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This paper discusses the application of wavelet transform for information compression, analysis of discrete wavelet transform tools using the software. Algorithms for audio signal compression and image compression using wavelets are considered.

A number of domestic and foreign publications devoted to research on the possibility of using laser surface treatment technologies for cleaning from dirt, removing paint coatings and preparing the metal surface for subsequent technological operations are considered. The most striking examples of the use of technologies in the foreign aviation industry are given and the high readiness of their implementation in practice is noted. Theoretical information about laser technology is presented and the most progressive directions are highlighted.

A review of modern scientific publications in the field of methods for preparing the surface of aluminum alloys for electroplating is presented. It is shown that the most widely used methods of preparation are: zinc treatment, high-porosity anodic oxidation and immersion nickel plating. A number of combined methods for preparing the surface of aluminum alloys for electroplating are given. Methods of direct application of electroplating coatings on aluminum and its alloys without the use of a sublayer, both by electrolytic and chemical methods, are considered.

Influence of nickel sulfate additives in silicate-alkaline electrolyte for microarc oxidation of titanium alloys on properties of formed electrolyte-plasma coatings was investigated. The influence of the component composition of the electrolyte on the chemical composition of the coatings, their protective ability, porosity and electrical characteristics was established. It is shown that the most corrosion-resistant coatings are formed from electrolytes with a low content of nickel sulfate, and an increase in the content of nickel in the coating does not lead to a significant change in its electrical conductivity.

The article presents the results of researche of galvanic corrosion possibility of brazed connections of steels 13Сr11Ni2W2MoV and 12Cr18Ni10Тi with use of the solders VPr4 and VPr50, which are used in design of aviation engineering engines. The research was carried out by electrochemical methods. Corrosion currents’ density and contact pairs’ potentials in chloride solutions have been determined. It is determined that 13Сr11Ni2W2MoV steel can be exposed to galvanic corrosion in a place of brazed connection. Thus the greatest danger to it is represented by VPr4 solder. The mechanism of corrosion of 13Сr11Ni2W2MoV steel in neutral environments has been examined and recommendations about its protection against galvanic corrosion are made.

Different detergent compositions for removing contaminants from metal surfaces are considered. Components of detergent compositions and their effect on the properties are described. Examples of promising studies in this area are given, including those related to improving detergent properties, anticorrosion characteristics, fire safety and environmental friendliness. Attention is paid to compositions that provide simultaneous washing and preservation of metal. It is reported to determine effect of detergent compositions on other materials of aircraft.

The results of a comparative analysis of the structure and properties of the plasma electrolytic coating formed in a silicate–phosphate electrolyte with the time varied from 10 to 60 min are considered. The structure of the protective nonmetallic inorganic coating is studied by scanning electron microscopy, and structural changes are revealed and compared. The change in the chemical composition with the oxidation time is examined, and the distribution of chemical elements over the coating depth is established. The layered state of the coating fabricated by plasma electrolytic oxidation is confirmed. The changes in the protective properties of the coatings are evaluated.

Provides an overview of foreign scientific and technical literature in the field of protective galvanic coatings for heat-resistant alloys based on nickel and γ-TiAl. Various types and systems of alloying of galvanic coatings are considered, which can be used to protect parts of the hot part of gas turbine engines from high-temperature sulfide-oxide corrosion at operating temperatures up to 1000 °С. Data on the influence of the deposition technology, electrolyte composition, additives on the properties of coatings, the morphology of individual coatings, as well as the results of corrosion tests of some coatings are presented.

The efficiency of various variants of the component composition of alkaline electrolytes of plasma electrolytic oxidation (PEO) was studied. Technical liquid glass, NaOH, Na2B4O7, Na3PO4, and NaAlO2 were used as components of aqueous solutions. All of the studied components of electrolytes are the most common for use in PEO processes of aluminum alloys. The influence of the component composition of electrolytes on their stability during 30 days of exposure was evaluated, and the most stable compositions were selected. The structure and properties of coatings formed on samples of aluminum alloy AK6 during PEO are studied. The dependences of the hardness of coatings and their growth rate on the composition of the electrolyte are established. Possible variants of coating growth in the PEO process with different component composition of electrolytes are proposed.

Various surface preparation techniques of aluminum foil made from AMg2N alloy and their effect on the strength of adhesive joints made by VK-25 phenolic-elastomer adhesive and VK-36T modified epoxy adhesive have been considered. To prepare the surface, pickling process, titania and alumina deposition, MAO coating, chemical oxidizing, and deposition of EP-076 adhesion primer have been employed. It has been shown that optimal characteristics of honeycomb fillers are achieved after foil surface preparation via chemical oxidizing along with organic coating. The effect of the foil thickness on the strength of adhesive joints has been studied.

The results of the commissioning of the IKFS-2 instrument and its subsequent operation onboard the Meteor-M no. 2 polar orbiting meteorological satellite are presented. Comparison of the IKFS-2 data with independent satellite measurements shows that its performance characteristics are in accordance with the design specification. It is therefore possible to realize the IKFS-2 mission objectives for obtaining data on the meteorological parameters and composition of the atmosphere.

The first Russian advanced infrared (IR) atmospheric sounder IKFS-2 was launched in July 2014 on the “Meteor-M” No. 2 meteorological satellite. It is planned that this instrument and similar devices will continue to operate until 2025 aboard the current and subsequent satellites of “Meteor-M” series. IKFS-2 is a Fourier transform spectrometer covering the spectral domain of 5–15 µm. It belongs to a class of hyperspectral IR sounders, designed to measure the outgoing IR radiance spectra and to provide information on the thermodynamic parameters and the composition of the atmosphere such as vertical temperature and humidity profiles, estimates of the ozone and other trace gases total column amounts. In the paper, the IKFS-2 operation on board “Meteor-M” No. 2 is analyzed, including the assessment of the measurements’ quality (the errors of radiometric and spectral calibration) and their information content. Since launch, the instrument performance has been remained stable, and the actual IKFS-2 characteristics (threshold value of NESR, uncertainty of onboard radiometric and spectral calibrations, spectral resolution) meet the planned requirements. There is a good agreement between IKFS-2 measurements and measurements of independent satellite instruments (SEVIRI, IASI). The paper also provides an overview of the developed scientific basis for simulation and interpretation (“inversion”) of satellite measurements. The examples of output IKFS-2 level 2 products (vertical profiles of temperature and humidity, total ozone content) are given together with the error analysis. The performance of atmospheric (temperature and humidity) profile retrievals and the feasibility of total ozone content estimates are evaluated by comparison with independent ground-based or satellite measurements.

The present paper describes the results of studies directed to novel catalytic processes design for the environmentally friendly production of cellulose. The new delignification catalyst which is produced by chemical interaction of elemental sulfur with hydrazine in superbase medium was used for the improvement of efficiency and ecological purity of the conventional pulping process. This catalyst reduces the concentration of polysulfides in pulping liquor and the yield of side sulfur-containing compounds (by 1.5 times). The processes of wood delignification with sulfur-free reagents based on catalytic pulping with acetic acid and hydrogen peroxide and on the delignification of steam-activated wood with NaOH or Na 2 CO 3 solutions have prospects for the environmentally benign production of cellulose. The new catalytic process of vanillin production by oxidation of lignosulfonates with molecular oxygen was described.

A novel catalyst of wood delignification (DC), which is produced by chemical interaction of amine and elemental sulfur in superbase medium, has been synthesized. The kinetics and mechanism of the novel catalyst action have been investigated in wood delignification.

According to Mitchell’s chemiosmotic theory of energy coupling, there are special enzymic systems carrying out translocation of electrons or protons across biological membranes [ 1 ] . Such a translocation should include the stages of electron (proton) transfer through a water-lipid interface, the processes being catalyzed (a) by certain enzymes operating in the energy coupling sites of the respiratory and photosynthetic redox chains, and (b) by H+-ATPase. In this paper, we shall report a method of investigation of the enzyme-mediated charge transfer across a water-lipid interface. The method consists in the measurement of the Volta potential difference between an octane and water solution, containing the enzyme system studied. Positive charging of the octane phase was found to be induced by soluble mitochondrial ATPase (Fr) in an ATP-dependent fashion, or by bacteriorhodopsin from Halobacterium halobium in a light-dependent fashion. In both cases, a lipid-soluble proton acceptor proved to be necessary. Cytochrome oxidase and succinate-cytochrome c-reductase were shown to carry out negative charging of octane if a lipid-soluble electron acceptor and water soluble elec

The interaction of inorganic phosphate with native and nucleotide-depleted F1-ATPase was studied. F1-ATPase depleted of tightly bound nucleotides loses the ability to bind inorganic phosphate. The addition of ATP, ADP, GTP and GDP but not AMP, restores the phosphate binding. The nucleotides affecting the phosphate binding to F1-ATPase are located at the catalytic (exchangeable) site of the enzyme. The phosphate is thought to bind to the same catalytic site where the nucleotide is already bound. It is thought that ADP is the first substrate to bind to F1-ATPase in the ATP synthesis reaction.

One of the crucial problems faced by living cells is that of preventing futile ATP hydrolysis in de-energized conditions. To solve this problem there exists a complex mechanism to regulate H+-ATPase activity. When the transmembrane H+-potential difference ( Δ μ H + ) is low, the H+-ATPase rapidly assumes its inactive state. Studies over the last several years have clarified some details of this molecular mechanism in chloroplasts, mitochondria and some bacteria.

Nucleotide-depleted mitochondrial F 1 -ATPase binds 3'-(2')- O -(2-nitro-4-azidobenzoyl)-derivatives of ATP (NAB-ATP) and GTP (NAB-GTP) when these nucleotide analogues are added to the enzyme in equimolar quantities in the presence of Mg 2+ (uni-site catalysis conditions). The binding of NAB-ATP is accompanied by its hydrolysis and inorganic phosphate dissociation from the enzyme; NAB-ADP remains bound to F 1 -ATPase. The F 1 -ATPase·NAB-ADP complex has no ATPase activity and its reactivation in the presence of an excess of ATP is accompanied by NAB-ADP release. The illumination of the F 1 -ATPase complexes with NAB-ADP or NAB-GDP leads to the covalent binding of one nucleotide analogue molecule to the enzyme and to the irreversible inactivation of F 1 -ATPase. It follows from the results obtained that the modification of just one of the F 1 -ATPase catalytic sites is sufficient to complete the inhibition of ATPase activity.

The quaternary structure of isolated and membrane-bound F1-ATPase (submitochondrial particles) has been studied by electron microscopy. A model of the molecule has been proposed: six protein masses are arranged in two layers approximately at the vertices of a triangular antiprism. Computer averaging of the images showed that the frontal view of the molecule can be approximately characterized by mirror plane symmetry.

Publisher Summary This chapter explores the process through which nicotinamide nucleotide transhydrogenase catalyzes the reversible transport of the hydride ion. This enzyme is widely distributed in nature and is particularly common in the inner membrane of mitochondria and of many bacteria. A new general principle for transhydrogenase functioning is suggested. The mechanism proposed explains the way in which transfer of the hydride ion between nicotinamide nucleotides, in the course of the forward or reverse transhydrogenase reaction, ensures generation of Δμ H+ of opposite directions across the mitochondrial membrane. Moreover, this new mechanism, unlike other schemes makes it possible to explain why the simultaneous presence of substrates for both the forward reaction and the reverse reaction is not accompanied by uncoupling of the membrane due to H + leakage through the transhydrogenase.

The oxidants of the SH groups (o-iodozobenzoate, oxidized glutathione, etc.) and the divalent cations of some metals (Zn2+ and Cd2+) significantly slow down the rate of inactivation by the protein inhibitor of the isolated F1-ATPase and ATPase in submitochondrial particles. Modification of SH groups in the ATPase does not change the rate of inactivation but completely prevents the effect of oxidants.

Publisher Summary When formulating and developing the chemiosmotic hypothesis, several alternative schemes were postulated for the mechanism utilizing ΔμH+ to synthesize ATP. It is assumed that there is translocation of adenine nucleotides and phosphate between the mitochondrial matrix and the area of the membrane where a proteolipid system (factor F,) is localized, the latter organizing a proton transfer from the catalytic site of the ATP synthetase to the extramitochondrial medium. This chapter proposes that the first stage of ATP synthesis consists of deprotonation of the substrates, ADP, and/or Pi, and complete neutralization of the ADP3 and P3- anions by six positive ligands. These processes are assumed to take place at the F1, noncatalytic site exposed to the mitochondrial matrix.