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Surf Sled 2.0
Get PDFThis Preliminary Design Review documents the complete detail of our final design and justifies that our specifications were met. For our senior project though California Polytechnic University, we were assigned a design and build challenge from the company AmpSurf. The project was sponsored by the Founder of AmpSurf, Dana Cummings, and involved designing and manufacturing a fully functional Surf Sled. The objective was to safely carry a physically impaired AmpSurf client across the sand on a surfboard and launch them into the ocean. The goal for our team was to improve upon a previous design, Surf Sled 1.0, to be given feedback from Mr. Cummings and the volunteers who operated it. This document highlights our new design and the critical components that allow for smoother and more efficient operation than the previous version. This includes a new turning system, frame design, bunk design, and wheel system. The manufacturing processes used have been discussed in great detail, along with our testing results. Overall we were very pleased to present a successful verification prototype to our sponsor following our senior expo. This report also details what we have learned throughout the design and manufacturing processes and how we plan to apply it to future projects
University of Washington Bill & Melinda Gates Center for Computer Science & Engineering
Get PDFThe purpose of this report is to analyze and evaluate the prescriptive and performance-based criteria used to design the fire protection systems installed in the Gates Center for Computer Science and Engineering at the University of Washington, Seattle Campus. The Gates Center is a five-story building housing business and assembly spaces such as classrooms, workrooms, offices, a lecture hall, event center, and a café. The main architectural feature is a central atrium, which connects the ground, first, second, and third floors of the building.
Aspects of the prescriptive-based fire protection design include egress, automatic sprinkler systems, detection and notification devices, and structural elements. Egress capacity exceeded occupant load and an adequate number of exits were provided on each floor. One area of concern is the egress pathway for occupants on the first floor, east side of the building. In an emergency, architectural drawings show occupants egressing through the staircase as well as through the atrium due to the limited exit capacity of the staircase. However, if the fire is in the atrium, the conditions in which occupants will egress through will be worse than where they originated. Although the atrium has a smoke extraction system installed, a second staircase should have been added on the east portion of the building.
The smoke extraction system in the atrium is compliant with NFPA 92 and is comprised of six rooftop fans and makeup air pathways. Control logic enables the fans to operate upon detection of water flow or smoke. Once the fans initiate, motorized dampers are opened to allow for makeup air to infiltrate the space. Initiating devices such as sprinklers and smoke detectors are key to the operation of the smoke extraction system.
Analysis of the automatic suppression system revealed no deficiencies as the city’s water supply exceeded the building’s demand. The building demand was dictated by the most hydraulically remote area, which was the fourth-floor events space. Regarding hazard classification, the only space that could have been classified differently is the café pantry, which was classified as light hazard but ordinary hazard group one seems more fitting. Finally, installed sprinkler heads had proper spacing and flow characteristics.
Both fire alarm and notification system analysis and structural analysis concluded that the Gates Center complies with local codes. Voltage-drop calculations demonstrated the installed wiring complies with NFPA 72. Regarding structural analysis, the building construction type, allowable height and number of stories, and interior fire ratings all complied with local codes and university mandates. An aspect of passive protection that lacked documentation is interior finish ratings. The report reviews finish requirements, but no conclusion on whether the Gates Center complies was made.
For the performance-based design, a life safety analysis was performed using tenability criteria. Tenability criteria used in the analysis includes visibility, room temperature, smoke layer height, and toxic gas production. Two design fires were hypothesized and evaluated using fire correlations, Consolidated Fire and Smoke Transport (CFAST), and Fire Dynamic Simulator (FDS). The first design fire is an office fire, which was chosen to model an ultra-fast developing fire and analyze flashover effects. The office furniture has a peak heat release rate of 6900 kW, 375 seconds after the fire ignites, which corresponds to an alpha value of 0.049 kW/s2. The second design fire analyzed a 7-ft Christmas tree, having a peak heat release rate of 7.3MW, located in the events space. This design scenario represents a severe fire resulting from a large fuel load and analyzes the tenability criteria over time. The fourth-floor events space is also the most remote location in the building, representing the worst-case required safe egress time. For this design fire, the available safe egress time was calculated as the time to reach untenable conditions. In both cases, the available safe egress time is compared to the required safe egress time.
Recommendations to the Gates Center include added features to the egress and fire detection strategy. An additional staircase on the east end of the building would eliminate the need for occupants to egress through the atrium. In addition, all the stairs serving the second, third, and fourth floors terminate inside the building and discharge to hallways with the same fire rating as the staircase. However, having at least one exit discharge directly to the exterior on the first floor would be nice for occupants and fire fighters to access. Another recommendation includes the installation of a heat detector in the café pantry. Although classified as light hazard, ordinary group one is better suited for the fuel hazards stored in the space. From design fire results, sofas should not be allowed in offices unless the office is large enough for two sprinkler heads. This will limit the fuel load in a small space and help reduce the time to flashover. In addition, Christmas trees should not be displayed in the fourth-floor events space due to its high fuel load and remote location. The events space is most likely to house people who are unfamiliar with the building, which is not favorable for tenability criteria, nor egress time. However, it should be noted that the design fires were chosen to stress the fire protection system and the likelihood of having such large fuel loads is relatively small
How Many Trans People Get Abortions? An Introduction to Critical Data Studies
Get PDFAs abortion restrictions escalate, scholars and activists have struggled to incorporate transgender individuals into their organizing efforts. On one hand, most people recognize that not everyone who needs an abortion identifies as a woman. On the other hand, many are reluctant to abandon or complicate the rallying cry of abortion as a woman\u27s issue. Caught at a perceived crossroad, stakeholders wonder, how many transgender people actually get abortions? in the hopes that this number might guide their social movement strategies. In this assignment, students will use the concept of critical data studies to examine the politics of how we collect and interpret data. Specifically, they will learn about critical data studies from an introductory article in Trans Studies Quarterly, then conduct a case study using two short articles from the journal Contraception that attempt to estimate the number of trans abortion-seekers. This activity engages a number of core topics in feminist theory, including the relationship between knowledge and power, building coalitions across difference, and questions of identity, essentialism, and what constitutes a “woman.
Teaching Intersectionality: Moving Between Theory and Practice
Get PDFIn this critical commentary, I reflect on teaching intersectionality in the classroom. By continuously shifting between theory and practice, students are able to understand and later apply intersectionality. First, I discuss how I introduce intersectionality through classroom discussion. Second, I highlight how the importance of self-reflection and analysis to aid in understanding. Lastly, I mention ways I incorporate intersectionality throughout the course
Learn by Doing: Website UX Research for Academic Libraries
Get PDFSeries of UX assessment studies, evaluating and improving the Robert E. Kennedy Library\u27s digital landscape of front-facing web interfaces, discovery platforms, and virtual portals. Objectives include understanding the unique needs and behaviors of REKL website’s target users and discovering the challenges and barriers that are experienced when using the website
Floating Offshore Wind Turbine Project
Get PDFOffshore wind is a developing industry in the Central Coast with the advent of the future offshore wind project planned off the north coast of San Luis Obispo County. This senior design project aligns with the recently leased wind energy project as a detailed study on the structural design, geotechnical design, and construction of a single 14 MW floating offshore wind turbine (FOWT) located 40 km NW of Morro Bay (NOAA buoy 46028). A preliminary design of a spar FOWT is presented in this project as a solution to the rapidly increasing water depth off the coast of Morro Bay, anchored to the seafloor by a single suction caisson. Key design parameters and methodologies are identified based on research projects and operating wind turbines to form the conceptual design that is in compliance with Det Norske Veritas (DNV) codes. The turbine tower and spar floating platform are designed against the ultimate limit states (buckling and yielding) per DNV. Mass estimations and worst-case environmental loading have been calculated to analyze the floatability and determine the required ballast to satisfy the intact stability in the hydrostatic analysis of the structure. Worst-case loading and upscaled scenarios were considered in the suction caisson design conservatively. Construction operations at the staging location of Port Hueneme also including a project execution schedule and cost estimate are outlined in the report to analyze the feasibility of the project
Biomechanical Knee Joint for Exoskeleton
Get PDFOur senior design project consisted of designing and manufacturing a biomechanically accurate, actuated knee joint to be integrated into an exoskeleton being developed by the Lower Limb Exoskeleton Assist Project (LLEAP), a part of the EMPOWER student association at Cal Poly, San Luis Obispo. As the human knee flexes and extends throughout gait motion, the center of rotation changes. Currently marketed exoskeletons have one point of rotation, which over constrains the knee and causes misalignment between the user and the suit [1]. Our goal was to mimic natural knee joint motion by changing the center or rotation, thus reducing misalignment and limiting power loss. We designed this knee joint for our prospective exoskeleton user: Carlo Ruggiero, a 21-year-old Cal Poly student with a complete C8 injury to his spine which resulted in loss of function and sensation from his chest and below.
Our design consists of a linear actuator mounted along the outside of the user’s thigh, which drives a four-bar linkage in line with the user’s knee. After manufacturing and testing our design, it was found that the joint met the necessary power requirements and reached the required angles for human gait. However, the linear actuator that was purchased was too long to fit properly on the user’s leg and is unable to vary its speed.
This verification prototype proves that mimicking knee joint motion for exoskeleton applications is feasible but requires integration of a linear actuator with greater power density and the ability for speed control. We also recommend using biomedical imaging to accurately determine the center of rotation throughout actuation. This would allow for tuning of the lengths of the links in the four-bar linkage to match the user’s knee biomechanics more precisely
On Teaching Diversity and Inclusion
Get PDFIn 2020, I was asked to design a module called “Diversity and Inclusion in Practice” for a new online MA. To design a module around this theme was to reckon with a paradox. Scholars such as Sara Ahmed, working across feminist, queer, and critical race studies, have given us theoretical and methodological frameworks not simply for celebrating “diversity” but for exploring this term itself as a function of power. While the use of terms such as diversity and inclusion may be a strategic necessity for social justice work around higher education’s current agenda, this “language of diversity” (Ahmed 2012: 51) is also part of an ambivalent institutional performance. In this essay, I chart my thought process in determining how to put ambivalence “in[to] practice” in my design and delivery of a module about D&I itself. I question how to avoid simply replicating models of D&I training like unconscious bias, mobilising instead the relationship between the theory of D&I and the practice of it. And I explore how the professional and personal experiences and contributions of students on this part-time, online MA shape the role of the classroom at the intersection of pedagogy and politics
Current Source DC-DC Converter for Undersea Fiber Optic Sensors
Get PDFToday, there are nearly 400 cable networks spanning roughly 750,000 miles to connect our world together. With thousands of miles of cable already lying on the ocean floor, with thousands more to come, many have recognized a unique opportunity in using this cable infrastructure as an attachment point for sensors to help study and monitor the ocean. Placing sensors onto a submarine cable is not a simple task; the sensors will require power that they receive from a transmission cable, from a battery, or from the submarine cable itself. Unfortunately, the existing power feed configuration for submarine cables typically only accounts for cable repeaters and their specified current requirement. Therefore, a converter will be required to properly power the sensors. Because only the current is a known value (as the voltage will be variable depending on the position along the cable), a current source DC-DC converter must be used. This project entails the design and construction of a current source DC-DC converter that is intended to meet the following specifications for the sensors: step down an input current of 0.9 amps to 0.625 amps, maintain an output voltage of 24 volts, and an output power of 15 watts.
The goal of this project was to create a current-source DC-DC converter that stepped down a 0.9A input current to a 0.625A output current at 24V. The designed circuit successfully stepped down the input current to the proper output; however, further improvements will be needed to achieve the desired efficiency and output ripple specifications. Overall, the constructed circuit provides a proof of concept of the current source design that can be iterated upon for better results in the future