49 research outputs found
Effect of the C/N ratio modification on the corrosion behavior and performance of carbonitride coatings prepared by cathodic arc deposition
This study focuses on investigating carbonitride coatings, specifically CNTi-(Zr, ZrNb, and ZrSi), as promising candidates for enhancing the durability and efficiency of Ti6Al4V materials used in nuclear fusion technology. X-ray diffraction analysis identified distinct phases, including TiN, ZrN, ZrC, and TiC. The corrosion studies showed complete degradation of the TiN, ZrC, and ZrN phases in the TiZrCN coating after tests, while the TiC phase exhibited relative stability. The surface morphologies and elemental mapping analysis demonstrated the loss of homogeneity in element distribution after corrosion process. The addition of Si and Nb elements into TiZrCN significantly influenced the coatings' corrosion behavior, with breakaway corrosion observed in CNTi- (Zr and ZrSi) coatings and localized corrosion in CNTi-(ZrNb) coatings. Notably, the CNTi-(ZrSi) coating formed an oxide phase in the presence of NaCl, whereas the CNTi-(ZrNb) coating exhibited continuous resistance and a low corrosion rate. Irradiation was carried out for the generation of active isotopes, showing that no radioactive isotopes were formed in any of the investigated samples
Creating nanoporous graphene with swift heavy ions
This article has an erratum: DOI 10.1016/j.carbon.2017.03.065We examine swift heavy ion-induced defect production in suspended single layer graphene using Raman spectroscopy and a two temperature molecular dynamics model that couples the ionic and electronic subsystems. We show that an increase in the electronic stopping power of the ion results in an increase in the size of the pore-type defects, with a defect formation threshold at 1.22–1.48 keV/layer. We also report calculations of the specific electronic heat capacity of graphene with different chemical potentials and discuss the electronic thermal conductivity of graphene at high electronic temperatures, suggesting a value in the range of 1 Wm−1 K−1. These results indicate that swift heavy ions can create nanopores in graphene, and that their size can be tuned between 1 and 4 nm diameter by choosing a suitable stopping power.Peer reviewe
RESEARCH OF THE THYXO-6-PHENYLPYRIMIDIN-4-OH ALKYLATION REACTION WITH C4-C9 ALKYLHALOGENIDES
Development of methods for the preparation of radiopure <sup>82</sup>Se sources for the SuperNEMO neutrinoless double-beta decay experiment
A radiochemical method for producing 82Se sources with an ultra-low level of contamination of natural radionuclides (40K, decay products of 232Th and 238U) has been developed based on cation-exchange chromatographic purification with reverse removal of impurities. It includes chromatographic separation (purification), reduction, conditioning (which includes decantation, centrifugation, washing, grinding, and drying), and 82Se foil production. The conditioning stage, during which highly dispersed elemental selenium is obtained by the reduction of purified selenious acid (H2SeO3) with sulfur dioxide (SO2) represents the crucial step in the preparation of radiopure 82Se samples. The natural selenium (600 g) was first produced in this procedure in order to refine the method. The technique developed was then used to produce 2.5 kg of radiopure enriched selenium (82Se). The produced 82Se samples were wrapped in polyethylene (12 μm thick) and radionuclides present in the sample were analyzed with the BiPo-3 detector. The radiopurity of the plastic materials (chromatographic column material and polypropylene chemical vessels), which were used at all stages, was determined by instrumental neutron activation analysis. The radiopurity of the 82Se foils was checked by measurements with the BiPo-3 spectrometer, which confirmed the high purity of the final product. The measured contamination level for 208Tl was 8-54 μBq/kg, and for 214Bi the detection limit of 600 μBq/kg has been reached.</p
Formation Of Elements Of Entrepreneurial Activity In Pupils Of The Preschool Educational Organization
This article focuses on the formation of elements of entrepreneurial activity in children in preschool education, teaching entrepreneurship from an early age, preparing the next generation for the development of this field and the further development of the economy
Statistical distributions and reliability functions with type-2 fuzzy parameters
Type-2 fuzzy sets were initially given by Zadeh as an extension of type-1 fuzzy sets. There is a gnawing interest in type-2 fuzzy set and its memberships (named secondary memberships) to handle the uncertainty in type-1 fuzzy set and its primary membership values. However; arithmetical operators on type-2 fuzzy sets have computational complexity due to third dimension of these sets. In this study, we present some mathematical operators which can be easily applied to type-2 fuzzy sets and numbers. Also, mathematical functions of type-2 fuzzy numbers are given according to their monotonicity These functions are adapted to reliability and distribution functions of the random variables with the type-2 fuzzy parameters. These functions are applied to Exponential, Chi-square, Weibull distributions with respect to monotonicity of the parameters of these distributions
The main properties of the catalytic reforming catalyst
The article presents the results of adhesion, flowability, hygroscopicity, and wettability of RG-482, 582-1.2 catalyst dust under laboratory conditions. It is determined that the smaller the particle size, the easier they stick to the surface of the apparatus. The stickiness of dust was determined by the size of the solid particles of catalyst dust. In the course of the experiments, it was also proved that this catalyst dust is not sticky, this is because the catalyst dust mainly contains fine solid particles, a two-stage efficient process line for cleaning atmospheric air from fine solid particles was proposed