The influence of carrier gas pressure on the retention of sorbates on monolithic capillary columns in gas chromatography

The influence of carrier gas pressure on the retention factor k′ of light hydrocarbons C₁–C₄ in a monolithic capillary column based on divinylbenzene was studied. It was shown that, for monolithic columns and nonideal carrier gases, the pressure dependence of lnk′ was nonlinear over a wide pressure range and could be described by the classic Everett equation. It was concluded that the competitive adsorption model failed to describe the experimental data correctly, especially for strongly retained sorbates and/or heavy carrier gases. Original Russian Text ? A.A. Korolev, V.E. Shiryaeva, T.P. Popova, A.V. Kozin, A.A. Kurganov, 2009, published in Zhurnal Fizicheskoi Khimii, 2009, Vol. 83, No. 4, pp. 776–783.     

Nonlinear Damping and Nonlinear Phase Shift of Intense Spin Waves in Screened Ferrite Films

Technical Physics - We analyze for the first time nonlinear damping and nonlinear phase shift of intense surface spin waves in screened yttrium–iron garnet films. Nonlinear damping...     

Production of Intense Ion Beams of Boron and Iron Using the MIVOC Method from ECR Ion Source on the DC-60 Cyclotron

This article describes experiments carried out in 2017–2018 at the DC-60 accelerator complex (Astana branch of the Institute of Nuclear Physics, Almaty, Kazakhstan) to develop methods for producing intense beams of multicharged iron and boron ions with the use of volatile organometallic compounds (Metal Ions from Volatile Compounds (MIVOC)). Beams of iron and boron ions were obtained for the first time on the DC-60 cyclotron, and the acceleration modes of ⁵⁶Fe¹⁰⁺ and 11B²⁺ ions were optimized to energies of 1.75 and 1.5 MeV/n, respectively.     

Interpolation formulas for maxwell viscosity of certain metals as a function of shear-strain intensity and temperature

The purpose of this study is the construction of interpolation formulas for the dependence of Maxwell viscosity, a quantity which is the reciprocal of shear-strain relaxation time , on shear-strain intensity and temperature for several metals: iron, aluminum, copper, and lead. This function was interpolated in various temperature and deformation velocity ranges in accordance with available experimental data for iron (0 10⁷ sec^–1, 200 ° T 1500 °); aluminum (0 10⁷ sec^–1, 300 ° T 900 °); copper (0 10⁵ sec^–1, 300 ° T 1300 °); lead (0 10⁶ sec^–1, 90 ° T 400 °); temperatures in °K.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 4, pp. 114–118, July–August, 1974.     

Calculation of the aerodynamic characteristics of a helicopter lifting rotor subjected to air gusts

A numerical method of calculating the unsteady aerodynamic characteristics of a helicopter lifting rotor smoothly enveloped by an air gust arriving from an arbitrary direction is proposed. The problem is solved in the non-linear formulation for an incompressible medium. The flow over each blade is simulated by a system of discrete vortices. The deformation of the vortex trail from the blades under the influence of the gust is taken into account. The results of the calculations are reported.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 2, pp. 153–158, March–April, 1987.     

Wave Resistance of Amphibian Aircushion Vehicles During Motion on Ice Fields

The steady motion of amphibian aircushion vehicles over water covered with continuous ice is studied. The ice sheet is simulated by a viscoelastic ice plate. An analysis is made of the effect of the aspect ratio of the vehicle, the depth of the water reservoir, and ice characteristics on the wave resistance of the vehicle and the speed of the vehicle at which the wave resistance is maximal.     

Sorption purification of a halide cobalt electrolyte with organic reagents immobilized on activated carbon

Purification of ammonium-chloride-bromide cobalt-containing electrolyte to remove ions of impurity metals with an adsorbent containing complexing organic reagents immobilized on the surface of synthetic activated carbon was studied.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 12, 2004, pp. 1990–1995.Original Russian Text Copyright © 2004 by Manilevich, Kozin, Bogdanova, Demchenko, Makovetskii.     

Fiber Bragg grating photoacoustic detector for liquid chromatography

Fiber Bragg Gratings (FBGs) are known to be sensitive acoustic transducers and have previously been used for the photoacoustic detection of small solid samples. Here, we demonstrate the use of an FBG as an on-line detector for liquid chromatography. The FBG was inserted into a silica capillary and the photoacoustic response from the effluent was generated by a 10 ns pulsed laser. The acoustic pulse was quantified by the FBG through a characteristic change in the reflection spectrum. Good repeatability and linear response were obtained over three orders of magnitude (R(2) > 0.99), and the limit of detection of Coumarin 440 was determined to be 5 microM. The technique was successfully coupled to high performance liquid chromatography and applied to on-line analysis of a three-compound solution. Photoacoustic detection in liquid chromatography using FBGs is a label-free method, which can be applied to the detection of any chromogenic compound irrespective of its fluorogenic properties. It is a simple, inexpensive, and inherently micron-sized technique, insensitive to electromagnetic interference.     

Kinetics and Mechanism of the Electro-oxidation of Gold in Thiocarbamide Solutions

The kinetics and mechanism of the electrooxidation of gold and thiocarbamide in sulfuric acid solutions of thiocarbamide (TC) have been investigated. The potentials for the oxidation of gold in TC solutions to [Au(TC)₂]⁺ _ads and [Au(TC)₃]³⁺ _ads are 0.132 and 0.561 V (relative to the standard silver chloride electrode). The electrooxidation of thiocarbamide in sulfuric acid solution is characterized by two maximums on voltammograms at 0.983 V (formation of formamidine disulfide, FAD) and 1.437 V (oxidation of FAD, sulfides and hydrosulfides of gold(I)). The calculated rate constants for the electrosolution of gold at the maximum current of the voltammogram is k ₁ = 1.15·10^–5 cm/s and at the minimum current is k ₂ = 3.13·10^–6 cm/s in sulfuric solutions of TC. A mechanism is proposed for the electrosolution of gold and TC in sulfuric acid solutions of thiocarbamide.     

Wave formation in explosive welding

A hypothetical analogy between wave formation in explosive welding and the Karman vortex street is analyzed, and the physical laws of the wave formation process are investigated.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 3, pp. 63–72, May–June, 1971.