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Rate-Dependent Interlaminar Shear Characterization In Solid-State Extruded Ultrahigh Molecular Weight Polyethylene Film Composites, Frank David Thomas Jr. Oct 2025

Rate-Dependent Interlaminar Shear Characterization In Solid-State Extruded Ultrahigh Molecular Weight Polyethylene Film Composites, Frank David Thomas Jr.

Theses and Dissertations

Ultrahigh Molecular Weight Polyethylene (UHMWPE) cross-ply [0o/90o] thin film composites are emerging as an effective material for impact applications due to their high axial strength-to-weight ratio and favorable delamination properties. Mode-II interlaminar shear (ILS) fracture-driven delamination has been shown to be a significant energy absorption mechanism. Therefore, accurately characterizing ILS behavior as a function of strain rate in these composites is essential to inform computational models. Since these composites are significantly thinner and weaker in both interlaminar shear and transverse tension than traditional carbon fiber epoxy composites, standard ILS Mode II test methods/specimens such as end-notched flexure (ENF) are expected …


Enhancing Two-Phase Heat Spreading: Development And Performance Evaluation Of Hermetically Sealed Hybrid Heat Sinks, Walker Ryan Champion Oct 2025

Enhancing Two-Phase Heat Spreading: Development And Performance Evaluation Of Hermetically Sealed Hybrid Heat Sinks, Walker Ryan Champion

Theses and Dissertations

Modern, high-performance technology presents challenges for thermal management based on power density. To cool heat fluxes to this degree, conventional liquid-cooled heat sinks are utilized because air cooling becomes insufficient (>100 𝑊/𝑐𝑚2 ). This study introduces a hybrid heat sink that integrates liquid cooling with a dropwise-enhanced vapor chamber, contains a hermetic seal, and achieves high thermal performance with low energy consumption. The temperature hotspots, thermal resistances, gravitational/pin effects, temperature uniformity, and coefficient of performance were investigated. Experimental results demonstrate a high cooling capacity of 600 W over a 6.25 𝑐𝑚2 heating area with a low cooling …


Performances In Last-Mile Deliveries Involving Cyclic Services Of Shuttles And Cargo Bikes, Byung Kwon Lee, Young Joo Kim, Joyce M. W. Low Oct 2025

Performances In Last-Mile Deliveries Involving Cyclic Services Of Shuttles And Cargo Bikes, Byung Kwon Lee, Young Joo Kim, Joyce M. W. Low

Research Collection Lee Kong Chian School Of Business

This study introduces a novel approximation model that integrates the ideologies of order statistics and max-plus algebra in representing the collection and distribution service schemes of a last-mile delivery system. Under the respective schemes, electric cargo bikes (e-bikes) perform the last-mile delivery near a microhub with shuttles collecting packages from multiple local logistics hubs (or local hubs, for short) and/or distributing packages to multiple microhubs. The framework is designed to estimate the cyclic capacity under varying cargo carrying capacities of the e-bikes and service network configurations. Real-world data, such as the geographic conditions of the streets around the microhubs in …


Influence Of Channel Geometry And Inflow Hydrograph On Hydraulics And Air Volume Around Shafts Of A Stormwater Main, Lylie Vindie Wilkie Oct 2025

Influence Of Channel Geometry And Inflow Hydrograph On Hydraulics And Air Volume Around Shafts Of A Stormwater Main, Lylie Vindie Wilkie

Theses and Dissertations

Stormwater management in urban areas is complex, in part because of difficulties related to modeling water flowing in closed conduits, as well as to controlling odor, noise, and pipe corrosion. This thesis summarizes the main findings of a study on how changes in inflow discharge and the geometry of a stormwater main may affect water flow, and how changes in water depth impact air volume and pressure around an air shaft. The study is conducted using CHAN, a one-dimensional model that simulates both flow hydraulics in mains and associated changes in air volume and pressure around air shafts. Main difference …


Erosion Of Bermuda Grass Covered Soils, Oru-Ntui Johnwatters Nkiri Oct 2025

Erosion Of Bermuda Grass Covered Soils, Oru-Ntui Johnwatters Nkiri

Theses and Dissertations

Earthen embankments are the most common type of embankment due to the relatively low cost, simplicity, and material availability. However, they are also the most prone to erosion related failure, typically due to overtopping and piping. Research has been conducted to identify ways to control soil erosion and protect earthen embankments with different approaches such as addition of chemicals and biopolymer to the soil, installation of protective layering (geotextiles, concrete), increased soil compaction, and use of vegetation. This thesis considers the use of Bermuda Grass to increase resistance to erosion and protect embankments from failure during overtopping. Grass coverage and …


Multiscale Geometric Analysis In Endovascular Therapies: Ex Vivo, In Silico Approaches, Dima Hussein Ali Bani Hani Oct 2025

Multiscale Geometric Analysis In Endovascular Therapies: Ex Vivo, In Silico Approaches, Dima Hussein Ali Bani Hani

Theses and Dissertations

In this work, we address a persistent global challenge of vascular disease, specifically peripheral artery disease (PAD), and arteriovenous fistula (AVF) complications in patients with end-stage kidney disease (ESKD). The important role of vascular geometry in disease intervention plans and the development of endovascular therapeutic strategies (e.g., Drug-coated balloon (DCBs)) is critical in addressing these challenges.

This study evaluates the feasibility of co-delivery of paclitaxel (PTX) and valsartan (VAL) using urea-based coatings in DCB, analyzes the coating morphology and microstructural changes to improve therapeutic results. A computational finite element model was developed to complement experimental work, simulate tissue-coating interactions, compute …


Gut Microbiome Dynamics In Heart Failure And The Therapeutic Potential Of Nmeg-Cgrp, Kamryn Michael Gleason Oct 2025

Gut Microbiome Dynamics In Heart Failure And The Therapeutic Potential Of Nmeg-Cgrp, Kamryn Michael Gleason

Theses and Dissertations

Heart failure (HF) is increasingly recognized as a multisystem disease often linked to gut dysbiosis; however, its specific effects on gut microbial composition remain poorly understood. This study examined long-term changes in the gut microbiome in a murine HF model induced by transverse aortic constriction (TAC) and evaluated the effects of NMEG-CGRP. TAC mimics pressure overload-induced cardiac dysfunction, replicating key features of HF. CGRP, a neuropeptide with vasodilatory and cardioprotective effects, shows potential as a therapy for HF but is limited by rapid degradation. A stabilized analog, NMEG-CGRP, was used to assess its impact on cardiac and gastrointestinal health. Mice …


Determination Of Tensile Strength Distribution Of Single Carbon Fibers At Microscale Gagelengths, Karan Deepak Shah Oct 2025

Determination Of Tensile Strength Distribution Of Single Carbon Fibers At Microscale Gagelengths, Karan Deepak Shah

Theses and Dissertations

High performance carbon fibers are widely used as reinforcements in composite material systems for aerospace, automotive, and defense applications. The tensile strength of commercial fibers is significantly less than its theoretical limits. The composite systems are often overdesigned, thus any increase in the fiber tensile strength can yield significant cost and weight savings. Modification of fiber surface treatment (sizing) during manufacturing is a potential route to enhance fiber strength. Single fiber tensile testing at millimeter-scale is typically used to characterize the effect of sizing on the fiber strength. However, the longitudinal tensile failure of a composite system is a result …


Multiphysics Modeling, Analysis, And Design Of Ceramic Hollow Fiber Membranes For Oxygen Separation, Hamed Abdolahimansoorkhani Oct 2025

Multiphysics Modeling, Analysis, And Design Of Ceramic Hollow Fiber Membranes For Oxygen Separation, Hamed Abdolahimansoorkhani

Theses and Dissertations

Oxygen plays a central role in numerous industrial processes. Several technologies have been reported for producing oxygen from air. Among them, oxygen transport membrane (OTM) technology—based on mixed-conducting, gas-tight ceramic membranes—has attracted significant attention due to its high oxygen selectivity, relatively low capital and operating costs, and versatility for both ex-situ and in-situ applications. Mathematical modeling of OTMs offers a powerful tool to investigate internal multi-physics transport phenomena, providing deeper insight into fundamental mechanisms while serving as a cost-effective approach for optimizing membrane stack designs.

After a comprehensive introduction, in the first part of this dissertation (chapter 2), a comprehensive …


Cold Spray On Fiber Reinforced Polymer Substrates For Composite Repair And Tooling Applications, Patrick Allen Bailey Oct 2025

Cold Spray On Fiber Reinforced Polymer Substrates For Composite Repair And Tooling Applications, Patrick Allen Bailey

Theses and Dissertations

Cold Spray technology was first developed in the 1980’s and is an additive manufacturing and repair technique. It works by heating a pressurized carrier gas upwards of 600 °C and inserting metal particles downstream such that when they impact a substrate, the energy transformation causes plastic deformation of the particles. This thesis presents a use case for metal and polymer CS powder on fiber reinforced and fused filament fabrication polymer substrates. The state of the art for CS discusses the most up-to-date research within the field, and where new investigations are required. This research investigates the required process parameters to …


Insect-Foundation: A Foundation Model And Large Multimodal Dataset For Vision-Language Insect Understanding, Thanh-Dat Truong, Hoang-Quan Nguyen, Xuan-Bac Nguyen, Ashley Dowling, Xin Li, Khoa Luu Oct 2025

Insect-Foundation: A Foundation Model And Large Multimodal Dataset For Vision-Language Insect Understanding, Thanh-Dat Truong, Hoang-Quan Nguyen, Xuan-Bac Nguyen, Ashley Dowling, Xin Li, Khoa Luu

Electrical Engineering and Computer Science Faculty Publications and Presentations

Multimodal conversational generative AI has shown impressive capabilities in various vision and language understanding through learning massive text-image data. However, current conversational models still lack knowledge about visual insects since they are often trained on the general knowledge of vision-language data. Meanwhile, understanding insects is a fundamental problem in precision agriculture, helping to promote sustainable development in agriculture. Therefore, this paper proposes a novel multimodal conversational model, Insect-LLaVA, to promote visual understanding in insect-domain knowledge. In particular, we first introduce a new large-scale Multimodal Insect Dataset with Visual Insect Instruction Data that enables the capability of learning the multimodal foundation …


On Modeling Of Multiplicative Bias Factor For Multivariate Degradation Data, Bingxin Yan, Qiuzhuang Sun, Zhisheng Ye Oct 2025

On Modeling Of Multiplicative Bias Factor For Multivariate Degradation Data, Bingxin Yan, Qiuzhuang Sun, Zhisheng Ye

Research Collection College of Integrative Studies

Multivariate degradation data are increasingly common due to advances in sensor technology. They provide rich information for reliability analysis and remaining useful life (RUL) prediction. The multivariate measurement typically contains actual degradation of multiple performance characteristics (PCs) and measurement errors. The multiple PCs often have different physical meanings with different orders of magnitude, making the associated measurement errors vary in the orders of magnitude as well. It is highly desirable to have a parsimonious model accounting for the possible correlation in degradation measurements, so that more flexibility can be reserved for modeling the actual multivariate degradation. This study proposes a …


Make Yourself Comfortable: Nudging Urban Heat And Noise Mitigation With Smartwatch-Based Just-In-Time Adaptive Interventions (Jitai), Clayton Miller, Xuan Yun Chua, Matias Quintana, Binyu Lei, Filip Biljecki, Mario Frei Oct 2025

Make Yourself Comfortable: Nudging Urban Heat And Noise Mitigation With Smartwatch-Based Just-In-Time Adaptive Interventions (Jitai), Clayton Miller, Xuan Yun Chua, Matias Quintana, Binyu Lei, Filip Biljecki, Mario Frei

Research Collection College of Integrative Studies

Humans can play a more active role in improving their comfort in the built environment if given the right information at the right place and time. This paper outlines the use of Just-in-Time Adaptive Interventions (JITAI) implemented in the context of the built environment to provide information that helps humans minimize the impact of heat and noise on their daily lives. This framework is based on the open-source Cozie iOS smartwatch platform. It includes data collection through micro-surveys and intervention messages triggered by environmental, contextual, and personal history conditions. An eight-month deployment of the method was completed in Singapore with …


Co2-Induced Changes In Rheology, Structural Evolution, And Particle Characteristics Of Cement Paste, Seongho Han, Tae Yong Shin, Seung Mo Kim, Jae Hong Kim, Kamal H. Khayat Oct 2025

Co2-Induced Changes In Rheology, Structural Evolution, And Particle Characteristics Of Cement Paste, Seongho Han, Tae Yong Shin, Seung Mo Kim, Jae Hong Kim, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The injection of carbon dioxide (CO2) into cementitious systems has emerged as a promising approach to enhancing sustainability in concrete production. This study explores the impact of CO2 injection on the rheological behavior, structural build-up, and particle size evolution of cement paste by systematically varying the water-to-cement ratio (w/c) (0.35, 0.4, and 0.5) and CO2 concentration (0.06, 0.28, and 0.84 mol). Rheological analysis revealed a significant increase in initial yield stress with CO2 injection. Using the Modified Bingham model, yield stress increased by 72 % and 150 % for 0.28- and 0.84-mol CO2, …


Extraction Of Aluminum From Lunar Regolith Through Molten Salt Electrolysis, Jacob N. Ortega, Todd P. Sander, Jeffrey D. Smith, Fateme Rezaei, David J. Bayless, William Schonberg, Daniel S. Stutts, Frank D. Han Oct 2025

Extraction Of Aluminum From Lunar Regolith Through Molten Salt Electrolysis, Jacob N. Ortega, Todd P. Sander, Jeffrey D. Smith, Fateme Rezaei, David J. Bayless, William Schonberg, Daniel S. Stutts, Frank D. Han

Materials Science and Engineering Faculty Research & Creative Works

This paper presents the methodology, development, and results of an end-to-end regolith-to-metal concept for producing aluminum in-situ on the lunar surface, namely, the Lunar In-Situ Aluminum Production through Molten Salt Electrolysis (LISAP-MSE) method. Using electrolytic reduction, aluminum oxide (i.e., alumina) can be reduced into aluminum and oxygen via electrolysis in a molten salt bath. A steady supply of hydrogen chloride could allow this in-situ resource utilization (ISRU) method to supply several necessary materials consumed in the electrolytic reduction step of the process to produce bulk aluminum metal, oxygen, water, and silica from anorthite abundant in lunar highland regions. In this …


Tensile Performance Sensitivity To Variations Of Standard 17-4 Ph Heat Treatments On Lpbf-Produced Material, Ben Brown, Cory Read, Joseph Newkirk, Frank Liou Oct 2025

Tensile Performance Sensitivity To Variations Of Standard 17-4 Ph Heat Treatments On Lpbf-Produced Material, Ben Brown, Cory Read, Joseph Newkirk, Frank Liou

Materials Science and Engineering Faculty Research & Creative Works

Standard heat treatments for metals of a particular composition are typically designed with the assumption of a conventional starting microstructure, such as that produced by casting or wrought processing. When applied to metals fabricated by Laser Powder Bed Fusion (LPBF) metal additive manufacturing (AM), these heat treatments can produce inconsistent performance due to the unique as-built microstructures. This study investigates how modifications to standard heat treatments for 17-4 PH steel influence the microstructure and mechanical properties of LPBF-fabricated material. Specimens were produced and subjected to varying solutionizing and homogenizing treatments followed by standard aging treatments. Microstructures were characterized using optical …


Tensile And Fatigue Properties Of Haynes ® 233 Manufactured By Wire-Arc Additive Manufacturing, Samuel Onimpa Alfred, Frank W. Liou, Mehdi Amiri Oct 2025

Tensile And Fatigue Properties Of Haynes ® 233 Manufactured By Wire-Arc Additive Manufacturing, Samuel Onimpa Alfred, Frank W. Liou, Mehdi Amiri

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Haynes® 233 is a newly developed nickel-based superalloy currently in the early stages of commercial adoption. With the growing interest in fabricating large and complex components using wire-arc additive manufacturing (WAAM), this alloy presents a promising option for industrial applications. This study investigates the microstructure, tensile, and fatigue properties of heat-treated (HT) WAAM Haynes ® 233 and compares them to its wrought counterpart. Yield strength (YS), ultimate tensile strength (UTS), and fatigue strength of WAAM Haynes ® 233 are 709.4 MPa, 890.1 MPa, and 253.8 MPa, respectively. These values indicate a 63.8 % increase in YS, a 1.11 % decrease …


Melting Behavior Of Direct Reduced Iron Pellets With Different Carbon Content In Molten Steel And Molten Slag, Fabian Andres Calderon Hurtado, Joseph Govro, Arezoo Emdadi, Ronald J. O'Malley Oct 2025

Melting Behavior Of Direct Reduced Iron Pellets With Different Carbon Content In Molten Steel And Molten Slag, Fabian Andres Calderon Hurtado, Joseph Govro, Arezoo Emdadi, Ronald J. O'Malley

Materials Science and Engineering Faculty Research & Creative Works

This study investigates the melting behavior of direct reduced iron (DRI) pellets in molten slag and steel baths, focusing on how the carbon content influences the melting rate through the stirring effects of gas evolution on heat transfer. A computational model using COMSOL Multiphysics 6.1 is developed to simulate the temperature profile at the pellet's core and the gas evolution resulting from the reaction between FeO and carbon within the pellet. The model is validated using experimental data from this study as well as literature on the DRI pellet–molten slag system. Results indicate that, despite the increased enthalpy demand associated …


Evaluation Of Towed Tem Potential For Rapid Characterization Of Levee Foundations, Kolawole Arowoogun, Katherine Grote, Jeremy Maurer Oct 2025

Evaluation Of Towed Tem Potential For Rapid Characterization Of Levee Foundations, Kolawole Arowoogun, Katherine Grote, Jeremy Maurer

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Assessing the geologic conditions of levee foundation soils is a challenging task owing to the extensive length of most levees and the heterogeneity of many alluvial deposits. Traditional investigation techniques (such as boring and cone penetrometer testing [CPT]) are expensive, invasive, and provide spatially-limited information. As a result, they are restricted to pre-identified problematic zones in the levee. To overcome these challenges, geophysical instruments capable of better spatial coverage are proposed for rapid geoelectrical characterization of levees. In this study, we presented a field-based application of the towed time-domain electromagnetic method (tTEM) system in characterizing the subsurface geology adjacent to …


Multi-Period Risk-Aware Procurement Optimization Under Covid-19 Disruption, Jonathan Chase, Hoong Chuin Lau, Jinfeng Yang, Lu Liu Oct 2025

Multi-Period Risk-Aware Procurement Optimization Under Covid-19 Disruption, Jonathan Chase, Hoong Chuin Lau, Jinfeng Yang, Lu Liu

Research Collection School Of Computing and Information Systems

Supply chain resilience has been a topic of active research in the operations research and AI communities for several years, but the COVID-19 pandemic threw the frailties of global supply chains into sharp relief. Disruptions and delays caused by fresh outbreaks leading to lockdowns, put severe strain on supply chains in many industries. In this work we develop lockdown-resilient procurement capabilities for a global technology company. First, through analysis of lockdown data from China we develop a logarithmic regression-based lockdown prediction method to complement a supplier risk metric for conventional risks. Second, we develop a multi-period stochastic optimization model that …


Real-Time Task Scheduling Strategy For 3d Printing Cloud Platforms In Health Scenes, Jianjia He, Jian Wu, Jingran Ni, Yuning Zhang, Keng Siau Oct 2025

Real-Time Task Scheduling Strategy For 3d Printing Cloud Platforms In Health Scenes, Jianjia He, Jian Wu, Jingran Ni, Yuning Zhang, Keng Siau

Research Collection School Of Computing and Information Systems

In health scenes, 3D Printing Cloud Platform (3DPCP) needs to cope with unpredictable fluctuations in tasks and resources, but traditional scheduling methods have problems such as incomplete consideration of factors, poor optimization, and weak dynamic adaptability, which make it difficult to meet real-time scheduling requirements. To this end, the real-time task scheduling problem of 3DPCP for health scenes is defined, a real-time task scheduling model is established, the design time of user personalized services is considered, a rescheduling scheme is designed in combination with task variations and device variations, and a scheduling strategy that incorporates dynamic mechanisms and improved multi-objective …


Laboratory Investigation Of High-Temperature Preformed Particle Gels For Fluid Control In Granite Cores For Geothermal Applications, K. Caleb Darko, Yanbo Liu, Thomas P. Schuman, Mingzhen Wei, Baojun Bai Oct 2025

Laboratory Investigation Of High-Temperature Preformed Particle Gels For Fluid Control In Granite Cores For Geothermal Applications, K. Caleb Darko, Yanbo Liu, Thomas P. Schuman, Mingzhen Wei, Baojun Bai

Chemistry Faculty Research & Creative Works

To understand the applicability of high-temperature preformed particle gel (HT-PPG) for control of short-circuiting in enhanced geothermal systems (EGSs), core flooding experiments were conducted on fractured granite cores under varying fracture widths, gel particle sizes and swelling ratios. Key parameters such as injection pressure, water breakthrough pressure, and residual resistance factor were measured to evaluate HT-PPG performance. The gel exhibited strong injectability, entering granite fractures at pressure gradients as low as 0.656 MPa/m; HT-PPG yields a superior sealing performance by significantly reducing the permeability; and dehydration occurs during HT-PPG propagation, with a dehydration ratio ranging from 4.71% to 11.36%. This …


The Suitability Of Advanced Geospatial Technologies In Monitoring Mine Surface Displacement, Long Quoc Nguyen, Tuyet Minh Dang, Lipecki Tomasz Sep 2025

The Suitability Of Advanced Geospatial Technologies In Monitoring Mine Surface Displacement, Long Quoc Nguyen, Tuyet Minh Dang, Lipecki Tomasz

Journal of Sustainable Mining

This study conducts a thorough review of the current scientific literature on the application of geospatial methods in the assessment of mining-induced displacement. The scope of research included technologies for determining deformation, subsidence, and landslide in mining areas. Global Navigation Satellite Systems, Unmanned Aerial Vehicles, Terrestrial Laser Scanners, Remote Sensing, and fusion methods are approaches used to solve the research objectives. Additionally, the paper also mentions some advantages, disadvantages, and scope of application of these methods. The investigation revealed that the displacement detection method most commonly used at the moment is satellite radar interferometry.


Durable Low-Friction Graphite Coatings Enabled By A Polydopamine Adhesive Underlayer, Adedoyin Ayomide Abe, Fernando Maia De Oliveira, Deborah Okyere, Mourad Benamara, Jingyi Chen, Yuriy I. Mazur, Min Zou Sep 2025

Durable Low-Friction Graphite Coatings Enabled By A Polydopamine Adhesive Underlayer, Adedoyin Ayomide Abe, Fernando Maia De Oliveira, Deborah Okyere, Mourad Benamara, Jingyi Chen, Yuriy I. Mazur, Min Zou

Mechanical Engineering Faculty Publications and Presentations

This study investigates the tribological performance and wear mechanisms of graphite and polydopamine/graphite (PDA/graphite) coatings on stainless steel under dry sliding conditions. While graphite is widely used as a solid lubricant, its poor adhesion to metal substrates limits long-term durability. Incorporating an adhesion-promoting PDA underlayer significantly improved coating lifetime and wear resistance. Tribological testing revealed that PDA/graphite coatings maintained a coefficient of friction (COF) below 0.15 for over seven times longer than graphite-only coatings. High-resolution scanning electron microscopy, SEM, and profilometry showed that PDA improved coating adhesion and suppressed lateral debris transport, confining wear to a narrow zone. Surface and …


Plasmonic Nanoparticle Integration On Fiber Optic: Role Of Organic Linker And Functionalization Length In Refractive Index Sensing, Shela Ilmiyah, Mohamad Syahadi, Muflikhah Muflikhah, Yuwana Pradana, Zainul Arifin Iman Supardi, Iwan Darmadi, Lia Aprilia Sep 2025

Plasmonic Nanoparticle Integration On Fiber Optic: Role Of Organic Linker And Functionalization Length In Refractive Index Sensing, Shela Ilmiyah, Mohamad Syahadi, Muflikhah Muflikhah, Yuwana Pradana, Zainul Arifin Iman Supardi, Iwan Darmadi, Lia Aprilia

Makara Journal of Science

Nanoplasmonic fiber optic sensors leverage the optical fiber’s inherent compactness and surface sensitivity via evanescent-field interactions with the localized surface plasmon resonance of the metallic nanoparticles. One of the popular approaches is self-assembly owing to its relatively low cost. Despite its low cost, the self-assembly technique has low reproducibility and exhibits low sensitivity because of low nanoplasmonic coverage on the fiber optic surface. In this study, several fabrication techniques were explored to assess the refractive index sensitivity by comparing three common organosilanes, i.e., (3-Aminopropyl)triethoxysilane (APTES), (3-Aminopropyl)trimethoxysilane, and (3-Mercaptopropyl)trimethoxysilane. Comparative analyses assessed the anchoring efficiency of the three silanes, sensor reproducibility, …


Quantifying The Decay Timescale Of Volcanic Sulfur Dioxide In The Stratosphere, Paul A. Nicknish, Kane Stone, Susan Solomon, Simon Carn Sep 2025

Quantifying The Decay Timescale Of Volcanic Sulfur Dioxide In The Stratosphere, Paul A. Nicknish, Kane Stone, Susan Solomon, Simon Carn

Michigan Tech Publications

The injection of sulfur dioxide (SO2) into the stratosphere and its subsequent oxidation to form sulfate aerosols after large volcanic eruptions can have profound effects on Earth's climate. The removal of volcanic SO2 in the stratosphere is thought to be driven by its gas-phase oxidation by the hydroxyl radical (OH); once oxidized, it goes on to form sulfate aerosols. However, it has also been suggested that heterogeneous oxidation on ash could also be important or even dominant, which would imply the faster removal of SO2 and thus the faster formation of aerosols, at least in ash-rich plumes. Additionally, recent work …


Common Ground Newsletter Fall 2025, Missouri University Of Science And Technology Sep 2025

Common Ground Newsletter Fall 2025, Missouri University Of Science And Technology

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Carbonated High-Al Steel Slag As Supplementary Cementitious Material: Synergy Of Carbonation At Elevated Temperature And Addition Of Gypsum, Nannan Zhang, Gao Deng, Wenyu Liao, Chuanlin Hu, Lingyu Chi, Hongyan Ma Sep 2025

Carbonated High-Al Steel Slag As Supplementary Cementitious Material: Synergy Of Carbonation At Elevated Temperature And Addition Of Gypsum, Nannan Zhang, Gao Deng, Wenyu Liao, Chuanlin Hu, Lingyu Chi, Hongyan Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

High-Al steel slags, such as ladle metallurgy furnace (LMF) slag, substantially retard the early hydration of cement when incorporated into cement pastes, primarily due to the high mayenite content. In this study, carbonation of slag at elevated temperatures of 60°C and 80°C, combined with gypsum addition, was proposed to synergistically mitigate the retardation effect and enhance the early-age strength of cement pastes. The physical and chemical properties of slags carbonated at various temperatures were analyzed to elucidate their impact on cement performance as a supplementary cementitious material. The results indicate that higher temperatures enhance carbonation reactivity, accelerating the carbonation of …


Pendant Micro-Droplet Evaporation Fabricates Fiber-Optic Mof Gas Sensor In Seconds, Abhishek Prakash Hungund, Bohong Zhang, Narasimman Subramaniyam, Thomas Spudich, Ryan O'Malley, Farhan Mumtaz, Rex E. Gerald, Jie Huang Sep 2025

Pendant Micro-Droplet Evaporation Fabricates Fiber-Optic Mof Gas Sensor In Seconds, Abhishek Prakash Hungund, Bohong Zhang, Narasimman Subramaniyam, Thomas Spudich, Ryan O'Malley, Farhan Mumtaz, Rex E. Gerald, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

The development of photonic-based gas sensors using metal–organic frameworks (MOFs) and other microporous solids is often a multistep, complex process, typically involving MOF synthesis, purification, and attachment of microcrystals to an optical fiber end face. This study introduces a one-step method that integrates MOF synthesis and sensor head fabrication directly onto the fiber end face, forming an extrinsic Fabry–Perot interferometer (EFPI) with a thin film of MOF microcrystals. The resulting film, only 3–10-μm-thick, enhances sensor response by enabling rapid gas detection within seconds. Utilizing a pendant micro-droplet evaporation technique, this method forms a microporous MOF layer in situ, allowing unreacted …


Magnesium Sulfate Attack Of Alite Paste And Mitigation By Surface Carbonation: Monitoring And Comparison Using Novel Portable Fiber-Optic Raman Probe, Bohong Zhang, Gao Deng, Hongyan Ma, Jie Huang Sep 2025

Magnesium Sulfate Attack Of Alite Paste And Mitigation By Surface Carbonation: Monitoring And Comparison Using Novel Portable Fiber-Optic Raman Probe, Bohong Zhang, Gao Deng, Hongyan Ma, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

Sulfate attack on cement matrix is still a "confused world" especially when magnesium sulfate (MgSO4) is the sulfate source. Accurate assessment of sulfate attack is essential for evaluating the structural integrity and durability of concrete in relevant environments. This study presents a portable fiber-optic Raman probe approach with 125 μm spatial resolution, designed for depth-resolved sulfate ingress monitoring in tricalcium silicate (C₃S, Alite) pastes. The probe is also used to evaluate the effectiveness of surface carbonation in mitigating sulfate attack. The results demonstrate a strong correlation between sulfate penetration depth and Raman spectral intensity ratios of sulfate-related vibrational …