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A Layer-by-Layer Analysis of the Corrosion Properties of Diffusion Zinc Coatings

Biryukov A., Galin R., Zakharyevich D., Wassilkowska A., Kolesnikov A., Batmanova T.

Archives of Metallurgy and Materials

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2020

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Vol. 65, iss. 1

99--102

EN

To obtain anti-corrosive thermo-diffusion zinc coatings, the authors use highly effective zinc saturating mixtures. This technology makes it possible to obtain coatings with a high zinc content in the δ-phase as well as a zinc-rich phase of FeZn13 (ζ-phase) on the coating surface. As a result of long-term studies into the corrosion properties of thermo-diffusion zinc (TDZ) coatings conducted by the authors, a number of features of their corrosive behavior have been established. The corrosion rate of those coatings in desalted and chloride-containing media is lower than those of galvanic or hot-dip zinc coatings. The corrosion behavior depends on the content of zinc on the surface and the texture features of the coating. The results showed that on the surface of thermo-diffusion coatings in the corrosion on media containing chloride ions, zinc hydroxychloride (simonkolleite - Zn5Cl2[OH]8[H2O]) has been formed. Compared to coatings obtained by other methods, the rate of simonkolleite formation was higher on TDZ coatings, which might have a positive effect on their resistance in aggressive atmospheres.

2

Modeling of Heat Engineering Parameters of Casting and Rolling Complexes Work

Biryukov A., Ivanova A.

Archives of Foundry Engineering

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2019

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iss. 3

11--14

EN

The paper consists the problem of developing a scientific toolkit allowing to predict the thermal state of the ingot during its formation in all elements of the casting and rolling complex, between the crystallizer of the continuous casting machine and exit from the furnace. As the toolkit for the decision making task the predictive mathematical model of the ingot temperature field is proposed. Displacement between the various elements of the CRC is accounted for by changing the boundary conditions. Mass-average enthalpy is proposed as a characteristic of ingot cross-section temperature state. The next methods of solving a number of important problems with the use of medium mass enthalpy are developed: determination of the necessary heat capacity of ingots after the continuous casting machine for direct rolling without heating; determination of the rational time of alignment of the temperature field of ingots having sufficient heat capacity for rolling after casting; determination of the total amount of heat (heat capacity) required to supply the metal for heating ingots that have insufficient amount of internal heat.

3

On the Atmospheric Extinction Reduction Procedure in Multiband Wide-Field Photometric Surveys

Zakharov A., Mironov A., Biryukov A., Kroussanova N., Prokhorov M., Beskin G., Karpov S., Bondar S., Ivanov E., Perkov A., Sasyuk V.

Acta Astronomica

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2015

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Vol. 65, No. 2

197--204

EN

We propose an improved method for the atmospheric extinction reduction within optical photometry. Our method is based on the simultaneous multicolor observations of photometric standards. Such data are now available within the modern wide-field sky surveys and contain a large amount of information about instant atmospheric conditions. So, it became possible to estimate the extinction parameters on the basis of a quite short observational dataset and, hence, to trace the rapid stars twinkling accurately. Having been developed for a new MiniMegaTORTORa observational system, the proposed method can be adopted for a wide range of modern observational programs.

4

Cryptanalysis of the Full AES Using GPU-Like Special-Purpose Hardware

Biryukov A., Großschädl J.

Fundamenta Informaticae

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2012

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Vol. 114, nr 3/4

221-237

EN

The block cipher Rijndael has undergone more than ten years of extensive cryptanalysis since its submission as a candidate for the Advanced Encryption Standard (AES) in April 1998. To date, most of the publicly-known cryptanalytic results are based on reduced-round variants of the AES (respectively Rijndael) algorithm. Among the few exceptions that target the full AES are the Related-Key Cryptanalysis (RKC) introduced at ASIACRYPT 2009 and attacks exploiting Time- Memory-Key (TMK) trade-offs such as demonstrated at SAC 2005. However, all these attacks are generally considered infeasible in practice due to their high complexity (i.e. 2^99.5 AES operations for RKC, 2^80 for TMK). In this paper, we evaluate the cost of cryptanalytic attacks on the full AES when using special-purpose hardware in the form of multi-core AES processors that are designed in a similar way as modern Graphics Processing Units (GPUs) such as the NVIDIA GT200b. Using today's VLSI technology would allow for the implementation of a GPU-like processor reaching a throughput of up to 10^12 AES operations per second. An organization able to spend one trillion US$ for designing and building a supercomputer based on such processors could theoretically break the full AES in a time frame of as little as one year when using RKC, or in merely one month when performing a TMK attack. We also analyze different time-cost trade-offs and assess the implications of progress in VLSI technology under the assumption that Moore’s law will continue to hold for the next ten years. These assessments raise some concerns about the long-term security of the AES.