Miracle-dz/UniFAR-FTUs huggingface dataset:
Far-infrared and Submillimeter Polarization of OMC-1: Evidence for Magnetically Regulated Star Formation

This paper presents large-scale polarization maps (8' × 8') of the Orion molecular cloud (OMC-1) at far-infrared (100 μm; 35'' resolution) and submillimeter (350 μm; 18'' resolution) wavelengths. The magnetic field shows a pinch at scales less than 0.5 pc with a centroid that is on the OMC-1 ridge, a site of high-mass star formation. We infer that gravitational collapse pulled the magnetic field into an hourglass shape. We estimate that the magnetic, kinetic, and gravitational energies are in equipartition on the ridge and that the magnetic energy dominates in the surrounding ambient envelope. We consider a model in which the ridge and thus high-mass stars gravitationally collapsed out of a cloud that was initially supported by the magnetic field. At flux peaks, there is a reduction in the percent polarization. This effect is discussed in relation to temperature, optical depth, and wavelength.
BVI reddenings of Magellanic Cloud Cepheids

On discute des rougissements photoelectriques BVI c de 29 cepheides du GNM et 48 cepheides du PNM. On trouve une valeur moyenne pour E(B-V) de 0,074 mag dans le GNM et de 0,054 mag dans le PNM, avec une faible dispersion
Technical issues and requirements of experiments and facilities for fusion nuclear technology

The technical issues, development problems and required experiments and facilities for fusion nuclear technology have been investigated. The results have been used to develop a technical framework for a test plan that identifies the role, timing, characteristics and costs of major experiments and facilities. A major feature of this framework is the utilization of non-fusion facilities over the next 15 years, followed by testing in fusion devices beyond about the year 2000. Basic, separate effect and multiple interaction experiments in non-fusion facilities will provide property data, explore phenomena and provide input to theory and analytic modelling. Experiments in fusion facilities can proceed in two phases: (1) concept verification and (2) component reliability growth. Integrated testing imposes certain requirements on fusion testing device parameters; these requirements have been quantified. The nuclear subsystems addressed in the study are: (a) blanket and first wall; (b) tritium processing system; (c) plasma interactive components; and (d) radiation shield. The two generic classes of liquid and solid breeder blankets have significant engineering feasibility issues, and new experimental data must be obtained before selection of an attractive design concept. Liquid metal blanket issues are dominated by problems related to momentum, heat and mass transfer, which can be addressed in non-neutron test facilities. Solid breeder blanket issues are, however, dominated by the effects of radiation, including heating, transmutation and damage, which can be reasonably addressed in fission reactors. The tritium processing uncertainties are primarily related to the control and recovery systems, and most can be addressed in existing and planned non-neutron facilities. A dominant feature of plasma interactive components is the strong interrelation to both plasma physics and nuclear technology. Required facilities include thermomechanical test stands and confinement devices with sufficiently long plasma burn. The radiation shield poses no feasibility issues, but improved accuracy of predictions will reduce design conservatism and lower costs.
SPATIO-TEMPORAL RECONSTRUCTION OF VORTEX DYNAMICS IN AXISYMMETRIC WAKES

Abstract With time recording Digital-Particle-Image Velocimetry and spatio-temporal reconstruction technique, we obtained detailed quantitative results of the evolution of the velocity and vorticity field in the wake of axisymmetric bluff bodies—a sphere and an axially oriented cylinder with an elliptic nose and a blunt base. Experiments were carried out for Reynolds numbers of Re=500, 700 and 1000 in the transition range from “regular” to “irregular” shedding. DPIV-recordings in radial cross-sections at several distances downstream of the bodies allowed us to reconstruct the dynamics of the streamwise vorticity over a large number of shedding cycles. Our results prove that the wake in this regime consists of a double-sided chain of oppositely oriented hairpin vortices. In addition, the results show a well-defined low-frequency modulation of the vortex shedding, with a distinct peak in the frequency spectrum at a Strouhal number of about Sr≈0·05 (in case of the sphere). The wake pattern in this “irregular” shedding regime typically exhibits periodic packets of 3–4 “regular” shedding cycles which are interrupted by phases with less action. The results indicate the coexistence of a long-wave instability of axisymmetric wakes against helical waves in addition to the primary instability causing the vortex shedding process.
Onset of exchange bias in ultrathin antiferromagnetic layers

Current theoretical explanations of exchange biasing are based upon magnetic domains in the antiferromagnetic layer being responsible for the phenomenon. Both the ideas of planar and perpendicular domain walls have been developed in explaining the various observed effects. Here the exchange bias (H e x ) has been investigated as a function of the antiferromagnetic (AF) layer thickness (t A F ) in IrMn/Co and FeMn/Co exchange biased systems. The results indicate that the onset of biasing occurs for t A F which appears to be far too low (∼ 10 A) to accommodate planar domain walls (∼200 A) within the AF layer. From these results it is inferred that planar domain walls cannot therefore be responsible for biasing, and that theoretical calculations involving perpendicular domain walls in the antiferromagnetic layers appear to be the more plausible explanation.
Quantum computing with photons: introduction to the circuit model, the one-way quantum computer, and the fundamental principles of photonic experiments

Quantum physics has revolutionized our understanding of information processing and enables computational speed-ups that are unattainable using classical computers. This tutorial reviews the fundamental tools of photonic quantum information processing. The basics of theoretical quantum computing are presented and the quantum circuit model as well as measurement-based models of quantum computing are introduced. Furthermore, it is shown how these concepts can be implemented experimentally using photonic qubits, where information is encoded in the photons’ polarization.
Silicon waveguide-integrated optical power monitor with enhanced sensitivity at 1550nm

We describe the fabrication and operation of an optical power monitor, monolithically integrated with a silicon-on-insulator rib waveguide. The device consists of a p+‐v‐n+ structure with a detection volume coincident with the single-mode supporting waveguide. Detection of optical signals at wavelengths around 1550nm is significantly enhanced by the introduction of midband-gap generation centers, which provide partial absorption of the infrared light. The most efficient device extracted 19% of optical power from the waveguide and showed a responsivity of 3mA∕W. These devices are fabricated using current standard processing technology and are fully compatible with silicon waveguide technology and integrated operational amplifier circuits.
Sensitivity and transient response of microwave reflection measurements

Microwave reflection measurements are widely used for the characterization of minority‐carrier lifetimes in semiconductors. A theoretical description of the technique is presented. The approach is based on a dielectric multilayer model that accounts for experimental parameters such as microwave frequency, sample thickness and doping, and the distance to an optional reflector behind the sample. With a new definition of the sensitivity in transient microwave reflection measurements, the most sensitive configuration is investigated for a given semiconductor thickness and conductivity. Good agreement between the theoretical simulation and measurements is demonstrated. The model is also used for calculating microwave reflection transients from the excess carrier decay after pulsed laser excitation. It is found that the reflected microwave power mirrors the carrier decay if three criteria are fulfilled: The carrier generation must be homogeneous; low‐injection conditions are required; and the reflector must be .
Global Measurements of Sea Surface Temperature, Wind Speed and Atmospheric Water Content from Satellite Microwave Radiometry

Abstract Satellite microwave measurements of sea surface temperature (SST), sea surface wind speed, atmospheric water vapor and cloud liquid water have been analyzed for the three-month period from July to October 1978. During this period the Scanning Multichannel Microwave Radiometer (SMMR) on the Seasat satellite provided continuous orbital coverage of the world's oceans. Monthly contour maps and zonal averages of the SMMR measurements have been produced to examine the consistency of the Seasat data over longer temporal and spatial scales than has hitherto been investigated. With small (∼0.5°C) bias corrections to the SST estimates, the SMMR appears capable of detecting SST anomalies of ≲1°C, except where radio frequency inteference occurs. The SMMR wind speed and water vapor distributions indicate large-scale atmospheric circulation patterns, and provide complete coverage in regions of sparse ship and radiosonde data. The SMMR cloud liquid water measurements show features similar to those observed in m.
Invertibility and a Topological Property of Sobolev Maps

Let O be a bounded domain in Rn, let d : O¯ ? O¯ be a homeomorphism, and consider a function u : O¯ ? Rn that agrees with d on ? O. If u is continuous and injective then u(O) = d(O). Motivated by problems in nonlinear elasticity the relationship between u(O) and d(O) is analyzed when the continuity and invertibility assumptions are weakened. Specifically maps that are continuous on almost every line and maps that lie in the Sobolev space W1,p with n - 1 < p < n are considered.
Infrared imaging spectroscopy of the galactic center: distribution and motions of the ionized gas

High spatial (≤ 1») and spectral (100 km s −1 FWHM) resolution images of the Galactic center taken in the 2.17 μm Brγ line of hydrogen show a coherent streamer of gas corresponding to the «extended northern arm» and central bar seen in thermal radio maps. The total mass of gas in this structure is approximately 5 M ○ . , assuming circular cross-section and case B recombination. At least ten stellar sources have coincident Brγ emission and are likely hot stars. Several of these (IRS 13, IRS 16NE, IRS 16C, and the AF star 3 « west of IRS 12) produce broad lines in excess of 340 km s −1 FWHM. The distribution and kinematics of the extended filament strongly suggest orbital motion
FORMATION OF ARTIFICIAL BATIO3/SRTIO3 SUPERLATTICES USING PULSED LASER DEPOSITION AND THEIR DIELECTRIC PROPERTIES

We have formed strained dielectric superlattices of BaTiO3 (BTO) and SrTiO3 (STO) by a pulsed laser deposition technique. A large strain of 400–500 MPa is introduced at the interface between the BTO and STO layers. A large dielectric constant of 900 was observed with a stacking periodicity of 2 unit cells/2 unit cells. The superlattices show drastically different electrical behavior from that of the solid solution (Sr,Ba)TiO3 films. Broad maxima of the dielectric constants occur around 40–50 °C and the values remain large even for a temperature above 200 °C.
A Quantitative Evaluation of Potential Radio Identifications for 3EG EGRET Sources

The method of Mattox et al. for identifying EGRET sources with 5 GHz radio sources has been applied to the 3EG EGRET catalog of Hartman et al. Complete results are tabulated. We tabulate separately 46 EGRET sources with radio identifications which we expect to have a high probability of being correct. We suggest that these sources are appropriate for most studies of the properties of γ-ray blazars as a class. All but one of these 46 sources were classified by Hartman et al. as high-confidence identifications; and the additional source was classified by Hartman et al. as a plausible identification. We also tabulate separately 37 additional "plausible identifications of EGRET sources with radio sources. " These less secure possibilities include the remaining 21 "high-confidence identifications" of Hartman et al., three of the 27 "lower confidence potential blazar identifications" of Hartman et al., and an additional 15 plausible identifications which have not been suggested previously. Many of these sources require new radio and optical observations to establish them as blazars. We suggest that the 23 "lower-confidence potential blazar identifications" of Hartman et al. which we do not find plausible should not be used in studies of the properties of the EGRET blazars. For this analysis, we have made elliptical fits to the 95% confidence contours of the position uncertainty regions of the 3EG sources which are tabulated in an Appendix.
Spectral CT data acquisition with Medipix3.1

This paper describes the acquisition of spectral CT images using the Medipix3.1 in spectroscopic mode, in which the chip combines 2 × 2 pixel clusters to increase the number of energy thresholds and counters from 2 to 8. During preliminary measurements, it was observed that the temperature, DAC and equalisation stability of the Medipix3.1 outperformed the Medipix3.0, while maintaining similar imaging quality. In this paper, the Medipix3.1 chips were assembled in a quad (2 × 2) layout, with the four ASICs bump-bonded to a silicon semiconductor doped as an np-junction diode. To demonstrate the biological imaging quality that is possible with the Medipix3.1, an image of a mouse injected with gold nano-particle contrast agent was obtained. CT acquisition in spectroscopic mode was enabled and examined by imaging a customised phantom containing multiple contrast agents and biological materials. These acquisitions showed a limitation of imaging performance depending on the counter used. Despite this, identification of multiple materials in the phantom was demonstrated using an in-house material decomposition algorithm. Furthermore, gold nano-particles were separated from biological tissues and bones within the mouse by means of image rendering.
Structural analysis of the Minispiral from high-resolution Brγ data

Integral field spectroscopy of a roughly 40″ × 40″ region about the Galactic Center was obtained at 2.16 μm (Br ) using BEAR, an imaging Fourier Transform Spectrometer, at a spectral resolution of 21.3 km s–1and a spatial resolution of ≃0.5″. The analysis of the data was focused on the kinematics of the gas flows concentrated in the neighborhood of SgrA* , traditionally called the “Minispiral”. From the decomposition into several velocity components (up to four) of the line profile extracted at each point of the field, velocity features were identified. Nine distinguishable structures are described: the standard Northern Arm, Eastern Arm, Bar, Western Arc, as well as five additional moving patches of gas. From this analysis, the Northern Arm appears not limited, as usually thought, to the bright north-south lane seen on intensity images, but consists instead of a continuous, weakly-emitting, triangular-shaped surface having a bright western rim, and narrowed at its forward apex in the vicinity of SgrA* where a strong velocity gradient is observed. The gravitational field of the central Black Hole can account for both the strong acceleration in this region and the tidal compression of the forward tip of the Northern Arm. Keplerian orbits can be fitted to the velocity field of the bright lane, which can be interpreted as formed by the bending of the western edge of the flowing surface. These results raise questions regarding the formation of the Sgr A West gas structures.
Scanning reciprocal space for solving unknown structures: energy filtered diffraction tomography and rotation diffraction tomography methods

Abstract Structure solutions of CaFe2O4 from energy filtered and unfiltered precession electron diffraction tomography and rotation electron diffraction tomography data, collected on two different microscopes, are reported. The collected data are analysed with three available software packages (ADT3D, PETS and EDT-PROCESS) and the obtained results are compared. In all cases the structure solution is successfully achieved. Energy filtered precession electron diffraction tomography, performed here for the first time, gives sharper diffraction peaks and less background compared to the unfiltered data and the final recovered model is closer to the X-ray refinement. Simultaneously the first crystal structure solution obtained from the rotation electron diffraction tomography data is reported.
The general state-space model for a two-dimensional linear digital system

The general state-space model for a 2-D linear digital system is presented. A new definition of state-transition matrix is given. Based on the definition, it is easy to calculate the state-transition matrix for any linear digital system. The general response formula for a system follows simply from the definition. A new definition of the characteristic function of a system and a theorem parallel to the Cayley-Hamilton theorem are also given. The presented results apply to any linear causal system.
Determining the Effective Hydraulic Properties of a Highly Heterogeneous Soil Horizon

In this study, we have attempted to determine the effective hydraulic properties of a highly heterogeneous soil horizon composed of two elementary pedological volumes (EPVs). Our upscaling approach was guided by the “scaleway” approach, in which the properties of a complex system can be estimated by multiple discrete upscaling steps. This approach was tested on a data set from laboratory measurements of hydraulic conductivity at the EPV scale, while an explicit three‐dimensional soil structure was considered at the horizon scale. We then formulated a decision tree to guide the choice of the appropriate upscaling method to determine the effective hydraulic conductivity at the horizon scale. In the case of low contrast between hydraulic conductivities at the EPV scale, the effective hydraulic conductivity at the horizon scale can be achieved by calculating the Wiener bounds, which requires only the proportion of the different EPVs. In the case of high contrast between hydraulic conductivities at the EPV scale, we recommend either calculating the Cardwell and Parson bounds, or performing a direct three‐dimensional numerical simulation to solve Richards' equation, which requires an explicit representation of the three‐dimensional structure of the soil horizon. The Cardwell and Parsons bounds remains a good and easily available approximation. Otherwise, more accurate estimation can be obtained by numerical simulation, although this is time consuming. A decision map is proposed to help choose the best method to estimate the effective hydraulic conductivity.
Cone‐Decompositions and Degenerate Critical Points

Let M be a compact, smooth, 2‐connected, 2m‐dimensional manifold with ∂M simply connected. If M has the homotopytype of an m‐dimensional CW‐complex, then it supports a smooth, self‐indexed function, maximal, constant and regular on ∂M with at most cat(M) + 2 critical points, all of which are of a certain ‘reasonable’ type. To such a critical point there corresponds, homotopically, the attachment of a cone. Conversely, to a cone attachment we may associate, under certain dimensionality and connectivity conditions, a ‘reasonable’ critical point. 1991 Mathematics Subject Classification: primary 55M30, 57R70; secondary 58E05, 55P50, 55P62.
Structural heterogeneity and medium-range order in Zr{sub x}Cu{sub 100-x} metallic glasses

Realistic three-dimensional atomistic structures of Zr{sub x}Cu{sub 100-x} (x=35,50) bulk metallic glasses are constructed using a combination of x-ray diffraction experiment and computational modeling. A cluster correlation method is developed to analyze the medium-range order in amorphous systems. We show that the glass systems consist of a stringlike backbone network formed by icosahedral clusters and a liquidlike structure filling in the remaining space. These findings are consistent with those obtained from our independent classical molecular-dynamics studies with embedded-atom method potential for ZrCu system. Such a heterogeneous structure provides a fundamental structural perspective of dynamical heterogeneity and glass formation.
Detection of light speed anisotropy via a high-speed Ives–Stillwell experiment

The Mansouri–Sexl theory is a well-known test of the theory of relativity. In one of their three papers (R. Mansouri and S.U. Sexl. Gen. Rel. Grav. 8, 809 (1977). ), Mansouri and Sexl deal with the transverse Doppler effect under a set of restrictive conditions. In this paper, we deal with the same effect under the most general conditions and will argue for a novel way of detecting high-order effects in a vacuum via an increased laboratory-speed re-enactment of the Ives–Stilwell experiment. We will demonstrate the presence of a high-order error term and we will set the experimental conditions for detecting such a term.PACS No.: 03.30+p
Origin of bcc to fcc phase transition under pressure in alkali metals

The electronic, dynamical and elastic properties of body-centered cubic (bcc) alkali metals (Li, Na, K, Rb and Cs) at high pressure are extensively studied to reveal the origin of the phase transition from bcc to face-centered cubic (fcc) by using ab initio calculations. The calculated 3D Fermi surface (FS) shows an anisotropic deformation by touching the Brillion zone boundary at the N point with pressure for Li, K, Rb and Cs due to the s→p and s→d charge transfers, respectively. However, no clear charge transfer is found in Na, in favor of an isotropic FS even at very high pressure. The traditional charge transfer picture and the newly proposed Home–Rothery model in understanding the bcc→fcc transition are thus questionable in view of their difficulties in Na. In this paper, a universal feature of pressure-induced instability of the tetragonal shear elastic constant C ′ and the softening of the transverse acoustic phonons along the [0ξξ]-direction near the zone center for all the alkali metals is identified. Analysis of the total energy results suggests that C ′ instability associated with the soft mode is the driving force for the bcc→fcc transition, which could be well characterized by the tetragonal Bain's path.
Dynamic behavior of liquids in elastic tanks

The finite element procedure is used in conjunction with a simple source distribution on all surfaces of a liquid, which is contained in a tank of virtually arbitrary geometry, to obtain expressions for the mass and stiffness (because of the gravity) matrices of the liquid. The accuracy of the formulation is evaluated by the numerical solution of eigenvalue problems appropriate to simple rigid tanks for which exact analytical solutions are available. Good agreement is obtained. Once the mass and stiffness matrices of the liquid are obtained, they can be combined with those of an elastic tank in order to study the dynamic behavior of liquids in elastic tanks. The matrices for the elastic tank can be generated by any of a variety of currently available finite element or finite difference programs. The dynamic behavior of a liquid in an elastic circular cylindrical tank is treated by making use of a standard finite element program. Very good agreement with the known exact analytical results is obtained. In addition, a tank geometry which cannot be readily analyzed by any of the previously available methods is considered.