Influence of elastic foundations and carbon nanotube reinforcement on the hydrostatic buckling pressure of truncated conical shells

In this study,the effects of elastic foundations(EFs)and carbon nanotube(CNT)reinforcement on the hydrostatic buckling pressure(HBP)of truncated conical shells(TCSs)are investigated.The first order shear deformation theory(FOSDT)is generalized to the buckling problem of TCSs reinforced with CNTs resting on the EFs for the first time.The material properties of composite TCSs reinforced with CNTs are graded linearly according to the thickness coordinate.The Winkler elastic foundation(W-EF)and Pasternak elastic foundation(P-EF)are considered as the EF.The basic relations and equations of TCSs reinforced with CNTs on the EFs are obtained in the framework of the FOSDT and solved using the Galerkin method.One of the innovations in this study is to obtain a closed-form solution for the HBP of TCSs reinforced with CNTs on the EFs.Finally,the effects of the EFs and various types CNT reinforcements on the HBP are investigated simultaneously.The obtained results are compared with the results in the literature,and the accuracy of results is confirmed.

The Change of Physical-Mechanical Properties of Viscoelastic Liquids in Consideration of Nanoparticles

The paper studies the viscoelastic body described by the generalized Maxwell model. This model consists of several parallel-connected simple models of Maxwell. Assuming the interaction of atoms of the body with embedded nanoparticles leads to a change in model parameters. It is shown that with the addition of nanoparticles with a specific property, it can change the value of the deformation points of a viscoelastic body. This change depends on the number of elements.

Effect of Aluminum Nano-Particles on Microrelief and Dielectric Properties of PE+TlInSe₂Composite Materials

The paper presents the results of studies surface microrelief, frequency-temperature characteristics of the imaginary part of the dielectric permittivity and dielectric loss of PE+TlInSe2 composite materials in 25。C - 150。C temperature and 25 Hz - 1 MHz frequency range before and after application of the aluminum nano-particles with a size of 50 nm. The change in the amount of semicon-ductor filler TlInSe2 and aluminum nano-particles changes the state of the surface and the frequency-temperature characteristics of composite materials PE+xvol.%TlInSe2, which allows to obtain composites with the desired dielectric permittivity and dielectric loss.

Optical Functions, Band Structure and Effective Masses of Electrons and Holes in InGaTe₂

This paper has presented results of calculations of optical functions for e||c and e^c polarizations in 0 - 12 eV energy interval, band structure and effective masses of electrons and holes of ternary compound InGaTe2. Genesis of valence band was investigated by using group-theoretical analyses. The main features of spectra of optical functions, the parameters of transition and their theoretical nature were found out. Identified interband transitions are responsible for the main peaks in the optical functions. Calculated results are in good agreement with the known experimental data.

The Effect of γ-Radiations on Dielectric Properties of Composite Materials PE + x vol% TlGaSe₂

The purpose of the paper is to study the effect of gamma irradiation on the temperature dependence of the dielectric constant and dielectric loss (tanδ) of composite materials PE + x vol% (0≤ x ≤ 10). Measurements are carried out with an alternating current at a frequency of 1 kHz using the measuring bridge E-20. Measurements are carried out at temperature range 300 - 450 K, irradiated at doses of 50, 100 and 150 kGy. It is revealed that in all irradiated samples with increasing volumetric filler content increase the dielectric characteristics of composites PE + x vol%. TlGaSe2. Temperature variation of the dielectric parameters, after gamma irradiation are the result of occurring in the electron-ion and polarization at the interface of the matrix polymer with filler of TlGaSe2.

Dielectric Properties of Fishbone Kutum and Composite Materials with Its Participation

This paper presents the results of studying the frequency dependence of permittivity and dielectric loss of fishbone (Fb) Kutum and polyethylene composites filled with nanoparticles fishbone Kutum and the influence of aluminum(Al) nanoparticles with dimensions 80-nm on the dielectric properties of polymer composites. Studies were carried out at the frequency range of 0 - 1 MHz. It was found that the variation of the volume of filler content of fishbone and aluminum nanoparticles might be prepared composite materials with the required dielectric parameters.

The Growth of Single Crystals of InGaSe2 Compounds, Their X-Ray-Phase Analysis, Electronic Structure and Optical Functions

Growing of InGaSe2 single crystals has been carried out by employing the Brijman-Stockbargor methods. On the base of X-ray-analysis it has been found that the given phase is crystallized into tetragonal symmetry. The temperature dependence of electric conductivity has been studied. Band structure has been computed. Optical functions, effective masses of electrons and holes have been calculated. Origin of formation of valence and conductance bands as well as the width of forbidden band for InGaSe2 have been determined.

Piezomodulation of Connection Conductance TlInTe2

This paper discusses the development method of strain sensors based on acicular single crystal compound TlInTe2 is grown by Bridgman-Stockbarger technique. Creating mechanically reliable ohmic contacts on said obtained single crystals was carried out directly by spot welding wires corresponding to the ends of the capacitor discharge heated in a stream of inert gas from the single crystal TlInTe2. This method of creating contacts proved effective and reliable. Sensors made by this manner stuck to the calibrated beams of steel thickness of 1 mm, a length of 30 mm and a corresponding optimal regime got sensors with a maximum piezo-sensitivity. It was found that if enshrined at one end of a thin steel sheet with glued crystals TlInTe2 initiate periodic mechanical vibrations to the same frequency, occurs conductivity modulation. The effect of piezo-modulation conductance depending on the degree of deformation, illumination in interval of deformation and lux illumination in room temperature were studied. The study showed that the more mechanical deformation and illumination are, the more modulation amplitude is. We studied the modulation of the conductivity of crystals during mechanical deformation values of 8, 14, 19, 23 and 27 × 10-5and illuminance 1000, 2750, 4750 and 6500 suites. Investigations the level piezo-signal depending on the amplitude of mechanical vibrations at frequency of 85 Hz, it is found that with increasing magnitude of the mechanical deformation of 7 × 10-5 and 26 × 10-5 amplitude increases six times. It is shown that the piezoresistive effect is clearly manifested in dynamic mode. Additional conductivity occurs during mechanical deformation. When the illuminated samples piezoconductivity magnitude increases linearly.

The Surface Fractal Structure of Fish Scales

By atomic force, microscopy studied the morphology of the surface of the scale of the Caspian Kutum. Analysis of the structure of channels of sensory systems showed that the nanostructures are not only fractal, but also self-similar. Fractal trajectories originate from the primary nucleus and extend to the sprawling low-density structure radically outwards scales like Lichtenberg figures. However, in contrast to the figures, Lichtenberg fractal band scales of fish each year are surrounded by concentric threads. The most likely mechanism for the formation of structural self-organization on the surface of the scales can be a model Witten-Sander.

Temperature-Frequency Characteristics of Dielectric Properties of Compositions LDPE + xvol%Bi2Te3

In the paper, the results of investigations of temperature and frequency dependences of dielectric permeability and dielectric loss of compositions LDPE + xvol%Bi2Te3 are stated. The investigations were carried out at frequency 10 – 105 Hz and temperature 20°C - 150°C intervals, respectively. It was revealed that increase of percentage of the filler Bi2Te3 in the matrix, reduces to increase of dielectric permeability and dielectric loss of composites LDPE + xvol%Bi2Te3 in connection with the change reducing to Maxwell-Wagner’s volume polarization and emergence of comparative strong inner field in semiconductor clusters.

Platinum Silicide-Silicon Schottky Diode Characteristics

Photoelectric measurements are used to obtain additional information on the transportation mechanism of Schottky barrier structures. The main purpose of the study is to investigate the photoelectric properties of Shottky diodes based on PtSi - n - Si and PtSi - p - Si contacts.

Transitional Recovery Voltages at Capacitive Currents Switching-off by Vacuum and SF6 Circuit-Breakers

Results of calculation the recovery voltages conditioned by capacitive currents switching-off by high voltage vacuum and auto-compression （SF6） circuit-breakers are presented in the article. The purpose of research was evaluating the maximum values of recovery voltages and also studying the dependence of recovery voltages on some influencing factors, especially on type of circuit-breaker presented in numerical models with its dielectric strength restoration law, chopping current and operation time. The research was carried out with using computer simulation.