In the paper, parametric equations of right conoidal surfaces with an orthogonal coordinate system with different guiding curves are obtained for the first time. Parametric equations for conoids with guide curves sine, cosine and parabola are presented. In the MathCad system, the constructions of right conoids with selected guide curves with various initial geometric parameters are visually performed and presented in the paper for the possibility of expanding their use in architectural design, construction and other industries.

Keywords: conoid, orthogonal coordinate system, sine, cosine, parabola, parametric equation, MathCad system

The paper deals with the problem of choosing the most rational form of spatial metallic cross-barrel coating. Mathematical models of flat structural coating, elliptical paraboloid and hyperbolic paraboloid coatings in SCAD software package based on finite element method are analyzed. Nodal connections of rod elements of coatings are taken according to the system “Kislovodsk”. The obtained parameters of stress-strain state of three different structural coverings allow us to speak about practically identical operation of the structures.

Keywords: structural covering, spatial covering, cross-bar covering, stress-strain state, “Kislovodsk” system, SCAD program complex, finite element method, hyperbolic paraboloid, elliptic paraboloid

In this article is reviewed the nature of organic hybrid nanocomposites. Promising directions in the field of organic hybrid nanocomposite materials will be methods for the synthesis of multicomponent materials, as well as the type of "net net" and "host-guest". The fundamental problem with the chemistry and physics of nanocomposites is dependent "structure-property". Solving this problem will move from research materials to their purposeful design.

Keywords: nanocomposite sol-gel technology, synthesis, nanoparticles.

The composite cathode material of the core@shell type with the LiMn2O4@LiCoO2 formula of has been successfully synthesized using the solid-state reactions in several stages. Its structure has been studied by means of X-ray diffraction, scanning and transmission electron microscopy and vibrational infrared spectroscopy. Electrochemical investigation in two-electrode cell has been showed improvement of characteristics of the synthesized cathode material than the constituent components. The specific power of LiMn2O4@LiCoO2 is 650 mWh/g, against 450 and 500 mWh/g for LiCoO2 and LiMn2O4, respectively.

Keywords: lithium-ion batteries, cathode materials, Delafosse, X-ray structural analysis, electron microscopy, electrochemical properties

Fe-doped AlN nanorods were studied by means of x-ray absorption spectroscopy above the Fe K- and L2,3- edges. Theoretical simulations of the x-ray absorption spectra show that Fe atoms mainly substitute Al. A minor fraction of Fe interstitials or Fe-Al-N ternary alloy can be identified as well. Bader’s AIM analysis predicts that neutral substitutional FeAl defect is in 2+ charge state, though Al in pure AlN is in 3+ charge state.  Fe L2,3 absorption spectra and photoluminescence data indicate the coexistence of Fe2+/Fe3+ in AlN:Fe nanorods so different charge states of substitutional FeAl should co-exist.

Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production

The catalytic activity of Pt/C and PtxNi/C electrocatalysts prepared by  borohydride methode was studed. It was established that the specific activity  of fresh prepared Pt3,7Ni/C  catalyst  in oxygen  electroreduction  reaction is higher in compare with Pt/C material. After treatment of Pt3,7Ni/C material in the hot acid  nickel in the surface layers of nanoparticles was dissolved and the composition of nanoparticles was changed to Pt5,6Ni. The electrochemical surface area of the Pt5,6Ni catalyst and specific activity was slightly decreased after corrosion treatment. 

Keywords: platinum electrocatalysts, corrosion stability of the nanoparticles, fuel cells, X-ray diffraction, borohydride synthesis

With the use of pulsed laser deposition and carbothermal synthesis а photosensitive structure on the basis of the Schottky barrier Au/ZnO(nanorods)/ZnO(film)/ZnO(nanorods)/Au was obtained. The parameters of the carbothermal method of synthesis of nanorods ZnO were optimized. Under directly applied bias of 7V current sensitivity of luminous flux for this photodetector is observed in the UV and visible regions of the spectrum, and is 0.14 A/W - for 325 nm and 0.18 A/W - to 405 nm, which means that this structure has the ability of potential applications in various fields for the control of UV radiation (for example, for the monitoring of solar UV radiation, control of UV radiation in air and disinfecting water devices).

Keywords: ZnO nanorods, Schottky barrier, photodetector, photosensitivity

ZnO nanorod arrays have been synthesized on silicon wafers by chemical vapor deposition (CVD) technique with different  temperature modes, without metal catalyst.  With this method   vertically aligned ZnO nanostructures  were grown at the quite low temperatures.  Modification of the method allowed to place silicon substrates in areas with different  ratios of concentrations of the molecules in the vapor phase. Photoluminescence spectroscopy and electron microscopy studies have shown that morphologies and optical properties of nanorods depends on different ratios of concentrations of the molecules in the vapor phase.

Keywords: ZnO nanorods,chemical vapor deposition (CVD), photoluminescence

The arrays of ZnO nanorods were obtained on the sapphire substrates by means of pulsed laser deposition under the high pressure of argon. The conditions of synthesis were optimized, and their influence on the morphology of  ZnO nanostructures were revealed. It is shown that the concentration of oxygen vacancies in ZnO nanorods can be changed by regulation of the synthesis temperature from 850 to 915 °. This process can be controlled by the ratio of intensities of the photoluminescence emission in the visible and ultraviolet regions. So, it allows to create nanostructures for UV photodetectors or chemosensors depending on the temperature choice.

Keywords: ZnO nanorods, laser deposition, PLD, photoluminescence

Одним из важнейших факторов, исключающих возникновение дефектов типа пор, расслоений, участков с неполной полимеризацией связующего в формуемой высоконагруженной полимерной композитной конструкции, является управляемость процесса во всем объеме композита. Для обеспечения однородности процесса полимеризации связующего предложен метод многокритериальной оптимизации процесса на основе математической модели, связывающей процессы распространения тепла и кинетики полимеризации. Система связанных уравнений процесса, учитывающая экзотермическое тепло, выделяемое при полимеризации термореактивного связующего, изменение теплоемкости и теплопроводности композита при фазовых переходах от жидкого к гелеобразному и, далее, к твердому состоянию, точную геометрию технологической системы, включая прессформу, а также интенсивность тепловыделения независимо управляемых нагревателей, реализована в виде конечноэлементной модели. Предложенный метод синтеза закона оптимального управления нагревателями, использующий метод множеств Парето, проиллюстрирован на примере полимеризации разностенной композитной конструкции, формуемой из стеклопластика.

Keywords: Композиционные материалы; Процесс полимеризации; Оптимальное управление; Кинетические уравнения; Уравнения в частных производных в задачах управления и оптимизации, Конечно-элементное моделирование, Фронт Парето

In this work we have investigated the structure of individual single-walled and multi-walled carbon nanotubes by high-resolution electron microscopy and electron diffraction. To grow carbon nanotubes we used a catalytic chemical vapor deposition method. It was shown, that this synthesis protocol gave in general single-walled and double-walled carbon nanotubes with a high level of crystallinity. The diameters of the nanotubes were in the range 1.5 - 7 nm. We also observed that there was a certain level of amorphous carbon deposited on the nanotube surface during the growth. In this work we also present the structure analysis of the double-walled carbon nanotube by means of electron diffraction. We show that the structural date derived from electron microscopy and electron diffraction agree within the experimental error.

Keywords: Carbon nanotubes, electron diffraction, electron microscopy

A method of expanding the bandwidth and improve the performance of the differential voltage divider – attenuator (AT), which have parasitic capacitance on the outputs C01, C02. Wide range of transmission of the AT provided by introducing a compensation circuit C01, C02, which is achieving data quality indicators. Simulation results of desired are shown.

Keywords: a resistive voltage divider, differential attenuator, the parasitic сapacitance load, speed, upper frequency limit, analog-to-digital converters.

Intracellular microinjection - a method of direct introduction of cellular organelles and solutions of substances into living cells. The technique of microinjection into nerve cells by puncturing their processes - axons , which are often surrounded by a dense glial sheath, are described. To puncture the sheath a special injector transmitting microvibrations of ultrasonic frequency on the injection capillary was designed. The results of using the proposed microinjection technique for introducing fluorescent marker in large axons of model object - crayfish ventral nerve cord, to visualize the morphology of axons, were shown.

Keywords: intracellular microinjection, neuron, axon, glial sheath, ultrasound vibration, piezoelectric transducer

The model of the ideal video camera is described, the form of the intrinsic and extrinsic camera parameters is showed. The relations between coordinates of a point in the world coordinate system with coordinates of this point on the image plane are given. The problem of finding extrinsic camera parameters from corresponded world and image points is posed. The error of found extrinsic parameters is estimated by simulation for several configurations of calibration objects consisting of a variable number of points on different distances from the camera and with different angles between them. On the basis of simulation results recommendations are given for the choice of the calibration object in order to improve the accuracy of the extrinsic camera parameters. The best results may be obtained with a configuration consisting of points that have a large angular distance between them and are posed on different distance from camera.

Keywords: camera calibration, extrinsic camera parameters, position and orientation estimation, calibration object

This work deals with the study of atomic and electronic structure of kaolinite samples (Glukhovtsy deposit) and montmorillonite (Millerovsky deposit) by density functional theory. The applicability of existing exchange-correlation potential in the local density approximation (LDA) and the generalized gradient approximation (GGA) is analised for an adequate description of the physical properties of layered aluminosilicate. An experimental and theoretical study of the IR spectra of minerals, as well as the identification of the most intense absorption bands, performed in the approximation of DFT using the exchange-correlation potential PW91. The analysis of the band structure of these minerals, which showed that these compounds are direct-gap insulators.

Keywords: DFT, clay, clay minerals, phyllosilicates, atomic and electronic structure, crystalline systems, IR spectrum band strukutra, the electron density