Miracle-dz/UniFAR-FTUs huggingface dataset:
Statistical Equilibrium Principles in 2D Fluid Flow: From Geophysical Fluids to the Solar Tachocline

An overview is presented of several diverse branches of work in the area of effectively 2D fluid equilibria which have in common that they are constrained by an infinite number of conservation laws. Broad concepts, and the enormous variety of physical phenomena that can be explored, are highlighted. These span, roughly in order of increasing complexity, Euler flow, nonlinear Rossby waves, 3D axisymmetric flow, shallow water dynamics, and 2D magnetohydrodynamics. The classical field theories describing these systems bear some resemblance to perhaps more familiar fluctuating membrane and continuous spin models, but the fluid physics drives these models into unconventional regimes exhibiting large scale jet and eddy structures. From a dynamical point of view these structures are the end result of various conserved variable forward and inverse cascades. The resulting balance between large scale structure and small scale fluctuations is controlled by the competition between energy and entropy in the system free energy, in turn highly tunable through setting the values of the conserved integrals. Although the statistical mechanical description of such systems is fully self-consistent, with remarkable mathematical structure and diversity of solutions, great care must be taken because the underlying assumptions, especially ergodicity, can be violated or at minimum lead to exceedingly long equilibration times. Generalization of the theory to include weak driving and dissipation (e.g., non-equilibrium statistical mechanics and associated linear response formalism) could provide additional insights, but has yet to be properly explored.
Astrophysical Conditions for Planetary Habitability

With the discovery of hundreds of exoplanets and a potentially huge number of Earth-like planets waiting to be discovered, the conditions for their habitability have become a focal point in exoplanetary research. The classical picture of habitable zones primarily relies on the stellar flux allowing liquid water to exist on the surface of an Earth-like planet with a suitable atmosphere. However, numerous further stellar and planetary properties constrain habitability. Apart from "geophysical" processes depending on the internal structure and composition of a planet, a complex array of astrophysical factors additionally determine habitability. Among these, variable stellar UV, EUV, and X-ray radiation, stellar and interplanetary magnetic fields, ionized winds, and energetic particles control the constitution of upper planetary atmospheres and their physical and chemical evolution. Short- and long-term stellar variability necessitates full time-dependent studies to understand planetary habitability at any point in time. Furthermore, dynamical effects in planetary systems and transport of water to Earth-like planets set fundamentally important constraints. We will review these astrophysical conditions for habitability under the crucial aspects of the long-term evolution of stellar properties, the consequent extreme conditions in the early evolutionary phase of planetary systems, and the important interplay between properties of the host star and its planets.
Cooling Rates of Molecular Clouds Based on Numerical Magnetohydrodynamic Turbulence and Non-LTE Radiative Transfer

We have computed line-emission cooling rates for the main cooling species in models of interstellar molecular clouds. The models are based on numerical simulations of supersonic magnetohydrodynamic (MHD) turbulence. Non-LTE radiative transfer calculations have been performed to properly account for the complex density and velocity structures in the MHD simulations. Three models are used. Two of the models are based on MHD simulations with different magnetic field strength (one model is super-Alfvénic, while the other has equipartition of magnetic and kinetic energy). The third model includes the computation of self-gravity (in the super-Alfvénic regime of turbulence). The density and velocity fields in the simulations are determined self-consistently by the dynamics of supersonic turbulence. The models are intended to represent molecular clouds with linear size L ≈ 6 pc and mean density ⟨n⟩ ≈ 300 cm-3, with the density exceeding 104 cm-3 in the densest cores. We present 12CO, 13CO, C18O, O2, O I, C I, and H2O cooling rates in isothermal clouds with kinetic temperatures 10-80 K. Analytical approximations are derived for the cooling rates. The inhomogeneity of the models reduces photon trapping and enhances the cooling in the densest parts of the clouds. Compared with earlier models, the cooling rates are less affected by optical depth effects. The main effects come, however, from the density variation, since cooling efficiency increases with density. This is very important for the cooling of the clouds as a whole, since most cooling is provided by gas with density above the average.
Far-field Imaging beyond the Diffraction Limit Using a Single Radar

Far-field imaging beyond the diffraction limit is a long sought-after goal in various imaging applications, which requires usually an array of antennas or mechanical scanning. Here, we present an alternative and novel concept for this challenging problem: a single radar system consisting of a spatial-temporal resonant aperture antenna (referred to as the slavery antenna) and a broadband horn antenna (termed the master antenna). We theoretically demonstrate that such resonant aperture antenna is responsible for converting parts of the evanescent waves into propagating waves, and delivering them to the far-field. We also demonstrate that there are three basic requirements on the proposed subwavelength imaging strategy: the strong spatial-temporal dispersive aperture, the near-field coupling, and the temporal (or broadband) illumination. Such imaging concept of a single radar provides unique ability to produce real-time data when an object is illuminated by broadband electromagnetic waves, which lifts up the harsh requirements such as near-field scanning, mechanical scanning or antenna arrays remarkably. We expect that this imaging methodology will make breakthroughs in super-resolution imaging in the microwave, terahertz, optical, and ultrasound regimes.
An Improved Photometric Calibration of the Sloan Digital Sky Survey Imaging Data

We present an algorithm to photometrically calibrate wide-field optical imaging surveys, which simultaneously solves for the calibration parameters and relative stellar fluxes using overlapping observations. The algorithm decouples the problem of “relative” calibrations from that of “absolute” calibrations; the absolute calibration is reduced to determining a few numbers for the entire survey. We pay special attention to the spatial structure of the calibration errors, allowing one to isolate particular error modes in downstream analyses. Applying this to the SDSS imaging data, we achieve ~1% relative calibration errors across 8500 deg2 in griz; the errors are ~2% for the u band. These errors are dominated by unmodeled atmospheric variations at Apache Point Observatory. These calibrations, dubbed “ubercalibration,” are now public with SDSS Data Release 6 and will be a part of subsequent SDSS data releases.
Lighter and Simpler Design Paradigm for Widespread Use of Ankle Exosuits Based on Bio-Inspired Patterns

Soft wearable robots are attracting immense attention owing to their high usability and wearability. In particular, studies on soft exosuits have achieved remarkable progress. Walking is one of the most basic human actions in daily life. During walking, the ankle joint has considerable influence. Therefore, an exosuit design paradigm having a light and simple structure was developed with the goal of fabricating a soft exosuit that supports the ankle. The new exosuit matches the performance of existing exosuits while being as comfortable as everyday wear. A walking test through a combination with a mobile actuator system, which can maximize these advantages, was also conducted. The combination with the mobile system demonstrates the potential of using the new ankle exosuit as inner wear that maximizes the advantages of a lighter and simpler design. The exosuit design paradigm could serve as an effective guideline for manufacturing assistive exosuits for various body parts in the future.
Compression mechanisms and equations of state

The derivations of equations of state to describe the volume-pressure variation of a solid are based upon certain assumptions about the properties of the solid. For finite strain equations of state, these assumptions include homogeneity and isotropy of the strain distribution in the sample, the continuous differentiability of the equation of state parameters with respect to extensive variables, and the assumption that terms involving higher-order powers of the finite strain do not contribute significantly to the free energy of the material. We examine these assumptions and demonstrate that, within the experimental uncertainties, crystalline solids with no or limited degrees of internal structural freedom compress in the manner predicted by finite strain equations of state, even though in some cases the assumptions involved in the derivation of the equation of state are demonstrably violated. In more complex structures with a larger number of degrees of structural freedom, a variety of behaviour is observed; most undergo continuous structural change with increasing pressure and the evolution of the volume with pressure again follows that predicted by the finite strain equations of state. However, a significant number of complex structures undergo changes in compression mechanism which, in some cases, result in significant deviations from the behaviour predicted by the equations of state.
Investigation of the unique nulling properties of PSR B0818−41

We investigate the unique nulling properties PSR B0818−41 with the GMRT at 325 and 610 MHz. A strong trend in the intensity fluctuations of the individual pulses just before and after the nulls is observed by us for this pulsar. In addition, we report a possible connection between the intensity fluctuations and the drift rate of subpulses just before and after the nulls. We find some very specific and well correlated changes in the radio emission properties of PSR B0818−41 when the emission restarts after a null. These could imply that the phenomenon of nulling is associated with some kind of a “reset” of the pulsar radio emission engine.
Madden-Julian Oscillation impacts on Australian temperatures and extremes

We assess seasonally-varying impacts of the Madden-Julian Oscillation (MJO) on Australian maximum and minimum temperature anomalies and extremes, and their modulation by the El Niño – Southern Oscillation (ENSO), for the period June 1974 to May 2022. Our composite-based approach uses observed temperatures from the Australian Gridded Climate Data, and 850 hPa wind data from the NCEP-NCAR Reanalysis, to show how relationships to temperature and circulation evolve over the eight-phase lifecycle of the MJO, which we derive from the real-time multivariate MJO index. The MJO has significant impacts on Australian temperatures and winds in all parts of the country at various times throughout the year, and to varying degrees. Two of the most pronounced impacts are (i) daytime warming across south-eastern Australia in MJO phase 3 during spring associated with a strong anomalous anticyclone, and (ii) night-time cooling over Queensland in MJO phase 7 during winter associated with anomalous advection of cool/dry continental air. La Niña acts to significantly lessen both of these impacts, while El Niño enhances both the phase 3 warming over southern Australia in spring and the phase 7 overnight cooling over southern Queensland in winter. We show how the MJO can combine with El Niño and La Niña to have strong compounding influences, thus highlighting the importance of understanding interactions between multiple modes of climate variability and how they relate to Australian temperatures and extremes.
Flow bouncing and electron injection observed by Cluster

Characteristics of particles and fields in the flow‐bouncing region are studied based on multipoint observations from Cluster located at 13–15RE downtail during a substorm event around 12:50 UT on 7 September 2007. The Cluster spacecraft were separated by a distance of up to 10,000 km and allowed to determine the mesoscale evolution of the current sheet as well as the development of the dipolarization front. We show that the flow bouncing took place associated with a tailward‐directed j × B force in a disturbed current sheet in addition to an enhanced tailward pressure gradient force. Multiple Earthward propagating dipolarization fronts accompanied by enhanced flux of energetic electrons were observed before the flow bouncing. The sequence of events started with a localized dipolarization front and ended with a large scale (>10RE) dipolarization front accompanied by a major increase in energetic electrons at all spacecraft and immediately followed by flow bouncing. Multiple dipolarization fronts result in the formation of compressed magnetic field with a plasma bulge bounded by thin ion‐scale current layers, a favorable condition for flow bouncing. These observations suggest that to understand the flow bouncing and related acceleration of plasma in the near‐Earth tail, both the large‐scale MHD properties and the transient and small‐scale effect of the plasma interaction with the Earth‐dipole field need to be taken into account.
Simulated observations of young gravitationally unstable protoplanetary discs

The formation and earliest stages of protoplanetary discs remain poorly constrained by observations. ALMA will soon revolutionise this field. Therefore, it is important to provide predictions which will be valuable for the interpretation of future high sensitivity and high angular resolution observations. Here we present simulated ALMA observations based on radiative transfer modelling of a relatively massive (0.39 M_solar) self-gravitating disc embedded in a 10 M_solar dense core, with structure similar to the pre-stellar core L1544. We focus on simple species and conclude that C17O 3-2, HCO+ 3-2, OCS 26-25 and H2CO 404-303 lines can be used to probe the disc structure and kinematics at all scales.
Predicting Successful Throwing Technique in Judo from Factors of Kumite Posture Based on a Machine-Learning Approach

Identifying the key points of a movement performed by an expert is required for beginners who want to acquire a motor skill. By repeating a learning cycle, the beginner tries the movement, focusing on the key points. We can find many guiding methods for adopting motor skills in the fields of coaching and training for sports. However, the methods strongly depend on the experience of trainers and coaches, who need to select the appropriate methods for different types of athletes. Although methods based on objective information obtained from videos and sensors applicable to individual movements have been proposed in order to overcome the subjectivity of these approaches, we cannot apply those to movements that include external factors, such as pushing and/or attacks from an opponent, as seen in combat sports. Furthermore, such sports require fast feedback of the analysis to the athletes in order to find the key factors of offensive/defensive techniques at the training site. Focusing on judo throwing techniques, this paper proposes a novel real-time prediction method called RT-XSM (Real-Time Extraction method for Successful Movements) that predicts which throwing technique is most likely to be successful based on Kumite posture just before the throw. The RT-XSM uses logistic regression to analyze datasets consisting of the factors of Kumite posture (a standing posture when both players grip each other) and throwing technique classification. To validate the proposed method, this paper also demonstrates experiments of the RT-XSM using datasets acquired from video scenes of the World Judo Championships.
An Effective Average Tax Rate as the Deciding Factor in Tax Competitiveness in the Context of Foreign Investment Influx

A higher tax burden in individual countries need not always deter investors from investing profitably. Countries use tax burden levels in the form of changes in tax rates to attract foreign investment. The main objective of this study is to examine the tax competitiveness of the Slovak Republic compared to European Union (EU) countries (EU-27) and to evaluate the origin, extent, and form of investments from foreign investors in tangible and intangible assets in the Slovak Republic. To meet this objective, we first calculate the average tax rate for specific crossborder investments coming to Slovakia from all EU countries. To determine tax competitiveness, we compare the calculated effective average tax rate (EATR) with the EATR in individual EU countries. Finally, we perform an analysis of EATR and foreign direct investment (FDI) using cluster analysis, which categorises EU countries and evaluates their tax competitiveness. The analysis and comparison of values are conducted for the year 2019, while the countries are divided into old (EU-15) and new (EU-12) EU member countries. The article concludes that the calculated Slovak EART for cross-border investment is more profitable for old EU member countries and is, thus, more tax-competitive versus investors’ countries of origin. We can further state that the tax burden is among the most important indicators for investors and, thus, a lower EATR value than that in an investor’s country of origin contributes to the inflow of equity participation of FDI in Slovakia.
THEORETICAL ESTIMATES OF STELLAR e− CAPTURES. I. THE HALF-LIFE OF 7Be IN EVOLVED STARS

The enrichment of Li in the universe is still unexplained, presenting various puzzles to astrophysics. One open issue is that of obtaining reliable estimates for the rate of e− captures on 7Be for T and ρ conditions that are different from the solar ones. This is of crucial importance for modeling the Galactic nucleosynthesis of Li. In this framework, we present here a new theoretical method for calculating the e− capture rate in typical conditions for evolved stars. Furthermore, we show how our approach compares with state-of-the-art techniques for solar conditions, where various estimates are available. Our computations include (1) “traditional” calculations of the electronic density at the nucleus, to which the e− capture rate for 7Be is proportional, for different theoretical approaches including the Thomas–Fermi, Poisson–Boltzmann, and Debye–Hückel (DH) models of screening; and (2) a new computation, based on a formalism that goes beyond the previous ones, adopting a mean-field “adiabatic” approximation to the scattering process. The results obtained with the new approach as well as with traditional ones and their differences are discussed in some detail, starting from solar conditions, where our approach and the DH model essentially converge to the same solution. We then analyze the applicability of both our method and the DH model to a rather broad range of T and ρ values, embracing those typical of red giant stars, where both bound and continuum states contribute to the capture. We find that over a wide region of the parameter space explored, the DH approximation does not really stand, so that the more general method we suggest should be preferred. As a first application, we briefly reanalyze the 7Li abundances in red giant branch and asymptotic giant branch stars of the Galactic disk in light of a revision in the Be decay only; however, we emphasize that the changes we find in the electron density at the nucleus would also induce effects on the electron screening (for p-captures on Li itself, as well as for other nuclei) so that our new approach might have rather wide astrophysical consequences.
Testing the Accretion-induced Field-decay and Spin-up Model for Recycled Pulsars

Millisecond radio pulsars have long been proposed to form from a spin-up recycling process in a binary system. In this paper we demonstrate that the accretion-induced field-decay and spin-up model for recycled pulsars can indeed produce those millisecond pulsars with relatively weak magnetic fields of $10^8-10^9$ G and short spin periods of a few milliseconds. Our results also suggest that the value of the currently observed highest spin frequency of millisecond pulsars may simply be constrained by the amount of mass available for accretion.
Collapse and revival of a Dicke-type coherent narrowing in potassium vapor confined in a nanometric thin cell

A nanometer-thin cell (in the direction of laser beam propagation) has been elaborated with the thickness of the atomic vapor column varying smoothly in the range of L = 50 − 1500 nm ? > . The cell allows one to study the behavior of the resonance absorption over the D1 line of potassium atoms by varying the laser intensity and the cell thickness (from L = λ / 2 ? > to L = 2 λ ? > with the step λ / 2 ? > where λ = 770 nm ? > is the resonant wavelength of the laser). It is shown that despite the huge Doppler broadening ( > 0.9 GHz ? > at the cell temperature 170 ◦ C ? > ), at low laser intensities a narrowing of the resonance absorption spectrum is observed for L = λ / 2 ? > ( ∼ 120 MHz ? > at FWHM) and L = 3 / 2 λ ? > , whereas for L = λ ? > and L = 2 λ ? > the spectrum broadens. At moderate laser intensities narrowband velocity selective optical pumping (VSOP) resonances appear at L = λ ? > and L = 2 λ ? > with the linewidth close to the natural one. A comparison with saturated absorption spectra obtained in a 1.4 cm-sized K cell is presented. The developed theoretical model well describes the experiment.
Prevalence of Zinc Deficiency in Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

Malabsorptive disorders are closely associated with micronutrient deficiencies. In inflammatory bowel disease (IBD), trace element deficiencies pose a clinical burden from disease onset throughout its course, contributing to morbidity and poor quality of life. We aimed to conduct a systematic review and meta-analysis of the prevalence of zinc deficiency in IBD. Literature screening was performed on six electronic databases until 1 May 2022. Two independent investigators assessed the 152 retrieved articles for inclusion criteria, met by only nine, that included 17 prevalence entries for Crohn’s disease (CD) (n = 9) and ulcerative colitis (UC) (n = 8). No exclusion criteria were applied to language, deficiency cut-offs, population age, general health status, country, or study setting (cohort or cross-sectional). The prevalence of zinc deficiency in blood was scored positive if due to a single disease, not cumulative factors. Zinc deficiency prevalence across selected studies showed higher values in CD than in UC. Pooled analyses by the IBD subgroup showed a total population of 1677 with CD, for an overall mean zinc deficiency prevalence of 54% and 95% confidence intervals (CI) ranging from 0.51 to 0.56, versus 41% (95%CI 0.38–0.45) in the UC population (n = 806). The overall prevalence at meta-analysis was estimated at 50% (95%CI 0.48–0.52), but with high heterogeneity, I2 = 96%. The funnel plot analysis failed to show any evidence of publication bias. The risk of bias across selected studies was moderate to low. In IBD contexts, one of two patients suffers from zinc deficiency. Mismanagement of micronutrient deficiencies plays a role in inflammation trajectories and related cross-pathways. Clinicians in the field are advised to list zinc among trace elements to be monitored in serum.