bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rate-, state-, and pressure-dependent friction model based on the elastoplastic theory
Authors: Ozaki Shingo , Matsuura Takeru , Maegawa Satoru 
Published: January 2020

AbstractAdhesion is one of essences with respect to rubber friction because the magnitude of the friction force is closely related to the magnitude of adhesion on a real contact area. However, the real contact area during sliding depends on the state and history of the contact surface. Therefore, the friction force occasionally exhibits rate-, state-, and pressure dependency. In this study, to rationally describe friction and simulate boundary value problems, a rate-, state-, and pressure-dependent friction model based on the elastoplastic theory was formulated. First, the evolution law for the friction coefficient was prescribed. Next, a nonlinear sliding surface (frictional criterion) was adopted, and several other evolution laws for internal state variables were prescribed. Subsequently, the typical response characteristics of the proposed friction model were demonstrated, and its validity was verified by comparing the obtained results with those of experiments conducted considering the contact surface between a rough rubber hemisphere and smooth acrylic plate.
Microstress cycle and contact fatigue of spiral bevel gears by rolling-sliding of asperity contact
Authors: Cao Wei , Ren Si , Pu Wei , Xiao Ke 
Published: January 2020

AbstractThe rolling contact fatigue (RCF) model is commonly used to predict the contact fatigue life when the sliding is insignificant in contact surfaces. However, many studies reveal that the sliding, compared to the rolling state, can lead to a considerable reduction of the fatigue life and an excessive increase of the pitting area, which result from the microscopic stress cycle growth caused by the sliding of the asperity contact. This suggests that fatigue life in the rolling-sliding condition can be overestimated based only on the RCF model. The rubbing surfaces of spiral bevel gears are subject to typical rolling-sliding motion. This paper aims to study the mechanism of the micro stress cycle along the meshing path and provide a reasonable method for predicting the fatigue life in spiral bevel gears. The microscopic stress cycle equation is derived with the consideration of gear meshing parameters. The combination of the RCF model and asperity stress cycle is developed to calculate the fatigue life in spiral bevel gears. We find that the contact fatigue life decreases significantly compared with that obtained from the RCF model. There is strong evidence that the microscopic stress cycle is remarkably increased by the rolling-sliding motion of the asperity contact, which is consistent with the experimental data in previous literature. In addition, the fatigue life under different assembling misalignments are investigated and the results demonstrate the important role of misalignments on fatigue life.
Hierarchical Porous RGO/PEDOT/PANI Hybrid for Planar/Linear Supercapacitor with Outstanding Flexibility and Stability
Authors: Liu Fuwei , Xie Luoyuan , Wang Li , Chen Wei , Wei Wei , Chen Xian , Luo Shaojuan , Dong Lei , Dai Qilin , Huang Yang , Wang Lei 
Published: January 2020

AbstractMany hybrid electrodes for supercapacitors (SCs) are a reckless combination without proper structural design that keeps them from fulfilling their potential. Herein, we design a reduced graphene oxide/poly(3,4-ethylenedioxythiophene)/polyaniline (RGO/PEDOT/PANI) hybrid with hierarchical and porous structure for high-performance SCs, where components fully harness their advantages, forming an interconnected and conductive framework with substantial reactive sites.Thus, this hybrid achieves a high capacitance of 535 F g−1 along with good rate capability and cyclability. The planar SC based on this hybrid deliver an energy density of 26.89 Wh kg−1 at a power density of 800 W kg−1. The linear SC developed via modifying a cotton yarn with the hybrid exhibits good flexibility and structural stability, which operates normally after arbitrary deformations. This work provides a beneficial reference for developing SCs.
Graphitic Carbon Quantum Dots Modified Nickel Cobalt Sulfide as Cathode Materials for Alkaline Aqueous Batteries
Authors: Zhu Yirong , Li Jingying , Yun Xiaoru , Zhao Ganggang , Ge Peng , Zou Guoqiang , Liu Yong , Hou Hongshuai , Ji Xiaobo 
Published: January 2020

AbstractCarbon quantum dots (CQDs) as a new class of emerging materials have gradually drawn researchers’ concern in recent years. In this work, the graphitic CQDs are prepared through a scalable approach, achieving a high yield with more than 50%. The obtained CQDs are further used as structure-directing and conductive agents to synthesize novel N,S-CQDs/NiCo2S4 composite cathode materials, manifesting the enhanced electrochemical properties resulted from the synergistic effect of highly conductive N,S-codoped CQDs offering fast electronic transport and unique micro-/nanostructured NiCo2S4 microspheres with Faradaic redox characteristic contributing large capacity. Moreover, the nitrogen-doped reduced graphene oxide (N-rGO)/Fe2O3 composite anode materials exhibit ultrahigh specific capacity as well as significantly improved rate property and cycle performance originating from the high-capacity prism-like Fe2O3 hexahedrons tightly wrapped by highly conductive N-rGO. A novel alkaline aqueous battery assembled by these materials displays a specific energy (50.2 Wh kg−1), ultrahigh specific power (9.7 kW kg−1) and excellent cycling performance with 91.5% of capacity retention at 3 A g−1 for 5000 cycles. The present research offers a valuable guidance for the exploitation of advanced energy storage devices by the rational design and selection of battery/capacitive composite materials.
The Role of Palliative Care in Reducing Symptoms and Improving Quality of Life for Patients with Idiopathic Pulmonary Fibrosis: A Review
Authors: Zou Richard H. , Kass Daniel J. , Gibson Kevin F. , Lindell Kathleen O. 
Published: January 2020

AbstractIdiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease with a median survival of 3–4 years from time of initial diagnosis, similar to the time course of many malignancies. A hallmark of IPF is its unpredictable disease course, ranging from long periods of clinical stability to acute exacerbations with rapid decompensation. As the disease progresses, patients with chronic cough and progressive exertional dyspnea become oxygen dependent. They may experience significant distress due to concurrent depression, anxiety, and fatigue, which often lead to increased symptom burden and decreased quality of life. Despite these complications, palliative care is an underutilized, and often underappreciated, resource before end-of-life care in this population. While there is growing recognition about early palliative care in IPF, current data suggest referral patterns vary widely based on institutional practices. In addition to focusing on symptom management, there is emphasis on supplemental oxygen use, pulmonary rehabilitation, quality of life, and end-of-life care. Importantly, increased use of support groups and national foundation forums have served as venues for further disease education, communication, and advanced care planning outside of the hospital settings. The purpose of this review article is to discuss the clinical features of IPF, the role of palliative care in chronic disease management, current data supporting benefits of palliative care in IPF, its role in symptom management, and practices to help patients and their caregivers achieve their best quality of life.
Effect of interfacial drag force model on code prediction for upward adiabatic two-phase bubbly flow in vertical channels
Authors: Hibiki Takashi , Ozaki Tetsuhiro 
Published: January 2020

AbstractAccurate modeling of the interfacial drag force is one of the keys to predicting thermo-fluid parameters using one-dimensional nuclear thermal-hydraulic system analysis code architected through the two-fluid model. The interfacial drag force appears in the interfacial momentum transfer term and governs the velocity slip or the relative velocity between gas and liquid phases. The most straightforward method to model the interfacial drag force is to model the force through the drag law (drag law approach). A drag coefficient and interfacial area concentration should be given to close the interfacial drag force model. Among them, the modeling of the interfacial area concentration has been one of the weakest links in the interfacial drag force modeling due to the lack of reliable data covering a wide test condition including prototypic nuclear reactor conditions and lack of physically sound interfacial area model. To avoid a considerable uncertainty in the prediction of the interfacial area concentration, Andersen and Chu (1982) proposed the interfacial drag force model using the drift-flux parameters (Andersen approach). The Andersen approach is practical for the simulation of a slow transient flow and a steady flow. Major system analysis codes such as USNRC TRACE have adopted the Andersen approach in the interfacial drag force modeling. Some attempts to improve the code performance have been considered using the drag law approach with the interfacial area transport equation. The dynamic modeling of the interfacial area concentration has the potential to improve the prediction accuracy of the interfacial area concentration in a transient flow and developing flow. Due to the importance of the improved interfacial drag force modeling, the implementation and evaluation of the interfacial area transport equation in USNRC TRACE code has been performed by Talley et al. (2011, 2013). The study claimed that the introduction of the interfacial area transport equation into the TRACE code improved the code performance in an adiabatic bubbly flow analysis significantly. The present study assessed the code calculation made by Talley et al. (2011) and identified several issues in the code calculation results. The present study analytically demonstrated that the drag law approach became identical with the Andersen approach for the distorted particle regime (or a major bubble shape regime in bubbly flow) due to the balancing-out of the interfacial area concentration (or bubble size) in the numerator and denominator of the interfacial drag force formulation. The code calculation using TRAC code endorsed the analytical assessment of the insignificant or no merit of the interfacial area transport equation in the code performance of the adiabatic bubbly flow analysis. The present study also pointed out the inconsistency of the code calculation made by Talley et al. (2011).
Concentration of meropenem in patients with sepsis and acute kidney injury before and after initiation of continuous renal replacement therapy: a prospective observational trial
Authors: Nowak-Kózka Ilona , Polok Kamil J. , Górka Jacek , Fronczek Jakub , Gielicz Anna , Seczyńska Bożena , Czuczwar Mirosław , Kudliński Bartosz , Szczeklik Wojciech 
Published: January 2020

Abstract
Background
The effect of renal replacement therapy on drug concentrations in patients with sepsis has not been fully elucidated because the pharmacokinetic properties of many antimicrobials are influenced by both pathophysiological and treatment-related factors. The aim of this study was to determine meropenem concentrations in patients with sepsis before and after the initiation of continuous venovenous hemodialysis with regional citrate anticoagulation (RCA-CVVHD).

Methods
The study included 15 critically ill patients undergoing RCA-CVVHD due to sepsis-induced acute kidney injury. All participants received 2 g of meropenem every 8 h in a prolonged infusion lasting 3 h. Meropenem concentrations were measured in blood plasma using high-performance liquid chromatography coupled with tandem mass spectrometry. Blood samples were obtained at six-time points prior to and at six-time points after introducing RCA-CVVHD.

Results
The median APACHE IV and SOFA scores on admission were 118 points (interquartile range [IQR] 97–134 points) and 19.5 points (IQR 18–21 points), respectively. There were no significant differences in the plasma concentrations of meropenem measured directly before RCA-CVVHD and during the first 450 min of the procedure. The drug concentration reached its peak 2 h after initiating the infusion and then steadily declined.

Conclusions
The concentration of high-dose meropenem (2 g every 8 h) administered in a prolonged infusion was similar before and after the introduction of RCA-CVVHD in patients with sepsis who developed acute kidney injury.
Maximum Southwest Greenland Ice Sheet Recession in the Early Holocene
Authors: Lesnek A. J. , Briner J. P. , Young N. E. , Cuzzone J. K. 
Published: January 2020

AbstractEstablishing the timing of maximum Holocene warmth in the Arctic is critical for understanding global climate system response to external forcing. In Greenland, challenges in obtaining climate records that span the full Holocene have hampered efforts to robustly identify when the Holocene Thermal Maximum occurred. Reconstructing land‐based ice sheet history can fill this gap because these ice sheet regions respond sensitively to summer temperature. We synthesize new and published 10Be and 14C ages from southwest Greenland to map Greenland ice sheet margin positions from 12 to 7 ka and calculate retreat rates from 12 to 0 ka. We found that maximum Greenland ice sheet recession occurred between ~10.4 and 9.1 ka. Our reconstruction suggests that summer air temperatures in southwest Greenland were highest from ~10.4 to 9.1 ka, providing support for an early regional Holocene Thermal Maximum. These results can serve as benchmarks for comparison with ice sheet and climate model simulations.
Identifying Active Kelvin–Helmholtz Vortices on Saturn's Magnetopause Boundary
Authors: Burkholder B. L. , Delamere P. A. , Johnson J. R. , Ng C.‐S. 
Published: January 2020

AbstractFor
Cassini magnetopause encounters, we analyse plasma and magnetic fields. The boundary can be unstable to the Kelvin–Helmholtz instability (KHI), which can drive large‐scale flows identifiable in plasma measurements. Bulk flow reversed from the expected direction near the magnetopause can indicate vorticity associated with active KH, and events are found dominantly in the dawn–subsolar region. KHIs are also responsible for magnetic field fluctuations, and hybrid simulations indicate heating, and transport is significant in an actively growing vortex. Cassini observations are filtered for disturbed magnetic fields near the magnetopause, similar to the signatures from hybrid simulations, with significant fluctuation and current sheet crossings. We also find that these occur most frequently in the dawn–subsolar region. A turbulent heating rate density and mass diffusion coefficient are calculated for these disturbed events and compared with the hybrid simulation to test whether enhanced values for these quantities can identify active KH events.
An Assessment of PBL Heights and Low Cloud Profiles in CAM5 and CAM5‐CLUBB Over the Southeast Pacific Using Satellite Observations
Authors: Kubar Terence L. , Xie Feiqin , Ao Chi O. , Adhikari Loknath 
Published: January 2020

AbstractInstantaneous satellite cloud top height (CTH) data from Moderate Resolution Imaging Spectroradiometer and Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observation, as well as planetary boundary layer (PBL) heights corresponding to the minimum refractivity gradient (PBLHN) from GPS radio occultation over the Southeast Pacific, are jointly used for the first time to assess the ability of three versions of National Center for Atmospheric Research Community Atmosphere Model 5 (CAM5) to simulate low‐level cloud extent and boundary layer heights. Observed CTH and PBLHN match most closely in the stratocumulus and stratocumulus‐to‐cumulus transition region, but CTH becomes lower than PBLHN since not all trade cumulus clouds reach the inversion. Simulated CTH and PBLHN are too shallow, but clouds with a new subgrid low cloud parameterization, Cloud Layers Unified by Binormals (CAM5‐CLUBB), have a reduced bias, with the CTH‐PBLHN distribution from Hi‐Res CAM5‐CLUBB, the most similar to observations. For PBLHN > 2.7 km, the base CAM5 model shows a bimodal cloud structure and surface‐to‐500 hPa ascent not seen in observations and European Centre for Medium‐Range Weather Forecasts Re analysis Interim data.
Variability in Direct and Diffuse Solar Radiation Across China From 1958 to 2017
Authors: He Yanyi , Wang Kaicun 
Published: January 2020

AbstractLong‐term variability of direct and diffuse solar radiation (Rdir and Rdif) is essential for climate change study. However, Rdir and Rdif observations suffer from low spatiotemporal coverage and inhomogeneity. This study improved hybrid models to calculate Rdir and Rdif from sunshine duration and meteorological data at ~2,000 stations from 1958 to 2017 over China and demonstrated their reliability. We identified that Rdir observations show a spurious steep downtrend before 1990 due to the sensitivity drift of the measuring instruments, implying an overestimation of global dimming. Long‐term trends and spatiotemporal details in Rdir and Rdif were also revealed. From 1958 to 1989, our results show that Rdir displays a significant downtrend (−3.52 W m−2 per decade), whereas Rdif shows a significant increasing trend (0.84 W m−2 per decade), especially over the North China Plain. From 1990 to 2017, Rdir decreases nonsignificantly by −0.47 W m−2 per decade but Rdif shows a slight decline of −0.28 W m−2 per decade.
Assessing Energy Budget of Laboratory Fault Slip Using Rotary Shear Experiments and Micro‐Computed Tomography
Authors: Zhao Qi , Glaser Steven D. , Tisato Nicola , Grasselli Giovanni 
Published: January 2020

AbstractQuantitative assessment of the energy budget of earthquake events is one of the key aspects for understanding the physics of earthquakes. Investigation of laboratory fault slips under controlled conditions can provide insights on this important aspect of the natural and induced earthquakes. We conducted a rotary shear experiment under X‐ray micro‐computed tomography, which allowed in situ and operando measurement of macroscopic stresses and imaging of the newly formed fractures inside the sample. We estimate each component of the energy budget and found that friction energy loss (EF), fracture energy (EG), and radiated energy (ER) account for 70.16%, 15.68%, and 14.15% of the total energy budget, respectively. Quantitative analysis of the micro‐computed tomography images indicates that the energy consumed by creating slip‐induced off‐fault fractures (
) accounts for only 0.3% of the total energy, less than 2% of the total EG.
Pacific Modulation of the North Atlantic Storm Track Response to Sudden Stratospheric Warming Events
Authors: Afargan‐Gerstman Hilla , Domeisen Daniela I. V. 
Published: January 2020

AbstractSudden stratospheric warming (SSW) events have been suggested to be followed by a surface impact, though this response varies between events. Using reanalysis data, we identify two types of tropospheric responses to SSWs: Two thirds of the SSW events are dominated by a zonally symmetric tropospheric response with an equatorward shift of the jet in the Atlantic, consistent with the canonical SSW response in the form of a negative signature of the North Atlantic Oscillation. For the remaining third of SSW events, a zonally asymmetric response is found, associated with a poleward shift of the jet in the Atlantic. The Pacific is found to contribute to the sign of the North Atlantic response, as synoptic wave propagation from the Eastern Pacific links the Pacific and Atlantic storm tracks for both equatorward and poleward jet responses.
A New Substorm Onset Mechanism: Increasingly Parallel Pressure Anisotropic Ballooning
Authors: Oberhagemann L. R. , Mann I. R. 
Published: January 2020

AbstractRecent observations demonstrating that auroral beads are observed prior to the majority of substorm onsets (Kalmoni et al., 2017, https://doi.org/10.1002/2016GL071826) have reinforced the potential importance of ballooning instabilities for near‐Earth magnetospheric substorm onset. Here we examine pressure anisotropic ballooning instabilities in stretched magnetotail geometries. Our results show that transition from an initially perpendicular anisotropy toward parallel anisotropy reduces the plasma β threshold for triggering a ballooning instability. Such increasingly parallel anisotropies can form as a direct consequence of tail stretching that occurs during the late substorm growth phase through the well‐known effects of drift shell splitting and the competition between betatron and Fermi processes in the tail. We propose such increasingly parallel ballooning triggers auroral substorm onset on field lines in the transition region between dipolar and tail‐like fields, consistent with observational constraints on the location of the onset arc with respect to the ion isotropy boundary in the magnetotail.
The Delayed Island Mass Effect: How Islands can Remotely Trigger Blooms in the Oligotrophic Ocean
Authors: Messié Monique , Petrenko Anne , Doglioli Andrea M. , Aldebert Clément , Martinez Elodie , Koenig Guillaume , Bonnet Sophie , Moutin Thierry 
Published: January 2020

AbstractIn oligotrophic gyres of the tropical ocean, islands can enhance phytoplankton biomass and create hotspots of productivity and biodiversity. This “island mass effect” (IME) is typically identified by increased chlorophyll concentrations next to an island. Here we use a simple plankton model in a Lagrangian framework to represent an unexplained open ocean bloom, demonstrating how islands could have triggered it remotely. This new type of IME, termed “delayed IME,” occurs when nitrate is limiting, N:P ratios are low, and excess phosphate and iron remain in water masses after an initial bloom associated with a “classical” IME. Nitrogen fixers then slowly utilize leftover phosphate and iron while water masses get advected away, resulting in a bloom decoupled in time (several weeks) and space (hundreds of kilometers) from island‐driven nutrient supply. This study suggests that the fertilizing effect of islands on phytoplankton may have been largely underestimated.
Martian Thermospheric Warming Associated With the Planet Encircling Dust Event of 2018
Authors: Jain S. K. , Bougher S. W. , Deighan J. , Schneider N. M. , González Galindo F. , Stewart A. I. F. , Sharrar R. , Kass D. , Murphy J. , Pawlowski D. 
Published: January 2020

AbstractWe report the first observations of Martian thermospheric warming associated with the Planet Encircling Dust Event (PEDE) of 2018. We used dayglow observations made by the Imaging Ultraviolet Spectrograph instrument aboard the MAVEN spacecraft to retrieve the upper atmosphere temperature structures. Our analysis shows that the two‐cell meridional circulation pattern may be operating before the PEDE‐2018, which resulted in the cooling of lower/middle latitudes and warming at higher latitudes. However, after the onset, the existing circulation pattern gets dampened, resulted in a weaker latitudinal temperature structure. We saw that mean temperatures rose by about 20 K for the same local time after the onset of the dust storm. Our 3‐D Mars General Ionosphere Thermosphere Model calculations were able to reproduce the temperatures during the predust and early dust storm but failed to fully capture the temperature trend during the growth phase of the PEDE of 2018.