Engineering Commons^™

Dynamic Modulus Of Sbs-Modified Asphalt Mixtures Added With Ground Tire Rubber Content, Azharul Islam

College of Graduate Studies: Theses & Dissertations

The study investigates the improvement of the dynamic shear modulus in the base and styrene butadiene styrene (SBS) modified asphalt mixture by accumulating varying amounts of ground tire rubber through an Asphalt mixture performance tester (AMPT). This thesis specifically explores how different percentages of ground tire rubber (GTR) influence the mechanical properties and durability of the asphalt mixture articulated with two grades, PG 64-22 and PG 76-22. The experimental framework consisted of preparing asphalt mixtures blended with 10% to 15% of the binder for PG 64-22 and 3% to 8% of GTR for PG 76-22. The laboratory testing involved using …

One-Dimensional Numerical Analysis Of A Novel Elastohydrodynamic Seal For Supercritical Co2 Power Cycles With Experimental Validation And Future Approach, Cole B. Hayne

College of Graduate Studies: Theses & Dissertations

This thesis presents a numerical analysis and experimental verification approach for a novel elastohydrodynamic (EHD) seal designed with the specific application of supercritical carbon dioxide (sCO₂) power cycles. Brayton power cycles with sCO₂ as the working fluid have gained significant traction as potential large-scale power generation methods. This increase in interest and research is primarily due to their many beneficial characteristics, such as high thermal efficiency, compact geographic footprint, reduced capital costs, and lower water and fuel usage than comparable power cycles. Despite these many positive qualities, proper sealing technology remains one of the primary barriers to …

Multiphysics Modeling Of Material Response To High-Intensity X-Ray And Laser Pulses: Heating, Ablation, And Plasma Expansion, Youssef Abouhussien

Theses and Dissertations

This dissertation presents a computational framework to investigate material response under high-intensity X-ray fluxes produced by an exo-atmospheric nuclear detonation and laser-material irradiations, with a focus on heating, ablation, and plasma expansion phenomena relevant to satellite vulnerability and high-energy-density environments. A hybrid Monte Carlo and Two-Temperature Model (MC-TTM) was developed to simulate X-ray and laser energy deposition and thermal relaxation in metals and semiconductors across a range of X-ray and laser pulse durations from femtoseconds to nanoseconds. Results demonstrate distinct thermal behavior between materials, with ablation thresholds and phase transitions captured in good agreement with experimental data.

In parallel, a …

Development Of A Mediation Model Of Pain Cognition In Adult Patients With Sickle Cell Disease, Daniel M. Sop

Theses and Dissertations

Pain is a hallmark of Sickle Cell Disease (SCD), a genetic hemoglobinopathy characterized by chronic hemolytic anemia, vaso-occlusion, and organ damage. While acute vaso-occlusive crises (VOC) have been extensively studied, the mechanisms underlying chronic pain and its interplay with brain function remain unclear. This dissertation investigates the relationships between cerebral blood flow (CBF), fluid cognition, and pain sensitivity in adults with SCD, utilizing advanced imaging techniques and validated assessment tools.

Arterial spin labeling (ASL) and functional magnetic resonance imaging (fMRI) were employed to measure CBF and brain activity, respectively. Pain sensitivity was assessed using the Pain Sensitivity Questionnaire (PSQ), and …

Development, Synthesis And Characterization Of Advanced Low- Cobalt And High-Nickel Cathode Materials For Lithium-Ion Batteries, Arjun Patel

Theses and Dissertations

This dissertation focuses on the improvement of structural and electrochemical stability of active materials for lithium-ion batteries. It explores the modification strategies to mitigate the issues related to Ni-rich cathode materials, along with the continuous production of cathode precursors using a slug flow reactor to improve the quality of the product.

The First part of the dissertation examines the effect of substitution of cobalt with aluminum and iron on the electrochemical stability of Ni-rich lithium nickel cobalt manganese oxide (NCM) materials. This study investigates how Al and Fe doping work and how they impact the performance and stability of these …

The Bacteriostatic, Regenerative, And Immunomodulatory Properties Of Extracellular Matrix Particles For Lung Injury, Keera P. Rhoads

Theses and Dissertations

Acute respiratory distress syndrome (ARDS) is a prevalent, life-threatening lung condition, affecting nearly 200,000 Americans annually, with a 40% international mortality rate. There is no cure for ARDS, and current pharmacological treatments have limited effectiveness. Symptoms can be mitigated with mechanical ventilation, though this often leads to ventilator-induced lung injuries (VILI) and puts critically ill patients at risk of infections, including ventilator-associated pneumonia (VAP). A promising therapeutic is the extracellular matrix (ECM), a complex network of structural proteins and bioactive molecules that has been shown to have anti-inflammatory properties and prevent fibrosis. We aim to utilize the regenerative and immunomodulatory …

Hafnium Oxide-Based Nanoheterostructures For Catalytic Radiosensitization And Enhanced X-Ray Radiotherapy, Marlen Dariela Calix Quezada

Theses and Dissertations

Orthovoltage X-ray beams are attractive for surface and intra-operative radiotherapy. Yet, their clinical utility is constrained by rapid attenuation and the limited dose that can be delivered without harming healthy tissue. High-Z hafnium oxide (HfO₂) nanoparticles can boost local energy deposition through the photoelectric effect, while catalytic surface defects accelerate water radiolysis. Harnessing both mechanisms in a single nano-heterostructure could enable potent radiosensitization at diagnostic-range energies.

This thesis develops and evaluates HfO₂-based nanoheterostructures, both bare and Au-decorated, as catalytic radiosensitizers.

Two types of HfO₂ were evaluated, one was synthesized following a specific route and the …

Rehabilitation In Stroke-Related Flexor Synergy, Shawn J. Dirocco

Theses and Dissertations

Upper extremity abnormal flexor synergy caused by stroke can impair individuals by coupling upper extremity muscles with deltoid activation. Previous studies have shown that reduction in deltoid loading can decrease flexor synergy. Robotic rehabilitation has the ability to allow for reduced deltoid loading while assisting or constraining joints along the arm to increase rehabilitation outcomes. The effects of higher degree of freedom low impedance robotics needs to be tested to learn how various parameters affect flexor synergy in comparison to end point robotics. During the first experiment, we tested 16 chronic stroke patients with flexor synergy problems in 3 tasks. …

Integrating Medical Plastic Waste Pyrolysis And Circular Economy For Environmental Sustainability, Attia Attia, Mohamed Bassyouni Prof., Reem Nasser Eng., Moataz El-Bagoury Eng., Islam Shaker Eng., Yasser Elhenawy Prof., Dina Aboelela Dr.

Biochemical Engineering

A critical assessment of pyrolysis technologies and reactor designs was discussed, highlighting various reactor configurations. This study explored the influence of catalysts, temperature, heating rate, and residence time on the pyrolysis process, and addressed their effects on product distribution and composition. Safety considerations and strategies for mitigating the potential environmental impacts of pyrolysis were presented. Comparative analyses of the environmental impacts of traditional waste disposal methods versus pyrolysis-based approaches provided insights into the potential reduction of greenhouse gas emissions and other pollutants. The circular economy approach was explored in the context of medical plastic waste pyrolysis. The potential for closing …

Extending Revised Lewis Gear Root Bending Stress Model To Addendum Modified Cylindrical Gears, Edward E. Osakue

Faculty Publications

This paper presents a new revised Lewis gear bending root stress model for both standard profile and profile-shifted cylindrical gears. The three parameters that are used to extend the root bending stress capacity of standard profile gears to profile-shifted gears are the profile shift radius factor, the profile shift load factor, and the modified Lewis stress factor. These three parameters are functions of the profile shift factor. The new bending capacity model is used to estimate the bending stresses for some standard profile gears with nominal helix angles between 0o to 41.41o and compared with estimates of AGMA model. The …

A Bevel Gear Root Bending Stress Model, Edward E. Osakue, Rasoul Saneifard

Faculty Publications

A reversed Lewis root bending stress capacity model for bevel gears is presented. The model is developed from first principle based on the Tredgold’s approximation of a bevel gear. The approximation conceptually transforms a bevel gear into a spur gear. The load distribution of the bevel gear facewidth is assumed to be triangular so that the stress at the gear is constant over the facewidth. Six design cases of root bending stress computations from different references are done using the new and AGMA models. The stress estimates from the new and AGMA models were compared. The stress deviations associated with …

Scalable Machine Learning Framework For Adaptive Irrigation Management Of Maize And Soybean In The U.S. Midwest, Precious N. Amori, Derek M. Heeren, Yeyin Shi, Eric Wilkening, Ivo Z. Goncalves, Guillermo R. Balboa, Daran R. Rudnick, Abia Katimbo, Randall S. Ritzema

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Conventional soil water balance (SWB) irrigation scheduling tools, such as FAO-56-based Spreadsheets and the Spatial Evapotranspiration Modeling Interface (SETMI), rely heavily on manual inputs and periodic field measurements, leading to delayed recommendations and missed opportunities to prevent crop stress. More critically, these tools lack the computational scalability and adaptability to leverage the high-frequency, high-volume datasets now available through modern sensing technologies. As precision irrigation increasingly depends on integrating spatially and temporally nuanced field information, there is a pressing need for decision-support systems that can process Big Data efficiently and respond in real-time. To overcome these limitations, we developed and validated …

Numerical Simulation Of The Fracture Resistance Of A Flame Deflector Under Impact And High Temperature By Using The Extended Finite-Element Method, Guangzhong Liu, Yuqing Feng, Tong Lin, Zhixin Xiong, Zhenting Chen

Journal of Marine Science and Technology–Taiwan

During the launch of rockets at sea, the flame deflector of the launch platform is subject to transient impact loads and high temperatures, which can result in the fracturing of the flame deflector, thereby endangering the platform and launch safety. In this study, dynamic crack propagation in a flame deflector under the aforementioned conditions was numerically investigated using the extended finite-element method (XFEM). The bulk of the flame deflector was modeled using shell elements, the local area in which the crack evolves was modeled using solid elements, and discontinuities were modeled using enrichment functions in the XFEM. The degrees of …

Overseas Agent Selection For International Logistics Companies: A Case Study, Hung-Ta Lin, Hua-An Lu

Journal of Marine Science and Technology–Taiwan

International logistics companies (ILCs) have aggressively participated in the supply chain systems of production industries as part of global trade development. They have adopted diversified and multinational models by expanding their overseas services to align with the various characteristics of regional economic patterns. Assigning specific local agents for their forwarding operations has been one of the key strategies for overseas services. Notably, the performance of these selected agents has significantly influenced service quality in their respective regions. In collaboration with the top management of an ILC, this study proposes an evaluation framework comprising 4 criteria and 16 subcriteria for selecting …

Cfrp Retrofitting For Enhancing Damping In Cushion Mounts For Marine Applications, Chih-Lung Hou, Guang-Min Luo, Sheng-Yuan Chen

Journal of Marine Science and Technology–Taiwan

Reducing vibration transmission and dynamic response is critical for data processing devices, precision instruments, and machinery in environments with frequent shocks, such as naval applications. These devices are often mounted to ships with cushion mounts. This study presents a cost-effective and rapid method for retrofitting mounts with carbon fiber reinforced polymers; the method greatly improved damping and effectively reduced vibration transmission. Specimens were produced and subjected to experimental modal analysis, and finite element models were developed for comparison. The frequency response functions and modes of the structural components from both methods were compared to assess the improvement in the damping …

Application Of Genetic Algorithm In Container Vessel Stowage Planning With Carbon Tax Considerations, Ming-Feng Yang, Wei-Hao Su, Ko-Meng Hu, Yu-Hsuan Li

Journal of Marine Science and Technology–Taiwan

This study developed a method for optimizing stowage planning for container vessels, a crucial aspect of international trade logistics. Over 80% of global trade depends on containerized transportation; thus, effective stowage planning is essential for minimizing transportation costs and enhancing operational efficiency. In the proposed hybrid optimization approach, integer programming is combined with a genetic algorithm to generate optimal stowage plans. The key factors considered in this method include load capacity limits, stacking constraints, and carbon tax regulations. The proposed method involves maximizing space utilization while minimizing logistics costs, with particular emphasis on reducing port dwell times. The findings of …

Research On Multi-Ship Collision Avoidance Decision-Making Based On Improved Velocity Obstacle Method Using Dynamic Elliptical Ship Domains, Tang Xinwei, Li Weifeng

Journal of Marine Science and Technology–Taiwan

The velocity obstacle method offers collision avoidance solutions for critical multi-ship encounter scenarios. This thesis introduces a Reciprocal Velocity Obstacle (RVO) approach based on dynamic elliptical ship domains for multi-ship collision avoidance. Initially, the concept of dynamic elliptical ship domains is presented, building upon the original static elliptical ship domain Velocity Obstacle (VO) method. Subsequently, multi-ship encounter scenarios are simulated in both virtual environments and real nautical charts, comparing the two methods. The analysis results demonstrate the improved method's excellent performance in both cases, underscoring its advantages. This research provides more effective collision avoidance strategies for multi-ship encounters.

Exploring The Red Sea Crisis’S Supply Chain Disruption Impacts On The Shipping Industry, Po-Hsing Tseng, Nick Pilcher

Journal of Marine Science and Technology–Taiwan

Since October 7, 2023, the Houthi militia in Yemen has continuously attacked Israel and its nearby ships in the Red Sea. This crisis has impacted on global ship operations, freight rates, and shipping networks, since this conflict seriously affects the international trade between Europe and Asia and brings many unpredictable butterfly effects (e.g. supply chain disruption, and high transportation costs in shipping and air cargo). This papero explores its impact on the supply chain and suggests potential solutions;, and to consider perceptions on who should be responsible for the crisis, and who will actually shoulder the responsibility for the crisis. …

Dna Barcoding In Species Identification Of Flying Fish (Exocoetidae) And Halfbeaks (Hemiramphidae) Larvae: A Comparative Study Of The Database Over A Decade, Hui-Ling Ko, Kwang-Tsao Shao, Ching-Yi Chen, Yen-Wei Chang

Journal of Marine Science and Technology–Taiwan

The families Exocoetidae and Hemiramphidae comprise migratory species, whose identification based on their external morphological characteristics can be challenging because of their similarities. DNA barcoding has been used in taxonomic and evolutionary studies to address these issues. The morphological characteristics of fish larvae change rapidly and often lack distinctive features, posing a challenge for species-level identification. This study used DNA barcoding to identify flying fish and half-beaked larvae. Using plankton nets, sampling was conducted seasonally between 2010 and 2013 in Nanwan, Taiwan. A total of 903 individuals were collected, of which 111 were identified as flying and half-beaked fish based …

Operational Risk Evaluation Of Oil Tankers Via Multivariate Gaidai Reliability Framework Incorporating Memory Effects, Oleg Gaidai, Shicheng He, Jinlu Sheng, Yan Zhu, Alaa Elsayed, Mahmoud El-Wazery

Journal of Marine Science and Technology–Taiwan

The retreat of Arctic Sea ice may exert a major impact on economy，potentially transforming the nature of commerce between Asia, Europe, and the Americas. Projections indicate a 40% reduction in transit distance and a 30% decrease in voyage time between Europe and northwest Asia compared to traditional routes such as the Suez Canal. However, even during summer navigation, fragmented floating ice persists, generating stochastic ice loads on vessel bows and hulls through complex ship-to-ice interaction. For structural design, statistical extrapolation methods are required to accurately assess excessive areal bow/hull stresses. This study proposes a novel multi-modal structural damage risk assessment …

Key Steering Characteristics For Training Remote Operators Of Maritime Autonomous Surface Ships In Collision Avoidance, Soyeong Lee, Ik-Hyun Youn

Journal of Marine Science and Technology–Taiwan

Maritime Autonomous Surface Ships (MASS) require remote operators (ROs) who need to be trained in collision avoidance (CA) maneuvers. In order to develop a training system, this study investigated differences in the steering characteristics of expert and novice navigators such as the timing of the initial rudder operation, rudder angle at a relative bearing 0°, heading at the maximum rate of turn to starboard, and, heading at the closest point of approach. The experts exhibited relatively consistent and controlled steering patterns characterized by earlier rudder adjustments and smoother heading transitions while novices demonstrated delayed reactions and greater variability in heading …

Subsurface Origin Of Tex86 Signals Revealed By Cross-Seasonal Gdgt Distributions In Suspended Particulate And Sediment Samples From The Southern East China Sea, Hung-Lin Tsai, Da-Chen Lin

Journal of Marine Science and Technology–Taiwan

The TetraEther indeX of 86 carbon atoms (TEX₈₆) proxy, which is based on isoprenoid glycerol dialkyl glycerol tetraethers (isoGDGTs) produced by Thaumarchaeota in marine environments, is widely used to reconstruct past sea surface temperatures (SSTs). However, evidence suggests that this proxy often instead reflects subsurface conditions, particularly in dynamic marginal seas. Therefore, we conducted a cross-seasonal study of glycerol dialkyl glycerol tetraether (GDGT) distributions in the southern East China Sea (ECS), which is characterized by strong monsoonal and current-driven hydrographic variability. We analyzed surface sediments and the high-resolution vertical profiles of suspended particulate matter (SPM) collected from 2016 …

The Current Status And Challenges Of Efforts To Generate Blue Carbon Credits In Okinawa Prefecture, Takashi Tamura, Wei-Chung Chen, Takafumi Sasaki

Journal of Marine Science and Technology–Taiwan

In Okinawa Prefecture, the Mozuku aquaculture industry is keen on establishing Blue Carbon Credits. This enthusiasm stems from various perspectives, including climate change mitigation, improvement of fishing grounds, industry maintenance, and enhancement of fishing ground surveillance functions. However, the industry faces several challenges. One significant challenge is the lack of a clear remaining coefficient for Mozuku, which complicates the creation of credits. Additionally, there is a shortage of manpower within the fisheries cooperative, further exacerbating the problem. To address these challenges, it is crucial to secure human resources that can promote system understanding and establish a financial base for undertaking …

In-Situ And Laboratory Sound Velocities Of Unconsolidated Sediments In The Western South Korea Plateau Of The East Sea, Kiju Park, Gil Young Kim, Yuri Kim, Bo Yeon Yi, Nyeon Keon Kang, Gwang Soo Lee

Journal of Marine Science and Technology–Taiwan

The in-situ velocity of unconsolidated shelf sediments in the western South Korea Plateau of the East Sea was directly measured using the Korea Institute of Geoscience and Mineral Resources (KIGAM) Seafloor Acoustic Probe. Physical properties, including laboratory velocity, were also measured for core samples collected from the same location. The laboratory measurements were conducted at a temperature of 23℃ and under atmospheric pressure. Owing to the in-situ temperature and pressure (0.5–1.5℃ and 100–180 atm, respectively) at the sampling site, the laboratory velocity was adjusted to the in-situ conditions. In addition, a comparison with a theoretical prediction model (Biot-Stoll model) was …

Diel Variations In Abundance Of Viral, Picoplankton, And Nanoplankton In Coastal Waters Of Taiwan In Spring, Patrichka Wei-Yi Chen, Madeline Olivia, Vladimir Mukhanov, Ufimtseva Margarita, Liashko Tatiana, Sakhon Evgenii, Supriyadi Supriyadi, Intan Dwi Puspitasari, Arpita Ghosh, An-Yi Tsai

Journal of Marine Science and Technology–Taiwan

The diel variations of viruses (< 0.2 μm), picoplankton (0.2-2 μm; heterotrophic bacteria, Synechococcus spp., and picoeukaryotes), and nanoflagellates (2-20 μm; heterotrophic and pigmented nanoflagellates) were examined for 2 days with approximately 4 h of temporal sampling in the spring of 2024 in coastal surface waters of the subtropical western Pacific. The abundance of bacteria did not follow a consistent diel pattern, and viral abundance was positively correlated with bacterial abundance. Synechococcus spp. was found to grow during the light period and with peak abundance at night, exhibiting a remarkably diel pattern; however, the pattern was opposite in picoeukaryotes. In the size-fractionation experiments, after 32 h of …

New Insights Into Decapod Chemical Communication: A Focus On The Hydrothermal Vent Crab Xenograpsus Testudinatus, Jishnu Panamoly Ayyappan, Mark June S. Consigna, Li-Chun Tseng, Jiang-Shiou Hwang

Journal of Marine Science and Technology–Taiwan

Chemical communication in decapod crustaceans has been extensively studied for over 150 years, with most of the research focusing on sex pheromones. These crustaceans inhabit chemically complex environments and rely on diverse chemical signals for essential behaviors such as mate recognition, predator avoidance, and social interaction. This review synthesizes key findings from studies on shrimp, crayfish, lobsters, and crabs, the most well-documented taxa in crustacean chemical ecology. Various appendages, including the first and second antennae, mouthparts, and walking legs, are involved in chemosensory detection. Special emphasis is placed on chemical communication in extreme environments such as hydrothermal vents (HVs), with …

Apply Cluster Analysis To Improve Interpretation Of Ert Images, Yin-Chun Hung, Yu-Xiang Zhao

Journal of Marine Science and Technology–Taiwan

The completeness and accuracy of collecting and investigating geotechnical and marine engineering geological conditions are key to the success or failure of engineering development. Traditional marine engineering and geotechnical surveys often require the assistance of geophysical methods to fully present the geological conditions. Electrical Resistivity Tomography (ERT) is an advanced geophysical method that produces accurate cross-sections of underground resistivity. Although 2D ERT has been widely used in geotechnical engineering and marine engineering, many uncertainties remain hidden behind the vivid and colorful resistivity profiles. To apply 2D ERT profiles effectively in geotechnical and marine geological surveys and monitoring, it is essential …

Geo-Chemical Fractionations Of Phosphorus In Sediments Of Thuy Trieu Lagoon And Cam Ranh Bay, Vietnam, Phu H. Le, Ngoc H. Pham, Dung T. Le, Tuan Linh T. Vo, Binh V. Tran, The V. Ho

Journal of Marine Science and Technology–Taiwan

The geochemical fractions of phosphorus (P) and its bioavailability in sediments of Thuy Trieu Lagoon and Cam Ranh Bay were investigated. Twenty-four surface sediment samples were collected in the dry season (Jun 2024) and the rainy season (Oct 2024). A sequential extraction procedure was applied to identify the phosphorus (P) fractions in sediments, including Exchangeable P (Ex-P), iron-bound P (Fe-P), aluminum-bound P (Al-P), calcium-bound P (Ca-P), and residual P (Res-P). Total P (TP) ranged from 214.9 to 2365.2 µg.g^-1, and the Ca-P fraction was the dominant chemical form in sediments. Based on the results of Pearson correlation and …

Beyond Basic Needs : Exploring The Antecedents And Outcomes Of Seafarers’ Well-Being, Chian Liou, Cheng Kuo Sung, Kimberly Hsiu-Chin Lee, Jiunn Liang Guo

Journal of Marine Science and Technology–Taiwan

Given the importance of seafarers’ mental health and the limited literature on this topic, this study aims to explore the causes and consequences of seafarers’ well-being. A questionnaire survey was conducted, and the data were analyzed using structural equation modeling and hierarchical regression analysis. Consistent with the predictions of the happy and productive worker thesis, this study found that the more satisfied the seafarers are with the shipping company’s seafarer policy, the higher their well-being tends to be, leading to a more positive work attitude. Interestingly, the study found that a company effect is significantly present in this correlation; that …

Empowering Shipping Management Competence With Artificial Intelligence: A Strategic Approach To External Environmental Volatility, Yu-Kai Huang, Cheng-Hsien Hsieh, Chi-Chang Lin, Yu-Tzu Chang, Yu-Chao Cheng

Journal of Marine Science and Technology–Taiwan

The shipping industry is undergoing significant transformation with advancements in artificial intelligence (AI), yet challenges remain in effectively adopting AI technologies. This study addresses the key concerns influencing AI adoption in shipping management. Using the Analytic Hierarchy Process (AHP) integrated with the PEST model, an evaluation framework was developed to assess AI applications in shipping companies. Based on expert input collected through the Delphi method, four constructs and twelve criteria were identified, with the 'Technological' dimension being the most critical. 'Robustness,' 'Costs,' and 'Data quality' emerged as the top factors affecting AI implementation. The framework offers practical insights for shipping …