Miracle-dz/UniFAR-FTUs huggingface dataset:
BAND-LIMITED CORONAGRAPHS USING A HALFTONE-DOT PROCESS. II. ADVANCES AND LABORATORY RESULTS FOR ARBITRARY TELESCOPE APERTURES

The band-limited coronagraph is a nearly ideal concept that theoretically enables perfect cancellation of all the light of an on-axis source. Over the past several years, several prototypes have been developed and tested in the laboratory, and more emphasis is now on developing optimal technologies that can efficiently deliver the expected high-contrast levels of such a concept. Following the development of an early near-IR demonstrator, we present and discuss the results of a second-generation prototype using halftone-dot technology. We report improvement in the accuracy of the control of the local transmission of the manufactured prototype, which was measured to be less than 1%. This advanced H-band band-limited device demonstrated excellent contrast levels in the laboratory, down to ∼10−6 at farther angular separations than 3λ/D over 24% spectral bandwidth. These performances outperform the ones of our former prototype by more than an order of magnitude and confirm the maturity of the manufacturing process. Current and next-generation high-contrast instruments can directly benefit from such capabilities. In this context, we experimentally examine the ability of the band-limited coronagraph to withstand various complex telescope apertures.
Wind asymmetry imprint in the UV light curves of the symbiotic binary SY Mus

Context: Light curves (LCs) of some symbiotic stars show a different slope of the ascending and descending branch of their minimum profile. The origin of this asymmetry is not understood well. Aims: We explain this effect in the ultraviolet LCs of the symbiotic binary SY Mus. Methods: We model the continuum fluxes in the spectra obtained by the International Ultraviolet Explorer at 10 wavelengths, from 1280 to 3080 \AA. We consider that the white dwarf radiation is attenuated by $H^0$ atoms, $H^-$ ions and free electrons in the red giant wind. Variation in the nebular component is approximated by a sine wave along the orbit as suggested by spectral energy distribution models. The model includes asymmetric wind velocity distribution and the corresponding ionization structure of the binary. Results: We determined distribution of the $H^0$ and $H^+$, as well as upper limits of $H^-$ and $H^0$ column densities in the neutral and ionized region at the selected wavelengths as functions of the orbital phase. Corresponding models of the LCs match well the observed continuum fluxes. In this way, we suggested the main UV continuum absorbing (scattering) processes in the circumbinary environment of S-type symbiotic stars. Conclusions: The asymmetric profile of the ultraviolet LCs of SY Mus is caused by the asymmetric distribution of the circumstellar matter at the near-orbital-plane area.
DWARF GALAXIES AND THE COSMIC WEB

We use a cosmological simulation of the formation of the Local Group of Galaxies to identify a mechanism that enables the removal of baryons from low-mass halos without appealing to feedback or reionization. As the Local Group forms, matter bound to it develops a network of filaments and pancakes. This moving web of gas and dark matter drifts and sweeps a large volume, overtaking many halos in the process. The dark matter content of these halos is unaffected but their gas can be efficiently removed by ram pressure. The loss of gas is especially pronounced in low-mass halos due to their lower binding energy and has a dramatic effect on the star formation history of affected systems. This “cosmic web stripping” may help to explain the scarcity of dwarf galaxies compared with the numerous low-mass halos expected in ΛCDM and the large diversity of star formation histories and morphologies characteristic of faint galaxies. Although our results are based on a single high-resolution simulation, it is likely that the hydrodynamical interaction of dwarf galaxies with the cosmic web is a crucial ingredient so far missing from galaxy formation models.
Graphene Incorporated Electrospun Nanofiber for Electrochemical Sensing and Biomedical Applications: A Critical Review

The extraordinary material graphene arrived in the fields of engineering and science to instigate a material revolution in 2004. Graphene has promptly risen as the super star due to its outstanding properties. Graphene is an allotrope of carbon and is made up of sp2-bonded carbon atoms placed in a two-dimensional honeycomb lattice. Graphite consists of stacked layers of graphene. Due to the distinctive structural features as well as excellent physico-chemical and electrical conductivity, graphene allows remarkable improvement in the performance of electrospun nanofibers (NFs), which results in the enhancement of promising applications in NF-based sensor and biomedical technologies. Electrospinning is an easy, economical, and versatile technology depending on electrostatic repulsion between the surface charges to generate fibers from the extensive list of polymeric and ceramic materials with diameters down to a few nanometers. NFs have emerged as important and attractive platform with outstanding properties for biosensing and biomedical applications, because of their excellent functional features, that include high porosity, high surface area to volume ratio, high catalytic and charge transfer, much better electrical conductivity, controllable nanofiber mat configuration, biocompatibility, and bioresorbability. The inclusion of graphene nanomaterials (GNMs) into NFs is highly desirable. Pre-processing techniques and post-processing techniques to incorporate GNMs into electrospun polymer NFs are precisely discussed. The accomplishment and the utilization of NFs containing GNMs in the electrochemical biosensing pathway for the detection of a broad range biological analytes are discussed. Graphene oxide (GO) has great importance and potential in the biomedical field and can imitate the composition of the extracellular matrix. The oxygen-rich GO is hydrophilic in nature and easily disperses in water, and assists in cell growth, drug delivery, and antimicrobial properties of electrospun nanofiber matrices. NFs containing GO for tissue engineering, drug and gene delivery, wound healing applications, and medical equipment are discussed. NFs containing GO have importance in biomedical applications, which include engineered cardiac patches, instrument coatings, and triboelectric nanogenerators (TENGs) for motion sensing applications. This review deals with graphene-based nanomaterials (GNMs) such as GO incorporated electrospun polymeric NFs for biosensing and biomedical applications, that can bridge the gap between the laboratory facility and industry.
A NLTE analysis of boron abundances in metal-poor stars

The non-local thermodynamic equilibrium (NLTE) line formation of neutral boron in the atmospheres of cool stars are investigated. Our results confirm that NLTE effects for the B I resonance lines, which are due to a combination of overionization and optical pumping effects, are most important for hot, metalpoor, and low-gravity stars; however, the amplitude of departures from LTE found by this work are smaller than that of previous studies. In addition, our calculation shows that the line formation of B I will get closer to LTE if the strength of collisions with neutral hydrogen increases, which is contrary to the result of previous studies. The NLTE line formation results are applied to the determination of boron abundances for a sample of 16 metal-poor stars with the method of spectrum synthesis of the B I 2497 Å resonance lines using the archived HST/GHRS spectra. Beryllium and oxygen abundances are also determined for these stars with the published equivalent widths of the Be II 3131 Å resonance and O I 7774 Å triplet lines, respectively. The abundances of the nine stars which are not depleted in Be or B show that, no matter the strength of collisions with neutral hydrogen may be, both Be and B increase with O quasi-linearly in the logarithmic plane, which confirms the conclusions that Be and B are mainly produced by primary process in the early Galaxy. The most noteworthy result of this work is that B increases with Fe or O at a very similar speed as, or a bit faster than Be does, which is in accord with the theoretical models. The B/Be ratios remain almost constant over the metallicity range investigated here. Our average B/Be ratio falls in the interval [13±4, 17±4], which is consistent with the predictions of spallation process. The contribution of B from the ν-process may be required if the B/B isotopic ratios in metal-poor stars are the same as the ⋆Based on observations made with ESO telescopes and NASA/ESA Hubble Space Telescope obtained from the ESO/ST-ECF Science Archive Facility; based on spectral data retrieved from the ELODIE archive at Observatoire de Haute-Provence (OHP). Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China; [tan, sjr, gzhao]@bao.ac. cn Graduate University of Chinese Academy of Sciences, Beijing 100049, China
The Influence of Processes Innovation Strategy on the Performance of Commercial Banks in Kenya

The study was conducted to examine the influence of processes innovation strategy on the performance of commercial banks in Kenya given the dynamism in the business environment hence the need for organizations to move with speed and make choices that add value to customers and those which will enable the organization remains relevant in such a dynamic business environment. Diffusion of innovation theory was incorporated in the study since it widely supports the spread of agency banking, mobile technology, and online banking. An explanatory research design was used. Both primary and secondary data were collected. Primary data was collected using a questionnaire while secondary data was collected from relevant literature materials, the organization’s annual reports, and the website. Cronbach’s Alpha coefficient was used to test the reliability of the data with an acceptable level of 0.7 at a confidence level of 95%. The study targeted tier 2 Commercial Banks in Kenya with the top management bank employees as the key respondents. The target population was 144 top management bank employees. The study employed a census targeting the entire population of 144 top management bank employees. Out of the 144-target population, 120 top management employees responded to the questionnaire hence results from the findings were based on the 120 respondents. Descriptive and inferential statistics were used in analyzing the data. Descriptive statistics entailed the measure of central tendency (mean) and the measure of dispersions (standard deviation). The statistical package for social sciences (SPSS) was used to generate the descriptive statistics. Inferential statistics entailed regression and correlation analysis. Data were presented using tables. The study established that there was a significant influence of process innovation strategy on the performance of commercial banks in Kenya. The findings of the study concluded that mobile banking and internet banking have greatly enabled customers to access essential services in the comfort of their homes or offices and without necessarily having to go to the bank whereas agency banking has significantly reduced the queues in the banking halls and customers do not have to wait for long hours to be served at the bank. The study recommended that banks need to adopt a process innovation strategy in order to enhance performance.
Enseñanza basada en problemas aplicada a la Ingeniería Química. Análisis bibliométrico: estudio comparativo de Scopus y WoS

La convergencia al Espacio Europeo de Educación Superior requiere la introducción de nuevas metodologías docentes con el fin de fomentar el autoaprendizaje, la adquisición de competencias profesionalizantes y la transmisión de conocimientos. La enseñanza basada en problemas es un método de innovación docente que permite que los estudiantes adquieran, estructuren y sinteticen de manera colectiva nuevos conocimientos que aplican ante casos reales. La enseñanza basada en problemas en el área de la ingeniería química comenzó a finales del siglo XX, sin embargo, la aplicación de este tipo de metodología no está completamente generalizada. Este trabajo presenta un estudio bibliométrico sobre la utilización de la enseñanza basada en problemas en la ingeniería química utilizando las dos principales bases de datos actuales (Scopus y WoS). Se han encontrado un total de 113 y 89 documentos en Scopus y WoS, respectivamente. Existe una mayor prevalencia de participaciones en congresos, frente a otros medios de publicación y el lenguaje mayoritario es el inglés. La mayor producción científica sobre el campo analizado se encuentra en Estados Unidos, aunque existe un interés generalizado en los cinco continentes. El análisis de las palabras clave muestra un creciente interés por la motivación del alumnado y la enseñanza activa dirigida a aspectos prácticos y profesionalizantes claves en la enseñanza de la ingeniería química.
Disorder effects on thermal transport on the surface of topological superconductors by the self-consistent Born approximation

We have studied the longitudinal thermal conductivity of the surface of a three-dimensional time-reversal symmetric topological superconductor with random disorder. Majorana fermions on the surface of topological superconductors have a response to the gravitational field, which is realized as a thermal response to the temperature gradient inside of the material. Because of the presence of both time-reversal symmetry and particle-hole symmetry, disorder on the surface emerges in the Hamiltonian only as spatial deformations of the pair potential. In terms of the gravitational field, the disorder results in spatial fluctuations of the metric. We consider disorder effects on the thermal conductivity perturbatively within the self-consistent Born approximation. The density of states is calculated with the Green's function technique and the thermal conductivity of the surface modes is derived through the electronic conductivity using Wiedemann-Franz law for the Majorana fermions.
The Steklov spectrum and coarse discretizations of manifolds with boundary

We consider the class of compact n-dimensional Riemannian manifolds with cylindrical boundary, Ricci curvature bounded below by a given constant and injectivity radius bounded below by a positive constant, away from the boundary. For a manifold M of this class, we introduce a notion of discretization, leading to a graph with boundary which is roughly isometric to M, with constants depending only on the dimension and bounds on curvature and injectivity radius. In this context, we prove a uniform spectral comparison inequality between the Steklov eigenvalues of the manifold M and those of its discretization. Some applications to the construction of sequences of surfaces with boundary of fixed length and with arbitrarily large Steklov spectral gap are given. In particular, we obtain such a sequence for surfaces with connected boundary. The applications are based on the construction of graph-like surfaces which are obtained from sequences of graphs with good expansion properties.
VGS31b: a highly inclined ring along a filament in a void. Implication for the cold accretion

VGS31b is a highly-inclined ring galaxy found along a filament in a void (Kreckel et al. 2012). Detailed photometry, by using u, g, r, i, z SDSS images, has shown that the overall morphology of VGS31b is very tricky, due to (i) the presence of a highly inclined (72 deg) ring-like structure, which reaches the galaxy center tracing a "spiral-like" pattern, (ii) a one sided tail towards North-East and (iii) a bar in the central regions (Beygu et al. 2013). Such structure is reasonably the result of a "second event" in the evolution history of this galaxy, which could be a gravitational interaction with a companion galaxy or with the environment. The main aim of the present work is to address the most reliable formation scenario for this object, by comparing the observed properties, i.e. structure, baryonic mass, kinematics and chemical abundances, with the theoretical predictions. In particular, we have used archival spectroscopic data, to derive the metallicity in the ring: we found a very low, sub-solar average value of Z = 0.3 Zsun, comparable with other polar ring/disk galaxies, but lower than those measured for ordinary spirals of similar luminosity. The study of the chemical abundances in polar ring/disk galaxies and related objects has received an increasing attention in recent years, since it has revealed to be a key-parameter to disentangle among the formation scenarios suggested for this class of objects: major merging, tidal accretion or cold accretion. In the present work we check the cold accretion of gas through a "cosmic filament" as a possible scenario for the formation of the ring-like structure in VGS31b.
Serendipitous discovery of the faint solar twin Inti 1

Methods. We determine the atmospheric parameters and differential abundances using high-resolution ($R \approx 50 000$), high signal-to-noise (S/N $\approx$ 110 - 240 per pixel) Keck HIRES spectra for our solar twin candidate, the previously known solar twin HD 45184, and the Sun. Results. For the bright solar twin HD 45184, we found $T_{\rm{eff}} = 5864 \pm 9$ K, log $g = 4.45 \pm 0.03$ dex, $v_{t} = 1.11 \pm 0.02$ $\rm{km\ {s}}^{-1}$, and [Fe/H]$ = 0.04 \pm 0.01$ dex, which are in good agreement with previous works. The star Inti 1 has atmospheric parameters $T_{\rm{eff}} = 5837 \pm 11$ K, log $g = 4.42 \pm 0.03$ dex, $v_{t} = 1.04 \pm 0.02$ $\rm{km\ {s}}^{-1}$, and [Fe/H]$ = 0.07 \pm 0.01$ dex that are higher than solar. The age and mass of the solar twin HD 45184 (3 Gyr and 1.05 $\rm{M_{\odot}}$) and the faint solar twin Inti 1 (4 Gyr and 1.04 $\rm{M_{\odot}}$) were estimated using isochrones. The differential analysis shows that HD 45184 presents an abundance pattern that is similar to typical nearby solar twins; this means this star has an enhanced refractory relative to volatile elements, while Inti 1 has an abundance pattern closer to solar, albeit somewhat enhanced in refractories. The abundance pattern of HD 45184 and Inti 1 could be reproduced by adding $\approx 3.5\ \rm{M_{\oplus}}$ and $\approx 1.5\ \rm{M_{\oplus}}$ of Earth-like material to the convective zone of the Sun. Conclusions. The star Inti 1 is a faint solar twin, therefore, it could be used to calibrate the zero points of different photometric systems. The distant solar twin Inti 1 has an abundance pattern similar to the Sun with only a minor enhancement in the refractory elements. It would be important to analyze other distant solar twins to verify whether they share the Sun's abundance pattern or if they are enhanced in refractories, as is the case in the majority of nearby solar twins.
Constraining the location of the emitting region in Fermi blazars through rapid γ-ray variability

We consider the 1.5-yr Fermi/Large Area Telescope (LAT) light curves (E>100 MeV) of the flat spectrum radio quasars 3C 454.3 and PKS 1510−089, which show high activity in this period of time. We characterize the duty cycle of the source by comparing the time spent by the sources at different flux levels. We consider in detail the light curves covering periods of extreme flux. The large number of high-energy photons collected by LAT in these events allows us to find evidence of variability on time-scales of a few hours. We discuss the implications of significant variability on such short time-scales that challenge the scenario recently advanced in which the bulk of the γ-ray luminosity is produced in regions of the jet at large distances (tens of parsec) from the black hole.
Preparation of Side-By-Side Bicomponent Fibers Using Bio Polyol Based Thermoplastic Polyurethane (TPU) and TPU/Polylactic Acid Blends

In this study, side-by-side bicomponent fibers were prepared by melt spinning using bio-based thermoplastic polyurethane (TPU) and TPU/polylactic acid (PLA) blends. The morphology, thermal and mechanical properties of the fibers were investigated. To this end, the synthesis of TPU using biomass-based polyols and the preparation of TPU/PLA blends were preceded. Their morphological and structural characteristics were investigated. The synthesis of TPU was confirmed through Fourier transform infrared analysis, and as a result of gel permeation chromatograph analysis, a compound having a weight average molecular weight of 196,107 was synthesized. The TPU/PLA blends were blended in the ratio of 80/20, 60/40, 40/60, and 20/80 through a melt extruder. They formed a sea–island structure as a result of scanning electron microscope analysis, and an increase in the PLA content in the TPU matrix caused a decrease in the melt flow index. Finally, TPU/(TPU/PLA) side-by-side bicomponent fibers were prepared by utilizing the above two materials. These fibers exhibited tensile strengths of up to 3624 MPa, with improved biocarbon content of up to 71.5%. These results demonstrate the potential of TPU/(TPU/PLA) side-by-side bicomponent fibers for various applications.
OGLE-2009-BLG-092/MOA-2009-BLG-137: A DRAMATIC REPEATING EVENT WITH THE SECOND PERTURBATION PREDICTED BY REAL-TIME ANALYSIS

We report the result of the analysis of a dramatic repeating gravitational microlensing event OGLE-2009-BLG-092/MOA-2009-BLG-137, for which the light curve is characterized by two distinct peaks with perturbations near both peaks. We find that the event is produced by the passage of the source trajectory over the central perturbation regions associated with the individual components of a wide-separation binary. The event is special in the sense that the second perturbation, occurring ∼100 days after the first, was predicted by the real-time analysis conducted after the first peak, demonstrating that real-time modeling can be routinely done for binary and planetary events. With the data obtained from follow-up observations covering the second peak, we are able to uniquely determine the physical parameters of the lens system. We find that the event occurred on a bulge clump giant and it was produced by a binary lens composed of a K- and M-type main-sequence stars. The estimated masses of the binary components are M1 = 0.69 ± 0.11 M☉ and M2 = 0.36 ± 0.06 M☉, respectively, and they are separated in projection by r⊥ = 10.9 ± 1.3 AU. The measured distance to the lens is DL = 5.6 ± 0.7 kpc. We also detect the orbital motion of the lens system.
Recursive Markov Process for Iterated Games with Markov Strategies

The dynamics in games involving multiple players, who adaptively learn from their past experience, is not yet well understood. We analyzed a class of stochastic games with Markov strategies in which players choose their actions probabilistically. This class is formulated as a $k^{\text{th}}$ order Markov process, in which the probability of choice is a function of $k$ past states. With a reasonably large $k$ or with the limit $k \to \infty$, numerical analysis of this random process is unfeasible. This study developed a technique which gives the marginal probability of the stationary distribution of the infinite-order Markov process, which can be constructed recursively. We applied this technique to analyze an iterated prisoner's dilemma game with two players who learn using infinite memory.