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Vol 6, No 4 (2022)
256-265 741
Abstract

The copper Heliocles coin and two silver Demetrius coins dated to the II century BC from the archaeological works of the Uzundara fortress of the Greco-Bactrian Kingdom were studied using non-destructive structural diagnostics methods. The phase analysis of the coins was performed using the X-ray diffraction method. Also, the spatial distribution of the internal components of the coins was investigated by neutron imaging methods. It has been established that the dominant phase of the Heliocles coin is copper, however, a small volume of patina was found. It is mainly represented by tenorite CuO phase. The neutron tomography method indicates a deep penetration of tenorite into the thickness of the coin, and its volume fraction can reach 10% of the total volume. Two Demetrius coins consist entirely of silver. The complex profile of coins due to the features of a coinage was reconstructed. The phase composition, the content of the composite phases and three-dimensional models of the studied coins were obtained.

266-274 733
Abstract

This work presents a study on the structure of a bronze mirror found in the Akterek burial complex by using neutron radiography and tomography. The manufacturing features and the physical state of this mirror was analyzed by three-dimensional model. It turned out that the rim on the edge was made of a different alloy, and the border between the rim and the base of the mirror is also visually visible. The morphological features and spatial distribution of pores and voids formed during secondary casting with the application of various patterns and ornaments have been studied in detail. The neutron tomography data made it possible to study the remains of a thin layer of corrosion on the surface of the mirror.

275-284 472
Abstract

The reaction pp → {pp}sp0 , where {pp}s denotes a diproton, i.e. an unbound interacting proton pair in the 1S0 , state, was investigated in order to obtain a differential cross section ds/dW at small angles
in the energy range 1.6–2.4 GeV. This work is intended for the presentation of the main procedures in the processing of experimental data.

285-297 636
Abstract

The article is devoted in the casting process of alloying the surface of castings by impregnating the powder composition with liquid iron when pouring the last casting mold. It is established that the impregnability of powder with liquid iron depends on the temperature of the metal, the thickness of the coatings and the particle size composition of the powders.

298-305 530
Abstract

The effect of graphene oxide on the spectral and luminescent properties of xanthene dyes was studied. During the interaction of graphene oxide (GO) with a cationic dye, aggregation of Rhodamine 6G occurs, which is expressed as an increase in the optical density of the short-wavelength shoulder in the absorption spectrum of the dye. GO sheets can act as adsorption centers for dye molecules due to the influence of the Coulomb and intermolecular forces between GO and Rhodamine 6G. This effect is practically not pronounced for anionic dyes. The quenching of the dye fluorescence intensity in the presence of GO was observed. Fluorescence quenching was equal to 2.4 times for Eosin, 5.8 times for Bengal rose, and 22.1 times for Rhodamine 6G. As shown by spectral-kinetic measurements, the fluorescence lifetime was also decreased in this case. Dye fluorescence quenching occurs through the process of electron transfer from the dye to GO. The results obtained can be used for the photodegradation of organic dyes by using of composite materials with graphene oxide.



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ISSN 2522-9869 (Print)
ISSN 2616-8537 (Online)