Miracle-dz/UniFAR-FTUs huggingface dataset:
Spectrum of Navier $p$-biharmonic problem with sign-changing weight

In this paper, we consider the following eigenvalue problem {{l} (|u"|^{p-2}u")"=\lambda m(x)|u|^{p-2}u, x\in (0,1), u(0)=u(1)=u"(0)=u"(1)=0, where $1<p<+\infty$, $\lambda$ is a real parameter and $m$ is sign-changing weight. We prove there exists a unique sequence of eigenvalues for above problem. Each eigenvalue is simple and continuous with respect to $p$, the $k$-th eigenfunction, corresponding to the $k$-th positive or negative eigenvalue, has exactly $k-1$ generalized simple zeros in $(0,1)$.
Newly identified YSO candidates towards LDN 1188

We present an analysis of young stellar object (YSO) candidates towards the LDN 1188 molecular cloud. The YSO candidates were selected from the WISE all-sky catalogue, based on a statistical method. We found 601 candidates in the region, and classified them as Class I, Flat, and Class II YSOs. Groups were identified and described with the Minimal Spanning Tree (MST) method. Previously identified molecular cores show evidence of ongoing star formation at different stages throughout the cloud complex.
Quark Sector of the QCD Groundstate in Coulomb Gauge

The variational approach to Yang-Mills theory in Coulomb gauge is extended to full QCD. For the quark sector we use a trial wave functional, which goes beyond the previously used BCS-type state and which explicitly contains the coupling of the quarks to transverse gluons. This quark wave functional contains two variational kernels: One is related to the quark condensate and occurs already in the BCS-type states. The other represents the form factor of the coupling of the quarks to the transverse gluons. Minimization of the energy density with respect to these kernels results in two coupled integral (gap) equations. These equations are solved numerically using the confining part of the non-Abelian color Coulomb potential and the lattice static gluon propagator as input. With the additional coupling of quarks to transverse gluons included the low energy chiral properties increase substantially towards their phenomenological values. We obtain a reasonable description of the chiral condensate, which for a vanishing current quark mass is obtained in the range of 190 – 235 MeV. The coupling of the quarks to the transverse gluons enhances the constituent quark mass by about 60% in comparison to the pure BCS ansatz.
Active Galactic Nuclei and their Role in Galaxy Evolution: The Infrared Perspective

The remarkable progress made in infrared (IR) astronomical instruments over the last 10-15 years has radically changed our vision of the extragalactic IR sky, and overall understanding of galaxy evolution. In particular, this has been the case for the study of active galactic nuclei (AGN), for which IR observations provide a wealth of complementary information that cannot be derived from data in other wavelength regimes. In this review, I summarize the unique contribution that IR astronomy has recently made to our understanding of AGN and their role in galaxy evolution, including both physical studies of AGN at IR wavelengths, and the search for AGN among IR galaxies in general. Finally, I identify and discuss key open issues that it should be possible to address with forthcoming IR telescopes.
On the missing second generation AGB stars in NGC 6752

In recent years the view of Galactic globular clusters as simple stellar populations has changed dramatically, it is now thought that basically all globular clusters host multiple stellar populations, each with its own chemical abundance pattern and colour‐magnitude diagram sequence. Recent spectroscopic observations of asymptotic giant branch starsin theglobular cluster NGC6752 have disclosed al ow [Na/Fe] abundance for the whole sample, suggesting that they are all first generation stars, and that all second generation stars fail to reach the AGB in this cluster. A scenario proposed to explain these observations invokes strong mass loss in second generation horizontal branch stars ‐ all located at the hot side of the blue and extended horizontal branch of this cluster ‐ possibly induced by the metal enhancement associated to radiative levitation. This enhanced mass loss would prevent second generation stars from reaching the asymptotic giant branch phase, thus explaining at the same time the low value of the ratio between horizontal branch and asymptotic giant branch stars (the R2 parameter) observed in NGC 6752. We have critically discussed this mass-loss scenario, finding
Hα features with hot onsets - I. Ellerman bombs

Ellerman bombs are transient brightenings of the wings of the Balmer lines that uniquely mark reconnection in the solar photosphere. They are also bright in strong Ca ii and ultraviolet lines and in ultraviolet continua, but they are not visible in the optical continuum and the Na i D and Mg i b lines. These discordant visibilities invalidate all published Ellerman bomb modeling. I argue that the assumption of Saha-Boltzmann lower-level populations is informative to estimate bomb-onset opacities for these diverse diagnostics, even and especially for H α , and employ such estimates to gauge the visibilities of Ellerman bomb onsets in all of them. They constrain Ellerman bomb formation to temperatures 10 000−20 000 K and hydrogen densities around 10 15 cm -3 . Similar arguments likely hold for H α visibility in other transient phenomena with hot and dense onsets.
Lattice Boltzmann Modeling of a Sessile and a Body Force-Driven Sliding Droplet over a Grooved Surface

This work presents the numerical modeling of a droplet’s sessile and dynamic behavior on a grooved surface. A droplet is placed on horizontal and vertical sliding conditions to observe its behavior under wettable and non-wettable conditions. The numerical analysis uses the multicomponent multiphase Shan-Chen Lattice Boltzmann Model (SC-LBM). The Cassie–Baxter and Wenzel states are reproduced for the sessile condition, and the enhancement of the contact angle is appreciated under the action of the grooved-ridged horizontal surface. The sliding droplet is analyzed through the Bond number by varying the ratio between the body force and the surface tension number. For Cassie–Baxter and Wenzel wettability conditions, a critical Bond number was discovered above which the sliding droplet will continue to deform indefinitely. The numerical model proved its suitability to predict the gradual deformation of a droplet over a grooved vertical surface subject to a tangential body force until the droplet eventually reaches a sessile condition or a breakup.
Saturating the holographic entropy bound

The covariant entropy bound states that the entropy, $S$, of matter on a light sheet cannot exceed a quarter of its initial area, $A$, in Planck units. The gravitational entropy of black holes saturates this inequality. The entropy of matter systems, however, falls short of saturating the bound in known examples. This puzzling gap has led to speculation that a much stronger bound, $S\ensuremath{\lesssim}{A}^{3/4}$, may hold true. In this note, we exhibit light sheets whose entropy exceeds ${A}^{3/4}$ by arbitrarily large factors. In open Friedmann-Robertson-Walker universes, such light sheets contain the entropy visible in the sky; in the limit of early curvature domination, the covariant bound can be saturated but not violated. As a corollary, we find that the maximum observable matter and radiation entropy in universes with positive (negative) cosmological constant is of order ${\ensuremath{\Lambda}}^{\ensuremath{-}1}$ (${\ensuremath{\Lambda}}^{\ensuremath{-}2}$), and not $|\ensuremath{\Lambda}{|}^{\ensuremath{-}3/4}$ as had hitherto been believed. Our results strengthen the evidence for the covariant entropy bound, while showing that the stronger bound $S\ensuremath{\lesssim}{A}^{3/4}$ is not universally valid. We conjecture that the stronger bound does hold for static, weakly gravitating systems.
Advances in atomic data for neutron-capture elements

Abstract Neutron(n)-capture elements (atomic number Z > 30), which can be produced in planetary nebula (PN) progenitor stars via s-process nucleosynthesis, have been detected in nearly 100 PNe. This demonstrates that nebular spectroscopy is a potentially powerful tool for studying the production and chemical evolution of trans-iron elements. However, significant challenges must be addressed before this goal can be achieved. One of the most substantial hurdles is the lack of atomic data for n-capture elements, particularly that needed to solve for their ionization equilibrium (and hence to convert ionic abundances to elemental abundances). To address this need, we have computed photoionization cross sections and radiative and dielectronic recombination rate coefficients for the first six ions of Se and Kr. The calculations were benchmarked against experimental photoionization cross section measurements. In addition, we computed charge transfer (CT) rate coefficients for ions of six n-capture elements. These efforts will enable the accurate determination of nebular Se and Kr abundances, allowing robust investigations of s-process enrichments in PNe.
BROAD H i ABSORBERS AS METALLICITY-INDEPENDENT TRACERS OF THE WARM-HOT INTERGALACTIC MEDIUM

Thermally broadened Lyα absorbers (BLAs) offer an alternative method to highly ionized metal lines for tracing the warm-hot intergalactic medium (WHIM) at T>105 K. However, observing BLAs requires data of high quality and accurate continuum definition to detect the low-contrast features, and a good knowledge of the velocity structure to differentiate multiple blended components from a single broad line. Even for well-characterized absorption profiles, disentangling the thermal line width from the various thermal and non-thermal contributors to the observed line width is ambiguous. We compile a catalog of reliable BLA candidates along seven active galactic nucleus sight lines from a larger set of Lyα absorbers observed by the Space Telescope Imaging Spectrograph on the Hubble Space Telescope (HST). We compare our measurements based on independent reduction and analysis of the data to those published by other research groups. We examine the detailed structure of each absorber and determine a reliable line width and column density. Purported BLAs are grouped into probable (15), possible (48), and non-BLA (56) categories. Combining the first two categories, we infer a line frequency , comparable to observed O vi absorbers, also thought to trace the WHIM. We discuss the overlap between BLA and O vi absorbers (20%–40%) and the distribution of BLAs in relation to nearby galaxies (O vi detections in BLAs are found closer to galaxies than O vi nondetections). We assume that the line width determined through a multi-line curve of growth (COG) is a close approximation to the thermal line width. Based on 164 measured COG H i line measurements, we statistically correct the observed line widths via a Monte Carlo simulation. Gas temperature and neutral fraction are inferred from these statistically corrected line widths and lead to a distribution of total hydrogen columns. Summing the total column density over the total observed path length, we find a BLA contribution to the closure density of ΩBLA = 6.3+1.1−0.8 × 10−3 h−170 based on 104 Monte Carlo simulations of each BLA system. There are a number of critical systematic assumptions implicit in this calculation, and we discuss how each affects our results and those of previously published work. In particular, the most comparable previous study by Lehner et al. gave ΩBLA = 3.6 × 10−3 h−170 or 9.1 × 10−3 h−170, depending on which assumptions were made about hydrogen neutral fraction. Taking our value, current O vi and BLA surveys can account for ∼ 20% of the baryons in the local universe while an additional ∼ 29% can be accounted for in the photoionized Lyα forest; about half of all baryons in the low-z universe are found in the intergalactic medium. Finally, we present new, high signal-to-noise ratio observations of several of the BLA candidate lines from Early Release Observations made by the Cosmic Origins Spectrograph on HST.
Frustration-driven C4 symmetric orders in a hetero-structured iron-based superconductor

Jong Mok Ok, 2 S. -H. Baek, ∗ C. Hoch, R. K. Kremer, S. Y. Park, Sungdae Ji, 5 B. Büchner, J.-H. Park, 5, 6 S. I. Hyun, J. H. Shim, Yunkyu Bang, E. G. Moon, I. I. Mazin, and Jun Sung Kim 2, † Department of Physics, Pohang University of Science and Technology, Pohang 790-784, Korea Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang 790-784, Korea IFW Dresden, Helmholtzstr. 20, 01069 Dresden, Germany Max-Planck-Institut für Festkörperforschung, Heisenbergstraβe 1, D-70569 Stuttgart, Germany Max Planck POSTECH Center for Complex Phase Materials, Pohang University of Science and Technology, Pohang 790-784, Korea Division of Advanced Materials Science, Pohang University of Science and Technology, Pohang 790-784, Korea Department of Chemistry, Pohang University of Science and Technology, Pohang 790-784, Korea Department of Physics, Chonnam National University, Korea Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea Naval Research Laboratory, code 6390, 4555 Overlook Avenue S.W. , Washington, DC 20375, USA (Dated: June 27, 2017)
Development and Validation of Online Survey Instrument on Sustainable Development for Science Teachers: Focus on Pili ( Canarium ovatum )

Development and validation of online survey instrument on sustainable development for science teachers: focus on pili (canarium ovatum). (2), ABSTRACT Teachers are the frontline workers in sustaining quality education; hence, assessing their knowledge, attitudes, and behaviors (KAB) allows them and the administrators to create better training, programs, and instructional materials. The objective is to develop and validate a quick and accessible online instrument to assess the teachers’ KAB towards sustainable development in the Philippine context, as part of a bigger project to integrate Pili ( Canarium ovatum ) into education. The researchers administered the instrument using a cross-sectional survey method through Google Forms in which respondents ( n = 206) had voluntarily answered. The 24-item tool, anchored on the 2030 sustainable development goals and their complex systems, is reliable and valid based on the confirmatory factor analysis, and Cronbach’s alpha and Fleiss’s kappa estimates. The results showed that having favorable knowledge and attitudes toward sustainable development is inadequate to create positive behaviors. The adaptation of the developed instrument, the use of findings for intercultural and cross-cultural studies, and further investigations are recommended.
Local disalignment can promote coherent collective motion through rapid information transfer

When particles move at a constant speed and have the tendency to align their directions of motion, ordered large scale movement can emerge despite significant levels of noise. Many variants of this model of self-propelled particles have been studied to explain the coherent motion of groups of birds, fish or microbes. Here, we generalize the exactly aligning collision rule of the classical model of self-propelled particles to the case where particles after the collision tend to move in slightly different directions away from each other, as characterized by a collision angle $\alpha$. We map out the resulting phase diagram and find that, in sufficiently dense systems, small disalignment can lead to higher global alignment of particle movement directions. We show that in this dense regime, global alignment is accompanied by a grid-like spatial structure which allows information to rapidly percolate accross the system by a "domino" effect. Our results elucidate the relevance of disalignment for the emergence of collective motion in models with exclusively repulsive interaction terms.
Light Hadron Masses from Lattice QCD

This article reviews lattice QCD results for the light hadron spectrum. An overview of different formulations of lattice QCD with discussions on the fermion doubling problem and improvement programs is given. Recent developments in algorithms and analysis techniques that render calculations with light, dynamical quarks feasible on present day computer resources are summarized. Finally, spectrum results for ground state hadrons and resonances using various actions are summarized.
An eclipsing binary black hole candidate system in the blazar Mrk 421

Removing outbursts from multiwavelength light curves of the blazar Mrk~421, we construct outburstless time series for this system. A model-independent power spectrum light curve analysis in the optical, hard X-ray and gamma-rays for this outburstless state and also the full light-curves, show clear evidence for a periodicity of ~ 310 days across all wavelengths studied. A subsequent full maximum likelihood analysis fitting an eclipse model confirms a periodicity of 310 \pm 1 days. The power spectrum of the signal in the outburstless state of the source does not follow a flicker noise behaviour and so, the system producing it is not self-organised. This and the fact that the periodicity is better defined in the outburstless state, strongly suggests that it is not produced by any internal physical processes associated to the central engine. The simplest physical mechanism to which this periodicity could be ascribed is a dynamical effect produced by an orbiting supermassive black hole companion eclipsing the central engine. Interestingly, the optimal eclipse model infers a brightness enhancement of (136.4 \pm 20 )%, suggesting an eclipse resulting in a gravitational lensing brightening. Consisting with this interpretation, the eclipse occurs for only ( 9.7 \pm 0.2)% of the orbital period.
Horse Riding Simulator Design to Replicate Human Walking Gait for Hippotherapy in Cerebral Palsy Rehabilitation

Hippotherapy is a popular rehabilitation method for children with cerebral palsy (CP), which is done by riding an actual horse or a horse riding simulator (HRS) device. Riding a real horse is more expensive than using an HRS device due to its high maintenance cost. However, most HRS devices commonly sold in the market are designed as exercise devices, not rehabilitation devices. Most of them are designed to simulate a horse’s walk, trot, canter, or gallop gait at various speeds. Hippotherapy aims to improve the walking ability of CP patients. Therefore, the device should aim to replicate the walking gait of a healthy human, the end goal of hippotherapy. This problem motivates us to design and build a specialized HRS device replicating the walking gait of a healthy human that is suitable for hippotherapy, which is achievable by simulating a horse walking gait with several adjustments. We first studied and observed the walking gait cycle of a horse, then analyzed and derived a formulation of it. We then continue by designing an HRS device using a single electrical rotational motor and mechanical means to replicate the walking gait of a horse, then tune it to an extent to replicate a human walking gait. To measure the performance of our design, we compare the gait of the user when riding our device versus walking.
Development of an Earthworm-Based Intestinal Soft Robot Equipped with a Gripper

An endoscopy is a tool that is used to examine the interior of a hollow organ or cavity of the body by inserting directly into the organ. However, intestinal endoscopy is not friendly to patients due to discomfort, and it can easily cause intestinal damage or even perforation due to the use of the rigid materials of the endoscopy. Here, we provide an earthworm-based intestinal soft robot equipped with a gripper for application on intestinal exams or surgery. The intestinal soft robot is composed of a frontal radial actuator, a central axial actuator, a rear radial actuator and a gripper. The first three actuators drive the robot to move freely in some specific pipes by altering its own deformation, and the gripper, fixed at the end of the frontal radial actuator, is used to pick up “foreign bodies” into and out of the pipes for the purpose of intestinal applications. The different experiments validated that the intestinal soft robot could move forward and backward autonomously in a rigid pipe, a flexible pipe, and a mucus-containing pipe and could extract objects from these pipes. The ultimate weight that the intestinal soft robot extracts is up to 220 g, and the maximum moving speed is 12.0 cm/min in the rigid pipe. This intestinal soft robot is non-destructive to the operating environment, providing a friendly and novel method for the application of intestinal diseases.
PCR based method for authentication of pork in raw and processed products as well as in binary meat mixtures

In this study, amplification of species-specific marker of mitochondrial DNA origin was carried out to detect pork in raw, processed and meat mixtures containing varying concentrations of pork, viz. 1, 10, 50, 75 and 100%. The species-specific marker for pork was tested in raw pork from different breeds/varieties of pig such as Hampshire, Yorkshire, Ghungroo, Duroc, Rani, and Asha. The size of the amplified product was 290 bp in all the breeds/ varieties. The results were consistent in processed pork products, viz. frankfurter sausage, salami, cocktail sausage, pork slice, ham, and pork curry which were subjected to different cooking temperatures ranging from 75 to 121Â°C. In case of all the mixtures with different concentrations of pork, similar results were observed. Subsequently, this marker was tested for cross-amplification by checking them with beef, carabeef, mutton, chevon, chicken, and duck meat and no amplification was observed. The results suggested that the DNA marker used in this study is highly species-specific and reliable to detect pork adulteration, unambiguously, in raw, processed as well as in meat mixtures containing pork. This technique is rapid, simple and economical as compared to other methods of pork adulteration detection.
Preferential Heating and Acceleration of Heavy Ions in Impulsive Solar Flares

We simulate decaying turbulence in a homogeneous pair plasma using a three-dimensional electromagnetic particle-in-cell method. A uniform background magnetic field permeates the plasma such that the magnetic pressure is three times larger than the thermal pressure and the turbulence is generated by counter-propagating shear Alfvén waves. The energy predominately cascades transverse to the background magnetic field, rendering the turbulence anisotropic at smaller scales. We simultaneously move several ion species of varying charge to mass ratios in our simulation and show that the particles of smaller charge to mass ratios are heated and accelerated to non-thermal energies at a faster rate. This is in accordance with the enhancement of heavy ions and a non-thermal tail in their energy spectrum observed in the impulsive solar flares. We further show that the heavy ions are energized mostly in the direction perpendicular to the background magnetic field, with a rate consistent with our analytical estimate of the rate of heating due to cyclotron resonance with the Alfvén waves, of which a large fraction is due to obliquely propagating waves.