Assurance of metrological traceability of water determination results in functional materials and pure substances

The problem of water determination in the creation of pure substances and new functional materials with a low moisture content is considered. The structure, metrological characteristics, and prospects of application of the state primary standard of mass fraction and mass (molar) concentration of water in solid and liquid substances and materials GET 173-2013 are presented. Examples of developing thermogravimetric and chemical analyses are provided.     

State Primary Standard of the Units of the Disperse Parameters of Aerosols,Suspensions, and Powdered Materials

An analysis is made of the use of measuring instruments for obtaining the disperse parameters of aerosols, suspensions, and powder materials and their metrological assurance is considered. The State primary standard for the disperse parameters is described together with its purpose, its operating principles, and its technical and metrological characteristics.     

Plasma-chemical Synthesis of Fe<Subscript>3</Subscript>O<Subscript>4</Subscript> Nanoparticles for Doping of High-Temperature Superconductors

Ferrite nanoparticles (Fe₃O₄) have been produced by the direct low-pressure plasma-chemical synthesis. X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), vibration magnetometry (VSM), and Mössbauer spectroscopy (NGR) were used for measurements, showing that the produced nanoparticles have an average size of 9.4 nm, a crystalline phase of magnetite, possess a property of superparamagnetism at room temperature, and have a blocking temperature of 89 K. The peculiarities of nanoparticle behavior in the magnetic field, related to a large specific surface area, are discussed.     

Use of doubly charged ions in the determination of certain rare earth elements in neodymium, samarium, europium, and their compounds by inductively coupled plasma mass spectrometry

It is proposed to use doubly charged ions of the rare earth elements (REEs) to be determined in samples of neodymium, samarium, europium, and gadolinium by inductively coupled plasma mass spectrometry (ICP-MS) in order to reduce spectral interferences caused by oxide and hydroxide matrix ions. Optimal conditions for the registration of the doubly charged ions of REEs (resolution, depth of plasma sampling, generator output power, and argon flow in a nebulizer) are developed. The limits of determination for the REEs determined using singly and doubly charged ions in the samples of Nd, Sm, Eu, and Gd are evaluated. It is shown that the use of the signal from the doubly charged ions of odd isotopes allows reducing the limits of determination for Dy, Ho, Tm, and Er in neodymium, samarium, europium, and their oxides by one to two orders of magnitude.     

Measurement methods and problems in the reproduction of mass concentrations of total and free chlorine in natural and industrial water media

Industrial and other sites, in which the mass concentration of total and free active chlorine must be monitored in natural and industrial water media, are indicated. The creation of reference working standards reproducing the size of the mass concentration unit of total and free chlorine is needed for assurance of measurement uniformity. Features of measurement methods and the reproduction of this unit are examined.     

Determination of fluorine in inorganic substances (Overview)

This is a review of physical and chemical methods of determination of fluorine in inorganic substances which have been published in the last decade. Promising new indirect variants of molecular absorption spectrometry are presented, as well as widely applied methods of ion chromatography, potentiometry with fluoride selective electrode, and others.     

Monte Carlo simulation of the kinetic collisional equation with external fields

In this paper we consider a spatially homogeneous weakly collisional particle system, the state of which is described by a nonlinear kinetic equation with the Landau-Fokker-Planck collision integral and external heat sources. A quasi-linear diffusion operator and an external electric field are used as heating operators. Particle heating and acceleration and the runaway effect are analyzed. The numerical method used to study this phenomenon is the direct simulation Monte Carlo (DSMC) method.