Miracle-dz/UniFAR-FTUs huggingface dataset:
A possible detection mechanism for pre-low-mass X-ray binaries

This work presents a possible detection mechanism for close, detached, neutron star-red dwarf binaries, which are expected to be the evolutionary precursors of low-mass X-ray binaries (LMXBs). Although this pre-low-mass X-ray binary (pre-LMXB) phase of evolution is predicted theoretically, as yet no such systems have been identified observationally. The calculations presented here suggest that the X-ray luminosity of neutron star wind accretion in a pre-LMXB system can be expected to exceed the intrinsic X-ray luminosity of the red dwarf secondary star. Furthermore, the temperature of the radiation emitted from the neutron star wind accretion process is expected, within the confines of a reasonable set of conditions, to lie within the detection range of X-ray satellites. Sources with X-ray luminosities greater than that expected for a red dwarf star, but the positions of which coincide with that of a red dwarf star, are then candidate pre-LMXB systems. These candidate systems should be surveyed for the radial velocity shifts that would occur as a result of the orbital motion of a red dwarf star within a close binary system containing a high-mass compact object.
A theoretical approach for analyzing the restabilization of wakes

A linear stability analysis provides the basis for an analysis of the effects of prescribed changes upon the global stability characteristics of a bluff body wake. The analysis is applied in particular to the problem of placing a small cylinder in the wake of a larger one in order to suppress the vortex street. A prediction of the alteration in the critical Reynolds number of the system as a function of the location of the second cylinder relative to the first is presented and is shown to compare favorably with experimental results. The effect upon shedding frequency is also considered. The approach relies on the solution of an adjoint eigenvalue problem and an inhomogeneous adjoint boundary value problem. These adjoint solutions are shown to be a key component in the analysis of a variety of wake control strategies.
The dynamics of flow around a cylinder at subcritical Reynolds numbers

Mean and fluctuating pressure and skin friction around a circular cylinder in cross‐flow were studied in the subcritical Reynolds number range, 104–105. Results are presented for two cases, namely, with and without a splitter plate behind the cylinder. The splitter plate was used to suppress vortex shedding. The nonlinear dynamics of the flow around the cylinder was examined to characterize the process of laminar separation in terms of the number of degrees of freedom, and to determine whether the process is chaotic. For this purpose, the Grassberger–Procaccia correlation dimension and the largest Lyapunov exponent were estimated from the time series of the pressure data. The results indicate a correlation dimension of the order of 10–12 both in the presence and absence of the splitter plate. The largest Lyapunov exponent was found to be positive in both cases, suggesting that the process of laminar separation is chaotic. These results are new and are significant from the point of view of modeling and controlling the phenomenon of laminar separation in the future.
A low-cost adsorbent deriving from eggshell modified with Mg(II)-doped hydroxyapatite for removal of Cd2+ from water

The industrial by-product cadmium can pollute the environment and be harmful to humans after being discharged from wastewater. In this study, a low-cost adsorbent deriving from kitchen waste eggshells (BC), was modified by magnesium-doped hydroxyapatite in order to form a new adsor - bent (MHBC) capable of removing Cd 2+ from water. When compared to BC, the adsorption capac - ity of MHBC was found to be greatly improved, while their equilibrium adsorption capacities were 4.82 and 49.41 mg·g –1 , respectively. Kinetic, isothermal, and environmental factors’ analy - ses suggested that chemisorption played a major role in the Cd 2+ adsorption process delivered by MHBC. Particularly, chemical complexation, ion exchange, and electrostatic interaction could be the main mechanisms involved. Both the pseudo-second-order kinetics equation and the Sips iso - therm model were found to fit the adsorption process well. Sips model revealed that the maxi - mum adsorption capacity of MHBC at 25°C was 68.898 mg·g –1 . Acidic conditions and the presence of Mg 2+ , Pb 2+ , Cu 2+ , and Zn 2+ were found to reduce the adsorption capacity of MHBC for Cd 2+ . After three cycles, the removal percentage of Cd 2+ by MHBC was still able to reach 78.75%. Therefore, our study suggests that MHBC is a highly efficient, green, and sustainable Cd 2+ -removing adsorbent.
The FU Orionis Binary System and the Formation of Close Binaries

The faint star next to FU Orionis recently discovered by Wang et al. has been observed with adaptive optics at the Subaru Telescope. Infrared JHK′L′ photometry shows clear infrared excess, indicating that the object is a pre-main-sequence star. Its infrared K-band spectrum is very different from that of FU Orionis and suggests a star of spectral type K. We discuss these observations in light of the hypothesis that FUors may be newborn binaries that have become bound when a small nonhierarchical multiple system breaks up. This scenario predicts that FU Orionis must be a close binary (<10 AU), and if so the newly discovered companion is the outlying member in a triple system. We discuss various implications of this scenario; in particular, we note that FUor eruptions should commonly occur during a relatively brief evolutionary phase partly overlapping with and immediately following the formation of Herbig-Haro jets. If this is the dominant mechanism to trigger FUor outbursts, then FUor eruptions should preferentially occur in close binaries, i.e., in about 20% of all stars.
Theoretical and numerical analysis of propagation and scattering of eigen- and non-eigenmodes of an irregular integrated-optical waveguide

We consider theoretical and numerical methods for studying propagation and scattering of laser radiation of eigenmodes and non-eigenmodes in an irregular integrated-optical waveguide. Scattering of non-eigenmodes in an irregular integratedoptical waveguide is investigated for the first time. We present the calculated dispersion curves for TE and TM eigenmodes and TE non-eigenmodes. For the leaky TE0 modes we plot the dependence of the complex dispersion relation and show the vertical complex profile of the field. The dependence of the scattered laser radiation field on the effective refractive index is obtained for the given parameters of the waveguide. We compare for the first time the calculated complex scattering diagram of laser radiation outside the waveguide layer in the plane, perpendicular to the plane of incidence, for the leaky and guided TE0 modes.
Predição de Desempenho de Estudantes: Uma Revisão Sistemática de Literatura

A Inteligência Artificial (IA) na Educação tem sido utilizada para lidar com problemas de evasão e desempenho acadêmico de estudantes. Este artigo tem por objetivo apresentar uma Revisão Sistemática de Literatura (RSL) de trabalhos que abordam a predição de desempenho de estudantes. O trabalho buscou responder as seguintes questões: (a) Como os modelos de predição de estudante são utilizados no processo de ensino-aprendizagem; (b) Qual o conjunto de variáveis que melhor explica a predição de desempenho dos estudantes; (c) Como é um modelo de predição do desempenho dos estudantes. Os resultados mostram que embora haja trabalhos que apresentam altos valores de acurácia na predição, ainda existe uma grande oportunidade em relacionar e evidenciar quais são os benefícios para os estudantes e/ou professores.
H I absorption and OH emission in IC 694/NGC 3690

Le systeme des galaxies en interaction IC 694/NGC 3690 (Arp 299 - Mrk 171) est etudie a partir des observations VLA de l'absorption H I et de l'emission OH. Les observations et la reduction des donnees sont presentees. Le champ de vitesse dans Arp 299 tel qu'observe dans les donnees H I est ensuite discute. L'activite de flambee stellaire et la nature du megamaser OH sont egalement discutees.
Interaction of Isotropic Light with a Compact Plant Leaf

A transparent plate with rough plane-parallel surfaces is used as a theoretical model to explain the interaction of diffuse light with a compact plant leaf. Effective optical constants of a corn leaf have been determined from leaf reflectance and transmittance measured over the spectral range 0.5–2.5 μ with a recording spectrophotometer. The effective index of refraction at 0.5 μ for the corn leaf is not inconsistent with the refractive index of epicuticular wax. The effective absorption spectra of the corn leaf appears to be a superposition of the absorption coefficients of chlorophyll and pure liquid water. Residual spectral data from other leaf constituents are at the resolution limit of the spectrophotometer. The plate model of a leaf is also used to determine moisture content of the corn leaf from reflectance and transmittance measurements.
FIGURATIVE LANGUAGE IN JOHN MAYER’S SELECTED SONGS: A STYLISTIC ANALYSIS

This research identified and described the figurative language found in five selected John Mayer songs with broken heart themes. The method used in this study is a qualitative descriptive method. Based on the analysis, hyperbole dominates in this study. Songwriters use hyperbole in the song lyrics to emphasize to the listeners what the songwriter wanted to say or what he'd done in his life, the writer used hyperbole to represent his feelings and to express what he wants to say. John Mayer''s selected songs contain meanings beyond the sentence or figurative language. 31 sentences use figurative language in the song lyric, hyperbole is the most dominant type of figurative language that appears in this song because it is used to emphasize a situation or condition for special effects. The use of hyperbole is what then makes the pieces very beautiful and meaningful as it is known that hyperbole is used to strengthen the impression by exaggerating, this is what then gives a strong impression on some of the song lyrics.
Cherenkov radiation by an electron bunch moving in Hermitian medium

Detailed theoretical investigation and computer calculations on Cherenkov radiation (CR) by an electron bunch moving uniformly in Hermitian medium (CRH) with and without absorption are presented in the paper. The theory shows that in the CRH, not only the current density but also the charge density of the particle contribute to the Cherenkov radiation. It has been found that there are two modes in the CRH; in general, only one of them is radiative mode and another one is local field. The frequency area where both of these two modes are radiative modes simultaneously is studied. The comparison of the two modes is given in the paper and the relation of the existence of these two modes is improved. The comparison of the calculations shows that the radiation power of mode “o” is larger than that of mode “e. ” It indicates that the group velocity in the CRH is slower than the phase velocity. Detailed computer calculations are given in the paper, and some interesting physical phenomena of CR are revealed. The th.
Weather conditions as cross-sectional moderators of the associations between the physical environment and walking behavior in the Netherlands

Abstract There is increasing evidence that people’s walking behavior is linked to the physical environment to which they are exposed. However, whether this association is moderated through local weather conditions is largely unclear. Based on Dutch National Travel Survey data, we applied latent class analysis to determine co-occurring weather conditions and used Tobit regression model to examine whether and, if so, to what extent weather conditions moderated the associations between the physical environment and different walking patterns on weekdays and weekends. We found that in warm and dry weather conditions on weekdays, people living nearby bus stops were more likely to walk to public transit. However, the same correlation was not found on weekends. In inclement weather (i.e., warm, very windy, rainy), people were less likely to walk to public transit. In warm, windy, and slightly rainy conditions, address density was negatively related to recreational walking. On weekends, people were more likely to walk for leisure outside the residential neighborhood (e.g., large open spaces, parks) in warm and dry conditions. Our results indicate that the combined impact of weather and the physical environment needs to be taken into account in walking infrastructure planning.
Automated large‐scale mapping and analysis of relict charcoal hearths in Connecticut (USA) using a Deep Learning YOLOv4 framework

In the past decade, numerous studies have successfully mapped thousands of former charcoal production sites (also called relict charcoal hearths) manually using digital elevation model (DEM) data from various forested areas in Europe and the north‐eastern USA. The presence of these sites causes significant changes in the soil physical and chemical properties, referred to as legacy effects, due to high amounts of charcoal that remain in the soils. The overwhelming amount of charcoal hearths found in landscapes necessitates the use of automated methods to map and analyse these landforms. We present a novel approach based on open source data and software, to automatically detect relict charcoal hearths in large‐scale LiDAR datasets (visualized with Simple Local Relief Model). In addition, the approach simultaneously provides both general as well as domain‐specific information, which can be used to further study legacy effects. Different versions of the methodology were fine‐tuned on data from north‐western Connecticut and subsequently tested on two different areas in Connecticut. The results show that these perform adequate, with F1‐scores ranging between 0.21 and 0.76, although additional post‐processing was needed to deal with variations in LiDAR quality. After testing, the best performing version of the prediction model (with an average F1‐score of 0.56) was applied on the entire state of Connecticut. The results show a clear overlap with the known distribution of charcoal hearths in the state, while new concentrations were found as well. This shows the usability of the approach on large‐scale datasets, even when the terrain and LiDAR quality varies.
Theoretical Global Seismology

PrefaceCh. 1Historical Introduction3Ch. 2Continuum Mechanics25Ch. 3Equations of Motion56Ch. 4Normal Modes109Ch. 5Seismic Source Representation146Ch. 6Anelasticity and Attenuation193Ch. 7Rayleigh-Ritz Method237Ch. 8Spheroidal and Toroidal Oscillations257Ch. 9Elastic and Anelastic Perturbations327Ch. 10Synthetic Seismograms363Ch. 11Love and Rayleigh Waves405Ch. 12Mode-Ray Duality451Ch. 13Perturbation Theory537Ch. 14Mode Splitting and Coupling596Ch. 15Body-Wave Ray Theory669Ch. 16Surface-Wave JWKB Theory737App. AVectors and Tensors811App. BSpherical Harmonics838App. CGeneralized Spherical Harmonics877App. DWhole Earth Catalogue932Bibliography967Index999
Evaluation and analysis of chromatic aberrations in images

Optical designers typically use aberration diagrams based on ray tracing to analyze the chromatic aberration performance of their optical system. However to evaluate the impact of chromatic aberrations on color fringes in images optical imaging simulations are necessary including the effect of spectral response of the sensor or film, exposure time, Gamma corrections, etc. We have analyzed the correspondence of classical chromatic aberration measures versus analysis based on image simulations. We propose a metric directly linked to color fringes in images which can be used to constrain and specify the chromatic aberration performance of an optical system.
Self-avoiding walk connectivity constant and theta point on percolating lattices

The average connectivity constant mu of self-avoiding walks (SAWs) is obtained from exact enumeration of SAWs on Monte Carlo generated percolating clusters in a randomly diluted square lattice. For averages over the (infinite) percolating cluster, mu decreases almost linearly with bond dilution (1-p), where p is the bond occupation concentration. The authors find mu (pc)=1.31+or-0.03 at the percolation threshold pc and could not detect any significant difference between mu (pc) and pc mu (1). The variation of theta -point for SAWs on the same lattice with dilution is also estimated, analysing the partition function zeros. Within the limited accuracy of their analysis, its variation with dilution is observed as being quite weak and the theta -point increases somewhat (compared to pure lattice value) near pc; they find a non-vanishing theta point (Ktheta (pc) equivalent to 0.59, where K0=J/k theta ) on the square lattice percolation cluster at pc.
Alternating current magnetic susceptibility of a molecular magnet submonolayer directly patterned onto a micro superconducting quantum interference device

We report the controlled integration, via dip pen nanolithography, of monolayer dots of ferritin-based CoO nanoparticles (12 μB) into the most sensitive areas of a microSQUID sensor. The nearly optimum flux coupling between these nanomagnets and the microSQUID improves the achievable sensitivity by a factor 102, enabling us to measure the linear susceptibility of the molecular array down to very low temperatures (13 mK). This method opens the possibility of applying ac susceptibility experiments to characterize two-dimensional arrays of single molecule magnets within a wide range of temperatures and frequencies.
Transient immune deficiency accompanied with homozygous CBL rare variant

A critical role in cellular proliferation is played by Casitas B‐lineage Lymphoma proto‐oncogene (CBL). Germline heterozygous CBL variants give rise to CBL syndrome, which is phenotypically similar to RASopathy. Somatic mutations in CBL have been reported in patients with juvenile myelomonocytic leukemia (JMML).
Comparing the Dynamics of Free Subduction in Cartesian and Spherical Domains

The effects of sphericity are regularly neglected in numerical and laboratory studies that examine the factors controlling subduction dynamics. Most existing studies have been executed in a Cartesian domain, with the small number of simulations undertaken in a spherical shell incorporating plates with an oversimplified rheology, limiting their applicability. Here, we simulate free‐subduction of composite visco‐plastic plates in 3‐D Cartesian and spherical shell domains, to examine the role of sphericity in dictating the dynamics of subduction, and highlight the limitations of Cartesian models. We identify two irreconcilable differences between Cartesian and spherical models, which limit the suitability of Cartesian‐based studies: (a) the presence of sidewall boundaries in Cartesian models, which modify the flow regime; and (b) the reduction of space with depth in spherical shells, alongside the radial gravity direction, which cannot be captured in Cartesian domains. Although Cartesian models generally predict comparable subduction regimes and slab morphologies to their spherical counterparts, there are significant quantitative discrepancies. We find that simulations in Cartesian domains that exceed Earth's dimensions overestimate trench retreat. Conversely, due to boundary effects, simulations in smaller Cartesian domains overestimate the variation of trench curvature driven by plate width. Importantly, spherical models consistently predict higher sinking velocities and a reduction in slab width with depth, particularly for wider subduction systems, enhancing along‐strike slab buckling and trench curvature. Results imply that sphericity must be considered for understanding the dynamics of Earth's wider subduction systems, and is already a significant factor for slabs of width 2,400 km.
The infrared optical properties of SiO2 and SiO2 layers on silicon

The complex index of refraction N=n−ik for amorphous SiO2 is derived in the energy range 0.03–1.0 eV by Kramers‐Kronig analysis of reflectance data. The results are used to compute the transmission, reflectance, and absorptivity of thin layers of SiO2 on Si substrates in the vicinity of the 0.14‐eV (9 μ) lattice absorption band of SiO2. The dependence of these quantities on the layer thickness and angle of incidence is discussed.
Classificação Multi-classe para Análise de Qualidade de Feedback

O feedback é um fator muito importante no processo de ensino-aprendizagem e crucial na Educação a Distância, pois, como professores e alunos estão separados no espaço e/ou tempo, é através do feedback que o aluno vai entender como está o seu desempenho na disciplina e quais são os próximos passos do aprendizado. Existem na literatura modelos de feedback que ajudam o professor a estruturar e fornecer um feedback de qualidade ao aluno. Nesse trabalho utilizamos o conceituado modelo de feedback de Hattie e Timperley que divide o feedback em categorias (tarefa, processamento da tarefa, regulação e pessoal). É possível encontrar na literatura trabalhos que analisam feedback automaticamente com base nesse modelo. Contudo, esses trabalhos utilizam algoritmos tradicionais de aprendizagem de máquina e treinam classificadores binários para cada nível de feedback. Dessa forma, este trabalho tem como objetivo utilizar algoritmos de deep learning para classificação multi-classe de feedback com base no modelo de Hattie e Timperley.
Solar wind structure at large heliocentric distances: An interpretation of Pioneer 10 observations

Examination of hourly values of the solar wind speed observed by the Pioneer 10 spacecraft beyond a heliocentric distance of 4 AU reveals (1) a prevalent ‘sawtoothlike’ speed-time profile, most speed fluctuations displaying a rapid rise and a much slower decline, and (2) the nearly universal appearance of abrupt (on the 1-hour time resolution of these data) changes in the speed on the rising portions of the speed fluctuations. These previously unreported characteristics, as well as the rate of decay of stream amplitudes derived earlier by Collard and Wolfe, are in general agreement with the predictions of stream propagation models that neglect any conversion of kinetic energy to thermal energy outside of shock fronts. Thus the Pioneer 10 observations give the first confirmation of the general concept of solar wind stream evolution employed in these models, i.e., that solar wind speed inhomogeneities appear to steepen to form shock waves and that the ‘wave amplitudes’ decay slowly as the shock waves propagate outward from the sun.
Radiative Recombination in Highly Excited CdS

The processes involved in the laser effect in CdS excited by electron bombardment have been studied with the aid of an experimental technique allowing the spectral dependence of the optical gain to be obtained. It is shown that at least three different processes can lead to a laser effect in CdS. The first, which corresponds to a low gain, is due to the annihilation of a free exciton with the emission of a photon and an LO phonon. The second, yielding a medium gain, is due to an exciton-exciton interaction; and the third, which results in a high gain, involves an exciton-electron interaction. These last two processes have been studied theoretically, and the results are compared with the experimental data.