bluuebunny/crossref_metadata_2025_split huggingface dataset:
Operational behaviour of graded diamond grinding wheels for end mill cutter machining
Authors: Denkena Berend , Bergmann Benjamin , Raffalt Daniel 
Published: February 2022

AbstractThe varying related material removal rate during deep grinding of cemented carbide end mill cutters results in an unevenly wear of the grinding wheel. This study therefore presents a simulation-based model for the load-adjusted design of grinding wheels to achieve balanced radial wear, as well as an evaluation of this model. The related material removal rate along the width of the grinding wheel is determined by a Dexel based material removal simulation for different end mill geometries. Based on these results an equation is derived to adapt the abrasive layer properties to the local load differences. Three grinding wheels with different types of gradients are then manufactured by a grinding tool manufacturer based on this equation. These and two grinding wheels with constant abrasive layer properties are used for deep grinding of ten end mills each. Afterwards the radial wear of each grinding wheel is measured by a confocal microscope. An analysis of the cutting edge chipping is done to evaluate the influence on the graded grinding wheels on the cutting edge quality. It was found that a reduction of the wear difference over the grinding wheel width of 52% and an improved cutting edge quality can be achieved by using graded grinding tools. This allows the time intervals between dressing steps to be increased without compromising the accuracy of the grinding process, thus also increasing its productivity. Finally, this article shows that the presented model allows for a more balanced wear behaviour, but has to be extended by considering further factors influencing radial wear.
Evaluation of the Hydraulic Conductivity of Geosynthetic Clay Liners
Authors: Hou Juan , Teng Yuyang , Bao Shifen , Li Hao , Liu Lei 
Published: February 2022

Abstract
The hydraulic conductivity of geosynthetic clay liners (GCLs) is not fully understood and certain gaps in knowledge are still present, such as the effect of coupled mechanical and chemical processes. The current study aimed to develop a simplified mathematical model to predict the hydraulic conductivity of GCLs, particularly regarding the coupled effects of mechanical and chemical processes. Based on Darcy's Law and Poiseuille’s Law, the method combines diffuse double layer (DDL) theory and fractal theory. External factors such as confining pressure and the concentration of the permeating solution, and inherent properties such as exchangeable cations, ionic radius, montmorillonite surface fractal dimension, the distance between two montmorillonite layers (m) after swelling at the exchangeable cation i (i denotes the primary exchangeable cations, such as Na+, Ca2+, K+, and Mg2+ in bentonite), density, and coefficient of viscosity of interlayer water between two montmorillonite layers, were considered. The proposed theoretical model gave relatively accurate predictions. A practical estimate of GCL hydraulic conductivity was also derived. The predictions were compared with experimental results and good qualitative agreement was found. From the experimental results, the proposed prediction model has a maximum deviation of ~1:10–10:1, and the empirical model has a mean deviation of ~1:15–15:1.
Antiviral drug research for Japanese encephalitis: an updated review
Authors: Joe Shaun , Salam Abdul Ajees Abdul , Neogi Ujjwal , N Naren Babu , Mudgal Piya Paul 
Published: February 2022

AbstractJapanese encephalitis (JE) caused by the Japanese encephalitis virus (JEV) is one of Asia's most common viral encephalitis. JEV is a flavivirus, common in rural and sub-urban regions of Asian countries. Although only 1% of JEV-infected individuals develop JE, there is a 20–30% chance of death among these individuals and possible neurological sequelae post-infection. No licensed anti-JE drugs are currently available, despite extensive efforts to develop them. Literature search was performed using databases such as PubMed Central, Google Scholar, Wiley Online Library, etc. using keywords such as Japanese encephalitis virus, antiviral drugs, antiviral drug screening, antiviral drug targets, etc. From around 230 papers/abstracts and research reviews retrieved and reviewed for this study, approximately 180 most relevant and important ones have been cited. Different approaches in drug testing and various antiviral drug targets explored so far have been thoroughly searched from the literature and compiled, besides addressing the future perspectives of the antiviral drug development strategies. Although the development of effective anti-JE drugs is an urgent issue, only supportive care is currently available. Recent advancements in understanding the biology of infection and new drug targets have been promising improvements. Despite hindrances such as the unavailability of a proper drug delivery system or a treatment regimen irrespective of the stage of infection, several promising anti-JE candidate molecules are in different phases of clinical trials. Nonetheless, efficient therapy against JEV is expected to be achieved with drug combinations and a highly targeted drug delivery system soon.
Graphical abstract
Structure of Pc 5 Compressional Waves Observed in the Duskside Outer Magnetosphere: MMS Observations
Authors: Tian Anmin , Degeling Alexander W. , Park Jong‐Sun , Shi Quanqi , Nowada Motoharu , Pitkänen Timo , Li Wenya , Xiao Chao 
Published: February 2022

AbstractThe geometrical structure of the Pc 5 compressional wave is important in judging its generation mechanism and the wave‐particle interaction process. In this work, 117 magnetic troughs (where magnetic field strength transiently decreases) identified from 50 Pc 5 compressional wave events in the duskside (15.5–18.5 local time) magnetosphere are studied based on the Magnetospheric Multiscale (MMS) data. We derived the three dimensional geometry of the magnetic trough by including the normal and velocity information at its boundaries from the multi‐spacecraft analysis method. The magnetic trough has a magnetic bottle shape along the magnetic field line with the most probable center (with weakest magnetic field) located at θ = , while the widest part of the magnetic bottle located around θ (θ denotes the angle between spacecraft position vector and the ambient magnetic field). The cross section of the magnetic trough is eccentric and has a “wedge‐like” shape whose average open angle is ∼23° toward radial outward. It is found that the radial component of the current density is the dominant one at the boundaries, and the value is generally proportional to the depth of the magnetic trough. The generation of these Pc 5 compressional waves can be attributed to the drift Alfvén ballooning mirror instability. This work reveals the possible changes of magnetic field configuration caused by the Pc 5 compressional wave in the magnetosphere and may bring new ideas to the interaction way between wave field and ring current particles.
Categorizing MHD Discontinuities in the Inner Heliosphere by Utilizing the PSP Mission
Authors: Liu Y. Y. , Fu H. S. , Cao J. B. , Yu Y. , Liu C. M. , Wang Z. , Guo Z. Z. , He R. J. 
Published: February 2022

AbstractThe interplanetary discontinuities (IDs) have been widely observed in astrophysical and space plasmas, while their characteristics and evolutions within 0.3 AU are still unclear due to the limitation of spacecraft orbits in previous missions. Here, we report three ID events, including a rotational discontinuity (RD), a tangential discontinuity (TD), and a suspected contact discontinuity (CD), detected by the Parker Solar Probe in a previously unexplored region of the heliosphere as close to the Sun as 0.13 AU. By the combination of the minimum variance analysis technique, the Walén relation and the continuity condition of the electric field, the ID orientations, propagations, and thicknesses are determined, showing a smaller typical ID thickness on the order of 100 km therein. Automated event selection using a magnetic field change threshold criterion is conducted with the PSP field data on Orbits 4 and 5. In total, 3,948 IDs are collected, yielding a ratio of . The IDs within 0.4 AU account for 87% of the total IDs, resulting in sharp ID occurrence rate decrease with heliocentric distance, from ∼140 days−1 for RDs and ∼8 days−1 for TDs at 0.13 AU to about 1 day−1 for both RDs and TDs at r > 0.6 AU. Within 0.3 AU, the RDs with tiny propagation angles, i.e., the angles between the magnetic fields and the RD normals, predominate in all kinds of IDs. We further analyze the jump conditions of these IDs statistically, and find that the changes in magnetic fields and particle parameters are theoretically consistent.
Interhemispheric Asymmetries in Magnetosphere and Ionosphere Magnetic Field Residuals Between Swarm Observations and Earth Magnetic Field Models
Authors: Shi Yining , Moldwin Mark B. 
Published: February 2022

AbstractWe present a statistical study of magnetic field vector residual between Swarm observations and two Earth magnetic field models: the 13th generation International Geomagnetic Reference Field (IGRF) model and the CHAOS‐7 model. Statistics of these residuals are important for estimating potential errors for satellite operations when using Earth magnetic models as a reference, as well as for magnetosphere‐ionosphere‐thermosphere studies examining energy input into the system. Magnetic field residuals are calculated as vector differences between observations and model estimation at Swarm satellite positions from 2014 to 2020. Magnetic field residuals for both models increase as geomagnetic activity level increases, and the largest magnitude of vector difference can be around 1800 nT with relatively small angle differences. The CHAOS‐7 model shows lower magnetic field residuals compared to IGRF‐13. North‐south hemispheric asymmetries are seen in magnetic field residuals for high Kp values larger than 6 with the southern hemisphere (SH) having more frequent occurrence of magnetic field residuals larger than 300 nT, especially during SH summer. Most large residual values appear in the high‐latitude region with SH seeing additional large residuals around the South Atlantic Anomaly region. Midnight and noon sectors show the strongest interhemispheric asymmetries. The northern hemisphere shows more frequent occurrence of large residuals above 75° magnetic latitude throughout all local times compared to the SH. Identifying asymmetries in large magnetic residuals under high geomagnetic activity levels is helpful for studying the difference in response to ionospheric disturbances in the two hemispheres.
Spatiotemporal Variations of Shallow Very Low Frequency Earthquake Activity Southeast Off the Kii Peninsula, Along the Nankai Trough, Japan
Authors: Takemura Shunsuke , Obara Kazushige , Shiomi Katsuhiko , Baba Satoru 
Published: February 2022

AbstractCross‐correlation analysis was applied to long‐term onshore broadband records from April 2004 to March 2021 to detect and relocate shallow very low frequency earthquakes (VLFEs) southeast off the Kii Peninsula, along the Nankai Trough, Japan. We then determined the moment rate functions of detected shallow VLFEs using the Monte Carlo‐based simulated annealing method. According to this new comprehensive catalog, shallow VLFEs are widespread beneath the accretionary prism toe, but shallow VLFEs with large cumulative moments are localized around the western edge of the paleo‐Zenisu Ridge, which is subducted beneath southeast off the Kii Peninsula. Our results from the long‐term shallow VLFE catalog are well consistent with previous studies in this region, suggesting that heterogeneous structures and stress conditions due to the subducted paleo‐Zenisu Ridge promote the occurrence of shallow slow earthquakes. The relocated shallow VLFE epicenters illustrated three major episodes characterized by a similar activity area and five minor episodes characterized by different areas. The three major episodes exhibited slow frontal migration with different initiation locations, directions, and speeds, as well as several rapid reverse migrations. Episodes of minor activity were distributed in different locations within part of the area of major activity. Different patterns of shallow VLFE migration could reflect temporal changes in the pore‐fluid distribution or stress conditions of the plate boundary.
New Insights Into the Recent Magma Dynamics Under Campi Flegrei Caldera (Italy) From Petrological and Geochemical Evidence
Authors: Buono G. , Paonita A. , Pappalardo L. , Caliro S. , Tramelli A. , Chiodini G. 
Published: February 2022

AbstractThe Campi Flegrei caldera is considered the most dangerous volcano in Europe and is currently in a new phase of unrest (started in 2000 and still ongoing) that has persisted intermittently for several decades (main crisis occurred from 1950 to 1952, 1970–1972, and 1982–1984). Here, by combining the petrological and geochemical data collected in recent decades with numerical simulations, we place new constraints on the source(s) of the current dynamics of the volcano. In particular, we show that the measured (N2‐He‐CO2) geochemical changes at the fumaroles of Solfatara hydrothermal site are the result of massive (about 3 km3) magma degassing in the deep portion (≥200 MPa, 8 km of depth) of the plumbing system. This degassing mechanism would be able to flood the overlying hydrothermal system with hot gas, thus heating and fracturing the upper crust inducing shallow seismicity and deformation. This implies that the deep magma transfer process (≥8 km) has been decoupled from the source of deformation and seismicity, localized in the first kilometers (0–4 km) of caldera‐filling rocks. This information on magma transfer depth can have important implications for defining the best monitoring strategies and for forecasting a future eruption. Finally, this study highlights how petrological and geochemical data allow us to explore the dynamics of the deep portion of the plumbing system and thus trace the occurrence of recharge episodes, in a portion of the ductile lower crust where magma transfer occurs in the absence of earthquakes.
Frontal Dynamics in the Alboran Sea: 1. Coherent 3D Pathways at the Almeria‐Oran Front Using Underwater Glider Observations
Authors: Zarokanellos Nikolaos D. , Rudnick Daniel L. , Garcia‐Jove Maximo , Mourre Baptiste , Ruiz Simon , Pascual Ananda , Tintoré Joaquin 
Published: February 2022

AbstractOcean fronts are areas that can support phytoplankton production through fertilization in the sunlit layer and the subduction of biogeochemical properties from the surface to the interior of the ocean. The Almeria‐Oran (AO) front is formed from the juxtaposition of fresh inflowing Atlantic waters and more saline re‐circulating Mediterranean waters. A fleet of three gliders flying in parallel lines was deployed across the AO to obtain observations in the CALYPSO project. These observations were combined with remote sensing and modeling simulations, thus providing a novel approach to identifying the three‐dimensional transport and the submesoscale across‐front circulation. The resulting 33 cross‐front sections reveal spatial and temporal changes in the frontal boundary, with isopycnals steepening and/or relaxing. The observations revealed strong horizontal density gradients (up to ∼1.4 kg m−3) and the spatial variability was observed over different length scales (∼10–45 km). The potential vorticity decreased across the front due to the vorticity component in the horizontal density gradient direction. The predominant cyclonic relative vorticity on the dense side of the AO is associated with downwelling processes. The biogeochemical observations also suggest vertical transport along coherent pathways through baroclinic instability. Phytoplankton biomass enhancement occurs as a result, and is subducted below the euphotic layer. The observed oxygen filaments show upwelling and downwelling, providing a mechanism for oxygenating deeper layers and reducing the ventilation of deep low‐oxygenated waters. Understanding the mechanisms of vertical transport can help us evaluate the dynamics of ocean fronts and their impacts on biological carbon storage.
Layered Ejecta Craters in the Candidate Landing Areas of China's First Mars Mission (Tianwen‐1): Implications for Subsurface Volatile Concentrations
Authors: Niu Shengli , Zhang Feng , Di Kaichang , Gou Sheng , Yue Zongyu 
Published: February 2022

AbstractOne important scientific objective of China's first Mars mission (Tianwen‐1) is to investigate the martian surface soil characteristics and water‐ice distribution. Layered ejecta craters (LECs) on Mars are characterized by their fluidized ejecta deposits which have been interpreted to indicate volatiles in the substrate where the impact occurred. Thus, they have potential to serve as important planetary exploration sites/targets of geological significance. In this study, we estimated the absolute model ages (AMAs) of 68 LECs with diameters >4 km using the Context Camera (an instrument onboard the Mars Reconnaissance Obiter, MRO) images in the two candidate landing areas of Tianwen‐1 mission, aiming to reveal temporal‐spatial variation of the regional subsurface volatiles, in particular water ice. The results from a combination of the derived AMAs and the ejecta mobility (EM) values for the southern Utopia‐Isidis Planitia (SUIP) and southern Chryse Planitia (SCP) show that the LECs in both regions plausibly have formed throughout the Amazonian and Hesperian periods. However, the subsurface volatile concentrations might have undergone different evolution histories: SUIP shows a relatively stable trend with time, while there seems a general downward trend in SCP. The presence of the fresh ∼1.5‐km‐diameter LECs suggests that volatile concentrations might have been at depth less than 150 m. We conclude with a discussion of recommendations for Tianwen‐1 and future explorations that have the ability to effectively detect any signs of past and present water/ice on Mars, which contain a wealth of information of past and recent climate.
Controls on Larsen C Ice Shelf Retreat From a 60‐Year Satellite Data Record
Authors: Wang Shujie , Liu Hongxing , Jezek Kenneth , Alley Richard B. , Wang Lei , Alexander Patrick , Huang Yan 
Published: February 2022

AbstractRapid retreat of the Larsen A and B ice shelves has provided important clues about the ice shelf destabilization processes. The Larsen C Ice Shelf, the largest remaining ice shelf on the Antarctic Peninsula, may also be vulnerable to future collapse in a warming climate. Here, we utilize multisource satellite images collected over 1963–2020 to derive multidecadal time series of ice front, flow velocities, and critical rift features over Larsen C, with the aim of understanding the controls on its retreat. We complement these observations with modeling experiments using the Ice‐sheet and Sea‐level System Model to examine how front geometry conditions and mechanical weakening due to rifts affect ice shelf dynamics. Over the past six decades, Larsen C lost over 20% of its area, dominated by rift‐induced tabular iceberg calving. The Bawden Ice Rise and Gipps Ice Rise are critical areas for rift formation, through their impact on the longitudinal deviatoric stress field. Mechanical weakening around Gipps Ice Rise is found to be an important control on localized flow acceleration and the propagation of two rifts that caused a major calving event in 2017. Capturing the time‐varying effects of rifts on ice rigidity in ice shelf models is essential for making realistic predictions of ice shelf flow dynamics and instability. In the context of the Larsen A and Larsen B collapses, we infer a chronology of destabilization processes for embayment‐confined ice shelves, which provides a useful framework for understanding the historical and future destabilization of Antarctic ice shelves.
Spatio‐Temporal Hourly and Daily Ozone Forecasting in China Using a Hybrid Machine Learning Model: Autoencoder and Generative Adversarial Networks
Authors: Cheng Meiling , Fang Fangxin , Navon Ionel M. , Zheng Jie , Tang Xiao , Zhu Jiang , Pain Christopher 
Published: February 2022

AbstractEfficient and accurate real‐time forecasting of national spatial ozone distribution is critical to the provision of effective early warning. Traditional numerical air quality models require a high computational cost associated with running large‐scale numerical simulations. In this work, we introduce a hybrid model (VAE‐GAN) combining a generative adversarial network (GAN) with a variational autoencoder (VAE) to learn the dynamic ozone distributions in spatial and temporal spaces. The VAE‐GAN model can not only decipher the complex nonlinear relationship between the inputs (the past states/ozone and meteorological factors) and outputs (ozone), but also provide ozone forecasts for a long lead‐time beyond the training period. The performance of VAE‐GAN is demonstrated in hourly and daily spatio‐temporal ozone forecasts over China. The training datasets from 2013 to 2017 and validation datasets from 2018 to 2019 are the collection of data from the air quality reanalysis datasets. With the use of VAE, large dataset sizes are decreased by three orders of magnitude, enabling hourly and daily forecasts to be computed in seconds. Results show that the VAE‐GAN achieves a reasonable accuracy in the prediction of both the spatial and temporal evolution patterns of hourly and daily ozone fields, as compared to the Nested Air Quality Prediction Modeling System (commonly used in China), the reanalysis data and observations during the validation period. Thus, the VAE‐GAN is a cost‐effective tool for large data‐driven predictions, which can potentially reinforce air pollution prediction efforts in providing risk assessment and management in a timely manner.
Development of a Reservoir Flood Control Scheme for Global Flood Models
Authors: Hanazaki Risa , Yamazaki Dai , Yoshimura Kei 
Published: February 2022

AbstractIntegrating reservoir flood control operations in global flood forecasting systems is important for accurately estimating discharge and other variables. Because existing modeling operational rules and parameters do not reflect the actual variability due to a lack of associated data, globally applicable modeling of flood regulation needs to be studied further. In this study, we developed a flood control operation scheme with refined parameters and algorithms to tackle this problem. We used recently developed objective data sets of reservoir dynamics to more realistically estimate different reservoir parameters, such as flood storage capacity. Furthermore, the algorithm for the operational rule was modified by introducing a new release coefficient such that the peak attenuation depended on the reservoir's ability to regulate floods. The operation scheme for 2,169 dams was introduced into the CaMa‐Flood global hydrodynamic model. Compared to the simulation without reservoirs, the Nash‐Sutcliffe Efficiency and peak discharge error in the daily river discharge improved at 62.2% and 49.9% of the gauges, respectively, after the integration. Compared to the parameter estimated by a method in previous studies, the newly estimated flood storage capacity parameters reduced the peak discharge error at 47% of the gauges downstream of the reservoirs where the flood storage capacity ratio is small (≤50%). Furthermore, the modification of operational rules had the effect of mitigating people exposed to flooding by ∼10%. This study informs the integration and the refinements of the reservoir operation scheme to improve global flood simulation and forecasting.