Engineering Commons^™

Behavior Of Concrete Beams With Corroded Reinforcement Retrofitted With Carbon Fiber Reinforced Polymer, Needa Marwan Lingga

Civil and Environmental Engineering Master's Project Reports

Severe premature deterioration has been reported in a large number of reinforced concrete (RC) structures in corrosive environments. This research project focused on the behavior of beams that contained corroded steel and were retrofitted with CFRP. The steel in RC beams were assumed to be fully corroded, representing the most severe loss in steel cross-section. Unidirectional CFRP sheets were used to strengthen the deteriorated beams. The experimental program included testing five simply supported rectangular cross section concrete beams. All beams were approximately 1/3^rd scale models, 4in. x 6in. cross sections, and 6ft. long. In three beams, the oiled steel …

A Study On The Current State Of Contaminants Of Concern Research, With A Focus On Biosolids And Regulations, Maren Mariah Fulton

Civil and Environmental Engineering Master's Project Reports

Wastewater treatment plants are a major source of contaminants of emerging concern, as these facilities are the main receptors of these products via household, commercial, and industrial drains, and transport via stormwater runoff. Biosolids are composed of numerous constituents, with a number of environmentally persistent and potentially toxic contaminants of emerging concern identified as present in large concentrations. Research is needed to understand the transport and fate mechanisms of these compounds in biosolids. Additionally, this research is needed to determine a new priority framework to regulate CECs, both on the national level and regional levels. Wastewater treatment plant influent and …

Identification And Reduction Of Retracker-Related Noise In Altimeter-Derived Sea Surface Height Measurements, Edward D. Zaron, Robert Decarvalho

Civil and Environmental Engineering Faculty Publications and Presentations

Data from the Jason-2 calibration/validation mission phase have been analyzed to identify the correlation between sea surface height (SSH) and significant wave height (SWH) errors.A cross-spectral analysis indicates that the SSH and SWH errors are nearly white and significantly correlated at scales from 12 to 100 km, consistent with the hypothesized error source, the waveform retracker. Because of the scale separation between the SWH signal and noise, it is possible to correct the SSH data by removing the SSH noise correlated with the SWH noise. Such a correction has been implemented using the empirical correlation found during the Jason-2 calibration …

The Effect Of Channel Deepening On Tides And Storm Surge: A Case Study Of Wilmington, Nc, R. Familkhalili, Stefan A. Talke

Civil and Environmental Engineering Faculty Publications and Presentations

In this study we investigate the hypothesis that increasing channel depth in estuaries can amplify both tides and storm surge by developing an idealized numerical model representing the 1888, 1975, and 2015 bathymetric conditions of the Cape Fear River Estuary, NC. Archival tide gauge data recovered from the U.S. National Archives indicates that mean tidal range in Wilmington has doubled to 1.55m since the 1880s, with a much smaller increase of 0.07mobserved near the ocean boundary. These tidal changes are reproduced by simulating channel depths of 7m (1888 condition) and 15.5m (modern condition). Similarly, model sensitivity studies using idealized, parametric …

Utilizing High Resolution Bus Gps Data To Visualize And Identify Congestion Hot-Spots In Urban, Nicholas B. Stoll, Travis B. Glick, Miguel Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Congestion and travel delay on urban roadways can influence the roadways’ operating costs and service attractiveness. This research used high-resolution bus data to examine sources of delay on urban arterials. A set of tools was created to help visualize trends in bus behavior and movement; these tools allowed larger traffic trends to be visualized along urban corridors and streets. With buses as probes and examining aggregated bus behavior, contoured speed plots were used to understand the behavior of roadways outside the zone of influence of bus stops. Speed plots were used to discover trends and travel patterns with only a …

M2 Internal Tides And Their Observed Wavenumber Spectra From Satellite Altimetry, Richard D. Ray, Edward D. Zaron

Civil and Environmental Engineering Faculty Publications and Presentations

A near-global chart of surface elevations associated with the stationary M₂ internal tide is empirically constructed from multimission satellite altimeter data. An advantage of a strictly empirical mapping approach is that results are independent of assumptions about ocean wave dynamics and, in fact, can be used to test such assumptions. A disadvantage is that present-day altimeter coverage is only marginally adequate to support mapping such short-wavelength features. Moreover, predominantly north–south ground-track orientations and contamination from nontidal oceanographic variability can lead to deficiencies in mapped tides. Independent data from Cryosphere Satellite-2 (CryoSat-2) and other altimeters are used to …

Real-Time Monitoring Of Personal Exposures To Carbon Dioxide, Elliott T. Gall, Toby Cheung, Irvan Luhung, Stefano Schiavon, William W. Nazaroff

Mechanical and Materials Engineering Faculty Publications and Presentations

Elevated indoor CO₂ levels are indicative of insufficient ventilation in occupied spaces and correlate with elevated concentrations of pollutants of indoor origin. Adverse health and well-being outcomes associated with elevated indoor CO₂ levels are based on CO₂ as a proxy, although some emerging evidence suggests CO₂ itself may impact human cognition. Using portable monitors, we conducted an exposure study with 16 subjects in Singapore to understand the levels, dynamics and influencing factors of personal exposure to CO₂. Participants carried a CO₂ monitor continuously for 7-day periods recording their exposure levels at 1-min intervals. …

Sparse Adaptive Local Machine Learning Algorithms For Sensing And Analytics, Jack Cannon

Maseeh Summer Undergraduate Research Experience

The goal of digital image processing is to capture, transmit, and display images as efficiently as possible. Such tasks are computationally intensive because an image is digitally represented by large amounts of data. It is possible to render an image by reconstructing it with a subset of the most relevant data. One such procedure used to accomplish this task is commonly referred to as sparse coding. For our purpose, we use images of handwritten digits that are presented to an artificial neural network. The network implements Rozell's locally competitive algorithm (LCA) to generate a sparse code. This sparse code is …

3d Fpga Cell Matrix By Self-Assembly, Jeffrey Udall

Maseeh Summer Undergraduate Research Experience

Physical size limitations in miniaturizing two-dimensional (2D) transistors are becoming more difficult to overcome. In order to continue increasing the processing power of electronic circuits, new design paradigms are needed. Three-dimensional (3D) architectures provide a solution to this issue and are currently being implemented via wafer stacking. However, more significant gains in terms of packing and speed can be achieved by CMOS components with truly integrated 3D cellular architectures. One of these is the Cell Matrix, a self-configurable defect- and fault-tolerant architecture, which is ideally suited for ultra large-scale integration. For this project, we worked to expand the Cell Matrix …

Quantitative Comparison Of A Nanoengineered Alumina Coated Cnt Arrays To Sio2 Coated Cnts And Solution Based Delivery System, Shree Aier

Maseeh Summer Undergraduate Research Experience

To meet the growing need for nanoengineered biocompatible materials to serve as drug delivery platforms, in this research, carbon nanotube arrays were fabricated by chemical vapor deposition, followed by an alumina coating by the high yielding, tightly controlled atomic layer deposition. This nanoengineered vertically aligned alumina nanowire array serves as a platform for delivering antigens, which act as cancer adjuvants. The physicochemical characteristics of the nanowires (NWs) can significantly influence the delivery of a biomolecule to immune cells. To investigate the material characteristics, the delivery efficiency of the antigen using NWs was quantitatively assessed by flow cytometry. Further, the mechanism …

Design For Fractal Grid Generated Turbulence, Moira Gion

Maseeh Summer Undergraduate Research Experience

Fractal geometry can be used to find organization or order in something that appears to be in disorder, or chaos. Turbulence is viewed as one place where fractal geometry can be found in nature. The irregularity in fluid flow is dependent on the initial conditions. In the past, the idea of self-similarity has been used to develop statistical theories of energy cascade in a turbulent flow. Recent studies have done experiments on obstructing flows with fractal objects to observe intermittency, (or self-similarity) within a turbulent flow. Experiments on fractal grid generated turbulence has been performed by other research groups, so …

High-Performance Computing For Drought Prediction, Henry Cooney

Maseeh Summer Undergraduate Research Experience

In recent decades, there has been considerable interest in using satellite soil moisture data to examine the global water-energy cycle and manage water resources. Current satellites are limited in their sensing depth, and can only directly measure top soil layers. Using a particle filter, this data may be fused with the output of a hydrologic simulation to improve simulation results, and characterize a hydrologic system at the watershed level. However, this approach increases computational requirements dramatically, and requires rethinking to accommodate data scaling and achieve good performance.

We present a detailed performance study of several alternative implementations of the hybrid …

Quantum Yield Optimization For Semiconductor Photocatalysis Systems, Ryan Catabay

Maseeh Summer Undergraduate Research Experience

The utilization of photocatalysis has a well-known potential for mineralizing organic contaminants in water purification processes. A continuous flow photocatalytic reactor was developed in order to test the quantum yield of titanium dioxide, a semiconductor material well known for its photocatalytic properties. In order to build this reactor, multiple manufacturing methods were performed: manual and CNC machining, laser cutting, waterjet cutting, and chemical synthesis. A continuous flow reactor was particularly designed for a controlled, variable radiant flux of ultraviolet light. This continuous UV radiation excites the photocatalyst, generating electron hole pairs that form hydroxyl radicals, which in turn mineralize organic …

Complex Capillary Fluidic Phenomena For Passive Control Of Liquids In Low-Gravity Environments, Logan Torres

Maseeh Summer Undergraduate Research Experience

In an effort to further apply the recent results of puddle jumping research, we seek to expand the oblique droplet impact studies of others by exploiting large liquid droplets in the near weightless environment of a drop tower. By using the spontaneous puddle jump mechanism, droplets of volumes 1 mL ≤ V ≤ 3 mL with corresponding Weber numbers of We ≈ 1 are impinged on surfaces inclined in the range 40° ≤ α ≤ 80° (measured from the horizontal plane). Impact surface wetting characteristics exhibit static contact angles θstatic = 165 ± 5°. All impacts result in complete rebound. …

Emerging Adaptive Architectures For Biomolecular Computation, Matthew Fleetwood

Maseeh Summer Undergraduate Research Experience

The goal of this work is to explore applications of reservoir computing in biomolecular computation. Reservoir computing is a unique model for representing a mapping from one instance in time to a specific output. A neural network of randomly connected neurons is linked with a single output neuron or multiple output neurons. The output neurons are capable of mapping inputs to desired outputs using adaptable algorithms. This framework is investigated by using the Python programming language and object oriented design and programming. Neurons are created in programs by bundling information like input data and attributes of the network, which utilize …

Engineered Mushing Cooker, Aimee Ritter

Maseeh Summer Undergraduate Research Experience

This project revolves around building methanol cookers for dog mushers in the Iditarod and for the Denali Park Ranger Kennel in Denali National Park, Alaska. Traditional cookers are bulky, slow to burn, and use up a lot of fuel. Our goal has been to revolutionize the way mushing cookers look and perform. Our cookers are built to pack well in the sleds, heat up to 3 gallons of snowmelt, perform in arctic climates, use methanol (specifically HEET) for fuel, and be lightweight. A traditional cooker would use 3 to 4 bottles or more of HEET (36-48+oz.) and take at least …

Head Wave Correlations In Ambient Noise, John Thomas Gebbie, Martin Siderius

Electrical and Computer Engineering Faculty Publications and Presentations

Ambient ocean noise is processed with a vertical line array to reveal coherent time-separated arrivals suggesting the presence of head wave multipath propagation. Head waves, which are critically propagating water waves created by seabed waves traveling parallel to the water-sediment interface, can propagate faster than water-only waves. Such eigenrays are much weaker than water-only eigenrays, and are often completely overshadowed by them. Surface-generated noise is different whereby it amplifies the coherence between head waves and critically propagating water-only waves, which is measured by cross-correlating critically steered beams. This phenomenon is demonstrated both experimentally and with a full wave simulation.

A Brief Review Of Speaker Recognition Technology, Clark D. Shaver, John M. Acken

Electrical and Computer Engineering Faculty Publications and Presentations

This paper reviews the development of speaker recognition systems from pre-computing days to current trends. Advances in various sciences which have allowed autonomous speaker recognition systems to become a practical means of identity authentication are also reviewed.

Do Characteristics Of Walkable Environments Support Bicycling? Toward A Definition Of Bicycle-Supported Development, Christopher D. Muhs, Kelly Clifton

Civil and Environmental Engineering Faculty Publications and Presentations

Does walkability equate with bikeability? Through a comprehensive review of studies of the built environment and bicycling, including mode choice, route choice, safety, and urban design literature, this paper addresses this question. Previous work has raised the issue that the two modes are functionally different, despite them often being combined into a nonmotorized category, and has highlighted research challenges. Existing studies of bikeability have largely focused on infrastructure. This paper contributes to the literature on bicycling and the built environment by providing a thorough review of past research with a focus on the relationships between land use, urban form, and …

Modeling And Experimental Demonstration Of A Hopfield Network Analog-To-Digital Converter With Hybrid Cmos/Memristor Circuits, Xinjie Guo, Farnood Merrikh-Bayat, Ligang Gao, Brian D. Hoskins, Fabien Alibart, Bernabe Linares-Barranco, Luke Theogarajan, Christof Teuscher, Dmitri B. Strukov

Electrical and Computer Engineering Faculty Publications and Presentations

The purpose of this work was to demonstrate the feasibility of building recurrent artificial neural networks with hybrid complementary metal oxide semiconductor (CMOS)/memristor circuits. To do so, we modeled a Hopfield network implementing an analog-to-digital converter (ADC) with up to 8 bits of precision. Major shortcomings affecting the ADC's precision, such as the non-ideal behavior of CMOS circuitry and the specific limitations of memristors, were investigated and an effective solution was proposed, capitalizing on the in-field programmability of memristors. The theoretical work was validated experimentally by demonstrating the successful operation of a 4-bit ADC circuit implemented with discrete Pt/TiO_{2− …}

Formal Modeling And Verification Of Delay-Insensitive Circuits, Hoon Park

Dissertations and Theses

Einstein's relativity theory tells us that the notion of simultaneity can only be approximated for events distributed over space. As a result, the use of asynchronous techniques is unavoidable in systems larger than a certain physical size. Traditional design techniques that use global clocks face this barrier of scale already within the space of a modern microprocessor chip. The most common response by the chip industry for overcoming this barrier is to use Globally Asynchronous Locally Synchronous (GALS) design techniques. The circuits investigated in this thesis can be viewed as examples of GALS design. To make such designs trustworthy it …

Analysis Of Capillary Flow In Interior Corners : Perturbed Power Law Similarity Solutions, Joshua Thomas Mccraney

Dissertations and Theses

The design of fluid management systems requires accurate models for fluid transport. In the low gravity environment of space, gravity no longer dominates fluid displacement; instead capillary forces often govern flow. This thesis considers the redistribution of fluid along an interior corner. Following a rapid reduction of gravity, fluid advances along the corner measured by the column length z = L(t), which is governed by a nonlinear partial differential equation with dynamical boundary conditions. Three flow types are examined: capillary rise, spreading drop, and tapered corner. The spreading drop regime is shown to exhibit column length growth L ~ …

From Boolean Equalities To Constraints, Sergio Antoy, Michael Hanus

Computer Science Faculty Publications and Presentations

Although functional as well as logic languages use equality to discriminate between logically different cases, the operational meaning of equality is different in such languages. Functional languages reduce equational expressions to their Boolean values, True or False, logic languages use unification to check the validity only and fail otherwise. Consequently, the language Curry, which amalgamates functional and logic programming features, offers two kinds of equational expressions so that the programmer has to distinguish between these uses. We show that this distinction can be avoided by providing an analysis and transformation method that automatically selects the appropriate operation. Without this distinction …

Multi-Criteria Evaluation Of Cmip5 Gcms For Climate Change Impact Analysis, Ali Ahmadalipour, Arun Rana, Hamid Moradkhani, Ashish Sharma

Civil and Environmental Engineering Faculty Publications and Presentations

Climate change is expected to have severe impacts on global hydrological cycle along with food-water-energy nexus. Currently, there are many climate models used in predicting important climatic variables. Though there have been advances in the field, there are still many problems to be resolved related to reliability, uncertainty, and computing needs, among many others. In the present work, we have analyzed performance of 20 different global climate models (GCMs) from Climate Model Intercomparison Project Phase 5 (CMIP5) dataset over the Columbia River Basin (CRB) in the Pacific Northwest USA. We demonstrate a statistical multicriteria approach, using univariate and multivariate techniques, …

On Valuing Biopharmaceutical Product Pipelines: An Effectuation Model And Evidence, Mark J. Ahn, Anne S. York, Wei Wu, Yulianto Suharto, Tugrul Unsal Daim

Engineering and Technology Management Faculty Publications and Presentations

New creative approaches are needed to manage emerging biotechnology innovations, regulations, and payor environments to enhance product pipeline productivity, valuation, and risk management. Biopharmaceutical firms must make dynamic resource allocation decisions on their relative levels of internal R&D and external strategic alliances in furthering their pipelines. As the predominant method of using discounted cash flow (DCF) methodologies may lead to chronic underinvestment and performance, we evaluated the integration of traditional DCF with an effectuation model of analysis. Unlike traditional financial models that begin with the end goal of assumed known cash flows and recursively solve for portfolio optimization, the effectuation …

Advances In Autonomous-Underwater-Vehicle Based Passive Bottom-Loss Estimation By Processing Of Marine Ambient Noise, Lanfranco Muzi

Dissertations and Theses

Accurate modeling of acoustic propagation in the ocean waveguide is important to SONAR-performance prediction, and requires, particularly in shallow water environments, characterizing the bottom reflection loss with a precision that databank-based modeling cannot achieve. Recent advances in the technology of autonomous underwater vehicles (AUV) make it possible to envision a survey system for seabed characterization composed of a short array mounted on a small AUV. The bottom power reflection coefficient (and the related reflection loss) can be estimated passively by beamforming the naturally occurring marine ambient-noise acoustic field recorded by a vertical line array of hydrophones. However, the reduced array …

The Prediction Predicament, William "Ike" Eisenhauer

Engineering and Technology Management Faculty Publications and Presentations

The article focuses on the prediction of predicament in terms of forecasting at industrial engineering level. Topics discussed include business optimize resources via forecasting; audience who cannot comprehend the methodology used for forecasting in healthcare operations; and use of forecasting for performance measurement.

Predicted Stresses In A Ball-Grid-Array (Bga)/Column-Grid-Array (Cga) Assembly With A Low Modulus Solder At Its Ends, Ephraim Suhir, Reza Ghaffarian

Mechanical and Materials Engineering Faculty Publications and Presentations

A simple, easy-to-use and physically meaningful predictive model is suggested for the assessment of thermal stresses in a ball-grid-array or a column-grid-array with a low modulus solder material at the peripheral portions of the assembly. It is shown that the application of such a design can lead to a considerable relief in the interfacial stresses, even to an extent that inelastic strains in the solder joints could be avoided. If this happens, the fatigue strength of the bond and of the assembly as a whole will be improved dramatically: low-cycle fatigue conditions will be replaced by the elastic fatigue condition, …

Could Application Of Column-Grid-Array (Cga) Technology Result In Inelastic-Strain-Free State-Of-Stress In Solder Material?, Ephraim Suhir, Reza Ghaffarian, Johann Nicolics

Mechanical and Materials Engineering Faculty Publications and Presentations

Physically meaningful and easy-to-use analytical stress model is developed for a short cylinder (beam) clamped at the ends and subjected to bending caused by the ends offset. The offset is due, in its turn, to an external lateral force that has to be determined from the known offset. It is envisioned that such a beam can adequately represent the state of stress in a column-grid-array (CGA) solder joint interconnection experiencing thermal loading due to the thermal expansion/contraction mismatch of the IC package and the printed circuit board (PCB). The CGA designs are characterized by considerably higher stand-off heights than ball-grid-array …

A Proposed Integrated Data Collection, Analysis And Sharing Platform For Impact Evaluation, Andreas Kipt, Waylon Brunette, Jordon Kellerstrass, Matthew Podolsky, Javier Rosa, Mitchell Sundt, Daniel Wilson, Gaetano Borriello, Eric Brewer, Evan A. Thomas

Mechanical and Materials Engineering Faculty Publications and Presentations

Global poverty reduction efforts value monitoring and evaluation, but often struggle to translate lessons learned from one intervention into practical application in another intervention. Commonly, data is not easily or often shared between interventions and summary data collected as part of an impact evaluation is often not available until after the intervention is complete. Equally limiting, the workflows that lead to research results are rarely published in a reproducible, reusable, and easy-to-understand fashion for others. Information and communication technologies widely used in commercial and government pro- grams are growing in relevance for international global development professionals and offer a potential …