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The elastic (Young’s) modulus and relaxation properties (amplitude-independent internal friction) of bcc metals and alloys (vanadium, V–4Cr–4Ti, V–W–Cr, and V–Ta–Cr—Zr alloys) have been studied in the temperature range of 25–400°С by means of dynamic mechanical spectroscopy within a low-frequency range (0.5–30.0 Hz). No carbon in vanadium and V–W–Cr alloy in solid-solution state is revealed. In the case of vanadium and V–W–Cr alloy, the solid-solution concentrations of oxygen and nitrogen and the diffusion characteristics thereof (diffusion activation energy, characteristic relaxation time, and the preexponential factor in the diffusion equation) have been determined. In the case of V–4Cr–4Ti alloy, carbon, oxygen, and nitrogen solid solutions have not been observed. In V–Ta–Cr–Zr alloy, the solid-solution concentrations of interstitial atoms (C, O, N) are substantially lower than those in vanadium and V–W–Cr alloy. The values of elastic modulus in vanadium alloys can be either higher or lower than the elastic modulus inherent in vanadium depending on type of alloy (alloying) and on temperature. The V–4Ti–4Cr alloy exhibits the smallest value of the elastic modulus among all the materials under study. The temperature curves of the elastic (Young’s) modulus for the studied materials exhibit no features, except for a slight local relaxation of the Young’s modulus in the case of vanadium and V–W–Cr alloy in the temperature range of the relaxation peaks.

The effect of high-temperature thermomechanical treatment (HTMT) with deformation in the austenitic region on the regularities of low-temperature embrittlement of low-activation 12% chromium ferritic-martensitic steel EK-181 is investigated in comparison with traditional heat treatment (THT) during dynamic tests on impact toughness and static tests on uniaxial tension in the range from -196 to 20 degrees C. It is found out that HTMT increases both the tensile strength properties of steel and its impact toughness. At the same time, the temperature of its ductile-brittle transition does not practically change relative to the THT. It is observed that the features of steel microstructure after HTMT, the formation of delaminations (during fracture of Charpy-type specimens) in the planes parallel to the plane of hot rolling, have a positive effect on its impact toughness.

Static and fatigue strength at room temperature under conditions of repeated stretching of lowactivated ferrite-martensite 12% chromium steels EK-181 (Fe–12Cr–2W–V–Ta heat treatment + aging in lead at 600°C, 3000 h), EP-823 (Fe–12Cr–W–V–Ni–Mo–Nb, annealed condition), and alloy V–4Ti–4Cr (heat treatment + aging in lead at 600°C, 3000 h) were studied. It was shown that for materials there is straight-line dependence between the level of rupture resistance values and fatigue strength. The maximum fatigue limit of 600 MPa appears in steel EK-181 after a standard heat treatment and aging in lead at 600°C, 3000 h, and the minimal one of 300 MPa is observed in vanadium and V–4Ti–4Cr alloys. The fatigue failure mechanism is predominately of ductile character for all materials studied. The fatigue cracking originates near the surface and in some cases clustering of nonmetallic inclusions is the place of origin. The fatigue crack propagation is related to formation of a typical striation relief. Significant distinctions in the fracture surface relief of specimens after standard heat treatment and aging in liquid lead are not observed.

Introduction. The EEG-data of patients with discirculatory encephalopathy and healthy subjects by the multidimensional scaling method are analyzed. The research subject is graphs of the vectors arrangement dynamics in the two-dimensional attribute space of EEG-data of healthy and patient subjects corresponding to each of the leads and cognitive tests. The aim was to test feasibility of the multidimensional scaling method in the EEG analysis for the classification of trial subjects for patients and healthy persons. The study objectives are the following: EEG taking in trial subjects with simultaneous testing for cognitive deteriorations; multidimensional scaling of correlation matrices in the STATISTICA system, and visual analysis of the obtained graphs. Materials and Methods. Capabilities of the multivariable technique of statistical analysis of test data - multidimensional scaling - the STATISTICA software package - are investigated. The processed data are obtained as a result of recording EEG of healthy subjects and patients with discirculatory encephalopathy using “Encephalan-131-03” electroencephalograph from 16 unipolar leads. The EEG is taken by simultaneous testing of the trial subjects by cognitive tests. Research Results. Visual analysis of the multidimensional scaling diagrams of healthy subjects has shown that the distribution of the pairwise coordinates corresponding to the tests (leads), for each of the leads (test) is characterized, generally, by a close location of the coordinates relative to each other, and in some cases - by coincidence. In patients with discirculatory encephalopathy, two-dimensional planes of the multivariate scaling are characterized by a more chaotic distribution of the spatial coordinates of each of the leads or test. Discussion and Conclusions. The efficiency effect of the multidimensional scaling as a classifier of trial subjects’ EEG is confirmed. The possibility of using the multidimensional scaling as an additional method in the diagnosis of discirculatory encephalopathy is proposed.

The effect of low-temperature damaging irradiation on the high-temperature embrittlement (cold shortness) in metals was investigated in a previously proposed model. The cold shortness state with possible brittle fracture in metals is not formed in the irradiation process because of the dynamical radiation processes arising.

The state of a low-temperature embrittlement (cold brittleness) and dislocation mechanisms for formation of the temperature of a ductile-brittle transition and brittle fracture of metals (mono- and polycrystals) with various crystal lattices (BCC, FCC, HCP) are considered. The conditions for their formation connected with a stress-deformed state and strength (low temperature yield strength) as well as the fracture breaking stress and mobility of dislocations in the top of a crack of the fractured metal are determined. These conditions can be met for BCC and some HCP metals in the initial state (without irradiation) and after a low-temperature damaging (neutron) irradiation. These conditions are not met for FCC and many HCP metals. In the process of the damaging (neutron) irradiation such conditions are not met also and the state of low-temperature embrittlement of metals is absent (suppressed) due to arising various radiation dynamic processes, which increase the mobility of dislocations and worsen the strength characteristics.

The dislocation mechanisms of formation of the ductile–brittle transition temperature and the low-temperature brittle fracture of metals (single crystals, polycrystals) with various crystal lattices (bcc, fcc, hcp) are considered. The conditions of appearance of cold shortness and intracrystalline crack propagation (brittle fracture) are determined. These conditions can be met in bcc and some hcp metals and cannot be met in fcc and many hcp metals. The nondestructive internal friction (at 100 kHz) method is used to determine the temperature ranges of cold shortness (ductile–brittle transition temperatures) in bcc metals (ferritic–martensitic EK-181 steel, V–4Ti–4Cr alloy), which depend on their structure–phase state and strength (yield strength).

У статті представлено результати досліджень поверхні емалі зуба із застосуванням атомно-силової мікроскопії.Мета дослідження – використання атомно-силової мікроскопії для вивчення топографії поверхні нормальної зубної емалі.Матеріали і методи. Для проведення атомно-силової мікроскопії було виготовлено зразки зрілої зубної емалі дев’яти третіх молярів без будь-яких захворювань твердих тканин. Зуби для виготовлення зразків емалі було взято після їх видалення. Щойно видалені зуби обробляли 13 % розчином перекису водню, ретельно промивали дистильованою водою, висушували. Щічну поверхню емалі розрізали на зразки за допомогою лмазного диска. Топологічні зображення поверхні зразків емалі зуба отримували за допомогою атомно-силового мікроскопа Solver P47-PRO (NT -MDT ) у напівконтактному режимі роботи з частотою розгортки 1Гц. У роботі використовували зондові датчики NSG 10-A з радіусом заокруглення вістря 10 нм. У результаті отримано низку зображень поверхні емалі різного масштабу та роздільною здатністю 256×256 точок.Результати досліджень та їх обговорення. Встановлено, що рельєф поверхні емалі особливо добре видно на зображеннях ділянок розміром 1×1 мкм, це пояснюється кратністю збільшення. Результати досліджень профілю вказують на те, що емалеві призми не є однакового розміру й для здорової емалі характерні мінімальні перепади висоти. Середньо-квадратична шорсткість поверхні емалі у зразках в середньому становила 25,6 нм при середній висоті призм емалі 115 нм на відрізку 2,5×2,5 мкм.Висновки. Застосування АС -мікроскопії дозволяє оцінити такі характеристики поверхні емалі, як тривимірне зображення рельєфу поверхні, визначення геометричних розмірів емалевих призм, обчислення середньої висоти емалевих призм і середньо-квадратичної шорсткості поверхні, що відкриває нові можливості дослідження стану поверхні зубної емалі, вивчення її структури, морфології і обчислення параметрів поверхні.

Shock fracture mechanisms of different scales were investigated on epoxy composite materials reinforced with silicon carbide microparticles of different concentrations. It is shown that the high heterogeneity of the epoxy composites at different structural scales is one of the factors responsible for their physical and mechanical properties. Under dynamic loading, the material reveals a developed structural scale hierarchy which provides self-consistent deformation and fracture of the material bulk with the lead of rotational deformation modes. As a result, microcracks develop due to low shear strain limited in addition by reinforcing particles. At the start of a main crack, microscale mechanisms dominate, whereas the propagation of its front is governed by macroscale fracture mechanisms.

The influence of P-V-T data on isothermal modulus of elasticity KT of water was investigated and analyzed in the pressure range from 0.1 to 142 MPa and temperatures from 293 to 352 K by the addition of single-walled carbon nanotubes functionalized with carboxyl groups.

Досліджено особливості формування та сезонної динаміки фауни підстилкових безхребетних територій, що перебувають під техногенним тиском металургійної та коксохімічної промисловості. Виявлено сезонні коливання чисельності, кількості видів, зміни таксономічної та функціональної структури герпетобію. Проаналізовано динаміку рівня біорізноманіття угруповань наґрунтових артропод

Peculiarities of formation and seasonal dynamics of litter invertebrates fauna in the territories under technogenic load of metallurgical and by-product coke industry are investigated. Features of the seasonal fluctuations of number, species quantity, taxonomic and functional structure of litter mesofauna are revealed. The dynamics analysis of the biodiversity of litter arthropods communities is carried out.

We investigate formation of pores in the process of formation of the epoxy matrix–polyvinyl alcohol–disperse filler system and their influence on the impact toughness. The optimal ratio of the components for the preparation of a material with given properties is determined.

The functional asymmetry of the nervous system of insects was studied on an example of two taxonomically and ecologically closed darkling beetles: Anatolica eremita (Steven, 1829) and Tentiria nomas taurica (Pallas, 1781). Species-specificity of motor-spatial asymmetry is revealed for imago of these species. Spatial differentiation of specimens’ movement for “right-handers”, “left-handers” and “ambidexters” with different degree of the sign display was investigated. Fluctuations and distributing of values of the asymmetry ratio for both species of the darkling beetles were determined. Influence of the first priority of the locomotion direction on further orientational manifestations was analysed.

In the present work PVT data of the C60 fullerene aqueous solution (C60 FAS) were measured as a function of the concentration of C60 molecules using the variable cell method with metal bellows in the temperature range from 295 to 360 K at pressures from 0.1 to 103.2 MPa. On the liquid–vapor equilibrium line the density (ρ) of the C60 FAS was measured using the pycnometer method. As a result, numerical values for the isothermal modulus of elasticity (K T ), isobaric expansivity (α P ), isothermal deviation of entropy factor (TΔS), enthalpy (ΔH), and internal energy (ΔU) have been determined. Finally, an equation of state for the C60FAS was obtained for the first time.

Thermodynamic properties of fullerene C60 solution in toluene were investigated in the range of pressures from 0.1 to 103.1 MPa and temperatures from 313 to 371 K. The correct equation of state for C60 toluene solution was determined using theexperimental PVT data.

The structure, vibrational and calorical properties of fullerene C60 in toluene solution were investigated both experimentally and theoretically in detail. The aggregation kinetics results indicated that the structure of C60 aggregates in toluene could be described as a fractal system. The electronic absorption spectra of C60 toluene solution with different concentration testify to the molecular character of absorption. The vibrational spectrum of smallest stable spherical cluster formed from the 13 single fullerene C60 molecules in toluene solution was calculated using the molecular dynamics approach and compared with Raman spectroscopy data. The numerical values of thermodynamical coefficients αP, βT,βS, cP, cV and sound velocity were determined from the (P-ρ-T) data measured for C60 toluene solution.

The structure and thermophysical properties of fullerene C60aqueous solutions were investigated both experimentally and theoretically. The aggregation kinetics results indicated that the structure of fullerene C60aggregates in water could be described as a fractal system. The IR and electronic absorption spectra obtained confirm the presence of the crystalline phase in aqueous solution. The numerical values of thermodynamic coefficientsα P,β T,β S,c P, andc V, and sound velocity were determined from the measured (P–V–T) data. The vibrational spectrum of the crystalline structure (Thsymmetry group) formed from the hydrated single fullerene C60molecules in aqueous solutions was calculated using the molecular dynamics approach.

It investigates the thermophysical properties and the equation of state of single-walled carbon nanotubes in liquid toluene. The equation of state is established for the investigated system. It analyzes the dependence of its constants on temperature and characteristics of the structure. Numerical values of isothermal elastic modulus are obtained as functions of pressure. It is found that the addition of carbon nanotubes in toluene caused the increase of the energy of molecular interaction in the investigated system.

Measurements of density for glycerol–water solutions have been carried out along a co-existing curve by using the pycnometer method in the range of temperatures from 293 to 363 K and in the range of concentration from 0.225 to 0.552 mol fraction of glycerol. It's shown that the concentration curve of density is not monotone. The density of the glycerol–water solution is a jump function of concentration. The peak of this curve is observed at concentration of 0.33 mol fraction of glycerol. It is found that this concentration is characterized by the highest values of isobaric expansion. We also found that the investigated glycerol–water solutions are obtained with compression based on configurational rather than energetic principles.

The (P-V-T) data of C60 fullerene water solutions (C60FWS) were measured in dependence on the concentration of C60 molecules (0.05 and 0.15mg/ml) using the metallic bellows method with differential inductive sensor of linear shifts in the temperature range of 295 to 400K and pressure range of 0.1 to 153 MPa. The sound velocity (vs) in C60FWS was determined by the direct pulse method of fixed distance. The density (p) of C60FWS was measured using the pycnometer method. As a result, we found the numerical values for the isobaric coefficient of thermal expansion (α P ), the isothermal (βr) and adiabatic (β5) compressibility coefficients, and also the molar heat capacity (c p and c v ) for CfioFWS under ambient conditions.

This article describes the conceptualization and development of the Saturday Club for Adopted Kids (a four-session, multiage, bookwriting group for adopted children and young people) and the benefits of offering such a project-oriented group in which adoptees can tell their stories and share their experiences in an environment that supports their recovery from early trauma and offers them a way to transform the meaning of their personal losses into social action to help others. Club participants produced a book, Kids Speak Out on Adoption, based on their experiences, perceptions, and feelings.

Vacuum mounts are used [i] to reduce the time consumed by auxiliary operations in preparing specimens for adhesion-strength test. A disadvantage of some designs of these is that there are large errors of measurement due to the use of slow mechanical devices for recording the failure force. Also, these instruments do not allow one to identify the initial phase, i.e., the load at which cracks are produced. Identifying such defects is very important in tests for example on joint sealing. We have proposed a device for examining adhesion strength in which these deficiencies are eliminated [2].