Engineering Commons^™

New Insights Into Dynamic Evolution Of Colloidal Network Structure During Early-Age Hardening Of Cementitious Materials, Hengrui Liu, Kaiyin Zhao, Shipeng Zhang, Hanghua Zhang, Shuangshuang Liu, Lucen Hao, Hongyan Ma, Kamal Khayat, Chi Sun Poon

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The evolution of microstructure in cementitious materials during their transition from fluid to solid state plays a critical role in determining their ultimate mechanical strength and overall performance. This hydration stage primarily involves a dynamic densification process occurring within the colloidal network. However, the field of cement-based materials currently lacks a comprehensive theoretical framework and associated parameters capable of effectively characterizing the specific structural regions within this network. In this study, we propose an Improved Particle Linkage (IPL) theory for describing the strength, types, and quantities of particle linkages within colloidal network. The IPL theory classifies the internal network structure …

Design And Validation Of A Wearable Respiratory Protection System For Wildland Firefighters, Oliver Pilon

Master's Theses

Wildland and Wildland–Urban Interface firefighters are routinely exposed to hazardous smoke with fine particulate matter, carbon monoxide, volatile organic compounds, and other toxic combustion products. Existing protective gear has significant limitations and shortcomings for these conditions. Respirators with tight-fitting facepieces make it difficult to breathe and speak. On the other hand, self-contained breathing apparatuses are too heavy, have a limited duration of use, and do not work well with long wildland fire scenes, while smaller protective equipment like N-95’s and gaiters provide very little protection. These constraints contribute to low adoption rates and prolonged occupational exposure.

This thesis presents the …

Quantitative Comparison Of Different Ultrasound Simulation Approaches For Civil Engineering Applications, Fabian Dethof, Simon Schmid, Jean-Marie Henault, Thomas Schumacher, Sylvia Kessler, Salvador Villalobos

Civil and Environmental Engineering Faculty Publications and Presentations

Interpreting ultrasonic waveforms is often challenging, especially in the presence of tilted boundaries that introduce multiple reflections, mode conversions, and echoes. To analyze such complex signal patterns, wavefield simulations provide a valuable tool. To ensure confidence in the simulation results, the accuracy of the numerical method is crucial. Another consideration when using simulations is their computational expense. Especially in civil engineering applications, large structures need to be investigated, which may not be feasible given the available resources. In this study, different numerical methods and software implementations commonly used for simulations in civil engineering are compared, including the Elastodynamic Finite Integration …

On Signifiable Computability: Part Iii: A Note On Unnameable Functions On Natural Numbers, Vladimir A. Kulyukin

Computer Science Faculty and Staff Publications

A writing system 𝔚 on an alphabet 𝒜 is a tuple (ℜ,𝔐), where ℜ is a finite set of text formation rules and 𝔐 is a finite rule application mechanism that generates texts on 𝒜. A natural writing system forms natural language texts on an alphabet such as Sanskrit on Devanagari. An artificial writing system generates formal language texts on an alphabet such as Lisp on Unicode. Let ℕ ={0,1,2,…} be the set of natural numbers. A function on natural numbers 𝑓 :ℕ^𝑘 ↦ ℕ, 0 < 𝑘 ∈ ℕ, is nameable by a writing system on an alphabet if, and only if, the system can generate a text on the alphabet that names f and no other function. We show that there exist functions on natural numbers unnameable in principle in that they cannot be named by any writing system on any alphabet. Our results imply the following computability-theoretic hierarchy of functions on natural numbers: computable ⊊ partially computable ⊊ nameable ⊊ 𝔉, where 𝔉 is the set of functions on ℕ.

Elevating The Underrepresented And Marginalized Using Experiences In Stem (Lumens): A Stem Diversity And Inclusion Initiative, Robert Cobb Jr, Paula E. Faulkner, Deiadra Modlin, Obinna Chiekezi, Victoria Cobbold, Madison Beaudoin

Journal of Research Initiatives

The study offered a 5-week summer immersion program to address the shortage of students from underrepresented populations enrolling in degree programs and seeking careers in science, technology, engineering, and mathematics (STEM). The study also addressed the importance of offering summer immersion programs to close the achievement gap. A quantitative descriptive design was used to gather data from participants related to STEM lessons during the program. Gender, grade level, and race served as the demographic variables. The study included 21 secondary students in grades 9–12. Pre- and post-tests assessed participants' knowledge gain regarding STEM lessons. Data analyzed with SPSS version 29 …

Design And Development Of A 12-Degree-Of-Freedom Quadruped Robot, Kai De La Cruz

Master's Theses

This thesis presents the design, analysis, and experimental validation of a 12-degree-of-freedom (DOF) quadruped robot developed as a research platform for legged locomotion and control. The system builds upon the Cal Poly Legged Robotics Group’s prior 8-DOF quadruped, addressing key limitations in manipulability, load distribution, and mechanical robustness by introducing a 3-DOF leg architecture.

The mechanical design emphasizes lightweight construction, structural integrity, and modularity to support future research extensions. Static and dynamic loading models were developed to inform component sizing and material selection. A carbon-fiber chassis and redesigned leg assemblies were fabricated and validated through finite element analysis and physical …

Mechanistic Framework Of Wood Decomposition In Post-Storm Vegetative Debris Piles Using Continuous Quality Theory, Thomas T. Lee

Master's Theses

Storm events generate significant quantities of vegetative debris composed of wood, branches, twigs, and other organic materials. Efficient post-storm resource recovery and carbon accounting depend on reliable predictions of decomposition within these large, heterogeneous debris piles. While small-scale wood decay is well studied, decomposition dynamics within multi-layer debris piles remain poorly characterized, limiting municipalities' ability to estimate material longevity and resource recovery potential.

To address this gap, this study develops the WOOD_DK (Wood Organic Oxidation and DegraDation Kinetics) model, a preliminary, exploratory one-dimensional multilayer decomposition framework simulating coupled temperature, moisture, oxygen, and carbon dynamics in MATLAB. Microbial decomposition follows Continuous …

A Simulation Framework For Edge Lane Roads And Bicycle Shared Roadways, Nick Sauciur

Master's Theses

Edge Lane Roads, also referred to as Advisory Bike Lanes, are a shared roadway treatment that designates space for cyclists while allowing flexible use of the roadway by motorists. They are commonly applied on lower speed corridors and can be used both where roadway width is limited and where agencies seek to manage vehicle speeds, clarify cyclist positioning, or improve shared roadway operations. The configuration provides visually designated space for cyclists while allowing motorists to encroach into that space when yielding to opposing traffic. Although interest in these facilities is growing in North America, quantitative tools for evaluating their operational …

Portable Ice Cube Maker, Ayden Ziegler, Emiliano Hansen, Wyatt Engdahl, Dane Hansen

Mechanical Engineering

This Final Design Report outlines the senior design project undertaken by a team of mechanical engineering students at California Polytechnic State University, San Luis Obispo, for the development of a portable backpacking ice cube maker. The project aims to design, build, and test a lightweight, compact device that produces ice cubes for backpackers in remote outdoor environments. The goal is to create a functional prototype that is durable, user-friendly, and suitable for backcountry use. This document details background research, project objectives, and project plan, and current design status.

Microstructural Evolution Of Zirconium Diboride Irradiated With 5–10 Mev Au Ions At Room Temperature And 570 °C, Narrie Loftus, José Olivares, Miguel Crespillo, Esther Enríquez Pérez, Jeremy Watts, Eric W. Bohannan, Gregory Hilmas, William Fahrenholtz, Joseph Graham

Materials Science and Engineering Faculty Research & Creative Works

Zirconium diboride was irradiated with 5 MeV Au^2 + , 7 MeV Au⁴⁺ and 10 MeV Au³⁺ ions at room temperature and 570 °C to doses from 1 to 8 displacements per atom (dpa). Grazing incidence X-ray diffraction (GIXRD) analysis revealed no secondary phase formation. Rietveld analysis of the GIXRD data indicated an accumulation of microstrain at low dpa and room temperature. Dislocations observed in transmission electron microscopy (TEM) cross-sections are likely the main contributor to the microstrain. High dpa and high-temperature samples exhibit lower lattice distortion than lower dpa samples, suggesting the presence of enhanced defect …

Thermally Stable Sic Particulate-Reinforced Sic Composites Up To 2000 ℃ Fabricated By Precursor Impregnation And Pyrolysis Method, Jian Gu, Vu Viet Hung, Lun Feng, William G. Fahrenholtz, Daejong Kim, Seyoung Kim, Sea Hoon Lee

Materials Science and Engineering Faculty Research & Creative Works

The thermo-mechanical properties of SiC particulate-reinforced SiC composites (SiC-PRCs), fabricated using precursor impregnation & pyrolysis (PIP) process, were analyzed up to 2000 ℃. The relative density of the SiC-PRCs after 4 PIP cycles was 88.6 %. The number of PIP cycles required decreased to nearly half compared with the conventional PIP method by using ultra-high concentration slurries up to 70 vol%. In addition, room-temperature bending strength (215 MPa) and Young's modulus (269 GPa) improved as the solid loading of the slurry increased. The bending strength increased to 232 MPa at 2000 ℃ in Ar. Despite the thermal deterioration of the …

A Software Package For Generating Robust And Accurate Potentials Using The Moment Tensor Potential Framework, Josiah Roberts, Biswas Rijal, Simon Divilov, Jon Paul Maria, William G. Fahrenholtz, Douglas E. Wolfe, Donald W. Brenner, Stefano Curtarolo, Eva Zurek

Materials Science and Engineering Faculty Research & Creative Works

We present the Plan for Robust and Accurate Potentials (PRAPs), a software package for training and using moment tensor potentials (MTPs) in concert with the Machine Learned Interatomic Potentials (MLIP) software package. PRAPs provides an automated workflow to train MTPs using active learning procedures, and a variety of utilities to ease and improve workflows when utilizing the MLIP software. PRAPs was originally developed in the context of crystal structure prediction, in which one calculates convex hulls and predicts low energy metastable and thermodynamically stable structures, but the potentials PRAPs develops are not limited to such applications. PRAPs produces two potentials, …

Superhard Refractory High-Entropy Diborides, M. D. Hossain, N. S. Mcilwaine, N. O. Marquez-Rios, A. C. Feltrin, V. Chawla, R. A. Mayanovic, W. G. Fahrenholtz, D. Penumadu, E. Zurek, D. W. Brenner, D. E. Wolfe, S. Divilov, H. Eckert, S. Curtarolo

Materials Science and Engineering Faculty Research & Creative Works

Using first-principles calculations and companion experimental validations, we demonstrate that the valence electron concentration (VEC) can be used to self-consistently parameterize the bonding characteristics of high-entropy diborides (HEBs) and in turn predict their mechanical properties. When VEC is 10.0 per formula unit (f.u.), HEBs enter the superhard category where Hv>40GPa because bonding states are optimally filled to resist shear deformation. Conversely, above or below a VEC of 10.0, the hardness decreases due to the filling of antibonding or the emptying of bonding states of the HEBs, respectively. This result is supported by analyses of the electronic structure, bonding, antibonding, …

A Borophosphate Glass Doped With Cobalt Oxide Improves Skeletal Muscle Structure And Function In Myopathic Mice, Jacob A. Kendra, Alexandra G. Naman, Rebekah L. Blatt, Carla D. Zingariello, Richard K. Brow, Steven S. Segal, Aaron B. Morton

Materials Science and Engineering Faculty Research & Creative Works

Skeletal muscle myopathy remains a significant cause of disability with limited treatment strategies. Advancements in tissue engineering have led to the development of borophosphate bioactive glasses (BPBGs) capable of enhancing skeletal muscle structure and function. Using a mouse model of severe myopathy (D2.mdx), we investigated muscle force, regeneration, angiogenesis and inflammation at 14, 70 and 140 days post-treatment (dpt). Tibialis anterior (TA) muscles of D2.mdx mice that received a single injection of cobalt oxide-doped BPBG (CoO-TRIM) particles exhibit greater active force, myofiber size, and regeneration through 70 dpt compared to control D2.mdx mice injected with Saline. Vascular endothelial growth factor …

Electroactive Pvdf/Ti3c2tx Mxene Functionalized Nanofiber Mats With High Surface Potential For High-Efficiency Indoor & Outdoor Submicron Pm(0.3-2)Μm Filtration, Ashish Kakoria, Mirza Muhammad Zaid, Aamir Iqbal, Mahsa Moradi, Lina Zheng, Guang Xu

Mining Engineering Faculty Research & Creative Works

Fine PM0.3-2.0 rapidly penetrates the respiratory system and causes health problems. Commercial filters remove 0.3 μm particles at ∼95 % efficiency but impose high pressure drops that make breathing difficult. We fabricate a novel electrospun PVDF-Ti₃C₂Tx nanofiber mat for PM0.3–2.0 filtration. Where a high electric field stretched PVDF and PVDF-Ti₃C₂Tx solutions into ultrafine fibers that were collected as porous nanofibrous mats. PVDF was chosen for its electroactive behavior and high dielectric constant, enabling efficient electrostatic filtration. The incorporation of Ti₃C₂Tx MXene enhances surface charge density and interfacial polarization, …

Advancing Activated Carbon Production: Utilizing Pine Pruning Biochar Via Induction Heating With Co2and Iron-Based Catalysts, Ahmet Erdem, Muthanna H. Al-Dahhan, Ahmed Jasim

Chemical and Biochemical Engineering Faculty Research & Creative Works

This study introduces an induction heating approach for producing activated carbon from biochar obtained by thermal degradation of pine pruning waste from timber-related industries, using CO₂ and iron-based catalysts as activation agents. Activation experiments were performed using a 10 kW high-frequency induction system (28–40 kHz) under continuous CO₂ flow (15 mL min⁻¹), with electric current intensities of 200, 300, 400, and 500 A (corresponding to 700–1100°C) and durations of 30, 60, and 90 min, employing 45 g of iron-based catalysts (Fe–Ni–Ti–C, 85:6:3:6 wt.%) per 3 g biochar (15:1 w/w). Mass loss increased from 13.7 % (200 A, …

Dvr Service Evaluation And Fee Sufficiency Study, Mallory Brown, Andrew Martin, Jeeyen Koo, Jennifer Walton

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet’s (KYTC) Department of Vehicle Regulation (DVR) administers numerous fees and taxes. Many administered by the two divisions in DVR — Motor Vehicle Licensing (DMVL) and Motor Carriers (DMC) — have remained unchanged for many years despite salary increases, the adoption of more complex and expensive technologies, and inflation raising administrative costs. This report provides in-depth assessments of 10 fees and taxes (selected by division administrators). Six are administered by DMVL — certificate of title, duplicate title, vehicle title history report, additional registration fee, reflectorized license plate fund, and trailer registrations — and four are managed by …

The Illusion Of Causality In Llms: A Developmentally Grounded Analysis Of Semantic Scaffolding And Benchmark–Capability Mismatches, Daisuke Akiba

Publications and Research

Recent benchmarks increasingly report that large language models (LLMs) exhibit human-like causal reasoning abilities, including counterfactual inference and intervention planning. However, many such evaluations rely on domains that are heavily represented in training data and embed strong semantic cues, raising the possibility that apparent causal competence may reflect semantic pattern recombination rather than structure-sensitive causal reasoning. Drawing on human developmental theories of causal induction, this perspective argues that genuine causal understanding requires robustness to novelty and reliance on conditional structure rather than semantic familiarity. To illustrate the testability of this claim, the paper includes a pilot demonstration using synthetic causal …

Applying Direct Numerical Simulations To Investigate Wave Forcing Against A Vertical Wall, Hunter Boswell, Frank D. Han, Gaurav Savant, Guirong Yan, Wouter Mostert

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Current engineering standards lack the ability to predict the peak impact forces of breaking waves impinging directly upon coastal structures. In this study solitary waves impacting vertical and tapered walls are investigated. To capture the detailed physics of the wave profile that impacts the wall, two-dimensional direct numerical simulations are applied to model the wave traveling over a simplified bathymetry consisting of an initially uniform depth, followed by a uniform beach ramp and then terminating in a uniform depth inshore region and vertical wall. Such an approach can simulate wave runup on land and then the impact with the vertical …

Data-Driven Non-Precipitation Echo Removal Of Nexrad Radars Based On A Random Forest Classifier Using Polarimetric Observations And Goes-16 Data, Munsung Keem, Bong Chul Seo, Witold F. Krajewski, Sangdan Kim

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Highlights: What are the main findings? A Random Forest-based model using dual-polarimetric radar features achieves >99% accuracy in classifying precipitation and non-precipitation echoes. Multi-scale spatial variability features enhance discrimination between genuine precipitation and spurious echoes. Fusion of GOES-16 infrared satellite data with NEXRAD radar effectively removes non-precipitation echoes with precipitation-like signatures, including wind turbine clutter. A CAPPI scan strategy improves near-radar precipitation detection by recovering valid echoes misclassified at the lowest elevation due to side-lobe interference and limited sampling volume. What are the implications of the main findings? The model's robustness to noise and overfitting, combined with minimal hyperparameter tuning, …

Understanding Human Arm Stiffness Modulation In Overground Phri: The Roles Of Kinematics, Perturbation, And Trunk Sway, Mohsen Mohammadi Beirami, Sambad Regmi, Devin Michael Burns, Yun Seong Song

Psychological Science Faculty Research & Creative Works

This study examines human arm kinematics during overground physical human-robot interaction (pHRI). Previous work showed humans adjust arm stiffness with changing trajectory uncertainty, but the roles of arm kinematics and muscle activation remained unclear. Building on a preliminary study, we analyzed arm movements with more participants (10 individuals) to achieve more reliable findings and examined two potential influences that arose in the preliminary study: the robot's perturbation effect (a brief hand push) and left-to-right trunk sway. Using a linear mixed-effects model, we evaluated the effects of participant, block, and trajectory condition on arm angles. Results showed minimal kinematic contribution to …

Unhsc Scm Performance Fact Sheets, Unh Stormwater Center

UNH Stormwater Center

No abstract provided.

Cathy's Trike, Jameson Stengel, Victor Robles, Asher Becker

Mechanical Engineering

Cathy Hoenig needs a better way to safely steer her trike since she recently had her arm amputated at the elbow. Right now, the standard steering setup doesn’t work for her because it’s designed for someone with two arms. The main issue is that because she can't hold the steering bar with both hands, she loses control and stability while riding, which takes away from her freedom and independence. We’re looking to design some kind of support or adaptive steering system that’ll let her feel safe and confident on her trike again. Our goal is to create a solution that …

Bonderson Workbench, Han Xu, Aidan Robleto, Sean Murphy, Victor Duran

Mechanical Engineering

This project redesigns the existing creative workbenches in Cal Poly's Bonderson High Bay to improve mobility and functionality for students and staff in the Mechanical Engineering Department.

Fsae Bespoke Brake Calipers For Hub Motor Architecture, Connor William Vaughan, Liam Upton Walsh, Bradley Brian Kern

Mechanical Engineering

Brakes are the most critical safety system on any performance vehicle, and as Cal Poly Racing transitions their Formula SAE car from a single rear motor to a four-in-wheel motor setup with regenerative braking, the team identified an opportunity to develop a bespoke brake caliper tailored to their specific needs. This document outlines the research, design, manufacturing, and validation of custom front brake calipers designed to improve upon commercial motorcycle calipers in key areas such as serviceability, mounting rigidity, thermal behavior, mass, and hub motor integration. The resulting design is a two-piece, four-piston, radially-mounted aluminum caliper featuring titanium pistons, toolless …

An Analysis Of Injury And Fatality Trends In The U.S. Construction Industry, Ryan Dutt

Construction Management

Construction work is one of the most dangerous industries in the United States, with different trades and work types showing various risk levels for injuries and fatalities. This paper’s objective is to identify the safety trends in construction over the past 10 to 20 years and understand the trades, accident types, and construction sectors with the highest safety risks. All of the data was obtained from the Occupational Safety and Health Administration (OSHA), the Bureau of Labor Statistics (BLS), the National Institute for Occupational Safety and Health (NIOSH), and the National Safety Council (NSC) databases, broken down by trade, accident …

Slo Botanical Garden Outdoor Classroom, Nathan Berger, Jake Galster

Construction Management

This paper focuses on the construction and completion of outdoor benches and tabletops for the renovation of the SLO Botanical Garden’s Outdoor Classroom. This project is student lead for the completion of the Cal Poly SLO Construction Management curriculum requirement of a senior project by the project team consisting of Nathan Berger and Jake Galster. The objective of the project is to build two 12’ long benches that allow the SLO Botanical Garden staff to store four bins beneath each bench. The table tops objective to provide students in the outdoor classroom a flat and level workspace that is removable …

Thousand Hills Pet Resort Ada Compliant Access Ramp And Connecting Deck: Preconstruction Activities, Sonya Nahama Wijoyo

Construction Management

This paper presents the design and preconstruction of an ADA-compliant access ramp and connecting deck system for two mobile homes located at Thousand Hills Pet Resort. The primary objective was to enhance accessibility and safety for residents by providing code-compliant, durable, and functional access to the mobile homes on site. This project is interdisciplinary between construction management and architectural engineering. The project began with a site evaluation to assess existing conditions. Field measurements and site observation guided planning decisions and helped identify potential challenges. Following the site evaluation, the project proceeded into the design phase, where the ramp and deck …

Skip The Grid 25-26: A Safety-Driven Solar Installation Project In The Navajo And Hopi Nations, James R. Wall

Construction Management

Skip the Grid is an interdisciplinary service-learning project that provides sustainable energy solutions to families with school-aged children living in the Navajo and Hopi Nations. In March 2026, a team of 23 students from five academic disciplines at California Polytechnic State University (Cal Poly) partnered with Heart of America, SOLV Energy, and NextPower to complete the fifth year of the program. The project's purpose was to improve quality of life and support educational success by providing reliable access to electricity, lighting, and refrigeration in underserved communities. Participants were organized into five installation teams consisting of Cal Poly students, faculty, industry …

The Future Of Commercialized Bamboo Construction, Katie Hunt

Construction Management

Bamboo construction is a niche area of research and development in the sustainable construction realm. The material has impressive structural properties and minimal carbon emissions relative to the world’s most common building materials (concrete, steel, and timber). It has long been used to build homes in tropical regions around the world. Outside of these regions, bamboo is rarely used for construction despite its abundant benefits as a sustainable building material. This report took an interview-based approach to address why bamboo is not more popular in the American commercial construction market and where it has potential for growth in the global …