bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modified biochar: synthesis and mechanism for removal of environmental heavy metals
Authors: Liu Zhixin , Xu Ziyi , Xu Linfeng , Buyong Faeiza , Chay Tay Chia , Li Zhuang , Cai Yawen , Hu Baowei , Zhu Yuling , Wang Xiangke 
Published: June 2022

AbstractWith social progress and industrial development, heavy metal pollution in water and soils environment is becoming more serious. Although biochar is a low-cost and environmentally friendly adsorbent for heavy metal ions, its adsorption and immobilization efficiency still need to be improved. As an upgraded version of biochar, modified biochar has attracted extensive attention in the scientific community. This review summarized the recent research progress on the treatment methods on heavy metal pollutants in water and soils using biochar. The features and advantages of biochar modification techniques such as physical modification, chemical modification, biological modification and other categories of biochar were discussed. The mechanism of removing heavy metals from soil and water by modified biochar was summarized. It was found that biochar had better performance after modification, which provided higher surface areas and more functional groups, and had enough binding sites to combine heavy metal ions. Biochar is a very promising candidate for removing heavy metals in environment. Furthermore, some high valent metal ions could be reduced to low valent metals, such as Cr(VI) reduction to Cr(III), and form precipitates on biochar by in-situ sorption-reduction-precipitation strategy. However, it is still the direction of efforts to develop high-efficiency modified biochar with low-cost, high sorption capacity, high photocatalytic performance, environmentally friendly and no secondary pollution in future.
Towards a better understanding of the role of Fe cycling in soil for carbon stabilization and degradation
Authors: Song Xuxin , Wang Pei , Van Zwieten Lukas , Bolan Nanthi , Wang Hailong , Li Xiaomin , Cheng Kuan , Yang Yang , Wang Milan , Liu Tongxu , Li Fangbai 
Published: June 2022

AbstractIron (Fe) minerals play an important role in stabilizing soil organic carbon (SOC). Fe-mediated SOC protection is mainly achieved through adsorption, co-precipitation, or aggregation. However, newly emerging evidence indicates that the electron transfer role of Fe exerts a crucial influence upon SOC turnover. In this review, we address the pathways of Fe mineral-associated soil organic carbon (Fe-SOC) formation and decomposition, and summarize the Fe-mediated biogeochemical, including redox reactions, and physical processes that control SOC cycling. The reduction of Fe can release SOC from Fe-SOC coprecipitates and Fe(III) cemented micro-aggregates, with the process also releasing CO2from the metabolic coupling of SOC oxidation and Fe reduction. The abiotic oxidation of Fe(II) by oxidants can also oxidize SOC to produce CO2due to reactive oxygen species production. Therefore, the functional roles of Fe on SOC sequestration may be a double-edged sword, and these processes are rarely explored concurrently. We conclude that the roles of Fe minerals in SOC stability depend on the properties of the Fe mineral, edaphic properties, and anthropogenic influence. We highlight knowledge gaps and promising directions of future research in redox-dynamic environments to optimize carbon storage in soil.Graphical Abstract
On Internal Tides Driving Residual Currents and Upwelling on an Island
Authors: Rogers Justin S. , Mayer Frederick T. , Davis Kristen A. , Fringer Oliver B. 
Published: June 2022

AbstractWe present a modeling study of an idealized island with sloping sides in a stratified ocean with internal tides propagating through the domain, which transform into nonlinear internal waves as they encounter shallow depths. In the base condition, representative of a mid‐latitude island with relatively steep super critical slopes, the nonlinear internal waves shoaling on the island wrap around the island, scatter, and create an asymmetric wavefield. Radiation stress gradients from this wavefield and rotation are balanced by pressure gradients and turbulent vertical diffusion in the momentum equations which drive residual mean currents around the island. We explore the effects of different physical parameters including no rotation, higher Froude number, subcritical slope, addition of barotropic tides, larger excursion number, and addition of large‐scale mean currents. All simulations showed formation of residual currents of varying intensity, upwelled deep waters in shallow regions, and cooler waters on the side of the island consistent with the direction of incoming internal tides. While the no rotation and strong mean flow conditions created some upwelling, of all the modeled conditions, the subcritical slope has the greatest potential for creating favorable conditions for benthic organisms through enhanced upwelling. Areas of the world's oceans with stratified waters sufficient to sustain internal tide motions, strong internal tide energy, and local subcritical bottom slopes are likely to have cooler waters and more upwelled deep waters than the surrounding areas, and potentially serve as thermal refugia from future ocean warming.
Benthic Carbon Remineralization and Iron Cycling in Relation to Sea Ice Cover Along the Eastern Continental Shelf of the Antarctic Peninsula
Authors: Baloza M. , Henkel S. , Geibert W. , Kasten S. , Holtappels M. 
Published: June 2022

AbstractRapid and profound climatic and environmental changes have been predicted for the Antarctic Peninsula with so far unknown impact on the biogeochemistry of the continental shelves. In this study, we investigate benthic carbon sedimentation, remineralization and iron cycling using sediment cores retrieved on a 400 mile transect with contrasting sea ice conditions along the eastern shelf of the Antarctic Peninsula. Sediments at comparable water depths of 330–450 m showed sedimentation and remineralization rates of organic carbon, ranging from 2.5 to 13 and 1.8–7.2 mmol C m−2 d−1, respectively. Both rates were positively correlated with the occurrence of marginal sea ice conditions (5%–35% ice cover) along the transect, suggesting a favorable influence of the corresponding light regime and water column stratification on algae growth and sedimentation rates. From south to north, the burial efficiency of organic carbon decreased from 58% to 27%, while bottom water temperatures increased from −1.9 to −0.1°C. Net iron reduction rates, as estimated from pore‐water profiles of dissolved iron, were significantly correlated with carbon degradation rates and contributed 0.7%–1.2% to the total organic carbon remineralization. Tightly coupled phosphate‐iron recycling was indicated by significant covariation of dissolved iron and phosphate concentrations, which almost consistently exhibited P/Fe flux ratios of 0.26. Iron efflux into bottom waters of 0.6–4.5 μmol Fe m−2 d−1 was estimated from an empirical model. Despite the deep shelf waters, a clear bentho‐pelagic coupling is indicated, shaped by the extent and duration of marginal sea ice conditions during summer, and likely to be affected by future climate change.
High‐Resolution Thermophysical Analysis of the OSIRIS‐REx Sample Site and Three Other Regions of Interest on Bennu
Authors: Rozitis B. , Ryan A. J. , Emery J. P. , Nolan M. C. , Green S. F. , Christensen P. R. , Hamilton V. E. , Daly M. G. , Barnouin O. S. , Lauretta D. S. 
Published: June 2022

AbstractThe OSIRIS‐REx (Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer) spacecraft sampled asteroid (101955) Bennu on 20 October 2020 and will return the collected regolith to Earth in 2023. Before sample collection, spectral observations of four regions of interest on Bennu's surface were acquired at high spatial resolution (2–9 m per spectrometer spot) to identify the most suitable site for sampling and provide contextual information for the returned sample. In this study, we investigate thermal‐infrared (6–50 μm) observations of these four regions, including the site that OSIRIS‐REx ultimately sampled, using the Advanced Thermophysical Model with input digital terrain models derived from laser altimetry. From model‐to‐measurement comparisons, we find that the observed brightness temperatures depend strongly on small‐scale topography, local variations in thermal inertia, and the observation phase angle. Thermal inertia mapping reveals spatial variations that distinguish the different boulder types found on Bennu. A boulder bearing carbonate veins has higher thermal inertia than average, suggesting that cementation processes reduced its porosity. The thermal inertia of the site sampled is 190 ± 30 J m−2 K−1 s−1/2, which is consistent with observations of a fine‐grained regolith mixed with porous rocks. Thermophysical modeling of the site sampled predicts that the maximum temperatures experienced by the collected sample while on Bennu were 357 ± 3 and 261 ± 3 K for the surface and 50 cm depth, respectively. We predict that OSIRIS‐REx will return a sample with thermophysical properties unique from those of meteorites.
Antecedent Topography and Sediment Dispersal: The Influence of Geologically Instantaneous Events on Basin Fill Patterns
Authors: Sincavage Ryan , Liang Man , Pickering Jennifer , Goodbred Steven , Passalacqua Paola 
Published: June 2022

AbstractFavorable topographic gradients and channel bed aggradation are often cited as primers for river channel avulsion. Sylhet Basin in Bangladesh subsides relatively rapidly and presents a topographically favorable channel course for the Brahmaputra River. Holocene occupations of this region remained routed along the basin's western margin, depositing tens of meters of amalgamated channel sands but leaving the central basin under‐filled. The localized backwater effect from a seasonal lake that forms in Sylhet Basin, referred to as a “hydraulic barrier,” has been proposed as a mechanism for keeping the channel pinned to the western margin. Using a 1‐D channel profile model and a 2‐D depth‐averaged hydrodynamic model, we test the preferred flow path between two possible channel courses under a range of physical conditions. Results show that the hydraulic barrier interpretation is implausible unless water depths are increased beyond the physical dimensions of Sylhet Basin. Reducing topographic slope along the two pathways does not sufficiently enhance the local backwater to steer the channel to the basin center. Only the introduction of a scoured antecedent channel along the western margin induces a strong preference for bypass of the central basin. These results corroborate field evidence that Holocene outburst floods scoured a paleochannel that became the preferred course for the Brahmaputra within Sylhet Basin in the mid to late Holocene. We conclude that modification of basin topography by large, infrequent flood events can exert a persistent influence on channel steering that is comparable to previously documented effects of monsoon variability and tectonic deformation.
Reclamation of Tidal Flats Within Tidal Basins Alters Centennial Morphodynamic Adaptation to Sea‐Level Rise
Authors: Guo Leicheng , Zhu Chunyan , Xu Fan , Xie Weiming , van der Wegen Mick , Townend Ian , Wang Zheng Bing , He Qing 
Published: June 2022

AbstractReclamation of low‐lying tidal flats and floodplains adjacent to present shorelines has been implemented worldwide for both coastal defense and development. While it is technically feasible to monitor the short‐term impact of tidal flat embankments, it is challenging to identify long‐term and cumulative morphodynamic impact, particularly considering centennial sea‐level rise (SLR). In this study, we construct a process‐based hydro‐morphodynamic model for a schematized tidal basin and examine its morphodynamic evolution under the combined influence of SLR and tidal flat embankments. We see that rising sea levels lead to inundation of low‐lying floodplains just above high water, creating new intertidal flats that mitigate the drowning impact of SLR. This mitigation effect is lost if the low‐lying floodplains and tidal flats are reclaimed, preventing any shoreline migration under SLR. Removing a large portion of intertidal flats within the tidal basin induces significant changes in basin hypsometry and potentially, a reversal of flood/ebb dominance. The resulting hydro‐morphodynamic impact of large‐scale tidal flat embankment is more significant than SLR at a centennial time scale. This suggests a need for much greater management awareness regarding the cumulative impact of human activities. These findings imply that allowing lateral shoreline migration under SLR sustains tidal basin's inherent morphodynamic buffering capacity, whereas reclaiming tidal flats significantly alters hydro‐morphodynamic adaptation at the decadal to centennial time scales. It highlights the importance of conserving low‐lying floodplains and tidal flats in tide‐dominated systems to counteract the drowning impact of SLR.
Modeling Spatial Distribution of Carbon Sequestration, CO2 Absorption, and O2 Production in an Urban Area: Integrating Ground‐Based Data, Remote Sensing Technique, and GWR Model
Authors: Khodakarami Loghman , Pourmanafi Saeid , Soffianian Ali Reza , Lotfi Ali 
Published: June 2022

AbstractThe main purpose of this research is to model the spatial distribution of carbon sequestration, CO2 absorption, and oxygen production by trees within Isfahan city, Iran, in 2020. To quantify carbon sequestration, we accessed a sample group of trees with measured biophysical attributes. First, we calculated the biomass and carbon sequestration of a tree using the allometric and photosynthesis equations. Then, to model the spatial distribution of carbon sequestration, we used geographic weighted regression (GWR) method. In this model, the amount of calculated carbon sequestration was the dependent variable, whereas the difference between vegetation indexes of Excess Green Plant Index minus Excess Red Plant Index (ΔExGR) from the Worldview image was the independent variable. Subsequently, the spatial distribution map of CO2 absorption and oxygen production was generated. The total value of annual carbon sequestration, CO2 absorption, and O2 production was about 7704.22, 28274.502, and 20570.16 tons, respectively. The results showed that there was a strong correlation between the ΔExGR index of the canopy with calculated carbon. Integrating the ΔExGR index from a high‐resolution image with calculated carbon can contribute to developing a fast, accurate, and low‐cost method in estimating carbon sequestration and modeling its spatial distribution in urban areas. In conclusion, the results of this research can be implemented by land‐use planners to integrate urban ecosystem service concept (i.e., carbon sequestration) in planning process toward sustainability of the cities.
Contrasting Volcanic Deformation in Arc and Ocean Island Settings Due To Exsolution of Magmatic Water
Authors: Yip Stanley Tze Hou , Biggs Juliet , Edmonds Marie , Liggins Philippa , Shorttle Oliver 
Published: June 2022

AbstractTwo of the most widely observed co‐eruptive volcanic phenomena—Ground deformation and volcanic outgassing—Are fundamentally linked via the mechanism of magma degassing and the development of compressibility, which controls how the volume of magma changes in response to a change in pressure. Here we use thermodynamic models—Constrained by petrological data—To reconstruct volatile exsolution and the consequent changes in magma properties. We use the fraction of SO2 exsolved during decompression to predict co‐eruptive SO2 flux and magma compressibility to predict co‐eruptive surface deformation (both normalized by erupted volume). We conduct sensitivity tests using properties of typical basalts to assess how varying magma volatile content, crustal properties, and chamber geometry affect co‐eruptive deformation and degassing. We find that magmatic H2O content has the most impact on both SO2 flux and volume change. Our findings have general implications for typical basaltic systems in arc and ocean island settings. The higher water content of arc magmas makes them more compressible than ocean island magmas and leads to muted or non‐existent deformation being observed during arc eruptions. Our models are consistent with observation: Deformation has been detected during 48% of basaltic eruptions in ocean island settings (16/33) during the satellite era (2005–2020), but only 11% of basaltic eruptions in arc settings (7/61).
Illuminating the Motions of Jupiter's Auroral Dawn Storms
Authors: Rutala M. J. , Clarke J. T. , Mullins J. D. , Nichols J. D. 
Published: June 2022

AbstractJupiter's auroral main emission (ME) has long been considered to be the result of currents keeping plasma corotating with the surrounding magnetosphere. As a result, the ME corotates with the planet, and individual auroral features making up the ME roughly follow suit. Jupiter's dawn storms, some of the rarest and brightest auroral features within the ME, are an exception, as they do not corotate but instead remain fixed near local dawn. The causes of this enigmatic motion are not fully understood. To test the significance of this motion, we have developed a process to identify auroral features and measure their degree of corotational motion, including dawn storms, in archival Hubble Space Telescope images of the Jovian ultraviolet aurorae. We compare motions of features inside and outside the dawn sector, characterizing the exact motions of dawn storms and providing context for these motions for the first time. In keeping with previous studies, we expected to identify features fixed near local dawn in 10% of observations; instead, we find that half of all features near local dawn lag corotation. We show that subcorotating dawn emissions are far more common than previously thought, and that the drivers of this motion must be similarly common. Corotational motion must be considered when identifying the processes driving all dawn aurorae, including the dawn storms. We explore the consistency of this result with various theories of dawn ME formation and propose that aspects of the known current system relating to the Sun‐Jupiter geometry can explain this behavior.
Evolved Gas Analyses of Sedimentary Rocks From the Glen Torridon Clay‐Bearing Unit, Gale Crater, Mars: Results From the Mars Science Laboratory Sample Analysis at Mars Instrument Suite
Authors: McAdam A. C. , Sutter B. , Archer P. D. , Franz H. B. , Wong G. M. , Lewis J. M. T. , Clark J. V. , Millan M. , Williams A. J. , Eigenbrode J. L. , Knudson C. A. , Freissinet C. , Glavin D. P. , Stern J. C. , Navarro‐González R. , Achilles C. N. , Ming D. W. , Morris R. V. , Bristow T. F. , Rampe E. B. , Thorpe M. T. , House C. H. , Andrejkovičová S. , Bryk A. B. , Fox V. K. , Johnson S. S. , Mahaffy P. R. , Malespin C. A. 
Published: June 2022

AbstractEvolved gas analysis (EGA) data from the Sample Analysis at Mars (SAM) instrument suite indicated Fe‐rich smectite, carbonate, oxidized organics, Fe/Mg sulfate, and chloride in sedimentary rocks from the Glen Torridon (GT) region of Gale crater that displayed phyllosilicate spectral signatures from orbit. SAM evolved H2O data indicated that the primary phyllosilicate in all GT samples was an Fe‐rich dioctahedral smectite (e.g., nontronite) with lesser amounts of a phyllosilicate such as mixed layer talc‐serpentine or greenalite‐minnesotaite. CO2 data supported the identification of siderite in several samples, and CO2 and CO data was also consistent with trace oxidized organic compounds such as oxalate salts. SO2 data indicated trace and/or amorphous Fe sulfates in all samples and one sample may contain Fe sulfides. SO2 data points to significant Mg sulfates in two samples, and lesser amounts in several other samples. A lack of evolved O2 indicated the absence of oxychlorine salts and Mn3+/Mn4+ oxides. The lack of, or very minor, evolved NO revealed absent or very trace nitrate/nitrite salts. HCl data suggested chloride salts in GT samples. Constraints from EGA data on mineralogy and chemistry indicated that the environmental history of GT involved alteration with fluids of variable redox potential, chemistry and pH under a range of fluid‐to‐rock ratio conditions. Several of the fluid episodes could have provided habitable environmental conditions and carbon would have been available to any past microbes though the lack of significant N could have been a limiting factor for microbial habitability in the GT region.
Association of day-of-injury plasma glial fibrillary acidic protein concentration and six-month posttraumatic stress disorder in patients with mild traumatic brain injury
Authors: Kulbe Jacqueline R. , Jain Sonia , Nelson Lindsay D. , Korley Frederick K. , Mukherjee Pratik , Sun Xiaoying , Okonkwo David O. , Giacino Joseph T. , Vassar Mary J. , Robertson Claudia S. , McCrea Michael A. , Wang Kevin K. W. , Temkin Nancy , Mac Donald Christine L. , Taylor Sabrina R. , Ferguson Adam R. , Markowitz Amy J. , Diaz-Arrastia Ramon , Manley Geoffrey T. , Stein Murray B. ,   TRACK-TBI Investigators, Badjatia Neeraj , Duhaime Ann-Christine , Feeser V. Ramana , Keene C. Dirk , Madden Christopher , Merchant Randall , Puccio Ava , Schnyer David , Taylor Sabrina R. , Valadka Alex , Yue John K. , Yuh Esther L. , Zafonte Ross 
Published: June 2022

AbstractSeveral proteins have proven useful as blood-based biomarkers to assist in evaluation and management of traumatic brain injury (TBI). The objective of this study was to determine whether two day-of-injury blood-based biomarkers are predictive of posttraumatic stress disorder (PTSD). We used data from 1143 individuals with mild TBI (mTBI; defined as admission Glasgow Coma Scale [GCS] score 13–15) enrolled in TRACK-TBI, a prospective longitudinal study of level 1 trauma center patients. Plasma glial fibrillary acidic protein (GFAP) and serum high sensitivity C-reactive protein (hsCRP) were measured from blood collected within 24 h of injury. Two hundred and twenty-seven (19.9% of) patients had probable PTSD (PCL-5 score ≥ 33) at 6 months post-injury. GFAP levels were positively associated (Spearman’s rho = 0.35, p < 0.001) with duration of posttraumatic amnesia (PTA). There was an inverse association between PTSD and (log)GFAP (adjusted OR = 0.85, 95% CI 0.77–0.95 per log unit increase) levels, but no significant association with (log)hsCRP (adjusted OR = 1.11, 95% CI 0.98–1.25 per log unit increase) levels. Elevated day-of-injury plasma GFAP, a biomarker of glial reactivity, is associated with reduced risk of PTSD after mTBI. This finding merits replication and additional studies to determine a possible neurocognitive basis for this relationship.