Miracle-dz/UniFAR-FTUs huggingface dataset:
An Electronic Publication Dedicated to Early Stellar Evolution and Molecular Clouds Desorption of Co and O 2 Interstellar Ice Analogs Does Radiative Feedback by the First Stars Promote or Prevent Second Generation Star Formation?

Solid O 2 has been proposed as a possible reservoir for oxygen in dense clouds through freeze-out processes. The aim of this work is to characterize quantitatively the physical processes that are involved in the desorption kinetics of COO 2 ices by interpreting laboratory temperature programmed desorption (TPD) data. This information is used to simulate the behavior of COO 2 ices under astrophysical conditions. The TPD spectra have been recorded under ultra high vacuum conditions for pure, layered and mixed morphologies for different thicknesses, temperatures and mixing ratios. An empirical kinetic model is used to interpret the results and to provide input parameters for astrophysical models. Binding energies are determined for different ice morphologies. Independent of the ice morphology, the desorption of O 2 is found to follow 0 th-order kinetics. Binding energies and temperature-dependent sticking probabilities for CO–CO, O 2 –O 2 and CO–O 2 are determined. O 2 is slightly less volatile than CO, with binding energies of 912±15 versus 858±15 K for pure ices. In mixed and layered ices, CO does not co-desorb with O 2 but its binding energies are slightly increased compared with pure ice whereas those for O 2 are slightly decreased. Lower limits to the sticking probabilities of CO and O 2 are 0.9 and 0.85, respectively, at temperatures below 20 K. The balance between accretion and desorption is studied for O 2 and CO in astrophysically relevant scenarios. Only minor differences are found between the two species, i.e., both desorb between 16 and 18 K in typical environments around young stars. Thus, clouds with significant abundances of gaseous CO are unlikely to have large amounts of solid O 2. We study the effect of starlight from the first stars on the ability of other minihaloes in their neighbourhood to form additional stars. The first stars in the Λ cold dark matter (ΛCDM) universe are believed to have formed in minihaloes of total mass ∼ 10 5−6 M ⊙ at redshifts z > ∼ 20, when molecular hydrogen (H 2) formed and cooled the dense gas at their centres, leading to gravitational collapse. Simulations suggest that the Population III (Pop III) stars thus formed were massive (∼ 100 M ⊙) and luminous enough in ionizing radiation to cause an ionization front (I-front) to sweep outward, through their host minihalo and beyond, into the intergalactic medium. Our previous work suggested that this I-front was …
Bridging Microscopic Nonlinear Polarizations toward Far-Field Second Harmonic Radiation

Since the first observation of second harmonic generation, there have been extensive studies on this nonlinear phenomenon, to not only clarify its physical origin but also realize unconventional applications, including multiplexed holography, bio-imaging, and tunable second harmonic transistors. While the controlled, strong nonlinearity derived from plasmonic field enhancement and metamaterials has recently rejuvenated this field, a complete picture describing the underlying microscopic mechanism is, until today, still under debate. One of the main reasons for this dispute lies in the lack of a verified model describing the contribution of different microscopic nonlinear polarization components to the radiation, confirmed by rigorous experimental or theoretical assessments. Here, we study second harmonic k-space far-field radiation from plasmonic structures with different aspect ratios and resonances, to reveal the structure-dependent contributions of the distinct nonlinear polarizations. By evaluating far-fields from each component of the nonlinear polarizations in the hydrodynamic model, in perfect agreement with our experiments, we show that the surface-parallel or bulk nonlinear polarizations, generally deemed to be weak, could dominate over the surface-normal component in the far-field radiation, in contrast to the common assumption. Signifying the accurate consideration of all nonlinear polarization sources, our findings address the need for new strategies in the design of highly efficient and directional nonlinear metamaterials.
Inhibitory Learning versus Habituation in an Experimental Exposure Intervention for People With Heightened Health Anxiety: Increase of Distress Tolerance as a Joint Mechanism of Change?

The Inhibitory Learning Theory (ILT; Craske et al., 2008) changed the focus of exposure-based treatment from erasing excitatory associations and fear reduction (habituation (HA)) to reinforcing inhibitory associations and fear toleration (inhibitory learning (IL)). Studies which directly compare both approaches, IL versus HA, are scarce. The present study aimed at implementing and comparing an IL-based (n = 26; Age: M = 23.59, SD = 4.38) with a HA-based (n = 28; Age: M = 25.46, SD = 6.22) experimental exposure approach (including in vivo, interoceptive, and in sensu exposure) in a sample of people with heightened health anxiety. A significant pre- to post-intervention reduction of state health anxiety (p < .001), which was especially associated with an increase of distress tolerance (DT) pre- to post-exposure (F (1, 50) = 12.2, p < . 001, ηp2 = . 20), was observed. A superiority of the IL-based over the HA-based exposure intervention was not detected in relation to major outcomes (e.g., state health anxiety), as well as in relation to a change of DT. The present study underlines the importance of strengthening DT (for heightened health anxiety) during an exposure-based intervention.
Financial data modeling by Poisson mixture regression

In many financial applications, Poisson mixture regression models are commonly used to analyze heterogeneous count data. When fitting these models, the observed counts are supposed to come from two or more subpopulations and parameter estimation is typically performed by means of maximum likelihood via the Expectation–Maximization algorithm. In this study, we discuss briefly the procedure for fitting Poisson mixture regression models by means of maximum likelihood, the model selection and goodness-of-fit tests. These models are applied to a real data set for credit-scoring purposes. We aim to reveal the impact of demographic and financial variables in creating different groups of clients and to predict the group to which each client belongs, as well as his expected number of defaulted payments. The model's conclusions are very interesting, revealing that the population consists of three groups, contrasting with the traditional good versus bad categorization approach of the credit-scoring systems.
A Numerical Scheme for Collisions of Stars: Godunov-type Particle Hydrodynamics

Since Lucy and Gingold & Monaghan invented smoothed particle hydrodynamics (SPH), it has been used to study a variety of astrophysical problems. A broad discussion of the method can be found in a review by Monaghan. However, the most serious disadvantage of SPH remains to be overcome: it cannot handle strong shocks accurately. Especially in three dimensional calculation, particles often penetrate each other, and there are typically large post-shock oscillations.
Accurate modelling of left-handed metamaterials using a finite-difference time-domain method with spatial averaging at the boundaries

The accuracy of finite-difference time-domain (FDTD) modelling of left-handed metamaterials (LHMs) is dramatically improved by using an averaging technique along the boundaries of the LHM slabs. The material frequency dispersion of the LHMs is taken into account using auxiliary differential equation (ADE) based dispersive FDTD methods. The dispersive FDTD method with averaged permittivity along the material boundaries is implemented for a two-dimensional (2D) transverse electric (TE) case. A mismatch between analytical and numerical material parameters (e.g. permittivity and permeability) introduced by the time discretization in FDTD is demonstrated. The expression of numerical permittivity is formulated and it is suggested to use corrected permittivity in FDTD simulations in order to model LHM slabs with their desired parameters. The influence of the switching time of the source on the oscillation of field intensity is analysed. It is shown that there exists an optimum value that leads to fast convergence in simulations.
Combined use of anaerobic and aerobic moving bed biofilm reactors for micropollutants’ removal from wastewater

A novel laboratory-scale continuous flow wastewater treatment system, consisting of an anaerobic moving bed biofilm reactor (AnMBBR) and an aerobic MBBR, was used for investigating the removal of hydroxybenzothiazole (OH-BTH) and selected benzotriazoles from municipal wastewater. The system was operated under three different Experimental Phases where different organic loadings were applied: 0.82 kg COD m-3 d-1 (Phase A), 0.2 kg COD m-3 d-1 (Phase B) and 2.1 kg COD m-3 d-1 (Phase C). The system achieved sufficient COD removal, nitrification and biogas production. All target micropollutants were partially removed during the experiments. Total removal efficiencies ranged from 32% for 5-methyl-1H-benzotriazole (5TTR) to 97% for OH-BTH. The contribution of the strictly anaerobic bioreactor was important for 5TTR, 5-chlorobenzotriazole (CBTR) and xylytriazole (XTR), while the use of aerobic bioreactors resulted to important increase of target compounds removal and it was exclusively responsible for the removal of OH-BTH and benzotriazole (BTR).
Radio and X-ray observations of the radio halo source in A1367

Radio and X-ray observations of the 'radio halo' in A1367 are presented. The radio spectral index distribution is derived combining data at 610 and 1415 MHz taken with the Westerbork Synthesis Radio Telescope (WSRT). A high-resolution Very Large Array (VLA) map allows us to discriminate between the extended cluster emission and a triple radio source associated with a background stellar object (most probably a QSO) which appears projected onto it. X-ray observations taken with the high-resolution imager on board the Einstein satellite reveal an X-ray source associated with this background object. A second weak X-ray enhancement is found projected onto the extended radio component. Inverse Compton scattering of the synchrotron-emitting particles provides a possible interpretation of such a source. The presence of large-scale magnetic fields and particle acceleration due to the turbulent motion of galaxies through the intergalactic medium is discussed in relationship to the observed peculiarities of the galaxies found in this region.
Universal relaxor polarization in Pb ( Mg 1 / 3 Nb 2 / 3 ) O 3 and related materials

The dielectric permittivity \ensuremath{\varepsilon} at frequencies from ${(10}^{\ensuremath{-}1}\char21{}{10}^{\ensuremath{-}5})\mathrm{Hz}$ to ${10}^{5}\mathrm{Hz}$ is studied in perovskite $(1\ensuremath{-}x)\mathrm{Pb}({\mathrm{Mg}}_{1/3}{\mathrm{Nb}}_{2/3}){\mathrm{O}}_{3}\ensuremath{-}x{\mathrm{PbTiO}}_{3}$ relaxor ferroelectric ceramics of different compositions $x=0.35,$ 0.25, and 0, which exhibit, below the temperature of the diffuse $\ensuremath{\varepsilon}(T)$ maximum ${T}_{m},$ a tetragonal ferroelectric, a rhombohedral ferroelectric, and a nonergodic relaxor phase, respectively. The universal relaxor dispersion previously observed at temperatures near and above ${T}_{m}$ in the ceramics of $x=0.25$ is also found to exist in other compositions. This dispersion is described by the fractional power dependence of the real and imaginary parts of susceptibility on frequency, ${\ensuremath{\chi}}_{U}^{\ensuremath{'}}(f)\ensuremath{\propto}{\ensuremath{\chi}}_{U}^{\ensuremath{''}}(f)\ensuremath{\propto}{f}^{n\ensuremath{-}1}. $ The real part of the universal relaxor susceptibility ${\ensuremath{\chi}}_{U}^{\ensuremath{'}}$ is only a comparatively small fraction of the total permittivity ${\ensuremath{\varepsilon}}^{\ensuremath{'}},$ but ${\ensuremath{\chi}}_{U}^{\ensuremath{''}}$ is the dominant contribution to the losses in a wide frequency-temperature range above ${T}_{m}. $ In the high-temperature phase a divergent temperature behavior is observed, ${\ensuremath{\chi}}_{U}^{\ensuremath{'}}(T)\ensuremath{\propto}(T\ensuremath{-}{T}_{0}{)}^{\ensuremath{-}\ensuremath{\gamma}}$ and ${\ensuremath{\chi}}_{U}^{\ensuremath{''}}(T)\ensuremath{\propto}(T\ensuremath{-}{T}_{0}{)}^{\ensuremath{-}\ensuremath{\gamma}},$ with ${T}_{0}l{T}_{m}$ and $\ensuremath{\gamma}\ensuremath{\cong}2,$ for all the three compositions studied. The universal relaxor susceptibility is attributed to the polarization of polar nanoregions, which are inherent in the relaxor ferroelectrics. A microscopic model of this polarization is proposed, according to which the dipole moments of some ``free'' unit cells inside the polar nanoregion can freely choose several different directions, while the direction of the total moment of the nanoregion remains the same. The ensemble of interacting polar nanoregions is described in terms of a standard spherical model, which predicts the quadratic divergence of susceptibility above the critical temperature, in agreement with the experimental results.
Calculation of mode coupling for quadrupole excitations in a Bose-Einstein condenstate

In this paper, we give a theoretical description of resonant coupling between two collective excitations of a Bose-condensed gas on, or close to, a second-harmonic resonance. Using analytic expressions for the quasiparticle wave functions, we show that the coupling between quadrupole modes is strong, leading to a coupling time of a few milliseconds (for a TOP trap with radial frequency ∼ 100 Hz and ∼10 4 atoms). Using the hydrodynamic approximation, we derive an analytic expression for the coupling matrix element. These can be used with an effective Hamiltonian (that we also derive) to describe the dynamics of the coupling process and the associated squeezing effects.
Low-energy singlet and triplet excitations in the spin-liquid phase of the two-dimensional J 1 − J 2 model

We analyze the stability of the spontaneously dimerized phase of the frustrated Heisenberg antiferromagnet\char22{}the ${J}_{1}{\ensuremath{-}J}_{2}$ model\char22{}in two dimensions. The lowest triplet excitation, corresponding to breaking of a singlet bond, is found to be stable in the region $0.38\ensuremath{\lesssim}{J}_{2}{/J}_{1}\ensuremath{\lesssim}0.62. $ In addition we find a stable low-energy collective singlet mode, which reflects the spontaneous violation of the discrete symmetry. The spontaneous dimerization vanishes at the point of second-order quantum transition into the N\'eel ordered phase $[{(J}_{2}{/J}_{1}{)}_{c1}\ensuremath{\approx}0.38]. $ We argue that the disappearance of dimer order is related to the vanishing of the singlet energy gap at the transition point.
Learning Quality of Senior High School Distance Education During the COVID-19 Pandemic

In the new normal, educational institutions find ways for teaching-learning to continue. It is remarkable that distance education has been a great means of continuous learning. In this kind of learning condition, access to quality learning is paramount. The main goal of this research was to determine the effect of the factors of distance education on learning quality during the time of the COVID-19 pandemic. The research design was an exploratory descriptive approach that involved the teachers and students in the Senior High School (SHS) Department of four different campuses. Based on the results, the factors in distance education such as instructional design, support system, and implementation significantly predicted the learning quality of SHS students during the COVID-19 pandemic. When grouped according to campuses, the perceived level of learning quality in distance education noted a significant difference. This may indicate that learning quality can be intensified by the factors in distance education and be carried out on the four campuses. This intensification may be considered in the formulation of the Distance Education Program in the SHS on all campuses of the university.
Molecular verification of commercialized Neoseiulus californicus (McGregor) settlement before spider mite appearance in a Japanese pear orchard

Abstract A report of our earlier study described a phytoseiid mite Neoseiulus californicus (McGregor) (Acari: Phytoseiidae) release system using a moisturized sheltered sachet for spider mite control. For the present study, we installed the predator release systems on 43 out of 71 trees in a Japanese pear orchard to survey the dispersal of N. californicus released from the predator release system. In the orchard, Japanese pear trees were trained on the overhead horizontal trellis system. Consequently, the trees were mutually connected through the trellis training system. We collected phytoseiid mites on the tree leaves and were subjected to PCR to examine their species composition. Results demonstrated that N. californicus were 62.37% of the total of 3,247 phytoseiid mites collected. Using microsatellite markers, commercialized N. californicus that had been released from the predator release systems were discriminated from indigenous N. californicus. Results demonstrated that phytoseiid mites consisting mainly of the commercialized N. californicus occurred one week earlier in trees with the predator release systems. Results also demonstrated that the commercialized N. californicus dispersal occurred mainly in trees installed with the predator release systems.
Resolving streamflow diel fluctuations in a small agricultural catchment with an integrated surface‐subsurface hydrological model

During dry periods, stream discharge in vegetated catchments can naturally fluctuate up to 10% daily. Despite intensive efforts put in observing and interpreting diel fluctuations of stream discharge across a range of instrumented natural catchments worldwide, the capability of state‐of‐the‐art hydrological models to reproduce and explain such processes has rarely been tested. Here, we used CATHY, a physics‐based integrated surface‐subsurface hydrological model (ISSHM), to simulate the stream discharge in a small tile‐drained agricultural catchment in Switzerland, where streamflow diel fluctuations appeared in dry periods. The model was able to satisfactorily reproduce the measured stream discharge, including the observed diel fluctuations. Next, we designed and simulated a series of modelling scenarios aimed to disentangle the processes contributing to the diel fluctuations in stream discharge. These scenarios revealed the predominant role of evapotranspiration (ET) in the establishment of diel fluctuations in stream discharge. Irrigation sustained the baseflow in dry periods and caused short‐living streamflow peaks, which did not directly cause, but superposed to, diel patterns. Vegetation rooting depths and response to oxygen stress in the root zone slightly affected the amplitude of the streamflow diel fluctuations, while changes in the saturated hydraulic conductivity driven by diel soil temperature fluctuations caused an amplitude of the streamflow diel signal 10 times smaller compared to the one caused by ET. Our study demonstrates that ISSHMs such as CATHY can provide high‐fidelity spatially‐distributed dynamic simulations of evapotranspiration and irrigation fluxes, as well as soil moisture and groundwater flows, enhancing our understanding of the role of these hydrological processes during dry periods and thus making these models useful tools for a more sustainable management of agricultural catchments.
The COBE normalization for standard cold dark matter

The Cosmic Background Explorer Satellite (COBE) detection of microwave anisotropies provides the best way of fixing the amplitude of cosmological fluctuations on the largest scales. This normalization is usually given for an n = 1 spectrum, including only the anisotropy caused by the Sachs-Wolfe effect. This is certainly not a good approximation for a model containing any reasonable amount of baryonic matter. In fact, even tilted Sachs-Wolfe spectra are not a good fit to models like cold dark matter (CDM). Here, we normalize standard CDM (sCDM) to the two-year COBE data and quote the best amplitude in terms of the conventionally used measures of power. We also give normalizations for some specific variants of this standard model, and we indicate how the normalization depends on the assumed values on n, Omega(sub B) and H(sub 0). For sCDM we find the mean value of Q = 19.9 +/- 1.5 micro-K, corresponding to sigma(sub 8) = 1.34 +/- 0.10, with the normalization at large scales being B = (8.16 +/- 1.04) x 10(exp 5)(Mpc/h)(exp 4), and other numbers given in the table. The measured rms temperature fluctuation smoothed on 10 deg is a little low relative to this normalization. This is mainly due to the low quadrupole in the data: when the quadrupole is removed, the measured value of sigma(10 deg) is quite consistent with the best-fitting the mean value of Q. The use of the mean value of Q should be preferred over sigma(10 deg), when its value can be determined for a particular theory, since it makes full use of the data.
THE EFFECT OF VARIATIONS OF COMPOSITION OF FELSDPAR AND THE SHELL OF PENSI SHELL (Corbicula Moltkiana) FROM LAKE MANINJAU ON THE FLEXIBILITY OF DENTURE

Utilization of waste pensi shells (Corbicula Moltkiana) in Lake Maninjau has not been fully optimal so that a more economical business is needed. One of them is the use of calcium oxide in pensi shells. Calcium oxide is one of the most commonly used calcium in the manufacture of dentures. This study aims to determine the value of the optimum flexural strength of the denture in order to obtain a higher quality denture material on the pensi shell that can be utilized and which has economic value. The method used is the experimental method. The sample used in this study with a size of 90 mm X 18 mm X 8 mm for testing flexibility / flexural strength. The total samples used in this study were 12 samples for testing the flexibility/flexural strength using a bending testing machine. For the use of pensi shell material, a calcination process was carried out at a temperature of 1000℃ on the pensi shell material and then characterized using XRF to determine the ingredients. The results of the characterization using XRF showed that pensi shells contain calcium elements of 97.121% and about 3% other elements such as Si, Al, P, Ag, Mn and Fe. Then the pensi shell material is mixed with other ingredients such as felsdpar, quartz, and kaolin. The material is mixed and then molded for flexural testing specimens. Based on the test results of this study, the highest flexibility value for denture samples was found in sample 4 with the most variations of pensi shell powder. The highest denture flexibility value is 25.778 MPa with a variation of 30 gram pensi shell powder in sample 4. The lowest denture flexibility value is 5.727 MPa with a variation of 0 gram pensi shell powder in sample 1. This is due to the addition of pensi shell powder. can increase the value of flexibility in dentures. The increase in the flexibility value was influenced by the CaO content obtained from the pensi shell powder.
Notes on the distribution of quadratic forms in singular normal variables

SUMMARY Conditions for a quadratic form in singular normal variables to follow a x2 distribution are obtained, correcting and extending previous results by Good (1969). Connexions with the noncentral case and independence of two quadratic forms are also given extending earlier results by Ogasawara & Takahashi (1951). Finally, a further generalization of the well-known theorem of Cochran (1934) is presented. 1. CENTRAL X2 DISTRIBUTION Throughout this section let x follow a multivariate normal distribution with mean vector 0 and covariance matrix C, possibly singular, and let A be a symmetric matrix, not necessarily semidefinite. Then Good (1969) obtained conditions for x'Ax to follow a x2 distribution; these conditions simplify those proved earlier by Ogasawara & Takahashi (1951), and more recently by Khatri (1963), Rayner & Livingstone (1965), Rao (1966) and