Частотно-перестраиваемое устройство на основе многослойного полосково-щелевого перехода и его применение для измерения диэлектрических свойств материалов

The paper presents the results of theoretical and experimental researches of a frequency-tunable device based on the multilayer strip-slot transition with the U-shaped slot resonator of the variable length. The application of the presented device makes it possible to implement a resonant method for measuring the dielectric properties of materials in the microwave frequency range. The numerical simulation in the rigorous formulation of the electrodynamics problem is performed for the theoretical research. The aim of the theoretical research is to determine the electrical characteristics of the multilayer strip-slot transition with the U-shaped slot resonator of the variable length. The results of numerical simulation prove the possibility of applying the multilayer stripslot transition with the U-shaped slot resonator of the variable length to implement the resonant method for measuring the dielectric properties of materials in the microwave frequency range. The experimental research is performed on the sample of the multilayer strip-slot transition with the U-shaped slot resonator of the variable length in the frequency range (850–1250) MHz. Measurements of S-parameters of the multilayer strip-slot transition with the U-shaped slot resonator of the variable length are accomplished using the vector network analyzer. The material under research is BaFe10Ti2O19. The results of theoretical and experimental researches are in good qualitative and quantitative agreement. Представлены результаты теоретических и экспериментальных исследований частотно-перестраиваемого устройства на основе многослойного полосково-щелевого (МПЩ) перехода с П-образным щелевым резонатором. Использование данного устройства позволяет реализовать резонансный метод измерения диэлектрических свойств материалов в сверхвысокочастотном диапазоне. Теоретические исследования заключаются в проведении численного моделирования в строгой постановке электродинамической задачи, направленной на определение характеристик МПЩ-перехода с П-образным щелевым резонатором переменной длины. Результаты численного моделирования доказывают возможность применения МПЩ-перехода с П-образным щелевым резонатором переменной длины для реализации резонансного метода измерения диэлектрических свойств материалов в указанном диапазоне частот. Экспериментальные исследования проведены на макете МПЩ-перехода с П-образным щелевым резонатором переменной длины в диапазоне частот (850–1250) МГц. Оценка его резонансных свойств осуществлялась при использовании векторного анализатора цепей OBZOR TR1300/1. В качестве исследуемого материала использовался материал BaFe10Ti2O19. Результаты теоретических и экспериментальных исследований находятся в хорошем количественном и качественном согласовании. Фомин Д. Г., Дударев Н. В., Даровских С. Н. Частотно-перестраиваемое устройство на основе многослойного полосково-щелевого перехода и его применение для измерения диэлектрических свойств материалов. Ural Radio Engineering Journal. 2021;5(3):225–238. DOI: 10.15826/urej.2021.5.3.002.

20.5 kA current leads for ATLAS Barrel Toroid superconducting magnets

Three pairs of 20.5 kA current leads for the ATLAS Toroid Magnets have been designed, manufactured and tested at Kurchatov Institute. The current leads have a high mechanical reliability and the vacuum tightness under 30 bars of internal pressure. The insulation between the current carrying parts and the mounting flange, the hydraulic connections and the temperature gauges withstand the overvoltage of at least 2 kV. The current leads are fully equipped with diagnostics needed for safety and control. The current leads were tested up to 24 kA. According to CERN's specification they were also tested in the absence of any cooling at very slow current discharge rate (5 A/s) from 20.5 kA to zero without any excessive overheating. Nowadays the current leads are successfully used at the ATLAS Magnet Test Facility at CERN. (6 refs)

Dislocation of the penis: a rare case of genital trauma

Traumatic dislocation of the penis is one of the rarest types of genital trauma. This type of injury is accompanied by a violation of the integrity of the skin and the penile ligamentous apparatus, with the dislocation of the penis into the scrotum under the skin of the thigh, or the area of the pubic joint. The low occurrence frequency of such injuries and the small number of observations described in the literature entails the absence of generally accepted treatment tactics for this category of patients. The article describes a clinical case of successfully treated traumatic dislocation of the penis with penile transposition into the pubic joint area and the formation of subcutaneous urinary leakage after late treatment of the patient for medical care

Systems Analysis of the Functional Condition Children with Neurosensory Bradyacuasia

Purpose: The psycho-physiological features and anthrop-somatic-viceroy parameters in children with neurosensory bradyacuasia (NSB) were investigated.Materials and Methods: It is spent comparative research of boys with НСТ, divided into age subgroups: 7-10 years, 11-13 and 14-16 years. Were executed audio-logic, anthropometrical, physical analyses, psychological testing for revealing of verbal and nonverbal characteristics of intellectual development, it is registered electroencephalogram (EEG) and the evoked potentials.Results: In each group prominent features of the inter-central mutual relations in a brain cortex are revealed. It is established that the condition intra- and inter-hemispheres’ integration and character of spectral density of ranges EEG capacity can represent itself as functional criterion of development NSB. At acquired NSB age-related characteristics of the alpha - rhythm power is not boosted, at inherent - the level of left-side coherent links increases. The decrease of amplitude of visual evoked potential positive components can be connected to failure the hard of hearing children notice function.Summary: The data of the factorial analysis of set anthropometrical, physical and viceroy indicators, parameters of bioelectric activity of a brain, can be diagnostic criteria of anthrop-somatic-viceroy continuum components of a studied pathology

Shock-wave and spalling phenomena in ultrafine-grained and coarse-grained (α + β) alloy Ti-Al-V treated by a nanosecond relativistic high-current electron beam

The results of experimental and theoretical research of shock-wave and spalling phenomena in ultrafine-grained and coarse-grained (α + β) alloy Ti–6.2% Al–4.0% V (wt %) treated by a nanosecond relativistic high-current electron beam are presented. Data on the dynamics of mass velocity, temperature and shock waves as well as on the interaction of the unloading wave with the rarefaction wave reflected from the back surface have been obtained for an axisymmetric position of the target. It is shown that the strain rate increase from 10−3 to 105 s−1 in the both grain structures does not change the fracture mechanism and the phase composition in the zone of spalling. The obtained theoretical dependence of the spalling layer thickness to the target thickness corresponds to experimental data

Investigation of structural-scale levels of spall fracture induced by a nanosecond relativistic high-current electron beam in ultrafine-grained Ti–Al–V–Mo alloy

The results of an experimental and theoretical study of shock-wave processes and spall fracture in an ultrafine-grained and coarse-grained (α + β) Ti–Al–V–Mo alloy under the action of a nanosecond relativistic high-current electron beam are reported. Mathematical modeling is performed to show that when an electron beam with a power density of 1.65 × 1010 W/cm2 impacts this alloy, a shock wave with a compression amplitude of 13 GPa appears and its reflection gives rise to a tensile wave. Its amplitude increases with decreasing target thickness. The calculated increase in the thickness of the spalled layer at the rear surface of the target corresponds to the experimental data. It is established experimentally that plastic deformation precedes the spall fracture sequentially at three structural-scale levels. At the beginning pores are formed and merge, then microcracks are formed at different angles to the back surface of the target between the pores, and then a macrocrack is formed. As a result, the macrocrack surface is not smooth but exhibits pits of ductile fracture

Implementation of the LDA+U method using the full potential linearized augmented plane wave basis

We provide a straightforward and efficient procedure to combine LDA+U total energy functional with the full potential linearized augmented plane wave method. A detailed derivation of the LDA+U Kohn-Sham type equations is presented for the augmented plane wave basis set, and a simple ``second-variation'' based procedure for self-consistent LDA+U calculations is given. The method is applied to calculate electronic structure and magnetic properties of NiO and Gd. The magnetic moments and band eigenvalues obtained are in very good quantitative agreement with previous full potential LMTO calculations. We point out that LDA+U reduces the total d charge on Ni by 0.1 in NiO

Optical studies of gap, hopping energies and the Anderson-Hubbard parameter in the zigzag-chain compound SrCuO2

We have investigated the electronic structure of the zigzag ladder (chain) compound SrCuO2 combining polarized optical absorption, reflection, photoreflectance and pseudo-dielectric function measurements with the model calculations. These measurements yield an energy gap of 1.42 eV (1.77 eV) at 300 K along (perpendicular) to the Cu-O chains. We have found that the lowest energy gap, the correlation gap, is temperature independent. The electronic structure of this oxide is calculated using both the local-spin-density-approximation with gradient correction method, and the tight-binding theory for the correlated electrons. The calculated density of electronic states for non-correlated and correlated electrons shows quasi-one-dimensional character. The correlation gap values of 1.42 eV (indirect transition) and 1.88 eV (direct transition) have been calculated with the electron hopping parameters t = 0.30 eV (along a chain), t_yz = 0.12 eV (between chains) and the Anderson-Hubbard repulsion on copper sites U= 2.0 eV. We concluded that SrCuO_2 belongs to the correlated-gap insulators.Comment: 24 pages, 8 figures, to be published in Phys.Rev.

THE PROBLEM OF QUALITY ASSESSMENT OF PERSONNEL POTENTIAL OF HEALTH ORGANIZATIONS

The article considers problems of assessment of the quality of human resource capacity of health organizations. The analysis of existing methods of an estimation of personnel potential. Describes the main components of the system of personnel policy of the medical organization. Developed graphical representation of personnel potential of the employee