4,126 research outputs found
Suitability of variance shift keying for real conditions
This paper investigates the possibility of real-life using the brand new type of digital modulation, which implies the transmission of white Gaussian noise whose variance changes in time. That modulation has been entitled as variance shift keying. The signals obtained on its basis have a high level of transmission security, and they even cannot be detected by standard means of matched filtering. However, the paper suggests the decision on how to process these signals at the receiver site. It is proposed to use a specially developed optimal receiver, whose restoration quality appears to be better in comparison with the conventional cumulative receiver. The digital simulation of propagation in frequency selective media has shown the signal with variance shift keying is possible to be used in real conditions since its distribution of instantaneous amplitudes remains Gaussian. © 2018 Academic Mind.The work was supported by Act 211 Government of the Russian Federation, contract № 02.A03.21.0006. The research was executed by the grant of the Ministry of education and science of the Russian Federation (project № 8.2538.2017/4.6)
Influence of electrolysis regimes on composite electroplate generation and structure
A study is made of periodic current parameters with a reverse anodic component influencing structural features of coats of zirconium carbide and aluminium oxide on a nickel matrix. A rise in the coherent dissipation area with increasing cathodic component results in lower micropotentials, higher adhesion to a substrate and better microhardness. Promotion of nucleation and uniform microtexture are responsible for the ordered distribution of disperse particles within the matrix and for their fractional selection in the coat
Coulometric analysis of organic compounds (review)
Methods for electrogeneration of coulometric titrants are described, and oxidation-reduction properties and other characteristics of the titrants are discussed. Examples of titrants used for determination of organic compounds of various classes in nonaqueous and mixed solvents are given. ©1998 Plenum Publishing Corporation
Thermo-chemical treatment of iron based composite electroplates
A scheme of renovating and hardening the parts with the use of composite electrochemical coatings is described. The powders of CrB 2 and Al 2O 3 serve as a dispersed phase in the electrodeposited coating from electrolytes containing FeCl 2 and FeSO 4. Chemical-and-thermal treatment (CTT) of parts was carried out at 210°C via sulfonitriding. Comparative tests of modified coatings and St45 for wear resistance in contact with 12KhN4A steel as a counterbody and for corrosion showed the improved characteristics after CTT
The role of electrolysis regimes in the development of functional composition coatings
The ways to obtain the composition electrochemical coatings with nickel and iron matrix are discussed. The required coating properties are provided by the uniform distribution of the second phase particles both on the surface and in the volume of coatings. The latter is achieved by the matching of the periodical current regimes. The technological parameters are also given
Glutathione salts of O,O-diorganyl dithiophosphoric acids: Synthesis and study as redox modulating and antiproliferative compounds
© 2017 Elsevier Inc. Reactions of glutathione (GSH) with O,O-diorganyl dithiophosphoric acids (DTPA) were studied to develop bioactive derivatives of GSH. Effective coupling reaction of GSH with DTPA was proposed to produce the ammonium dithiophosphates (GSH–DTPA) between the NH2 group in γ-glutamyl residue of GSH and the SH group in DTPA. A series of the GSH–DTPA salts based on O-alkyl or O-monoterpenyl substituted DTPA were synthesized. Enhanced radical scavenging activity of the GSH–DTPA over GSH was established with the use of DPPH assay and improved fluorescent assay which utilizes Co/H2O2 Fenton-like reaction. Similarly to GSH, the dithiophosphates induced both pro- and antioxidant effects in vitro attributed to different cellular availability of the compounds. Whereas extracellularly applied GSH greatly stimulated proliferation of cancer cells (PC-3, vinblastine-resistant MCF-7 cells), the GSH–DTPA exhibited antiproliferative activity, which was pronounced for the O-menthyl and O-isopinocampheolyl substituted compounds 3d and 3e (IC50 ≥ 1 μM). Our results show that the GSH–DTPA are promising redox modulating and antiproliferative compounds. The approach proposed can be extended to modification and improvement of bioactivity of various natural and synthetic peptides
The effect of electrolyte composition on structure and properties of composite electrochemical coatings with copper matrix
A problem of wear resistance and hardness improvement is considered for copper coatings. Copper plating electrolyte is modified with addition of amine complexing agents and TiO 2 dispersed phase. Role of electrolyte composition and dispersed phase nature in structure forming and properties of composite electrochemical coatings Cu-TiO 2 is investigated. Diffraction layer-by-layer investigation of the composite coatings shows uniform distribution of dispersed phase in the deposit bulk and surface. The wear resistance of coatings is increased by 30-35%
Socioeconomic processes in the CIS countries
© MCSER-Mediterranean Center of Social and Educational Research. Proposed instruments used to measure inequality in living standards in five CIS countries: Azerbaijan, Belarus, Kazakhstan, Russia and Ukraine. Compared countries in the aggregate represent most of the economic and human potential of community; In addition, a number of them are consolidated with each other with deeper forms of integration. Currently differentiation of incomes of the population estimated by the traditional factors (index- numbers): funds and Gini, which is determined by socioeconomic inequality
Restoration of Static JPEG Images and RGB Video Frames by Means of Nonlinear Filtering in Conditions of Gaussian and Non-Gaussian Noise
The use of nonlinear Markov process filtering makes it possible to restore both video stream frames and static photos at the stage of preprocessing. The present paper reflects the results of research in comparison of these types image filtering quality by means of special algorithm when Gaussian or non-Gaussian noises acting. Examples of filter operation at different values of signal-to-noise ratio are presented. A comparative analysis has been performed, and the best filtered kind of noise has been defined. It has been shown the quality of developed algorithm is much better than quality of adaptive one for RGB signal filtering at the same a priori information about the signal. Also, an advantage over median filter takes a place when both fluctuation and pulse noise filtering. ©2017. American Geophysical Union. All Rights Reserved
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