Digital Commons Network^™

Effect Of Aquaponic Vs. Hydroponic Nutrient Solution, Led Light Intensity And Photoperiod On Indoor Plant Growth Of Butterhead, Romaine And Kale (L. Sativa, B. Oleracea), Sean M. Foster

Master's Theses

Vertical farming has been proposed as a solution for providing food security for an increasing, urbanized human population. Light-emitting diode (LED) technology has become increasingly affordable and efficient, making it an ideal choice as artificial lighting for indoor farms. Still largely undiscovered parameters are the optimal plant varieties and types of production systems for plant growth, profit, and human nutrition. Aquaponics may be able to provide sustainable animal protein for vertical farms, increasing their ability to provide more substantial nutrition to consumers. This research aimed to better understand vertical farming as a food production system, and to determine if aquaponics …

Modification Of A Ground Based Atomic Oxygen Simulation Apparatus To Accommodate Three Dimensional Specimens, Charles Ward

Master's Theses

The space environment presents various challenges when designing systems and selecting materials for applications beyond Earth’s atmosphere. For mission success, these challenges must be considered. One of the detrimental aspects of the space en- vironment is Atomic Oxygen, AO. Only present in harmful quantities in Lower Earth Orbit, LEO, AO causes significant damage to materials by breaking molecular bonds. California Polytechnic State University’s, Cal Poly’s, space environments laboratory features an apparatus capable of simulating this environment. Very thin or short samples were tested to observe the mass loss due to erosion of the sample material. Recent modifications to the system …

Detection Method Of Subclinical Atherosclerosis Of The Carotid Artery With A Hemodynamics Modeling Approach, Marisa Peressini

Master's Theses

Subclinical atherosclerosis is an important area of research to evaluate stroke risk and predict localization of plaque. The current methods for detecting atherosclerosis risk are insufficient because it is based on The Framingham Risk Score and carotid intima media thickness, therefore an engineering detection model based on quantifiable data is needed. Laminar and turbulent flow, dictated by Reynolds number and relative roughness, was modeled through the carotid artery bifurcation to compare shear stress and shear rate. Computer-aided design and fluid flow software were used to model hemodynamics through the carotid artery. Data from the model was derived from governing equations …

Foraging Ecology Of Parrotfishes In The Greater Caribbean: Impacts Of Specialization And Dietary Preferences On Marine Benthic Communities, Madelyn V. Roycroft

Master's Theses

Coral reefs are one of the world’s most diverse yet heavily impacted marine ecosystems. As a result of many direct and indirect stressors, coral reefs have experienced major degradation over the last several decades. Declines in coral reefs in the Caribbean have been particularly acute and generally associated with the loss of key herbivores and an increase in algae. Herbivorous fishes such as parrotfishes can positively impact coral reefs by removing algae that compete with corals for light and space. However, many parrotfishes are also important coral predators. Predation on corals, known as corallivory, can adversely affect coral growth, reproduction …

Orbital Constellation Design And Analysis Using Spherical Trigonometry And Genetic Algorithms: A Mission Level Design Tool For Single Point Coverage On Any Planet, Joseph R. Gagliano

Master's Theses

Recent interest surrounding large scale satellite constellations has increased analysis efforts to create the most efficient designs. Multiple studies have successfully optimized constellation patterns using equations of motion propagation methods and genetic algorithms to arrive at optimal solutions. However, these approaches are computationally expensive for large scale constellations, making them impractical for quick iterative design analysis. Therefore, a minimalist algorithm and efficient computational method could be used to improve solution times. This thesis will provide a tool for single target constellation optimization using spherical trigonometry propagation, and an evolutionary genetic algorithm based on a multi-objective optimization function. Each constellation will …

Nutrient Removal In Microalgae Raceway Ponds And Nitrification Modeling, Esmeralda Diego

Master's Theses

This thesis explores the treatment of municipal wastewater using pilot-scale raceway ponds and looks specifically at the capability of the raceways in removing BOD and nitrogen. Nine 33 square-meter algal raceway ponds were used to conduct research at the San Luis Obispo Water Resources Recovery Facility. Main objectives of this study were to increase the removal of total ammonia nitrogen (NH₃-N plus NH₄⁺-N) from municipal wastewater through increased assimilation and nitrification. Raceway ponds with CO₂ addition were operated in series with an intermediate settling step and a total hydraulic retention time (HRT) of 4 …

Comparative Analysis Of Physiological Measurements And Environmental Metrics On Predicting Heat Stress Related Events, Mckenzie Lee Barlow

Master's Theses

Exposure to high heat and humidity can lead to serious health risks, including heat exhaustion and heat stroke. Wet Bulb Globe Temperature (WBGT) and heat index have historically been used to predict heat stress events, but individualized factors are not included in the measurement. It has been shown that there is a relationship between cardiovascular measurements and heat stress, which could be used to measure heat stress risk on an individual level. Research has been done to find relationships between cardiovascular metrics in a workplace environment, however the study did not include the use of a controlled environment as a …

Effect Of Bioaugmentation Product Biowish® Aqua™ On Nitrogen Removal In Wastewater, Patrick Cassidy Kalvass

Master's Theses

Biological nutrient removal (BNR) from wastewater, and specifically nitrogen removal, is a growing concern to wastewater dischargers such as municipalities. Excess nutrients in effluent can create problems such as eutrophication, toxicity to aquatic life, and dissolved oxygen depletion in receiving waters. BNR systems have been installed in many locations with success, but their operation presents operational and financial demands greater than conventional biological treatment. Nitrogen removal is typically performed in sequential autotrophic nitrification and denitrification, which increases needed energy input, operational complexity, and therefore cost. Simultaneous nitrification-denitrification (SNdN) achieved in a single system has also been successfully implemented, however operational …

Object Tracking In Games Using Convolutional Neural Networks, Anirudh Venkatesh

Master's Theses

Computer vision research has been growing rapidly over the last decade. Recent advancements in the field have been widely used in staple products across various industries. The automotive and medical industries have even pushed cars and equipment into production that use computer vision. However, there seems to be a lack of computer vision research in the game industry. With the advent of e-sports, competitive and casual gaming have reached new heights with regard to players, viewers, and content creators. This has allowed for avenues of research that did not exist prior.

In this thesis, we explore the practicality of object …

Zinc Sunscreens Affect Development Of Strongylocentrotus Purpuratus Embryos, Brittany E. Cunningham, Nikki L. Adams

Master's Theses

The growing popularity of physical sunscreens will also lead to an increased release of the ingredients from zinc oxide (ZnO) sunscreens into marine environments. Though zinc (Zn) is a necessary micronutrient in the ocean, greater than natural Zn concentrations are being released into marine environments by use of sunscreens. The extent of the consequences of the addition of Zn to the ocean are not fully understood. We investigated effects of materials released by zinc oxide (ZnO) sunscreens on the development of California purple sea urchin, Strongylocentrotus purpuratus. Embryos developed in various concentrations of Zn, the sources of which included …

Enhanced Detection Of Corrosion And Coating Aging Mechanisms Using Core-Shell Quantum Dots, Raymond Thai

Master's Theses

Understanding aging mechanisms in coatings during their servicable life is complicated, due to the inherent stochastic nature of exposure profiles, service environments, and rare weather events. Thus, the development of improved test methods for service life prediction and accelerated weathering relies on the availability of infallible degradation and exposure data, delivered as a function of cumulative time in service. In a related application, non-destructive evaluative methods rely on the premise of being able to probe or monitor in situ mechanisms within a coating system without interfering with actual aging mechanisms. Ultimately, quantumdots can be utilized as in situ sensors for …

Extended-Use Ecg Monitor, Daniel Aaron Soski

Master's Theses

In this thesis, a prototype ECG monitor was developed that is integrated into an elastic shirt and takes a 3-lead ECG for over 5 days. The high-quality measurements can be used to identify markers indicative of various detrimental heart conditions. Measurements recorded by the device are encrypted and stored onto a micro-SD card. Current Holter monitors are expensive and have functional lives less than 48 hours; however, extended duration monitoring has been proven more useful in diagnosis. The device designed demonstrates that ECG measurements can be taken over longer durations without sacrificing quality, comfort, or device cost.

Prediction Of The Degradation Of Emerging Contaminants During Oxidative Treatment Via Analysis Of Reaction Rate Constants, Kellie Cochran

Master's Theses

Globally, water supplies are diminishing in quality while demand is continually increasing. The municipal water and wastewater sector has been paying increased attention to unregulated emerging organic contaminants. Advanced oxidation processes (AOPs), which produce hydroxyl radicles (•OH), have been developed and implemented to remove recalcitrant emerging contaminants left by conventional treatment processes. The current understanding of the removal efficacy of AOPs for emerging contaminants is limited. This study analyzes the ability of an AOP involving ozone and multi-walled carbon nanotubes (MWCNTs) in removing three specific emerging contaminants: caffeine, atrazine, and phenytoin, which were selected based on their persistence and ubiquity …

Study Of The Effect Of Biowish Aqua On Simultaneous Nitrification And Denitrification In A Membrane Aerated Bioreactor, Joelle Arakaki

Master's Theses

This research entails the investigation of the effects of a bioaugmentation product from BiOWiSH^® called Aqua, referred to as “Aqua” for the remainder of this paper, on the nitrogen removal rate in a membrane aerated bioreactor (MABR). This research was conducted using a MABR design that consisted of a silicone membrane and continuous flow airline with compressed air. The membrane system was designed to supply oxygen, creating an aerated layer at the membrane-biofilm interface and an anoxic layer at the biofilm-water interface. Laboratory experiments were conducted to compare the nitrogen removal rates of natural bacteria alone to natural bacteria …

Preparation Of Supramolecular Amphiphilic Cyclodextrin Bilayer Vesicles For Pharmaceutical Applications, Kate E. Frischkorn

Master's Theses

Recent pharmaceutical developments have investigated using supramolecular nanoparticles in order to increase the bioavailability and solubility of drugs delivered in various methods. Modification of the carbohydrate cyclodextrin increases the ability to encapsulate hydrophobic pharmaceutical molecules by forming a carrier with a hydrophobic core and hydrophilic exterior. Guest molecules are commonly added to these inclusion complexes in order to add stability and further increase targeting abilities of the carriers. One such guest molecule is adamantine combined with a poly(ethylene glycol) chain. Vesicles are formed by hydrating a thin film of amphiphilic cyclodextrin and guest molecules in buffer solution that mimics physiological …

Effects Of Raceway Pond Water And Nutrient Recycling On Microalgae Production And Harvesting, Christian A. Bowen

Master's Theses

To be environmentally sustainable, algae biofuel production requires extensive recycling of water and nutrients during algae cultivation. Such recycling can be in the form of reuse of external wastewaters, such as from municipal sewers, but, to achieve significant biofuels production, internal recycling at the algae farms is also needed. A potential difficulty with internal recycling is the accumulation of auto-inhibitory compounds in recycled algae pond water. An additional concern is that nutrients in the residuals from algae biofuel manufacturing will be only partly bioavailable. Both these factors can limit the extent of internal recycling. Ultimately, combining external and internal recycling …

Adaptation Of Vt-Dbr Lasers For Lidar, Luke Horowitz

Master's Theses

Vernier Tuned Distributed Bragg Reflector (VT-DBR) lasers have had great success in the field of Swept-Source Optical Coherence Tomography (SS-OCT) due to their continuous and nearly 40 nm wavelength tuning range in a single longitudinal mode. Fast sweeps allow for real time imaging with micrometer resolution at a distance of a few centimeters. While this laser has proven quite useful as a medical imaging tool via OCT, it has yet to similarly prove itself for general light detection and ranging (LIDAR) applications due to range limitations that arise from a finite laser coherence length. The goal of this thesis is …

Orbital Optimization Of Interplanetary Trajectories With Environmental Perturbations, Eric S. Woods

Master's Theses

For a detailed analysis of orbital optimization, it is desired to incorporate a spacecraft environment model in order to have maximum confidence that the analysis will produce an accurate trajectory. Such a model requires the addition of orbital perturbations, or small forces acting on the spacecraft throughout its trajectory that can eventually accumulate in large distances over time. The optimization method that this thesis is concerned with is STOpS (Spacecraft Trajectory Optimization Suite), a Matlab optimizer created by Timothy J. Fitzgerald that utilizes an Island Model Paradigm with five different optimization algorithms. STOpS was originally built to model trajectories with …

Bird Abundance At Bird Feeders In Response To Temperature, Wind Speed And Precipitation During The Winter Season, Siddhant Kahal

Master's Theses

The goal of this project is to explore how 23 different bird species respond to 3 climatic attributes. These attributes are lower than average temperatures, wind speed and precipitation level. Information about the bird species and all of the data associated with them is provided by Project FeederWatch (PFW). This is a citizen based survey study that provides key information about bird species abundance through the use of backyard and community feeders. The study volunteers from across the United States and Canada monitor these bird feeders and note important information about the species such as the number of individuals seen. …

Evaluation Of Electrochemical And Laser Polishing Of Selectively Lasermelted 316l Stainless Steel, Julian R. Lohser

Master's Theses

Selective laser melting has shown incredible growth as a metallic additive manufacturing process in recent years. While it does provide many solutions and new ways to approach challenges, it does not come without issues of its own, namely, surface roughness. In the as-printed state, the surface roughness of selectively laser melted parts is unacceptable for use in engineering applications. Additionally, selective laser melting is used to produce complex geometries with hard to reach features, preventing conventional mechanical polishing from being successful. Therefore, it is necessary to evaluate non-mechanical polishing processes as treatments for surface roughness. In this study, electrochemical and …

The Gods Have Taken Thought For Them: Syncretic Animal Symbolism In Medieval European Magic, Solange Nicole Kiehlbauch

Master's Theses

This thesis investigates syncretic animal symbolism within medieval European occult systems. The major question that this work seeks to answer is: what does the ubiquity and importance of magical animals and animal magic reveal about overarching medieval perceptions of the world? In response, I utilize the emerging subfield of Animal History as a theoretical framework to draw attention to an understudied yet highly relevant aspect of occult theory and practice. This work argues that medieval Europeans lived in a fundamentally “enchanted” world compared to our modern age, where the permeable boundaries between physical and spiritual planes imbued nature and its …

Finite-Difference Modeling Of The Batch Process Smoldering Combustion Of Wastewater, Laura H. Kawashiri

Master's Theses

A MATLAB model was developed for the smoldering combustion of wastewater in the context of a decentralized residential wastewater treatment appliance. Data from a batch process sewage smoldering experiment was simulated using implicit finite-difference approximations, assuming one-dimensional transient conductive heat transfer. The time-dependent temperature profiles within the column represented the main parameters of interest and were used to verify recoverable heat energy estimations. Given that the modeling method used for this thesis represents a unique approach, the assumptions and limitations of this model are thoroughly described in the context of reproducing results for other smoldering setups. A lack of convergence …

Utilizing Permanent On-Board Water Storage For Efficient Deep Space Radiation Shielding, Nathan Ryan Gehrke

Master's Theses

As space technologies continue to develop rapidly, there is a common desire to launch astronauts beyond the ISS to return to the Moon and put human footsteps on Mars. One of the largest hurdles that still needs to be addressed is the protection of astronauts from the radiation environment seen in deep space. The most effective way to defend against radiation is increasing the thickness of the shield, however this is limited by strict mass requirements. In order to increase the thickness of the shield, it is beneficial to make mission critical items double as shielding material.

The human rated …

Neuro-Silicon Interface Of A Hirudo Medicinalis Retzius Cell Integrated With Field Effect Transistor, Kurt Christian Sjoberg

Master's Theses

The focus of this thesis was to measure the intracellular voltage of a living neural cell using a silicon transistor. The coupling of neurological tissues with silicon devices is of interest to the fields of neurology, neuroscience, electrophysiology and cellular biology. In previous work by Peter Fromherz, single neurons were successfully coupled to transistors [1]. This thesis aims to show proof of concept of the fabrication of a simple neuro-silicon interface using wafer processing methods currently available at Cal Poly. The types of transistors and cells used, the methods for dissecting and preparing the cells, the electrophysiology methods for validating …

Influencing Exploration In Actor-Critic Reinforcement Learning Algorithms, Andrew R. Gough

Master's Theses

Reinforcement Learning (RL) is a subset of machine learning primarily concerned with goal-directed learning and optimal decision making. RL agents learn based on a reward signal discovered from trial and error in complex, uncertain environments with the goal of maximizing positive reward signals. RL approaches need to scale up as they are applied to more complex environments with extremely large state spaces. Inefficient exploration methods cannot sufficiently explore complex environments in a reasonable amount of time, and optimal policies will be unrealized resulting in RL agents failing to solve an environment.

This thesis proposes a novel variant of the Actor-Advantage …

The Dissolution Of Diatoms In Marine Microbial Mats, Almariet Palm

Master's Theses

Microbial mats are self-contained organosedimentary ecosystems that played an important role in the evolution of early life on Earth. Understanding the conditions of their formation and preservation in the fossil record could provide valuable insights into microbe-mineral interactions and paleoenvironmental reconstruction. Diatoms are found at the surface of extant microbial mats, but their frustules are not observed at depth and rarely in fossil microbialites, which suggest their frustules dissolve. The objective of this study is to investigate the role of cyanobacterial photosynthesis, which locally elevates pH, in the dissolution of diatoms frustules. Field data and laboratory studies determined the effect …

Investigation On The Dissociative Photoionization Mechanism Of Furfural, Investigation Of The Absolute Photoionization Cross Sections Of Three Potential Propargylic Fuels, And Ab Initio Analysis On Potential Superbases Of Several Hyperlithiated Species: Li3f2o And Li3f2(Oh)N (N = 1, 2, 3), Matthew Winfough

Master's Theses

This thesis presents the study photoionization cross sections of three different propargylic biofuels; dipropargyl ether, propargyl alcohol, and propargylamine, in chlorine radical-initiated combustion experiments at the Chemical Dynamics Beamline (9.0.2) at the Advanced Light Source of the Ernest Orlando Berkeley National Laboratory in Berkeley, California. Additionally, the unimolecular dissociative photoionization mechanism of furfural was studied using photoelectron photoionization coincidence (PEPICO) spectroscopy at the vacuum ultraviolet beamline at the Swiss Light Source of the Paul Scherrer Institut in Villigen, Switzerland. Dissociation products and mechanisms for furfural were identified over a photon energy range of 10.9 to 14.5 eV. Lastly, a study …

Sweden's Great Escape: Industrialization And The Changing Productivity Cost Of Winter, Charlotte Taylor, Jesse Anttila-Hughes

Master's Theses

We combine a paleoclimate reconstruction of the North Atlantic Oscillation (NAO)- a key determinant of Scandinavian winter intensity- with four centuries of historical production data from Sweden, to examine the changing influence of climate variability on production over time. We find the colder, drier winters associated with the negative phase of the NAO led to reduced economic production for much of Swedish history, and that this relationship changed with development: during industrialization, Sweden underwent a transition from ‘level’ effects, where harsh winters lowered average incomes, to ‘growth’ effects, where it reduced growth in improving living standards. Post-industrialization, neither ‘level’ nor …

Country Risk And Agricultural Productivity: An Efficiency Study, Tosin Babatunde

Master's Theses

Do the social, economic and political environment in a country affect agricultural efficiency? We address this question by estimating a stochastic frontier model of agricultural productivity in 138 countries from 1984 to 2013. By observing how the business condition, level of social harmony and quality of government in a country affect agricultural inefficiency, we find there to be a positive effect. However, land quality as quantified by percentage of land irrigated, and openness to global trade have a more positive effect on decreasing agricultural productivity. We also find that consistent with literature, former British colonies exhibit higher technical efficiency.

Crosslinguistic Influence Of Chinese Efl Learners On English Acquisition, Weijia Tang

Master's Theses

This thesis introduces both positive and negative crosslinguistic influence of Chinese EFL learners on English Acquisition. Most Chinese EFL learners have difficulties in English acquisition due to the negative crosslinguistic influence caused by the differences between mother tongue and the target language. In order to help Chinese EFL learners to tackle this problem, comparative analysis is done between English and Mandarin Chinese in terms of phonetics and phonology, morphology, part syntax, and pragmatics.

The focus of this thesis is to investigate both the positive and negative crosslinguistic influence phenomena in the process of English acquisition conducted by Chinese EFL learners …