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Articles 181 - 210 of 7868

Full-Text Articles in Civil and Environmental Engineering

Class-Wise Histogram Matching-Based Domain Adaptation In Deep Learning-Based Bridge Element Segmentation, Tarutal Ghosh Mondal, Zhenhua Shi, Haibin Zhang, Genda Chen Jan 2025

Class-Wise Histogram Matching-Based Domain Adaptation In Deep Learning-Based Bridge Element Segmentation, Tarutal Ghosh Mondal, Zhenhua Shi, Haibin Zhang, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study focused on the problem of domain shift in deep learning-based bridge element segmentation. The impracticability of accounting for all possible variabilities vis-à-vis structural shape, size, color, texture, illumination, and other operational conditions in the training process leads to the deterioration in the model performance when applied to test data from novel unseen domains. In such situations, rebuilding the model with labeled training data from the target domain becomes prohibitively expensive and time-consuming in many practical cases. Recent advancements in unsupervised domain adaptation techniques are known to provide viable solutions to this problem. However, it was observed in this …


Challenges In Numerical Simulation Of Frost Heave, Antai Dong, Xiong Zhang Jan 2025

Challenges In Numerical Simulation Of Frost Heave, Antai Dong, Xiong Zhang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Frost heave of soil extensively exists in northern regions and poses a significant threat to infrastructure in cold regions. Despite over a century of research, challenges persist in numerically simulating frost heave. This study addresses two key issues: (1) What is the primary driving force for liquid water transfer during the freezing process? (2) How can we correctly represent unfrozen water content? Critical insights are derived from the theoretical analysis of coupled hydrothermal migration during soil freezing processes, followed by a case simulation using COMSOL Multiphysics. It concludes that of the water content gradient, suction gradient, and hydraulic gradient, only …


Material Suppliers’ Perspective On Collaboration In Industrial Construction Projects, Seogjae Choi, William J. O'Brien Jan 2025

Material Suppliers’ Perspective On Collaboration In Industrial Construction Projects, Seogjae Choi, William J. O'Brien

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Material suppliers' involvement in construction project planning has been recommended as an effective measure to improve project performance by using their expertise. However, the recommendation is not universal, and some researchers disputed the value of early involvement of suppliers depending on material type. Moreover, prior studies considered main contractors' and owners' perspectives mostly in examining how to increase the involvement of suppliers. To add material suppliers' perspective, this study conducted interviews with experienced professionals from 16 material suppliers including standardized, make-to-order, and custom products. The results are specified by separating the type of materials and sub-phases of planning. The results …


Hydraulic Connectivity And Hydrochemistry Influence Microbial Community Structure In Agriculturally Affected Alluvial Aquifers In The Midwestern United States, Hunter W. Schroer, Kendra Markland, Fangqiong Ling, Craig L. Just Jan 2025

Hydraulic Connectivity And Hydrochemistry Influence Microbial Community Structure In Agriculturally Affected Alluvial Aquifers In The Midwestern United States, Hunter W. Schroer, Kendra Markland, Fangqiong Ling, Craig L. Just

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Alluvial aquifers can provide ecosystem services and drinking water but much remains unknown about human effects on aquifer microbiomes. Therefore, we used amplicon sequencing and hydro chemical characterization to pair microbial communities with environmental conditions across 37 alluvial aquifer wells. The study region spanned eastern Iowa and southern Minnesota (USA) and contained a combination of drinking water and monitoring wells. In terms of microbial ecology, dominant phyla across the wells included Proteobacteria, Bacteroidota, Patescibacteria, Planctomycetota, and Nitrospirota. Tritium, an indicator of infiltration and surface water influence, was the highest correlated variable with the Shannon index (α-diversity) by the Spearman rank …


Forecasting State-Level Construction Labor Earnings For Enhanced Project Cost Control: An Econometric And Deep-Learning Analysis Of The Leading Economic Indicators, Ahmed Shiha, Islam H. El-Adaway Jan 2025

Forecasting State-Level Construction Labor Earnings For Enhanced Project Cost Control: An Econometric And Deep-Learning Analysis Of The Leading Economic Indicators, Ahmed Shiha, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

As a major input to several work packages, the labor element constitutes a critical component for successful performance of construction projects. Localized labor shortages, fundamental changes in prevailing wage laws, and historical shifts in the unionization rates of construction workers impair the adequate estimation of construction labor costs in diverse labor market dynamics. Meanwhile, existing studies have utilized national-level indicators to study the trends of construction labor costs, but the relationship between the multifaceted local economic factors and state-level construction labor costs remains understudied. This paper fills such a knowledge gap. A three-stage methodology is adopted: (1) data collection of …


Guest Editorial, Li Ai, Xiao Tan, Arslan Akbar, Guirong Yan Jan 2025

Guest Editorial, Li Ai, Xiao Tan, Arslan Akbar, Guirong Yan

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.


Polarimetry Based Radar Estimation Of Extreme Rainfall: Case Studies, Bong Chul Seo, Witold F. Krajewski, James A. Smith Jan 2025

Polarimetry Based Radar Estimation Of Extreme Rainfall: Case Studies, Bong Chul Seo, Witold F. Krajewski, James A. Smith

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The study evaluated radar-derived polarimetric rainfall estimates for extreme rain events that occurred in the Kansas City Metropolitan area in the United States. To derive quantitative precipitation estimates (QPE), we implemented two polarimetric algorithms based on specific attenuation (A) and specific differential phase (KDP), along with the reflectivity (Z) based one using data from two radars in the study area. The analysis to assess radar-rainfall estimates (R) utilizes ground observations from a dense network of about 170 rain gauges. Based on our analysis results, the two polarimetric estimates from R(A) and R(KDP) outperform the conventional estimation R(Z). R(A) appeared to …


Aqueous Carbonation Of Steel Slags: A Comparative Study On Mechanisms, Nannan Zhang, Gao Deng, Wenyu Liao, Hongyan Ma, Chuanlin Hu Jan 2025

Aqueous Carbonation Of Steel Slags: A Comparative Study On Mechanisms, Nannan Zhang, Gao Deng, Wenyu Liao, Hongyan Ma, Chuanlin Hu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study investigated the aqueous carbonation mechanisms of three typical steel slags: ladle metallurgy furnace (LMF) slag containing high Al content, electric arc furnace (EAF) slag featuring high Si content and relatively low Al content, and ladle-arc fusion (LAF) slag with medium-Al content. It was found that the carbonation kinetics of the three slags were similar and followed the surface coverage model within the first 6 h of carbonation. Initially, the carbonation process was primarily governed by the reaction product precipitation. After 3 h of carbonation, the process was dominated by mineral dissolution, controlled by the uncovered reactive sites. The …


Reevaluating The Van’T Hoff And Arrhenius Equations: How Temperature And Pressure Affect Chemical Reaction Thermodynamics, Equilibrium, And Kinetics, Jianmin Wang Jan 2025

Reevaluating The Van’T Hoff And Arrhenius Equations: How Temperature And Pressure Affect Chemical Reaction Thermodynamics, Equilibrium, And Kinetics, Jianmin Wang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The van’t Hoff equation, which is used to calculate the effect of temperature on equilibrium constants, was derived from the Gibbs – Helmholtz equation that relates the molar Gibbs free energy to the molar enthalpy of a chemical reaction. However, the Gibbs – Helmholtz equation was developed for systems that do not consider contributions of Gibbs free energy from chemical species. Consequently, the van’t Hoff equation and the Arrhenius equation derived from it are technically incomplete.

By employing Hess’s law and the appropriate Gibbs free energy equation for chemical reaction systems, this investigation develops theoretical equations to calculate the effects …


An Improved Table Method For Coded Target Identification With Application To Photogrammetric Analysis Of Soil Specimen During Triaxial Testing, Xiaolong Xia, Xiong Zhang, Sara Fayek, Zhaozheng Yin Jan 2025

An Improved Table Method For Coded Target Identification With Application To Photogrammetric Analysis Of Soil Specimen During Triaxial Testing, Xiaolong Xia, Xiong Zhang, Sara Fayek, Zhaozheng Yin

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Accurate and efficient recognition and identification of coded targets are of great importance in coded target-based photogrammetry. Recently, a deep learning-based method has been utilized to recognize the coded targets. Then, a table method has been developed to decode the coded targets, identify falsely identified coded targets, and recover missing coded targets. This method takes advantage of the geometric arrangement of the coded targets. In this paper, an improved table method has been developed to improve the coded targets recognition and identification results. Blob analysis, instead of deep learning, is utilized to recognize coded targets. Then, the RANSAC algorithm was …


Individual Design Task Final Report Security Design, Ciarrah Bell Jan 2025

Individual Design Task Final Report Security Design, Ciarrah Bell

Honors Academy

"The Environmental Services Campus project is a comprehensive development designed to support the City of Springfield’s Environmental Services operations, with a focus on functionality, sustainability, and safety. The campus includes administrative office space, staff parking, a maintenance vehicle garage, and educational facilities aimed at community outreach. A component of the project is establishing site-wide security that not only protects personnel and assets but also integrates seamlessly with the architectural and environmental goals of the facility.

The primary focus of the Security IDT is the development and implementation of a comprehensive security strategy for the entire site. This includes designing and …


Flexural Post-Cracking Performance Of Macro Synthetic Fiber Reinforced Super Workable Concrete Influenced By Shrinkage-Reducing Admixture, Jingjie Wei, Nima Farzadnia, Kamal H. Khayat Jan 2025

Flexural Post-Cracking Performance Of Macro Synthetic Fiber Reinforced Super Workable Concrete Influenced By Shrinkage-Reducing Admixture, Jingjie Wei, Nima Farzadnia, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Most literature has focused on the effect of shrinkage-reducing admixture (SRA) in shrinkage mitigation resistance of concrete. This study aims to examine the impact of SRA on the efficiency of macro synthetic fibers (MSF) in enhancing the flexural post-cracking behavior of fiber-reinforced super workable concrete (FR-SWC). A comparative analysis of the influence of fiber combinations on the flexural post-cracking behavior of beams is also included. Results showed that a higher dosage of SRA, particularly at 5 % by mass of binder, had a noticeable negative impact on flexural post-cracking performance of beams while exhibiting positive effect on workability and shrinkage …


Active Phytoextraction Of Toluene Shifts The Microbiome And Enhances Degradation Capacity In Hybrid Poplar, Michael Benisrael, Dasiel Obregon, Philipp Wanner, Jeremy Fernandes, Joel G. Burken, Ramon Aravena, Beth L. Parker, Elizabeth A. Haack, David T. Tsao, Kari E. Dunfield Jan 2025

Active Phytoextraction Of Toluene Shifts The Microbiome And Enhances Degradation Capacity In Hybrid Poplar, Michael Benisrael, Dasiel Obregon, Philipp Wanner, Jeremy Fernandes, Joel G. Burken, Ramon Aravena, Beth L. Parker, Elizabeth A. Haack, David T. Tsao, Kari E. Dunfield

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Hybrid poplars are widely recognized for their effectiveness in remediating subsurface aromatic hydrocarbon contaminants, including benzene, toluene, ethylbenzene, and xylene isomers (BTEX). While BTEX compounds are frequently found in the transpiration streams of poplars at contaminated sites, the microbial dynamics within these trees, particularly in response to hydrocarbon exposure, remain underexplored. This study utilized high-throughput amplicon sequencing to investigate the trunk microbiome in hybrid poplars at a field-scale toluene phytoremediation site. Across the plant growth season (spring to late summer), we observed a significant seasonal increase in bacterial diversity and richness, particularly in trees located in areas with the highest …


Innovative Air Convection Embankment For Cold/Arctic Region Low-Volume Roads, Hanli Wu, Jenny Liu, Xiong Zhang, Steve Saboundjian Jan 2025

Innovative Air Convection Embankment For Cold/Arctic Region Low-Volume Roads, Hanli Wu, Jenny Liu, Xiong Zhang, Steve Saboundjian

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Roadbed thaw settlement is a unique challenge for the durability of low-volume roads (LVRs) in permafrost regions. Air convection embankment (ACE) is an effective technique that acts as a semi-heat-transfer system to control temperature variation and reduce the thaw depth of subsoil. However, limited by the shortage of the necessary crushed rocks within a short distance, building an ACE in Alaska, U.S., is prohibitively expensive. Previous studies identified the feasibility of using cellular concrete for ACE and determined the optimized thickness of the cellular concrete aggregate interlayer for ACE. However, the economic efficiency and thermal and mechanical performance of the …


Bond Behavior Of Magnesium Potassium Phosphate Cement (Mkpc) Coating For Steel Reinforcement, Eric Williams Jan 2025

Bond Behavior Of Magnesium Potassium Phosphate Cement (Mkpc) Coating For Steel Reinforcement, Eric Williams

Masters Theses

"This research investigates the bond behavior of magnesium potassium phosphate cement (MKPC) coated mild steel deformed bars in conventional concrete and concrete repair materials. For typical steel reinforcement in concrete, a thin “passive layer” develops around the reinforcement, which protects the reinforcement from corrosion. The concrete carbonates over time, reducing the protection of the passive layer and allowing chlorides, which corrode the reinforcement, to penetrate at an increasing rate. In some cases, to combat this corrosion, a protective layer is added to the reinforcement prior to installation. Common protective layers include epoxy coatings or zinc galvanization. MKPC is a novel …


System Design For Highly Accurate And Efficient Target Detection In Triaxial Testing, Qingqing Fu Jan 2025

System Design For Highly Accurate And Efficient Target Detection In Triaxial Testing, Qingqing Fu

Masters Theses

Accurate and automated recognition of coded targets is crucial for high-precision photogrammetry-based measurements in triaxial testing. Traditional recognition methods, including those based on deep learning and table decoding, often struggle with issues such as perspective distortion, rotation, and variable lighting, leading to unreliable results. While deep learning approaches offer some improvements, they remain computationally intensive and sensitive to environmental factors.

This thesis introduces an innovative system that replaces deep learning algorithms with a blob analysis-based method for efficient and robust recognition of coded targets. The system also employs newly designed solid points of varying sizes and patterns, eliminating the need …


Identifying Early Warning Signs Of Construction Labor Shortages, Ahmed Shiha, Islam H. El-Adaway Jan 2025

Identifying Early Warning Signs Of Construction Labor Shortages, Ahmed Shiha, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Construction labor shortages constrain project-level objectives and national development plans. The goal of this study is to utilize the lagged effects of macroeconomic conditions as early warning signs of construction labor shortages. To this end, the authors adopted a methodology, encompassing (1) retrieval of publicly available data and preprocessing of construction labor shortage as the target variable and macroeconomic measures as the explanatory variables, (2) identification of short-term associations between shortages and economic cycles using the Granger causality test, (3) examination of long-term relationships between labor shortages and economic conditions using the Johansen cointegration test, and (4) estimation of the …


Integration Of Physics-Informed Neural Networks And Transfer Learning For Rainfall Induced Landslide Forecasting, Shian Cao, Weibing Gong Jan 2025

Integration Of Physics-Informed Neural Networks And Transfer Learning For Rainfall Induced Landslide Forecasting, Shian Cao, Weibing Gong

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Rainfall-induced landslides are a significant geological hazard, causing severe economic losses and casualties. Accurate forecasting of these events is particularly challenging due to the complex interactions of spatial and temporal factors governing slope stability. The Iverson model, which uses the Richards equation to describe water infiltration in unsaturated soils, is a widely adopted framework for analyzing rainfall-induced landslides. However, its reliance on traditional numerical methods limits its scalability and efficiency, particularly for complex boundary conditions and transient behaviors near slope failure. To address these limitations, we propose a physics-informed neural network (PINN) enhanced with transfer learning (TL-PINN) to solve the …


2d Numerical Modeling Of Pavements On Expansive Soil In Extreme Climates, Ekansh Agarwal, Xiong Zhang, Ning Luo Jan 2025

2d Numerical Modeling Of Pavements On Expansive Soil In Extreme Climates, Ekansh Agarwal, Xiong Zhang, Ning Luo

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study focuses on modeling a rigid pavement slab on expansive soil in extreme climates to understand the interaction between weather, pavement, and soil. Lightweight superstructures such as pavements are particularly prone to damage due to the differential settlement of expansive soils. In the context of climate change, the occurrence of severe droughts followed by intense rainfall has risen, causing severe impacts on crack initiation and development, and thus infiltration patterns in the structures built on expansive soils. Pavements are typically designed for a limited lifespan, and early failure may occur if climate change is not considered during design. This …


Quantifying Deviation Of Elasticity In The Quasi-Elastic Domain Of Granular Soils, Wen Deng, Yufan Jin, Pingxin Xia, Qingqing Fu, Xiong Xia, Xiaoxia Guo Jan 2025

Quantifying Deviation Of Elasticity In The Quasi-Elastic Domain Of Granular Soils, Wen Deng, Yufan Jin, Pingxin Xia, Qingqing Fu, Xiong Xia, Xiaoxia Guo

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The absence of purely elastic properties in granular soil is attributed to the reversible sliding that occurs between particles during the loading–unloading cycle, leading to the dissipation of energy through friction. Instead of the strictly elastic domain, we opt for a quasi-elastic domain to examine elastic behavior within the confines of elastic theory. Within this quasi-elastic realm, the response deviates to some extent from the idealized pure elastic behavior posited by the elastic theory. As a result, the elastic constitutive relations applied to granular materials are no longer strictly accurate and may exhibit deviations. With the aim of exploring the …


Effect Of Gluconate Molecules On The Reaction Kinetics Of C-(N)-A-S-H And N-A-S-H Gel Formation, Jiafeng Kong, Chao Sun, Zuhua Zhang, Chenglong Cai, Yubin Cao, Yanru Wang, Hongyan Ma, Xuesen Zeng, Hao Wang Jan 2025

Effect Of Gluconate Molecules On The Reaction Kinetics Of C-(N)-A-S-H And N-A-S-H Gel Formation, Jiafeng Kong, Chao Sun, Zuhua Zhang, Chenglong Cai, Yubin Cao, Yanru Wang, Hongyan Ma, Xuesen Zeng, Hao Wang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Organic ligands are widely used to regulate setting in cementitious binders, yet their chemistry-selective action in geopolymers (GPs) remains unclear. Here we isolate the role of sodium gluconate (SG) in early reaction kinetics across a Ca-rich GP that forms a calcium-(sodium)-aluminosilicate hydrate (C-(N)-A-S-H) gel and a Ca-poor GP that forms a sodium-aluminosilicate hydrate (N-A-S-H) gel. Four GPs spanning Ca/Si ≈ 1.01 to 0.01 were prepared with identical activator chemistry and dosages of SG up to 5 wt.% of precursors. Setting time, isothermal calorimetry, pore-solution speciation (TOC, ICP-OES, and pH), selective dissolution (reaction extent), low-field1H NMR, XRD, FTIR, SEM-EDS, …


Every Publication Needs An Author Verified Tl;Dr Statement, Sarah Oerther, Daniel B. Oerther Jan 2025

Every Publication Needs An Author Verified Tl;Dr Statement, Sarah Oerther, Daniel B. Oerther

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.


Mitigating Frost Heave And Thaw Weakening In Roads Using Wicking Geotextile, Javad Galinmoghadam Jan 2025

Mitigating Frost Heave And Thaw Weakening In Roads Using Wicking Geotextile, Javad Galinmoghadam

Doctoral Dissertations

"Excess water is known to be the primary cause of soil and foundation problems. In cold regions, water-related problems are exacerbated by seasonal freezing and thawing cycles. Frost heave and thaw weakening is the leading cause of premature pavement failure and consume considerable budgets of the Department of Transportations in cold regions. The first step to designing mitigation measures is the ability to predict frost heave under different conditions. This study aims to introduce a new method for quantifying frost heave using a prediction model based on the state surface approach. This proposed model addressed many inconsistencies and limitations of …


Exploring The Feasibility Of Innovative Integration Of Phase Change Materials For Thermo-Adaptive Asphalt Pavements, Farshad Saberi Kerahroudi Jan 2025

Exploring The Feasibility Of Innovative Integration Of Phase Change Materials For Thermo-Adaptive Asphalt Pavements, Farshad Saberi Kerahroudi

Doctoral Dissertations

"Current research examined the feasibility and efficiency of employing phase change materials (PCMs) in asphalt pavement materials to result in thermo-adaptive asphalt pavement. The PCM was introduced to the asphalt materials in three different scales, including asphalt binder, asphalt mastic, and asphalt mixture. After investigating asphalt at different scales, mix blending method was found as the easiest method without any complexity to mix asphalt binder with PCM. The testing results could reveal an improvement in the high temperature performance of asphalt binder without sacrificing the low temperature performance with the presence of PCM and Gilsonite. Also, introducing PCM to asphalt …


Evaluating And Relaxing The Limits On Flexural Reinforcement Ratio Of Masonry Shear Walls, Tousif Mahmood Jan 2025

Evaluating And Relaxing The Limits On Flexural Reinforcement Ratio Of Masonry Shear Walls, Tousif Mahmood

Doctoral Dissertations

Reinforced masonry shear walls (RMSWs), essential for lateral and out-of-plane load-resisting systems in modern construction are constrained by TMS 402/602 code limits on reinforcement ratios ("ρ" _"max" ) and axial compressive stresses (≤10% of masonry compressive strength, f_m^'), undermining masonry’s inherent compression capacity under high axial loads. This dissertation investigates the seismic performance of reinforced masonry shear walls (RMSWs) subjected to high axial compressive stresses (10–20% of f_m^'), with a focus on walls violating the maximum reinforcement ratio ("ρ" _"max") and axial load limits of TMS 402-22. Through experimental testing of 30 large-scale fully grouted (FG) and partially grouted (PG) …


Dynamic Response, Assessment, And Retrofitting Of Prestressed Concrete Bridge Girders Subjected To Lateral Impact Loads, Haitham A. Abdelmalek Jan 2025

Dynamic Response, Assessment, And Retrofitting Of Prestressed Concrete Bridge Girders Subjected To Lateral Impact Loads, Haitham A. Abdelmalek

Doctoral Dissertations

Over height vehicle collisions pose a growing threat to the resilience of bridge infrastructure across the United States. According to the American Road & Transportation Builders Association (ARTBA, 2024), approximately 36% of all U.S. bridges require major repair or replacement, with an estimated cost of $400 billion. This dissertation investigates the structural dynamic response, damage assessment, and retrofitting strategies for prestressed concrete (PC) bridge girders subjected to lateral impact loading.

The research comprised two main phases: (1) numerical modeling and (2) experimental testing. A validated 3D nonlinear finite element (FE) model was developed to conduct parametric studies on impact behavior, …


Thermo-Rheological And Tribological Properties Of Low- And High-Oleic Vegetable Oils As Sustainable Bio-Based Lubricants, Abiodun Saka, Tobechukwu K. Abor, Anthony C. Okafor, Monday U. Okoronkwo Jan 2025

Thermo-Rheological And Tribological Properties Of Low- And High-Oleic Vegetable Oils As Sustainable Bio-Based Lubricants, Abiodun Saka, Tobechukwu K. Abor, Anthony C. Okafor, Monday U. Okoronkwo

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Vegetable oil-based lubricants have attracted increased research attention in recent decades as sustainable alternatives to conventional petroleum-based lubricants in metal machining. However, more studies are required to fully elucidate the thermo-rheological and tribological properties. This study presents an investigation of the thermo-rheological and tribological properties of different vegetable oils, including low- and high-oleic soybean oil, high-oleic sunflower, safflower, and canola oils. The lubricity, and evolution of viscosity and thermodynamic properties as a function of temperature were investigated to obtain important parameters including the viscosity index, flow behavior index, flow activation energy, specific heat capacity, thermal conductivity, coefficient of friction, contact …


Gfrp Reinforced Bridge Barriers: Experiment Testing, Manish Kumar Gadhe Jan 2025

Gfrp Reinforced Bridge Barriers: Experiment Testing, Manish Kumar Gadhe

Masters Theses

This study focused on evaluating the performance of concrete bridge barriers reinforced with Glass Fiber Reinforced Polymer (GFRP) compared to those reinforced with conventional mild steel. Four full-scale barriers were constructed, three using GFRP bars as the reinforcement and one with mild steel reinforcement. These were cast on two concrete slabs to ensure consistent support conditions. The use of GFRP aims to address durability concerns associated with steel reinforced concrete (RC), particularly corrosion of these bars in harsh environments.

To simulate real-world impact scenarios, a weighted cart was launched at each barrier using a guided sled system. Sensors, including load …


Nutrient Fate, Mass Balance, Species Selection, And Plant Management Strategies With Floating Treatment Wetlands, Carla Campbell Jan 2025

Nutrient Fate, Mass Balance, Species Selection, And Plant Management Strategies With Floating Treatment Wetlands, Carla Campbell

Doctoral Dissertations

Excess nutrients in shallow urban ponds can lead to harmful algal blooms, low dissolved oxygen, and internal phosphorus cycling. These effects can compromise municipal water supplies and cause negative impacts on fisheries and recreation. Floating treatment wetlands (FTWs) show promise to mitigate surface water nutrient pollution. However, despite recent research, many aspects of FTWs remain poorly characterized. The contribution of FTW components to nutrient removal, local species selection, and plant management strategies were the focus of this dissertation. Mesocosm experiments revealed that the combination of plants and coir fiber growth media in FTWs appeared to positively affect plant biomass gain …


Controlling Nitrogen Pickup During Induction Melting Of Ultrahigh-Strength Cr-Ni-Mo-V Steels, Kingsley T. Amatanweze, Viraj A. Athavale, Mario F. Buchely, Laura N. Bartlett, Ronald J. O'Malley, Daniel M. Field Jan 2025

Controlling Nitrogen Pickup During Induction Melting Of Ultrahigh-Strength Cr-Ni-Mo-V Steels, Kingsley T. Amatanweze, Viraj A. Athavale, Mario F. Buchely, Laura N. Bartlett, Ronald J. O'Malley, Daniel M. Field

Materials Science and Engineering Faculty Research & Creative Works

Nitrogen pickup during air induction melting can result in porosity and a loss of fracture toughness in ultrahigh-strength quenched and tempered steel castings. Nitrogen atoms are easily adsorbed into liquid steel upon exposure to the air, and argon shrouding alone has limited effectiveness. Previous studies have shown that proper charge sequencing and maintaining a high amount of dissolved oxygen in the melt prior to tapping and deoxidation can limit nitrogen pickup in the melt. In the current study, the effect of melt practice and charging procedure on nitrogen pickup was studied as a function of hold time in a series …