Engineering Commons^™

Enhancing Miter Saw Safety: Challenges And Prospects Of Brake Incorporation With An Automatic Blade Retraction System, Derek Cole

University Honors Theses

Miter saws pose significant safety risks with thousands of injuries reported annually. Despite this risk, they are still used every day as they are a necessity for thousands of workers in the United States and globally. This leaves a demand to make these machines safer to mitigate any potential harm. This research addresses the critical need for an automatic safety system for miter saws, aiming to enhance user safety by retracting and stopping the blade upon skin contact. This analysis identified the primary challenge: The large force generated when braking at high speed on a miter saw blade, translates the …

Optimizing Recombinant Cas9 Expression: Insights From E. Coli Bl21(De3) Strains For Enhanced Protein Purification And Genome Editing, Shilpi Agrawal, Made Harumi Padmaswari, Abbey L. Stokes, Daniel Maxenberger, Morgan Reese, Adila Khalil, Christopher E. Nelson

Biomedical Engineering Faculty Publications and Presentations

The CRISPR-Cas9 system is a revolutionary tool in genetic engineering, offering unprecedented precision and efficiency in genome editing. Cas9, an enzyme derived from bacteria, is guided by RNA to edit DNA sequences within cells precisely. However, while CRISPR-Cas9 presents notable benefits and encouraging outcomes as a molecular tool and a potential therapeutic agent, the process of producing and purifying recombinant Cas9 protein remains a formidable hurdle. In this study, we systematically investigated the expression of recombinant SpCas9-His in four distinct Escherichia coli (E. coli) strains (Rosetta2, BL21(DE3), BL21(DE3)-pLysS, and BL21(DE3)-Star). Through optimization of culture conditions, including temperature and …

Scaffold-Free Development Of Multicellular Tumor Spheroids With Spatial Characterization Of Structure And Metabolic Radial Profiles, Shelby N. Bess, Gaven K. Smart, Matthew J. Igoe, Timothy J. Muldoon

Biomedical Engineering Faculty Publications and Presentations

Purpose

In vitro assays are essential for studying cellular biology, but traditional monolayer cultures fail to replicate the complex three-dimensional (3D) interactions of cells in living organisms. 3D culture systems offer a more accurate reflection of the cellular microenvironment. However, 3D cultures require robust and unique methods of characterization.

Methods

The goal of this study was to create a 3D spheroid model using cancer cells and macrophages, and to demonstrate a custom image analysis program to assess structural and metabolic changes across spheroid microregions.

Results

Structural characterization shows that cells at the necrotic core show high normalized fluorescence intensities of …

Automated Expanding Christmas Tree, Ben Mosemann, Zoey Camarillo, Xiomara Medina, Will Tedone

Mechanical Engineering

The Civic Ballet of San Luis Obispo (SLO) needs a new expanding Christmas tree for their 2024 production of The Nutcracker. This Final Design Review Report outlines pertinent information regarding the Cal Poly Mechanical Engineering Senior Project of Team F14 (“D.R.E.I.D.E.L.S.”), who was tasked of designing and building the new expanding Christmas tree frame. Our team’s name, “D.R.E.I.D.E.L.S.,” stands for Design and Research of Expansion Integrated Dramaturgy Ergonomic Leveraging Systems. We thought this would be a fun, creative, and ironic name for our team.

In this report, our team will discuss how we procured the materials required and manufactured and …

The Wildland Firefighter Respiratory Protection Device, Oliver Pilon, Xaviera Pons, Calder Wood, Tommy Ozawa, Jack Adema, Payton Mayer

Biomedical Engineering

This paper presents the development of First Respire and their design of a powered air-purifying respirator (PAPR) specifically curated for wildland firefighter while simultaneously addressing the critical absence of respiratory protection for wildland firefighters operating in the challenging wildland-urban interface (WUI) environments. Current respiratory protection options, such as bandanas and N95 masks, fall short in providing adequate defense against toxic particulate matter and gases, exposing firefighters to increased risks of health complications, including cancers and respiratory diseases. Through collaborative efforts of the Wildfire Conservancy, the WUI Fire Institute at Cal Poly, and CAL FIRE, First Respire aims to create a …

Focused Led Sintering, Dylan Defazio, Nilav Maulik, Branden Majors, Michael Fontillas

Mechanical Engineering

This report provides a detailed overview of the final design of our light-emitting diode (LED) focusing system. Our system incorporates a converging lens and a specially designed "glass funnel," which acts as a thick fiber optic that narrows the light to a fine point through internal reflection. The glass components of our system are precisely housed in a part made using advanced computer-numeric controlled (CNC) Mill and CNC Lathe manufacturing processes. This ensures high precision and durability of the overall system. Our LED focusing system is designed with a 60-watt stage light. The decision to use a glass funnel as …

Port Adapter For Unported Pressure Sensors, Peter Kristjaan Tomson, Yasser Fahad Aldaoud, Terak Benjamin Hornik

Mechanical Engineering

Boundary layer research is an exciting and ever-changing field in fluid mechanics; thus, the need for high-quality empirical data is ever-growing in importance. Dr. Westphal, a professor at California Polytechnic State University, San Luis Obispo’s (Cal Poly) Mechanical Engineering Department in conjunction with Northrup Grumman is conducting just such research. Dr. Westphal has elected to make the change to pressure sensors that do not come with a built-in port to connect to pitot-static tubes. This necessitates a solution to adapt an unported pressure sensor to his testing apparatus which requires a tubed connection. This document outlines the Final Design Review …

Cal Poly Battle Bot, Jyotaaver S. Nirula, Johnathan W. Waldmire, Andrew D. Peterson, Nathaniel Ab Davis

Mechanical Engineering

This senior project endeavored to design, construct, and optimize a 120lb robot combatant tailored for the competitive arena of combat robotics. The project is a collaborative effort between mechanical, computer, and electrical engineering students at Cal Poly, combining diverse expertise to achieve a unified goal. Our competition, RoboGames, was in April of this year in Northern California.

The mechanical engineering team assumed primary responsibility for the physical components of the battle bot, focusing on three pivotal components: a robust drivetrain, armor, and a highperformance vertical spinner. These elements constitute the foundation of the battle bot's offensive and defensive capabilities, crucial …

Nsf-Eri Evolution Of Liquid Sheet Edges Project: Soap Film Frame Withdrawal And Positioning Apparatus, Samir S. Patel, Sophia Young, Nicole N. Morgan

Mechanical Engineering

The experimental investigation of instabilities along retracting liquid sheet edges seeks to answer a fundamental fluid mechanics question. We’ve successfully delivered an experimental apparatus to conduct research and answer this question. This document chronicles a design overview of our apparatus, our manufacturing process, our design verification, and recommendations for future steps. The final product is a document outlining our final design (i.e., our ‘Final Design Review’ (FDR)).

Liftwalker, Kai A. De La Cruz, Lexie Caterine, Adam Monroe, Jame Whealan

Mechanical Engineering

The LiftWalker’s purpose is to lift users with degenerative diseases from a seated to standing position and support them as they practice the motion of walking as a form of physical therapy. The current LiftWalker is upward of $5,000 so we redesigned the LiftWalker to be more accessible around the world. This meant using affordable and accessible materials and manufacturing processes. To achieve this, we made our design mostly out of bike parts and off-the-shelf components. When it came to the lift system, we found that to maintain a safe and comfortable design it was best to purchase a trailer …

Autolacing The Dml, Harrison Hong, Chanh Tu Derek Lam, Candice Espitia, Paolo Navarro

Mechanical Engineering

The design challenge present is the design of a system to efficiently speed up the lacing of the dry mat loop (DML), part of the GAF production line. For this year, the scope of the project focuses on research and creating a proof of concept for the mechanism responsible for moving the mat within the DML. Compiled research focuses on competitor solutions, material properties, and possible mover mechanisms to be integrated into the major design. Competitor solutions provide an idea of raw material manipulation options. Material properties and possible mover mechanisms provide the foundation for ideation and concept prototyping. The …

2024 Marine Energy Collegiate Competition, Nora Riedinger, Miles Mikkelsen, Brendan Stratford, Derek Tom, Zach Kwast, Harmon Yanikian-Sutton, Kennedy Urcelay, Tori Thomas, Brady Caron

Mechanical Engineering

PolyWave Energy is the second team from California Polytechnic University at San Luis Obispo to compete in the Marine Energy Collegiate Competition. PolyWave Energy consists of Mechanical Engineering, Electrical Engineering, and Business Administration students who have worked together from September 2023 to May 2024 on designing, building, and testing a marine power device to serve a selected market.

In response to the escalating concerns surrounding carbon emissions, climate change, and the depletion of fossil fuels, California Polytechnic State University’s Polywave Energy team has developed a sustainable and reliable energy source for Autonomous Underwater Vehicle (AUV) charging. Through extensive research of …

Robot Rodeo, Daniel Rickers, Tyler Vaughn, Vinayak Sharath, Berent Baysal, Promit Das Gupta

Mechanical Engineering

This document outlines the Final Design Review (FDR) for an autonomous robot developed in response to the Naval Surface Warfare Center (NSWC) Ship Maintenance Robot Rodeo Challenge. Through extensive analysis, we selected a design concept, built a verification prototype, and tested the prototype in the NSWC Robot Rodeo Competition. The design overview portion of this report will present the details of our design while explaining how it will function. Next, is our implementation section, which provides evidence about our procurement, manufacturing, and assembly of our product. Our design verification follows and explains the tests that we conducted on the robot …

Acoustic Activation Imaging With Intravenous Perfluoropropane Nanodroplets Results In Selective Bioactivation Of The Risk Area, S. Li, C. Chen, J. Lof, E. A. Stolze, J. Sklenar, X. Chen, J. J. Pacella, F. S. Villanueva, T. O. Matsunaga, E. Carr Everbach, S. J. Radio, S. N. Westphal, S. Shiva, F. Xie, X. Leng, T. R. Porter

Engineering Faculty Works

Background: Acoustically activatable perfluoropropane droplets (PD) can be formulated from commercially available microbubble preparations. Diagnostic transthoracic ultrasound frequencies have resulted in acoustic activation (AA) predominately within myocardial infarct zones (IZ). Objective: We hypothesized that the AA area following acute coronary ischemia/reperfusion (I/R) would selectively enhance the developing scar zone, and target bioeffects specifically to this region. Methods: We administered intravenous PD in 36 rats and 20 pigs at various stages of myocardial scar formation (30 minutes, 1 day, and 7 days post I/R) to determine what effect infarct age had on the AA within the IZ. This was correlated with …

Modeling The Effectiveness Of Bioremediation On Methyl Tertiary-Butyl Ether In Groundwater, Logan Bundy

Master's Theses

Methyl tertiary-butyl ether (MTBE) and its degraded form tertiary-butyl alcohol (TBA) are both known carcinogens that have contaminated groundwater aquifers across the United States. MTBE is a synthesized compound, once widely used as an additive in gasoline to increase oxygenation. Because of its popularity, MTBE was released into the environment primarily through fuel combustion and leaking underground storage tanks. These two compounds are known to be recalcitrant to most conventional physico-chemical treatment methods. Previous studies have suggested that bioremediation is effective at degrading MTBE and TBA in contaminated groundwater. Bioremediation involves the injection of oxygen, nutrients, and pre-adapted bacterial cultures …

Short Arc Initial Orbit Determination For Leo Objects And The Impact Of Observation Eelevation On Predictive Accuracy, Alexis Digregorio

Master's Theses

The expansion of space activities has led to an increase in congestion. With this increase, there has been a growing emphasis on the importance of space situational awareness. Without it, the space environment can become hazardous, with increasing threats of collision and debris generation. As the utilization of space continues to grow, effective methods for tracking objects to maintain situational awareness must also be considered. One approach to tracking objects in space involves a series of steps, including optical observations and orbit estimations using initial orbit determination methods, followed by additional observations and continuous tracking. However, a challenge with this …

Analysis Of Rural Broadband Adoption Dynamics: A Theory-Driven Agent-Based Model, Ankit Agarwal, Casey Canfield

Engineering Management and Systems Engineering Faculty Research & Creative Works

Demand for broadband internet has far outpaced its availability. In addition, the "new normal" imposed by the COVID-19 pandemic has further disadvantaged unserved and underserved areas. To address this challenge, federal and state agencies are funding internet service providers (ISPs) to deploy broadband infrastructure in these areas. To support goals to provide broadband service to as many people as possible as quickly as possible, policymakers and ISPs may benefit from better tools to predict take rates and formulate effective strategies to increase the adoption of high-speed internet. However, there is typically insufficient data available to understand consumer attitudes. We propose …

Modeling The Acoustic Transmission Line With Applied Damping, Connor C. Getz

Master's Theses

The transmission line is an underappreciated style of loudspeaker enclosure characterized by an acoustic labyrinth stemming from the rear of the speaker driver. In practice, the transmission line enclosure produces airy sound uncharacteristic of other styles, at the cost of more pronounced resonant peaks. The most important practical drawback of this loudspeaker enclosure design is the difficulty of properly applying damping to these enclosures. Ideally, this difficulty can be mitigated using an analytical model that accurately predicts the SPL frequency response of a transmission line loudspeaker system for a given geometry and mass of damping material.

This research takes the …

Waste Illuminates Worlds: Printed Modular Lamp Design Based On Brick And Clay Tile, Yechen Zhu

Masters Theses

The building industry in the New England area is often in a state of entropy, with abandoned brick buildings contributing to urban decay. The recycling rate of brick and clay tile wastes generated by construction and demolition is only 12.2%, meaning the majority is sent to landfills. The expansion of landfills can lead to significant environmental and community challenges, including increased traffic from waste transport, habitat destruction, ecosystem degradation, and contributions to climate change. Specifically, the Bethlehem landfill in New Hampshire, which is planned to undergo a 5.71-acre lateral expansion through 2026, has already encountered issues such as leachate spills …

Team F16: Autonomous Research Plane, Andrew Sugamele, Andrew Whitacre, Nicholas Toal, Cole Bushur

Mechanical Engineering

The autonomous research plane is a remote-controlled plane used for both in-flight data collection and to explore new manufacturing methods for Design Build Fly, an engineering club on campus. The club does not have the resources or time to implement data collection for their competition plane, so we built a plane in parallel, following similar rules to mimic the work and schedule that the club would use during their season. We first did research and analysis to determine the structure of the plane, geometry of wings, sizing of the tail, and what airfoil to choose. The manufacturing process included making …

Using Micromoments And Concept Maps To Enhance Entrepreneurially Minded Learning Of Indoor Air Pollution Control, Jean M. Andino, Erick Salvador Vasquez-Guardado, Ricardo Gomez Gonzalez, Xiaojing Yuan, Nilza D. Aples

Chemical and Materials Engineering Faculty Publications

Micromoments targeted toward indoor air quality were introduced to students in an Air Quality Engineering course to enhance their entrepreneurial mindset. Three micromoment activities, i.e., “Question Frenzy”, “Make It Relevant”, and “How Do We Make It Better?” that are linked, respectively, to the curiosity, connections, and creating value elements of EM were deployed in the class in the context of the use of a Corsi Rosenthal cube (a do-it-yourself structure that has recently become popular as an inexpensive way to reduce indoor particle pollution). Students generated concept maps pre-and post- micromoment intervention using the freely available CMap Tools software. The …

Mechanical Environment Influences Muscle Activity During Infant Rolling, Danielle N. Siegel, Safeer F. Siddicky, Wyatt D. Davis, Erin M. Mannen

Mechanical and Biomedical Engineering Faculty Publications and Presentations

An infant's musculoskeletal and motor development is largely affected by their environment. Understanding how different mechanical environments affect an infant's movements and muscle use is necessary to inform the juvenile products industry and reduce incidents involving inclined nursery products each year. The purpose of this study was to determine how the coordinated movements and corresponding muscle activation patterns are affected by different mechanical environments, specifically the back incline angle. Thirty-eight healthy infants (age: 6.5 ± 0.7 months; 23 M/15 F) were enrolled in this IRB-approved in-vivo biomechanics study. Surface electromyography sensors recorded muscle activity of the erector spinae, abdominal muscles, …

Modeling And Design Parameter Optimization To Improve The Sensitivity Of A Bimorph Polysilicon-Based Mems Sensor For Helium Detection, Sulaiman Mohaidat, F. M. Alsaleem

Durham School of Architectural Engineering and Construction: Faculty Publications

Helium is integral in several industries, including nuclear waste management and semiconductors. Thus, developing a sensing method for detecting helium is essential to ensure the proper operation of such facilities. Several approaches can be used for helium detection, including based on the high thermal conductivity of helium, which is several times higher than air. This work utilizes the high thermal conductivity of helium to design and analyze a bimorph MEMS sensor for helium sensing applications. COMSOL Multiphysics software (version 6.2) is used to carry out this investigation. The sensor is constructed from poly-silicon and SiO₂ materials with a trenched …

Polypropylene As Partial Fine Aggregate Substitute In Concrete, Samuel E. Royston, Chrisitan G. Achkar, Nicholas B. Tabarez

Architectural Engineering

The objective of this project is to discover a structurally effective method in repurposing recyclable plastic waste through its partial substitution for traditional fine aggregate in concrete.

Results obtained from analysis indicate a 25 percent compressive strength reduction with polypropylene at a 10 percent partial substitution for total sand content. This material successfully performed as an alternative, presenting a ductile mode of failure.

Three material alternatives - polypropylene, polyethylene, and rubber - were substituted for a percentage of sand. These materials underwent concrete cylinder crushing tests to determine their ultimate crushing strength, with the intent of identifying the most effective …

Cardboard Concrete Column Formwork, Danny Shrestha, Joelle Schalesky

Architectural Engineering

This project is an exploration of cardboard as a potential material for construction formwork for concrete columns. Multiple material tests were conducted to explore the behavior of cardboard and concrete. Multiple specimens of cardboard were tested for modulus of elasticity, moment of inertia, and tensile strength. Concrete was tested for its apparent lateral fluid pressure under vibration. Cardboard formwork was then designed and constructed based on these tested behaviors. The final design of the formwork consisted of folding cardboard sheets lined with hardboard, supported by wood studs, and tied by plastic banding straps.

Ultimately, two concrete columns―8' and 10' in …

Moment Monument, Brayden Alec Martinez, Carsten Walker Huber, Gaspar Emmanuel Solorio, Jared Thomas Schieferle

Architectural Engineering

We designed our project, dubbed the Moment Monument, in part to live out our dream of applying engineering and design skills towards creating a lasting impression on Cal Poly’s campus, as well as to develop a visual aid for future engineering students in steel design classes. The Moment Monument is in the Experimental Structures Laboratory, which is a space in the university’s ‘Poly Canyon’ that is reserved for students to build and test different applications of architecture, structural engineering, and construction. In recent years, it has been diffi cult to receive approval to build in the canyon due to high …

Early Detection Of Structural Damage In Uhpfrc Structures Through The Combination Of Acoustic Emission And Ultrasonic Stress Wave Monitoring, Numa Bertola, Thomas Schumacher, Ernst Niederleithinger, Eugen Brühwiler

Civil and Environmental Engineering Faculty Publications and Presentations

Ultra-High-Performance Fiber-Reinforced Cementitious Composite (UHPFRC) offers several advantages compared to concrete, notably due to the strain hardening behavior under tensile actions. Structures made of this composite material are lightweight and highly durable, thanks to the UHPFRC waterproofing quality. Nonetheless, the tensile behavior leads to a different cracking pattern than conventional concrete and is not fully understood yet. This paper presents a combined approach using both passive ultrasonic (US) stress wave (or acoustic emission) and active US stress wave monitoring to localize and quantify damage progression in a full-scale UHPFRC beam during experimental load testing. The proposed monitoring approach involves 24 …

Moringa Connect: Design And Fabrication Of The Drum For A Moringa Leaf Dryer Prototype, Braden Deck

Construction Management

Moringa Connect, founded in 2013 by MIT alumnus Kwami Williams, supports over 5,000 African farmers, primarily in Ghana, by providing a direct sales, manufacturing, and shipping platform for nutrient-dense moringa leaves. Despite significant social and economic benefits for the local farmers, the current drying process in Accra, Ghana, is inefficient, requiring extensive human handling. To address this, a team of five Cal Poly students partnered with Moringa Connect to design a prototype rotating hopper to streamline the drying process and reduce production costs. The project faced numerous challenges, including material sourcing constraints in Ghana and the need for extensive fabrication …

Investigating The Performance Of Bendable Concrete Against Traditional Concrete, Landon J. Poston

Construction Management

The qualitative research in this case study evaluates the importance of bendable concrete within various construction settings. The data aims to justify the interest in bendable concrete, as well as why it is not being used more in structural work. The intended stakeholders of this paper are concrete suppliers, contractors, and researchers who are looking for more imperative ways to manufacture a more sustainable form of concrete. Through a brief online meeting and a Google Form questionnaire, company participants were able to provide the knowledge and feedback desired for how bendable concrete can be incorporated more in the future of …

Development Of A Two-Photon Imaging System, Jesseca Hollenbaugh

University Honors Theses

The objective of this project was to convert a Sarastro 2000 confocal laser scanning microscope (CLSM) into a system capable of far-field two-photon excitation (TPE) imaging for the use of the PSU Biology department. TPE microscopy operates on the ability of fluorophores to accept two photons each with half the energy of a desired transition in a single quantum event via a virtual energy state and then emit a higher energy photon upon relaxation. This is preferable to single-photon excitation (SPE) imaging due to lower photon imaging, causing less damage to delicate biological samples, as well as the inherent localization …