bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurement of re-entry plasma density using microwave reflectometer in laboratory
Authors: Shin Gi Won , Kim Jae Hyeon , Lee Sun Hee , Bang In Young , Kim Ji Hwan , Park Yeon Soo , Kwon Hee Tae , Kim Woo Jae , Kwon Gi-Chung 
Published: October 2022

A laboratory-scale experiment was conducted to reproduce plasma with properties similar to re-entry plasma and measure the plasma density using a microwave reflectometer system. To reproduce a similar re-entry plasma, a high-temperature refractory anode vacuum arc plasma method was used among arc plasma discharge methods, and arc plasma having high temperature, high speed, and high-density plasma characteristics was discharged inside a vacuum chamber. A hot refractory anode made of tungsten was used to show high-temperature plasma characteristics, and high-density plasma characteristics were demonstrated using re-evaporation around the anode. In addition, high-speed plasma characteristics were exhibited using a brass cathode. This kind of arc plasma discharge has a high temperature and is characterized by high fluctuation. It was determined that a microwave reflectometer system with good spatial resolution and non-invasiveness would be suitable to measure plasma with these characteristics. The reflection coefficient was measured using a reflector system by comparing the voltage between the traveling wave applied to the plasma and the reflected wave reflected by the plasma, and the technique of analyzing the plasma density using the difference between these reflection coefficients was used. In this study, the plasma density according to the pressure change was typically measured as 1012–1013 cm−3, which showed a similar tendency to the result of measuring the actual re-entry plasma density.
A low phase and amplitude noise microwave source for vapor cell atomic clocks
Authors: Ju Bowen , Yun Peter , Hao Qiang , Nie Shuai , Liu Guobin 
Published: October 2022

A low-noise microwave source plays a key role in high-performance passive atomic clocks. Here, we propose and implement a microwave frequency synthesizer featuring a low phase and amplitude noise. With the help of a high-Q factor surface acoustic wave band-pass filter, we generate a microwave with targeted frequency by frequency multiplication of a low noise local oscillator at a radio frequency with the closest integer. At the frequency offset of 1 Hz, 10 Hz, 100 Hz, 1 kHz, and 10 kHz, the absolute phase noise of the output 3.417 GHz signal is −53.0, −83.3, −107.7, −119.2, and −124.0 dBc/Hz, respectively. After the microwave-to-optical conversion, the expected intermodulation effect contribution to the frequency stability of the coherent population trapping (CPT) atomic clock is 5.95 × 10−14 at an averaging time of 1 s. Meanwhile, with a feature of low fluctuation of this chain’s output microwave power at the level of 1.19 × 10−5 W at 1 s, its contribution to the frequency stability of the CPT atomic clock is 7.85 × 10−14 at the 1 s integration time. Our simple and low noise microwave chain is an ideal microwave source for high-performance, compact CPT clocks and could also be applied to cold atom or ion based microwave clocks.
Fiber Bragg grating sensor array for detecting heat flux in vacuum
Authors: Titus J. B. , Griswold M. E. , Granstedt E. M. , Magee R. M. , Charkhesht N. , Schroeder J. H. , Meekins M. , Allfrey I. ,   TAE Team
Published: October 2022

In TAE Technologies’ current experimental device, C-2W (also called “Norman”), record-breaking, advanced beam-driven field-reversed configuration plasmas are produced and sustained in steady state utilizing variable energy neutral beams, advanced divertors, edge-biasing electrodes, and an active plasma control system [Gota et al., Nucl. Fusion 61, 106039 (2021)]. A novel diagnostic has been developed by TAE Technologies to leverage an industrial fiber Bragg grating (FBG) sensor array to detect heat flux along the wall of the vacuum vessel from a plasma discharge. The system consists of an optical fiber with FBG sensors distributed along its length, housed in a pressurized steel sheath. Each FBG sensor is constructed to reflect a different wavelength, the exact value of which is sensitive to the strain and temperature at the location of the grating in the fiber. The fiber is illuminated with broadband light, and the data acquisition system analyzes the spectrum of reflected light to determine the temperature at the location of each FBG. We have installed four of these vacuum-rated FBG sensor arrays on the C-2W experiment, each with 30 individual FBG sensors spaced at 0.15 m intervals along the 5 m fiber, with a 100 Hz acquisition rate. The measurement of temperature change due to a plasma discharge provides a single data point at each sensor location, creating a 120-point heat map of the vacuum vessel.
Design of a new charge exchange recombination spectroscopy diagnostic for impurity transport experiments at Wendelstein 7-X
Authors: Swee Colin , Geiger Benedikt , Albosta Ryan , Ford Oliver , Loch Stuart , Nornberg M. D. , Schellpheffer Jacob , Wegner Thomas ,   W7-X Team
Published: October 2022

In this study, we present the design of a new charge exchange recombination spectroscopy (CXRS) system for Wendelstein 7-X (W7-X), which aims at measuring line radiation from highly ionized iron impurities after laser blow off injections over transport timescales. New fiber bundles with a core diameter of 600 µm have been added to one of the existing optical systems at W7-X used for CXRS. The fibers direct collected light to five newly developed single channel high frame rate F/2.8 spectrometers. The new custom-made spectrometers are built using entirely off-the-shelf and 3D printed components, and employ a round-to-linear fiber bundle, instead of an entrance slit, to maximize light throughput. The detector is an ultra-low readout noise EM-CCD camera capable of frame rates of up to 10 000 fps for about 500 consecutive frames when operated using a single readout channel. Such high frame rates will enable the study of inward convection of injected impurities. An initial sensitivity study is performed using a newly developed Markov chain Monte Carlo approach based on the pySTRAHL impurity transport code. This study indicates that, with the addition of the new CX diagnostic, impurity convection velocities can be inferred.
Deterministic programming of human pluripotent stem cells into microglia facilitates studying their role in health and disease
Authors: Speicher Anna M. , Korn Lisanne , Csatári Júlia , Gonzalez-Cano Laura , Heming Michael , Thomas Christian , Schroeter Christina B. , Schafflick David , Li Xiaolin , Gola Lukas , Engler Alexander , Kaehne Thilo , Vallier Ludovic , Meuth Sven G. , Meyer zu Hörste Gerd , Kovac Stjepana , Wiendl Heinz , Schöler Hans R. , Pawlowski Matthias 
Published: October 2022

Microglia, the resident immune cells of the central nervous system (CNS), are derived from yolk-sac macrophages that populate the developing CNS during early embryonic development. Once established, the microglia population is self-maintained throughout life by local proliferation. As a scalable source of microglia-like cells (MGLs), we here present a forward programming protocol for their generation from human pluripotent stem cells (hPSCs). The transient overexpression of PU.1 and C/EBPβ in hPSCs led to a homogenous population of mature microglia within 16 d. MGLs met microglia characteristics on a morphological, transcriptional, and functional level. MGLs facilitated the investigation of a human tauopathy model in cortical neuron–microglia cocultures, revealing a secondary dystrophic microglia phenotype. Single-cell RNA sequencing of microglia integrated into hPSC-derived cortical brain organoids demonstrated a shift of microglia signatures toward a more-developmental in vivo–like phenotype, inducing intercellular interactions promoting neurogenesis and arborization. Taken together, our microglia forward programming platform represents a tool for both reductionist studies in monocultures and complex coculture systems, including 3D brain organoids for the study of cellular interactions in healthy or diseased environments.
Inhibition of RAS-driven signaling and tumorigenesis with a pan-RAS monobody targeting the Switch I/II pocket
Authors: Wallon Lauren , Khan Imran , Teng Kai Wen , Koide Akiko , Zuberi Mariyam , Li Jianping , Ketavarapu Gayatri , Traaseth Nathaniel J. , O’Bryan John P. , Koide Shohei 
Published: October 2022

RAS mutants are major therapeutic targets in oncology with few efficacious direct inhibitors available. The identification of a shallow pocket near the Switch II region on RAS has led to the development of small-molecule drugs that target this site and inhibit KRAS(G12C) and KRAS(G12D). To discover other regions on RAS that may be targeted for inhibition, we have employed small synthetic binding proteins termed monobodies that have a strong propensity to bind to functional sites on a target protein. Here, we report a pan-RAS monobody, termed JAM20, that bound to all RAS isoforms with nanomolar affinity and demonstrated limited nucleotide-state specificity. Upon intracellular expression, JAM20 potently inhibited signaling mediated by all RAS isoforms and reduced oncogenic RAS-mediated tumorigenesis in vivo. NMR and mutation analysis determined that JAM20 bound to a pocket between Switch I and II, which is similarly targeted by low-affinity, small-molecule inhibitors, such as BI-2852, whose in vivo efficacy has not been demonstrated. Furthermore, JAM20 directly competed with both the RAF(RBD) and BI-2852. These results provide direct validation of targeting the Switch I/II pocket for inhibiting RAS-driven tumorigenesis. More generally, these results demonstrate the utility of tool biologics as probes for discovering and validating druggable sites on challenging targets.
Recent changes in spoken British English in verbal and nominal constructions
Authors: Schneider Gerold 
Published: October 2022

Abstract
Starting from a data-driven approach, the current paper compares the BNC1994 spoken to the BNC2014. We first narrow down possible research questions due to differences in the compilation and transcription of the two BNC generations. Then we investigate three robustly detectable changes at the level of lexis and morphosyntax: (1) gender and class differences, (2) the increase of be- and get-passive constructions and -ing forms from the verbal domain, and (3) the increase of noun compounds from the nominal domain. We also focus on the social context in which linguistic changes are embedded: which noun compounds particularly increase; which words are overused by which gender or social class? Technology seems to be a driver in the further advance of the construction of noun compounds, and strong swearing seems to have decreased between 1994 and 2014.
Constraining GUP models using limits on SME coefficients
Authors: Gomes André Herkenhoff 
Published: October 2022

Abstract
Generalized uncertainty principles (GUP) and, independently, Lorentz symmetry violations are two common features in many candidate theories of quantum gravity. Despite that, the overlap between both has received limited attention so far. In this brief paper, we carry out further investigations on this topic. At the nonrelativistic level and in the realm of commutative spacetime coordinates, a large class of both isotropic and anisotropic GUP models is shown to produce signals experimentally indistinguishable from those predicted by the standard model extension (SME), the common framework for studying Lorentz-violating phenomena beyond the standard model. This identification is used to constrain GUP models using current limits on SME coefficients. In particular, bounds on isotropic GUP models are improved by a factor of 107 compared to current spectroscopic bounds and anisotropic models are constrained for the first time.
Modeling heavy-ion fusion cross section data via a novel artificial intelligence approach
Authors: Dell’Aquila Daniele , Gnoffo Brunilde , Lombardo Ivano , Porto Francesco , Russo Marco 
Published: October 2022

Abstract
We perform a comprehensive analysis of complete fusion cross section data with the aim to derive, in a completely data-driven way, a model suitable to predict the integrated cross section of the fusion between light-to-medium mass nuclei at above barrier energies. To this end, we adopted a novel artificial intelligence approach, based on a hybridization of genetic programming and artificial neural networks, capable to derive an analytical model for the description of experimental data. The approach enables to perform a global search for computationally simple models over several variables and a considerable body of nuclear data. The derived phenomenological formula can serve to reproduce the trend of fusion cross section for a large variety of light to intermediate mass collision systems in an energy domain ranging approximately from the Coulomb barrier to the onset of multi-fragmentation phenomena.
Navier–Stokes equations: regularity criteria in terms of the derivatives of several fundamental quantities along the streamlines—the case of a bounded domain
Authors: Guo Zhengguang , Kučera Petr , Skalak Zdenek 
Published: October 2022

Abstract
In this paper we deal with the conditional regularity of the weak solutions of the Navier–Stokes equations on a bounded domain endowed with Navier boundary conditions, Navier-type boundary conditions or Dirichlet boundary conditions. We prove the regularity criteria which are based on the directional derivatives of several fundamental quantities along the streamlines, namely the velocity magnitude, the kinetic energy, the pressure, the velocity field and the Bernoulli pressure. In striking contrast to the known criteria in which the mentioned quantities were differentiated along a fixed vector, our criteria are mostly optimal for the whole range of parameters and have a clear physical meaning.
A traveling wave bifurcation analysis of turbulent pipe flow
Authors: Engel Maximilian , Kuehn Christian , de Rijk Björn 
Published: October 2022

Abstract
Using various techniques from dynamical systems theory, we rigorously study an experimentally validated model by [Barkley et al 2015 Nature
526 550–3], which describes the rise of turbulent pipe flow via a PDE system of reduced complexity. The fast evolution of turbulence is governed by reaction-diffusion dynamics coupled to the centerline velocity, which evolves with advection of Burgers’ type and a slow relaminarization term. Applying to this model a spatial dynamics ansatz and geometric singular perturbation theory, we prove the existence of a heteroclinic loop between a turbulent and a laminar steady state and establish a cascade of bifurcations of various traveling waves mediating the transition to turbulence. The most complicated behaviour can be found in an intermediate Reynolds number regime, where the traveling waves exhibit arbitrarily long periodic-like dynamics indicating the onset of chaos. Our analysis provides a systematic mathematical approach to identifying the transition to spatio–temporal turbulent structures that may also be applicable to other models arising in fluid dynamics.
Poincaré series for surfaces with boundary
Authors: Chaubet Yann 
Published: October 2022

AbstractWe provide a meromorphic continuation for Poincaré series counting orthogeodesics of a negatively curved surface with totally geodesic boundary, as well as for Poincaré series counting geodesic arcs linking two points. For the latter series, we show that the value at zero coincides with the inverse of the Euler characteristic of the surface.
Existence and uniqueness of equilibrium states for systems with specification at a fixed scale: an improved Climenhaga–Thompson criterion*
Authors: Pacifico Maria Jose , Yang Fan , Yang Jiagang 
Published: October 2022

Abstract
We consider the uniqueness of equilibrium states for dynamical systems that satisfy certain weak, non-uniform versions of specification, expansivity, and the Bowen property at a fixed scale. Following Climenhaga–Thompson’s approach which was originally due to Bowen and Franco, we prove that equilibrium states are unique even when the weak specification assumption only holds on a small collection of orbit segments. This improvement will be crucial in a subsequent work, where we will prove that (open and densely) every Lorenz attractor supports a unique measure of maximal entropy.
Circularly polarized scalar induced gravitational waves from the Chern-Simons modified gravity
Authors: Zhang Fengge , Feng Jia-Xi , Gao Xian 
Published: October 2022

Abstract
We investigate the scalar induced gravitational waves (SIGWs) in the Chern-Simons (CS) modified gravity during the radiation dominated era. The SIGWs are circularly polarized, which provide us a tool to test the possible parity violation in the early universe. We derive the semianalytic expressions to evaluate the fractional energy density of the SIGWs, ΩGW, which receives contributions from the general relativity (GR) and the correction due to the parity-violating term, respectively. We find that the degree of the circular polarization of the SIGWs can be as large as of order unity, although the contribution to ΩGW from the CS term is at most of the same order as that from the GR.
An Improved Radio Pointing Model for SHARC II of the Caltech Submillimeter Observatory Telescope
Authors: Chen Weirui , Wang Zheng , Zhou Xiaojun 
Published: October 2022

Abstract
In this research, we develop a new method of upgrading the radio pointing model of an important instrument of the Caltech Submillimeter Observatory (CSO) telescope, i.e., the Submillimeter High Angular Resolution Camera II (SHARC II), by making three types of structural reconstruction of its existing model. First, the axial displacement of the secondary reflector of the telescope is introduced to the radio pointing model for SHARC II. Second, the multi-layer perceptron is applied for better describing higher-order terms in the radio pointing model, which are hard to be mathematically formulated. Third, a receding horizon modeling method is proposed to replace the time-dependent term in the existing model, for better reducing the negative impact of the time drift on the model’s accuracy. Results of numerical experiments and statistical significance analysis based on the real pointing data of SHARC II show that the reconstructed radio pointing model can improve the accuracy of estimating the pointing error, and the proposed method of upgrading the radio pointing model is effective. Considering that the CSO telescope will be moved from the old site at Maunakea, Hawaii to the new site at the Chajnantor Plateau in Chile, the proposed methods of upgrading the radio pointing model are expected to be employed for pointing correction after the telescope is refurbished at the new site.
Maximum mass of anisotropic charged strange quark stars in a higher dimensional approach (D ≥ 4)
Authors: Saha A. , Goswamiy K.B. , Dasz B. , Chattopadhyayx P.K. 
Published: October 2022

Abstract
In this article, a new class of solutions of Einstein-Maxwell field equations of relativistic strange quark stars obtained in dimensions

, is shown. We assume that the geometry of space-time is pseudo-spheroid, embedded in Euclidean space of

dimensions. The MIT bag model equation of state

is employed to study the relevant properties of strange quark stars. For the causal and non-negative nature of the square of the radial sound velocity

, we observe that some restrictions exist on the reduced radius

, where R is a parameter related to the curvature of the space-time, and b is the radius of the star. The spheroidal parameter λ used here defines the metric potential of the

component, which is pseudo-spheroidal in nature. We note that the pressure anisotropy and charge have some effects on λ. The maximum mass for a given surface density (

) or bag constant

assumes a maximum value in dimension

and decreases for other values of D. The generalized Buchdahl limit for a higher dimensional charged star is also obeyed in this model. We observe that in this model, we can predict the mass of a strange quark star using a suitable value of the electric charge (Q) and bag constant (B). Energy and stability conditions are also satisfied in this model. Stability is also studied considering the dependence of the Lagrangian perturbation of radial pressure (

) on the frequency of normal modes of oscillations. The tidal Love number and tidal de-formability are also evaluated.
Torsion Fields Generated by the Quantum Effects of Macro-bodies
Authors: Chen Da-Ming 
Published: October 2022

Abstract
We generalize Einstein’s General Relativity (GR) by assuming that all matter (including macro-objects) has quantum effects. An appropriate theory to fulfill this task is Gauge Theory Gravity (GTG) developed by the Cambridge group. GTG is a “spin-torsion” theory, according to which, gravitational effects are described by a pair of gauge fields defined over a flat Minkowski background spacetime. The matter content is completely described by the Dirac spinor field, and the quantum effects of matter are identified as the spin tensor derived from the spinor field. The existence of the spin of matter results in the torsion field defined over spacetime. Torsion field plays the role of Bohmian quantum potential which turns out to be a kind of repulsive force as opposed to the gravitational potential which is attractive. The equivalence principle remains and essential in this theory so that GR is relegated to a locally approximate theory wherein the quantum effects (torsion) are negligible. As a toy model, we assume that the macro matter content can be described by the covariant Dirac equation and apply this theory to the simplest radially symmetric and static gravitational systems. Consequently, by virtue of the cosmological principle, we are led to a static universe model in which the Hubble redshifts arise from the torsion fields.
Optimal data generation for machine learned interatomic potentials
Authors: Allen Connor , Bartók Albert P 
Published: October 2022

Abstract
Machine learning interatomic potentials (MLIPs) are routinely used atomic simulations, but generating databases of atomic configurations used in fitting these models is a laborious process, requiring significant computational and human effort. A computationally efficient method is presented to generate databases of atomic configurations that contain optimal information on the small-displacement regime of the potential energy surface of bulk crystalline matter. Utilising non-diagonal supercell (Lloyd-Williams and Monserrat 2015 Phys. Rev. B 92 184301), an automatic process is suggested for ab initio data generation. MLIPs were fitted for Al, W, Mg and Si, which very closely reproduce the ab initio phonon and elastic properties. The protocol can be easily adapted to other materials and can be inserted in the workflow of any flavour of MLIP generation.