Miracle-dz/UniFAR-FTUs huggingface dataset:
Hierarchy of graphene wrinkles induced by thermal strain engineering

Here, we study hierarchy of graphene wrinkles induced by thermal strain engineering and demonstrate that the wrinkling hierarchy can be accounted for by the wrinklon theory. We derive an equation λ = (ky)0.5, explaining evolution of wrinkling wavelength λ with the distance to the edge y observed in our experiment by considering both bending energy and stretching energy of the graphene flakes. The prefactor k in the equation is determined to be about 55 nm. Our experimental result indicates that the classical membrane behavior of graphene persists down to about 100 nm of the wrinkling wavelength.
ON THE ANISOTROPY IN EXPANSION OF MAGNETIC FLUX TUBES IN THE SOLAR CORONA

Most one-dimensional hydrodynamic models of plasma confined to magnetic flux tubes assume circular tube cross sections. We use potential field models to show that flux tubes in circumstances relevant to the solar corona do not, in general, maintain the same cross-sectional shape through their length and therefore the assumption of a circular cross section is rarely true. We support our hypothesis with mathematical reasoning and numerical experiments. We demonstrate that lifting this assumption in favor of realistic, non-circular loops makes the apparent expansion of magnetic flux tubes consistent with that of observed coronal loops. We propose that in a bundle of ribbon-like loops, those that are viewed along the wide direction would stand out against those that are viewed across the wide direction due to the difference in their column depths. That result would impose a bias toward selecting loops that appear not to be expanding, seen projected in the plane of sky. An implication of this selection bias is that the preferentially selected non-circular loops would appear to have increased pressure scale heights even if they are resolved by current instruments.
Creation of quasiparticles in graphene by a time-dependent electric field

We investigate the creation of massless quasiparticle pairs from the vacuum state in graphene by the space homogeneous time-dependent electric field. For this purpose the formalism of (2+1)-dimensional quantum electrodynamics is applied to the case of a nonstationary background with arbitrary time dependence allowing the S-matrix formulation of the problem. The number of created pairs per unit graphene area is expressed via the asymptotic solution at $t\to\infty$ of the second-order differential equation of an oscillator type with complex frequency satisfying some initial conditions at $t\to-\infty$. The obtained results are applied to the electric field with specific dependence on time admitting the exact solution of Dirac equation. The number of created pairs per unit area is calculated analytically in a wide variety of different regimes depending on the parameters of electric field. The investigated earlier case of static electric field is reproduced as a particular case of our formalism. It is shown that the creation rate in a time-dependent field is often larger than in a static field.
Phase Bifurcations of Strongly Correlated Electron Gas at the Conditions of dHvA Effect

In a framework of catastrophe theory we investigate the equilibrium set for the system of strongly correlated electron gas at the conditions of dHvA effect and show that the discontinuities accompanied the diamagnetic phase transition (DPT) is handled by Riemann-Hugoniot catastrophe. We show that applicability of the standard condition for observation of DPT $a\ge$1 where $a$ is the differential magnetic susceptibility is valid only in the nearest vicinity of triple degenerate point corresponding to the center of dHvA period, but for arbitrary value of magnetic field in every period of dHvA oscillations this condition is modified in accordance with the bifurcation set of cusp catastrophe. While at the center of dHvA period the symmetric supercritical pitchfork bifurcation gives rise to the second order phase transition on temperature, the deviation of magnetic field from the value corresponding to the center of dHvA period results in the change of the phase transition order from the second to the first one both on temperature and magnetic field. In the framework of developed theory we obtain good agreement with available experimental data.
Spin-wave propagation and transformation in a thermal gradient

The influence of a thermal gradient on the propagation properties of externally excited dipolar spin waves in a magnetic insulator waveguide is investigated. It is shown that spin waves propagating towards a colder region along the magnetization direction continuously reduce their wavelength. The wavelength increase of a wave propagating into a hotter region was utilized to realize its decomposition in the partial waveguide modes which are reflected at different locations. This influence of temperature on spin-wave properties is mainly caused by a change in the saturation magnetization and yields promising opportunities for the manipulation of spin waves in spin-caloritronic applications.
Fibrewise rational H-spaces

We prove fibrewise versions of classical theorems of Hopf and Leray-Samelson. Our results imply the fibrewise H-triviality after rationalization of a certain class of fibrewise H-spaces. They apply, in particular, to universal adjoint bundles. From this, we may retrieve a result of Crabb and Sutherland [Proc. London Math. Soc. (2000), 747-768], which is used there as a crucial step in establishing their main finiteness result.
GMC Collisions as Triggers of Star Formation. IV. The Role of Ambipolar Diffusion

We investigate the role of ambipolar diffusion (AD) in collisions between magnetized giant molecular clouds (GMCs), which may be an important mechanism for triggering star cluster formation. Three-dimensional simulations of GMC collisions are performed using a version of the Enzo magnetohydrodynamics code that has been extended to include AD. The resistivities are calculated using the 31-species chemical model of Wu et al. (2015). We find that in the weak-field, 10 μ G case, AD has only a modest effect on the dynamical evolution during the collision. However, for the stronger-field, 30 μ G case involving near-critical clouds, AD results in the formation of dense cores in regions where collapse is otherwise inhibited. The overall efficiency of formation of cores with n H ≥ 10 6 cm − 3 in these simulations is increases from about 0.2% to 2% once AD is included, comparable to observed values in star-forming GMCs. The gas around these cores typically has relatively slow infall at speeds that are a modest fraction of the free-fall speed.
Evidence for Precession due to Supercritical Accretion in Ultraluminous X-Ray Sources

Most ultraluminous X-ray sources (ULXs) are thought to be supercritical accreting compact objects, where massive outflows are inevitable. Using the long-term monitoring data with the Swift X-ray Telescope, we identified a common feature in bright, hard ULXs: they display a quasi-periodic modulation in their hard X-ray band but not in their soft band. As a result, some sources show a bimodal distribution on the hardness intensity map. We argue that these model-independent results can be well interpreted in a picture that involves supercritical accretion with precession, where the hard X-ray emission from the central funnel is more or less beamed, while the soft X-rays may arise from the photosphere of the massive outflow and be nearly isotropic. It implies that precession may be ubiquitous in supercritical systems, such as the Galactic microquasar SS 433. How the hard X-rays are modulated can be used to constrain the angular distribution of the hard X-ray emission and the geometry of the accretion flow. We also find that two ULX pulsars (NGC 5907 ULX-1 and NGC 7793 P13) show similar behaviors but no bimodal distribution, which may imply that they have a different beaming shape or mechanism.
Categorisation of organisation dualities using the Delphi technique

This paper presents the case of a non-traditional use of the Delphi method in order to explore organisational duality and reach a consensus on the 23 organisational dualities which allow for a classification into a three-tier organisational policy model (TTOP-model). The expert group was composed of seven experts from the field of management. The process ran for four rounds to reach the final consensus examining 25 dualities and eventually focusing them down to the final 23. In addition to their practical relevance of understanding the dualities, the findings also have implications for both the literature on strategic management and the paradox lens on organisational theory through an understanding of duality in terms of the TTOP model. This research not only advances conversations in strategic management but also helps to increase confidence when adopting the Delphi method for a wider recognition of the method within both interpretivist studies and paradox research.
Telogen effluvium after COVID-19 vaccination among public in Saudi Arabia

Background: Number of reports linked Telogen effluvium to coronavirus disease 2019 (COVID-19) infection. However, data about Telogen effluvium after COVID-19 vaccination are limited. Objectives: To estimate prevalence of Telogen effluvium among those who received COVID-19 vaccination. Methods: A cross-sectional study was performed during July 2021. Adults who received one of recognized COVID-19 vaccine irrespective of previous COVID-19 infection were asked to fill a questionnaire. Results: The majority of participants were females (90.3%). The most common age group was between 21 and 30 years (51.9%). Out of 991 participants who were included in the current analysis, 670 (67.6%) reported post-vaccination hair fall. The probable causes of post-vaccination hair fall were vaccine-related in 185 (27.6%) participants, other causes in 326 (48.7%) participants, and unclear in 326 (48.7%) participants. Post-vaccination hair fall was significantly higher among females compared with males (68.5% versus 57.9%, P = 0.036), those who did not suffer compared with those who suffered from hair fall before vaccination (72.1% versus 63.4%, P = 0.003), and those who did not report compared with those who reported preexisting conditions that might be related to hair fall (74.5% versus 57.3%, P < 0.001). Conclusion: We are reporting a high prevalence of post-vaccination hair fall, which affected approximately two-thirds of participants who received COVID-19 vaccines. Only 28% of these participants were apparently vaccine related. The role of COVID-19 infection and stress caused by infection and vaccine cannot be excluded. Primary care physician and dermatologist need to consider the possibility of COVID-19 vaccine as a potential cause of hair loss.
Integrated K-band spectra of old and intermediate-age globular clusters in the Large Magellanic Cloud

Current stellar population models have arguably the largest uncertainties in the near-IR wavelength range, partly due to a lack of large and well calibrated empirical spectral libraries. In this paper we present a project whose aim it is to provide the first library of luminosity weighted integrated near-IR spectra of globular clusters to be used to test the current stellar population models and serve as calibrators for future ones. Our pilot study presents spatially integrated K-band spectra of three old (≥10 Gyr) and metal poor ([Fe/H] ∼− 1.4), and three intermediate age (1–2 Gyr) and more metal rich ([Fe/H] ∼− 0.4) globular clusters in the LMC. We measured the line strengths of the Na i ,C ai and 12 CO (2–0) absorption features. The Na i index decreases with increasing age and decreasing metallicity of the clusters. The DCO index, used to measure the 12 CO (2–0) line strength, is significantly reduced by the presence of carbon-rich TP-AGB stars in the globular clusters with age ∼1 Gyr. This is in contradiction to the predictions of the stellar population models of Maraston (2005, MNRAS, 362, 799). We find that this disagreement is due to the different CO absorption strength of carbon-rich Milky Way TP-AGB stars used in the models and the LMC carbon stars in our sample. For globular clusters with age ≥ 2G yr we fi ndDCO index measurements consistent with the model predictions.
HOW GALACTIC ENVIRONMENT REGULATES STAR FORMATION

In a new simple model I reconcile two contradictory views on the factors that determine the rate at which molecular clouds form stars—internal structure versus external, environmental influences—providing a unified picture for the regulation of star formation in galaxies. In the presence of external pressure, the pressure gradient set up within a self-gravitating turbulent (isothermal) cloud leads to a non-uniform density distribution. Thus the local environment of a cloud influences its internal structure. In the simple equilibrium model, the fraction of gas at high density in the cloud interior is determined simply by the cloud surface density, which is itself inherited from the pressure in the immediate surroundings. This idea is tested using measurements of the properties of local clouds, which are found to show remarkable agreement with the simple equilibrium model. The model also naturally predicts the star formation relation observed on cloud scales and at the same time provides a mapping between this relation and the closer-to-linear molecular star formation relation measured on larger scales in galaxies. The key is that pressure regulates not only the molecular content of the ISM but also the cloud surface density. I provide a straightforward prescription for the pressure regulation of star formation that can be directly implemented in numerical models. Predictions for the dense gas fraction and star formation efficiency measured on large-scales within galaxies are also presented, establishing the basis for a new picture of star formation regulated by galactic environment.
On column density thresholds and the star formation rate

We present the results of a numerical study designed to address the question of whether there is a column density threshold for star formation within molecular clouds. We have simulated a large number of dierent clouds, with volume and column densities spanning a wide range of dierent values, using a state-of-the-art model for the coupled chemical, thermal and dynamical evolution of the gas. We show that star formation is only possible in regions where the mean (area-averaged) column density exceeds 10 21 cm 2 . Within the clouds, we also show that there is a good correlation between the mass of gas above a K-band extinction AK = 0:8 and the star formation rate (SFR), in agreement with recent observational work. Previously, this relationship has been explained in terms of a correlation between the SFR and the mass in dense gas. However, we nd that this correlation is weaker and more time-dependent than that between the SFR and the column density. In support of previous studies, we argue that dust shielding is the key process: the true correlation is one between the SFR and the mass in cold, well-shielded gas, and the latter correlates better with the column density than the volume density.
The interpretation of the field angle dependence of the critical current in defect-engineered superconductors

We apply the vortex path model of critical currents to a comprehensive analysis of contemporary data on defect-engineered superconductors, showing that it provides a consistent and detailed interpretation of the experimental data for a diverse range of materials. We address the question of whether electron mass anisotropy plays a role of any consequence in determining the form of this data and conclude that it does not. By abandoning this false interpretation of the data, we are able to make significant progress in understanding the real origin of the observed behavior. In particular, we are able to explain a number of common features in the data including shoulders at intermediate angles, a uniform response over a wide angular range and the greater discrimination between individual defect populations at higher fields. We also correct several misconceptions including the idea that a peak in the angular dependence of the critical current is a necessary signature of strong correlated pinning, and conversely that the existence of such a peak implies the existence of correlated pinning aligned to the particular direction. The consistency of the vortex path model with the principle of maximum entropy is introduced.
On the discovery of fast molecular gas in the UFO/BAL quasar APM 08279+5255 at z=3.912

We have performed a high sensitivity observation of the UFO/BAL quasar APM 08279+5255 at z=3.912 with NOEMA at 3.2 mm, aimed at detecting fast moving molecular gas. We report the detection of blueshifted CO(4-3) with maximum velocity (v95\%) of $-1340$ km s$^{-1}$, with respect to the systemic peak emission, and a luminosity of $L' = 9.9\times 10^9 ~\mu^{-1}$ K km s$^{-1}$ pc$^{-2}$ (where $\mu$ is the lensing magnification factor). We discuss various scenarios for the nature of this emission, and conclude that this is the first detection of fast molecular gas at redshift $>3$. We derive a mass flow rate of molecular gas in the range $\rm \dot M=3-7.4\times 10^3$ M$_\odot$/yr, and momentum boost $\dot P_{OF} / \dot P_{AGN} \sim 2-6$, therefore consistent with a momentum conserving flow. For the largest $\dot P_{OF}$ the scaling is also consistent with a energy conserving flow with an efficiency of $\sim$10-20\%. The present data can hardly discriminate between the two expansion modes. The mass loading factor of the molecular outflow $\eta=\dot M_{OF}/SFR$ is $>>1$. We also detect a molecular emission line at a frequency of 94.83 GHz, corresponding to a rest frame frequency of 465.8 GHz, which we tentatively identified with the cation molecule $\rm N_2H^+$(5-4), which would be the first detection of this species at high redshift. We discuss the alternative possibility that this emission is due to a CO emission line from the, so far undetected, lens galaxy. Further observations of additional transitions of the same species with NOEMA can discriminate between the two scenarios.
Morpho-kinematics of the planetary nebula NGC 3242: an analysis beyond its multiple-shell structure

In this paper we present the results of optical high-resolution imaging and spectroscopy of the complex planetary nebula (PN) NGC~3242. Our study is based on the analysis of the narrowband H$\alpha$ $\lambda$6563\AA , [O III] $\lambda$5007\AA , [N II] $\lambda$6584\AA , and [S II] $\lambda$6724{\AA} images, and high- resolution spectroscopy using spectral ranges centered on the H$\alpha$ $\lambda$6564\AA , [N II] $\lambda$6583\AA , and [O III] $\lambda$5007\AA . We detected and analysed morphological components beyond the multiple shell structure of this PN, to investigate the small-scale morphological components aligned towards its major axis (such as knots and ansae, as well as the arc-like features) and its surroundings. Thus, we investigated the morpho-kinematical properties of NGC~3242, as well as their nature and formation. Our results regarding the elliptical double-shell structure and the distance to this nebula are in concordance with previous studies. Furthermore, we have used the software SHAPE to construct a 3D model of NGC~3242, allowing us to successfully reproduce our observational data. We conclude that the prominent knots emitting in the [N II] line are fast, low-ionisation emission regions (FLIERs) related to high velocity jets and the so-called ansae-like features rather resemble bubbles. The disruptions immersed in the halo, whose emission was detected in the the [O III] high-excitation emission line, remarkably display high velocities and were formed likely in an earlier ejection event, in comparison to the innermost FLIERs and bubbles. Finally, according to our model, the kinematical ages of the structures in NGC~3242 range from 390 to 5400 yr.
The PEP survey: infrared properties of radio-selected AGN

By exploiting the VLA-COSMOS and the Herschel-PEP surveys, we investigate the Far Infrared (FIR) properties of radio-selected AGN. To this purpose, from VLA-COSMOS we considered the 1537, F[1.4 GHz]>0.06 mJy sources with a reliable redshift estimate, and sub-divided them into star-forming galaxies and AGN solely on the basis of their radio luminosity. The AGN sample is complete with respect to radio selection at all z<~3.5. 832 radio sources have a counterpart in the PEP catalogue. 175 are AGN. Their redshift distribution closely resembles that of the total radio-selected AGN population, and exhibits two marked peaks at z~0.9 and z~2.5. We find that the probability for a radio-selected AGN to be detected at FIR wavelengths is both a function of radio power and redshift, whereby powerful sources are more likely to be FIR emitters at earlier epochs. This is due to two distinct effects: 1) at all radio luminosities, FIR activity monotonically increases with look-back time and 2) radio activity of AGN origin is increasingly less effective at inhibiting FIR emission. Radio-selected AGN with FIR emission are preferentially located in galaxies which are smaller than those hosting FIR-inactive sources. Furthermore, at all z<~2, there seems to be a preferential (stellar) mass scale M ~[10^{10}-10^{11}] Msun which maximizes the chances for FIR emission. We find such FIR (and MIR) emission to be due to processes indistinguishable from those which power star-forming galaxies. It follows that radio emission in at least 35% of the entire AGN population is the sum of two contributions: AGN accretion and star-forming processes within the host galaxy.
LYα FOREST TOMOGRAPHY FROM BACKGROUND GALAXIES: THE FIRST MEGAPARSEC-RESOLUTION LARGE-SCALE STRUCTURE MAP AT z > 2

We present the first observations of foreground Lyα forest absorption from high-redshift galaxies, targeting 24 star-forming galaxies (SFGs) with z ∼ 2.3–2.8 within a 5′ × 14′ region of the COSMOS field. The transverse sightline separation is ∼2 h−1 Mpc comoving, allowing us to create a tomographic reconstruction of the three-dimensional (3D) Lyα forest absorption field over the redshift range 2.20 ⩽ z ⩽ 2.45. The resulting map covers 6 h−1 Mpc × 14 h−1 Mpc in the transverse plane and 230 h−1 Mpc along the line of sight with a spatial resolution of ≈3.5 h−1 Mpc, and is the first high-fidelity map of a large-scale structure on ∼Mpc scales at z > 2. Our map reveals significant structures with ≳ 10 h−1 Mpc extent, including several spanning the entire transverse breadth, providing qualitative evidence for the filamentary structures predicted to exist in the high-redshift cosmic web. Simulated reconstructions with the same sightline sampling, spectral resolution, and signal-to-noise ratio recover the salient structures present in the underlying 3D absorption fields. Using data from other surveys, we identified 18 galaxies with known redshifts coeval with our map volume, enabling a direct comparison with our tomographic map. This shows that galaxies preferentially occupy high-density regions, in qualitative agreement with the same comparison applied to simulations. Our results establish the feasibility of the CLAMATO survey, which aims to obtain Lyα forest spectra for ∼1000 SFGs over ∼1 deg2 of the COSMOS field, in order to map out the intergalactic medium large-scale structure at 〈z〉 ∼ 2.3 over a large volume (100 h−1 Mpc)3.