Engineering Commons^™

Experimental Investigation Of Active Wingtip Vortex Control Using Synthetic Jet Actuators, Peter J. Sudak

Master's Theses

An experiment was performed in the Cal Poly Mechanical Engineering 2x2 ft wind tunnel to quantify the effect of spanwise synthetic jet actuation (SJA) on the drag of a NACA 0015 semispan wing. The wing, which was designed and manufactured for this experiment, has an aspect ratio of 4.20, a span of 0.427 m (16.813”), and is built around an internal array of piezoelectric actuators, which work in series to create a synthetic jet that emanates from the wingtip in the spanwise direction. Direct lift and drag measurements were taken at a Reynolds Number of 100,000 and 200,000 using a …

Interfacial Interactions Between Carbon Nanoparticles And Conjugated Polymers, Yanqi Luo

Master's Theses

Conjugated polymer based electronics, a type of flexible electronic devices, can be produced from solution by traditional printing and coating processes in a roll-to-roll format such as papers and graphic films. This shows great promise for the emerging energy generation and conversion. The device performance of polymer electronics is largely dependent of crystalline structures and morphology of photoactive layers. However, the solution crystallization kinetics of conjugated polymers in the presence of electron acceptor nanoparticles has not been fully understood yet. In this study, solution crystallization kinetics of poly (3-hexylthiophene) in the presence of carbon nanotubes and graphene oxide has been …

Nerve Fiber Diameter Measurements Using Hematoxylin And Eosin Staining And Brightfield Microscopy To Assess The Novel Method Of Characterizing Peripheral Nerve Fiber Distributions By Group Delay, Jorge Arturo Vazquez

Master's Theses

Peripheral neuropathies are a set of common diseases that affect the peripheral nervous system, causing damage to vital connections between various parts of the body and the brain and spinal cord. Different clinical conditions are known to selectively impact various size nerve fibers, which often makes it difficult to diagnose which peripheral neuropathy a patient might have. The nerve conduction velocity diagnostic test provides clinically useful information in the diagnosis of some peripheral neuropathies. This method is advantageous because it tends to be minimally invasive yet it provides valuable diagnostic information. However, this test does not determine characteristics of peripheral …

Treatment Of Nitrogen Oxides By Chlorella Vulgaris Algae In Photobioreactors, Steven Shihady

Master's Theses

The effectiveness of algae to treat NO₂and NO in simulated flue gas was tested using Chlorella vulgaris in photobioreactors (PBRs) using NO_xconcentrations between 30 ppm to 780 ppm. NO_xdissolved and reacted in water to form NO₃^-and NO₂^-in the PBR growth medium, providing a nitrogen source that the algae readily assimilated for cell synthesis. Three 20-L photobioreactors were inoculated with a pure culture of C. vulgaris prepared in Bristol growth medium and algae were grown in the PBRs at 25°C and pH of 7.0 in a modified Bristol medium …

Stereo Vision System Module For Low-Cost Fpgas For Autonomous Mobile Robots, Connor Citron

Master's Theses

Stereo vision uses two adjacent cameras to create a 3D image of the world. A depth map can be created by comparing the offset of the corresponding pixels from the two cameras. However, for real-time stereo vision, the image data needs to be processed at a reasonable frame rate. Real-time stereo vision allows for mobile robots to more easily navigate terrain and interact with objects by providing both the images from the cameras and the depth of the objects. Fortunately, the image processing can be parallelized in order to increase the processing speed. Field-programmable gate arrays (FPGAs) are highly parallelizable …

Development And Use Of Moisture-Suction Relationships For Geosynthetic Clay Liners, Jacob Law Risken

Master's Theses

A laboratory test program was conducted to determine the moisture-suction relationships of geosynthetic clay liners (GCLs). Moisture-suction relationships were determined by combining suction data from pressure plate tests, contact filter paper tests, and relative humidity tests, then fitting water retention curves (WRCs) to the data. WRCs were determined for wetting processes and drying processes in terms of gravimetric moisture content and volumetric moisture content.

The effects of GCL type, hydration solution, wet-dry cycles, and temperature on the moisture-suction relationships were analyzed. The three GCLs of the test program consisted of configurations of woven and nonwoven geotextiles reinforced with needlepunched fibers. …

Grid-Scale Energy Storage: A Proposed Control Algorithm For Sodium Sulfur Batteries, Daniel Spaizman

Master's Theses

With carbon dioxide levels in our atmosphere reaching record highs and 2020 quickly approaching, California is expected to pave the way for the United States in terms of replacing fossil fuel generation facilities with various renewable energy power plants. It is well documented that the inherent variability and limited duty cycle of renewables has hindered their growth. Energy storage technologies represent the bridge that can help us cross the divide from where we stand to where we must stand in the next 6 years. Utility companies value services such as peak shaving, voltage support, and frequency regulation, all of which …

Synthesis And Characterization Of Cdse/Zns Core/Shell Quantum Dot Sensitized Pcpdtbt-P3ht:Pcbm Organic Photovoltaics, Buddy J. Bump

Master's Theses

Durable, cheap, and lightweight polymer based solar cells are needed, if simply to meet the demand for decentralized electrical power production in traditionally “off-grid” areas. Using a blend of Poly(3-hexylthiophene-2,5-diyl) (P3HT), Phenyl-C61-butyric acid methyl ester (PCBM), and the low band-gap polymer Poly[2,6-(4,4-bis-(2- ethylhexyl)-4H-cyclopenta [2,1-b;3,4-b′]dithiophene)-alt-4,7(2,1,3-benzothiadiazole)] (PCPDTBT), we have fabricated devices with a wide spectral response and 3% power conversion efficiency in AM 1.5 conditions; however, this thin film system exhibits only 0.43 optical density at 500 nm. To improve the performance of this polymer blend photovoltaic, we aim to increase absorption by adding CdSe(ZnS) core (shell) quantum dots. Four groups of …

Influence Of Grain Size And Widmanstätten Colonies On Variability Of Tensile Properties Of Forged Ti-6al-4v, Blake T. Gaspar

Master's Theses

When testing forgings for specifications, it was found that some parts did not meet the requirements for mechanical properties. This triggered an investigation into two of the parts from the lot that did not meet specification. The ultimate reason for failure was due to lower than necessary yield strength and ultimate tensile strength values, as well as unwanted variability between regions of the part. Therefore, samples of the regions were tensile tested to determine the differences that existed in yield strength, ultimate tensile strength, and elongation. After tensile testing, quantitative metallography and fractography were conducted to identify aspects of the …

An Investigation Into The Properties And Fabrication Methods Of Thermoplastic Composites, Ann E. Livingston-Peters

Master's Theses

As applications for thermoplastic composites increase, the understanding of their properties become more important. Fabrication methods for thermoplastic composites continually improve to match designs specifications. These advanced thermoplastics have begun to show an improvement in mechanical properties over those found in thermoset composites commonly used in industry. Polyaryletherketones (PEK) have high service temperatures, good mechanical properties, and improved processing capabilities compared to thermoplastics used in the past making them important to the aerospace industry. The wide range of types of PEK make them suitable for a variety of applications, but selection of specific chemistries, processing parameters, and composite stack-ups determine …

Developent Of A Phospholipid Encapsulation Process For Quantum Dots To Be Used In Biologic Applications, Logan Grimes

Master's Theses

The American Cancer Society predicts that 1,665,540 people will be diagnosed with cancer, and 585,720 people will die from cancer in 2014. One of the most common types of cancer in the United States is skin cancer. Melanoma alone is predicted to account for 10,000 of the cancer related deaths in 2014. As a highly mobile and aggressive form of cancer, melanoma is difficult to fight once it has metastasized through the body. Early detection in such varieties of cancer is critical in improving survival rates in afflicted patients. Present methods of detection rely on visual examination of suspicious regions …

Design, Implementation, And Test Of A Micro Force Displacement System, Evan Derek Cate

Master's Theses

The design and implementation of a micro-force displacement system was completed to test the force-displacement characteristics of square silicon diaphragms with side lengths of 4mm, 5mm, and 7mm with a thickness of 10um. The system utilizes a World Precision Instruments Fort 10g force transducer attached to a World Precession Instruments TBM4M amplifier. A Keithley 2400 source meter provided data acquisition of the force component of the system. A micro prober tip was utilized as the testing probe attached to the force transducer with a tip radius of 5um. The displacement of samples was measured using a Newport M433 linear stage …

A Study On The Vibrational Performance Characteristics Of An E22 Isolator After Outgassing And Bake-Out, Alma Melendez

Master's Theses

The launch environment experiences many vibration, shock, and acoustic loads. A great concern is the high random vibration levels that can damage components and spacecraft structures, which can cause a mission failure. An effective method of reducing high frequency energy is using isolators. Overall, the need for vibration isolation has been increasing because there has been an increase in the use of mechanisms in which vibrations are prevalent. In addition, there has not been extensive research on the effects of isolators that are outgassed and cured. Therefore, it is important to investigate and understand the vibrational effects on isolators. It …

Smart Wall Outlet Design And Implementation For The Dc House Project, Kevin Roy Mendoza

Master's Theses

Most everyday AC appliances are designed to operate off of 120V coming from the wall outlet in our homes. This voltage is a standard set from our established infrastructure. Unlike AC devices, DC devices do not have any set standard of voltage they all will run off of. This presents a problem for the DC house as the various loads that will be used will have different required input voltages. One set voltage for a wall outlet will not suffice for the DC House. This Smart Wall Outlet is designed with a DC-DC converter that will have its output voltage …

A Frequency-Domain Method For Active Acoustic Cancellation Of Known Audio Sources, Ryan D. Rocha

Master's Theses

Active noise control (ANC) is a real-time process in which a system measures an external, unwanted sound source and produces a canceling waveform. The cancellation is due to destructive interference by a perfect copy of the received signal phase-shifted by 180 degrees. Existing active noise control systems process the incoming and outgoing audio on a sample-by-sample basis, requiring a high-speed digital signal processor (DSP) and analog-to-digital converters (ADCs) with strict timing requirements on the order of tens of microseconds. These timing requirements determine the maximum sample rate and bit size as well as the maximum attenuation that the system can …

Water And Nutrient Recycling In High Rate Algae Ponds Fed In Primary Treated Municipal Wastewater, Michael Field Chang

Master's Theses

Algal biofuels present a promising future alternative to petroleum based fuels. Water nutrient recycling is a key step to increase the sustainability of algae biofuel production facilities. This thesis discusses the process of nutrient and water recycling in high rate algae raceway ponds (HRAP) fed primary treated municipal wastewater. Research was conducted primarily at the San Luis Obispo Water Resource Reclamation Facility (SLOWRRF). Nine 30 m², 0.3 m deep HRAP’s were operated continuously from June 1, 2013 to April 17, 2014. The ponds were arranged in three sets of triplicate ponds, with two pond sets run on 3-day …

Characterizing The Reproducibility Of The Properties Of Electrospun Poly(D, L-Lactide-Co-Glycolide) Scaffolds For Tissue-Engineered Blood Vessel Mimics, Toni M. Pipes

Master's Theses

“Blood vessel mimics” (BVMs) are tissue-engineered constructs that serve as in vitro preclinical testing models for intravascular devices. The Cal Poly Tissue Engineering lab specifically uses BVMs to test the cellular response to stent implantation. PLGA scaffolds are electrospun in-house using the current “Standard Protocol” and used as the framework for these constructs. The performance of BVMs greatly depends on material and mechanical properties of the scaffolds. It is desirable to create BVMs with reproducible properties so that they can be consistent models that ultimately generate more reliable results for intravascular device testing. Reproducibility stems from the consistency of the …

Flight Testing Small Uavs For Aerodynamic Parameter Estimation, Adam Thomas Chase

Master's Theses

A flight data acquisition system was developed to aid unmanned vehicle designers in verifying the vehicle's design performance. The system is reconfigurable and allows the designer to choose the correct combination of complexity, risk, and cost for a given flight test. The designer can also reconfigure the system to meet packaging and integration requirements. System functionality, repeatbility, and accuracy was validated by collecting data during multiple flights of a radio-controlled aircraft. Future work includes sensor fusion, thrust prediction methods, stability and control derivative estimation, and growing Cal Poly's small-scale component aerodynamic database.

Reduced-Order Reference Models For Adaptive Control Of Space Structures, Alexander I. Scherling

Master's Theses

In addition to serving as a brief overview of aspects relevant to reduced-order modeling (in particular balanced-state and modal techniques) as applied to structural finite element models, this work produced tools for visualizing the relationship between the modes of a model and the states of its balanced representation.

Specifically, error contour and mean error plots were developed that provide a designer with frequency response information absent from a typical analysis of a balanced model via its Hankel singular values. The plots were then used to analyze the controllability and observability aspects of finite element models of an illustrative system from …

Optimization Of Growth Parameters For Algal Regrowth Potential Experiments, Chadwick D. Boggess

Master's Theses

Water cost is one of the key deterrents in making algal biofuels a feasible alternative to traditional petroleum fuels. Research into recycling of algal media was conducted in a laboratory setting at the California Polytechnic State University in San Luis Obispo. A growth assay was created to allow for algal cultures, specifically Ward’s Chlorella sp., to proliferate in sealed culture vessels. Bold’s Basal Medium (BBM) was selected as the media due to its extensive use with freshwater algal strains. However, this medium can limit algal growth through nutrient limitation and it became necessary to augment the original recipe. 50mM …

Variable Precision Tandem Analog-To-Digital Converter (Adc), Colton A. Parsons

Master's Theses

This paper describes an analog-to-digital signal converter which varies its precision as a function of input slew rate (maximum signal rate of change), in order to best follow the input in real time. It uses Flash and Successive Approximation (SAR) conversion techniques in sequence.

As part of the design, the concept of "total real-time optimization" is explored, where any delay at all is treated as an error (Error = Delay * Signal Slew Rate). This error metric is proposed for use in digital control systems. The ADC uses a 4-bit Flash converter in tandem with SAR logic that has variable …

The Effect Of Pretreatment Methods On Methane Yield And Nutrient Solubilization During Anaerobic Digestion Of Microalgae, Alexander Scott Hill

Master's Theses

Microalgal biomass is a candidate feedstock for biofuel production. To improve the sustainability of algae biofuel production, following biofuel recovery, the biomass nutrients should be recycled for additional algae growth. Anaerobic digestion of algae or oil-extracted algae is a means of recovering carbon and other nutrients, while offsetting algae production electricity demand. The major limiting factor in microalgae digestion is the low biodegradability of the cell walls. In the present study, various pretreatment technologies were tested at bench scale for their ability to improve raw, non-lipid-extracted algae biodegradability, which was assessed in terms of methane yield, volatile solids destruction, and …

Mos Current Mode Logic (Mcml) Analysis For Quiet Digital Circuitry And Creation Of A Standard Cell Library For Reducing The Development Time Of Mixed Signal Chips, David Marusiak

Master's Theses

Many modern digital systems use forms of CMOS logical implementation due to the straight forward design nature of CMOS logic and minimal device area since CMOS uses fewer transistors than other logic families. To achieve high-performance requirements in mixed-signal chip development and quiet, noiseless circuitry, this thesis provides an alternative toCMOSin the form of MOS Current Mode Logic (MCML). MCML dissipates constant current and does not produce noise during value changing in a circuit CMOS circuits do. CMOS logical networks switch during clock ticks and with every device switching, noise is created on the supply and ground to deal with …

Cooperative Construction In Schools In California, John Mauck Donley

Master's Theses

Cooperative Construction in Schools in California

John M. Donley

The construction industry has lost efficiency since 1964, while becoming increasingly more litigious. Schools in California can ill afford the time to allow the construction industry time to fully evolve. It may take years or decades to fully improve the efficiency of, and reduce the conflict within the construction industry.

At the same time, the construction industry has developed new processes to improve efficiency and reduce conflict. These processes are beginning to be broadly embraced by the industry. They all contain cooperative elements. Taken together they represent a new organizing principle …

Regen: Optimizing Genetic Selection Algorithms For Heterogeneous Computing, Scott Kenneth Swinkleb Winkleblack

Master's Theses

GenSel is a genetic selection analysis tool used to determine which genetic markers are informational for a given trait. Performing genetic selection related analyses is a time consuming and computationally expensive task. Due to an expected increase in the number of genotyped individuals, analysis times will increase dramatically. Therefore, optimization efforts must be made to keep analysis times reasonable.

This thesis focuses on optimizing one of GenSel’s underlying algorithms for heterogeneous computing. The resulting algorithm exposes task-level parallelism and data-level parallelism present but inaccessible in the original algorithm. The heterogeneous computing solution, ReGen, outperforms the optimized CPU implementation achieving a …

The Effect Of Fiber Depth On The Estimation Of Peripheral Nerve Fiber Diameter Using Group Delay And Simulated Annealing Optimization, Nam Tran

Master's Theses

Peripheral neuropathy refers to diseases of or injuries to the peripheral nerves in the human body. The damage can interfere with the vital connection between the central nervous system and other parts of the body, and can significantly reduce the quality of life of those affected. In the US, approximately between 15 and 20 million people over the age of 40 have some forms of peripheral neuropathy. The diagnosis of peripheral neuropathy often requires an invasive operation such as a biopsy because different forms of peripheral neuropathy can affect different types of nerve fibers. There are non-invasive methods available to …

Analysis Of Environmentally Friendly Marking Ink For Military Equipment And Electronics, Liang Li

Master's Theses

Recent advancements in corrosion-resistance coating technology has reduce the use of environmentally harmful compounds such as Hexavalent Chromium by replacing Hexavalent Chromium in primers and topcoat. However, marking inks were neglected in the process. Products such as Enthone 50 series are still widely used, which contain compounds such as lead, hexavalent chromium, bisphenol A (BPA), Cadmium Sulfide, and more. Excluding catalyst compositions in Enthone, the chemicals in the ink alone contained three reproductive toxicant and numerous carcinogens. Therefore, it was essential to search and validate the performance of potential marking ink that would meet the standards in military applications.

Eleven …

Multi-Criteria Decision Modeling For Best Value Selections In Target Value Design Integrated Project Delivery, Brent Patrick Griffis

Master's Theses

Integrated Project Delivery (IPD) combined with Target Value Design (TVD) is a better way to deliver value for the client than traditional guaranteed maximum price (GMP) methods. With traditional GMP delivery methods, the interests of the parties are often at odds. The goal of IPD is to align all party interests in order to achieve a win-win scenario. Due to the aligning nature of IPD and the fact that each party’s success is dependent on achieving the project objectives as a whole; a non-biased, transparent, decision-making process is necessary in order to deliver the project objectives within the constraints of …

High-Speed Mobile Networks For Modern Farming And Agricultural Systems, Santos Najar

Master's Theses

ABSTRACT

High-Speed Mobile Networks for Modern Farming and Agricultural Systems

J.Santos Najar-Ramirez

High-speed mobile networks are necessary for agriculture to inventory individual plant health, maximize yield and minimize the resources applied. More specifically, real-time information on individual plant status is critical to decisions regarding the management of resources reserved and expended. This necessity can be met by the availability of environmental sensors (such as humidity, temperature, and pH) whose data is kept on storage servers connected to static and mobile local area networks. These static and mobile local area networks are connected to cellular, core and satellite networks. For …

Data Chunking In Quasi-Synchronous Ds-Cdma, Trevor Dalke

Master's Theses

DS-CDMA is a popular multiple access technique used in many mobile networks to efficiently share channel resources between users in a cell. Synchronization between users maximizes the user capacity of these systems. However, it is difficult to perfectly synchronize users in the reverse link due to the geographic diversity of mobile users in the cell. As a result, most commercial DS-CDMA networks utilize an asynchronous reverse link resulting in a reduced user capacity. A possible compromise to increase the user capacity in the reverse link is to implement a quasi-synchronous timing scheme, a timing scheme in which users are allowed …