bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrogen generation through metal waste corrosion: a systematic investigation on old/post-consumer scrap Al6063-series alloy
Authors: Gupta Meenal , Selleri Filippo , Ficarella Antonio , Bocchetta Patrizia 
Published: January 2025

Abstract
In this study, aluminum-based wastes are used as energy carriers for on-demand hydrogen production through sustainable, eco-friendly, and cost-effective controlled electrochemical corrosion in aqueous solution. The electrochemical process is very effective because it (i) uses waste metals to produce hydrogen, (ii) corroborates to circular economy, (iii) produces high purity hydrogen, (iv) is based on simple hydrolysis reaction of metals in relevant solutions, (v) electricity is not required and (iv) recovers part of the chemical Gibbs energy of the electrochemical corrosion usually entirely lost in the environment. We systematically studied the generation of hydrogen from industrial waste Dust Scrap Aluminum Alloy (DSAA) belonging to Al 6063 series for the first time. The process is investigated in a novel hand-made batch reactor with a low-cost commercial body suitable to an easy scale-up. Kinetics of DSAA hydrolysis reaction was explored by measuring the variation of aluminium ion concentration at different immersion times through Inductively Coupled Plasma (ICP) and weight loss measurements at different temperatures and NaOH catalyst concentrations. The effect of hydrolysis reaction on the composition and morphology of the metal surfaces in terms of formed oxide layers was studied in detail using Optical Polarizing Microscopy (OPM), Energy dispersive X-ray (EDX) and Scanning Electron Microscopy (SEM) techniques. The criteria used to evaluate the hydrogen reactor performance were hydrogen (i) yield and (ii) production rate. The experimental results showed that a strong increase in NaOH concentration (from 0.75 to 5 M) corresponding to a slow increase in hydrolysis reaction temperature (from 38.8 to 49.9 °C) lead to an improvement in hydrogen generation rate of one order of magnitude, i.e. from 35.71 to 421.41 ml/(g∙min). Low but constant rate of hydrogen can be generated for longer times at low NaOH concentrations (0.75 M), while fast and variable hydrogen generation rate occurs at higher concentrations (5 M) in short times. In the case study of Al 6063 series waste scrap, the hydrolysis reactor parameters can be regulated to deliver hydrogen generation rates from 35.71 to 421.41 ml/(g min) according to requirements. We expect that the results presented in this work will encourage researchers to study the possible use of other metal-based and multi-material plastic/metal wastes thermodynamically prone to electrochemical corrosion process as possible source of hydrogen.

Graphical Abstract
Applications of dimension interpolation to orthogonal projections
Authors: Fraser Jonathan M. 
Published: January 2025

Abstract
Dimension interpolation is a novel programme of research which attempts to unify the study of fractal dimension by considering various spectra which live in between well-studied notions of dimension such as Hausdorff, box, Assouad and Fourier dimension. These spectra often reveal novel features not witnessed by the individual notions and this information has applications in many directions. In this survey article, we discuss dimension interpolation broadly and then focus on applications to the dimension theory of orthogonal projections. We focus on three distinct applications coming from three different dimension spectra, namely, the Fourier spectrum, the intermediate dimensions, and the Assouad spectrum. The celebrated Marstrand–Mattila projection theorem gives the Hausdorff dimension of the orthogonal projection of a Borel set in Euclidean space for almost all orthogonal projections. This result has inspired much further research on the dimension theory of projections including the consideration of dimensions other than the Hausdorff dimension, and the study of the exceptional set in the Marstrand–Mattila theorem.
Granger predictability of real oil prices by us money and inflation in Markov-switching regimes
Authors: Cevik Emrah I. , Dibooglu Sel , Gillman Max , Benk Szilard 
Published: January 2025

Abstract
This paper presents new evidence that US money supply growth and inflation rates Granger predict real oil prices in a two-regime Markov switching vector autoregression (MS-VAR) model. An asset pricing theory motivates the empirical work by showing how jumps in real oil prices approximately follow jumps in the discount factor to keep constant the competitive return to oil capital. Using monthly data from January 1978 to June 2024, we consider alternative data combinations of US money supply growth rates, US inflation rates, and real oil prices to establish volatility regimes through goodness of fit testing. We set baseline model as that model with the highest likelihood in explaining the real oil price, which combines M2, the CPI less energy prices (CPIE), and real oil prices. Robustness considers two M2 variants combined with the CPIE that have the next highest likelihoods, for two alternative models. In the high volatility regime, results show robust Granger predictability of real oil prices by the baseline M2 and the M2 variants. In the low volatility regime for the baseline model, the CPIE inflation rate Granger predicts real oil prices. The paper contributes these new MS-VAR results that combined with the theory provide nuanced non-conventional support that monetary factors contribute to heightened real oil price episodes in volatile times as well as in calmer periods.
Design and optimization of a new NiTi-based shape memory alloy structures for damping applications via additive manufacturing
Authors: Biasutti Tiziana , Bettini Paolo , Grande Antonio Mattia , Sala Giuseppe , Colosimo Bianca Maria , Nespoli Adelaide 
Published: January 2025

Abstract
Shape Memory Alloys (SMA), such as NiTi-based systems, are functional materials suitable for damping applications due to their pseudoelastic effect. This property allows to obtain simple, lightweight structures capable of absorbing energy through a mechanical hysteresis and able to recover significant deformations. For this reason, SMA are attractive candidates for the development of novel devices in many fields, such as the biomedical one or in aerospace and in automotive. Recently, the development of Additive Manufacturing (AM) of metals has considerably expanded the design and production possibilities of SMA-based devices, potentially overcoming the limited workability of these materials through conventional manufacturing techniques, which is one of the main limitations to their wider adoption. This study presents a preliminary investigation of a NiTi octahedral cell structure fabricated via Laser Powder Bed Fusion (L-PBF) starting from a NiTi powder with Ni content of 50.8 at. %. Cells of different sizes were manufactured and subjected to compression tests up to 0.8 mm displacement in order to evaluate their mechanical and functional performances. Furthermore, a numeric model was used to redesign the geometry in order to optimize the structure's damping capacity. The material input data of the numerical model were obtained from mechanical and thermal analyses on square prisms, which were printed with the primary axis oriented perpendicular and at an inclination of 60° to the building platform. Finally, the optimized cell was manufactured and mechanically tested at different temperatures. The obtained results prove the high efficiency of the structure when used for damping applications and highlight the potential of AM to produce NiTi structures that combine load-bearing capabilities and functional responses.
Calculating Sedimentation Rates of Oxic Pelagic Clays Using Core Top Thorium Isotopes
Authors: Costa Kassandra M. , Ossa Ossa Frantz , Dunlea Ann , Pavia Frank J. , Tegler Logan , Auro Maureen , Andersen Morten , Nielsen Sune G. 
Published: January 2025

AbstractOxic pelagic clays are an important component of seafloor sediment that may hold valuable information about past ocean chemistry due to their affinity for and accumulation of biogeochemically important metals. We present a new approach to calculating site‐specific sedimentation rates (SRs) by comparing authigenic sediment thorium isotope compositions (230Th/232Th) to seawater dissolved 230Th/232Th in a suite of deep (>3,000 m) pelagic core sites. We extracted the authigenic sediment fraction using an HHAc leach protocol, which major element chemistry (Al, Mn, Fe, Ti) suggested was less affected by lithogenic contamination than the HCl leach. Four different methods were tested for extracting the appropriate initial 230Th/232Th from seawater: using either the nearest water column station (methods 1 and 2) or a regionally averaged profile (methods 3 and 4) and using either the bottommost profile measurement (methods 1 and 3) or linear regression of the profile and extrapolation to the seafloor (methods 2 and 4). Method 3 outperformed the other methods in reconstructing previously published SRs from pelagic clays in the North Pacific. The new thorium‐based SRs were then combined with estimates from the total sediment thickness on ocean crust and non‐lithogenic cobalt accumulation to determine the best estimates for SRs of oxic pelagic clays. The Pacific has the lowest SR (median 0.28 cm/kyr), while the Atlantic is higher (median 0.46 cm/kyr) and the Indian Ocean is highest (median 0.75 cm/kyr). These new estimates are consistent with the expected spatial patterns of sedimentation, but they revise the absolute SR values downward from available gridded SR maps.
Footwall Geology and Deformation at Flip‐Flop Mid‐Ocean Ridge Detachment Faults: 64°35′E Southwest Indian Ridge (SWIR)
Authors: Mahato S. , Cannat M. 
Published: January 2025

AbstractUsing bathymetry and ROV dives, we investigate two successive flip‐flop detachment faults (D1 active, D2 older) in the near‐amagmatic 64°35′E region of the SWIR. Kilometer‐sized benches on the upper slopes of D1 footwall form the D1 degraded breakaway. Scarps at the top expose the D2 fault zone with deformed serpentinized peridotite, sigmoidal phacoids, planar fractures, and serpentinite microbreccia/gouge horizons. Two ROV sections of the D1 footwall show contrasting deformation styles, corresponding to distinct morphological domains, which relate to contrasting fault and footwall strength. One section documents corrugations, outcrops dominated by sigmoidal phacoids, and planar fractures with thin, discontinuous serpentinite microbreccia/gouge horizons. ROV dives in this corrugated domain show that NNE‐trending km‐spaced ridges and WNW‐trending narrow benches in the shipboard bathymetry correspond, respectively, to broad undulations (mega‐corrugations) of the D1 fault and to several antithetic minor normal faults (cumulated horizontal offset of ∼285 m). The other section, lacking corrugations, broad ridges, and antithetic fault, has thicker and more continuous serpentinite microbreccia/gouge horizons, indicating a weaker fault. The abundance of such weak gouges probably reflects hydrous fluid availability during deformation. We link mega‐corrugations in the western domain and km‐scale lobes of D1 emergence to a broad detachment damage zone with up to ∼600 m‐thick mega‐phacoids of less deformed serpentinized peridotite. Small antithetic normal faults in the corrugated domain are interpreted as due to bending forces in the D1 footwall. Our findings highlight the three‐dimensional, non‐planar structural and morphological variability of the exhumed D1 detachment fault zone along the ridge‐axis.
The Metabolic Balance of Lake Superior's Mixed Layer
Authors: Gunawardana Panditha V. S. L. , Pearce Nolan J. T. , Austin Jay A. , Hollenhorst Thomas , Hoffman Joel C. , Xenopoulos Marguerite A. 
Published: January 2025

AbstractUnderstanding carbon (C) dynamics in large lake ecosystems poses challenges due to their size, causing uncertainty in their contribution to the global C cycle. Here, we used autonomous underwater vehicles to calculate upper mixed‐column (UMC) metabolism in Lake Superior. We paired 7 years of high‐resolution dissolved oxygen and temperature data from 17 glider missions with in situ meteorological data to calculate daily gross primary production, ecosystem respiration, and net ecosystem metabolism. We found the UMC of Lake Superior to be net heterotrophic (primary production < ecosystem respiration) most of the time, suggesting its role as a net source of CO2 to the atmosphere. Heterotrophy was pronounced during cold and transitional days (<14°C) and in nearshore regions (<10 km distance from the shore). When scaled, our results indicate that Lake Superior released 84–112 Tg CO2 y−1, which is twice the rate of C it fixes from the UMC itself.
Deep Neural Networks for Refining Vertical Modeling of Global Tropospheric Delay
Authors: Yuan Peng , Balidakis Kyriakos , Wang Jungang , Xia Pengfei , Wang Jian , Zhang Mingyuan , Jiang Weiping , Schuh Harald , Wickert Jens , Deng Zhiguo 
Published: January 2025

AbstractKinematic airborne platforms are becoming increasingly vital for Earth observation. They highlight the critical need for accurate tropospheric delay corrections across varying altitudes, especially as most existing models are limited to Earth's surface. Although analytical functions have been used to model vertical reductions in tropospheric delays, they struggle to capture the intricate vertical variations of atmospheric state. In response, we introduce a novel approach that utilizes deep neural networks (DNN) to reconstruct global three‐dimensional zenith hydrostatic delay (ZHD) and zenith wet delays (ZWD) derived from numerical weather models (NWM). Our method reconstructs NWM‐derived ZHD and ZWD globally up to 14 km above the Earth's surface, with average precision levels of 0.4 and 0.8 mm, respectively. Compared to the analytical third‐order exponential model, the DNN approach demonstrates substantial improvement with global average root‐mean‐square reductions of 63% for ZHD and 36% for ZWD.
Two‐ and Three‐Dimensional Propagation Characteristics of Co‐Volcanic Ionospheric Disturbances Induced by the 2022 Tonga Volcano Eruption Using Dense GNSS Network Data
Authors: Mei Dengkui , Zhang Xiaohong , Ren Xiaodong , Le Xuan , Liu Hang , Freeshah Mohamed 
Published: January 2025

AbstractOn 15 January 2022, the submarine volcano in Hunga Tonga‐Hunga Ha’apai (hereinafter Tonga volcano) erupted at 04:14 universal time. This study investigated the two‐ and three‐dimensional co‐volcanic ionospheric disturbances (CVIDs) induced by the strong Tonga volcano. Based on dense Global Navigation Satellite System network data in Australia, the two‐dimensional detrended total electron content maps were first generated by using the Savitzky‐Golay filtering method. Using a compressed sensing‐based computerized ionospheric tomography approach, the three‐dimensional ionospheric electron densities were reconstructed. After the eruption, the distinctive CVIDs began to be mostly observed over southeastern Australia, about 4,000 km from the volcano. Two patterns of observable CVIDs, that is, fast‐mode and slow‐mode CVIDs, traveled outward from the Tonga volcano at speeds of 600–850 and 200–350 m/s, respectively. The slow‐mode CVIDs were related to the Lamb and secondary gravity waves, while the fast‐mode CVIDs were related to acoustic waves. Three‐dimensional reconstruction results demonstrated that as the CVIDs propagated upward, the electron densities fluctuated at most altitude‐longitude slices, and the wave‐like propagating patterns were clearly observed around the peak ionospheric heights of 260–340 km. At the peak ionospheric height, the ionospheric parameters derived from the two ionosondes over Australia also detected similar wave‐like features. Two‐dimensional and three‐dimensional observational evidence of the Tonga‐induced CVIDs enhances research on volcanic eruption effects over the upper ionosphere.
Characterization and Modeling of Equatorial Ionization Anomaly Crest and Trough Positions Using Multiple‐Source Fused Data During the Solar Minimum Period
Authors: Wang Kaixin , Feng Jiandi , Zhang Ting , Zhao Zhenzhen , Han Baomin 
Published: January 2025

AbstractCharacterizing the spatial and temporal variations of the equatorial ionization anomaly (EIA) is essential for understanding ionospheric dynamical processes and further developing empirical total electron content (TEC) models. Using the multiple‐source fused TEC data during the solar minimum period, the EIA crest and trough positions were extracted, analyzed, and modeled. We primarily investigated the longitudinal differences in the probability of bimodal occurrence (PBO) and its time dependence at each longitude. The main results are as follows: (a) The PBO exhibits significant longitudinal variation, with a wave‐number‐3 structure from 11:00 to 13:00 LT and a wave‐number‐4 structure around 15:00 LT. There is a sequential enhancement and recession among four sectors from east to west between 09:00 LT and 15:00 LT. (b) The seasonal dependence of PBO varies across sectors, particularly during the solstice months. The wavenumber spectral components of TEC along the longitudinal direction exhibit similar temporal patterns, suggesting that the atmospheric tides may modulate the local time and seasonal dependence of PBO. (c) Two EIA position models were developed. The model based on longitude and month can accurately capture the seasonal and spatial variations in the locations of peaks and troughs, with a mean residual of 0° and a standard deviation of 2.1°–2.3°.
Kinematic Characteristics and Water Mass Transports of Submesoscale Coherent Vortices in the Northeastern South China Sea
Authors: Wei Yi , Zhang Zhiwei , Zhang Xincheng , Sun Zhongbin , Zhao Wei , Tian Jiwei 
Published: January 2025

AbstractAs a unique phenomenon occurring in the subsurface ocean, submesoscale coherent vortices (SCVs) are believed to have a pivotal role in the long‐distance ocean tracer transports. SCVs have been widely observed in the global oceans; however, most of them are captured accidentally, and their kinematic characteristics and water mass transports have only been studied in a limited number of regions. Here, we use 4‐year observations of velocity, temperature, and salinity from five moorings in the northeastern South China Sea (NESCS) to examine dozens of newly discovered SCVs. A total of 34 SCVs were identified during the observational period, including 25 convex lens‐like anticyclones and 9 concave lens‐like cyclones. The maximum swirl velocity, mean radius, and vertical length scale of the anticyclones (cyclones) are 0.19 ± 0.07 m s−1 (0.19 ± 0.07 m s−1), 26.4 ± 13.9 km (17.0 ± 5.4 km), and 204 ± 62 m (188 ± 53 m), respectively. Vertically, the velocity structure of the observed SCVs conforms to a Gaussian function when the effect of stratification is removed. Water mass analysis suggests that 88% (30/34) of the SCVs carried Kuroshio water, which demonstrates the mechanism proposed by Zhang et al. (2022), https://doi.org/10.1029/2021jc018117 that they are formed by Kuroshio‐islands interactions in the Luzon Strait. This category of SCVs is therefore named Luzon Strait island wake eddies (Liddies). We further estimate that Liddies can result in an equivalent mean volume transport of 0.20 Sv westward across the Luzon Strait, which suggests that they play a non‐negligible role in the subsurface water transports between the NESCS and the northwestern Pacific.
River Mouth Hydrodynamics: The Role of the Outlet Geometry and Transient Tidal and River Discharge Conditions on the Jet Structure
Authors: Ruiz‐Reina Antonio , López‐Ruiz Alejandro , Ortega‐Sánchez Miguel 
Published: January 2025

AbstractThe hydrodynamics of river mouths are the result of a complex interaction between river flow, tidal conditions, and outlet geometry. This complex interaction of factors shapes the jet that flows onto the continental shelf and influences the dynamics of these areas. This work analyses the influence of idealized but realistic outlet geometries under steady and unsteady hydrodynamic conditions on the jet structure. The analysis is carried out using a numerical model which is validated by comparison with the classical jet theory for highly simplified conditions where this theory applies. The results show that both the outlet geometry and the transient hydrodynamic conditions have a significant influence on the jet structure and evolution along the nearshore. For constant river discharge and water level conditions, the results indicate that the nearshore profile plays a key role in determining the expansion or contraction of the jet. The momentum balance shows that the jet behavior is related to the momentum transport and the barotropic terms. In cases where the river discharge and tidal conditions are transient, the jet alternates between a structure with two velocity maxima at the edges or a single peak in the center during the tidal cycle depending on the phase lag between the tidal conditions and the river hydrograph. These two different jet structures play an important role in the morphodynamic evolution of the river mouths and bar development, favoring in some cases the formation of lateral levees parallel to the channel walls.
Constraining the Acetone Photolysis Quantum Yield: Current Insights and Atmospheric Chemistry Implications
Authors: Link M. F. , Brewer J. , Farmer D. K. , Ravishankara A. R. 
Published: January 2025

AbstractAcetone photolysis is a potentially important source of hydroperoxyl and hydroxyl radicals (HOx) to the upper troposphere. The extent to which acetone photolysis is a significant source of HOx in the upper troposphere is unclear in part because of scarce measurements of the acetone photolysis quantum yield (Φacetone) in the actinic region (i.e., λ > 300 nm). Past measurements of the Φacetone have derived temperature‐ and pressure‐dependent parameterizations that lead to significantly different conclusions about the importance of acetone to HOx formation in the upper troposphere. Here, we focus on previously published data to derive the recommended Φacetone for atmospheric chemical modeling. Using Stern‐Volmer analyses, we determine temperature‐ and pressure‐dependent Φacetone using updated measurements of fundamental acetone photolysis parameters. We also use simulations of the Φacetone produced from recent photophysical modeling to derive temperature‐ and pressure‐dependent parameterizations of the Φacetone. In contrast to the current Φacetone parameterization used in atmospheric chemical modeling, our parameterization reflects a predicted nonzero Φacetone in the wavelength region above 320 nm. Despite the increased Φacetone values in the higher wavelength region of the acetone photolysis action spectrum, the modeled effect on HOx production is not significantly different from HOx produced using the current recommended Φacetone parameterization. Uncertainties in the acetone photolysis mechanism remain; thus, more direct temperature‐ and pressure‐dependent measurements of Φacetone are warranted.