Miracle-dz/UniFAR-FTUs huggingface dataset:
Theory of Tunnel Magnetoresistance

We present a review of theories of tunnel magnetoresistance (TMR) putting an emphasis on the role of electron scattering due to randomness. We adopt the linear response theory and generalize the conductance formula to calculate the electrical conductance in layered structures. The effect of randomness is treated in the coherent potential approximation and⁄or direct numerical simulation. Because the momentum conservation parallel to the junction planes does not hold in the presence of randomness, number of tunneling path through the barrier increases. Using a simple tight-binding model, we demonstrate first how the tunnel conductance and TMR are influenced by the randomness and by the shape of the Fermi surface of the metallic electrodes. The theory is applied to epitaxial tunnel junctions of Fe⁄MgO⁄Fe. It is shown that the basic concept of tunneling in the presence of randomness is also hold in realistic junctions. Magnetoresistance of tunnel junctions with semimetals and those with manganites is studied to clarify the effect of their electronic structures and interaction on TMR.
Dutycycle Influence on the Progenitor Properties of Millisecond Pulsars

Using a stellar evolutionary code, we carried out the investigation on the progenitor properties of millisecond pulsars with a varying dutycycle parameter. Our simulation results show that dutycycle play an important role on the final spin-period. The final spin-period for d = 0.001 and d = 0.1 is 4.75 ms, 1.49 ms respectively. For the same initial donor star mass and initial orbital period, the mass transfer evolutionary track indeed exists difference although the curve is quite similar. For other values of initial donor mass and initial orbital period, we find that the whole varying trend is consistent with each other. DOI: http://dx.doi. org/10.11591/telkomnika.v11i7. 2806
Comparison of algorithms to solve sparse matrix in EM scattering problem

In applying the method of moments to solve the EM scattering problems, it is necessary to solve a large matrix when the dimension of the scatterer is larger than several wavelengths. Tremendous amount of computer CPU time will be spent on solving the matrix equation. When only the far field properties such as scattering cross section is of interest, we can use the sparse matrix technique to reduce the amount of compucation. In this paper, some algorithms are compared to solve the sparse matrix. The Gaussian elimina$ion algorithm, Cholesky decomposition algorithm, several versions of conjugate gradient methods are used. The number of multiplications and divisions(fl0ps) are counted for comparing the efficiency of these algorithms. The effect of the nonzero element positions to the efficiency is also studied by defining the clustering index.
Influence of the Electron Irradiation in the SEM on Terbium Molybdate Surface Potential State

The Scanning Electron Microscopy (SEM) allows not only to observe domains in ferroelectrics but also to investigate the physical properties of these materials. In this work the electron beam of the SEM was used to modify and to investigate the properties of the surface of ferroelectric ferroelastic terbium molybdate. The Tb2(MoO4)3 sample of 3.5 × 4.5 × 1 mm3 in size was cut perpendicularly to the [001] axis that is parallel to the spontaneous polarization PS(0.0019C × m−2). The orthorhombic axes [100] and [010] were directed along the sample diagonals in the (001) plane. The [010] axis is about 0, 3% longer than the [100] axis. The ferroelectric structure consisting of two 180◦-domains was created in the single domain sample by compressing it along the [010] axis. These domains will be referred to as “+” and “−”. We have used the secondary electron emission mode (SEE) in the SEM for the studying the surface potential states of the opposite domains. The beam energies were always smaller than 10 keV, the beam current was of about 10−11 A. Figure 1 shows the images of the double-domain sample of Tb2(MoO4)3. Figure 1a was obtained at the beginning of the experiment. A distinct contrast is seen. The dark and bright parts of the image represent “+” and “−” domains respectively. This means that in the initial state SEE from the “−” domain is larger than SEE from the “+” domain. Figure 1b was obtained after the irradiation the sample during some few minutes. The contrast is absent. It means that the potential states and the SEE currents from different domains are identical. Figure 1c was obtained after sustaining the sample without the irradiation during two days. The inverse contrast takes place. The initial contrast rehabilitates itself after sustaining the sample during about 10 days.
Medium-Resolution Stellar Spectra in the L Band from 2400 to 3000 cm−1 (3.3 to 4.2 Microns)

We present a brief atlas of L-band (3.3–4.2 μm) spectra for 42 stars plus the Sun and a sunspot observed at a resolving power of R ∼ 3000. This contribution is intended to supplement our previous K-band, H-band, and J-band spectral atlases. The L-band data, which cover some or all of the 2400 to 3000 cm-1 (3.3–4.2 μm) region, are mainly for luminous late-type stars. In reducing these data, special care has been taken to remove telluric features, especially water vapor. We identify temperature- and luminosity-sensitive atomic and molecular indices to aid in the classification of stellar spectra in the L band. The data are available electronically.
Stability and Transition on Swept Wings.

Abstract : The thrust of this research program has been the improvement of our capabilities for analyzing stability and transition in compressible boundary-layers as they appear in technologically important flows. Examples of such flows are swept wings of commercial airplanes or the highly cambered blades of gas turbines. We have extended the parabolized stability equations (P SE) for these situations and developed methods for solving these equations in disturbance environments reaching from the low atmospheric levels to the volatile high levels in gas turbines. The extension required both a basic study on the stability analysis of 3D flows and formulating the equations in general curvilinear coordinates. Proper choices have been made to minimize the effect of the parabolization. Major efforts have been spent on characterizing the disturbance environment. More recently, emphasis has been directed toward the control of stability and transition using neural networks.
Explanatory & Predictive Power of Momentum Accounting - the AEX An Empirical Study of the Amsterdam Stock Exchange Component Companies (Het Verklarend En Voorspellend Vermogen Van Momentum Accounting)

The research question we want to answer in this paper is: have the financial variables of the triple-entry framework of momentum accounting explanatory and predictive power? A detailed example is presented of Royal Philips Electronics N.V. Although in this study we cannot generalize the result of this example on a statistical basis to a population we try to replicate it with other firms. To this purpose we use data of 17 of the 24 firms that that are listed on the AEX; the Amsterdam stock ex-change. We presuppose that when we find more confirmatory examples our confidence may grow in the underlying (accounting) theory. The empirical data used are quarterly financial statements data of van Royal Philips Electronics N.V. and the annual financial statements data of 17 out of the 24 AEX listed firms. Our analysis shows that it is possible to explain ex post the trend of net wealth of Philips as well as for 17 of the AEX listed firms and in more than halve of those cases the trend can be forecasted ahead one to three years.
Dielectric effects on the optical properties of single silicon nanocrystals

Optical detection of small single silicon nanocrystals is reported for crystals embedded in various environments. It is found that an external dielectric material has considerable influence on the photoluminescence (PL) properties of optically active states localized in the SiO2 shell. The PL is controlled by two interfaces, namely the Si/SiO2 and SiO2/matrix interfaces. The electron-phonon interaction, as well as the electronic stabilization energy, is controlled by these interfaces. A simple model is derived that can qualitatively describe the effect of the different embedding matrices on the electron-phonon coupling.
MISR Calibration and Implications for Low-Light-Level Aerosol Retrieval over Dark Water

Abstract Studying aerosols over ocean is one goal of the Multiangle Imaging Spectroradiometer (MISR) and other spaceborne imaging systems. But top-of-atmosphere equivalent reflectance typically falls in the range of 0.03 to 0.12 at midvisible wavelengths and can be below 0.01 in the near-infrared, when an optically thin aerosol layer is viewed over a dark ocean surface. Special attention must be given to radiometric calibration if aerosol optical thickness, and any information about particle microphysical properties, are to be reliably retrieved from such observations. MISR low-light-level vicarious calibration is performed in the vicinity of remote islands hosting Aerosol Robotic Network (AERONET) sun- and sky-scanning radiometers, under low aerosol loading, low wind speed, relatively cloud free conditions. MISR equivalent reflectance is compared with values calculated from a radiative transfer model constrained by coincident, AERONET-retrieved aerosol spectral optical thickness, size distribution, and s.
Do eddington–sweet circulations exist?

Abstract The initial value problem for a rotating baroclinic star is considered. Arguments are derived suggesting that the steady meridional circulations first postulated by Vogt (1925) and Eddington (1925) do not exist and that instead a state of a purely zonal velocity field is approached from rather arbitrary initial conditions. By extending previous criteria for stability with respect to axisymmetric disturbances to the case of non-vanishing Prandtl number, it is shown that the purely zonal velocity field may be stable in special cases. In realistic situations, it tends to be unstable, but the preferred instability is likely to introduce nonaxisymmetric toroidal eddies rather than meridional circulations.
The use of EUV lithography to produce demonstration devices

In this paper, we describe the integration of EUV lithography into a standard semiconductor manufacturing flow to produce demonstration devices. 45 nm logic test chips with functional transistors were fabricated using EUV lithography to pattern the first interconnect level (metal 1). This device fabrication exercise required the development of rule-based 'OPC' to correct for flare and mask shadowing effects. These corrections were applied to the fabrication of a full-field mask. The resulting mask and the 0.25-NA fullfield EUV scanner were found to provide more than adequate performance for this 45 nm logic node demonstration. The CD uniformity across the field and through a lot of wafers was 6.6% (3σ) and the measured overlay on the test-chip (product) wafers was well below 20 nm (mean + 3σ). A resist process was developed and performed well at a sensitivity of 3.8 mJ/cm2, providing ample process latitude and etch selectivity for pattern transfer. The etch recipes provided good CD control, profiles and end-point discrimination, allowing for good electrical connection to the underlying levels, as evidenced by electrical test results. Many transistors connected with Cu-metal lines defined using EUV lithography were tested electrically and found to have characteristics very similar to 45 nm node transistors fabricated using more traditional methods.
A new approach to electric‐acoustic stimulation

When low‐frequency acoustic stimulation is combined with either real or simulated electric stimulation from a cochlear implant (electric‐acoustic stimulation, or EAS), speech intelligibility in noise can improve dramatically. This improvement has been shown in simulation to be due in part to the presence of fundamental frequency (F0) and amplitude envelope information in the low‐frequency region. The current experiment extends those findings to implant patients. Six patients who had residual low‐frequency hearing in either their implanted or unimplanted ear participated. A target talker was combined with multitalker babble and presented to the implant. In the low‐frequency region, patients heard either no stimulus, target speech, or a tone that was modulated in frequency to track the dynamic changes in F0, and in amplitude with the amplitude envelope of the low‐pass target speech. Results showed that the tone provided, on average, about 58 percentage points of improvement over electric‐only stimulation. B.
High-pressure behavior of β-Ga2O3 nanocrystals

Freestanding nanocrystalline β-Ga2O3 particles with an average grain size of 14 nm prepared by chemical method was investigated by angle-dispersive synchrotron x-ray diffraction in diamond-anvil cell up to 64.9 GPa at ambient temperature. The evolution of x-ray diffraction patterns indicated that nanocrystalline monoclinic β-Ga2O3 underwent a phase transition to rhombohedral α-Ga2O3. It was found that β- to α-Ga2O3 transition began at about 13.6–16.4 GPa, and extended up to 39.2 GPa. At the highest pressure used, only α-Ga2O3 was present, which remained after pressure release. A Birch–Murnaghan fit to the P-V data yielded a zero-pressure bulk modulus at fixed B0′=4: B0=228(9) GPa and B0=333(19) GPa for β-Ga2O3 and α-Ga2O3 phases, respectively. We compared our results with bulk β-Ga2O3, and concluded that the phase-transition pressure and bulk modulus of nanocrystalline β-Ga2O3 are higher than those of bulk counterpart.
Order-of-magnitude estimates of the nonlinear optical susceptibility

We develop simple mathematical models that lead to order-of-magnitude predictions of the sizes of the electronic, nuclear, and electrostrictive contributions to the nonlinear optical susceptibility. We find that all three of these processes make comparable contributions to the third-order susceptibility. , even though the optical-frequency linear susceptibility is dominated by the electronic response. We also find that when the mathematical expressions describing these contributions to the third-order susceptibility are written in terms of fundamental physical constants, they are identical to within numerical factors of the order of unity and are given in Gaussian units by X (3) = h 8 /8m 4 e 10 = 4.25 × 10 -16 cm 2 s -1 V 2 .
Evaluation of Modeling Water-Vapor-Weighted Mean Tropospheric Temperature for GNSS-Integrated Water Vapor Estimates in Brazil

AbstractMeteorological application of Global Navigation Satellite System (GNSS) data over Brazil has increased significantly in recent years, motivated by the significant amount of investment from research agencies. Several projects have, among their principal objectives, the monitoring of humidity over Brazilian territory. These research projects require integrated water vapor (IWV) values with maximum quality, and, accordingly, appropriate data from the installed meteorological stations, together with the GNSS antennas, have been used. The model that is applied to estimate the water-vapor-weighted mean tropospheric temperature (Tm) is a source of uncertainty in the estimate of IWV values using the ground-based GNSS receivers in Brazil. Two global models and one algorithm for Tm, developed through the use of radiosondes, numerical weather prediction products, and 40-yr ECMWF Re-Analysis (ERA-40), as well as two regional models, were evaluated using a dataset of ~78 000 radiosonde profiles collected at 22.
Thickness Effects on Physical and Ferroelectric Properties of Bi3.35La0.85Ti3O12 (BLT) Films with c-axis-Preferred and Random Orientations

Thickness effects on dependences of physical and ferroelectric properties were investigated for two kinds of Bi3.35La0. 85Ti3O12 (BLT) film with c-axis-preferred and random orientations. BLT films were prepared on Pt/TiOx/SiO2/Si substrates by the metalorganic decomposition (MOD) method, and their crystalline orientation was controlled by baking and rapid thermal annealing (RTA) conditions. When scaling down thickness from 210 to 70 nm, the c-axis-oriented film showed a big reduction in switching polarization (P*-P∧) from 13 to 6 µC/cm2 due to the predominant negative effect of the increased degree in c-axis-preferred orientation rather than the positive effect of increased grain size. However, the randomly oriented film showed no physical change such that it maintained a large polarization of 15–16 µC/cm2 in spite of the thickness reduction. Coercive field (2Ec) and fatigue-free property showed no significant thickness dependence for both BLT films.
Refractive index sensitivity of fibre-optic long period gratings coated with SiO2 nanoparticle mesoporous thin films

A fibre-optic refractive index sensor based on a long period grating (LPG) with a nanoassembled mesoporous coating of alternate layers of poly(allylamine hydrochloride) (PAH) and SiO2 nanospheres was demonstrated. PAH/SiO2 coatings of different thicknesses were deposited onto an LPG operating near its phase matching turning point in order to study the effect of the film thickness and porosity on sensor performance. Three aqueous solutions of ethanol, glucose and sucrose of different concentrations were used to allow characterization of the refractive index (RI) over a wide RI range (1.3330–1.4906). The device showed a high sensitivity (1927 nm/refractive index unit) to RI changes with a response time less than 2 s. In particular, the current study suggested that the low RI of the mesoporous film, 1.20 at 633 nm, facilitates the measurement of external indices higher than that of the cladding, extending the range of operation of LPG-based RI sensors. The ability of this device to monitor, in real time, RI changes during a dilution process is demonstrated and discussed.
PHONON STRUCTURES AND STOKES SHIFT IN RESONANTLY EXCITED LUMINESCENCE OF SILICON NANOCRYSTALS

We have studied luminescence Stokes shift and phonon-assisted luminescence in H-terminated and surface-oxidized Si nanocrystals by means of resonant excitation spectroscopy. For resonant excitation at energies within a broad luminescence band, TO- and TA-phonon related structures in luminescence spectra are observed in both H-terminated and surface-oxidized Si nanocrystals. In oxidized Si nanocrystals, the luminescence Stokes shift is large and the phonon-related structures are unclear compared to the case of H-terminated Si nanocrystals. The origin of the luminescence Stokes shift and surface localized states in surface-oxidized Si nanocrystals are discussed.
A study of the image quality in a lossy NFSL

Recently, the near-field superlens (NFSL) based on the negative permittivity (ε < 0) has been much attraction issue because of its useful application in a near-field imaging system beyond the diffraction limits. Silver in the UV region and silicon carbide in the mid-IR regime has been reported as suitable materials for the NFSL. However, these materials have the intrinsic absorption loss, which blurs the near-field image. In this research, we theoretically predict enhancement of image quality in a lossy NFSL system using the full-wave numerical approach and electrostatic approximation method. As a result, we recognized that an unmatched NFSL has better image quality compared to the traditional match NFSL.
Adaptive rotor current control for wind-turbine driven DFIG using resonant controllers in a rotor rotating reference frame

This paper proposes an adaptive rotor current controller for doubly-fed induction generator (DFIG), which consists of a proportional (P) controller and two harmonic resonant (R) controllers implemented in the rotor rotating reference frame. The two resonant controllers are tuned at slip frequencies ωslip+ and ωslip−, respectively. As a result, the positive-and negative-sequence components of the rotor current are fully regulated by the PR controller without involving the positive-and negative-sequence decomposition, which in effect improves the fault ride-through (FRT) capability of the DFIG-based wind power generation system during the period of large transient grid voltage unbalance. Correctness of the theoretical analysis and feasibility of the proposed unbalanced control scheme are validated by simulation on a 1.5-MW DFIG wind power generation system.
Optimal Backward Perturbation Bounds for Underdetermined Systems

Let $A$ be an $n \times m,(m < n)$ matrix, $b$ be an $m$-dimensional vector, and $y$ be an $n$-dimensional nonzero vector. In this paper we consider the following open problem: find an explicit expression of the optimal backward perturbation bound $\eta_{\theta}(y)$ defined by $$ \eta_{\theta}(y)=\inf\{\|(F^T, \theta g)\|_F: y\;{\rm is}\;{\rm the} \;{\rm minimum}\;2\hbox{\rm -norm}\;{\rm solution}\;{\rm to}\;(A+F)^Tx=b+g\},$$ where $\theta$ is a positive number. This problem is solved.
Absolute time position of picosecond laser pulse

We are presenting some new aspects of detection of absolute time position of picosecond laser pulses. The ground-space optical links for precise and accurate time scale synchronization are running or preparing in frame of several space agencies. We are involved in several projects in position of single photon detector and timing designer. The typical optical link consists of ground segment - picosecond laser pulse transmitter, telescope, single photon avalanche detector, timing electronics, and time reference; and space segment - corner cube retroreflectors, single photon sensitive optical receiver with event timer board, and time reference to be synchronized. To ensure absolute time position we have to calibrate absolute internal delay of several semiconductor photodiodes in picosecond range detecting picosecond laser pulses on several wavelengths. The experimental results demonstrating unobvious dependence on detector type and entire experiment arrangement and its possible theoretical interpretation will be presented.
Multivariate Bi-Aspect Testing for the Two-Sample Location Problem

Abstract The multivariate extension of the bi-aspect nonparametric testing procedure for the two-sample location problem presented in Marozzi (2004) is discussed. Two solutions are presented: the former is focused on each variable, the latter is focused on each of the two aspects involved in the bi-aspect (the categorical and the numerical one). Formal proofs of exactness, unbiasedness, and consistency of the multivariate tests are given. Such properties hold even when population first and second moments do not exist.
The Step-Mountain Coordinate: Physical Package

Abstract A comprehensive physical package has been developed for a regional eta coordinate model with the steplike mountain representation. This paper describes the basic problems, concepts and numerical techniques developed, and reviews primarily those aspects of the performance of the model which reflect the effects of the parameterized physical processes. The Level 2.5 turbulence closure model in the Mellor-Yamada hierarchy was chosen to represent the turbulence above the surface layer. A severe instability encountered in the early experiments in the turbulent kinetic energy (TKF) equation was found to be of a numerical origin. The instability was removed by a suitably designed time-differencing scheme. As implemented in the eta-coordinate model, the Level 2.5 turbulence closure model is computationally remarkably inexpensive. An unconditionally stable, trivially implicit, time-differencing scheme is proposed for the vertical diffusion. The Mellor-Yamada Level 2 turbulence closure scheme is used for th.