Miracle-dz/UniFAR-FTUs huggingface dataset:
EUV Observations of EX Hydrae: 107 K Gas near a White Dwarf Surface

We have observed the intermediate polar EX Hydrae for 180,000 s with the Extreme Ultraviolet Explorer. The EUV flux is strongly modulated at both the binary period (98 minutes) and the white dwarf spin period (67 minutes). The secondary star eclipse is total, with a duration of 41 ± 2 s. The ingress and egress of the secondary eclipse have a duration <3 s (68% confidence). The centroid of the secondary eclipse is independent of the white dwarf spin phase to within 6 s. The eclipse attributed to the disk bulge has an energy dependence consistent with photoelectric absorption through a neutral column of about 1.3 × 1020 cm-2. Folded on the white dwarf spin period, the EUV flux is modulated by a factor of 3.7. The shape of the light curve can be accurately matched with a simple geometrical absorption model, although the variation in modulation depth with energy (e.g., EUV vs. X-rays) requires a more sophisticated model. The EUV spectrum reveals many narrow emission lines characteristic of a plasma around 107 K, and possibly features indicating temperatures as low as 106 K. Assuming optically thin emission, we find a volume emission measure around 3 × 1054 cm-3 for the 107 K plasma, and an accretion rate around 3 × 1016 g s-1. By direct geometrical arguments we constrain the EUV emission region to a region extending over less than 4% of the white dwarf surface area located within 0.5 white dwarf radii (in the orbital plane) and 4.5 white dwarf radii (perpendicular to the plane) relative to the center of the white dwarf. Two independent arguments lead to the conclusion that the electron density is >1013 cm-3, probably >1015 cm-3, in the EUV-emitting region.
Dark Matter annihilations in halos and the reionization of the universe

It is well known that annihilations in the homogeneous fluid of dark matter (DM) can leave substantial imprints in the cosmic microwave background (CMB) anisotropy power spectrum. However, the relevance of DM annihilations in halos is still subject to debate, with previous works reaching different conclusions on this point. Furthermore, models of DM annihilations in halos have been invoked to solve the tension between WMAP measurement of the reionization optical depth and astrophysical Gunn-Peterson bound, requiring a significantly smaller value of the optical depth to reionization. This tension, although smaller, still exists in the new Planck data. In this work, we revisit these problems and aim at clarifying the situation, thanks to the most accurate treatment of DM annihilations in halos to this day. We find that the ionization fraction does exhibit a very particular (and potentially constraining) pattern, but the currently measurable reionization optical depth is left almost unchanged: For plausible halo models the modification of the signal with respect to the one coming from annihilation in the smooth background is tiny, below cosmic variance within currently allowed parameter space. We thus conclude that the impact of the virialised DM structures cannot be uncovered by CMB power spectra measurements, unless very peculiar models are invoked for the redshift evolution of the DM annihilation signal (e.g. via unconventional velocity dependence of the annihilation cross section). On the other hand, a precise measurement of the ionization fraction or of the temperature history of the universe (notably via the 21 cm signal) seems to be the most promising way for using halo formation as a tool in DM searches, improving over the current sensitivity of cosmological probes.
A review of the efficiency of self-healing concrete technologies for durable and sustainable concrete under realistic conditions

Self-healing is recognized as a promising technique for increasing the durability of concrete structures by healing cracks, thereby reducing the need for maintenance activities over the service life and decreasing the environmental impact. Various self-healing technologies have been applied to a wide range of cementitious materials, and the performance has generally been assessed under ‘ideal’ laboratory conditions. Performance tests under ideal conditions, tailored to the self-healing mechanism, can demonstrate the self-healing potential. However, there is an urgent need to prove the robustness and reliability of self-healing under realistic simulated conditions and in real applications before entering the market. This review focuses on the influence of cracks on degradation phenomena in reinforced concrete structures, the efficiency of different healing agents in various realistic (aggressive) scenarios, test methods for evaluating self-healing efficiency, and provides a pathway for integrating self-healing performance into a life-cycle encompassing durability-based design.
Magnetic fields and rotation in white dwarfs and neutron stars

Recent spectropolarimetric observations of Ap and Bp stars with improved sensitivity have suggested that most Ap and Bp stars are magnetic with dipolar fields of at least a few hundred gauss. These new estimates suggest that the range of magnetic fluxes found for the majority of magnetic white dwarfs is similar to that of main-sequence Ap‐Bp stars, thus strengthening the empirical evidence for an evolutionary link between magnetism on the main sequence and magnetism in white dwarfs. We draw parallels between the magnetic white dwarfs and the magnetic neutron stars and argue that the observed range of magnetic fields in isolated neutron stars (Bp ∼ 10 11 ‐10 15 G) could also be explained if their mainly O-type progenitors have effective dipolar fields in the range of a few gauss to a few kilogauss, assuming approximate magnetic flux conservation with the upper limit being consistent with the recent measurement of a field of Bp ∼ 1100 G for θ Orion C. In the magnetic field‐rotation diagram, the magnetic white dwarfs can be divided into three groups of different origin: a significant group of strongly magnetized slow rotators (P rot ∼ 50 ‐100 yr) that have originated from single-star evolution, a group of strongly magnetized fast rotators (P rot ∼ 700 s), typified by EUVE J0317‐853, that have originated from a merger, and a group of modest rotators (P rot ∼ hours‐days) of mixed origin (single-star and CV-type binary evolution). We propose that the neutron stars may similarly divide into distinct classes at birth, and suggest that the magnetars may be the counterparts of the slowly rotating high-field magnetic white dwarfs. Ke yw ords: stars: magnetic fields ‐ stars: neutron ‐ white dwarfs.
Computer simulation of granular shear flows

Detailed understanding of flowing granular materials is severely hampered by the deficiencies of present experimental methods. To help increase the information base, a computer simulation has been developed to describe two-dimensional unidirectional flows of inelastic fully rough particles. This paper presents the results of a Couette shear-flow simulation. The results include distributions of velocity, density and granular temperature (a measure of the kinetic energy contained in the random particle motions). The effects of density and shear rate on the granular temperature are explored. Shear and normal forces on the solid walls are compared with experimental and theoretical results. The behaviour of the particles in the simulated flow is examined and assessments are made of the collision angle and velocity distributions. The development of a distinct, ‘layered’ microstructure is observed in high-density granular flows.
A circularly polarized small-size microstrip antenna with a cross slot

An antenna with a low profile, small size, and a light weight is required in mobile satellite communications. A new, circularly polarized small-size microstrip antenna using a proximity coupled feed method is proposed. A simple configuration based on a cross slot with unequal slot lengths on a circular patch is adopted to realize a small-size element antenna. The proposed antenna has no 90/spl deg/ hybrid coupler for circular polarization. The measured results verify the circular polarization, and the antenna radius was reduced by about 36% by using the slot lengths which are nearly equal to the diameter of the circular patch antenna. Good impedance and axial ratio characteristics have been obtained.
Exhumation and Preservation of the Jinchuan Ni‐Cu‐PGE Deposit under the East Longshou Mountain Thermal Evolution, Revealed by Apatite Fission Track Thermochronology

Uplift and exhumation are important factors affecting the preservation of deposits. The anatomy of uplift‐cooling evolution and exhumation in the East Longshou Mountain is of significant research value in understanding changes in the Jinchuan Ni‐Cu‐PGE deposit since its formation. This study uses apatite fission track (AFT) thermochronology to reconstruct the thermal history of the East Longshou Mountain, including the Jinchuan mine, revealing the uplift and exhumation history of the East Longshou Mountain and elucidating the preservation status of the Jinchuan deposit. The AFT ages in the East Longshou Mountain are distributed from 62.3 ± 3.0 Ma to 214.7 ± 14 Ma, with significant differences in ages in distinct areas, the central and pooled ages being consistent within the margin of error. Inverse thermal history models reveal two rapid cooling events associated with exhumation from the Early Jurassic to the Early Cretaceous (200–100 Ma) and since the Miocene (15–0 Ma), the former attributable to the far‐afield response to the closure of the Paleo‐Tethys Ocean and plate assembly at the southern margin of Eurasia, the latter associated with the initial India‐Eurasia plate collision. A slow cooling event from the Early Cretaceous to the Miocene (100–15 Ma) is thought to be related to the arid environment in northwest China since the Cretaceous. These cooling events have diverse responses and cooling rates in different blocks of the East Longshou Mountain: the southwest and centre of which are mainly cooled over 200–120 Ma and 120–0 Ma, with cooling rates of ~0.25 and ~0.33 °C/Ma (~1.25 and ~0.33 °C/Ma in the centre); the Jinchuan mine primarily cooled over 160–100 Ma, 100–15 Ma and 15–0 Ma, with cooling rates of ~1.33, ~0.25 and ~2.00 °C/Ma. These differentiated coolings imply that the uplift of the East Longshou Mountain before the Miocene (~15 Ma) was integral. Strong uplift then occurred in the vicinity of the mining area, which is a critical period for the uplift of the Jinchuan deposit to the surface, meaning that the Jinchuan deposit was exposed no earlier than the Miocene (~15 Ma). Based on mineralization depth information obtained by previous researchers, in conjunction with the calculation and simulation results of this study, it can be seen that the bulk of the Jinchuan intrusion may still be preserved at depth.
Structure–Function Parameters in the Convective Boundary Layer from Large-Eddy Simulation

Abstract The conventional theory of the scattering of transmitted acoustic, microwave, and optical radiation by turbulence uses the refractive index structure-function parameter CN2. The authors calculate the vertical profiles of the structure function parameters on which CN2 depends, those for temperature and humility, CT2 and CQ2, and their joint structure-function parameter, CTQ, from large-eddy simulation (LES) data for convective boundary layers. The results agree well with experimental measurements. Modern views of wave propagation through turbulence with substantial intermittency, such as that found in the high Reynolds number flows in geophysics, suggest that the structure–function parameter be interpreted as a local flow variable rather than the traditional ensemble average. Through the refined Kolmogorov–Obukhov similarity hypotheses, a set of local structure–function parameters is defined that depends on locally averaged values of the molecular destruction rates of velocity and scalar variances.
Whole-genome sequencing of the clinical isolate of Legionella pneumophila ALAW1 from the West Bank allows high-resolution typing and determination of pathogenicity mechanisms

ABSTRACT Background Legionella pneumophila is water-based bacterium causing Legionnaires’ disease (LD). We describe the first documented case of nosocomial LD caused by L. pneumophila sequence type (ST) 461 and serogroup 6. The etiology of LD was confirmed by culturing the bronchoalveolar lavage sample retrieving L. pneumophila strain ALAW1. A 7-days treatment of the LD patient with Azithromycin and Levofloxacin allowed complete recovery. Methods In details, we sequenced the whole genome of the L. pneumophila ALAW1 using Illumina HiSeq platform. The sequence of ALAW1 was aligned with the genome sequence from the closely related reference strain Alcoy 2300/99 and a whole-genome phylogeny based on single nucleotide polymorphisms (SNPs) was created using Parsnp software. Also, the TYGS web-server was used in order to compare the genome with type strain. Results An analysis of the population structure by SNP and TYGS comparison clustered ALAW1 with the reference genome Alcoy 2300/99. Blastp analysis of the type IV secretion Dot/Icm system genes showed that these genes were highly conserved with (≤25%) structural differences at the protein level. Conclusions Overall, this study provides insights into detailed genome structure and demonstrated the value of whole-genome sequencing as the ultimate typing tool for Legionella.
Factors Affecting Behavioural Intention of Online Food Delivery Service Consumers in Kathmandu Valley

The paper aims to investigate the factors influencing behavioural intention of online food delivery services in the Kathmandu Valley. The paper applied a cross-sectional survey research design with structured questionnaires. The data were collected from 277 respondents. The Covariance-Based Structural Equation Model (CB-SEM) was used to test hypotheses. The behavioural intention of online food delivery services is positively influenced by performance expectancy, social influence, and facilitating conditions. However, effort expectancy has no significant influence on behaviour intention for online food delivery services. In this paper, the researcher and manager will gain theoretical and managerial insights. This is among the few studies that investigate the factors influencing online food delivery services by applying the unified theory of acceptance and use of technology (UTAUT) in the Nepalese context.
Asymptotics for Linear Processes

A method of deriving asymptotics for linear processes is introduced which uses an explicit algebraic decomposition of the linear filter. The method leads to substantial simplifications in the asymptotics and offers a unified approach to strong laws and central limit theory for linear processes. Sample means and sample covariances are covered. The results also accommodate both homogeneous and heterogeneous innovations as well as innovations with undefined means and variances.
Size-dependent yield stress in twinned gold nanowires mediated by site-specific surface dislocation emission

Large-scale molecular dynamics simulations were performed to demonstrate the synergistic effects of twin boundaries and free surfaces on dislocation emission in gold nanowires under tensile loading. It is revealed that the addition of nanoscale twins to crystalline nanowires can act to either increase or decrease their resistance to slip in tension, depending on both sample diameter and number of twins per unit length. Site-specific surface dislocation emission and image forces due to twin boundaries are used to explain the size-dependence of yield stress in twinned gold nanowires.
Interfacial reactions on annealing molybdenum‐silicon multilayers

The structure and interfacial reaction in sputtered Mo‐Si multilayers have been studied using cross‐section transmission electron microscopy, electron diffraction, Rutherford backscattering, and low‐angle x‐ray diffraction. Low‐temperature (T<550 °C) annealing was performed in a rapid‐thermal‐annealing furnace and in situ in the microscope. No solid‐state amorphization was observed, in spite of the presence of amorphous alloy interfacial layers in the as‐deposited structure. Instead, the amorphous interlayers crystallize, and growth of the crystalline product, hexagonal‐MoSi2, proceeds. The bilayer period contracts during the reaction, as the disilicide is more dense than its constituents.
Test Report Generation for Android App Testing Via Heterogeneous Data Analysis

The rising of the Android market demands higher quality assurance of Android applications (apps) to sharpen the competitive edge, and techniques for traditional software have problems adapting for mobile apps. Android apps often require testing on a large-scale device cluster, which produces a large amount of test reports consisting of heterogeneous data, e.g., hardware information, GUI screenshots, runtime logs. Such data are hard to merge to be unified analyzed, while they serve as an essential basis for bug inspection and fixing. Existing test report generation or analysis techniques can only handle testing data from different devices separately. They simply list all the information to app developers and have no further processing to summarize test reports. Besides, they neglect the inner connection of the heterogeneous data. Such techniques cannot improve the report reviewing effectiveness and efficiency, and they can hardly find the inner links and rules of the bug occurrence on different devices. As a result, developers still need to devote many efforts to inspect and fix bugs. In this paper, a large amount of test reports are investigated by the authors, as to construct a structured bug model to analyze heterogeneous data of the testing results. According to the investigation, we also define the Bug Inconsistency of testing results from multiple devices and build a novel bug taxonomy. In general, an automated approach is proposed to generate structured and comprehensible test reports from raw testing results from multiple devices. Based on the approach, a tool, namely BreGat, is implemented to evaluate the classification and deduplication capability of our approach. The experimental results of 30 Android apps on 20 devices show that BreGat can successfully cover 83% bug categories and exclude 76% duplicate bugs. Furthermore, a user study involving 16 developers shows that our test reports are more comprehensible and BreGat greatly improves the bug inspection efficiency compared to the state-of-the-art tool.
Studies on Microjet Control Effectiveness in High-Temperature Supersonic Impinging Jets

This study examines the influence of jet temperature on the impinging jet flowfield and compares the effectiveness of microjet control for a Mach 1.5 ideally expanded jet. The tests were performed on a 36.2-mm-diam jet of air, heated to stagnation temperatures up to 1200 K. The jet impinged normally onto a traversable ground plane oriented between 1.5 and 12 throat diameters from the nozzle exit. Findings indicate that the impingement tones persist and generally become more prominent at higher temperatures, and the lift loss levels increase. Microjet injection produced substantial reductions of overall noise levels and considerable lift recovery, although the effectiveness is slightly lower for elevated jet temperatures. In the nozzle-to-ground range resulting in the highest pressure fluctuation levels on the lift plate, reductions reached 9 dB for the 1200 K jet and 10 dB for the cold jet. There was consistent behavior regarding the suppression of near-field and far-field overall sound pressure levels, w.
ON THE TRANSPORT OF QUASI-GEOSTROPHIC POTENTIAL VORTICITY1

Abstract The meridional transport of quasi-geostrophic potential vorticity is calculated from atmospheric data from 1 yr. The calculation is based on available data for the transports of relative momentum and sensible heat from eight standard pressure levels. The results show that the transport of potential vorticity is negative (southward) in the major part of the troposphere above the lowest layer of the atmosphere. A small region of positive (northward) transport is found in connection with the subtropical jet stream in summer. The computed transports of potential vorticity are used in a calculation of the mean annual heat sources in the atmosphere from a steady state quasi-geostrophic model. The results show that the atmosphere is heated south of 50°N and cooled north of this latitude and that the major heat source and heat sink are found around 70 cb. The calculation compares favorably with the determination of the heat sources from heat budget calculation. It is shown that the transport of potential.
Constraining Coupling Constants' Variation with Supernovae, Quasars, and GRBs

Dirac, in 1937, proposed the potential variation of coupling constants derived from his large numbers hypothesis. Efforts have continued since then to constrain their variation by various methods, including astrophysical and cosmological observations. We briefly discuss several methods used for the purpose while focusing primarily on the use of supernovae type 1a, quasars, and gamma-ray bursts as cosmological probes for determining cosmological distances. Supernovae type Ia (SNeIa) are considered the best standard candles since their intrinsic luminosity can be determined precisely from their light curves. However, they have only been observed up to about redshift z = 2.3, mostly at z ≤ 1.5. Quasars are the brightest non-transient cosmic sources in the Universe. They have been observed up to z = 7.5. Certain types of quasars can be calibrated well enough for their use as standard candles but with a higher degree of uncertainty in their intrinsic luminosity than SNeIa. Gamma-ray bursts (GRBs) are even brighter than quasars, and they have been observed up to z = 9.4. They are sources of highly transient radiation lasting from tens of milliseconds to several minutes and, in rare cases, a few hours. However, they are even more challenging to calibrate as standard candles than quasars. Both quasars and GRBs use SNeIa for distance calibration. What if the standard candles’ intrinsic luminosities are affected when the coupling constants become dynamic and depend on measured distances? Assuming it to be constant at all cosmic distances leads to the wrong constraint on the data-fitted model parameters. This paper uses our earlier finding that the speed of light c, the gravitational constant G, the Planck constant h, and the Boltzmann constant k vary in such a way that their variation is interrelated as \({G \sim c^{3} \sim h^{3} \sim k^{3/2}}\) with \({\overset{.}{G}/G = 3\overset{.}{c}/c = 3\overset{.}{h}/h = 1.5\overset{.}{k}/k}\) = 3.90(±0.04) × \({10^{-10}}\) yr\({^{-1}}\) and corroborates it with SNeIa, quasars, and GRBs observational data. Additionally, we show that this covarying coupling constant model may be better than the standard \({\Lambda}\)CDM model for using quasars and GRBs as standard candles and predict that the mass of the GRBs scales with z as \({((1+z)^{1/3}-1)}\). Noether’s symmetry on the coupling constants is now transferred effectively to the constant in the function relating to their variation.
Analysis of random dopant-induced effects through numerical solution of randomly perturbed nonlinear Poisson equation

A new approach to the analysis of random dopant-induced effects in semiconductor devices is proposed. This approach is based on numerical solution of randomly perturbed nonlinear Poisson equation by using a "small signal analysis" (perturbation) technique. This technique is computationally much more efficient than the existing "statistical" techniques and it yields the information that can be directly used for the design of dopant fluctuation-resistant structures of semiconductor devices.