Wetting and spreading phenomena in liquid bismuth-alkali halide systems

This investigation is devoted to the study of the features of wetting phenomena in high temperature systems that are promising as environments for processing and disposal of man-made and radioactive wastes. New data on the phase wetting transition in two-phase liquid media have been obtained by analyzing the values of the adhesion of salt melts to liquid metals. The present study is focused on the systems composed of molten alkali halides and liquid bismuth. Their adhesion was calculated using experimental data on the surface tension of metals and salts, as well as the interfacial tension between metals and salts. A regular change in the adhesion work is illustrated depending on the temperature, electrical potential and nature of the contact phases. The transition phenomenon from incomplete wetting to full wetting has been established. It is shown that this transition is facilitated by an increase in temperature, a potential jump in the phase contact plane, and the polarizability of salt phase ions. The potential dependence of the adhesion work near the wetting transition point is described by a power equation with a critical index equal to 1.1.https://doi.org/10.15826/elmattech.2023.2.02

Decrease of atmospheric neutron counts observed during thunderstorms.

We report here, in brief, some results of the observation and analysis of sporadic variations of atmospheric thermal neutron flux during thunderstorms. The results obtained with unshielded scintillation neutron detectors show a prominent flux decrease correlated with meteorological precipitations after a long dry period. No observations of neutron production during thunderstorms were reported during the three-year period of data recording

ENHANCEMENT OF STRENGTH PROPERTIES IN BIOCOMPATIBLE Ti-Nb-Zr ALLOYS BY SEVERE PLASTIC DEFORMATION

Перспективным направлением развития производства медицинских имплантатов из биоинертных материалов является создание сплавов с низким модулем упругости, полученных методами интенсивной пластической деформации (ИПД). В исследуемых образцах из прутков плавки 92 (Ti-40Nb-5Zr) и плавки 94 (Ti-40Nb-5Zr-2Ta-2Sn) после интенсивной пластической деформации методом abc-прессования с последующей прокаткой установлено повышение предела прочности по сравнению с исходным состоянием после горячей прокатки с 620 до 940 Мпа и с 610 до 760 МПа соответственно. Изготовлен образец и методом ДМА определена зависимость модуля упругости от температуры нагрева в диапазоне от комнатной до 600 °С.A promising direction in the development of the production of medical implants made of bioinert materials is the creation of alloys with a low elastic modulus, obtained by severe plastic deformation (SPD) methods. In the studied samples from rods of melt 92 (Ti-40Nb-5Zr) and melt 94 (Ti-40Nb-5Zr-2Ta-2Sn), after severe plastic deformation by the abc-pressing method followed by rolling, an increase in ultimate strength was found compared to the initial state after hot rolling from 620 to 940 MPa and from 610 to 760 MPa, respectively. A sample was made and the dependence of the elastic modulus on the heating temperature in the range from room temperature to 600 °C was determined using the DMA method.Исследование выполнено при финансовой поддержке Министерства науки и высшего образования Российской Федерации в рамках Программы развития Уральского федерального университета имени первого Президента России Б.Н. Ельцина в соответствии с программой стратегического академического лидерства «Приоритет-2030»

Draft Genome Sequences from a Novel Clade of <i>Bacillus cereus Sensu Lato </i>Strains, Isolated from the International Space Station

The draft genome sequences of six Bacillus strains, isolated from the International Space Station and belonging to the Bacillus anthracis-B. cereus-B. thuringiensis group, are presented here. These strains were isolated from the Japanese Experiment Module (one strain), U.S. Harmony Node 2 (three strains), and Russian Segment Zvezda Module (two strains)

Effect of KCl and CsCl on the Electrical Conductivity of Molten LiF–KBr at the Critical Composition

The electrical conductivity was measured from the melting point to 1280 K for molten 0.7 LiF–0.3 KBr (its composition corresponds to the top of the miscibility gap) containing (2.3, 4.4, 6.5, 8.8, and 11.2) mol % KCl or (1.2, 2.5, 5.5, and 10.2) mol % CsCl to establish the influence of this solute on the stability of the two-phase system. These results indicate that the temperature dependences of the conductivity along the saturation lines for all of the mixtures studied herein are similar to one another. Hence, this demonstrates that small additions of KCl and CsCl to the dissolving melt of LiF-KBr do not exert a substantial influence on its type of criticality. In the vicinity of the critical point, the temperature dependence on conductivity differences for melts is investigated and is described by the equation Δκ ≈ (<i>T</i>_c – <i>T</i>)^<i>k</i>, where <i>k</i> is the critical exponent (<i>k</i> = 0.98). The critical temperature changes as a function of the mixture composition and depends on the ion size of the salt added. The critical temperature increases continuously with the addition of CsCl to molten LiF-KBr, whereas it decreases as the fraction as KCl is added. This circumstance must occur during the organization process, as salts accumulate in the dissolving molten mixture, and they prevent the confluence of the phases at a given operating temperature. To interpret the experimental results, the charged hard sphere model for ionic melts in the Debye–Hückel approximation was used with an account of the excluded volume

Role of hydrogen bond alternation and charge transfer states in photoactivation of the Orange Carotenoid Protein

Here, we propose a possible photoactivation mechanism of a 35-kDa blue light-triggered photoreceptor, the Orange Carotenoid Protein (OCP), suggesting that the reaction involves the transient formation of a protonated ketocarotenoid (oxocarbenium cation) state. Taking advantage of engineering an OCP variant carrying the Y201W mutation, which shows superior spectroscopic and structural properties, it is shown that the presence of Trp201 augments the impact of one critical H-bond between the ketocarotenoid and the protein. This confers an unprecedented homogeneity of the dark-adapted OCP state and substantially increases the yield of the excited photoproduct S*, which is important for the productive photocycle to proceed. A 1.37 Å crystal structure of OCP Y201W combined with femtosecond time-resolved absorption spectroscopy, kinetic analysis, and deconvolution of the spectral intermediates, as well as extensive quantum chemical calculations incorporating the effect of the local electric field, highlighted the role of charge-transfer states during OCP photoconversion

Role of hydrogen bond alternation and charge transfer states in photoactivation of the Orange Carotenoid Protein

Here, we propose a possible photoactivation mechanism of a 35-kDa blue light-triggered photoreceptor, the Orange Carotenoid Protein (OCP), suggesting that the reaction involves the transient formation of a protonated ketocarotenoid (oxocarbenium cation) state. Taking advantage of engineering an OCP variant carrying the Y201W mutation, which shows superior spectroscopic and structural properties, it is shown that the presence of Trp201 augments the impact of one critical H-bond between the ketocarotenoid and the protein. This confers an unprecedented homogeneity of the dark-adapted OCP state and substantially increases the yield of the excited photoproduct S*, which is important for the productive photocycle to proceed. A 1.37 Å crystal structure of OCP Y201W combined with femtosecond time-resolved absorption spectroscopy, kinetic analysis, and deconvolution of the spectral intermediates, as well as extensive quantum chemical calculations incorporating the effect of the local electric field, highlighted the role of charge-transfer states during OCP photoconversion