bluuebunny/crossref_metadata_2025_split huggingface dataset:
Triton’s Variable Interaction With Neptune’s Magnetospheric Plasma
Authors: Liuzzo Lucas , Paty Carol , Cochrane Corey , Nordheim Tom , Luspay‐Kuti Adrienn , Castillo‐Rogez Julie , Mandt Kathleen , Mitchell Karl L. , Holmström Mats , Addison Peter , Simon Sven , Poppe Andrew R. , Vance Steven D. , Prockter Louise 
Published: October 2021

AbstractThe tilt between Neptune’s magnetic and rotational axes, along with Triton’s orbital obliquity, causes a strong time variability of the moon’s local electromagnetic environment. To constrain Triton’s interaction with the ambient magnetospheric plasma, we apply a hybrid (kinetic ions, fluid electrons) model including the moon’s ionosphere and induced field. To represent the extremes in the changes to the local electromagnetic field over a synodic rotation, we consider two orientations between the ambient magnetic field and flow velocity. For each, we first investigate the (analytical) magnetic signatures associated with the superposition of Triton’s induced field and the magnetospheric field in the absence of any plasma interaction effects. To constrain the effect of Triton’s ionosphere on the currents, we model the interaction between the ionospheric and magnetospheric plasma in isolation from the moon’s inductive response, before combining these effects to investigate the complex scenario of plasma interaction and induction. Finally, we explore the sensitivity of the plasma interaction to changes in the ambient plasma density and the strength of Triton’s inductive response. Despite plasma interaction signatures that dominate the plasma perturbations far from the moon (beyond Triton radii), we illustrate that the induced field is clearly discernible within Triton radii, regardless of the moon’s location within Neptune’s magnetosphere. We find that the orientation of the magnetospheric field and velocity vectors strongly affects Triton’s plasma interaction; at times, resembling those of Jupiter’s or Saturn’s moons, while at others, revealing unprecedented signatures that are likely unique to moons of the ice giants.
Magnetic Structure and Propagation of Two Interacting CMEs From the Sun to Saturn
Authors: Palmerio Erika , Nieves‐Chinchilla Teresa , Kilpua Emilia K. J. , Barnes David , Zhukov Andrei N. , Jian Lan K. , Witasse Olivier , Provan Gabrielle , Tao Chihiro , Lamy Laurent , Bradley Thomas J. , Mays M. Leila , Möstl Christian , Roussos Elias , Futaana Yoshifumi , Masters Adam , Sánchez‐Cano Beatriz 
Published: October 2021

AbstractOne of the grand challenges in heliophysics is the characterization of coronal mass ejection (CME) magnetic structure and evolution from eruption at the Sun through heliospheric propagation. At present, the main difficulties are related to the lack of direct measurements of the coronal magnetic fields and the lack of 3D in‐situ measurements of the CME body in interplanetary space. Nevertheless, the evolution of a CME magnetic structure can be followed using a combination of multi‐point remote‐sensing observations and multi‐spacecraft in‐situ measurements as well as modeling. Accordingly, we present in this work the analysis of two CMEs that erupted from the Sun on April 28, 2012. We follow their eruption and early evolution using remote‐sensing data, finding indications of CME–CME interaction, and then analyze their interplanetary counterpart(s) using in‐situ measurements at Venus, Earth, and Saturn. We observe a seemingly single flux rope at all locations, but find possible signatures of interaction at Earth, where high‐cadence plasma data are available. Reconstructions of the in‐situ flux ropes provide almost identical results at Venus and Earth but show greater discrepancies at Saturn, suggesting that the CME was highly distorted and/or that further interaction with nearby solar wind structures took place before 10 AU. This work highlights the difficulties in connecting structures from the Sun to the outer heliosphere and demonstrates the importance of multi‐spacecraft studies to achieve a deeper understanding of the magnetic configuration of CMEs.
Influence of Permafrost Type and Site History on Losses of Permafrost Carbon After Thaw
Authors: Manies Kristen L. , Jones Miriam C. , Waldrop Mark P. , Leewis Mary‐Cathrine , Fuller Christopher , Cornman Robert S. , Hoefke Kristen 
Published: October 2021

AbstractWe quantified permafrost peat plateau and post‐thaw carbon (C) stocks across a chronosequence in Interior Alaska to evaluate the amount of C lost with thaw. Macrofossil reconstructions revealed three stratigraphic layers of peat: (a) a base layer of fen/marsh peat, (b) peat from a forested peat plateau (with permafrost), and (c) collapse‐scar bog peat (at sites where permafrost thaw has occurred). Radiocarbon dating revealed that peat initiated within the last 2,500 years and that permafrost aggraded during the Little Ice Age (ca. 250–575 years ago) and degraded within the last several decades. The timing of permafrost thaw within each feature was not related to thaw bog size. Their rate of expansion may be more influenced by local factors, such as ground ice content and subsurface water inputs. We found C losses due to thaw over the past century were up to 46% of the C available, but the absolute amount of C lost (kg m−2) was over 50% lower than losses previously described in other Alaskan peatland chronosequences. We hypothesize that this difference stems from the process by which permafrost aggraded, with sites that formed permafrost epigenetically (significantly later than most peat accumulation) experiencing less absolute C loss with thaw than sites that formed syngenetically (simultaneously with peat accumulation). Epigenetic peat from our site had lower C:N ratios as compared to Alaskan sites that have syngenetic peat. This difference could help predict the magnitude of C loss with thaw across a range or permafrost types and histories.
Simulating Linear Kinematic Features in Viscous‐Plastic Sea Ice Models on Quadrilateral and Triangular Grids With Different Variable Staggering
Authors: Mehlmann C. , Danilov S. , Losch M. , Lemieux J. F. , Hutter N. , Richter T. , Blain P. , Hunke E. C. , Korn P. 
Published: October 2021

AbstractObservations in polar regions show that sea ice deformations are often narrow linear features. These long bands of deformations are referred to as Linear Kinematic Features (LKFs). Viscous‐plastic sea ice models have the capability to simulate LKFs and more generally sea ice deformations. Moreover, viscous‐plastic models simulate a larger number and more refined LKFs as the spatial resolution is increased. Besides grid spacing, other aspects of a numerical implementation, such as the placement of velocities and the associated degrees of freedom, may impact the formation of simulated LKFs. To explore these effects this study compares numerical solutions of sea ice models with different velocity staggering in a benchmark problem. Discretizations based on A‐,B‐, and C‐grid systems on quadrilateral meshes have similar resolution properties as an approximation with an A‐grid staggering on triangular grids (with the same total number of vertices). CD‐grid approximations with a given grid spacing have properties, specifically the number and length of simulated LKFs, that are qualitatively similar to approximations on conventional Arakawa A‐grid, B‐grid, and C‐grid approaches with half the grid spacing or less, making the CD‐discretization more efficient with respect to grid resolution. One reason for this behavior is the fact that the CD‐grid approach has a higher number of degrees of freedom to discretize the velocity field. The higher effective resolution of the CD‐discretization makes it an attractive alternative to conventional discretizations.
A QBO Cookbook: Sensitivity of the Quasi‐Biennial Oscillation to Resolution, Resolved Waves, and Parameterized Gravity Waves
Authors: Garfinkel Chaim I. , Gerber Edwin P. , Shamir Ofer , Rao Jian , Jucker Martin , White Ian , Paldor Nathan 
Published: October 2021

AbstractAn intermediate complexity moist general circulation model is used to investigate the sensitivity of the quasi‐biennial oscillation (QBO) to resolution, diffusion, tropical tropospheric waves, and parameterized gravity waves. Finer horizontal resolution is shown to lead to a shorter period, while finer vertical resolution is shown to lead to a longer period and to a larger amplitude in the lowermost stratosphere. More scale‐selective diffusion leads to a faster and stronger QBO, while enhancing the sources of tropospheric stationary wave activity leads to a weaker QBO. In terms of parameterized gravity waves, broadening the spectral width of the source function leads to a longer period and a stronger amplitude although the amplitude effect saturates in the mid‐stratosphere when the half‐width exceeds m/s. A stronger gravity wave source stress leads to a faster and stronger QBO, and a higher gravity wave launch level leads to a stronger QBO. All of these sensitivities are shown to result from their impact on the resultant wave‐driven momentum torque in the tropical stratosphere. Atmospheric models have struggled to accurately represent the QBO, particularly at moderate resolutions ideal for long climate integrations. In particular, capturing the amplitude and penetration of QBO anomalies into the lower stratosphere (which has been shown to be critical for the tropospheric impacts) has proven a challenge. The results provide a recipe to generate and/or improve the simulation of the QBO in an atmospheric model.
Deep neural network‐based adaptive zero‐velocity detection for pedestrian navigation system
Authors: Zhang Liqiang , Chen Boxuan , Li Hu , Liu Yu 
Published: October 2021

AbstractThe zero‐velocity update (ZUPT) method is an effective way to reduce accumulated velocity errors of pedestrian navigation systems (PNSs). For a typical scheme, a stance phase detection module based on a fixed threshold is used to trigger the ZUPT algorithm. However, the detector is not robust enough for dynamic gait speeds. The false detection will degrade the navigation performance. In this letter, to improve the stance phase detector, the adaptive zero‐velocity detection problem is cast under dynamic gait speeds as a sequential threshold of a traditional detector inferring problem and a zero‐velocity detection framework proposed by combining a deep neural network with a traditional binary gait phase detector. Sufficient experimental results show that the proposed method outperforms other discussed learning‐based methods taking into account the trade‐off among model performance, structure, and size. Compared with the traditional method with a fixed threshold, the real‐world high‐dynamic positioning experiments show that this proposed method reduces the root mean squared error (RMSE) of absolute distance error by 48.7%, RMSE of start‐end error by 12.5%, and average RMSE of position error by 19.2%.
A dynamic distributed energy storage control strategy for providing primary frequency regulation using multi‐armed bandits method
Authors: Sun Jianfeng , Zhao Yuan , Zhang Nianchu , Chen Xinyi , Hu Qinran , Song Jieying 
Published: October 2021

AbstractMaintaining frequency stability is a crucial but challenging task for the stable operation of a power system. The distributed energy storage (DES) can charge or discharge for both upward and downward frequency regulation, exploring and effectively using the regulation capabilities will provide a strong backup for frequency regulation. Here, a dynamic DES control strategy for providing primary frequency regulation is proposed. The different behaviours of storage owners are considered when they respond to the regulation requests from the aggregator. This kind of uncertainty would lead to a mismatch between the final aggregation result and the expected target. Hence, the multi‐armed bandit approach is applied to learn users’ response behaviour and select the optimal set of users to mitigate the mismatch. Case studies on the IEEE RTS 24‐bus system demonstrate that the proposed method's mismatch between the actual aggregation result and the regulation target is less than half as much as the conventional method, and it can restore the frequency 20 events earlier than the traditional method.
Influence of bubbles on electric field distribution of butt‐gaps in superconducting cable insulation layer
Authors: Zhang Jiahui , Xue Peng , Xiang Bin , Gao Lei , Jiang Xiaohua 
Published: October 2021

AbstractSuperconducting energy pipeline (SEP) is a new type of electrical energy transmission. It contains high‐temperature superconducting cables and liquefied natural gas pipelines and can simultaneously transmit electricity and liquefied natural gas (LNG). However, when the superconducting tapes in the superconducting cables in SEP quench and generate heat, bubbles will generate in the butt‐gaps of the insulation layer of superconducting cables, which can reduce the insulation strength of the cables significantly. In addition, the effects of bubbles in the butt‐gap of the insulation layer on the insulation properties of the superconducting cables are unknown. The objective here is to obtain the influences of bubbles in the insulation layer of superconducting cables in capacitive field, transitional field, and resistive field. Simulation results show that: Compared with the absence of bubbles, the big bubbles can increase the capacitive field strength of the PP film, the butt‐gap, and the kraft by 37.54%, 30.89%, and 18.5%, and increase the transition time from the capacitive field to the resistive field, but has almost no effect on the butt‐gap in the resistive field.
GSA‐ELM: A hybrid learning model for short‐term traffic flow forecasting
Authors: Cui Zhihan , Huang Boyu , Dou Haowen , Tan Guanru , Zheng Shiqiang , Zhou Teng 
Published: October 2021

AbstractAccurate and timely short‐term traffic flow forecasting is an essential component for intelligent traffic management systems. However, developing an effective and robust forecasting model is challenging due to the inherent randomness and nonlinear characteristic of the traffic flow. In this paper, a gravitational search algorithm optimized extreme learning machine, termed GSA‐ELM, is proposed to unlock the potential performance for short‐term traffic flow forecasting. The extreme learning machine avoids the tedious backpropagation by analytically determining the optimal solution. The gravitational search algorithm globally searches the optimal parameters for the extreme learning machine. The forecasting performance of the GSA‐ELM is evaluated on four benchmark datasets by comparing several state‐of‐the‐art models. The four benchmark datasets are real‐world traffic flow data from highways A1, A2, A4, A8 near the ring road of Amsterdam. The MAPEs of the GSA‐ELM model are , , and on four benchmark datasets, respectively, whereas the RMSEs of the GSA‐ELM model are 287.89, 203.04, 221.39 and , respectively. The experimental results demonstrate the superior performance of the proposed model.
Detection of sea‐surface target of coastal defense radar based on Stacked Autoencoder (SAE) algorithm
Authors: Yan He , Chen Chao , Jin Guodong , Zhang Jindong , Zhang Gong , Zhu Daiyin 
Published: October 2021

AbstractIn recent years, machine learning theory has set off a wave of research in the field of radar signal processing. In this study, a novel algorithm for sea‐surface target detection based on a stacked autoencoder (SAE) is proposed, which has already been applied in the authors’ coastal defense radar system. In the proposed algorithm, the sea surface echo data are cut into a large number of two‐dimensional (2‐D) images through a sliding window, mapping the cell under test (CUT) and the 2‐D images one by one and performing classification or detection from the perspective of 2‐D signal processing. Experimental results of simulated data and real radar data show that the proposed algorithm based on the SAE has better target detection performance compared with the traditional cell averaging constant false alarm rate (CA‐CFAR) algorithm. Besides, the proposed algorithm shows certain interference suppression ability in real data processing. As far as it is known, there is no public report on the detection of 2‐D sea surface targets based on the SAE algorithm in coastal defense radar.
Sedierung mit Propofol: perfusorgesteuerte Applikation versus intermittierende Bolusgabe – Methodenvergleich und Sicherheit
Authors: Wehrmann Till 
Published: October 2021

ZusammenfassungIn Zusammenschau mit den umfangreichen Erfahrungen mit dieser Technik in der Anästhesie (hier nicht im Detail aufgeführt) muss die Propofolapplikation als Perfusor als sichere Technik (bei entsprechender Überwachung der Sedierung durch eine qualifizierte Person) angesehen werden. Dies wird auch durch die inzwischen größere Zahl von Studien zum Einsatz in der Endoskopie bestätigt. Da bei der Mehrzahl der gastroenterologischen Endoskopien jedoch nur eine kürzere Zeitspanne benötigt wird (< 45 Minuten), erscheint hier der Vorteil einer perfusorgesteuerten Propofolapplikation im Vergleich zum Aufwand gegenüber der intermittierenden Bolusgabe doch limitiert. Insofern hat sich die Verwendung von Perfusoren zur Propofolgabe bisher in der deutschen Endoskopie nicht durchgesetzt. Hingegen wird bei lang dauernden Interventionen (z. B. POEM, Großflächen-ESD, umfangreiche Pankreas-Nekrosektomien etc.) häufiger die Hilfe der Anästhesie in Anspruch genommen, tendenziell führen diese dann aber eher eine TIVA (mit Intubation des Patienten) durch als eine perfusorgesteuerte Sedierung. Insofern ist der Einsatz der perfusorgesteuerten Propofolapplikation zwecks Sedierung – meines Wissens – in Deutschland bisher auf einige wenige Zentren beschränkt.Die PCSA erscheint als eine theoretisch attraktive Methode, bei jedoch in Deutschland fehlenden Vergütungsstrukturen in der Endoskopie und technisch höherem Aufwand ist die Anwendung derzeit limitiert, da zudem auch nicht alle Patienten bereit sind, hier selbst in die Verantwortung zu übernehmen.
Bradyarrhythmias in Cardio-Oncology
Authors: Fonseca Marta , Cheng Evaline , Do Duc , Haldar Shouvik , Kutty Shelby , Yang Eric H. , Ghosh Arjun K. , Guha Avirup 
Published: October 2021

AbstractThe relationship between bradyarrhythmias and cancer therapies has not been well described but is increasingly recognized. There have been extensive advances in oncological pharmacotherapy, with several new classes of drugs available including targeted agents, immune checkpoint inhibitors and CAR T cell therapy. This increasing repertoire of available drugs has revolutionized overall prognosis and survival of cancer patients but the true extent of their cardiovascular toxicity is only beginning to be understood. Previous studies and published reviews have traditionally focused on conventional chemotherapies and in arrhythmias in general, particularly tachyarrhythmias. The number of patients with both cancer and cardiovascular problems is increasing globally and oncologists and cardiologists need to be adept at managing arrythmia based scenarios. Greater collaboration between the two specialties including studies with prospective data collection in Cardio-Oncology are much needed to fill in knowledge gaps in this arena. This case-based review summarizes current available evidence of cancer treatment-related bradyarrhythmia incidence (including its different subtypes), possible mechanisms and outcomes. Furthermore, we propose a stepwise surveillance and management protocol for patients with suspected bradyarrhythmia related to cancer treatment.
Theory of frequency-selective homonuclear dipolar recoupling in solid-state NMR
Authors: Xiao Hang , Zhang Zhengfeng , Yang Jun 
Published: October 2021

In solid-state nuclear magnetic resonance, frequency-selective homonuclear dipolar recoupling is key to quantitative distance measurement or selective enhancement of correlations between atoms of interest in multiple-spin systems, which are not amenable to band-selective or broadband recoupling. Previous frequency-selective recoupling is mostly based on the so-called rotational resonance (R2) condition that restricts the application to spin pairs with resonance frequencies differing in integral multiples of the magic-angle spinning (MAS) frequency. Recently, we have proposed a series of frequency-selective homonuclear recoupling sequences called SPR (short for Selective Phase-optimized Recoupling), which have been successfully applied for selective 1H–1H or 13C–13C recoupling under from moderate (∼10 kHz) to ultra-fast (150 kHz) MAS frequencies. In this study, we fully analyze the average Hamiltonian theory of SPR sequences and reveal the origin of frequency selectivity in recoupling. The theoretical description, as well as numerical simulations and experiments, demonstrates that the frequency selectivity can be easily controlled by the flip angle (p) in the (p)ϕk(p)ϕk+π unit in the pSPR-Nn sequences. Small flip angles lead to frequency-selective recoupling, while large flip angles may lead to broadband recoupling in principle. The result shall shed new light on the design of homonuclear recoupling sequences with arbitrary frequency bandwidths.
Photodissociation dynamics of methyl vinyl ketone oxide: A four-carbon unsaturated Criegee intermediate from isoprene ozonolysis
Authors: Wang Guanghan , Liu Tianlin , Caracciolo Adriana , Vansco Michael F. , Trongsiriwat Nisalak , Walsh Patrick J. , Marchetti Barbara , Karsili Tolga N. V. , Lester Marsha I. 
Published: October 2021

The electronic spectrum of methyl vinyl ketone oxide (MVK-oxide), a four-carbon Criegee intermediate derived from isoprene ozonolysis, is examined on its second π* ← π transition, involving primarily the vinyl group, at UV wavelengths (λ) below 300 nm. A broad and unstructured spectrum is obtained by a UV-induced ground state depletion method with photoionization detection on the parent mass (m/z 86). Electronic excitation of MVK-oxide results in dissociation to O (1D) products that are characterized using velocity map imaging. Electronic excitation of MVK-oxide on the first π* ← π transition associated primarily with the carbonyl oxide group at λ &gt; 300 nm results in a prompt dissociation and yields broad total kinetic energy release (TKER) and anisotropic angular distributions for the O (1D) + methyl vinyl ketone products. By contrast, electronic excitation at λ ≤ 300 nm results in bimodal TKER and angular distributions, indicating two distinct dissociation pathways to O (1D) products. One pathway is analogous to that at λ &gt; 300 nm, while the second pathway results in very low TKER and isotropic angular distributions indicative of internal conversion to the ground electronic state and statistical unimolecular dissociation.