Digital Commons Network^™

Rf Reliability Comparison Between Dc Stressed And Non-Dc-Stressed Gan-On-Si Hemts In A 1ghz Class F Power Amplifier, Ryan W. White

Master's Theses

Gallium Nitride (GaN) is a wide band gap semiconductor with an energy gap of 3.4eV. The large energy gap of this III-V semiconductor gives it the ability to withstand high electric fields, high operating temperatures, and allows for high power density. These properties of GaN maintain their advantage at high frequencies and are ideal for use in power amplifiers. This thesis discusses the reliability of a GaN high electron mobility transistor (HEMT) used in a class F power amplifier configuration. GaN HEMTs have only been commercially available since 2006 and as a result their long term reliability is still under …

Consumer Purchase Decisions Regarding Screw Cap Wines, Lauren M. Jeter

Master's Theses

Screw cap wine closures provide many benefits in maintenance of wine quality over time, however acceptance of their use by purchasers has varied. This work first investigates how factors like age, gender, income and education affect the decision to purchase screw cap wines and to what extent these factors impact consumer decisions to bring screw cap wine to various social settings. The results of a questionnaire pooling attitudes and behaviors of wine purchasers (n=319) indicate that factors such as age, wine knowledge, income and gender influence a consumer’s decision to purchase screw cap wine. Education and income positively impact the …

Implementation Of Novel Group Delay Decomposition Method And Surgical Protocol For Assessing Peripheral Neuropathy, Sammy Paul Nicolas

Master's Theses

This paper outlines a surgical procedure for exposing and stimulating the sciatic nerve of an anesthetized rodent for purposes of obtaining conduction velocity readings. The ability to accurately quantify nerve conduction velocity has potential for use in the field of diagnostic medicine and disease characterization. An accurate reading depends on both the surgical method used to expose the desired nerve without imposing onto it any physical trauma as well as the stimulation protocol used to initiate action potentials. This paper contains the specific steps required to set up the necessary hardware and software for electrical stimulation as well as a …

Determination Of Human Powered Helicopter Stability Characteristics Using Multi-Body System Simulation Techniques, Sean M. Brown

Master's Theses

Multi-Body System Simulation combined with System Identification was developed as a method for determining the stability characteristics of a human powered helicopter(HPH) configurations. HPH stability remains a key component for meeting competition requirements, but has not been properly treated. Traditional helicopter dynamic analysis is not suited to the HPH due to its low rotation speeds and light weight. Multi-Body System Simulation is able to generate dynamic response data for any HPH configuration. System identification and linear stability theory are used to determine the stability characteristics from the dynamic response. This thesis focuses on the method development and doesn't present any …

Optimizing The Mechanical Characteristics Of Bamboo To Improve The Flexural Behavior For Biocomposite Structural Application, Jay Lopez

Master's Theses

Global awareness and preservation have spurred increasing interest in utilizing environmentally friendly materials for high-performance structural applications. Biocomposites pose an appealing solution to this issue and are characterized by their sustainable lifecycles, biodegradable qualities, light weight, remarkable strength, and exceptional stiffness. Many of these structural qualities are found in applications that exhibit flexural loading conditions, and this study focuses on improving the bending performance of engineered biocomposite structures. The current application of biocomposites is increasing rapidly, so this expanding research explores other natural constituent materials for biocomposite structures under flexural loading.

The renewable material investigated in this study was experimentally …

Reliability Analysis Of Low-Silver Bga Solder Joints Using Four Failure Criteria, Erin A. Kimura

Master's Theses

The appropriate selection of failure criterion for solder joint studies is necessary to correctly estimate reliability life. The objective of this study is to compare the effect of different failure criteria on the reliability life estimation. The four failure criteria in this study are a 20% resistance increase defined in the IPC-9701A standard, a resistance beyond 500 Ω, an infinite resistance (hard open), and a failure criterion based on X-bar and R control charts. Accelerated thermal cycling conditions of a low-silver BGA study included 0°C to 100 °C with ten minute dwell times and -40°C to 125°C with ten minute …

Validation Of The Self-Compassion Scale: Correlations With The Beck Depression Inventory-Ii, Pär Daniel Andréasson

Master's Theses

Self-compassion denotes a compassionate and empathic attitude toward oneself (Neff, 2003b). In the past decade, the Self-Compassion Scale (SCS) has been used to measure self-compassion in individuals and its effects on social, psychological, and physiological functioning. While many studies have found positive effects of high self- compassion showing promise for the use of the construct in clinical and empirical applications, there is a dearth of literature regarding the psychometric properties of the SCS. Furthermore, previous studies have not evaluated the individual subscales of the SCS as they relate to other inventories. This study evaluated the SCS and its subscales in …

Constant Conduction Angle Biasing For Class C Monolithic Rf Power Amplifiers, Gursewak Singh Rai

Master's Theses

In modern wireless communication systems, a base station typically serves a few hundred users within its cell coverage. To combat the near-far problem – the situation where a nearby user’s strong cellular signal masks the cellular signal of a faraway user – base stations continually enforce power control. That is, nearby users must lower their transmit power. In CDMA technology, power control can be as large as 70-80dB. At low power outputs, this greatly impacts the performance of the RF power amplifier (PA) in the cellular device. For small RF drives, the magnitude of the output RF current approaches the …

Fault Mapping With The Refraction Microtremor And Seismic Refraction Methods Along The Los Osos Fault Zone, Justin Riley Martos

Master's Theses

The presence of active fault traces in proximity to any new infrastructure project is a major concern for the design process. The relative displacements that can be experienced in surface fault rupture during a seismic event must be either entirely avoided or mitigated in some way. Blind faults present a significant challenge to engineers attempting to identify these hazards. Current standards of practice employed to locate these features are time consuming and costly. This work investigates the geophysical methods of refraction microtremor (ReMi) and seismic refraction with regard to their applicability in this task. By imaging a distinct lateral variation …

Mechanical Optimization And Buckling Analysis Of Bio-Composites, Cameron D. Chan

Master's Theses

Today’s environmental concerns have led a renewed search in industry to find new sustainable materials to replace non-renewable resources. President Barack Obama also quoted in the recent 2012 Presidential Debate “that there is a need to build the energy sources of the future and invest in solar, wind, and bio-fuels.” Bio-composites are believed to be the future and the new substitute for non-renewable resources. Bio-composites are similar to composites in that they are made up of two constituent materials; however the main difference is that bio-composites are made from natural fibers and a biopolymer matrix. This research investigates the buckling …

Narrative Abilities Of Optimal Outcome Children And Adolescents With A Previous History Of Autism Spectrum Disorder (Asd), Joyce Suh

Master's Theses

Background: Autism Spectrum Disorders (ASDs) have traditionally been considered a lifelong condition; however there appear to be a subset of people who make such significant improvements that they no longer meet diagnostic criteria for autism. The current study examines whether these “optimal outcome” (OO) children and adolescents continue to have subtle language and socio-cognitive deficits. Method: The narratives of 15 children and adolescents with a history of ASD who achieved optimal outcomes (OO), 15 high-functioning children and adolescents with a current ASD diagnosis (HFA), and 15 typically developing peers (TD) were evaluated. Results: OO children and adolescents have few residual …

The Impact Of Water On Girls' Formal Education: A Study Of Kenyan Secondary Schools, Jennifer Emick

Master's Theses

This study applies a human rights lens to view how the lack of access to potable water in Kenya’s rural areas impacts girls’ education. This research is intended to serve as a baseline for iteration and expansion, with the long-term goal of developing a greater understanding of the ways in which water development projects and the smarter provision of basic resources can be used as strategies for achieving gender equality in both education and civic participation.

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

Master's Theses

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

Survey Of Surface Fault Rupture And Structure Interation, Lucy Redmond

Master's Theses

This report aims to raise awareness of the hazards of surface fault rupture and to identify parameters that influence structural performance during earthquake fault rupture. In researching structures subject to surface rupture, both damaged and sound, guidelines and procedures to evaluate buildings in potential hazard areas are developed herein. Little to no guidance on how to design for surface fault offset exists in current codes and design guides. Thus it is important create tools for designers to appropriately analyze structures by developing guidance and requirements to aid designers in their strength assessment of a structure subject to this particular hazard. …

Thermal Qualification Program Of Nasa's Multiple Payload Ejector (Mpe) For Responsive Deployment Of Small Satellites On A Single Launch Vehicle, Roland Coelho

Master's Theses

This thesis describes the passive thermal design of NASA’s Multiple Payload Ejector (MPE) using optical coatings and insulation blankets, thermal analysis performed on the MPE in worst case hot and cold orbits as well as thermal vacuum chamber simulation, the results of the MPE system level qualification thermal vacuum test, and the correlation of data between the modeling analysis and the thermal vacuum test. Initial conditions, environments, and model construction are discussed along with the Thermal Desktop predictions for worst case flight conditions and thermal balance. The temperature data from the thermal vacuum test is compared with the predictions from …

Effects Of Experimentally Increased Testosterone On Movement And The Effects Of Sex And Age On Relative Cortical Volumes In The Northern Pacific Rattlesnake (Crotalus O. Oreganus), Julius A. Frazier

Master's Theses

ABSTRACT

Effects of Experimentally Increased Testosterone on Movement and the

Effects of Sex and Age on Relative Cortical Volumes in the Northern Pacific

Rattlesnake (Crotalus o. oreganus)

Julius A. Frazier

Hormones have been shown to play a crucial role in vertebrate reproductive behaviors. Androgens such as testosterone (T) stimulate male sexual behaviors such as mate-searching. Increases in movement and sex differences in navigational demands associated with increased movement are positively related to the volumes of cortical brain regions associated with navigational ability. In mammals and birds, the development and morphology of the hippocampal region, a structure within the …

Transferability And Robustness Of Predictive Models To Proactively Assess Real-Time Freeway Crash Risk, Cameron Hunter Shew

Master's Theses

This thesis describes the development and evaluation of real-time crash risk assessment models for four freeway corridors, US-101 NB (northbound) and SB (southbound) as well as I-880 NB and SB. Crash data for these freeway segments for the 16-month period from January 2010 through April 2011 are used to link historical crash occurrences with real-time traffic patterns observed through loop detector data.

The analysis techniques adopted for this study are logistic regression and classification trees, which are one of the most common data mining tools. The crash risk assessment models are developed based on a binary classification approach (crash and …

Finite Element Model Updating For Rotary Machinery, Nathalie Gotin

Master's Theses

The main approach of this thesis was to develop a mathematical model that represents a rotary machine. Experimental data was used to define a finite element model (FEM). In order to obtain the experimental data, the rotary machine had to be balanced. An impact hammer test made it possible to obtain frequency response functions (FRF). The frequency response functions were curvefitted in order to obtain the mode shapes and natural frequencies.

Mathematical models have been created with ABAQUS and Matlab. For the Matlab Model the assumption has been made that the rotor machine consists of a specific number of beam …

Challenging Space Through Activism: Scaling Local And Global Issues At The 2012 London Olympic Games, Bridget Botelho

Master's Theses

This qualitative study focuses on issues of space created by the Olympic Games in London and the ways in which activists demonstrated against these issues by using space to their advantage. The Olympic Games is a phenomenon that scales local, national and international space in various ways, through its effects on global culture, identity, and economic processes. The games have a history of protest and activism, but the issues created by the games and struggles against them are not often discussed. My study aims to analyze the spatial effects of the Olympics on a local and global level through the …

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

Master's Theses

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

An Economic Analysis Of Wine Grape Production In The State Of Connecticut, Jeremy L. Jelliffe

Master's Theses

The Connecticut Wine and Vineyard industry has grown at a steady 3.9% per year over the past decade (ATTTB, 2009). Economic models estimate that the wineries sub-sector contributes $38 million dollars to the state economy and direct employment of 106 residents (Lopez et al., 2010). Programs to support and foster further growth of the industry and CT farm vineyard culture include the Department of Agriculture’s CT Wine Trail and the annual CT Wine festival (DOAG, 2010). Farmland preservation groups also support vineyard development since grape growing tends to secure tracts of farmland for long periods of time.

Investment analysis for …

Measurement And Analysis Of The Standby Power Of Twenty-Seven Portable Electric Spas, Andrew Ian Hamill

Master's Theses

Portable electric spas are typically the largest electrical load in homes that have one. In recent years, the California Energy Commission’s California code of regulations, Title 20 has been revised to regulate the maximum allowable standby power for a portable electric spa based on the spa volume. The goal of this regulation is to require improvements to the lowest performing models, for which simple and cost effective improvements are readily available, without eliminating average or better performing products.

In this research, the standby power of twenty seven portable electric spas was measured and compared to the Title 20 requirement. These …

Hydrodynamic Focused Passive Separation Under Continuous Flow In A Microfluidic Chip, Jad Kanbar

Master's Theses

A continuous flow, passive separation device was designed using an equivalent circuit to create variable flow rates for hydrodynamic focusing to drain channels and collection outlets. By varying the diameter of the sample inlet connection into the reservoir, the particle position was influenced significantly, which enabled desired separations. Additionally it was noted that the relative, horizontal position of the inlet also had a significant influence on particle position within the device. A dimensionless number, the Characteristic Sample Inlet, was developed to relate geometric properties of the inlet reservoir to downstream particle distribution. It was found that a 2:1 ratio between …

Optimal Slewing Of A Constrained Telescope Using Seventh Order Polynomial Input Torques, Julia K. Bush

Master's Theses

Two-axis gimbals are frequently used to point cameras and telescopes at various points of interest for surveillance, science, and art. The rotation of a two-axis gimbal system is governed by nonlinear angular momentum equations of motion. This paper presents a method for slewing a telescope in space with a gimbaled sensor attached to a nominally non-rotating spacecraft using two seventh order polynomial input functions to characterize torques. To accomplish this task, picking the optimal coefficients of the seventh order polynomial was necessary. It was also desired to use constraint equations to limit the excursion, angular velocity, angular acceleration, and jerk …

Responding To Dangerous Accidents Among The Elderly: A Fall Detection Device With Zigbee-Based Positioning, Michael R. Putnam

Master's Theses

The following paper describes a fall detection and activity monitoring system with position detection based on Zigbee transceivers.The main objective is to reduce the time taken for emergency personnel to respond to falls among the elderly. Especially when the victim is unconscious or delirious, position tracking reduces location determination time within a busy hospital or nursing home environment and facilitates immediate treatment. Reduced response times correlate to decreased morbidity and mortality rates. Background is provided on the major wireless network advances currently deployed in a healthcare setting for asset and personnel tracking, etiology of falls, and several methods of detecting …

Identification Of Orbital Objects By Spectral Analysis And Observation Of Space Environment Effects, Jason B. Rapp

Master's Theses

This report presents an investigation and development of the methods for orbital object identification. Two goals were accomplished in this master’s thesis; the development of a method of inverting material proportions from an object’s combined spectrum, and the investigation of methods and initialization of measurement of space environment effects on spectral features of common spacecraft materials. A constrained least squares approach was chosen for inverting spectral proportions from the combined spectra. The final results fall within 1 - 15% of the original spectrum, depending on the quality and noise levels of the original spectrum. Additionally, the effects of outgassing and …

Analysis Of A Goldschmied Propulsor Using Computational Fluid Dynamics Referencing California Polytechnic's Goldschmied Propulsor Testing, Cory A. Seubert

Master's Theses

The Goldschmied Propulsor is a concept that was introduced in mid 1950's by Fabio Goldschmied. The concept combines boundary layer suction and boundary layer ingestion technologies to reduce drag and increase propulsor efficiency. The most recent testing, done in 1982, left questions concerning the validity of the results. To answer these questions a 38.5in Goldschmied Propulsor was constructed and tested in Cal Poly's 3x4ft wind tunnel. The focus of their wind tunnel investigation was to replicate Goldschmied's original testing and increase the knowledge base on the subject. The goal of this research was to create a computational fluid dynamics (CFD) …

Anti-Corrosion Performance Of Primer And Top Coat Formulations For Metal Substrates, Laural Elizabeth Hargrove

Master's Theses

This project involved the improvement of several properties of the current “universal” primer coating sold by Kelly-Moore Paint Company. This formulation is an all purpose primer used both for interior and exterior applications. However, its corrosion resistance has room for improvement. The addition of sodium nitrite, an aminocarboxylate salt, and a zinc phosphate-based additive were all tested as corrosion inhibitors. In addition, during the project the coating binder was changed to improve adhesion. After a systematic experimental program, a new “universal” primer with increased corrosion resistance and adhesion was formulated.

A direct to metal top coat formulation sold by Kelly-Moore …

Hierarchical Routing Protocols In Wireless Sensor Networks, Andrew David Lebeau

Master's Theses

In recent wireless sensor network research, using a mobile data center (sink) to collect data has shown the ability to decrease the overall energy expenditure of the sensor field. Before the introduction of mobile sinks, many different routing protocols were developed under the assumption of a stationary sink. This work compares three such routing protocols, one hierarchical and two non-hierarchical, under the assumption of a mobile sink to determine which is best. The three protocols are tested against varying sink speed, node communication radius, and sensor field node populations. Different sink movement strategies and modifications to the routing protocols are …

An Alternative Dual-Launch Architecture For A Crewed Asteroid Mission, Steven M. Korn

Master's Theses

This thesis is a feasibility study for a crewed mission to a Near Earth Asteroid (NEA). An alternate dual-launch architecture is proposed and analyzed against a more established architecture. Instead of a rendezvous in a low-Earth parking orbit, the new architecture performs the rendezvous while the two spacecraft are on an Earth-escape trajectory to the destination NEA. After selecting a target asteroid, 2000 SG344, each architecture will have its best mission compared to the best mission of the other architecture.

Using the new architecture, a mission is created to the chosen NEA, 2000 SG344. A back-up Orion MPCV and a …