Engineering Commons^™

New Era In Designing And Governing Cooling Intensity Of Liquid Quenchants To Decrease Distortion During Hardening Of Steel Parts, Nikolai I. Kobasko, Anatolii A. Moskalenko, P. N. Logvynenko, George E. Totten, Volodymyr V. Dobryvechir

Mechanical and Materials Engineering Faculty Publications and Presentations

It was proved in last decade that very intensive and uniform cooling eliminates quench crack formation and significantly decreases distortion of quenched steel parts as compared with their slow cooling in mineral oils. That opened a new era in design ing and governing cooling intensity of liquid quenchants for strengthening steel parts and decrease their distortion after quenching. The new approaches were developed by authors to provide accelerated and uniform cooling steel parts during quenching by creation on their surface thin insulating layers. For this purpose low concentration of water polymer solutions of inverse solubility are used as a quenchant. …

Experimental And Numerical Investigation On The Bond Strength Of Self-Sensing Composite Joints, Shafique Ahmed, Thomas Schumacher, Jennifer Mcconnell, Erik T. Thostenson

Civil and Environmental Engineering Faculty Publications and Presentations

Laboratory experiments demonstrate that a novel carbon nanotube (CNT)-based sensing layer embedded in the bondline of an adhesively bonded structural joint can detect and monitor deformation and damage progression of the adhesive layer. In this study, experimental and numerical investigations were performed to identify any effect of an embedded CNT-based sensing layer on the bond strength of that joint. To evaluate the mechanical behavior of such a bondline configuration, two sets of single-lap specimens, with and without sensing layer, were prepared and tested to determine the bond strengths of the respective types. Two-dimensional digital image correlation (2D DIC) was utilized …

Power System Spoof Detection With A Hybrid Hardware/Software Benchmarking Framework, Keaton Dieter, Ben Mccamish, Eduardo Cotilla-Sanchez, Robert B. Bass, Scott Wallace, Xinghui Zhao

Electrical and Computer Engineering Faculty Publications and Presentations

The integration of monitoring and control networks at different voltage levels and across utility boundaries has made it harder to maintain and assess the resilience of power systems due to increasing cyber attacks. On the software side, a variety of research efforts pursue cyber protection algorithms, such as spoof detection techniques. On the hardware and firmware side, research has demonstrated the feasibility of adversarial attacks by providing an entry point at the device level. This work proposes and evaluates two detection performance metrics for a variety of cyber spoofing attacks introduced in a realistic Phasor Measurement Unit (PMU) network for …

Event Detection Using Correlation Within Arrays Of Streaming Pmu Data, Rich Meier, Ben Mccamish, Eduardo Cotilla-Sanchez, Jordan Landford, Robert B. Bass, David Chiu

Electrical and Computer Engineering Faculty Publications and Presentations

Phasor measurement units provide real-time power system monitoring. We present a data analysis method that leverages statistical correlation and analysis methods to identify power system events. This research uses archived phasor measurement unit data to show that the method is useful for detecting power system events. Results from a lighting strike case study are presented. A monitoring stratagem based on PMU clustering is discussed, and the viability of monitoring pertinent statistical parameters over various clustering schemes is demonstrated.

Human-Centered Design Of An Air Quality Feedback System To Promote Healthy Cooking, Chantal Iribagiza

Dissertations and Theses

Household air pollution (HAP) is responsible for almost 4 million premature deaths every year, a burden that is primarily carried by women and children in developing countries. The mortality and morbidity impact of HAP can be significantly alleviated through clean cookstove interventions. However, for these interventions to be effective, the new intervention stove must be a substantially cleaner technology and adoption should be high and sustained over time.

Woody biomass is the fuel of choice in many developing communities, and contributes substantially to HAP. Several organizations have launched clean cooking interventions to address this issue. However, the majority of those …

Reliability Of Solder Joints In Embedded Packages Using Finite Element Methods, Valeri Aisha Yunusa

Dissertations and Theses

Solder joints serve as both mechanical and electrical connections between elements in a package. They are subjected to shear strains generated as a result of the different behaviors of the elements in the package (tension and compression) due to the differences in coefficients of thermal expansion during service conditions.

Some of the causes of solder joint failures are due to the following:

Vibration: small rapid displacements of parts of the assembly. This is not necessarily an issue with electronic components but larger parts like automobiles.

Humidity: the package being exposed to water or ionic species can undergo corrosion if an …

Cyclists' Queue Discharge Characteristics At Signalized Intersections, Kirk Thomas Paulsen

Dissertations and Theses

Wider bike facilities intuitively accommodate a greater number of cyclists in the same amount of time, but specific queue discharge characteristics associated with varying widths and/or types of bike facilities have not been thoroughly documented.

The focus of this research analyzed queues of cyclists at four signalized intersections in Portland, OR with varying widths on the approach and downstream intersection legs. A total of 2,820 cyclists within 630 groups of queued cyclists were observed at five different intersection layouts in Portland, Oregon. The layouts consisted of: a standard bike lane six feet wide connecting bicyclists to a standard bike lane …

Assessment Of Seismic Retrofit Prioritization Methodology For Oregon's Highway Bridges Based On The Vulnerability Of Highway Segments, Selamawit Tesfayesus Mehary

Dissertations and Theses

Geologists have indicated that the question is not if a catastrophic earthquake will occur in Oregon but when one will occur. Scientists estimate that there is close to 40 percent conditional probability that a Cascadia subduction zone earthquake of magnitude 8.0 or above will strike Oregon in the next 50 years. In addition, the majority of Oregon's bridge inventory was built prior to the current understanding of bridge response and prior to current understanding of the expected earthquake demands. In order to minimize potential bridge damage in the case of an earthquake, one approach is to retrofit seismically deficient bridges. …

Adoption Of An Internet Of Things Framework For Distributed Energy Resource Coordination And Control, Tylor Slay

Dissertations and Theses

Increasing penetration of non-dispatchable renewable energy resources and greater peak power demand present growing challenges to Bulk Power System (BPS) reliability and resilience. This research investigates the use of an Internet of Things (IoT) framework for large scale Distributed Energy Resource (DER) aggregation and control to reduce energy imbalance caused by stochastic renewable generation. The aggregator developed for this research is Distributed Energy Resource Aggregation System (DERAS). DERAS comprises two AllJoyn applications written in C++. The first application is the Energy Management System (EMS), which aggregates, emulates, and controls connected DERs. The second application is the Distributed Management System (DMS), …

Investigation Of The Acoustic Response Of A Confined Mesoscopic Water Film Utilizing A Combined Atomic Force Microscope And Shear Force Microscope Technique, Monte Allen Kozell

Dissertations and Theses

An atomic force microscopy beam-like cantilever is combined with an electrical tuning fork to form a shear force probe that is capable of generating an acoustic response from the mesoscopic water layer under ambient conditions while simultaneously monitoring force applied in the normal direction and the electrical response of the tuning fork shear force probe. Two shear force probes were designed and fabricated. A gallium ion beam was used to deposit carbon as a probe material. The carbon probe material was characterized using energy dispersive x-ray spectroscopy and scanning transmission electron microscopy. The probes were experimentally validated by demonstrating the …

Emulating Balance Control Observed In Human Test Subjects With A Neural Network, Wade William Hilts

Dissertations and Theses

Human balance control is a complex feedback system that must be adaptable and robust in an infinitely varying external environment. It is probable that there are many concurrent control loops occurring in the central nervous system that achieve stability for a variety of postural perturbations. Though many engineering models of human balance control have been tested, no models of how these controllers might operate within the nervous system have yet been developed. We have focused on building a model of a proprioceptive feedback loop with simulated neurons. The proprioceptive referenced portion of human balance control has been successfully modeled by …

Short-Term Tracking Of Orientation With Inertial Sensors, Golriz Sedaghat

Dissertations and Theses

In the past several years, IMU's have been widely used to measure the orientation of a moving body over a continuous period of time. Although, inertial navigation is a common approach for estimating the orientation, it greatly suffers from the accumulation of error in the orientation estimation. Most of the current common practices apply zero velocity update as a calibration method to address this problem and improve the estimation accuracy. However, this approach requires the sensors to be stationary frequently.

This thesis introduces a novel method of calibration for estimating the elevation and bank angles of the orientation over a …

Electro-Drop Bouncing In Low-Gravity, Erin Stivers Schmidt

Dissertations and Theses

We investigate the dynamics of spontaneous jumps of water drops from electrically charged superhydrophobic dielectric substrates during a sudden step reduction in gravity level. In the brief free-fall environment of a drop tower, with a non-homogeneous external electric field arising due to dielectric surface charges (with surface potentials 0.4-1.8 kV), body forces acting on the jumped drops are primarily supplied by polarization stress and Coulombic attraction instead of gravity. This electric body force leads to a drop bouncing behavior similar to well-known phenomena in 1-g₀, though occurring for much larger drops (~0.5 mL). We show a simple …

Lateral Deformation Behavior Of Mass Timber Beam To Column Gravity Connection, Tyler James Williams

Civil and Environmental Engineering Master's Project Reports

A beam-to-column connection consisting of glulam beam and column and cross laminated timber floor slab was developed and experimentally evaluated for use in buildings that are expected to undergo earthquake-­­induced lateral drift. The connection utilized a passive gap closure mechanism designed to allow beam rotations during lateral drift while minimizing residual separation between the beam and the column following an earthquake. Full scale cyclic experiments were used to validate the connection’s minimal rotational stiffness and demonstrate low damage performance for lateral drifts exceeding 4.5% drift. The connection exhibited no degradation in gravity load capacity throughout the imposed lateral deformations. An …

Exploring The Relationship Of Bikeshare And Transit In The United States Of America, David Rafael Soto Padín

Civil and Environmental Engineering Master's Project Reports

Bicycling and bike-share have been growing in US cities as transportation alternatives. Despite impressions that bikeshare systems exist solely for tourism, recreation or privileged users, research has shown that bike-share is becoming a transportation mode used by a diverse set of users for various transportation needs. Additionally, a positive relationship has been established between bike-share and transit although most studies on this matter have focused on systems outside the United States. Bike share and transit benefit each other by: (1) contributing to sustainable transportation goals by improving mobility and greenhouse gas reductions, (2) solving the "last mile" problem, (3) reduce …

A 3d Model For Earthquake-Induced Liquefaction Triggering And Post-Liquefaction Response, Arash Khosravifar, Ahmed Elgamal, Jinchi Lu, John Li

Civil and Environmental Engineering Faculty Publications and Presentations

A constitutive soil model that was originally developed to model liquefaction and cyclic mobility has been updated to comply with the established guidelines on the dependence of liquefaction triggering to the number of loading cycles, effective overburden stress (Kσ), and static shear stress (Kα). The model has been improved with new flow rules to better capture contraction and dilation in sands and has been implemented as PDMY03 in different computational platforms such as OpenSees finite-element, and FLAC and FLAC3D finite-difference frameworks. This paper presents the new modified framework of analysis and describes a guideline to calibrate the input parameters of …

Non-Linear Deformation Analysis Of An Embankment Dam, Silas T. Sanderson

Civil and Environmental Engineering Master's Project Reports

Non-linear deformation analysis (NDA) of embankment dams is becoming more common as geotechnical engineers seek to better understand how critical infrastructure will perform under high seismic loading. In order to perform this type of analysis, site specific ground motions and engineering properties of the embankment dam are required. The NDA modeling effort consists of a static and seepage analysis to establish an initial stress state followed by a dynamic analysis to simulate the embankment response to ground motions. Using this approach, a two dimensional NDA was performed on an embankment dam using the NDA program FLAC. This report discusses the …

Methods For Estimating Vehicle Fuel Consumption In Urban Road Networks Using Geographical Attributes, Ryan G. Conrad

Civil and Environmental Engineering Master's Project Reports

This paper presents statistical techniques for estimating vehicle fuel consumption in urban road networks based on vehicle and geographical factors. A routing algorithm utilizing mapping data from OpenStreetMap and elevation data from the Shuttle Radar Topography Mission is presented and used to generate paths that minimize vehicle fuel consumption. The concept of a fuel consumption estimating function is proposed as an extension of the well-known distance-estimating functions that are widely used in logistics planning and research.

Statistical models are developed that estimate fuel consumption in three tested urban areas with vehicle weight, elevation and regional travel speed characteristics being the …

Flip-Chip (Fc) And Fine-Pitch-Ball-Grid-Array (Fpbga) Underfills For Application In Aerospace Electronics—Brief Review, Ephraim Suhir, Reza Ghaffarian

Mechanical and Materials Engineering Faculty Publications and Presentations

In this review, some major aspects of the current underfill technologies for flip-chip (FC) and fine-pitch-ball-grid-array (FPBGA), including chip-size packaging (CSP), are addressed, with an emphasis on applications, such as aerospace electronics, for which high reliability level is imperative. The following aspects of the FC and FPGGA technologies are considered: attributes of the FC and FPBGA structures and technologies; underfill-induced stresses; the roles of the glass transition temperature (T_g) of the underfill materials; some major attributes of the lead-free solder systems with underfill; reliability-related issues; thermal fatigue of the underfilled solder joints; warpage-related issues; attributes of accelerated life …

Boro-Austempering Treatment Of Ductile Cast Irons, Fábio Edson Mariani, Carolina Soares, Amadeu Lombardi Neto, George Totten, Luiz Carlos Casteletti

Mechanical and Materials Engineering Faculty Publications and Presentations

Samples of ductile cast irons alloyed with Cu, Cu-Ni and Cu-Ni-Mo were austempered, borided and boro-austempered and characterized for hardness and micro-adhesive wear behavior. The kinetics of layer formation was also studied. The boriding method used was molten borax bath, in periods of 2 and 4 hours at temperatures of 850, 900 and 950º C. The direct austempering treatment was performed immediately following the boriding treatment (from 850, 900 and 950º C) using molten salt baths at temperatures of 240, 300 and 360º C for 4 hours (boro-austempering treatment). For comparative purposes, the conventional austempering treatment was also conducted. Optical …

Reconsidering The Foundations Of Thermodynamics From An Engineering Perspective, Terry Bristol

Mathematics and Statistics Faculty Publications and Presentations

Currently, there are two approaches to the foundations of thermodynamics. One, associated with the mechanistical Clausius-Boltzmann tradition, is favored by the physics community. The other, associated with the post-mechanical Carnot tradition, is favored by the engineering community. The bold hypothesis is that the conceptual foundation of engineering thermodynamics is the more comprehensive. Therefore, contrary to the dominant consensus, engineering thermodynamics (ET) represents the true foundation of thermodynamics. The foundational issue is crucial to a number of unresolved current and historical issues in thermodynamic theory and practice. ET formally explains the limited successes of the ‘rational mechanical’ approaches as idealizing special …

Precipitation Impacts On Groundwater Levels In The Ephemeral Holgate Lake: A Modflow Inquiry, Amory Cervarich

Civil and Environmental Engineering Undergraduate Honors Theses

Holgate Lake, an ephemeral lake located in southeast Portland, has a history of flooding and inundating residential areas. The appearance of the lake is hypothesized to be a function of precipitation-driven changes in groundwater levels. A model was developed using MODFLOW-NWT, a U.S. Geological Survey (USGS) modular hydrologic program, to analyze parameters contributing to the appearance of the lake. The model was most sensitive to changes in aquifer properties including hydraulic conductivity and storativity. The model displayed low sensitivity to changes in precipitation, evapotranspiration, and conductance of surface waters. Results from the analysis contribute to a better understanding of the …

Biomimetic Design And Construction Of A Bipedal Walking Robot, Alexander Gabriel Steele

Dissertations and Theses

Human balance and locomotion control is highly complex and not well understood. To understand how the nervous system controls balance and locomotion works, we test how the body responds to controlled perturbations, the results are analyzed, and control models are developed. However, to recreate this system of control there is a need for a robot with human-like kinematics. Unfortunately, such a robotic testbed does not exist despite the numerous applications such a design would have in mobile robotics, healthcare, and prosthetics.

This thesis presents a robotic testbed model of human lower legs. By using MRI and CT scans, I designed …

Electric Water Heater Modeling For Distributed Energy Resource Aggregation And Control, Anne E. Clarke

Dissertations and Theses

Today's utilities face new challenges due to the continually increasing penetration of residential solar and other distributed, stochastic generation sources. In order to maintain balance and stability in the grid without building costly, large-scale generation plants, utilities are turning to distributed energy resources for use in demand response programs. Demand response is a cost-efficient way to balance grid load/generation without the need for increased capital investment in traditional generation resources. Demand response programs are excellent exploiters of end-user devices that otherwise further accentuate the daily load curve and thus, add to the difficulties created by daily load peaks.

Electric water …

Dark Current Rts-Noise In Silicon Image Sensors, Benjamin William Hendrickson

Dissertations and Theses

Random Telegraph Signal (RTS) noise is a random noise source defined by discrete and metastable changes in the magnitude of a signal. Though observed in a variety of physical processes, RTS is of particular interest to image sensor fabrication where progress in the suppression of other noise sources has elevated its noise contribution to the point of approaching the limiting noise source in scientific applications.

There have been two basic physical sources of RTS noise reported in image sensors. The first involves a charge trap in the oxide layer of the source follower in a CMOS image sensor. The capture …

Webinar: Firsthand Data Collection: Students Get Behind The Wheel Of Vehicle Dynamics, Roger Lindgren, Jordan Preston

TREC Webinar Series

Vehicle operating dynamics data have a fundamental impact on the design of roadways, but collecting this type of data is not part of your typical college curriculum. Instead, engineering students are handed a textbook, leaving them without a firsthand experience of how accelerations and decelerations “feel” to the driver, the ultimate consumer of their designs. Seeking to change this norm, Roger Lindgren and C.J. Riley, civil engineering professors at the Oregon Institute of Technology, undertook a NITC education project to incorporate more real-world data collection and analysis into transportation courses. This webinar will offer a detailed look at the recently …

Minimum Required Length For Geotechnical Lateral Stability Of Rocksocketed Pile Shafts, Arash Khosravifar, Zia Zafir

Civil and Environmental Engineering Faculty Publications and Presentations

The original strong-rock (SR) p-y curves for rock-socketed shafts exhibit a brittle response where the post-peak resistance drops to approximately zero. This brittle response could result in a progressive failure of the rock p-y curves which, in turn, results in excessive pile lengths. This paper proposes a modification to the strong-rock (SR) p-y curves where the post-peak residual strength is equal to 20% of the ultimate resistance (0.2*pult). This residual resistance is proposed based on the assumption that the lateral resistance of cracked rock (after the peak point) should not be smaller than the lateral resistance of heavily weathered rock …

New Approaches For Memristive Logic Computations, Muayad Jaafar Aljafar

Dissertations and Theses

Over the past five decades, exponential advances in device integration in microelectronics for memory and computation applications have been observed. These advances are closely related to miniaturization in integrated circuit technologies. However, this miniaturization is reaching the physical limit (i.e., the end of Moore's Law). This miniaturization is also causing a dramatic problem of heat dissipation in integrated circuits. Additionally, approaching the physical limit of semiconductor devices in fabrication process increases the delay of moving data between computing and memory units hence decreasing the performance. The market requirements for faster computers with lower power consumption can be addressed by new …

Flexural Strength, Ductility, And Serviceability Of Beams That Contain High-Strength Steel Reinforcement And High-Grade Concrete, Anas Yosefani

Dissertations and Theses

Utilizing the higher capacity steel in design can provide additional advantages to the concrete construction industry including a reduction of congestion, improved concrete placement, reduction in the required reinforcement and cross sections which would lead to savings in materials, shipping, and placement costs. Using high-strength reinforcement is expected to impact the design provisions of ACI 318 code and other related codes.

The Applied Technology Council (ATC-115) report "Roadmap for the Use of High-Strength Reinforcement in Reinforced Concrete Design" has identified key design issues that are affected by the use of high-strength reinforcement. Also, ACI ITG-6, "Design Guide for the Use …

Wind Energy And Wind-Energy-Inspired Turbulent Wakes: Modulation Of Structures, Mechanisms And Flow Regimes, Elizabeth H. Camp

Dissertations and Theses

The interaction of turbulent wakes with one another and with the adjacent fluid directly impacts the generation of electricity in wind turbine arrays. Computational modeling is well suited to the repeated iterations of data generation that may be required to inform understanding of the function of wind farms as well as to develop control schemes for plant function. In order to perform such computational studies, a simplified model of the turbine must be implemented. One of the most computationally efficient parametrizations of the blade utilizes a stationary disk which has a prescribed drag and produces a wake. However, since accurate …