Sorption of uranium, radium, and thorium from saline solutions on hydrolyzed wood lignin

Sorption of U, Ra, and Th from multicomponent aqueous salt solutions on hydrolyzed wood lignin is studied. The mechanism of radionuclide sorption from saline solutions is suggested on the basis of the results of sequential extraction.     

Determination of platinum and gold in biological materials by neutron activation analysis

A procedure for platinum and gold determination utilizing, neutron activation combined with radiochemical separation, has been developed. The reaction¹⁹⁸Pt (n, )¹⁹⁹ is used for Pt determination. Four procedures for gold separation are examined: (1) adsorption on untreated polyurethane foam (UPF). (2) extraction with dibutyl sulphide. (3) reduction of gold to elementary state in conc. H₂SO₄, and extraction of gold as diethyldithiocarbamate complex. The extraction with Cu(DDC)₂ is chosen as the most suitable process and applied to platinum and gold determinations in Bowen's Kale and mice organs, previously treated with Biocisplatinum^® specimens.     

Beam of monoenergetic neutrons for the calibration of a dark-matter detector

A new method has been proposed for obtaining a beam of monoenergetic neutrons with almost arbitrary energies. The production of the beam for the calibration of a dark-matter detector with liquid argon as a working medium has been described.     

Phase diagrams of Heusler alloys with inversion of the exchange interaction

The phase diagrams of magnetically ordered Heusler alloys with the inversion of the exchange interaction have been studied using the phenomenological Landau theory of phase transitions. It has been shown that the shape of the phase diagrams in these alloys depends on the magnitudes and signs of the phenomenological parameters in the Landau functional. At certain magnitudes and signs of the parameters of the Landau functional, the phase diagrams have thermodynamic paths that allow one to explain the experimentally observed sequences of the phase transitions in the Heusler alloys.     

Determination of Cu and Ni in French geological standards AN-G,BE-N and MA-N

Using radiochemical separation, the content of Cu and Ni were determined in French geological standards AN-G (anorthosite) BE-N (basalte) and MA-N (granite). Separation was done by solvent extraction of Cu(II) and Co(III) (reaction⁵⁸Ni(n, p)⁵⁸Co) as DDC complexes in CHCl₃.     

Theoretical Approach to Investigation of the Magnetic and Magnetocaloric Properties of Heusler Ni–Mn–Ga Alloys

Physics of the Solid State - The magnetic and magnetocaloric properties of Heusler Ni2 + xMn1 – xGa alloys (x = 0.16, 0.18, and 0.3) have been studied...     

Study of the Chelyabinsk Meteorite Magnetism by Nuclear Gamma-Resonance Spectroscopy

Crystallography Reports - Three fragments of the Chelyabinsk meteorite have been investigated by Mössbauer spectroscopy in a temperature range of 300–830 K. They are found to contain...     

Experimental investigations of the relation between electrical conductivity and natural magnetic anisotropy in ferrites containing cobalt

A deep relation between the crystalline structure, the nature and energy of the interatomic interaction, and the different physicochemical properties is exhibited with special clarity in ferrites. Therefore a comprehensive discussion of the physical properties of ferrites with the peculiarities of magnetic transitions in ferrites taken into account, along with an investigation of the structure, is of great significance. In this connection, we posed the problem of investigating the effect of magnetic anisotropy on the electrical properties of ferrites containing various amounts of cobalt ions, which make, as is well known, an anomalously large contribution to the magnetic anisotropy constant of ferrite-spinels and lead to a change in sign. Investigations of the electrical properties of ferrites have shown that a change in the activation energy of the electrical conductivity [1] and an anomaly in the temperature behavior of the spontaneous Hall field [2] are observed upon the transition of ferritesfrom a ferri- to a paramagnetic state. It is natural to assume that these anomalous changes are related to the disappearance of magnetic order inside a ferromagnetic semiconductor, which indicates a relation of the conductivity electrons to the magnetic structure. However, the magnetic order in crystals of ferro- and ferrimagnets can be altered in other ways besides a transition through the Curie point. The magnetic structure can be altered in a definite way also upon a change in the sign of the constant of natural magnetocrystalline anisotropy ₁ (i.e., when the direction of weak magnetization is changed in a crystal). Investigations of the effects of these kinds of changes in the magnetic structure on the motion of current carriers in ferrites are of great interest. It is important in this connection to carry out investigations in the temperature region in which the investigated object is in the ferrimagnetic state, i.e., the spontaneousmagnetization is not destroyed, and its direction in the crystal was altered only as a result of a change in the sign of ₁. It is completely permissible to assume that there occurs in the ferrite a change in the intracrystalline field, which affects in a definite way the wave functions of the electrons participating in the conductivity. Thus, even these simple qualitative discussions indicate that such investigations can give valuable information on the effect of a magnetic subsystem on kinetic phenomena in magnetic semiconductors — ferrites. Our investigations of the effect of a magnetic subsystem on the transport phenomenon differ from the experiments of a number of authors [3, 4, 5] in that these authors have investigated the temperature dependences of electrical resistance in the temperature range in which the sign of the magnetic anisotropy constant changes, i.e., the direction of the magnetization vector is altered not due to the effect of external magnetic fields, but as a result of a change in the anisotropic properties upon being heated up.Deceased.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 7–13, July, 1979.     

The phase diagrams of Ni–Mn–Ga alloys in the magnetic field

With the help of the Ginzburg–Landau theory the temperature–magnetic field phase diagrams of Heusler alloys Ni–Mn–Ga are theoretically investigated. The influence of the parameters of the magnetoelastic constants and elastic moduli on the phase diagrams are discussed. It is shown that with the determined combination of the phenomenological parameters, the critical magnetic field for the phase transition appears. The theoretically predicted value of the critical magnetic field is possible to be achieved in the experiment with the help of modern magnetic field sources.     

Extraction and neutron activation determination of trace amounts of indium in air

A method for tracing hot stack gases with indium and its quick analysis by extraction with HDEHP in toluene from aqueous nitric acid followed by neutron activation analysis is described.