Binding Energy of Cubic Carbon Atoms

Energy spectrum of gas particles in plasma is broad, ranging from fractions to 10s of electron volts. Proportion of particles with required energetic parameters, participating in cubic carbon c-C synthesis, is small. External energy deposition can transfer an inert carbon atom to active state and change its electronic configuration. Binding energy of c-C atom depends on energy sources interaction. In this work, the calculations found the binding energy value that was compared with value of energy of the bond between the carbon atoms in ethane. The advisability of external source, activated carbon atoms generator, is marked. It has been established that by adding accelerated carbon atoms with energy of 9,687 eV into reactor it is possible to increase productivity of films, coatings and bulk crystals growth.

Electronic Properties of Graphene Nanoribbons Doped with Pyrrole-Like Nitrogen

Doping of graphene nanoribbons with various chemical elements leads to a change in their band structure, which significantly expands the range of applications of these objects in modern electronic devices. In this work, the authors investigate graphene nanoribbons of the «armchair» and «zigzag» types with different concentrations of pyrrole-like nitrogen at the edges. The SCC-DFTB method was used to establish the most energetically favorable configurations of pyrrole-like nitrogen at each edge of graphene nanoribbons. The relationship between the energy gaps of graphene nanoribbons and the content of the considered functional nitrogen-containing groups in them was determined. Calculations have shown that, by incorporating into the atomic lattice, pyrrole-like nitrogen at the «zigzag» edge transfers a greater amount of charge to nearby carbon atoms, which makes such nanoribbons more chemically active in comparison with «armchair» type nanoribbons. Nitrogen doped «zigzag» graphene nanoribbons may be a promising chemoresistive element of nanosensors; however, these conclusions require further calculations.

Thin-Film Absorbing Elements of Adapter-Attenuators for HIC

One of the urgent tasks in the design of hybrid integrated circuits (HIC) is the construction of adapter-attenuators – film absorbing elements providing a wide range of attenuations with specified values of input and output resistances. Known variants of adapter-attenuators based on a homogeneous and piecewise homogeneous resistive film provide (by introducing asymmetry in the dimensions of the input and output contacts, changing the location of a piecewise homogeneous resistive film, introducing dielectric or conductive regions) a resistance transformation coefficient of no more than 3 and 10–12, respectively. In this work, promising topologies of adapter-attenuators for HIC with a close to optimal profile of input and output contacts are proposed, which allow not only to obtain a wide range of transformation coefficients (more than 100), but also to reduce the maximum values of the potential gradient and power density by 10‒30 times. The rectangular topology calculations were made using the apparatus of the theory of functions of a complex variable. Modeling of the optimized topology of adapter-attenuators for HIC was carried out by the finite element method implemented in the Elcut software package. The calculated ratios and graphs showing the relationship of attenuation, the transformation coefficient, the gain in the value of the potential gradient and the power density, depending on the ratio of the size of the film element and the resistivity of the resistive films used, have been provided. The features of adapter-attenuators fitting have been considered. The results obtained are especially important for the pulse mode of operation of adapter-attenuators’ film element for HIC.

Tracking Filter for Radio Surveillance upon UAV Detection

Unsanctioned intrusion of unmanned aerial vehicle (UAV) on the territory of the guarded object is primarily detected by specialized radio surveillance systems. The results obtained by radio surveillance systems are used for aiming of UAV visual identification and radio jamming systems. In this work, the problems of UAV detection and tracking of the target trajectory are considered. The known tracking filter systems for radio surveillance application were analyzed and a specialized matrix tracking filter system was proposed, which uses in its algorithm a dynamically changing energy potential of the radio surveillance system. The developed tracking filter system efficiency is evaluated using methods of matrix calculation, mathematical modeling, and probability theory. It has been established that the developed tracking filter system lets the radio surveillance equipment most effectively initiate trajectories of UAV, set its movement window, consider radio surveillance equipment characteristics, and approximate the trajectory of UAV at times of missed detections connected to radar cross-section fluctuations of moving targets. A high efficiency of the developed system has been achieved by decreasing the inaccuracy of the target position prediction two times in comparison with the known tracking filter systems. The obtained results allow easy scaling of the developed tracking filter system for its application as a part of any radio surveillance system.

Investigation of the Chemical Composition of Films Obtained by Electric Arc Spraying of Graphite and Titanium from Two Sources

A promising material for cold cathodes creation are carbon films with both acceptable emission properties and satisfactory adhesion to the substrate. It is known that inclusions of metallic elements (chromium, titanium, etc.) improve the adhesion of the carbon film to the substrate. One of the methods for producing coatings based on carbon and titanium is electric arc spraying of a Ti/C composite cathode in an argon atmosphere. The disadvantage of this method is the presence in the total plasma flow of carbon microparticles, which are sources of structural defects in the growing film. Magnetic separation of carbon plasma solves the above problem. In this work, composite metal-carbon films were obtained by simultaneous electric arc spraying of graphite in a magnetic field and of titanium from two evaporators. The composition of the films was studied by Raman spectroscopy (RS) and X-ray photoelectron spectroscopy (XPS). It has been established that the samples obtained are composite films consisting of graphite nanoparticles, Ti14C13 nanoclusters or Ti8C12, titanium oxides, and titanium carbide TiCxN1–x compounds.

Modified Predictive Control System of the DC-DC Boost Converter

Nowadays, predictive control systems are becoming more and more popular, which significantly reduce the cost of setting up converters. However, DC-DC converter control problem persists. In this work, a modified model of the predictive control system (MPCS) for step-up DC-DC converters is presented. For its implementation, a nonlinear model of a converter with discrete time switching was derived, which describe a continuous conduction mode of operation. The synthesis of the controller was achieved by formulating the objective function that should be minimized considering the dynamic model of the converter. The proposed predictive control strategy, used as a voltage control system, allows keeping the output voltage at the reference level. The modified system for calculating the objective function makes it possible to significantly reduce the required computing power and expand the prediction horizon. The results of modeling have been presented that demonstrate the advantages of the proposed control method: a fast transient response and a high degree of robustness.

Development of Servo Drive Positioning Control System Using PID Controller and Fuzzy Logic Controller

Servo drives are one of the most widely utilized devices in various mechanical systems and industrial applications to provide precise position control. The study of servo driver produc-tiveness and performance index is the important task. In this work, PID controller and fuzzy log-ic controller (FLC) were developed to control the position of a DC servo drive. The MATLAB Simulink program was investigated and implemented to calculate the values of servo drive pa-rameters, and a scheme for simulating the operation of a servo drive using different controllers was presented. A mathematical model of a DC servo drive for a positioning control system has been proposed. The control characteristics of the PID controller, fuzzy logic controller and fuzzy PID controller are compared. The simulation results have shown that the PID controller allows for an overshoot of about 1 % with a settling time of about 4 sec. The use of the fuzzy PID con-troller reduces the maximum overshoot to 1 % and decreases the settling time to 2 sec. As a re-sult, the fuzzy PID controller allows for better performance and efficiency compared to other controllers.

Automatic FPGA Placement Configuration for Customer Designs

Searching for new ways to improve the efficiency of integrated circuits (IC) led to the development of specialized heterogeneous configurable IC (FPGA) and systems-on-a-chip. Their key feature is an extended interpretation of standard cell library, containing ready-to-use IP cores along with standard cells. Specific customer designs require the flexibility of the configurable heterogeneous IC’s architecture and, therefore, automatic CAD clustering and placement algorithms configuration. The development of efficient configuration methods and algorithms is impossible without relying on the mathematical apparatus. In this work, such mathematical apparatus is provided. The authors described a set-theoretic model of a hierarchical project and formalized the hierarchical approach to the netlist, using the apparatus of mathematical logic, set and graph theories. The correspondence between the customers designs’ elements and FPGA’s elements has been formalized to provide fast clustering and placement configuration. The obtained results provide the basis for future efficient methods for automatic placement and clustering configuration.

X-ray Photoelectron Spectroscopy of Surface Layers of Faceted Zinc Oxide Nanorods

The control of the nanomaterials surface’s hydrophilic properties is of interest for various applications, including optics, photocatalysis, and spintronics. In this work, techniques for designing the defective structure of the surface layers of faceted zinc oxide nanorods during sacrificial doping with iodine by hydrothermal synthesis were considered. The features of the chemical composition of the surface of the obtained layers were studied using X-ray photoelectron spectroscopy (XPS). It was found that peaks corresponding to the binding energy of iodine were not observed in the X-ray photoelectron spectra. An additional peak with a binding energy of 531.8 eV, corresponding to the oxygen of OH groups, was observed in the O 1s level spectrum for zinc oxide nanorods doped with iodine. During the heat treatment of the synthesized layers, iodine evaporates, which leads to a change in the surface composition and an increase in the oxygen content of the surface hydroxyl groups. A model has been proposed to explain the experimental results. It has been established that XPS techniques are effective for analyzing the defective surface structure of functional layers based on faceted zinc oxide nanorods.

Overview of the Semiconductor Industry in the World and in Russia: Production and Equipment

The world’s leading manufacturers of semiconductor products are currently the United States, South Korea, Japan, the EU, and China. Russia’s share in world production is insignificant (0.06 %). The main volume of global production of specialized equipment for the semiconductor industry is concentrated in five leading companies: Applied Materials, Tokyo Electron, ASML, Lam Research and KLA Corporation. This kind of equipment is not produced in Russia, which leads to dependence on the import of such equipment. In this work, the current situation in the global and Russian markets of semiconductor products, as well as the markets of processing equipment and industrial robots used in the semiconductor industry, are described. The authors consider the solution to the problem of providing the semiconductor industry with processing equipment and industrial robots in the leading countries of the world and the possibility of solving this problem in Russia. As the analysis of foreign trade and equipment consumption in the world has shown, the main factor in determining the country’s position in the world market is the foreign policy environment while ensuring its technological security. In the case of China and Russia, it is necessary to create domestic machine-building production of equipment for the semiconductor industry.