The Design and Development of the Electrical Power System for the LightCube 1U CubeSat

Description
The LightCube mission is a CubeSat whose goal is to allow users to manually flash a light that is observable by the naked eye. LightCube required the design of custom electronics because of its small size and unique mission. The

The LightCube mission is a CubeSat whose goal is to allow users to manually flash a light that is observable by the naked eye. LightCube required the design of custom electronics because of its small size and unique mission. The majority of the volume of LightCube was taken up by the payload electronics, precluding any use of most off the shelf CubeSat components. A custom EPS system was designed and developed by students at ASU to meet all the power requirements of LightCube. The satellite’s solar panels were constrained to a 1U size and the batteries were given a limited volume. The EPS was architected with these constraints in mind to optimize for the space given. It consists of a charging circuit, two converters, voltage and current measuring circuits, and a separate battery board which includes a battery fuel gauge, current sensor, inhibit circuitry, temperature sensor, heater, and optional linear battery charger. One of the underlying goals of this design was to make the EPS and battery board as simple as possible. The design was intentionally simple and left out other features such as a microcontroller for ease and speed of development as well as minimize complexity to lower the risk of catastrophic failure due to radiation or other space events.
Date Created
2024
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Integrating Haptic Devices and Mixed Reality for Enhanced Learning Experiences

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Description
Virtual reality (VR) provides significant opportunities for students to experience immersive education. In VR, students can travel to the international space station, or go through a science experiment at home. However, the current tactile feedback provided by these systems do

Virtual reality (VR) provides significant opportunities for students to experience immersive education. In VR, students can travel to the international space station, or go through a science experiment at home. However, the current tactile feedback provided by these systems do not feel real. Controllers do not provide the same tactile feedback experienced in the physical world. This dissertation aims to bridge the gap between the virtual and physical learning environments through the development of novel haptic devices capable of emulating tactile sensations found in physical science labs. My research explores haptic devices that can emulate the sensations of fluids in vessels within the virtual environment. Fluid handling is a cornerstone experience of science labs. I also explore how to emulate the handling of other science equipment. I describe and research on four novel devices. These are 1) SWISH: A shifting-weight interface of simulated hydrodynamics for haptic perception of virtual fluid vessels, 2) Geppetteau, 3) Vibr-eau, and 4) Pneutouch. SWISH simulates the sensation of virtual fluids in vessels using a rack and pinion mechanism, while Geppetteau employs a string-driven mechanism to provide haptic feedback for a variety of vessel shapes. Vibr-eau utilizes vibrotactile actuators in the vessel’s interior to emulate the behavior of virtual liquids. Finally, Pneutouch enables users to interact with virtual objects through pneumatic inflatables. Through systematic evaluations and comparisons with baseline comparisons, the usability and effectiveness of these haptic devices in enhancing virtual experiences is demonstrated. The development of these haptic mechanisms and interfaces represents a significant step towards creating transformative educational tools that provide customizable, hands-on learning environments in both Mixed (MR) and Virtual Reality (VR) - now called XR. This dissertation contributes to advancing the field of haptics for virtual education and lays the foundation for future research in immersive learning technologies.
Date Created
2024
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A Framework for the Design and Optimization of Composites with Electromagnetic Wave Scattering Properties Utilizing Two-Point Spatial Correlation Functions

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Description
In the age of 5th and upcoming 6th generation fighter aircraft one key proponent of these impressive machines is the inclusion of stealth. This inclusion is demonstrated by thoughtful design pertaining to the shape of the aircraft and rigorous material

In the age of 5th and upcoming 6th generation fighter aircraft one key proponent of these impressive machines is the inclusion of stealth. This inclusion is demonstrated by thoughtful design pertaining to the shape of the aircraft and rigorous material selection. Both criteria aim to minimize the radar cross section of these aircraft over a wide bandwidth of frequencies corresponding to an ever-evolving field of radar technology. Stealth is both an offensive and defensive capability meaning that service men and women depend on this feature to carry out their missions, and to return home safely. The goal of this paper is to introduce a novel method to designing disordered two-phase composites with desired electromagnetic properties. This task is accomplished by employing the spatial point correlation function, specifically at the two-point level. Effective at describing the dispersion of phases within a two-phase system, the two-point correlation function serves as a statistical function that becomes a realizable target for heterogeneous composites. Simulated annealing is exercised to reconstruct two-phase composite microstructures that initially do not match their target function, followed by two separate experiments aimed at studying the impact of the provided inputs on its outcome. Once conditions for reconstructing highly accurate microstructures are identified, modifications are made to the target function to extract and compare dielectric constants associated with each microstructure. Both the real and imaginary components, which respectively affect wave propagation and attenuation, of the dielectric constants are plotted to illustrate their behavior with increasing wavenumber. Conclusions suggest that favorable values of the complex dielectric constant can be reverse-engineered via careful consideration of the two-point correlation function. Subsequently, corresponding microstructures of the composite can be simulated and then produced through 3-D printing for testing and practical applications.
Date Created
2024
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Beyond Christianity: CS Lewis’ Analysis of Marital Commitment

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Description
This thesis aims to delve into the multifaceted views of renowned author and theologian C.S. Lewis on the institution of marriage, as presented through his literary works. Although Lewis does not dedicate one single work to the importance of Christian

This thesis aims to delve into the multifaceted views of renowned author and theologian C.S. Lewis on the institution of marriage, as presented through his literary works. Although Lewis does not dedicate one single work to the importance of Christian marriage, he does provide various insights throughout his fictional and nonfictional works, which, when considered within his philosophical, moral framework, offer a compelling case for why marital commitment is conducive to helping shape moral individuals regardless of faith or background. This research seeks to synthesize Lewis’ nuanced perspectives on marital relationships through a comprehensive analysis, shedding light on their significance within his broader theological and philosophical framework. The objective of this thesis is not to defend Lewis’ (or the Christian) conception of marriage but merely to attempt to show that his rational arguments, bridging the gap between faith and reason, can appeal to a larger audience.
Date Created
2024
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Meta-Analysis for Multi-Cancer Early Detection Biomarker Discovery

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Description
Cancer poses a significant worldwide burden where ongoing efforts are targeted towards improving patient outcomes in which a significant contribution results from cancer screening. Multi-cancer early detection tests have been introduced which measure a series of biomarkers to detect signals

Cancer poses a significant worldwide burden where ongoing efforts are targeted towards improving patient outcomes in which a significant contribution results from cancer screening. Multi-cancer early detection tests have been introduced which measure a series of biomarkers to detect signals that may indicate carcinogenesis in its earliest stages and work in tandem with other diagnostic techniques to localize and verify tumor formation across multiple cancer types. Molecular biomarkers such as autoantibodies are promising candidates for early detection across multiple cancers. This study identifies autoantibodies that are aberrantly expressed across multiple cancer types that may be used to discriminate between healthy individuals and those with cancer from a single serum sample. Multiple datasets are integrated from prior studies to examine 8,200 sera autoantibodies from 5 cancer types including lung adenocarcinoma, basal-like breast cancer, advanced colorectal cancer, ovarian cancer, and HER2+ breast cancer. The diagnostic utility of these autoantibodies is assessed for combined cancer types by meta-receiver operating characteristic (ROC) curve analysis. A meta-analysis data processing pipeline is utilized for processing each biomarker with statistical analysis performed across ROC metrics for each meta-curve including partial area under the curve and sensitivity at a 90% specificity threshold. Results identified 26 autoantibody biomarkers that are useful for multi-cancer detection and may be developed for future clinical applications in cancer screening.
Date Created
2024
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Impact of Urban Diets on the Nutritional Physiology of Mealworms

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Description
Mealworms (Tenebrio molitor), the larval stage of yellow mealworm beetles, are a popular feeder insect for birds, amphibians, reptiles, fish, and even human populations throughout the world. As such, the goal of this work was to understand how the diet

Mealworms (Tenebrio molitor), the larval stage of yellow mealworm beetles, are a popular feeder insect for birds, amphibians, reptiles, fish, and even human populations throughout the world. As such, the goal of this work was to understand how the diet of mealworms impacts their nutritional quality as variations in quality can impact the animals (and humans) that consume them. In this study, 500 mealworms were divided among each of the following substrates designed to model food sources available in urban versus rural, more natural areas: 100% wheat germ (control); 100% Styrofoam; mixture of soil, grasses, and leaves from urban lawns; a mixture of soil, grasses and leaves from rural lawns; 50% mixture of wheat germ + carrots; natural fertilizer; or fertilizer with weed killer. The mealworms were maintained at room temperature and the diets were replaced bi-weekly to prevent spoilage and to remove mealworm waste. Once a week for three weeks, mealworms were sampled from each substrate and frozen at -20°C. After 3 weeks, mealworms housed in wheat germ + carrots weighed significantly more than all other groups (p<0.05), whereas those housed in Styrofoam or urban lawn substrates weighed significantly less at week 3 as compared to week 1 (p<0.01). The urban lawn substrate resulted in greater molting and contained the highest number of pupae, but also the greatest mortality among the substrates. The Bradford method measured the total protein content of mealworms homogenized in phosphate-buffered saline. Mealworms maintained on wheat germ had significantly greater total protein content as compared to mealworms transitioned to any other diet (p<0.05). So, compared to wheat germ, urban foods generally reduced protein, total sugars, and crude fat, although they also decreased oxidized lipoproteins. Urban lawn had lower oxidized lipoprotein content than wheat germ, but levels were higher compared to wheat germ with carrots and natural fertilizer. In addition, urban foods generally increase the water content in mealworms. Urban foods were not much different from rural lawns as no there was difference between urban and rural lawns. Differences in body mass and total protein support the hypothesis that mealworms' nutritional quality is altered by ingesting urban substrates. These data suggest that mealworms (and potentially other insects) in cities may be exposed to food substrates that result in less nutritional value than those living in more natural areas as mimicked by the rural lawn substrates and wheat germ control, although they may be higher in water content.
Date Created
2024
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Intracellular Amplification for Applications in Single-cell DNA Sequencing

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Description
Single-cell DNA sequencing (scDNA-seq) can identify genetic differencesbetween individual cells and has broad applications in studying biology. For example, because scDNA-seq preserves haplotypes, it enables the addition of information about the fitness of different combinations of mutations into studies that

Single-cell DNA sequencing (scDNA-seq) can identify genetic differencesbetween individual cells and has broad applications in studying biology. For example, because scDNA-seq preserves haplotypes, it enables the addition of information about the fitness of different combinations of mutations into studies that quantify the fitness of individual mutations. However, it requires separating cells manually or using machinery, which is time-consuming and costly as every cell requires a separate reaction. Thus, most studies are limited to a few hundred cells, and scaling up is expensive and challenging. This problem also makes it difficult to multiplex samples or to study multiple sample types in the same experiment. To solve these problems, I introduce a novel method for sequencing DNA in heterogeneous cell populations by using the cell itself as a container for sequencing reactions, eliminating the need to isolate individual cells. The method involves diffusing DNA polymerase and barcoded primers into intact cells and amplifying its DNA Intracellularly. To ensure that DNA from each cell can be uniquely identified, I use combinatorial barcoding, which assigns a specific barcode to each cell using a unique combination of non-unique nucleotide block sequences. This allows for the pooling of cells, making the method multiplexable and enabling the analysis of dozens of samples containing thousands of cells. The method is flexible and allows for targeted sequencing of a region of interest and whole genome sequencing. I optimize the method for various organisms and applications so it can be made accessible to a wide range of research groups.
Date Created
2024
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