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Investigating rebar corrosion of cement mortar and concrete with fly ash and inhibitor based on experimental and numerical tests
No full textThe corrosion of reinforcements in concrete is one of the major reasons for structure failure. This paper aims to evaluate the combined effect of fly ash and inhibitors on rebar corrosion through experimental test and numerical simulation. Different mortar samples containing ordinary Portland cement (OPC), class F fly ash (FA), and Sodium nitrite (SN) are prepared and tested. Similarly, concrete samples were prepared with OPC and FA to compare mortar results. The water-absorption percentage, rapid chloride permeability, compressive strength, and splitting tensile strength of presented mortar or concrete groups are measured to obtain the transporting and mechanical properties. The impressed current (IC) accelerated corrosion test is then performed to induce the corrosion of embedded rebar. At different corrosion durations, the corrosion potential (Ecorr) and linear polarization resistance (Rp), rebar pull-out strength (τp), and steel mass loss of retrieved rebar are measured to reveal the corrosion development process. Result shows that the theoretical calculated steel mass loss (Faraday\u27s law) at early stage is higher than the gravimetric-measured values, which can be explained by low impressed current efficiency at early age due to the protection of passive layer. FA lowers the corrosion rate by reducing the chloride penetration rate and forming a denser pore structure. SN slightly increases the chloride permeability but still postpones the corrosion development due to the increased chloride concentration threshold and delayed disruption of passive layer. Numerical simulation depicts the first crack initiation and crack development associated with rust accumulation and rebar pull-out strength reduction in the crack. Overall, the findings of this research enhance the understanding of reinforcement corrosion and its detrimental effect on reinforced-concrete mechanical strength changes with corrosion process
Machine Learning and Analytical Approaches to Predict the Direct Aqueous Mineral Carbonation Efficiency of Olivine-Rich Rocks
No full textDirect aqueous ex situ mineral carbonation of CO2-reactive silicate minerals involves the reaction of silicate minerals with carbon dioxide (CO2) to form stable carbonate minerals. Previous studies have shown that the efficiency of mineral carbonation depends on both process variables and feed mineralogy. However, modeling tools for predicting carbonation efficiency remain limited. In this study, two categories of models were developed to predict mineral carbonation efficiency and CO2uptake. These two approaches include (a) an analytical model based on a first-order reaction and (b) six data-based machine learning (ML) models. Olivine-rich rocks were used as the feed materials, and both the carbonation efficiency and the CO2uptake were determined using a direct mineral carbonation protocol. The experimental results were compared with predictions from both analytical and ML models. The analytical model showed fair agreement with the experimental data. In contrast, the ML models demonstrated superior predictive performance, provided that a sufficient data set is available for training. Accuracy further improved when multiple models were integrated into an ensemble, yielding a root mean squared error value of 7.72. Feature importance analysis from ML models identified key processes and input variables influencing carbonation efficiency. This work demonstrates the utility of both analytical and ML models for predicting mineral carbonation efficiency and highlights the relative importance of process variables in the direct ex situ mineral carbonation
Enhancing winter climate simulations of the Great Lakes: insights from a new coupled lake–ice–atmosphere (CLIAv1) system on the importance of integrating 3D hydrodynamics with a regional climate model
No full textThe Laurentian Great Lakes significantly influence the climate of the Midwest and Northeast United States due to their vast thermal inertia, moisture source potential, and complex heat and moisture flux dynamics. This study presents a newly developed coupled lake–ice–atmosphere (CLIAv1) modeling system for the Great Lakes by coupling the National Aeronautics and Space Administration (NASA) Unified Weather Research and Forecasting (NU-WRF) regional climate model (RCM) with the three-dimensional (3D) Finite Volume Community Ocean Model (FVCOM) and investigates the impact of coupled dynamics on simulations of the Great Lakes’ winter climate. By integrating 3D lake hydrodynamics, CLIAv1 demonstrates superior performance in reproducing observed lake surface temperatures (LSTs), ice cover distribution, and the vertical thermal structure of the Great Lakes compared to the NU-WRF model coupled with the default 1D Lake Ice Snow and Sediment Simulator (LISSS). CLIAv1 also enhances the simulation of over-lake atmospheric conditions, including air temperature, wind speed, and sensible and latent heat fluxes, underscoring the importance of resolving complex lake dynamics for reliable regional Earth system projections. More importantly, the key contribution of this study is the identification of critical physical processes that influence lake thermal structure and ice cover – processes that are missed by 1D lake models but effectively resolved by 3D lake models. Through process-oriented numerical experiments, we identify key 3D hydrodynamic processes – ice transport, heat advection, and shear production in turbulence – that explain the superiority of 3D lake models to 1D lake models, particularly in cold season performance and lake–atmosphere interactions. Critically, all three of these processes are dynamically linked to water currents – spatially and temporally evolving flow fields that are structurally absent in 1D models. This study aims to advance our understanding of the physical mechanisms that underlie the fundamental differences between 3D and 1D lake models in simulating key hydrodynamic processes during the winter season, and it offers generalized insights that are not constrained by specific model configurations
Effect of Aging Duration on the Microstructure and Corrosion Characteristics of 17-4 PH Stainless Steel
Get PDFHeat treatment plays a critical role in inducing key microstructural changes necessary to enhance corrosion resistance of 17-4 PH stainless steel (SS). During the process, precipitates form within the metal matrix, contributing to the strength of the martensitic steel. Inconsistencies in the literature concerning the response of 17-4PH SS to heat treatment have been noted. Therefore, this study examines the impact of aging duration on microstructural characteristics, microhardness, and corrosion resistance of material. The solution heat-treatment process consisted of heating the material to 1040 °C for one hour and rapid cooling in water. Subsequently, aging treatment was carried out at 480 °C for varying durations of 1 hour, 4 hours, 8 hours, and 32 hours. Corrosion rates were measured through electrochemical tests using Tafel extrapolation method in a 3.5 wt.% NaCl solution. The findings indicated that aging durations had a significant effect on corrosion resistance, detailed microstructural analysis helped correlate corrosion behaviour with phase changes and precipitation formation. This study offers valuable insights for optimizing heat treatment processes to improve the durability and performance of 17-4PH SS in NaCl corrosion medium
Sensing of lung cancer biomarkers using titanium carbide (TiC) MXenes
No full textRecent studies have shown that titanium carbide MXenes are promising 2D materials for sensing volatile organic compounds (VOCs) in human breath. While pristine titanium carbide MXenes exhibit, in general, metallic characteristics, functionalization modifies their electronic properties. In this study, a TiC monolayer functionalized with oxygen (O), a hydroxyl group (OH), sulfur (S), and fluorine (F) is investigated for its sensing characteristics for various VOCs, namely aniline (CHN), ethylbenzene (CH), 4-methyloctane (CH), and undecane (CH). The results based on van der Waals density functional theory indicate that most VOCs undergo chemisorption on the functionalized monolayers, except in the case of CHN and CH on TiCF. The calculations of electrostatic potential and Bader charge analysis affirm this, aniline acts as an electron donor, primarily attributed to the electron-donating nature of its N atom, whereas other molecules act as electron acceptors in the adsorbed complexes. The calculated current-voltage characteristics show the high sensitivity of aniline when interacting with the OH-functionalized TiC monolayer, compared to other complexes. This may be due to the low work function of the OH-functionalized monolayer, together with the donor nature of aniline. The insights gained from this study are expected to contribute to the future development of biomarkers with targeted VOC selectivity through the appropriate functionalization of MXenes
Aging the Imprint: Enhanced Performance of a Silver Prussian Blue Analogue-MIP Electrochemical Sensor for Sulfamethoxazole Detection in Milk
No full textAntibiotic residues such as sulfamethoxazole (SMX) in milk pose significant public health risks and contribute to the growing threat of antimicrobial resistance. This work presents a simple, low-cost electrochemical sensor based on a silver Prussian Blue analogue (Ag-PBA) and molecularly imprinted polymer (MIP) for sensitive and selective SMX detection in milk. Silver nanostructures were electrodeposited and modified into Ag-PBA, followed by electropolymerization of a template-monomer solution that had been preincubated for three months to promote stable complex formation onto screen-printed carbon electrodes. This extended incubation strategy, not previously reported for MIP systems, yielded higher sensitivity to SMX than a fresh solution. The Ag-PBA/MIP sensor exhibited a linear detection range from 0.1 to 10 μM, covering the European Union\u27s maximum residue limit of 0.4 μM for SMX in milk. The sensor demonstrated good selectivity against structurally similar sulfonamides and other antibiotic residues found in milk. Milk preparation methods were optimized to enhance SMX oxidation, and analyte loss during sample treatment was assessed by comparing samples spiked with SMX before and after preparation
Study of the IC 443 Region with the HAWC Observatory
Get PDFSupernova remnants are one potential source class considered a PeVatron (i.e., capable of accelerating cosmic rays above PeV energies). The shock fronts produced after the explosion of the supernova are ideal regions for particle acceleration. IC 443 is a supernova remnant that has been studied extensively at different wavelengths. Using 2966 days of gamma-ray data from the High Altitude Water Cherenkov (HAWC) observatory, we study the emission of IC 443 with the objective of finding signatures of cosmic-ray acceleration at the PeV scale. Using a maximum likelihood method, we find a point source located at (α=94.°42, δ=22.°35) that we associate with IC 443. The measured spectrum is a simple power law with an index of −3.14±0.18, which is consistent with previous TeV observations. Although we cannot confirm that IC 443 is a hadronic PeVatron, we do not find any sign that the spectrum has a cutoff at tens of TeV energies, with the spectrum extending to ∼30 TeV. Furthermore, we also find a new extended component in the region whose emission is described by a simple power law with an index of −2.49±0.08 and which we call HAWC J0615+2213. While we show evidence that this new source might be a new TeV halo, we defer a detailed analysis of this new source to another publication
Alberta, MI (NRHP Initial Submission)
Get PDFThis is the full initial submission for Alberta Village (the Ford Center) to be listed on the National Register of Historic Places. This application was submitted to the State Historic Preservation Office in August 2025. This application document was developed to support the consideration of Alberta Village (the Ford Center) as a historic site.
From the summary paragraph of the application:
The Village of Alberta in the Upper Peninsula of Michigan was originally built as a Ford company town and lumber mill in 1935. In 1954 the village and approx. 1,800 acres of surrounding timber lands were donated to Michigan Technological University and what is now known as The Ford Forestry Center (also commonly referred to as the Alberta Campus or simply Alberta) is a three square mile property operated by MTU’s College of Forest Resources and Environmental Science (CFRES). Built in 1935 as a model village that both produced lumber but also exemplified a way of living in Depression America, Alberta has, in multiple ways, continued Henry Ford’s visions of a self-sufficient “village industry” that contributed to the larger industrial production of the company. In addition, as a “forest community” and “sustained yield” timber management site, it continues to provide student experiences and sustainable practices (including some residential time spent there). With 27 extant contributing buildings, 23 built before the transfer in 1954 and 4 in the initial phase of Michigan Tech ownership (19541968), the built landscape of both the village and the surrounding woods, which remain uncleared and isolated in the northern forests of Michigan without any significant development in the surrounding area provide historical physical integrity, the location’s feel, and sense of place
Per- and Polyfluoroalkyl Substances (PFAS) in Urban Stormwater Runoff: Insights from a Roadside Rain Garden
Get PDFUrban stormwater runoff is increasingly recognized as a critical but underexplored pathway for per- and polyfluoroalkyl substances (PFAS) to enter aquatic environments. This work investigated the occurrence and behavior of 40 PFAS compounds in stormwater runoff entering a roadside rain garden in Secaucus, New Jersey, during six storm events between August 2023 and July 2024. Total PFAS concentrations (Σ40 PFAS) ranged from 1437 to 1615 ng/L, with perfluorobutane sulfonate (PFBS, 239–303 ng/L) and perfluorohexanoic acid (PFHxA, 115–137 ng/L) consistently emerging as dominant species. Perfluorocarboxylic acids (PFCAs) and perfluorosulfonic acids (PFSAs) together accounted for over 70% of the total PFAS mass. Despite its intended role in water quality improvement, the rain garden showed no measurable change in PFAS concentrations (differences of only 0.03–1.10%). These findings highlight the persistence and mobility of PFAS in urban stormwater runoff and the limited efficacy of conventional green infrastructure in mitigating PFAS contamination. Furthermore, they underscore the ineffectiveness of conventional green infrastructure for PFAS mitigation and the urgent need for advanced treatment technologies integrated into urban water management frameworks
3D-printed porous ceramic liners for high-temperature noise control applications
No full textCeramics and ceramic matrix composites offer the potential for the development of high-temperature acoustic liners that could be integrated into aircraft engines in regions where traditional liners fail. Building on previous work using clay extrusion to produce porous ceramic structures, we now explore a vat photopolymerization method capable of creating more precise geometries and finer microstructural details. In this approach, a commercial ceramic printer employing digital light photopolymerization is used to fabricate porous architectures. The resulting “green” parts are fired and sintered in a controlled atmosphere to achieve the final ceramic composition. Acoustic testing is then conducted under normal incidence using a two-microphone impedance tube, allowing us to analyze how the porous architecture influences sound absorption behavior. The findings highlight the feasibility of vat photopolymerization for producing high-temperature ceramic acoustic liners with enhanced design freedom, thereby broadening the potential for noise reduction solutions in aircraft engine environments