Extending the service life of insulation systems through the use of chemically active components

The effect of ageing on the performance of insulation systems is studied. A program has been developed that determines the residual life of polymeric insulation taking into account all of the factors affecting the insulation’s state. Experimental data on the effect of the chemically active components of the substance adsorbed in the insulation microflaws and the effect of the epoxy oligomer on polyarylates during production are presented. A way to remove the structural and production flaws facilitating the active ageing process is considered.     

Analytical theory of regenerative heat transfer and study of its thermodynamic efficiency

An analytical theory of the cyclic process of regenerative heat transfer is developed. Introduction of operator-valued functions of integral operators allowed the authors to formulate an equation for determination of periodic solutions. A solution of this equation is found in a linear approximation with respect to switching times. A functional — exergic efficiency — is introduced on periodic solutions. The analytical solution obtained made it possible to study the dependence of the introduced criterion on the parameters of the system and to describe the time mode of the process in which the thermodynamic efficiency is maximum. Comparison of the analytical theory and a numerical analysis of the problem showed that upon choosing an operating mode of the apparatus that fits the maximum values of the introduced criterion, one can use results of the analytical solution at all admissible values of the switching times. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 73, No. 2, pp. 237–243, March–April, 2000.     

Three-dimensional reconstruction for scanning electron microscope

The paper describes the reconstruction algorithm of the 3D shape of a microobject’s surface based on an image stereopair, acquired with a Scanning Electron Microscope (SEM). Presented is the model of constructing the image in a SEM. The corresponding points are detected by using the SIFT algorithm. Employing the RANSAC method the points of correspondence are used to define the relative position of an object in a stereopair. A point cloud is created in a 3D space and interpolated in order to reconstruct a 3D surface.     

Near-field optical studies of local photomodification in nanostructured materials

Fractal aggregates of silver nanoparticles are studied experimentally using atomic force microscopy and photon scanning tunnelling microscopy. Large changes in the near-field optical response of fractal aggregates are observed after the irradiation of samples with nanosecond laser pulses. The threshold energy density for photomodification using a 532 nm laser is measured to be 9 mJ cm⁻². It is shown that photomodification-induced changes in the local optical response can be two orders of magnitude larger than changes in far-field absorption.     

The effect of nanodiamond surface modification on interaction with <Emphasis Type="Italic">Pseudomonas putida</Emphasis> K12

Interactions between nanodiamonds with an unmodified surface and nanodiamonds with chlorinated, as well as aminated, surfaces and the bacterium surfaces and Pseudomonas putida K12 were studied. It was revealed that only nanodiamonds with a modified surface possessed a considerable biocidal effect. Aminated nanodiamonds were twice as efficient as chlorinated ones. Electron microscopy showed that nanodiamonds were adsorbed onto the cell surface and damaged it. It is proposed that the higher biocidity of the aminated nanoparticles was caused by a positive charge inducing electrostatic interaction with the negatively charged surface of the bacterial cytoplasmic membrane.     

Pulverized-coal injection in blast furnaces at OAO Zaporozhstal’

Information is provided regarding the conversion of blast furnaces at OAO Zaporozhstal’ to pulverized-coal injection, with gradual reduction in the consumption of coke and natural gas. Since the introduction of a Kuttner pulverized-coal system in early 2013, coke consumption has decreased from 492 to 393 kg/t, with increase in productivity from 7719 to 8779 t/day.     

Groupcast routing with the possibility of choosing a channel transmission method

Consideration was given to the following statement of the problem of groupcast routing in the wireless multihop network: in the class of tree-like routes, it is required to determine a minimal-cost route calculated with account for the transmission method used by the MAC protocol. If this method takes advantage of the broadcast nature of the wireless medium, then the number of attempts of transmission made by a route retransmitter and their cost depend on the retransmitter neighbor nodes on the route. This peculiarity makes the considered groupcast routing problem sufficiently distinct from the classical Steiner tree problem. The sensitivity of the route cost to the transmission methods used was analyzed. Also a number of the groupcast routing algorithms were proposed which allow for the structure of the transmission methods and enable one to reduce the cost of routes.     

Clock Shift and Interstate Coherence of?Multi-Level Atoms

In contrast to two-level atoms, the interstate coherence of both three-level bosons and fermions contributes to the collisional frequency shift of internal transitions in a cold homogeneous gas. In particular, the measured contact shift of the b?c (a?d) hyperfine transition in 3D atomic hydrogen in the presence of incoherently populated state a (b) yields the difference a _t ?a _s =30(5)?pm between the triplet and singlet s-wave scattering lengths, which is a factor of 2 smaller than the previous result. The dynamic contact shift of the b?c resonance due to the Rabi oscillations between the coherently populated states a and b under the simultaneous continuous excitation of the a?b transition can explain the low-temperature electron-nuclear double resonance spectra of 2D hydrogen. The role of field inhomogeneity, spin diffusion, relaxation and recombination is discussed.