Miracle-dz/UniFAR-FTUs huggingface dataset:
Properties of terrestrial gamma ray flashes detected by AGILE MCAL below 30 MeV

We present the characteristics of 308 terrestrial gamma ray flashes (TGFs) detected by the Minicalorimeter (MCAL) instrument on board the AGILE satellite during the period March 2009–July 2012 in the ±2.5° latitude band and selected to have the maximum photon energy up to 30 MeV. The characteristics of the AGILE events are analyzed and compared to the observational framework established by the two other currently active missions capable of detecting TGFs from space, RHESSI and Fermi. A detailed model of the MCAL dead time is presented, which is fundamental to properly interpret our observations. The most significant contribution to dead time is due to the anticoincidence shield in its current configuration and not to the MCAL detector itself. Longitude and local time distributions are compatible with previous observations, while the duration distribution is biased toward longer values because of dead time. The intensity distribution is compatible with previous observations, when dead time is taken into account. The TGFs cumulative spectrum supports a low production altitude, in agreement with previous measurements. We also compare our sample to lightning sferics detected by the World Wide Lightning Location Network and suggest a new method to assess quantitatively the consistency of two TGF populations based on the comparison of the associated lightning activity. According to this method, AGILE and RHESSI samples are compatible with the same parent population. The AGILE TGF catalog below 30 MeV is accessible online at the website of the ASI Science Data Center http://www.asdc. asi.it/mcaltgfcat/.
Novel designs for the DECADE coaxial plasma gun

New designs for the coaxial plasma injector (cablegun) used in the plasma opening switch (POS) of the DECADE pulsed-power facility were tested experimentally. A two-beam Mach-Zehnder interferometer operating in heterodyne mode was used to acquire, in addition to time-varying path-integrated electron number density and effective injection velocity, transverse radial scans for the ejected plasma. Abel inversion of this projected data yielded electron number density at a given downstream position as a function of radial position and time. Modifications to the baseline DECADE cablegun (a copper-core copper-sheath coaxial arrangement, with a Teflon insulator and a 60-degree muzzle cone) were investigated. Replacement of the copper center conductor with tungsten reduced radiative ablation of copper into the plasma and produced higher effective injection velocity with somewhat lower number density and similar radial divergence properties to that of the baseline cablegun. Substitution of the Teflon insulator with polyethylene continued that trend. The effect of cone angle was investigated by means of a simple flat-face arrangement whose plasma exhibited similar divergence to that of the baseline cablegun, although with lower number density, higher velocity, and more pronounced modulation in response to the driver current. The addition of a boron-nitride auxiliary nozzle proved effective at controlling the plasma divergence and concentrating the free electrons on axis while reducing the effects of driver current modulation.
Energy partitioning in the Io plasma torus

The plasma state of the hot torus is studied with a local, homogeneous, steady state model described by a set of coupled quasi-linear equations for the distribution functions of S+, S++, S+++, O+, and O++. The equations contain model Fokker-Planck operators for ion-ion and ion-electron collisions, a species- and energy-independent loss rate τ−1, impact ionization of S, S+, S++, O, and O+, recombination of S+++, and 11 charge exchange reactions. The only free parameters, which are not governed by physical processes contained in the model, are the ion confinement or residence lifetime τ and the neutral densities of sulfur, nS, and oxygen, nO. Equivalently, if nS, nO, and the electron density ne are adopted as parameters, then τ is determined by imposing charge neutrality. Under the constraints that the pickup mechanism for newly created ions is the dominant energy source and that the torus is in equilibrium between collisional energy loss from ions to electrons and radiative UV loss from ions excited by ion-electron collisions, the densities, average energies, and distribution functions of all ion species and the temperature of the electrons, which are assumed to be Maxwellian, are calculated as functions of the input parameters. Among the results are the following: (1) The ion velocity distributions are significantly non-Maxwellian for the major species, with high-energy tails extending to the pickup energy. A quasi-thermal core exists for the O+ and/or S+ ion velocity distribution functions only if the EUV luminosity of the torus is less than 0.2 eV cm−3 s−1. The core “temperature” is at most Ti ∼ 100 eV; the average energy of the total distribution is generally less than 0.5 of the pickup energy. The ion velocity distributions do not drive the ion loss cone instability for parameters generally typical of the torus. (2) The EUV luminosity of the torus during the Voyager 1 encounter was ∼0.15 eV cm−3 S−1, a factor of ∼1.8 less than that reported by Shemansky and Smith (1981). This downward revision in the EUV intensities is in agreement with calibration adjustments adopted by Holberg et al. (1982) at longer wavelengths (912–1050 A). (3) During the Voyager 1 encounter the approximate average torus ion densities were S+: <350, S++: 420, S+++: 10–20; O+: 660, O++: 40–80 cm−33 with Te ∼ 4.8 eV, τ ∼ 60 days, and ne ∼ 2000 cm−3. The average neutral torus densities were nS ∼ 6 and nO ∼ 30 cm−3 and consistent with an SO2 source. (4) The upper limit obtained by Brown et al. (1983b) on O++ concentrations is only applicable to short duration periods when transient, large eruptions of sulfur-driven volcanoes occur on the surface of Io (McEwen and Soderblom, 1983) and mass loading of the neutral torus is preferentially by sulfur. The resultant plasma torus contains S+ and S++ densities of ∼600, O+ ∼120, O++ < 10, and S+++ < 40 cm−3. The increased mass loading reduces τ to ∼1 week.
Linear Stability Theory Applied to Boundary Layers

The objective of this review is to provide a critical evaluation of linear stability theory for wall-bounded shear flows, with an emphasis on results, not techniques. The results deal with applications to different flowfields related to aircraft systems. Because the flight condition is usually a low-disturbance environment, stability plays an important role in the transition process. Linear stability theory is not a new topic, so emphasis is placed on the most recent accomplishments.
Photonic Waveguide Devices Directly Written into Dielectric Materials Using Femtosecond Laser Pulses

In this paper we will present our most recent contributions to the fleld of femtosec- ond laser direct written waveguides. In particular, at the CUDOS at Macquarie we employed novel femtosecond laser beam delivery techniques in order to fabricate low-loss photonic waveg- uide devices for application in technologies such as telecommunications. After trialling various passive devices including waveguides, 1-N splitters and waveguide-Bragg gratings in non-doped glasses, we transferred our technologies into Erbium/Ytterbium co-doped media resulting in ac- tive Photonic devices.
Estimation of chlorophyll content in the typical steppe vegetation of Inner Mongolia, China, using various red-edge position extraction techniques

Abstract The red-edge position (REP) was extracted from reflectance spectral data at canopy and leaf scale using six different methods in the temperate typical steppe of Inner Mongolia with relatively high species richness. The results suggested that the REPs varied with the extraction methods, sampling sites, plant species, and estimation scales. At the canopy scale, chlorophyll content (CC) was estimated with the linear extrapolation method, and the polynomial fitting technique had coefficients of determination ( R 2 > 0.4 ). The chlorophyll estimates at Leymus chinensis- and Stipa grandis-dominated sites were slightly better than those from the large sampling sites with multiple dominant plant species. At the leaf scale, the linear extrapolation method and the polynomial fitting technique presented high coefficients of determination ( R 2 > 0.6 ). CC estimated at L. chinensis-dominated sites was substantially higher than at S. grandis-dominated sites as well as the large sampling site. The results using the maximum first-derivative method and Lagrangian interpolation techniques revealed a discontinuity, whereas the REPs, as extracted by the linear interpolation method, were shifted toward longer wavelengths. The linear interpolation and inverted Gaussian method were easily saturated. The results obtained with the polynomial fitting technique and the linear extrapolation method had higher sensitivity and accuracy for estimation of CC.
Real-time, high-resolution, space-time analysis of sea surface temperatures from multiple platforms

Abstract A sea surface temperature (SST) analysis system designed to initialize short-term atmospheric model forecasts is evaluated for a month-long, relatively clear period in May 2004. System inputs include retrieved SSTs from the Geostationary Operational Environmental Satellite (GOES)-East and the Moderate Resolution Imaging Spectroradiometer (MODIS). The GOES SSTs are processed via a sequence of quality control and bias correction steps and are then composited. The MODIS SSTs are bias corrected and checked against the background field (GOES composites) prior to assimilation. Buoy data, withheld from the analyses, are used to bias correct the MODIS and GOES SSTs and to evaluate both the composites and analyses. The bias correction improves the identification of residual cloud-contaminated MODIS SSTs. The largest analysis system improvements are obtained from the adjustments associated with the creation of the GOES composites (i.e., a reduction in buoy/GOES composite rmse on the order of 0.3°–0.5°C). A.
Critical currents of small Bi 2 Sr 2 CaCu 2 O 8 + x intrinsic Josephson junction stacks in external magnetic fields

We present a study of the critical currents of small sized intrinsic Josephson junction stacks in external magnetic fields applied parallel to the ${\mathrm{CuO}}_{2}$ layers. The stacks consisting of 5--12 junctions were realized as mesa structures patterned on top of ${\mathrm{Bi}}_{2}{\mathrm{Sr}}_{2}{\mathrm{CaCu}}_{2}{\mathrm{O}}_{8+x}$ single crystals. Lateral mesa dimensions ranged from $10\ifmmode\times\else\texttimes\fi{}10$ to $0.8\ifmmode\times\else\texttimes\fi{}0.8\ensuremath{\mu}{\mathrm{m}}^{2}. $ For the largest structures a complex magnetic field dependence of the critical currents was found. With decreasing mesa dimensions the critical currents systematically approached a Fraunhofer-type magnetic field dependence. Measurements agree well with the results of numerical calculations using coupled sine-Gordon equations.
Temperature Dependence of Multiphonon Nonradiative Decay at an Isolated Impurity Center

The fluorescent lifetime of the $^{4}T_{2}$ excited state of ${\mathrm{Co}}^{2+}$ in KMg${\mathrm{F}}_{3}$ is measured from 1.6 to 550 \ifmmode^\circ\else\textdegree\fi{}K. The radiative lifetime is calculated from the oscillator strength of the $^{4}T_{1}\ensuremath{\rightarrow}^{4}T_{2}$ transition and the nonradiative decay rate deduced. This varies over four orders of magnitude. Its temperature dependence is in good agreement with that predicted for linear coupling to a continuum of harmonic phonons, with parameters deduced from the zero-phonon and one-phonon spectrum. To obtain agreement, the decrease of the energy gap with temperature, which is primarily due to anharmonicity, must be taken into account. The absolute value of the nonradiative decay rate is two orders of magnitude smaller than predicted by the model. It is shown that this discrepancy, and the much more dramatic discrepancy found in ruby, can reasonably be attributed to anharmonicity. The continuum model is compared with a discrete-frequency model, and it is shown that the "effective frequency" of the continuum, however, defined, is closer to its mean frequency than to its maximum.
High‐speed method for computing the exact solution for the pressure variations in the nearfield of a baffled piston

A method is presented whereby the pressure variations at any point in the field of a baffled piston may be efficiently calculated. If a solution for the impulse response of a piston of a given geometry is known, then for harmonic excitation the steady‐state field may be computed by evaluating the driving‐frequency component of the Fourier transform of the impulse response. This method involves a single integration, whereas the direct numerical solution requires a double numerical integration. An exact, closed‐form solution for the impulse response of a rectangular piston is derived. With this solution and the known solution for the impulse response of a circular piston the steady‐state solutions for these two geometries are obtained. Three‐dimensional and contour plots of data obtained for a circular piston and for a plane of symmetry of a rectangular piston field are presented. The plots for the circular piston compare favorably with previously published plots of data calculated by a double integration.
Impact of Online Education on Satisfaction and Academic Performance during COVID-19 among Students: A Review Study

With the unexpected shift far from the classroom in many parts of the globe, a few are questioning whether or not the adoption of online studying will retain to persist publish pandemic, and the way this type of shift might affect the global education market. There are many studies said no satisfaction and overall performance of faculty kids on online education, some different studies imply partial or complete satisfaction and performance of students on online schooling, and few studies talk about the factors that decide the satisfaction and educational performance of school kids. There are 20 studies the researcher chose to discuss about it. Out of that 20, the 10 studies result shows that there were satisfaction and academic performance among the students by online education. Another six studies talk opposite to those 10 studies, but four studies said that some factors such as environment and method of teaching are deciding the satisfaction and academic performance among the students who attending the online education.
Local and global smoothing of discontinuous finite element functions using a least squares method

The concepts and potential advantages of local and global least squares smoothing of discontinuous finite element functions are introduced. The relationship between local smoothing and the ‘reduced’ integration' technique is established. Examples are presented to illustrate the application of the two smoothing techniques to the finite element stresses from several structural analysis problems. The paper concludes with some practical recommendations for discontinuous finite element function smoothing.
Flow physics of discrete boundary layer suction – measurements and predictions

The primary objective of this work is to determine the detailed characteristics of the flow features induced in a boundary layer by suction through laminar flow control (LFC) perforations. An additional goal is to validate a predictive method for generic LFC suction surfaces and to apply this technique to typical flight condition configurations. Fundamental insights into the flow physics of LFC suction surfaces are obtained from a unique series of high-resolution three-component laser Doppler velocimetry (LDV) flow field measurements. The flow fields induced by isolated super-scale perforations under low-speed conditions are mapped and found to be strongly three-dimensional and profoundly different from the idealized concept of continuously distributed suction. Over a range of sub- and super-critical suction flow rates a variety of suction-dependent complex flow features are identified, including a pair of contra-rotating streamwise vortices, multiple co-rotating streamwise vortices, spanwise variations of the mean flow and inherently unstable boundary layer profiles. The measurements reveal that suction-induced transition commences with an instability of these attached vortices, resulting in the development of a pair of turbulent wedges downstream of the perforation. A finite-volume Navier–Stokes method is validated by simulating a variety of low-speed experiments and comparisons are made between the LDV measurements and the predicted flow field. The computational technique reproduces all of the observed flow features, although it slightly under-predicts their magnitude and extent. By analysing the predicted flow fields the mechanism for the formation of the trailing vortex pair is established. Earlier flow visualization experiments, which exhibited vortex shedding, are also simulated by solving the time-dependent governing equations and it is found that the principal unsteady flow features are captured. Despite the challenge posed to the computational method by the diverse range of flow phenomena induced by discrete suction, the predictions provide good agreement with the measurements and observations. The computational tool is subsequently applied to predict the flow fields of single and multiple rows of actual-scale micro-perforations under low-speed and typical transonic flight conditions. A range of suction-induced flow features are predicted and a variety of distinct flow modes are identified. The low-speed critical suction limits are also measured and a design criterion, based on the sucked streamtube characteristics, is established. The basis of this critical suction criterion is also validated for transonic flight configurations.
FEEDING ECOLOGY OF A PARROT ASSEMBLAGE IN THE BRAZILIAN CERRADO

In this study, during two years, I documented the feeding habits of a parrot assemblage in response to food resources offer (abundance, nº of food species, and diversity), across a habitat mosaic in the Brazilian Cerrado. In addition, to each parrot species, I compared variations in those parameters across seasons, as well as in the feeding niche breadth. The feeding activity of every parrot species paralleled both food abundance and the number of food species available. In fact, despite fluctuations, food abundance, the number of food species, and diversity exhibited similar values through seasons, suggesting a trend for adequate food supply across the three major habitat types (palm swamp, gallery forest, and the dominant Cerrado vegetation). Excepting Orthopsittaca manilata (foraged only on Mauritia flexuosa fruit pulp), all other five species (Ara ararauna, Amazona aestiva, Alipiopsitta xanthops, Eupsittula aurea, and Diopsittaca nobilis) showed wide feeding niche breadth. Their broad diets resulted from the opportunist use of a rich collection of seasonal food species. Moreover, they presented diet association according to plant part eaten, in which parrot’s diet displayed a gradient that had an increasingly greater dominance of seeds (A. ararauna, A. aestiva, and A. aurea), to a diet composed mainly by fruit pulp and flowers (A. xanthops, and D. nobilis). The accelerated fragmentation process of the Brazilian Cerrado has been suppressing habitat types in which unpredictable and scattered food patches might be available to parrots. Thus, conservation plans should prioritize the inclusion of habitat mosaics, at least, in the form documented here. As a concern, in the smaller Cerrado remnants, food resources available may be scarce, mainly in terms of the variety and abundance year-round required by parrots.
Distant satellites as probes of our Galaxy's mass distribution

A new method of statistical analysis based on Bayes' theorem is devised and used directly to yield confidence intervals for the mass of the Galaxy once the eccentricity distribution of its satellites are specified. If the satellites have an isotropic velocity distribution, then the Galactic mass is less than about 5.2 x 10 to the 11th solar masses at the 95 percent confidence level. If the Galaxy is modeled as an infinite halo with constant circular speed v(c) and the velocities are isotropic, then the analysis predicts v(c) of less than about 165 km/s at the 95 percent confidence level. If the satellite orbits are more radial, then the estimates are lower. These results suggest that the Galaxy's massive dark halo extends to less than about 50 kpc from the Galactic center. 24 references.
Inflammatory Biomarkers Differ among Hospitalized Veterans Infected with Alpha, Delta, and Omicron SARS-CoV-2 Variants

Mortality due to COVID-19 has been correlated with laboratory markers of inflammation, such as C-reactive protein (CRP). The lower mortality during Omicron variant infections could be explained by variant-specific immune responses or host factors, such as vaccination status. We hypothesized that infections due to Omicron variant cause less inflammation compared to Alpha and Delta, correlating with lower mortality. This was a retrospective cohort study of veterans hospitalized for COVID-19 at the Veterans Health Administration. We compared inflammatory markers among patients hospitalized during Omicron infection with those of Alpha and Delta. We reported the adjusted odds ratio (aOR) of the first laboratory results during hospitalization and in-hospital mortality, stratified by vaccination status. Of 2,075,564 Veterans tested for COVID-19, 29,075 Veterans met the criteria: Alpha (45.1%), Delta (23.9%), Omicron (31.0%). Odds of abnormal CRP in Delta (aOR = 1.85, 95% CI:1.64–2.09) and Alpha (aOR = 1.94, 95% CI:1.75–2.15) were significantly higher compared to Omicron. The same trend was observed for Ferritin, Alanine aminotransferase, Aspartate aminotransferase, Lactate dehydrogenase, and Albumin. The mortality in Delta (aOR = 1.92, 95% CI:1.73–2.12) and Alpha (aOR = 1.68, 95% CI:1.47–1.91) were higher than Omicron. The results remained significant after stratifying the outcomes based on vaccination status. Veterans infected with Omicron showed milder inflammatory responses and lower mortality than other variants.