Engineering Commons^™

Kinetics Of Corrosion Of Bn-Zro2-Sic Ceramics In Contact With Si-Killed Steel, Abhishek Kumar, Vivek Thapliyal, David G.C. Robertson, Jeffrey D. Smith

Materials Science and Engineering Faculty Research & Creative Works

The mechanism and kinetics of corrosion of BN-ZrO₂-SiC (MYCROSINT®SO43) by molten Si-killed steel was studied. Isothermal corrosion tests were performed for duration between 2 and 8 h. Refractory and steel composition and morphology changes were investigated. A kinetic model using process simulation software METSIM and thermochemical software FactSage was developed to understand refractory-steel interactions. The corrosion process showed a deviation from parabolic kinetics and was fitted by a combination of linear and parabolic terms. It was determined that corrosion of the BN-ZrO₂-SiC refractory was governed by dissolution of SiC and BN and removal of ZrO_{2 …}

Origin Of Interfacial Polar Order In Incipient Ferroelectrics, Yijia Gu, Nan Wang, Fei Xue, Long-Qing Chen

Materials Science and Engineering Faculty Research & Creative Works

There are ample experimental evidences indicating that the ferroelastic domain walls of incipient ferroelectrics, such as SrTiO₃ and CaTiO₃, are polar. The emergence of such interfacial polar order at a domain wall is exciting and believed to arise from the coupling between a primary order parameter, such as a strain or an antiferrodistortive (AFD) order parameter, and polarization. There have been several mechanisms proposed to explain the emergence of interfacial polar order, including biquadratic coupling, AFD-antiferroelectric coupling, and flexoelectric coupling. Using CaTiO₃ as an example, we demonstrate, using both asymptotic analytics and numerical calculation, that the …

The Contour Deformation Method For Calculating The High-Frequency Scattered Field By The Fock Current On The Surface Of The 3-D Convex Cylinder, Yu Mao Wu, Li (Lijun) Jun Jiang, Weng Cho Chew, Ya Qiu Jin

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the high-frequency diffracted waves like the creeping waves are comprehensively analyzed by the Fock currents. On invoking the contour deformation method, the highly oscillatory Fock currents are efficiently calculated. Furthermore, the workload for the calculation of Fock currents is frequency-independent. To capture the high-frequency wave physics phenomenon, the Fock current is separated into the classical physical optics (PO) current and the nonuniform (NU)-Fock current along the shadow boundary and in the deep shadow region. To calculate the highly oscillatory scattered wave fields from the Fock current, quadratic approximations of the phase functions in the integrand are adopted. …

Simulations Of Nanoscale Ni/Al Multilayer Foils With Intermediate Ni2al3 Growth, I. E. Gunduz, S. Onel, C. C. Doumanidis, C. Rebholz, Steven F. Son

Purdue Energetics Research Center Articles

Nanoscale multilayers of binary metallic systems, such as nickel/aluminum, exhibit self-propagating exothermic reactions due to the high formation enthalpy of the intermetallic compounds. Most of the previous modelingapproaches on the reactions of this system rely on the use of mass diffusionwith a phenomenological derived diffusion coefficient representing single-phase (NiAl) growth, coupled with heat transport. We show that the reaction kinetics, temperatures, and thermal front width can be reproduced more satisfactorily with the sequential growth of Ni2Al3 followed by NiAl, utilizing independently obtained interdiffusivities. The computational domain was meshed with a dynamically generated bi-modal grid consisting of fine and coarse zones …

The Integration Of Heat Resources In A Solar Thermal-Heat Pump Hydronic System, John Degrove

Purdue Polytechnic Masters Theses

According to the U.S. Department of Energy, roughly 41% of the energy consumed in the U.S. is used the power buildings. Within that number, almost half is used to heat or cool the building. Current technologies allow for consistent thermal management, but most utilize energy harvested from fossil fuels or convert electricity back into thermal energy. Background literature shows that the utilization of alternative heat resources such as heat pumps and solar thermal collectors can greatly reduce the energy used for heat delivery while producing adequate heating performance. A combined hydronic system using a bank of solar thermal collectors in …

Experimental And Analytical Study Of An Open Cathode Polymer Electrolyte Membrane Fuel Cell., Alex Martin Bates

Electronic Theses and Dissertations

In this thesis four different fuel cell designs were simulated with consideration for electrochemical effects, reactant species transport, and heat transfer. Simulation results include the mass fraction of hydrogen, oxygen, and water, temperature gradient, pressure gradient, and velocity profile. One of the fuel cell designs was experimentally tested using two different membrane electrolyte assemblies; one high performance and the other high durability. The polarization curve resulting from simulation compares well with the polarization curve produced by experimental work. A 16 cell fuel cell stack was simulated with consideration for stack compression. The same fuel cell stack was tested experimentally for …

Vanadium Trichloride Thermochemical Solar Energy Storage System Analysis., Caleb Michael Rogers

Electronic Theses and Dissertations

As annual energy consumption grows, developing renewable solar energy conversion systems, storage systems, and high density electrical energy production systems is growing increasingly important. The proposed system utilizes vanadium trichloride thermal decomposition to produce chlorine gas and vanadium dichloride. A second reaction combines gaseous hydrogen chloride and the product vanadium dichloride to reform vanadium trichloride and produce hydrogen gas. Hydrogen gas and chlorine gas can be stored indefinitely and electrical energy is obtained from the chemicals by a non-humidified dry membrane hydrogen – chlorine fuel cell. The fuel cell produces the gaseous hydrogen chloride needed to reform vanadium trichloride. The …

Feasibility Testing Of Chill Filtration Of Brown Spirits To Increase Product Stability., Juan Cristobal Merizalde Carrillo

Electronic Theses and Dissertations

This thesis summarizes a feasibility study focused on filtering American whiskey, matured in new toasted and charred casks, at 25 ºF in order to remove haze which forms when product is diluted from cask strength (62% ABV) to bottling strength (40 – 50% ABV). Chill filtration is a process already implemented in the brown spirits industry in order to guarantee the stability of products at different ethyl alcohol concentrations. The filtration trials and cellulose-pad performance were evaluated in terms of economics, turbidity reduction, test time, throughput, color reduction, and shelf life stability. Those trials with satisfactory overall color and stability …

Right Hand Fork Pedestrian Bridge Final Report, Ren Gibbons

Undergraduate Honors Capstone Projects

Right Hand Fork is a tributary canyon whose stream enters the Logan River nine miles east of the mouth of Logan Canyon near Logan, Utah. The access bridge to a popular recreational area, the Hobbit Caves, was damaged in 2011 by flooding. We propose that a new bridge be designed and constructed for the Forest Service to replace the current structure to ensure public safety and minimize environmental impact. We plan to use a longer bridge span that will situate the abutments higher on the stream bank and reduce possible water damage during flood events. Bridge costs will be minimized …

Binding Innovation Technologies, Restoring Freedom To The World Of Snowboard Bindings, Matthew Lee Munsee

Undergraduate Honors Capstone Projects

Snowboarding technology has progressed by leaps and bounds since the sport's inception in the 1980's. However, there is one area that has gotten progressively worse. That area is flexibility and freedom of expression. In order to make the sport safer, the industry responded by making stiffer boots and bindings. Our goal is to bring back the high level of flexibility that built the sport while maintaining or exceeding current safety standards. We also need to reduce heel side shock so as to increase the comfort of the rider. Our design consists of three major systems that drastically increase flexibility, safety, …

Mimicking Robotic Backhoe, Taylor Chad Bybee

Undergraduate Honors Capstone Projects

The proposed project is to design and create a small robotic arm that mimics movements of a similar physical model. The manual model can be manipulated by a human. Sensors inside the manual model will detect the position in each part of the arm. The information from the sensors will then be relayed, processed, and forwarded to the mimicking model. The mimicking robotic model will appropriately respond to match the smaller model, thus mimicking its position and movements.

Distributed Coordinate Tracking Control Of Multiple Wheeled Mobile Robots, Yifan Xing

Theses and Dissertations - UTB/UTPA

In this thesis, distributed coordinate tracking control of multiple wheeled-mobile robots is studied. Control algorithms are proposed for both kinematic and dynamic models. All vehicle agents share the same mechanical structure. The communication topology is leader-follower topology and the reference signal is generated by the virtual leader. We will introduce two common kinematic models of WMR and control algorithms are proposed for both kinematic models with the aid of graph theory. Since it is more realistic that the control inputs are torques so dynamic extension is studied following by the kinematics. Torque controllers are designed with the aid of backstepping …

Effect Of Crimping, Multilayering, And Twisting On Polymer Fibers For Acl Replacement, Mariana Ocampo

Theses and Dissertations - UTB/UTPA

The Anterior Cruciate Ligament (ACL) is the most common knee injury in the United States; roughly 150,000 ACL surgeries are performed annually. The ACL lacks self-healing properties due to its location inside the knee’s intra – articular environment (IA). Treatments for ACL ruptures involve the use of autogenous grafts or allografts. More suitable treatments can be found in new bio engineered tissue scaffolds, composed of natural and synthetic polymers. The polymers provide stronger mechanical properties and the ability to promote cell adhesion. It is believed that mimicking the crimping pattern of human ligaments will enhance polymer properties. Four polymers were …

Electrocardiogram Data Collection Under Network Attacks On The Mac Platform, Golshan Famitafreshi

Theses and Dissertations - UTB/UTPA

Increasing heart disease among human beings needs more precise treatment, which requires monitoring of electrocardiogram (ECG). In many cases, real time monitoring of ECG is needed via wireless or wireline networks. Use of network-connected computers for monitoring proposes can raise security issues, which can be created by viruses, worms, or external agents such as DoS attack traffic. Any alteration of this biomedical signal can lead to wrong diagnosis and wrong treatment. Furthermore, in healthcare industry, HIPAA rules require health information to be kept secure by providing confidentiality, integrity, and availability. This thesis investigates how integrity and availability of remotely monitored …

Evaluation Of Security Vulnerabilities Of Popular Computer And Server Operating Systems Under Cyber Attacks, Rodolfo Baez Jr.

Theses and Dissertations - UTB/UTPA

Nowadays many operating systems are including security features in order to prevent network attacks, and since one of the roles of the OS is to manage the resources as efficient as possible. It is imperative to investigate the protection that is provided. Therefore, the scientific significance of this thesis was to evaluate, what type of built-in defense mechanisms that different OS’s had in place in order to mitigate these network attacks. In this thesis, we considered the security of the following globally deployed computer OS’s: Microsoft’s Windows 7, Apple’s OS X Lion, and Ubuntu 13.10. Furthermore, we also tested four …

Security Integrity Of Ekg Signal Monitoring Under Different Network Attack Conditions, Raghava Teja Pingali

Theses and Dissertations - UTB/UTPA

This thesis focuses on issues related with monitoring of EKG signals under different network attack traffic conditions. It is becoming common for modern hospitals to monitor real time EKG signals of patients on computers that are usually connected to networks. If the network suffers with attack conditions, it can affect connected computers and alter EKG signals monitoring, hence raising false alarms. Denial of Service attacks may silently affect the real time monitoring of EKG signals. Altering of EKG signals may result in loss of integrity and it can violate CIA triad of security. In this thesis, different attack conditions were …

Aerodynamic Flow Field Characterization Of Airfoils With And Without Leading Edge Modifications, Oscar Hernandez

Theses and Dissertations - UTB/UTPA

Recently, much focus has been on comprehending the aerodynamic properties associated with the humpback whales pectoral fin. The perturbations found on its leading edge are believed to attribute to the humpbacks maneuverability significantly. These tubercles are assumed to be analogous to strakes on an aircraft, which generate large-scale vortices. More specifically, the vortices prompted by the leading edge increase the momentum exchange within the boundary layer, allowing the flow to remain attached at higher angles of attack, thus delaying stall and in turn increase lift by a passive means of reducing drag. The focus of this investigation is on characterizing …

Design And Development Of Two Component Hydrogel Ejector For Three-Dimensional Cell Growth, Thomas Dunkle, Jessica Deschamps, Connie Dam

Honors Scholar Theses

Hydrogels are useful in wound healing, drug delivery, and tissue engineering applications, but the available methods of injecting them quickly and noninvasively are limited. The medical industry does not yet have access to an all-purpose device that can quickly synthesize hydrogels of different shapes and sizes. Many synthesis procedures that have been developed result in the formation of amorphous hydrogels. While generally useful, amorphous hydrogels exhibit limited capability in tissue engineering applications, especially due to their viscous properties. This endeavor aims to modulate the appropriate gelation parameters, optimize the injection process, and create a prototype that allows for the extrusion …

Outer-Sphere Adsorption Of Para-Substituted Benzoates On Gibbsite: A Molecular Dynamics Investigation, Lukas Mcnaboe

Honors Scholar Theses

In soils, the spread of toxic organic anions through groundwater can be partially mitigated by the formation of inner- and outer-sphere complexes with aluminum (hydr)oxides. In current practice, a constant soil-water partition coefficient is used to describe the relative quantity of sorbed compound to that in solution. However this method is empirical and site-specific. In order to establish a thermodynamically relevant sorption model, sorption reactions between many mineral phases and organic compounds must be characterized. While there exists a wealth of research quantifying the sorption potential of ferric oxide mineral phases, there remains a gap in knowledge of these parameters …

Finite Element Analysis Of The Application Of Ultrasound-Generated Acoustic Radiation Force To Biomaterials, Nicole J. Piscopo

Honors Scholar Theses

While most bone fractures can heal simply by being stabilized, others can take a longer time to rejoin or they could fail to merge back together completely. Numerous studies have shown the positive effects that ultrasonic therapy have had on delayed-union and non-union bone fracture repair but little is known as to what specific biological mechanisms are at play. Ultrasound may be a valuable tool for bone tissue regeneration at these fracture sites using a tissue engineering approach, however, more must be understood about its impact on stimulating tissues to heal before this can be a reality. For that reason, …

Phased Array Beamsteering In Composite Laminates For Guided Wave Structural Health Monitoring, Peter Osterc

Doctoral Dissertations and Master's Theses

In this study a guided wave phased array beamsteering approach is applied to composite laminates. Current beamsteering algorithms derived for isotropic materials assume omnidirectional wave propagation. Due to inherent anisotropy in composites, guided wave propagation varies with direction and wavefronts no longer have perfect circular shapes.

By examining slowness, velocity and wave curves, as well as amplitude variation with direction for a given composite laminate, the wavefront from a single source can be described as a function of the angle of propagation and distance from origin. Using this approach, a more general delay and sum beamforming algorithm for composite laminates …

Stress-Strain Behavior By Image Analysis, Mix Density And Pre-Strain Effects Of Eps Geofoam, Chen Liu

Theses - ALL

In order to have a deeper understanding of the engineering performances of EPS geofoam, it is necessary to study the stress-strain response and internal strain distribution when loaded. In this investigation, the key objective is to study the stress-strain behavior of EPS geofoam under different conditions and develop construction practical suggestions when using geofoam. The scope of this research is divided into three main sections: (1) study the effect of induced anisotropy on the stress-strain behavior of EPS geofoam; (2) evaluate stress distribution within EPS blocks by using image analysis system; (3) analyze the effect of combining different EPS densities …

Bs News May/June

Building Services Engineering

No abstract provided.

An Automated Method For Hot-To-Cold Geometry Mapping, Brandon Levi Doolin

Theses and Dissertations

An Automated Method for Hot-to-Cold Geometry Mapping.

An Investigation Of Off-Design Operation In High Suction Performance Inducers, Ryan Collins Cluff

Theses and Dissertations

Three-dimensional two-phase unsteady CFD simulations were run on three and four-blade inducers for the purpose of analyzing differences in cavitation stability at design and off-design flow rates. At design flow rates, there were very small differences between the breakdown curves for the three and four-bladed inducers. However, at lower cavitation numbers, the three-bladed inducer exhibited up to three times the rotor forces than the four-bladed inducer. When moving to off-design flow rates, both inducers experienced multiple modes of cavitation instabilities including rotating cavitation, alternate-blade cavitation, and cavitation surge. The four-bladed inducer began experiencing the formation of these modes of instability …

Use Of Precisely Sculptured Thin Film (Stf) Substrates With Generalized Ellipsometry To Determine Spatial Distribution Of Adsorbed Fibronectin To Nanostructured Columnar Topographies And Effect On Cell Adhesion, Tadas Kasputis, Alex Pieper, Keith Brian Rodenhausen, Daniel Schmidt, Derek Sekora, Charles Rice, Eva Schubert, Mathias Schubert, Angela K. Pannier

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Sculptured thin film (STF) substrates consist of nanocolumns with precise orientation, intercolumnar spacing, and optical anisotropy, which can be used as model biomaterial substrates to study the effect of homogenous nanotopographies on the three-dimensional distribution of adsorbed proteins. Generalized ellipsometry was used to discriminate between the distributions of adsorbed FN either on top of or within the intercolumnar void spaces of STFs, afforded by the optical properties of these precisely crafted substrates. Generalized ellipsometry indicated that STFs with vertical nanocolumns enhanced total FN adsorption two-fold relative to flat control substrates and the FN adsorption studies demonstrate different STF characteristics influence …

Remote Heart Rate Estimation Using Consumer-Grade Cameras, Nathan E. Ruben

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

There are many ways in which the remote non-contact detection of the human heart rate might be useful. This is especially true if it can be done using inexpensive equipment such as consumer-grade cameras. Many studies and experiments have been performed in recent years to help reliably determine the heart rate from video footage of a person. The methods have taken an analysis approach which involves temporal Itering and frequency spectrum examination. This study attempts to answer questions about the noise sources which inhibit these methods from estimating the heart rate. Other statistical processes are examined for their use in …

Methods For Growing Retinal Pigment Epithelial Cells: Current Protocols And Future Recommendations, Aaron H. Fronk

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The retinal pigment epithelium (RPE) is a layer of tissue found in the vertebrate eye between Bruch’s membrane and the photoreceptor layer of the neural retina [1]. It is derived from the outer layer of the optic cup [2], possesses an innate immune system [3], and consists of a monolayer of highly pigmented cells that fit together in a tight matrix (fig. 1) [4]–[6]. The monolayer is often compared to a mosaic or cobblestones in its configuration, while the shape of the individual cells is usually described as polygonal/hexagonal, columnar (aligned perpendicular to the underlying membrane), or “epithelioid”. The cells …

Use Of Direct Metal Laser Sintering For Tooling In High Volume Production, Joel W. Hendrickson

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Metal 3D printing has caught the attention of many large industries. There have been stories of great success using metal 3D printing. Some of the largest industries to successfully use metal 3D printing are aerospace and medical. These industries have succeeded with metal 3D printing because of their need for light and complex parts. These success stories lead other industries to investigate how metal 3D printing or Direct Metal Laser Sintering (DMLS) can help them. Industries that are involved in high volume production ask how they can take advantage of the complexity and customization that is available with 3D printing. …

Innovative And Efficient Simulation-Optimization Tools For Successful Groundwater Management And Conflict Resolution, Bassel Timani

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Simulation-Optimization (S-O) models are exemplary for strategic groundwater management planning. The two components of an S-O model serve different purposes. The simulation component models the aquifer and computes state variables resulting from stimuli such as extraction or diversion while the optimizor computes an optimal set of stimuli that maximize an objective function and satisfy a set of constraints. With the increased use of S-O model for larger and more complex real-world study areas, the use of fast and efficient S-O models has risen. Response matrix methods (RMMs) are usually used as substitute simulators within an S-O to solve the posed …