Miracle-dz/UniFAR-FTUs huggingface dataset:
On the Inertial Stability f the Equatorial Middle Atmosphere

Abstract A theory of inertial instability on the equatorial beta-plane is developed with application to the inertial stability of the equatorial middle atmosphere at the solstices. It is shown that the stability of this region depends primarily on two unknowns. First, there is the question of whether eddy diffusion can be regarded as stabilizing, or whether this diffusion actually arises from the instability itself. Second, because the diabatic circulation would appear to induce a cross-equatorial shear much greater than that observed, or than that modeled in Holton and Wehrbein (1980), it appears that the gravity wave-induced decelerations would he crucial to the stability of this flow. Unfortunately, the parameterization scheme of Leovy (1964) designed to mimic this effect obscures the issue, since this “frictional drag” concept is invalid on a local basis (Lindzen, 1981). The expected structure and vertical wavelength of the equatorial inertial instability is discussed in the context of this simple mod.
X-Ray Emission from the Wind-Blown Bubble in the Planetary Nebula BD +30°3639

An X-ray spectrum of a wind-blown bubble in the planetary nebula BD +30°3639, acquired by the Advanced Satellite for Cosmology and Astrophysics (ASCA), shows the presence of hot (T = 3 × 106 K) gas dominated by the Ne Kα line complex. There is circumstantial evidence for the enhanced abundances of other H- and He-burning products, although O is not as abundant as in the extremely C-rich stellar wind of the W-R central star. The temperature of the hot gas is several times lower than expected behind the shock from the 700 km s-1 stellar wind. This might be caused by variations in the stellar wind speed and its chemical abundances induced by the central star evolution, and possibly aided by mixing of the stellar wind gas with the nebular material. Mixing is hinted by the discovery of small (0.″2) dusty clumps in the Hubble Space Telescope (HST) narrowband images of the nebula in [S III] λ9532 and [O II] λ3727 emission lines. These clumps are projected against an axisymmetric, nearly square nebular shell and are most likely associated with the neutral and molecular envelope surrounding the wind-blown bubble and the wind-swept shell.
Analysis of bilinear systems using Walsh functions

By using Walsh functions to analyze bilinear systems, it is shown that the nonlinear differential system equation can be converted to a linear algebraic generalized Lyapunov equation that can be solved for the coefficients of the state x(t) in terms of the Walsh basis functions. This Lyapunov equation provides an approximate closed-form solution for a bilinear system. Some guidelines are given for selecting the number of terms in the Walsh approximating series. >
Niobium trilayer process for superconducting circuits

A Nb-AlO/sub x/-Nb trilayer process was developed that consistently produces junctions with V/sub m/>40 mV. Critical current density was controlled reproducibly from 200 to 7000 A/cm/sup 2/ by controlling the oxygen pressure in the process chamber during thermal oxidation of the aluminum. A multilayer AlO/sub x/ barrier was used to produce junctions for Josephson circuit applications requiring low critical currents ( 40 mV) Josephson junctions have been fabricated with low stress ( >
Self-aligned n-channel metal-oxide-semiconductor field effect transistor on high-indium-content In0.53Ga0.47As and InP using physical vapor deposition HfO2 and silicon interface passivation layer

In this work, we present the electrical and material characteristics of TaN∕HfO2∕In0.53Ga0. 47As and InP substrate metal-oxide-semiconductor capacitors and self-aligned n-channel metal-oxide-semiconductor field effect transistor (n-MOSFET) with physical vapor deposition Si interface passivation layer. Excellent electrical characteristics, thin equivalent oxide thickness (∼1.7nm), and small frequency dispersion (<2%) were obtained. n-channel high-k InGaAs- and InP-MOSFETs with good transistor behavior and good split capacitance-voltage (C-V) characteristics on In0.53Ga0. 47As and InP substrates have also been demonstrated.
Narrow-band $\rm{H}{\beta}$ images of star-formation regions in HII galaxies

Aims. Create a catalog of images of HII galaxies and their individual star-formation regions in order to study the distribution of the gas emission and their underlying stellar continuum. Methods. We have used Hβ narrow-band images of 43 selected HII galaxies obtained at ESO NTT 3.58 m telescope using the SUSI2 camera. Results. Surface photometric Hβ fluxes and equivalent widths for all objects and star-formation regions are presented in this catalog. A myriad of filamentary structure were found in the pure Hβ emission-line or continuum-subtracted images, probably attributed to expanding shells as a consequence of the star-formation activity. Our results indicate that the number of regions with high Hβ equivalent width or young regions increase with the instrumental resolution, showing that the instrumental resolution is a bias to determine the cluster ages. Therefore, we showed that some of the observed giant HII regions may have been formed by ensembles of unresolved star forming regions or candidates to host Super Star Clusters. Pure Hβ emission-line images, continuum contours and EW(Hβ) maps showing the morphology of the gaseous and stellar emission in HII galaxies and their individual star-formation regions were obtained. All calibrated continuum and Hβ emission line fluxes and the derived Hβ equivalent width images are available in fits format from http://www.on. br/astro/etelles/HIIgalaxies/Hbeta/.
Mixed interval–fuzzy two-stage integer programming and its application to flood-diversion planning

Innovative prevention, adaptation, and mitigation approaches as well as policies for sustainable flood management continue to be challenges faced by decision-makers. In this study, a mixed interval–fuzzy two-stage integer programming (IFTIP) method is developed for flood-diversion planning under uncertainty. This method improves upon the existing interval, fuzzy, and two-stage programming approaches by allowing uncertainties expressed as probability distributions, fuzzy sets, and discrete intervals to be directly incorporated within the optimization framework. In its modelling formulation, economic penalties as corrective measures against any infeasibilities arising because of a particular realization of the uncertainties are taken into account. The method can also be used for analysing a variety of policy scenarios that are associated with different levels of economic penalties. A management problem in terms of flood control is studied to illustrate the applicability of the proposed approach. The results indicate that reasonable solutions have been generated. They can provide desired flood-diversion alternatives and capacity-expansion schemes with a minimized system cost and a maximized safety level. The developed IFTIP is also applicable to other management problems that involve uncertainties presented in multiple formats as well as complexities in policy dynamics.
Four‐dimensional variational assimilation of special sensor microwave/imager total column water vapour in the ECMWF model

Special Sensor Microwave/Imager (SSM/I) radiances have been used to infer a total column water‐vapour amount using a one‐dimensional variational retrieval in the European Centre for Medium‐Range Weather Forecasts (ECMWF) forecast model. These retrievals are then assimilated using the operational, four‐dimensional variational (4DVar) analysis at ECMWF. the impact of assimilating the total column water vapour on the ECMWF analyses and forecasts is assessed. the primary impact is on the model analysed humidity fields in the tropics and southern hemisphere where 2 to 4% more water vapour is included in the lower troposphere. the addition of moisture in the model also has an impact on the meridional circulation. No impact is seen in the mean extratropical forecast performance but a case study is presented of the improved forecast of low‐pressure systems in the Southern Ocean, when SSM/I data are used in 4DVar.
EXOSAT X-ray spectra of quasars

We have measured the X-ray spectra in the 0.1-10 keV energy range for 17 AGNs (mostly PG quasars) using the EXOSAT Low and Medium Energy arrays. The sample has been selected on the basis of soft X-ray flux and includes all the AGNs in the 1981 Zamorani et al. and 1986 Tananbaum et al. publications with an Einstein flux greater than 6×10 −12 ergs cm −2 s −1
The Peculiar Type Ic Supernova 1997ef: Another Hypernova

SN 1997ef has been recognized as a peculiar supernova from its light curve and spectral properties. The object was classified as a Type Ic supernova (SN Ic) because its spectra were dominated by broad absorption lines of oxygen and iron, lacking any clear signs of hydrogen or helium line features. The light curve is very different from that of previously known SNe Ic, showing a very broad peak and a slow tail. The strikingly broad line features in the spectra of SN 1997ef, which were also seen in the hypernova SN 1998bw, suggest the interesting possibility that SN 1997ef may also be a hypernova. The light curve and spectra of SN 1997ef were modeled first with a standard SN Ic model assuming an ordinary kinetic energy of explosion EK = 1051 ergs. The explosion of a CO star of mass MCO ≈ 6 M☉ gives a reasonably good fit to the light curve but clearly fails to reproduce the broad spectral features. Then, models with larger masses and energies were explored. Both the light curve and the spectra of SN 1997ef are much better reproduced by a C+O star model with EK = 8 × 1051 ergs and MCO = 10 M☉. Therefore, we conclude that SN 1997ef is very likely a hypernova on the basis of its kinetic energy of explosion. Finally, implications for the deviation from spherical symmetry are discussed in an effort to improve the fits to the observations.
Preservation of Some Aging Properties and Stochastic Orders by Weighted Distributions

By assuming that a random variable X possesses an aging property, we provide conditions under which the corresponding weighted version X 1, with weight function w 1(·), would also possess this aging property. Similarly, by assuming that two random variables X and Y are ordered with respect to a stochastic order, we provide conditions under which the corresponding weighted versions X 1 and Y 2, with weight functions w 1(·) and w 2(·), respectively, preserve this stochastic ordering. We also point out fallacies in the similar results claimed by Jain et al. (1989) and Bartoszewicz and Skolimowska (2006) and correct them.
Vectorial elements for the Galactic disc tide effects in cometary motion

The classical Matese-Whitman theory of Oort Cloud comet perturbations has been revisited and extended. An explicit solution for the motion of the mean ascending node is given; it involves an elliptic integral of the third kind. Equations of the mean orbit are formulated in terms of the Cartesian components of the Laplace and angular momentum vectors (vectorial elements). The equations are solved in terms of elliptic functions and the solution is free of the ambiguity related to the orientation of the perihelion that was present in previous work. The Cartesian equations of motion for the vectorial elements form a Hamiltonian system of the Lie-Poisson type. This allows them to be integrated numerically by means of Hamiltonian splitting methods. The formulae of such an integrator are derived with a Hamiltonian function split into two parts.
Self-sustained states at Kolmogorov microscale

It is shown theoretically how the scaling of coherent structures in shear flows changes their asymptotic development at large Reynolds number. Based on the theory a family of nonlinear self-sustained states at Kolmogorov microscale is numerically identified on the laminar–turbulent boundary of shear flows. Theoretically and numerically the states connect to known asymptotic states existing at larger scale. The asymptotically very small amplitude of the new states may explain why strongly sheared, linearly stable laminar flows can cause a turbulent transition by small disturbances. The numerically obtained Kolmogorov-scale solutions can be used to describe the theoretically minimal self-sustained structures appearing in various shear flows.
Spectrum of Hydrogen Atom in Space-Time Non-Commutativity

We study space-time noncommutativity applied to the hydrogen atom and its phenomenological effects. We find that it modifies the potential part of the Hamiltonian in such a way we get the Kratzer potential instead of the Coulomb one and this is similar to add a dipole potential or to consider the extended charged nature of the proton in the nucleus. By calculating the energies from the Schr\"odinger equation analytically and computing the fine structure corrections using perturbation theory, we study the modifications of the hydrogen spectrum. We find that it removes the degeneracy with respect to both the orbital quantum number l and the total angular momentum quantum number j; it acts here like a Lamb shift. Comparing the results with the experimental values from spectroscopy, we get a new bound for the space-time non-commutative parameter. We do the same perturbative calculation for the relativistic case and compute the corrections of the Dirac energies; we find that in this case too, the corrections are similar to a Lamb shift and they remove the degeneracy with respect to j ; we get an other bound for the parameter of non-commutativity.
Stellar Spectral Classification, by Richard O. Gray and Christopher J. Corbally

Many spiral galaxies exhibit a quasi-spherical distribution of unresolved stars around the nucleus. These socalled stellar bulges come in many sizes, sometimes dominating the light from the whole galaxy while in other cases being dwarfed by the light from the spiral arms. Giant elliptical galaxies have a similar form and perhaps a common origin to classical bulges, where star formation is believed to have been triggered by a major merger, or interaction between similarly massive galaxies. In other cases multiple bursts of star formation may have set off internal instabilities, a process thought more likely in the growth of the Milky Way Galaxy. The 5-day IAU Symposium 245, held in Oxford in July 2007, was the first major review of galaxy bulges since that in Baltimore in 1998. As such it was very timely, bringing together 175 participants to report and discuss a wide range of new observations, computer simulations and theoretical modelling. The Proceedings are structured to reflect the Symposium, in four main parts: Formation and Evolution of Bulges, Star Formation and Nuclear Activity, Stellar Populations, and Distant Bulges and Large Surveys. Three issues particularly caught the attention of this nonspecialist reviewer. First, a consensus seems to be emerging that the bulge of our local galaxy consists of old stars, and is in the class of ‘pseudo-bulges’, formed by internal perturbations rather than a major merger. That appears to be true for all galaxies in the Local Group. However, we can anticipate that situation will change in the future as the Milky Way Galaxy and M31 (Andromeda) are on a collision course, which could presumably lead to the formation of a classical bulge. A second major topic of the conference concerned the importance of AGN feedback, and while it is generally accepted that energetic winds and jets from the nuclei of galaxies must have a major effect on the galaxy-wide evolution, it remains uncertain whether the remarkably tight correlation of bulge and central black hole masses is due to energetic feedback or simply to the available gas supply being exhausted. Finally, despite much progress in both observation and computer simulation there remain important discrepancies between the predictions of the currently favoured LCDM cosmology and observations of bulges at high red shift from the latest deep sky surveys. While this short review cannot attempt to properly summarise the outcome of the Symposium, indeed many questions and conflicting views remain, for anyone studying galaxies or an adjacent topic this Proceedings seems certain to be an important reference for several years to come.
Natural Convection around Horizontal Tubes with Smooth, Rough, and Machined Surfaces

This study concerns natural convection around horizontal tubes with smooth, rough, and machined surfaces. The study is motivated by the need for understanding the machining effect or the use of a rough surface layer on the natural convection process. An experimental system is constructed that includes a thick wall metal tube equipped with thermocouples for measuring the surface temperature. A heating element is inserted inside the tube and is coupled with a power supply that can be adjusted to achieve surface temperatures of 60–160°C. The tube surface is machined at various depths of 1–3 mm. Also, four grades of sandpaper are used to cover the tube surface. An analysis of measured data is based on variations in the Nusselt number as a function of the Rayleigh number and surface condition. Results show that the measured data for the smooth tube are consistent with literature results. Although surface machining increases the heat transfer area, it lowers the heat transfer rate because of the low thermal conductivity of air, which replaces the removed metal in the machined grooves. Similarly, covering the tube surface with sandpaper reduces the rate of heat transfer from the tube surface because of contact resistance and the thermal resistance of the sandpaper. Data analysis that takes into consideration the above resistances, where the contact and sandpaper thermal resistances are eliminated, show enhancement of up to 30%. This implies that the direct roughening of a metal surface would enhance the heat transfer rate by 30%.
Simulation of swimming oblate jellyfish with a paddling-based locomotion

Abstract The hydrodynamics of a swimming jellyfish depends on the morphology of the species. For example, oblate jellyfish appear to generate wide vortex structures near the bell margin. The vortex structures affect both the propulsion system and the feeding structure because the swimming and prey capturing activities are interrelated processes in these taxa. A three-dimensional computational model was established for an oblate jellyfish to analyse how the vortex structures present in the wake affect the swimming mechanism and the propulsion efficiency, which is defined as the ratio of power output (thrust multiplied by centre velocity) to power input (energy rate required for bell contraction). An improved penalty immersed boundary method was adopted to consider the interactions between the swimming jellyfish and the ambient fluid. The vortex structures in the wake of the swimming jellyfish were investigated in detail. The vortices generated by the contraction and expansion of the jellyfish bell interact with the vortex structures generated by the forward-moving behaviour of the jellyfish. The resulting vortex structures not only transfer momentum to the swimming jellyfish via the fluid, thereby providing the main source of thrust, but also have an implication for feeding. The effects of the elastic properties of the jellyfish on the propulsion were examined. The propulsion efficiency reaches its optimum value at particular elastic properties. We also investigated the effect of the swimming pattern of jellyfish on the propulsion efficiency. The efficiency increases with the flapping frequency and force duration.
Structure of Odd-N Superheavy Elements

Structure of the odd-N superheavy elements with Z ≲ 118 and N ≲ 175 is investigated using the self-consistent Skyrme-Hartree-Fock-Bogoliubov method with pairing. Microscopic analysis of one-quasiparticle neutron states, alpha-decay energies, and deformations is performed. Good agreement was obtained with the recently reported α-decay chains of 289114 and 293118. © 1999 The American Physical Society.
Depolarisation due to snow at 11.6 GHz

Depolarisation events due to snow covering a period of three years on an 11.6 GHz, 18 km link employing linear and circular polarisation are presented. These are used to demonstrate the variability of wet and dry hydrometeor scattering. By deriving the equivalent differential phase-shift from the measurements it is possible to show the relative importance of differential phase and amplitude effects in depolarisation for the different hydrometeors.
Abell 1451 and 1RXS J131423.6-251521: A multi-wavelength study of two dynamically perturbed clusters of galaxies

We present results from optical, X-ray and radio observations of two X-ray bright ($L_{\rm X} \sim 10^{45}$ erg s -1 ) galaxy clusters. Abell 1451 is at redshift $z=0.1989$ and has line-of-sight velocity dispersion $\sigma_{\rm v} = 1330$ km s -1 as measured from 57 cluster galaxies. It has regular X-ray emission without signs of substructure, a Gaussian velocity distribution, lack of a cooling flow region and significant deviations from the observed scaling laws between luminosity, temperature and velocity dispersion, indicating a possible merging shock. There is only one spectroscopically confirmed cluster radio galaxy, which is close to the X-ray peak. 1RXS J131423.6-251521 (for short RXJ1314-25) has $z=0.2474$ and $\sigma_{\rm v} = 1100$ km s -1 from 37 galaxies. There are two distinct galaxy groups with a projected separation of ≈ 700 kpc. The velocity histogram is bi-modal with a redshift-space separation of ~1700 km s -1 , and the X-ray emission is double peaked. Although there are no spectroscopically confirmed cluster radio galaxies, we have identified a plausible relic source candidate.
Cyclic Subgroup Separability of Generalized Free Products

Abstract We derive a criterion for a generalized free product of groups to be cyclic subgroup separable. We see that most of the known results for cyclic subgroup separability are covered by this criterion, and we apply the criterion to polygonal products of groups. We show that a polygonal product of finitely generated abelian groups, amalgamating cyclic subgroups, is cyclic subgroup separable.
Stratospheric Influences on Tropospheric Weather Systems

Abstract Four cases of tropospheric weather systems (two sea level cyclones, one sea level anticyclone, and one blocking midtropospheric anticyclone) are investigated with the goal of understanding the role of stratospheric versus tropospheric processes in their developments. The relative contributions of the stratosphere and troposphere to geopotential height tendency fields (1000 mb for the sea level systems, 500 mb for the midtropospheric system) are quantified through vertical integration of thermodynamic processes (advective, adiabatic, and diabatic) over and following tendency centers associated with these systems. Previously known or suspected tropospheric contributions to system development, as well as the influence of stratospheric warm-air advection in the sea level cyclogenesis cases, are confirmed by the diagnoses. New findings include identification of the influence of stratospheric adiabatic cooling in the sea level and midtropospheric anticyclogenesis cases. It is further found that the str.
THE FREQUENCY OF SPECTROSCOPIC BINARIES

differed by more than 20 km/sec. The results gave 20 percent for all main-sequence stars and somewhat less for giants and supergiants. Petrie (1960) discussed the percentage of the spectroscopic binaries from another point of view and reached different conclusions. He considered three groups, of about 500 stars each, of B, A, and F5-M objects for which at least three individual radial velocities existed. He established then the observed dispersion of the individual velocities and subtracted from this the distribution of