Miracle-dz/UniFAR-FTUs huggingface dataset:
Redshift and Optical Properties for S Statistically Complete Sample of Poor Galaxy Clusters

From the poor cluster catalog of White et al. (1996), we define a sample of 71 optically-selected poor galaxy clusters. The surface-density enhance- ment we require for our clusters falls between that of the loose associations of Turner and Gott (1976) and the Hickson compact groups (Hickson, 1982). We review the selection biases and determine the statistical comleteness of the sample. For this sample, we report new velocity measurements made with the ARC 3.5-m Dual-Imaging spectrograph and the 2.3-m Steward Observatory MX fiber spectrograph. Combining our own measurements with those from the literature, we examine the velocity distributions, velocity dispersions, and 1-d velocity substructure for our poor cluster sample, and compare our results to other poor cluster samples. We find that approximately half of the sample may have significant 1-d velocity substructure. The optical morphology, large-scale environment, and velocity field of many of these clusters is indicative of young, dynamically evolving systems. In future papers, we will use this sample to derive the poor cluster X-ray luminosity function and gas mass function (see astro-ph/9606120), and will examine the optical/X-ray properties of the clusters in more detail.
Anisotropic and gyrotropic version of Polder and van Santen's mixing formula

Abstract In order to account for the permittivity contrast between a host medium and inhomogeneities embedded in it the continuous rotating medium concept with a spatially random permittivity tensor ϵ0[ϵ(ω, r)δ ij +iα(ω, r)e ijl h l ) is introduced. Here ϵ(ω, r) is the dimensionless permittivity, α(ω, r)≡Ω (∂ϵ(ω, r)/∂ω), Ω (rad s−1) is the angular frequency of rotation of the random medium around the h axis and e ijl is the third rank antisymmetric tensor (the Levi-Civita tensor). Under this assumption and with the application of strong fluctuation theory and the bilocal approximation we find the effective permittivity tensor (EPT); in the low-frequency limit the quasistatic EPT represents the anisotropic and gyrotropic version of Polder and van Santen's mixing formula. In Nature there exists a large variety of rotating inhomogeneous media (millisecond pulsars, dust particles in air flowing in turbulent motion, polluted water in rotation). In order to demonstrate the gyrotropicity a simple laboratory expe.
High-average-power (>20-W) Nd:YVO 4 lasers mode locked by strain-compensated saturable Bragg reflectors

Strain-compensated double InGaAs quantum-well saturable Bragg reflectors (SBR’s) with high damage thresholds have been developed for use as mode-locking elements in high-average-power neodymium lasers. Nd:YVO4 lasers have been developed with these new SBR’s, which produce transform-limited pulses of 21-ps duration at 90 MHz and an average power of 20 W in a diffraction-limited output beam. The peak pulse power at an output power of 20 W was 10.6 kW. A comparison of the operating parameters of strained single and strain-compensated double-well SBR’s indicates that the damage threshold increased by a factor of at least 2–3. Long cavity laser variants were investigated to assess the limitations of further power scaling. At a repetition frequency of 36-MHz stable mode-locked pulses with peak pulse powers of 24.4 kW and pulse energies of 0.6 µJ could be generated.
The Definition of El Niño.

Abstract A review is given of the meaning of the term "El Nino" and how it has changed in time, so there is no universal single definition. This needs to be recognized for scientific uses, and precision can only be achieved if the particular definition is identified in each use to reduce the possibility of misunderstanding. For quantitative purposes, possible definitions are explored that match the El Ninos identified historically after 1950, and it is suggested that an El Nino can be said to occur if 5-month running means of sea surface temperature (SST) anomalies in the Nino 3.4 region (5°N–5°S, 120°–170°W) exceed 0.4°C for 6 months or more. With this definition, El Ninos occur 31% of the time and La Ninas (with an equivalent definition) occur 23% of the time. The histogram of Nino 3.4 SST anomalies reveals a bimodal character. An advantage of such a definition is that it allows the beginning, end, duration, and magnitude of each event to be quantified. Most El Ninos begin in the northern spring or perh.
Towards high resolution quantitative subsurface models by full waveform inversion

Full waveform inversion (FWI) has the potential to recover detailed quantitative property models of the subsurface, but the process is computationally expensive. Currently available computer systems do not allow to use the full bandwidth of the acquired seismic data, which effectively reduces the resolution that can be obtained. In this paper, we propose a novel approach to obtain high resolution subsurface models from broad-band FWI. The method is based on localization of the inversion, while subsequently the interaction between local domains is estimated. A global field update is calculated which honours the non-linear relationship between the subsurface properties and the measured seismic data. By using this non-linearity, the spectral gap between the a priori background model and the seismic bandwidth will be closed and spatially broad-band properties can be estimated from a band-limited seismic signal.
Stretching and Distortion of Material Line Elements in Two-Dimensional Turbulence

A study is made of the stretching and distortion of material line elements in turbulence both analytically and numerically. Approximations for the statistics of these processes derived by perturbative expansions are tested by comparison with dynamical simulations in two dimensions. An integral time scale associated with the Lagrangian statistics of the velocity gradients plays a key role in the approximations. A rough estimation of the time scale is obtained by a dynamical short-time analysis by making use of the Navier-Stokes equation.
Explicit formulae for stationary distributions of stress release processes

Stress release processes are special Markov models attempting to describe the behaviour of stress and occurrence of earthquakes in seismic zones. The stress is built up linearly by tectonic forces and released spontaneously when earthquakes occur. Assuming that the risk is an exponential function of the stress, we derive closed form expressions for the stationary distribution of such processes, the moments of the risk, and the autocovariance function of the reciprocal risk process.
Multi-scale bi-domain Bayesian classifier designed for infrared image segmentation

An extended Bayesian classifier, which is able to fuse information in original image and in its wavelet domain, is designed for infrared image segmentation. The algorithm begins with a re-sampling process over the original image and a wavelet transformation of the original image. Then, the Spatially Variant Mixture Model (SVMM) is applied in the bootstrap samples and the wavelet coefficients. The corresponding parameters are estimated by EM (Expectation Maximum) algorithm. Finally, a two-element Bayesian classifier is constructed. One part of the classifier is designed to exploit information in the original image, and the other part is designed to exploit information obtained in the wavelet domain. Theoretic analysis and experimental results confirms that the approach is efficient for infrared image segmentation, robust to noise and less computationally involved.
A Possible Detection of a Second Light-Time Orbit for the Massive, Early-Type Eclipsing Binary Star AH Cephei

All published and newly observed times of minimum light of the massive, early-type eclipsing binary star AH Cep were analyzed. After subtracting the light-time effect due to the well-known third body from the residuals of the observed times of minimum light, it was found that the second-order O - C residuals varied in a cyclical way. It was assumed that the secondary oscillations were produced by a light-time effect due to a fourth body so all the times of minimum light were reanalyzed with a differential least-squares scheme in order to obtain the light-time orbits due to both the third and fourth bodies. The periods, eccentricities, and semiamplitudes of the light-time orbits for the third and fourth bodies were derived as P3 = 67.6 and P4 = 9.6 yr, e3 = 0.52 and e4 = 0.64, and K3 = 0.0608 and K4 = 0.0040 days, respectively. The radial velocities of AH Cep published so far do not conflict with the hypothesis of the multiplicity of the system, but their accuracies are not high enough to support the interpretation. Other properties of the distant bodies are discussed for assorted possible inclinations of their orbits.
Hamilton echelle spectra of young stars. I: Optical veiling

An extensive set of veiling measurements of T Tauri stars covering almost the entire optical spectrum is presented. These are based on Hamilton echelle spectra obtained during 1987-1989. A full range of T Tauri stars, from weak to continuum stars is studied; in some cases, several spectra of a given target are seen in which the veiling has changed, occasionally dramatically. Veilings are determined using two new methods: one which concentrates on the residual intensities of selected spectral lines, and the other which compares the autocorrelation functions for a T Tauri star and a veiled standard. The general shape of the veiling is often as predicted by accretion disk models: almost flat in the red and increasing in the blue. Cooler stars have generally higher veiling, implying that the veiling power is relatively independent of stellar mass. The relation between veiling and the narrow and broad emission lines supports a nonstellar origin for the veiling and broad line components, and a stellar origin for the narrow lines. 42 refs.
A Temperature-Dependent Model of the Thermospheric Odd Nitrogen

The diurnal variations of odd nitrogen species (N, NO) in the thermosphere are modelled by solving the time-dependent, one-dimensional continuity equations with the diffusion transport which have been developed by OGAWA and SHIMAZAKI (1975). By comparing the calculated results with N and NO distributions which were determined in an airglow (NI 5, 200A and NO gamma-bands) and mass spectrometric observations the following conclusions have emerged. (1) The quantum yield of N(2D) in the reactions energetically capable of producing the excited species should be larger than 0.5, and probably as large as 0.9. (2) The quenching of N(2D) by atomic oxygen is important at altitudes above 120km. In order to be consistent with the observation of NI 5, 200A airglow, the quenching coefficient must be as large as 1×10-12cm3s-1. (3) The variability of NO density profiles obtained by various experimenters is largely interpreted to be due to the large diurnal variations of odd nitrogen expected from a large diurnal change in the thermospheric temperature which is also under the control of solar activities.
Expansion of the global error for numerical schemes solving stochastic differential equations

Given the solution (Xt ) of a Stochastic Differential System, two situat,ions are considered: computat,ion of Ef(Xt ) by a Monte–Carlo method and, in the ergodic case, integration of a function f w.r. t. the invariant probability law of (Xt ) by simulating a simple t,rajectory. For each case it is proved the expansion of the global approximat,ion error—for a class of discret,isat,ion schemes and of funct,ions f—in powers of the discretisation step size, extending in the fist case a result of Gragg for deterministic O.D. E. Some nn~nerical examples are shown to illust,rate the applicat,ion of extrapolation methods, justified by the foregoing expansion, in order to improve the approximation accuracy
High piezoelectric activity in (Na,K)NbO3 based lead-free piezoelectric ceramics: Contribution of nanodomains

The origin of high piezoelectric response in (Na0.52K0.48−x)(Nb0.92−xSb0.08)O3-xLiTaO3 lead-free ceramics was investigated by looking into the composition-dependent domain morphology by means of transmission electron microscopy. Nanodomains of alternate orthorhombic and tetragonal domains with a width of 20–50 nm were surprisingly observed but only for compositions near polymorphic phase coexistence zone. The formation of nanodomain morphology was considered to result from the reduction of the domain wall energy owing to the vanishing of the polar anisotropy, which ultimately induced enhanced piezoelectric properties. The result indicated that nanodomains are not proprietary features of traditional Pb-based piezoelectric ceramics with a morphotropic phase boundary.
One-point turbulence structure tensors

The dynamics of the evolution of turbulence statistics depend on the structure of the turbulence. For example, wavenumber anisotropy in homogeneous turbulence is known to affect both the interaction between large and small scales (Kida & Hunt 1989), and the non-local effects of the pressure–strain-rate correlation in the one-point Reynolds stress equations (Reynolds 1989; Cambon et al. 1992). Good quantitative measures of turbulence structure are easy to construct using two-point or spectral data, but one-point measures are needed for the Reynolds-averaged modelling of engineering flows. Here we introduce a systematic framework for exploring the role of turbulence structure in the evolution of one-point turbulence statistics. Five one-point statistical measures of the energy-containing turbulence structure are introduced and used with direct numerical simulations to analyse the role of turbulence structure in several cases of homogeneous and inhomogeneous turbulence undergoing diverse modes of mean deformation. The one-point structure tensors are found to be useful descriptors of turbulence structure, and lead to a deeper understanding of some rather surprising observations from DNS and experiments.
Fatigue of Fabrics

The effect of temperature and time of application of load on the growth and the apparent ``tensile strength'' of fabrics was studied with a number of new tests. The results gave considerable information about the mechanism of failure of mechanical fabrics at low loads in service which could not be obtained with standard textile tests.A ``fatigue'' test was developed which measured the lives of samples at elevated temperatures when subjected to a constant average load and a superimposed cyclic stress. The change in life with temperature on this test is enormously greater than the change of tensile strength with temperature. Over a considerable range the logarithm of the life under a given load is a linear function of the reciprocal of the absolute temperature, showing that the failure depends on a viscous or plastic flow within the fibers. Calculated activation energies for this flow process increase for different fibers in the order rayon, cotton, Nylon. The construction of the fabric affects the absolute.
Spectroscopic study of the pulsations in the roAp star HD 24712

We present results of the radial velocity (RV) analysis of spectroscopic time-series observations of the roAp star HD 24712 (HR 1217). Only lines of the rare-earth elements (REE) show substantial amplitudes in the RV data. The progressive change of the RV pulsation phase with the optical depth for lines of the same element gives strong evidence for a running wave. The surface abundance distribution should be taking into account in interpreting of the phase shifts between the RV curves for dierent elements. We did not nd phase jumps at the magnetic eld extrema reported earlier by Mkrtichian & Hatzes (2005).
A subdomain Galerkin/Least squares method for first-order elliptic systems in the plane

A finite element method for the approximation of solutions of linear, first-order elliptic systems in two-dimensional domains is considered. The method differs from previous techniques in that the discretization is effected prior to the application of a least squares method. Optimal error estimates in ${\text{\bf H}}^1 (\Omega )$ and ${\text{\bf L}}^2 (\Omega )$-norms are derived for piecewise linear finite element trial spaces. Numerical examples are provided that illustrate the theoretical convergence rates and that indicate that the method is easy to implement and is computationally efficient.
Simulations of the ENSO Hydroclimate Signals in the Pacific Northwest Columbia River Basin

Abstract Natural fluctuations in the atmosphereocean system related to the El NinoSouthern Oscillation (ENSO) induce climate variability over many parts of the world that is potentially predictable with lead times from seasons to decades. This study examines the potential of using a model nesting approach to provide seasonal climate and streamflow forecasts suitable for water resources management. Two ensembles of perpetual January simulations were performed with a regional climate model driven by a general circulation model (GCM), using observed climatological sea surface temperature (SST) and the mean SST of the warm ENSO years between 1950 and 1994. The climate simulations were then used to drive a macroscale hydrology model to simulate streamflow. The differences between the two ensembles of simulations are defined as the warm ENSO signals. The simulated hydroclimate signals were compared with observations. The analyses focus on the Columbia River basin in the Pacific Northwest. Results show that the .
Applications of singular value decomposition in structural optimisation

The usage of the singular value decomposition (SVD) in scope of structural optimisation is motivated. We briefly outline several applications of SVD from different scientific fields to point out their similarities with structural optimisation. Here, our focus is on model reduction, on numerical defects and on their quantitative description using SVD. In this context we address the singular value decomposition of matrices which appear in an optimisation algorithm, i.e. the pseudo load matrix and the sensitivity matrix. In this contribution on the example of topology optimisation we would like to clarify all the properties of SVD. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Illuminance texture due to surface mesostructure

We study the illuminance texture due to three-dimensional surface mesostructure. In the conventional rendering algorithms various methods of approximate photometry are used whose domains of validity have been ill defined. We introduce the necessary photometric concepts and do a comparative study of rendering algorithms. In the computer graphics/vision literature the physically distinct causes of illuminance variation, namely, the obliqueness of surface elements and the effects of vignetting of extended sources, are thoroughly confused. This leads to serious errors when expressions are used in contexts outside their original realm. The treatment of the texture that is due to the illumination of surface mesostructure is an example. Erroneous results are obtained when simple expressions for the illuminance of convex bodies are interpreted in terms of equivalent sources and when these again are used in calculations involving different geometrical structures. We classify current methods in terms of the approximations (often implicitly) made and compare results for a large class of applications: that of surface mesostructure on convex objects. Large differences among the various approximative methods are found. We discuss simple methods that might be used to produce more realistic results at reasonable computational cost.
New method for the calculation of atomic phase shifts: Application to extended x-ray absorption fine structure (EXAFS) in molecules and crystals

The scattering of electrons of kinetic energy up to 1000 eV by an atom is of special interest in the understanding of extended x-ray absorption fine-structure (EXAFS) spectra. An important physical feature is the reduction of the exchange and correlation potential as the kinetic energy of the electron increases. This is taken into account by replacing the atom by an electron gas with spatially varying density and calculating the self-energy using the plasmon pole approximation. This results in a set of complex phase shifts which is then applied to the EXAFS problem. Comparison is made with phase shifts extracted from experimental EXAFS spectra and excellent agreement is obtained. Direct comparison of the theoretical and experimental spectra again shows excellent agreement in both the amplitude and the phase. We also analyze the EXAFS spectra by a Fourier-transform technique which first removes the amplitude and phase shift using the calculated result. The importance of a proper choice of zero of energy ${E}_{0}$ is emphasized. We choose ${E}_{0}$ by the requirement that the imaginary part and the absolute value of the Fourier transform should peak at the same distance, thus assuring that the absolute phase is given correctly. Using this procedure the nearest-neighbor distances in ${\mathrm{Br}}_{2}$, Ge${\mathrm{Cl}}_{4}$, and crystalline germanium are determined. In all cases the results are within 0.01 \AA{} of the known distances. Several shells in germanium are also determined, with accuracy of better than 1%. Application of our method to crystalline copper indicates that the outer shells are more seriously affected by multiple-scattering problems and our procedure permits us to discard peaks that are spurious or unreliable. The present determination of the nearest-neighbor distance in copper is found to be in error by 0.014 \AA{}. Results of the application of this method to the determination of the bond lengths of a variety of compounds are summarized.
Computational methods for unsteady transonic flows

Computational methods for unsteady transonic flows are surveyed with emphasis upon applications to aeroelastic analysis and flutter prediction. Computational difficulty is discussed with respect to type of unsteady flow; attached, mixed (attached/separated) and separated. Significant early computations of shock motions, aileron buzz and periodic oscillations are discussed. The maturation of computational methods towards the capability of treating complete vehicles with reasonable computational resources is noted and a survey of recent comparisons with experimental results is compiled. The importance of mixed attached and separated flow modeling for aeroelastic analysis is discussed and recent calculations of periodic aerodynamic oscillations for an 18 percent thick circular arc airfoil are given.
InP-Based Planar-Antenna-Integrated Schottky-Barrier Diode for Millimeter- and Sub-Millimeter-Wave Detection

An InP-based Schottky-barrier diode (SBD) is monolithically integrated with a wideband log-periodic toothed antenna for detecting millimeter- and sub-millimeter-waves at frequencies of up to the terahertz (THz) range. A module with a quasi-optical collimation lens fabricated for practical use exhibits sensitivities of 1000 V/W at 300 GHz and 125 V/W at 1.2 THz with good linearity. Near-distance wireless transmission of 5 Gbit/s data with a 240 GHz carrier is also examined using the fabricated SBD module.