Mechanical Engineering Commons^™

Improved Method Of Evaluating Gas-Phase Air Cleaners Considering Adsorption And Desorption Mechanisms To And From Internal Test Chamber Surfaces, Casey Douglas Coffland

Dissertations and Theses

Portable air cleaners are playing an increasingly important role in managing indoor air quality in response to pressing issues like wildfire smoke events. Smoke is a complex mixture of gases and particulate matter; while established test methods exist for particulate matter, the dynamic behavior of gaseous pollutants is not well accounted for in current test methods. This is because prevailing air cleaner testing methods typically treat background losses as irreversible, whereas gases can engage in partitioning to and from test chamber surfaces. Ignoring these sorption interactions causes inaccurate estimation of an air cleaner's impact.

A new approach has been developed …

Topographical Mobility Envelope Modeling And Geometric Analysis For Off-Road Unmanned Ground Vehicles, Huashuai Fan

ETDs from 2020-2029

This dissertation introduces topographical mobility as a quantitative framework for assessing off-road unmanned ground vehicle performance based on geometric interaction between the vehicle and terrain. Rather than relying on conventional discrete indices, the proposed formulation evaluates mobility directly from vehicle and terrain geometry, expressing vehicle capability in terms of radius constraints implied by its dimensions and suspension state. On the vehicle side, longitudinal and lateral mobility radii are derived analytically from vehicle geometry—wheelbase, track width, ground clearance, and lowest underbody point location—quantifying the minimum terrain radius negotiable without underbody interference. Suspension state is shown to alter longitudinal mobility radius by …

Centrifugally Spun Silica Fibers For Lithium-Ion Battery Anodes: Structure And Cycling Stability, Alejandra Guerrero, Valeria Tirado, Jason Parsons, Mataz Alcoutlabi

Mechanical Engineering Faculty Publications

Introduction: Silicon dioxide (SiO2) fiber structures have attracted attention as alternative anode materials for lithium-ion batteries because of their ability to improve cycling stability compared to commercial silicon particles.

Materials and methods: SiO2 composite fibers were prepared by centrifugal spinning of polyvinylpyrrolidone (PVP)/SiO2 precursor solutions followed by calcination at 500–700 ◦C for different holding times to produce short-fiber composites and micro-belt SiO2 fiber structures. The morphology and crystal structure of the SiO2 short fibers and micro-belts were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and X-ray Photoelectron Spectroscopy (XPS). Electrochemical performance was evaluated using CR2032 half-cells.

Results: The …

Optimizing Graphene Oxide In Self-Compacting Concrete: A Sustainable Nano-Material Strategy For Enhanced Durability And Structural Performance, Mohammed Shakeebulla Khan, Vijaya G. S

Journal of Sustainable Construction Materials and Technologies

In order to reduce the environmental impact of the constructed world, advanced and sustainable construction materials are needed. This work is a summary of the comprehensive study on a novel self-compacting concrete with nano-engineered material (graphene oxide) modified self-compacting concrete (GO-SCC). The optimum dosage of GO was determined using Taguchi method, Analysis of Variance (ANOVA) and Response Surface Methodology (RSM) multi-objective statistical optimization method, and was found to be 0.10% by weight of cement (bwoc). This dosage of 0.10% GO led to the overall desirability score of 0.87, which confirmed that this was the optimum dosage for six response variables …

Processing Mechanism And Efficacy Maintenance Strategy Of Ginseng Active Ingredients Based On Spectroscopy Technology, Yang Hantong, Kong Linghui, Jiang Mengmeng, Wang Yingxiu, Li Xiangguo

Food and Machinery

Ginseng, as a medicinal and edible plant, has ginsenosides as its core active components, which are widely applied due to their physiological functions such as antioxidant and anti-inflammatory activities; however, their structures and activities are easily affected by food processing. During processing steps such as cleaning, steaming/boiling, and fermentation, temperature, pH, and microbial enzyme systems alter the types, contents, and stability of active components through reactions such as hydrolysis and oxidation. The intrinsic linkage mechanism of "component transformation-activity-bioavailability" constitutes a core focus and challenge in current research. This study, based on spectroscopic techniques including high-performance liquid chromatography (HPLC), nuclear magnetic …

Beneficial Investigation Of Sustainable Recycled Waste Plastic In Treating The Consolidation Behavior Of Fine Soil, Aram Mohammed Raheem, Cumaraswamy Vipulanandan, Mohammed Hiwa Abdullrahman, Ali Tariq Omer

Journal of Sustainable Construction Materials and Technologies

Recycled waste plastic is one of the regular garbage utilized as a sustainable material in soil remediation. This study examines the efficacy of utilizing local recycled waste plastic as an ecological quantifiable along with soil containing fine particles to analyze the consolidation behavior. Various recycled waste plastic contents ranging from 2% to 10% were employed experimentally in two patterns where in the first pattern the recycled waste plastic were mixed as dry material with the fine soil particles while in the second pattern a sandwich layer of 10% of the recycled waste plastic was placed in the middle of the …

Enhanced Thermal Energy Storage In Buildings: Impregnation, Leakage, And Environmental Performance Of Organic And Inorganic Pcm Composites, Gökhan Genç, Esra Yılmaz, M. Yusuf Yazıcı

Journal of Sustainable Construction Materials and Technologies

This study experimentally investigates the impregnation and leakage performance of various organic (tobacco, sawdust, bay leaf, black cumin) and inorganic (vermiculite, perlite, bentonite, sepiolite) carrier materials used for phase change material (PCM) integration in building applications. The commercial paraffin-based PCM RT-31 was used as the thermal storage medium. Impregnation and leakage tests were conducted to evaluate the PCM absorption capacity, form stability, and energy storage potential of each carrier. The results revealed that perlite (C = 80%) and bay leaf (C = 78%) exhibited the highest impregnation capacities due to their porous and fibrous structures; however, they also demonstrated significant …

Modeling Of Tensile Stress-Strain Response For Steel Fiber Reinforced Self-Compacting Concretes, Anıl Niş, Nilufer Özyurt, Turan Özturan

Journal of Sustainable Construction Materials and Technologies

Main aim of the research was to further understand self-compacting concrete reinforced with steel fibers (SFR-SCC) behavior and to contribute modeling of the tensile stress-strain diagrams for the standardization of the fiber reinforced materials for structural utilization. Fiber reinforced materials has not been used without structural rebar because of the absence of stress-strain curve in tension required for the structural design codes. Hence, an inverse analysis (multi-layer model) was further modified for various steel fibers to predict tensile stress-strain behaviour. For this purpose, 5 different mixes; control, reinforced with long fibers with 0.5% and 1%, short fiber with 0.5% and …

Load Profile Analysis And Forecasting For Rural Mini Grids In Uganda, Prossy Mutesi, Santos L. Kihwele, Emmanuel S. Matee

Tanzania Journal of Science

Accurate load forecasting is essential for the reliable and cost-effective operation of rural mini grids, where constrained generation capacity and high penetration of renewable energy resources require well-informed operational decisions. This study examines electricity demand characteristics and forecasting performance for the Buzaami and Ssenyondo mini grids in Uganda, with particular focus on diurnal load profiles, peak demand behavior, and seasonal variability. 2022 operational data show extended peak demand from early morning to late evening, driven by socio-economic activities that strain resource scheduling and reliability management. To address these challenges, the study evaluates and compares Long Short-Term Memory (LSTM) networks, fuzzy …

Optimization Of Bio-Briquettes Production From Cassava Stems Co-Blended With Sisal Bole Bagasse Using Response Surface Methodology, Agnes Nshoma Msobi, Neema O. Msuya, Kando Khalifa Janga

Tanzania Journal of Science

This research aimed at producing bio-briquettes from cassava stems and sisal bole bagasse as an alternative source of cooking energy. A Response Surface Methodology (RSM) with Face - Centered Central Composite Design (FCCCD) featured a multi-objective optimization of the effect of the production parameters, focusing on maximizing char yield and Higher Heating Value (HHV) of the produced briquette while minimizing carbonization temperature and residence time. The findings showed that bio-briquettes produced at the lowest temperature (250 ℃) and residence time (30 min) and the blending ratio of 75% by 25% had the highest char yield of 76.92% and HHV of …

Ontology-Based Decision Support System For Improving Aquaculture Management, Thuy Thi Thu Pham, Phuong Thi Can, Nga Thi Thanh Ha

Journal of Marine Science and Technology–Taiwan

Early detection of shrimp diseases is vital for reducing losses and ensuring sustainable aquaculture. In this study, a novel ontology-driven framework for shrimp disease diagnosis that integrates environmental knowledge with machine learning-based image analysis is proposed. An ontology was constructed from a structured dataset of environmental parameters and farm conditions related to shrimp diseases, which formally represents concepts such as farm characteristics, environmental factors, symptoms, and disease types. Two public shrimp image datasets were subsequently used to train convolutional neural networks (ResNet50 and MobileNetV2) for automated disease classification. The predicted disease labels and confidence scores were mapped onto the ontology. …

Case Study On Operational Performance Improvement By Turbocharger Nozzle-Ring Modification In Shipboard Generators, Jong-Hun Im, Mukyeong Kang, Sang-Deuk Lee

Journal of Marine Science and Technology–Taiwan

Owing to increasingly stringent emission regulations imposed by the International Maritime Organization and rising fuel prices, the demand for enhanced energy efficiency and emission control in marine power systems is increasing. This study presents a case study in which the performance of an aging auxiliary generator is restored by modifying the turbocharger nozzle ring. The vessel, a 12-year-old crude-oil tanker, experienced repeated operational issues with its No. 3 generator. This included elevated exhaust gas temperatures, reduced intake air pressure, and frequent turbocharger surges. To address these challenges, the nozzle-ring blade angle was reduced by approximately 2° using spare components, while …

Towards Sustainable Marine Education: Assessing High School Students’ Understanding Of Conservation Concepts, Cheng-Chieh Chang, Tsuyoshi Sasaki, Ya-Yin Liao, Ling-Ya Hung, Liang-Ting Tsai

Journal of Marine Science and Technology–Taiwan

This study assesses the concepts of marine resource conservation and sustainability among Taiwanese high school students by developing a Chinese version of the Marine Resources Conservation and Sustainability Scale. Grounded in the cognitive, socio-emotional, and behavioral learning objectives outlined in UNESCO’s Education for Sustainable Development Goals (ESDGs), the scale targets students aged 16 to 18 to examine gender differences in marine knowledge and conservation concepts. The scale comprises 31 items across four dimensions: the first section evaluates marine knowledge, while the remaining dimensions utilize a four-point Likert scale to assess cognitive, socio-emotional, and behavioral learning objectives, respectively. The results indicate …

Dynamic Governance Of Transboundary Fisheries Through Deep Learning And High-Frequency Vessel Tracking Data For Climate-Resilient Management: An Application To The East China Sea, Qin Lin, Yaqing Shu, Manel Grifoll, Hongxiang Feng

Journal of Marine Science and Technology–Taiwan

Transboundary fisheries governance is increasingly challenged by jurisdictional conflicts, regulatory asymmetries, and climate-induced stock shifts in fish stocks, especially in contested regions like the East China Sea (ECS). This study capitalizes on China’s high-frequency BeiDou Navigation Satellite System (BDS) data (June 2021–May 2022) to pioneer a CNN-BiLSTM deep learning model to dynamically identify fishing hotspots and evaluate policy effectiveness. By integrating vessel trajectories, environmental variables, and regulatory events, we examine spatiotemporal patterns of fishing effort relative to seasonal bans, extreme weather, and quota systems. Key findings reveal: (1) post-moratorium (September–December) concentration of fishing intensity, peaking in November; (2) significant weather-driven …

Lock Scheduling Decisions And Strategy Optimization Under Operation Interruption Scenarios, Junhe Li, Qiang Zhang, Junpeng Jiang, Jiangchao Bao

Journal of Marine Science and Technology–Taiwan

Locks are critical nodes in inland waterway transportation systems that concentrate vessel traffic between upstream and downstream reaches, making their operations highly sensitive to hydrological conditions. Therefore, disruptions caused by droughts, floods, or routine maintenance can easily trigger congestion. To address this issue, this study systematically examines the interrelationships among the number of ships awaiting passage, scheduling strategies, the trade-off between lock chamber utilization and ship waiting time, the influence of ship entry sequences on user satisfaction, and the combined effects of these factors on overall lock scheduling performance. Based on these analyses, an integrated decision-making model for two-stage ship …

Corrosion Protection Assessment Of Offshore Wind Turbine Substructures Using Beasy Cp Simulation Analysis, Chuan-Yang Wan, Hung-Hua Sheu, Sheng-Yu Wang, Yao-Ming Wang, Wei-De Chen, Ming-Yuan Lin, Hung-Bin Lee

Journal of Marine Science and Technology–Taiwan

This study investigates the corrosion protection assessment of offshore wind turbine substructures established in the waters off Keelung, Taiwan. First, a cathodic protection system for the monopile foundation is designed and established. The Boundary Element Method (BEM) is applied using the BEASY simulation software to develop a 3D geometric model for cathodic protection. In the steel monopile simulation analysis, the exposed marine environment is set based on the sea conditions of the Keelung small boat marina, including parameters such as salinity, resistance, and polarization curves, to establish an effective cathodic protection system for underwater structures. By simulating these parameters, a …

Face-To-Face Versus Distance Education In Competence-Based Maritime Education And Training, Clara Borén, Marcella Castells-Sanabra, Manel Grifoll

Journal of Marine Science and Technology–Taiwan

The COVID-19 pandemic created significant challenges for higher education, with universities being shut down and face-to-face teaching and assessment shifting to an online format. This presented an opportunity to focus on the continuity of learning through distance education, especially in the maritime context, due to the on-board training requirements, and even though five years have passed, this shift has reshaped the education landscape, proving that remote learning has come to stay.

At the Barcelona School of Nautical Studies, we have developed a weather routing software in the framework of distance education and teaching innovation. We conducted a teaching trial alternatively …

A Bibliometric And Visualization Analysis Of Global Giant Clam Research, Chia-Hsiang Chen, Chih-Hsien Chang

Journal of Marine Science and Technology–Taiwan

In this study, bibliometric analysis and visualization tools were used to investigate the academic network and knowledge structure surrounding global giant clam research. A total of 551 relevant publications from the Web of Science database, published from 1900 to 2024, were analyzed. The findings indicate that research on giant clams has experienced considerable growth since 2012, peaking in publication output in 2021. Sixty-six countries were represented in the study sample, with the United States, Australia, China, Singapore, and Japan being the most represented ones. Notably, the rate of international collaboration was only 29%, highlighting a need for additional integrated cross-border …

The Effect Of Mwcnt-Oil Impregnation Of Sintered Components On Their Wear And Corrosion Resistance, Maha Khaled Abdelfadeel

Theses and Dissertations

Powder Metallurgy (PM) offers an advantageous route for manufacturing complex and near net-shape components. Their inherent interconnected porosity that promotes the action of self lubrication compromises their structural integrity by creating pathways for corrosion and excessive wear. This research investigates the efficacy of Multi-Walled Carbon Nanotubes (MWCNTs) as a nano additive within the impregnating base oil (SN-150 base oil). An experimental matrix was designed to evaluate the influence of MWCNTs with different concentrations of 0.05, 0.1, and 0.2 wt.% and ultrasonic dispersion with varying sonication times of 30 and 60 minutes on the tribological and electrochemical performance of sintered steel …

Adaptive Design Strategies For A Dual-Shaft Pvc Shredder, Gavin Balderas

University Honors Theses

This capstone project involved the design and development of a mid-size plastic shredder, created to process strong, ductile PVC sheets up to ½" thick. This application falls between the capabilities of consumer grade plastic shredders and heavy-duty industrial machines. Over 400 million tons of plastic produced annually and less than 10% of it is recycled; there is an ever-growing need for plastic recycling accessibility and infrastructure. This project aimed to create a compact dual-shaft shredder that can shred thick PVC sheets while being powered by a 120V outlet. Research into blade geometry and orientations aided an iterative design process driven …

Rapid-Prototyping Nanofabrication: Lcd-Based Projection Lithography And Physical Vapor Deposition, Sabeel Saleem Mohammmed

University Honors Theses

The semiconductor industry's continued growth, driven in large part by demand for artificial intelligence hardware, has highlighted the need for greater workforce development in regions adjacent to major fabrication centers like Oregon's Silicon Forest. This capstone project lays the groundwork for a small scale and student led semiconductor fabrication lab at Portland State University by demonstrating two of the core steps in chip manufacturing: photolithography and thin film deposition. Rather than relying on conventional fixed reticles, this work explores a unique, low cost approach to patterning that uses an ultraviolet-compatible liquid crystal display (LCD) as a programmable reticle, allowing arbitrary …

Scalable Flat In-Plane-Motion Mechanical Springs (Sfims) Force Vs Displacement Data, Jared Hunter, Larry L. Howell

ScholarsArchive Data

Force versus displacement data is captured in CSV files for five configurations of Scalable, Flat, In-Plane Motion Mechanical Springs (SFIMS). The five configurations are the Folded Beam Suspension, the Chevron, the Interlaced Chevron, the Canted Triple Folded Beam Suspension, and a Variable Stiffness SFIMS.

Moisture-Induced Degradation And Mechanical Durability Of Mineral-Filled Polylactide (Pla) Composites, Barbara Szaraniec, Aleksandra Ptaszkowska, Alicja Rapacz-Kmita

Journal of Sustainable Construction Materials and Technologies

This study investigates the influence of mineral fillers on the hydrolytic stability and mechanical durability of polylactide (PLA) composites under accelerated aqueous ageing conditions. Composites containing halloysite nanotubes (HNT) and bentonite-based fillers (BM, BS, BSP) at 2 wt.% were prepared using a powder-coating and injection moulding approach. Accelerated hydrolytic degradation was conducted at 50 °C for up to six weeks. The degradation behaviour was evaluated through mass variation, water absorption, incubation medium analysis (pH and electrical conductivity), mechanical testing, surface observations, and contact angle measurements. The results revealed a clear filler-dependent response. Bentonite-filled composites exhibited increased water absorption and accelerated …

Comparative Analysis Of Leaflet Materials, Stent Materials, And Stent Cell Density For Bileaflet Transcatheter Mitral Valve Design, Joseph Chibuike Nwokeafor, Joshua D. Hofmeister, Breandan B. Yeats, Lakshmi Prasad Dasi, Charanjit S. Rihal, Juan A. Crestanello, Leigh Griffiths, Mohamad A. Alkhouli, Hoda Hatoum

Michigan Tech Publications

Background: The biomechanical performance of bileaflet transcatheter mitral valves (TMVs) depends on complex interactions between leaflet material behavior and stent design. However, the contributions of leaflet materials and constitutive models, stent materials, and stent geometry to valve function and durability remain poorly understood. Methods: A parametric finite element study was conducted using a CAD model of a bileaflet TMV subjected to physiological pressure loading. Five leaflet material models were evaluated: 3 glutaraldehyde-fixed tissues—bovine pericardium (BP; FBP1, FBP2) and porcine pericardium (PP; FPP)—and 2 unfixed tissues—bovine (UBP) and porcine pericardium (UPP). BP was modeled as a linear elastic (FBP1) and Ogden …

Applications Of Geosynthetics In Tunnels Construction: A Sustainable Approach To Carbon Footprint Reduction, Ibraheem Rais, Abdullah H. Alsabhan, Md. Rehan Sadique, Shamshad Alam

Journal of Sustainable Construction Materials and Technologies

The use of geosynthetics has transformed tunnelling practices by enhancing structural integrity, durability, and environmental sustainability. This review adopts a systematic literature review design, covering publications from 2000 to 2025 sourced from Scopus, Web of Science, ScienceDirect, and Google Scholar. The selected studies were screened based on relevance, quality, and focus on tunnelling applications, then thematically analyzed into four domains: geosynthetic types, applications, sustainability, and performance evaluation. This review focuses on the applications of various geosynthetics, including geotextiles, geogrids, geocomposites, geocells, and geomembranes, in tunnelling projects. These materials play crucial roles in reinforcing tunnel walls and slopes, improving load distribution, …

A Provable Semi-Infinite Programming Approach For Solving Constrained Dynamic Games, Tyler C. Gardner, Matthew W. Harris, Logan Lancaster

Mechanical and Aerospace Engineering Student Publications and Presentations

Many engineering problems must account for the non-cooperative decisions and actions of multiple players. These problems can be modeled within a game-theoretic framework. The approach herein is to model such problems as mathematical games, convert them to semi-infinite programs, and utilize a semi-infinite program solver whose output is provably an ϵ-optimal Nash equilibrium. The approach is successfully benchmarked on two low-dimensional problems. Two types of higher-dimensional linear quadratic dynamic games are then investigated: ones where each player’s problem is convex and ones where at least one player’s problem is nonconvex. Within each type, variations based on information structure, control …

Mars Rover Wheels And Drive, Presley S. Sacavitch, Ryan W. Trevena, Dylan A. Mack, Daniel Hudak

Mechanical Engineering

Cal Poly’s Poly1Rover team, advised by Professor Rich Murray, aims to deploy four student-designed mini-Mars rovers, each equipped with a sample-tube retrieval claw, before 2030. However, the wheels of Poly1Rover’s current 6th generation rover are not ready for deployment to Mars, as they do not utilize space-grade materials, are not optimized for manufacturability, and lack sufficient spoke compliance to absorb landing and high-impact loads. This project will be developed by a team of Mechanical Engineering students at California Polytechnic State University, San Luis Obispo (Cal Poly): Daniel Hudak, Dylan Mack, Presley Sacavitch, and Ryan Trevena. Next Intent is providing funding …

Formula Sae Planetary Gearbox Characterization Dynamometer, Trevor Marco Toma, Thomas Welden Pierce, Ethan Liu

Mechanical Engineering

This report outlines a custom hub motor dynamometer requested by the Cal Poly Racing FSAE team. The need for this testing platform is to characterize an existing Formula SAE planetary gearbox for a proposed 4WD powertrain. Hub motors, compact electric machines integrated directly into each outboard wheel, offer significant advantages in efficiency, traction, and chassis packaging compared to conventional RWD drivetrains. By mapping torque capacity, efficiency, lubrication method effectiveness, and fatigue life, the team can validate gearbox design and performance.

This senior project group designed and built a dynamometer according to these specifications which will allow for successful testing to …

Nodal Elimination For E3 Hemp Mitigation: A Physics-Informed Graph Theory Approach, Connor A. Lehman, Rush Robinett, Quinnlin R. Lehman, David G. Wilson, Wayne Weaver

Michigan Tech Publications

This paper presents a comparison of methods to determine the minimum number of placement locations for neutral blocking, global linear quadratic regulator (G-LQR), and local linear quadratic regulator (L-LQR) controllers throughout a power grid to prevent transformer saturation during the onset of an E3 high-altitude electromagnetic pulse (HEMP) disturbance. Different device placement configurations yield different efficacies in E3 HEMP mitigation. The first placement method discussed is a genetic algorithm (GA), which serves as a baseline optimizer test case. The scaling and run time of the GA depend on the complexity of the objective function and often times becomes intractable as …

A Comparative Study Of Model Predictive Control And The Stanley Method For Vehicle Path Tracking Applications, Noah S. Fitzgerald

Master's Theses

This thesis compares a model predictive controller (MPC) and a lateral Stanley controller for vehicle path-tracking applications under simulation-based and perception-driven operating conditions. Both controllers were evaluated in simulation using a nonlinear dynamic bicycle model executing single and double lane change maneuvers. Following simulation-based evaluation, both controllers were implemented on hardware within a perception-driven steering-control pipeline. This pipeline utilized recorded sensor data from the MXcarkit 1/8^th-scale autonomous vehicle platform, incorporating lane instance segmentation and homography-based roadway estimation.

Under idealized simulation conditions, the MPC demonstrated improved trajectory-tracking performance during aggressive maneuvers while requiring greater steering activity and computational effort …