Miracle-dz/UniFAR-FTUs huggingface dataset:
Axisymmetric gravity currents at high Reynolds number: On the quality of shallow-water modeling of experimental observations

The motion of an axisymmetric gravity current that is released from a lock and then propagates over a horizontal boundary is considered. Attention is focused on the interpretation of the experimentally observed propagation (for Boussinesq systems at high Reynolds number) by means of the shallow-water inviscid model. Comparisons of the theoretical one-layer model results with previously published measurements of M. A. Hallworth, H. E. Huppert, and M. Ungarish [J. Fluid Mech. 447, 1 (2001)] and M. D. Patterson, J. E. Simpson, S. B. Dalziel, and G. J. F. van Heijst [Phys. Fluids 18, 046601 (2006)] prove that the model provides reliable insights and fairly accurate predictions (sometimes even better than obtained by full Navier-Stokes simulations) of distance of propagation and shape of interface, except for a very short initial phase. The limit of validity of the inviscid approximation is calculated, and it is shown that the above-mentioned experiments are within it. Some apparent discrepancies and scatter o.
Characteristics of CALIPSO and CloudSat Backscatter at the Top Center Layers of Mesoscale Convective Systems and Relation to Cloud Microphysics

Abstract Following the discovery of anomalously high values of lidar integrated attenuated backscatter near the top center layers of mesoscale convective systems (MCSs) observed by the NASA Lidar In-Space Technology Experiment (LITE), a search of Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP) data on board the Cloud Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) platform revealed the same phenomena in a sample of eight MCSs investigated. The backscatter depolarization ratio also showed changes concurrent with the high integrated backscatter and either increased or decreased concurrently with the anomalous backscatter. Simultaneous CloudSat data in the A-Train formation showed a cloud-top altitude similar to that measured by CALIOP, indicating fairly large ice crystals were reaching cloud top. Based on previous work, the CALIOP and CloudSat returns were likely due to a mix of small ice droxtals or frozen drops extending in a continuous spectrum to large crystals composed o.
Bibliography of Photon Total Cross Section (Attenuation Coefficient) Measurements 10 eV to 13.5 GeV, 1907-1993

A bibliography is presented of papers reporting absolute measurements of photon (XUV, x-ray, gamma-ray, bremsstrahlung) total interaction cross sections or attenuation coefficients for the elements and some compounds. The energy range covered is from 10 eV to above 10 GeV. These papers are part of the reference collection of the National Institute of Standards and Technology Photon and Charged Particle Data Center. They cover the period from 1907 through 1993 and into 1994. Thus this report is an update of the 1986 earlier report NBSIR 86-3461, and also includes additional papers dating back as far as 1966 which have since been found or brought to the attention of the author. Included with each reference are annotations specifying the energy range covered and the substances studied. This updated bibliography now includes 573 non-duplicative references to available measured data, plus 42 references to critical evaluations and review articles.
Prescribed performance fuzzy adaptive fault-tolerant control of non-linear systems with actuator faults

This study investigates the adaptive fuzzy fault-tolerant control (FTC) problem for a class of uncertain non-linear strict-feedback systems with unmeasured states. The considered non-linear systems contain unknown continuous functions and do not satisfy the matching condition. The actuator failures under study are types of both abrupt faults and lock-in-place and loss of effectiveness. The fuzzy logic systems are employed to approximate the unknown continuous functions, and a fuzzy state observer is developed and the unmeasured states are obtained. Under the framework of the backstepping design technique and incorporated by the dynamic surface control approach and predefined performance bounds, an adaptive fuzzy FTC method has been presented. From the Lyapunov stability analysis, it is shown that all the signals of the resulting closed-loop system are bounded and the tracking error surfaces remain within the prescribed performance bounds in the presence of unknown non-linear actuator faults. The simulation results and comparisons with the previous methods indicate the effectiveness of the proposed adaptive fuzzy FTC.
Improved wavefront reconstruction algorithm for Shack–Hartmann type wavefront sensors

In the present work, we propose an improved wavefront reconstruction algorithm for zonal wavefront estimation using Shack–Hartmann type wavefront sensors. We start with the well known W H Southwell reconstruction algorithm, where phase at a central point is described in terms of horizontal and vertical slope values. We develop the mathematical expressions to show that by incorporating the diagonal slope values in addition to the horizontal and vertical slope values, accuracy in phase estimation can be increased. We present here experimental results that demonstrate significant improvement in the wavefronts, estimated using the proposed algorithm, in comparison to the Southwell algorithm.
Statistical Properties of Rain Cells in the Padana Valley

Abstract A large collection of radar reflectivity maps gathered from 1988 to 1992 at the Spino d’Adda experimental station, located in the Padana Valley, has been exploited to investigate the statistical properties of rain structures and their descriptors. The results of this analysis can be of interest for meteorological, hydrological, and telecommunication applications. The authors found that the isosuperficial diameter follows an exponential distribution; when the threshold of rain intensity is increased, disappearance is dominant over fragmentation; moreover, the number of “mother cells” that generate N “daughter cells” decreases exponentially with N. To give a complete but concise characterization of the geometrical, physical, and morphological properties of rain cells, a set of analytical descriptors has been introduced and statistically defined through their probability density functions and the centrality, dispersion, and excursion parameters. As a final point, comparative statistical analyses hav.
The evolution of refractory interstellar grains in the solar neighborhood

The abundance of thermally condensed refractory grains and corresponding interstellar metal depletions are investigated using models for the evolution of the solar neighborhood. The calculations include a self-consistent treatment of red giant winds; planetary nebulae; protostellar nebulae and supernovae as sources of grains; star formation and encounters with supernova blast waves as sinks, for a variety of birthrate histories; chemical evolution models; and mass-loss parameters. We find that the maximum possible fraction of an element that can be locked up in thermally condensed cores is about 60% for the highly refractory elements like Ca, Al, and Ti, and about 30% for the more abundant refractory elements like Si, Mg, Mn, and Fe, independent of model parameters. Typically observed interstellar depletions (approx.10--10/sup 3/) and their elemental variations can therefore not be interpreted in terms of condensation efficiencies in the sources, and must instead be attributed to the selective growth of mantles in interstellar clouds. The strong upper limit on the abundance of thermally condensed grains yields constraints on the nature and composition of interstellar grains and the filling factor of the interstellar coronal gas. The relative importance of various condensation sites is also discussed, and we find that any interstellar grainmore » model that requires the depletion of any element in thermally condensed grains to be larger than approx.1. 2 must require the formation of grains in supernovae. « less
Driving Electric Field Effects on Piezoelectric Transducers

Electromechanical properties for lead zirconate-titanate Pb(ZrxTi1-x)O3 (PZT) based ceramic and lithium niobate LiNbO3 (LN) crystal piezoelectric transducers were studied from a driving electric field viewpoint. The vibration velocity linearly increases with the driving field for a 128°-rotated Y-cut LN transducer and its maximum vibration velocity which can be used is 2.7 m/s when driven with the driving field of 7 ×102 V/m. The transducer is mechanically broken when driven with a higher field. The vibration velocity for the PZT based ceramic transducer initially increases with an increasing field and then gradually converges onto a certain value accompanied by heat generation. These phenomena are caused by the decrease in the mechanical quality factor with an increasing field. The 0.45PbZrO3–0.45PbTiO3–0.10Pb(Mn1/3Sb2/3)O3 ceramic transducer is capable of generating 0.68 m/s with 5.5 ×103 V/m.
The subluminous spectroscopically peculiar type Ia supernova 1991bg in the elliptical galaxy NGC 4374

We present photometric and spectroscopic observations of SN 1991bg, a very peculiar Type Ia supernova located in the outskirts of the E1 galaxy NGC 4374 (M84) in the Virgo cluster. At maximum brightness SN 1991bg was 1.6 mag subluminous in V and 2.5 mag subluminous in B, compared with normal SNe Ia. The colors were unusually red, but the object was not significantly reddened by dust. The decline from maximum was certainly quite steep; we measure an initial linear V fading of 0.10 mag/d rather than the typical value of 0.06 mag/d for SNe Ia, and a late-time decline of 0.034 mag/d rather than 0.026 mag/d
On the secular instability of axisymmetric rotating stars to gravitational radiation reaction

A generalization of the Eulerian variational principle derived by Ipser and Managan, for nonaxisymmetric neutral modes of axisymmetric fluid configurations, is developed. The principle provides a variational basis for calculating the frequencies of nonaxisymmetric normal modes proportional to e/sup i/(sigmat + mphi). A modified form of this principle, valid for sigma near 0, is also developed. The latter principle is used to locate the points where the frequency of a nonaxisymmetric normal mode of an axisymmetric rotating fluid configuration passes through zero. lt is at these points that the configuration becomes secularly unstable to gravitational radiation reaction (GRR). This is demonstrated directly by including the GRR potential and showing that the imaginary part of sigma passes through zero and becomes negative at these points. The imaginary part of the frequency is used to estimate the e-folding time of the mode. This variational principle is applied to sequences of rotating polytropes. The sequences are constructed using four rotation laws at each value of the polytropic index n = 0.5, 1.0, 1.5, 2.0, and 3.0. The values of (T/W)/sub m/, the ratio of the rotational kinetic energy to the magnitude of the gravitational potential energy at the onset of instability, and timescalesmore » for the modes with m = 2, 3, and 4 are estimated for each sequence. The value of (T/W)/sub 2/ is largely independent of the equation of state and rotation law. For m > 2, (T/W)/sub m/ decreases as the equation of state becomes softer, i.e., as the polytropic index n increases, and increases as the amount of differential rotation increases. The most striking result of this behavior occurs for uniform rotation. « less
Intracellular Peptides in Cell Biology and Pharmacology

Intracellular peptides are produced by proteasomes following degradation of nuclear, cytosolic, and mitochondrial proteins, and can be further processed by additional peptidases generating a larger pool of peptides within cells. Thousands of intracellular peptides have been sequenced in plants, yeast, zebrafish, rodents, and in human cells and tissues. Relative levels of intracellular peptides undergo changes in human diseases and also when cells are stimulated, corroborating their biological function. However, only a few intracellular peptides have been pharmacologically characterized and their biological significance and mechanism of action remains elusive. Here, some historical and general aspects on intracellular peptides’ biology and pharmacology are presented. Hemopressin and Pep19 are examples of intracellular peptides pharmacologically characterized as inverse agonists to cannabinoid type 1 G-protein coupled receptors (CB1R), and hemopressin fragment NFKF is shown herein to attenuate the symptoms of pilocarpine-induced epileptic seizures. Intracellular peptides EL28 (derived from proteasome 26S protease regulatory subunit 4; Rpt2), PepH (derived from Histone H2B type 1-H), and Pep5 (derived from G1/S-specific cyclin D2) are examples of peptides that function intracellularly. Intracellular peptides are suggested as biological functional molecules, and are also promising prototypes for new drug development.
Broad-band properties of the CfA Seyfert Galaxies. II - Infrared to millimeter properties

IR and mm observations of the 48 Seyfert 1 and 2 galaxies (SG1s and SG2s) of the CfA sample (Huchra and Berg, 1987) are reported. Data obtained (1) in the NIR using the 1.55-m reflector at Stewart Observatory and the 3-m IRTF during 1984-1986, (2) in the FIR with IRAS, and (3) at 1.3 mm using the 12-m NRAO telescope at KPNO in June 1984 are presented in extensive tables and graphs and characterized in detail. None of the objects was detected at 1.3 mm, and the IR spectra of the SG2s are found to be significantly steeper (indicating thermal emission) than those of SG1s and QSOs (nonthermal emission). Turnover in the IR emission below 100 microns (in half of the objects detected at three or more IRAS wavelengths) is shown to be consistent with an accretion disk in dust-free SG1s and with unusually warm (35-65 K) dust in SG2s. It is inferred that a 60-100-micron cool excess is masking turnover in the other SGs, so that a general association of SG nuclei with strong star formation can be confirmed.
A new construction of (t, s)-sequences and some improved bounds on their quality parameter

where the supremum is extended over all subintervals J of [0, 1]s with one vertex at the origin. For a sequence S of points x1, x2, . in [0, 1] s, the star discrepancy of the first N terms of S is defined as D∗ N (S) = D ∗ N (x1, . . . , xN ). We say that S is a low-discrepancy sequence if D N (S) = O(N (logN)) for all N ≥ 2. This is conjectured to be the least possible order of magnitude of the star discrepancy that can be obtained, and the conjecture has been proved for s = 1 by Schmidt [21] (see also [8, Section 2.2]). Currently, the most powerful methods of constructing low-discrepancy sequences are built on the theory of (t, s)-sequences which was developed by Niederreiter [11] on the basis of earlier work by Sobol’ [24] and Faure [3]. We refer to the monographs [13, Chapter 4] and [20, Chapter 8] as well as to the recent survey article [14] for general background on this theory. The fact that, for any integers s ≥ 1 and b ≥ 2, there exists a (t, s)-sequence in base b for some integer t ≥ 0 was first shown by Niederreiter [12]. The star discrepancy of a (t, s)-sequence S in base b satisfies the following bound (see [11] and [13, Chapter 4]): D N (S) ≤ Cb(s, t)N (logN) +O(N(logN)) for all N ≥ 2,
Spatial structure of the interstellar gas toward the globular cluster M22

High-resolution spectra of Na I interstellar lines are presented for 14 stars in the globular cluster M22. The interstellar gas foreground to the cluster at distance about 2.6 kpc occurs essentially in two velocity ranges. There is a low-velocity component which is quite uniform across the cluster. This gas feature is likely to be a part of the extensive and nearby H I cloud first mapped in the radio region. There is also gas at higher velocities detected between +25 and 60 km/s which is observed with both a single- and a multi-component structure. Significant profile variations for this gas occur on a scale less than 1 arcmin. The location of this gas is not known but it may be associated with the Sagittarius arm. Spectra of the K I interstellar line for a nearby star roughly 1.3 deg from the cluster and for two cluster members provide useful estimates for the column densities of the gas components. 20 refs.
Alfvénic turbulence in the polar wind: A statistical study on cross helicity and residual energy variations

A study of MHD turbulence properties in the polar wind has been performed with Ulysses data. The parameters under examination are the normalized cross helicity and the normalized residual energy. The correlation coefficient between velocity and magnetic field fluctuation vectors has also been computed. Both southern and northern phases of full immersion in the high-latitude fast wind have been examined. Observations during the short low-latitude phase around the Ulysses perihelion have been used as a term of comparison. Our results indicate that in the region up to about 2 AU the turbulence evolution leads to a decrease of cross helicity and Alfvenic correlation when distance increases. Farther out no appreciable variation is observed. It is concluded that in the high-latitude heliosphere the MHD turbulence maintains a clear Alfvenic character even at large distances. As regards the residual energy, a clear imbalance in favor of the magnetic fluctuations is everywhere present. This imbalance becomes even more pronounced for increasing distance inside 2 AU, due to turbulence evolution. Other effects lead to an inversion of this trend in the outer region. It is noteworthy that the polar turbulence does not appear too different from that observed inside the trailing edge of low-latitude fast streams.
X-ray-heated models of stellar flare atmospheres - Theory and comparison with observations

A sequence of five model atmospheres consisting of the photosphere, chromosphere, and transition region is computed. The models represent the response of the gas in a magnetically confined loop to intense flare energy release. It is assumed that the energy release is confined to the corona, and the effects of chromospheric evaporation and indirect heating of the lower atmosphere by X-rays emitted from the coronal plasma are included. Line and continuum surface fluxes are presented in the wavelength range 1000-9000 A and are compared with those observed during a giant flare on the M dwarf star AD Leo
Bioaerosols Play a Major Role in the Nasopharyngeal Microbiota Content in Agricultural Environment

Background: Bioaerosols are a major concern for public health and sampling for exposure assessment purposes is challenging. The nasopharyngeal region could be a potent carrier of long-term bioaerosol exposure agents. This study aimed to evaluate the correlation between nasopharyngeal bacterial flora of swine workers and the swine barns bioaerosol biodiversity. Methods: Air samples from eight swine barns as well as nasopharyngeal swabs from pig workers (n = 25) and from a non-exposed control group (n = 29) were sequenced using 16S rRNA gene high-throughput sequencing. Wastewater treatment plants were used as the industrial, low-dust, non-agricultural environment control to validate the microbial link between the bioaerosol content (air) and the nasopharynxes of workers. Results: A multivariate analysis showed air samples and nasopharyngeal flora of pig workers cluster together, compared to the non-exposed control group. The significance was confirmed with the PERMANOVA statistical test (p-value of 0.0001). Unlike the farm environment, nasopharynx samples from wastewater workers did not cluster with air samples from wastewater treatment plants. The difference in the microbial community of nasopharynx of swine workers and a control group suggest that swine workers are carriers of germs found in bioaerosols. Conclusion: Nasopharynx sampling and microbiota could be used as a proxy of air sampling for exposure assessment studies or for the determination of exposure markers in highly contaminated agricultural environments.
Cohort extensions of the Poisson common factor model for modelling both genders jointly

The earlier work on mortality modelling and forecasting has largely focused on the study of a single population. Recently, there is an emerging strand of literature that emphasises the interrelationship between multiple populations. In this paper, we examine some cohort extensions of the Poisson common factor model for modelling both genders jointly. The cohort effect is specified in six alternatives which are applied to data-sets from five developed regions. We find that direct parameterisation of cohort effect could improve model fitting, reduce the need for additional period factors, and produce consistent mortality forecasts for females and males. Furthermore, we find that the cohort effect appears to be gender indifferent for the populations examined and has an interaction effect with age in certain cases.
The Bernstein-Von Mises theorem for Markov processes

Since the appearance of P. Billingsley's monograph [2] on the large sample inference in Markov processes in which the weak consistency and asymptotic normality of the maximum likelihood estimate was investigated, there has been considerable interest in the further development of the theory along other directions. Billingsley's work was mainly concerned with extending the results of H. Cramer ([4] page 500). Among more recent developments one might mention the proof of the almost sure consistency of the maximum likelihood estimator following the ideas of A. Wald by G. Roussas [7], and the results on asymptotic Bayes estimates obtained by Lorraine Schwartz [9]. In the present paper we extend to Markov processes one of the fundamental results in the asymptotic theory of inference, viz., the approach of the posterior density (in a sense to be made precise later) to the normal. When the observed chance variables are independent and identically distributed, this result was obtained by L. LeCam in [5] (page 309). The same author offers another derivation of this result in [6]. Special cases of the theorem were first given by S. Bernstein and R. von Mises (for reference see [5]). The regularity conditions satisfied by the transition probability density of the Markov process are given in Section 1. We prove in Theorem 2.4 of Section 2 those properties of the maximum likelihood estimator that are needed for the proof of the main result of the paper given in Section 3 (Theorem 3.1). Theorem 3.1 is stated in a form which is general enough to include the Bernstein-von Mises theorem as well as the somewhat sharper versions that are available when it is known that the prior probability distribution has a finite absolute moment of order m. Theorem 3.2 deduces these results as a consequence of Theorem 3.1. The latter result also enables us to prove a theorem on the asymptotic behavior of regular Bayes estimates. This is done in Theorem 4.1 of Section 4.