Miracle-dz/UniFAR-FTUs huggingface dataset:
Relaxation Process of Excitonic Molecules in CuCl under the Two-Photon Resonant Excitation. I. Mutual Collision of Excitonic Molecules

Line shapes of the giant two-photon absorption (GTA) band for the direct generation of excitonic molecules (EM) and the subsequent secondary emission of the EM resonantly generated have been studied in CuCl at various pump powers with the use of a high resolution spectroscopic method. The mutual collision of the EM, the rate of which is nearly proportional to their density, is found to be the main origin for causing the broadening of the GTA band, the decrease of the Raman yield and the rapid increase of the EM luminescence. The collision rate increases up to 10 12 /sec for the pump power of ∼1 MW/cm 2 . With the use of pump and probe method further evidence is obtained for the effectiveness of the mutual collision of the EM.
An analytical algorithm with a wave age factor for altimeter wind speed retrieval

Based on the specular reflection theory of electromagnetic waves at rough sea surface and the wind wave spectrum model with a wave age factor, the sea surface wind speeds are retrieved from the normalized radar backscatter cross‐section (NRCS) measured by TOPEX/Poseidon (T/P) Ku‐band altimeter using the mean square slope (MSS) calculated from the spectrum models of the wind waves and the gravity‐capillary waves. A relationship between wave age and non‐dimensional wave height is applied to compute the wave age factor using the significant wave height (SWH) and wind speeds obtained from buoy or altimeter simultaneously. The study indicates that the wave age factor has a significant impact on the retrieval of altimeter wind speed. Compared with the operational algorithm for retrieving altimeter wind speed, the wind speed retrieved from the new analytical algorithm based on the wind wave spectrum model with the wave age factor, proposed in this study, can match the buoy measurements better. The effects of the wave age factor on altimeter wind speed retrieval are also shown quantitatively through a series of experiments and measurements. The comparison with the operational algorithm indicates that both the bias and root mean square error (RMSE) between wind speeds retrieved by the proposed analytical algorithm and those observed by the buoy decrease significantly. In the Gulf of Mexico, with the new analytical algorithm, more accurate altimeter wind speeds are retrieved.
The vibrational spectrum of a KTiOPO4 single crystal studied by Raman and infrared reflectivity spectroscopy

Potassium titanyl orthophosphate KTiOPO4 has been studied by Raman and infrared reflectivity spectroscopy in the range from a low temperature to room temperature and for various scattering configurations. The absence of a structural phase transition below room temperature is confirmed. The phonon modes are classified within their symmetry species, and their parameters such as damping, oscillator strength and integrated intensity are obtained. On the basis of an internal and external mode analysis and by comparison with related compounds such as RbTiOPO4 and KH2PO4, the origin of the various vibrational groups is discussed. The main part of the scattered intensity is shown to be due to vibrations of the Ti-O bonds.
ROSAT Survey Observations of the Monogem Ring

Maps of the ‘‘Monogem Ring,’’ also known as the Gemini‐Monoceros X‐ray enhancement, in the R1 (110–284 eV), R2 (140–284 eV), and R4+R5 (500–1100 eV) bands from the ROSAT All‐Sky Survey have been generated. The Monogem Ring has a fragmented, shell‐like structure in the R1 and R2 bands and extends across the galactic plane with little or no absorption; only part of the ring is visible in the R4+R5 band. There are intrinsic spectral variations within the ring, most notably from the low longitude side to the high longitude side, which would be consistent with a temperature increase from log (T/K)=5.95 to log (T/K)=6.34, assuming a Raymond & Smith (1977) equilibrium model with normal abundances and a constant neutral hydrogen column density (NH) of 5.0×1019 cm−2.The Monogem Ring is modeled as a supernova remnant (SNR) in the adiabatic stage at various distances between 100 and 1300 pc. If the distance to the ring is 300 pc and the average temperature is log (T/K)=6.15, the initial ambient density is 5.2×10−3 c.
Effective properties of metamaterials

Properties of metamaterials are usually discussed in terms of biaxial anisotropic material parameters. To consider the underlying constitutive relations as valid, it is required that only weak spatial dispersion occurs. At operational frequencies of optical metamaterials this assumption often ceases to be valid. A description using effective material properties tends to be inadequate and new approaches are required. We outline here our latest achievements along this direction and discuss two approaches. The first one assumes that if it is not possible to introduce useful effective properties, a more primary source of information should be used to quantify metamaterials, leading to a characterization of metamaterials in terms of Jones matrices. We discuss the implications of this description and show that all metamaterials can be categorized into five classes, each with distinct properties. The second approach resorts to an effective description but restricts its considerations to a dispersion relation, characterizing the propagation of light in bulk metamaterials, and an impedance, characterizing the coupling between metamaterials and their surroundings. Definitions of both properties linked to a single Bloch mode are discussed and metamaterials are introduced which can be homogenized while considering only this single mode.
High-energy Yb-doped fiber MOPA in the ns-kHz regime for large-scale laser facilities front-end

We report on dual-stage fibered Master Oscillator Power Amplifier system designed to meet stringent requirements of large-scale laser facilities front-end sources. The combination of high power continuous wave laser and electro-optical modulator allows the generation of multi-kHz nanosecond pulses with accurate tailored temporal pulse profiles. The seed pulses are amplified in a preamplifier to achieve 20 μJ pulse energy (33 dB gain) launched inside the power amplifier. We finally obtained a strictly single mode beam, narrow-bandwidth, multi-kHz nanosecond pulse amplification at mJ level, with more than 50 dB optical signal-to-noise ratio, 15 dB polarization extinction ratio and sub-nanosecond resolution temporal shaping. The choice of optimal parameters and the temporal pulse shaping have been performed thanks to numerical simulations (including forward and backward amplified spontaneous emission) in excellent agreement with the results.
MULTIGRID ACCELERATION OF SECOND‐ORDER ENO SCHEMES FROM LOW SUBSONIC TO HIGH SUPERSONIC FLOWS

SUMMARY In the present work the multigrid strategy is applied to second-order EN0 schemes for the computation of steady compressible flows. The performances of the algorithm are analysed in many flow situations, ranging from low subsonic to high supersonic flows, for both internal and external problems. Three different Riemann solvers were considered in the study of computational efficiency and solution accuracy.
Unambiguous Doppler frequency estimation in an MTI radar

In pulse radars, the Doppler frequency estimation is used to determine the object velocity. Many estimation methods have been developed for signals sampled with a rate higher than required by the Shannon sampling theorem. However, in a long range radar the minimum sampling interval is determined by the time needed for the microwave pulse to travel to and from the range perimeter. The frequencies of the Doppler return signal may significantly exceed the resulting unambiguous frequency range. Thus, an MTI (moving target indicator) radar lacks the ability to measure velocity unambiguously. In MTI radar systems periodically nonuniform (staggered) sampling is used to avoid the blind speed effect. M different sampling intervals are used in one stagger cycle. We show that in this case, signal frequency can be recovered from the samples. The method proposed exploits the properties of integer remainders derived from the Chinese remainder theorem. With a proper choice of sampling intervals, it allows for ambiguity resolving in a wide frequency range and with low error sensitivity.
A trajectory analysis of body mass index for Finnish children

The aim of this study is to investigate the early development of body mass index (BMI), a standard tool for assessing the body shape and average level of adiposity for children and adults. The main aim of the study is to identify the primary trajectories of BMI development and to investigate the changes of certain growth characteristics over time. Based on our longitudinal data of 4223 Finnish children, we took anthropometric measurements from birth up to 15 years of age for birth years 1974, 1981, 1991 and 1995, but only up to 11 years of age for the birth year 2001. As a statistical method, we utilized trajectory analysis with the methods of nonparametric regression. We identified four main trajectories of BMI growth. Two of these trajectories do not seem to follow the normal growth pattern. The highest growth track appears to yield to a track that may yield to overweight and the low birth BMI track shows that the girls’ track differs that of boys on the same track, and on the normal tracks. The so-called adiposity rebound time decreased over time and started earlier for those on the overweight track. According to our study, this kind of acceleration of growth might be more of a general phenomenon that also relates to the other phases of BMI development. The major change seems to occur especially for those children on high growth tracks.
On the filtering properties of ensemble averaging for storm-scale precipitation forecasts

AbstractThe mean (ENM) of an ensemble of precipitation forecasts is generally more skillful than any of the members as verified against observations. A major reason is that the averaging filters out nonpredictable features on which the members disagree. Previous research showed that the nonpredictable features occur at small scales, in both numerical forecasts and Lagrangian persistence nowcasts. Hence, it is plausible that the unpredictable features filtered through ensemble averaging would also occur at small scales. In this study, the exact range of scales affected by averaging is determined by comparing the statistical properties of precipitation fields between the ENM and the individual members from a Storm-Scale Ensemble Forecasting (SSEF) system run during NOAA’s 2008 Hazardous Weather Testbed (HWT) Spring Experiment. The filtering effect of ensemble averaging results in a low-intensity bias for the ENM forecasts. It has been previously proposed to correct the ENM forecasts by recalibrating the int.
Cube‐Resonance Method to Determine the Elastic Constants of Solids

The Rayleigh‐Ritz method of eigenvalue approximation is used to obtain a solution for the free vibrations of an elastic solid. The resonant frequencies of an isotropic cube, calculated by this method, agree with the frequencies of the Lame modes, for which an exact solution is possible, up to eight significant digits. Experimental measurements of the 13 lowest‐frequency modes of a cube of fused quartz are all within 0.5% of the results computed by using the elastic constants determined by another method. These constants differ from the elastic constants determined directly from the experimental frequencies by less than 0.2% for the shear modulus and by less than 0.003 for the value of Poisson's ratio. The cube‐resonance method of elastic constant determination is also applicable to substances of more general crystallographic symmetry.
Reflow dynamics of thin patterned viscous films

This letter presents a study of viscous smoothening dynamics of a nanopatterned thin film. Ultrathin film manufacturing processes appearing to be a key point of nanotechnology engineering and numerous studies have been recently led in order to exhibit driving parameters of this transient surface motion, focusing on time scale accuracy method. Based on nanomechanical analysis, this letter shows that controlled shape measurements provided much more detailed information about reflow mechanism. Control of reflow process of any complex surface shape, or measurement of material parameter as thin film viscosity, free surface energy, or even Hamaker constant are therefore possible.
Composite Materials and Measurement of Their Acoustic Properties

A composite material consists of two or more materials and its optimum acoustic properties can be designed by selecting its constituents. Unidirectional composite materials have a very low transverse Poisson's ratio of less than 0.1. By considering such composite material features, the applications of carbon fiber-epoxy and highly crystalline polyethylene fiber-polyurethane composite materials to a medical transducer array are proposed. The sound velocities and densities of the composite materials are measured and their transverse Poisson's ratios are calculated from experimental data.
A Model for Hydrometer Growth and Evolution of Raindrop Size Spectra in Cumulus Cells.

Abstract A relatively simple model of warm and cold rain microphysics in cumulus cells is developed. The proposed model avoids the large amounts of computation required in a non-parameterized treatment and yet removes some of the restrictions imposed by Kessler's microphysical parameterization. The growth of cloud droplets is bypassed, but evolution of particle size spectra for larger hydrometeors and the effects of differential fallspeeds are allowed by the growth of rain and graupel particles in a total of 25 size categories. The processes included are condensation, evaporation, accretion, collection, breakup, freezing, deposition, riming and melting. Experiments in the context of a kinematic updraft indicate results comparable to those of a stochastic model in warm rain development. It is found that a counterbalancing mechanism between auto- conversion and accretion causes the results to be relatively insensitive to assumptions about the auto- conversion process. Further sensitivity tests point out the.
Experiments on capillary-gravity waves of solitary type on deep water

It is shown that capillary-gravity waves of solitary type on deep water can be generated by the resonant excitation of a water surface at a speed close to the phase-speed of free waves. This speed depends upon the wave amplitude. When the source of excitation is removed, the waves are shown to propagate as free solitary waves, damped by viscosity.
The Five College Radio Astronomy Observatory CO Survey of the Outer Galaxy

Images from the FCRAO CO Survey of the Outer Galaxy and a description of the calibration and processing of the data are presented. The survey is comprised of 1,696,80012CO J = 1-0 spectra sampled every 50'' between Galactic longitudes 102. °49 and 141. °54 and latitudes -3. °03 and 5. °41. The VLSR ranges from -153 to +40 km s-1 sampled every 0.81 km s-1 with a velocity resolution of 0.98 km s-1. The survey provides the highest spatial dynamic range imaging of the molecular interstellar medium ever obtained. We describe the observing procedure and characterize the random and systematic noise of the survey. The images reveal a wide diversity of spatial structure within the molecular interstellar medium. We identify several voids with angular extents of 2°-5° in diameter that may result from the cumulative interactions of ultraviolet radiation fields and stellar winds from newborn massive stars with ambient interstellar gas. It is demonstrated that a significant fraction of the integrated intensity summed over the survey field originates from regions with low peak antenna temperature and low column density assuming a conversion between integrated CO emission and molecular hydrogen column density. Assuming kinematic distances to the observed emission, we derive the radial profile of mass surface density and the variations of the z midplane and scale height of the molecular gas distribution with galactocentric radius.
Correlating the Formation Protocols of Solid Electrolyte Interphases with Practical Performance Metrics in Lithium Metal Batteries

: The solid electrolyte interphase (SEI) is regarded as the most important and least understood component of lithium metal batteries (LMBs). Similarly, the connection between SEI formation protocols and the practical performance metrics in LMBs is even less understood. Here, we demonstrate the effects of constant current and constant voltage SEI formation protocols on Coulombic efficiency (CE) and corrosion losses in LMBs. The formation protocols produce SEIs that reduce parasitic lithium − electrolyte reactions, improving early cycle CE and mitigating corrosion of lithium metal. In addition, we establish that the thicker constant current SEIs formed at low current densities are better for passivating lithium than constant voltage SEIs, possibly due to reduced electrolyte permeability in the constant current SEIs. Using these SEI formation protocols in a high-performing electrolyte, we improve first-cycle CE by ∼ 5%, improve compounded CE in the first 5 cycles by ∼ 7%, and reduce corrosion-induced CE losses by ∼ 8%.
3-Dimensional compound ultrasound field of view

A compounded field of view ultrasound image is derived from correlated frames of ultrasound image data. An operator manually translates an ultrasound probe across a patient target area. Frames of sensed echo signals are processed to detect probe motion without the use of a dedicated position sensor or motion sensor. Motion is detected by correlating the frames for probe translation among as many as 6 degrees of freedom. Image registration then is performed for correlated portions to compound a large ultrasound image. Such image encompasses an area larger than a single field of view image frame for the given manually-scanned transducer probe.
Investigating the impact of thresholding and thinning methods on the performance of partial fingerprint identification systems: a review

Abstract. A fingerprint identification system is an application of pattern recognition and image processing. The performance of a fingerprint-based biometric system relies on pre-processing techniques employed on fingerprint images. Especially, thresholding and thinning methods are used to detect minutiae points representing local features and are often utilized to identify a person uniquely. However, studies on partial fingerprints exposed the MasterPrint vulnerability for partial fingerprint identification systems wherein the system performs non-unique user identification. The thresholding and thinning techniques may lead to spurious minutiae generation and stimulate huge MasterPrints. Here, we investigate the impact of thresholding and thinning methods on identification accuracy and the percentage of MasterPrint generated using a partial fingerprint identification method. The experiments comprise four thresholding methods, namely, iterative optimal thresholding, Otsu’s global image thresholding, Niblack local thresholding, and Bernsen’s local image thresholding. Furthermore, it employs four thinning methods, namely, Khalid, Mariusz, Marek thinning algorithm, Khalid, Marek, Mariusz, Marcin thinning algorithm, Hilditch thinning algorithm, and Stentiford thinning algorithm. The results demonstrate that the identification accuracy and percentage of MasterPrint generated varies significantly by replacing the underlying pre-processing methods. Consequently, each combination of thresholding and thinning methods might not be suitable for user identification in high-security applications using a partial fingerprint identification method. The investigation outcomes provide the guidelines to demonstrate the robustness of a partial fingerprint identification method.
A Randomized Large-Scale Cross-Sectional Serological Survey of Hepatitis E Virus Infection in Belgian Pig Farms

Hepatitis E virus (HEV) is the causative agent of hepatitis E disease in humans. While sporadic HEV infections, which occur in industrialised countries and are typically due to HEV genotypes 3 or 4, are asymptomatic and self-limiting, a chronic form of the disease can lead to liver cirrhosis in immunocompromised individuals. Pigs share HEV 3 and 4 genotypes and are thus considered a major animal reservoir for human infection. A subset of animals has been shown to carry HEV particles at the age of slaughter, rendering raw or undercooked pig products potential vectors for human infection. To provide an overview of the current dissemination of HEV in Belgian pig herds, this study was designed as a randomized, robust, large-scale, cross-sectional, serological survey. HEV genotypes and subtypes recently circulating in Belgium (2020–2021) were investigated. Sample stratification as well as epidemiological investigation through the available demographic data of the sampled herds showed that HEV widely circulated in the Belgian pig population during this time and that a change in the circulating HEV strains may have occurred in the last decade. Herd size and type were identified as risk factors for HEV herd-seropositivity. Identifying farms at risk of being HEV-positive is an important step in controlling HEV spread and human infection.
Rossby Wave Propagation on a Realistic Longitudinally Varying Flow

Abstract The response of a barotropic model, linearized about a climatological 300-mb December–February time-mean flow to localized forcing, is considered. In order to aid the design of the experiments and interpretation of the results, a simplified analysis is made of the basic flow in terms of zonal wind, meridional vorticity gradient, and stationary wavenumber. From the analysis the possible existence of a strong waveguide in the Asian jet and weaker waveguides in the North Atlantic and Southern Hemisphere jets is deduced. The possibility of propagation into the equatorial east Pacific and Atlantic oceans and even across these regions is also suggested. These features are confirmed by barotropic model integrations for a variety of perturbation vorticity source positions and shapes. These integrations also show preferred propagation regions arching across North America, from Europe to the Arabian Gulf and, in the Southern Hemisphere, into the equatorial Indian Ocean and Indonesian regions. They also sho.
A Convexity Property in the Theory of Random Variables Defined on a Finite Markov Chain

1. Summary. Let P = (pjk) be the transition matrix of an ergodic, finite Markov chain with no cyclically moving sub-classes. For each possible transition (j, k), let Hj,k(x) be a distribution function admitting a moment generating function fjk(t) in an interval surrounding t = 0. The matrix P(t) = {pjkfjk(t)} is of interest in the study of the random variable S. = Xi + * * * + X. , where Xm has the distribution Hjk(x) if the mth transition takes the chain from state j to state k. The matrix P(t) is non-negative and theref6re possesses a maximal positive eigenvalue ai(t), which is shown to be a convex function of t. As an application of the convexity property, we obtain an asymptotic expression for the probability of tail values of the sum S. Xin the case where the Xm are integral random variables. The results are related to those of Blackwell and Hodges [1], whose methods are followed closely in Section 5, and Volkov [4], [5], who treats in detail the case of integer-valued functions of the state of the chain, i.e., the case fJk(t) = exp(flkt) (fik integral).