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The authors validate the use of magnetic hydrocycloning in extraction of weak magnetic-responsive slime particles from finely dispersed magnetic suspension. Efficiency of a lab-scale magnetic hydrocyclone with regular electromagnetic system of copper wires on the cone, without superconductive materials involved, in extraction of magnetite particles –20 m in size is described. The test results prove recoverability of hematite and other weakly magnetic minerals in magnetic hydrocycloning at the required flux density of 2–10 T created by a superconductive magnetic system under conditions of cooling at the liquid nitrogen temperature, which minimizes energy intake of magnetic separation. The use of the superconductive magnetic system and high-temperature materials on the hydrocyclone cone enables efficient extraction of weakly magnetic particles, for instance, red mud –10 m in size. [ABSTRACT FROM AUTHOR]

In this paper is presented a two-dimension analytical model for linear permanent magnet inner armature double-sided synchronous motors (LPMIADSSMs). The flux density in all areas of the proposed machine is calculated based on the sub-domain method. According to this method, the machine areas are divided into eleven sub-regions such as first external, first mover, first PM, first air gap, first winding, stator, second winding, second air gap, second PM, second external and second mover, which sign as FE, FR, FP, FAG, FW, S, SW, SAG, SP, SE and SR. To find the flux density equations, it is mandatory to solve the extracted Maxwell equations and apply the boundary conditions between each two sub-regions, which lead to find the unknown coefficients for flux density in each sub-region. In addition, the influences of magnetization patterns, i.e., parallel, ideal Hal Bach, 2-segment Halbach and bar magnet in the shifting direction of the flux distribution and armature reaction (AR), are investigated. To validate the obtained results, the proposed model results are compared with those obtained from finite element method (FEM) and Maxwell software. [ABSTRACT FROM AUTHOR]

The electromagnetic background was measured in the living quarters of the Vostok Station located on the Antarctic plateau distant from the potential sources of technogenic electromagnetic fields. The level of E-radiation in the range from 0.8 to 8 GHz was determined using a MERA integral dosimeter. Based on the results of long-term continuous (one to 4 months) measurements, the mean flux density was equal to 1.5 ± 0.8 nWt/cm, which is nearly 7000 times lower than the admissible level for population adopted in Russia. The Antarctic Vostok Station can be considered as a plausible location for biomedical investigations into the effects of low-frequency electromagnetic radiation. [ABSTRACT FROM AUTHOR]

The very close d-axis and q-axis inductances of the flux-switching permanent magnet (FSPM) machine make it even similar to a surface-mounted permanent magnet (SPM) machine, especially those with fractional slot and concentrated windings (FSCW), which is usually applied in a light-power situation where small size and high power density are desired. Based on finite element analysis (FEA), the FSPM machine with 6-slots/5-poles (5 pole pairs) is designed for light servo applications and further compared to an SPM machine with 9-slots/8-poles (4 pole pairs), covering electromagnetic, thermal, and mechanical behaviors. The rotor skewing of the FSPM machine is also studied. Finally, the prototypes of the FSPM and SPM machines are manufactured and experimental measurements are carried out to validate the FEA results. [ABSTRACT FROM AUTHOR]

The search for pulsars outside the plane of the galaxy in an area of 300 sq. deg. was carried out with the LPA LPI antenna at 111 MHz, with a sensitivity 5 to 10 times better than that of previous surveys. The search was performed in the summed power spectra. With an accumulation time equivalent to 100 hours of continuous observations for each point of the area, 5 known pulsars were found with a signal-to-noise ratio (S/N) from 20 to 1300 in the first harmonic of the spectrum. Average profiles are obtained for the detected pulsars. Estimates are given for the peak and integrated flux densities of the found pulsars for individual sessions and for power spectra summed over 5.5 years, using the developed method based on measurements of harmonic heights in the power spectrum. No new pulsars were found in the area. Apparently, when searching for pulsars in the area, we approached the lower limit of the luminosity of second pulsars. The survey completeness is at the level of 0.5 mJy. [ABSTRACT FROM AUTHOR]

The composition of GET 39-2021 State primary standard of units of volumetric activity of radioactive aerosols, radon, thoron, and radon flux density is presented. Methods for reproducing and transferring the units of volumetric activity of radioactive aerosols, radon, thoron, and radon flux density are described. Possible sources of error are identified, and their quantitative assessment is performed. The metrological characteristics of GET 39-2021 are provided. GET 39-2021 ensures the uniformity of measurements of the volumetric activity of radioactive aerosols, radon, thoron, and radon flux density in various fields, including the nuclear industry, at enterprises for the extraction and processing of nuclear raw materials, etc. In the nuclear industry, GET 39-2021 can be used to ensure the radiation protection of personnel and the environment during the construction and commissioning of new-generation nuclear reactors. [ABSTRACT FROM AUTHOR]

In this paper, we state the problem of constructing evolution equations describing the dynamics of condensed matter with an internal structure. Within the framework of this statement, we describe the class of evolution equations for vector and pseudovector fields on ℝ3 with an infinitesimal shift defined by a second-order, divergent-type differential operator, which is invariant under translations of ℝ3 and time translations and is transformed covariantly under rotations of ℝ3. The case of equations of this class with preserved solenoidality and unimodality of the field is studied separately. A general formula for all operators corresponding to these equations is established. [ABSTRACT FROM AUTHOR]

This work reports radon-thoron monitoring at two depths (60 and 90 cm) and at 82 sites around Jawalamukhi thrust of NW Himalaya, India using Solid State Nuclear Track Detectors (SSNTDs). Further, radium contents of soil samples have been measured using NaI(Tl) crystal detectors and the exhalation rates have been measured using SMART Rn Duo monitor. The average radon-thoron concentrations at two different depths are found to be 3043 ± 691 Bq m−3, 4969 ± 561 Bq m−3 & 448 ± 416 Bq m−3, 773 ± 117 Bq m−3. Average value of area exhalation rate found to be 299.9 × 10−3 Bq m−2 h−1 with radium contents of value 51.04 Bq kg−1. The convective velocity of radon-thoron along with their flux densities has also been calculated. The average magnitudes of flux densities for radon-thoron found to be 44.96 × 10−2 Bq m−2 s−1 and 15.57 × 10−2 Bq m−2 s−1 whereas the convective velocities calculated to 8.38 × 10−6 m s−1 and 25.69 × 10−3 m s−1. The recorded values of thoron are lower than the recorded radon values. Moreover, the value of radon and thoron is higher at depth 90 cm than at depth 60 cm. The anomalous radon-thoron concentrations have been observed along the Jawalamukhi thrust and at some other sites suggesting secondary porosity or presence of local fault/lineament. A good correlation between area exhalation rates and radium contents, as well as between mass exhalation rates and radium has been observed. However weak correlation between porosity and area exhalation rates has been observed in this region. [ABSTRACT FROM AUTHOR]

It is proposed to use a porous heat-insulating glass-ceramic material (GCM) in the form of segments based on glass, a plasticizer, organic additives, and a gas generator for thermal insulation of pipelines of heating pipe mains and utilities. Research on the use of GCMs in the heat supply pipelines was conducted according to the key methodology for studying new materials, including their composition, structure, properties, changes under the influence of external factors, and their applications. The effectiveness of the thermal insulation materials for thermal insulation of pipes was evaluated on the basis of the physical and technical characteristics of the heat-transfer medium, pipes, and thermal insulation materials. The study involved the determination of the heat losses and thermal resistances through the insulated surface of the aboveground supply and return pipelines of heat networks. When calculating the heat loss through the pipe with various heat insulators in use, the layer thickness was assumed to be the same. The studies have shown that, when using shells made of granular glass-ceramic material, the loss of heat transmitted by thermal conductivity is 1.36 times lower than that for a vermiculite shell, 2.45 times lower than that for mineral wool segments, and 2.11 times lower than that for 500 grade sovelite shells. The use of products made of granular glass-ceramic material significantly reduces the heat loss and the thickness of the thermal insulating layer of the pipelines and ensures fuel and energy savings. [ABSTRACT FROM AUTHOR]

The effect of the flux density of concentrated solar radiation (CSR) on the properties of material with a piroxene structure fused in a Large Solar Furnace (LSF) is studied. It is revealed that the density and shape of the distribution of the CSR flow over the diameter of the focal zone of the LSF have a strong effect on the homogeneity of the melt. Exposure of the melt to high-density CSR contributes to the formation of a homogeneous and uniform state of the melt. Cooling the melt by pouring it into water (quenching) helps to fix the amorphous state of the material. Observing the appropriate firing modes from fused material, glass, it is possible to obtain a glass-crystalline material with a pyroxene structure of diopside-hedenbergite composition Ca(MgFe2+)Si2O6 with high wear resistance. A mechanism of interaction of CSR with the material, which is based on zone structure, is suggested. According to this mechanism, heating of the material upon irradiation by the CSR is based on photoabsorption, which increases the density of states in the "tails" of energy zones, which results in the fusion of the material. [ABSTRACT FROM AUTHOR]

A space vector pulse width modulation with a non-sinusoidal power supply (NSVPWM) is proposed to improve the stator iron utilization in a multiphase motor. When compared with three phase motors, there are more control freedoms in multiphase motors. The space vector distribution under a non-sinusoidal power supply is analyzed to achieve an optimized selection. Then the harmonic injection proportional coefficient is derived aiming at flux density optimization, which includes the air-gap and the yoke flux distribution. 15 kW and 630 kW nine-phase concentrated winding induction motors are used as practical examples. By maintaining the amplitudes of the air-gap flux density and the yoke flux density as well as the stator copper loss, the electromagnetic torque densities are compared under various load conditions. Experimental results show that when compared with the traditional sinusoidal method, the output torque is improved by 5.45% with the proposed NSVPWM method. [ABSTRACT FROM AUTHOR]

With the rapid development of high-temperature superconductors, it is of great significance to get the precise current density and flux distribution within thin high-temperature superconducting films subjected to a transport current and an applied magnetic field. The transport current distribution and flux density in thin high-temperature superconducting films are calculated by a numerical method based on the Kim model and exponential model in this paper. The influences of transport current, applied magnetic field, width, and thickness of a superconducting film on the current distribution are discussed. The results reveal that the thickness has a significant effect on the critical current density of superconducting films. [ABSTRACT FROM AUTHOR]

Microcoils are essential components in magnetic sensors made using Micro-electro-mechanical systems (MEMS) technology. Nonspiral microcoils have fabrication advantages over conventional spiral coils and can be effectively used in MEMS micro sensors for generation and detection of magnetic fields. In this work, an analytical model of peak flux density, sensitivity, and resolution for the nonspiral planar microcoil is reported for the first time. Self and mutual inductances of a non-spiral coil are used to calculate the flux density at the innermost turn of the coil. The model derived is compared with standard fabrication results, and it is found to be in good agreement with the experimental results. [ABSTRACT FROM AUTHOR]

The distribution of radionuclides in the soil catena from the bank of the Desna River to the watershed is studied. It is found that changes in the concentration of radionuclides in certain sampling points do not exceed the value of experimental error. The contamination density of Cs in the studied area coincides with the values of the forecast maps developed by the Federal Service for Hydrometeorology and Environmental Monitoring. Intense burrowing activity of moles affecting the redistribution of radionuclides is observed. [ABSTRACT FROM AUTHOR]

Substituted lithium ferrites having the chemical formula, LiCdFeO and LiZnFeO, with different iron (metal) contents (2, 4, 6, 8 and 10) in wt% have been prepared by solid-state technique. Complex permeability and power loss of all samples have been measured by network analyser in the frequency range of 50-5000 kHz. Magnetic properties like saturation magnetization, coercivity, retentivity have been measured by vibrating sample magnetometer (VSM). The permeability of cadmium doped lithium ferrites exhibited higher values than zinc doped lithium ferrites. The power loss of cadmium doped lithium ferrites is lesser as compared to zinc doped lithium ferrites in the frequency range of 50-5000 kHz and at flux density of 10 mT. The behaviour of power loss with flux density has been found near about same for both series. Magnetic and power loss behaviour of the samples suggest that a small amount of Fe content can improve the properties of ferrite samples for microwave devices. [ABSTRACT FROM AUTHOR]

To investigate the impact of size on its performance in designing an axial-magnetized permanent magnet micromotor, the finite element method is adopted to simulate the magnetic field of the dual rotor motor, and the flux density wave form distributed in the airgap is obtained. The influence of the external dimensions, pole numbers and magnet thicknesses of the rotor, and the airgap distances on the flux density, are analyzed and analytical results are given. With the increase of the airgap distance, the flux density under more poles reduces more quickly than under fewer poles. With the increase of the magnet thickness, the flux density is a rising curve, and after the magnet thickness attains a certain point, the flux density is almost a constant. While reducing the diameter of the rotor, the decrease of the flux density slows down as magnet thickness is reduced. To avoid having a seriously distorted waveform, the distance between inner and outer radii of the rotor must be larger than 1.5 millimeter. Results of the magnetic field analysis can guide a microminiaturization of the motor. Moreover, the results are analyzed theoretically and the simulated values are almost consistent with the experimental values. [ABSTRACT FROM AUTHOR]

An acoustical model of the boundary friction process has been developed where the transformation of surface Rayleigh waves into bulk Rayleigh waves is considered, taking dislocation damping into account. A relationship similar to an inverse resonance curve has been found between the specific friction force and the Rayleigh wave frequency. The specific friction force has been shown to be proportional to the wavelength of the surface microrelief and in inverse proportion to the square of the surface dislocation density. [ABSTRACT FROM AUTHOR]

Metal layer was deposited by the reduction of NiCl2 and CoCl2 in polyacrylonitrile film after applying an external magnetic field in directions parallel and perpendicular to the surface of the film; the magnetic properties of the metal-deposited film were investigated. When the parallel magnetic field was applied, the values of coercivity (Hc), remanent flux density (Br) and maximum flux density (Bs) increased regardless of the composition of the metal ions, compared with the case without the application of the magnetic field. From the scanning electron micrographs and X-ray diffraction analyses, it was shown that the growth of crystalline orientation in the deposited metals was enhanced by applying a parallel magnetic field. [ABSTRACT FROM AUTHOR]