Miracle-dz/UniFAR-FTUs huggingface dataset:
THE ROLE OF CHAOTIC ORBITS IN THE DETERMINATION OF POWER SPECTRA OF PASSIVE SCALARS

This paper relates properties of the power spectrum of a passive scalar convected by a chaotic fluid flow to the distribution of finite time Lyapunov exponents. The properties considered include the early time evolution of the power spectrum, the late time exponential decay of the scalar variance, and the wave number dependence of the power spectrum in the presence of a source of scalar variance. Theoretical predictions are tested by comparing full numerical solutions of the relevant partial differential equation to solutions of a model system which includes diffusion and involves integrations along the fluid orbits only. The model system is shown to give results in close agreement with the numerical solutions of the full problem. This suggests the possible general utility of the model equations for a broad range of problems involving passive scalar convection.
Accuracy of Satellite Land Surface Reflectance Determination

Abstract An accuracy budget of the surface reflectance determination from Meteosat geostationary satellite data is performed. Error analysis allows identification of three main problems: calibration uncertainty of the Meteosat instrument, atmospheric corrections, and surface effects (spectral and directional). Calibration accuracy is 10%, leading to a 10% relative uncertainty on reflectance. Spectral effects of the surface lead to a maximum bias of 0.01 for a vegetated surface as sensed by Meteosat, while directional effects can lead to a bias of 0.035 between two measurements taken at two different sun zenith and azimuth angles at the same view angle over savannas. The maximum error due to the atmosphere is estimated to be of the order of 0.03 in reflectance for a surface reflectance of 0.40 and 0.01 for, a surface reflectance of 0.10. Validation with in situ measurement is within the expected error over savanna. But the difference is still high over the southwest France site of HAPEX-MOBILHY, certainly .
A shallow-water theory of river bedforms in supercritical conditions

A supercritical free-surface turbulent stream flowing over an erodible bottom can generate a characteristic pattern of upstream migrating bedforms known as antidunes. This morphological instability, which is quite common in fluvial environments, has attracted speculative and applicative interests, and has always been modelled in 2D or 3D mathematical frameworks. However, in this work we demonstrate that antidune instability can be described by means of a suitable one-dimensional model that couples the Dressler equations to a mechanistic model of the sediment particle deposition/entrainment. The results of the linear stability analysis match the experimental data very well, both for the instability region and the dominant wavelength. The analytical tractability of the 1D modeling allows us (1) to elucidate the key physical processes which drive antidune instability, (2) to show the secondary role played by sediment inertia, (3) to obtain the dispersion relation in explicit form, and (4) to demonstrate the .
Direct Numerical Study of the Effects of Particle Parameters on a Particle-Laden Flow

Two-phase flows with particles appear widely in nature and industrial applications. Thus it is very important to research the characteristics of particle-laden flows. In this paper, a series numerical simulation of a particle-laden channel flow was carried out to investigate the effects of particle parameters. The interaction between the continuous phase and particles was calculated by the two-way Euler–Lagrange coupled method. The Stokes number was found to be the characteristic parameter to indicate the distribution of the particle. The particle's preferential concentration in the low-speed and low-vorticity zones was verified. The turbulence suppression occurred in these simulations and the turbulence modulation by particles was found to have an approximate linear correlation with the average mass loading. However, the particle diameter and the particle density ratio was also found to influence the turbulence modulation.
Threshold growth dynamics

We study the asymptotic shape of the occupied region for monotone deterministic dynamics in d-dimensional Euclidean space parametrized by a threshold θ > 0, and a Borel set N ⊂ R d with positive and finite Lebesgue measure. If A n denotes the oocupied set of the dynamics at integer time n, then A n+1 is obtained by adjoining any point x for which the volume of overlap between x+N and A n exceeds θ. Except in some degenerate cases, we prove that n −1 A n converges to a unique limiting «shape» L starting from any bounded initial region A 0 that is suitably large. Moreover, L is computed as the polar transform for 1/w, where w is an explicit width function that depends on N and θ
Spin Polarization and Exchange Interaction in a Diluted Magnetic Qunautm Dot

The spin interaction energy of different ions with and without an itinerant electron is evaluated for different dot radii. Magnetization is calculated for various concentrations of ions with different dot sizes. Spin polaronic shifts are estimated using a mean field theory. The lowest binding energies of electrons in a quantum dot are also calculated. Results are obtained for structures as a function of the dot radius variationally. It is found that (i) more number of spins enhance the spin polaronic effect and it varies linearly with the concentration, (ii) spin polarization of ions increases with the concentration for any dot radii, (iii) the magnetization of Mn subsystem increases with the concentration of ions and this feature is predominant for smaller dots, and (iv) variation of increase in ionization energy is sharper for smaller dots with increase in concentration. These results are discussed with the available data in literature.
Factors that increase processing demands when listening to speech

Listening effort is an increasingly important concept for applied hearing researchers, but it has not been well elaborated in the cognitive literature. We propose that listening effort is the product of two factors: the processing demands imposed by the listening situation, and the cognitive resources that an individual brings to bear, to compensate for demands. Whereas cognitive resources differ markedly among individuals, processing demands are generally constant in a given listening situation, at least for normal-hearing individuals, and fall into at least three different categories: (i) perceptual demands, (ii) linguistic demands, and (iii) concurrent task demands. Perceptual demands are increased when the speech is degraded, when concurrent interfering sounds are present, or when the listener is hearing impaired. Linguistic demands are increased, for example, when speech is semantically or syntactically complex, or when meaning is ambiguous. Finally, when a listener is performing another task (such a.
Some New Surfaces of General Type

In this paper we shall give two series of rare examples of algebraic surfaces of general type. One is a series of surfaces with positive topological indices and another with the geometric genus $p_{g}=0$ . In Part I, we construct surfaces with positive topological indices. In [V] (1966), A. Van de Ven pointed out that there are not many known examples of algebraic surfaces of general type with positive topological indices. By the index theorem of Hirzebruch, the topological index $\tau(S)$ of a surface $S$ is equal to $(K_{S}^{2}-2e(S))/3$ where
Sound scattering of a plane wave obliquely incident on a cylinder

The solution of sound scattering of a plane wave obliquely incident on an isotropic elastic cylinder of infinite length is obtained and verified by experiment. The solution is expressed in terms of phase angles associated with partial scattered waves. It is found that, when the angle of incidence is small, supplementary resonances, which are not present in the case of normal incidence, are excited. The peaks and dips resulting from the resonances appear in the farfield form function ‖f∞‖. Experimental results for several different metals show good agreement with the calculated ones.
Global uniqueness of a multidimensional inverse problem for a nonlinear parabolic equation by a Carleman estimate

An inverse problem with the single measurement datum for a nonlinear parabolic equation in n-D is considered. The unknown coefficient q(u, y) depends on the solution u and (n ? 1) spatial variables y = (x2, ., xn). Such problems were not studied in the past for n ? 2. A global uniqueness result is proved by the method of Carleman estimates.
Comparative evaluation of efficacy of skin staples and conventional sutures in closure of extraoral surgical wounds in neck region: A double-blind clinical study

ABSTRACT Background: The development of the skin stapling technique for surgical wound closure is less time-consuming than the conventional sutures. Aim: This study aims to evaluate the efficacy of skin staples and 4-0 prolene conventional suture in closure of extraoral surgical wounds in neck region in elective maxillofacial surgery. Materials and Methods: The study was conducted on a total of 60 patients, who were equally divided into three groups. In Group 1, wound closure was done using skin staples; in Group 2, wound closure was done using 4-0 prolene suture, and in Group 3, wound closure was done using both skin staples and 4-0 prolene suture. These groups were compared in terms of rate of wound closure; early postoperative pain; pain on the removal of staple and suture; rate of removal of staple and suture; scar evaluation by the clinician, patient, and two-blind observers on 15th day, 1 month, 3 months, and 6 months. Results: The rate of closure was significantly faster in staple group than in suture group. There was no significant difference in the postoperative pain, pain on removal and rate of removal between the two methods of closure. However, within the groups, more postoperative pain was observed in wound with incision length of >5 cm. Initially, on 10th postoperative day, the appearance of scar was significantly better in suture group but after 6 months, scar was better in staple group. Conclusion: The staple method of wound closure appears to be better than conventional suture in terms of rate of closure and scar appearance.
Direct visualization of yielding in model two-dimensional colloidal gels subjected to shear flow

Colloidal gels can undergo a solid to liquid transition, and the yielding and subsequent microstructural reorganizations are responsible for the complex rheological properties of these materials. In the present work, video microscopy is used to study the details of the microstructure during the yielding transition, using planar monolayers of model aggregated suspensions subjected to homogeneous interfacial shear flows. The microstructural heterogeneity of the quiescent structure on both local and larger length scales is characterized in detail. The pertinent length scales can be directly linked to the aggregation pathway. The large scale heterogeneity in the microstructure, rather than the local scale properties, determines the length scales observed during the initial yielding of the gel structure. The break-up and subsequent reaggregation leads to a local compaction and increasingly more heterogeneous structure. As the surface coverage increases, the heterogeneity and deformations become more and more l.
Transient reflectivity as a probe of ultrafast carrier dynamics in semiconductors: A revised model for low-temperature grown GaAs

We revisit pump-probe transient reflectivity (PPTR) as a probe of ultrafast carrier dynamics in photoconductive materials, using low-temperature grown GaAs (LT-GaAs) as an exemplar. The carrier dynamics in a series of annealed LT-GaAs wafers were measured by PPTR. The wafer growth and anneal conditions were tailored to produce a material system with a sub-picosecond carrier lifetime. The PPTR signals from these wafers are bipolar with time constants on the order of 100 fs and 1 ps, consistent with previous literature reports on LT-GaAs. We examined the utility of numerical simulations of the pump-probe transients described in [V. Ortiz et al., J. Appl. Phys. 102, 043515 (2007)] to model our experimental results. We discovered a discrepancy between the model's predictions and experiment with respect to the scaling of the PPTR response with injected carrier density, and show that this discrepancy is rooted in how the model accounts for the index of refraction change due to band filling (BF) and band gap renormalization (BGR). We demonstrate that any model that includes a non-negligible BGR effect is inconsistent with our experimental observations of LT-GaAs. We present a revised model to simulate PPTR signals that account for BF and incorporate optical absorption from mid-gap states. This model can reproduce the experimental results on LT-GaAs and enables comparative assessments of alternate trapping and recombination hypotheses. For LT-GaAs, we compared point defects and nanoparticles as sites for Shockley-Read-Hall recombination, with the result that nanoparticle trapping and recombination centers most accurately reproduce the PPTR probe of carrier dynamics in LT-GaAs.
Electrical properties of SrTiO3 thin films on Si deposited by magnetron sputtering at low temperature

Deposition of SrTiO3 (STO) thin films by radio-frequency magnetron sputtering in an ultrahigh vacuum system at a low substrate temperature (∼200 °C) was performed in order to produce high-quality STO/p-Si (100) interfaces and STO insulator layers with dielectric constants of high magnitude. The STO films were identified as polycrystalline by x-ray diffraction, and were approximated with a layered structure according to the best fitting results of raw data from both Rutherford backscattering spectroscopy and variable angle spectroscopic ellipsometry. Room-temperature current–voltage and capacitance–voltage (C–V) measurements on Al/STO/p-Si diodes clearly revealed metal–insulator–semiconductor behavior, and the STO/p-Si interface state densities were of the order of 1011 eV−1 cm−2. The dielectric constant of the STO film was 65, and the dielectric loss factor varied between 0.05 and 0.55 for a frequency range of 1 kHz–10 MHz. For a 387 nm thick STO film, the dielectric breakdown field was 0.31 MV cm−1, and .
Observations of electron distributions in magnetosheath mirror mode waves

The behavior of the electron distribution function within mirror mode waves in the Earth's magnetosheath is studied using observations made by the electron experiment on Active Magnetospheric Particle Tracer Explorers United Kingdom Subsatellite (AMPTE UKS). The results of a detailed pitch angle analysis show that in the mirror mode troughs the electron distribution displays two distinct features related to particle trapping: (1) The “deeply” trapped electrons (those with pitch angles close to 90° in the magnetic field troughs) are significantly cooled with respect to the rest of the electron population and (2) the “shallowly” trapped electrons (those with pitch angles just greater than the critical pitch angle for trapping) are significantly heated with respect to the rest of the electron population. This is explained as a result of the trapped electron population undergoing a combination of Fermi acceleration and deceleration and betatron deceleration. The untrapped electron population appears to behave adiabatically as it travels alternately through mirror mode peaks and troughs. This behavior is confirmed by the use of Liouville mapping techniques, which also allow us to estimate the electric potential associated with the mirror mode wave.
Improved thermal conductivity in isotopically enriched chemical vapor deposited diamond

The thermal conductivity κ of an isotopically enriched (0.055% 13C) polycrystalline diamond plate made by chemical vapor deposition (CVD) has been measured for heat flowing in a direction either parallel (κ∥) or perpendicular (κ⊥) to the plane of the plate. The room‐temperature conductivities (κ∥=21.8 and κ⊥=26 W cm−1 K−1) are higher than for any CVD diamond previously reported, and the κ⊥ value is higher than the best gem‐quality single crystal with the natural abundance (1.1%) of 13C. Analysis of the temperature dependence of κ∥ reveals that the point‐defect scattering of phonons is in fact significantly lower than expected for the natural abundance of 13C and that it is responsible for the improved conductivity. The observed anisotropy κ∥/κ⊥=0.84 at room temperature is associated with the anisotropic grain structure.
Are olfactory and gustatory symptoms useful at predicting disease severity markers in COVID-19 infection?

ABSTRACT Context: The relationship between olfactory and gustatory dysfunction (OGD) and COVID-19 infection severity is still unclear. Aim: To investigate the correlation between OGD in COVID-19-infected individuals and RT-PCR results, chest CT scan abnormality, lymphocyte counts, hospital admission units, age, body temperature, and blood oxygen saturation. Setting and Design: Case–control study. Materials and Methods: The sample was composed of laboratory and chest X-ray confirmed COVID-19-infected patients from four hospitals. The patients were divided into case and control groups based on the presence of OGD symptoms. The predictor variable was OGD. The outcome variable was gender, hospital admission unit, chest CT scan abnormality, PCR, lymphocyte counts, age, body temperature, and blood oxygen saturation. Statistical Analysis Used: Bivariate statistics were computed and the P value was set at 0.05. Results: The sample consisted of 189 patients. Smell and taste disorders were found in 31.7% and 24.3% of patients, respectively. OGD was significantly correlated with positive PCR results (P < 0.001) and general unit admission (P < 0.05) during hospitalization. Additionally, patients with OGD had significantly lower mean age (P < 0.001), higher body temperature (P < 0.01), and blood oxygen saturation (P < 0.01). However, OGD was not correlated with gender, chest CT scan abnormality, or lymphocyte counts (P > 0.05). Conclusions: OGD symptoms can be used to detect COVID-19-infected patients. OGD can be used to predict less severe disease mainly by its correlation with the less amount of hospital care, more negative PCR results, higher body temperature, and higher blood oxygen saturation.
Robust Inference for Near-Unit Root Processes with Time-Varying Error Variances

The autoregressive Cauchy estimator uses the sign of the first lag as instrumental variable (IV); under independent and identically distributed (i.i.d.) errors, the resulting IV t-type statistic is known to have a standard normal limiting distribution in the unit root case. With unconditional heteroskedasticity, the ordinary least squares (OLS) t statistic is affected in the unit root case; but the paper shows that, by using some nonlinear transformation behaving asymptotically like the sign as instrument, limiting normality of the IV t-type statistic is maintained when the series to be tested has no deterministic trends. Neither estimation of the so-called variance profile nor bootstrap procedures are required to this end. The Cauchy unit root test has power in the same 1/T neighborhoods as the usual unit root tests, also for a wide range of magnitudes for the initial value. It is furthermore shown to be competitive with other, bootstrap-based, robust tests. When the series exhibit a linear trend, however, the null distribution of the Cauchy test for a unit root becomes nonstandard, reminiscent of the Dickey-Fuller distribution. In this case, inference robust to nonstationary volatility is obtained via the wild bootstrap.
Nucleation in ferromagnetic nanowires—magnetostatics and topology

Magnetization reversal in nanowires can be accomplished locally via thermal nucleation of soliton-antisoliton pairs. It is demonstrated that the total nonlocal magnetostatic energy can be reduced to a local anisotropy if the particle diameter is smaller than the magnetic length scale. Topological restrictions of the curling mode are discussed. Barrier energies for nucleation at sample ends are computed and close agreement with recent experiments on Ni-nanowires is found.
Detection and clustering of light charged particles via system‐identification techniques

The problem considered in this work is the classification of the particles produced by the collision of a heavy ion beam on a target. Each particle is captured by a detector and results in a signal (which is the impulse response of a dynamic linear system), which is measured by a digital acquisition system. The assumption made herein is that the shape of the impulse‐response contains complete information on the particle, and the classification can be done by pulse‐shape, analysis.
Anti-fungal therapy: An overview for maxillofacial surgeons in post-covid-19 fungal infections

ABSTRACT India is well known as the diabetes “capital” of the world but now it is also becoming the mucormycosis “capital” of the world. Indian Council of Medical Research has formed an “Evidence-Based Advisory in The Time of COVID-19 on Screening, Diagnosis, and Management of Mucormycosis. ” As per this advisory, an oral and maxillofacial surgeon forms an integral part of the team dedicated to fight this epidemic of mucormycosis. Also, there are other fungal infections such as aspergillosis which are getting reported in these patients affecting the paranasal sinuses and the jaws. Aggressive surgical debridement and a thorough knowledge of anti-fungal therapy are must in treating these fungal infections. The aim of this article is to give an overview on the available anti-fungal therapy required to manage the ever-increasing rise in fungal infections faced by maxillofacial surgeons in post-COVID-19 patients.