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AbstractChanges in the magnetic hysteresis properties of the (Fe0.8Cr0.1Ni0.1)75C25 alloy during the formation of the phase composition at different stages of mechanosynthesis and subsequent annealing are studied by means of X-ray diffraction and Mössbauer spectroscopy.

AbstractThe formation and doping of phases during mechanical synthesis followed by annealing in the (Fe0.80Cr0.05Ni0.15)75C25 alloy are studied by the method of X-ray diffraction, Mössbauer spectroscopy, and magnetic measurements. It is shown that after mechanical synthesis, the nanocomposite contains mainly two phases (amorphous phase and cementite A). During annealing, as a result of crystallization of the amorphous phase, cementite B is formed, in which the nickel concentration is higher than in mechanically synthesized cementite A. Upon an increase in the annealing temperature, austenite with a nonuniform nickel concentration is formed. The Curie temperature of such austenite reaches 500°C. It is established that cementite in mechanically synthesized nanocomposite (Fe,Cr,Ni)75C25 has a higher stability to temperature variations than mechanically synthesized composite (Fe,Ni)75C25.

The lead-lead isochron age of chondrules in the CR chondrite Acfer 059 is 4564.7 ± 0.6 million years ago (Ma), whereas the lead isotopic age of calcium-aluminum–rich inclusions (CAIs) in the CV chondrite Efremovka is 4567.2 ± 0.6 Ma. This gives an interval of 2.5 ± 1.2 million years (My) between formation of the CV CAIs and the CR chondrules and indicates that CAI- and chondrule-forming events lasted for at least 1.3 My. This time interval is consistent with a 2- to 3-My age difference between CR CAIs and chondrules inferred from the differences in their initial 26 Al/ 27 Al ratios and supports the chronological significance of the 26 Al- 26 Mg systematics.

AbstractFormation of phases in nanocomposites of composition of carbide steels alloyed with chromium and nickel obtained as a result of mechanosynthesis in a planetary ball mill and further annealing was studied. It was shown that the structure mainly consisting of nickel-alloyed austenite and chromium-alloyed cementite is realized in composite (Fe0.80Cr0.10Ni0.10)83C17 after annealing at temperatures of 700–800°C. The size of cementite grains is in the nanometer range.

AbstractThe formation of phases in mechanically synthesized (Fe0.90−xMn0.10Nix)75C25 alloys, where х = 0.05 and 0.10, is studied via X-ray diffraction, Mössbauer spectroscopy, and magnetic measurements. It is shown that certain products form during the mechanosynthesis of the initial powders in a planetary ball mill: cementite doped mainly with manganese, ferrite, and an amorphous phase doped mainly with nickel. Annealing at 500°C and higher temperatures leads to the formation of a composite consisting of cementite and austenite doped mainly with nickel. Cementite regions with two different Curie temperatures form as the alloys cool after high-temperature (700°C) annealing, due to differences in the manganese doping of cementite in these regions.

X-ray, Mössbauer, and magnetic methods have been used to determine the structural-phase state of nanocomposites—carbide steels doped with chromium and nickel (Fe0.90 –xMn0.10Nix)83C17, where x = 0.05 and 0.10, obtained by mechanosynthesis followed by annealings. The magnetic (para- or ferro-) states of the phases and their influence on the formation of magnetic hysteresis properties of carbide steels have been studied.

Mössbauer spectroscopy and magnetic measurements have been used to investigate the formation of phases in the process of mechanosynthesis of a nanocomposite of composition (Fe 0.93 Cr 0.07 ) 75 C 25 in a planetary ball mill with the subsequent annealings at various temperatures. It has been shown that, at the initial stage of the mechanosynthesis, an amorphous Fe-C phase is formed. Later, an amorphous Fe-Cr-C phase is formed and, in the process of the subsequent mechanosynthesis, an alloyed cementite is formed from it. It has been found that, due to the products of the pickup from the milling balls made of ShKh15 steel, the changes in the initial composition (Fe 0.93 Cr 0.07 ) 75 C 25 of the powders that reach 5 wt % have almost no effect on the phase composition, specific saturation magnetization, and the coercive force of samples annealed at 800°C for 1 h.

In the solar corona, magnetic reconnection occurs due to the finite resistivity of the plasma. At the same time, this resistivity leads to ohmic heating. Therefore, the reconnecting current sheet should heat the surrounding plasma. This paper presents experimental evidence of such plasma heating being caused by magnetic reconnection. We observed the effect during a C1.4 solar flare on 2003 February 16 at the active region NOAA 10278, near the solar limb. Thanks to such a location, we successfully identified all the principal elements of the flare: the flare arcade, the flux rope, and, most importantly, the presumed position of the current sheet. By analyzing the monochromatic X-ray images of the Sun obtained by the CORONAS-F/SPIRIT instrument in the Mg xii 8.42 Å spectral line, we detected a high-temperature (T ≥ 4 MK) emission at the predicted location of the current sheet. The high-temperature emission appeared during the CME’s impulsive acceleration phase. We believe that this additionally confirms that the plasma heating around the current sheet and the magnetic reconnection inside the current sheet are strongly connected.

The energy distribution of weak emission events (nanoflares) in the solar corona measured for two stages of solar cycle 24, at the minimum and at the beginning of the rise in solar activity, is presented. Our study is based on data from two instruments, TESIS/CORONAS-PHOTON (for the cycle minimum; 2009) and AIA/SDO (the rising phase, 2010–2011), for which we have applied a unified event detection algorithm. The database collected by us comprises more than 105 flares. For all events we have measured the flux in the EUV spectral range and determined the thermal energy located in the range from 1023 to 1026 erg and distributed according to a power law: N(E)dE ∼ N−αdE. The index of the power-law distribution α in all of the cases studied has turned out to be more than two (α = 2.2–2.9). This means that the integrated energy of nanoflares increases when passing to weaker events. This scenario argues for the model of coronal heating by nanoflares. The index α reaches its maximum at the cycle minimum and then drops, implying a decrease in the fraction of weak events. This may be because part of the energy is redistributed in favor of large flares. The total energy of nanoflares in the range 1023–1026 erg has turned out to be lower than the energy losses of the solar corona through radiation by a factor of 30. For the coronal heating to be explained by nanoflares, their distribution with the same power-law index must extend at least to 1021 erg.

Abstract The study of milk productivity of local breeds of cattle (Alatau, Aulieata, Red Steppe) revealed an increase in milk yield with increasing lactation period, with a stable average daily milk yield. Monitoring showed that the productivity of cows increases with the age of the animals. Evaluation of milk quality (fat and protein content, somatic cells) confirmed the stability of characteristics and satisfactory udder condition. Studies were conducted in the farm partnership “Khilnichenko and K” of Zhetisu region for the Alatau breed, in the farms “Yesbol” and “Zhantai” of Aktobe region for the Red Steppe breed, and in the farms “Umrali Ata” and “Uzbekova” of Turkestan region for the Aulieata breed. The obtained data showed that the milk yield of cows of the Alatau breed increases with age and lactation, reaching 5769.6 kg on the third and older lactations, with an average milk yield on herd 5537.8 kg. Fat and protein content in the milk of the Alatau breed remained consistently high (3.88% and 3.29%, respectively). The average milk yield of the Aulieata breed was 4006.6-4296.6 kg, with a fat content of 3.88-3.91% and protein content of 3.22-3.25%. The Red Steppe breed showed lower milk yields (2985.3-3201.4 kg), but stable milk quality parameters (fat - 3.61-3.84%, protein - 3.10%). The level of somatic cells in all breeds was within normal limits, indicating satisfactory udder health. Analysis of spermograms of bulls-producers of domestic (Alatau, Aulieata, Red Steppe) and foreign (Angler, Schwyz, Zebu) selection confirmed high indicators of sperm viability (more than 64%) and sperm survival (more than 40 hours), which indicates their high reproductive efficiency for breeding programs of return crossbreeding. The study confirms the strategic importance of conservation and rational use of genetic resources of local breeds for sustainable livestock breeding and adaptation to changing conditions, offering science-based approaches to breeding and management of the gene pool of cattle in Kazakhstan. Resumo O estudo da produtividade leiteira de raças bovinas locais (Alatau, Aulieata, Red Steppe) revelou um aumento na produção de leite com o alongamento do período de lactação, mantendo uma produção média diária de leite estável. O monitoramento indicou que a produtividade das vacas aumenta com a idade dos animais. A avaliação da qualidade do leite (teor de gordura e proteína, células somáticas) confirmou a estabilidade das características e a condição satisfatória do úbere. Estudos foram conduzidos na parceria agrícola “Khilnichenko e K” da região de Zhetisu para a raça Alatau, nas fazendas “Yesbol” e “Zhantai” da região de Aktobe para a raça Red Steppe, e nas fazendas “Umrali Ata” e “Uzbekova” da região do Turquestão para a raça Aulieata. Os dados obtidos mostraram que a produção de leite das vacas da raça Alatau aumenta com a idade e a lactação, atingindo 5769,6 kg na terceira lactação e lactações mais avançadas, com uma produção média de leite no rebanho de 5537,8 kg. O teor de gordura e proteína no leite da raça Alatau permaneceu consistentemente alto (3,88% e 3,29%, respectivamente). A produção média de leite da raça Aulieata foi de 4006,6-4296,6 kg, com um teor de gordura de 3,88-3,91%, e teor de proteína de 3,22-3,25%. A raça Red Steppe apresentou menores produções de leite (2985,3-3201,4 kg), mas parâmetros de qualidade do leite estáveis (gordura: 3,61-3,84%, proteína: 3,10%). O nível de células somáticas em todas as raças estava dentro dos limites normais, indicando saúde satisfatória do úbere. A análise de espermogramas de touros produtores de seleção nacional (Alatau, Aulieata, Red Steppe) e estrangeira (Angler, Schwyz, Zebu) confirmou altos indicadores de viabilidade espermática (mais de 64%) e sobrevivência espermática (mais de 40 horas), o que indica sua alta eficiência reprodutiva para programas de melhoramento de cruzamento de retorno. O estudo confirma a importância estratégica da conservação e da utilização racional dos recursos genéticos das raças locais para a criação sustentável de gado e a adaptação às condições climáticas em mudança, oferecendo abordagens baseadas na ciência para a criação e gestão do pool genético do gado no Cazaquistão.