Miracle-dz/UniFAR-FTUs huggingface dataset:
Temperature dependence of coercivity in melt-spun and die upset neodymium-iron-boron

We compare the temperature dependence of the intrinsic coercivity Hci between 5 and 600 K in rapidly quenched Nd‐Fe‐B ribbons and a die upset Nd‐Fe‐B magnet. At room temperature, ribbons have higher coercivity than the die upset magnet, but have a smaller technical temperature coefficient of coercivity β between 25 and 125 °C: Hci=15.1 kOe and β=−0.38%/°C for the ribbons, while Hci=10.4 kOe and β=−0.64%/°C for the die upset magnet. Because the die upset magnet has a stronger temperature dependence, the Hci(T) curves converge at low temperature. The ribbons can be phenomenologically modeled using Hci(T)=cHA(T)−Neff4πMs(T), the two terms representing the strength of domain wall pinning at grain boundaries and the effective local demagnetizing field, respectively. The model parameters c=0.25 and Neff=0.26 are significantly smaller than the corresponding values obtained in sintered Nd‐Fe‐B magnets. This model is less successful in describing Hci(T) for the die upset magnet. Their qualitatively different behav.
Analysis of electron injection in laser wakefield acceleration using betatron emission in capillary tubes

The dynamics of ionization-induced electron injection in the high density (~ 1:2 × 1019cm-3) regime of Laser Wakefield Acceleration (LWFA) was investigated by analyzing betatron X-ray emission inside dielectric capillary tubes. A comparative study of the electron and betatron X-ray properties was performed for both self-injection and ionization-induced injection. Direct experimental evidence of early onset of ionization-induced injection into the plasma wave was obtained by mapping the X-ray emission zone inside the plasma. Particle-In-Cell (PIC) simulations showed that the early onset of ionization-induced injection, due to its lower trapping threshold, suppresses self-injection of electrons. An increase of X-ray fluence by at least a factor of two was observed in the case of ionization-induced injection due to an increased trapped charge compared to self-injection mechanism.
Higher Initial Ideals of Homogeneous Ideals

Introduction Borel-fixed ideals Monomial orders Some algebraic lemmas Defining the higher initial ideals Representing the higher initial ideals Group action on $R^{s+1}(I)$ Describing the action on $R^{s+1}(I)$ Borel-fixedness Higher initial ideals of hyperplane sections Representing the higher initial ideals of general hyperplane sections Higher initial ideals as combinatorial structures Reading cohomological information Examples: Points and curves in $\mathbf P^3$ References.
Characterization of spectral and spatial distributions of penetration, scatter and lead X-rays in Ga-67 SPECT

Ga-67, a tumor-seeking imaging agent, has proven useful in the management of Hodgkin's disease and non-Hodgkin's lymphoma. However, Ga-67 presents challenges to accurate lesion detection and activity quantitation due to the range of energies of the gamma rays emitted. Medium- to high-energy photons produce collimator penetration, scatter and lead X-rays, which degrade contrast, resolution and quantitation in images of the more abundant, lower-energy photons. To study the effects of these interactions and to provide a tool for detection and estimation studies, the authors developed and tested a Monte Carlo (MC) simulation program. Simulated characteristic lead X-rays were compared with the difference of measurements made with and without the camera collimator, using Tc-99m (140.5 keV) in a tin source-collimator. Simulated energy spectra and images were compared with measurements of Cr-51 (320 keV) to evaluate collimator penetration and scatter, and backscatter from components behind the NaI crystal. Finally, spectra and images were compared for several emission peaks of Ga-67. The simulation provided good estimates of both spectral and spatial distributions.
Pressure regulation for earth pressure balance control on shield tunneling machine by using adaptive robust control

Most current studies about shield tunneling machine focus on the construction safety and tunnel structure stability during the excavation. Behaviors of the machine itself are also studied, like some tracking control of the machine. Yet, few works concern about the hydraulic components, especially the pressure and flow rate regulation components. This research focuses on pressure control strategies by using proportional pressure relief valve, which is widely applied on typical shield tunneling machines. Modeling of a commercial pressure relief valve is done. The modeling centers on the main valve, because the dynamic performance is determined by the main valve. To validate such modeling, a frequency-experiment result of the pressure relief valve, whose bandwidth is about 3 Hz, is presented as comparison. The modeling and the frequency experimental result show that it is reasonable to regard the pressure relief valve as a second-order system with two low corner frequencies. PID control, dead band compensation control and adaptive robust control (ARC) are proposed and simulation results are presented. For the ARC, implements by using first order approximation and second order approximation are presented. The simulation results show that the second order approximation implement with ARC can track 4 Hz sine signal very well, and the two ARC simulation errors are within 0.2 MPa. Finally, experiment results of dead band compensation control and adaptive robust control are given. The results show that dead band compensation had about 30° phase lag and about 20% off of the amplitude attenuation. ARC is tracking with little phase lag and almost no amplitude attenuation. In this research, ARC has been tested on a pressure relief valve. It is able to improve the valve’s dynamic performances greatly, and it is capable of the pressure control of shield machine excavation.
Space rigidized resin fiberglass sandwich materials.

Fiberglass sandwich materials, of both woven and sewn construction, have great potential as the reinforcement for plastic laminated space structures. Techniques have been developed for impregnating the fiberglass sandwich with plastic resins, packaging the impregnated material in a small volume, and deploying and rigidizing the full size structure in the space environment. The resinous matrices and the method of curing (rigidizing) are: gelatin, hardened by solvent loss; polyester, with ultraviolet initiated cure; polyurethane foam, thermally cured; and gas catalyzed polyurethane resin. The chemical rigidizing systems are compared for handling characteristics, storage life, systems limitations, and rigidizing time. Strength properties of rigidized sandwich and flat laminates are presented. The gelatin system has special promise because it is hardened only by the vacuum of space, and it has a high degree of plastic memory. Also the gelatin/fiberglass rigidization is reversible. A gelatin structure can be rigidized and hardened, tested on the ground, and then replasticized for use in space. All of the materials appear to be suitable for fairly long time use in the space environment.
Thirteen‐Moment Theory of the Thermal Force on a Spherical Particle

A linearized version of Grad's thirteen‐moment equations have been solved with generalized velocity slip and temperature jump boundary conditions, and a theory of the thermal force acting on a spherical particle obtained for the entire range of Knudsen numbers. The theory is in good general agreement with all experimental data and gives the correct dependence on the thermal conductivity of the particle. In the range of large Knudsen numbers the solution is functionally the same as Waldman's and also gives the correct infinite mean free path limit. As a by‐product of the theory, thermal accommodation coefficients can be predicted with fair to good accuracy. For particles of high thermal conductivity and high thermal accommodation coefficient, the theory also predicts the possibility of a reversal of the thermal force near the continuum limit.
Stress induced effects for advanced polarization control in silicon photonics components

We review the use of the oxide cladding stress-induced photoelastic effect to modify the polarization dependent properties in silicon-on-insulator (SOI) waveguide components, and highlight characteristics particular to this high index contrast (HIC) systems. The birefringence in SOI waveguides has its origin in the electromagnetic boundary conditions at the waveguide boundaries, and can be further modified by the presence of stress in the waveguiding materials. With typical stress levels in S i O 2 films, which are often used as the upper cladding, the waveguide effective index can be altered anisotropically up to the order of 1 0 − 3 for ridges with heights ranging from 1 𝜇 m to 5 𝜇 m. This effect can be used effectively to counter the waveguide geometrical birefringence, allowing the waveguide cross-section profiles to be optimized for design criteria other than null geometrical birefringence. Design strategies are developed for using stress engineering to achieve a variety of functions. Polarization insensitive arrayed waveguide gratings (AWGs), polarization insensitive ring resonators, and polarization splitters and filters are demonstrated using these design principles.
Open‐loop stable solutions of periodic optimal control problems in robotics

We present a numerical method that optimizes the open‐loop stability of solutions of periodic optimal control problems. We consider general periodic processes that may have several phases, each characterized by its own set of differential equations, and discontinuities of the state variables and the right hand side between phases. Stability is measured in terms of the spectral radius of the monodromy matrix which results in a nonsmooth optimization criterion. We have applied this method to design walking robots that can perform stable periodic gaits without any sensors or feedback; three such examples are presented in this paper.
Censored regression with the multistate accelerated sojourn times model

Many disease processes are characterized by two or more successive health states, and it is often of interest and importance to assess state‐specific covariate effects. However, with incomplete follow‐up data such inference has not been satisfactorily addressed in the literature. We model the logarithm‐transformed sojourn time in each state as linearly related to the covariates; however, neither the distributional form of the error term nor the dependence structure of the states needs to be specified. We propose a regression procedure to accommodate incomplete follow‐up data. Asymptotic theory is presented, along with some tools for goodness‐of‐fit diagnostics. Simulation studies show that the proposal is reliable for practical use. We illustrate it by application to a cancer clinical trial.
Magnetostriction in rare-earth based antiferromagnets

Magnetostriction in systems with rare-earth elements is a very general topic of interest because it characterizes the electronic magnetism of compounds as well as the interaction of the magnetic and the lattice system. The magnetostrictive behaviour of classical ferromagnets is widely investigated. The interpretation of the data is based on domain dynamics, crystal field effects and other magnetoelastic mechanisms, which are extremely difficult to separate. Therefore, in the last few years there has been great activity in the area of magnetostriction of antiferromagnets. In contrast to ferromagnets, in antiferromagnets a large variety of magnetic structures can be stabilized at different temperatures and magnetic fields. This fundamental property of antiferromagnets allows one to separate and distinguish the different mechanisms of magnetostriction. New classes of magnetic compounds with antiferromagnetic order, for example the borocarbides and some special manganites, have also focused research efforts on the magnetostrictive behaviour in order to gain a more complex picture of these materials. In particular, changes of symmetry caused by lattice distortions attracted great interest. Moreover, some antiferromagnetic compounds with giant magnetostrictive effects of more than 1% have been found and the number of publications in this area is growing. The aim of the present review is to summarize experimental data as well as theoretical models concerning spontaneous and forced magnetostriction in antiferromagnetic systems, where the magnetic properties are dominated by the rare-earth magnetism. Above this, the available data, which were acquired with different motivations and therefore are of heterogeneous character, are systematized. After a summary of experimental methods the standard model of rare-earth based magnetostriction is reviewed. Then experimentally determined expansion and magnetostriction data of the pure rare-earth metals are discussed followed by selected rare-earth compounds and giant magnetostriction materials. The potential of a theoretical model which takes into account the crystal field effects as well as the (anisotropic) exchange striction is demonstrated in the interpretation of some of the experimental data.
Evaluation of a real-time polymerase chain reaction assay using analyte-specific reagents for detection of methicillin-resistant Staphylococcus aureus nasal carriage.

OBJECTIVE To validate a real-time polymerase chain reaction (PCR) assay for the detection of methicillin-resistant Staphylococcus aureus (MRSA) that is capable of accommodating 30 patient samples in a single batch without compromising the level of sensitivity and specificity associated with PCR testing. STUDY DESIGN A real-time PCR analyte-specific reagent (ASR) assay was compared to conventional culture methods using dual swab samples collected from the nares of 151 patients. RESULTS Of the 151 specimens, 49 (32%) were positive for MRSA by PCR, whereas 40 (26%) were positive by culture methods. The Roche LightCycler 2.0 (Roche Diagnostics, Indianapolis, Indiana, U.S.A.) and its associated ASRs were capable of analyzing 30 patient samples and 2 controls in < 2 hours. Current data suggest that 4-10% of our patient specimens harbor both coagulase negative Staphylococcus and S aureus in the same sample. Samples such as this are reflexed to culture, only 24% of which contain MRSA. Efficiency in the laborato-ry was greatly improved. The sensitivity, specificity, positive predictive value and negative predictive value were 100%, 92%, 82% and 100%, respectively. CONCLUSION The Roche LightCycler 2.0 PCR platform is a sensitive and efficient screening method for determining the nasal carriage of MRSA with a rapid turnaround time in the clinical laboratory.
Single-shot dynamic transmission electron microscopy

A dynamic transmission electron microscope (DTEM) has been designed and implemented to study structural dynamics in condensed matter systems. The DTEM is a conventional in situ transmission electron microscope (TEM) modified to drive material processes with a nanosecond laser, “pump” pulse and measure it shortly afterward with a 30-ns-long probe pulse of ∼107 electrons. An image with a resolution of <20nm may be obtained with a single pulse, largely eliminating the need to average multiple measurements and enabling the study of unique, irreversible events with nanosecond- and nanometer-scale resolution. Space charge effects, while unavoidable at such a high current, may be kept to reasonable levels by appropriate choices of operating parameters. Applications include the study of phase transformations and defect dynamics at length and time scales difficult to access with any other technique. This single-shot approach is complementary to stroboscopic TEM, which is capable of much higher temporal resolution .
Fabrication and lateral electronic transport measurements of gold nanowires

A technique for fabrication of gold nanowires on a Si(111) surface in ultrahigh vacuum and their electronic transport properties are presented. Gold wires with widths as small as 4 nm are produced by using a gold-coated piezoresistive cantilever in atomic force microscope contact mode. This technique allows patterns to be written at will. In situ electronic transport measurements of a gold wire as long as 7 μm and 4 nm wide show unambiguous metallic behavior. This fabrication method could become pivotal within the next generation of nanoscale microprocessors.
Global minimum structure optimisation of Lennard-Jones clusters by hybrid PSO

Structural optimisation of Lennard-Jones clusters (LJ) is a classical NP-hard problem due to the exponential increased local optima. In this paper, a hybrid particle swarm optimisation (PSO) is designed to solve this problem. To increase the escaping probability from local optimum, each particle maintains two different phase motion: attraction and repulsion in which attraction phase aims to exploitation, while repulsion motion tends to make the exploration capability. To further increase the population diversity, one-Gaussian mutation is applied to the best location found by entire swarm. Then, a well-known local search strategy, limited memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS) is employed to make an efficient local search. Simulation results show this new hybrid algorithm is effective for LJ2-LJ17 when compared with standard version and original attractive and repulsive PSO.
Einstein Observatory survey of X-ray emission from solar-type stars - The late F and G dwarf stars

Results of a volume-limited X-ray survey of stars of luminosity classes IV and V in the spectral range F7-G9 observed with the Einstein Observatory are presented. Using survival analysis techniques, the stellar X-ray luminosity function in the 0.15-4.0 keV energy band for both single and multiple sources. It is shown that the difference in X-ray luminosity between these two classes of sources is consistent with the superposition of individual components in multiple-component systems, whose X-ray properties are similar to those of the single-component sources. The X-ray emission of the stars in our sample is well correlated with their chromospheric CA II H-K line emission and with their projected equatorial rotational velocity. Comparison of the X-ray luminosity function constructed for the sample of the dG stars of the local population with the corresponding functions derived elsewhere for the Hyades, the Pleiades, and the Orion Ic open cluster confirms that the level of X-ray emission decreases with stellar age. 62 references.
Inverse Magnetostrictive Effect of Ultrasonic Stress Waves in Steel

The pronounced changes in the state of magnetization of ultrasonically, irradiated SAE 1019 steel are utilized to determine acoustic stresses, modes of propagation of 20‐kc/sec ultrasonic‐stress waves, and variations in these parameters as functions of acoustic energy density (⩽109 erg/cm3) superimposed static tensile stress (⩽1010 dyn/cm2), and temperature (⩽Curie point). The quantitative results from these studies are fundamental for research on the mechanisms of plastic deformation, zone melting, and fracturing of metal crystals by high‐amplitude ultrasonic stress waves. The results also reveal potentials of inverse magnetostriction in investigations on magnetization, and relations between magnetostriction and Young's modulus, phase transition, and phenomena associated with the internal structure of the materials.
Efficient construction and solution of MoM matrix equation with compressed sensing technique

A novel method which employs the recently developed theory of compressed sensing (CS) in method of moments (MoMs) is presented. With linear transform, the construction of the impedance matrix and the solving of the unknown vector in MoM are converted into the construction of a sparse matrix and the solving of a sparse vector, respectively. Under this framework of sparsity, the CS technique can be introduced to construct highly underdetermined equations, which can be solved with the orthogonal matching pursuit algorithm. Thus, the computational cost of both impedance matrix construction and MoM equation solving can be saved dramatically. The performance of the proposed method is illustrated by numerical studies of electromagnetic field integral equations.
Vibrations and Waves

• Simple Harmonic Motion • Energy in the Simple Harmonic Oscillator • The Period and Sinusoidal Nature of SHM • The Simple Pendulum • Damped Harmonic Motion • Forced Vibrations; Resonance • Wave Motion • Types of Waves: Transverse and Longitudinal • Energy Transported by Waves • Intensity Related to Amplitude and Frequency • Reflection and Transmission of Waves • Interference; Principle of Superposition • Standing Waves; Resonance • Refraction • Diffraction • Mathematical Representation of a Traveling Wave
Radiation resistance of compound semiconductor solar cells

1‐MeV electron irradiation effects on molecular beam epitaxy‐grown AlGaAs and InGaAs solar cells have been determined and compared with our previous results for radiation damage of InP and GaAs solar cells in order to clarify radiation resistance of compound semiconductor solar cells. Differences of radiation resistance of AlGaAs, GaAs, and InGaAs cells are found to be explained by band‐gap energy effects on solar cell degradation. Moreover, 1‐MeV electron irradiation results of several solar cells such as InP, InGaP, InGaAsP, GaAs, AlGaAs, InGaAs, Si, Ge, and CuInSe2 have also been analyzed by considering their damage constants, band‐gap energies, and optical absorption coefficients. It is found that superior radiation‐resistance of CuInSe2 and InP‐based solar cells is explained by the higher optical absorption coefficient of CuInSe2 and lower defect introduction rates (damage constants) of InP‐based materials compared to other compound semiconductor materials.
Analytic framework for the modeling of effective media

Synthetic materials in which new electromagnetic properties are obtained from the combination of two or more materials have been of theoretical and practical interest for nearly a century. The ability to explain and predict the properties of these materials has traditionally relied on combining physicomathematical models of the effective environment seen by the various constituents of the mixture with some assumptions about the way these microscopic properties should translate into macroscopic homogeneous parameters. Thus, even in the simplest case of the binary mixture, with every new set of assumptions, a new effective medium theory (EMT) results, and, with each new theory, stronger claims of correctness and applicability are made. This issue of correctness becomes critical when the properties of one of the constituents is unknown a priori and the claim is made that by inverting a fit of experimental results to the EMT model those properties can be ascertained. For this inverse procedure to be possible,.
A Census of Planar Triangulations

Let P be a closed region in the plane bounded by a simple closed curve, and let S be a simplicial dissection of P. We may say that S is a dissection of P into a finite number α of triangles so that no vertex of any one triangle is an interior point of an edge of another. The triangles are ‘'topological” triangles and their edges are closed arcs which need not be straight segments. No two distinct edges of the dissection join the same two vertices, and no two triangles have more than two vertices in common.
The Ca II infrared triplet as indicator of anomalous Ca isotopic mixture in HgMn stars

For the first time we present observational evidence for an anomalous isotopic structure of Ca  in mercury-manganese (HgMn) stars. The centroid wavelengths of Ca  infrared triplet lines in a number of stars have been found redshifted with respect to the centroids of the terrestrial Ca  lines. The record holder is the star HD 175640 for which the measured wavelength is consistent with Ca  being present in the atmosphere entirely in form of the heaviest stable iso- tope 48 Ca. This is a very striking result as 48 Ca makes up only 0.187% of the terrestrial Ca mixture.