Miracle-dz/UniFAR-FTUs huggingface dataset:
Strain‐induced effects in (111)‐oriented InAsP/InP, InGaAs/InP, and InGaAs/InAlAs quantum wells on InP substrates

Strain‐induced effects in quantum wells of InAsxP1−x/InP, InxGa1−xAs/InP, and InxGa1−xAs/ In0.52Al0. 48As on (111) InP substrates are investigated. The strain induces a large piezoelectric field in these structures, and causes a large change in their energy band edges. Consequently the band structure of the quantum wells is dramatically modified, and the dependence of interband transition energies on alloy composition is different from that of quantum wells on (100) substrates. Moreover, a larger critical layer thickness is found for the quantum wells studied.
An Analysis of the Relationship Between Rainfall and the Occurrence Of Traffic Accidents

Abstract Analysis of METROMEX rainfall data and traffic accident reports for seven southern Illinois cities within the area of the St. Louis precipitation anomaly revealed a statistically significant increase in the number of accidents reported during rainy periods compared to non-rainy periods in each city. When observations for the cities were combined, a statistically significant linear trend between mean number of accidents and amount of rainfall was identified. A measure of accident severity, computed by the mean number of injuries for each accident, increased in some of the cities when it rained but decreased in others. None of these increases or decreases were statistically significant. It is speculated that the St. Louis precipitation anomaly probably results in an increase in the occurrence of traffic accidents in the area of its effect.
Diagnosis of systematic differences between multiple parametrizations of warm rain microphysics using a kinematic framework

This paper introduces the Kinematic Driver Model (KiD) and its application. KiD is a 1D modelling framework developed at the UK Met Office to facilitate a consistent intercomparison of the microphysics parametrizations employed in a number of cloud‐resolving models and numerical weather prediction models. The development of the KiD model was born out of GCSS intercomparison results, which show a wide range of microphysical behaviour and a need to explain the behaviour of different microphysics schemes without the complication of dynamic or radiative feedbacks. This paper describes the KiD model and one of the standard test cases for warm microphysics. Results from a comparison of warm microphysics schemes are presented. The schemes tested produce very different surface precipitation rates and onset timings, as well as different accumulated precipitation. In general, single‐moment bulk schemes produce the most rapid onset of precipitation and the widest range in accumulated surface precipitation. Sensitivity tests within the KiD show that including a diagnostic intercept parameter for the rain size distribution reduced variation between the single‐moment schemes. However, the early onset of precipitation is a persistent feature of single‐moment schemes. Double‐moment bulk schemes exhibit improved timing for the precipitation onset relative to an explicit bin model and comparison of accumulated precipitation shows much better agreement. However, double‐moment schemes tend to produce relatively large peak precipitation rates, particularly with the deeper cloud. Further sensitivity tests within the KiD demonstrate that using a three‐moment scheme, with variable shape parameter, significantly improves the simulation peak precipitation rate relative to an explicit bin model. The tests and results presented in this paper are described to act as a reference for other users to compare with their microphysics schemes and aid microphysics parametrization development. Copyright © 2012 British Crown copyright, the Met Office. Published by John Wiley & Sons Ltd.
Temperature dependence of the low-frequency noise properties in Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub y/ intrinsic Josephson junctions

We have measured the temperature dependence of the low-frequency noise properties across for mesa stacks of intrinsic Josephson junctions (IJJs) in single crystals of Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub y/ (BSCCO) in the absence of an external magnetic field. The measured curves for noise spectrum density S/sub V/(f) showed a 1/f frequency dependence at temperatures in the range from 4.3 K to 150 K except 36 K. We estimated the magnitude of the S/sub V/(f) by using Rogers and Buhrman's empirical theory and Machlup's formula. From the observed curves for S/sub V/(f), we estimated a 1/f noise level /spl eta/ for a BSCCO IJJ biased at a sub-gap voltage of approximately 10/sup -5/ /spl mu/m/sup 2/, and this value was almost completely independent of temperature in the range between 4.3 K and 40 K. We also found that the /spl eta/ values above T/sub c/ were smaller by a factor of approximately 10 than those below T/sub c/. The /spl eta/ value for the BSCCO IJJ is approximately two orders of magnitude greater than for an epitaxial NbN/MgO/NbN tunnel junction biased above-gap voltage. We consider that the observed variation in the noise level with temperature is not interpretable in terms of a magnetic origin and the 1/f noise in a BSCCO IJJ may be somehow associated with stress or defects in the BiO and/or SrO layers act as tunnel barriers.
Theoretical and experimental study on AC loss in HTS tape in AC magnetic field carrying AC transport current

AC loss characteristics of high temperature superconducting tape in external AC magnetic field carrying AC transport current were theoretically and experimentally studied. We measured the AC transport current and magnetization losses in a conventional Bi2223/Ag multifilamentary tape in the external AC magnetic field carrying the AC transport current. The measured AC magnetization loss, AC transport current loss and total AC loss were compared with the numerical results. The measured AC loss characteristics of the tape can not be explained by the critical state model. Numerical calculations on the AC losses in the tape were performed by using our analytical model introducing the electric field and current density relation locally determined in the filamentary region of the tape. The numerical losses by our model reasonably agree with the measured data.
Diffusion of vacancies and interstitials to edge dislocations

The steady‐state diffusion of radiation‐produced point defects in the stress field of an edge dislocation is solved by a perturbation method. The drift term entering the diffusion equation includes the size interaction and the inhomogeneity interaction as well as the effects of externally applied loads. By comparing the perturbation solution with the rigorous solution of Ham, we show that the perturbation solution is always adequate provided the drift term is proportional to the gradient of the interaction energy of the point defect with the dislocation. The steady‐state distributions of vacancies and interstitials is such that voids or vacancy clusters preferentially grow on the compressive side of the edge dislocation. The external stresses give rise to an orientation‐dependent bias of the edge dislocation which is shown to provide a possible mechanism for radiation‐induced creep.
The offset dependent behavior of narrow optical emission features in the Red Rectangle proto-planetary nebula

Context. The Red Rectangle proto-planetary nebula provides a unique laboratory to study the physical conditions and chemical processes in stellar outflows. Snapshots of the ongoing chemical evolution are obtained by monitoring spectra as function of the offset from the central star. Aims: The focus in this study is on the characterization of narrow optical emission features, that are superimposed on top of extended red emission (ERE). The primary aim is to provide a two-dimensional catalogue of these features for offsets varying from 3'' to 20'' from the central star. Methods: Medium resolution emission spectra for this catalogue have been obtained through optical long-slit measurements using the New Technology Telescope (EMMI-NTT) in La Silla, Chile. Results: The recorded spectra cover the range between 5550 and 6800 A. A complete overview of the central band positions and bandwidths (FWHMs) is provided for both stronger (previously reported) and weaker narrow features. Only some bands are omnipresent in the nebula outflows and other bands only appear further away from the central star. Conclusions: The optical emission bands show intensity variations over the nebula. We suggest that these variations reflect a spatially resolved photochemistry where larger species are photolysed, producing daughter molecules which may be the carriers of the optical emission bands. Based on observations collected at the European Southern Observatory, Chile. Program ID: 080.C-0814(A).
Experimental and theoretical analysis of direct-write laser micromachining of polymethyl methacrylate by CO2 laser ablation

CO2 laser micromachining provides a flexible and low-cost means for the rapid prototyping and manufacturing of miniaturized polymer systems such as polymethyl methacrylate (PMMA) microfluidic chip devices. In this paper, the relationships between the process variables (profile and depth of laser-ablated channels) and the process parameters (laser power and scanning velocity) are investigated. In contrast with the fabrication of 100–500μm wide channels reported in previous work, we focus on the fabrication of narrower channels using low laser power which can reduce the cost of the fabrication system and low scanning speeds. In this work, the laser power used for channel fabrication ranged from 0.45to1. 35W and the scanning speeds ranged from 2to14mm∕s. The width of fabricated channels ranged from 44to240μm and their depths ranged from 22to130μm. Physical models were developed for predicting the depth and the profile of laser-ablated channels. The profile model incorporates the threshold fluence for CO2 lase.
Statistical inference for non-stationary GARCH(p,q) models

: This paper studies the quasi-maximum likelihood estimator (QMLE) of non-stationary GARCH( p,q ) models. By expressing GARCH models in matrix form, the log-likelihood function is written in terms of the product of random matrices. Oseledec’s multiplicative ergodic theorem is then used to establish the asymptotic properties of the log-likelihood function and thereby, showing the weak consistency and the asymptotic normality of the QMLE for non-stationary GARCH( p,q ) models.
Comparison of monolithic and splitting solution schemes for dynamic porous media problems

Proceeding from the governing equations describing a saturated poroelastic material with intrinsically incompressible solid and fluid constituents, we compare the monolithic and splitting solution of the different multi‐field formulations feasible in porous media dynamics. Because of the inherent solid–fluid momentum interactions, one is concerned with the class of volumetrically coupled problems involving a potentially strong coupling of the momentum equations and the algebraic incompressibility constraint. Here, the resulting set of differential‐algebraic equations (DAE) is solved by the finite element method (FEM) following two different strategies: (1) an implicit monolithic approach, where the equations are first discretized in space using stable mixed finite elements and second in time using stiffly accurate implicit time integrators; (2) a semi‐explicit–implicit splitting scheme in the sense of a fractional‐step method, where the DAE are first discretized in time, split using intermediate variables, and then discretized in space using linear equal‐order approximations for all primary unknowns. Finally, a one‐ and a two‐dimensional wave propagation example serve to reveal the pros and cons in regard to accuracy and stability of both solution strategies. Therefore, several test cases differing in the used multi‐field formulation, the monolithic time‐stepping method, and the approximation order of the individual unknowns are analyzed for varying degrees of coupling controlled by the permeability parameter. In the end, we provide a reliable recommendation which of the presented strategies and formulations is the most suitable for which particular dynamic porous media problem. Copyright © 2009 John Wiley & Sons, Ltd.
Molecular ordering and domain morphology of molecularly thin triacontane films at SiO2/air interfaces.

The molecular ordering and the domain morphology of molecularly thin triacontane films at SiO2/air interfaces has been investigated at room temperature by scanning force microscopy, X-ray diffraction, and X-ray reflexion. Our results suggest that the room temperature structure is influenced by the surface freezing behaviour of triacontane, i.e. its solidification adjacent to the interface already some degrees (≈ 69 °C) above the bulk melting temperature (≈ 66 °C). Depending on the amount of alkane available either a closed monolayer topped by separated chunks of bulk (solidified droplets) or, in the case of only submonolayer alkane coverage fractal, seaweed-shaped domains are observed. In both cases, adjacent to the interface the molecules are oriented upright and packed in a rectangularly centered unit cell with a lateral correlation of much more than 200 molecules. A fractal dimension of 1.64 ± 0.06 indicates that the domains are formed by diffusion-limited aggregation.
Sintered magnetic cores of high Bs Fe84.3Si4B8P3Cu0.7 nano-crystalline alloy with a lamellar microstructure

Fabrication of bulk cores of nano-crystalline Fe84.3Si4B8P3Cu0. 7 alloy with a lamellar type of microstructure is reported. Amorphous ribbon flakes of size ∼1.0–2.0 mm were compacted in the bulk form by spark plasma sintering technique at different sintering temperatures. High density (∼96.4%) cores with a uniform nano-granular structure made from α-Fe (∼31 nm) were obtained. These cores show excellent mechanical and soft magnetic properties. The lamellar micro-structure is shown to be important in achieving significantly lower magnetic core loss than the non-oriented silicon steel sheets, commercial powder cores and even the core made of the same alloy with finer and randomly oriented powder particles.
Ecosystem Implementations in Smart City Through Block Chain Technology

Urban dwellers' quality of life may be improved by adopting unified, extensible, yet secure e - services thanks to the ongoing urban growth. Government entities are aware of how useful blockchains can be in addressing community issues. Bitcoin, which was primarily associated with the digital money bitcoins, provides a novel viewpoint as to how cities might be structured as well as a more open economical system for managing resources. This paper examines the potential benefits of ledger tech businesses for the growth of smart communities and suggests a Smart City ecological architecture based on intelligent contract involving firms, residents, or government agencies. It also provides an outline of the possible application areas for this technology. The findings might serve as a springboard for the creation of regional efforts to use the cryptocurrency as a framework for transactions and communications with in government service.
Construction of Efficient Authenticated Key Agreement Protocol for Intelligent Transportation System

To enable intelligent transportation systems, the Internet of Vehicles (IoV) uses wireless communications between roadside units, onboard units), phones, and other gadgets within a vehicle to deliver a new convenient, comfortable, and safe driving experience. IoV is now more exposed and frequently targeted because of its greatly increased reliance on wireless communication, control, and computer technology, To put it another way, an adversary may target such an open channel to intercept, change, inject malicious messages, or erase loaded data. This could lead to replay, impersonation, middle attack, privileged insider, and other related attacks. An authentication protocol should strive to accomplish security, anonymity, and untraceability among other critical aspects. In this research, we suggest a brand-new key agreement and mutual authentication methodology for IoV powered Intelligent transportation system (ITS). We demonstrate that our suggested system is secure against several known threats in IoV- the enabled ITS environment. Furthermore, a thorough comparison of our proposed system to eight other competing ones reveals that it has the lowest communication and computational costs. In addition, it is more secure and provides more functionality characteristics.
A Wideband Compact Polarization-Insensitive Absorber using Modified Resistive Jerusalem Cross FSS

This paper proposes a Frequency Selective Surface (FSS) based Circuit Analog Absorber (CAA) using an array of modified, resistor loaded, Jerusalem cross geometry. The absorber consists of two FR4 dielectric layers separated by an air spacer. The top layer supports the FSS while the bottom layer supports the ground plane. The proposed absorber provides minimum 10 dB reflection reduction of the incoming electromagnetic wave starting from 2.167 GHz to 6.647 GHz, resulting in a fractional bandwidth of 101.657%. The overall footprint of the absorber is quite low. The unit cell size of the proposed design is 0.137 lambda x 0.137 lambda with thickness of 0.081 lambda (lambda being the wavelength corresponding to lower cut-off frequency of the absorption band). Being four fold symmetric geometry, the absorber is insensitive to incident polarization and shows stable response up to 30 degree angle of incidence. It is observed and additional Jerusalem cross at a rotated angle along with a slight modification in the form of a circular aperture at the center of the FSS improves overall absorption.
Structure and Evolution of a Severe Squall Line over the Arid Region in Northwest China

Abstract The structure and evolution of a long-lived squall line associated with a disastrous dust storm, called a black storm, that occurred over the arid region in northwest China are described. Data used in the present study were those from routine observations in China and those acquired from surface observations of the Heife River Field Experiment. The squall line evolved within an extremely dry environment in which surface water vapor mixing ratios were less than 2.5 g kg−1 and the level of free convection (LFC) was very high. The surface cold-air outflow that emanated from the squall line propagated rapidly, producing strong horizontal convergence at the leading edge of the cold pool. The deep, dry mixed layer that developed over the desert region, owing to strong solar surface heating, played a significant role in determining the squall line evolution. The maximum depth of the mixed layer was estimated as more than 4 km, which is often found over the desert regions of China. The growth of the deep.
From Correctable Memory Errors to Uncorrectable Memory Errors: What Error Bits Tell

Uncorrectable memory errors are one of the major failure causes in datacenters. In this paper, we present an empirical study correlating correctable errors (CEs) and uncorrectable errors (UEs) using the large-scale field data across 3 major dual in-line memory module (DIMM) manufacturers from a contemporary server farm of ByteDance. Different from the previous studies, our study is the first to comprehend the error-bit information of CEs and the DIMM part numbers. Unlike the traditional chipkill error correction code (ECC), in contemporary Intel server platforms the ECC gets weakened, not able to tolerate some error-bit patterns from a single chip. Using obtainable coarse-grained ECC knowledge, we derive a new indicator from the error-bit information: risky CE occurrence in terms of ECC guaranteed coverage. From the data, we show that the new indicator has a consistently high sensitivity and specificity in the test of future UE occurrences across DIMMs from different manufacturers. This leads us to conjecture that the weakened ECC substantially contributes to many UEs today. The new risky CE indicator is then applied in predicting the future UE occurrence based on the CE history. We empirically demonstrate how practically useful predictors are constructed in conjunction with other useful attributes such as certain micro-level fault indicators and DIMM part numbers, achieving the state-of-the-art performance.
Using the Ensemble Approach, Predict Students' Achievement

Pupils are the future of a country since they immediately contribute to its development and prosperity via the information they acquire. The kids should be given all the advantages and adequate care they merit for their development and development in order to correctly mould them, which will also mould their classmates since it will inspire them to do better and subsequently lead to better development. To forecast student performances and identify at-risk pupils as as possible so that the proper steps to improve their performance may be taken, computer software and deep neural networks may be utilized. Many additional methods have also been used to measure the effectiveness of the different algorithms. The primary goal of the study is to develop a unique dataset, forecast academic achievement, and then assess that prediction's accuracy using several tree-based group methodologies.
Capacity Optimization in Coding Metasurface-Based Reconfigurable Intelligent Surface-Aided MIMO

In this paper, the channel capacity of a reconfigurable intelligent surface (RIS)-aided multiple-input multiple-output (MIMO) is analyzed. A 1-blt coding metasurface is used to design the RIS. To determine the optimum channel capacity of this RIS-aided MIMO, the water filling algorithm is utilized. During the capacity optimization, it is considered that the transmitter has the full knowledge of channel state information (CSI). Moreover, the optimum channel capacity of the suggested RIS-aided MIMO for variation in the number of elements in the metasurface and signal-to-noise ratio (SNR) are presented.
Adaptive Dynamic Analysis-based Optical Coherence Tomography Angiography for Blood Vessel Tail Artifacts Suppression

Optical coherence tomography angiography (OCTA) for blood vessel 3-D structure imaging suffers from blood vessel tail artifacts when using a long decorrelation time (e.g., repeat B-scan acquisition in regular OCTA) or loss of micro vessel signal when using a short decorrelation time. In this work, we developed an adaptive first order field autocorrelation function (g1) analysis-based technique to suppress the tail artifacts under macro vessels while enhancing the dynamic signal of micro vessels. The proposed method is based on the differences of the decorrelation rate and the phase variations of g1 between the vessel voxels and the artifacts regions. A short or a long decorrelation time was applied to obtain the dynamic index of the tail artifacts region or the blood vessel region, respectively. Compared to the post image processing-based techniques, the proposed approach addresses this problem through the physical basis and shows a good performance in suppressing the tail artifacts while enhancing the detection of the micro vessels.