Engineering Commons^™

How To Tell When A Product Of Two Partially Ordered Spaces Has A Certain Property?, Francisco Zapata, Olga Kosheleva, Karen Villaverde

Departmental Technical Reports (CS)

In this paper, we describe how checking whether a givenproperty F is true for a product A₁ X A₂ of partiallyordered spaces can be reduced to checking several relatedproperties of the original spaces A_i.

This result can be useful in the analysis of propertiesof intervals [a,b] = {x: a <= x <= b}over general partially ordered spaces -- such as the spaceof all vectors with component-wise order or the set of allfunctions with component-wise ordering f <= g <-->for all x (f(x) <= g(x)). When we consider sets of pairs ofsuch objects A₁ X A₂, it is natural to define the orderon this set in terms of orders in A₁ and A₂ -- this is, e.g.,how ordering and intervals are defined on the set R² of all2-D vectors.

This result …

Numerical Modeling Of Aquaculture Dissolved Waste Transport In A Coastal Embayment, Subhas K. Venayagamoorthy, Hyeyun Ku, Oliver B. Fringer, Alice Chiu, Rosamond L. Naylor, Jeffrey R. Koseff

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Marine aquaculture is expanding rapidly without reliable quantification of effluents. The present study focuses on understanding the transport of dissolved wastes from aquaculture pens in near-coastal environments using the hydrodynamics code SUNTANS (Stanford Unstructured Nonhydrostatic Terrain-following Adaptive Navier-Stokes Simulator), which employs unstructured grids to compute flows in the coastal ocean at very high resolution. Simulations of a pollutant concentration field (in time and space) as a function of the local environment (bathymetry), flow conditions (tides and wind-induced currents), and the location of the pens were performed to study their effects on the evolution of the waste plume. The presence of …

Development And Implementation Of Challenge-Based Instruction In Engineering Graphics, Gregory A. Potter

Theses and Dissertations - UTB/UTPA

This thesis discusses the challenge-based instructional (CBI) lessons currently being developed for the Engineering Graphics course at UTPA. This endeavor concentrates on student retention, as well as the students’ ability to practically apply their new skills. Minority science, technology, engineering, and math (STEM) students have been found, in recent studies, to depart from STEM undergraduate fields to some extent because of the lack of real world connections to the subject matter. Also, the traditional way of teaching theory first and then assigning a task may actually stifle creative thought and innovation required in later STEM courses. Our use of CBI …

Probabilistic Assessment Of The Friendship Trail Bridge, Rajan Sen, Gray Mullins, Niranjan Pai

Civil and Environmental Engineering Faculty Publications

The analysis performed in this study is theoretical and uses data found in the open literature rather than actual data for the bridge. The results presented indicate that the bridge is unlikely to meet a service life of an additional 20 years at reliability levels required by prevailing design codes while foregoing routine maintenance. In the light of the lower than typical reliability predicted by the analysis, more frequent bridge inspections will be needed to maintain safety in the event the bridge is repaired. vii The predictions are critically dependent on assumptions relating to the corrosion rate and statistical distributions …

Stress Relaxation Of Glass Using A Parallel Plate Viscometer, Guy-Marie Vallet

All Theses

Currently, grinding and polishing is the traditional method for manufacturing optical glass lenses. However, for a few years now, precision glass molding has gained importance for its flexibility in manufacturing aspheric lenses. With this new method, glass viscoelasticity and more specifically stress relaxation are important phenomena in the glass transition region to control the molding process and to predict the final lens shape.
The goal of this research is to extract stress relaxation parameters in shear of Pyrex¨ glass by using a Parallel Plate Viscometer (PPV). The PPV machine was originally created to measure the viscosity of glass solid cylinders …

Morphology Changes In Pcpdtbt:Pcbm And P3ht:Pcpdtbt:Pcbm And Its Effect On Polymer Solar Cell Performance, Galen David Cauble

Physics

Polymer solar cell morphology is sensitive to both heat and time. By thermally annealing polymer solar cells the morphology of the devices can be altered causing immediate changes in device performance. Blending PCPDTBT:PCBM with P3HT:PCPDTBT combines the absorption characteristics of each to create a more even absorption spectrum. Subjecting PCPDTBT:PCBM, and P3HT:PCPDTBT:PCBM polymer solar cells to thermal annealing as well as recording device performance through time has shown that P3HT:PCPDTBT:PCBM devices react positively to thermal annealing (increasing from 0.8% to 1.4%) while PCPDTBT:PCBM devices have varied reactions. Furthermore, the P3HT:PCPDTBT:PCBM devices have achieved efficiencies of 1.6% in AM 1.5 compared …

Evaluation Of Safe Routes To School Programs: Qualitative And Quantitative Analysis Of Parental Decision-Making, Lynn Weigand, Noreen Mcdonald

TREC Final Reports

In the United States, walking to school declined from 42% of 5-18 year olds in 1969 to 16% in 20011. The US Department of Transportation has responded to this dramatic decrease by funding the Safe Routes to School program for $612 million in SAFETEA-LU. The program’s funding emphasize infrastructure improvements such as completing sidewalks and adding crosswalks by requiring between 70% and 90% of funding be allocated toward infrastructure. However, recent research shows that 2 of 3 children who currently are driven to school, but live close enough to walk, do so because it is more convenient for parents. Currently, …

In Situ Analysis Of Crack Propagation In Polymer Foams, Elio E. Saenz, Leif A. Carlsson, Anette M. Karlsson

Mechanical Engineering Faculty Publications

This article presents an experimental study on the microscopic mechanisms associated with crack propagation in closed cell polymer foams. A brittle, slightly cross-linked polyvinyl chloride (PVC) foam of density 60 kg/m³ and a ductile thermoplastic polyether sulfone (PES) foam of density 90 kg/m³ were examined. The PVC and PES foams have similar cell size (≈0.7 mm) but the cell edges of the PES foam were much thicker than those in the PVC foam. Overall, it was observed that the elements of both foams fractured in an extensional mode. Crack propagation in the PVC foam was inter-cellular, where agglomerates …

A History-Dependent Nonwetting Phase Trapping Model For Multiphase Flow Characteristic Curves, Christopher Patterson

All Theses

Characteristic curves used in numerical multiphase flow simulators describe relative permeability-saturation and capillary pressure-saturation relationships for flow simulations. Characteristic curves are typically non-hysteretic; meaning they are monotonic functions of saturation and are limited to a single value for residual saturation. Implications of residual saturation are important for environmental, petroleum, and geologic carbon sequestration modeling. However, hysteretic characteristic curves predict that trapped residual saturation depends on the local saturation history. The use of hysteretic characteristic curves is critical to predicting the residual saturation and ultimately the mobility of a nonwetting phase such as supercritical CO2 or a nonaqueous phase liquid (NAPL). …

Model-Based System Fault Diagnosis Utilizing Adaptive Threshold With Application To Automotive Electrical Systems, Ali Hashemi

All Theses

Recent advancement in the field of automotive industry is largely due to the addition of electrical and electronic equipment; some of the safety features in the vehicle and advanced driver assistance systems are examples of such equipment. Furthermore, safe operation of the vehicle is highly dependent on the electrical power generation and storage system (EPGS). Therefore, to ensure optimal operation of this system, a reliable diagnosis of the system is essential. However, as the complexity of the electrical systems has increased, the identification of a malfunction has become an increasingly difficult task to handle.
In the current work, a model-based …

Influence Of Natural Organic Matter On Plutonium Sorption To Gibbsite, Laura Simpkins

All Theses

Understanding plutonium geochemical behavior is imperative to the development of schemes for remediation of plutonium environmental contamination and accurate assessment of risks posed by the disposal of plutonium bearing wastes. The primary mechanism of plutonium mobility in the environment is subsurface transport. The mobility of plutonium is significantly influenced by redox and complexation reactions. Although the effects of surface mediated redox reactions on plutonium's subsurface mobility have been previously documented, little has been done to determine the impact of organic materials on sorption behavior and oxidation states. To adequately predict the behavior of plutonium in the environment, the influence of …

Substrate Topography Design And Fabrication For Osteoblast And Dental Pulp Stem Cells Studies, Gloria Chen

All Theses

Research for cell guidance based tissue engineering has rapidly grown due to the increasing interest in tissue engineering and reconstructive medicine applications, such as cranial reconstruction. Many research teams have begun the process of identifying what factors influence cell behavior (including cell growth, proliferation, alignment and spreading). Published studies have pointed to the influence of the cell medial pH, substrate stiffness, chemistry and topography. Conclusive results are often hard to identify since researchers often vary many of these factors simultaneously and it is hard to decouple individual factor influence. These reports also points out that the cellular response can be …

Oxygenate Synthesis During Co Hydrogenation On Cocuzno- Based Catalysts, Yu-Tung Tsai

All Dissertations

The research of catalytic synthesis of methanol and other higher alcohols from CO hydrogenation has received great attention since 1980s. The focus of this research is to establish a better fundamental insight into heterogeneous metal catalysts for oxygenate (especially alcohol) synthesis by CO hydrogenation.
Co-based catalysts have been reported widely as the high-performance Fischer-Tropsch Synthesis (FTS) catalysts. The solid base, hydrotalcite (HT), using as a support for Co catalysts resulted in higher activity for CO hydrogenation comparing to other supports (pre-calcined hydrotalcite, MgO and Al₂O₃). The activities of Co/HT reduced at different reduction temperatures (300-600oC) were …

Does A Link Exist Between Examination Performance And Lecture Attendance For First Year Engineering Students ?, Aidan O'Dwyer

Conference papers

The objective of this study is to examine if a link exists between lecture attendance and examination performance of Level 7, Year 1, Electrical Engineering students at Dublin Institute of Technology in the Electrical Systems subject. Lecture attendance was monitored and analysed over four academic years (2007-8, 2008-9, 2009-10 and 2010-11). The average lecture attendance for students in the three academic years from 2007-10 was 55%, increasing noticeably in the 2009-10 academic year. A statistically significant weakly positive correlation between lecture attendance and examination performance was established. Each 10% increase in student attendance at lectures improved both Module 1 examination …

Anti-Stokes Fluorescence Imaging Of Microscale Thermal Fields In Thin Films, A. N. Kuzmin, A. Baev, A. V. Kachynski, Timothy S. Fisher, Ali Shakouri, P. N. Prasad

Birck and NCN Publications

We demonstrate that the in-plane thin film heat transport can be accurately mapped via confocal anti-Stokes fluorescence imaging using fluorescent dye probes and nanoheaters. We employ 3D finite elements analysis to evaluate the thermal conductivity of a control sample and to assess the validity of a point heat source approximation. We have found that this approximation is adequate with use of a tightly focused laser beam, providing a robust means for determining the thermal conductivity of a sample under investigation. (C) 2011 American Institute of Physics. [doi:10.1063/1.3606429]

Computational Study Of The Seebeck Coefficient Of One-Dimensional Composite Nano-Structures, Raseong Kim, Mark S. Lundstrom

Birck and NCN Publications

The Seebeck coefficient (S) of composite nano-structures is theoretically explored within a self-consistent electro-thermal transport simulation framework using the non-equilibrium Green's function method and a heat diffusion equation. Seebeck coefficients are determined using numerical techniques that mimic experimental measurements. Simulation results show that, without energy relaxing scattering, the overall S of a composite structure is determined by the highest barrier within the device. For a diffusive, composite structure with energy relaxation due to electron-phonon scattering, however, the measured S is an average of the position-dependent values with the weighting factor being the lattice temperature gradient. The results stress the importance …

Observation Of Nonclassical Scaling Laws In The Quality Factors Of Cantilevered Carbon Nanotube Resonators, Ajit Vallabhaneni, Jeff Rhoads, Jayathi Y. Murthy, Xiulin Ruan

Birck and NCN Publications

This work examines the quality factors (Q factors) of resonance associated with the axial and transverse vibrations of single-wall carbon nanotube (SWCNT) resonators through the use of molecular dynamics (MD) simulation. Specifically, the work investigates the effect of device length, diameter, and chirality, as well as temperature, on the resonant frequency and quality factor of these devices and benchmarks the results of MD simulations against classical theories of energy dissipation. The quality factor (Q) associated with transverse vibration is found to increase with increasing device length (Q similar to L(theta), where 0.8 < theta < 1.4) and decrease with increasing device diameter (Q similar to D(-mu), where 1.4 < mu < 1.6), while the Q associated with axial vibration is almost independent of length and diameter. We show that to accurately predict temperature dependence of Q, the external and internal energies need to be properly decomposed, and temperature quantum correction should be performed. For both vibrational modes, Q shows a temperature dependence Q similar to T(-alpha), where alpha > 1 when below Debye temperature due to quantum …

A Cross-Layer Design For The Performance Improvement Of Real-Time Video Transmission Of Secondary Users Over Cognitive Radio Networks, Haiyan Luo, Song Ci, Dalei Wu

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

Cognitive radio (CR) has been proposed as a promising solution to improve connectivity, self-adaptability, and efficiency of spectrum usage. When used in video applications, user-perceived video quality experienced by secondary users is a very important performance metric to evaluate the effectiveness of CR technologies. However, most of the current research only considers spectrum utilization and effectiveness at medium access control (MAC) and physical layers, ignoring the system performance of the upper layers. Therefore, in this paper, we aim to improve the user experience of secondary users for wireless video services over CR networks. We propose a quality-driven cross-layer optimized system …

Modeling, Finite Element Analysis, And Optimization Of Non-Pneumatic Tire (Npt) For The Minimization Of Rolling Resistance, Mallikarjun Veeramurthy

All Theses

Recently, the development of non-pneumatic tires (NPT) such as the Michelin Tweel is receiving increased attention due to potential advantages over pneumatic tires such as low mass, no run flat, good contact pressure distribution, and low rolling resistance (RR). This study focuses on the design of a NPT based on properties of vertical stiffness, contact pressure, and rolling energy loss. Using a finite element (FE) model, a parametric study is conducted to study the effect on vertical stiffness, contact pressure, and rolling resistance (RR) response considering three design variables: (1) thickness of the spokes, (2) the shear band thickness, and …

An Investigation Into Segmenting Traffic Images Using Various Types Of Graph Cuts, Jonathan Dinger

All Theses

In computer vision, graph cuts are a way of segmenting an image into multiple areas. Graphs are built using one node for each pixel in the image combined with two extra nodes, known as the source and the sink. Each node is connected to several other nodes using edges, and each edge has a specific weight. Using different weighting schemes, different segmentations can be performed based on the properties used to create the weights. The cuts themselves are performed using an implementation of a solution to the maximum flow problem, which is then changed into a minimum cut according to …

Biomedical Signal Transceivers, Reza Fazel-Rezai, Noah Root, Ahmed Rabbi, Duckhee Lee, Waqas Ahmad

Electrical Engineering Faculty Publications

With the growing costs of healthcare, the need for mobile health monitoring devices is critical. A wireless transceiver provides a cost effective way to transmit biomedical signals to the various personal electronic devices, such as computers, cellular devices, and other mobile devices. Different kinds of biomedical signals can be processed and transmitted by these devices, including electroencephalograph (EEG), electrocardiograph (ECG), and electromyography (EMG). By utilizing wireless transmission, the user gains freedom to connect with fewer constraints to their personal devices to view and monitor their health condition.

In this chapter, in the first few sections, we will introduce the reader …

Dynamics And Control Of The Shoot-The-Moon Tabletop Game, Peng Xu

All Theses

The classic table-top game Shoot-the-Moon has interesting dynamics despite its simple structure, consisting of a steel ball rolling on two cylindrical rods. The two sloped rods are hinged at the lower ends and allowed to freely slide in a slot at the higher end. The ball can amazingly roll upward along the rods under carefully manipulation of the rods. There is also an interaction between ball rotation and translation that cause the ball to ``shoot'' (quickly accelerate).
In this thesis, the kinematics are developed for Shoot-the-Moon and then equations of motion are derived using both Lagrangian and Newtonian approaches. The …

Determination Of Freshwater Algal Biomass And Sulfolipid Content As Functions Of Inorganic Carbon Treatment, Melissa Morella

All Theses

Cultures of mixed freshwater algae were grown in open batch reactors made up of modified BG-11 media that contained 0, 25, 50 or 100% of the suggested inorganic carbon content (0, 0.5, 0.1 and 0.2 g/L Na₂CO₃) to assess the subsequent production of the high-value product, sulfoquinovosyl diacylglycerol (SQDG). After 25 days of growth, the reactors were composed of primarily Oscillatoria growth. All four reactors exhibited a trend of increasing biomass and alkalinity with time, and an initial increase then decrease in pH. The total inorganic carbon (TIC) in all reactors exhibited a mirrored, opposite trend …

Enhanced Mimo Lmmse Turbo Equalization: Algorithm, Simulations, And Undersea Experimental Results, Jun Tao, Jingxian Wu, Yahong Rosa Zheng, Chengshan Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, an enhanced linear minimum mean square error (LMMSE) turbo equalization scheme is proposed for multiple-input multiple-output (MIMO) communication systems with bit-interleaved coded modulation (BICM) in the time domain and multiplexing in the space domain. the proposed turbo equalization scheme outperforms the conventional LMMSE turbo equalization by adopting two new signal processing techniques. First, it performs hybrid soft interference cancellation (HSOIC) by subtracting the soft decisions of the interfering symbols, and the soft decisions are calculated by using a hybrid of the a priori information at the equalizer input and the a posteriori information at the equalizer output. …

Dynamic, Stochastic, Computational, And Scalable Technologies For Smart Grids, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

The smart electric power grid will evolve into a very complex adaptive system under semi-autonomous distributed control. its spatial and temporal complexity, non-convexity, non-linearity, non-stationarity, variability and uncertainties exceed the characteristics found in today's traditional power system. the distributed integration of intermittent sources of energy and plug-in electric vehicles to a smart grid further adds complexity and challenges to its modeling, control and optimization. Innovative technologies are needed to handle the growing complexity of the smart grid and stochastic bidirectional optimal power flows, to maximize the penetration of renewable energy, and to provide maximum utilization of available energy storage, especially …

Sol-Gel Derived Silver-Incorporated Titania Thin Films On Glass: Bactericidal And Photocatalytic Activity, Betul Akkopru Akgun, Anthony W. Wren, Caner Durucan, Mark R. Towler, Nathan P. Mellott

Chemical and Biochemical Engineering Faculty Research & Creative Works

Titanium dioxide (TiO₂) and silver-containing TiO₂ (Ag-TiO₂) thin films were prepared on silica pre-coated float glass substrates by a sol-gel spin coating method. The bactericidal activity of the films was determined against Staphylococcus epidermidis under natural and ultraviolet (UV) illumination by four complementary methods; (1) the disk diffusion assay, (2) UV-induced bactericidal test, (3) qualitative Ag ion release in bacteria inoculated agar media and (4) surface topographical examination by laserscan profilometry. Photocatalytic activity of the films was measured through the degradation of stearic acid under UV, solar and visible light conditions. The chemical state and …

Clinical Risk Factors For Osteoporosis In Ireland And The Uk: A Comparison Of Frax And Qfracturescores, N. M. Cummins, E. K. Poku, Mark R. Towler, O. M. O'Driscoll, S. H. Ralston

Chemical and Biochemical Engineering Faculty Research & Creative Works

Recently two algorithms have become available to estimate the 10-year probability of fracture in patients suspected to have osteoporosis on the basis of clinical risk factors: the FRAX algorithm and QFractureScores algorithm (QFracture). The aim of this study was to compare the performance of these algorithms in a study of fracture patients and controls recruited from six centers in the United Kingdom and Ireland. A total of 246 postmenopausal women aged 50-85 years who had recently suffered a low-trauma fracture were enrolled and their characteristics were compared with 338 female controls who had never suffered a fracture. Femoral bone mineral …

Special Issue On Approximate Dynamic Programming And Reinforcement Learning, Silvia Ferrari, Jagannathan Sarangapani, Frank L. Lewis

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Structural Analyses Of Wind Turbine Tower For 3 Kw Horizontal Axis Wind Turbine, Tae Gyun Gwon

Master's Theses

Structure analyses of a steel tower for Cal Poly's 3 kW small wind turbine is presented. First, some general design aspects of the wind turbine tower are discussed: types, heights, and some other factors that can be considered for the design of wind turbine tower. Then, Cal Poly's wind turbine tower design is presented, highlighting its main design features. Secondly, structure analysis for Cal Poly's wind turbine tower is discussed and presented. The loads that are specific to the wind turbine system and the tower are explained. The loads for the static analysis of the tower were calculated as well. …

Characterizing Nerve Fiber Activation By Varying Fiber Diameter And Depth Within A Conductive Medium: A Finite Element Approach, Nathan Daniel Soto

Master's Theses

In some instances neuropathies can be diagnosed through a conduction velocity test. However, not all neuropathies can be classified using this method. Gaining an understanding of how the stimulus level varies for different fiber sizes at different fiber depths within a conductive medium will provide useful information for simulation studies.

Following a two-step approach using COMSOL and MATLAB, a simulation was implemented to investigate the stimulus necessary to activate different sized fibers at different depths. In this two-step approach, COMSOL was used to describe the voltage profile that would be present within a conductive medium after a stimulus was applied. …