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Missouri University of Science and Technology

2024

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Full-Text Articles in Engineering

Hafnium Oxide Coating To Improve The Oxidation Behavior Of Zirconium Diboride, Jan E. Förster, William G. Fahrenholtz, Gregory E. Hilmas, Ravisankar Naraparaju Dec 2024

Hafnium Oxide Coating To Improve The Oxidation Behavior Of Zirconium Diboride, Jan E. Förster, William G. Fahrenholtz, Gregory E. Hilmas, Ravisankar Naraparaju

Materials Science and Engineering Faculty Research & Creative Works

Hafnium dioxide (HfO2) coatings were successfully deposited on zirconium diboride (ZrB2) using reactive magnetron sputtering. After the oxidation at 1500°C or 1600°C, the mutual dissolution of HfO2 and thermally grown ZrO2 was observed which has resulted in the formation of a mixed oxide zone. As the enrichment of the mixed oxide zone by ZrO2 progresses, monoclinic/tetragonal phase transition temperature of ∼1790°C for nominally pure HfO2 moves towards ∼1500 °C. Finally, the inevitable phase transition from monoclinic to tetragonal structure results in the development of cracks, pores, and gaps within the mixed oxide …


Enhancing Frp-Concrete Interface Bearing Capacity Prediction With Explainable Machine Learning: A Feature Engineering Approach And Shap Analysis, Yanping Zhu, Woubishet Zewdu Taffese, Genda Chen Nov 2024

Enhancing Frp-Concrete Interface Bearing Capacity Prediction With Explainable Machine Learning: A Feature Engineering Approach And Shap Analysis, Yanping Zhu, Woubishet Zewdu Taffese, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study introduces a novel approach to predict the shear bearing capacity of FRP-concrete interfaces using explainable machine learning. Eight algorithms are employed: three standalone models (Artificial Neural Network, Support Vector Regression, and Decision Tree) and five ensemble learning models (Bagging, Random Forest, Adaptive Boosting, Gradient Boosting, and Extreme Gradient Boosting). Four scenarios with varying input features, including engineered features inspired by mechanics-based bearing capacity equations, are examined. Notably, the inclusion of engineered features such as the stiffness of the FRP strip (Kf) significantly enhanced prediction accuracy and efficiency, although the width correction coefficient (bf/bc) did not yield significant benefits, …


Human-Centered Approach For Resilience Assessment Of Healthcare Networks Subjected To Sequential Earthquakes, Emad Hassan, Hussam Mahmoud Nov 2024

Human-Centered Approach For Resilience Assessment Of Healthcare Networks Subjected To Sequential Earthquakes, Emad Hassan, Hussam Mahmoud

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Healthcare services are critical for community resilience and stability as their role after disastrous events is indispensable to reducing casualties and returning the community to normalcy. Sequential mainshock-aftershock events can damage hospital components, reduce utility availability, and cause multiple patient surges. No studies have been conducted to evaluate the impact of mainshock-aftershock events on healthcare resilience. Accordingly, here we investigate the impact of multiple earthquakes on the healthcare network in Shelby County, Tennessee, and determine the optimal resources needed to enhance its functionality. The functionality is estimated by combining functionality quantity and quality terms. The quantity is calculated based on …


Circular Economy Integration In Leed: A Decade Of Materials And Resources Credit Achievement Patterns, Radwa Eissa, Islam H. El-Adaway Nov 2024

Circular Economy Integration In Leed: A Decade Of Materials And Resources Credit Achievement Patterns, Radwa Eissa, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Previous studies consistently label the Materials and Resources (MR) credit category of the Leadership in Energy and Environmental Design (LEED) as the least attainable, despite its critical role in transitioning to a circular economy (CE). To this end, a long-standing gap exists in understanding the MR credit achievement, especially in LEED v4, which has been in use for nearly over a decade. This paper evaluates the level of CE integration in LEED v4 across 971 US-based certified projects. The study comprehensively analyzed the projects achievement patterns of the five MR credits: Building Life Cycle Impact Reduction (C1), Environmental Product Declarations …


Synthesis And Properties Of (Hf,Mo,Ti,W,Zr)B2–(Hf,Mo,Ti,W,Zr)C Dual Phase Ceramics, S. Filipović, S. M. Smith, G. Hilmas, W. Fahrenholtz, N. Obradović, S. Curtarolo Nov 2024

Synthesis And Properties Of (Hf,Mo,Ti,W,Zr)B2–(Hf,Mo,Ti,W,Zr)C Dual Phase Ceramics, S. Filipović, S. M. Smith, G. Hilmas, W. Fahrenholtz, N. Obradović, S. Curtarolo

Materials Science and Engineering Faculty Research & Creative Works

Dense, dual phase (Hf,Mo,Ti,W,Zr)B2–(Hf,Mo,Ti,W,Zr)C ceramics were synthesized with varying contents of Mo and W. The final (Hf0.317Mo0.025Ti0.317W0.025Zr0.317)C–(Hf0.317Mo0.025Ti0.317W0.025Zr0.317)B2 was a nominally pure, dual phase ceramic, while compositions with higher amounts of Mo and W contained multiple phases. The final microstructures had submicron grains due to pinning effects. Vickers hardness values were up to 48.6 ± 2.2 GPa for an applied load of 0.49 N for the ceramic with optimized composition and densification. The solubility limits for Mo and …


Topography Of The 410 And 660 Km Discontinuities Beneath The Tibetan Plateau And Adjacent Areas, Zexin Miao, Stephen S. Gao, Muchen Sun, Kelly H. Liu Oct 2024

Topography Of The 410 And 660 Km Discontinuities Beneath The Tibetan Plateau And Adjacent Areas, Zexin Miao, Stephen S. Gao, Muchen Sun, Kelly H. Liu

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

To investigate the three-dimensional spatial distribution of subducted oceanic slab segments and their consequential effect on the thermal and hydrous composition of the mantle transition zone (MTZ) beneath the entire Tibetan Plateau, we conducted a comprehensive analysis of approximately 655,000 P-to-s receiver functions (RFs), obtained from 735 broadband seismic stations. These RFs were utilized to delineate the 410 km (d410) and 660 km (d660) seismic discontinuities, which represent the upper and lower boundaries of the MTZ, respectively. The RFs were grouped within circular bins with a radius of 1 degree and stacked to image the discontinuities. The mean apparent depths …


Spatial And Temporal Variations Of Seismic Azimuthal Anisotropy Following The 2019 Ridgecrest Earthquake Sequence In Southern California, Yan Jia, Stephen S. Gao, Kelly H. Liu Oct 2024

Spatial And Temporal Variations Of Seismic Azimuthal Anisotropy Following The 2019 Ridgecrest Earthquake Sequence In Southern California, Yan Jia, Stephen S. Gao, Kelly H. Liu

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

To investigate the spatial and temporal variations of seismic azimuthal anisotropy in the vicinity of the conjugate fault network activated by the 4 July 2019 (UTC) M6.4 foreshock and the 6 July 2019 M7.1 mainshock in Ridgecrest, California, a total of 1,470 shear wave splitting measurements were obtained from local events recorded by five seismic stations over the period of July 2019 to January 2020. The results suggest a strong asymmetry in anisotropy forming mechanisms across the NW-SE striking Eastern Little Lake Fault, which is the main fault of the area. In the area located to the northeast of the …


Pozzolanic Reactivity Of Carbonated High-Calcium Fly Ash: A Mechanism Study, Gao Deng, Nannan Zhang, Wenyu Liao, Hongyan Ma, Yongjia He, Linnu Lu, Lingyu Chi Oct 2024

Pozzolanic Reactivity Of Carbonated High-Calcium Fly Ash: A Mechanism Study, Gao Deng, Nannan Zhang, Wenyu Liao, Hongyan Ma, Yongjia He, Linnu Lu, Lingyu Chi

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This research investigates the impact of accelerated carbonation treatment on the pozzolanic reactivity of high-calcium fly ash (HFA) by monitoring the reaction heat of HFA/carbonated HFA (CFA)-calcium hydroxide (CH) blends and elucidates the underlying factors influencing the pozzolanic reactivity. The results indicate that in HFA/CFA-CH blends, CFA exhibits a comparable pozzolanic reactivity to that of HFA. This is attributed to the carbonation products accelerating the formation of MonoCarb aluminate (main) and C-S-H, compensating for the reduced heat resulting from the diminished highly reactive components after the carbonation treatment. Additionally, the increased surface area due to carbonation treatment is favorable for …


Performance Of Project Delivery Methods For Us Airport Projects: A Holistic Quantitative Risk-Based Assessment Through Perceptions Of Associated Industry Experts, Ramy Khalef, Islam H. El-Adaway Oct 2024

Performance Of Project Delivery Methods For Us Airport Projects: A Holistic Quantitative Risk-Based Assessment Through Perceptions Of Associated Industry Experts, Ramy Khalef, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The aviation sector received an underperforming D+ score, indicating its deteriorating qualities in comparison with the overall US infrastructure. In response, US governmental bodies issued investment bills that target the improvement of the nation's airport system. Airport projects are still being implemented through design-bid-build (DBB), which is notorious for its ineffective risk shift, low contractor input, and poor cost and schedule performance. Studies show that design-build (DB) possesses prospective cost and schedule benefits. Despite this, there is still reluctance toward DB's usage in airport projects. Moreover, current studies lack in offering frameworks that assist airport practitioners in guiding stakeholders toward …


Carboxymethyl Cellulose-Based Preformed Particle Gels For Water Management In Oil And Gas Reservoirs, Ahmed Ben Ali, Ahmed Hamza, Abdulaziz A. Almakimi, Mohammed Saad, Ibnelwaleed A. Hussein, Baojun Bai Oct 2024

Carboxymethyl Cellulose-Based Preformed Particle Gels For Water Management In Oil And Gas Reservoirs, Ahmed Ben Ali, Ahmed Hamza, Abdulaziz A. Almakimi, Mohammed Saad, Ibnelwaleed A. Hussein, Baojun Bai

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Carboxymethyl cellulose (CMC) based materials have been proposed as preformed particle gels (PPGs) for reducing excessive water production in oil and gas reservoirs. Multi-sized dry particles ranging between 100 and 1180 μm have been synthesized using microwave-assisted grafting copolymerization of CMC and acrylamide (AM)/n,n''-methylene-bisacrylamide (MBA). FTIR and SEM confirmed CMC crosslinked polyacrylamide's chemical structure and morphology (CMC/CPAM). Thermo-gravimetric analysis has demonstrated the thermal stability of dry PPGs up to 309 °C. CMC/CPAM showed slightly high absorbency in brine 2 (TDS = 67.3 g/L) compared to brine 1 (TDS = 33.65 g/L), 1% NaCl, and deionized water, with swelling ratios (SR) …


Impact Of Tib2 Source On The Microstructure And Properties Of Tib2–Sic–B4c Ceramics, Steven M. Smith, Suzana Filipovic, William G. Fahrenholtz, Gregory E. Hilmas, Carlo Baldisserri, Laura Silvestroni Oct 2024

Impact Of Tib2 Source On The Microstructure And Properties Of Tib2–Sic–B4c Ceramics, Steven M. Smith, Suzana Filipovic, William G. Fahrenholtz, Gregory E. Hilmas, Carlo Baldisserri, Laura Silvestroni

Materials Science and Engineering Faculty Research & Creative Works

To date, the thermal and electrical properties of three-phase ceramics containing a boride phase, silicon carbide, and boron carbide have not been studied in detail. Further, the effect of the source of the boride powder has also not been investigated. This study produced three-phase ceramics containing titanium diboride, silicon carbide, and boron carbide using three different TiB2 sources: commercial powder, TiB2 synthesized by boro/carbothermal reduction, or (Ti,Cr)B2 synthesized by boro/carbothermal reduction to address the effect of the TiB2 source. Ceramics containing synthesized TiB2 or (Ti,Cr)B2 reached >99% relative density, while the ceramic produced from …


Common Ground Newsletter Fall 2024, Missouri University Of Science And Technology Sep 2024

Common Ground Newsletter Fall 2024, Missouri University Of Science And Technology

Common Ground

-Internship Experiences

-Lady Softball Trio

-Summer Camps

-Design Teams


Environmental Engineering 3.0: Faced With Planetary Problems, Solutions Must Scale-Up Caring, Daniel B. Oerther, Sarah Oerther, Linda A. Mccauley Sep 2024

Environmental Engineering 3.0: Faced With Planetary Problems, Solutions Must Scale-Up Caring, Daniel B. Oerther, Sarah Oerther, Linda A. Mccauley

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Forum papers are thought-provoking opinion pieces or essays founded in fact, sometimes containing speculation, on a civil engineering topic of general interest and relevance to the readership of the journal. The views expressed in this Forum article do not necessarily reflect the views of ASCE or the Editorial Board of the journal.


Quantitative Assessment Of The Architect's Role Under Us Standard Construction Contracts: A Graph Theory Approach, Mariam Elazhary, Ahmed Shiha, Islam H. El-Adaway, Sammi Young Sep 2024

Quantitative Assessment Of The Architect's Role Under Us Standard Construction Contracts: A Graph Theory Approach, Mariam Elazhary, Ahmed Shiha, Islam H. El-Adaway, Sammi Young

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Evaluating the Architect's Role in Construction Contracts is Vital for Improving the Contractual Relationship and Preventing Disputes. Standard Contracts Define the Architect as an Owner's Agent And/or a Contract Administrator. Studies Often Use Qualitative and Subjective Evaluations to Analyze the Architect's Role. However, there is a Lack of Quantitative Measures that Objectively Evaluate the Architect's Capacities in Construction Contracts. This Paper Fills This Knowledge Gap. This Study Proposes a Quantitative Graph Theory-Based Approach to Analyze the Architect's Roles under Three Standard Forms of Construction Contracts in the US: (1) Extracting and Classifying Party Interactions; (2) Modeling the Interactions using Network …


The Role Of The Metaverse In Transforming The Management Skill Set Of Construction Practitioners, Ali M. Saad, Islam H. El-Adaway Sep 2024

The Role Of The Metaverse In Transforming The Management Skill Set Of Construction Practitioners, Ali M. Saad, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.


Reduction In Scc Form Pressure Through In-Situ Co2 Mineralization, Sean Monkman, Soo Duck Hwang, Kamal Khayat Sep 2024

Reduction In Scc Form Pressure Through In-Situ Co2 Mineralization, Sean Monkman, Soo Duck Hwang, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

One challenge of using self-consolidating concrete (SCC) for cast-in-place structural applications is that the rheological properties of the concrete (low yield stress and low plastic viscosity) can lead to increased lateral pressure exerted on the formwork. High structural build up and thixotropy can reduce the lateral pressure, thereby allowing for simpler formwork and faster construction. The addition of CO2 to SCC, in proportions from 0.063 % to 0.250 %, by weight of cement, was investigated as a rheology modifier. The CO2 served to increase the plastic viscosity with little impact on the dynamic yield stress up to a …


Price Escalation In Construction Projects: Examining National And International Contracts, Bahaa Chammout, Islam H. El-Adaway, Mohammad Abdul Nabi, Rayan H. Assaad Sep 2024

Price Escalation In Construction Projects: Examining National And International Contracts, Bahaa Chammout, Islam H. El-Adaway, Mohammad Abdul Nabi, Rayan H. Assaad

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The construction industry has witnessed unprecedented disruptions in the supply chain (SC) over the past four years due to the consecutive impacts of the 2018 steel and aluminum tariffs, the COVID-19 pandemic, and the Russian-Ukrainian war. SC disruptions have been linked to price escalations, the management of which varies across different construction contracts. Thus, there is a timely need to understand the contractual implications of price escalation clauses. This article fulfills this research requirement by following an interdependent research methodology. First, the authors analyzed and compared price escalation provisions under various US-based, international, and UK-based standard design-bid-build contracts. Second, the …


Transfer Learning With Spinally Shared Layers, H. M.Dipu Kabir, Subrota Kumar Mondal, Syed Bahauddin Alam, U. Rajendra Acharya Sep 2024

Transfer Learning With Spinally Shared Layers, H. M.Dipu Kabir, Subrota Kumar Mondal, Syed Bahauddin Alam, U. Rajendra Acharya

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Transfer-learned models have achieved promising performance in numerous fields. However, high-performing transfer-learned models contain a large number of parameters. In this paper, we propose a transfer learning approach with parameter reduction and potential high performance. Although the high performance depends on the nature of the dataset, we ensure the parameter reduction. In the proposed SpinalNet shared parameters, all intermediate-split-incoming parameters except the first-intermediate-split contain a shared value. Therefore, the SpinalNet shared parameters network contains three parameter groups: (1) first input-split to intermediate-split parameters, (2) shared intermediate-split-incoming parameters, and (3) intermediate-split-to-output-split parameters. The total number of parameters becomes lower than the …


Forecasting Construction Material Prices Using Macroeconomic Indicators Of Trading Partners, Ahmed Shiha, Islam H. El-Adaway Sep 2024

Forecasting Construction Material Prices Using Macroeconomic Indicators Of Trading Partners, Ahmed Shiha, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Supply chain instabilities and inflated material prices have had a disruptive impact on cost estimating of construction projects. While several research efforts used national macroeconomic indicators to forecast the prices of domestically produced construction materials, none of the existing studies investigated whether the lagged macroeconomic indicators of the main trading partners could enhance the predictability of the prices of cement, steel, and lumber in the US construction sector. This paper fills this knowledge gap. The authors adopted a multi-step methodology that included: (1) collecting data on the target variables and the candidate leading indicators; (2) identifying the structural breaks in …


Genetically Linked Litho- And Organo-Facies In Meter-Scale Cycles Of Lacustrine Deposits Within The Permian Lucaogou Formation In The Bogda Mountains, Northwest China: Implications For Paleoenvironment And Organic Matter Origin, Xin Zhan, Wan Yang, Qiao Feng, Zhao Wen Zhan, Sile Wei, Yujiao Zhang, Hongquan Kang, Tao Cheng, Hongyan Zhao, Wenjie Cai Sep 2024

Genetically Linked Litho- And Organo-Facies In Meter-Scale Cycles Of Lacustrine Deposits Within The Permian Lucaogou Formation In The Bogda Mountains, Northwest China: Implications For Paleoenvironment And Organic Matter Origin, Xin Zhan, Wan Yang, Qiao Feng, Zhao Wen Zhan, Sile Wei, Yujiao Zhang, Hongquan Kang, Tao Cheng, Hongyan Zhao, Wenjie Cai

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

A close correlation between lithofacies and organofacies in meter-scale high-order cycles composed of lacustrine sediments enables comparison and refinement of lithofacies-defined cyclostratigraphy. Four lithofacies and four organofacies have been identified in fluctuating profundal high-order cycles in the lower-Permian Lucaogou Formation, southern Bogda Mountains, NW China. The four lithofacies include interbedded and interlaminated coarse siltstone and very fine sandstone, black shale, wackestone and dolostone, and calcareous and dolomitic shales. Four distinctive organofacies have been identified, on the basis of geochemical composition of organic matter and specific biomarker proxies related to organic matter types, rather than to depositional conditions and thermal maturity. …


Response Of ¹¹B Enriched Zrb2 Ultra-High Temperature Ceramic To Neutron Irradiation At Elevated Temperatures, Yan Ru Lin, Takaaki Koyanagi, David J. Sprouster, Christian M. Petrie, William Fahrenholtz, Greg Hilmas, Yutai Katoh Sep 2024

Response Of ¹¹B Enriched Zrb2 Ultra-High Temperature Ceramic To Neutron Irradiation At Elevated Temperatures, Yan Ru Lin, Takaaki Koyanagi, David J. Sprouster, Christian M. Petrie, William Fahrenholtz, Greg Hilmas, Yutai Katoh

Materials Science and Engineering Faculty Research & Creative Works

ZrB2, an ultra-high temperature ceramic (UHTC) is being considered for use in fusion reactor first-wall structures, yet its response to irradiation remains poorly understood. This study employed scanning/transmission electron microscopy (S/TEM), synchrotron X-ray diffraction (XRD), finite element calculations, and thermal property measurements to thoroughly investigate the neutron-irradiation effects on 11B-enriched ZrB2. Neutron irradiations were conducted at 220 °C and 620 °C, with a neutron fluence of 2.2 x 1025 neutron/m2 (energy > 0.1 MeV), resulting in 3.9 dpa and 4200 appm He. The study revealed the unusual prevalence of prism loops and a > c anisotropic lattice …


Consistent Intraocular Pressure Reduction By Solid Drug Nanoparticles In Fixed Combinations For Glaucoma Therapy, Da Huang, Pedro Norat, Lin Qi, Anna Chernatynskaya, James D. Cole, Vimalin Jeyalatha Mani, Lei Xu, Xiaorong Liu, Hu Yang Aug 2024

Consistent Intraocular Pressure Reduction By Solid Drug Nanoparticles In Fixed Combinations For Glaucoma Therapy, Da Huang, Pedro Norat, Lin Qi, Anna Chernatynskaya, James D. Cole, Vimalin Jeyalatha Mani, Lei Xu, Xiaorong Liu, Hu Yang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Efficient topical drug delivery remains a significant challenge in glaucoma management. Although nanoparticle formulations offer considerable promise, their complex preparation processes, co-delivery issues, and batch consistency have hindered their potential. A scalable fabrication strategy is developed here for preparing solid drug nanoparticles (SDNs) with enhanced drug delivery efficiency. Utilizing hydrophobic antiglaucoma drugs brimonidine (BM) and betaxolol (BX), uniform fixed combination BM/BX SDNs are fabricated through a continuous process, improving batch-to-batch consistency for combined glaucoma treatment. With trehalose being used as a lyoprotectant, BM/BX SDNs can be stored as dry powder and easily reconstituted in phosphate buffered saline. Importantly, reconstituted BM/BX …


Molecular Dynamics Simulation Insights Into Rejuvenating Aged Asphalt With Waste Soybean Oil And Polymers, Ke Shi, Feng Ma, Zhen Fu, Jenny Liu, Ruimeng Song, Dongdong Yuan, Yujie Tang Aug 2024

Molecular Dynamics Simulation Insights Into Rejuvenating Aged Asphalt With Waste Soybean Oil And Polymers, Ke Shi, Feng Ma, Zhen Fu, Jenny Liu, Ruimeng Song, Dongdong Yuan, Yujie Tang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study utilized molecular dynamics simulations to assess the rejuvenation of aged asphalt (AA) with waste soybean oil (WSO) and functionalized SBS polymers, focusing on: 1) constructing and validating models for virgin asphalt (VA), AA, and composite rejuvenated asphalt with WSO and polymers; 2) analyzing diffusion effects and binding abilities in these rejuvenated models; 3) evaluating interface binding and diffusion behaviors in composite rejuvenated models. The addition of functionalized SBS molecules and WSO improved the diffusion rates of various components within these models. Specifically, functionalized linear-SBS (LSBS) molecules demonstrated superior diffusion performance compared to star-SBS (SSBS) molecules. Incorporating WSO and …


Investigation Of The Cohesive Behavior Of Water-Intervened Rejuvenated Sbs-Modified Bitumen, Ke Shi, Feng Ma, Zhen Fu, Jenny Liu, Ruimeng Song, Dongdong Yuan, Yujie Tang Aug 2024

Investigation Of The Cohesive Behavior Of Water-Intervened Rejuvenated Sbs-Modified Bitumen, Ke Shi, Feng Ma, Zhen Fu, Jenny Liu, Ruimeng Song, Dongdong Yuan, Yujie Tang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

When water interacts with bitumen, the diffusion and cohesion characteristics between the components of bitumen are negatively impacted. Molecular dynamics simulations were employed to construct various bitumen models, including bitumen–bitumen (without water), water-containing single bitumen, water-containing bitumen–bitumen, and bitumen–water–bitumen models. The primary research objectives were as follows: comparing the changes in the densities of bitumen models with and without water, analyzing the interlayer cohesive energies of bitumen models interacting with water, evaluating the hydrogen bonds in water-containing bitumen models, and characterizing the diffusion behaviors of bitumen components. The results indicated that when water interacted with the bitumen, it filled internal …


Effect Of Superabsorbent Polymer On 3d Printing Characteristics As Rheology-Modified Agent, Yu Cun Gu, Kamal H. Khayat Aug 2024

Effect Of Superabsorbent Polymer On 3d Printing Characteristics As Rheology-Modified Agent, Yu Cun Gu, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study aims to investigate the effects of two superabsorbent polymer (SAP) types, S1 and S2 (with continual absorption and rapid desorption, respectively) as rheology-modified agent on 3D printing characteristics. Three base mixtures were selected with different thixotropic behaviors (i.e., mixtures with high re-flocculation (τfloc), high structuration rate (Athix), and both low τfloc and Athix, respectively). The initial mini-slump flow of 190±10 mm was secured by adjusting superplasticizer (SP) or water demand (increasing w/b by either 0.025 or 0.05). An extrudable region was determined within the range of τfloc (200-890 Pa) and Athix (15-60 Pa/min). The use of the S2 …


Coupled Effect Of Fiber Type And Reinforcement Ratio On Flexural Behavior Of Reinforced Beams Cast With Super Workable Concrete, Jingjie Wei, Le Teng, Kamal H. Khayat Aug 2024

Coupled Effect Of Fiber Type And Reinforcement Ratio On Flexural Behavior Of Reinforced Beams Cast With Super Workable Concrete, Jingjie Wei, Le Teng, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study investigated the effect of 5-dimensional hooked-end fiber (5D) on the structural performance of beams and compared its efficiency with other fibers in strengthening structural performance of reinforced concrete (RC) beams with an increase in reinforcement ratio (ρ). The potential of using fibers to reduce the longitudinal rebar based on various design criteria was investigated. The fibers included 5D, a combination of 80 % 3-dimensional hooked-end and 20 % short steel fibers (STST), and two combinations of macro synthetic fibers A and B (MSF). Experimental results indicated that, compared to non-fibrous beams, using 5D was the most efficient in …


Tectonic Implications Of Seismic Anisotropy Layering Beneath The Southern Tibetan Plateau Revealed By Integrated Shear Wave Splitting And Receiver Function Analyses, Cong Shen, Stephen S. Gao, Fansheng Kong, Kelly H. Liu Aug 2024

Tectonic Implications Of Seismic Anisotropy Layering Beneath The Southern Tibetan Plateau Revealed By Integrated Shear Wave Splitting And Receiver Function Analyses, Cong Shen, Stephen S. Gao, Fansheng Kong, Kelly H. Liu

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

To investigate continental dynamics underneath the south-central Tibetan plateau, which composes the Himalayan, Lhasa, and Qiangtang blocks, we have conducted comprehensive examinations of seismic azimuthal anisotropy in the crust using receiver functions (RFs) and crustal and mantle anisotropy using teleseismic shear wave splitting (SWS) analysis. In the Qiangtang block, the observed predominantly E-W fast orientations from RF and SWS analyses with similar magnitude are interpreted as resulting from eastward crustal flow with minor contributions from the mantle. In the Lhasa block, the crustal anisotropy is approximately N-S oriented, which is parallel to the strike of rift basins and southward crustal …


Extrudability Window And Offline Test Methods To Predict Buildability Of 3d Printing Concrete, Yu Cun Gu, Kamal H. Khayat Aug 2024

Extrudability Window And Offline Test Methods To Predict Buildability Of 3d Printing Concrete, Yu Cun Gu, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This Study Investigates the Effect of Thixotropy and Stiffness Evolution on the Extrudability and Buildability of 3D Printing Concrete. Different Types of Supplementary Cementitious Materials and Limestone Filler Were Used to Prepare Mortars with Varying Levels of Thixotropy and Early-Age Stiffness. Mixtures with Yield Stress and Flocculation (Τfloc) of 180–400 and 420–950 Pa, Respectively, Exhibited Adequate Extrudability Without Plastic Collapse. the Printing Was Completed 8–15 Min after Mixing at a Vertical Build-Up Rate of 138 Mm/min. Several Process Parameters, Including Rest Time to Secure a Penetration Resistance of 150 KPa (T150) and Penetration Resistance at Various Rest Times Were Developed …


Determination Of Binary Co2/H2 Adsorption Isotherms And Kinetics Over Porous Organic Cage Cc3 Via Zero-Length Column Technique, Jimmy D.L. Moreno, Kyle Newport, Ali A. Rownaghi, Fateme Rezaei Aug 2024

Determination Of Binary Co2/H2 Adsorption Isotherms And Kinetics Over Porous Organic Cage Cc3 Via Zero-Length Column Technique, Jimmy D.L. Moreno, Kyle Newport, Ali A. Rownaghi, Fateme Rezaei

Chemical and Biochemical Engineering Faculty Research & Creative Works

Understanding the dynamics of mixed-gas adsorption is essential for industrial-scale adsorptive separations. Also, obtaining binary adsorption isotherms is essential to gain a better understanding of adsorbate-adsorbent interactions in multicomponent gas mixtures. Porous organic cages (POCs) are highly porous, crystalline materials, with a small average pore window that make them promising candidates for separation applications. In this work, we utilized zero-length column (ZLC) technique to not only determine the kinetics of CO2/H2 separation over CC3 but also obtain the binary adsorption isotherms. The ultra crystalline diffusivities of 1.49 x 10–4 and 8.31 x 10–5 cm2 …


Design And Development Of Uio-67-Coated Pim-1-Based Composites And Demonstration Of Their Detoxification Performance, Sukanta K. Mondal, Peter O. Aina, Ali A. Rownaghi, Fateme Rezaei Aug 2024

Design And Development Of Uio-67-Coated Pim-1-Based Composites And Demonstration Of Their Detoxification Performance, Sukanta K. Mondal, Peter O. Aina, Ali A. Rownaghi, Fateme Rezaei

Chemical and Biochemical Engineering Faculty Research & Creative Works

Polymer-supported MOF composites have emerged as versatile candidates for various separation and catalytic applications. In this study, we demonstrate design and development of UiO-67-coated Ce(OH)4@PIM-1 composites via dip-coating, drop-casting, solid-phase coating, and supramolecular assembly, and assess their preparation-structure-performance relations. The catalytic performance of the composites was investigated through hydrolysis of dimethyl 4-nitrophenyl phosphate (DMNP), as a nerve agent simulant. The findings revealed that while dip-coating method was unable to achieve a thick and uniform coverage of the MOF layer on the Ce(OH)4@PIM-1, the supramolecular assembly gave rise to 16 wt.% MOF loading and the composite prepared …