Engineering Commons^™

Hybrid Nanostructured Textile Bioelectrode For Unobtrusive Health Monitoring, Pratyush Rai

Graduate Theses and Dissertations

Coronary heart disease, cardiovascular diseases and strokes are the leading causes of mortality in United States of America. Timely point-of-care health diagnostics and therapeutics for person suffering from these diseases can save thousands of lives. However, lack of accessible minimally intrusive health monitoring systems makes timely diagnosis difficult and sometimes impossible. To remedy this problem, a textile based nano-bio-sensor was developed and evaluated in this research. The sensor was made of novel array of vertically standing nanostructures that are conductive nano-fibers projecting from a conductive fabric. These sensor electrodes were tested for the quality of electrical contact that they made …

Design And Fabrication Of Inverter And Rectifier Modules For Indirect Matrix Converter Applications, Saikishore Talakokkula

Graduate Theses and Dissertations

In power converter applications, silicon carbide (SiC) power semiconductor devices are preferred over their silicon counterparts due to many advantages such as wide bandgap, high junction temperatures and low on-state resistance. The SiC devices provide reduced conduction and switching losses. Due to the above mentioned advantages the power conversion efficiency of SiC devices is better compared to that of silicon (Si) devices.

This thesis studies the implementation of 1200V/17A Normally-off SiC JFETs for an indirect matrix converter (IMC) application. A discussion on the parasitic inductance optimization is presented based on the electromagnetic simulation results extracted from the Ansoft Q3D extractor. …

Interleukin Expression After Injury And The Effects Of Interleukin-1 Receptor Antagonist, Connie S. Chamberlain, Ellen M. Leiferman, Kayt E. Frisch, Stacey L. Brickson, William L. Murphy, Geoffrey S. Baer, Ray Vanderby

Faculty Work Comprehensive List

Ligament healing follows a series of complex coordinated events involving various cell types, cytokines, as well as other factors, producing a mechanically inferior tissue more scar-like than native tissue. Macrophages provide an ongoing source of cytokines to modulate inflammatory cell adhesion and migration as well as fibroblast proliferation. Studying interleukins inherent to ligament healing during peak macrophage activation and angiogenesis may elucidate inflammatory mediators involved in subsequent scar formation. Herein, we used a rat healing model assayed after surgical transection of their medial collateral ligaments (MCLs). On days 3 and 7 post-injury, ligaments were collected and used for microarray analysis. …

Non-Redundant Sensor Fault Detection Using An Improved Dynamic Model, Brandon Cannon, Robert C. Leishman, Timothy W. Mclain, Joseph Jackson, Jovan Boskovic

Faculty Publications

This paper proposes a method of detecting faults in non-redundant sensors. Such a method is advantageous for small unmanned aerial vehicles (UAVs), which are prevented from carrying redundant sensors due to size, weight, and power constraints. The method we propose uses a multiplicative extended Kalman lter (MEKF) for estimation and employs hypothesis testing to detect faults. This method has been shown to detect bias, drift, and increased noise in a non-redundant sensor real-time on board an autonomous rotorcraft.

Robust Motion Estimation With Rgb-D Cameras, Robert C. Leishman, Daniel Koch, Timothy W. Mclain

Faculty Publications

Estimating vehicle motion using vision sensors in real time has been greatly explored in the past few years due to speed improvements and advances in computer hardware. Six degree of freedom motion estimation using vision information is desirable due to a vision sensors low cost, low power requirements and light weight and for the quality of the solutions that can be obtained using few assumptions about the environment. However, cameras have the downside of not providing good estimates when visual features are sparse or not available. Also, there are problems with changes in lighting and when light is low or …

Computational Biomechanical Modeling Of The Human Knee During Kneeling, Tariq R. Abo-Alhol

Electronic Theses and Dissertations

Total knee replacement benefits patients who suffer from severe knee pain or joint stiffness and other joint related illnesses that limit everyday activities. There has been an increase in the number of procedures performed each year and a need to evaluate the performance of these implants during specialized activities such as kneeling. Most computational studies lack insight into inter-patient variability and the results do not apply to large population. This study developed: (1) three-dimensional explicit finite element (FE) models to investigate natural and implanted knee joint kinematics and bone strain and (2) a platform to enable population-based evaluation by combining …

A Methodology For Designing Airports For Enhanced Security Using Simulation, Oliver Nwofia, Christopher A. Chung

Journal of Aviation Technology and Engineering

With the advent of the new security measures, today’s airports have become increasingly complex and congested. Air and passenger traffic continues to increase; consequently, the need for intelligent design concepts is required. Unlike all other existing airport designs that focused exclusively on operational performance, this study focused on the development of a new airport terminal design methodology that takes a proactive approach to minimizing the effects of security disruptions while simultaneously maximizing operational performance and passenger flow. The study addressed the impact of security operations on both the design of airport facilities and passenger flows, and discussed options and scenarios …

The Next Step Toward Widespread Residential Deep Energy Retrofits, Florida Solar Energy Center, Janet Mcilvaine

FSEC Energy Research Center®

The Building America Partnership for Improved Residential Construction (BA-PIRC) has been working with affordable housing entities to identify cost-effective technical pathways to achieve energy savings levels of 30% and safeguard or enhance indoor air quality (IAQ), durability, and comfort (McIlvaine et al. 2012; Fairey and Parker 2012).

Cross-Layer Optimized Wireless Video Surveillance, Yun Ye

Department of Computer Electronics and Engineering: Dissertations, Theses, and Student Research

A wireless video surveillance system contains three major components, the video capture and preprocessing, the video compression and transmission over wireless sensor networks (WSNs), and the video analysis at the receiving end. The coordination of different components is important for improving the end-to-end video quality, especially under the communication resource constraint. Cross-layer control proves to be an efficient measure for optimal system configuration. In this dissertation, we address the problem of implementing cross-layer optimization in the wireless video surveillance system.

The thesis work is based on three research projects. In the first project, a single PTU (pan-tilt-unit) camera is used …

2-Dimensional Personal Motion Energy Harvester For Low Power Electronics, Manuel Gutierrez, Sean Scott, Dimitrios Peroulis

The Summer Undergraduate Research Fellowship (SURF) Symposium

In a lab, it becomes crucial to have a way to monitor that lab workers aren’t exposed to too much radiation. Such a device that detects this should have an energy harvester so that batteries aren’t required. The need for an energy harvester that generates power from a user’s movements in 2 dimensions is needed. This energy harvester is needed to power a radiation monitor. An energy harvester that generates power based off movements in 2 dimensions was developed. The energy harvester was created through a series of prototypes. Each prototype was built from a CAD drawing and a stereolithography …

A Characterization Of The Knee Moment Using The Niagara Foot, Kerron James

Mechanical Engineering Theses

A variety of low cost prosthetic feet exist, but sufficient data on these kinds of feet is limited. This study evaluated the effects of the Niagara Foot™ on an amputee performing walking tasks. Specifically, the study determined the effects of this foot on the amputee's residual knee compared to the amputees current prosthetic foot. An active transtibial amputee was used to perform walking tasks across a force plate to collect ground reaction forces of the amputee while wearing the Niagara Foot and the Ottobock® 1C31+ Trias. Motion capture was used to record the amputee's movements in the room. The data …

Reliability Analysis Of Shallow Foundations Bearing Capacity On Sand, Ali Alhajami

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Bearing capacity of shallow foundation is one of the most challenging problems for engineers. The difficulty comes from multiple sources of variability and uncertainty. There is an uncertainty in live load. Soil properties including: unit weight, cohesion, and angle of friction represent sources of variability in the determining bearing capacity. The current theories used in practice only estimate bearing capacity and does not give an exact value for it because of these sources of variability. Currently, there are Terzaghi, Meyerhof, Vesic, and Hansen theories for dealing with this problem. Based on previous research Terzaghi theory was found to be the …

Understanding The Physics Of Flat-Spectrum Radio Quasars Using Maultiwavelength Observations, Karthik C. R

University Departments

No abstract provided.

Design Practice, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs on "Design Practice" on July 30, 2013.

Power Storage & Control, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs on "Power Storage & Control" on July 30, 2013.

Overview Of Eps, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs on an "Overview of EPS" on July 30, 2013.

Power Sources, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs on "Power Sources" on July 30, 2013.

A Kalman Filter Based Attitude Heading Reference System Using A Low Cost Inertial Measurement Unit, Matthew Leccadito

Theses and Dissertations

This paper describes, the development of a sensor fusion algorithm-based Kalman lter ar- chitecture, in combination with a low cost Inertial Measurement Unit (IMU) for an Attitude Heading Reference System (AHRS). A low cost IMU takes advantage of the use of MEMS technology enabling cheap, compact, low grade sensors. The use of low cost IMUs is primar- ily targeted towards Unmanned Aerial Vehicle (UAV) applications due to the requirements for small package size, light weight, and low energy consumption. The high dynamics nature of smaller airframes, coupled with the typical vibration induced noise of UAVs require an e cient, reliable, …

An Efficient Cost Function For The Optimization Of An N-Layered Isotropic Cloaked Cylinder, Jason V. Paul, Peter J. Collins, Ronald A. Coutu Jr.

Electrical and Computer Engineering Faculty Research and Publications

In this paper, we present an efficient cost function for optimizing n-layered isotropic cloaked cylinders. Cost function efficiency is achieved by extracting the expression for the angle independent scatterer contribution of an associated Green's function. Therefore, since this cost function is not a function of angle, accounting for every bistatic angle is not necessary and thus more efficient than other cost functions. With this general and efficient cost function, isotropic cloaked cylinders can be optimized for many layers and material parameters. To demonstrate this, optimized cloaked cylinders made of 10, 20 and 30 equal thickness layers are presented for …

Analyzing Surface Protein Expression And Internalization, William Truong, Josergio Zaragoza

Bioengineering Senior Theses

G-protein coupled receptors (GPCRs) are currently the largest class of membrane receptors and are targeted by a majority of the modern drug therapeutics. In addition, they partake in many physiological and pathological processes such as inflammation, growth, and hormone responses. Most importantly, GPCRs are targets of many disease-specific pathways such as Alzheimers, hypertension, leukemia, and depression. As a result, there is an immense interest in studying GPCRs as this area provides further knowledge into the specific disease pathways and allows the discovery of novel therapeutics. In order to have a better understanding of pathways, scientists have studied GPCR activation. The …

Accuracy Improvement Of Quantitative Analysis By Spatial Confinement In Laser-Induced Breakdown Spectroscopy, L. B. Guo, Z. Q. Hao, M. Shen, W. Xiong, X. N. He, Z. Q. Xie, M. Gao, X. Y. Li, X. Y. Zeng, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

To improve the accuracy of quantitative analysis in laser-induced breakdown spectroscopy, the plasma produced by a Nd:YAG laser from steel targets was confined by a cavity. A number of elements with low concentrations, such as vanadium (V), chromium (Cr), and manganese (Mn), in the steel samples were investigated. After the optimization of the cavity dimension and laser fluence, significant enhancement factors of 4.2, 3.1, and 2.87 in the emission intensity of V, Cr, and Mn lines, respectively, were achieved at a laser fluence of 42.9 J/cm2 using a hemispherical cavity (diameter: 5 mm). More importantly, the correlation coefficient of the …

Hysteretic Response Of Chemical Vapor Deposition Graphene Field Effect Transistors On Sic Substrates, Edward Cazalas, Isaac Childres, Amanda Majcher, Ting Fung Chung, Yong P. Chen, Igor Jovanovic

Birck and NCN Publications

Graphene field effect transistors (GFETs) fabricated by chemical vapor deposition graphene deposited onto SiC substrates exhibit sensitivity to broadband visible light. The hysteretic nature of this GFET type was studied utilizing a new current-voltage measurement technique in conjunction with current-time measurements. This measurement method accounts for hysteretic changes in graphene response and enables transfer measurements that can be attributed to fixed gate voltages. Graphene hysteresis is shown to be consistent with electrochemical p-type doping, and current-time measurements clearly resolve a hole to electron to hole carrier transition in graphene with a single large change in gate voltage. (C) 2013 AIP …

Diagnostic Ultrasound Induced Inertial Cavitation To Non-Invasively Restore Coronary And Microvascular Flow In Acute Myocardial Infarction, X. Feng, S. Gao, J. Wu, J. Lof, S. Radio, F. Vignon, W. Shi, J. Powers, E. Unger, E. Carr Everbach, J. Liu, T. R. Porter

Engineering Faculty Works

Ultrasound induced cavitation has been explored as a method of dissolving intravascular and microvascular thrombi in acute myocardial infarction. The purpose of this study was to determine the type of cavitation required for success, and whether longer pulse duration therapeutic impulses (sustaining the duration of cavitation) could restore both microvascular and epicardial flow with this technique. Accordingly, in 36 hyperlipidemic atherosclerotic pigs, thrombotic occlusions were induced in the mid-left anterior descending artery. Pigs were then randomized to either a) 1/2 dose tissue plasminogen activator (0.5 mg/kg) alone; or same dose plasminogen activator and an intravenous microbubble infusion with either b) …

Spatial And Temporal Estimation Of Nanomechanical Properties Via Atomic Force Microscopy, Eric Mccullough

Theses and Dissertations

Engineering the next generation of smart materials will require new methods of surface characterization, analysis and identification that can be performed not only in three dimensional space but also in the temporal dimension. Of particular interest is the understanding of mechanical properties of complex systems at the micro and nanoscales. Current techniques for such measurements are hampered by challenges including their inability to probe systems in complex microenvironments, non-destructively, or at nanometer resolution. This thesis outlines work in the development of techniques to study diverse systems and determine their mechanical properties using the Atomic Force Microscope as the primary tool. …

The Effect Of Concurrent Cognitive-Visuomotor Multitasking And Task Difficulty On Dynamic Functional Connectivity In The Brain, Plamen Nikolov

Theses and Dissertations

This thesis investigated the effect of visuomotor and working memory 1) task difficulty and 2) multitasking on dynamic functional connectivity in the brain. Studies have only recently begun to investigate functional connectivity within the scope of concurrent dual task or varying task difficulty conditions (Cocchi, Zalesky, et al. 2011; Rietschel et al. 2012). A series of EEG recordings were conducted during execution of visuomotor or working memory tasks within a novel paradigm using BCI2VR custom MATLAB toolbox. Functional connectivity was correlated with task-related coherence (TRCoh) analysis between two task conditions involving either variation in task difficulty or concurrent execution during …

Semi-Interpenetrating Network Gelatin Fiber Sca Old For Oral Mucosal Delivery Of Insulin, Leyuan Xu

Theses and Dissertations

Common therapy for diabetes mellitus is subcutaneous administration of insulin that is subject to serious disadvantages, such as patient noncompliance and occasional hypoglycemia. Hence, oral administration of insulin could be more convenient and serve as a desired route. However, oral administration of insulin is severely limited by the low bioavailability of insulin through the gastrointestinal tract. In this study, a semi-interpenetrating network gelatin fiber scaffold (sIPN GF) was fabricated for oral mucosal delivery of insulin as an alternative route. This sIPN GF was engineered from an electrospun gelatin fiber scaffold (GF), which was further crosslinked with polyethylene glycol diacrylate (PEG-DA) …

55th Annual Rocky Mountain Conference On Magnetic Resonance

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 55th annual meeting of the Rocky Mountain Conference on Magnetic Resonance, co-endorsed by the Colorado Section of the American Chemical Society and the Society for Applied Spectroscopy. Held in Denver, Colorado, July 28 - August 1, 2013.

Entropy Applications In Industrial Engineering, Saeed Zamiri Marvizadeh

Department of Industrial and Management Systems Engineering: Dissertations, Theses, and Student Research

Entropy is a fundamental measure of information content which has been applied in a wide variety of fields. We present three applications of entropy in the industrial engineering field: dispatching of Automatic Guided Vehicles (AGV), ranking and selection of simulated systems based on the mean performance measure, and comparison between random variables based on cumulative probability distributions.

The first application proposes three entropy-based AGV dispatching algorithms. We contribute to the body of knowledge by considering the consequence of potential AGV moves on the load balance of the factory before AGVs are dispatched. Kullback-Leibler directed divergence is applied to measure the …

Improving Vehicle Trip Generation Estimations For Urban Contexts: A Method Using Household Travel Surveys To Adjust Ite Trip Generation Rates, Kristina Marie Currans

Dissertations and Theses

The purpose of this research is to develop and test a widely available, ready-to-use method for adjusting the Institute of Transportation Engineers (ITE) Trip Generation Handbook vehicle trip generation estimates for urban context using regional household travel survey data. The ITE Handbook has become the predominant method for estimating vehicle trips generated by different land uses or establishment, providing a method for data collection and vehicle trip estimation based on the size of the development (e.g. gross square footage, number of employees, number of dwelling units). These estimates are used in traffic impact analysis to assess the amount of impact …

Agenda: Changing Regulatory Frameworks For Shale Development And "Social License To Operate", University Of Colorado Boulder. Getches-Wilkinson Center For Natural Resources, Energy, And The Environment

Changing Regulatory Frameworks for Shale Development and "Social License to Operate" (July 24)

Rapid development of unconventional shale resources in recent years has raised a series of regulatory issues both here and abroad. Because of the "distributed" nature of shale development and the significant increase in wells in key basins, local land-use conflicts have also erupted in certain areas of the country, leading to restrictions and moratoria on drilling by state, county, and municipal governments and raising questions about the industry's continued social license to operate in key jurisdictions. This moderated panel discussion will assess the current regulatory framework governing shale gas development and the changing dynamics among federal, state, and local regulation …