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SSRN 2023年

作者： Santos, Karyne Ferreira Ribeiro, António Simões Bettencourt Silva, Eugênia Fonseca Postgraduate program in Structural Engineering and Construction - PECC Department of Civil and Environmental Engineering SG-12 Building University of Brasilia - UnB DF Brasília Brazil National Laboratory for Civil Engineering LNEC Portugal

This study introduces a novel cracking methodology used in high-strength concrete (HSC) with superabsorbent polymers (SAP) to unveil its actual self-healing potential without fibre reinforcement. Although high-strength concrete allows for more creative structural designs and reduces the amount of building materials used, it often suffers from self-desiccation, which can cause cracking issues. SAP's inclusion in HSC not only addresses the autogenous shrinkage problem but also enhances concrete's self-healing capabilities. This research focuses on the dual role of SAP in mitigating autogenous shrinkage and promoting self-healing in high-strength concrete. An innovative technique was employed to induce uniform, controlled cracks under direct tension by isolating the self-healing agent's effect. The cracking process was developed using nonlinear finite element analysis. Two SAP concentrations (0.3% and 0.6%) were tested on specimens with a consistent crack width of 200 µm. These specimens underwent daily wetting-drying cycles over four months, with evaluations at 7 and 28 days post-cracking. Self-healing effectiveness was measured through mechanical recovery and microscopic examination of crack closure. Results, as expected, revealed a modest healing level but showed the actual potential of self-healing that this kind of concrete (HSC) can be counted on, offering crucial insights into self-healing concrete's practical applications and limitations. This study demonstrates SAP's versatility and highlights another advantage of SAP in high-strength concrete. This advantage, while slight, encourages the use of SAP in concrete and advances the creation of more durable construction materials. © 2023, The Authors. All rights reserved.

关键词： Crack closure

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Unravelling biosynthesis and biodegradation potentials of microbial dark matters in hypersaline lakes

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environmental Science and Ecotechnology 2024年第4期20卷 177-188页

作者： Zhiguang Qiu Yuanyuan Zhu Qing Zhang Xuejiao Qiao Rong Mu Zheng Xu Yan Yan Fan Wang Tong Zhang Wei-Qin Zhuang Ke Yu School of Environment and Energy Peking University Shenzhen Graduate SchoolShenzhen518055China AI for Science(AI4S)-Preferred Program Peking UniversityShenzhen518055China Southern University of Sciences and Technology Yantian Hospital Shenzhen518081China Institute of Biomedicine and Biotechnology Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen518055China State Key Laboratory of Isotope Geochemistry CAS Center for Excellence in Deep Earth ScienceGuangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou510640China School of Atmospheric Sciences Sun Yat-sen UniversitySouthern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai519082China Department of Civil Engineering University of Hong Kong999077Hong KongChina Department of Civil and Environmental Engineering Faculty of EngineeringUniversity of AucklandNew Zealand

Biosynthesis and biodegradation of microorganisms critically underpin the development of biotechnology,new drugs and therapies,and environmental ***,most uncultured microbial species along with their metabolic capacities in extreme environments,remain *** we unravel the metabolic potential of microbial dark matters(MDMs)in four deep-inland hypersaline lakes in Xinjiang,*** metagenomic binning,we uncovered a rich diversity of 3030 metagenomeassembled genomes(MAGs)across 82 phyla,revealing a substantial portion,2363 MAGs,as previously unclassified at the genus *** unknown MAGs displayed unique distribution patterns across different lakes,indicating a strong correlation with varied physicochemical *** analysis revealed an extensive array of 9635 biosynthesis gene clusters(BGCs),with a remarkable 9403 being novel,suggesting untapped biotechnological ***,some MAGs from potentially new phyla exhibited a high density of these *** biosynthesis,our study also identified novel biodegradation pathways,including dehalogenation,anaerobic ammonium oxidation(Anammox),and degradation of polycyclic aromatic hydrocarbons(PAHs)and plastics,in previously unknown microbial *** findings significantly enrich our understanding of biosynthesis and biodegradation processes and open new avenues for biotechnological innovation,emphasizing the untapped potential of microbial diversity in hypersaline environments.

关键词： Biosynthesis Biodegradation Hypersaline lakes Metagenome-assembled genomes Microbial dark matters

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Temporal dynamics of pedestrian injury severity: A seasonally constrained random parameters approach

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International Journal of Transportation Science and Technology 2024年

作者： Abdulrazaq, Mujeeb Abiola Fan, Wei David Program Department of Civil and Environmental Engineering University of North Carolina at Charlotte EPIC Building Room 3366 9201 University City Boulevard CharlotteNC28223-0001 United States Department of Civil and Environmental Engineering University of North Carolina at Charlotte EPIC Building Room 3261 9201 University City Boulevard CharlotteNC28223-0001 United States

Pedestrians are the most at-risk group in the transportation system, experiencing a troubling and persistent rise in both the frequency and proportion of fatalities over the past decade. In 2022, pedestrian fatalities in the United States reached a record high since 1981. Despite extensive research examining crash severity models from various perspectives, there is a notable paucity of studies investigating the impact of seasonal variations. This study addresses this gap by examining the seasonal variation in potential contributing factors to pedestrian-vehicle crash severity, utilizing nine years of the most recent pedestrian crash data from North Carolina. Preliminary analysis shows higher crash frequencies during darker seasons, with the highest frequency observed in the fall. Seasonally temporally constrained random parameter logit models, incorporating heterogeneity in both means and variances, are employed to explain the unobserved heterogeneity inherent in the variables and to mitigate biased parameter estimation. The necessity for segmentation is corroborated through pairs of likelihood ratio tests. The model outcomes reveal significant seasonal variations in several important variables. For instance, hit-and-run incidents exhibit the highest marginal effects in the spring. During the summer, male drivers, weekends, and alcohol impairment for both drivers and pedestrians have the most substantial marginal effects. In the fall, young drivers (aged under 24), darkness irrespective of lighting, and work zones show the highest magnitude of marginal effects. This study offers a novel perspective on pedestrian safety analysis and provides data-driven recommendations to enhance safety planning, resource allocation, and overall improvements in the transportation system. © 2024 Tongji University and Tongji University Press

关键词： Pedestrian safety Temporal instability Vulnerable road users Risk factors Heterogeneity model

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Mixotrophic Chlorella pyrenoidosa biofilm with enhanced biomass production, microalgal activity, and nutrient removal from nutrient-rich wastewater

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Journal of environmental Sciences (China) 2025年 157卷 366-377页

作者： Wu, Xiongwei Jin, Cong Zhang, Chiqian Li, Ping Huang, Jim Junhui Wu, Jing Wu, Jinhua Hu, Zhiqiang School of Environment and Energy South China University of Technology Guangzhou510006 China Zhongshan Institute of Modern Industrial Technology of South China University of Technology Zhongshan528400 China Civil Engineering Program College of Engineering & Computer Science Arkansas State University JonesboroAR72467 United States Environmental Research Institute National University of Singapore Singapore117411 Singapore Department of Civil and Environmental Engineering University of Missouri-Columbia 65211 United States

Microalgae possess significant advantages in nitrogen and phosphorus removal from nutrient-rich wastewater that are highly efficient and independent of the C/N ratio. However, challenges such as low biomass productivity, high variability in nutrient removal under different trophic types, and difficulty in harvesting biomass limits the large-scale application of microalgae wastewater treatment. This study attempted to employ mixotrophic microalgae biofilm to address these issues. The biomass production, microalgal activity, and nutrient removal of Chlorella pyrenoidosa biofilms with different trophic types were compared for nutrient-rich wastewater treatment. The results showed that the biomass productivity of the mixotrophic microalgal biofilm (0.215 g/(L·d)) was 2.3, 8.6, and 6.0 times higher than that of photoautotrophic microalgal biofilm, heterotrophic microalgal biofilm, and photoautotrophic suspended microalga, respectively. Additionally, the dehydrogenase activity (DHA), indicating microalgal activity, of the mixotrophic biofilm was 2.3 and 16.5 times higher than that of photoautotrophic and heterotrophic biofilms, respectively. Meanwhile, the mixotrophic biofilm removed 96.0 % of NH4+-N and 99.2 % of PO43–-P, more efficient than that with other types of biofilms and suspended microalgae. In an open-ended air-lift photobioreactor, the mixotrophic microalgal biofilm produced biomass at 0.12 g/(L·d) and removed 90.0 % of NH4+-N and 97.6 % of PO43–-P. This study suggests that the mixotrophic microalgal biofilm shows promise in treating nutrient-rich wastewater and producing microalgal biomass for value-added products. © 2024

关键词： Microalgae

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Development and performance assessment of a new opensource Bayesian inference R platform for building energy model calibration

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Discover Mechanical engineering 2023年第1期2卷 1-25页

作者： Hou, Danlin Zhan, Dongxue Wang, Liangzhu Hassan, Ibrahim Galal Sezer, Nurettin Centre for Zero Energy Building Studies Department of Building Civil and Environmental Engineering Concordia University 1455 de Maisonneuve Blvd. West Montreal H3G 1M8 QC Canada Mechanical Engineering Program Texas A & amp M University at Qatar P.O. Box 23874 Engineering Building Education City Al Rayyan Doha Qatar

Many factors contribute to the inherent uncertainty of energy consumption modeling in buildings. It is essential to perform a calibration and sensitivity analysis in order to manage these uncertainties. Despite the availability of several calibration methods, they are often deterministic and lack quantified uncertainties. Moreover, the selection of parameters in building energy modeling for calibration depends on the user’s experience. Therefore, a more rigorous selection process is required. This study developed a new automated Bayesian Inference calibration platform running as an R package. A sensitivity analysis module and a Bayesian inference module determine the calibration parameters and uncertainties, respectively. The Meta-model module is developed to replace the building energy model for the Markov Chain Monte Carlo process to save computing time. The proposed platform is successfully demonstrated on a synthetic high-rise office building and a real high-rise residential building in a hot and arid climate. The relationship between the number of calibration parameters, calibration performance, and the accuracy of the Meta-model is further discussed. The developed calibration platform in this study proved to have clear advantages over the existing platforms, with the ability to reasonably estimate building energy performance in a short computing time. © The Author(s) 2023.

关键词： Bayesian inference Building energy model Calibration Markov Chain Monte Carlo (MCMC) Sensitivity analysis Uncertainty

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Evaluating the impact of fertilizer and crop prices on phosphorus concentrations in Great Lakes watersheds

Journal of the Agricultural and Applied Economics Associatio...

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Journal of the Agricultural and Applied Economics Association 2024年第4期3卷 756-773页

作者： Sampriti Sarkar Preet Lal Molly Sears Frank Lupi Department of Agricultural Food and Resource Economics Michigan State University East Lansing Michigan USA Environmental Science and Policy Program Michigan State University East Lansing Michigan USA Department of Civil and Environmental Engineering Michigan State University East Lansing Michigan USA

Crop and input prices affect agricultural production and water pollution. Fertilizer prices fluctuated over the past two decades, recently increasing substantially. Corn prices also increased after authorization of the Renewable Fuel Standard. This paper estimates the effect of fertilizer and corn prices on total phosphorus (TP) and dissolved phosphorus (DP) concentrations across 226 Great Lakes region watersheds. Findings indicate that a 10% rise in fertilizer prices reduces TP by 3% and DP by 6.9%. Counterfactual analysis shows that without recent fertilizer price hikes, nutrient concentrations would be higher, underscoring the impact of crop and input prices on phosphorus pollution.

关键词： corn production fertilizer application non-point source pollution phosphorus pollution

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Response to Comment on"Mechanistic Understanding ofSuperoxide Radical-Mediated Degradation of PerfluorocarboxylicAcids"

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environmental SCIENCE & TECHNOLOGY 2022年第8期56卷 5289-5291页

作者： Bai, Lu Jiang, Ying Xia, Deming Wei, Zongsu Spinney, Richard Dionysiou, Dionysios D. Minakata, Daisuke Xiao, Ruiyang Xie, Hong-Bin Chai, Liyuan Institute of Environmental Engineering School of Metallurgy and Environment Central South University Changsha 410083 China. Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution Changsha 410083 China. Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education) School of Environmental Science and Technology Dalian University of Technology Dalian 116024 China. Centre for Water Technology (WATEC) & Department of Engineering Aarhus University Hangøvej 2 Aarhus N DK-8200 Denmark. Department of Chemistry and Biochemistry The Ohio State University Columbus Ohio 43210 United States. Environmental Engineering and Science Program University of Cincinnati Cincinnati Ohio 45221 United States. Department of Civil and Environmental Engineering Michigan Technological University Houghton Michigan 49931 United States.

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Application of a Physical-Mathematical Model of Leachate Ion Diffusion Through Compacted Soils from Diffusion Tests 16th

Application of a Physical-Mathematical Model of Leachate Ion...

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16th International Conference of the International Association for Computer Methods and Advances in Geomechanics, IACMAG 2021

作者： Baran, Camilla Turon Cavalcante, André Luís Brasil Department of Civil and Environmental Engineering Geotechnical Post-Graduation Program University of Brasília Brasilia70910-900 Brazil

ISBN: (纸本)9783030645175

Molecular diffusion can transport ions from the leachate through a compacted soil barrier in landfills since it depends only on the concentration gradient. This mechanism is described by equations that depend on the effective diffusion coefficient in soils for each chemical element. Laboratory tests are necessary to estimate this coefficient, by testing a compacted soil layer subject to a contaminating solute, which results in curves of the variation of the concentration over time and along the soil thickness. The purpose of the paper is to apply the semi-analytical method called Equivalent Contaminated Layer Solution (ECL) for determining the diffusion and sorption coefficients for specific contaminants. It was adjusted a computational model that allows the calibration and visualization of diffusive tests in time and space, with a three-dimensional surface. The methodology was carried out using the software Wolfram Mathematica. The experimental data used were taken from previous studies. It was modelled the diffusion of chloride, chrome, cadmium, nickel and copper. The results of the models were validated for a hypothetical compacted clayey liner. The method applied allowed us to analyse the ion migration in compacted clayey liners from solid waste landfills. © 2021, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Contamination

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Partitioning Uncertainty from Climate Change Inputs on Streamflow Projections in the Bicol River Basin, Philippines

SSRN

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SSRN 2025年

作者： Bañares, Ernie Nograles Mehboob, Muhammad Shafqat Panda, Manas Ranjan Engineering Graduate Program School of Engineering University of San Carlos Cebu City6000 Philippines College of Engineering and Architecture Sorsogon State University Sorsogon City4700 Philippines Department of Civil Engineering School of Engineering University of San Carlos Cebu City6000 Philippines Department of Civil & Environmental Engineering Yonsei University Seoul Korea Republic of

Increasing threats to global water resources from climate change emphasize the importance of comprehending its impacts on hydrology for effective water management. This article quantifies climate input uncertainty in streamflow projections for the Libmanan-Pulantuna Watershed (LPW) in the Bicol River Basin, Philippines. Using the Water Evaluation and Planning (WEAP) model, we simulated streamflow based on future climate projections (FCPs) from Intergovernmental Panel on Climate Change (IPCC) greenhouse-gas emission scenarios, utilizing Coupled Model Intercomparison Project phases 5 (CMIP5) and 6 (CMIP6) datasets. Four Global Circulation Models (GCMs) and three bias correction techniques (Linear Scaling, Quantile Mapping, and Detrended Quantile Mapping) were applied. Results showed significant differences between the CMIP datasets, with raw CMIP6 better capturing historical climate patterns. Bias correction methods reduced projection biases in precipitation and air temperatures. Projections revealed increasing low flows and decreasing high flows, especially under high-emission scenarios, worsening water shortages during critical periods. Analysis of Variance (ANOVA) showed that climate models were a major source of uncertainty in hydrological projections. Combined FCPs and GCMs contributed to 50%-75% of total uncertainty across flow percentiles and future periods (near-future, mid-future, far-future). These findings underscore the importance of careful model selection and effective bias correction for reliable hydrological projections, crucial for water management strategies in areas like the Bicol River Basin, where water resources are essential for communities and ecosystems. © 2025, The Authors. All rights reserved.

关键词： Rivers

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Photocatalytic degradation of perfluorooctane sulfonic acid and perfluorooctanoic acid using titanium dioxide/graphene oxide nanocomposite immobilized on polyvinyl alcohol film

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Case Studies in Chemical and environmental engineering 2024年 10卷

作者： Boonchata, Putthicha Boontanon, Narin Jindal, Vinod Aung, Humm Kham Zan Zan Visvanathan, Chettiyappan Fujii, Shigeo Boontanon, Suwanna Kitpati Graduate Program in Environmental and Water Resources Engineering Department of Civil and Environmental Engineering Faculty of Engineering Mahidol University Research Center and Technology Development for Environmental Innovation Faculty of Environment and Resource Studies Mahidol University Department of Chemical Engineering Faculty of Engineering Mahidol University Graduate School of Global Environmental Studies Kyoto University

In full-scale units, the real application of nanoparticles photocatalytic degradation is still challenging due to the requirement of post separation for recovery of fine particles. This work investigated the removal efficiencies of perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) using titanium dioxide (TiO₂) nanoparticles coupling with graphene oxide (GO) sheets immobilized in polyvinyl alcohol (PVA) matrix via solution-casting and a heat-treatment process to achieve the TiO₂/GO/PVA nanocomposite film as a photocatalyst. The operative parameters were focused on initial solution pH value, GO concentration, and heat-treatment time, which subsequently determined the optimal indices for the catalyst film. The structure characterization of the Ti–O–C bond indicated that a strong interaction between GO and TiO₂ had been formed at the hydrolysis process while TiO₂/GO nanoparticles were chemically embedded in PVA matrix by the heat-treatment method. The photocatalytic degradation of PFOS and PFOA produced a nanocomposite film with 25 wt% TiO₂/GO that was treated at 120 °C for 3 h and exhibited a remarkable removal activity in acidic solution with a pH of 3. This condition efficiently degraded PFOS and PFOA by approximately 95.99 % and 96.89 %, respectively, through a photocatalytic reaction. This research presents a straightforward method to synthesize TiO₂/GO/PVA catalyst that influences persistent organic pollutants (POPs) under ultraviolet irradiation, which is of practical significance for environmental applications. © 2024 The Authors

关键词： Graphene oxide PFOA PFOS Photocatalytic Polyvinyl alcohol Titanium dioxide

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