bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of sapphire substrate orientation on Sn-doped α-Ga2O3 grown by halide vapor phase epitaxy using α-Cr2O3 buffers
Authors: Polyakov Alexander , Nikolaev Vladimir , Stepanov Sergey , Almaev Alexei , Pechnikov Alexei , Yakimov Eugene , Kushnarev Bogdan O , Shchemerov Ivan , Scheglov Mikhail , Chernykh Alexey , Vasilev Anton , Kochkova Anastasia , Guzilova Lyubov , Pearton Stephen J 
Published: September 2022

Abstract
Heavily Sn-doped films of α-Ga2O3 were grown by halide vapor phase epitaxy (HVPE) on basal plane c-sapphire and on (10-12) r-sapphire substrates with and without α-Cr2O3 thin buffers prepared by magnetron sputtering and annealing in air at 500 °C for 3 h. For both substrate orientations, the use of α-Cr2O3 buffers led to three major effects. The first was a substantial decrease of the half-width of the symmetric and asymmetric x-ray reflections. The second was an order of magnitude decrease of the net donor concentration produced by flowing the same amounts of Sn into the reactor. Third, there was a reduction in the concentration of the major electron trap in the films near E
c − 1 eV by more than a factor of two. These results show the major influence of sapphire substrate orientation on the electrical and structural properties of α-Ga2O3 grown by HVPE.
Strain-induced two-dimensional topological insulators in monolayer 1T′-RuO2
Authors: Lu Xin , Zhou Pan , Chen Shuhui , Sun Lizhong 
Published: September 2022

Abstract
Because of their unique structure and novel physical properties, two-dimensional (2D) transition metal dichalcogenides (TMDs) have received a lot of attention in recent years. In this paper, we propose a new 2D TMD 1T′-RuO2 with tunable topological properties. Based on first-principles calculations, we demonstrate that it has good dynamics, thermodynamic, energetic stability, and anisotropic mechanical properties. Although 1T′-RuO2 is a typical semiconductor with a direct bandgap, it can be transformed into topological insulator by applying uniaxial tensile strains. The topological phase transition is attributed to the d–d band inversion at Γ point. The nontrivial topological property is further validated by the topological edge states. We predict that monolayer 1T′-RuO2 is an excellent material for future electronic devices with tunable topological properties.
Magnetic field reversal of electric polarization and pressure-temperature-magnetic field magnetoelectric phase diagram of the hexaferrite Ba0.4Sr1.6Mg2Fe12O22
Authors: Yu Zhipeng , Zhai Kun , Wang Qingkai , Ding Hao , Nie Anmin , Wang Bochong , Xiang Jianyong , Wen Fusheng , Mu Congpu , Xue Tianyu , Shen Shipeng , Liu Zhongyuan 
Published: September 2022

Abstract
Pressure, as an independent thermodynamic parameter, is an effective tool to obtain novel material system and exotic physical phenomena not accessible at ambient conditions, because it profoundly modifies the charge, orbital and spin state by reducing the interatomic distance in crystal structure. However, the studies of magnetoelectricity and multiferroicity are rarely extended to high pressure dimension due to properties measured inside the high pressure vessel being a challenge. Here we reported the temperature-magnetic field-pressure magnetoelectric (ME) phase diagram of Y type hexaferrite Ba0.4Sr1.6Mg2Fe12O22 derived from static pyroelectric current measurement and dynamic magnetodielectric in diamond anvil cell and piston cylinder cell. We found that a new spin-driven ferroelectric phase emerged at P = 0.7 GPa and sequentially ME effect disappeared around P = 4.3 GPa. The external pressure may enhance easy plane anisotropy to destabilize the longitudinal conical magnetic structure with the suppression of ME coefficient. These results offer essential clues for the correlation between ME effect and magnetic structure evolution under high pressure.
Strain-induced stacking transition in bilayer graphene
Authors: Georgoulea Nina C , Power Stephen R , Caffrey Nuala M 
Published: September 2022

Abstract
Strain, both naturally occurring and deliberately engineered, can have a considerable effect on the structural and electronic properties of 2D and layered materials. Uniaxial or biaxial heterostrain modifies the stacking arrangement of bilayer graphene (BLG) which subsequently influences the electronic structure of the bilayer. Here, we use density functional theory (DFT) calculations to investigate the interplay between an external applied heterostrain and the resulting stacking in BLG. We determine how a strain applied to one layer is transferred to a second, ‘free’ layer and at what critical strain the ground-state AB-stacking is disrupted. To overcome limitations introduced by periodic boundary conditions, we consider an approximate system consisting of an infinite graphene sheet and an armchair graphene nanoribbon. We find that above a critical strain of

∼

1
%

, it is energetically favourable for the free layer to be unstrained, indicating a transition between uniform AB-stacking and non-uniform mixed stacking. This is in agreement with a simple model estimate based on the individual energy contributions of strain and stacking effects. Our findings suggest that small levels of strain provide a platform to reversibly engineer stacking order and Moiré features in bilayers, providing a viable alternative to twistronics to engineer topological and exotic physical phenomena in such systems.
A first-principles study of theoretical superconductivity on RbH by doping without applied pressure
Authors: Villa-Cortés S , Olea-Amezcua M A , De la Peña-Seaman O 
Published: September 2022

Abstract
The structural, electronic, lattice dynamics, electron–phonon (el–ph) coupling, and superconducting (SC) properties of the alkali-metal hydride RbH, metallized through electron-doping by the construction of the solid-solution Rb

1
−
x

Sr
x
H, are systematically analyzed as a function of Sr-content within the framework of density functional perturbation and Migdal-Eliashberg theories, taking into account the effect of zero-point energy contribution by the quasi-harmonic approximation. For the entire studied range of Sr-content, steady increments of the el–ph coupling constant and the SC critical temperature are found with progressive alkaline-earth metal content through electron-doping, reaching the values of λ = 1.92 and

T
c

=
51.3
(
66.1
)

K with

μ
∗

= 0.1(0). The steady rise of such quantities as a function of Sr-content is consequence of the metallization of the hydride as an increase of density of states at the Fermi level is observed, as well as the softening of the phonon spectrum, mainly coming from H-optical modes. Our results indicate that electron-doping on metal-hydrides is an encouraging alternative to look for superconductivity without applied pressure.
Infrared pattern based method for inspecting multi-nozzle spraying tools
Authors: Schulz Florian , Reincke Franziska , Beyrau Frank 
Published: September 2022

Abstract
Multi-nozzle spraying tools are applied in numerous industrial applications, one of the most common being die-casting. To ensure the quality of a cast product and to avoid production downtimes proper functioning is required, e.g. in terms of spray targeting, mass flow, or reproducibility. To enable regular functional controls of a spraying tool, we have developed a specific measuring principle based on monitoring the spray impact on a heated plate using infrared thermography. In this paper, the performance of the developed measuring principle is examined. The study is performed with a typical spraying tool from foundries, it has nine external mixing air–water nozzles, which are freely adjustable in their orientation. During an injection, the spray impacts a heated plate positioned in front of the spraying tool and creates a wetting pattern that is individual to each spraying tool, like a fingerprint. The recorded cooling pattern can be used to determine the position of the individual spray impact areas, the size of the spray impact areas, and the intensity of the cooling. Based on these parameters, conclusions can be drawn about the functionality of the water-bearing lines and the air-bearing lines—as well as the correct alignment of the individual nozzles. The result shows that the presented measuring principle leads to very high precision and reproducibility of the evaluated parameters. Thus, the developed measuring system enables detailed functional tests of complex spraying tools.
Interfacial friction of vdW heterostructures affected by in-plane strain
Authors: Zhou Xuanling , Chen Peijian , Xu Rong-Guang , Zhang Cun , Zhang Jiazhen 
Published: September 2022

Abstract
Interfacial properties of van der Waals (vdW) heterostructures dominate the durability and function of their booming practical and potential applications such as opoelectronic devices, superconductors and even pandemics research. However, the strain engineering modulates of interlayer friction of vdW heterostructures consisting of two distinct materials are still unclear, which hinders the applications of vdW heterostructures, as well as the design of solid lubricant and robust superlubricity. In the present paper, a molecular model between a hexagonal graphene flake and a rectangular SLMoS2 sheet is established, and the influence of biaxial and uniaxial strain on interlayer friction is explored by molecular dynamics. It is found that the interlayer friction is insensitive to applied strains. Strong robustness of superlubricity between distinct layers is owed to the structure’s intrinsic incommensurate characteristics and the existence of Moiré pattern. In engineering practice, it is of potential importance to introduce two distinct 2D materials at the sliding contact interface to reduce the interfacial friction of the contact pair and serve as ideal solid lubricants. Our research provides a further basis to explore the nanotribology and strain engineering of 2D materials and vdW heterostructures.
Nano-scale simulation of neuronal damage by galactic cosmic rays
Authors: Peter Jonah S , Schuemann Jan , Held Kathryn D , McNamara Aimee L 
Published: September 2022

Abstract
The effects of realistic, deep space radiation environments on neuronal function remain largely unexplored. In silico modeling studies of radiation-induced neuronal damage provide important quantitative information about physico-chemical processes that are not directly accessible through radiobiological experiments. Here, we present the first nano-scale computational analysis of broad-spectrum galactic cosmic ray irradiation in a realistic neuron geometry. We constructed thousands of in silico realizations of a CA1 pyramidal neuron, each with over 3500 stochastically generated dendritic spines. We simulated the entire 33 ion-energy beam spectrum currently in use at the NASA Space Radiation Laboratory galactic cosmic ray simulator (GCRSim) using the TOol for PArticle Simulation (TOPAS) and TOPAS-nBio Monte Carlo-based track structure simulation toolkits. We then assessed the resulting nano-scale dosimetry, physics processes, and fluence patterns. Additional comparisons were made to a simplified 6 ion-energy spectrum (SimGCRSim) also used in NASA experiments. For a neuronal absorbed dose of 0.5 Gy GCRSim, we report an average of 250 ± 10 ionizations per micrometer of dendritic length, and an additional 50 ± 10, 7 ± 2, and 4 ± 2 ionizations per mushroom, thin, and stubby spine, respectively. We show that neuronal energy deposition by proton and

α

-particle tracks declines approximately hyperbolically with increasing primary particle energy at mission-relevant energies. We demonstrate an inverted exponential relationship between dendritic segment irradiation probability and neuronal absorbed dose for each ion-energy beam. We also find that there are no significant differences in the average physical responses between the GCRSim and SimGCRSim spectra. To our knowledge, this is the first nano-scale simulation study of a realistic neuron geometry using the GCRSim and SimGCRSim spectra. These results may be used as inputs to theoretical models, aid in the interpretation of experimental results, and help guide future study designs.
Real-time prediction of stomach motions based upon gastric contraction and breathing models
Authors: Zhang Yuhang , Cao Yue , Kashani Rojano , Lawrence Theodore S , Balter James M 
Published: September 2022

Abstract

Objective. Precision radiation therapy requires managing motions of organs at risk that occur during treatment. While methods have been developed for real-time respiratory motion tracking, non-breathing intra-fractional variations (including gastric contractile motion) have seen little attention to date. The purpose of this study is to develop a cyclic gastric contractile motion prediction model to support real-time management during radiotherapy. Approach. The observed short-term reproducibility of gastric contractile motion permitted development of a prediction model that (1) extracts gastric contraction motion phases from few minutes of golden angle stack of stars scanning (at patient positioning), (2) estimate gastric phase of real-time sampled data acquired during treatment delivery to these reconstructed phases and (3) predicting future gastric phase by linear extrapolation using estimation results from step 2 to account for processing and system latency times. Model was evaluated on three parameters including training time window for step 1, number of spokes for real-time sampling data in step 2 and future prediction time. Main results. The model was tested on a population of 20 min data samples from 25 scans from 15 patients. The mean prediction error with 10 spokes and 2 min training was 0.3 ± 0.1 mm (0.1–0.7 mm) with 5.1 s future time, slowly rising to 0.6 ± 0.2 mm (0.2–1.1 mm) for 6.8 s future time and then increasing rapidly for longer forward predictions, for an average 3.6 ± 0.5 mm (2.8–4.7 mm) HD95 of gastric motion. Results showed that reducing of train time window (5–2 min) does not influence the prediction performance, while using 5 spokes increased prediction errors. Significance. The proposed gastric motion prediction model has sufficiently accurate prediction performance to allow for sub-millimeter accuracy while allowing sufficient time for data processing and machine interaction and shows the potential for clinical implementation to support stomach motion tracking during radiotherapy.
Performance analysis of the centroid method predictor implemented in the JET real time network
Authors: Gadariya D , Vega J , Stuart C , Rattá G , Card P , Murari A , Dormido-Canto S , Contributors JET 
Published: September 2022

Abstract
Recently, a linear disruption predictor (Vega et al 2020 Nucl. Fusion
60 026001) was installed in the JET real-time network for disruption mitigation purposes. From a mathematical point of view, the predictor is based on computing centroids of disruptive examples and non-disruptive examples in a two-dimensional space. This is the reason for calling it centroid method (CM). It uses a single signal: the mode lock normalized to the plasma current. The predictor is not based on thresholds to trigger alarms but on the differences of amplitudes between consecutive samples. The article analyses its results for the range of discharges 94 152–97 137 (June 2019–March 2020), including discharges of both baseline scenario and hybrid scenario. The article presents a comparison between the CM predictor and several different disruption detection systems operational in the JET real-time event detection platform named PETRA (Plasma Events Triggering for Alarms). The CM predictor outperforms all the other classifiers implemented in PETRA, according to all the main statistical indicators normally used to qualify these tools.
Verified modeling of a low pressure hydrogen plasma generated by electron cyclotron resonance
Authors: Sigeneger F , Ellis J , Harhausen J , Lang N , van Helden J H 
Published: September 2022

Abstract
A self-consistent fluid model has been successfully developed and employed to model an electron cyclotron resonance driven hydrogen plasma at low pressure. This model has enabled key insights to be made on the mutual interaction of microwave propagation, power density, plasma generation, and species transport at conditions where the critical plasma density is exceeded. The model has been verified by two experimental methods. Good agreement with the ion current density and floating potential—as measured by a retarding energy field analyzer—and excellent agreement with the atomic hydrogen density—as measured by two-photon absorption laser induced fluorescence—enables a high level of confidence in the validity of the simulation.
Fascicles split or merge every ∼560 microns within the human cervical vagus nerve
Authors: Upadhye Aniruddha R , Kolluru Chaitanya , Druschel Lindsey , Al Lababidi Luna , Ahmad Sami S , Menendez Dhariyat M , Buyukcelik Ozge N , Settell Megan L , Blanz Stephan L , Jenkins Michael W , Wilson David L , Zhang Jing , Tatsuoka Curtis , Grill Warren M , Pelot Nicole A , Ludwig Kip A , Gustafson Kenneth J , Shoffstall Andrew J 
Published: September 2022

Abstract

Objective. Vagus nerve stimulation (VNS) is Food and Drug Administration-approved for epilepsy, depression, and obesity, and stroke rehabilitation; however, the morphological anatomy of the vagus nerve targeted by stimulatation is poorly understood. Here, we used microCT to quantify the fascicular structure and neuroanatomy of human cervical vagus nerves (cVNs). Approach. We collected eight mid-cVN specimens from five fixed cadavers (three left nerves, five right nerves). Analysis focused on the ‘surgical window’: 5 cm of length, centered around the VNS implant location. Tissue was stained with osmium tetroxide, embedded in paraffin, and imaged on a microCT scanner. We visualized and quantified the merging and splitting of fascicles, and report a morphometric analysis of fascicles: count, diameter, and area. Main results. In our sample of human cVNs, a fascicle split or merge event was observed every ∼560 µm (17.8 ± 6.1 events cm−1). Mean morphological outcomes included: fascicle count (6.6 ± 2.8 fascicles; range 1–15), fascicle diameter (514 ± 142 µm; range 147–1360 µm), and total cross-sectional fascicular area (1.32 ± 0.41 mm2; range 0.58–2.27 mm). Significance. The high degree of fascicular splitting and merging, along with wide range in key fascicular morphological parameters across humans may help to explain the clinical heterogeneity in patient responses to VNS. These data will enable modeling and experimental efforts to determine the clinical effect size of such variation. These data will also enable efforts to design improved VNS electrodes.
Fast inference of spinal neuromodulation for motor control using amortized neural networks
Authors: Govindarajan Lakshmi Narasimhan , Calvert Jonathan S , Parker Samuel R , Jung Minju , Darie Radu , Miranda Priyanka , Shaaya Elias , Borton David A , Serre Thomas 
Published: September 2022

Abstract

Objective. Epidural electrical stimulation (EES) has emerged as an approach to restore motor function following spinal cord injury (SCI). However, identifying optimal EES parameters presents a significant challenge due to the complex and stochastic nature of muscle control and the combinatorial explosion of possible parameter configurations. Here, we describe a machine-learning approach that leverages modern deep neural networks to learn bidirectional mappings between the space of permissible EES parameters and target motor outputs. Approach. We collected data from four sheep implanted with two 24-contact EES electrode arrays on the lumbosacral spinal cord. Muscle activity was recorded from four bilateral hindlimb electromyography (EMG) sensors. We introduce a general learning framework to identify EES parameters capable of generating desired patterns of EMG activity. Specifically, we first amortize spinal sensorimotor computations in a forward neural network model that learns to predict motor outputs based on EES parameters. Then, we employ a second neural network as an inverse model, which reuses the amortized knowledge learned by the forward model to guide the selection of EES parameters. Main results. We found that neural networks can functionally approximate spinal sensorimotor computations by accurately predicting EMG outputs based on EES parameters. The generalization capability of the forward model critically benefited our inverse model. We successfully identified novel EES parameters, in under 20 min, capable of producing desired target EMG recruitment during in vivo testing. Furthermore, we discovered potential functional redundancies within the spinal sensorimotor networks by identifying unique EES parameters that result in similar motor outcomes. Together, these results suggest that our framework is well-suited to probe spinal circuitry and control muscle recruitment in a completely data-driven manner. Significance. We successfully identify novel EES parameters within minutes, capable of producing desired EMG recruitment. Our approach is data-driven, subject-agnostic, automated, and orders of magnitude faster than manual approaches.
Simulated effects of W dust ablation and deposition on the pedestal edge in JET D and DT experiments
Authors: Lazzaro E. , Causa F. , Gervasini G. , Ghezzi F. , Borodin D. , Borodkina I. , Douai D. , Huber A. , Pawelec E. , Solano E. , Sertoli M. , Widdowson A. 
Published: September 2022

Abstract
A modelling analysis is performed on JET D and DT discharges, where W dust influx across the separatrix, in the pedestal edge region may affect L–H–L mode transition. The experimental basis of the proposed approach stems from the observation that transient impurity events (TIEs) are often associated with the presence of a shower of particles seen in the camera images and with strong optical emission. If the localised source of radiation is a number of heated or ablated large dust particles, then the questions addressed here are: how far will the ablated dust material penetrate and what effect will this have on the edge of the pedestal in relevant JET D and in a high fusion yield D–T discharges. The methodology is based on the use of an upgraded version of the ballistic code DUSTTRACK and a new code PELLYTIX for dust ablation modelling. Considering a reasonable amount of dust released from the tiles, the analysis shows that the ablation-penetration depth is visible in the density profiles modification, but not disastrous for tokamak operation in high regimes.
Improved methodology for affordable, reliable deep building renovations
Authors: Orova M , Reith A 
Published: September 2022

Abstract
European Union energy efficiency goals put refurbishments in focus as the existing building stock takes a high share in the final energy consumption meanwhile current refurbishment rates are lower than expected. This research attempts to answer the question: How can renovation processes be improved to raise renovation rates? The methodology development process consisted of identifying the methodological background, the phases and steps of the renovation process and the validation strategies. As a result, five methodological phases were identified. Renovations start with the Feasibility phase where a simple financial and technical assessment is carried out. During the Preparation phase necessary information is collected which results in a calibrated simulation model that can support the design. In the Design phase the renovation options are developed and assessed together with a business plan for financing the implementation through renovation cycles. The renovation measures are carried out during the Implementation phase. In the Operation phase the performance of the refurbished building is monitored and improved. The developed methodology is expected to provide more affordable, reliable building renovations, which reduces the performance gap, the upfront investment and the disruption of user life by reducing overall time on site. This results in an increased investment efficiency leading to higher uptake of refurbishments.