Miracle-dz/UniFAR-FTUs huggingface dataset:
Numerical study of self-interaction of Bernstein waves by nonlinear Landau damping

When Bernstein waves (B waves) are excited in a magnetized plasma, their self-interaction by nonlinear Landau damping (NLD) becomes the dominant mechanism for the electron heating of the bulk plasma. We examine this behaviour numerically. This occurs only for B waves with relatively small k∥ because the damping of the B waves becomes very small. This occurs in the relatively broad B-wave frequency range betweenω/ωc = 1.45 and 1.78. For B waves with large k∥ (k∥R > 0.15), virtual waves are not generated via self-interaction due to NLD because the quasi-linear cyclotron damping of the B waves becomes the dominant mechanism. The numerical results agree well with experimental ones.
Cue weighting and vestibular mediation of temporal dynamics in sound localization via head rotation

Our studies have quantified the salience and weighting of dynamic acoustic cues in sound localization via head rotation. Results support three key findings: (1) low-frequency interaural time-difference (ITD) is the dominant dynamic binaural difference cue; (2) when available, high-frequency spectral cues dominate front/rear localization; and (3) the temporal dynamics of dynamic cue processing are particular to auditory-vestibular integration. ITD dominance is shown indirectly in findings that head movements are highly effective for localizing low-frequency targets but not narrow-band high-frequency targets and that only normal low-frequency hearing is required to localize via dynamic cues. Direct evidence comes from manipulation of dynamic binaural cues in spherical-head simulations lacking spectral cues. If the stimulus provides access to dominant high-frequency spectral cues, location illusions involving head-coupled source motion fail. For low-frequency targets, localization performance improves with i.
Energetic Electrons in 3He-Enhanced Solar Energetic Particle Events

Using both the Electron, Proton, and Alpha Monitor and Ultra Low Energy Isotope Spectrometer instruments on board the Advanced Composition Explorer, we investigated from 1997 September to 1999 December a total of 27 3He-rich solar energetic particle (SEP) ion events. The majority of these events (16 out of 27) have a clear association with impulsive injections of energetic electrons (38-53 keV). However, we find that the maximum electron intensity is statistically uncorrelated with the 3He/4He ratio (at 0.4-2.0 MeV nucleon-1). We therefore examined the electron associations in the general class of impulsive 4He ion SEP events over the same time period. The general class is statistically indistinguishable from the 3He-enhanced subclass: 43 out of 97 impulsive 4He ion events were associated with impulsive electron events. The weak correlations between maximum electron intensities and maximum helium intensities (either 3He or 4He) are statistically indistinguishable between the general class of impulsive He events and the special class that was 3He enriched. Consequently, we have found no evidence (at the energies we studied) that the energetic electron population that escapes into interplanetary space is causally involved in the preferential enrichment of 3He. However, this does not rule out the possibility that a separate (nonescaping) population of electrons in the corona participates in the preferential acceleration of 3He.
Spin driving reconstructions on the GaAs(001): Mn surface

The scanning tunneling microscopy (STM) experiment reveals a 2 X 2 surface reconstruction on GaAs(001):Mn. A comprehensive theory for spin-driven reconstructions is developed by the first-principles methods: Mn incorporation results in two structural motifs to accommodate the spin degree of freedom. Low-energy reconstructions are generally antiferromagnetic to preserve the semiconducting band gaps. The gaps, however, decrease with increasing Mn coverage, leading to metallic surfaces. At one-monolayer coverage, the transition is complete. The calculated STM images agree with experiment.
Mapping of strain fields about thin film structures using x-ray microdiffraction

Substrate distortions were mapped near pseudomorphically grown SiGe thin film etched lines of various widths from 1.5 to 20 μm on Si(001) and 190 μm diameter Ni dots on Si(111) using reflection x-ray microdiffraction topography. The strain field extended 30–120 times the thickness of the film away from the feature edge. The profile of the enhanced diffracted intensity was found to follow a characteristic curve when the distance from the feature edge is normalized by a mean interaction distance that depends on the feature size. This normalization and the observed strain decay profiles cannot be predicted or modeled using existing micromechanical models.
Early expansion and luminosity evolution of supernovae

The initial planar expansion of a supernova can be described by a self-similar solution if the progenitor star is sufficiently compact that radiative transfer effects do not play an important role during this phase. The later free expansion of the gas leads to radial power laws for the density and pressure profiles, although the effects of spherical geometry give some inaccuracy in this result. If the initial expansion does set up power laws for the density and pressure, effects of radiative diffusion can be described by a self-similar diffusion wave that moves back into the gas
Multiconfiguration Dirac–Fock calculations of transition probabilities of some tungsten ions

We present a comprehensive theoretical study of atomic characteristics of ten tungsten ions in a broad range of wavelengths, energy levels and transition probabilities. The results of multiconfiguration Dirac–Fock and relativistic configuration interaction calculations including the Breit interaction calculations are presented. The valence–valence, core–valence and core–core corrections are also considered. The calculated values including core–valence correlations were found to be similar and to compare very well with other theoretical and experimental values. We believe that our extensive calculated values can guide experimentalists in identifying the fine-structure levels in their future work.
Spin-Wave Results for the Staggered Magnetization of Triangular Heisenberg Antiferromagnet

The staggered magnetization of the Heisenberg antiferromagnet on triangular lattice is calculated by means of the usual spin-wave theory. The magnetization is derived from the ground-state energy as its derivative with respect to the staggered field, and given in a form of 1/ S expansion, S being the magnitude of spins. The second-lowest correction, a term of O (1/ S ), consists of two contributions; one from the first-order effect of four-boson terms in the Hamiltonian, and another from the second-order perturbation due to a three-boson term. Each contribution diverges when the exchange interaction is isotropic, but the divergent parts of the two contributions are found to cancel, leaving a finite result for the staggered magnetization to this order. Numerical result for the staggered magnetization is S -0.2613+0.0055/ S .
Galaxy populations in galaxy clusters selected by the Sunyaev-Zeldovich Effect

We present a study of the galaxy populations in massive galaxy clusters selected by their Sunyaev–Zel’dovich Effect (SZE) signatures. Selection via the SZE is approximately mass- limited where the mass limit varies only slightly with redshift, making it an ideal selection method for studying the evolution of the galaxy content of clusters. We begin by introducing the SZE, the South Pole Telescope (SPT), and the larger research project in which this Thesis is embedded. We then present the core galaxy population studies of this Thesis. In Chapter 3, we present the first large-scale follow-up of an SZE-selected galaxy cluster sample. Of 224 galaxy cluster candidates in the sample, we optically confirm 158 clusters and measure their photometric redshifts. We find a redshift range of 0.1
DYNAMICAL INTERACTIONS BETWEEN LARGE CONVECTIVE CLOUDS AND ENVIRONMENT WITH VERTICAL SHEAR

Abstract The physics of convective clouds depends not only upon thermodynamic processes but also upon the interactions with the environmental wind field. When vertical shear is present, a hydrodynamic (nonhydrostatic) pressure field is induced by relative motions near the boundaries of a large convective system which does not move with the ambient winds. This tends to make the cloud tilt away from the vertical, but at the same time vertical gradients of hydrodynamic pressure aid the formation of new convection. Expressions are derived for the accelerations concerned. Quantitative estimates based upon experimental analogies show that vertical accelerations due to the induced pressure field may be of the same order as those associated with ordinary buoyancy forces. These account for the self-propagating nature of squall-line-type thunderstorms and their ability to continue at night when thunderstorms in stagnant air masses tend to die out. The hypothesis accounts for the observed movements of this type of r.
Timescale Invariance of Rapid X-Ray Variability of the Black Hole Candidate GRO J1719–24

We present the results of an analysis of the time variability of the soft X-ray transient GRO J1719-24 (Nova Oph 1993), as observed with BATSE. Our analysis covers the entire ~80 day outburst, beginning with the first detection of this black hole candidate on 1993 September 25. We obtained power density spectra (PDSs) of the data in the 20-100 keV energy band, covering the frequency interval 0.002-0.488 Hz. The PDSs show a significant quasi-periodic oscillation peak, the centroid frequency of which increased from ~0.04 Hz at the onset of the outburst to ~0.3 Hz at the end. Additional noise is present in the PDSs, which we describe in terms of two components. We find that the evolution of the PDSs can be described as a gradual stretching by a factor of ~7.5 in frequency of the power spectrum, accompanied by a decrease of the power level by the same factor, such that the integrated power in a scaled frequency interval remains constant.
Control of linear dynamic systems with set constrained disturbances

A linear dynamic system with input and observation uncertainties is studied. The uncertainties are constrained to be contained in specified sets. No probabilistic structure is assumed. The problem of keeping the state of the system in a specified region is investigated. Necessary and sufficient conditions for a solution to the problem and an algorithm that constructs the control are derived for open-loop and closed-loop control laws. The algorithm is also approximated by a bounding ellipsoid algorithm. Two special control laws, linear and "linear-plus-dead-band," are studied, and the regions that contain the state and control are characterized. Ellipsoids that bound the state and control are also derived, and a simple example of linear and linear-plus-dead-band control laws is presented.
Observation of a Vortex in Front of a Half-Submerged Circular Cylinder

Experimental evidence is reported that a two-dimensional vortex is formed in front of a half-submerged circular cylinder, which is supported horizontally near the surface of water in a towing tank and moved in the direction normal to its axis. The experiment was mode at Reynolds numbers (based on the velocity and the radius of the cylinder) less than about 5×10 3 . The upstream vortex seems to be due to the forward movement of the surface layer of water driven by the cylinder.
Acoustic waves in unbounded shear flows

The linear evolution of acoustic waves in a fluid flow with uniform mean density and uniform shear of velocity is investigated. The process of the mean flow energy extraction by the three-dimensional acoustic waves, stimulated by the non-normal character of the linear dynamics in the shear flow, is analyzed. The thorough examination of the dynamics of different physical variables characterizing the wave evolution is presented. The physics of gaining of the shear energy by acoustic waves is described.
Hydrodynamics and entanglement in the AdS/CFT correspondence

In this thesis we present two applications of the AdS/CFT correspondence. The first one is the analysis of transport properties of fermionic modes in strongly coupled field theories. In particular we study the properties of the diffusion constant of the phonino in N=4 SYM at zero and finite density. We find that the diffusion constant depends on the chemical potential and therefore we conclude that it does not have a universality property analogous to the one of the shear viscosity. The second application deals with the behavior of entanglement entropy in theories with massive degrees of freedom. To identify the mass contributions to entanglement entropy we compute it in a setup with backreacted massive flavor branes and identify some of the mass dependent terms. We find that the logarithmic term has a different coefficient from the one computed in free field theory, a result that qualitatively agrees with previous holographic results. Furthermore we identify some other terms predicted in the field theory but not found before in a holographic setting.
Highland VR: Exploring Virtual Reality for Collaborative Balance Training

Today virtual reality applications mainly allow consumers to en-gage in immersive alternative realities for fun and entertainment. However, researchers and therapists investigate their use for skill improvement and even fear prevention. In this work, we focus on balance training in virtual reality, which is directly linked to fear of heights. We first present a high definition virtual world supporting the training. Next, we highlight how different training attempts can support the learning process. Finally, we propose including the collaborative aspect into balance training, allowing for collaborative training and helping instructors to integrate and adapt to prior training sessions performed at home. Beyond balance training, the collaborative aspect will be helpful whenever feedback and performance review is required.
Physical, mechanical and acoustic properties of Terminalia superba, Cleistopholis patens and Holarrhena floribunda woods used in sculpture and instrument making in Benin

Wood is important in several fields including sculpture and instrument making. In the last two fields, Terminalia superba , Cleistopholis patens, and Holarrhena floribunda are three of Benin’s most used wood species . In this work, we have, on prismatic samples (500 mm × 20 mm × 20 mm) of the wood of these species, used the acoustic method Beam Identification by Non-destructive Grading (BING) of CIRAD-Forêt to de termine the density ρ, Young's modulus E, shear modulus G and internal friction tan 𝛿 that allowed the evaluation of the specific stiffness modulus E/ρ and the other acoustic parameters. These tests showed that T. superba, C. patens and H. floribunda wood species have specific moduli of elasticity of 18 ± 3, 17 ± 2 and 15 ± 1 GPa, respectively; internal friction of the order of 10 -2 and sound velocities of the order of 4000 m s -1 . All these three species have an average acoustic strength above 1.40 MPa s m -1 with acoustic radiation above 7 m 4 kg -1 s -1 for a high ACE above 1000 m 4 kg -1 s -1 for T. superba and C. patens and low around 674 m 4 kg -1 s -1 for H. floribunda. All these species have a medium stability in service and a low propensity to deformation due to their shrinkage anisotropy. In view of these results, the wood of these species can be used in both structural and acoustic works specifically in sound insulation, art sculpture and instrument making.
OXYGEN-INDUCED VACANCY FORMATION ON A METAL SURFACE

Using scanning tunneling microscopy, low-energy ion scattering, and quantitative low-energy electro diffraction, we find about 17% metal vacancies on the oxygen-covered Cr(100) surface. The oxyge atoms occupy all the hollow sites of the first layer, including those neighboring a Cr vacancy. We argu that the vacancy formation is energetically favored and not caused by stress but by electronic effec [S0031-9007(98)08211-8]
Formation controllability of high-order linear time-invariant swarm systems

The controllability problem of high-order linear time-invariant (LTI) continuous-time swarm systems is investigated. A necessary and sufficient condition for complete controllability of homogeneous swarm systems is given. The controllability of graph is important and is analysed in detail. The concept of formation controllability is proposed and the relationship between complete controllability and formation controllability is studied.
Nonlinear Wave Packet Evolution on a Baroclinicaily Unstable Jet

Abstract Numerical simulations of the inviscid, nonlinear life cycle of wave packets emerging from a zonally localized initial disturbance on a baroclinically unstable jet are studied. The study reveals the following. 1) Linear wave packet theory accurately bounds the upstream and downstream development of the synoptic disturbance throughout the nonlinear evolution. 2) The short, shallow, slowly propagating waves at the upstream fringe of the wave packet equilibrate at low amplitudes and never come to dominate the wave packet evolution. 3) Upslxeampropagating Rossby waves are excited in the vicinity of the synoptic wave packet, which cause the generation of strong barotropic jets mostly upstream of the dominant body of the wave packet. This prevents the barotropicgovernor mechanism from limiting the growth Of the disturbances in the main body of the packet; the main equilibration mechanism is a simple homogenization of the lower-layer potential vorticity in the vicinity of the wave packet. 4) The waves th.
A Note on Finsler Modules

Let E be a full Finsler B-module, : A ! B a -isomorphism of C -algebras. Define the module action by ax = (a)x and the map x 7! A(x) by A(x) = 1 ( B(x)). Then it is straightforward to show that E is a full Finsler A- module. In this paper we shall establish a converse statement to the above.
Aspect sensitivity of stratospheric VHF radio wave scatterers, particularly above 15‐km altitude

The aspect sensitivity of VHF radar scatter in the stratosphere is investigated with particular emphasis being placed on the region above 15-km altitude. It is found that the scatter is highly aspect sensitive below about 18 km in the stratosphere as is well known, but above this height the scatter becomes more isotropic again. The highest degree of aspect sensitivity occurs around 18-km altitude, where the backscatter polar diagram has a 1/e half-width θs of less than 1.5°, and the horizontal correlation length can exceed 30 m. At heights above 20 km, however, θs is in excess of 4° and increases with increasing height. At any one height there is a range of scatterer shapes, from scatterers with large length-to-depth ratios up to almost isotropic scatterers. These results are confirmed using studies of backscattered power as a function of angle, comparisons of radial velocities as a function of beam bore-tilt angle, and studies of the spectral width compared to the expected beam-broadened spectral width. The results complement and support the only other published study of scatterer anisotropy in the region of 15- to 30-km altitude (Hocking et al., 1986).
Investigating SUMER Coronal Hole Observations: A Robust Method of Raster Reduction

We present a physically constrained, comprehensive, and robust means of reducing long-duration spectroscopic raster observations made in the important 1530-1555 Å wavelength range by the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) instrument on the Solar and Heliospheric Observatory (SOHO). Our method performs corrections in spatial, spectral, and temporal domains following application of the standard SUMER data reduction package to minimize the net Doppler shift of neutral and singly ionized silicon emission lines in the chromosphere. We have applied this method to seven raster observations of the same equatorial coronal hole acquired over a 5 day period, 1999 November 3-8, and to the well-studied observations of 1996 September 21-22. This technique allows us to make physically consistent analyses of multiple SUMER rasters and will aid in future investigations of the solar "rest" wavelength of the important Ne VIII 770 Å emission line and, as a result, of the properties of transition region blueshifts—specifically, their correlation to multithermal radiance structure, supergranular network patterns, and the coronal magnetic environment at the perceived lower boundary of solar wind outflow.
A Path-Integral Approach to Large-Scale Matter Distribution Originated by Non-Gaussian Fluctuations

The possibility that, in the framework of a biased theory of galaxy clustering, the underlying matter distribution be non-Gaussian itself, because of the very mechanisms generating its present status, is explored. It is shown that a number of contradictory results, seemingly present in large-scale data, in principle can recover full coherence, once the requirement that the underlying matter distribution be Gaussian is dropped. For example, in the present framework, the requirement that the two-point correlation functions vanish at the same scale (for different kinds of objects) is overcome. A general formula, showing the effects of a non-Gaussian background on the expression of three-point correlations in terms of two-point correlations, is given. 28 references.
Experimental validation of different methods for controlling a flexible nozzle using embedded SMA wires as both positioning actuator and sensor

One of the main selling points of smart materials is the potential to exploit their multi-functional capabilities. For example, a shape memory alloy (SMA) wire can be used as a positioning actuator by heating the wire to induce contraction and as a positioning sensor by measuring the resistance across the length of the wire. While SMA's have found application in many on-off type applications, their ability to 'sense' their own change in length has not been fully exploited. This is because when coupled with a compliant structure, SMA wires exhibit non-linear, hysteretic behavior that depends not only on the phase transformation within the material, but also the thermal and force interactions between the wires and structure itself. If the resistance across an SMA can be reliably mapped to wire strain, a closed-loop controller can easily vary the length of the wire by changing the amount of electrical power put into the wire that causes Joule heating. This paper analyzes the fidelity of different mapping schemes when employed in a closed-loop controller. The schemes are tested in the context of a dual-joint flexible nozzle that is designed to control both the release position and trajectory of an emitted fluid flow. The mapping methods include consideration of the force coupling that results from opposing SMA actuators. The challenges of practical implementation issues are discussed alongside the results to develop the best mappingcontrol scheme for this application. Results show that simple linear-mapping solutions offer 2D nozzle tip position tracking with errors of 2 mm over a range of 12 mm on both axes, with minimal investment of calibration time, while more involved solutions that include force coupling and account for hysteresis can bring positioning errors to less than 500 um.