bluuebunny/crossref_metadata_2025_split huggingface dataset:
Zeta Potential of a Natural Clayey Sandstone Saturated With Carbonated NaCl Solutions at Supercritical CO2 Conditions
Authors: Hidayat Miftah , Sarmadivaleh Mohammad , Derksen Jos , Vega‐Maza David , Iglauer Stefan , Vinogradov Jan 
Published: July 2022

AbstractThe zeta potential is a measure of electric potential at the mineral‐electrolyte interfaces. The zeta potential of natural sandstones depends on mineralogy, electrolyte pH, concentration, composition, amount of dissolved CO2, and temperature. We report for the first time the zeta potential measured on clayey sandstone comprising quartz, kaolinite, illite, albite and microcline saturated with NaCl solutions at supercritical CO2 conditions. Our results demonstrate that zeta potentials in clayey sandstone samples at supercritical CO2 conditions are significantly different from similar measurements conducted under ambient conditions and from those obtained with clean sandstones. Supercritical CO2 zeta potential remains negative but is influenced by clays and feldspars due to their significant presence and exposure to large pores, which yields less negative zeta potential compared to quartz, under identical conditions. Our results have significant implications to natural subsurface systems such as CO2 geo‐sequestration sites, aquifers, geothermal sources and hydrocarbon reservoirs.
Impact of Sea Surface Temperature Variability at Different Ocean Basins on Dust Activities in the Gobi Desert and North China
Authors: Liu Guanyu , Li Jing , Jiang Zhongjing , Li Xichen 
Published: July 2022

AbstractDust activities are closely related to local meteorological conditions partly driven by remote ocean variability. Here, we investigate the impact of tropical Pacific, North Atlantic, and Arctic ocean variability on dust activities in the Gobi Desert and North China and attempt to quantify their contributions. Three individual Sea Surface Temperature (SST) forcing experiments were performed to simulate the teleconnection from the three ocean basins. Two random forest regression models were established to link the meteorological variables to boreal Spring Dust Activity Frequency (SDAF). Results show that with SST (sea ice concentration for the Arctic) anomaly, tropical Pacific SST variability results in the most change in SDAF in the Gobi Desert, whereas the North Atlantic SST variability plays a more critical role in North China. Considering the observed SST variability, the tropical Pacific becomes more critical in affecting dust activities in both regions.
On the Linearity of External Forcing Response in Solar Geoengineering Experiments
Authors: Virgin J. G. , Fletcher C. G. 
Published: July 2022

AbstractAs an idealized proxy for solar geoengineering, the GeoMIP G1 experiment forces Earth System Models with prescribed reductions in solar radiation to balance increases in atmospheric CO2. One key source of uncertainty is the magnitude of solar constant reduction required to offset a CO2 quadrupling. Here, we employ single‐forcing simulations with Community Earth System Model to decompose the distinct radiative adjustments associated with solar and CO2 forcing in the G1 experiment. We find that radiative adjustments to both single forcings have a net positive effect on top of atmosphere energy balance such that they both increase the net G1 forcing. Stratospheric temperature and shortwave cloud adjustments are the main sources of positive adjustment in both Solar and CO2 simulations. We also show that net radiative adjustment in G1 cannot be represented linearly with CO2 and solar forcing adjustments, which is primarily traced to reductions in boundary layer clouds.
Proton and Helium Ion Acceleration at Magnetotail Plasma Jets
Authors: Richard L. , Khotyaintsev Yu. V. , Graham D. B. , Vaivads A. , Nikoukar R. , Cohen I. J. , Turner D. L. , Fuselier S. A. , Russell C. T. 
Published: July 2022

AbstractWe investigate two flow bursts in a series of Earthward bursty bulk flows (BBFs) observed by the Magnetospheric Multiscale spacecraft in Earth's magnetotail at (−24, 7, 4) RE in Geocentric Solar Magnetospheric coordinates. At the leading edges of the BBFs, we observe complex magnetic field structures. In particular, we focus on one BBF which contains large‐amplitude magnetic field fluctuations on the time scale of the proton gyroperiod, and another with a large scale dipolarization. For both events, the magnetic field structures are associated with flux increases of supra‐thermal ions with energies ≳100 keV. We observe that helium ions dominate the ion flux at energies ≳150 keV. We investigate the ion acceleration mechanism and its dependence on the mass and charge state of H+ and He2+ ions. We show that for both events, the ions with gyroradii smaller than the dawn‐dusk scale of the structure are accelerated by the ion bulk flow. For ions with larger gyroradii, the acceleration is likely due to a localized spatially limited electric field for the event with a large‐scale dipolarization. For the event with fluctuating magnetic field, the acceleration of ions with gyroradii comparable with the scale of the magnetic fluctuations can be explained by resonance acceleration.
A Multi‐Resolution Finite‐Element Approach for Global Electromagnetic Induction Modeling With Application to Southeast China Coastal Geomagnetic Observatory Studies
Authors: Yao Hongbo , Ren Zhengyong , Tang Jingtian , Zhang Keke 
Published: July 2022

AbstractWe present a multi‐resolution finite‐element approach for three‐dimensional (3D) electromagnetic (EM) induction modeling in spherical Earth. First, the secondary electric field approach is employed so that both magnetospheric and ionospheric current sources are naturally considered. Second, the multi‐resolution tetrahedral grids are used to approximate the heterogeneous crust and mantle, so that the local ocean effects at coastal and island observatories can be accurately simulated. Furthermore, a parallel goal‐oriented hp‐adaptive finite‐element method with Nédélec vector elements is employed to guarantee the accuracy of solutions for arbitrary 3D conductivity distributions. Finally, two synthetic models are used to verify the accuracy and efficiency of our newly developed forward modeling solver. Results show that accurate solutions can be obtained for problems with several million to hundreds of millions of unknowns in a few minutes using 128 cores on a cluster. We apply this approach to correct the near‐surface ocean effects for several unused Chinese coastal observatories by performing multi‐resolution 3D modeling. The corrected data are inverted for the subsurface layered mantle conductivity structures. The conductivity model beneath southeast China is more resistive than that beneath northeast China by more than half an order of magnitude. By comparing the inverse models with the latest laboratory conductivity‐depth profiles, the estimated transition zone water content is less than 0.01 wt% beneath southeast China irrespective of which laboratory data is used. Considering the low‐velocity anomalies in this region, which suggest high‐temperature structures, less water is expected. We, therefore, infer that the mantle transition zone beneath southeast China is dry.
Biofilm cultivation facilitates coexistence and adaptive evolution in an industrial bacterial community
Authors: Henriksen Nathalie N. S. E. , Hansen Mads Frederik , Kiesewalter Heiko T. , Russel Jakob , Nesme Joseph , Foster Kevin R. , Svensson Birte , Øregaard Gunnar , Herschend Jakob , Burmølle Mette 
Published: July 2022

AbstractThe majority of ecological, industrial and medical impacts of bacteria result from diverse communities containing multiple species. This diversity presents a significant challenge as co-cultivation of multiple bacterial species frequently leads to species being outcompeted and, with this, the possibility to manipulate, evolve and improve bacterial communities is lost. Ecological theory predicts that a solution to this problem will be to grow species in structured environments, which reduces the likelihood of competitive exclusion. Here, we explored the ability of cultivation in a structured environment to facilitate coexistence, evolution, and adaptation in an industrially important community:Lactococcus lactisandLeuconostoc mesenteroidesfrequently used as dairy starter cultures. As commonly occurs, passaging of these two species together in a liquid culture model led to the loss of one species in 6 of 20 lineages (30%). By contrast, when we co-cultured the two species as biofilms on beads, a stable coexistence was observed in all lineages studied for over 100 generations. Moreover, we show that the co-culture drove evolution of new high-yield variants, which compared to the ancestor grew more slowly, yielded more cells and had enhanced capability of biofilm formation. Importantly, we also show that these high-yield biofilm strains did not evolve when each species was passaged in monoculture in the biofilm model. Therefore, both co-culture and the biofilm model were conditional for these high-yield strains to evolve. Our study underlines the power of ecological thinking—namely, the importance of structured environments for coexistence—to facilitate cultivation, evolution, and adaptation of industrially important bacterial communities.
Sulfation of sialic acid is ubiquitous and essential for vertebrate development
Authors: Ertunc Nursah , Phitak Thanyaluck , Wu Di , Fujita Hiroshi , Hane Masaya , Sato Chihiro , Kitajima Ken 
Published: July 2022

AbstractGlycosylation of proteins and lipids occurs in vertebrates, usually terminating with sialylation, which regulates the physicochemical and biological properties of these glycoconjugates. Although less commonly known, sialic acid residues also undergo various modifications, such as acetylation, methylation, and sulfation. However, except for acetylation, the enzymes or functions of the other modification processes are unknown. To the best of our knowledge, this study is the first to demonstrate the ubiquitous occurrence of sulfated sialic acids and two genes encoding the sialate: O-sulfotransferases 1 and 2 in vertebrates. These two enzymes showed about 50% amino acid sequence identity, and appeared to be complementary to each other in acceptor substrate preferences. Gene targeting experiments showed that the deficiency of these genes was lethal for medaka fish during young fry development and accompanied by different phenotypes. Thus, the sulfation of sialic acids is essential for the vertebrate development.
Weakened pacific overturning circulation, winter monsoon dominance and tectonism re-organized Japan Sea paleoceanography during the Late Miocene global cooling
Authors: Matsuzaki Kenji M. , Ikeda Masayuki , Tada Ryuji 
Published: July 2022

AbstractThe Late Miocene global cooling (LMGC; approximately 7.9–5.8 Ma) was associated with remarkable changes in monsoon dynamics, biogenic bloom in the global oceans, and the rise of modern ecosystems at the expense of old biota. However, the possible linkage between the environmental changes and ecosystem shifts during the LMGC is still debated. In this paper, we show the high-resolution changes in the fluxes of selected radiolarian species, suggesting a drastic reorganization in the paleoceanography and ecosystem in the Japan Sea during the LMGC. The endemic radiolarian Cycladophora nakasekoi dominated the Japan Sea until 7.4 Ma when the Japan Sea sediment changed from dark radiolarian-rich sediment to organic-poor diatom ooze. Changes in the fluxes of C. nakasekoi and Tricolocapsa papillosa, the latter related to changes in the Pacific central water (PCW), show 100, 200, and ~ 500 ka cycles with their high flux mostly within the darker sediment intervals during the low-eccentricity period until 7.4 Ma, suggesting that orbitally paced PCW inflow might have been the major nutrient source into the Japan Sea. At about 7.4 Ma, these species decreased at the expense of increased Larcopyle weddellium, a radiolarian related to the North Pacific intermediate water (NPIW), and Cycladophora sphaeris, a subarctic radiolarian species, implying a decrease in PCW inflow and an increase in the inflow of NPIW and subarctic shallow water. Such a change would have been related to the LMGC-induced weakening in the Pacific Meridional overturning circulation and the southward shift of the subarctic front due to intensified East Asian winter monsoon. Such a drastic reorganization in the hydrography in the Japan Sea probably caused changes in nutrient provenance from the PCW to the NPIW and resulted in faunal turnover, marked by the disappearance of the old regional and endemic faunal components, such as C. nakasekoi.
Greenhouse gases emission reduction for electric power generation sector by efficient dispatching of thermal plants integrated with renewable systems
Authors: Ahmed Ijaz , Rehan Muhammad , Basit Abdul , Hong Keum-Shik 
Published: July 2022

AbstractThis research aims to contribute in developing a mathematical model for the composite probabilistic energy emissions dispatch (CPEED) with renewable energy systems, and it proposes a novel framework, based on an existing astute black widow optimization (ABWO) algorithm. Renewable energy power generation technology has contributed to pollution reduction and sustainable development. Therefore, this research aims to explore the CPEED problem in the context of renewable energy generation systems to enhance the energy and climate benefits of the power systems. Five benchmark test systems, combined with conventional thermal power plants and renewable energy sources such as wind and solar, are considered herein to obtain the optimum solution for cost and pollutant emission by using the ABWO approach. The ascendancy is not limited to environmental impacts, but it also provides the diversification of energy supply and reduction of reliance on imported fuels. As a result, the research findings contribute in lowering the cost of fuel and pollutant emissions, correlated with electricity generation systems, while increasing the renewable energy usage and penetration. Finally, the performance and efficacy of the designed scheme have been fully validated by comprehensive experimental results and statistical analyses.
Inferring the underlying multivariate structure from bivariate networks with highly correlated nodes
Authors: Loske Philipp , Schelter Bjoern O. 
Published: July 2022

AbstractComplex systems are often described mathematically as networks. Inferring the actual interactions from observed dynamics of the nodes of the networks is a challenging inverse task. It is crucial to distinguish direct and indirect interactions to allow for a robust identification of the underlying network. If strong and weak links are simultaneously present in the observed network, typical multivariate approaches to address this challenge fail. By means of correlation and partial correlation, we illustrate the challenges that arise and demonstrate how to overcome these. The challenge of strong and weak links translates into ill-conditioned matrices that need to be inverted to obtain the partial correlations, and therefore the correct network topology. Our novel procedure enables robust identification of multivariate network topologies in the presence of highly correlated processes. In applications, this is crucial to avoid erroneous conclusions about network structures and characteristics. Our novel approach applies to other types of interaction measures between processes in a network.
Fluorescence in situ hybridisation in Carnoy’s fixed tonsil tissue
Authors: Clark S. T. , Waldvogel-Thurlow S. , Wagner Mackenzie B. , Douglas R. G. , Biswas K. 
Published: July 2022

AbstractFluorescence in situ hybridisation (FISH) is a powerful molecular technique that enables direct visualisation of specific bacterial species. Few studies have established FISH protocols for tonsil tissue in Carnoy’s fixative, accordingly limiting its application to investigate the pathogenesis of tonsillar hyperplasia. Tonsil tissue from 24 children undergoing tonsillectomy for either recurrent tonsillitis or sleep-disordered breathing were obtained during a previous study. The specificity of each of the five FISH probes (Fusobacterium spp., Bacteroides spp., Streptococcus spp., Haemophilus influenzae and Pseudomonas spp.) were successfully optimised using pure and mixed bacterial isolates, and in Carnoy’s fixed tonsil tissue. Bacteroides spp. were present in 100% of patients with microcolonies. In comparison, the prevalence of Fusobacterium spp. was 93.8%, Streptococcus spp. 85.7%, H. influenzae 82.35% and Pseudomonas spp. 76.5%. Notable differences in the organisation of bacterial taxa within a single microcolony were also observed. This is the first study to establish a robust FISH protocol identifying multiple aerobic and anaerobic bacteria in Carnoy’s fixed tonsil tissue. This protocol provides a strong foundation for combining histological and microbiological analyses of Carnoy’s fixed tonsil samples. It may also have important implications on the analysis of microorganisms in other human tissues prepared using the same techniques.
Using off-gas for insights through online monitoring of ethanol and baker’s yeast volatilome using SESI-Orbitrap MS
Authors: Mengers Hendrik G. , Zimmermann Martin , Blank Lars M. 
Published: July 2022

AbstractVolatile organic compounds play an essential role in every domain of life, with diverse functions. In this study, we use novel secondary electrospray ionisation high-resolution Orbitrap mass spectrometry (SESI-Orbitrap MS) to monitor the complete yeast volatilome every 2.3 s. Over 200 metabolites were identified during growth in shake flasks and bioreactor cultivations, all with their unique intensity profile. Special attention was paid to ethanol as biotech largest product and to acetaldehyde as an example of a low-abundance but highly-volatile metabolite. While HPLC and Orbitrap measurements show a high agreement for ethanol, acetaldehyde could be measured five hours earlier in the SESI-Orbitrap MS. Volatilome shifts are visible, e.g. after glucose depletion, fatty acids are converted to ethyl esters in a detoxification mechanism after stopped fatty acid biosynthesis. This work showcases the SESI-Orbitrap MS system for tracking microbial physiology without the need for sampling and for time-resolved discoveries during metabolic transitions.
Novel method for an optimised calculation of modal analysis of girder bridge decks
Authors: Gaute-Alonso Alvaro , Garcia-Sanchez David , Ramos-Gutierrez Óscar Ramón 
Published: July 2022

AbstractA correct modal analysis of girder bridge decks requires a correct characterisation of the deformation of their cross-section, governed by the longitudinal bending of the girders and the transverse bending of the slab. This paper presents a novel method that allows the modal analysis of girder bridge decks by applying a matrix formulation that reduces the structural problem to one degree of freedom for each girder: the deflection at the centre of the beam span. A parametric study is presented that analyses the structural response of 64 girder bridge decks. The study compares the dynamic structural response obtained by the proposed method with that obtained by traditional grillage calculation methods. The method is experimentally contrasted by a dynamic load test of a full-scale girder bridge. As a result of the analysis, the proposed method reflects adequate convergence with the experimental dynamic structural response. The use of the proposed novel analysis method contributes to the intelligent modelling process for the analysis of the dynamic behaviour of bridges opening the way to easily feed a Digital Twin accelerating the demands of the Decision Support System in real time.
Improved Passive Gamma Emission Tomography image quality in the central region of spent nuclear fuel
Authors: Virta Riina , Bubba Tatiana A. , Moring Mikael , Siltanen Samuli , Honkamaa Tapani , Dendooven Peter 
Published: July 2022

AbstractReliable non-destructive methods for verifying spent nuclear fuel are essential to draw credible nuclear safeguards conclusions from spent fuel. In Finland, spent fuel items are verified prior to the soon starting disposal in a geological repository with Passive Gamma Emission Tomography (PGET), a uniquely accurate method capable of rod-level detection of missing active material. The PGET device consists of two highly collimated detector banks, collecting gamma emission data from a 360° rotation around a fuel assembly. 2D cross-sectional activity and attenuation images are simultaneously computed. We present methods for improving reconstructed image quality in the central parts of the fuel. The results are based on data collected from 2017 to 2021 at the Finnish nuclear power plants with 10 fuel assembly types of varying characteristics, for example burnups from 5.7 to 55 GWd/tU and cooling times from 1.9 to 37 years. Data is acquired in different gamma energy windows, capturing the peaks of Cs-137 (at 662 keV) and Eu-154 (at 1274 keV), abundant isotopes in long-cooled spent nuclear fuel. Data from these gamma energy windows at well-chosen angles are used for higher-quality images, resulting in more accurate detection of empty rod positions. The method is shown to detect partial diversion of nuclear material also in the axial direction, demonstrated with a novel measurement series scanning over the edge of partial-length rods.
Haptic virtual surgery simulation system under field programmable analogue array-based hybrid control
Authors: Ru Sun , Yang Ting , Zhang Liang , Wang Lin , Fu Yili , Tavakoli Mahdi 
Published: July 2022

AbstractIn this paper, a bilateral haptic virtual surgery simulation system under a hybrid controller was studied. An analogue controller realized by a field programmable analogue array (FPAA) was paralleled in the operator robot side, which reduced the impact of controller discretisation on the system. A system stability conditions under hybrid control with multiple-operators were deduced. The stability analysis indicates that the addition of analogue derivative term widens the range of haptic controls gains that satisfy the multiple-users’ stability conditions. Finally, the human’s performance of a stiffness discrimination task was studied in an independently developed minimally invasive surgical (MIS) platform. The experiment results show that, human operators under the hybrid controller achieve the highest task success rates.