Miracle-dz/UniFAR-FTUs huggingface dataset:
Wide-range (0.33%–100%) 3C–SiC resistive hydrogen gas sensor development

Silicon carbide (SiC) resistive hydrogen gas sensors have been fabricated and tested. NiCr planar ohmic contacts were deposited on both a 4μm 3C–SiC epitaxial film grown on n-type Si(001) and directly on Si to form the resistive sensor structures. Detection at concentrations as low as 0.33% and as high as 100% (H2 in Ar) was observed with the 3C–SiC sensor while the Si sensor saturated at 40%. The 3C–SiC sensors show a remarkable range of sensitivity without any saturation effects typically seen in other solid-state hydrogen gas sensors. Under a constant 2V bias, these sensors demonstrated an increase in current up to 17mA upon exposure to pure H2. Preliminary experiments aimed at determining the gas sensing mechanism of these devices have been conducted and are also reported.
Luminescence properties of the porphyrin/porous silicon composites

A study of luminescence properties of water‐soluble and hydrophobic porphyrin and chlorin molecules immobilized in oxidized (i.e. non‐luminescent) and as‐prepared (i.e. luminescent) porous silicon (porSi) layers is carried out. It is found that the oxidized porSi matrix itself does not introduce any quenching effect on the porphyrin fluorescence, but the fluorescence is subjected to the concentration quenching. At maximum porphyrin/chlorin concentration used (ca. 10–3 M in impregnation solutions) the quenching is strong in case of hydrophobic porphyrins and sufficiently moderate for water‐soluble ones, especially for cationic porphyrin TMPyP4. A concentration of the latter in porSi layer is determined by direct measurements. Both hydrophobic and water‐soluble porphyrins immobilized on the surface of as‐prepared porSi are found to quench the luminescence of the latter. In case of hydrophobic porphyrins the quenched porSi luminescence is regained almost to the initial value on the time scale of tens of hours, whereas in case of water‐soluble porphyrins the fluorescence spectrum of the latter builds up in course of time. Possible mechanisms responsible for these effects are discussed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Boltzmann Equation in the Theory of Electrical Conduction in Metals

The motion of conduction electrons in a metal in an electric field, scattered by an irregular static potential, is considered; this model is applicable to the resistance due to lattice waves at high temperatures, and to imperfections at any temperature. In §2 the Boltzmann equation is re-derived without the customary perturbation theory, avoiding the usual necessity of averaging over phases of different electron states after repeated small time intervals. The assumption that the scattering centres are distributed at random in the crystal is alone sufficient. The theory is, however, still dependent on assuming that h/τ<<kT, where τ is the collision time, as is the usual perturbation theory. §3 gives a general formula for the conductivity of the model, not subject to any assumption. This helps to justify an argument by Landau according to which the usual theory is valid provided h/τ<<η, where η is the cut-off energy of the Fermi distribution. No direct evaluation of the formula has been achieved.
Inelastic Scattering of Thermal Neutrons from Liquid Helium

The scattering of neutrons by liquid helium has been studied over a wide range of wave-vector transfers, 0.2 < Q < 9.0 A−1, and energy transfers . The measurements were performed with both a time-of-flight rotating crystal spectrometer and a triple-axis crystal spectrometer. The scattering at 1.1 °K showed a sharp one-phonon peak and a broad diffuse background. Measurements have been made of the energy and intensity of both components. At large wave-vector transfers the scattering is of the form expected from a system of almost free helium atoms. Measurements of the temperature dependence of the results at the smallest and largest wave vectors have been made. In the former case they show well-defined excitations above the λ point which are better defined for large wave vectors, while in the latter case they can be interpreted as giving evidence for the macroscopic occupation of the zero-momentum state. The results are compared with the available theoretical predictions.
Pulsar disk systems

We argue that the radio pulsars and the X-ray pulsars differ mainly in the fact that the latter are surrounded by an accretion disk, while the former are surrounded by a fossil collapse disk presumably left over from the formation event. We attribute the difference between these two types of pulsars to a strong interaction (enforced accretion) of the X-ray pulsars with their disks as opposed to a relatively weak interaction (and negligible accretion) in the case of the radio pulsars. A number of observational problems (e.g., role of alignment, ion confinement, nulling, drifting subpulses, braking index, residuals, and the supernova association) are readily addressed in terms of the disk model. Moreover, the model is consistent with a ''hollow cone'' type of emission pattern. Rough estimates here suggest that pulsars with disks could function with magnetic fields at the neutron star surface as low as 10/sup 9/ gauss, far below that often assumed; conventional field strengths of 10/sup 12/ gauss are not excluded, however.
Control system design by using a multi-controller approach with a real-time experimentation for a robot wrist

The idea of the multi-controller approach is to design local controllers, each of them combined with a special environment. One problem of this approach is to select the best local controller or even several controllers in order to design the final control law, which will be applied to the plant. In this paper, a 'switching' algorithm based on a symbolic fuzzy system is used. The main goal is basically to blend the control signals provided by several controllers, which are modelreference output feedback controllers (RST controllers) in our method. Nonetheless, an interesting issue is the stability of the global structure with a reference signal. In this paper, we present research studies on the stability analysis of the proposed multi-controller approach by using Lyapunov theory and linear matrix inequalities (LMIs). The derivative of a candidate quadratic Lyapunov function is calculated thanks to a weighted sum of local derivatives. Finally, a real-time experimentation on a robot wrist shows the effectiveness of the approach.
An integrated statistical approach for volume reconstruction from unregistered sequential slices

We address the problem of volume reconstruction from a sequence of cross-sections in the case where the cross-section positions are unknown. This implies performing simultaneous registration and reconstruction. We propose a statistical formulation of the problem leading to an energy minimization algorithm as well as an automatic calibration procedure for the energy parameters. This method has been developed in the context of micro-rotation confocal microscopy. Experiments in this context illustrate the ability of this method to reconstruct efficiently the object of interest.
The Spectroscopy of Quantum Dot Arrays

For three decades individual transistors in integrated semiconductor circuits have been getting smaller and smaller. Soon they will be approaching the 100‐nanometer regime, where the classical description of diffusive electron motion breaks down and quantum concepts become important, bringing about fundamental changes in electronic and optical properties. Already in the widely used silicon MOSFET transistors, the interface between the semiconductor and the oxide layer serves as a potential well less than 10 nm wide. While electrons remain free to wander in the plane of the interface, their motion in the perpendicular direction is quantized by this very narrow well. Such two‐dimensional electron systems, best realized in high‐mobility modulation‐doped semiconductor heterostructures, have been found over the years to exhibit new and quite unexpected quantum phenomena, like the integral and fractional quantum Hall effects.
TWO- AND THREE-DIMENSIONAL ALGORITHMS FOR MICROWAVE IMAGING AND INVERSE SCATTERING

In this paper the Contrast Source Inversion method using a multiplicative weighted L2-norm Total Variation regularizer is applied to two- and three-dimensional image reconstruction from electromagnetic microwave tomography data. This iterative method avoids solving a full forward problem in each iteration which makes the method suitable to handle a large scale computational problem. Numerical results both from simulation and experimental data with high contrast biological objects in two- and three-dimensional are presented and discussed.
Whispering-gallery modes and permeability tensor measurements in magnetized ferrite resonators

Whispering-gallery modes in axially magnetized ferrite disk samples have been studied using rigorous Rayleigh-Ritz and finite-element analyses. The influence of radial magnetization on the resonant frequencies of both WGE and WGH modes was investigated, both theoretically and experimentally. Permeability tensor components of biased ferrites were determined from measurements of the resonant frequencies of the WGH/sub n00/ and the WGE/sub n00/ mode families.
The X-ray cluster Abell 744

X-ray and optical observations of the cluster of galaxies Abell 744 are presented. The X-ray flux (assuming H(0) = 100 km/s per Mpc) is about 9 x 10 to the 42nd erg/s. The X-ray source is extended, but shows no other structure. Photographic photometry (in Kron-Cousins R), calibrated by deep CCD frames, is presented for all galaxies brighter than 19th magnitude within 0.75 Mpc of the cluster center. The luminosity function is normal, and the isopleths show little evidence of substructure near the cluster center. The cluster has a dominant central galaxy, which is classified as a normal brightest-cluster elliptical on the basis of its luminosity profile. New redshifts were obtained for 26 galaxies in the vicinity of the cluster center; 20 appear to be cluster members. The spatial distribution of redshifts is peculiar; the dispersion within the 150 kpc core radius is much greater than outside. Abell 744 is similar to the nearby cluster Abell 1060. 31 references.
Hadron accelerators for radiotherapy

Over the last twenty years the treatment of cancer with protons and light nuclei such as carbon ions has moved from being the preserve of research laboratories into widespread clinical use. A number of choices now exist for the creation and delivery of these particles, key amongst these being the adoption of pencil beam scanning using a rotating gantry; attention is now being given to what technologies will enable cheaper and more effective treatment in the future. In this article the physics and engineering used in these hadron therapy facilities is presented, and the research areas likely to lead to substantive improvements. The wider use of superconducting magnets is an emerging trend, whilst further ahead novel high-gradient acceleration techniques may enable much smaller treatment systems. Imaging techniques to improve the accuracy of treatment plans must also be developed hand-in-hand with future sources of particles, a notable example of which is proton computed tomography.
Local Likelihood Analysis of Survival Data With Censored Intermediate Events

AIDS Clinical Trials Group protocol 193A was a randomized trial designed to compare survival and progression-free survival among patients on different treatment regimens. A complicating feature of the analysis of progression-free survival is that different censoring mechanisms operated on progression and survival, which resulted in more complete information on survival. A simple analysis that uses the minimum of the times to progression and survival and the minimum of the corresponding censoring times may sacrifice the extra information available on survival. To address this problem, we have developed a method that exploits the bivariate nature of these data and thereby uses all of the available information. We obtain smooth, nonparametric estimates of the hazard functions for a terminal event, before and after the occurrence of an intermediate event. These hazards can be used to estimate the distribution of progression-free survival. Our method uses local likelihood estimation, which assumes that the underlying true hazard functions can be approximated locally by polynomials. We use an iterative imputation algorithm to perform the estimation when the intermediate events are right censored.
The Use of Tensors to Describe and Predict Fiber Orientation in Short Fiber Composites

The properties of a set of even‐order tensors, used to describe the probability distribution function of fiber orientation in suspensions and composites containing short rigid fibers, are reviewed. These tensors are related to the coefficients of a Fourier series expansion of the probability distribution function. If an n‐th‐order tensor property of a composite can be found from a linear average of a transversely isotropic tensor over the distribution function, then predicting that property only requires knowledge of the n‐th‐order orientation tensor. Equations of change for the second‐ and fourth‐order tensors are derived; these can be used to predict the orientation of fibers by flow during processing. A closure approximation is required in the equations of change. A hybrid closure approximation, combining previous linear and quadratic forms, performs best in the equations of change for planar orientation. The accuracy of closure approximations is also explored by calculating the mechanical properties o.
Stability of a Random diffusion with linear drift

We consider a linear system with Markovian switching which is perturbed by Gaussian type noise. If the linear system is mean square stable then we show that under certain conditions the perturbed system is also stable. We also show that under certain conditions the linear system with Markovian switching can be stabilized by such noisy perturbation.
Steady wake behind a sphere

The characteristics of the steady wake behind a sphere were studied experimentally using dyed water for visualization. This work infers the possibility of the existence of a closed recirculating eddy behind a sphere even at R=10 or lower and shows that the eddy can preserve its steady state up to the case for R=190 (R represents the Reynolds number based on the diameter of the sphere). In addition, a new profile for the variation of the wake separation angle against the steady state Reynolds number is presented.
A Hybrid Mode-Matching Point-Matching Technique for Calculation of Dispersion Curve of Strip Gratings

Abstract The rigorous mode-matching technique combined with point matching is used in this article to find the dispersion curve of the traveling wave in a 1-D strip grating backed by a grounded homogeneous dielectric substrate. The strips are assumed to be infinitely thin. Unlike regular mode matching, a simple sub-domain orthogonal set is used in order to convert the algebraic equations obtained from boundary conditions into a matrix format. There is a good agreement between the results obtained using the proposed method and what was reported in the previous literature.
Stress integration approach to evaluate damping ratio in torsional tests

The complexity of determining strain associated with shear modulus and damping ratio in torsional tests has been resolved by means of several approaches. The stress integration approach is adequate when generating the plots of equivalent radius ratio versus strain more effectively over any range of strains in resonant column and torsional shear (RC/TS) tests. The stress integration approach was applied for hyperbolic, modified hyperbolic, and Ramberg–Osgood models in evaluating damping ratio. This study showed that using a single value of equivalent radius ratio in evaluating damping ratio is not appropriate. The combined hysteretic‐nonviscous damping model was developed and employed to consider the increased damping behavior at small strains using the stress integration approach. The results suggest that adding viscous behavior has no significant effect strain calculations in RC/TS testing. Copyright © 2010 John Wiley & Sons, Ltd.
Impurity survey after boronization in ASDEX Upgrade measured by a collector probe

Wall conditioning is carried out in today's fusion machines to control the plasma impurity content. In ASDEX Upgrade boronization is routinely used to optimize the plasma start-up in the limiter phase and the performance of low-density, high power scenarios. We present data on the impurity content in the scrape-off layer (SOL) immediately after a boronization monitored at eight consecutive, nearly identical H-mode discharges. Discharge-resolved measurements of the deposition of impurity species on a collector probe were carried out in the outer midplane of ASDEX Upgrade. While the amount of collected boron decreases slowly the impurity concentration of most elements increases slowly and steadily. The collected amount of the first wall material tungsten was below the detection limit. Spectroscopic data observe an increase at a very low level. In contrast Ca and Fe, possible precursors of dust formation, increase at a significantly higher rate.
Gaussian quadrature involving Einstein and Fermi functions with an application to summation of series

Polynomials 7rk(*) rk(* d X), k = 0,1, 2,. are constructed which are orthogonal with respect to the weight distributions dA(t) = (t/(et 1))' dt and dA(t) = (1/(et + 1))' dt, r = 1,2, on (0, oo). Moment-related methods being inadequate, a discretized Stieltjes procedure is used to generate the coefficients ak, Pk in the recursion formula 7rk+1(t) = (t ak) k(t) fk7rk1-(t), k = 0,1,2, . , so(t) = 1, 17j l(t) = 0. The discretization is effected by the Gauss-Laguerre and a composite Fejer quadrature rule, respectively. Numerical values of ak, IPk, as well as associated error constants, are provided for 0 < k < 39. These allow the construction of Gaussian quadrature formulae, including error terms, with up to 40 points. Examples of n-point formulae, n = 5(5)40, are provided in the supplements section at the end of this issue. Such quadrature formulae may prove useful in solid state physics calculations and can also be applied to sum slowly convergent series.
An Addendum to Kronecker’s Theory of Pencils

A natural group action on a three-tensor is considered in a special case where one of the vector spaces is two-dimensional. We are concerned with finding a complete set of invariants under this group action. Kronecker’s theory of pencils is viewed as giving a solution to this problem in the case of a smaller group action. In this paper we extend these results to get a complete set of invariants under the larger and more natural group action. This has direct implications on a problem in computational complexity: that of the optimal evaluation of a pair of bilinear forms.
Optimum phase noise reduction and repetition rate tuning in quantum-dot mode-locked lasers

Competing approaches exist, which allow control of phase noise and frequency tuning in mode-locked lasers, but no judgement of pros and cons based on a comparative analysis was presented yet. Here, we compare results of hybrid mode-locking, hybrid mode-locking with optical injection seeding, and sideband optical injection seeding performed on the same quantum dot laser under identical bias conditions. We achieved the lowest integrated jitter of 121 fs and a record large radio-frequency (RF) tuning range of 342 MHz with sideband injection seeding of the passively mode-locked laser. The combination of hybrid mode-locking together with optical injection-locking resulted in 240 fs integrated jitter and a RF tuning range of 167 MHz. Using conventional hybrid mode-locking, the integrated jitter and the RF tuning range were 620 fs and 10 MHz, respectively.
A coupled energy transport and hydrological model for urban canopies evaluated using a wireless sensor network

We propose a new surface exchange scheme coupling the transport of energy and water in urban canopies. The new model resolves the subfacet heterogeneity of urban surfaces, which is particularly useful for capturing surface exchange processes from vegetated urban surfaces, such as lawns or green roofs. We develop detailed urban hydrological models for surfaces consisting of either natural (soil and vegetation) or engineered materials with water‐holding capacity. The coupling of energy and water transport enables us to parametrize surface evaporation from different urban facets including soils, vegetation and water‐holding engineered surfaces. The new coupled model is evaluated using field measurement data obtained through a wireless sensor network deployed over the Princeton University campus. Comparison of model prediction and measured results shows that the proposed surface exchange scheme is able to predict widely varying surface temperatures for each subfacet with good accuracy. Different weather conditions and seasonal variability are found to have insignificant effect on the model performance. The new model is also able to capture the subsurface hydrological processes with reasonable accuracy, particularly for urban lawns. The proposed model is then applied to assess different mitigation strategies of the urban heat island effect.
Active sorting switch for biological objects

Active contactless optical sorting of microobjects represents very useful technique in many areas of biology, chemistry, and medicine. We suggest here a configuration that combines optical sorting, trapping, excitation, and detection paths and provides efficient sorting of biological samples according to their various parameters (fluorescence, Raman spectrum, CCD image, motion etc.). This approach is based on the shape of the laser beam and we succeeded in sorting of several types of living microorganisms.
Metalorganic chemical vapor deposition of atomically flat SrRuO3 films on stepped SrTiO3 substrates

Epitaxial SrRuO3 films with thicknesses of 50–80nm were systematically grown at 750°C on (100)SrTiO3 substrates by metalorganic chemical vapor deposition with different supply rates of the Sr and Ru source gases. Stoichiometric films with a low resistivity of 240–260μΩcm can be grown on polished (100)SrTiO3 substrates over a wide range of source gas supply rates. However, the surface flatness of the deposited film was very sensitive to changes the input source gas supply rate. SrRuO3 films having step and trace structured surfaces were grown on polished and atomically flat SrTiO3 substrates under an optimized input gas supply rate. A height of 7–8nm with a terrace width of 500–1000nm were obtained on polished SrTiO3 substrates, but a single unit cell height of about 0.4nm was obtained with a 200–300nm terrace width on atomically flat SrTiO3 substrates. This opens the possibility of the mass production of atomically flat conductive perovskite layers.
Fast magnetic field-line reconnexion in a compressible fluid. Part 2. Skewed field lines

Petschek's model of compressible reconnexion developed in part 1 is extended to include an additional transverse magnetic field. Part of the incoming Poynting flux is degraded into kinetic energy at an intermediate wave (rotational) discontinuity. Yet more is degraded into heat and kinetic energy at a slow shock lying downstream of it. Everywhere downstream of the rotational discontinuity, the transverse magnetic field exceeds its upstream value. As a result, the total release of magnetic energy from the antiparallel components of the incoming magnetic field calculated in part 1 is decreased by a factor lying between a half and unity. The weak radial inhomogeneity exemplified by the ‘local’ similarity solution is determined by consideration of the fast and slow magneto-acoustic and Alfvén waves emitted at the neutral point. The Alfvén waves lead to a weak singularity in the vicinity of the rotational discontinuity, while a similar singularity is found in the vicinity of the outflow axis of symmetry associated with an entropy wave.