Digital Commons Network^™

Corrosion Dynamics Of Cobalt-Chromium Alloy F-75 Powder, Tedman Tong

Master's Theses

The increasing usage of metal-on-metal joint replacements consisting of a cobalt-chromium-molybdenum alloy requires increasing concern regarding the inevitable generation of metallic wear debris. Patients with these joint replacements exhibit elevated concentrations of cobalt and chromium ions within their serum, blood and urine. The presence of these metal ions suggests the potential for bodily damage and indicates corrosive processes are acting upon wear debris.

To understand the behavior of these corrosive processes, powders of cobalt-chromium-molybdenum alloy F-75 were studied. Four powder sizes (44, 74, 105, and 420 µm diameter) were subjected to Hank’s Balanced Salt Solution (HBSS) for a 42 day …

The Effects Of Applied Strain And Heat Treatment On The Properties Of Niti Wire During Shape Setting, Frank Zapoticla

Master's Theses

NiTi components are commonly subjected to thermo-mechanical heat treatments during production and fabrication. This study investigates the effects of applied strain of 0-10% and heat treatments of 300-600ºC for times of 2-30 minutes during shape-setting of Ti–50.8 at% Ni wire with a nominal diameter of 0.495 mm and an initial transition temperature, Af, of 12ºC. Strain was applied prior to heat treatments by coiling NiTi wire, essentially producing coiled springs, around different diameter steel mandrels to obtain different strain levels. The samples of NiTi wire under applied strain were heat treated in a salt bath, followed by a rapid quench. …

St. Jude Medical: Enhanced Mics (Emics), Devanshi Shah

Master's Theses

Heart disease is one of the most prevalent diseases in the world. The survival chances for patients with ventricular fibrillation/ventricular tachycardia reduces significantly as time passes without treatment and even after getting timely treatment recurring episode are common. These patients can benefit from an Implantable Cardioverter Defibrillator (ICD) which can monitor heart rhythm and provide immediate treatment. Due to the ever changing physical conditions and disease progression, the ICD needs to collect diagnostic data as well as support programming by the physician. The ICD uses inductive telemetry and radio-frequency telemetry for the communication with the external devices such as a …

Enhanced Cal Poly Super System Simulink Model, Matthew Ogden Mcfarland

Master's Theses

The Cal Poly Sustainable Power for Electrical Resources (SuPER) project is a solar power DC distribution system designed to autonomously manage and supply the energy needs of a single family off-the-grid home. The following thesis describes the improvement and re-design of a MATLAB Simulink model for the Cal Poly SuPER system. This model includes a photovoltaic (PV) array, a lead-acid gel battery with temperature effects, a wind turbine model, a re-designed DC-DC converter, a DC microgrid, and multiple loads. This thesis will also include several control algorithms such as a temperature controlled thermoelectric (T.E.) cooler, intelligent load switching, and an …

Picasso Interface For Horizon Simulation Framework, Brian E. Kirkpatrick

Master's Theses

The Horizon Simulation Framework, or HSF, is a modeling and simulation framework compiled from C/C++ source code into a command line program. Picasso is an interface designed to control the input files to Horizon by providing visual tools to create and manipulate the XML files used to define an HSF system of assets, their environment, and other simulation parameters. Picasso also supports the visualization of Horizon output in several different forms, and import mechanics from online space object catalogues.

Implementation Of A Conrad Probe On A Boundary Layer Measurement System, Charles Rocky Ulk

Master's Theses

This thesis presents the design, calibration, and performance evaluation of a type of two-hole pressure probe anemometer known as a Conrad probe, as well as its subsequent implementation on an autonomous, compact boundary layer measurement device and its first application for subsonic in-flight measurements of a swept wing boundary layer. Calibration of the Conrad probe was accomplished using two calibration functions and a non-nulling method for resolving in-plane flow velocity direction and magnitude over a range of ±30 degrees. This approach to calibration and application offered the advantages of rapid data acquisition with lower energy consumption than alternative methods for …

Development Of Measurement Methods For Application To A Wind Tunnel Test Of An Advanced Transport Model, Robert S. Ehrmann

Master's Theses

California Polytechnic State University, San Luis Obispo is currently working towards developing a Computational Fluid Dynamics (CFD) database for future code validation efforts. Cal Poly will complete a wind tunnel test on the Advanced Model for Extreme Lift and Improved Aeroacoustics (AMELIA) in the National Full-Scale Aerodynamics Complex (NFAC) 40 foot by 80 foot wind tunnel at NASA Ames Research Center in the summer of 2011. The development of two measurement techniques is discussed in this work, both with the objective of making measurements on AMELIA for CFD validation.

First, the work on the application of the Fringe-Imaging Skin Friction …

Integration Of Microfluidics With Surface Plasmon Resonance, Scott B. Fratzke

Master's Theses

This thesis successfully integrates laminate microfluidic devices with an analytic Surface Plasmon Resonance (SPR) instrument. Integration was accomplished at low-cost using materials such as polydimethylsiloxane (PDMS), Poly(methyl methacrylate) (PMMA), Tygon tubing, and a 3-way stopcock. The main components of this thesis are the design and fabrication of the low-cost, in-house fluidics that can integrate with upstream microfluidics and the validation of the in-house fluidics using the Biosensing Instruments BI-2000 SPR instrument. The low-cost fluidics was designed and fabricated “in-house” using a novel investment casting technique that required the use of laser cutting technology to make a master cast, and candle …

Class-F Power Amplifier With Maximized Pae, Kai Shing Tsang

Master's Theses

Due to the rapid development of telecommunication devices, operating speeds are getting faster and more power is being consumed by those devices. Therefore, there is a big concern on how to prolong the battery life in order to fit consumers’ needs. Power amplifiers (PA) at the front end of wireless equipment have drawn a big concern from engineers because of their large power consumption in the system. There is a lot research conducted on PA solutions for improving power-added efficiency (PAE) of amplifiers. PAE is a figure of merit representing how efficient the PA converts DC power to RF power. …

St. Jude Medical: An Object-Oriented Software Architecture For Embedded And Real-Time Medical Devices, Atila Amiri

Master's Theses

Medical devices used for surgical or therapeutic purposes require a high degree of safety and effectiveness. Software is critical component of many such medical devices. The software architecture of a system defines organizational structure and the runtime characteristic of the application used to control the operation of the system and provides a set of frameworks that are used to develop that. As such, the design of software architecture is a critical element in achieving the intended functionality, performance, and safety requirements of a medical device. This architecture uses object-oriented design techniques, which model the underlying system as a set of …

Asynchronous Mips Processors: Educational Simulations, Robert L. Webb

Master's Theses

The system clock has been omnipresent in most mainstream chip designs. While simplifying many design problems the clock has caused the problems of clock skew, high power consumption, electromagnetic interference, and worst-case performance. In recent years, as the timing constraints of synchronous designs have been squeezed ever tighter, the efficiencies of asynchronous designs have become more attractive. By removing the clock, these issues can be mitigated. How- ever, asynchronous designs are generally more complex and difficult to debug. In this paper I discuss the advantages of asynchronous processors and the specifics of some asynchronous designs, outline the roadblocks to asynchronous …

Tribological Comparison Of Traditional And Advanced Firearm Coatings, Greg Boban

Master's Theses

The objective of this project is to find which type of coating has the best performance characteristics for finishing firearms. This is accomplished by measuring and comparing several performance characteristics, such as: adhesion, hardness, wear resistance, friction control, and corrosion resistance. Appearance is not a factor since any exterior coating that is flashy can be subdued or camouflaged with special purpose paints, which have proven durable enough for such purposes. Cost will not be a limiting factor for this experiment, but will be discussed in the conclusion as a secondary concern. This data will be used to identify the best …

Implementation Of Physiologic Pressure Conditions In A Blood Vessel Mimic Bioreactor System, Kevin Mark Okarski

Master's Theses

ABSTRACT

Implementation of Physiologic Pressure Conditions in a Blood Vessel Mimic Bioreactor System

Kevin Mark Okarski

Tissue engineering has traditionally been pursued as a therapeutic science intended for restoring or replacing diseased or damaged biologic tissues or organs. Cal Poly’s Blood Vessel Mimic Laboratory is developing a novel application of tissue engineering as a tool for the preclinical evaluation of intravascular devices. The blood vessel mimic (BVM) system has been previously used to assess the tissue response to deployed stents, but under non-physiologic conditions. Since then, efforts have been made to improve the vessel and bioreactor’s ability to emulate in …

Feasibility Of Manipulating Correlated Color Temperatures With A Phosphor Converted High-Powered Light Emitting Diode White Light Source, Matthew Michael Little

Master's Theses

In this thesis we examine the feasibility of developing a white light source capable of producing colors between 2500 and 7500 Kelvin on the black-body radiator spectrum by simply adjusting amperage to a blue and ultraviolet (UV) light emitting diode (LED). The purpose of a lighting source of this nature is to better replicate daylight inside a building at a given time of day. This study analyzes the proposed light source using a 385 nm UV LED, a 457 nm blue LED, a 479 nm blue LED, a 562 nm peak cerium doped yttrium aluminum garnet (YAG:Ce) phosphor, and a …

The Characterization And Analysis Of In-Vitro And Elevated Temperature Repassivation Of Ti-6al-4v Via Afm Techniques, Aaron J. Guerrero

Master's Theses

ABSTRACT

The Characterization and Analysis of In-vitro and Elevated Temperature Repassivation of

Ti-6Al-4V via AFM Techniques

Aaron J Guerrero

Research in the corrosion of orthopaedic implants is a growing research field where implants have been known to show adverse effects in patients who have encountered the unfortunate dissolution of their implants due to corrosion. Once corrosion begins within the body, many adverse biological reactions can occur such as late on-set infections resulting in severe health complications. The focus of this research is specifically related to the problem of late on-set infections caused by localized corrosion of orthopaedic implants. In medical …

Preference Driven University Course Scheduling System, Heather A. Bellardo

Master's Theses

University course planning and scheduling is the process of determining what courses to offer, how many sections are needed, determining the best term to offer each section, assigning a faculty member to instruct each section, and scheduling each section to a timeslot to avoid conflicts. The result of this task has an impact on every student and faculty member in the department. The process is typically broken down into three major phases: course offering planning, faculty assignment to planned course sections, and course scheduling into timeslots.

This thesis looks at each of these phases for the Industrial and Manufacturing department …

Distributed Generation: Issues Concerning A Changing Power Grid Paradigm, Scott G.M. Therien

Master's Theses

Distributed generation is becoming increasingly prevalent on power grids around the world. Conventional designs and grid operations are not always sufficient for handling the implementation of distributed generation units; the new generation may result in undesirable operating conditions, or system failure. This paper investigates the primary issues involved with the implementation of distributed generation and maintaining the integrity of the power grid. The issues addressed include power flow, system protections, voltage regulation, intermittency, harmonics, and islanding. A case study is also presented to illustrate how these issues can be addressed when designing distributed generation installation on an existent distribution system. …

Standalone Antenna Demonstration System, Alexander James Hempy

Master's Theses

Antenna systems play a significant role in today’s electronic communications. They are essential for cell phones, satellites, radio, and radar among many other important applications. This paper describes the design, assembly, and operation of an antenna demonstration system designed to instill interest in the field of antenna design among high school and undergraduate college students. The system is portable, supplied solely by DC power supplies, easily reproducible, and includes rotational axes to illustrate antenna performance limitations and requirements. It provides a visual indication of wireless signal strength and demonstrates several antenna performance characteristics including polarization, gain and directivity, radiation patterns …

Scale Model Shake Table Testing Of Underground Structures In Soft Clay, Victor A. Crosariol

Master's Theses

Underground structures perform an important role in transportation systems in many seismically active regions around the world, but empirical data regarding the seismic behavior of these structures is limited. This research works towards filling that empirical gap through the use of scale model shake table testing. Underground seismic soil-structure interaction (USSSI) effects were investigated for a stiff rectangular tunnel cross-section embedded within soft clay. San Francisco Young Bay Mud was used as a prototype soil for developing a scale model soil mixture consisting of kaolinite, bentonite, class C fly ash, and water. A single cell Bay Area Rapid Transit (BART) …

Numerical Examination Of Flow Field Characteristics And Fabri Choking Of 2d Supersonic Ejectors, Brett G. Morham

Master's Theses

An automated computer simulation of the two-dimensional planar Cal Poly Supersonic Ejector test rig is developed. The purpose of the simulation is to identify the operating conditions which produce the saturated, Fabri choke and Fabri block aerodynamic flow patterns. The effect of primary to secondary stagnation pressure ratio on the efficiency of the ejector operation is measured using the entrainment ratio which is the secondary to primary mass flow ratio.

The primary flow of the ejector is supersonic and the secondary (entrained) stream enters the ejector at various velocities at or below Mach 1. The primary and secondary streams are …

A Constant Conduction Angle Biased Rf Power Amplifier For Improved Linearization In Class C Operation, Greg Lacaille

Master's Theses

Class C power amplifiers offer higher efficiency than class B power amplifiers, but suffer from poor linearity. A feedback based biasing system to improve the linearity of a class C power amplifier is designed. A class B amplifier with a gain of 20 dB and 20 MHz bandwidth at 900 MHz acts as the launching point for the design. The biasing and output network of the class B power amplifier is modified to produce a class C amplifier at conduction angles of 180°, 162°, 126°, 90°, and 54°. A feedback based biasing system, which uses two matched and scaled down …

Novel Inverse Airfoil Design Utilizing Parametric Equations, Kevin A. Lane

Master's Theses

The engineering problem of airfoil design has been of great theoretical interest for almost a century and has led to hundreds of papers written and dozens of methods developed over the years. This interest stems from the practical implications of airfoil design. Airfoil selection significantly influences the application's aerodynamic performance. Tailoring an airfoil profile to its specific application can have great performance advantages. This includes considerations of the lift and drag characteristics, pitching moment, volume for fuel and structure, maximum lift coefficient, stall characteristics, as well as off-design performance.

A common way to think about airfoil design is optimization, the …

Pulse Density Modulated Soft Switching Cycloconverter, Jesse Timothy Adamson

Master's Theses

Single stage cycloconverters generally incorporate hard switching at turn on and soft switching at turn off. This hard switching at turn on combined with the slow switching speeds of thyristors (the switch of choice for standard cycloconverters) limits their use to lower frequency applications.

This thesis explores the analysis and design of a pulse density modulated (PDM), soft switching cycloconverter. Unlike standard cycloconverters, the controller in this converter does not adjust thyristor firing angles. It lets only complete half cycles of the input waveform through to the output. This allows and requires a much greater frequency step down from the …

Development Of A Meshless Method To Solve Compressible Potential Flows, Alejandro Ramos

Master's Theses

The utility of computational fluid dynamics (CFD) for solving problems of engineering interest has experienced rapid growth due to the improvements in both memory capacity and processing speed of computers. While the capability now exists for the solution of the Navier-Stokes equations about complex and complete aircraft configurations, the bottleneck within the process is the time consuming task of properly generating a mesh that can accurately solve the governing partial differential equations (PDEs). This thesis explored two numerical techniques that attempt to circumvent the difficulty associated with the meshing process by solving a simplified form of the continuity equation within …

Systems Engineering Analysis And Digital Communication Bus Design For The Cal Poly Super Project, Matt Marcus Camack

Master's Theses

With an expected lifetime of 20 years and an expected cost of $500, the Cal Poly Sustainable Power for Electrical Resources (SuPER) project needed a strong central design. This thesis looks at the work completed by students over the previous 5 years, with an eye on the future, to create the phase 2 design. Part of this new structure focuses on a distributed communication bus for monitoring system health and status. Instead of complex and costly computer or FPGA systems, the new system will run solely with microcontrollers. This reduces costs and will hopefully still be used within 5, 10, …

Aperture Coupled Microstrip Antenna Design And Analysis, Michael Paul Civerolo

Master's Theses

A linearly-polarized aperture coupled patch antenna design is characterized and optimized using HFSS antenna simulation software. This thesis focuses on the aperture coupled patch antenna due to the lack of fabrication and tuning documentation for the design of this antenna and its usefulness in arrays and orthogonally polarized communications. The goal of this thesis is to explore dimension effects on aperture coupled antenna performance, to develop a design and tuning procedure, and to describe performance effects through electromagnetic principles.

Antenna parameters examined in this study include the dimensions and locations of the substrates, feed line, ground plane coupling slot, and …

Http 1.2: Distributed Http For Load Balancing Server Systems, Graham M. O'Daniel

Master's Theses

Content hosted on the Internet must appear robust and reliable to clients relying on such content. As more clients come to rely on content from a source, that source can be subjected to high levels of load. There are a number of solutions, collectively called load balancers, which try to solve the load problem through various means. All of these solutions are workarounds for dealing with problems inherent in the medium by which content is served thereby limiting their effectiveness. HTTP, or Hypertext Transport Protocol, is the dominant mechanism behind hosting content on the Internet through websites. The entirety of …

Negative Conductance Load Modulation Rf Power Amplifier, Cody R. Neslen

Master's Theses

The number of mobile wireless devices on the market has increased substantially over the last decade. The frequency spectrum has become crowded due to the number of devices demanding radio traffic and new modulation schemes have been developed to accommodate the number of users. These new modulation schemes have caused very poor efficiencies in power amplifiers for wireless transmission systems due to high peak-to-average power ratios (PAPR). This thesis first presents the issue with classical power amplifiers in modern modulation systems. A brief overview of current attempts to mitigate this issue is provided. A new RF power amplifier topology is …

Digital Signaling Processor Resource Management For Small Office Phone Systems, John T. Gilkeson

Master's Theses

Contemporary small office phone systems are specialized computers that connect a variety of phones within the office and to the local phone company. These systems use digital signaling processors (DSPs) to convert signals from analog to digital and vice-versa. Many different types of applications run on the DSPs and different businesses have varying application needs. Given the systems have limited amounts of DSP resources and growing numbers of applications for a phone system, an administrator needs a way to configure the uses of resources based on their individual business needs.

This thesis provides an overview of a system for configuring …

Monocular Vision And Image Correlation To Accomplish Autonomous Localization, Matthew Paul Schlachtman

Master's Theses

For autonomous navigation, robots and vehicles must have accurate estimates of their current state (i.e. location and orientation) within an inertial coordinate frame. If a map is given a priori, the process of determining this state is known as localization. When operating in the outdoors, localization is often assumed to be a solved problem when GPS measurements are available. However, in urban canyons and other areas where GPS accuracy is decreased, additional techniques with other sensors and filtering are required.

This thesis aims to provide one such technique based on monocular vision. First, the system requires a map be generated, …