Investigating the Interior of Io: Constraining Scenarios of Its Internal Structure

Description
Jupiter’s moon Io is tidally locked with Jupiter and falls in a 4:2:1 orbital resonance with Europa and Ganymede, driving extreme tidal heating that makes it the most volcanically active body in the solar system. Io possesses a metallic core, as

Jupiter’s moon Io is tidally locked with Jupiter and falls in a 4:2:1 orbital resonance with Europa and Ganymede, driving extreme tidal heating that makes it the most volcanically active body in the solar system. Io possesses a metallic core, as does its Galilean sibling Ganymede, yet, unlike Ganymede, Io lacks a magnetic field. Here, I investigated the potential size, composition, and cooling rate of Io’s core to help determine why Io lacks a strong dynamo. First, I used mineral physics equations to determine that the radius of the core should be between ~650 km to 950 km for a composition ranging from pure Fe to a eutectic Fe-FeS alloy. Cosmochemical constraints from meteoritic analogues yield complementary constraints on the abundance of sulfur in the metallic core (~2.67–28.6 wt%). The mantle could be either fully or partially molten. I found that the scenario of a global magma ocean creates temperatures at the base of the mantle that are possibly too hot for core convection, but that a magma sponge regime could create core-mantle boundary temperatures cooler than the melting point of pure Fe, which could promote core convection. Therefore, I conclude that Io lacks a strong dynamo likely because it has a magma ocean with temperatures too high for convection. However, the possibility that Io’s mantle is a magma sponge suggests the importance for future missions to investigate the state of Io’s magnetic field.
Date Created
2024-05
Agent

Using Principles of Interpretation to Improve Undergraduate Geoscience Education

Description
Interpretation, a form of informal education often used in National Parks, has long been used outside the classroom to effectively engage broad audiences in learning about the geosciences and to encourage them to connect with the local environment. An educational

Interpretation, a form of informal education often used in National Parks, has long been used outside the classroom to effectively engage broad audiences in learning about the geosciences and to encourage them to connect with the local environment. An educational approach that draws on similar foundations to interpretation is place-based education (PBE), which focuses on connecting learning and fostering students' relationships with local cultures and places. Despite the similarities between the two pedagogies and a scarcity of geoscience-specific examples for active learning strategies, there has been little collaboration between interpretation and formal geoscience education. This paper investigates three case studies on PBE to explore where interpretive principles are already used and where they could be further applied to improve learning outcomes and increase student interest in the geosciences. Methodologies similar to the principles of interpretation can already be seen within these case studies to improve student outcomes, justifying further research on the use of interpretation within formal education. Increased communication and collaboration between informal and formal education resources could provide geoscience-specific approaches to effective teaching techniques and lead to further improvements in geoscience education.
Date Created
2024-05
Agent

Redefining Learning Strategies: Investigating Alternatives to Upper Division Engineering Textbooks in Junior Aerodynamics Classes

Description
Textbooks have traditionally served as the primary educational resources in classes for decades. However, with the transition to online learning prompted by the onset of the COVID-19 pandemic, there has been a significant shift towards online learning materials. As the

Textbooks have traditionally served as the primary educational resources in classes for decades. However, with the transition to online learning prompted by the onset of the COVID-19 pandemic, there has been a significant shift towards online learning materials. As the pandemic subsides, students, particularly those in engineering disciplines, have persisted in utilizing these alternative resources, prompting questions about their effectiveness and identifying the most suitable options. This study aims to uncover the underlying reasons for the decline in textbook usage and to identify the most effective resources for student learning. The study involved approximately 170 students enrolled in a Low Speed Aerodynamics course at Arizona State University (ASU). These students were invited to participate in a series of surveys after we introduced new changes to the course such as recitations, holistic grading, and an online interactive textbook. Around 40 students voluntarily responded to the surveys. Additionally, interviews were conducted with four professors to gather insights into why students may not be using textbooks, and to gather their opinions on recitations, the Connect software, and holistic grading, if they have incorporated these into their own courses. The survey findings revealed that although traditional textbooks offer detailed explanations to aid in grasping concepts, students often prefer alternative resources such as supplementary materials, recitations, and office hours for applying their knowledge to homework or tests. Holistic grading then provides meaningful feedback on the concepts they need to revisit after attempting to apply their understanding during tests. From our survey, it is evident that reaching a definitive solution regarding textbook selection and identifying optimal resources remains challenging. Nevertheless, students expressed a preference for interactions among peers and with professors, indicating that changes incorporating these elements were more favorably received. Further exploration into the continued implementation of holistic grading and recitations could provide insights into the enduring impact of the findings from this study over time.
Date Created
2024-05
Agent

Sea Turtles in Costa Rican Spirituality and Folklore: How Does This Influence Conservation Efforts?

Description
Sea turtles are threatened globally. Their conservation requires, not just scientists and governments, but communities as well. Conservationists have been developing ways to reduce tensions between governments, biologists, and local communities. While community-based conservation has been implemented successfully in certain cases, work must

Sea turtles are threatened globally. Their conservation requires, not just scientists and governments, but communities as well. Conservationists have been developing ways to reduce tensions between governments, biologists, and local communities. While community-based conservation has been implemented successfully in certain cases, work must be done to acknowledge the spiritual values of nature to garner more support for conservation from local communities. For this reason, we chose to analyze how sea turtles have been viewed spiritually in Latin America and globally throughout history by performing a literature review. Many coastal communities have centuries old spiritual beliefs regarding sea turtles. Furthermore, we conducted a case study in Ostional, Costa Rica, a village known for its sea turtle conservation, as well as its controversial sea turtle egg harvesting. From this study, which utilized surveys and interviews, we learned that spirituality is a motivator for conservation for the people of Ostional. Thus, we suggest that spirituality should be utilized as an appeal for local communities to support local conservation efforts. Governments and scientists should include spirituality in community-based conservation discourse. Further studies should assess how best to apply spiritual appeals in this discourse and its effectiveness overall, as well as among different age demographics.
Date Created
2024-05
Agent

EXPRESSIONAL DIFFERENCES BETWEEN THE SIZES OF MORPHOLOGICAL FEATURES IN URBAN AND NON-URBAN HERPETOFAUNA AROUND PHOENIX, ARIZONA

Description
The Phoenix metro area has become increasingly more urbanized over the past few decades, changing the pressures on native lizards to navigate these novel environments. Due to effects such as the Urban Heat Island, decreased vegetation cover, increased temperatures, and

The Phoenix metro area has become increasingly more urbanized over the past few decades, changing the pressures on native lizards to navigate these novel environments. Due to effects such as the Urban Heat Island, decreased vegetation cover, increased temperatures, and general changes in substrate types between environments, urban lizards have a variety of unique environmental pressures acting on them compared to their traditional habitats. In this study, I examined various morphological features in the common side-blotched lizard (Uta stansburiana) and the ornate tree lizard (Urosaurus ornatus) to determine if these novel pressures in urban environments have significantly changed the phenotypic expression of these features as compared to a non-urban environment. The morphological features examined were weight, head length and width, femur, tibia, foot, and toe length, arm, forearm, hand, and finger length, and snout-vent (SVL), tail, and total length, along with various proportional comparisons between related traits. I hypothesized that both common side-blotched lizards and ornate tree lizards would see an increase in mass and snout-vent length, an increase in tail length, and increase in head thickness, and a decrease in limb length in urban environments as compared non-urban environments. It was found that in common-side blotched lizards, while urban individuals tended to be larger in terms of length and mass, their heads tended to be proportionally shorter and thinner than non-urban individuals. In ornate tree-lizards, non-urban individuals were larger in every regard other than SVL. Both species saw a decrease in relative limb length in comparison to body length in urban environments. The trends observed in common-side blotched lizards may be explained by higher urban temperatures and novel substrates, while the trends observed in ornate tree lizards are likely due to prey availability, hunting strategy, and novel substrates.
Date Created
2024-05
Agent

Testing a Fast, Automated Reduction Pipeline for Colibri

Description
Gamma-ray bursts (GRBs) are a type of astrophysical transient resulting from the most energetic explosions known in the universe. The explosions occur in distant galaxies, and their bright initial emission may only last a few seconds. Colibri

Gamma-ray bursts (GRBs) are a type of astrophysical transient resulting from the most energetic explosions known in the universe. The explosions occur in distant galaxies, and their bright initial emission may only last a few seconds. Colibri is a telescope being built at the San Pedro Martir Observatory in Baja, CA, MX with high sensitivity in order to study these events at a high redshift. Due to how quickly GRBs occur, it is essential to develop an image reduction pipeline that can quickly and accurately detect these events. Using existing image reduction software from Coatli, which was programmed and optimized for speed using python, numerous time trials were performed in order to determine if the pipeline meets the time requirements with various factors being adjusted. The goal of this experiment is for the telescope to respond to, capture, and reduce the images in under 3 minutes. It was determined that the reduction was optimized when the number of files to be reduced was set equal to 16 or higher by changing the batch number and the blank sky subtraction function was performed. As for the number of exposures, one can take up to four 30 second exposures or twenty 5 second exposures and reduce them in under 3 minutes.
Date Created
2024-05
Agent

Evaluating the effects of partial or full replacement of chemical fertilizer with food waste fertilizer on growth and flowering of lettuce and petunia

Description
Traditional crop production faces a significant challenge due to overapplication, mining, and decreased supply of mineral nutrients. In addition to this, the urgent need to address global food waste has become increasingly apparent, as discarded food scraps in landfills contribute

Traditional crop production faces a significant challenge due to overapplication, mining, and decreased supply of mineral nutrients. In addition to this, the urgent need to address global food waste has become increasingly apparent, as discarded food scraps in landfills contribute to harmful greenhouse gas emissions. A promising solution that addresses both of these critical challenges includes the innovative utilization of food waste anaerobic digestate as a fertilizer for crop production. This study investigated whether using anaerobically digested food waste as fertilizer can fully replace or reduce the use of chemical fertilizer in vegetable and ornamental crop production. The seeds of lettuce (Lactuca sativa) ‘Nancy’ and petunia (Petunia × hybrida) ‘Easy Wave Velour Berry’ were sown into a soilless medium and grown in the indoor vertical farm at 22℃ under sole-source lighting at a photosynthetic photon flux density of 180 µmol∙m–2∙s–1 with a 20-h photoperiod. Four weeks after sowing, seedlings were transplanted and grown for three weeks in a greenhouse with an average daily temperature of 20 °C under ambient sunlight with an average daily light integral of 22 mol∙m–2∙d–1. The plants were fertilized using tap water mixed with different fertilizers, including a chemical fertilizer (15N-2.2P-16.6K), an organic fertilizer derived from anaerobically digested food waste (0.06N-0.026P-0.1191K), or a blend containing 50% chemical fertilizer and 50% food waste-based fertilizer, at the electrical conductivity of 0.7 mS·cm-1 during the young plant stage and 2.1 mS·cm-1 after transplant. At the young plant stage, lettuce and petunia have similar growth characteristics, including leaf number, SPAD index, and shoot and root fresh mass, when treated with either chemical or chemical + food waste fertilizer. In contrast, in both species, leaf area was 93-152% larger and fresh mass was 82-141% greater in plants treated with chemical or chemical + food waste fertilizer compared to food waste fertilizer. At the finishing stage, lettuce and petunia also showed similar growth and flowering characteristics under chemical or chemical + food waste fertilizer. However, in the lettuce finishing plants, fresh mass was 127-199% larger when supplied with chemical or chemical + food waste fertilizer compared to food waste fertilizer. In petunia, the number of flowers was 123-190% greater in chemical and chemical + food waste fertilizer compared to food waste fertilizer. In both lettuce and petunia at the finishing stage, the SPAD index, leaf number, root fresh mass, and root dry mass were similar among all treatments. These results suggest that food waste fertilizer applied as the sole source of plant nutrition is insufficient in comparison to chemical fertilizer at the same electrical conductivity. However, partially substituting some food waste fertilizer for chemical fertilizer reaps similar plant yield to chemical fertilizer on its own.
Date Created
2023-12
Agent

Electricity & the Arts: Creative Thesis Projects

Description
Engineering, and more specifically, electrical engineering can be a difficult topic to explain through spoken communication. Along with taking years of education to learn and understand necessary topics, the field is riddled with jargon and items that may take lectures

Engineering, and more specifically, electrical engineering can be a difficult topic to explain through spoken communication. Along with taking years of education to learn and understand necessary topics, the field is riddled with jargon and items that may take lectures to explain. However, this type of education may not be feasible for a younger or inexperienced audience. Therefore, engineers must find new ways to explain such difficult topics, especially in an attempt to garner interest in children, for example, through art.
Date Created
2023-12
Agent

The Future of Space Exploration: A look into how modern generations examine humanity's future investment into the cosmos

Description
For this study, my overarching goal was to understand the possibilities of humanity’s future in space exploration. Addressing the future of space exploration not only opens doors for a multitude of discoveries but may answer questions that can be essential

For this study, my overarching goal was to understand the possibilities of humanity’s future in space exploration. Addressing the future of space exploration not only opens doors for a multitude of discoveries but may answer questions that can be essential to our survival on Earth. This study, more specifically, aimed to determine how college students at Arizona State University, engineering and astronomy students in particular, visualize the future of space exploration, as in the future, they will become the leading experts at the forefront of all space-related developments. The method through which I have conducted this study is a short survey, consisting of a variety of questions, designed to encourage students to develop their own unique interpretations of space exploration and ultimately, its imminent future. The results ultimately demonstrated that most participants in the study believed that political obstacles were the most prevalent concern in the further development of space exploration. There also appeared to be a moderate outlook on the future success and vitality of space exploration among student scientists and engineers. From a statistical standpoint, there appeared to be no alarming difference of opinion between these two ASU student groups.
Date Created
2023-12
Agent

Cislunar Halo Orbits and Applications to FARSIDE Lunar Radio Telescope

Description

As part of NASA’s Artemis program, NASA intends to construct the Lunar Gateway space station in a near rectilinear halo orbit (NRHO) about the L2 Lagrange point of the Earth-Moon system in the near future. Gateway will help facilitate astronaut

As part of NASA’s Artemis program, NASA intends to construct the Lunar Gateway space station in a near rectilinear halo orbit (NRHO) about the L2 Lagrange point of the Earth-Moon system in the near future. Gateway will help facilitate astronaut landings on the surface of the Moon and support numerous scientific endeavors. One of these scientific endeavors is FARSIDE. FARSIDE is a radio telescope array concept that will be deployed on the surface of the far side of the moon. Because of this, FARSIDE will require an orbiter, such as Gateway, to act as a communication relay to be able to communicate with ground stations on Earth. This thesis analyzes how the Lunar Gateway space station can assist FARSIDE with its communication with Earth and how unintentionally scattered radio signals from FARSIDE could affect the telescope’s astronomical observations. It provides insight into the optimal deployment latitude on the lunar surface for FARSIDE. The thesis first begins with a literature review of the circular restricted three body problem (CR3BP) and halo orbit calculations. This is followed by an analysis of an example halo orbit for the distance, elevation angle, and azimuth angle it has viewed from two possible sites for FARSIDE over one period of its trajectory. Using this same approach, an analysis of the Lunar Gateway’s NRHO trajectory over one year was performed along with an analysis of the scattered radio flux from ground stations on Earth and the flux leakage from Gateway. Three different possible deployment latitudes for FARSIDE were investigated: the equator, 30 degrees, and -30 degrees. The analysis in this thesis ultimately showed that a deployment latitude below the equator would be the preferable choice to maximize the visibility of Lunar Gateway from FARSIDE considering the geometry of the Lunar Gateway’s orbit.

Date Created
2023-05
Agent