New Results Of Measurements Research Articles

Интеллектуальная модель управления рисками нарушения характеристик электромеханических устройств в многостадийной системе переработки рудного сырья

The results of studies on the development of the structure of an intelligent model for managing the risks of violation of the characteristics of electromechanical devices in a multi-stage system for processing ore raw materials are presented. Such devices are involved in all cycles of the technological process, so the assessment of this risk for them is an urgent task. A method for assessing such risks is proposed, which is based on the assessment of the useful life of equipment, performed on the basis of the prediction of characteristics by a deep recurrent neural network, with further generalization of the results of such an assessment in a fuzzy inference block. Recurrent neural networks with long short-term memory were used, which are one of the most powerful tools for solving time series regression problems, including predicting their values for long intervals. The use of deep neural networks to predict the characteristics of electromechanical devices made it possible to obtain a high prediction accuracy, which made it possible to apply a relatively less accurate recurrent least squares method for the iterative process of estimating the useful life of equipment. This approach made it possible to build a computational evaluation process with its constant refinement as new results of measurements of the characteristics of electromechanical devices become available. The results of a model experiment with a software implementation of the proposed method, performed in the MatLab 2021a environment, are presented, which showed the consistency of the program modules and obtaining a risk assessment result that is consistent with the expected dynamics of its change.

Ways to control the inaccuracy of old and new results of measurements of the elastic properties of metallic elements

Abstract The older and newer results of measurements of elastic properties often show a large scatter of values, and not always do new tests result in more accurate values. The fact that for many metals there is often a need of new tests is not only associated with better test methods and machines, but also with the dissatisfaction with the older results, because they present different results for the same metals. Sometimes the handbook editors cannot decide if a new test presents a better value, and publish different results, leaving the reader with the option to decide, which value seems to be better. Of course, this cannot satisfy the researchers using the handbooks and thus, the present contribution shows some ways to select accurate values.

The interaction of laser radiation with strongly coupled plasmas

New results of measurements of s- and p-polarized reflectivity of nonideal plasma at the frequency of the external electromagnetic field ν las = 2.83 × 1014 s−1, free-electron number density n e = 3.3 × 1021 cm−3 (Coulomb nonideal plasma parameter Γ = 1.2) and n e = 5.2 × 1021 cm−3 (Γ = 1.4) are presented. These data are the result of the next stage of study of optics of a warm dense matter. We present a microscopic approach to describe the entire set of experimental data on the optics of strongly correlated plasma.

New Results of Measurements in the Neutrino-4 Experiment Devoted to Searches for Sterile Neutrinos

New Results of Measurements in the Neutrino-4 Experiment Devoted to Searches for Sterile Neutrinos

Analysis of the Results of the Neutrino-4 Experiment on the Search for the Sterile Neutrino and Comparison with Results of Other Experiments

We present new results of measurements of reactor antineutrino flux and spectrum dependence on the distance in the range 6-12 meters from the center of the reactor core at SM-3 reactor (Dimitrovgrad, Russia). Additional measurements were carried out and set of data to perform statistical analysis was almost doubled since the previous report. Using all collected data we performed the model independent analysis on the oscillation parameters $\Delta m^2_{14}$ and $\sin^2(2\theta_{14})$. The method of coherent summation of results of measurements allows us to directly observe the effect of oscillations. We observed an oscillation effect in vicinity of $\Delta m^2_{14} = (7.25\pm0.13_{st}\pm1.08_{sys}) \text{eV}^2$ and $\sin^2(2\theta_{14}) =0.26\pm0.08_{st}\pm 0.05_{sys}$. We provide a comparison of our results with results of other experiments on search for sterile neutrino. Combining the result of the Neutrino-4 and the results of measurements of the gallium anomaly and reactor anomaly we obtained value $\sin^2(2\theta_{14})\approx 0.19\pm0.04(4.6\sigma)$. Also was performed comparison of Neutrino-4 experimental results with results of other reactor experiments NEOS, DANSS, STEREO, PROSPECT and accelerator experiments MiniBooNE, LSND and the IceCube experiment also. Sterile neutrino mass which can be calculated using the Neutrino-4 data in assumption that $m^2_4 \approx \Delta m^2_{14}$ is $m_4 = (2.68 \pm 0.13)\text{eV}$. Considering estimations of mixing angles obtained in other experiments we can calculate masses of electron neutrino, muon neutrino and tau neutrino: $m^{\text{eff}}_{\nu_e} = (0.58 \pm 0.09)\text{eV}, m^{\text{eff}}_{\nu_{\mu}} = (0.42 \pm 0.24)\text{eV}, m^{\text{eff}}_{\nu_{\tau}} \leq 0.65\text{eV}$. Extended PMNS matrix for (3 + 1) model with one sterile neutrino is provided, neutrino flavor mixing scheme with sterile neutrino and global fit of reactor experiments.

Open charm studies at Belle

We present the new results of measurements of the exlusive cross sections of the e+ e− annihilation to charmed meson pairs as a function of √ ceneter-of-mass energy from the open charm threashold up to $ \sqrt s = {\rm{6 GeV}} $ using initial state radiation technique. The analysis is based on a data sample collected by the Belle detector with an integrated luminosity of 951 fb−1. The accuracy of the cross section measurement is increased by a factor of 2 in comparison with the first Belle study. We have performed the first angular analysis + −→ D*± D*∓ of the $ {e^{\rm{ + }}}{e^ - } \to {D^{* \pm }}{D^{* \mp }} $ process and decomposed this exclusive cross section into three components corresponding to the different D* helicities.

Investigation of HTS Tape Stacks for Levitation Applications

Currently, high-temperature superconductor (HTS) bearings are most commonly designed with bulk REBa 2 Cu 3 O 7-x (REBCO), but these HTS bulks have several drawbacks, such as brittleness and the complexity of sample preparation. An alternative for levitation systems is to use stacks of REBCO coated conductors (HTS tapes). The main advantages of HTS tapes are the simplicity of manufacturing elements in the required shape and high strength stability. For the development of HTS bearings, it is important to characterize both the levitation force along the axis connecting the magnet and the superconductor, and the stability of the system in response to lateral displacement. In this paper, we present new results of measurements of the levitation force between a permanent magnet and a stack of HTS tapes containing from 10 to 100 tapes of 12 mm × 12 mm. Measurements were conducted in zero-field cooling mode. We observed hysteresis of the levitation force in the case of lateral displacement. In addition, we have investigated the decay in the levitation force due to lateral displacement with each cycle of movement. It is shown that the decay rate tends to be constant on increasing the number of tapes in the stack.

Clearance gap flow: extended pneumatic measurements and simulations by discontinuous Galerkin finite element method

In the present paper, new results of measurements of the compressible viscous fluid flow in narrow channels with parallel walls under the conditions of aerodynamic choking are presented. Investigation was carried out using the improved test section with enhanced capability to accurately set the parallelism of the channel walls. The measurements were performed for the channels of the dimensions: length 100 mm, width 100 mm and for various heights in the range from 0.5 mm to 4 mm. The results in the form of distribution of the static pressure along the channel axis including the detailed study of the influence of the deviation from parallelism of the channel walls are compared with previous measurements and with numerical simulations performed using an in-house code based on Favre averaged system of Navier-Stokes equations completed with turbulence model of Spalart and Allmaras and a modification of production term according to Langtry and Sjolander. The spatial discretization of the governing equations is performed using the discontinuous Galerkin finite element method which ensures high order spatial accuracy of the numerical solution.

Determination of the Density of Toluene in the Range from (293 to 373) K and from (0.1 to 30) MPa

A hydrostatic balance densitometer with a magnetic suspension coupling has been used to measure the density of liquid toluene in the range from (293 to 373) K and pressures up to 30 MPa. New results of measurements of the density of toluene in the compressed liquid region are presented and compared with literature data. The uncertainty of the present density data is estimated to be within ± 0.01 % across the full temperature and pressure range.

Ways to control the inaccuracy of old and new results of measurements of the elastic properties of metallic elements

Abstract The older and newer results of measurements of elastic properties often show a large scatter of values, and not always do new tests result in more accurate values. The fact that for many metals there is often a need of new tests is not only associated with better test methods and machines, but also with the dissatisfaction with the older results, because they present different results for the same metals. Sometimes the handbook editors cannot decide if a new test presents a better value, and publish different results, leaving the reader with the option to decide, which value seems to be better. Of course, this cannot satisfy the researchers using the handbooks and thus, the present contribution shows some ways to select accurate values.

Salt neutrino detector for ultrahigh-energy neutrinos

Rock salt and limestone are studied to determine their suitability for use as a radio-wave transmission medium in an ultrahigh energy (UHE) cosmic neutrino detector. A sensible radio wave would be emitted by the coherent Cherenkov radiation from negative excess charges inside an electromagnetic shower upon interaction of a UHE neutrino in a high-density medium (Askar’yan effect). If the attenuation length for the radio wave in the material is large, a relatively small number of radio-wave sensors could detect the interaction occurring in the massive material. We measured the complex permittivity of the rock salt and limestone by the perturbed cavity resonator method at 9.4 and 1 GHz to good precision. We obtained new results of measurements at the frequency at 1.0 GHz. The measured value of the radio-wave attenuation length of synthetic rock salt samples is 1080 m. The samples from the Hockley salt mine in the United States show attenuation length of 180 m at 1 GHz, and then we estimate it by extrapolation to be as long as 900 m at 200 MHz. The results show that there is a possibility of utilizing natural massive deposits of rock salt for a UHE neutrino detector. A salt neutrino detector with a size of 2×2×2 km would detect 10 UHE neutrino/yr generated through the GZK process.

New measurements of magnetic fields of roAp stars with FORS 1 at the VLT

Magnetic fields play a key role in the pulsations of rapidly oscillating Ap (roAp) stars since they are a necessary in- gredient of all pulsation excitation mechanisms proposed so far. This implies that the proper understanding of the seismological behaviour of the roAp stars requires knowledge of their magnetic fields. However, the magnetic fields of the roAp stars are not well studied. Here we present new results of measurements of the mean longitudinal field of 14 roAp stars obtained from low resolution spectropolarimetry with FORS 1 at the VLT.

Simultaneous Measurement of the Density and Viscosity of Compressed Liquid Toluene

A vibrating-wire densimeter described previously has been used to perform simultaneous measurements of the density and viscosity of toluene at temperatures from 222 to 348 K and pressures up to 80 MPa. The density measurements are essentially based on the hydrostatic weighing principle, using a vibrating-wire device operated in forced mode of oscillation, as a sensor of the apparent weight of a cylindrical sinker immersed in the test fluid. The resonance characteristics for the transverse oscillations of the wire, which is also immersed in the fluid, are described by a rigorous theoretical model, which includes both the buoyancy and the hydrodynamic effects, owing to the presence of the fluid, on the wire motion. It is thus possible, from the working equations, to determine simultaneously, both the density and the viscosity of the fluid from the analysis of the resonance curve of the wire oscillation, the density being related essentially to the position of the maximum and the viscosity to its width. New results of measurements of the density and viscosity of toluene in the compressed liquid region are presented, and compared with literature data. The density results extend over a temperature range 222 K≤T≤348 K, and pressures up to 80 MPa. The viscosity results cover a temperature range of 248 K≤T≤348 K and pressures up to 80 MPa. The uncertainty of the present density data is estimated to be within ±0.1% at temperatures 298 K≤T≤350 K, and ±0.15% at 222 K≤T≤273 K. The corresponding overall uncertainty of the viscosity measurements is estimated to be ±2% for temperatures 298 K≤T≤350 K, and ±3% for 248 K≤T≤273 K.

Isotopic cross sections of 12C fragmentation on hydrogen measured at 1.87 and 2.69 GeV/nucleon

We present new results of measurements of the isotopic cross sections of 12C fragmentation in the energy region of a few GeV/n. The experiment has been performed at the Dubna synchrophasotron using the magnetic spectrometer ANOMALON, equipped with Cherenkov counters. In this experiment 12C is the projectile and liquid hydrogen is a target. The isotopic cross sections obtained in the measurement are compared with the values predicted by the models: semi-empirical (Silberberg and Tsao) and parametric (Webber, Kish and Schrier). This work is a continuation of the previous one where similar results, but at 3.66 GeV/n, are presented.

Changes of the oscillation frequency of a quartz resonator in contact with a binary liquid mixture of critical composition as function of temperature, revisited

AbstractNew results of measurements of the temperature dependence of changes of the oscillatory frequency Δf(T) of a quartz oscillator in contact with two binary liquid mixtures of critical composition are reported (systems: 2‐butoxyethanol/water; 2,6‐dimethyl pyridine/water, lower critical point). Both systems exhibit an unexpected Δf(T) behaviour approaching the critical temperature. The results lead to the conclusion that even near the critical temperature Δf(T) is determined only by the background viscosity of the systems. The influence of critical contributions to the viscosity can be neglected. It is assumed that this effect is caused by the large shear gradient produced by the quartz oscillator.

Atomic Rayleigh scattering of photons in the momentum-transfer range0−10mc

The new results of measurements of coherent scattering of photons by bound atomic electrons over a momentum transfer $q$ range $0\ensuremath{-}4mc$ together with those from other recent measurements with a coverage in the momentum transfer up to $10mc$ are presented for a critical evaluation of the previous and new calculations on Rayleigh scattering. This evaluation reveals the ranges of applicability of the form-factor formalism in the nonrelativistic and relativistic domain and demonstrates the trend of behavior of the exact theoretical predictions as a function of $\frac{q}{\ensuremath{\alpha}\mathrm{Zm}}$.

Certain New Results of Measurements of the Total Magnetic Field of the Sun and of the Stars

Certain New Results of Measurements of the Total Magnetic Field of the Sun and of the Stars

Некоторые новые результаты измерений общего магнитного поля Солнца и звезд

Некоторые новые результаты измерений общего магнитного поля Солнца и звезд