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Exploring The Feasibility Of The Resonance Corridor Method For Post Mission Disposal Of High-LEO Constellations
Get PDFIn the upcoming decade, the proliferation of high-LEO constellations is expected to exceed 20,000 objects, yet comprehensive Post Mission Disposal (PMD) strategies for these constellations are currently lacking. With the inherent challenges of efficiently deorbiting satellites from High-LEO orbits, there arises an urgent need to explore innovative approaches. Building upon insights garnered from the ReDSHIFT project and anticipating the proliferation of high-LEO constellations such as OneWeb, TeleSat, and GuoWang, this thesis delves into the potential viability of the Resonance Corridor Method for PMD. The investigation encompasses key metrics, including deorbit timelines and requirements to meet regulatory standards or recommendations, with comparisons drawn against alternative methods like Perigee Decrease and Graveyard Orbit solutions. Through this analysis, scenarios emerge where the Resonance Corridor method demonstrates advantages, offering feasible delta-v values while ensuring compliance with regulatory standards and recommendations. The findings yield categorizations of high-LEO constellation shells into specific disposal feasibility groups, thereby providing valuable insights into how space sustainability practices can be added into spacecraft design to align with evolving space debris mitigation standards. Additionally, certain altitude-inclination combinations are found to naturally align with the resonance corridor method, while others necessitate minor architectural adjustments to optimize effectiveness
Deciphering The Contribution Of Microglia To Neurodegeneration In Friedreich\u27s Ataxia
Get PDFFriedreich\u27s ataxia (FRDA) is the most prevalent inherited ataxia, affecting one in every 50,000 individuals in the United States. This hereditary condition is caused by an abnormal GAA trinucleotide repeat expansion within the first intron of the frataxin gene resulting in decreased levels of the frataxin protein (FXN). Insufficient cellular frataxin levels results in iron accumulation, increased reactive oxygen species production and mitochondrial dysfunction. Tissues most heavily impacted are those most dependent on oxidative phosphorylation as an energy source and include the nervous system and muscle tissue. This is evident in the clinical phenotype which includes muscle weakness, ataxia, neurodegeneration and cardiomyopathy. However, there has been a lack of data regarding the cell type specific contributions in FRDA pathogenesis. We generated a cohort of induced pluripotent stem cells (iPSCs) consisting of FRDA patient lines, CRISPR-Cas9 edited controls, carriers and non-related controls. Our preliminary data identified a hyperinflammatory microglial phenotype with extensive defects in mitochondrial function; since microglia are the primary innate immune cell of the brain, we hypothesized microglia may decrease neuronal viability which contributes to FRDA pathology. To investigate this, the iPSC cohort was utilized to generate microglia (iMGs) and neurons to better understand microglia-mediated neurodegeneration and how this contributes to pathology. An in vitro co-culture model composed of neurons, astrocytes and microglia was employed to better understand microglia-neuronal communication in FRDA. Healthy neurons co-cultured with FRDA iMG or with FRDA iMG-conditioned media demonstrated higher incidences of caspase-3 mediated apoptosis. These findings were recapitulated in vivo as xenotransplantation of FRDA microglia progenitors into a murine model resulted in reduced Purkinje cell survival in the cerebellum. Previous research has demonstrated the therapeutic potential of wildtype microglia to rescue the FRDA phenotype in the Y8GR mouse model of FRDA. To further explore the potential mechanisms behind this rescue, the delivery of mitochondria and FXN to FRDA microglia and neurons was investigated. CRISPR-Cas9 edited microglia demonstrated transfer of healthy mitochondria to FRDA microglia and neurons in an in vitro co-culture model. To investigate the transfer of frataxin protein, an FRDA iPSC line was transduced with an FXN-GFP lentivirus. Restoring FXN expression was demonstrated to rescue the FRDA microglial morphological phenotype. FXN-GFP microglia demonstrated transfer of frataxin protein to FRDA microglia suggesting the potential role of microglia as a therapeutic vehicle in FRDA. Together these findings show that FRDA microglia have a deleterious effect on neuronal viability, while healthy microglia may work as a therapeutic vehicle through the delivery of mitochondria and frataxin to FRDA cells
Urban Design Guidelines: San Antonio Road Corridor, Palo Alto, CA
Get PDFUrban design guidelines are a set of principles, standards, and recommendations that guide the planning, development, and construction of urban spaces. The guidelines aim to enhance the physical environment of cities and communities, improving functionality, aesthetics, sustainability, and overall quality of life. They provide a basis for making design decisions that are consistent with the City’s needs and the community’s interest.
This document is specifically tailored to the San Antonio Road Corridor in Palo Alto. Each section is supported by extensive research on existing conditions, case studies, and best practices. The document includes an introduction, a brief overview of existing conditions, and three key overarching principles developed to address specific issues and opportunities for improvement within the site boundaries: Site Design & Architecture, Public Realm, and Environment & Sustainability. Within each are several guidelines with rationales and implementation strategies aimed at suggesting improvements
Designing, Estimating, and Building a Deck and Overhang for the Paso Robles Police Department Shooting Range
Get PDFThis paper covers the design, estimating, and construction process by a team of students from Cal Poly to provide a deck and overhang for the Paso Robles Police Department Shooting Range. The project, initiated in the winter of 2024, aimed to provide a durable, functional, and aesthetically pleasing deck and overhang suitable for a barbecue and lounge area. The paper focuses on the design and estimation phases, as well as material procurement and construction. Through meetings with the client, the team developed a design that met the police department\u27s criteria for functionality, durability, and cost. The design process involved collaboration and many iterations of feedback to refine the structure\u27s layout, features, and materials. Key features of the design included a spacious, elevated deck with a sturdy overhang to provide shade and protection from the elements. Feedback from professionals in the industry led to adjustments such as reinforcing the deck’s support structure, optimizing the overhangs dimensions, and supplementing cost-effective materials. The paper concludes with lessons learned, emphasizing the importance of effective communication, detailed documentation, and a builder-focused mindset in construction projects
Skip the Grid: Navajo Nation Solar Power Project
Get PDFSkip the Grid, an initiative aimed at empowering communities in need was brought to life through the collaborative efforts of California Polytechnic State University San Luis Obispo (Cal Poly) students, industry partners like SOLV Energy, and the educational non-profit organization Heart of America (HOA). This project was a true testament to the power of teamwork and innovation. Our mission was to assist families of school-aged children in the Navajo Nation by providing them with solar energy systems, including batteries and lighting. We aimed to create a lasting impact by equipping these families with essential resources. In addition, we integrated educational opportunities for the children by supplying toys, books, arts and crafts, and organizing a STEM event for over K-12 students. Families were selected through a partnership with the Consolidated School District in Shiprock, New Mexico, and HOA to receive these off-grid power installations. This third installment of Skip the Grid sought to improve in terms of size, efficiency, and overall impact. Thanks to the dedicated efforts of all parties involved, the project successfully delivered solar power and lighting to many families in March 2024. This initiative exemplifies the transformative potential of interdisciplinary collaboration and community service
MORP: Monocular Orientation Regression Pipeline
Get PDFOrientation estimation of objects plays a pivotal role in robotics, self-driving cars, and augmented reality. Beyond mere position, accurately determining the orientation of objects is essential for constructing precise models of the physical world. While 2D object detection has made significant strides, the field of orientation estimation still faces several challenges. Our research addresses these hurdles by proposing an efficient pipeline which facilitates rapid creation of labeled training data and enables direct regression of object orientation from a single image. We start by creating a digital twin of a physical object using an iPhone, followed by generating synthetic images using the Unity game engine and domain randomization. Our deep learning model, trained exclusively on these synthetic images, demonstrates promising results in estimating the orientations of common objects. Notably, our model achieves a median geodesic distance error of 3.9 degrees and operates at a brisk 15 frames per second
Liquefaction Case Histories From Oceano, California During The 2003 San Simeon Earthquake
Get PDFOn December 22nd, 2003, the Mw=6.5 San Simeon earthquake occurred 12 kilometers east of San Simeon, California, causing damage to buildings, roads, and other infrastructure throughout the central coast. The community of Oceano, 80 kilometers southeast of the epicenter, experienced damage to foundations, roads, and utilities due to liquefaction and lateral spreading. The unique geologic environment in Oceano caused a local amplification of ground motions, liquefaction, and lateral spreading. This study entailed developing ten liquefaction case histories from Oceano during the 2003 San Simeon earthquake. Four of the ten case histories are liquefaction cases and six are non-liquefaction cases, with Cyclic Stress Ratio (CSR) ranging from 0.17 to 0.43 and average corrected cone tip resistance (qc1) ranging from 2.67 to 23.53 kN/m^2. Subsurface data used to represent the geologic conditions in each case history included CPT soundings provided by the United States Geological Survey (Holzer et al., 2004). Ground motion data used to represent the earthquake conditions in each case history included the nearest relatively free field ground motion recordings from the SLO Rec Center Seismic Monitoring Station provided by the PEER strong motion center (PEER Ground Motions Database, 2003). CPT soundings were grouped together to develop representative case histories, allowing for averaging of parameters. The stratum with the single highest potential for liquefaction was selected and used as the ‘critical layer’ in each case history. To accurately represent the ground motion felt by each critical layer, a site response model was used to calculate average shear stress, which was used to calculate Cyclic Stress Ratio. The site response model was built using DEEPSOIL V6.1 with measured seismic shear wave velocities. Velocities were measured using passive geophysical methods in conjunction with Spatial Autocorrelation (SPAC) methods to process the data into shear wave velocity profiles. Measured velocities ranged from approximately 117 to 469 meters per second at depths ranging from 0 to 50 meters below the ground and were normally dispersive
A Hip Hop Dialogic: Exploring Hip Hop Feminism in the College Classroom
Get PDFIn this paper, we explore the use of Hip Hop feminist pedagogy in an undergraduate classroom. We discuss the ways an in-class deliberation activity can: 1) engage students in ethical argumentation and critical reasoning on Black and Latina women’s representations in Hip Hop music and culture; 2) invoke discussions about the sexual and racial politics inherent in Hip Hop, including the objectification, hyper-visualization and marginalization of Black and Latina women; and 3) prompt students to think about Black and Latina women’s resistance to dominant male discourses and the ways women participation in the music and culture can be identified as simultaneously empowering