Engineering Commons^™

Preparation Of Glass-Ceramics Largely Using Steelmaking Slags And Study On The Effect Of Iron Content On Properties Of Glass-Ceramics, Huan Feng

Huan Feng

Glass-ceramics were prepared using steelmaking industry waste containing high iron content based on powder sintering and crystallization method. Anthracite was used in varying amounts as the reducing agent to recover iron in raw materials. X-ray diffraction analysis (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscope (SEM) coupled with Energy Dispersive X-ray spectrometer (EDX) were used to study the microstructure of glass-ceramics formed. Bending strength and micro-harness of the samples were compared. When 12g of anthracite was used, ionic iron (Fe 2+ /Fe 3+ ) content was reduced to 4.7% and total iron content was reduced to 8.0 ...

Exploring The Compactability And Workability Of Rap, Elizabeth Poblete

Civil Engineering Undergraduate Honors Theses

Despite its economic and environmental benefits, the widespread use of Cold In-Place Recycling (CIR) is currently inhibited, to some degree, by a lack of laboratory testing and evaluation, specifically in the areas of compactability and workability of the reclaimed mixture stabilized with asphalt emulsion. The purpose of this study was to explore the influence of admixtures in CIR using modified Superpave Gyratory Compactor (SGC) compaction metrics. The primary stabilization technique considered in this research was asphalt emulsion, an application in which asphalt binder is suspended in water, allowing it to be stored and applied at ambient temperature, rather than the ...

Using Multifactor Inputs Bp Neural Network To Make Power Consumption Prediction, Hao Song

Graduate Dissertations and Theses

With the development of modern information and technology (IT), smart grids became one of the major components of smart cities, to take full advantage of the smart grid, the capability of intelligent scheduling and planning of electricity delivery is essential. For this purpose, researchers have investigated methodologies for power consumption prediction and demand side management (DSM). In addition, conducting a comprehensive analysis and obtaining an accurate evaluation of power consumption are the premise and basis for a more robust and efficient power grid design and transformation. Therefore, it is meaningful to explore forecasting models that are able to reflect the ...

Achieving Universal Liaisons And Healthcare Contact Center Centralization Through The Use Of Decision Support Tools, Jared S. Fiacco

Graduate Dissertations and Theses

Healthcare contact centers often experience a large volume of calls and traditional standardized guidelines can be difficult to follow during an active call. While more common workflows can be memorized, they change often because Healthcare is a dynamic field. Constant updates to workflows, an abundance of different processes and provider preferences, and a fast paced environment can lead Customer Service Liaisons (CSLs) to handle patient inquiries incorrectly. Active decision support tools enable a CSL to follow an updated workflow without needing to navigate through complex guidelines and emails. This research shows that contact center centralization through the use of decision ...

Design And Qualification Of A Robust Polyurethane Based Conformal Coating Process For Sodimms, Rajat Dhiman

Graduate Dissertations and Theses

Conformal coatings protect printed circuit board assemblies, including the electronic components that the assemblies are populated with. A variety of materials and application methods can be used to conformally coat assemblies. The process setup is crucial to repeatable process reliability. The manual spray based conformal coating is widely used. This method of application was selected due to its compatibility, affordability, and efficiency with the required application. Polyurethanes, one of the families of conformal coatings, provide resistance against abrasion, heat, and chemicals while reducing the risk of tin whiskers. In order to minimize the need for rework and create an efficient ...

Computational Fluid Dynamics Modeling And In Situ Physics-Based Monitoring Of Aerosol Jet Printing Toward Functional Assurance Of Additively-Manufactured, Flexible And Hybrid Electronics, Roozbeh (Ross) Salary

Graduate Dissertations and Theses

Aerosol jet printing (AJP)—a direct-write, additive manufacturing technique—has emerged as the process of choice particularly for the fabrication of flexible and hybrid electronics. AJP has paved the way for high-resolution device fabrication with high placement accuracy, edge definition, and adhesion. In addition, AJP accommodates a broad range of ink viscosity, and allows for printing on non-planer surfaces. Despite the unique advantages and host of strategic applications, AJP is a highly unstable and complex process, prone to gradual drifts in machine behavior and deposited material. Hence, real-time monitoring and control of AJP process is a burgeoning need. In pursuit ...

Development Of Collagen-Based Scaffolds For Differentiation Of Induced Pluripotent Stem Cells, Siteng Fang

Graduate Dissertations and Theses

Collagen hydrogel has been broadly studied and applied in engineering 3D scaffold materials in tissue engineering. A collagen hydrogel can provide cells with a porous and soft environment to proliferate and differentiate. However, lacking mechanical stiffness and shrinkage resistance made it a challenge to sustain shape and size during a long stem cell differentiation process. In addition, a cytocompatible scaffold for human induced pluripotent stem cell (iPSC)-laden culture has not been fully investigated. The goal of this study is to develop stable and biocompatible collagen-based scaffolds that are suitable for direct seeding and lineage progression of iPSCs. In this ...

Multi-Objective Design Optimization Of Reverse Total Shoulder Arthroplasty To Maximize Range Of Motion And Joint Stability, Josie A. Elwell

Graduate Dissertations and Theses

Reverse total shoulder arthroplasty was developed to restore range of motion (ROM) and joint stability to patients with pre-operative conditions that are not addressed by conventional replacements. Although reverse total shoulder arthroplasty is the current gold standard for treating a range of indications, the effects of varying its design on functional outcomes of the procedure are still not well understood.

To that end, it is not yet clear which configurations, in terms of both design and surgical placement parameters, maximize range of motion and stability of the joint. It was hypothesized that there is trade-off between the two. These types ...

Assessing The Tensile And Fatigue Behavior Of Aerosol Jet Printed Nano Silver Particle Traces On Polyimide Substrates, Roshan Muralidharan

Graduate Dissertations and Theses

Flexible interconnects are integral to flexible hybrid electronics. Aerosol jet, inkjet or screen printing offer various advantages and disadvantages compared to electroplating, but the behavior of printed metal traces under various types of loading is very different and not yet well understood. This thesis presents an assessment of the electromechanical behavior of aerosol jet printed Nano silver particles on two common polyimide substrates, Upilex and Kapton.

There are many different aspects to electromechanical testing of flexible interconnects, but this work focuses on the effects of tension and cyclic loading. In comparison to the much more widely researched electroplated copper or ...

Use Of A Triboelectric Generator For A Tunable Wideband Energy Harvester And A Threshold Shock Sensor, Daniel S. Nelson

Graduate Dissertations and Theses

The prevalence of triboelectricity as a transduction mechanism has increased rapidly in recent years. We will discuss two uses for triboelectric generators. One design is a tunable wideband energy harvester. An axial force and amplitude limiter work together to create an energy harvester that can accommodate various frequency sources and have a large operating bandwidth. The addition of the compressive axial force also softens the system, which allows for higher voltage outputs. A proof of concept of a threshold shock sensor is proposed that incorporates bi-stability along with the triboelectric effect. A clamped-clamped buckled beam will switch stable states when ...

Investigation Of Small-Scale Thermal Recovery And Storage Systems, Suvhashis Thapa

Doctoral Dissertations

An approach to recover and store waste heat is presented in this dissertation. The waste heat is the energy that is rejected to the environment without being put to practical use and it is a result of both equipment inefficiency and thermodynamic limitation on the equipment and the process. In a typical Otto cycle, for instance, out of the total energy consumed by the system, only one-third of the energy is converted into useful work and the rest is discharged in the environment as waste heat [1]. For a spark ignition, a 1.4 liters internal combustion engine with the ...

Design And Synthesis Of Novel Nanometallic Catalysts And Electrode Materials For Green Fuel Cells, Jing Zhang

Graduate Dissertations and Theses

The United Nations formally adopted 17 sustainable development goals (SDGs) at its 2015 summit. Many of these goals addressed issues such poverty, hunger, health, education, climate-change, gender equality, water, sanitation, energy, urbanization, environment and social justice. The seventh SDG seeks to ensure access to affordable, reliable, sustainable and modern energy for all. So among all renewable forms of energy, fuel cells with high efficiency have attracted a lot of attention recently. In particular, the direct ethanol fuel cells (DEFCs) and microbial fuel cells (MFCs) are significant due to their green fuel, less waste generated and environmental friendliness. Hence the overall ...

Mechanical Reinforcement Of Polyacrylamide Hydrogels Using Pristine Single-Walled Carbon Nanotubes, Wuxiang Feng

Graduate Dissertations and Theses

Hydrogels have great promise as an innovative biomedical material possessing many advantages such as high water content, porous structure, and excellent biocompatibility. Although hydrogels have been used to develop some successful applications, they commonly do not have sufficient mechanical strength required for artificial soft tissues. Here, the author fabricated reinforced PAAm hydrogels using single-walled carbon nanotubes as reinforcing materials. The fusion of SWCNTs and the PAAm matrix successfully generated SWCNTs/PAAm hybrid gels with improved mechanical strength. Moreover, the aqueous dispersion of SWCNTs used for engineering the hybrid gels remained excellent stability after two months. SEM images from previous research ...

Ensemble Machine Learning To Predict Family Consent For Organ Donation, Md Ehsan Khan

Graduate Dissertations and Theses

There is ever increasing disparity between number of organs needed for transplantation and numbers available for donation to save lives. As a result, thousands of people die every year waiting for organs. Therefore, it is now more important than ever before to take serious actions to decrease this disparity. One way to bridge gap between organ demand and supply is to increase family consent for organ donation. This research studied the factors associated with family consent. Machine Learning approach had been used in very few literature to understand factors related to family consent. This study uses six Ensemble Machine Learning ...

Cyber-Physical Embedded Systems With Transient Supervisory Command And Control: A Framework For Validating Safety Response In Automated Collision Avoidance Systems, Daniel K. Trembley

Graduate Dissertations and Theses

The ability to design and engineer complex and dynamical Cyber-Physical Systems (CPS) requires a systematic view that requires a definition of level of automation intent for the system. Since CPS covers a diverse range of systemized implementations of smart and intelligent technologies networked within a system of systems (SoS), the terms “smart” and “intelligent” is frequently used in describing systems that perform complex operations with a reduced need of a human-agent. The difference between this research and most papers in publication on CPS is that most other research focuses on the performance of the CPS rather than on the correctness ...

Utilizing Data Mining Techniques And Ensemble Learning To Predict Development Of Surgical Site Infections In Gynecologic Cancer Patients, John R. Mcdonough

Graduate Dissertations and Theses

Surgical site infections are costly to both patients and hospitals, increase patient mortality, and are the most common form of a hospital acquired infection. Gynecological cancer surgery patients are already at higher risk of developing an infection due to the suppression of their immune system. This research leverages popular data mining techniques to create a prediction model to identify high risk patients. Implemented techniques include logistic regression, naive Bayes, recursive partitioning and regression trees, random forest, feed forward neural network, k-nearest neighbor, and support vector machines with linear kernel. Weighted stacked generalization was implemented to improve upon the individual base ...

Image Series Prediction Via Convolutional Recurrent Neural Networks With Limited Training Data, Zao Zhang

Graduate Dissertations and Theses

This thesis focuses on developing deep learning algorithms that can be used to forecast the image series under limited training data. Specifically, we study the problem of using a pine tree's existing appearance images to predict its future appearance images.

Side-Information For Steganography Design And Detection, Tomas Denemark

Graduate Dissertations and Theses

Today, the most secure steganographic schemes for digital images embed secret messages while minimizing a distortion function that describes the local complexity of the content. Distortion functions are heuristically designed to predict the modeling error, or in other words, how difficult it would be to detect a single change to the original image in any given area. This dissertation investigates how both the design and detection of such content-adaptive schemes can be improved with the use of side-information.

We distinguish two types of side-information, public and private: Public side-information is available to the sender and at least in part also ...

Understanding The Surface Fouling Mechanism Of Ultrananocrystalline Diamond Microelectrodes Using Microfluidics For Neurochemical Detection, An-Yi Chang

Doctoral Dissertations

Electrochemical methods are widely used for chronic neurochemical sensing, but thus far, the organic solution redox reactions fouled the electrodes' surface. It caused the reduction of sensitivity and the electrodes' lifetime.

Here, we present the boron-doped nanocrystalline diamond microelectrodes (BDUNCD) as the next generation electrode material for neurochemical sensor development. To aid in long-term chronic monitoring of neurochemicals, they have a wide window of electrochemical potential, extremely low background current, and excellent chemical inertness. The main research goal is to reduce the rate of electrode fouling due to the reaction by-products, and significantly extend their useful lifetime.

We systematically characterize ...

Full Simulation For The Qweak Experiment At 1.16 And 0.877 Gev And Their Impact On Extracting The Pv Asymmetry In The N→Δ A Transition, Hend Abdullah Nuhait

Doctoral Dissertations

The Qweak project is seeking to find new physics beyond the Standard Model. It is aimed to measure the weak charge of the proton, which has never been measured, at 4% precision at low momentum transfer. The experiment is performed by scattering electrons from protons and exploiting parity violation in the weak interaction at low four-momentum transfer.

In this experiment, two measurements were considered: which are elastic and inelastic. The elastic is to measure the proton's weak charge. In addition, the inelastic asymmetry measurement, which will extract the low energy constant dΔ. That measurement works in the neutral ...

Stretching The Limits Of Dynamic Range, Shielding Effectiveness, And Multiband Frequency Response, Matthew J. Hartmann

Doctoral Dissertations

In this dissertation, an RF MEMS variable capacitor suitable for applications requiring ultrawide capacitive tuning ranges is reported. The device uses an electrostatically tunable liquid dielectric interface to continuously vary the capacitance without the use of any moving parts. As compared to existing MEMS varactors in literature, this device has an extremely simple design that can be implemented using simple fabrication methods that do not necessitate the use of clean room equipment. In addition, this varactor is particularly suited for incorporating a wide range of liquid dielectric materials for specific tuning ratio requirements.

Additionally, the shielding effectiveness performance of graphene-doped ...

Electrochemical Behavior Of Dense Electrodes For Impedancemetric Nox Sensors, Nabamita Pal

Doctoral Dissertations

NOx (NO and NO2) exhaust gas sensors for diesel powered vehicles have traditionally consisted of porous platinum (Pt) electrodes along with a dense ZrO2 based electrolyte. Advancement in diesel engine technology results in lower NOx emissions. Although Pt is chemically and mechanically tolerant to the extreme exhaust gas environment, it is also a strong catalyst for oxygen reduction, which can interfere with the detection of NOx at concentrations below 100 ppm. Countering this behavior can add to the complexity and cost of the conventional NO x sensor design. Recent studies have shown that dense electrodes are less prone to heterogeneous ...

Trihalomethane, Dihaloacetonitrile, And Total N-Nitrosamine Precursor Adsorption By Carbon Nanotubes: The Importance Of Surface Oxides And Pore Volume, Erin Needham

Graduate Theses and Dissertations

As drinking water sources become increasingly impaired, enhanced removal of natural organic matter (NOM) may be required to curb formation of disinfection byproducts (DBPs) upon chlor(am)ination. While carbon nanotubes (CNTs) can adsorb NOM, their properties for DBP precursor adsorption have not been elucidated. Nine types of CNTs were assessed for trihalomethane (THM), dihaloacetonitrile (DHAN), and total N-nitrosamine (TONO) precursor adsorption. Batch isotherm experiments were completed with lake water and, to simulate an impaired condition, effluent from a wastewater treatment plant (WWTP). Adsorption varied with CNT type and dose, with TONO precursors having the highest percent removals from WWTP ...

Development Of A Multiband Remote Sensing System For Determination Of Unsaturated Soil Properties, Cyrus D. Garner

Graduate Theses and Dissertations

A multiband system including active microwave sensing and visible-near infrared reflectance spectroscopy was developed to measure unsaturated soil properties in both field and laboratory environments. Remote measurements of soil volumetric water content (θv), soil water matric potential (ψ), and soil index properties (liquid limit [LL], plastic limit [PL], and clay fraction [CF]) were conducted. Field-based measurement of θv was conducted using a ground-based radar system and field measurements within 10 percentage points of measurements acquired with traditional sampling techniques were obtained. Laboratory-based, visible and near infrared spectroscopy was found to be capable of obtaining empirical, soil specific regression functions (partial ...

Effect Of Column Axial Load On Skewed Smf Rbs Connection Demands, Clovis Desrochers

Graduate Theses and Dissertations

Steel buildings in high seismic areas often require special structural systems to transfer large lateral forces induced by earthquake accelerations. The selection of an appropriate seismic steel system (braced frame, moment frame, shear wall, etc.) is often influenced by architectural considerations. Moment frame configurations offer the most architectural flexibility, but are limited by code prequalification requirements that limit the use of non-orthogonal (skewed) beam-column connection geometries. A recent study has investigated laterally skewed moment frame connections, indicating that skew increases the potential for column twist and column flange yielding; however, it is unclear how realistic column axial loads will affect ...

Numerical Simulation Of Metallic Uranium Sintering, Bruce Berry

Graduate Theses and Dissertations

Conventional ceramic oxide nuclear fuels are limited in their thermal and life-cycle properties. The desire to operate at higher burnups as is required by current utility economics has proven a formidable challenge for oxide fuel designs. Metallic formulations have superior thermal performance but are plagued by volumetric swelling due to fission gas buildup. In this study, we consider a number of specific microstructure configurations that have been experimentally shown to exhibit considerable resistance to porosity loss. Specifically, a void sizing that is bimodally distributed was shown to resist early pore loss and could provide collection sites for fission gas buildup ...

A Comparison Of Force And Pressure Coefficients On Dome, Cube And Prism Shaped Buildings Due To Straight And Tornadic Wind Using Three Dimensional Computational Fluids Dynamics, Majdi A. A. Yousef

Graduate Theses and Dissertations

Tornadoes induce very different wind forces than a straight-line (SL) wind. A suitably designed building for a SL wind may fail when exposed to a tornado-wind of the same wind speed. It is necessary to design buildings that are more resistant to tornadoes. Most studies have been conducted to investigate tornado forces on cubic, gable-roof and cylinder buildings. However, little attention has been paid to investigate tornado force on dome buildings; hence, further research is conducted in this study. The forces on a dome, cube and prisms were analyzed and compared using Computational Fluid Dynamics (CFD) for tornadic and SL ...

Understanding N-Nitrosodimethylamine Formation In Water: Chloramine Chemistry, Kinetics, And A Proposed Reaction Pathway, Huong Thu Pham

Graduate Theses and Dissertations

The formation of N-nitrosodimethylamine (NDMA) in drinking water systems is a concern because of its potential carcinogenicity and occurrence at toxicologically relevant levels. The postulated mechanism for NDMA formation involves a substitution between dichloramine and amine-based precursors to form an unsymmetrical dimethylhydrazine (UDMH), which is then oxidized by ground-state molecular oxygen to form NDMA. However, this latter reaction is spin forbidden, thus likely occurs at a slow rate. It is hypothesized that the reaction between monochloramine and hydroxylamine (a nitrification product) may form an intermediate, which is involved in the NDMA formation pathway. This intermediate may also be generated from ...

Computer Simulation Of Pore Migration Due To Temperature Gradients In Nuclear Oxide Fuel, Ian Wayne Vance

Graduate Theses and Dissertations

A phase-field simulation model is being presented that captures the thermal-gradient-driven migration of pores in oxide fuel associated with fuel restructuring. The model utilizes a Cahn-Hilliard equation supplemented with an advection term to describe the vapor transport of fuel material through the pore interior due to gradients in vapor pressure. In addition, the model also captures changes in a migrating pores’ morphology. Simulations demonstrate that the model successfully predicts pore migration towards the hottest portion of the fuel, the centerline. The simulations also demonstrate changes in pore shape that are in agreement with previous experimental observations. Initially isotropic pores are ...

Exploring Compaction Effects On Cold In-Place Recycling Mixtures Using Emulsified Asphalt, Erica Ann Yeung

Graduate Theses and Dissertations

Cold in-place recycling (CIR) is a process that takes three to four inches of existing pavement surface and reuses 100% of it by milling and crushing it, adding asphalt emulsions and/or additives to it, before placing and re-compacting it. There is currently very little research regarding the interaction between the crushed aggregate and asphalt emulsion during the CIR process. In this study, the interactions between the combinations of crushed aggregates and asphalt emulsions were investigated along with select compaction metrics and a raveling performance test. The three types of aggregates included coated limestone, recycled asphalt pavement (RAP), and coated ...