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A laboratory technique was developed for obtaining an ultra-low-background hybrid material based on organic glass — polymethyl methacrylate (PMMA). 157Gd nuclei are used as an efficient absorber of thermal neutrons in the hybrid material. A uniform distribution of gadolinium in the PMMAmatrix is achieved by introducing the gadolinium in the form of a coordination compound — gadolinium acetylacetonate — into the hybrid material. A uniform gadolinium distribution was achieved in a 5 cm thick matrix of hybrid material with gadolinium mass content from 1.0 to 1.5%. It is shown that at 298 K the mechanical characteristics of the hybrid material samples coincide with nominally pure PMMA, but at 77 K the hybrid material is inferior to pure PMMA within admissible requirements.

The cycle of citric acid production with the formation of gypsum-containing waste was considered and options for processing and utilization of citrogypsum were proposed. The methods obtained include: the use of citrogypsum in the production of building materials, the extraction of rare earth metals, as well as the creation of a high-quality organic-mineral fertilizer, during the creation of which it is possible to reduce the negative effect not only from the accumulation of citrogypsum, but also from manure stored in the filtration fields. In the future, the resulting fertilizer can be used for reclamation of technologically disturbed territories.

Gypsum binders are among the most environmentally friendly from the point of view of their production. The raw material base for their production is represented not only by natural raw materials, but also by a wide variety of technogenic materials, phosphogypsum is the most multi-ton and studied of them. At the same time, citrogypsum is also a promising raw material for the production of gypsum binders and, in comparison with phosphogypsum, does not contain toxic impurities that require the development of additional measures for their removal. Synthesis of the binder from gypsum-containing waste is possible with the use of various technologies using autoclaves, chemical reagents and at elevated temperature and atmospheric pressure. Each method has its own advantages and disadvantages. The most acceptable from the point of view of industrial production is the method of calcination at atmospheric pressure, but it does not allow producing high-strength binders and products based on them. It is possible to increase the efficiency of using such binders for the production of small-piece products by applying special molding modes with increased pressing pressure. The possibility of obtaining a binder from the waste of citric acid – citrogypsum production by calcination in a semi-industrial plant is shown. Using standard methods, a complete analysis of the resulting binder was performed: granulometry, grain shape and morphology, normal density and setting time. A comparison was made with construction gypsum (G5) and high-strength gypsum (G16). The possibility of obtaining small – piece products from a synthesized binder with a dry compressive strength of 20 MPa is shown by using the semi-dry pressing method at high pressures.

The paper proposes a method for calculating the main design parameters and operational characteristics of the HPEC using the Helmholtz equations of state. N-pentane, freon R11, and acetone were considered as the working fluid. The calculations were performed using the CoolProp 6.3.0 library. It was found that the most profitable for HPEC operating on the Rankin cycle with low-potential sources is n-pentane. LD expander operation and mass flow rate of the working fluid are calculated. The calculations were performed using the freely distributed open source library CoolProp 6.3.0. The calculations show that the most profitable WF for HPEC running on the Rankin cycle with low-potential sources is n-pentane. It is determined that the increase in costs when the temperature decreases before the SD is due to a decrease in the level of operation of the Lд expander, which in turn depends on the value of the steam enthalpy at the entrance to the ex-pander.

Here we propose the conception of small-size piezoelectric accelerator of charged particles that operates due to the piezoelectric effect at varying mechanical force applied to piezoelectrics in vacuum. The accelerating voltage and the energy of accelerated particles are estimated. In the proof-of-principle experiment we demonstrate the effect of the emission of X-ray radiation at the mechanical compression of piezoelectric ceramics in vacuum. The compression leads to the appearance of charges and potentials on the surfaces of the piezoelectrics and also to the arising of the electric field in vacuum. Electrons are accelerated in the electric field, strike the matter and produce the X-ray radiation. In the experiment, we have observed emission of the characteristic and bremsstrahlung X-ray radiation of energy up to 60 keV due to the compression of piezoelectric ceramics in vacuum. This means that electrons are accelerated in the piezoelectric accelerator up to the energy at least of 60 keV. The agreement of calculated and experimental data confirms the conception. Advantages of the piezoelectric accelerator and possibilities of its development and applications are discussed.

The possibility of using PZT-19 ceramic in a pyroelectric x-ray generator is investigated experimentally. Measurements of the x-ray spectra showed the possibility of obtaining on a ceramic surface in vacuum potentials up to 7 kV, which is very low compared with typical similar values for pyroelectric crystals of lithium niobate and tantalate. This feature is due to the significant permittivity of the ceramic. It is shown that the main criterion for picking a ceramic for a pyroelectric x-ray generation could be the maximum value of the ratio of the pyroelectric constant to the permittivity.

Use of acoustic emission signals makes it possible to analyze deformation processes in the bulk of a crystalline titanium structure formed under the effect of a concentrated strain created by loading of a diamond pyramid. The obtained results of the process of development of deformation twins make it possible to assert that their formation, output, and storage on the specimen’s surface are possible under certain external stresses exceeding the value of internal stresses in the crystal bulk.

Twinning, that occurs in titanium VT1-0 crystals under the action of a concentrated stress, is studied by micro- indentation methods, recording of acoustic signals and probe microscopy. Some parameters and description of forms of a twinned interlayer in polycrystalline titanium VT1-0 are provided. The possibility of studying this process by recording acoustic emission signals is demonstrated.

Background/Objectives: The paper presents the experimental results of a study of the processes of grazing interaction of fast charged particles with structured surfaces. Methods/Statistical Analysis: The experiments performed to study the radiation arising when the electrons pass along a structural surface are carried within a small angle region. According to the results presented in Figure 4 the maximum of electrons lifting can be observed at angles close to 1°-2°. So it will be necessary to use different grounding schemes to improve the yield efficiency. This can be achieved when both sides are grounded. Findings: The contribution of the structure of the target surface to the scattering of the incidence primary electrons was observed for different geometries for the interaction process of a 10keV electron beam with a diffraction grating. The experimental results demonstrate the possibility of increasing the total time of the interaction between the electron beam and the target, which opens the possibility to increase the effectiveness of radiation sources, based on diffraction mechanisms. Applications/Improvements: The effect of contactless transmission of electrons through dielectric channels causes great attention because of the potential use of simple and independent systems for electron beams formation.

Stages of the process of plastic deformation in twinning materials have been experimentally studied for VT1-0 titanium alloy. Mechanisms of hardening and stress relaxation are established based on analysis of the signals of acoustic emission recorded during microindentation.

In the work we have presented the results of experimental studies and mathematical modeling for the processes of the structure formation in a transition zone of wedge-type twins system in commercially pure titanium. The process of interaction of structure defects with twinning dislocations during the formation of a wedge-type twin was taken into consideration. It is shown that the interaction alters the stress maximum in vicinity of boundaries in the system two wedge-type twins.