Miracle-dz/UniFAR-FTUs huggingface dataset:
TURBULENCE-INDUCED RELATIVE VELOCITY OF DUST PARTICLES. IV. THE COLLISION KERNEL

Motivated by its importance for modeling dust particle growth in protoplanetary disks, we study turbulence-induced collision statistics of inertial particles as a function of the particle friction time, τp. We show that turbulent clustering significantly enhances the collision rate for particles of similar sizes with τp corresponding to the inertial range of the flow. If the friction time, τp, h, of the larger particle is in the inertial range, the collision kernel per unit cross section increases with increasing friction time, τp, l, of the smaller particle and reaches the maximum at τp, l = τp, h, where the clustering effect peaks. This feature is not captured by the commonly used kernel formula, which neglects the effect of clustering. We argue that turbulent clustering helps alleviate the bouncing barrier problem for planetesimal formation. We also investigate the collision velocity statistics using a collision-rate weighting factor to account for higher collision frequency for particle pairs with larger relative velocity. For τp, h in the inertial range, the rms relative velocity with collision-rate weighting is found to be invariant with τp, l and scales with τp, h roughly as . The weighting factor favors collisions with larger relative velocity, and including it leads to more destructive and less sticking collisions. We compare two collision kernel formulations based on spherical and cylindrical geometries. The two formulations give consistent results for the collision rate and the collision-rate weighted statistics, except that the spherical formulation predicts more head-on collisions than the cylindrical formulation.
Structural instability and the Mott-Peierls transition in a half-metallic hollandite : K$_{2}$Cr$_{8}$O$_{16}$

In order to explore the driving mechanism of the concomitant metal-insulator and structural transitions in quasi-one-dimensional hollandite K$_{2}$Cr$_{8}$O$_{16}$, electronic structures and phonon properties are investigated by employing the {\it ab initio} density functional theory (DFT) calculations. We have found that the imaginary phonon frequency reflecting the structural instability appears only in the DFT+$U$ ($U$: Coulomb correlation) calculation, which indicates that the Coulomb correlation plays an essential role in the structural transition. The lattice displacements of the softened phonon at X explain the observed lattice distortions in K$_{2}$Cr$_{8}$O$_{16}$ perfectly well, suggesting the Peierls distortion vector {\bf Q} of X (0, 0, 1/2). The combined study of electronic and phonon properties reveals that half-metallic K$_{2}$Cr$_{8}$O$_{16}$, upon cooling, undergoes the correlation-assisted Peierls transition to become a Mott-Peierls ferromagnetic insulator at low temperature.
Resolved photometry of young massive clusters in the starburst galaxy NGC 4214

ABSTRACT We present the results of deep high resolution imaging performed withACS/HRC@HST in the most active region of the nearby starburst galaxy NGC 4214.We resolved the stellar populations of ﬁve Young Massive Clusters and their sur-rounding galactic ﬁeld. The star formation history of this region is characterized bytwo main bursts occurred within the last 500 Myr, with the oldest episode spread outacross an area larger than that covered by the most recent one. The ages derived forthe analysed clusters cover a wide range between 6.4 <logt/yr <8.1 in agreementwith those predicted by recent analyses based on integrated photometry. The com-parison between the mass of the young associations and that of the surrounding ﬁeldpopulation with similar ages indicates a high cluster formation eﬃciency (Γ ∼ 33%)which decreases when old populations are considered. The mass function of the majorassembly has been found to be slightly ﬂatter than the Salpeter (1955) law with ahint of mass segregation. We found no clear signatures of multiple stellar populationsin the two young (logt/yr < 6.8) associations where we were able to resolve theirinnermost region. The masses and sizes of three clusters indicate that at least one ofthem could evolve toward a globular cluster-like structure.Key words: methods: data analysis – methods: observational – techniques: photo-metric – galaxies: individual: NGC 4214 – galaxies: star clusters: general – galaxies:starburst.
Skip-MLP Network for Point Cloud Classification

The encoding method for local neighborhood of sampling points is the bottleneck of point cloud learning. Existing encoding methods do not perform well on point clouds with low density, which seriously affects its application in real-world scenarios. In this paper, we propose a novel encoding method for local neighborhood of sampling points, named Skip-MLP. It can establish the spatial relationship among sampling points while encoding the local neighborhood. We simultaneously adopt a point sampling scheme based on learning, in order to enhance the adaptability of the sampling points selection strategy with point cloud density changing. Moreover, an attention module is introduced to perform finegrained encoding of the key features of the embedded sampling points neighborhoods. Experimental results on benchmarks demonstrate that Skip-MLP network is more efficient and robust than the previous methods for point cloud classification.
A brief history of the pion-nucleon coupling constant

This work provides a brief history of determinations of the pion-nucleon ($\pi N$) coupling constant from $\pi N$ and $N N$ data. From robust analyses of twenty reported values of the charged-pion coupling constant, exhibiting sizeable fluctuation, the result $f_c^2 = 762.9^{+6.5}_{-6.2} \cdot 10^{-4}$ is obtained. Similar values are extracted for the other two $\pi N$ coupling constants, $f_0^2$ and $f_p^2$, from fewer data. The average values of the various $\pi N$ coupling constants, extracted in this work, suggest no splitting, in agreement with the thesis of the Nijmegen group. Additional analysis of the $f_c^2$ and $f_0^2$ values, both reported in four studies, turned to be inconclusive: one of these studies suggests that $f_0 f_c$; no significant splitting effects are observed in the other two studies. The analysis of the low-energy $\pi N$ data with the ETH model indicates significant splitting and, under certain conditions, it implies that $f_0>f_c$. Also discussed in the paper are the electromagnetic corrections, which need to be applied to the strong shift and to the total decay width of the ground state of pionic hydrogen in order that estimates for the hadronic $s$-wave $\pi N$ scattering lengths be obtained; this is a relevant subject as $f_c^2$ may be extracted from the isovector scattering length by use of the Goldberger-Miyazawa-Oehme sum rule. Regarding the removal of the electromagnetic effects in the $\pi N$ system at threshold, my opinion is that Theory must find a way to provide reliable and accurate corrections, matching the level of accuracy of the experimental results.
A new prediction of wavelength selection in radial viscous fingering involving normal and tangential stresses

We reconsider the radial Saffman-Taylor instability, when a fluid injected from a point source displaces another fluid of higher viscosity in a Hele-Shaw cell, where the fluids are confined between two neighboring flat plates. The advancing fluid front is unstable and forms fingers along the circumference. The so-called Brinkman equation is used to describe the flow field, which also takes into account viscous stresses in the plane of the confining plates and, unlike the Darcy equation, not only viscous stresses due to the confining plates. We show why in-plane stresses cannot always be neglected and how they appear naturally in the potential flow problem. The dispersion relation obtained with the Brinkman equation agrees better with the experimental results than the classical linear stability analysis of radial fingering in Hele-Shaw cells that uses Darcy's law as a model for the fluid motion.
Summer Buffalo Milk Produced in China: A Desirable Diet Enriched in Polyunsaturated Fatty Acids and Amino Acids

The objective of the study was to compare and reveal differences in basic chemical parameters, fatty acids, amino acids, and lipid quality indices of crossbred buffalo (swamp x river type) milk produced in summer and winter. The buffalo milk samples were collected in summer (Jul–Aug) and winter (Dec–Jan) from Hubei province, China. The samples were detected by using CombiFoss apparatus, gas chromatography, and an automated specialized amino acid analyzer. The results showed that the basic chemical parameters, fatty acid profiles, lipid quality indices, and amino acid profiles of crossbred buffalo milk differed between summer and winter. Specifically, summer buffalo milk exhibited a higher content of MUFA (monounsaturated fatty acids) and PUFA (polyunsaturated fatty acids) than winter buffalo milk. Summer buffalo milk had a lower content of major SFA (saturated fatty acids), a higher content of ω-3 and DFA (hypocholesterolemic fatty acids), a lower ω-6/ω-3 ratio, a higher value of 3 unsaturated fatty acid indices (C14, C16, C18), and a lower value of IA (index of atherogenicity) and IT (index of thrombogenicity) than winter buffalo milk. Additionally, 17 amino acids, including 8 EAA (essential amino acids) and 9 NEAA (non-essential amino acids) were higher in summer buffalo milk. These results indicated that summer buffalo milk was more health-beneficial than winter buffalo milk. Therefore, summer buffalo milk might be a desirable diet option for human nutrition and health. Our findings provide valuable information for the research and development of buffalo dairy products in China or other Asian countries.
How Accurate are SuperCOSMOS Positions?

Abstract Optical positions from the SuperCOSMOS Sky Survey have been compared in detail with accurate radio positions that define the second realisation of the International Celestial Reference Frame (ICRF2). The comparison was limited to the IIIaJ plates from the UK/AAO and Oschin (Palomar) Schmidt telescopes. A total of 1 373 ICRF2 sources was used, with the sample restricted to stellar objects brighter than BJ = 20 and Galactic latitudes |b| > 10°. Position differences showed an rms scatter of $0.16\text{ arcsec}$ in right ascension and declination. While overall systematic offsets were < $0.1\text{ arcsec}$ in each hemisphere, both the systematics and scatter were greater in the north.
Optimization of Sintering Conditions to Enhance the Dielectric Performance of Gd3+ and Ho3+ Codoped BaTiO3 Ceramics

BaTiO3 dielectric capacitors, one of the important energy storage devices, play critical roles in storing electricity from renewable energies of water, wind, solar, etc. The synthesis of BaTiO3 ceramics with weak temperature dependence and a high dielectric constant at room temperature (εRT′) is an urgent problem to meet the miniaturization and large capacity of dielectric capacitors. Doping rare earth elements into BaTiO3 can solve this problem, but it is still challenging. In this work, we adopt a synergistic strategy of increasing εRT′ and improving the temperature stability by codoping Gd3+ and Ho3+, respectively, to address this challenge. By carefully adjusting the synthesis conditions in the solid-state reaction, codoping 7% Gd3+ and 7% Ho3+ in BaTiO3 (BGTH7) ceramics were synthesized. The temperature-dependent dielectric constant reveals that the obtained optimal BGTH7 ceramic satisfies the X7U specification and displays a stable ε′ in the temperature range of −55~125 °C. The optimal BGTH7 ceramic after sintering at 1400 °C for 6 h exhibits a high dielectric constant of 5475 and low dielectric loss (tan δ) of 0.0176, hitherto exhibiting the best performance in X7U ceramics. The findings in this work are conducive to the miniaturization and stabilization of dielectric energy storage devices.
Effects on the Titanium Implant Surface by Different Hygiene Instrumentations: A Narrative Review

Peri-implant disease is usually caused by the accumulation of dental biofilm around the implant, and this biofilm can irradiate the gingiva tissue, which leads to inflammation and, more severely, to a deterioration of the bone structure. There is a concern regarding the removal of biofilm from the implant surface by using different hygiene instruments. Some hygiene instruments may have some effect on the dental implant surface, resulting in roughening or damage to the implant surfaces. This study reviewed the effects of titanium implant surfaces on different hygiene instruments. A literature search was conducted from PubMed, ScienceDirect, and Scopus databases for articles published from 1992 to 2021. A total of 19 full-text papers with keywords of interest that met all the eligibility criteria were selected. Surface roughness was evaluated with a scanning electron microscope and also using a profilometer, laser scanning, scanning probe, and atomic force microscopes. A metal curette produced a roughened surface on the titanium implant, but a plastic curette did not alter the surface. Instrumentation with rubber cups left the surface unchanged and appeared to smoothen the surface, whereas the air-powder abrasive instrumentation altered the surface with the presence of micro pits and pores. A conventional metal ultrasonic scaler showed significant surface topographical changes and scratches on both titanium surfaces, as a diode laser, light-emitting diode (LED), and laser treatment did not show any alteration on the rough and smooth titanium surfaces. Thus, a non-metallic instrument such as a plastic curette, rubber cups, and novel technology including diode laser, LED, and laser treatment is appropriate and can be used for debridement on smooth and machined titanium implant surfaces as well as sandblasted and acid-etched (SLA), titanium plasma-sprayed (TPS), and resorbable blasted media (RBM) surfaces. The use of metallic instruments should be avoided, and it is not recommended.
Light and Electron Microscopic Studies of the Hindgut of Isophya nervosa (Orthoptera, Tettigoniidae)

ABSTRACT Isophya nervosa (Orthoptera, Tettigoniidae) is especially localized in Ankara, Çankırı, Eskişehir, Turkey. Although there are many systematic and taxonomic studies on I. nervosa, there is no study on the morphology and ultrastructure of the digestive. For this purpose, the hindgut of Isophya nervosa (Orthoptera, Tettigoniidae) was investigated by using light and electron microscopes in detail. The outer surface of the hindgut is covered with connective tissue and muscle layer containing abundant trachea. The lumen of all parts of hindgut (ileum, colon, rectum) is surrounded by a cuticular intima that lines single layer cuboidal epithelium throughout the entire length of the hindgut. The monolayer cuboidal epithelium in the colon, which is the middle part of the hindgut, has deep folds. The rectum is a wide elongated sac and has six rectal pads.
Birationally rigid complete intersections of high codimension

We prove that a Fano complete intersection of codimension and index in the complex projective space for and with at most multi-quadratic singularities is birationally superrigid. The codimension of the complement of the set of birationally superrigid complete intersections in the natural moduli space is shown to be at least . The proof is based on the technique of hypertangent divisors combined with the recently discovered -inequality for complete intersection singularities.
Origin of the numerals

Through the pagination of an Arabian Algerian manuscript of the beginning of the 19th century, we rediscover the original shape, the "Ghubari" shape, of the numerals. Contrary to some assumptions, particularly those which claim that they are derived from Indian characters, this "Ghubari" shape, whose use has completely disappeared, shows that the ten modern numerals derive from ten Arabic letters. The symbol of a "Ghubari" numeral corresponds to the Arabic letter whose "Abjadi" numerical value is equal to this numeral. The assumption of the Indian origin of the numerals is denied by the shape of the numerals and by the right left sociological logic of the representation of the numerals and the algorithms of the basic operations. The numerals are born in Maghreb or in Spain. In Europe, the "Ghubari" numerals became the modern numerals: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 and in the Middle East, borrowing two Hebrew letters, they gave the "Mashriki" numerals: ۰ ۱ ۲ ۳ ٩ ٨ ٧ ٦ ٥ ٤ .
Superrigidity, measure equivalence, and weak Pinsker entropy

We show that the class $\mathscr{B}$, of discrete groups which satisfy the conclusion of Popa's Cocycle Superrigidity Theorem for Bernoulli actions, is invariant under measure equivalence. We generalize this to the setting of discrete p.m. p. groupoids, and as a consequence we deduce that any nonamenable lattice in a product of two noncompact, locally compact second countable groups, must belong to $\mathscr{B}$. We also introduce a measure-conjugacy invariant called Weak Pinsker entropy and show that, if G is a group in the class $\mathscr{B}$, then Weak Pinsker entropy is an orbit-equivalence invariant of every essentially free p.m. p. action of G.
Koszul duality for Kac–Moody groups and characters of tilting modules

<p>We establish a character formula for indecomposable tilting modules for connected reductive groups in characteristic <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3. org/1998/Math/MathML" alttext="script l"> <mml:semantics> <mml:mi>ℓ<! -- ℓ --></mml:mi> <mml:annotation encoding="application/x-tex">\ell</mml:annotation> </mml:semantics> </mml:math> </inline-formula> in terms of <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3. org/1998/Math/MathML" alttext="script l"> <mml:semantics> <mml:mi>ℓ<! -- ℓ --></mml:mi> <mml:annotation encoding="application/x-tex">\ell</mml:annotation> </mml:semantics> </mml:math> </inline-formula>-Kazhdan–Lusztig polynomials, for <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3. org/1998/Math/MathML" alttext="script l greater-than h"> <mml:semantics> <mml:mrow> <mml:mi>ℓ<! -- ℓ --></mml:mi> <mml:mo>></mml:mo> <mml:mi>h</mml:mi> </mml:mrow> <mml:annotation encoding="application/x-tex">\ell > h</mml:annotation> </mml:semantics> </mml:math> </inline-formula> the Coxeter number. Using results of Andersen, one may deduce a character formula for simple modules if <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3. org/1998/Math/MathML" alttext="script l greater-than-or-equal-to 2 h minus 2"> <mml:semantics> <mml:mrow> <mml:mi>ℓ<! -- ℓ --></mml:mi> <mml:mo>≥<! -- ≥ --></mml:mo> <mml:mn>2</mml:mn> <mml:mi>h</mml:mi> <mml:mo>−<! -- − --></mml:mo> <mml:mn>2</mml:mn> </mml:mrow> <mml:annotation encoding="application/x-tex">\ell \ge 2h-2</mml:annotation> </mml:semantics> </mml:math> </inline-formula>. Our results are a consequence of an extension to modular coefficients of a monoidal Koszul duality equivalence established by Bezrukavnikov and Yun. </p>
Models of universe with a polytropic equation of state: III. The phantom universe

Pierre-Henri Chavanis Laboratoire de Physique Théorique (IRSAMC), CNRS and UPS, Université de Toulouse, France We construct models of universe with a generalized equation of state p = (αρ+kρ)c having a linear component and a polytropic component. The linear equation of state p = αρc with −1 ≤ α ≤ 1 describes radiation (α = 1/3), pressureless matter (α = 0), stiff matter (α = 1), and vacuum energy (α = −1). The polytropic equation of state p = kρc may be due to BoseEinstein condensates with repulsive (k > 0) or attractive (k < 0) self-interaction, or have another origin. In this paper, we consider the case where the density increases as the universe expands. This corresponds to a “phantom universe” for which w = p/ρc < −1 (this requires k < 0). We complete previous investigations on this problem and analyze in detail the different possibilities. We describe the singularities using the classification of [S. Nojiri, S.D. Odintsov, S. Tsujikawa, Phys. Rev. D 71, 063004 (2005)]. We show that for α > −1 there is no Big Rip singularity although w ≤ −1. For n = −1, we provide an analytical model of phantom bouncing universe “disappearing” at t = 0. We also determine the potential of the phantom scalar field and phantom tachyon field corresponding to the generalized equation of state p = (αρ+ kρ)c.
Polarized curvature radiation in pulsar magnetosphere

The propagation of polarized emission in pulsar magnetosphere is investigated in this paper. The polarized waves are generated through curvature radiation from the relativistic particles streaming along curved magnetic field lines and co-rotating with the pulsar magnetosphere. Within the 1/{\deg} emission cone, the waves can be divided into two natural wave mode components, the ordinary (O) mode and the extraord nary (X) mode, with comparable intensities. Both components propagate separately in magnetosphere, and are aligned within the cone by adiabatic walking. The refraction of O-mode makes the two components separated and incoherent. The detectable emission at a given height and a given rotation phase consists of incoherent X-mode and O-mode components coming from discrete emission regions. For four particle-density models in the form of uniformity, cone, core and patches, we calculate the intensities for each mode numerically within the entire pulsar beam. If the co-rotation of relativistic particles with magnetosphere is not considered, the intensity distributions for the X-mode and O-mode components are quite similar within the pulsar beam, which causes serious depolarization. However, if the co-rotation of relativistic particles is considered, the intensity distributions of the two modes are very different, and the net polarization of out-coming emission should be significant. Our numerical results are compared with observations, and can naturally explain the orthogonal polarization modes of some pulsars. Strong linear polarizations of some parts of pulsar profile can be reproduced by curvature radiation and subsequent propagation effect.
Effect of Current Ratio and Debt to Asset Ratio on Return On Asset Moderated by Firm Size

: This study aims to determine the effect of Current Ratio (CR), Debt to Asset Ratio (DAR) on Return On Asset (ROA) moderated by Firm Size (SIZE) on Index IDX 30 Companies Listed on Indonesia Stok Exchange for 2017-2020 period. Data analysis in this study was carried out statistically and statistically inferential. Statistical analysis includes multiple linear regression analysis, classical assumption test, t-test, and hypothesis which Multiple Regression Analysis does. The hypothesis testing results are partially carried out, namely the t-test shows that CR has a positive and insignificant effect on ROA. DAR partially has a positive and significant effect on ROA. Thus the result from moderating analysis, SIZE can moderate the effect of CR on the ROA but SIZE can’t moderate the DAR on ROA of Index IDX 30 Companies for the 2017-2020 period.