Miracle-dz/UniFAR-FTUs huggingface dataset:
Numerical simulation of martensitic phase transitions in shape memory alloys using an improved integration algorithm

The numerical simulation of structures made of shape memory materials is of increasing interest in different fields. Among others, the computation of pipe connectors or medical devices like endoscopic instruments and stents is a challenge. In such practical applications the pseudoelastic effect as well as the one‐way and two‐way shape memory effects are utilized. These material properties are caused by martensitic phase transitions between austenite and martensite. In the present contribution, a recently proposed constitutive theory is numerically treated in the context of the finite element method. This constitutive theory is formulated in the framework of continuum thermomechanics for geometrically linear problems and is able to represent the occurring martensitic phase transitions in shape memory alloys. For the numerical integration of the evolution equations, the backward Euler method is applied. In spite of the complexity of the constitutive theory, it is shown that an improved integration procedure can be formulated, which merely involves the solution of three non‐linear equations for three scalar‐valued unknown variables. Numerical examples show the capability of the proposed model and the improved integration algorithm. Copyright © 2006 John Wiley & Sons, Ltd.
Nanometrology on gratings with GISAXS: FEM reconstruction and fourier analysis

The aim of the semiconductor industry to decrease the feature size of integrated circuits poses a huge technological endeavor. Consequently, new challenges are arising for metrology on structures in the nanometer regime. Scatterometry is a fast method which provides non-contact non-destructive characterization of structures on photomasks or exposed wafers. However, the determination of important line structure parameters with subnanometer accuracy still needs further investigation. Grazing incidence small-angle X-ray scattering (GISAXS) is a scatterometry technique to measure both vertical and lateral structural features in the nanometer range with high sensitivity. We apply GISAXS to the investigation of structural parameters such as period length, sidewall angle, linewidth and height on silicon gratings. Our test structures with nominal widths of 35 nm to 100 nm and a pitch from 100 nm to 250 nm were fabricated by electron beam lithography. The diffraction patterns have been analyzed by power spectral density analysis which directly yields periodical modulations of the structured surface such as line width or groove width. We also apply a finite element method (FEM) to the diffraction peak intensity of the grating structure obtained with GISAXS for the geometric reconstruction of the line shape.
Optimal Models for Plant Disease and Pest Detection Using UAV Image

The use of deep learning methods to detect plant diseases and pests based on UAV images is an important application of remote sensing technology in modern forestry. This paper uses a CenterNet-based object detection method to construct models for plant disease and pest detection. The accuracy of the models is influenced by parameter alpha, which is used to control the affine transformation in the preprocessing of CenterNet. First, different alphas are sampled for training and testing. Next, the least square method is used to fit the curve between alpha and accuracy measured by mAP (mean average precision). Finally, the equation of the curve is fitted as mAP = -0.22 * alpha2 + 0.32 * alpha + 0.42. In comparison, an automated machine learning (AutoML) method is also conducted to automatically search for the best model. The experiments are done with 5,281 images as the training dataset, 1,319 images as the verification dataset, and 3,842 images as the test dataset. The results show that the best alpha value obtained by the least square method is 0.733, and the accuracy of the corresponding model is 0.536 in mAP@[. 5, . 95]. In contrast, the accuracy of the AutoML method model is higher with the model accuracy of 0.545 in mAP@[. 5, . 95]. However, the training time and training resource consumption of the AutoML method are about 3 times that of the least square method. Therefore, in practice, a trade-off should be made according to the accuracy requirements, resource consumption, and task urgency.
Effect of Losses in a Layered Structure Containing DPS and DNG Media

The problem of re∞ection and transmission of plane electromagnetic waves in a periodic multilayered structure containing double-negative (DNG) media is analyzed using a matrix formalism. A Lorentz model with a single resonance is used to describe the dispersion of the DNG medium. It is shown that the introduction of losses, in accordance with the Kramers- Kronig relations, is essential in order to obtain correct results on the performance of the structure.
Biochemical and histological effects of different light doses on hyperthermic therapy with gold nanorods

Efforts have been made to develop new treatments for cancer with fewer side effects and with a better outcome. Gold nanorods are promising as a cancer treatment device when activated by a light source, usually in near-infrared region. In this study we investigated the effect of different light doses applied to tumors containing gold nanorods and characterized the damage of the treatment in different intracellular locations. The gold nanorods were synthesized by a seed-mediated method and the soluble CTAB was eliminated from the nanorods solution, which was administered to Ehrlich tumor-bearing mice. The nanorods were activated on the tumor tissue by two doses of near-infrared light, either 216 or 600 J cm-2. After the irradiation, the tumors were collected and subjected to biochemical tests to investigate oxidative stress on cell membranes and to evaluate the total antioxidant capacity of cells, or they underwent histological procedures. Results show that the laser itself is responsible for membrane oxidative damage, regardless the presence of gold nanorods, but the nanoparticles are important to oxidative stress generation inside the cells. The intensity of histological damage is directly dependent on the light dose applied. These results are important to better understand how photothermal tumor ablation using gold nanorods occurs.
Improvement of critical current densities by fission tracks in U-doped high temperature superconductors

Results on the enhancement of critical current densities in melt-textured bulk (Y-123) superconductors, which were doped with and exposed to thermal neutron irradiation to create fission tracks, are presented. These tracks, which all originate from U-containing clusters of a stable UPtYBaO compound, form isotropic `starlike' defects with diameters of approximately 10 nm and lengths of . However, if we consider projections onto the symmetry plane of the flux line lattice and allow for a certain tilt modulus , their pinning-effective size is mostly (90%) between 10 and 20 nm, i.e. only twice as large as the characteristic defect structure (amorphous collision cascades with diameters of nm) introduced into undoped superconductors by fast neutron irradiation. We report on studies of and the irreversibility lines in superconductors containing various amounts (0.3-0.7 wt%) of uranium and various amounts of the fissionable isotope . In the best case (0.3 wt% U, thermal neutrons), we find (77 K) to be around (0 T) and (5 T). Control experiments on samples containing (nominally) only and exposure to thermal or to thermal plus fast neutrons confirm the above flux pinning considerations. As reported before for undoped melt-textured Y-123, the irreversibility lines remain practically unchanged due to the presence of strongly pinning Y-211 precipitates.
Excitonic and biexcitonic decoherence in self-assembled GaAs quantum dots as observed by phase-locked interferography

We observe single-photon interferograms for emission of a single self-assembled GaAs quantum dot. A phase stabilizer is applied to the interferometer, enabling us to trace autocorrelations of weak emissions with a photon-counting level. At low excitation, where the average number of excitons in a dot is less than one, interferography reveals a single exponential decay, reflecting excitonic decoherence. At moderately high excitation, polarization interference between the exciton-biexciton transitions is found to appear on the interferogram. The decoherence time and the binding energy of biexcitons are determined simultaneously.
The physics and chemistry of the Schottky barrier height

The formation of the Schottky barrier height (SBH) is a complex problem because of the dependence of the SBH on the atomic structure of the metal-semiconductor (MS) interface. Existing models of the SBH are too simple to realistically treat the chemistry exhibited at MS interfaces. This article points out, through examination of available experimental and theoretical results, that a comprehensive, quantum-mechanics-based picture of SBH formation can already be constructed, although no simple equations can emerge, which are applicable for all MS interfaces. Important concepts and principles in physics and chemistry that govern the formation of the SBH are described in detail, from which the experimental and theoretical results for individual MS interfaces can be understood. Strategies used and results obtained from recent investigations to systematically modify the SBH are also examined from the perspective of the physical and chemical principles of the MS interface.
High-pressure experimental and computational XANES studies of ( Mg , Fe ) ( Si , Al ) O 3 perovskite and (Mg,Fe)O ferropericlase as in the Earth’s lower mantle

Seven iron-containing oxides and silicates including $({\text{Mg}}_{0.88},{\text{Fe}}_{0.12})\text{SiO}$, $({\text{Mg}}_{0.86},{\text{Fe}}_{0.14})({\text{Si}}_{0.98},{\text{Al}}_{0.02}){\text{O}}_{3}$ perovskites, and $({\text{Mg}}_{0.80},{\text{Fe}}_{0.20})$ ferropericlase were studied using $\text{Fe}\text{ }K$-edge x-ray absorption near edge spectroscopy under pressure up to 85 GPa at ambient temperature. First-principles calculations of $\text{Fe}\text{ }K$-edges of $({\text{Mg}}_{0.88},{\text{Fe}}_{0.12})\text{SiO}$ perovskite and $({\text{Mg}}_{0.80},{\text{Fe}}_{0.20})\text{O}$ ferropericlase were performed using a spin-dependent method. The amount and quality of the data collected allows performance of a systematic study of the absorption edge features as a function of pressure in these geophysically important systems, providing direct experimental validation for band-structure calculations. The comparison between experiment and theory allows analyzing in detail the effect of Fe valence and spin state modifications on the spectra, allowing to confirm qualitatively the presence of a pressure induced spin pairing transition in (Mg,Fe)O ferropericlase and a high-spin intermediate spin crossover in $(\text{Mg},\text{Fe})(\text{Si},\text{Al}){\text{O}}_{3}$ perovskite.
Characterization of Dielectric Relaxation of Relaxor Ferroelectrics

The concept ‘relaxativity’ is proposed to describe the degree of dielectric relaxor in relaxor ferroelectrics, like the ‘fragility’ in supercooled liquid in describing glass forming ability during vitrification process. The calculated results of Pb(Mg1/3Nb2/3)O3-PbTiO3 relaxors and BaTiO3-BaZrO3 relaxors exhibit good coincidences with the intervals between their dielectric peak temperatures. The larger relaxativity is corresponding to larger configurational entropy and smaller spatial correlation length, or stronger local interactions for a relaxor.
BETSSI IIB : SUBMARINE TARGET STRENGTH MODELING WORKSHOP

: In September 2016, the BeTSSi IIb (Benchmarking of Target Strength Simulations ) workshop was held in The Hague, The Netherlands. Participants were offered the chance to benchmark their numerical simulation tools using a number of predefined structures that are relevant for understanding the target strength of submarines. In addition to a generic submarine model (with internal parts) and a number of simple structures (with and without internal components), which were simulated during the first and second workshop (2002 and 2014), the test cases were expanded to investigate the contribution of an isolated corner reflector and torpedo tubes. An overview of the workshop is given and a selection of the results is presented.
On the Intuitionistic Fuzzy Metric Spaces

In this paper, we define pre compact set in intuitionistic fuzzymetric spaces and prove that any subset of an intuitionistic fuzzy metric space is compact if and only if it is pre compact and complete. Also we define topologically complete intuitionistic fuzzy metrizable spaces and prove that any G δ set in a complete intuitionistic fuzzy metric spaces is a topologically complete intuitionistic fuzzy metrizable space and vice versa.
High‐power InGaN single‐quantum‐well‐structure blue and violet light‐emitting diodes

High‐power blue and violet light‐emitting diodes(LEDs) based on III–V nitrides were grown by metalorganic chemical vapor deposition on sapphire substrates. As an active layer, the InGaN single‐quantum‐well‐structure was used. The violet LEDs produced 5.6 mW at 20 mA, with a sharp peak of light output at 405 nm, and exhibited an external quantum efficiency of 9.2%. The blue LEDs produced 4.8 mW at 20 mA and sharply peaked at 450 nm, corresponding to an external quantum efficiency of 8.7%. These values of the output power and the quantum efficiencies are the highest ever reported for violet and blue LEDs.
Progressive optimization of time-frequency localization in subband trees

The time and frequency localizations of the product subband filter functions in tree structures are addressed and evaluated in this paper. The concept of progressive optimality is proposed as a new design approach. It is shown that the performance improvements are possible by using different PR-QMF banks at different nodes of a subband tree. <<ETX>>
Variation of Thermal Structure with Height of a Solar Active Region Derived from SOHO CDS and YOHKOH BCS Observations

We present observations of NOAA solar Active Region 7999 when it was near the west solar limb on 1996 December 2 and 3, using data from the Coronal Diagnostic Spectrometer (CDS) experiment on the SOHO satellite. Ratios of intensities of 2 MK material (as observed in CDS Fe XVI images) to 1 MK material (from CDS Mg IX images) indicate that there is a drop in the ratio of the hotter to the cooler material with height in the region, up to an altitude of about 105 km. At low altitudes the relative amount of 2 MK emission measure to 1 MK emission measure ranges from 8 to 10, while the ratio is minimum near 105 km, ranging from 1.3 to 3.5. The decrease with height of the CDS ratio qualitatively resembles the decrease in S XV election temperature with height (measurable up to ≈85,000 km) in the same active region obtained from the Bragg crystal spectrometer instrument on Yohkoh. The CDS images indicate that the highest S XV temperatures and largest CDS ratios correspond to regions of microflares, and somewhat lower S XV temperatures and CDS ratios correspond to diffuse regions. Above 105 km, the trend of the CDS ratios changes, either increasing or remaining approximately constant with height. At these altitudes the CDS images show faint, large-scale diffuse structures.
Robust fault tolerant tracking control with application to hybrid nonlinear systems

A class of nonlinear systems with faults, parametric uncertainties and without full state measurements are considered. A novel observer is designed whose estimation error is not affected by faults, and an observer-based fault tolerant tracking controller is proposed to make the outputs asymptotically track the reference signals while the states are bounded. The proposed fault tolerant control method can help to provide a switching detection scheme and a family of Lyapunov functions for a class of hybrid nonlinear systems with uncontrollable switchings, and to guarantee the global tracking performance. A three-tank system is taken as an example to show the efficiency of the proposed method.
Spectral representation of the three-body Coulomb problem. I. Nonautoionizing doubly excited states of high angular momentum in helium

We investigate high-lying doubly excited nonautoionizing states of helium with total angular momentum L = 1,2, . ,9 with the help of a configuration interaction approach. We provide highly precise nonrelativistic energies of these states and discuss the properties of the wave functions with respect to the particle exchange operator.
Dynamics of a Variable-Mass, Flexible-Body System

A new formulation of the dynamics of a variable-mass, e exible-body system is presented by extending Kane’ s equations for variable mass particles to e exible bodies characterized by load-dependent stiffness and assumed modes. The method captures the effects of thrust, mass center change, and changes in transverse vibration frequencies due to mass loss and thrust. An order- n formulation with prescribed motion of a gimballed nozzle is given for a e exible rocket. Equations for a planar e exible rocket are illustrated and solved numerically. Open-loop simulations with prescribed gimbal motion show that the difference in large motion e ight behavior between a rigid-body model and a e exible-body model of a rocket increases as the e exibility increases. Changes in bending frequencies of a e exible rocket due to mass loss and thrust-induced softening are shown.
Nonlinear Continuum Mechanics for Finite Element Analysis

1. Introduction 2. Mathematical preliminaries 3. Analysis of three-dimensional truss structures 4. Kinematics 5. Stress and equilibrium 6. Hyperelasticity 7. Large elasto-plastic deformations 8. Linearized equilibrium equations 9. Discretization and solution 10. Computer implementation Bibliography Index.
Partitioning technique for transformation of connected graphs into single-row networks

In this paper, we present our work called Connected Graph Sequence (CGS) which transforms a partially dense graph into the single-row network. Partially dense graph is a graph where a number of connected components, namely subgraphs, are connected by some links and each subgraph has a higher density value compare to the graph. The transformation is necessary in applications such as in the assignment of telephone channels to caller-receiver pairs roaming in cells in a cellular network on real-time basis. In this channel assignment application, each caller and receiver in a call is treated as a node, while their pair connection is treated as the edge. A specific case of the graph in the form of a partially dense graph is then transformed into its corresponding single-row network for assigning the channels to the caller-receiver pairs.
Fluctuation of Air-Water Two-Phase Flow in Horizontal and Inclined Water Pipelines

Air in water flow is a frequent phenomenon in hydraulic structures. The main reason for air entrainment is vortices at water intakes, pumping stations, tunnel inlets, and so on. The accumulated air, in a conduit, can evolve to a different flow pattern, from stratified to pressurized. Among different patterns, slug is most complex with extreme pressure variations. Due to lack of firm relations between pressure and influential parameters, study of slug flow is very important. Based on an experimental model, pressure fluctuations inside a circular, horizontal, and inclined pipe (90mm inside diameter and 10m long) carrying tow-phase air-water slug flow has been studied. Pressure fluctuations were sampled simultaneously at different sections, and longitudinal positions. The pressure fluctuations were measured using differential pressure transducers (DPT), while behavior of the air slug was studied using a digital camera. The objective of the paper is to predict the pressure variation in a pipeline or tunnel, involving resonance and shock waves experimentally. The results show that the more intensive phase interaction commences stronger fluctuations. It is shown, that the air-water mixture entering the pipe during rapid filling of surcharging can cause a tremendous pressure surge in the system and may eventually cause failure of the system (e.g., the maximum pressure inside the pipe would reach up to 10 times of upstream hydrostatic pressure as suggested by others too). Relations for forecasting pressure in these situations are presented as a function of flow characteristics, pipe geometry, longitudinal, and cross-sectional positions and head water.
Robust leader tracking from an unmanned ground vehicle

While many leader-follower technologies for robotic mules have been developed in recent years, the problem of reliably tracking and re-acquiring a human leader through cluttered environments continues to pose a challenge to widespread acceptance of these systems. Recent approaches to leader tracking rely on leader-worn equipment that may be damaged, hidden from view, or lost, such as radio transmitters or special clothing, as well as specialized sensing hardware such as high-resolution LIDAR. We present a vision-based approach for robustly tracking a leader using a simple monocular camera. The proposed method requires no modification to the leader’s equipment, nor any specialized sensors on board the host platform. The system learns a discriminative model of the leader’s appearance to robustly track him or her through long occlusions, changing lighting conditions, and cluttered environments. We demonstrate the system’s tracking capabilities on publicly available benchmark datasets, as well as in representative scenarios captured using a small unmanned ground vehicle (SUGV).
The ambiguity of random choices: Probability paradoxes in some physical processes

Intriguing problems whose solutions seem to run counter to intuition are sometimes discussed theoretically in probability textbooks; under close scrutiny, they often appear to originate from an incomplete specification of the sampling procedures. Interest in these oddities is not purely academic; the world of real point processes (with its multitude of applications in science and engineering) exhibits its own ‘‘paradoxes’’ that follow from certain ambiguities in the random choice of an event. The paper discusses some probabilistic subtleties that can be easily illustrated by ordinary demonstration experiments in the physics laboratory.
Acoustic Radiation from a Semi-Infinite Duct With a Subsonic Jet

The radiation of high-order spinning modes from a semi-infinite exhaust duct is studied numerically. The issues involved have applications to noise radiation from the exhaust duct of an aircraft engine. The numerical method is based on solutions of linearised Euler equations (LEE) for propagation in the duct and near field, and the acoustic analogy for far field radiation. A 2.5D formulation of a linearised Euler equation model is employed to accommodate a single spinning mode propagating over an axisymmetric mean flow field. In the solution process, acoustic waves are admitted into the propagation area surrounding the exit of an axisymmetric duct and its immediate downstream area. The wave admission is realised through an absorbing non-reflecting boundary treatment, which admits incoming waves and damps spurious waves generated by the numerical solutions. The wave propagation is calculated through solutions of linearised Euler equations, using an optimised prefactored compact scheme for spatial discretisation. Far field directivity is estimated by solving the Ffowcs Williams-Hawkings equations. The far field prediction is compared with analytic solutions with good agreement.