation systems. Currently, the preliminary implementations of such systems only use visual interfaces—meaning that they are inaccessible to blind and low vision users. According to the World Health Organization, about 39 million people in the world are blind. This necessitates the need for development and evaluation of non-visual interfaces for indoor navigation systems that support safe and efficient spatial learning and navigation behavior. This thesis research has empirically evaluated several different approaches through which spatial information about the environment can be conveyed …

Integration Of Process Parameter Control And Digital Image Correlation Methods In An Investigation Of The Variability Of Marine Polymer Matrix Composite Material Properties, Keith Andrew Berube

Electronic Theses and Dissertations

The very nature of continuous fiber composite materials, with their heterogeneous structure of layered and interwoven fibers bound together by a polymer resin matrix, lead to an inevitable variability in mechanical properties. This is especially true if the fabrication process is not well controlled. Unlike fabricating components with metals, where the properties of the material are known beforehand, the final properties of the composite material are determined during the process of fabricating the composite part. The research described herein was undertaken to better enable the use of polymer matrix composites in the marine construction industry by developing a knowledge base …

Towards A Fluid Solid Interaction Model Of A Dynamic Lung, Justin C. Jacobs

Electronic Theses and Dissertations

Because the pulmonary system is a site for both environmental particulate contamination, as well as drug delivery into the body, numerous research groups have focused on precisely understanding its inner-workings. Past research has demonstrated the need to realistically model the lung walls in order to accurately capture the complex airflow profile throughout all of the branches. Since this is paramount to properly replicating particulate transport in the lung, computational fluid dynamics simulations on their own are inadequate, as they cannot account for lung wall dilation. Only by coupling the fluid and solid domains can natural lung behavior can be effectively …

Thermally Actuated Resonant Silicon Crystal Nanobalances, Arash Hajjam

Electronic Theses and Dissertations

As the potential emerging technology for next generation integrated resonant sensors and frequency references as well as electronic filters, micro-electro-mechanical resonators have attracted a lot of attention over the past decade. As a result, a wide variety of high frequency micro/nanoscale electromechanical resonators have recently been presented. MEMS resonators, as low-cost highly integrated and ultra-sensitive mass sensors, can potentially provide new opportunities and unprecedented capabilities in the area of mass sensing. Such devices can provide orders of magnitude higher mass sensitivity and resolution compared to Film Bulk Acoustic resonators (FBAR) or the conventional quartz and Surface Acoustic Wave (SAW) resonators …

Flow Field Measurements For A Cross Flow Turbine, Matthew Cameron

Electronic Theses and Dissertations

Understanding the flow pattern around hydrokinetic devices is important for the development of tidal energy technology. The objective of the research is to provide the wake characteristics from laboratory measurements, including wake structure, and flow recovery in the near and far fields of a cross-flow turbine. The data can be used to assist in optimization of an array of turbines by providing experimental results for numerical models validation and industrial developers of tidal energy. Another critical use of this data will be to provide a basis for parameterization of energy extraction in coastal ocean models in resource assessment. The experimental …

Testing Of A Ducted Axial Flow Tidal Turbine, Thomas A. Lokocz

Electronic Theses and Dissertations

Energy independence and a reduction on the reliance on fossil fuels is a critical area of current research and development. Utilizing the energy in the world’s oceans can help the world move towards a more sustainable energy supply. One of the most promising sources of ocean energy is tidal energy or marine hydrokinetics, the topic of this thesis. This research analyzes the performance of a ducted axial flow tidal turbine and compares the result to an unducted turbine. While the focus of this research is on experimental results obtained in tow tank tests, the turbine and duct were designed using …

Physical Modeling Of Suction Caissons Loaded In Two Orthogonal Directions For Efficient Mooring Of Offshore Wind Platforms, Jade Chung

Electronic Theses and Dissertations

Over the past decade a number of Federal and State policies and programs have promoted the development of the wind energy industry, including the establishment of offshore wind. A strategy by the Department of Energy set objectives of reducing cost and reducing time to deployment through specific deliverables such as innovative anchor and mooring design for floating offshore systems and hardware design concepts including turbine array grids. This research program proposes and investigates use of suction caissons as combined anchors to resist line loads from multiple platforms as an efficient solution for anchoring a network of wind turbine platforms.

Suction …

Peak-To-Average-Power-Ratio (Papr) Reduction Techniques For Orthogonal-Frequency-Division- Multiplexing (Ofdm) Transmission, Bader Hamad Alhassoun

Electronic Theses and Dissertations

Wireless communication has experienced an incredible growth in the last decade. Two decades ago,the number of mobile subscribers was less than 1% of the world's population. As of 2011, the number of mobile subscribers has increased tremendously to 79.86% of the world's population.

Robust and high-rate data transmission in mobile environments faces severe problems due to the time-variant channel conditions, multipath fading and shadow fading. Fading is the main limitation on wireless communication channels. Frequency selective interference and fading, such as multipath fading, is a bandwidth bottleneck in the "last mile" which runs from the access point to the user. …

Depth Sensing Planar Structures: Detection Of Office Furniture Configurations, Brendan O'Shaughnessy

Electronic Theses and Dissertations

Handheld devices with depth sensors have the potential to aid low-vision users in performing tasks that are difficult with traditional modes of assistance. Heuristic studies have revealed that tables have a key functional role in indoor scene descriptions. The research question addressed in this thesis is: how can we robustly and efficiently detect tables in indoor office environments? This thesis presents a solution that utilizes a functional approach to robustly detect rectangular tables in depth images generated from a Kinect sensor.

Perhaps the most significant function of a table is to provide its users with a supporting plane. This demands …

Chemically Enhanced Water Removal In Papermaking, James John Beaupré

Electronic Theses and Dissertations

This work examines the utilization of chemical means to enhance the amount of water removed in the papermaking process prior to the application of heat. Through wet end application of a cationic surfactant, a significant increase in the amount of water removed in the forming and pressing sections is observed. This results in a reduction in the energy required to thoroughly dry the paper.

A variety of compounds hypothesized to potentially enhance dewatering were examined. A cationic surfactant, cetyltrimethylammonium bromide (CTAB), produced significant enhanced dewatering via addition to a pulp slurry. Extensive bench top testing characterized the extent of reduction …

Synthesis And Characterization Of Mesoporous Silica Membranes Modified By Atomic And Molecular Layer Deposition, David Emmett Cassidy

Electronic Theses and Dissertations

Inorganic membranes offer a means for chemical separations in a variety of applications including chemical processing, drug delivery systems, battery separators and fuel cells. There is currently a “pore size gap” in silica membranes between 1-2 nanometers. Synthesizing membranes with a fine control of the pore size and distribution within that gap is a significant challenge. This thesis reports findings on using atomic and molecular layer deposition as new synthesis approaches to controlling pore size and chemical functionality of silica membranes. Mesoporous silica membranes, prepared using surfactant-templates with pore diameters ~4nm, were modified using atomic layer deposition and molecular layer …

Surface Variable Effects On The Dynamic Properties Of Thoroughbred Horse Racetracks, Christie A. Mahaffey

Electronic Theses and Dissertations

Historically, equine racing surfaces have been selected and maintained without considering quantifiable data for horse biomechanics or surface mechanical properties. This approach is currently shifting in the racing industry, with an increased interest in understanding the mechanics of the hoof-surface interface to reduce injuries. This dissertation examines three components influencing the hoof-surface interface: 1) correlations between mineralogical composition of dirt tracks, track designs, and climate; 2) the effect of variable cushion depth on dynamic loading, and 3) the effects of different horseshoes on dynamic loading. The second and third pieces of this research are based on an experimental procedure designed …

Vertical Field Switching Blue Phase Liquid Crystals For Field Sequential Color Displays, Hui-Chuan Cheng

Electronic Theses and Dissertations

Low power consumption is a critical requirement for all liquid crystal display (LCD) devices. A field sequential color (FSC) LCD was proposed by using red (R), green (G) and blue (B) LEDs and removing the lossy component of color filters which only transmits ~30% of the incoming white light. Without color filters, FSC LCDs exhibit a ~3X higher optical efficiency and 3X higher resolution density as compared to the conventional color filters-based LCDs. However, color breakup (CBU) is a most disturbing defect that degrades the image quality in FSC displays. CBU can be observed in stationary or moving images. It …

High Performance Low Voltage Power Mosfet For High-Frequency Synchronous Buck Converters, Boyi Yang

Electronic Theses and Dissertations

Power management solutions such as voltage regulator (VR) mandate DC-DC converters with high power density, high switching frequency and high efficiency to meet the needs of future computers and telecom equipment. The trend towards DC-DC converters with higher switching frequency presents significant challenges to power MOSFET technology. Optimization of the MOSFETs plays an important role in improving low-voltage DC-DC converter performance. This dissertation focuses on developing and optimizing high performance low voltage power MOSFETs for high frequency applications. With an inherently large gate charge, the trench MOSFET suffers significant switching power losses and cannot continue to provide sufficient performance in …

Computational Methods For Analyzing Rna Folding Landscapes And Its Applications, Yuan Li

Electronic Theses and Dissertations

Non-protein-coding RNAs play critical regulatory roles in cellular life. Many ncRNAs fold into specific structures in order to perform their biological functions. Some of the RNAs, such as riboswitches, can even fold into alternative structural conformations in order to participate in different biological processes. In addition, these RNAs can transit dynamically between different functional structures along folding pathways on their energy landscapes. These alternative functional structures are usually energetically favored and are stable in their local energy landscapes. Moreover, conformational transitions between any pair of alternate structures usually involve high energy barriers, such that RNAs can become kinetically trapped by …

Systems Analysis For Urban Water Infrastructure Expansion With Global Change Impact Under Uncertainties, Cheng Qi

Electronic Theses and Dissertations

Over the past decades, cost-effectiveness principle or cost-benefit analysis has been employed oftentimes as a typical assessment tool for the expansion of drinking water utility. With changing public awareness of the inherent linkages between climate change, population growth and economic development, the addition of global change impact in the assessment regime has altered the landscape of traditional evaluation matrix. Nowadays, urban drinking water infrastructure requires careful long-term expansion planning to reduce the risk from global change impact with respect to greenhouse gas (GHG) emissions, economic boom and recession, as well as water demand variation associated with population growth and migration. …

Evaporation, Precipitation Dynamics And Instability Of Acoustically Levitated Functional Droplets, Abhishek Saha

Electronic Theses and Dissertations

Evaporation of pure and binary liquid droplets is of interest in thermal sprays and spray drying of food, ceramics and pharmaceutical products. Understanding the rate of heat and mass transfer in any drying process is important not only to enhance evaporation rate or vapor-gas mixing, but also to predict and control the final morphology and microstructure of the precipitates. Acoustic levitation is an alternative method to study micron-sized droplets without wall effects, which eliminates chemical and thermal contamination with surfaces. This work uses an ultrasonic levitation technique to investigate the vaporization dynamics under radiative heating, with focus on evaporation characteristics, …

Bst-Inspired Smart Flexible Electronics, Ya Shen

Electronic Theses and Dissertations

The advances in modern communication systems have brought about devices with more functionality, better performance, smaller size, lighter weight and lower cost. Meanwhile, the requirement for newer devices has become more demanding than ever. Tunability and flexibility are both long-desired features. Tunable devices are ‘smart’ in the sense that they can adapt to the dynamic environment or varying user demand as well as correct the minor deviations due to manufacturing fluctuations, therefore making it possible to reduce system complexity and overall cost. It is also desired that electronics be flexible to provide conformability and portability. Previously, tunable devices on flexible …

Multi-Level Safety Performance Functions For High Speed Facilities, Mohamed Ahmed

Electronic Theses and Dissertations

High speed facilities are considered the backbone of any successful transportation system; Interstates, freeways, and expressways carry the majority of daily trips on the transportation network. Although these types of roads are relatively considered the safest among other types of roads, they still experience many crashes, many of which are severe, which not only affect human lives but also can have tremendous economical and social impacts. These facts signify the necessity of enhancing the safety of these high speed facilities to ensure better and efficient operation. Safety problems could be assessed through several approaches that can help in mitigating the …

Towards Scalable Nanomanufacturing: Modeling The Interaction Of Charged Droplets From Electrospray Using Gpu, Weiwei Yang

Electronic Theses and Dissertations

Electrospray is an atomization method subject to intense study recently due to its monodispersity and the wide size range of droplets it can produce, from nanometers to hundreds of micrometers. This thesis focuses on the numerical and theoretical modeling of the interaction of charged droplets from the single and multiplexed electrospray. We studied two typical scenarios: large area film depositions using multiplexed electrospray and fine pattern printings assisted by linear electrostatic quadrupole focusing. Due to the high computation power requirement in the unsteady n-body problem, graphical processing unit (GPU) which delivers 10 Tera flops in computation power is used to …

A Retrospective Analysis And Field Study Of Nanotechnology Related Ergonomic Risk In Industries Utilizing Nanomaterials, Wanda Greaves-Holmes

Electronic Theses and Dissertations

The National Science Foundation estimates that two million skilled nanotechnology workers will be needed world wide by 2015 – one million of them in the United States (2001). In the absence of scientific clarity about the potential health effects of occupational exposure to nanoparticles, guidance in decision making about hazards, risk, and controls takes on new importance. Currently, guiding principles on personal protective equipment for workers who come in contact with nanomaterials have not been standardized universally. Utilizing the NASATLX, this dissertation investigates the adequacy and shortcomings of research efforts that seek to determine whether or not occupational exposure to …

Design And Characterization Of High Temperature Packaging For Wide-Bandgap Semiconductor Devices, Brian Grummel

Electronic Theses and Dissertations

Advances in wide-bandgap semiconductor devices have increased the allowable operating temperature of power electronic systems. High-temperature devices can benefit applications such as renewable energy, electric vehicles, and space-based power electronics that currently require bulky cooling systems for silicon power devices. Cooling systems can typically be reduced in size or removed by adopting wide-bandgap semiconductor devices, such as silicon carbide. However, to do this, semiconductor device packaging with high reliability at high temperatures is necessary. Transient liquid phase (TLP) die-attach has shown in literature to be a promising bonding technique for this packaging need. In this work TLP has been comprehensively …

Resilience Of Bridges Following Aftershocks, Diego Francisco Espinosa

Electronic Theses and Dissertations

The ability to predict the reduction in capacity of a structure after an earthquake is vital in the process of assessing a structure after a main-shock or an after-shock. Main-shocks are normally followed by a few aftershocks in a short period of time. Researchers in the past have focused for the most part on the effects of main-shocks on buildings. Very little research has been performed on the ability to predict the reduction in capacity of bridges in aftershocks. This thesis focuses on providing a way of assessing the reduction in capacity for main-shocks as compared to aftershocks and the …

Non-Reciprocal Wave Transmission In Integrated Waveguide Array Isolators, Tony Yatming Ho

Electronic Theses and Dissertations

Non-reciprocal wave transmission is a phenomenon witnessed in certain photonic devices when the wave propagation dynamics through the device along one direction differs greatly from the dynamics along the counter-propagating direction. Specifically, it refers to significant power transfer occurring in one direction, and greatly reduced power transfer in the opposite direction. The resulting effect is to isolate the directionality of wave propagation, allowing transmission to occur along one direction only. Given the popularity of photonic integrated circuits (PIC), in which all the optical components are fabricated on the same chip so that the entire optical system can be made more …

Structural Identification Through Monitoring, Modeling And Predictive Analysis Under Uncertainty, Hasan Burak Gökçe

Electronic Theses and Dissertations

Bridges are critical components of highway networks, which provide mobility and economical vitality to a nation. Ensuring the safety and regular operation as well as accurate structural assessment of bridges is essential. Structural Identification (St-Id) can be utilized for better assessment of structures by integrating experimental and analytical technologies in support of decision-making. St-Id is defined as creating parametric or nonparametric models to characterize structural behavior based on structural health monitoring (SHM) data. In a recent study by the ASCE St-Id Committee, St-Id framework is given in six steps, including modeling, experimentation and ultimately decision making for estimating the performance …

Turbidity Removal Efficiency And Toxicity Issues Associated With The Chitosan-Based Dual Bio-Polymer Systems, Rylee Hernandez

Electronic Theses and Dissertations

Stormwater runoff can be a great concern in the State of Florida due to the impact the quality of the runoff water can have on the natural water bodies. Stormwater runoff can carry pollutants and sediments which can cause both physical and biological risks in an aquatic ecosystem such as a lake, river, or pond. Polymers, namely the chitosan-based dual polymer system, can be used remove the sediment from this runoff to ensure the safety of the state’s water bodies. Three soils are used in this testing: AASTO soil classifications A-3(sandy soil) and A-2- 4 (silty-sand), and a soil with …

Evaluation Of Biosorption Activated Media Under Roadside Swales For Stormwater Quality Improvement And Harvesting, Andrew Charles Hood

Electronic Theses and Dissertations

Stormwater runoff from highways is a source of pollution to surface water bodies and groundwater. This project develops a bio-detention treatment and harvesting system that is incorporated into roadside swales. The bio-detention system uses Bold & Gold™, a type of biosorption activated media (BAM), to remove nutrients from simulated highway runoff and then store the water in underground vaults for infiltration, controlled discharge, and/or irrigation and other non-potable applications. In order to design a bio-detention system, media characteristics and media/water quality relationships are required. Media characteristics determined through testing include: specific gravity, permeability, infiltration, maximum dry density, moisture content of …

Forecasting Volcanic Activity Using An Event Tree Analysis System And Logistic Regression, William N. Junek

Electronic Theses and Dissertations

Forecasts of short term volcanic activity are generated using an event tree process that is driven by a set of empirical statistical models derived through logistic regression. Each of the logistic models are constructed from a sparse and geographically diverse dataset that was assembled from a collection of historic volcanic unrest episodes. The dataset consists of monitoring measurements (e.g. seismic), source modeling results, and historic eruption information. Incorporating this data into a single set of models provides a simple mechanism for simultaneously accounting for the geophysical changes occurring within the volcano and the historic behavior of analog volcanoes. A bootstrapping …