Miracle-dz/UniFAR-FTUs huggingface dataset:
An Accurate Sparse SAR Imaging Method for Enhancing Region-Based Features Via Nonconvex and TV Regularization

With the rapid development of compressed sensing theories and applications, sparse signal processing has been widely used in synthetic aperture radar (SAR) imaging during the recent years. As an efficient tool for sparse reconstruction, <inline-formula><tex-math notation="LaTeX">$\ell _1$</tex-math></inline-formula> optimization induces sparsity the most effectively, and the <inline-formula><tex-math notation="LaTeX">$\ell _1$</tex-math></inline-formula>-norm penalty is usually combined with the total variation norm (TV-norm) penalty to construct a compound regularizer in order to enhance the point-based features as well as the region-based features. However, as a convex optimizer, the analytic solution of <inline-formula><tex-math notation="LaTeX">$\ell _1$</tex-math></inline-formula> regularization-based sparse signal reconstruction is usually a biased estimation. Aiming at this issue, in this article, we quantitatively analyzed the variation of reconstruction bias with respect to the complex reflectivity of targets, the undersampling ratio and the noise power. In order to reduce the bias effect and improve the reconstruction accuracy, we adopted the nonconvex regularization-based sparse SAR imaging method with a nonconvex penalty family. Furthermore, we linearly combined the nonconvex penalty and the TV-norm penalty to form a compound regularizer in the imaging model, which can improve the reconstruction accuracy of distributed targets and maintain the continuity of the backscattering coefficient. Simulation results showed that compared with <inline-formula><tex-math notation="LaTeX">$\ell _1$</tex-math></inline-formula> regularization, nonconvex regularization can reduce the average relative bias from 10.88% to 0.25%; compared with the matched filtering method and <inline-formula><tex-math notation="LaTeX">$\ell _1$</tex-math></inline-formula> and TV regularization, nonconvex & TV regularization can reduce the variance of the uniformly distributed targets by 80% without losing of reconstruction accuracy. Experiments on Gaofen-3 SAR data are also exploited to verify the effectiveness of the proposed method.
ELECTRONIC NOSE CHEMICAL SENSOR VERSUS GAS CHROMATOGRAPHY: A FEASIBILITY STUDY FOR THE DIFFERENTIATION OF APPLE FLAVORS AND ESSENCES

The ability of chemical sensors to differentiate and match samples of apple flavors and essences is of interest to the flavor and food industries. This study evaluated the feasibility of using a prototype chemical sensor for the differentiation of apple flavors and essences. Volatile headspace gases from 20 flavors and four essences were measured with a gas chromatograph and the prototype chemical sensor. A principal component analysis (PCA) reduced the chemical sensor data into two principal factors that accounted for 96% of the variance in the sensor measurements. A hierarchical cluster analysis (HCA) of the PCA data put two flavors and essences into one cluster and the remaining 22 into another. The HCA analysis also provided a breakdown of the clusters into subgroups by similarity. The subgroups were used to determine matches with eight unknowns, six flavors, and two essences. The prototype chemical sensor correctly identified all six unknown flavors. Three were absolute matches, and three matched more than one unknown (one of which was the correct flavor). Visual comparisons of gas chromatograms of known and unknown samples led to absolute matches of five of the six unknown flavor samples. Neither measuring method identified the two unknown essences. These results suggest that it is feasible to use the chemical sensor prototype to differentiate between apple flavors or essences. One potential use of chemical sensor technology is in quality control and food safety programs of food ingredients and products.
THE RELATIONSHIP BETWEEN RETENTION, LINEAR FLOW, AND DENSITY DIFFERENCE IN COUNTERCURRENT CHROMATOGRAPHY

Countercurrent Chromatography is a high-resolution, liquid-liquid chromatography process which is generic in nature and can be used with a wide range of solvent systems. This paper shows there are simple relationships between the operational variables affecting CCC, which lead to a clearer understanding of how the process works. In the future, it will be easier to predict phase system behaviour from the physical characteristics of the phase system and the operating conditions of the coil planet centrifuge and, so, simplify the process of getting started with a new phase system.
Efficient KrCl (223 nm) excimer laser based on TPI thyratron as a high-voltage switch

The results of the experimental investigations of the discharge-pumped KrCl (223 nm) excimer laser with the TPI thyratron (pseudo spark gap) as a high-voltage switch are presented. The experimental investigation of the energy and temporal parameters of the pumping and radiation for KrCl laser on the Ne:Kr:HCl mixture with an excitation system of the LC-inverter type based on TPI 10k/20 thyratron was carried out. The comparative analysis of the laser pumping and radiation parameters with those obtained for excitation system based on a spark gap RU-65 as a high-voltage switch was performed. As a result the output radiation energy for a laser with thyratron TPI 10k/20 was obtained to be of 40% higher than that with spark gap RU-65 at the same pumping conditions. The higher output energy and efficiency of the TPI based laser was considered to be due to higher efficiency of energy transfer from storage to discharge circuit and to active media owing to lower energy losses into TPI thyratron in comparison with the RU-65 spark gap. For KrCl excimer laser in Ne:Kr:HCl mixture the total efficiency of 1.5% with output energy of 0.65 J was obtained for the first time.
Distribuzione del marine litter nelle spiagge della Sardegna: il caso di Cala dei Ponzesi e di Cala Spalmatore nell’isola dell’Asinara

The study aims to analyze and quantify compositions of marine litter along 2 beaches of Asinara Island-Italy during 3 surveys (winter’17, spring-summer‘19). Method used was based on guidelines of UNEP, JRC and DEFISHGEAR project. Preliminary results show that 1917 items were collected at Cala dei Ponzesi, while 816 were identified in 2019 surveys. 289 items were collected in 2 2019 surveys at Cala Spalmatore. It appears that plastic is the most important category of litter and plastic fragments, lolly sticks, plastic caps/lids unidentified, string and cord (<1 cm) are the most frequent debris
Numerical Investigation of Aeroelastic Flutter in Two-Dimensional Cascade of Compressor Blades

Following contribution presents numerical study of aeroelastic flutter in two-dimensional section of flat wing cascade in wind tunnel. The investigation is conducted as a parametric study of varying pitch angle of one (middle) blade in the cascade with each computational case performed on fixed computational grid. This approach can be viewed as an approximation of fluid-structure interaction realized on moving mesh. Numerical predictions were carried by means of CFD open-source codes OpenFOAM® and Nektar++. The particular aim was focused on assessment of numerical performance and accuracy of the numerical solvers as well as several turbulence models.
An analytical model of beam attenuation and powder heating during coaxial laser direct metal deposition

In the laser direct metal deposition process, interaction between the laser beam and powder from a coaxial powder delivery nozzle alters the temperature of powder and the amount and spatial distribution of laser intensity reaching the deposition melt pool. These factors significantly affect the process and are also important input parameters for any finite element or analytical models of the melt pool and deposition tracks. The analytical model in this paper presents a method to calculate laser attenuation and powder temperatures at every point below such a nozzle. It is applicable to laser beams that are approximately parallel over the beam–powder interaction distance of any initial intensity distribution (Top Hat, Gaussian, TEM01* or other). The volume below the nozzle is divided into the region above the powder consolidation plane, where the powder stream is annular, and below it, where it is a single Gaussian stream, and expressions derived for each region. Modelled and measured results are reasonably matched. Results indicate that attenuation is more severe once the annular powder stream has consolidated into a single stream but is not zero before that point. The temperature of powder reaching any point is not constant but the mean value is a maximum at the centre of the stream.
Point Cloud Registration Algorithm Based on Cauchy Mixture Model

In this paper, the Cauchy mixture distribution is used for rigid and affine registration. The Cauchy function has a wider effective range than the general window function, so it has a greater information utilization ratio than most registration algorithms. This means that the method can quickly match point clouds without initial registration and corresponding points. On the other hand, the computational complexity of Cauchy mixture model is lower than that of widely used Gaussian mixture model. This means that the introduction of Cauchy mixture model will save computing resources. However, the log-likelihood function of the Cauchy mixture distribution is a nonlinear function that is difficult to solve. This paper proposes an optimization method for the Cauchy mixture model, and discusses the advantages of the Cauchy mixture model in rigid and affine registration. In the experiment, compared with several other algorithms, our method quickly and accurately registers point clouds.
Towards Black-Hole Singularity-Resolution in the Lorentzian Gravitational Path Integral

Quantum gravity is expected to resolve the singularities of classical general relativity. Based on destructive interference of singular spacetime-configurations in the path integral, we find that higher-order curvature terms may allow to resolve black-hole singularities both in the spherically symmetric and axisymmetric case. In contrast, the Einstein action does not provide a dynamical mechanism for singularity-resolution through destructive interference of these configurations.
Electron crystallography of aluminum alloy phases

Abstract A series of structure analyses during 1994-2001 by electron crystallographic techniques applied to phases in aluminum alloys are reviewed. Methods for structure solution employ electron diffraction intensity data collected by the precession technique, by selected area micro-diffraction and by the convergent-beam technique. High-resolution electron microscope images (HRTEM) are treated by different kind of processing, including exit wave reconstruction. Crystallographic calculations are performed either by direct method or Patterson and Fourier procedures, assuming kinematical scattering, or by refinement from models derived from HRTEM images. Dynamical scattering calculations can be introduced in the refinement stage or as a correction procedure applied to part of the intensity data. The phases studied include primary Al-Fe-(Si) particles, Al-Mn-Si dispersoids, Al-Co quasicrystals and two types of precipitate phases in age-hardening Al-Mg-Si and Al-Zn-Mg alloys.
Evolution of Small Ti Clusters and the Dissociative Chemisorption of H2 on Ti

The sequential growth of small titanium clusters with up to 15 atoms and the dissociative chemisorption of H 2 on the minimum energy clusters have been studied within density functional theory under the generalized gradient approximation. It has been found that the low-energy clusters grow three dimensionally from Ti4 and follow a pentagonal growth pattern. The clusters Ti 7 and Ti 13 show a higher stability than other clusters with a configuration of pentagonal bipyramid and icosahedron structures, respectively. The second difference of binding energy plot indicates that these two clusters are highly stable; this agrees with the experimental collision-induced dissociation studies and previous theoretical calculations. For the first time, a systematic study of chemical reactivity of small Ti n clusters, with n = 2-15, toward dissociative chemisorption of H 2 is performed. It is found that the chemisorption occurs preferentially at the two adjacent edges of any Ti atom. The chemisorption energy as a function of the cluster size shows considerable structural changes in the Ti n clusters due to H 2 dissociation and adsorption, and the chemisorption energy of Ti 13 cluster is found to be the highest.
Preparation, X-ray structure, and dynamic solution behaviour of N,N',N''-tris(2,6-diisopropylphenyl)- guanidine, and its reaction with molybdenum carbonyl

The reaction of N,N'-bis(2,6-diisopropylphenyl)carbodiimide with lithium 2,6-diisopropylanilide, quenching with water and recrystallization from heptane produces the symmetric guanidine [DipNH]2C=NDip which crystallizes in the triclinic system, space group P, a = 10.6513(11), b = 10.8997(11), c = 16.2961(17) A, α = 80.524(12), β = 78.921(13), γ = 70.060(12)°, V = 1735.2(3) A3, Z = 2. The molecule crystallizes with three perpendicular 2,6-diisopropylphenyl groups, which surround and shield the central CN3 unit, and provide (almost) three-fold symmetry around the central atom. Its dynamic solution behaviour has been studied by VT NMR between -90 and +180°C, and is consistent with three distinct barriers to N-CAr rotation. Preliminary estimates of the Gibbs free energy of activation for the lower two barriers are 56 ± 2 and 73 ± 2 kJ mol1. Reaction of the title compound with Mo(CO)6 in refluxing n-heptane produces [DipNH]2C=NDip·Mo(CO)3, a complex in which Mo(CO)3 is η6-coordinated to one of the diisopropyl.
The epidemiology of adult fractures according to the AO/OTA fracture classification

ABSTRACT BACKGROUND: The epidemiology of adult fractures has been changing timely, in a multifactorial fashion. The aim of this study was to put forward a recent 5-year epidemiological analysis of adult fractures, according to the current AO/OTA fracture classification, in the current decade of action for road safety. METHODS: 5324 adult patients who were diagnosed with at least one fracture related with orthopedics and traumatology in a level-one trauma center were included in this retrospective, epidemiological descriptive study. The patients were grouped according to their ages as; 18–35, 36–55, 56–69, and ≥70. The fractures were examined according to the AO/OTA classification. RESULTS: 5865 fractures were present in 5324 patients. The mean age of the patients was 48.6±21.5. The number of patients according to the age groups was as follows; 1947 (36.6%), 1636 (30.7%), 881 (16.5%), and 860 (16.2%), respectively. The most frequent three fractures according to the AO/OTA fracture classification were; 7 (hand 19.6%), 23 (distal forearm, 12.1%), and 8 (foot, 11.8%). About 54.4% and 45.4% of the patients were treated non-surgically and surgically, respectively. About 0.2% of the patients preferred an alternative treatment. Overall mortality rate was 0.4%. CONCLUSION: To the best of our knowledge, this study represents the first analysis of adult fractures according to the AO/OTA classification, over a 5-year period. As a future prospect, further multi-centric epidemiological studies are warranted to constitute a sustainable action plan for the prevention of major traumas.
Modeling and Analysis of Soft Pneumatic Network Bending Actuators

This article presents an analytical model for soft pneumatic network actuators (PneuNets) consisting of a series of chambers made of elastomeric material and an inextensible bottom layer. The model links the input pressure with the bending angle in free space and the tip force of the PneuNets. The bending principle of the PneuNets is comprehensively analyzed through the analytical model. The bending angle of PneuNets is analyzed considering the deflection of the gap layer. The tip force of PneuNets is analyzed considering the equilibrium moment of the PneuNets at the applied pressure. This article focuses on the deformation of the gap layer of the PneuNets and the effect of gap length on the bending angle. The proposed model considers the deformation of the lateral wall of the chamber as the deformation of the nonlinear hyperelastic membrane. Futhermore, the contact moment is included considering the Hertzian contact between the adjacent chambers. Finite element analysis and physical experiments are carried out and the results show that the bending angle and tip force of the PneuNets can be effectively predicted by the analytical model with an error of less than 10%.
pH‐Solubility Relationship and Partition Coefficients for some Anti‐Inflammatory Arylaliphatic Acids

pka‐values of some anti‐inflammatory arylaliphatic acids were measured potentiometrically in DMSO/H2O (80% w/w). The values were confirmed by assessing the solubility of the acids as a function of the pH of the aqueous solutions. In this way, the intrinsic partition coefficient in octanol/water was defined. The discussion deals with the structure and reviews the few data available in the literature.
Use of Library and Library Resources in University Libraries of Northern India: A Comparative Study between Research Scholars and Faculty Members

The purpose of the study was to investigate research scholars (RS) and faculty members (FM) involvement in use of library, library resources, purpose behind using them and satisfaction from the resources in five university libraries of Northern India. The representative samples were selected based on sample size given by Krejcie and Morgan (1970). The representative sample was formed by taking 15% of respondents from each category from each university. The ‘Proportionate Stratified Random Sampling Technique’ was used. The data collected was analyzed with the help of statistical software package called SPSS and hypotheses were tested using Chi-Square test. The study was limited to five universities libraries of Northern India. No significant relationship was found in frequency of visit to the library between the research scholars (RS) and faculty members (RM) across the libraries. RS spent more time in their respective libraries as compared to FM and library is the prominent place for reading in the opinion of RS, whereas FM visited their respective libraries for circulation purpose. A significant difference was found between RS and FM about availability of required resources, information sources used by them except non-book materials, whereas a significant relationship was found in opinion of RS and FM satisfaction from the library collection. The findings will help the library authorities to understand the pattern of use of their library, purpose of visit, information sources consulted, reasons for use of print and e-resources and satisfaction from their respective collections between RS and
Inflation dynamics in Tunisia: a smooth transition autoregressive approach

The fact that inflation is still on the rise, despite measures undertaken by the Tunisian central bank, prompts questions as to whether or not inflation dynamics has changed, exhibiting higher levels of persistence and volatility. This paper employs the smooth transition autoregressive model (STAR) to analyze Tunisian inflation dynamics on monthly data over the last three decades. We distinguish three periods based on monetary reforms. The non-linearity tests suggest that the ESTAR specification describes better the behavior of inflation. Our results suggest changes in persistence and important shifts in volatility, which confirm the effectiveness of the monetary reforms to a certain extent given the past political instability and the democratic transition in Tunisia.
The nature of structure-bonded H2O in illite and leucophyllite from dehydration and dehydroxylation experiments

Thermogravimetric analysis combined with mass spectrometry was used to study H2O bound to samples of illite-1M, illite-2M2 and leucophyllite-1M. Samples were heated in a helium atmosphere at different temperatures and after heating at each given temperature were cooled to 35°C. Each cycle in the mass 18 spectrum of each illite sample contains a low-temperature peak at 60–80°C, a medium-temperature peak at 340–360°C, and a high-temperature peak at a temperature that is very close to the maximum temperature of sample heating of a given cycle. Within each heating-cooling cycle, the sample weight at the beginning of cooling is lower than that at the end of the same cooling stage because of H2O resorption. However, the number of H2O molecules released during each medium-temperature heating cycle is equal to the number of H2O molecules resorbed during the corresponding cooling stages.The weight losses, under medium-temperature heating, of the illite samples are related to dehydration when H2O molecules located in K-free sites of the illite interlayers are removed. The medium-temperature peak is reproducible for each cycle because during each cooling stage the illite interlayers resorb the same number of H2O molecules that were lost during the preceding dehydration.Two distinct features are characteristic of leucophyllite during heating-cooling treatments. First, the number of H2O molecules resorbed during cooling is significantly greater than the number of H2O molecules lost during dehydration. Second, the medium-temperature peaks in the spectrum appear only in the last five cycles and the maximum-peak temperature is 450–460°C. These data indicate that the heating-cooling treatments are accompanied by partial rehydroxylation. This rehydroxylation occurs during each coolingstage when a small number of resorbed H2O molecules are trapped in the interlayers, although most migrate into the octahedral sheet of the 2:1 layers and reform as OH groups. The crystal chemical factors responsible for the dehydration and rehydration as well as for the rehydroxylation reactions are discussed and speculation about the origin of the low- and medium-temperature H2O losses is presented.
Evidence for aqueous phase hydrogen peroxide synthesis in the troposphere

Recent studies of the oxidation of sulfur dioxide by hydrogen peroxide in solution indicate that this process may be the dominant mechanism for the conversion of SO2 to H2SO4 in cloud water where the typical pH is less than 5.5. In the interpretation of theoretical calculations and previous hydrogen peroxide measurements it has generally been assumed that the limiting factor in the acidification of precipitation is the amount of gas-phase H2O2 available to the cloud-precipitation system. Field observations of H2O2 during Acid Precipitation Experiment (APEX) missions revealed that in addition to vapor phase H2O2, there were present one or more atmospheric constituents which produced H2O2 in the aqueous phase, and there were other species which consumed the collected H2O2 vapor. We report here an investigation of these phenomena undertaken to ensure that the instrumentation was responding to H2O2 alone and to identify the species which interfered in the aqueous collection and measurement of H2O2 vapor. Our results showed that (1) the H2O2 found within the collectors frequently exceeded the amount initially present as vapor, (2) the species which produced H2O2 were relatively insoluble, (3) NO2 did not enhance H2O2 formation, (4) O3 enhanced H2O2 formation, and (5) SO2 depleted aqueous H2O2. The amount of aqueous H2O2 lost when SO2 vapor was added to ambient air was larger than expected. The results of these experiments have important implications for cloud water chemistry. If the processes occurring within the impinger can be extrapolated to droplets, the amount of H2O2 available for SO2 oxidation would not be limited by the amount of H2O2 vapor in precloud air but would also depend upon the concentration of the precursors capable of generating H2O2 in droplets.