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The use of chromium carbides in flux-cored wire for applying abrasion-resistant coatings is considered. It is found that such use of chromium carbides does not result in reinforcement of the resulting coatings by intact carbide particles. However, the replacement of ferrochrome by chromium carbides changes the structure of the wire and coatings, with increase in the hardness.

The effect of chromium carbide introduced into the charge of a flux cored wire on the structure and properties of the hardfacing deposit is considered. Hardfacing is performed in a shielding gas atmosphere using a flux cored wire. The composition of the flux cored wire is selected so that the iron-based hardfacing deposit alloyed with the Cr–B–Nb–C system is achieved. In hardfacing, chromium carbide decomposes and alloys the hardfacing deposit with chromium and carbon; this leads to the formation of chromium carbides in the hardfacing deposit and to an increase in its hardness. On average, the presence of chromium carbide in the charge of a flux cored wire leads to an increase in the wear resistance of the hardfacing deposit.

The use of chromium carbides to harden surfaced metal that is subject to abrasive wear is considered. With correct hardening of the applied layer, carbide formation extends the working life.

Alloplasmic lines are a suitable model for studying molecular coevolution and interrelations between genetic systems of plant cells. Whole chloroplast (cp) and mitochondrial (mt) genome sequences were obtained by the MiSeq System (Illumina). Organelle DNA samples were prepared from a set of 12 alloplasmic barley lines with different cytoplasms of Hordeum vulgare ssp. spontaneum and H. vulgare ssp. vulgare, as well as from their paternal varieties. A bioinformatic approach for analysis of NGS data obtained on an organellar DNA mix has been developed and verified. A comparative study of Hordeum organelle genomes' variability and disposition of polymorphic loci was conducted. Eight types of chloroplast DNA and 5 types of mitochondrial DNA were distinguished for the barley sample set examined. These results were compared with the previous data of a restriction fragment length polymorphism (RFLP) study of organelle DNAs for the same material. Formerly established data about a field evaluation of alloplasmic barley lines were revised in the light of information about organelle genomes gained after NGS. Totally 17 polymorphic loci were found at exons of chloroplast genomes. Seven of the SNPs were located in the genes of the Ndh complex. The nonsynonymous changes of nucleotides were detected in the matK, rpoC1, ndhK, ndhG and infA genes. Some of the SNPs detected are very similar in codon position and in the type of amino acid substitution to the places where RNA editing can occur. Thus, these results outline new perspectives for the future study of nuclear-cytoplasmic interactions in alloplasmic lines.Аллоплазматические линии являются подходящей моделью для изучения молекулярной коэволюции и взаимодействий между генетическими системами растительной клетки. C использованием MiSeq System (Illumina) были определены полногеномные последовательности ДНК органелл клетки – хлоропластов и митохондрий. ДНК органелл выделена из 12 образцов коллекции аллоплазматических линий ячменя с цитоплазмами Hordeum vulgare ssp. spontaneum (H. spontaneum) и H. vulgare ssp. vulgare (H. vulgare), а также из сортов ячменя доноров ядра. Разработан и верифицирован подход к анализу результатов NGS смесей хлоропластной и митохондриальной ДНК для сборки новых полных сиквенсов пластидных и митохондриальных геномов H. vulgare и H. spontaneum. Проведено сравнительное изучение изменчивости геномов органелл, локализованы полиморфные участки. Выделено восемь типов хпДНК и пять типов мтДНК. Полученная информация сопоставлена с результатами предыдущих исследований этих же линий методом полиморфизма длин рестрикционных фрагментов ДНК органелл. На основании сравнения полногеномных последовательностей хпДНК и мтДНК аллоплазматических линий и сортов доноров ядерных геномов пересмотрены полученные для них ранее данные по формированию признаков, связанных с продуктивностью. Семнадцать полиморфных локусов обнаружено в экзонах пластидных генов. Семь из них расположены в генах Ndh комплекса. Несинонимические замены нуклеотидов идентифицированы в генах matK, rpoC1, ndhK, ndhG, infA. Вероятно, некоторые SNP являются точками, где происходит эдитинг, о чем свидетельствуют позиции замены в кодоне и тип аминокислотной замены. Проведенное исследо- вание открывает новые перспективы для изучения ядерно-цитоплазматических взаимодействий на при- мере аллоплазматических линий.

The influence of nanoparticles introduced into a molten weld pool using a flux-cored wire on the structure and impact toughness of the weld metal is considered. The use of a flux-cored wire with tungsten carbide particles is shown to decrease the scatter of the impact toughnesses of the weld metal. The use of titanium carbide allows one to increase the average impact toughness.

The influence of tungsten carbide and titanium nitride nanoparticles on the structure and properties of the weld metal of welded joints made by automatic twin submerged arc welding is considered. The nanoparticles have been introduced into the weld pool as a part of the “master alloy” based on nickel powder (PNE-1 according to GOST 9722). It has been shown that modifying the weld metal with tungsten carbide nanoparticles holds promise for enhancing the impact strength. In addition, it has been found that titanium nitride is prone to dissociation under the same conditions. However, microalloying with titanium, which is due to the release of titanium from the nitride, leads to an increase in the impact strength of the weld metal.

A method was proposed for optimizing the process of oil shale pyrolysis with the addition of a cleaning unit. With the use of this method, the degree of removal of H2S and CO2 from pyrolysis gas was almost 100%, which makes it possible to use the resulting gas as fuel.

Advances in nanotechnology have made it possible to use nanosized particles for the modification of metals and alloys both in metallurgy and in welding. This article discusses the thermodynamic stability of titanium nitride nanosized particles in a molten pool on the basis of theoretical analysis and experiments. It is demonstrated that, upon the addition of titanium nitride to a molten pool, its dissociation should be expected in the overall temperature range; this has been confirmed experimentally.

This article discusses the possibility of introducing nanosized particles into a molten pool using a flux-cored wire. A flux-cored wire has been proposed with added composite granules obtained upon the combined treatment of nickel powder and nanosized particles. In order to avoid the overheating of particles, it has been proposed to add a flux-cored wire to a molten-pool tail using preheating. The following hardmelting particles have been tested: tungsten carbide (WC), titanium nitride (TiN), and aluminum oxide (Al2O3). It has been demonstrated that the addition of tungsten carbide to a molten pool improves the stability of weld-metal (WM) impact toughness while retaining its average value and the addition of aluminum oxide to a molten pool leads to increased average values of WM impact toughness while retaining its stability. Meanwhile, nanosized particles of titanium nitride in a molten pool are prone to dissociation, which leads to the formation of porosity, thus limiting the field of application of this modifier.

The addition of nanodispersed powders to the area of welded joint is a promising control mechanism of controlling the properties of the weld metal. This article is aimed at determining the influence of TiN, TiCN, and WC nanoparticles (

The influence of nanoscale refractory titanium carbide particles on the structure and properties of weld metal in automatic submerged arc welding is considered. Composite granules based on nickel were used to introduce the compound into the composition of the weld pool. Two schemes for introducing granules into the weld pool were tested, characterized by different temperature conditions: to the head part of the welding pool with the help of “ligature” and to the tail section with the help of additional filler wire. The prospects of introducing nano-sized titanium carbide into the tail part of the weld pool as part of a flux-cored wire are shown. With this method, the structure of the weld metal is observed to modify: the average size of the primary crystals of the weld metal is reduced by almost 50%. At the same time, the value of the toughness of the weld metal increases: the average value of this index increases by 36%. When titanium carbide is introduced as part of the “ligature” into the head of the weld pool, despite the effect of modifying (reducing the width of the primary crystals by 30%), the average value of the toughness of the weld metal decreases.

The paper considers the influence of nanosized particles of tungsten and titanium carbides on the structure and properties of the weld metal of welded joints made by automatic submerged-arc automatic arc welding. To add them into the weld pool, an alloying composition was used in the form of composite granules based on nickel powder (PNE-1 as per GOST 9722). The prospects of using nanosized tungsten carbide particles for modifying the weld metal with the aim to increase the values of impact strength were shown. However, titanium carbide in the same conditions leads to a decrease in the average value of impact strength, despite the modifying effect of its use.

Experimental data on the flammability limits and combustion kinetics of propane-air mixtures at atmospheric pressure in the presence and absence of CF3H, C2F5H, CF4, N2, and CO2 additives are presented. It was found that CF3H and C2F5H inhibit the process of combustion. At the same time, the effect of CF4, N2, and CO2 is caused only by mixture dilution, with a marked contribution of heat capacity in the case of CF4 and CO2. The mechanisms of chain termination by the inhibitors and the reasons for their different efficiency in the inhibition of hydrogen and propane combustion are explained.

A method to evaluate the particle-phonon coupling (PC) corrections to the single-particle energies in semi-magic nuclei, based on the direct solution of the Dyson equation with PC corrected mass operator, is presented. It is used for finding the odd-even mass difference between even Pb and Sn isotopes and their odd-proton neighbors. The Fayans energy density functional (EDF) DF3-a is used which gives rather highly accurate predictions for these mass differences already at the mean-field level. In the case of the lead chain, account for the PC corrections induced by the low-laying phonons $2^+_1$ and $3^-_1$ makes agreement of the theory with the experimental data significantly better. For the tin chain, the situation is not so definite. In this case, the PC corrections make agreement better in the case of the addition mode but they spoil the agreement for the removal mode. We discuss the reason of such a discrepancy., Comment: 10 pages, 3 figures, 11 tables. arXiv admin note: substantial text overlap with arXiv:1710.09159

The transmission spectrum of single-crystal silicon in the range of 2.75–3.25 eV has been obtained experimentally. An empirical formula is proposed to describe the spectral dependence of the optical density. The energy of the direct transition at the saddle point is found to be E(Γ15) − E(Γ25’) = 3.43 eV. Analysis of the spectral dependence showed that the observed absorption corresponds to direct transitions to the van Hove singularity M1 of the conduction band.