Engineering Commons^™

Material Characterization Of Ultra-High Performance Fiber Reinforced Concrete At Elevated Temperatures, Richard T. Way

Master's Theses

With the recent development of Ultra High Performance Fiber Reinforced Concrete (UHPFRC), there has been limited investigation into the mechanical and material properties of this composite at elevated temperatures. At elevated temperatures concrete is shown to undergo several material changes which affect the residual mechanical properties. Additionally, fast heating rates are known to cause a phenomenon called explosive spalling. This research investigates the effect of high temperature on the residual mechanical properties and chemical degradation of two types of UHPFRC. This was accomplished by casting and testing two different UHPFRC mixes and exposing them to elevated temperatures at two rates …

Material Characterization And The Effects Of Moisture And Drying On Injection Molded Torlon 5030, Michael R. Di Re

Master's Theses

The effects of water absorption and drying were studied on injection molded Torlon 5030, a high performance thermoplastic fabricated by Solvay Specialty Polymers. Torlon 5030 contains 30% by weight glass fibers in a polyamide-imide base resin. The objective behind this work was to test and better define relevant properties for industrial applications using this material. While the material design guide offers information on many mechanical properties including tensile, fatigue, and creep data; there is little to no publicly published data on the effects of water absorption and any subsequent drying of Torlon 5030. Blistering was also studied. With exposure to …

Microkinetic Modeling And Analysis Of Ethanol Partial Oxidation And Reforming Reaction Pathways On Platinum At Short Contact Times, Maura A. Koehle

Master's Theses

No abstract provided.

Automated Point-Of-Care Image Processing Methodology For The Diagnosis Of Malaria, Michael B. Jorgensen

Master's Theses

Malaria has profoundly influenced human history for over four thousand years and despite numerous attempts at eradication, the prevention, diagnosis, and treatment of malaria have been largely ineffective. More than five hundred million people are affected by malaria every year resulting in over one million deaths. Drug resistance development by the parasite has diminished the effectiveness of numerous treatment options due, in part, to overtreatment of negative patients based on insufficient clinical algorithms and diagnostic methods. The goal of this research was to develop an image analysis algorithm to diagnose malaria with a high degree of sensitivity and specificity in …

Multiplatform Analysis Seismic Evaluation Of A Non-Seismically Detailed Nonlinear Rc Structure Retrofitted With Magneto-Rheological Dampers, Eric R. Lovejoy

Master's Theses

In prior research, the MR damper's dynamic characteristics are typically modeled in the MATLAB/Simulink environment. Creating a structural model with nonlinear material properties, however, may be challenging in the MATLAB/Simulink environment without approximating the material behavior and neglecting effects such as P-∆ or panel zone behavior. More behaviorally accurate models of these structures can be produced using nonlinear finite element analysis tools such as Abaqus, OpenSees or ZuesNL. These analysis tools, however, are not traditionally used to model the complex nonlinear and controllable behavior of MR dampers, nor their associated control algorithms. One solution is to facilitate communication between these …

Condition-Dependent Risk Assessment Of Large-Scale Grid-Tied Photovoltaic Power Systems, Sherwin Li

Master's Theses

This thesis reviews the methods for evaluating the reliability of large PV systems and techniques for quantifying the impacts of PV interconnection on distribution system reliability. In addition, a comparative study is performed to evaluate the seasonal condition-dependent risk performance of central-inverter and string-inverter grid-tied PV power systems. Major contributions include: 1) risk analysis of seasonal impacts for string and centralized PV systems. Seasonal sensitivities of PV system risks to system structures, temperature variation, solar insolation, and capacitor equivalent series resistance are analyzed; and 2) the incorporation of the effect of operational conditions and the aging failure model into the …

Game Theory Approach To Transportation Network Vulnerability Measurement, Qixing Wang

Master's Theses

The vulnerability of a transportation network is strongly correlated with the ability of the network to withstand shocks and disruptions. A robust network with strategic redundancy allows for the redistribution or reassignment of traffic without unduly compromising system performance. As such, high-volume edges with limited alternative paths represent system vulnerabilities – a feature of transportation networks that has been exploited in the past to identify critical components. In this thesis, a mixed-strategy, two opponents, non-zero sum, combinatorial game theoretical framework are presented for measuring network vulnerability. Two solution approaches (Shortest Path Algorithm with Entropy function (SPE) & User Equilibrium Assignment …

A Finite Difference Implementation Of Phase Field Theory, Nicholas W. Oren

Master's Theses

Computationally handling cracks generally results in numerically unstable results. Specifically handling the infinite stresses at the crack tip as well as the abrupt change from virgin material to failed material creates numerical instabilities. This project seeks to determine if phase field physics theory, particularly the physics based modification developed by B. N. Cassenti, can be appropriately applied to cracks. Phase field theory introduces an additional state variable, the phase of the material. The phase represents the level of failure (by cracking), and diffuses the failure along a crack by specified equations. The modification, based on a variational principle, was tested …

Investigation Of In-Situ Immobilization Of Contaminated Sediments Using Alginate Gels For The Reduction Of Ecological Risk, Michael V. Podany Mr.

Master's Theses

Remediation methods for contaminated sediments include dredging, treatment and disposal and sediment isolation through capping. These methods are costly and adversely impact local ecosystems, in some cases causing major disturbances to the sediment bed and water column. A new remediation technique is proposed for slowly biodegradable contaminants using alginate hydrogels as a binding agent of sediment. The rational is that sediment particles bound in alginate hydrogel are less likely to be resuspended and the treatment is less disruptive than capping. Here we show addition of alginate increased the shear strength of sediment comprised of defined particle sizes. The increase in …

Weather-Based Damage Prediction Models For Electric Distribution Networks, David W. Wanik

Master's Theses

From thunderstorms to hurricanes, electric distribution networks are subject to a wide range of warm weather storm events. Tropical Storm Irene (2011) and Hurricane Sandy (2012) are two events in recent memory that disrupted over half of The Connecticut Light and Power Company’s (CL&P) service territory, which left some customers without power for up to eleven days. This research study investigates a damage prediction framework for both thunderstorms and hurricanes that combines two generalized linear models to probabilistically determine the occurrence and extent of damages, known as trouble spots, to the overhead power distribution network. The models are inputted with …

A Depolymerization Based Model Of Neuron Growth Cone Shape And Motility, Neerajha Nagarajan

Master's Theses

Cell migration is a ubiquitous process underlying critical biological mechanisms like wound healing, cancer metastasis and even neuron growth cone motility. It is a critical process for the living organisms as it ensures proper functioning of the system, for example, crawling fibroblasts endure closure of wounds during wound healing. Here we focus our interest on neuron growth cones, a sensory and motile organelle present at the tip of extending neurites, like the axons, in neurons. These are responsible for neuron pathfinding onto specific targets and synapses, in responses to various guidance cues. Interestingly, the motility of the growth cones is …

Analysis Of The Enzymatic Decomposition Of Barley Starch To Simple Carbohydrates, Mark Mathiew Williams

Master's Theses

The decomposition of barley starch plays a fundamental role in the final quality of fermented beverages in the brewing industry. The process of mashing involves steeping milled barley in water to stimulate the enzymatic decomposition of starch into simple carbohydrates. The temperature of the water significantly impacts the activity of the enzymes and in turn the resulting concentrations of sugar products. A kinetic model accurately predicting the types and quantities of sugars formed as a function of mash temperature would serve as a tool to tailor sugar profiles and optimize mashing procedures for a desired product.

Sixty minutes mashes were …

Environmental Justice Ties To Electronic Travel Surveys And Transit Accessibility, Nicholas A. Hart

Master's Theses

No abstract provided.

Development And Implementation Of A Calibration Procedure For Complex Impedance Spectrum Measurements With Applications To Embedded Battery Health Monitoring And Management Systems, William H. Morrison

Master's Theses

Energy storage devices such as rechargeable Lithium ion batteries are assuming an increasingly prominent role in society, covering applications from electric / hybrid electric vehicles to personal portable electronics. In response to this increasing demand, technologies that monitor battery health and remaining useful life have developed. One such system is the Smart Battery Status Monitor (SBSM), developed by the Idaho National Laboratory, Montana Tech and Qualtech Systems, Inc. The SBSM utilizes impedance spectrum measurements using a subsystem called the Impedance Measurement Box (IMB). The impedance measurements are complex quantities (having both a resistive and a reactive component) and are made …

Efficient Algorithms For Improving The Accuracy In Motifs Prediction, Jerlin C. Merlin

Master's Theses

Analysis of sequence homology has always played a major role in the understanding of biological factors such as protein domain identification, gene product relationships, and gene function determination. Short contiguous protein sequences that are conserved across proteins provide important information about such factors, and are of at most 15 residues in length. These segments of proteins are known as minimotifs. Identifying minimotifs has been of much use in the formulation of the hypothesis about the biological functions that otherwise might be uncharacterized. Mechanisms of motif predictions such as Minimotif Miner are widely used for predicting minimotifs. However, due to the …

Network- Level Pavement Performance And Management Study In Connecticut, Ramandeep S. Josen

Master's Theses

This thesis presents the analysis of asphalt pavement cracking data on the network level in Connecticut. Pavement performance indicators including longitudinal and transverse cracking as well as roughness are investigated with respect to numerous distinct factors that can be grouped into three categories, i.e. climatic-, pavement structure-, and traffic-related. High-quality climatic data was obtained from the national weather stations in Connecticut. Maintenance and construction data was used to determine the pavement age and structure amongst several other factors. Traffic data was acquired from the state records and accumulated traffic loading was estimated for all segments based on their age. High …

Using Nwp Analysis In Satellite Rainfall Estimation Of Heavy Precipitation Events Over Complex Terrain, Xinxuan Zhang

Master's Theses

This study investigates the use of Weather Research and Forecasting (WRF) high-resolution storm analysis in satellite rainfall estimation over complex terrains. Rainfall estimation here is based on the NOAA-Climate Prediction Center morphing (CMORPH) product. Specifically, CMORPH rainfall is adjusted by applying a power-law function whose parameter values are obtained from the comparison between WRF and CMORPH hourly rain rates. Results are presented based on the analyses of five storm cases that induced catastrophic floods in southern Europe. The WRF-based adjusted CMORPH rain rates exhibited improved error statistics against independent radar-rainfall estimates. We show that the adjustment reduces the underestimation of …

The Effects Of Bolt Pretension, In-Plane Eccentricity, And Friction On The Ductility Of Block Shear Connections, Kevin M. Zmetra

Master's Theses

Block shear is a complex failure mechanism in bolted and welded steel components such as gusset plates, webs of coped beams, angles and tees. It presumes a combination of tension rupture and shear yield. Multiple variables affect the block shear capacity and ductility of a connection. This study investigates the effects of bolt pretension, connection eccentricity and friction force transfer through a series of destructive experiments followed by refined finite element simulation. Clamping forces create a complex triaxial stress field compounded by the stress concentration at the bolt holes. In-plane load eccentricity with respect to the centerline of the connection …

The Role Of Transport Phenomena In The Direct Oxidation Of Solid Fuels, Charles J. Banas

Master's Theses

Direct carbon fuel cells have shown promise for stationary power generation by utilizing the direct oxidation of a solid carbon fuel source at the anode. In laboratory settings, researchers have reported up to 300mA/cm2 of current density from these cells types which suffer from mass transport losses. This paper studies the surface properties of the solid fuel source, and describes the process of CO2 evolution through an analogy to pool boiling. In nucleate boiling (a subset of pool boiling) vapor bubbles grow from nucleation sites where gas are trapped in micro-cavities on the surface. Carbon surfaces possess these same features, …

Active Storage And Ssd Caching In An Object Storage Environment, Michael T. Runde

Master's Theses

The advancing performance and lowering costs required to implement additional processing power on system peripherals such as disk drives are increasingly allowing additional computing ability to be located directly on individual drives. Active Storage attempts to take advantage of this excess by moving some computationally intensive applications directly to the disk drives. This can remove the bottlenecks seen through interconnects between the drives and the CPU of an initiating system as well as remove the need for systems to handle these applications.

The contributions of this thesis are in two areas. The first is the development of a framework designed …

Efficient Characterization Of Structural Dynamic Responses Under Uncertainties: From Order-Reduced Simulation To Data-Driven Emulation, Zeping Xia

Master's Theses

The efficiency of sampling remains as one of the major challenges for uncertainty analysis in structural dynamics. In the context of numerical experiments, this difficulty primarily lies in the fact that every single run of a numerical model, which usually is of large scale in modern engineering practice, would be expensive in terms of CPU times and memories. Nonetheless, understanding and predicting dynamic characteristics of structural systems with uncertainties is important for structural design, assessment and control. In order to develop fast and economical sampling techniques for characterizing structural dynamics, we explored two categories of methods from two opposite direction: …

Impact Of Salt On Denitrification Potential In Roadside Environments, Nakita A. Lancaster

Master's Theses

Urban systems are impacted by changes in hydrology and water chemistry, altering their ability to mitigate detrimental impacts to coastal water bodies, particularly those that result from high volumes of stormwater runoff. The elevated level of impervious cover increases not only runoff but also contaminant loading of nutrients, metals, and road salt used for deicing in cold weather climates. Current stormwater management strategies, while focused on managing the changes in hydrology associated with urbanization, also are designed to mitigate the pollutant loading. Here we investigate the impact that road salt will have on nitrogen removal in roadside environments. Sediments were …

Efficient Algorithms For Sorting On Gpus, Seema M. Munavalli

Master's Theses

Sorting is an important problem in computing that has a rich history of investigation by various researchers. In this thesis we focus on this vital problem. In particular, we develop a novel algorithm for sorting on Graphics Processing Units (GPUs). GPUs are multicore architectures that offer the potential of affordable parallelism. We present an efficient sorting algorithm called Fine Sample Sort (FSS). Our FSS algorithm extends and outperforms sample sort algorithm presented by Leischner[2], which is currently the fastest known comparison based algorithm on GPUs. The performance gain of FSS is mainly achieved due to the quality of the samples …

Phase-Resolved Characterization Of Conical Turbulent Premixed Flames: An Investigation Of Forced Blowoff Dynamics, Sayan Biswas

Master's Theses

Flame dynamics of a bluff body stabilized turbulent premixed flame as it approaches lean blowoff is of interest for practical applications. It is also important to understand the flame behavior under harmonic flow perturbations as it may occur due to acoustically unstable operation of compact combustors. In this study, a harmonically excited conical flame was studied to determine its behavior under strong burning and near blowoff conditions. Chemiluminescence imaging was employed using a Photron high speed camera to characterize the phase resolved flame characteristics for a range of excitation frequencies from 50 to 400 Hz in confined and unconfined geometries. …

Adaptive Energy Management Scheme In Real-Time Energy Harvesting Embedded Systems, Shruti Khare

Master's Theses

The main purpose of this thesis was to develop an online adaptive energy management scheme for energy harvesting embedded systems. Two energy prediction schemes were used, namely Exponentially Weighted Moving Average (EWMA) and Adaptive Forward Prediction (AFP), to schedule all the tasks with least deadline miss rate. The AFP scheme has a mean relative error of 6-10% which is much lower than exponentially weighted moving average (EWMA) algorithm with an error of 30%. The large difference in the error percentage between the two prediction algorithms is due to the adaptive nature of AFP as it tracks small changes in input …

Investigation Of Trends And Predictive Effectiveness Of Crash Severity Models, James E. Mooradian

Master's Theses

This thesis describes analysis using ordinal logistic regression to uncover temporal patterns in the severity level (fatal, serious injury, minor injury, slight injury or no injury) for persons involved in highway crashes in Connecticut, focusing on the demographic split between senior travelers (65 years and over) and non-senior travelers. Existing state sources provide data describing the time and weather conditions for each crash and the vehicles and persons involved over the time period from 1995 to 2009 as well as the traffic volumes and the characteristics of the roads on which these crashes occurred. Findings indicate an overall increase in …

Rainfall Organization And Geomorphologic Controls On The Flood Response Of Mild-Slope Basins In The South Atlantic Region Of Us, Yiwen Mei

Master's Theses

This study uses data from the Tar-River Basin in North Carolina to explore how space-time rainfall variability influences the hydrologic response from observational and modeling perspectives. For understanding the basin scale effect, the Tar-River Basin is divided into four cascade sub-basins ranging from 1106 km² up to 5654 km². The study evaluates the catchments’ response to rainfall for a large number of storm events by computing the event runoff coefficient based on streamflow observations and through simulations from a semi-distributed hydrological model. Comparison of observed to simulated hydrographs from the hydrological model shows that distributed rainfall forcing …

Short Term Monitoring Of Suspender Cables On An In-Service Highway Bridge, Gannon Stromquist-Levoir

Master's Theses

No abstract provided.

Agent-Based Modeling Of Emergency Building Evacuation, Vi Q. Ha

Master's Theses

Panic during emergency building evacuation can cause crowd stampede, resulting in serious injuries and casualties. Agent-based methods have been successfully employed to investigate the collective human behavior during emergency evacuation in cases where the configurational space is extremely simple - usually one rectangular room - but not in evacuations of multi-room or multi-floor buildings. This implies that the effect of the complexity of building architecture on the collective behavior of the agents during evacuation has not been fully investigated. Here, we employ a system of self-moving particles whose motion is governed by the social-force model to investigate the effect of …

A Stochastic Simulation Model Of Alarm Response Strategies On A Telemetry Floor, Tasneem M. Pishori

Master's Theses

The large quantity of alarms characteristic of clinical settings have resulted in nursing staff suffering from a phenomenon termed ‘alarm fatigue’. Alarm fatigue is desensitization via habituation – as these commonly heard noises cause caregivers to have delayed or no response to alarms. Alarm management was ranked number one on the annual top ten list of technology hazards afflicting healthcare institutions published by the ECRI Institute for 2012. Several patient safety organizations have established alarm fatigue as a priority concern, and are working to eradicate the issue from the healthcare environment by 2017. To better understand the problem, a simplified …