scholarly journals A new system for measuring alternating current magnetic susceptibility of natural materials over a wide range of frequencies

2010 ◽  
Vol 11 (11) ◽  
pp. n/a-n/a ◽  
Author(s):  
Kazuto Kodama
Keyword(s):  
Magnetic Susceptibility ◽  
Alternating Current ◽  
Natural Materials ◽  
Wide Range ◽  
New System

Suppression of Ferromagnetism in EuxCa1-xB6

2012 ◽  
Vol 190 ◽  
pp. 97-100 ◽  
Author(s):  
V.V. Glushkov ◽  
A.V. Kuznetsov ◽  
I. Sannikov ◽  
A.V. Bogach ◽  
S.V. Demishev ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Curie Temperature ◽  
Single Crystals ◽  
Effective Magnetic Moment ◽  
Paramagnetic State ◽  
Low Field ◽  
Wide Range ◽  
Free Ion ◽  
The Eu

We report the magnetic properties of EuxCa1-xB6 single crystals (0.756x1) studied in the wide range of temperatures (1.8-300 K) and magnetic fields (up to 50 kOe). It was found that low field magnetic susceptibility χ (T) follows the Curie-Weiss law χ~(T-Θp)-1 at high temperatures for all the concentrations studied. The effective magnetic moment of the Eu2+ ion estimated from the data diminishes from the free ion value μeff7.93μB (μB - Bohr magneton) for x=1 to μeff7.3μB for x=0.756. A universal behavior of magnetic susceptibility χ~(T-Θ)-α (α=1.5) is detected close to the Curie temperature TC in the paramagnetic state at both metallic (x>xC~0.8) and dielectric (xC.

The initial magnetic susceptibility of polydisperse ferrofluids: A comparison between experiment and theory over a wide range of concentration

2016 ◽  
Vol 145 (8) ◽  
pp. 084909 ◽  
Author(s):  
Anna Y. Solovyova ◽  
Olga A. Goldina ◽  
Alexey O. Ivanov ◽  
Aleksandr V. Lebedev ◽  
Ekaterina A. Elfimova
Keyword(s):  
Magnetic Susceptibility ◽  
Wide Range ◽  
Initial Magnetic Susceptibility

scholarly journals The Means to Improve Water Treatment and to Enhance Power Engineering Performance of the Water Source Heat Pump

2018 ◽  
Vol 61 (4) ◽  
pp. 372-380 ◽  
Author(s):  
L. R. Junussova ◽  
S. K. Abildinova ◽  
M. B. Aliyarova ◽  
S. V. Chicherin ◽  
T. Ja. Junussov
Keyword(s):  
Water Treatment ◽  
Heat Pump ◽  
Natural Water ◽  
Alternating Current ◽  
Power Engineering ◽  
Current Frequency ◽  
Heat Pump Unit ◽  
Wide Range ◽  
Compressor Performance

The subject matter of the paper is related to scientific-and-theoretical basis of power engineering characteristics of heat pump directly depending on the quality of treated water for reliable and uninterrupted operation of heat pump evaporator and compressor. On the basis of experimental data, energy parameters of the heat pump are calculated. The method of the combined technology of the heat pump “water – air” operation is considеred, the efficiency of which is based on the preliminary improvement of the quality of water softened with the use of a membrane ultrafiltration unit. This solution made it possible to reduce the load on the filters and to exclude the use of chemical reagents used in the classical schemes of water heating facilities. In order to improve the operation of the heat pump compressor, a method based on altering the speed of rotation of the shaft by means of electronic microprocessor devices has been proposed. To regulate the compressor performance, a frequency converter with a wide range of alternating current frequency is used. The intervals of alteration of frequency of the alternating current corresponding to energy-efficient values of coefficient of transformation of energy of the heat pump are investigated. The values of the energy conversion coefficient of the heat pump obtained in the course of experiments and determined by calculation are consistent within the experimental errors with the regulation of the compressor performance. The suggested experimental device made it possible to determine the dependence of the main characteristics of the unit of the heat pump unit on the number of revolutions of the compressor and to find out an effective range of its control (50–180 %). The development of advanced technologies for natural water treatment under conditions of increased anthropogenic loads on natural water sources is a priority one among the fundamental and applied research in the field of water treatment.

Porous and Nanoporous Semiconductors and Emerging Applications

2005 ◽  
Vol 876 ◽  
Author(s):  
Helmut Föll ◽  
Jürgen Carstensen ◽  
Stefan Frey
Keyword(s):  
Optical Properties ◽  
Fuel Cells ◽  
Pore Formation ◽  
Large Area ◽  
Paper Briefly ◽  
High Explosives ◽  
Single Crystalline ◽  
Natural Materials ◽  
Porous Semiconductors ◽  
Wide Range

AbstractPores in single crystalline semiconductors can be produced in a wide range of geometries and morphologies, including the “nano” regime. Porous semiconductors may have properties completely different from the bulk, and metamaterials with e.g. optical properties not encountered in natural materials are emerging. Possible applications of porous semiconductors include various novel sensors, but also more “exotic” uses as, e.g. high explosives or electrodes for micro fuel cells. The paper briefly reviews pore formation (including more applied aspects of large area etching), properties of porous semiconductors and emerging applications.

A Discussion on natural strain and geological structure - Strain and anisotropy in rocks

1976 ◽  
Vol 283 (1312) ◽  
pp. 27-42 ◽  
Keyword(s):  
Magnetic Susceptibility ◽  
Shear Wave ◽  
Finite Strain ◽  
Preferred Orientation ◽  
Seismic Velocities ◽  
Magnetic Susceptibility Anisotropy ◽  
Wave Velocities ◽  
Natural Strain ◽  
Shear Wave Velocities ◽  
Wide Range

The evaluation of finite strain in naturally deformed rocks is restricted by the limited occurrence of good natural strain indicators which are also homogeneous with respect to the matrix. This problem is overcome by establishing the relation between measured finite strain and those physical behaviour characteristics of rocks that are dependent upon the anisotropy resulting from deformation. Accordingly, the strain measured from natural indicators is calibrated against ( degree of preferred orientation, (b) magnetic susceptibility anisotropy, and (r) seismic anisotropy. This _ will permit three approaches to be used independently for the evaluation of strain, provided that a minimal number of actual strains are available. The relation between measured strain and the degree of preferred orientation of layer silicates as revealed by X-ray transmission goniometry is established for a group of fine grained tectonites of dominantly planar fabric which have an average deformation ellipsoid of form 1.6:1 :,0.26. The strains measured from the degree of preferred orientation are in remarkable agreement with those measured from natural strain indicators. The measured deformation ellipsoids for a wide range of strains are also compared to the correlative ellipsoids of magnetic susceptibility anisotropy. The axes of both sets of ellipsoids are coincidental and the shape relationship between deformation and magnetic susceptibility ellipsoids is established by linear regression. Finally, the anisotropy of seismic velocities is determined by measuring the pseudocompressional velocity and two orthogonally polarized pseudo shear wave velocities for each of a minimum of nine non-coplanar directions. The velocity surfaces thus obtained define an elastic or seismic velocity anisotropy ellipsoid, the axes of which are also precisely coincidental with those of the finite deformation ellipsoid. The influence of rock fabric upon seismic velocities is such that for a rock which has undergone a principal finite extension of 135 % and a finite shortening of 65 %, the difference of compressional and shear wave velocities between these two directions is in the ratio 1.26:1 for P waves and 1.33:1 for S waves.

scholarly journals Iron-containing phases in metallurgical and coke dusts as well as in bog iron ore

Nukleonika ◽  
2017 ◽  
Vol 62 (2) ◽  
pp. 187-195 ◽  
Author(s):  
Tadeusz Szumiata ◽  
Marzena Rachwał ◽  
Tadeusz Magiera ◽  
Katarzyna Brzózka ◽  
Małgorzata Gzik-Szumiata ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Spinel Structure ◽  
Iron Ore ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mineral Phases ◽  
Coke Plants ◽  
Wide Range ◽  
Specific Magnetic Susceptibility ◽  
Diffraction Patterns

Abstract Several samples of dusts from steel and coke plants (collected mostly with electro filters) were subjected to the investigation of content of mineral phases in their particles. Additionally, sample of bog iron ore and metallurgical slurry was studied. Next, the magnetic susceptibility of all the samples was determined, and investigations of iron-containing phases were performed using transmission Mössbauer spectrometry. The values of mass-specific magnetic susceptibility χ varied in a wide range: from 59 to above 7000 × 10−8 m-3·kg−1. The low values are determined for bog iron ore, metallurgical slurry, and coke dusts. The extremely high χ was obtained for metallurgical dusts. The Mössbauer spectra and X-ray diffraction patterns point to the presence of the following phases containing iron: hematite and oxidized magnetite (in coke and metallurgical dusts as well as metallurgical slurry), traces of magnetite fine grains fraction (in metallurgical dusts), amorphous glassy silicates with paramagnetic Fe3+ and Fe2+ ions, traces of pyrrhotite (in coke dusts), α-Fe and nonstoichiometric wüstite (in metallurgical slurry), as well as ferrihydrite nanoparticles (in bog iron ore). For individual samples of metallurgical dusts, the relative contributions of Fe2+/3+ ions in octahedral B sites and Fe2+ ions in tetrahedral A sites in magnetite spinel structure differs considerably.

New Magnetoresistance Results in GdB6

2012 ◽  
Vol 190 ◽  
pp. 77-80 ◽  
Author(s):  
M.A. Anisimov ◽  
A.V. Bogach ◽  
V.V. Glushkov ◽  
S.V. Demishev ◽  
N.A. Samarin ◽  
...  
Keyword(s):  
Experimental Data ◽  
Magnetic Susceptibility ◽  
Low Temperature ◽  
Spin Polarization ◽  
Complex Behavior ◽  
Negative Component ◽  
High Quality ◽  
Wide Range ◽  
Linear And Nonlinear ◽  
Local Spin Polarization

Detailed study of transverse magnetoresistance (MR) and magnetic susceptibility have been done on the high quality single crystals of antiferromagnet GdB6 (TN15.5K) in the wide range of temperatures 2-40K in magnetic fields up to 8T. The data obtained allow to establish the low temperature antiferromagnetic (AFMII) phase below T*~4.7K with the complex behavior of MR including the field hysteresis of the magnetoresistance. It was shown that MR behavior depends on the cooling-warming prehistory in AFM state of GdB6. The analysis of experimental data allowed us to deduce three contributions to MR in AFM(I), (T*) and paramagnetic (PM) phases of GdB6. In addition to the main negative component Δρ˿ρ~ H2 interpreted in terms of Yosida model both the linear and nonlinear magnetic contributions were also established. The anomalies of MR found in AFM(I) state seem to be associated with the local spin polarization of 5d-electron states of Gd3+ ion.

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