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Investigating The Removal Of Stormwater Pollutants In Small-Scale, Constructed Treatment Wetlands, Katlyn Edwards 2019 Rose-Hulman Institute of Technology

Investigating The Removal Of Stormwater Pollutants In Small-Scale, Constructed Treatment Wetlands, Katlyn Edwards

Rose-Hulman Summer Undergraduate Research Fellowships

Eutrophication of US surface waters is a growing problem due to nitrogen and phosphorus runoff in stormwater. In natural ecosystems, wetlands can absorb and remove a variety of water pollutants, including nutrients. Wetlands also provide flood control and wildlife habitat. Mimicking natural systems, constructed treatment wetlands can remove stormwater pollutants, are economic to build and maintain, provide a bionetwork for a wide range of plants and animals, and can be used for educational purposes.

While constructed treatment wetlands can remove stormwater pollutants such as total suspended solids, organic carbon, and nitrates, a significant reduction in phosphate concentrations has not been ...


Computational Studies Of Thermal Properties And Desalination Performance Of Low-Dimensional Materials, Yang Hong 2019 University of Nebraska - Lincoln

Computational Studies Of Thermal Properties And Desalination Performance Of Low-Dimensional Materials, Yang Hong

Student Research Projects, Dissertations, and Theses - Chemistry Department

During the last 30 years, microelectronic devices have been continuously designed and developed with smaller size and yet more functionalities. Today, hundreds of millions of transistors and complementary metal-oxide-semiconductor cells can be designed and integrated on a single microchip through 3D packaging and chip stacking technology. A large amount of heat will be generated in a limited space during the operation of microchips. Moreover, there is a high possibility of hot spots due to non-uniform integrated circuit design patterns as some core parts of a microchip work harder than other memory parts. This issue becomes acute as stacked microchips get ...


Cooperative Learning For The Consensus Of Multi-Agent Systems, Qishuai Liu 2019 University of Nebraska - Lincoln

Cooperative Learning For The Consensus Of Multi-Agent Systems, Qishuai Liu

Theses, Dissertations, and Student Research from Electrical & Computer Engineering

Due to a lot of attention for the multi-agent system in recent years, the consensus algorithm gained immense popularity for building fault-tolerant systems in system and control theory. Generally, the consensus algorithm drives the swarm of agents to work as a coherent group that can reach an agreement regarding a certain quantity of interest, which depends on the state of all agents themselves. The most common consensus algorithm is the average consensus, the final consensus value of which is equal to the average of the initial values. If we want the agents to find the best area of the particular ...


Distributed Edge Bundling For Large Graphs, Yves Tuyishime 2019 University of Nebraska - Lincoln

Distributed Edge Bundling For Large Graphs, Yves Tuyishime

Computer Science and Engineering: Theses, Dissertations, and Student Research

Graphs or networks are widely used to depict the relationships between data entities in diverse scientific and engineering applications. A direct visualization (such as node-link diagram) of a graph with a large number of nodes and edges often incurs visual clutter. To address this issue, researchers have developed edge bundling algorithms that visually merge similar edges into curved bundles and can effectively reveal high-level edge patterns with reduced visual clutter. Although the existing edge bundling algorithms achieve appealing results, they are mostly designed for a single machine, and thereby the size of a graph they can handle is limited by ...


Exploring Eye Tracking Data On Source Code Via Dual Space Analysis, Li Zhang 2019 University of Nebraska - Lincoln

Exploring Eye Tracking Data On Source Code Via Dual Space Analysis, Li Zhang

Computer Science and Engineering: Theses, Dissertations, and Student Research

Eye tracking is a frequently used technique to collect data capturing users' strategies and behaviors in processing information. Understanding how programmers navigate through a large number of classes and methods to find bugs is important to educators and practitioners in software engineering. However, the eye tracking data collected on realistic codebases is massive compared to traditional eye tracking data on one static page. The same content may appear in different areas on the screen with users scrolling in an Integrated Development Environment (IDE). Hierarchically structured content and fluid method position compose the two major challenges for visualization. We present a ...


Probabilistic Analysis Of Slide-Rocking Structures Under Earthquake Loads, Taylor J. Knickerbocker 2019 University of Nebraska-Lincoln

Probabilistic Analysis Of Slide-Rocking Structures Under Earthquake Loads, Taylor J. Knickerbocker

Civil Engineering Theses, Dissertations, and Student Research

Estimates of rare seismic hazard are essential for the resilience of critical infrastructure and facilities. However, these estimates are highly uncertain at long return periods due to the lack of observed earthquake records. Several ground motion prediction equations have been proposed to close this gap and estimate rare seismic demands; however, these models were developed based on more moderate earthquake records and can yield physically unrealizable ground motions when extrapolated to long return periods. For this reason, seismologists have proposed using precariously balanced rocks (PBRs) as a way to constrain rare seismic hazard. PBRs are a type of fragile geologic ...


Displacement Derived Energy Levels For Harvard Miniature Compaction, Ana Laura Errigo, Julia Loshelder 2019 University of Arkansas, Fayetteville

Displacement Derived Energy Levels For Harvard Miniature Compaction, Ana Laura Errigo, Julia Loshelder

Civil Engineering Undergraduate Honors Theses

Previously, the amount of energy provided by the Harvard Miniature tamper was adjusted by changing the number of blows per lift or the number of lifts or was not adjusted at all. However, this research was conducted to investigate the effect of adjusting the displacement of the spring (increased or decreased) to change the potential energy of the spring and therefore change the compacive effort with a specific type of soil. Thus, the objective was to match the compaction energies using the Harvard miniature method with the compaction energies obtained using the Proctor method. Specifically, the goal was to show ...


Development Of A Ground-Based Aerial-Tracking Instrument For Open-Path Spectroscopy To Monitor Atmospheric Constituents, Haden Hodges 2019 University of Arkansas, Fayetteville

Development Of A Ground-Based Aerial-Tracking Instrument For Open-Path Spectroscopy To Monitor Atmospheric Constituents, Haden Hodges

Civil Engineering Undergraduate Honors Theses

A ground-based aerial-tracking instrument, known as the Ground Tracker, designed to provide spectral data to quantify greenhouse gases is under development. The Ground Tracker includes an Optical System including a high power rifle scope, video camera, and spectrometer used to locate an active light source from the Emitter, and collect spectral data by utilizing an actuating mirror. The implementation of this instrument could be made low cost by utilizing existing weather balloon infrastructure to allow the Emitter to be placed into the lower stratosphere. The recovery of the emitter will be possible by tracking the GPS coordinates. Weather balloon instrument ...


Materials Science And Engineering, Joshua P. Steimel 2019 University of the Pacific

Materials Science And Engineering, Joshua P. Steimel

Pacific Open Texts

This text serves to provide a brief overview of some of the myriad of topics available for study in the field of Materials Science. This is by no means a comprehensive compilation of Materials Science and Engineering topics but is instead meant as an introduction to the topic for entry-level undergraduates who want to pursue a career studying materials.


Feasibility Of Circular Orbits For Proximity Operations In Strongly Perturbed Environments Around Uniformly Rotating Asteroids, Nicholas Peter Liapis 2019 Embry-Riddle Aeronautical University

Feasibility Of Circular Orbits For Proximity Operations In Strongly Perturbed Environments Around Uniformly Rotating Asteroids, Nicholas Peter Liapis

Dissertations and Theses

Asteroids have been mapped and observed since 1801 when an Italian astronomer Guiseppe Piazzi discovered Ceres (Serio, Manara, & Sicoli, 2002). Since then, asteroids have been growing in popularity throughout the scientific community because they are thought to hold the information we need to understand how the solar system developed and why life exists on earth, as well as potential precious resources. This research studies different types of orbits that have been performed to date around asteroids and how they can be reworked to require less control effort. Different types of missions that have been sent to asteroids are discussed, as ...


Nonlinear Estimation And Control Methods For Mechanical And Aerospace Systems Under Actuator Uncertainty, Krishna Bhavithavya Kidambi 2019 Embry-Riddle Aeronautical University

Nonlinear Estimation And Control Methods For Mechanical And Aerospace Systems Under Actuator Uncertainty, Krishna Bhavithavya Kidambi

Dissertations and Theses

Air flow velocity field control is of crucial importance in aerospace applications to prevent the potentially destabilizing effects of phenomena such as cavity ow oscillations, flow separation, flow-induced limit cycle oscillations (LCO) (flutter), vorticity, and acoustic instabilities. Flow control is also important in aircraft applications to reduce drag in aircraft wings for improved flight performance. Although passive flow control approaches are often utilized due to their simplicity, active flow control (AFC) methods can achieve improved flight performance over a wider range of time-varying operating conditions by automatically adjusting their level of control actuation in response to real-time sensor measurements. Although ...


Bioengineering Extracellular Matrix Scaffolds For Volumetric Muscle Loss, Kevin Roberts 2019 University of Arkansas, Fayetteville

Bioengineering Extracellular Matrix Scaffolds For Volumetric Muscle Loss, Kevin Roberts

Theses and Dissertations

Volumetric muscle loss overwhelms skeletal muscle’s ordinarily capable regenerative machinery, resulting in fibrosis and severe functional deficits which have defied clinical repair strategies. My work spans the design and preclinical evaluation of implants intended to drive the cell community of injured muscle toward a regenerative state, as well as the development of an understanding of the molecular responses of this cell community to biomaterial interventions. I demonstrate a new class of biomaterial by leveraging the productive capacity of sacrificial hollow fiber membrane cell culture; I show specifically that unique threads of whole extracellular matrix can be isolated by solvent ...


Five-Level Flying Capacitor Converter Used As A Static Compensator For Current Unbalances In Three-Phase Distribution Systems, Rafael Franceschi 2019 University of Arkansas, Fayetteville

Five-Level Flying Capacitor Converter Used As A Static Compensator For Current Unbalances In Three-Phase Distribution Systems, Rafael Franceschi

Theses and Dissertations

This thesis presents and evaluates a solution for unbalanced current loading in three-phase distribution systems. The proposed solution uses the flying capacitor multilevel converter as its main topology for an application known as Unbalanced Current Static Compensator. The fundamental theory, controller design and prototype construction will be presented along with the experimental results. The Unbalanced Current Static Compensator main objective is the balancing of the up-stream currents from the installation point to eliminate the negative- and zero-sequence currents originated by unbalanced single-phase loads.

Three separate single-phase flying capacitor converters are controlled independently using a d-q rotating reference frame algorithm to ...


Investigation Of The Effect Of Age On Regenerative Outcomes Following Treatment Of Volumetric Muscle Loss Injuries, John Taehwan Kim 2019 University of Arkansas, Fayetteville

Investigation Of The Effect Of Age On Regenerative Outcomes Following Treatment Of Volumetric Muscle Loss Injuries, John Taehwan Kim

Theses and Dissertations

Volumetric muscle loss (VML) is a traumatic injury in skeletal muscle resulting in the bulk loss of more than 20% of the muscle’s volume. Included in the bulk loss of muscle is the skeletal muscle niche comprised of nerve bundles, vasculature, local progenitor cells, basal lamina, and muscle fibers, overwhelming innate repair mechanisms. The hallmark of VML injury is the excessive accumulation of non-contractile, fibrotic tissue and permanent functional deficits. Though predominant in the younger demographic, the elderly population is also captured within VML injuries. There are many factors that change with aging in skeletal muscle that may further ...


Numerical Simulation Of Diffuse Ultrasonic Waves In Concrete, Hossein Ariannejad 2019 University of Nebraska - Lincoln

Numerical Simulation Of Diffuse Ultrasonic Waves In Concrete, Hossein Ariannejad

Civil Engineering Theses, Dissertations, and Student Research

Concrete can be subject to various type of damages. Some damages such as Alkali Silica Reaction (ASR) tend to start from the inside, where there is no easy way to identify or evaluate them in the early stage. The study of ultrasonic waves scatterings in non destructive testing (NDT) methods play a major role in identifying such damages. In an ultrasonic test, high frequency ultrasonic waves are used to interrogate the internal structure of concrete material, where the coarse aggregates and microcracks cause multiple scattering of ultrasonic waves. Experimental studies have demonstrated that diffuse ultrasonic waves scattered by boundaries, coarse ...


Towards A Theoretical Explanation Of How Pavement Condition Index Deteriorates Over Time, Edgar Daniel Rodriguez Velasquez, Carlos M. Chang Albitres, Vladik Kreinovich 2019 University of Texas at El Paso

Towards A Theoretical Explanation Of How Pavement Condition Index Deteriorates Over Time, Edgar Daniel Rodriguez Velasquez, Carlos M. Chang Albitres, Vladik Kreinovich

Departmental Technical Reports (CS)

To predict how the Pavement Condition Index will change over time, practitioners use a complex empirical formula derived in the 1980s. In this paper, we provide a possible theoretical explanation for this formula, an explanation based on general ideas of invariance. In general, the existence of a theoretical explanation makes a formula more reliable; thus, we hope that our explanation will make predictions of road quality more reliable.


Stamped Multilayer Graphene Laminates For Disposable In-Field Electrodes: Application To Electrochemical Sensing Of Hydrogen Peroxide And Glucose, Loreen R. Stromberg, John A. Hondred, Delaney Sanborn, Deyny Mendivelso-Perez, Srikanthan Ramesh, Iris V. Rivero, Josh Kogot, Emily Smith, Carmen Gomes, Jonathan C. Claussen 2019 Iowa State University

Stamped Multilayer Graphene Laminates For Disposable In-Field Electrodes: Application To Electrochemical Sensing Of Hydrogen Peroxide And Glucose, Loreen R. Stromberg, John A. Hondred, Delaney Sanborn, Deyny Mendivelso-Perez, Srikanthan Ramesh, Iris V. Rivero, Josh Kogot, Emily Smith, Carmen Gomes, Jonathan C. Claussen

Mechanical Engineering Publications

A multi-step approach is described for the fabrication of multi-layer graphene-based electrodes without the need for ink binders or post-print annealing. Graphite and nanoplatelet graphene were chemically exfoliated using a modified Hummers’ method and the dried material was thermally expanded. Expanded materials were used in a 3D printed mold and stamp to create laminate electrodes on various substrates. The laminates were examined for potential sensing applications using model systems of peroxide (H2O2) and enzymatic glucose detection. Within the context of these two assay systems, platinum nanoparticle electrodeposition and oxygen plasma treatment were examined as methods for improving sensitivity. Electrodes made ...


Design Of Capacitive Wireless Power Transfer Systems With Enhanced Power Density And Stray Field Shielding, Ujjwal Pratik 2019 Utah State University

Design Of Capacitive Wireless Power Transfer Systems With Enhanced Power Density And Stray Field Shielding, Ujjwal Pratik

All Graduate Theses and Dissertations

Wireless power transfer is becoming relevant today because of its effectiveness and convenience. It has been employed into consumer electronics such as cellular charging and electric vehicle charging. In general, inductive wireless power transfer (IPT) is mostly used for WPT. IPT requires coils and power transfer enhancing material such as ferrite to transfer power. However, Capacitive wireless Power Transfer (CPT) appears as an alternative because it requires cost effective and light metal plate couplers. Among CPT couplers, Vertical (stacked) Four-Plate Coupler (V4PC) structure offers the advantage of higher input and output self-capacitances, rotational misalignment.

Safety is one of the most ...


Parametric Study Of Mixture Component Contributions To Compressive Strength And Impact Energy Absorption Capacity Of A High Strength Cementitious Mix With No Coarse Aggregate, Md. Abdullah Al Sarfin 2019 Utah State University

Parametric Study Of Mixture Component Contributions To Compressive Strength And Impact Energy Absorption Capacity Of A High Strength Cementitious Mix With No Coarse Aggregate, Md. Abdullah Al Sarfin

All Graduate Theses and Dissertations

This research project has been undertaken to produce and characterize the behavior of High Strength Cementitious Mix (HSCM), which has considerably higher compressive strength compared to conventional concrete. Components of HSCM are cement, silica fume, sand, water, and high range water reducer. The material is tested for compressive strength and impact energy absorption capacity while the amount of above mentioned components are varied parametrically. The effect of these parameters are extensively studied and trends are reported. Finally, this research projects attempts to find correlations among compressive strength, compressive toughness, and impact toughness. Limitations of the experimental program are discussed and ...


Understanding Self-Assembly And Charge Transport In Organic Solar Cells Through Efficient Computation, Evan Miller 2019 Boise State University

Understanding Self-Assembly And Charge Transport In Organic Solar Cells Through Efficient Computation, Evan Miller

Boise State University Theses and Dissertations

Organic solar cells capable of sustainably generating electricity are possible if: (1) The structures assembled by photoactive molecules can be controlled, and (2) The structures favorable for charge transport can be determined. In this dissertation we conduct computational studies to understand relationships between organic solar cell compounds, processing, structure and charge transport. We advance tools for encapsulating computational workflows so that simulations are more reproducible and transferable. We find that molecular dynamic simulations using simplified models efficiently predict experimental structures. We find that the mobilities of charges through these structures—as determined by kinetic Monte Carlo simulations—match qualitative trends ...


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