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Open access publications related to sustainability research.

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Synthetic Aperture Radar for Geosciences
(Reviews of Geophysics, 2024-09-03) Meng, Lingsheng; Yan, Chi; Lv, Suna; Sun, Haiyang; Xue, Sihan; Li, Quankun; Zhou, Lingfeng; Edwing, Deanna; Edwing, Kelsea; Geng, Xupu; Wang, Yiren; Yan, Xiao-Hai
Synthetic Aperture Radar (SAR) has emerged as a pivotal technology in geosciences, offering unparalleled insights into Earth's surface. Indeed, its ability to provide high-resolution, all-weather, and day-night imaging has revolutionized our understanding of various geophysical processes. Recent advancements in SAR technology, that is, developing new satellite missions, enhancing signal processing techniques, and integrating machine learning algorithms, have significantly broadened the scope and depth of geosciences. Therefore, it is essential to summarize SAR's comprehensive applications for geosciences, especially emphasizing recent advancements in SAR technologies and applications. Moreover, current SAR-related review papers have primarily focused on SAR technology or SAR imaging and data processing techniques. Hence, a review that integrates SAR technology with geophysical features is needed to highlight the significance of SAR in addressing challenges in geosciences, as well as to explore SAR's potential in solving complex geoscience problems. Spurred by these requirements, this review comprehensively and in-depth reviews SAR applications for geosciences, broadly including various aspects in air-sea dynamics, oceanography, geography, disaster and hazard monitoring, climate change, and geosciences data fusion. For each applied field, the scientific advancements produced because of SAR are demonstrated by combining the SAR techniques with characteristics of geophysical phenomena and processes. Further outlooks are also explored, such as integrating SAR data with other geophysical data and conducting interdisciplinary research to offer comprehensive insights into geosciences. With the support of deep learning, this synergy will enhance the capability to model, simulate, and forecast geophysical phenomena with greater accuracy and reliability. Key Points - Synthetic Aperture Radar (SAR) for geosciences is comprehensively reviewed broadly including oceanography, geography, hazards, and climate change - Scientific advances contributed by SAR techniques for each topic are overviewed in-depth with recent developments and frontiers highlighted - Data, techniques, and scientific insights of SAR are summarized and prospected, highlighting the role of machine learning Plain Language Summary Synthetic aperture radar (SAR) uses microwaves to remotely see the Earth's surface under all weather conditions, day and night. SAR has been providing high-resolution images for many decades and they have been applied to many fields in geosciences. Several SAR sensors have been launched in recent years, significantly increasing the SAR data volume and leading to great developments in SAR technology, thereby improving our understanding of geophysical phenomena and processes. This work comprehensively overviews the application of SAR in geosciences, including oceanography, geography, geodesy, climatology, seismology, meteorology, and environmental science. Moreover, this review paper highlights the significance of SAR in various aspects of geosciences, summarizes recent advancements in SAR technology, and demonstrates unique insights and important contributions of SAR in understanding and solving geophysical questions. Future directions and outlooks include integrating SAR with other geophysical data and interdisciplinary applications for complex questions. This review serves as an up-to-date guide to the cutting-edge uses of SAR technology in comprehensive geophysical studies. It is aimed at researchers and practitioners in geosciences, as well as policymakers and stakeholders interested in leveraging SAR for geosciences.
Private versus Public Flood Insurance: Differences in Premiums and Uptake Observed in Two Coastal Housing Markets Using Survey Data
(Marine Resource Economics, 2025-01-01) Fielding, Samuel; Parsons, George
Using a natural experiment created by the 1982 Coastal Barrier Resources Act (CBRA), we measure the extent to which insurance premiums vary between private and publicly backed flood insurance policies. The CBRA resulted in homeowners living in neighboring housing markets in which some have access to the federally backed National Flood Insurance Program (NFIP) and others do not. Flood risks and other features of the neighborhoods are otherwise indistinguishable. Those without access to publicly backed insurance must purchase private insurance if they desire coverage. We compare insurance premiums and uptake in the two markets and find that premiums for private coverage are significantly higher than public rates (after controlling for other factors in a reduced-form regression), implying a subsidy by NFIP. We also find a much lower uptake of insurance in the areas without federally backed insurance. Our results are based on a mail survey of residents in two US coastal communities with a 50% response rate: North Bethany Beach, Delaware, and North Topsail Beach, North Carolina. We also present results related to perceptions of flood hazards, of being under- or overinsured, and measures taken to mitigate flood damage.
Fundamental Challenges and Opportunities for Textile Circularity
(Sustainability, 2024-12-18) Thomas, Kedron; Durrani, Hira; Brady, Julia; Ludwig, Kendall; Yatvitskiy, Michelle; Clarke-Sather, Abigail R.; Cao, Huantian; Cobb, Kelly
The negative environmental impacts of the current linear system of textile and apparel production are well-documented and require urgent action. The sector lacks an effective recycling system, resulting in massive waste and environmental pollution. This paper presents the results of qualitative research involving textile and apparel industry stakeholders, including representatives from brands and retailers, waste collectors, recyclers, non-profit organizations, academic institutions, and government agencies. Our research focused on stakeholder perceptions of the significance and importance of textile circularity, the challenges that exist for transitioning the textile and apparel industry from a linear system to a circular economy (CE), and resources that exist to support this transition. The results of this study call attention to the following urgent requirements: a consistent definition of CE to promote transparency and accountability and prevent greenwashing; improved systems for materials identification, sorting, and pre-processing of post-consumer textile waste to enable recycling; innovations in mechanical recycling technologies to maintain the value of recycled materials; and new, materials-driven approaches to design and manufacturing that are responsive to feedstock variability and diverse consumer needs. The research findings also suggest the need for flexible, regional CEs that are rooted in community partnerships.
Improving future agricultural sustainability by optimizing crop distributions in China
(PNAS Nexus, 2025-01-07) Guan, Qi; Tang, Jing; Davis, Kyle Frankel; Kong, Mengxiang; Feng, Lian; Shi, Kun; Schurgers, Guy
Improving agricultural sustainability is a global challenge, particularly for China's high-input and low-efficiency cropping systems with environmental tradeoffs. Although national strategies have been implemented to achieve Sustainable Development Goals in agriculture, the potential contributions of crop switching as a promising solution under varying future climate change are still under-explored. Here, we optimize cropping patterns spatially with the targets of enhancing agriculture production, reducing environmental burdens, and achieving sustainable fertilization across different climate scenarios. Compared with current cropping patterns, the optimal crop distributions under different climate scenarios consistently suggest allocating the planting areas of maize and rapeseed to the other crops (rice, wheat, soybean, peanut, and potato). Such crop switching can consequently increase crop production by 14.1%, with accompanying reductions in environmental impacts (8.2% for leached nitrogen and 24.0% for irrigation water use) across three representative Shared Socio-economic Pathways from 2020 to 2100. The sustainable fertilization rates vary from 148–173 kg N ha−1 in 2030 to 213–253 kg N ha−1 in 2070, significantly smaller than the current rate (305 kg N ha−1). These outcomes highlight large potential benefits of crop switching and fertilizer management for improving China's future agricultural sustainability.
Identifying potential introduced and natural sources of pollution in Delaware watersheds
(Applied and Environmental Microbiology, 2024-12-17) Bowen, Malique; Main, Christopher R.; Farag, Ibrahim F.; Biddle, Jennifer F.
Managing water quality with microbial impairment caused by Enterococcus poses unique challenges regarding the determination of fecal host origin. Most water monitoring is performed based on Enterococcus counts that neither detect the location of the introduction of pollution nor identify the type of contaminating Enterococcus. The use of sequenced-based microbial source tracking could allow for identification of fecal origin and potential remediation of pollution. The state of Delaware has numerous waterways with high microbial impairment from unknown sources, so we used sequence-based microbial source tracking to investigate potential microbial pollution in three watersheds with significant variation in land use and population density. In this study, we use a 16S rRNA sequence reference library of microbial communities from relevant fecal sources (wild animal, domestic animal, sediment, and septic/wastewater) to determine the most likely sources of microbial impairment in three Delaware watersheds. This study assigned sources of microbial contamination to mostly human-related sources (septic and wastewater) or unknown sources indicating that waste infrastructure may have a larger influence on microbial community structure in Delaware watersheds than previously considered. Our results suggest that long-term source tracking is valuable for ruling out native or domesticated animals as contributors to water pollution. IMPORTANCE Traditional microbial pollution monitoring utilizes specific fecal indicator bacteria that need to grow in the laboratory for detection. Here, we show the use of sequence information from whole microbial communities and an expanded reference library in microbial source tracking. Expanding the host detection range by including the whole microbial community may allow for a wider range of potential fecal origin identification even when specific fecal indicators are absent or in low concentration. We show that many Delaware waterways bear the signature of human influence compared to natural sources. In addition, the robust reference library built in this study can be used to conduct source tracking studies in the mid-Atlantic USA.
Heated Environment, Armed People: Between “Climate Change Conflict” and “Fragility Conflict” in the Sahel
(Journal of Asian and African Studies, 2024-11-05) Akinyetun, Tope Shola; Fatai-Abatan, Abiodun; Ogunbodede, Nife
The Sahel is a classic example of a region inundated by climate change and conflicts. The region is an ecological hotspot that is on the brink of collapse, as countries in the area are trapped in a vicious cycle of conflict, resource scarcity, and environmental threats, which increase the chances of political instability and civil unrest. Noting that there is a divergent scholarly viewpoint on the relationship between climate change and conflict, this study evaluates the climate change-conflict thesis vis-à-vis the fragility-conflict thesis. It argues that armed conflicts in the Sahel are not exclusively attributable to climate change; rather, other conventional drivers exacerbate the impact of climate change on conflicts. These conventional drivers, framed as fragility indices, play a more significant role in conflict escalation in the Sahel. To this end, this study provides a holistic perspective on conflict dynamics and underscores the intricate interplay between fragility and conflict proliferation. This study adopts a qualitative approach and analyzes secondary data, particularly journal articles, reports, briefs, and developmental indices. The findings show that conditions symptomatic of a fragile state increase the incidence and proliferation of armed conflict in the region. Thus, conflict in the Sahel is a product of amplified pre-existing socioeconomic vulnerabilities and governance challenges.
Large offshore wind farms have minimal direct impacts on air quality
(Environmental Research Letters, 2024-11-22) Golbazi, Maryam; Archer, Cristina L.
Wind power has rapidly grown over the past decade because it is clean, renewable, and abundant. However, wind farms can affect local weather conditions and possibly alter the transport, diffusion, and concentration of air pollutants. Given the unprecedented expansion of offshore wind farms planned along the U.S. East Coast by the Bureau of Ocean Energy Management (BOEM), This study aims to investigate if and how those future wind farms might directly affect air pollution along the U.S. East Coast, in particular the levels of ozone (O3), fine particulate matter (PM2.5), sulfur dioxide (SO2), and nitrogen dioxide (NO2). These pollutants are regulated at the federal and state levels and are harmful to human health. We exclusively study the direct effects of the wind turbines on air pollution (via meteorological changes), rather than investigating the indirect impacts of replacing fossil-fuel power plants with wind farms. We first run a numerical meteorological model, the Weather Research and Forecast (WRF) model, to simulate the meteorology along the U.S. East Coast during the summer of 2018 in two scenarios, with and without the wind farms. Then we use the output of these two sets of simulations from the WRF model as input to the Comprehensive Air Quality Model with extensions to simulate the changes in air quality in the study domain due to the wind farms. On average, we only find a minor increase in O3 levels within the wake of the New Jersey WEA. The minor changes to O3 can be attributed to the slight temperature increase below the turbine hub height, within the rotor area, as well as a significant decrease in wind velocity in the wake of the turbines and a slight increase in volatile organic compound levels. In addition, we report that the other three pollutants remain unchanged in the presence of wind farms. In summary, the direct impacts on air pollution by the BOEM-planned offshore wind farms are expected to be negligible.
Evaluation of soil properties and bulk δ15N to assess decadal changes in floodplain denitrification following restoration
(Restoration Ecology, 2024-10-29) Galella, Joseph G.; Rahman, Md. Moklesur; Yaculak, Alexis M.; Peipoch, Marc; Kan, Jinjun; Sena, Matthew; Joshi, Bisesh; Kaushal, Sujay S.; Inamdar, Shreeram
Stream and floodplain restoration is a popular billion-dollar industry in the United States, with many restorations being conducted to satisfy water pollution regulations and nutrient reduction goals. The long-term efficacy of these restorations is, however, not well studied, and key soil metrics that can be used for performance assessments have not been developed. We evaluated a chronosequence of 12 restoration sites spanning an age range of 0–22 years to assess changes in denitrification rates and associated soil parameters. Restored versus unrestored reaches were compared for denitrification rate and functional gene nosZ, bulk soil δ15N, soil organic carbon (SOC), soil organic matter (SOM), bulk density, and soil moisture. Denitrification, SOM, SOC, and soil moisture were all found to increase with site age at restored sites, with the largest increase for the 10–22 age category. Bulk density decreased with time, with a significant decrease in restored floodplain soils. Bulk soil δ15N was highest immediately after restoration, decreased with restoration age, and was not positively correlated with denitrification. This may reduce its potential as a proxy for denitrification. Overall, this study reveals that selected soil metrics (SOC, SOM, soil moisture, and bulk density) could serve as a valuable proxy for denitrification and could help assess the denitrification effectiveness of floodplain restorations at the decadal time scales. Ideally, the soil metrics should be combined with other short-term assessment measures, such as those for stream and groundwaters, for a robust performance assessment of restored floodplains. Implications for Practice - Soil characteristics have not been routinely used for assessing the long-term effectiveness of stream and floodplain restorations, and guidance is needed for their use. - Soil organic matter, moisture, and bulk density improved over time for restored floodplains and could be used as reliable proxies for denitrification nitrogen removal. - Site-specific differences in restoration design and construction (e.g. soil amendments such as woody debris/chips) could significantly affect the response of soil metrics. - Since soil characteristics change slowly over decadal time scales, restoration assessments should also include quicker, short-term performance measures such as those associated with surface and groundwater quality.
Model-Driven Manufacturing of High-Energy-Density Batteries: A Review
(Batteries & Supercaps, 2024-10-09) Maksimovna Vakhrusheva, Daria; Xu, Jun
Graphical Abstract This review offers a comprehensive review of recent advancements in model-driven manufacturing approaches for high-energy-density batteries. It highlights the integration of computational models with experimental manufacturing processes to optimize battery performance, reliability, and cost-effectiveness. Additionally, the review addresses the challenges associated with scaling up these model-driven approaches, focusing on critical issues such as model validation, parameter sensitivity, and the incorporation of artificial intelligence. Graphical Abstract available at: https://doi.org/10.1002/batt.202400539 Abstract The rapid advancement in energy storage technologies, particularly high-energy density batteries, is pivotal for diverse applications ranging from portable electronics to electric vehicles and grid storage. This review paper provides a comprehensive analysis of the recent progress in model-driven manufacturing approaches for high-energy-density batteries, highlighting the integration of computational models and simulations with experimental manufacturing processes to optimize performance, reliability, safety, and cost-effectiveness. We systematically examine various modeling techniques, including electrochemical, thermal, and mechanical models, and their roles in elucidating the complex interplay of materials, design, and manufacturing parameters. The review also discusses the challenges and opportunities in scaling up these model-driven approaches, addressing key issues such as model validation, parameter sensitivity, and the integration of machine learning and artificial intelligence for predictive modeling, process optimization, and quality assurance. By synthesizing current research findings and industry practices, this paper aims to outline a roadmap for future developments in model-driven manufacturing of high-energy density batteries, emphasizing the need for interdisciplinary collaboration and innovation to meet the increasing demands for energy storage solutions.
Enhanced Net Community Production With Sea Ice Loss in the Western Arctic Ocean Uncovered by Machine-Learning-Based Mapping
(Geophysical Research Letters, 2024-11-23) Zhou, Tianyu; Li, Yun; Ouyang, Zhangxian; Cai, Wei-Jun; Ji, Rubao
In the Arctic Ocean (AO), net community production (NCP) has displayed spatially heterogeneous responses to sea ice reduction and associated environmental changes. Using a random forest machine learning model trained with >42,000 in situ measurements and concurrent, collocated environmental predictors, we reconstructed 19 years of 8‐day, 6‐km NCP maps. During 2015–2021, the integrated NCP between late‐May and early‐September (intNCP) over the western AO was 10.95 ± 3.30 Tg C per year, with interannual variations positively tracking open water area. While the relationship between intNCP and open water area was quasi‐linear at high latitudes, strong nonlinearity was detected on the inflow shelf. The nonlinearity highlights that the intNCP increase resulted from area gain could be compounded by sea‐ice loss induced ecosystem adjustments. Additional retrospective analysis for 2003–2014 suggests a potential long‐term increase of export production and efficiency in the western AO with sea ice loss. Key Points: • A multiyear, gap‐free net community production (NCP) product was con- structed using a machine learning model for the western Arctic Ocean • Seasonally and regionally integrated NCP responded to sea ice loss quasi‐ linearly at high latitudes but non- linearly on the inflow shelf • Compared with the 2010s, carbon export production has increased in recent years, accompanying sea ice loss in the western Arctic Ocean Plain Language Summary Net community production (NCP) refers to the portion of phytoplankton production that remains unused by consumers and can be exported to the deeper part of the ocean. In the western Arctic Ocean (AO), NCP patterns are uneven due to complex interactions between the physical environment and the ecosystem. In this study, we developed a machine learning model of NCP in the western AO. The model used publicly available underway measurements and the associated environmental variables to create long‐term, high‐resolution maps of NCP. For the period of 2015–2021, we found that the integrated NCP between late‐ May and early‐September (intNCP) was 10.95 ± 3.30 Tg C per year in the western AO. intNCP varied from year to year and was higher when the open water area was larger. Notably, on the inflow shelf, intNCP increased at a faster rate than a linear relationship would suggest, due to both area expansion and ecosystem adjustments induced by sea ice loss. Our findings indicate that with long‐term sea ice loss, the western AO is likely to export more phytoplankton production to deeper ocean waters.
Zero-Valent Iron and Sand Filtration Reduces Levels of Cyclospora cayetanensis Surrogates, Eimeria tenella and Eimeria acervulina, in Water
(Microorganisms, 2024-11-16) Gutierrez, Alan; Tucker, Matthew S.; Yeager, Christina; Fournet, Valsin; Jenkins, Mark C.; Dubey, Jitender P.; Kniel, Kalmia E.; Rosenthal, Benjamin M.; Sharma, Manan
Recurring outbreaks of cyclosporiasis linked to fresh produce demonstrate the need to develop interventions to reduce C. cayetanensis in irrigation water. C. cayetanensis is resistant to commonly used irrigation water treatments, such as chemical sanitizers, making removal of oocysts by filtration the most suitable intervention. This study evaluated the reduction of Eimeria tenella and E. acervulina, as surrogates for C. cayetanensis, in water using filters packed with sand alone or mixtures of sand and zero-valent iron (ZVI). Water inoculated with Eimeria spp. oocysts was filtered through laboratory-scale (PVC column) and field-scale (swimming pool filter) filters packed with either 100% sand or 50% ZVI/50% sand (v/v). Filtered and backflush water was examined microscopically for oocysts. Laboratory-scale filters with 50% ZVI significantly (p < 0.05) reduced 99.9% of E. tenella oocysts compared to 55.3% with filters containing 100% sand. At the field-scale level, 50% ZVI filters significantly (p < 0.05) reduced 70.5% of E. acervulina oocysts compared to 54.5% by 100% sand filters. Filters were backflushed to examine the recovery of these parasites during routine filter-media cleaning procedures. Backflush recovery of oocysts ranged from 4.42–16.7%. The addition of ZVI significantly improved the reduction of Eimeria spp. oocysts at both filter scales. and should be further investigated as a potential irrigation water intervention to reduce C. cayetanensis.
Marine recreational fishery trends in total catch, catch per unit effort, and release rates in Delaware during 1981–2021
(Fisheries Management and Ecology, 2024-09-25) Whaley, Nicholas; Fontana, Julia; Hicks, Matthew; Marsaly, Benjamin Paul; Smoot, Timothy; Bandlow, Serena; Carlisle, Aaron; Hale, Edward
The impact of recreational fisheries on marine ecosystems is often overshadowed by commercial fisheries, although recreational fishing harvest can be substantial, especially for species that are either overfished or experiencing overfishing. Delaware is a small coastal state with ~1,000,000 residents and nearly 272,000 resident and non-resident anglers. We used publicly available data for Delaware's recreational fisheries during 1981–2021 to determine the nine most caught fish species and to evaluate trends in total numbers caught, harvested, released, and catch per unit effort (CPUE). The top nine most frequently captured fish by recreational anglers were Summer Flounder (Paralichthys dentatus), Atlantic Croaker (Micropogonias undulatus), Bluefish (Pomatomus saltatrix), Black Sea Bass (Centropristis striata), Weakfish (Cynoscion regalis), White Perch (Morone americana), Tautog (Tautoga onitis), Striped Bass (Morone saxatilis), and Spot (Leiostomus xanthurus). The proportion of fish released increased through time for all nine species, suggesting that the recreational fishery in Delaware is transitioning from a harvest-oriented to a catch-and-release-oriented fishery. Observations of higher release rates in recreational fisheries of Delaware are consistent with the findings elsewhere in the world for freshwater and marine systems.
REWET: A Tool to Model System Functioning and Restoration of Damaged Water Supply Systems
(Journal of Infrastructure Systems, 2024-09-14) Naeimi, Sina; Davidson, Rachel A.
The process of restoring water supply after service is interrupted is critical for determining the durations and spatial distribution of outages and thus the impacts that households, businesses, and others ultimately experience. Nevertheless, the restoration period is difficult to predict because it involves complex, dynamic interactions among the system hydraulics, operator restoration actions, and consumer adaptations to service interruptions. In this paper, we introduce a new computer model called Restoration of Water after an Event Tool (REWET) that (1) allows detailed representations of both the hydraulic operations of the system and the restoration process, (2) is flexible enough to apply to any system or disruptive event, enable varying levels of complexity, and allow deterministic or probabilistic analysis, and (3) is available as free, easy-to-use, open-source code. It uses pressure-demand driven hydraulic analysis and allows detailed discrete event simulation representation of the restoration process. We present case study applications of REWET for the Los Angeles water system and for a small, simple network to illustrate the tool’s functionality, flexibility, and key features.
Using DIC-δ13C Pair to Constrain Anthropogenic Carbon Increase in the Southeastern Atlantic Ocean Over the Most Recent Decade (2010–2020)
(Journal of Geophysical Research: Oceans, 2024-11-12) Gao, Hui; Jin, Meibing; Zhao, Hui; Hussain, Najid; Cai, Wei-Jun
The southeastern Atlantic Ocean is a crucial yet understudied region for the ocean absorption of anthropogenic carbon (Canth). Data from the A12 (2020) and A13.5 (2010) cruises offer an opportunity to examine changes in dissolved inorganic carbon (DIC), its stable isotope (δ13C), and Canth over the past decade within a limited region (1∼3°E, 32∼42°S). For the decade of 2010–2020, Canth invasion was observed from the sea surface down to 1,200 m based on both DIC and δ13C data. The mean Canth increase rate (1.08 ± 0.26 mol m−2 yr−1) during this period accelerated from 0.87 ± 0.05 mol m−2 yr−1 during the previous period (1983/84–2010). The δ13C-based Canth increase closely matches the DIC-based estimation below 500 m but is 26% higher in the upper ocean. This discrepancy is likely due to δ13C's longer air-sea exchange timescale, seasonal variability in the upper ocean, and the chosen ratio of anthropogenically induced changes in δ13C and DIC. Finally, column inventory changes based on the two methods also exhibit very similar mean Canth uptake rates. The paired DIC concentration and stable isotope dataset may enhance our ability to constrain Canth accumulation and its controlling mechanisms in the ocean. Key Points - Anthropogenic carbon uptake rate estimated from δ13C matches with that from dissolved inorganic carbon except in the surface in the southeastern Atlantic Ocean - Anthropogenic carbon changes exhibit significant vertical variations depending on water masses and circulation - Anthropogenic carbon increase rate during 2010–2020 has accelerated ∼19% from that during 1983/84–2010 in the study region Plain Language Summary The stable carbon isotope signal (δ13C) of oceanic dissolved inorganic carbon (DIC) is a sensitive tracer for the absorption of anthropogenic carbon from the atmosphere. We collected δ13C data from a limited region in the southeastern Atlantic Ocean and used them to examine the anthropogenic carbon changes over the most recent decade. From 2010 to 2020, anthropogenic carbon invasion can be found from the sea surface to a depth of 1,200 m with an accelerated increase rate compared to the period from 1983/84 to 2010. The δ13C-based estimation of anthropogenic carbon increase matches closely with the DIC-based estimation below 500 m but is significantly higher in the upper ocean. This discrepancy likely arises from differences in equilibrium timescales, the ratio of the anthropogenic δ13C/DIC change, and different influences by seasonal variability in the upper ocean. Nonetheless, the entire water column inventory changes based on both two methods show very close mean anthropogenic carbon uptake rates.
pH Distributions and Determining Processes Along the U.S. East Coast
(Journal of Geophysical Research: Oceans, 2024-09-11) Li, Xinyu; Xu, Yuan-Yuan; Cai, Wei-Jun
pH is a key index in ocean biogeochemical and acidification research. However, there remains a limited understanding of the spatial patterns and drivers of pH across different coastal oceans. In this study, we present the distribution of spectrophotometric pHT (in total proton scale) from a synoptic summer cruise in 2018. We examine the processes controlling pHT along the U.S. East Coast, covering the South Atlantic Bight (SAB), Mid-Atlantic Bight (MAB), and Gulf of Maine (GoM). Our findings reveal a continuous low pHT band associated with the oxygen minimum and CO2 maximum zone along the slope of the entire east coast, extending from the bottom layer (∼1,000 m) in the SAB to the middle layer (300–500 m) in the MAB and GoM. We also identified unique low pHT features in each subregion, including an onshore upwelling of the low pHT slope water in the SAB, a seasonal low pHT feature on the bottom of the MAB shelf associated with the Cold Pool water, and an inflow of low pHT slope water to the bottom of the GoM. Our findings suggest that net biological production plays a prominent role in regulating sea-surface pHT, driving it away from the air-sea equilibrated pHT and mitigating the pHT decrease caused by the anthropogenic carbon dioxide (CO2) uptake. Furthermore, net biological respiration dominates the interior pHT distributions. Our analysis provides new insights and establishes a foundation for interpreting future pH changes in response to processes such as water masses shifting, ocean warming, and anthropogenic carbon uptake in coastal oceans. Key Points - The subsurface pH minimum layer extends from the slope bottom in the south to the middle layer of the slope in the north - Each subregion has a distinct low-pH feature, including onshore upwelling, Cold Pool water, and Gulf bottom water - Surface pH deviates from air-sea gas equilibrium due to net biological production, while interior ocean pH is dominated by respiration Plain Language Summary Given that pH is a crucial index for assessing ocean acidification, understanding pH distribution patterns and its controlling factors in coastal oceans is essential. This study investigates pH from a summer 2018 cruise along the entire U.S. East Coast. We found that the surface-water pH deviates from the atmospheric equilibrium, primarily due to net biological production. Subsurface pH patterns are also mainly controlled by biological factors. Along the slope, a continuous low pH band is associated with the oxygen minimum zone, extending from the bottom in the SAB to the middle depth in the MAB and GoM. On the shelf, each subregion has unique subsurface low pH features, including a shoreward upwelling of the low pH slope water in the SAB, a seasonal low pH feature in the MAB Cold Pool, and an inflow of low pH slope water in the bottom of GoM. This research provides new insights into the processes controlling pH distribution and lays a foundation for interpreting current and future pH decadal trends in the context of climate change.
Influence of reef habitat on coral microbial associations
(Environmental Microbiology Reports, 2024-11-08) Gantt, Shelby E.; Kemp, Keri M.; Colin, Patrick L.; Hoadley, Kenneth D.; LaJeunesse, Todd C.; Warner, Mark E.; Kemp, Dustin W.
Corals have complex symbiotic associations that can be influenced by the environment. We compare symbiotic dinoflagellate (family: Symbiodiniaceae) associations and the microbiome of five scleractinian coral species from three different reef habitats in Palau, Micronesia. Although pH and temperature corresponded with specific host-Symbiodiniaceae associations common to the nearshore and offshore habitats, bacterial community dissimilarity analyses indicated minimal influence of these factors on microbial community membership for the corals Coelastrea aspera, Psammocora digitata, and Pachyseris rugosa. However, coral colonies sampled close to human development exhibited greater differences in microbial community diversity compared to the nearshore habitat for the coral species Coelastrea aspera, Montipora foliosa, and Pocillopora acuta, and the offshore habitat for Coelastrea aspera, while also showing less consistency in Symbiodiniaceae associations. These findings indicate the influence that habitat location has on the bacterial and Symbiodiniaceae communities comprising the coral holobiont and provide important considerations for the conservation of coral reef communities, especially for island nations with increasing human populations and development. Graphical Abstract available at: https://doi.org/10.1111/1758-2229.70051 In Palau, Micronesia, temperature and pH influence coral-Symbiodiniaceae associations but do not affect coral microbial community membership across nearshore and offshore reef habitats. Coral colonies near human development exhibited higher microbial diversity, greater bacterial community similarity across genera, and less consistent Symbiodiniaceae associations compared to both nearshore and offshore habitats. These findings reveal how habitat and proximity to urban development affect coral symbioses, offering insights for coral reef conservation as human development increases in coastal environments.
Towards highly efficient thin-film solar cells with a graded-bandgap CZ TSSe layer. Part II: Piecewise-homogeneous bandgap grading
(JPhys Energy, 2024-11-14) Ahmad, Faiz; Monk, Peter B.; Lakhtakia, Akhlesh
In Part I, we optoelectronically optimized a thin-film solar cell with a graded-bandgap CZTSSe photon-absorbing layer and a periodically corrugated backreflector, using the hybridizable discontinuous Galerkin (HDG) scheme to solve the drift-diffusion equations. The efficiency increase due to periodic corrugation was minimal, but significant improvement was achieved with a nonlinearly graded bandgap. Due to occasional failures of the HDG scheme from negative carrier densities, we developed a new computational scheme using the finite-difference method, which also reduced the overall computational cost of optimization. Later, a normalization error was discovered in the electrical submodel in Part I, but it did not alter the overall conclusions. We have now re-optimized the solar cells with (i) a homogeneous bandgap, (ii) a linearly graded bandgap, or (iii) a nonlinearly graded bandgap, and (iv) a piecewise-homogeneous bandgap which is easier to implement than a continuously graded bandgap. An efficiency of 13.53% is predicted with a three-layered piecewise-homogeneous CZTSSe layer. Furthermore, concentrating sunlight by a factor of one hundred can boost the efficiency to 16.70% with the piecewise-homogeneous bandgap.
Integrated Ex-Ante Life Cycle Assessment and Techno-Economic Analysis of Biomass Conversion Technologies Featuring Evolving Environmental Policies
(Systems & Control Transactions, 2024-07-10) Huynh, Dat T.; Ierapetritou, Marianthi
Biorefineries can reduce carbon dioxide emissions while serving the global chemical demand market. Governments are also using carbon pricing policies, such as carbon taxes, cap-and-trade models, and carbon caps, as a strategy to reduce emissions. The use of biomass feedstocks in conjunction with carbon capture usage and storage technologies are mitigation strategies for global warming. Businesses can invest in these technologies to accommodate the adoption of these policies. Rapid action is necessary to halt global warming, which results in aggressive policies. In this work, a multi-period process design and planning problem is developed for the design and capacity expansion of biorefineries. The three carbon pricing policies are integrated into the model and parameters are selected according to the aggressive scenario denoted by the Paris Agreement. The results show that the cap-and-trade policy achieves a higher net present value evaluation over the carbon tax model across all pareto points due to the flexibility of the allowances in the cap-and-trade policy. The carbon cap model substantial investments are required in carbon capture technologies to adhere to the emissions constraints.
Industrial Byproduct Hydrogen Recovery: Mixed Solvent Design, Process Optimization, and Assessment
(Energy & Fuels, 2024-09-05) Guo, Ziqi; Lei, Yang; Chen, Yuming; Liu, Xinyan; Wu, Xiaoqin; Chen, Yuqiu
Recovering industrial byproduct hydrogen helps to minimize the environmental impact associated with hydrogen production. In this study, we propose an innovative approach for hydrogen recovery using an ionic liquid (IL)–methanol mixed solvent. By solving a computer-aided ionic liquid design-based mixed-integer nonlinear programming optimization problem, butylmethylammonium tetrafluoroborate ([N4,1,0,0][BF4]) is identified as the best cosolvent candidate. Subsequently, two process designs for hydrogen recovery using the [N4,1,0,0][BF4]-methanol mixed solvent are proposed and then rigorously simulated in Aspen Plus, followed by a comprehensive process assessment study. Results indicate that the absorption process making use of the IL–methanol mixed solvent is not competitive due to its demand for a large amount of solvent, leading to high energy consumption, carbon emissions, and total annual cost (TAC). Conversely, the IL–methanol-based extractive distillation process achieves notable energy savings of 26.0%, a 24.2% reduction in carbon emissions, and a 10.2% decrease in TAC compared to a benchmark hydrogen recovery process. This study underscores the flexibility and potential of the IL–methanol-based extractive distillation technology in industrial hydrogen recovery applications, paving the way for sustainable and efficient hydrogen production processes.
Increased hydrophilicity of lignin-derivable vs. bisphenol-based polysulfones for potential water filtration applications
(RSC Sustainability, 2024-09-18) Mahajan, Jignesh S.; Shokrollahzadeh Behbahani, Hoda; Green, Matthew D.; Korley, LaShanda T. J.; Epps, Thomas H., III
The functionality inherent in lignin-derivable aromatics (e.g., polar methoxy groups) can provide a potential opportunity to improve the hydrophilicity of polysulfones (PSfs) without the need for the additional processing steps and harsh reagents/conditions that are typically used in conventional PSf modifications. As determined herein, lignin-derivable PSfs without any post-polymerization modification exhibited higher hydrophilicity than comparable petroleum-based PSfs (commercial/laboratory-synthesized) and also demonstrated similar hydrophilicity to functionalized BPA-PSfs reported in the literature. Importantly, the lignin-derivable PSfs displayed improved thermal properties relative to functionalized BPA-PSfs in the literature, and the thermal properties of these bio-derivable PSfs were close to those of common non-functionalized PSfs. In particular, the glass transition temperature (Tg) and degradation temperature of 5% weight loss (Td5%) of lignin-derivable PSfs (Tg ∼165–170 °C, Td5% ∼400–425 °C) were significantly higher than those of typical functionalized BPA-PSfs in the literature (Tg ∼110–160 °C, Td5% ∼240–260 °C) and close to those of unmodified, commercial/laboratory-synthesized BPA-/bisphenol F-PSfs (Tg ∼180–185 °C, Td5% ∼420–510 °C). Sustainability spotlight Commercial bisphenol A-polysulfones (BPA-PSfs) are hydrophobic in nature, and post-polymerization modification is often required to increase the hydrophilicity of commercial PSfs for water filtration applications. Such PSf modification adds extra processing steps and often requires harsh reaction conditions/reagents, and these extra functionalization steps also have a detrimental effect on application-specific thermal properties. Herein, bio-derivable PSfs were synthesized using potentially safer, lignin-derivable bisguaiacols. Notably, the lignin-derivable PSfs, without any post-polymerization modification, demonstrated similar hydrophilicity to functionalized BPA-PSfs reported in the literature, and they also exhibited improved thermal properties relative to functionalized BPA-PSfs. Moreover, the thermal properties of bio-derivable PSfs remained close to those of commercial BPA-PSfs. Overall, this work is aligned with the UN's Sustainable Development Goal 12 (responsible consumption and production of chemicals).

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