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Battery Hardware Simulator
Get PDFThis project aims to develop a battery hardware simulator, which will serve as a tool for studying microgrids. The primary objective is to create a simulation system that can emulate various battery technologies that are used in microgrids, including lithium-ion and lead acid. By utilizing this battery simulator, Cal Poly students can safely test battery management systems and battery-sensitive electronics without the inherent risks associated with real batteries. Our project implemented this design with a 4-quadrant programmable power supply (ITECH) connected to an AP Systems grid tied inverter. The power supply acts as the battery which can receive or supply power from or to the grid through the inverter. The power supply is programmed with different battery technology discharge profiles using the ‘List’ function
Sky Survey Radio Telescope
Get PDFThis document outlines the design of a radio telescope designed to perform hydrogen line sky surveys. The telescope produces radio images mapping the intensity and relative velocities of hydrogen concentrations to their sky coordinates. Over the course of a day, the telescope images the regions of space visible to it, allowing sky survey imagery to be updated daily. Sky survey images are comprised of an array of pixels corresponding to specific sky coordinates. Each 8-bit RGB pixel contains information on the concentrations of hydrogen in the brightness and relative velocity in the color. Radio images mapping the concentrations and velocities of hydrogen clouds are incredibly valuable and interesting tools for understanding the structure and behavior of our galaxy and the broader universe. This project aims to provide a tool for students at Cal Poly to become familiar with the techniques and tools used by radio astronomers
Surface Characterization of Low-Density Polyethylene Mulch
Get PDFPlastic pollution in aquatic systems has traditionally been highlighted in past and current research due to the increase in plastic production every year. Unfortunately, quantitative and qualitative data regarding plastic pollution on land systems such as agricultural mulch is limited. Agricultural mulch breaks down into macroplastics and then degrades into microplastics. The microplastics investigated in this study are all secondary microplastics: microplastics that form due to weathering of larger fragments of plastic. Weathering can occur due to a variety of factors; however, UV radiation and mechanical weathering have been the factors of focus on most current research in microplastic formulation. Microplastic characterization has commonly been done using Fourier-Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) instrumentation. FTIR analysis of the microplastic samples can be used to quantify the amount of photooxidation that occurred in association with UV radiation. SEM analysis of the microplastic samples provides insight on the surface characteristics, size, and shape of the microplastic samples. This study investigated the surface characterization of fresh and field deployed low-density polyethylene mulch to address the gap in knowledge regarding the effect of plastic pollution on agricultural soils and better understand microplastic formation on agricultural land systems. Shredding was identified as the dominant damage feature present in the LDPE mulch samples. The thickness of the mulch affected the total amount of damage and surface area loss due to weathering conditions
Microfabrication Lab Furnace Upgrade
Get PDFThis project, undertaken by the Mechanical Engineering Department at California Polytechnic State University, aimed to upgrade the control system, user interface, and control software for Cal Poly\u27s oxidation and diffusion furnaces. The upgrade was designed to enhance the usability of the furnaces for students learning in the microfabrication lab and improve the lab\u27s image for prospective students. The project involved a comprehensive design process, including mechanical design, controls, software, human factors, heat transfer, fluid mechanics, electrical design, integration, and testing. The implementation phase entailed procurement of over 300 distinct components, manufacturing, and assembly.
The project\u27s primary goal was to ensure safety and reliability, considering the operational conditions of the furnace and the associated safety requirements. A structural prototype was developed, which provided insights into the real-world operations of the design. The design verification process was exhaustive and thorough, conforming to the specifications detailed in the Specifications Table. Various tests were conducted to evaluate the functionality and safety of the system, including a dry run test, sensor test, and code testing.
The project matters as it enhances the educational experience for students in the microfabrication lab, providing a user-friendly control over the furnace system. It also improves the lab\u27s image, making it more appealing to prospective students. The project\u27s success demonstrates the effectiveness of a comprehensive design and implementation process in achieving safety and reliability in a complex engineering system
Therapeutic Mechanical Horse Project
Get PDFThis project team created a simple mechanical model of a horse that disabled children could ride on to feel more comfortable partaking in equine therapy. This project was sponsored by Jack’s Helping Hand as part of their equine therapy program. The team went through the entire design process of researching, ideating, prototyping, and testing to create the final product. Finite element analysis of the structural members of the horse was performed. The forces used in that model were later validated through testing of the strength of those same members after manufacturing. In the end, a self-actuating single degree of freedom horse was constructed primarily of wood and was successfully ridden by well over a hundred people at the senior expo. Since this project was entirely based on the idea of making its user more relaxed and comfortable, the positive feedback received at the expo was evidence of the project’s success
3D Printed Aircraft
Get PDFThis project is to design, build, and test a 3D-printable aircraft. The goal is to create a final design that will be able to fly for the longest duration possible, around 20 seconds. To determine the correct preliminary design and manufacturing process for a 3D printed RC aircraft, an analysis of multiple design options and manufacturing materials was performed. This allowed for a variety of choices for aircraft type, airfoil design, structure, among other topics to be narrowed down to the most promising option. It has been found that the aircraft will follow a design similar to industry motor-gliders, with a lightweight wing design and airfoil common to glider models. With regards to the manufacturability, the aircraft will be printed using a Fused Deposition Modeling (FDM) printer in carbon fiber polypropylene to optimize weight to strength ratio. These findings are critical to understanding the large scale applications of 3D printing in the aerospace industry, with a particular focus on fixed wing aircraft
Optimizing Solid Thermal Storage in Insulated Solar Electric Cookers
Get PDFInsulated Solar Electric Cookers, more commonly known by their acronym ISECookers, are an alternative to biomass cooking. The ISECooker in its simplest form is a solar panel connected to a heating element, in contact with a cooking pot in an insulated chamber. An aluminum puck can be heated as solid thermal storage (STS) for increased power and night time cooking. Power was limited to about 500 W by the interface between the STS and cookpot. Powdered graphite and silver were separately applied to increase thermal flow. However, the powdered graphite decreased the thermal flow, while powdered silver decreased the temperature difference between the STS and cook pot by only 2℃
Fire and Life Safety Evaluation of an Assisted Living and Memory Care Center
Get PDFThis culminating project has been submitted as part of the graduate program in Fire Protection Engineering at Cal Poly. It documents an Assisted Living and Memory Care Center’s compliance with applicable fire safety prescriptions contained in the 2019 California Building and Fire Codes (CBC and CFC). Performance-based methods incorporating deterministic design fires were then used to verify that the final building design and operating procedures met the life safety needs of its unique occupants.
The building under analysis was a 45,000 sq. ft, two-story, 58-bed residential care facility for the elderly. Occupants were all 60 years or older without acute medical conditions but with potential mild to severe mobility, sensory, and cognitive impairments. The fire- resistance-rated light-frame wood structure, its compartmentalized interior layout, and its active fire protection systems were found to satisfy the code provisions adopted by the local authority having jurisdiction. These included plentiful egress and exit capacity, localized fire and smoke containment, early smoke detection, audible and visual notification at levels appropriate to the occupants, and complete quick-response sprinkler coverage for life and property protection.
The priorities of the performance-based analysis were to check the adequacy of these code-compliant fire protection features, as well as to support housing accessibility and to inform staff training. These required realistic fire models to verify available safe egress times (ASETs), which were shorter for these residents than the general population due to their lower tolerances for heat and smoke exposure. Design fires took guidance from NFPA 101 Life Safety Code and the author’s research on the history of fatal care home fires. All fires were placed in residential wings using heat release data from calorimetry tests of residential furniture and mixed natural/ synthetic hydrocarbon contents in staff supply closets. Initial growth rates were between fast (0.0469 kW/s2) and ultrafast (0.1876 kW/s2), with peak heat release rates and embodied energies appropriate to the fuel packages but ultimately determined by ventilation conditions.
Model results supported the existing building design but showed that additional fuel control, compartmentation, detection/ notification, and automatic suppression would strengthen care staff’s response to and management of fires. Specifically, all rooms that communicate with residential corridors should have smoke detection and be fitted with door self-closers, following the findings of Performance Design Fires ‘B’ and ‘C.’ Where clients are housed also impacts their fire safety, so their facility intake forms/ health assessments should be used to guide placement— per Performance Design Fire ‘A,’ Assisted Living residents with the greatest cognitive, sensory, and locomotion disabilities should be housed closest to the lobby to receive prompt aid and minimize burns and smoke inhalation. These vulnerabilities also mean that sprinkler protection should be designed following the more rigorous commercial NFPA 13 standard as opposed to low- rise residential NFPA 13R, which was demonstrated in Performance Design Fire ‘D.’
Performance Design Fire ‘A’ was a nighttime living room furniture fire typical of all 40 Assisted Living dwellings. The occupant was assumed to be sleeping in the bedroom and not intimate with ignition; they were also capable of self-evacuation. Their required safe egress time (RSET) included a delay in waking to their low-frequency smoke alarm and traversing their unit to the corridor door, which totaled two minutes. At this time, the visibility through smoke was well below what would normally be accepted for design. The gasses at six feet above finished floor in the egress path were already too hot to move through (120°C), so the evacuee had to stoop, crouch, or even crawl, depending on the effectiveness of the sprinkler suppression. Since the sprinkler did temper heat, the asphyxiant fractional effective dose for incapacitation (FEDtot = 0.1) became the limiting tenability criteria; an especially respiratory-sensitive evacuee who took longer to find their door would have been incapacitated at two and a half minutes, but staff was expected to intervene by then. The slim margin for human error suggests that this scenario would benefit from a probabilistic assessment that includes ignition and suppression. A deterministic solution would be to regulate the flame spread and heat release of the furniture that residents bring in or are provided with.
In scenarios ‘B’ and ‘C,’ a mixed cellulose/ plastics design fire was placed in staff supply closets with doors open to the residential hallways in the Assisted Living and Memory Care wings. The door in Performance Design Fire ‘B’ was self-closing, so wedging it open represented an n = 1 managerial failure; the closet sprinkler was operational. The nighttime RSET of Assisted Living residents to reach an adjacent smoke compartment was three to four minutes, depending on their disability. The ASET was the time for the smoke layer to descend to six feet in the corridor, which was the only evacuation route. This occurred by a minute and a half for 44% of the dwelling units along the hallway, which was the earliest staff was expected to arrive and close the fire room door. Since visibility at the staff entrance to the corridor was below two meters, and required crouching or crawling to access the room, closing the fire room door was not a certainty. This scenario necessitated partial or full defend-in-place in the Assisted Living wing.
A similar result was found for the Memory Care wing in Performance Design Fire ‘C.’ A faulty sprinkler was an n = 1 device failure in this scenario because the closet door was not required to be self-closing. Occupants with dementia/ MNCD were assumed to be incapable of self-evacuation, and an RSET was not calculated for full staff evacuation of the wing, but it would have been much longer than the minute and a half ASET it took for smoke to descend to six feet in most of the corridor.
Performance Design Fire ‘D’ looked at ignition within a Memory Care dwelling and NFPA 13’s requirement for sprinklers in clothes closets, which goes beyond NFPA 13R. This model also assumed an n = 1 device failure of the sprinkler. In contrast with Design Fire ‘A,’ the RSET was the time it took for an attendant to rescue the fire room occupant. This was just over a minute; since the fire was shielded from the main room sprinkler by the closet door, the fire burned uncontrolled, and the heat became intolerable overhead (200°C) after a minute and a half. This slim margin for attendant error echoes the conclusions of Design Fire ‘A.’
A summary of ASETs versus RSETs and additional observations can be found in Chapter 11. Facility operator responsibilities, including fuel control, housekeeping, fire protection systems maintenance, and emergency preparedness plans, can be found in the fire safety plan in Chapter 12. These are primarily based on the requirements of the CFC and the findings of this report\u27s prescriptive and performance chapters
Child Sexual Assault Prevention and Intervention
Get PDFIn our paper, we discuss child sexual assault, its risk factors, short and long-term outcomes, as well as prevention and intervention programs that have been shown to be valuable. To limit research, our focus will be on children living in the United States who have been physically sexually assaulted. To spread awareness of child sexual abuse, we also developed a pamphlet (See Appendix) that will be distributed to CASAs, which stands for Court Appointed Special Advocates. The development of the pamphlet is described in the combined Method and Results section. We conclude our project and paper with a Discussion section that provides a critique of the entire project and suggestions for the future
Identifying the Stream Depletion Paradox by Monitoring a Stream’s Response to Aquifer Pumping from Neighboring Wells
Get PDFCurrent groundwater models utilize a constant head (Dirichlet) boundary condition which assumes stream stage is fixed and does not experience any drawdown in the event of pumping from an interconnected aquifer despite the presence of stream depletion. Therefore, constant head boundary implies that streams and lakes in a groundwater model behave as an infinite supply of water when aquifer pumping occurs. This study aimed to determine if a stream located in the California Central Coast experiences drawdown and depletion when pumping occurs within an aquifer-stream system. This was achieved by measuring stream stage, aquifer water levels, stream discharge, and the hydraulic conductivity of the subject streambed. Passively collected stream stage and aquifer water level data, actively collected stream discharge data, and in-situ streambed hydraulic conductivity measurements were taken from August 2022 to August 2023 and analyzed using time series analyses and hydraulic conductivity calculation methods. This study confirmed that stream depletion occurred during aquifer pumping and, at low discharge rates, stream stage exhibits observable drawdown in response to aquifer pumping which contradicts the constant head boundary assumption and confirms the existence of the stream depletion paradox in the subject aquifer-stream system. The streambed hydraulic conductivity was found to be relatively high and contained highly conductive gravels and coarse sands implying that the streambed has relatively high storage capacity in the subject stream. This research, subsequent data collection, and improvements to groundwater modeling will allow water managers and planners to sustainably manage local water resources which will be relied upon for generations to come