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When storing fruits and vegetables, vital processes (respiration, heat and carbon dioxide) are actively proceeding. These processes lead to loss of production, significantly affect the temperature, humidity and gas composition of the air in the storage. The optimal storage conditions for fruits and vegetables are rather low positive temperatures and rather high humidity with a sufficient oxygen content in the air. Achieving this difficult task is most effectively accomplished by using active ventilation systems in the storage. The article provides a comparative assessment of setting up air exchange by energy-efficient microclimate systems in potato storages. The results of field studies of air conditions during operation of active air distribution systems in a potato storage are presented. Studies have shown that intensive flow ventilation of products close to the supply duct leads to an increase in losses (shrinkage) of vegetables up to 15 %. Since a number of containers with products are adjacent to large supply air holes thus subjected to the most severe blowing, the quality of potatoes is bound to deteriorate. The use in the active ventilation system of a highly efficient regenerative rotary heat exchanger ( E ≥ 85-90 %) and electronically-switched EC fans allows saving heat and electric energy, as well as reducing the mass loss of products by 21-26 % with directional supply of treated air to the inter-container space and containers with products.

The results of investigation of phase and elemental compositions, defect substructure states, mechanical and tribological properties of the modified surface of Steel Gr1 are presented. The process of modification consists in plasma spraying of a Ni–Cr–B–Si-based powder coating followed by its irradiation with a high-intensity pulsed electron beam. It is shown that the coating surface formed by plasma spraying contains micro- and macro-pores and is characterized by high relief. A subsequent processing of the modified surface with a highintensity pulsed electron beam of a submillisecond duration in the mode of surface layer melting is accompanied by smoothing of the coating surface, saturation of the surface layer crystal lattice with Ni, Cr, B and Si atoms, formation of submicron cells of dendritic recrystallization, precipitation of nanosized particles of the second phase, and formation of quench structure. When combined, these treatments result in the formation of a hardened layer up to 1500 μm in thickness, whose microhardness and wear resistance by 4.6–6.5 and 4 factors exceed the respective characteristics of the initial steel.

The formation of martensitic α′ and α′′ phases in Ti-6Al-4V titanium alloy subjected to low energy high current pulsed electron beam (LEHCPEB) treatment with an energy density of 12–25 J/cm2 was revealed by X-ray diffraction and transmission electron microscopy. It was substantiated that the strain-induced phase transformation is the dominant mechanism underlying the deformation behavior of the melted surface layer of the titanium alloy samples during nanoindentation and scratch testing. It was found that the reverse transformation of the α′′ phase into the more close-packed α phase is responsible for the softening of the uppermost surface layer of the samples subjected to LEHCPEB treatment. The development of the direct and reverse α′′→α→α′′ martensitic transformations in the uppermost surface layer resulted in the improvement in elastic recovery of the treated Ti-6Al-4V samples after scratching.

—An yttrium aluminum garnet (YAG) luminescent ceramic activated by Ce3+ has been obtained by uniaxial static pressing followed by sintering in air at a temperature of 1650°C. The initial phosphor powder was characterized and the linear shrinkage dynamics studied. The morphological, elastoplastic, and optical-luminescent properties of the obtained YAG:Ce ceramic samples were studied. The technological mode for manufacturing ceramics of this type with a density of at least 98% and luminescence efficiency of 45% was determined.

The aim of the present work was to investigate the effect of the applied pressure, sintering temperature and ultrasonic treatment during the pressing process on the density and microstructure of translucent ceramics based on yttrium-aluminum garnet doped with cerium ions (Ce: YAG) obtained by conventional sintering of pressed compacts. The optimization of manufacturing conditions of the ceramics was carried out. It was shown that the ultrasonic treatment of initial powder in optimal sintering conditions leads to an increase in the relative density and grain size and decrease in the pore size of the sintered ceramics.

Current work describes the production of multi-component single-layer and multi-layer coatings by pulsed magnetron sputtering. The study scrutinizes the coatings in terms of their composition (X-ray diffraction analysis, XRD) and microstructure (transmission electron microscopy, TEM). The results demonstrate that the multi-component single-layer Al-Si-N coatings have nanocrystalline structure, while all the layers of the multi-layer Al-Si-N/Al-Si-0 coatings are amorphous due to the ingress of oxygen.

Transparent yttrium aluminum garnet (YAG) ceramics doped with cerium ions (Ce3+) were successfully synthesized using the spark plasma sintering (SPS) process at a temperature of 1600 °C, isothermal exposure 10 minutes, pressure 100 MPa and a heating rate 10 °C/min from a mechanical mixture of powders of yttrium, aluminum, and cerium oxides. Transmittance in the visible range for 1 mm thick samples is above 40 %; in the near infrared is above the 60 %. Vickers hardness was 15±1.05 GPa. The optimal SPS conditions have been discussed and suggested in order to obtain a good combination of density and transmittance.

In this work, composites based on 3 mol. % yttria-stabilized zirconia (3YSZ) with additives of 1, 5 and 10 wt. % multi-walled carbon nanotubes (MWCNT) were investigated. Samples were obtained by cold pressing followed by vacuum pressureless sintering at a temperature of 1500 °C. It was found that MWCNTs retain their structure after high-temperature sintering, they are located along the zirconia grain boundaries and they lead a grain refining effect for zirconia matrix. Nanotubes can significantly affect the phase composition of composites. Additives 5 wt. % and 10 wt. % MWCNT partially limits the monoclinic-tetragonal phase transition of ZrO2 and leads to the formation of a new phase of zirconium carbide. An increase of MWCNTs content in composites leads to a smooth decrease of the relative density from 99.2 % to 81.2 %. To obtain fully dense 3YSZ/MWCNT composites, longer sintering at higher temperatures is required compared to the conditions for sintering 3YSZ ceramics without additives.

On the quartz glass specimens, visually transparent single-layer SiAlN and two-layer SiAlN/TaN films were applied to compare their protective properties against shock impact of high-velocity (5-8 km/s) iron microparticles. The tests performed using a two-stage light-gas gun have shown that the most effective coatings are two-layer films. The structure, optical and mechanical properties of the films were determined.

There are many problems with energy supply and waste water utilization of recreational areas associated with increased environmental requirements and restrictions. These areas include the Baikal Lake, there are many settlements and tourist campings around. The use of traditional energy and wastewater systems at these sites is problematic. In the result of the our research a complex mobile independent power station was developed, which will allow to solve the above problems. This installation includes renewable energy equipment, which allows to receive electricity and heat energy, as well as utilize the wastewater.

Alteration in the deformation structure of copper single crystals and the Hadfield steel polycrystalline in the cross section depend on the distance from the friction surface. The following sequence of substructure formation has been determined: a mixing zone with nanograins and nanotwins, a fragmented substructure with microbands, microtwins, a cellular and tangled substructures, and a substructure with chaotic dislocation distribution. Hadfield steel has a much greater number of nanotwins in the surface layer than copper and it has a layer of microtwins. Evolution of dislocation structure when approaching the friction area was found to be similar to the evolution of substructures under active plastic deformation.

A new method to determine the peak intensity of focused relativistic laser pulses is experimentally justified. It is based on the measurement of spectra of electrons, accelerated in the beam waist. The detected electrons were emitted from the plasma, generated by nonlinear ionization of low-density gases (helium, argon, and krypton) in the focal area of a laser beam with the peak intensity >1020 W/cm2. The measurements revealed generation of particles with the maximum energy of a few MeV, observed at a small angle relative to the beam axis. The results are supported by numerical particle-in-cell simulations of a laser–low-density plasma interaction. The peak intensity in the focal region derived from experimental data reaches the value of 2.5 × 1020 W/cm2.

Wear and tear of concrete and reinforced concrete structures in harsh climatic conditions is analyzed as a fatigue process with various cumulative failures. For the criteria of their prediction, it is proposed to use dynamic models containing the kinetics of changes of informative and sensitive indicators of the constructive properties of concrete during cyclical freezing and thawing (CFT). An experimental-analytical generalization of the measurement of the following indicators is presented: strength, components of deformations, cracking, and the energy potential of concrete destruction during the exhaustion of its frost resistance. It is proposed, as a first approximation permissible under the conditions of the onset of fatigue parametric failures, to take the level of external temperature and humidity effects equivalent to (ultimately) 85 ÷ 90% of the frost resistance mark.

Based on the dynamics of the electron in the field of a laser pulse of relativistic intensity, the electron emission angles with respect to the laser pulse propagation axis are calculated. The angular distribution of accelerated electrons is analyzed together with their energy spectrum. It is shown that fast electrons forming the high-energy spectral region are emitted into a fixed angular cone.

We study the motion of an electron and emission of electromagnetic waves by an electron in the field of a relativistically intense laser pulse. The dynamics of the electron is described by the Newton equation with the Lorentz force in the right-hand side. It is shown that the electrons may be ejected from the interaction region with high energy. The energy spectrum of these electrons and the technique of using the spectrum to assess the maximal intensity in the focus are analysed. It is found that electromagnetic radiation of an electron moving in an intense laser field occurs within a small angle around the direction of the electron trajectory tangent. The tangent quickly changes its direction in space; therefore, electromagnetic radiation of the electron in the far-field zone in a certain direction in the vicinity of the tangent is a short pulse with a duration as short as zeptoseconds. The calculation of the temporary and spectral distribution of the radiation field is carried out.

The electron dynamics and radiation emission in the field of a relativistically intense laser pulse is studied. The electron motions induced by a focused laser beam are described on the basis of the Newton equation with the Lorentz force. The radiation emitted by the electron comprises a set of electromagnetic pulses having durations much shorter than the optical cycle. For a femtosecond driving laser pulse with duration of several optical cycles, durations of pulses emitted by the accelerated electron belong to the zeptosecond range. The spectral width of radiation emitted by the electron depends on durations of emitted pulses. The electron emits a modulated spectrum in the case of the linearly polarized driving pulse (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Motions of electrons driven by the fields of relativistically intense laser pulses are studied. The treatment is based on the numerical solution of the relativistic Newton's equation with the Lorentz force. It is demonstrated that an electron can be accelerated by a relativistically intense optical field up to a considerable part of the energy of its oscillation within the pulse. Energy spectra of the electrons scattered by an optical field are used to estimate the absolute value of the laser pulse intensity (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The fundamental and technological aspects of application of nanosized intermetallic compounds as implanted layers have been considered. The existing theoretical and experimental data on the effect of ion implantation on the structural state and physicomechanical properties of surface layers of metals (nickel and titanium) have been analyzed. The common features and differences in the phase composition and distribution of the phases formed by implantation over the alloyed metal layers are demonstrated.

This paper reports on the results of experimental investigations into the microstructure and the elemental and phase compositions of ion-alloyed nickel surface layers modified by high-intensity implantation of titanium ions. It is established that the implantation of titanium ions into nickel surface layers up to 1600 nm thick leads to the formation of intermetallic phases (namely, NiTi, Ni3Ti, and NiTi2), a solid solution of titanium in nickel, titanium oxides of different stoichiometries, and titanium carbide TiC. It is demonstrated that the phases formed in the ion-alloyed nickel surface layers have a nanocrystalline structure. The average size of the nanocrystal grains is equal to 40 nm.

The excitation of low-lying nuclear levels in a hot, dense plasma, produced by a subpicosecond pulse with intensity exceeding 1016 W/cm2, is investigated theoretically and experimentally. The basic channels of electronic (inelastic scattering and inverse internal electron convergence) and photon (photoexcitation) excitations of such states as well as the influence of the broadening of a nuclear level on the excitation efficiency and the presence of hot electronic component are examined. The experimental data from measurements of the decay kinetics of the low-lying nuclear level 6.238 keV of the stable isotope 181Ta, which were obtained on two experimental laser systems, are presented.

A 1.5 picosecond laser pulse with an intensity of more than 1018 W/cm2 was used to heat solid state magnesium targets. The unique characteristics of this plasma source together with a high resolution recording system ( λ Δλ = 10 4 ) allowed us to study multicharged ions with L- and M-shell dielectronic satellite structures in the wavelength range of 9.2–9.5 A. Ten spectral lines determined by 1s2p4l–1s24l and 1s2p3l–1s23l transitions in Mg X and of 43 spectral lines of Mg IX were identified and measured. Parameters of the plasma in the process of its evolution were deduced.

The x-ray emission spectrum of a magnesium plasma produced by a picosecond laser has been studied. Dielectronic satellites of the resonance line of the He-like Mg XI ion have been identified for the first time. These satellites result from radiative transitions from 1s2l2l'3l'' autoionizing levels of the Be-like Mg IX ion.

The properties of a magnesium plasma heated by picosecond laser pulses have been determined by x-ray spectral methods. Experiments were carried out at a laser power density ~ 1.5 1018 W/cm2. The x-ray spectra were detected by spectrographs with a plane CsAP crystal and a mica crystal bent into part of a spherical surface 10 cm in radius. The experimental data are compared with predictions of a calculation on the time-varying kinetics of multiply charged magnesium ions.

It has been shown experimentally that a source based on a plasma produced by a picosecond laser is extremely promising for systematic research on the satellite structures of multiply charged ions which have electrons in L or M shells. The combination of the unique characteristics of this source and the particular measurement apparatus used (with a spectral resolution Δλ/λ~10−4) has made it possible to refine the wavelengths of several transitions of Mg IX and X ions which had been identified previously, to identify for the first time ten spectral lines due to 1s2p4l → 1s24l and 1s2p3l → 1s23l transitions of the Mg X ion, and to measure the wavelengths of 47 spectral lines which have tentatively been attributed to the Be-like ion Mg IX.

A new method of the measurement of the maximal laser pulse intensity at the focal spot is suggested. The measurement of the energies of electrons ejected from the focal spot by laser radiation is used.

The spectral phase shift and both types of angular dispersion introduced by an acousto‐optic programmable dispersive filter (AOPDF) into a femtosecond laser beam at 800 nm have been measured with high precision. With the use of spectrally and spatially resolved interferometry we experimentally proved that the AOPDF controls the group delay dispersion (GDD) and third‐order dispersion with an accuracy of better than 1% and 3% of the preset values within the range of 2 fs2–1000 fs2 and 1000 fs3–40000 fs3, respectively. Both the angular deviation as well as the angular dispersion values are primarily dependent on the set absolute value of GDD of the continuously operating AOPDF. Besides of a small offset value, there is no added angular dispersion at 0 fs2, while this can be as large as 0.2 μrad/nm at 10000 fs2.

Results are presented of calculation of x-ray plasma images of glass shell targets with diagnostic additives Na, K, and Ca in the light of the intrinsic radiation of the resonance lines of H and He ions with Zn = 8, ii, 14, and 20, and also in the light of cw radiation in the wavelength range λ = 1-300 A. The calculation results are compared with laser-plasma images obtained in experiments with the “Del'fin-l” thermonuclear facility. The temperature and density of the plasma, the rate of corona expansion, the target mass ablation rate, and the hydrodynamic coefficient of laser-energy transfer into kinetic energy of the ablating shell are determined. The plasma images obtained by backlighting the shell target with an auxiliary x-ray source are analyzed with account taken of the radiation refraction. The required energy, temporal, and spectral characteristics of the auxiliary source are determined.

The paper describes an investigation of the characteristics of spherical focusing Bragg-reflection mirrors. The integral reflectivity of bent crystals at Bragg angles 80–90°, the width of the spectrum of the reflected x-rays, and the spatial resolution of the images formed by the focusing crystals are considered. Results are presented of the calculated integral reflectivity of bent silicon and quartz crystals of different orientation and in different orders of reflection. The feasibility is demonstrated of laser-plasma diagnostics using the images obtained with the aid of a multichannel x-ray microscope based on focusing crystals. Possible schemes of active diagnostics of a dense laser plasma using a monochromatic transilluminating x-ray beam are considered.

The Wigner distribution function is a convenient way to describe image transformations in optical systems: spatial shearing, spatial frequency shearing, circular rotation, hyperbolic rotation, etc. The hyperbolic rotation can be represented as scaling of the Wigner distribution function with a separate scale factor for each axis direction. It is shown that if an optical system with positive lenses provides circular rotation of the WDF in the phase plane, with negative lenses it will provide hyperbolic rotation of the WDF function in this phase plane.

The new method of calculating energy spectra of accelerated electrons, based on the parameterization by their initial coordinates, is proposed. The energy spectra of electrons accelerated by Gaussian ultra-short relativistic laser pulse at a selected angle to the axis of the optical system focusing the laser pulse in a low density gas are theoretically calculated. The two-peak structure of the electron energy spectrum is obtained. Discussed are the reasons for its appearance as well as an applicability of other models of the laser field.

The dynamics and energy spectra of electrons driven by a relativistically intense laser pulse are analyzed. The description is based on the numerical solution of the relativistic Newton’s equation with the Lorentz force generated by a strong focused optical field. After the interaction with it, electrons retain a considerable fraction of the energy of their oscillations during the interaction. The electron postinteraction energy spectrum is calculated. The energies in the spectrum high-energy tail are determined by the laser pulse intensity at the focal spot. An approach to estimating absolute values of the laser pulse intensity based on the measurement of the energy spectra of the electrons is proposed.

A study was made of the efficiency of conversion of target-heating laser radiation into x rays emitted by a plasma in a wide range of laser radiation power densities (5×1011–2×1014 W/cm2) and atomic numbers of the target material (4–92). Estimates were obtained of the exposure dose needed for x-ray photolithography of resists when such a laser-plasma source of soft x rays was used.

The problems concerning the development of high f-number spectrographs with high spectral and spatial resolution using holographic reflecting gratings, for the study of processes of harmonic generation in laser plasmas are considered. The concave holographic gratings and spectrograph schemes used in the “Delfin-1” installation are described. The anomalous generation of ω0 and 2ω0 harmonics from the subcritical density plasma region has been observed experimentally. Possible interpretations of the observed effect are given.

X-ray diffraction topographs from lattice defects in CaF2-crystals are produced with 0.5 nm X-ray pulses with 2.5 ns exposure time. The further development of this technique opens new and promising applications for time-resolved X-ray topography. Mit 0.5 nm-Rontgenimpulsen werden Rontgen-Beugungstopogramme von Gitterdefekten in CaF2-Kristallen in Belichtungszeiten von 2,5 ns erzeugt. Die weitere Entwicklung dieser Technik eroffnet neue perspektivreiche Anwendungen fur eine zeitaufgeloste Rontgentopografie.