Miracle-dz/UniFAR-FTUs huggingface dataset:
Acoustical Reflection and Scattering from the Underside of Laboratory-Grown Sea Ice: Measurements and Predictions (Abstract)

We have studied acoustical reflection and scattering properties of the underside of laboratory-grown sea ice. Our purpose was to determine the morphologic characteristics of undeformed sea ice that control acoustic scattering and reflection. So our experiments included both detailed studies of the structure of the ice as well as the application of a variety of acoustic methods. Ice sheets were grown in an outdoor pond (about 6 m by 13 m by 1.5 m) and exhibited features characteristic of undeformed, cold sea ice: an upper granular zone; a columnar zone of crystals with cross-sectional areas of about 1 cm2; vertical sheets of brine pockets; a bulk salinity of 9.1‰ distributed over 9 cm of ice; a dendritic interface at the ice/water boundary with dendrites about 0.5 mm across at the time of our measurements. Echo-amplitude fluctuations of normal-incidence sonar pings (100 kHz to 800 kHz) were measured as the sonars moved horizontally under the ice and accumulated into echo-amplitude histograms. (Data from a deteriorating ice sheet as well as data on lake ice were also collected.) We fitted the Rice probability density function (PDF) to the data and combined the resultant statistical parameter with Eckart acoustic scattering theory. The reflection coefficients calculated using this method ranged from 0.06 to 0.12, depending on environmental conditions. RMS roughness calculated using data from new sea ice was estimated to be about 0.3 mm. Because our ice thin sections show the ice to be porous and permeable at the interface with dendrites 0.5 mm thick, we suspect that the dendrites control the scattering as described by the echo-amplitude histograms. Further, we attribute the low reflection coefficients to the dendritic structure which may act as an impedance-matching zone into the columnar section of the sea ice. Transmission measurements were performed by positioning a transducer located at the ice/air interface directly over the transducer located in the water. The total attenuation through 18 cm of ice ranged from 12 dB at 50 kHz to 70 dB at 420 kHz (signal levels were measured relative to the same path in water).
VLBI Observations of the Gigahertz-Peaked Spectrum Galaxy PKS 1934−638

We present 8.4 GHz VLBI observations of the gigahertz-peaked spectrum source PKS 1934-638 made with the Australian Long Baseline Array. Our observations confirm the compact double nature of the source and yield measured separations of 42.7 ± 0.4 mas at epoch 2002 July and 42.6 ± 0.3 mas at epoch 2002 November, which, when combined with previous observations, yield a rate of separation of 23 ± 10 μas yr-1. This result suggests that over a timescale of 32.1 yr, the separation of the two components has changed marginally. Nominally, this provides support to the emerging consensus that compact symmetric objects (CSOs) are young sources. Our measurement of hot spot separation has, to our knowledge, the longest temporal coverage for a CSO reported in the literature.
ROSAT PSPC Observations of Cool Rich Clusters

We present the results of ROSAT PSPC observations of three cool (kT ⩽ 3 keV) Abell clusters of galaxies (A262, A539, and A2589). Spatially resolved X-ray spectroscopy shows that the gas in these clusters is essentially isothermal beyond the central cooling flow region. The PSPC spectra of A262 also show excess soft X-ray absorption above that expected from the galactic hydrogen column density. The excess absorption is not confined to the central cooling flow region but is distributed across the entire field of view with a slight increase in absorption at large radii. We show that this excess absorption coincides with a region of galactic cirrus observed by IRAS. Using the 100 μm flux density toward A262, we derive a column density of molecular gas that is comparable to the column density of atomic gas and can account for the excess absorption. The spatial distribution of the molecular gas is also consistent with the observed variation in soft X-ray absorption across the PSPC field of view. Using the observed density and temperature profiles of the hot gas in these clusters, we determine their gravitating masses from the equation of hydrostatic equilibrium. The anisotropy parameter of the member galaxies is then calculated from the observed line-of-sight velocity dispersion and the X-ray—determined mass. For A262, we find that the early-type galaxies are virialized with a nearly isotropic velocity dispersion, while most of the spiral galaxies cannot be virialized for any value of the anisotropy parameter. There is also a strong alignment between the optical isophotes of the central dominant galaxy, the cluster X-ray isophotes in both A262 and A2589, and the large-scale orientation of the host supercluster. These results are consistent with a formation scenario in which clusters form through the accretion of gas and galaxies along large-scale filaments. We also calculate the entropy profile of the hot gas for a sample of groups, cool clusters, and hot clusters. We find that the gas entropy in cool clusters increases very gradually with radius while rich clusters show a much steeper gradient. The entropy of the core gas (beyond the cooling flow region) is essentially a constant in groups and rich clusters. These results suggest that the diffuse gas in groups and clusters was preheated before, or during, gravitational collapse. The marginal radial increase in the gas entropy in groups indicates that gravitational heating was almost negligible and the gas passed through weak shocks only as it was accreted. The steeper entropy gradient in rich clusters is consistent with the stronger shock heating expected in more massive systems.
Language and the experience of learning university physics in Sweden

This qualitative study explores the relationship between the lecturing language (English or Swedish) and the related learning experiences of 22 undergraduate physics students at two Swedish universities. Students attended lectures in both English and Swedish as part of their regular undergraduate programme. These lectures were videotaped and students were then interviewed about their learning experiences using selected excerpts of the video in a process of stimulated recall. The study finds that although the students initially report no difference in their experience of learning physics when taught in Swedish or English, there are in fact some important differences which become apparent during stimulated recall. The pedagogical implications of these differences are discussed.
Noun distribution in natural languages

Abstract Previous research on word class distribution claimed that 37% of word tokens are nouns, suggesting that there might exist a certain regularity of noun proportion among human languages. To explore this possibility, we examined the proportion of noun and four other word classes within British and American English, and across seven languages in terms of different word frequency band. Results indicated that the noun proportion is evidently about or larger than 37%, and meanwhile increases with word rarity. Among frequent words, nouns increase as minor word classes decrease, whereas among rare words, the noun proportion remains a stable level.
The rate of convergence in ergodic theorems

Contents Introduction 0.1. Notation 0.2. On uniform estimates 0.3. Brief description of new results Chapter I. Rate of convergence in the pointwise ergodic theorem § 1. Growth of the dispersion 1.1. Spectral measures and power-function growth of dispersion 1.2. Proof of Theorem 3 1.3. Correlation coefficients and dispersion growth § 2. Decay of the probability of an e-deviation 2.1. The case of independent 2.2. Decay of and growth of 2.3. On the rate of approximation of by functions cohomologous to zero 2.4. Proofs of Theorems 11 and 12 § 3. On the law of the iterated logarithm 3.1. The growth of and the law of the iterated logarithm § 4. On uniform convergence 4.1. The fastest uniform convergence 4.2. Two criteria for weak mixing Chapter II. Oscillation of averages in the pointwise ergodic theorem § 5. Crossings of an interval § 6. e-fluctuations § 7. p-variation Chapter III. Rate of convergence and oscillations in other ergodic theorems § 8. Rate of convergence § 9. Oscillations Appendix 1. Interpretation in terms of non-standard analysis A1.1. The theory of internal sets A1.2. Elementary analogues of ergodic theorems Appendix 2. Estimates of large deviations of the random number of fluctuations of averages for independent terms A2.1. Formulation of the basic result A2.2. Outline of the proof of Theorem 33 Appendix 3. Fluctuations of bounded martingales Bibliography
THE RELATION BETWEEN GALAXY MORPHOLOGY AND ENVIRONMENT IN THE LOCAL UNIVERSE: AN RC3-SDSS PICTURE

We present results of an analysis of the local (z ∼ 0) morphology–environment relation for 911 bright (MB < −19) galaxies, based on matching classical RC3 morphologies with the Sloan Digital Sky Survey based group catalog of Yang et al., which includes halo mass estimates. This allows us to study how the relative fractions of spirals, lenticulars, and ellipticals depend on halo mass over a range of 1011.7–1014.8 h−1 M☉, from isolated single-galaxy halos to massive groups and low-mass clusters. We pay particular attention to how morphology relates to central versus satellite status (where “central” galaxies are the most massive within their halo). The fraction of galaxies which are elliptical is a strong function of stellar mass; it is also a strong function of halo mass, but only for central galaxies. We interpret this as evidence for a scenario where elliptical galaxies are always formed, probably via mergers, as central galaxies within their halos, with satellite ellipticals being previously central galaxies accreted onto a larger halo. The overall fraction of galaxies which are S0 increases strongly with halo mass, from ∼10% to ∼70%. Here, too, we find striking differences between the central and satellite populations. 20% ± 2% of central galaxies with stellar masses M* > 1010.5 M☉ are S0 regardless of halo mass, but satellite S0 galaxies are only found in massive (>1013 h−1 M☉) halos, where they are 69% ± 4% of the M* > 1010.5 M☉ satellite population. This suggests two channels for forming S0 galaxies: one which operates for central galaxies and another which transforms lower-mass ( M* ≲ 1011 M☉) accreted spirals into satellite S0 galaxies in massive halos. Analysis of finer morphological structure (bars and rings in disk galaxies) shows some trends with stellar mass, but none with halo mass; this is consistent with other recent studies which indicate that bars are not strongly influenced by galaxy environment. Radio sources in high-mass central galaxies are common, similarly so for elliptical and S0 galaxies, with a frequency that increases with the halo mass. Emission-line active galactic nuclei (mostly LINERs) are more common in S0s, but show no strong trends with environment.
Characterization of very fast states in the vicinity of the conduction band edge at the SiO2/SiC interface by low temperature conductance measurements

We have investigated the unique interface states (NI) generated by NO annealing at the SiO2/SiC interfaces by low-temperature conductance measurements, which is more suitable for characterization of very fast interface states than high-frequency conductance measurements at room temperature. Although only a part of the NI states can be evaluated by measurements at room temperature, the whole picture of the NI states, especially near the conduction band edge (0.07 eV ≤ EC−ET), has been revealed by the low temperature measurements. The NI peak was present at the interface even without NO annealing. The NI density increased with NO annealing temperature. The NI density at the energy levels shallower than 0.2 eV exceeded 1012 cm−2eV−1 after NO annealing. The capture cross section of the NI states is uniquely larger than that of conventional interface states.
Let-causatives and (a)symmetric DAT-NOM constructions.

Abstract in Undetermined The verb lata ‘let/make’ in Icelandic provides a unique opportunity to understand the behavior symmetric versus asymmetric DAT-NOM constructions, as well as the nature of nominative-accusative case alternations. In this paper, we take a close look at lata and examine a set of cases where DAT-NOM verbs are embedded under lata, resulting in the otherwise nominative object becoming accusative in some cases and remaining nominative in others.
Collective Phenomena in Active Systems

This dissertation investigates collective phenomena in active systems of biological relavance across length scales, ranging from intracellular actin systems to bird flocks. The study has been conducted via theoretical modeling and computer simulations using tools from soft condensed matter physics and non-equilibrium statistical mechanics. The work has been organized into two parts through five chapters. In part one (chapter 2 to 3), continuum theories have been utilized to study pattern formation in bacteria suspensions, actomyosin systems and bird flocks, whose dynamics is described generically within the framework of polar active fluids. The continuum field equations have been written down phenomenogically and derived rigorously through explicit coarse-graining of corresponding microscopic equations of motion. We have investigated the e↵ects of alignment interaction, active motility, non-conserved density, and rotational inertia on pattern formation in active systems. In part two (chapter 4 to 5), computer simulations have been performed to study the self-organization and mechanical properties of dense active systems. A minimal self-propelled particle (SPP) model has been utilized to understand the aggregation and segregation of active systems under confinement (Chapter 4), where an active pressure has been defined for the first time to characterize the mechanical state of the active system. The same model is utilized in Chapter 5 to understand the self-assembly of passive particles in an active bath. Collective Phenomena in Active Systems by Xingbo Yang B.A., Fudan University, 2010 Dissertation Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Physics in the graduate school of Syracuse University August 2015 © 2015 Xingbo Yang All Rights Reserved!
A Fourier transformation for Higgs bundles

Abstract We define and investigate a Fourier-Mukai transformation for Higgs bundles on smooth curves. It can be viewed as the purely algebro-geometric or holomorphic side of a Nahm-type transformation for Higgs bundles. The transform of a stable degree-0 Higgs bundle is an algebraic vector bundle on the cotangent bundle of the Jacobian of the curve; we show that it admits a natural extension to an algebraic vector bundle over a projective compactification of the base. The main result is that the original Higgs bundle can be recovered from this extension.
Effect of 1/f-type FM noise on semiconductor-laser linewidth residual in high-power limit

The FM-noise spectrum and the linewidth of 1.3 mu m DFB (distributed feedback) semiconductor lasers measured in the high-power state up to 20 mW are discussed. A 5-MHz residual linewidth is observed in the high-power limit. The FM-noise spectrum consists of white noise and 1/f noise. The spectral density of the white noise is reduced by the increase in the output power, whereas that of the 1/f noise is unchanged, which means that the linewidth residual in the high-power limit is caused by the 1/f noise rather than the white noise. The impact of the 1/f-type FM noise on coherent optical communication systems is also discussed. >
Design and performances of the Shack-Hartmann sensor within the Active Phasing Experiment

The Shack-Hartmann Phasing Sensor (SHAPS) has been integrated in the Active Phasing Experiment (APE) at ESO. It is currently under test in the laboratory. The tests on sky are foreseen for the end of 2008, when APE will be mounted at the Nasmyth focus of one of the VLT unit telescopes. SHAPS is based on the Shack-Hartmann principle: the lenslet array is located in a plane which is optically conjugated to the Active Segmented Mirror (ASM) of APE and is composed of two types of microlenses, circular and cylindrical, which give information about the wavefront slope and the piston steps, respectively. This proceeding contains a description of SHAPS and of the algorithms implemented for the wavefront reconstruction and for the phasing. The preliminary results obtained during the laboratory tests are discussed and compared with the theoretical predictions. The performances of SHAPS at the VLT and at the European Extremely Large Telescope (E-ELT) are estimated.
First variation of anisotropic energies and crystalline mean curvature of partitions

We rigorously derive the notion of crystalline mean curvature of an anisotropic partition with no restriction on the space dimension. Our results cover the case of crystalline networks in two dimensions, polyhedral partitions in three dimensions, and generic anisotropic partitions for smooth anisotropies. The natural equilibrium conditions on the singular set of the partition are derived. We discuss several examples in two dimensions (also for two adjacent triple junctions) and one example in three dimensions when the Wulff shape is the unit cube. In the examples we also analyze the stability of the partitions.
Pilot study of simulated spaciousness

Spaciousness is said to include the sense that the sound in a concert hall is enveloping, that the apparent source width is increased, and the general feeling of being in a room or space. Strong early lateral reflections are generally accepted as essential for adequate spaciousness. The influence of other factors such as the level and the spectrum of the sound is not so well understood. This paper reports the results of initial subjective evaluations of simulated sound fields with varied early lateral reflections. Using paired comparison tests, judgments of the apparent source width were found to be well correlated with two types of objective measures (LF and IACC). As reported in earlier studies, louder sounds were judged to be more spacious and lower frequencies also led to greater apparent source width. [Work partially supported by the Natural Sciences and Engineering Research Council of Canada. ]
Moment invariants for the Vlasov equation

Moment invariants [functions of the moments of a Vlasov distribution that are invariant under Sp(6)] are classified using Young diagrams. The connection between the moment invariants and the Poincare invariants is established. An application using the moment invariants as phase space coordinates is considered for a matching section in a particle‐beam accelerator, and a Lie–Poisson numerical integration algorithm for the moment dynamics is proposed.
Evaluation of systemic Omega-3 PUFAs effect on orthodontic tooth movement in a rabbit model: RCT.

OBJECTIVES To evaluate the effect of systemic administration of omega-3 fatty acids on orthodontic tooth movement (OTM) with histological analysis. MATERIALS AND METHODS OTM was induced in 20 adult albino New Zealand rabbits, divided into omega-3 and control groups, with nickel-titanium coil springs for 21 days. Omega-3 or saline was given every day via oral gavage during the experimental period. Animals were sacrificed for histomorphometric analysis of alveolar bone remodeling after 21 days of OTM. RESULTS A significant difference in OTM amount was found in the third week of OTM with means of 1.445 ± 0.13 and 1.72 ± 0.15 for the experimental and control groups, respectively. Histomorphometric analysis showed a significant reduction in the area of active bone-resorptive lacunae and a significant increase in osteoblastic activity in the omega-3 group after 3 weeks. CONCLUSIONS Strong evidence of the osteoclastic inhibitory effect of systemic omega-3 was found, which reduced the percentage and amount of OTM.
A probability model-based level set method for biomedical image segmentation

Level set methods are useful tools for medical image segmentation. In this paper, a novel image segmentation technique was developed that combines region statistical information with the level set method. The classical level set methods depend mainly on local edge-based image features to guide the convergence of the contour. This makes the method sensitive to noise and the initial estimate. The method has two features. The first is that it uses obtain region-based information by a mixture model. The second feature is that we combine region statistical information with curvature-based regularization penalizing the length of curve. The method is useful for a large variety of segmentation problems. We present some preliminary experimental results using synthetic images and, magnetic resonance (MR), ultrasound (US), computed tomography (CT) images to demonstrate our methods. The experimental results show that by incorporating region statistical information into the level set framework, an accurate and robust segmentation can be achieved.
Warehouse sizing to minimize inventory and storage costs

This paper considers a warehouse sizing problem whose objective is to minimize the total cost of ordering, holding, and warehousing of inventory. Unlike typical economic lot sizing models, the warehousing cost structure examined here is not the simple unit rate type, but rather a more realistic step function of the warehouse space to be acquired. In the cases when only one type of stock‐keeping unit (SKU) is warehoused, or when multiple SKUs are warehoused, but, with separable inventory costs, closed form solutions are obtained for the optimal warehouse size. For the case of multi‐SKUs with joint inventory replenishment cost, a heuristic with a provable performance bound of 94% is provided. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48: 299–312, 2001
Explanations for the cause of shear thickening in concentrated colloidal suspensions

In contrast to recent publications suggesting that particle cluster formation alone can play an important role in the shear thickening flow behavior of concentrated colloidal suspensions, we believe that there is little if any substantive evidence to prove it. To support this view, we use data from various studies, including data from studies concluding that layered flow is not involved. One reason for the confusion seems to center around the inability of various light-scattering and neutron-scattering techniques to show particle layering before shear thickening when the layers are not well defined. In this regard, one should understand that layered flow can occur without rigorous ordering of particles within the layers, and as the flowing suspension approaches the point of instability, the hydrodynamic forces driving for the instability will jostle the particles within the layers sufficiently to make it even harder to see the layering and any ordering, if it exists, within the layers. Having these views,.
Inboard boundary layer state on wind turbine blades

The paper is aimed at describing a fundamental phenomenon: the effect of rotation on the inboard blade boundary layer of a wind turbine. The three‐dimensional incompressible steady momentum integral boundary layer equations coupled with the entrainment equation are used to analyze the inboard stall‐delay due to rotation. Turbulence is modeled by using empirical correlations for the entrainment coefficient and the streamwise skin‐friction coefficient. A power‐law type of velocity profile is assumed for the streamwise turbulent velocity profiles and for cross‐flow velocity profiles the Mager parabolic model is used. The equations are written in cylindrical coordinates and are solved iteratively using a Runge–Kutta scheme. Special attention has been devoted to those term in the differential equations that change the boundary‐layer structure from that of two‐dimensional steady flow. It is concluded that the stall is delayed due to the boundary‐layer reattachment at the inboard sections in conjunction with forming of a spanwise standing vortex structure.