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A comparative analysis of the phase composition and morphology of primary crystals in hypereutectic alloys of the Al–Ca–Ni–X system (where X is Fe, Si, Mn) was carried out by calculation and experimental methods, including the construction of liquidus surfaces. Additional alloying of the base Al–6%Ca–3%Ni alloy with iron and silicon leads to the formation of coarse elongated primary crystals up to 100 μm in length. It was found that the addition of manganese, on the contrary, leads to the formation of relatively small (average size about 20 μm) compact primary crystals of two four-component phases. Presumably, they are phases based on ternary compounds Al9CaNi and Al10CaMn2. The composition of eutectics in quaternary alloys has been determined. All aluminum-calcium eutectics are characterized by a higher proportion of the second phases, a thinner structure compared to the aluminum-silicon eutectic in AK18 silumin, and are also capable of spheroidization upon heating, starting from 500 °C. The combination of compact and spherical particle morphology after annealing in the 63-2Mn alloy appears to be favorable for deformation. Comparison of the manufacturability of the experimental alloy Al–8%Ca–1%Ni–2%Mn and the grade silumin AK18 showed the advantage of the former. In terms of the totality of its characteristics, the experimental alloy can be considered as the basis for the development of hypereutectic alloys of a new generation as an alternative to piston silumins of the AK18 type. The experimental alloy, the microstructure of which is characterized by a compact morphology and small size of primary crystals and a fine structure of the eutectic, in contrast to hypereutectic silumins, does not require special modification.

Our vast world is growing and developing in all sorts of ways. A person becomes much more demanding to the conditions that surround him, as well as to himself. But what remains virtually unchanged in our lives? To this question, we can answer that this is our body. Whatever external changes occur, but as long as we are referred to the genus "people", as well as to the species "intelligent man", most of all physical and chemical processes in our body are still the same as hundreds of years ago. We consume the necessary components of food that our body requires, produce energy, and live off it. But no matter how much information a person has "in front of his nose "that he could master and, at least, live on the principle of" do not harm yourself", he will always seek to find ways of least resistance. This article will focus on sports supplements. We did not say a number of points in the paragraph above for nothing. The fact is that in the age of information technology, people become attached to appearance, and the leading positions are occupied by most successful individuals who constantly have to keep themselves in shape. The desire sometimes begets ill-considered. We are sure that most of the statistics on diseases of the gastrointestinal tract and Central nervous system are associated with incorrect principles of introduction of certain products into the diet, and sometimes even their complete exclusion (cases of anorexia). The question of sports food supplements stirred us up after one of the students addressed us with the phrase: "I started classes in the gym. What sports supplements do I need to take to get in shape?". Of course, we are already dizzy even with a single memory of this issue, but we will deal with it in detail in this article. Our goal is to convey to readers: what are sports supplements, why they are needed, how they affect the body and "what they are eaten with"?

The analysis of scientific and methodological literature revealed that modern living conditions are associated with a number of features that lay down high demands on the individual psychological properties of a person and cause stress in their psycho-physiological functioning. A particularly vulnerable category for adverse external effects are young people, who are more susceptible to maladaptation and deteriorating health due to age-related psychological immaturity and lack of necessary life experience. Such issues are actual: study of functional status criteria, development of signs of poststress disorders, active participation in physical culture and health activities of adolescents with post-traumatic stress disorders and finding ways to improve the quality of physical education to improve their psychophysical condition. One of effective means of physical education for psychological recovery is functional physical unloading. In this sense, it is effective to perform TRE-exercises that stimulate neurogenic tremor and are aimed at relieving tension, stress and traumatic experiences. Due to the urgency of this problem, the aim of our study was to evaluate the effectiveness of TRE-gymnastics exercises for the correction of the functional state of adolescents with posttraumatic stress disorders in PE classes. The study was conducted with the participation of 56 young students aged 18 to 22 (internally displaced persons, children of participants in the anti-terrorist operation, participants in the antiterrorist operation), who were asked to perform the TRE complex (Trauma Releasing Exercises) exercises by David.

Thermo-Calc calculations and experimental methods (optical and electron scanning microscopy, and electron microprobe analysis) were used to study the phase composition of alloys of the Al–Ca–Si–Sc–Zr system with the same scandium and zirconium contents (0.1 and 0.25 wt %, respectively) and the same total silicon and calcium content (6 wt %). It was shown that the hardening due to the precipitation of nanoparticles of the phase Al3(Zr, Sc)–L12 reaches a maximum after annealing at 300–450°C in alloys within the phase region (Al) + Al4Ca + Al2Si2Ca, where (Al) stands for a solid solution based on aluminum. In alloys within this region, almost all of the zirconium and scandium are contained in (Al), and the silicon content of the alloys is minimum. However, Zr and Sc additions have almost no effect on hardening in alloys within the (Al) + (Si) + Al2Si2Ca phase region. The aluminum–calcium eutectic has an essentially finer structure than that of aluminum–silicon.

A qualitative and quantitative analysis of the new Al-Ca-Mn-Fe phase diagram in the region of the aluminium corner is carried out using both thermodynamic calculations and experimental methods. Using the obtained data, the principal possibility of creating cast sparingly alloyed aluminium alloys with calcium, manganese, scandium and zirconium at allowable iron contents of up to 0.4% that do not require solution treatment and quenching in water is justified. At the selected concentrations, the entire amount of manganese (1%) is practically included in the aluminium matrix, while calcium (∼2%) and iron are in the multiphase eutectic, which has a fine structure. The joint introduction of 0.25% Zr and 0.1% Sc into the alloy leads to precipitation hardening due to the formation of the L12-Al3(Zr,Sc) phase nanoparticles during annealing. Based on the experimental data for the model multicomponent Al2CaMnFeZrSc alloy, it is shown that the mechanical properties of the castings of such alloys, which were obtained in a permanent mould and then simply annealed, are comparable to the commercial 356.0 alloy, heat-treated according to the T6 regime.

The phase composition of aluminum alloys in the Al-Ca-Fe-Si system, including the distribution of phases in the solid state and solidification reactions, has been studied. It is shown that the addition of iron and silicon to Al-Ca alloys leads to the formation of ternary Al2CaSi2 and Al10CaFe2 compounds. The equilibrium between these compounds implies the occurrence of the quaternary L → Al + Al4Ca + Al2CaSi2 + Al10CaFe2 eutectic reaction. The alloys near this eutectic have the best structure, which is typical of aluminum matrix composites. It is shown that Al-Ca alloys can have high manufacturability during both shape casting and rolling. This is due to the combination of a narrow temperature range of solidification and a favorable morphology for the eutectic, which has a fine structure. The combination of the mechanical and physical properties of the Al-Ca eutectic-based alloys significantly exceed those of branded alloys based on aluminum–silicon eutectics.

Phase transformations in the Al–Ca–Mg–Si system in the region of aluminum–magnesium alloys are investigated using the Thermo-Calc program. The liquidus projection of the quaternary system is constructed with a Mg content of 10% and it is shown that phases Al4Ca, Mg2Si, and Al2CaSi2 can crystallize (in addition to the aluminum solid solution (Al)) depending on the calcium and silicon concentrations. The crystallization character of quaternary alloys is investigated with the help of a polythermal cross section calculated at concentrations of 10% Mg and 84% Al. Based on the analysis of phase transformations occurring in alloys of this section, the presence of the Al–Al2CaSi2–Mg2Si quasi-ternary section in the Al–Ca–Mg–Si system was assumed. Three experimental alloys were considered from a quantitative analysis of the phase composition, notably, Al–10% Ca–10% Mg–2% Si, Al–4% Ca–10% Mg–2% Si, and Al–3% Ca–10% Mg–1% Si. Metallographic investigations and electron-probe microanalysis were performed using a TESCAN Vega 3 scanning electron microscope. Critical temperatures are determined using a DSC Setaram Setsys Evolution differential calorimeter. The experimental results agree well with the calculated data; in particular, a peak at t ~ 450°C is revealed for all alloys in curves of the nonequilibrium solidus and invariant eutectic reaction L → (Al) + Al4Ca + Mg2Si + Al3Mg2. It is established that the structure of the Al–3% Ca–10% Mg–1% Si alloy is closest to the eutectic alloy. It is no worse that the AMg10 alloy in regards to density and corrosion resistance and even surpasses it in hardness, which allows us to consider this alloy as the basis for the development of a new cast material: “natural composites.”

The phase composition of aluminum alloys of the Al – Ca – Ni – Sc system containing 0.3 wt.% Sc is studied. It is shown that the aluminum solid solution may be in equilibrium not only with binary phases (Al4Ca, Al3Sc and Al3Ni) but also with a ternary Al9NiCa compound. The temperature of attainment of maximum hardening due to precipitation of nanoparticles of phase Al3Sc is determined for all the alloys studied. Principal possibility of creation of castable alloys based on an (Al) + Al4Ca + Al9NiCa eutectic, the hardening heat treatment of which does not require quenching, is substantiated.

The phase composition of the Al–Ca–Si–Sc system is investigated in aluminum corner uisng computational (Thermo-Calc) and experimental (optical microscopy, scanning electron microscopy, and electron probe microanalysis) methods. The influence of annealing on the structure and hardness of alloys containing 0.3 wt % Sc is investigated in the region up to 550°C. It is shown that the maximum in the hardening curve caused by the isolation of nanoparticles of the Al3Sc (L12) is attained after annealing at temperatures of 300–350°C in alloys belonging to the phase region (Al) + Al4Ca + Al2Si2Ca ((Al) is the aluminum-based solid solution). Scandium completely enters the (Al) composition in alloys of this region, while the silicon concentration is minimal in it. On the other hand, hardening is almost absent in alloys from the (Al) + (Si) + Al2Si2Ca phase region. The possibility in principle to form the casting alloys based on the (Al) + Al4Ca + Al2Si2Ca eutectic hardened without quenching is substantiated.

The paper uses calculation (Thermo-Calc) and experimental (optical and electron scanning microscopy, electron microprobe analysis) methods and studies phase composition of the system Al–Ca–Si–Sc in the region of aluminum alloys. It studies the effect of annealing in the range of up to 550 °C on the structure and hardness of alloys containing 0,3 % of Sc. The study demonstrates that maximum hardening due to release of Al3Sc (L12) phase nanoparticles is achieved after annealing at temperatures of 300–350 °C in alloys falling within the phase region (Al) + Al4Ca + Al2Si2Ca ((Al) – solid aluminum-based solution). Scandium enters the (Al) composition in alloys of this region in full, and silicon concentration in such composition is minimal. On the other hand, hardening effect in alloys of the (Al) + (Si) + Al2Si2Ca phase region is near-zero. The study substantiates fundamental possibility of creating (Al) + Al4Ca + Al2Si2Ca eutectic-based cast alloys, which can be hardened without quenching.

The phase transformations in the Al-Ca-Mg-Si system have been studied using thermodynamic calculations and experimental methods. We show that at 10% Magnesium (Mg), depending on the concentrations of calcium (Ca) and silicon (Si), the following phases crystallize first (apart from the aluminum (Al) solid solution): Al4Ca, Mg2Si, and Al2CaSi2. We have found that the major part of the calculated concentration range is covered by the region of the primary crystallization of the Al2CaSi2 phase. Regardless of the Ca and Si content, the solidification of the aluminum-magnesium alloys ends with the following nonvariant eutectic reaction: L → (Al) + Al4Ca + Mg2Si + Al3Mg2. With respect to the temperature and composition of the liquid phase, this reaction is close to the eutectic reaction in the Al-Mg binary system. The addition of Ca and Si to the Al-10% Mg base alloy increases its hardness, reduces its density, and has no negative influence on its corrosion resistance. We have also established that the near-eutectic alloy containing about 3% Ca and 1% Si has the optimum structure.

We consider semigroups of endomorphisms of linearly ordered sets ℕ and ℤ and their subsemigroups of cofinite endomorphisms. We study the Green relations, groups of automorphisms, conjugacy, centralizers of elements, growth, and free subsemigroups in these subgroups.

The isocyanatophosphites (I) react with the isocyanates (II) to give the title compounds (III).